JPH07196208A - Conveying device and image forming apparatus - Google Patents

Abstract

(57) [Summary] [Purpose] The motor rating is reduced by controlling according to motor load detection. [Structure] First transport path for transporting paper (a) (b)
Paper feed roller 5 as the first transporting unit located at (c)
A drive roller 36 as a second conveying means located in a second conveying path (d) adjacent to the first conveying path; a first motor for driving the first conveying means; A second motor for driving the conveying means, and the first conveying path is on the upstream side, the second conveying means operates in synchronization with the speed of the first conveying means, When the transport path is on the upstream side, the first drive means and the second drive means are controlled so that the first transport means operates in synchronization with the speed of the second transport means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus such as a copying machine and a laser beam printer, which conveys and places a sheet material at a predetermined position of an image reading section. .

[0002]

2. Description of the Related Art Conventionally, when a document is placed on a platen of an image forming apparatus, a document feeder such as an ADF is separated from a document separating unit which separates the documents set on a document tray one by one. After the skew correction of the document is performed, the feeding unit that pulls out the document from the separating unit, the conveyance unit that is arranged adjacent to the feeding unit, and that conveys the document from the feeding unit to a predetermined position of the image forming apparatus, the image After the formation, it is composed of a paper discharge unit and the like for discharging the document discharged from the transport unit to the paper discharge tray. Further, a circulation type ADF having a structure in which the document tray and the paper discharge tray are the same so that the document can be recirculated is also incorporated in the image forming apparatus. Further, there are usually two types of circulating ADFs. In the first type, the document is conveyed from the document tray to the image reading position from one end of the platen of the image forming apparatus, and after the document is placed at an arbitrary position. The image reading unit of the image forming apparatus moves to read an image, and after the reading is completed, the document is discharged from the same end surface of the platen and reloaded on the tray (switch back type).

In the second type, depending on the size of the original, the original is conveyed from the one end side with the platen to the image reading position and placed, and after the image reading is completed, the same as the first type.
It has a sheet path for discharging to the tray from the same end side, and a sheet path (closed loop type) for transporting and discharging the document on the tray from the other end side of the platen glass after image reading is completed.

In such an apparatus, it is driven by the DC of the above-mentioned feeding section and conveying section, and the stop position is controlled by counting the encoder pulses on the DC motor shaft, and the moving distance of the document is also increased. Etc. were being measured. Therefore, it is not necessary to strictly control the speed of the motor, and thus simple speed control such as approximate PWM speed monitoring and PWM control is performed. In addition, when the original is stopped at a predetermined position on the platen, it may take a long time to stop due to the load inertia of the transport unit or the friction load may vary, so the original setting time and the stop position may vary. The document was stopped by using an electromagnetic brake together.

Recently, a method has been adopted in which the stop of the document conveyance is controlled by a pulse motor without using a DC motor.

Furthermore, the manuscript interval is made as close to zero as possible,
In a document placing mode (hereinafter referred to as a 2-inl mode) in which two documents are placed on the platen at the same time, the conveyance speed of the conveyance unit by a motor (hereinafter, referred to as a belt motor) for driving the conveyance unit and the upstream thereof. It is required that the feeding speeds of the feeding units located at are synchronized with each other, including the rising characteristics. In order to satisfy this requirement, the feeding unit may be driven by the belt moat in some cases. Further, when the driving of the feeding unit and the driving of the feeding unit are independent driving sources, a method of using the PLL control in order to match the speeds of the two, or driving the feeding unit only in the 2in1 mode and the feeding unit A method has been proposed in which the drive of the vehicle is connected by a clutch.

Further, when the independent drive source structure is adopted, the document stop control can be performed only after the document is removed from the feeding unit and the document is conveyed by the conveying unit alone. For this reason, a sensor is provided downstream of the feeding roller of the feeding unit to set a timing for stopping the document.

Further, in recent years, the paper to be conveyed has been diversified,
In particular, a transport device for handling thick paper has come to be provided, but transporting thick paper requires special control. Therefore, the transport device is provided with a thick paper transport mode, and the operator selects this mode. This made it possible to convey thick paper. Although a method of automatically detecting the thickness of the sheet to be conveyed and switching the mode is also proposed, there is no proposal of an inexpensive thickness detecting means, and the control relating to the thickness of the sheet also reduces the conveying speed by reducing the conveying speed. Only proposed.

Although a system having an image forming mode (hereinafter referred to as a flow reading mode) in which an optical system on the image forming apparatus side is fixed and a document is moved on the document conveying apparatus side to form an image has been proposed. , The conventional proposals are mainly those for exceptionally performing copying on irregular-sized originals or long originals, and there are very few proposals that touched the productivity at the time of scanning, and even in the system actually sold. Most of productivity is sacrificed. Further, in a document conveying apparatus that forms an image by flow reading, a relay roller is arranged between a separation unit that separates documents stacked on a tray and a sheet conveying unit that forms an image. It is necessary for all the transport units to be at a constant speed when sheets are transferred between the transport paths, and it has been proposed to connect both drive systems with a clutch or the like.

[0010]

However, in the above-mentioned conventional example, high-speed image formation has the following drawbacks.

In the above-mentioned switchback type, after the image of the original is read by the image reading unit in the image forming apparatus,
The time required to replace a document from the platen until the next document to be processed is placed on the platen (hereinafter referred to as the document replacement time) is always the time after the document is ejected from the platen. It took a long time because the original document was pulled in and there was a transport distance of about two original documents.

In the high-speed image forming apparatus, the sheet feeding time of the image forming apparatus (for example, the distance (distance) between the trailing edge of the first sheet and the leading edge of the second sheet divided by the process speed) is Since the shorter the speed becomes, the shorter the speed becomes. If the relationship of sheet material exchange time ≦ inter-sheet time is not satisfied at the time of image formation of 1 to 1 (one sheet of image is formed from one sheet of material). It becomes impossible to achieve 100% productivity in image formation at 1 to 1 hour. For the above reasons, the switchback type RDF cannot achieve 100% productivity in the high speed machine because the sheet material replacement time is long.

In the above-mentioned closed loop type, the large size (eg A3 etc.) carries out the switch-back conveyance similar to the first type, but the half size or less (eg A4 etc.).
Etc.) are processed by a closed loop path. In the closed loop path, after the image reading of the first original is completed, the next original is placed at the image reading position. In this type, the original replacement time is equal to one original plus the paper interval of the original. Since it requires only the transport distance of the above, it is possible to exchange documents faster than the switch-back type described above, but if the speed is further increased, the transport distance is already determined, so the transport speed will be increased. Became necessary.

However, by increasing the conveying speed, it becomes difficult to control the stop position with high accuracy, the damage of the original is increased when the original is jammed, the size of the apparatus is increased due to the increase in the speed of the motor, and the cost is increased. It had the drawback of generating a lot of noise.

As a countermeasure against these problems, it has been proposed to utilize the flow-reading in order to perform high-speed image formation without carrying out high-speed conveyance. However, it is impossible to execute all the image forming modes only in the flow reading mode,
At a minimum, it is necessary to add the function of the switchback type described above (for example, double-sided copying or variable-magnification copying).

When the switchback type is used for the flow-reading, a proper image cannot be obtained unless the image is read while the document is being conveyed in the conveying direction at the time of discharging when the switchback is performed. At this time, the above-mentioned transport unit and the feeding unit need to be controlled at a constant speed, and at this time, the speed of the transport unit must match the process speed at the time of image formation. The feeding unit must follow the speed as a reference, or the feeding unit must be slightly faster than the conveying unit in order to prevent buckling during document transfer.

On the other hand, when the document is placed in the fixed reading mode with the switchback type, the load of the feeding motor for driving the feeding unit is very large when the document is pulled out from the separating unit as described above. Therefore, if it is attempted to follow the speed of the transport unit having a comparatively light load, there is a problem that even if the control is complicated and it can be realized, it is very expensive.
Further, when the document is being delivered between the feeding unit and the transport unit, at worst, there is a problem that the document buckles unless the transport speed of the transport unit is controlled to be higher. . Further, even when the speed of the transport unit is controlled to be higher than the speed of the feeding unit, if the speed difference between the two is extremely large, for example, when a large-sized document is delivered, the document is bound by the feeding unit. However, the load on the transport unit becomes large, and there is a possibility of step out when the belt motor is a stepping motor with good controllability. In addition, even if the step is not lost, the original is applied with a considerable pulling force, which is not desirable from the viewpoint of protecting the original.

From the viewpoint of general control, the above-described ADF configuration has problems that the control by the DC motor and the electromagnetic brake is costly and that the electromagnetic brake operating noise becomes noise. . In addition, due to the nature of the DC motor, the current at start-up is large, and it is necessary to increase the power supply circuit capacity accordingly.

When a stepping motor is used,
The load of the belt motor greatly changes depending on whether or not there is a preceding paper on the platen glass 3, but in addition, the friction coefficient of the platen glass 3 changes with time, the motor current value changes criminally, and the sliding resistance of the mechanical transmission system changes with time. The belt motor loses synchronization during normal operation due to changes and changes in the natural frequency of the mechanical transmission system. In addition, when transporting thick paper, there are many adverse conditions for the stepping motor, such as large load fluctuations on the transport path.Therefore, the worst value of load fluctuation conditions on the platen and the worst value of load conditions on the transport path are satisfied. It is necessary to select a motor with a rating that meets the requirements for out-of-step motors, and naturally a high torque motor is required, but due to the nature of the motor, it is difficult to achieve both high torque and high speed. There was a limit to the reduction of time. Further, even if there is a motor that satisfies the above-mentioned conditions, it is very expensive.

In the 2 in 1 mode, the belt motor drives the conveying section and the feeding section, so that there is no problem with the synchronous rotation, but the original feeding operation is performed for the purpose of shortening the original exchange time. When performing the above, the feeding section needs to operate independently of the conveying section, and in order to satisfy both of these functions, a connecting clutch is required, and an increase in cost is inevitable.

When the feeding motor and the belt motor are driven separately, not only the coupling clutch is required at 2 in 1 but also the feeding roller as described above in order to improve the stopping accuracy. A resist sensor was required in the downstream of, and the cost increased.

Further, when the two clutches are connected to each other at a time other than 2 in 1 to try to improve the reliability of conveyance, the original replacement time varies because the original speed is synchronized with the slower speed. In order to solve this, even if the PLL control is incorporated, the synchronous control including the rising and falling of the motor cannot be performed only by the PLL control, so that the PL control is performed.
Since the L control and the clutch connection must be used together, the cost is increased. Further, if the motor for the feeding roller is changed to a stepping motor to improve the synchronization with the belt motor, a motor for driving the feeding unit is required to have a large motor torque in order to handle a thick original as described later. Therefore, the stepping motor becomes large and the cost increases.

Originally, although the control parameter had to be changed according to the thickness of the document to be conveyed, the document thickness detecting means was expensive. The control was not changed according to the above. Therefore, there is a problem that a paper arrival delay jam occurs due to the delay of the transportation time, and a noise when a thick original is transported is large.

Also, since thick originals generally have high rigidity,
If there is sliding resistance in the transport path, the load will be extremely heavy. In order to deal with these without changing the control parameter, for example, if the control parameter is set to the thick original side, the speed ripple becomes large due to the excessive gain of the speed control loop during the normal original feeding, and the original is recirculated to recirculate the original. When returning to the tray, there was a problem that the speed was too high and the amount of discharge was too large for recirculation.
On the contrary, if the control parameter is set to the normal document size, the speed is remarkably reduced when the sliding resistance of the conveying path is large, and as a result, the discharge amount is too small and the document remains on the discharge roller. Such a discharge failure may occur.

Further, in the above-described paper discharge operation, the motor is driven at high speed (about 1300 mm / min.) When the document to be conveyed is being delivered to and from the upstream conveyance path or is being conveyed alone.
When the document is discharged to the document tray while being rotated at a speed of (S), the speed is reduced to a low speed (about 200 mm / S) so that a problem does not occur in feeding the document during recirculation. This deceleration time needs to be performed in a short time such as the order of several tens of ms, and the loop time constant of speed control cannot be increased. As a result, if the open loop gain in the low frequency range is set to a large value, the open loop gain in the high frequency range becomes excessive and the phase margin cannot be secured, so the system may feel vibration and the speed ripple may increase. There is
When a thin original is conveyed, the original may be buckled due to a speed mismatch between the conveying paths. Therefore, as a practical matter, the open loop gain cannot be increased, and the load tends to be affected. On the other hand, when the open loop gain is set to a small value, when a thick document is conveyed, the speed decreases due to a sudden load change, and there is a problem that a jam due to paper delay or, in the worst case, the motor stops. Occur.

Further, when the stepping motor is used for conveying the original, the motor may be out of step due to the load fluctuation as described above. In particular, when the conveying motor for pulling out the original from the separating portion is a stepping motor, the load is significantly increased when the thick original is conveyed, and a motor having a considerable reserve must be used.

There is also proposed a method of avoiding the above problems by specially preparing a thick paper mode as described above so that the operator can activate this mode by key input or the like. When both originals and plain originals are mixed, it is necessary to carry the originals only in the thick paper mode, or to set the originals in the original feeder by dividing the originals according to the thickness of the originals. Was sacrificing his ability.

Further, when the image formation is performed in the flow-reading mode, if the drive system is connected by the clutch during the image formation, the impact at the time of connection causes unevenness of the conveyance speed in the sheet conveyance section, which causes image blurring. there were. In order to avoid this problem, a method of performing the connection timing while avoiding the image formation is being considered, but it is expected that the degree of freedom in design such as the transport path length will be lost in order to create an appropriate timing. . Further, the drive system needs to be connected at a high speed, and an expensive clutch needs to be used. In addition, operating noise is generated when the clutch is operated, which causes a problem from the viewpoint of noise.

Further, when one original conveying apparatus has a fixed reading mode and a flow reading mode, it is difficult to make both performances compatible with each other. This is because shortening the document replacement time is one of the standards that affect the performance of the device in the fixed reading mode, so the startup speed and acceleration during document transportation are maximized and the vibration of the transportation system is sacrificed to some extent. On the other hand, in the flow-reading mode, it is necessary to suppress the vibration of the transport system as much as possible in order to prevent image blur, and both the starting speed and the acceleration are minimized.

Therefore, an object of the present invention is to uniquely control the constant velocity control of the conveying section and the feeding section depending on the document conveying direction when the flow reading function is added to the switchback type RDF. We will try to solve the problem of not being able to do it.

A further object of the present invention is to solve the problem of step-out when using a pulse motor as a motor for document transportation and simultaneously using a pulse motor for document transportation, by linking the configuration of the transport system with individual drive systems. The solution is to provide a control means for controlling the motor and a control means for changing the control parameter of the motor based on the detection of the step-out factor and the detection result so that the minimum required motor rated operation can be performed.

A further object of the present invention is to detect the out-of-step and automatically correct the control parameter based on the cause of the out-of-step even if the out-of-step occurs due to an unforeseen situation or changes over time. It is to suppress the occurrence of step out as much as possible.

Further, the object of the present invention is to prevent the occurrence of a system error by automatically correcting the control parameters as described above and then restarting the motor to carry the paper even if a step-out occurs. To prevent.

A further object of the present invention is to realize a special document placement such as 2 in 1 at low cost by controlling the individual drive systems located upstream and downstream, including the rising thereof.

Further, the object of the present invention is to detect the paper thickness at low cost by detecting the required torque of the drive source for conveying the original document, and in the conveyance path, by means of the paper transmittance detecting means also serving as the paper detecting sensor. Is to be able to do.

A further object of the present invention is to automatically correct the speed control parameter on the basis of the thickness detection result to realize highly reliable sheet conveyance control.

Further, an object of the present invention is to automatically correct the control parameters of the pulse motor for carrying the document based on the thickness detection result to prevent the occurrence of out-of-step due to a sudden load change accompanying the document transport of the thick document as much as possible. To do.

A further object of the present invention is to prevent the step out of the pulse motor by dynamically controlling the torque of the motor by estimating the carrying load of the motor from the thickness detection result and the document carrying timing. To do.

Another object of the present invention is to provide a high-speed and highly reliable sheet conveying device in the original reading mode.

A further object of the present invention is to provide a document feeder which does not impair the performance of each mode of fixed reading and flow reading.

[0041]

In order to achieve the above object, the present invention provides a first transport path and a second transport path which are provided adjacent to each other, from the first transport path to the second transport path. When the sheet is transferred to the first transport path or from the second transport path to the first transport path, the speed of the transport path that first transports the paper is used as a reference to control the sheet transport. As a result, even if the load condition of the transport path located on the upstream side changes and the transport speed changes, the speed of the downstream transport path can follow.

Further, the present invention provides the first adjacently provided
When the first transport path and the second transport path are simultaneously activated, the first
The control means is provided so that the movement distance of the second conveyance path and the movement distance of the second conveyance path are equal to each other. It becomes possible to carry.

Further, according to the present invention, in a document feeding device for separating the documents stacked on the tray one by one, and transporting them onto a platen for reading an image of the documents and discharging the documents from the platen, And a conveyance control means for changing the torque for conveying the original based on the judgment result of the judgment means. It is designed to be able to.

Further, according to the present invention, in the original feeding apparatus for separating the originals stacked on the tray one by one, and feeding the originals onto the platen for reading the image and discharging the originals from the platen, The present invention is characterized by having a judging means for judging the state and a carrying control means for changing the carrying speed for carrying a document based on the judgment result of the judging means. However, it is possible to reliably carry the paper.

Further, according to the present invention, the originals are conveyed in an original conveying device which separates the originals stacked on the tray one by one and conveys the originals onto a platen for reading an image and discharging the originals from the platen. It has a monitoring means for monitoring the state of the motor, and a control means for controlling the torque of the motor based on the monitoring result by the monitoring means. It is designed so that the condition can be resolved.

Further, according to the present invention, the originals are conveyed in the original conveying apparatus which separates the originals stacked on the tray one by one, and conveys the originals onto the platen for reading an image and discharging the originals from the platen. And a control means for controlling the speed of the motor on the basis of the result of monitoring by the monitoring means. Even if it is dropped, it is possible to automatically solve the problem state so that the following problem does not occur.

Further, the present invention comprises a conveying means for conveying a sheet, a driving means for driving the conveying means, and a thickness detecting means for detecting the thickness of the sheet conveyed by the conveying means from the load torque applied to the driving means. The present invention is characterized in that the thickness can be detected only by the unit provided in the sheet conveying device.

Further, the present invention utilizes a transmissive sensor for detecting a sheet, which comprises a light emitting portion and a light receiving portion which are arranged so as to face the sheet conveying path, and can detect the thickness of the sheet on the conveying path. And is capable of detecting the thickness of the sheet without providing any special detecting means in the conveying path.

Further, the present invention is characterized in that it has control means for changing the control parameter for speed control based on the detection result from the paper thickness detecting means, so that the speed control parameter can be changed automatically.

Further, the present invention is characterized by having a judging means for judging the carrying load of the paper carrying means in advance, and a controlling means for controlling the carrying torque of the paper carrying means based on the judgment result of the judging means. The optimum torque can be set with.

Further, according to the present invention, there is provided a control means capable of synchronizing the carrying speed of the intermediate carrying means located between the two carrying means located upstream and downstream with the speed of either of the two carrying means. The present invention enables smooth sheet conveyance between two conveying means having different speeds.

Further, the present invention is characterized in that, in the image forming apparatus having different image forming modes, it has an original document transfer control means capable of selecting an optimum starting operation of the transfer means for each image forming mode. This is for maximizing the performance of the image forming apparatus in the mode.

Further, according to the present invention, even when the paper conveyance width is interrupted due to a defect in the paper conveyance width, the cause of the paper conveyance interruption is estimated, and the paper conveyance control parameter is automatically corrected according to the cause. The present invention is characterized in that it has a control means capable of continuing the sheet conveyance, and can prevent the system from stopping.

[0054]

Embodiments of the present invention will be described below with reference to the drawings.

<Description of FIGS. 1 and 2> In FIGS. 1 and 2, an RDF (circulation type document feeder of the present invention) 2 which is a sheet material feeder has a document tray 4 above and below it. The wide belt 7 wound around the drive roller 36 and the turn roller 37 is arranged. This wide belt 7
The sheet original P that is in contact with the platen 3 of the copying machine main body 1 and is placed on the original tray 4 is conveyed and placed at a predetermined position on the platen 3, or the sheet original P on the platen 3 is conveyed. Is carried out onto the document tray 4.

A pair of width direction regulating plates 33 are slidably arranged in the original tray 4 in the width direction of the sheet original P, and the width direction of the sheet original P placed on the original tray 1 is set. Restricting the stability of the sheet original P during feeding,
Consistency is ensured when carrying out onto the document tray 1. A jogging mechanism, which will be described later, is built in the width-direction restricting plate 33, and the sheet originals P conveyed onto the original tray 4 are pressed one by one against the original reference guide 33 to further improve the consistency. . Further, a document tray raising / lowering mechanism, which will be described later, allows swinging between FIGS. 1 and 2 about a swing center 40.

Adjacent to the document tray 4, a half-moon-shaped feed roller 5 and a stopper 21 which moves up and down by a stopper solenoid 108 (see FIG. 5) are provided, and when set on the document tray 4. The sheet document P is restricted by the protruding stopper 21 so that it cannot be advanced downstream. When the copy condition is input through the operation unit of the copying machine and the start key is pressed, the stopper 21 sinks and the path of the sheet document P is released,
The sheet document P is fed by the paper feed roller 5 and advances to the downstream portion. At this time, the original reference guide 3 on the original tray 1 part
Partition member motor 105 built in 3 (see FIG. 5)
The partitioning member 22 connected to the top rotates and rides on the uppermost sheet document P to discriminate between the unprocessed document and the processed document.

A transport roller 38 and a separation belt 6 which constitute a separation section are disposed downstream of the stopper 21, and one sheet original P that has been rotated in the arrow direction and advanced from the original tray 4 is provided. Each is separated and further transported to the downstream portion.

A weight 20 is provided above the stopper 21, and the number of sheet originals P on the original tray 4 is small, and the sheet originals P are separated by the feeding force of the paper feed roller 5. When the sheet solenoid P cannot be advanced to, the sheet is moved downward by the weight solenoid 109 (see FIG. 5), and the sheet document P is sandwiched between the sheet feeding roller 5 and the feeding force of the sheet feeding roller 5 is improved.

<Description of FIG. 4> From the separating portions 6 and 38 to the platen 3, there are document feeding paths (a), (b) and (c) (see FIG. 4). I)
(B) and (C) are bent and connected to the conveyance path on the platen 3 to guide the sheet document P onto the platen 3. In addition, entrance sensors 23a and 23b, which are transmissive optical sensors for detecting the presence or absence of the sheet original P placed on the original tray 4, are arranged near the paper feed roller 5.

On the left side of the main body of this RDF 2, there is a large roller 1
0 is provided, and the platen 3 to the large roller 10 are
A document discharge path (e) (f) extending around the outer periphery of and extending above the document tray 4 is formed (see FIG. 4). Further, a document reversing path (e) for branching from the upper side of the large roller 10 of the document discharging path (e) (f) to reverse the front and back of a double-sided document is constructed (see FIG. 4). The downstream portion of the document reversing path (e) merges with the document conveying path (b). A central roller 44 and a paper discharge roller 11 are provided on the downstream side of the document discharge path (f), and the sheet document P conveyed through the document discharge path (e) (f) is transferred to the document tray 4 The upper original stack P is carried out.

The wide belt 7 arranged above the platen 3 conveys and places the sheet document P at a predetermined position on the platen 3 and carries it out from the platen 3 after reading the image.

A feeding roller 9 is provided at the confluence of the document feeding paths (a), (b) and (c) and the document reversing path (e). A loop is formed on P to prevent the sheet original P from skewing. Near the upstream side of the feeding roller 9, paper feed sensors 25a and 25b, which are transmissive optical sensors for detecting the front end and the rear end of the sheet document P, are arranged, and the document feeding path (a) is provided.
It is possible to detect the sheet document P that has passed either of the conveyance paths of (b) and (c) and the document reversing path (e). A registration sensor (post-registration sensor) 39, which is a transmissive optical sensor for detecting the position of the sheet document P, is provided downstream of the feeding roller 9.
a and 39b are provided.

Below the large rollers 10 in the document discharge path (e) (f), the reversal sensors 26a, 26 which are transmissive optical sensors for detecting the sheet document P carried out from the platen 3.
In the document discharge path (f) between the large roller 10 and the discharge roller 11, a sheet that passes through the document discharge path (f) and is discharged onto the document tray 4 is provided with b. A discharge sensor 27a, which is a transmissive optical sensor for detecting the passage of the document P,
27b is provided.

A reversing flapper 34 for switching the path is disposed at a portion branched from the document discharge path (e) (f) to the document reversing path (e), and the reversing flapper solenoid 110 (FIG. 5). The path is switched by oscillating between the positions indicated by the solid line and the positions indicated by the chain line in FIG.

<Description of CP Separation> Further, on the right side of the main body of the RDF 2, to the image reading section on the platen 3, there is provided a second document separating means for conveying a sheet document from the right end of the platen glass and a second document feeding unit. A feeding path (h) (ri) (nu) (see FIG. 4) is configured.

The document tray 4 is oscillated with the positions shown in FIGS. 1 and 2 as the upper and lower limit positions in conjunction with the up-and-down swing operation of the document tray 4 which will be described later. As shown in FIG. 2, when the document tray 4 is at the lower limit position, the half-moon-shaped second paper feed roller 8, the conveyance roller 15 and the separation belt 14 that form the second separation unit are arranged adjacent to the lower limit position. However, the sheet originals P, which are rotated in the directions of the arrows and have advanced from the original tray 4, are separated one by one and are conveyed further downstream.

The original tray 4 has an upper limit depending on the size of the original placed on the tray and the input conditions of the image forming apparatus.
Alternatively, it is configured to take the lower limit position. When the tray 4 reaches the lower limit position, the above-mentioned stopper 21 of the tray 4 conveys the sheet originals P placed on the tray 4 in a bundle for a certain distance to the second separating means side. In the guides 60, 61 (see FIG. 6) arranged on the tray 4, the stopper slide base 41 is provided with an eccentric cam 43 via a link 42.
Is rotated to move through the roller 46 (see FIGS. 7 and 8). Home position for eccentric cam (Figs. 6 and 8)
A flag 53 and a transmissive sensor 45 for detecting the When the document tray 4 reaches the lower limit position, the sheet document stopper 19 causes the solenoid 111 (see FIG.
(Refer to FIG. 4), the support 31 is swung upward around the support shaft 31 to receive the sheet document P bundle-conveyed by the bundle conveying means. The sheet documents P conveyed in a bundle are always conveyed to a position where the presence of sheets is detected by the transmissive optical sensors 28a and 28b which are arranged in the vicinity of the upstream side of the second separating means and detect the presence of sheet documents (FIG. 3). reference). When the bundle conveyance is completed, the sheet document stopper 19 is placed on the sheet document P. A second feeding roller 16 is disposed downstream of the second separating means, and the second feeding roller 16 is provided.
Forms a loop on the arrived sheet document P to prevent the sheet document P from skewing. The above-mentioned second feeding roller 1
In the vicinity of the upstream side of 6, a second paper feed sensor 30a, which is a transmissive optical sensor for detecting the front end and the rear end of the sheet document P,
30b is provided. A relay roller 17 is provided on the further downstream side, and the sheet document P is provided in the second feeding path (E).
Transmissive optical sensor (image tip sensor) that detects the tip position of
18a and 18b are arranged. This image sensor 18
By a and 18b, feeding timing control of the transfer sheet material on which an image is formed in the image forming apparatus is performed.

When the second half-moon roller 15 is rotated and the lowermost sheet is conveyed until it is separated: 1) When the number of image forming copies is set to 1 by the input key in the image forming apparatus; As shown in FIG. 3, the sheet document that is left on the sheet document P and discharged by the sheet discharge roller is regulated so as not to enter the second separating unit.

2) When the number of image forming copies is set to n by the input key in the image forming apparatus (when one copy of the original is n circulations), the sheet original stopper 19 is set to the sheet as shown in FIGS. The original document is retracted upward until it circulates (n-1), and when the first sheet original document of the n-th circulation is reloaded on the original document tray 4, the sheet original document stopper 19
Is placed on the sheet document and regulates the entry of the first sheet document into the second separating section.

At the end of n circulation, the leading edge of the sheet document P is regulated by the sheet document stopper. After that, the document tray 4 moves upward and stops at the upper limit position.

Next, regarding the drive system of the RDF of the present invention,
This will be described with reference to FIG.

<Description of FIG. 5> FIG. 5 is a drive system diagram showing motors and solenoids for driving the conveying rollers and flappers.

In FIG. 5, reference numeral 100 indicates a first separating motor, and this separating motor 100 drives the conveying roller 38 and the separating belt 6 which are separating portions in the direction of the arrow in the figure. The belt motor 102 is a stepping motor, drives the drive roller 36 that drives the wide belt 7, and transmits the rotation of the drive roller 36 to the turn roller 37 by the wide belt 2.

The reversing motor 101 drives the large roller 10 and the paper discharge roller 11, and the well-known PLL control is performed, and the synchronous control with the belt motor is also possible. When the belt motor and the reversing motor are synchronously controlled, the peripheral speed of the wide belt 7 and the large roller 1
The peripheral speed of 0 will be the same.

Reference numeral 103 indicates a second separating motor. The separating motor 103 drives the conveying roller 15 and the separating belt 14 which are the second separating section in the direction of the arrow in the figure.

Reference numeral 104 is a conveying motor for driving the second feeding roller 16 and the relay roller 17, and is configured so that it can be synchronously controlled with the belt motor 102 and the second separating motor 103. In the present invention, the transport motor 104
Is a stepping motor, but a DC motor controlled by PLL can also be used.

Clock disks 100a, 101a, 10 having a plurality of slits formed on the shafts of the respective motors.
2a, 103a, 104a are provided, and clock sensors 100b, 101b, 102 for generating pulses by recognizing each slit by a transmission type optical sensor.
b, 103b, 104b, etc. are respectively provided.
The rotation of each motor is controlled by the clock sensors 100b and 101.
By counting the clocks b, 102b, 103b, 104b, the rotation amount of each conveying roller can be measured, and the movement amount of the sheet document P and the stepping motor step-out can be detected.

Reference numeral 110 indicates a reversing flapper solenoid for swinging the reversing flapper 34.
At the time of F, the reversing flapper 34 is at the solid line position in the figure, and the sheet document P that has passed through the document discharge path (e) (f) is carried out onto the document tray 4, and at the time of ON, the document discharge path (e).
The sheet document P passing through (f) is guided to the document reversing path (e).

The stopper solenoid 108 drives the stopper 21 to move up and down, and when it is OFF, it prevents the document stack P on the document tray 1 from advancing to the downstream side in accordance with the position in the figure, and when it is ON, the stopper 21 is moved. Is depressed and the path of the sheet document P is released (FIG. 6).

Reference numeral 109 indicates a weight solenoid for swinging the weight 20 up and down.
When in FF, it is in the position shown, and when it is ON, weight 2
By lowering 0 downward and pressing the sheet document P on the paper feed roller 5, the conveyance force by the paper feed roller 5 is increased. Reference numeral 111 denotes a document stopper solenoid, which swings the document stopper 19 up and down, and is located at the position indicated by the solid line in the OFF state and raised to the position indicated by the broken line in the ON state. Next, the swing operation of the document tray 4 will be described.

Reference numeral 107 denotes a tray swing motor, the motor output shaft of which is connected to the tray swing arm 48.
A tray swing shaft 47 is engaged with the lower surface of the document tray 4. The tray swing shaft 47 engages with the tip of the tray swing arm 48, and the opposite side of the tray swing arm 48 is fixed to the tray swing arm shaft 67.
The tray swinging arm 48 moves as shown in FIG.
The document tray 4 is swung between the positions shown in FIG.

Reference numeral 51 indicates an upper limit switch for detecting that the document tray 4 has reached the upper position, and reference numeral 5 indicates
Reference numeral 2 denotes a lower limit switch for detecting that the document tray 4 has reached the lower position. The rotation of the tray swing motor 107 is controlled by detecting the upper and lower limit switches 51, 52.

Next, the bundle conveying means on the document tray 4 will be described. Reference numeral 106 is a stopper slide motor for moving the stopper 21 in the direction of FIG. 2A. Figure 3
As shown in FIG. 5, the sheet original P is conveyed to the second separating section and returned to the initial position after the conveyance. Also, every time the sheet document is discharged from the sheet discharge roller 11 onto the document tray 4, the stopper 21 pushes the rear end of the sheet document toward the second separating portion side, and the sheet document P on the document tray 4 is pushed.
To improve the consistency in the transport direction (FIGS. 12 and 13). Next, the partition member of the document tray 1 will be described with reference to FIG. FIG. 15 is a diagram showing details of the configuration of the partition member.

In FIG. 15, the partition member motor 105
On the output shaft 117 of the partition flag 119 which is supported freely in the rotational direction, and the partition lever 1 which is fixed to the output shaft 117 and drives the partition flag 119 to rotate.
20 are arranged coaxially. As shown in the figure, the partition flag 119 has a part of its circumference cut off.
A partition member 22 made of a flexible material such as a polyester film or a leaf spring is fixed on the circumference, and rotates on the output shaft 117 integrally with the partition flag 119. Further, since the center of gravity of the partition flag 119 is located on the partition member 22 side, when the partition lever 120 is not driven, the partition flag 119 is stopped by its own weight when the partition member 22 comes to a position directly below. Reference numeral 121 denotes a partition sensor, which detects the partition flag 119 to determine the position of the partition member 7.

In FIG. 15, when the sheet originals P are fully loaded on the original tray 1, the distance between the end surface of the sheet originals P and the mounting portion of the partitioning member 22 is short and the partitioning member 22 has a strong rigidity. It is not deformed and is in a flat state along the sheet document P as illustrated.

In FIG. 15, when the number of sheet originals P stacked on the original tray 4 is small, a conventional partitioning member having rigidity has a tip of the member in contact with the surface of the sheet original P. Since it stops, the partition member floats up at the end position of the document due to a gap with respect to the document surface. Then, the sheet document P is placed above the partition member.
When the document is reloaded, the leading edge of the document collides with the partition member, and the document cannot be stably stacked on the document tray 4. However, as shown in FIG. 15, the partition member 22 has flexibility. Therefore, the partition member 7 is adapted to the surface of the document stack P by the driving force of the partition lever 120, and becomes flat along the document surface as in the case of full loading.

Therefore, the partition member 22 is used as the original tray 4
Regardless of whether the number of sheet originals P is large or small, the sheets are always in close contact with the surface of the original bundle P.
Even if the sheet original P is reloaded on the partition member 22, it does not collide with the partition member 22.
Sheet manuscript P stably without causing any trouble in carrying out
Can be loaded.

Next, the jogging mechanism will be described with reference to FIG.

FIG. 15 is a top view of the document tray 4.

In the figure, reference numeral 122 is a jogging guide which forms a part of the width direction regulating plate 33a, and is supported by the width direction regulating plate 33a so as to be retractable.

Link pins 126 and 127 that engage with one side of the jogging links 123 and 125 at two locations are provided on both sides of the jogging guide 122 opposite to both sides of the document. The other ends of the jogging links 123 and 125 are engaged with the jogging lever 129 by lever pins 130 and 131.

The jogging lever 129 is engaged with the jogging solenoid 132. Therefore, when the jogging solenoid 132 is turned on, the jogging guide 122 operates so as to press the sheet document P against the document reference guide 33, and the jogging solenoid 132 is turned off.
When F, the return spring 133 causes the jogging guide 12
2 operates so as to be separated from the end surface of the document. That is,
Each time the sheet original P is reloaded on the original tray 1 one by one, the jogging solenoid 132 is repeatedly turned on / off to reliably press the sheet original P against the original reference guide 33, and the sheets on the original tray are fed. The consistency of the manuscript P is improved.

Further, a slide volume (not shown) engages with the width direction regulating plate 33a, and the width direction regulating plate 3 is provided.
By moving 3a, it is possible to obtain size information in the width direction of the sheet material placed on the document tray 4.

Further, as shown in FIG. 1, a sheet material length detection sensor 68 is attached to the rear end of the document tray 4,
This sheet material length sensor (eg reflective sensor)
Is for determining whether the sheet material is LTR size (216 mm) or more or less.

The sheet material length detection sensor 68 detects L
When it is determined that the size is larger than the TR size, the sheet material placed on the document tray 4 is fed from the first separating unit side. When the sheet material length detection sensor 68 determines that the size is less than or equal to the LTR size, information on the width direction size of the sheet material is obtained from the slide volume that moves in conjunction with the width direction regulation plate 33a next. Judge whether or not A
If the size is 4, LTR size, the condition that the document tray is lowered and the second separating unit can feed the sheet is satisfied. Furthermore, depending on the image forming mode input to the image forming apparatus,
It is determined whether the paper is fed from the first separating means side or the second separating means side.

If the size is other than A4 or LTR size, the sheet material is fed from the first separating means side.

The standard for the size of the sheet material is just an embodiment of the present invention, and the standard value of the size can be arbitrarily selected.

<RDF control device ... FIG. 16> FIG. 16 is a block diagram showing the circuit configuration of the control device of the circulation type document feeder of the present embodiment. The control circuit is a one-chip device incorporating ROM, RAM and the like. Microcomputer (CPU) 2
01, and signals of various sensors are input to the input port of the microcomputer 201. The control circuit is backed up by a backup battery.
It also has AM.

<Analog Input> Also, the microcomputer 201
The output voltage from the slide volume for detecting the document width is input to the analog / digital conversion terminal of
The slide volume value can be continuously detected in 255 steps.

In addition to this, a voltage proportional to the motor currents of the first separating motor 100 and the second separating motor 103 is also input so that the thickness of the original can be detected by the method described later.

Further, the input from the light receiving side 23b of the original detection sensor is also input to another analog / digital conversion terminal, and the state of the sensor is monitored and the original thickness is detected.

Further, the thermistor and the humidity sensor are mounted inside the wide belt at a position near the platen glass to measure the temperature and humidity near the platen glass, and the analog output thereof is also input to the analog / digital terminal.

Further, each load is connected to the output port of the microcomputer 201 via a driver.

<Belt Motor Control> FIG. 10 shows a block diagram of the belt motor driver.

The belt motor 102 is a 4-phase stepping motor. For example, a commercially available stepping motor driver SLA7026M manufactured by Sanken Electric Co., Ltd. is used.
It is driven by a constant current driver circuit formed into an IC as described above. To the belt motor driver circuit 301, known four-phase motor excitation control signals 305, 306, 307, 308 and an analog voltage (belt motor current control signal) 309 for controlling the motor drive current are input from the microcomputer 201. . By changing the frequency of the excitation control signal, the peripheral speed of the belt motor 102 and further the wide belt 7 can be arbitrarily changed. Further, by changing the belt current control signal voltage, in the case of starting the motor, accelerating, at a constant speed, or when a document is straddled between the wide belt 7 and the conveying rollers before and after the wide belt 7, etc. The motor torque can be changed.

By inputting the belt motor clock from the belt clock sensor 102b to the microcomputer 201, it is possible to detect the step out of the belt motor.

Reversing Motor Control Circuit The reversing motor 101 is a DC motor, which is capable of synchronous rotation with the belt motor by PLL control. In addition, the reversing motor 101 is controlled by a unique PWM control signal from the microcomputer 201.
Control without L control is also possible. The detailed block diagram is shown in FIG.

The speed control of the reversing motor is performed by the reversing motor PWM signal 317 from the PWM output terminal of the microcomputer 201. Its Duty is the initial duty factor value determined from the motor characteristics and load conditions, and the analog duty factor as described later. / Determined by calculating the value obtained by digitally converting the correction voltage value appearing at the digital conversion terminal.

The inverting motor driver basically operates the drive transistor 3 in order to enable PWM control.
10 and a flywheel diode 311.
In addition, a transistor 312 for short brake is also prepared because a jam may occur or a sudden deceleration may be required. The control logic circuit 313 is prepared so that the braking operation is prioritized when the short brake signal 318 is output.

The phase / frequency detector 314 may, for example,
This is realized by the commercially available Toshiba model TC9192 or the like. The reference clock 319 of the phase / frequency detector is output from the microcomputer 201 and compared with the reverse motor clock 320 to output a voltage corresponding to the correction amount of the phase difference and frequency difference.

The output from the phase / frequency detector 314 is input to a loop filter circuit composed of an adder 315 and a lag / lead filter 316, and the loop gain is optimized and
Phase correction is performed.

The output of the loop filter circuit is the microcomputer 20.
1 is input to the analog / digital conversion terminal. Here, the voltage appearing at the analog / digital conversion terminal is D of the PWM signal output from the microcomputer 201 for controlling the carry motor.
It is a value proportional to the correction value for correcting the duty factor.

Furthermore, the capture signal 3 indicating from the phase / frequency comparator 314 to the microcomputer 201 that the number of rotations of the motor is in a range that can be locked by PLL control.
93 is output. This signal is output when the speed difference between the reverse motor reference clock 319 and the reverse motor clock 320 is within about 5%.

<First Embodiment of Changing Reverse Motor Control Parameter> FIG. 42 is a block diagram schematically showing a state relating to speed control in the microcomputer 201. The phase signal and frequency signal output from the phase / frequency detector 314 are
In FIG. 8, the signals are combined by the adder 315, but the description here will be made with the configuration in which the phase and the frequency are processed separately.
Therefore, 315a is a phase signal amplifier, 315b is a frequency signal amplifier, 316a is a phase signal lag lead filter circuit, and 316b is a frequency signal lag lead filter circuit. 321 is an initial duty calculation block for calculating the initial duty factor value from the above-mentioned motor characteristics and load conditions, 322 is a calculation block for correcting the initial duty based on the feedback amount from the phase / frequency detector 314, and 323 is an inversion motor. PWM generators 324a, 3 for generating PWM signal 317
24b is an analog / digital conversion circuit for phase signals and frequency signals, 325a and 325b are arithmetic blocks for generating error voltages for phase signals and frequency signals, respectively.
326a and 326b are phase signal and frequency signal gain setting blocks that can be arbitrarily set in the microcomputer 201, and 327 is a paper thickness detection circuit to be described later, 328.
The setting control unit 329 controls each setting of the initial duty calculation block 321, the frequency signal gain setting block 326b, and the sensitivity of the phase / frequency detection unit 314, and a sheet size detection unit 329.

The following calculations are performed in the initial duty generation block.

[0117]

[Formula 1] Di = K1 × {fs / (N × K _V ) + K _L }% K1: Constant related to drive voltage fs: Inverting motor reference clock frequency N: Number of slits in the slit plate of the inversion motor K _V : Motor the induced voltage constant constant related to K _L: in this constant related to the load on the motor, fs, and, K _L is the control parameter set by the setting means 328, in particular, K _L is the sheet thickness detection circuit The value is changed by the input from 327. That is, the paper thickness detection circuit 327
If the input from indicates that the paper is thin, K _L
Is a relatively small value K _L1 , a width value K _L2 is a normal paper, and a very large value K _L3 is a thick paper. These values are set based on the torque constant of the motor used and the load on the motor shaft measured when the paper is actually conveyed.

Further, the constant K _L related to the load of the motor is designed so that the value changes even when input from the conveyed paper size detection unit 329. For example, when a small paper size such as A5 size is input. , A value smaller than K _{L1 for} thin paper is set.

<Second Embodiment of Changing Inversion Motor Control Parameter> In the gain setting block 326, the gain is changed only for the frequency signal.

When the frequency signal loop is formed, the following relationship is established.

[0121]

Fg = Ga × Gsf / (1 + Ga × Gsf) ×
fs + (G1 × Di G1 × Ds−G2 × Im) / (1
+ Ga × Gsf) Gsf: Gain set by the gain setting block 326b Ga: Open loop gain excluding Gsf G1: Transfer gain from the initial duty generation block 321 to the reverse motor clock 320 G2: Reverse motor shaft related to the motor characteristics That represents the degree of influence of the load on the rotation speed of the motor Di: Output from the initial duty generation block 321 Duty Ds: Constant corresponding to the reference voltage for generating the error voltage Im: Variable proportional to the load of the reversal motor 101 In this equation, Im increases when the load of the reversing motor increases during thick paper conveyance, and the open loop gain Ga ×
When Gsf is small, it leads to a decrease in fg. Therefore, when the input from the paper thickness detection unit 327 to the setting control unit 328 is thick paper, the gain set in advance in the gain setting block 326b is controlled to be large. As a result, vibration of the control loop is likely to occur, but the thick original has a large rigidity due to its nature, and the buckling problem does not occur even if there is a considerable speed fluctuation.

On the contrary, by increasing the open loop gain, the influence of Im can be reduced, the delay of the sheet conveyance can be reduced, and the problem such as the stop of the motor can be avoided in advance.

Third Embodiment of Changing Inversion Motor Control Parameter> A phase / frequency comparator 31 is used as a method for increasing the open loop gain by the input from the paper thickness detecting section 327.
There is a method of increasing the sensitivity of No. 4 and the effect is almost the same as in the case of the second embodiment of changing the inversion monitor control parameter, but the phase sensitivity is also increased at the same time, so that the vibration in the phase control loop may become very large. Therefore, the effect is lower than that of the second embodiment.

<Belt-Reverse Motor Synchronous Control Embodiment 1>
The control at this time is as follows.

The reversing motor 101 is fixed to PWM_Dut
Start up at y, and do not perform PLL control at the time of rising (set to PWM only mode). Fixed D above
uty is calculated and determined based on the PWM setting Duty factor when the separated document is advanced to a predetermined position and controlled, and the rotation speed of the reversing motor 101 measured at this time.

However, the reverse motor reference clock synchronized with the excitation clock of the belt motor 102 (generated in the microcomputer 201) is input to the phase frequency comparator 314.

The acceleration pattern of the belt motor 102 is set to be close to the mechanical time constant of the reversing motor 101, but is set to be slightly slower than the rising speed pattern of the reversing motor 101. For the mechanical time constant, use the one set in advance at the factory.

[The mechanical time constant is determined by the electromotive force constant of the reversing motor, the torque constant, the sum of the drive circuit resistance and the motor winding resistance, the inertia of the motor itself, and the load inertia on the motor shaft. As long as the effect of temperature change can be ignored, there is almost no change over time, including the temperature environment. In this embodiment, the influence of the motor winding is minimized by optimizing the current detection resistor 390 of the motor. The mechanical time constant is measured at the assembly factory, the time constant data is stored in the nonvolatile memory in the controller, and the acceleration pattern of the belt motor 102 is determined based on this data. Further, the mechanical time constant of the reversing motor 101 to be stored is measured in a state in which the separation unit 6 and 38 and the document are straddled. If the mass of the mechanical parts such as the separation belt 6, the separation roller 38, the large roller 10 and the feeding roller 9 that greatly influence the inertial load is stable, the reversing motor 10 is used.
The mechanical time constant of the entire system can be calculated by only measuring the mechanical time constant of one unit or when there is no document. When approaching the steady rotation, the capture signal 393 is monitored, and if it is confirmed that it is within the capture range of the PLL, the PWM single mode is canceled and the mode is switched to the PLL mode.

The motor is stopped and jammed, assuming that some error occurs outside the capture range.

<Second Embodiment of Belt-Reverse Motor Synchronous Control>
FIG. 14 is a block diagram of a second embodiment realized by the belt motor 102 and the reversing motor 101.

In the control circuit of the belt motor 102 of the first embodiment, for example, a control IC such as Toshiba TA8415 is used.
The pulse rate signal 410 input to the control IC 400 is switched by the clock switching circuit 401. The pulse rate clocks input to the clock switching circuit 401 are the belt motor reference clock 411 and the reverse motor clock 320, and one of them is controlled by the clock switching signal 412.
Allow input to 400.

In addition to the above, from the microcomputer 201 to the control IC 4
00 to the belt motor 102 on / off signal 413,
A hold signal 414 for holding the excitation pattern of the belt motor 102 and a forward / reverse rotation signal 415 for controlling the rotation direction of the belt motor 102 are input.

In the above structure, the following control is performed.

When the document from the first separating means is conveyed, the clock switching signal is set so that the pulse rate signal 410 to the control IC 400 becomes the reverse motor clock 320.

The operation mode of the reversing motor 101 is set to the PWM single mode, and the reversing motor 101 is turned on by the PWM of the fixed duty or the control for gradually increasing the PWM_Duty.

When the reversing motor 101 is started with a fixed duty, the duty is set so that the pull-out torque of the belt motor 102 has a pulse rate with a sufficient margin with respect to the load torque.

In the case of the control for increasing the PWM_Duty stepwise, the reverse motor reference clock 319 corresponding to the target speed is input to the phase frequency comparator 314, and the capture signal 393 is input to the microcomputer 201. wait.

When the capture signal 393 is input,
After that, the reversing motor 101 is controlled by the PWM_Duty factor at the time of input.

When the trailing edge of the document passes through the post-registration sensor 39, the pulse rate signal 410 is switched to the belt motor reference clock 411 side, and the belt motor 102 is controlled thereafter by the belt reference clock 411.

When the original is conveyed from the second separating means,
The pulse rate signal 410 is fixed to the belt reference clock 411 side from the beginning, and the belt motor 102 is controlled by the belt reference clock 411. The reversing motor 101 is operated in the PLL synchronous mode, and the reversing motor reference clock 319 is the same as the belt reference clock 411.

In the case of the second embodiment, the control is simple, but the cost is disadvantageous because the control IC 400 and the like are added.

<Conveyor Motor Control Circuit> Conveyor motor 104
Is a 4-phase stepping motor, and a detailed block diagram of its control unit is shown in FIG.

The carry motor driver 330 is, for example, an IC driver such as a commercially available constant current driver SLA7026M manufactured by Sanken Electric.

The phase excitation control signal 337 to the carry motor driver 330 is generated, for example, by using a commercially available Toshiba control IC (TA8415), and this carry control IC 331 is turned on / off from the microcomputer 201. The control signal 336 and the hold control signal 335 are input.

Pulse rate clock 338 to control IC
The carrier control clock 339 from the microcomputer 201 or the second separated clock 340 from the second separated clock sensor 103b is input to the input terminal, and the switching is performed by the clock select circuit 332.

A clock switching signal 341 from the microcomputer 201 is input to the clock select circuit 332. If the clock switching signal 341 is low level, the second separation clock 340 is input to the transport control IC 331, and the transport motor 104 Moves in synchronization with the second separation motor 103. If the clock switching signal 341 is at the high level, the carrier control clock 33 is transferred to the carrier control IC 331.
9 is input, and the carry motor 104 can move independently. Alternatively, if the pulse rate clock frequency K1 of the belt motor 102 and the clock frequency K2 of the carry motor 104 are set, K1,
If K2 is determined, synchronous control with the belt motor 102 is possible.

[0147]

## EQU00003 ## D1.times.Z1.times.K1 / N1 = D2.times.Z2.times.K2 / N2 D1: Effective roller diameter determined by drive roller 36 and wide belt 7 Z1: Reduction ratio from belt motor 201 to drive roller 36 N1: Belt motor 201 is the number of locks required for one rotation D2: Roller diameter of the feeding roller 16 or the relay roller 17 Z2: Reduction ratio from the conveyance motor 104 to the feeding roller or the relay roller N2: The conveyance motor 104 is required for one rotation Number of clocks Further, the current value of the conveyance motor 104 is the belt motor 102.
Similar to the above, it can be controlled from the microcomputer 201, and the current value can be changed as required when the motor is started, when the originals straddle the rollers, or when a thick original is conveyed, and the motor torque can be controlled arbitrarily. It is possible. The carry motor current control signal 342 in FIG. 10 is a signal for controlling the current value and is output from the D / A converter output terminal of the microcomputer 201. A voltage corresponding to the carry motor current appears at both ends of the current detection resistor 333, and this voltage is controlled so as to match the carry motor current control signal voltage.

The carry motor clock 343 from the carry motor clock sensor 104b is input to the microcomputer 201 and is used for detecting a step out of the carry motor 104.

FIG. 43 is a block diagram schematically showing how the stepping motor control in the microcomputer 201 is concerned. Reference numeral 334 is a motor control parameter setting block for setting control parameters such as the acceleration and start pulse rate of the stepping motor, and the maximum pulse rate, and 345 outputs a motor control value based on the parameters from the motor control parameter setting block. In the control block, 345a is an acceleration control block for setting the motor acceleration, 345b is a control block for setting the motor start pulse, and 345c is a control block for setting the maximum pulse rate. 346 is a control block 34
5 is an excitation pattern generation block that receives an input from the motor controller 5 and generates an excitation pattern of the motor.

Further, the motor control parameter setting block 344 includes the thickness detection block 327 and the second separation sensor 2
A signal from 9 and a carry motor clock 343 for detecting the step-out of the motor are input, and the control parameters of the motor are determined by these signals.

The relationship between the required torque of the stepping motor and the acceleration is generally expressed by the following equation.

[0152]

[Formula 3] (At motor startup) Ta _1- (J _L + Jm) / g * (θ / 180) ^ 2 * π
* Z * (fs) ^ 2 (during motor acceleration) Ta ₂ = (J _L + Jm) / g * (θ / 180) * π *
(Ft-fs) / t Ta ₁ : Acceleration torque required for self-start Ta ₂ : Torque required to accelerate from fs to ft J _L : Moment of inertia of load Jm: Moment of inertia of rotor of motor g: Gravity acceleration θ: Step angle Z: Number of rotor teeth fs: Start pulse rate ft: High-speed operation pulse rate t: Acceleration time The pull-in torque (T _Min ) and pull-out torque (T _Mout ) required for the motor are the friction load _TL. And

[0153]

[ _Equation 4] (When the motor is started) T _Min > _TL T _Mout > _TL + Ta ₁ (When the motor is accelerated) T _Mout > _TL + Ta ₂ The thickness of the document detected by the second separation sensor and the second separation motor is thick. The friction load T _L has a very large value in the case of a document, and similarly has a small value in the case of a normal document or a thin document. Since the rating of the motor is usually selected according to the original, in order to enable the convey motor to convey a thick original, as is apparent from the above-mentioned relational expression, the acceleration time t is increased or the high speed is increased. There is a method of lowering the operation pulse rate to reduce the term of the required acceleration torque.

<First and Second Embodiments for Changing Control Parameters> When the torque characteristic of the motor is flat and the moment of inertia of the load is large, it is advantageous to increase the acceleration time. When the torque characteristics of the motor suddenly drop, it is advantageous to use a method of lowering the high-speed operation pulse rate, or a method of increasing this and a method of increasing the acceleration time.

<Third Embodiment for Changing Control Parameters>
Also, if there is no torque margin in the low range of the motor, there is a possibility that step out at the time of startup due to thick document conveyance may occur, and in this case as well, it is clear from the above equation that the startup pulse rate is lowered, Make sure to start at a pulse rate that can secure sufficient pudding torque and pullout torque.

Which method is to be adopted is a design matter, but it is also possible to automatically determine which method is to be adopted based on the step-out detection result of the carry motor clock 343.

That is, if the stepping motor is out of step at the step out timing, it is determined that the torque is insufficient at the time of startup, and the startup pulse rate at the time of conveying the thick original is lowered. When the pulse rate is reduced, the pull-in torque characteristic (not shown) at the actual load inertia moment is stored in the ROM, and the pull-in torque characteristic is determined based on this data. If step-out occurs during acceleration, determine that it is due to lack of acceleration torque and delay the acceleration time,
Reduce the high-speed operation pulse rate. If step-out occurs during steady-state speed operation after acceleration, it is determined that the torque at the high-speed operation pulse rate is insufficient, and the high-speed operation pulse rate is reduced.

<Separation Motor Control Circuit, Current Detection Circuit> FIG. 11 shows a detailed block diagram of the control units of the first and second separation motors.

Both the first separation motor 100 and the second separation motor 103 are DC motors, and the first separation motor PWM output 356 of the microcomputer 201 and the second separation motor PWM
It is possible to set an arbitrary speed by the output 366.

The speed control of the first and second separation motors is performed using the pulse width measuring function of the microcomputer 201. That is, the pulse cycle of the first and second separated clocks 359 and 369 is measured, and negative feedback control is performed to change the duty factor of the PWM outputs 356 and 366 so that the value falls within the approximate variation range, and the motor speed is adjusted. It is set within a predetermined variation range.

The first separation motor driver and the second separation motor driver are basically composed of drive transistors 350 and 360 and flywheel diodes 351 and 361 in order to perform PWM control.
In addition, since there is a case where a jam occurs or rapid deceleration is required, the short brake transistors 352 and 362 are provided.
Is also available.

The thickness of the original is detected by two methods.

<First Embodiment: Document Thickness Detection Circuit Using Separation Motor> The first method is a method of judging from the current value of the separation motor. The conveyance rollers 38 and 15 constituting the first and second separation sections. When a document enters the gap between the separation belts 6 and 14, it is noted that the separation motor current largely changes depending on the stiffness of the document, and the thickness of the document having a large relation to the stiffness of the document is detected.

A current detection resistor 35 is provided between the separation motors 100 and 103 and the flywheel diodes 351 and 361.
4, 364 are positioned, and the potential difference between both ends is amplified and input to the A / D terminal of the microcomputer 201. Drive transistor 3 because the current detection resistor is placed in the above position
Even when 50 and 360 are turned off, current can continue to flow through the detection resistors 354 and 364 due to the regenerative current of the motor.

FIG. 12 is data showing the relationship between the separation current and the document thickness. The horizontal axis represents the number of documents stacked on the document tray 4, and the vertical axis represents the current value of the separation motor. Using the document conveyance force of the separation mechanism as a parameter, a plain paper with a basis weight of 80 g / m ² and a thick paper with a basis weight of 207 g are used.
It is the result of measuring the motor current for a document of / m ² .

The current value is changed only by the thickness of the original, which has almost nothing to do with the conveying force of the original. Further, it can be seen that although there is a dependency on the number of documents loaded on the tray, it does not lead to erroneous detection.

From this, the thickness of the original can be detected by setting the threshold value by the motor current for separating the thick paper and the plain paper to about 1.4A. The change in threshold value due to secular change and machine-to-machine variation is solved by stepwise changing the threshold value in conjunction with the change in motor current (about 0.9 A in FIG. 12) when a document is not conveyed. it can.

<Second Embodiment: Document Thickness Detection by Reversing Motor> A second example of detecting the document thickness from the motor current is a method using the current value of the reversing motor.

In FIG. 9, a current detection resistor 390 is inserted between the reversing motor 101 and the flywheel diode 311 so that the motor current can be detected regardless of the PWM control of the reversing motor 101. Here, the current-voltage converted motor current signal is amplified by the amplifier 391 and becomes an inverted motor current signal 392, which is input to the A / D input terminal of the microcomputer 201.

While the separation nip point by the separation belt 6 and the separation conveyance roller 38 is close to the nip point by the large roller 10 and the feeding roller 9, the peripheral speed of the large roller 10 is the same as that of the separation conveyance roller 38. It is set to be higher than the peripheral speed, and when the document is conveyed over both the conveyance portions, the load of the reversing motor 101 that drives the large roller 10 becomes very large. The reverse motor current at this time is as shown in FIG.

In FIG. 13, reference numeral 440 is a reverse motor brake signal waveform, and the motor is on at a high level. 441
Is a reversing motor current when a thick document is conveyed, 442 is a reversing motor current waveform when a normal document is conveyed, and 443 is a reversing motor current when a thin document is conveyed.

The arrow 444 indicates that the manuscript is as described above.
This is a period of straddling the separating units 6 and 38 and the feeding units 9 and 10.

Further, 445 is a timing waveform of the first paper feed sensor 25, and 446 is a timing waveform of the post-registration sensor 39.

In the straddle conveyance period 444, it is understood that the reversing motor current is largely influenced by the thickness of the original document due to the influence of the separation gap and the stiffness of the original document. If the reverse motor current is sampled and measured within this period,
The thickness of the document can be estimated from the current value. In this embodiment, the sampling timing is set by the rise of the post-registration sensor 39.

According to the method of this embodiment, the thickness of the original can be measured by optimizing the arrangement of the sensors and minimizing the influence of the original bundle P on the original tray 4. In comparison, there is a problem that the detection timing is shifted.

The second method uses a transmissive optical sensor composed of a light emitting portion and a light receiving portion, and utilizes that the transmittance of a document placed between the light emitting portion and the light receiving portion changes depending on the thickness. Then, the thickness is detected. Although not shown, this optical thickness detection sensor is arranged in the vicinity of the first and second separating means in the downstream direction, and is performed when the originals are separated from the original stack P one by one.

<First Embodiment of Optical Thickness Detection> FIG. 17
Shows a block diagram of an optical thickness detector, and the detector also serves as the first and second separation sensors. The present invention will be described based on the first separation sensor.

When there is no document in the standby state, the microcomputer 201 emits light so that the analog / digital conversion input (hereinafter referred to as A / D input) of the microcomputer 201 = the separation sensor signal output level 420 becomes a constant value. Side sensor 2
The emitted light amount of 4b is changed by the D / A converter. The output value of this D / A converter is set to the correction voltage (42
I will call it 1). Reference numeral 24a is a light-receiving side sensor.

When the document feeding operation is started, the microcomputer 20
1 fixes the output value of the D / A converter to the correction value immediately before the start of conveyance.

In this state, when the originals separated one by one by the separating means are applied to the separation sensor 24, the separation sensor signal level changes depending on the transmittance of the originals, so it can be seen that the originals approach the sensor. If the original is relatively thin in this state, the separation sensor signal output is not saturated, so it can be determined that the original is thin.

When the original has a certain thickness, the signal output 420 of the separation sensor 24a is saturated, and it cannot be determined how thick the original is. When the microcomputer 201 determines that the sensor output is saturated, it outputs the light amount switching signal 423 to output the light amount switching transistor 42.
Turn off 4. Accordingly, the separation sensor light emitting element 24
Since the light quantity from b increases, the A / D input value is checked in this state. Separated sensor signal level 42 at this time
If the value of 0 is not saturated, the microcomputer 201 determines that the original has a normal thickness.

If the sensor output is kept saturated even if the light amount up circuit is activated as described above, the microcomputer 2
01 is determined to be a thick manuscript.

<Second Embodiment of Optical Thickness Detection> FIG. 18
Is the second document thickness detection method that uses an optical transmissive sensor.
3 is a block diagram of the embodiment of FIG.

Similar to the first embodiment, the correction by the D / A converter is performed in the standby state, and the correction value 421 of the D / A converter is fixed to the correction value immediately before the start when the original feeding operation is started. The determination is performed in the same manner as in the first embodiment.

When the original has a certain thickness, the separation sensor signal output 420 is saturated and it cannot be determined how thick the original is. When the microcomputer 201 determines that the output of the separation sensor signal 420 is saturated, it sets the load switching signal 427 to a high level to turn off the switching transistor 428 and increase the load resistance of the light receiving side sensor 24a of the separation sensor. And the separation sensor 24
The operating point of is entered from the saturation region to the active region. By this control, if the separation sensor signal output 420 is at a level that does not saturate, the microcomputer 201 determines that the original is a normal thickness, and if it remains at the saturation level, it is a thick original.

FIG. 19 shows the characteristics of the separation sensor signal output 420 with respect to the thickness of the original, in which the horizontal axis shows the original basis weight and the vertical axis shows the sensor output voltage. In the figure, the solid line is the sensor output when the correction value by the D / A converter is fixed to the correction value in the standby state. In this case, in the first embodiment, the light amount is the normal light amount, In the second embodiment, the case where the load resistance of the sensor is switched to the smaller one is shown (normal mode).

The broken line in the figure shows the characteristics when the light amount is increased in the first embodiment, and the characteristics when the load resistance is increased in the second embodiment (original thickness). Detection mode).

Also, the one-dot chain line arrow indicates the thin original determination range in the normal mode, and if the sensor output is in this range in the normal mode, it is determined to be a thin original. The two-dot chain line arrow indicates the thick document determination range, and if the sensor output is within this range in the document thickness detection mode, it is determined as a document.

<Third Embodiment of Optical Thickness Detection> The third method of optical thickness detection has the configuration of FIG. 17 and does not switch the light amount of the light emitting side sensor 24b, but the correction voltage 421 of the D / A converter. This is a method of determining the thickness of the document based on.

The sensor output in the standby state is corrected by the D / A converter, and the correction value 421 of the D / A converter is fixed to the correction value immediately before the start when the document feeding operation is started. Judgment is made in the same way as in the embodiment.

When the original has a certain thickness, the separation sensor signal output 420 is saturated and it cannot be determined how thick the original is. The microcomputer 201 gradually increases the output value of the D / A converter so that the separation sensor signal output 420 approaches the value when there is no document, with the document being present. The microcomputer 201 estimates the document thickness from the D / A converter correction value thus obtained. In the case of the present embodiment, when the correction voltage 423 of the D / A converter is small, it is a thin document, when it is medium, it is judged as a normal document, and when it is a very large value, it is judged as a thick document. .

In the case of this embodiment, it is very effective when the resolution of the D / A converter is excellent, but it is 8 bits.
Not suitable for resolution class D / A converters.

In any of the embodiments, when the series of document thickness detection is completed, the microcomputer 201 returns the setting of the sensor circuit to the setting of the standby state immediately before the start of document transportation,
The thickness of the next document to be conveyed can be detected.

Further, in any of the embodiments, if the original density is uniformly high, there is a possibility of erroneous detection by the transmissive sensor, and by combining with the above-described determination of the original thickness by the separation current, the thickness detection can be performed. The accuracy can be improved.

<Belt Motor Start-up Control> The start-up control of the belt motor is roughly classified into two types according to the image forming mode described above. When the original is fixed and the optical system of the image forming apparatus is scanned to form an image (fixed reading mode), it is necessary to control the start-up of the belt motor so that the original replacement time is minimized. When an image is formed while the original is conveyed on the side of the original conveying apparatus while the optical system of the image forming apparatus is fixed (scanning mode), it is necessary to control the vibration of the original conveying system during image formation to a minimum. Because there is.

Generally, it is difficult to make both of these controls compatible with each other, and the control is switched when the image forming mode is determined.

First, the start-up control of the belt motor in the fixed reading mode will be described.

The wide belt 7 is in contact with the platen glass 3 almost entirely, and the frictional force between the wide belt and the platen glass is extremely large. On the other hand, when a document enters between the wide belt and the platen glass, the coefficient of friction between the wide belt and the document is large, but the coefficient of friction between the document and the platen glass is very small. Further, FIG. 20 shows the results of measuring the temperature change of the friction coefficient between the wide belt and the platen glass. As shown in FIG.
The friction coefficient between the wide belt and the platen glass is greatly affected by the temperature and humidity on the platen. For example,
The friction coefficient at 40 to 50 ° C is 1.4 times or more that at 20 ° C.

As a result, the torque required for the belt motor is significantly different when the preceding document is present on the platen glass, when it is not present, when the platen temperature is high or low, and when the humidity is high or low.

Generally, the torque required for accelerating the stepping motor is expressed by the sum of the acceleration torque term and the load torque term which depend on the acceleration. When this is mathematically expressed, it becomes as follows.

First, the relationship between the required torque and the acceleration of the stepping motor is generally expressed by the following equation.

[0202]

(Equation 5) (At motor startup) Ta ₁ = (J _L + Jm) / g * (θ / 180) ^ 2 * π
* Z * (f1) ^ 2 (during motor acceleration) Ta ₂ = (J _L + Jm) / g * (θ / 180) * π *
(F2-f1) / δt Ta ₁ : Acceleration torque required for self-start Ta ₂ : Torque required to accelerate from f1 to f2 J _L : Moment of inertia of load Jm: Moment of inertia of rotor of motor g: Gravity acceleration θ: Step angle Z: Number of rotor teeth f1: Start pulse rate f2: High-speed operation pulse rate δt: Acceleration time Therefore, the pull-in torque (T
_Min ) and pullout torque (T _Mout )
_L

[0203]

( _Equation 6) (At motor startup) T _Min > T _L T _Mout > T _L + Ta ₁ (At motor acceleration) T _Mout > T _L + Ta ₂ <First embodiment of belt motor speed start-up control> Belt motor The speed rising control will be described with reference to the acceleration / deceleration pattern diagram shown in FIG.

In FIG. 7A, the horizontal axis represents the time axis and the vertical axis represents the pulse rate of the stepping motor. Further, f ₁ and f ₂ represent the pulse rate at the time of starting the motor and the pulse rate at the steady state as described above. The solid line pattern shows an acceleration / deceleration pattern when there is no preceding document on the platen glass 3, when the humidity near the platen is high, and when the platen glass temperature is 50 to 60 ° C., and the wavy line pattern shows the platen glass. When there is the preceding document on the upper side of the sheet 7, the platen glass shows an acceleration / deceleration pattern of normal temperature and normal humidity. A finer acceleration pattern can be generated by finely adjusting the condition of the original on the platen and the temperature and humidity parameters, but here, only two acceleration / deceleration patterns are used to simplify the description.

The points t ₁ to t ₇ on the time axis indicate the inflection points of the speed of each acceleration / deceleration pattern.

The area of the acceleration pattern indicates the moving distance of the document and is a value obtained by adding the length of the sheet in the transport direction and the document interval. The area surrounded by the solid line pattern and the area surrounded by the wavy line pattern are equal because the moving distance of the document is constant.

In the case of the solid line acceleration pattern, the acceleration time δt of the motor is (t ₃ −t ₁ ), and the time required to move the document is (t ₇ −t ₁ ).

In the case of the wavy pattern, the acceleration time δt of the motor is (t ₂ −t ₁ ), and the time required to move the document is (t ₆ −t ₁ ).

As described above, when the required torque T _M of the motor is constant and the preceding document is not present on the platen glass 3, the load _TL at the time of starting the motor is large and δt cannot be increased. In the case of the presence of the torque, the torque can be distributed to the acceleration torque term by the amount that the load _TL at the time of starting the motor is reduced, and the moving time of the document can be shortened by reducing δt as shown by the wavy line in FIG. 7A. .

<Second Embodiment of Belt Motor Speed Raising Control> A second embodiment of the belt motor speed raising control will be described with reference to an acceleration / deceleration pattern diagram shown in FIG. 7B.

In FIG. 7B, the horizontal axis indicates the time axis and the vertical axis indicates the pulse rate of the stepping motor. The solid line pattern shows an acceleration / deceleration pattern when there is no preceding document on the platen glass 3 or when the platen temperature is 50 to 60 ° C., and the wavy line pattern shows when there is a preceding document on the platen glass 7, The acceleration / deceleration pattern at normal temperature and normal humidity is shown.

Further, as described above, f ₁ and f ₂ represent the pulse rate at the time of starting the motor and the steady-state pulse rate when there is no preceding document. f ₃ represents the pulse rate at the steady speed when there is a preceding document, and the pulse rate can be increased by the amount of lightening the load at the time of starting.

The points t ₁ to t ₇ on the time axis indicate the inflection points of the speed of each acceleration / deceleration pattern. The area of the acceleration pattern indicates the moving distance of the document as in the first embodiment.

In the case of the solid line acceleration pattern, the acceleration time δt of the motor is (t ₂ −t ₁ ), and the time required to move the document is (t ₇ −t ₁ ).

In the case of the wavy pattern, the acceleration time δt of the motor is (t ₃ −t ₁ ), and the time required to move the document is (t ₆ −t ₁ ).

As described above, when the required torque T _M of the motor is constant, and when there is no preceding document on the platen glass 3, the load _TL at the time of starting the motor is large and the pulse rate at the steady speed cannot be increased. However, when there is a preceding document, the pulse rate at the steady speed can be increased by the reduction of the load _TL at the time of starting the motor, and as a result, the document moving time can be shortened. The method of reducing the document moving time according to this example is effective when the load inertia is large and the startup acceleration cannot be made large. Also,
This is also effective when the motor torque decays slowly with respect to the pulse rate.

<Third Embodiment of Belt Motor Speed Raising Control> A third embodiment of the belt motor speed raising control will be described with reference to an acceleration / deceleration pattern diagram shown in FIG. 7C.

In FIG. 7C, the horizontal axis represents the time axis and the vertical axis represents the pulse rate of the stepping motor. The solid line pattern shows the acceleration / deceleration pattern when there is no preceding document on the platen glass 3, when the platen temperature is 50 to 60 ° C., and when the humidity is high, and the wavy line pattern shows the preceding document on the platen glass 7. The acceleration / deceleration pattern in a certain case is shown.

Further, f ₁ and f ₂ indicate the pulse rate at the time of starting the motor and the steady-state pulse rate when there is no preceding document as described above. f ₃ represents the pulse rate at the time of starting when there is a preceding document, and the pulse rate can be increased by the amount of lightening the load at the time of starting.

The points t ₁ to t ₆ on the time axis represent the inflection points of the speed of each acceleration / deceleration pattern.

The area of the acceleration pattern indicates the moving distance of the document as described above, and is a value obtained by adding the length of the sheet in the transport direction and the document interval.

In the case of the solid line acceleration pattern and the wavy line acceleration pattern as well, the motor acceleration time δt is (t ₂ −t ₁ ), but the time required for moving the document is (t ₆ −t ₁ ) in the solid line pattern. _In the case of a wavy line pattern for ( ₁ ), (t ₅
-T ₁ ).

As described above, when the required torque T _M of the motor is constant, and when there is no preceding document on the platen glass 3, the load _TL at the time of starting the motor is large and the pulse rate at the time of starting cannot be increased. When there is a preceding document, the pulse rate at the time of starting can be increased by the amount that the load _TL at the time of starting the motor is reduced, and as a result, the time for moving the document can be shortened. The method of reducing the document moving time according to this example is particularly effective when the load inertia is large and the startup acceleration cannot be made large. It is also effective when the self-starting torque of the motor is large.

The startup control in the fixed reading mode has been described above. Next, the startup control of the belt motor in the flow reading mode will be described.

FIG. 44 shows the manner in which the start-up speed of the conveying system changes with respect to the acceleration profile of the belt motor 102. FIG. 44 (a) shows the speed of the conveyance system when it is accelerated by the motor acceleration profile having the fixed reading mode, and a large overshoot of the speed appears when the belt motor 201 starts to rotate at the starting pulse rate f1. It decays over time. In addition, a speed overshoot appears even when switching from the acceleration to the steady-rate pulse rate f2, and the time from startup to image formation (t3-t1).
It is necessary to increase the run time). This time greatly affects the productivity of the image forming apparatus, and it is necessary to increase the distance from the image reading position to the standby position of the original document to be scanned by the length of the running time. As a practical matter, the run-up time cannot be too long because the mechanical structure of the car is severely restricted.

<Fourth Embodiment of Belt Motor Speed Rising Control> FIG. 44B shows the acceleration profile of the belt motor 201 set so as to match the vibration of the conveying system. It is a profile. When the starting pulse rate is set to f3, which is smaller than the pulse rate f1 at the time of fixed reading, the pulse rate next to f3 is obtained from the overshoot amount of the velocity of the carrier system, and then the overshoot amount of the velocity of the carrier system is sequentially calculated. Set the pulse rate while observing. As a result, although the change in the pulse rate at the time of start-up is large and the acceleration is also large, the acceleration becomes very small in the vicinity of the pulse rate f2 of the steady speed, and the velocity vibration hardly appears when the steady speed is reached. The effect of this start-up method is that the run-up time described above is minimized in spite of reducing the vibration of the transport system. However, since the acceleration profile is complicated, the steady speed f
In a system in which 2 changes, there is a drawback that the program capacity of the controlling software becomes significantly large.

<Fifth Embodiment of Belt Motor Speed Rising Control> In FIG. 44 (c), the acceleration of the belt motor 201 is made as small as possible, and the pulse rate f2 at the steady speed is set.
This is an example in which the vibration of the transport system due to the change in acceleration in the vicinity is reduced. The pulse rate f4 at the time of start-up becomes higher than the start-up pulse rate f1 at the time of fixed reading, but this is an effective method in the carrier system where the settling time is short.

<Sixth Embodiment of Belt Motor Speed Rising Control> FIG. 44 (d) is for controlling the torque of the belt motor 201 to suppress the vibration of the conveying system. Make it as small as possible (I in Fig. 44 (d)).
2), at the same time as reducing the overshoot of the transport speed at the time of start-up, at the same time as switching to the steady speed f2, the motor torque is temporarily increased (I3 in FIG. 44 (d)),
This is a method of suppressing the vibration by the holding force of the motor. This method is effective when the inertial load on the motor is small.

<Control at the time of step-out of the belt motor> The belt clock sensor 102b of FIG. 5 is for detecting this, and immediately when the step-out is detected in the high speed continuous feeding mode and the normal switchback mode. , The operation of the conveyor path adjacent to the conveyor path by the belt motor is stopped, the cause of step-out is estimated by the following inference, and the motor control parameter is switched to the optimum value according to the estimated cause to restore the normal operation. . The control parameter at the time of return is stored in the backup memory, and the control thereafter is performed based on this parameter except for special cases.

<Belt Motor Out-of-Step Recovery Process> The belt motor out-of-step recovery process will be described with reference to the flowchart of FIG.

First, the motor is turned on, the initial value is loaded into the movement counter counted by the excitation clock of the belt motor, and the counter is started. The initial value is
If you start from the initial, zero is set,
In the case of a start after a restart process described later, a value obtained by correcting the count value at the time of stopping is set. At the same time, step-out is monitored by the output from the belt clock sensor 102b (BMrcv1).

The cause of the step-out is inferred based on the timing of occurrence, but the time from the motor start up to the step-out occurrence,
Alternatively, it can be performed based on the number of steps until occurrence of step-out and the profile of the acceleration / deceleration pattern of the motor. The time monitoring is a CP that monitors step-out when the acceleration / deceleration control of the stepping motor is performed using a dedicated control IC.
It is advantageous in that the load of U can be reduced, and monitoring by the number of steps is advantageous in that when the same CPU monitors acceleration / deceleration and step-out of the stepping motor, the step-out cause of the CPU can be easily estimated. .

<Example 1 of Step-out Recovery Process> First, at the time of start-up,
If the startup pulse rate does not rise (BMr
cv2), that is, when there is no clock output from the belt clock sensor 102b, or the movement counter is cleared, and the restart processing 1 is performed (BMrcv3).

The processing contents of the restart processing 1 are as follows. First, the motor current at the time of starting is temporarily increased (overdrive), or the control parameter is changed so as to reduce the pulse rate at the time of starting, and the process returns to the start. This assumes that the load at the time of startup becomes larger than the self-starting torque. If the process does not return to normal, the pulse rate at startup is increased or parameter change processing for reducing the motor current at startup is performed, and the process returns to start again. This is based on the assumption that the resonance point of vibration overlaps with the starting pulse rate. When the motor can be restarted by such restart processing, the paper conveyance is continued without performing abnormal processing such as paper jam. An error is generated if recovery does not occur in any of these cases. When it returns, normal paper conveyance is continued and error processing such as jamming is not performed.

<Second Embodiment of Step-out Recovery Processing> If step-out occurs during acceleration (BMrcv4), the movement counter is stopped and restart processing 2 is performed (BMrcv).
5).

Regarding the contents of the restart process 2, first, the restart process is performed to determine whether or not the paper conveyance can be continued. In other words, the paper is being delivered to and from the conveyance path before and after the conveyance path by the belt motor, and at the time of restart, the start characteristics of the conveyance path by the belt motor and the conveyance paths before and after this are not synchronized, and the paper may buckle. If the movement counter has reached the point where there is a certain value, the content of the restart processing is limited to the change of the motor control parameter, which will be described later, and the restart is not performed and the error processing is performed. If there is no problem as described above, control parameter change and restart processing, which will be described later, and sheet conveyance are continued. In the next step of the restart process 2, parameter processing for increasing the acceleration time and increasing the document moving time is performed, and the process is returned to the start. This is because the load may change abruptly due to mechanical vibration during acceleration, or the inertia load of the motor may increase. Also, even during acceleration, if the step-out occurs near the steady speed arrival point, it may be because the load torque of the motor has increased.
If the acceleration time process described above has no effect, the control parameter is changed to a control parameter with a reduced pulse rate up to a region where the pullout torque is large, and the process returns to the start. An error is generated if the above-mentioned control parameter changing process or the combination of processes has no effect.

<Third Step Out Recovery Process Embodiment 3> Even when out of step occurs in the steady speed range and the deceleration range (BMrcv6), the count value of the movement counter is stopped and the restarting process 3 is performed (BMrcv7).

Regarding the processing contents of the restart processing 3, first, after the restart processing, it is determined whether or not the paper conveyance can be continued.
When it is impossible to continue the sheet conveyance, only the control parameter is changed as in the case of the restart process 2. When step-out occurs in the steady speed range, whether or not to continue the paper conveyance is determined according to the same criteria as in the restart process 2. However, if step-out occurs in the deceleration range, acceleration / deceleration at restart is performed. Since it becomes profile noise, the paper conveyance is not continued. The parameters are changed so as to reduce the steady speed of the motor to a pulse rate with a torque margin, and the motor is restarted and restarted to complete the job for the document being handled. This is because the load torque is suddenly changed by some factor other than vibration. If the timing of step out in the steady speed region is almost the same (the count value of the belt clock from start to step out is stored in the backup memory), the pulse rate is not decreased and the timing of the problem occurs. Set the parameters so that the motor overdrive control is performed immediately before the start. This is because it is considered that the cause of the step-out is a rapid torque fluctuation as a result of pulling the originals between the wide belt 7 and the other conveying rollers. If the timing of step-out occurs randomly, set the parameter so that the pulse rate is lowered and the motor startup acceleration is reduced at the same time. If the effect does not appear even after performing the above processing, an error is generated.

<Communication> Furthermore, the communication IC 202 (FIG. 16)
The control data is exchanged with the main body of the copying machine via the, and as the received data, flow reading speed data (v) from the main body of the copying machine, original conveyance mode data such as single-sided / double-sided / flowing reading, Original feed trigger, Original exchange trigger,
There is a document ejection trigger, and further, as transmission data, document feeding / replacement / ejection operation completion signals, detected document size data, and a final document signal notifying the separation of the document stack,
There is a picture-destination signal in the flow reading mode.

Further, the built-in ROM of the microcomputer 201 is
A control procedure (control program) as shown in FIG. 21 and subsequent figures is stored in advance, and each input / output is controlled according to the control procedure.

(Main Flow) Next, the operation of this embodiment will be described based on the main flow chart shown in FIG.

Whether the document is set or not is determined by the first entrance sensor 2
3 is detected and the operation is started by depressing the copy key on the operation unit of the main body of the copying machine (main2).
At this time, it is determined whether or not the sheet length detection sensor 68 is off (main3), and if the determination is affirmative, the copy mode transmitted from the main body is determined (main4).
If it is in the flow-reading copy mode, the flow proceeds to (main5) to execute a series of copy processing in the flow-reading mode described later, and the operation is finished. In the case of a negative determination in (main4), the process proceeds to (main6), and it is determined whether or not a mode capable of a high-speed continuous transfer mode in which two or more originals are placed on the platen and a copying process is possible. Then (in this embodiment,
If the one-sided original copy mode is the high-speed continuous feed mode), if the determination is affirmative, the process proceeds to (main7) to execute a series of copying processes in the high-speed continuous feed mode, which will be described later, and end the operation. If a negative determination is made in (main3) and (main6), the process proceeds to (main8), and a series of copying processes are executed in a normal switchback mode described later to end the operation.

Here, the mode selection according to the document size is
In the present control example, the selection is restricted only by the feeding direction by turning on / off the sheet length detection sensor 68, but as described above, it is combined with the document width detection means by the slide volume provided under the document tray (not shown). The mode selection may be restricted according to the size of the original.

(Flow-reading mode) Next, the flow-reading mode will be described with reference to FIG.

A tray down process described later is performed to move the document tray to the lower limit position (draftmd1), and a document bundle transport process described later is performed to move the document stack P to the right side (draftmd2). Right-side separation processing and right-side separation post-processing, which will be described later, are performed to separate only one lower document (draftmd3, 4). After that, a document flow reading process is started in which the document image is read while the optical system of the copying machine main body is fixed at a predetermined position (d.
(rafftmd5), and then wait for the trailing edge of the document to be detected by the image-edge sensor 18 (draftmd5
6) Then, the document partition sensor 121 detects the break of the document stack (draftmd7), and if it is not the final document, the continuous paper discharge process described later is started to return the document to the document tray (draftmd8), drafttmd
Return to 3) and repeat the process. Also, (draftmd
In 7), if it is the final document, continuous paper discharge processing is performed (draftmd9), and then tray-up processing described later is performed to return the document tray to the upper limit position (d).
raftmd10), and a series of processing ends.

At this time, the optical system of the main body of the copying machine (not shown) is from the relay roller 17 to L when the length in the document feeding direction is L '(mm) as shown in FIG. ′
(Mm) or more, it is located downstream in the clockwise direction.
Further, the position control of the main body optical system may be performed by well-known stepping motor control or may be performed by other mechanical stopper structure.

(High speed continuous transfer mode) Next, the high speed continuous transfer mode will be described with reference to FIG.

A tray down process described later is performed to move the document tray to the lower limit position (doublemdl), and a document bundle transport process described below is performed to move the document stack P to the right side (doublembld2). Right-side separation processing, which will be described later, is performed to separate only one lower original (doublem3), and right-side paper feeding processing is performed to place the original on the right edge of the platen (doublem4).
After that, the document partition sensor 121 detects the separation of the document stack (doublemd6), and if it is not the final document, the right separation process (doublemd7) and the right paper feed process (doublemd8) are performed again, and then the platen is placed on the platen. At the same time that the document is moved to the left side, a document moving process described later is performed so that the next document waiting is placed on the right end of the platen (doublemd9). After that, an optical system moving original reading process is performed to read the original image while moving the optical system of the copying machine main body (doublemd10).
Upon completion, the intermittent paper discharge process is started to return the document to the document tray, and at the same time, the process returns to (doublemd6) and the process is repeated. If the document is the final document at (doublebld6), it is moved (d).
oublemd12), the optical system moving original reading process is performed (doublem13), and then the continuous feeding intermittent paper ejection process is performed (doublem14), and the tray-up process described below is performed to return the original tray to the upper limit position (d).
open md15), and a series of processing ends.

(Normal switchback mode) Next,
The normal switchback mode will be described with reference to FIG.

A left-side separation process (swmd1) described below is performed to separate only the lowermost document from the document stack P on the document tray (swmd1), and when completed, the left-side supply process described below is performed to place the document on the platen. Paper processing is performed (swmd2). Thereafter, an optical system moving original reading process for reading an original image is performed by scanning the original while moving the optical system of the copying machine main body (swmd3), and then the original partition sensor 121 divides the original bundle. When it is detected (swmd4) and it is not the final document, an intermittent sheet discharge process described later is started to return the document to the document tray (swmd4).
md5) and (swmd1) and the process is repeated. In addition, in (swmd4), if the document is the final document, intermittent paper discharge processing is performed (swmd6), and a series of processing ends.

(Tray UP Processing) The tray UP processing by the RDF will be described with reference to FIG.

In order to raise the document tray to the position shown in FIG. 1, the tray swing motor 107 is driven (trayup1) until the upper limit 51 is turned on, and the upper limit 51 is turned on.
When is turned on (trayup2), the drive of the tray swing motor 107 is stopped (trayup3).

(Tray DOWN Processing) The tray DOWN processing by the RDF will be described with reference to FIG.

In order to lower the original tray to the position shown in FIG. 2, the tray swing motor 107 is driven until the lower limit 52 is turned on (traydwn1), and the lower limit 5 is reached.
When 2 is turned on (traydwn2), the drive of the tray swing motor 107 is stopped (traydwm3).

(Bundle transport processing) Regarding bundle transport processing, FIG.
It will be described based on.

In the bundle conveying process, the sheet original stopper solenoid 111 is turned on and the stopper slide motor 106 is arranged to convey the original bundle on the original tray from the first paper feed port side to the second paper feed port side. Turn on (or
gsfeed1). After that, OFF / ON of the bundle conveying home position sensor 45 is detected (orgsfeed).
2, 2 '), the document bundle is conveyed by the stopper unit as described above. Then, the sheet document stopper solenoid 111 and the stopper slide motor 10
6 is turned off and the processing is ended (orgsfeed3).

(Right side separation process) The right side separation process will be described with reference to FIG.

In the right separation processing, if the first document is the first document (rsepa1), the partition member motor 1 is operated to operate the partition member for detecting the partition of the document stack P.
At the same time when 05 is turned on, the second separation motor 103 is turned on to separate the document stack P (rsepa2). Further, a jogging process, which will be described later, is performed to align the document bundle P in the width direction (rsepa3). After that, when the jogging process is completed, the process advances through the sheet path (C in FIG. 4) so that only the lowest document in the document stack is separated.
When the second paper feed sensor 25 detects the leading edge of the document (rsep
a4), the speed control for driving the second separation motor 103 at a low speed is started, the separation loop timer is started (rsepa5), and after this set time is over (rsep).
a6), by turning off the second separation motor 103 (rse
Since the leading edge of the original is abutted against the nip portion of the pair of feeding rollers at a low speed, it is possible to prevent the leading edge of the original from being damaged, reduce the collision noise, and stop in a state where a predetermined amount of loop is formed. . As a result, even if skewing occurs at the time of separation, the skewing is corrected. (Rse
If the original is not the first original in (pa1) (rsepa2 ')
Then, the second separation motor 103 is turned on, and the process proceeds to (rsepa6).

(Right Side Paper Feeding Process) The right side paper feeding process will be described with reference to FIG.

In the right side paper feeding process, the feeding roller pair 1
In order to drive 6 and 17 to convey the document from the sheet path (H) to the sheet path (R), a conveyance motor 104
Is turned on, and at the same time, the size check counter 2 for counting by the clock signal input from the carrier clock 104 is started (rent1). Then, the document is conveyed and its rear end passes through the second paper feed sensor 30 (r
ent2) and the size check counter 2 is stopped at the same time (rent3), and based on the data, FIG.
The size of the original is determined in size check processing 2 shown in FIG. Further, when the leading edge of the document is detected by the image destination sensor 18 (rent4), the belt motor 112 is turned on in the reverse direction to place the document on the sheet path (rent) (rent5), and further, by the image destination sensor 18. When the trailing edge of the original is detected (rent6), the conveyance motor 104 is turned off, and the original is placed at a predetermined position on the platen (the original trailing edge of FIG.
The registration counter 2 counted by the belt excitation clock is started to stop at the position D ') (rent 7). Registration counter 2 started above
When the process ends (rent8), the belt motor is stopped (rent9).

(Document Moving Process) The document moving process will be described with reference to FIG.

In the document moving process, the wide belt 7 is driven and the belt motor 112 is turned on in the reverse direction to move the document in the sheet path (L) (D), and the document is stopped at a predetermined position on the platen. In order to do so, the movement counter counted by the belt excitation clock is started (mv1). At this time, a belt motor speed start-up control, which will be described later, is performed depending on whether there is a preceding document on the platen glass. When the movement counter that has started is finished (mv2), the belt motor is turned off to accurately stop the document (mv3). Well-known slowdown control is also performed when stopping the belt motor.

At this time, the movement counter sets the length of the document in the feeding direction to L '(mm), and the distance between the high-speed continuous feeding placement reference (D') shown in FIG. 4 and the image sensor 18 to L'gap. (M
m), similarly, when the distance between the document fixed placement reference (D) and the above-mentioned (D ′) shown in FIG. 4 is L (mm), it is expressed by the following equation.

[0264]

[Formula 7] Movement counter = L- (2 * L '+ L'gap) (Continuous feeding intermittent paper ejection processing) Continuous feeding intermittent paper ejection processing FIG.
It will be described based on.

In the continuous feeding intermittent paper discharge process, the belt motor 112 is reversely turned on in order to discharge the original on the platen.
When the reversing motor is turned on (dlejct1), the document is conveyed from the sheet path (d) to the sheet path (f), and the trailing edge of the document is detected by the discharge sensor 27 (dlejct).
2) The belt motor is turned off, and the paper ejection counter for determining the distance for ejecting the original onto the original tray is started while controlling the speed of the reversing motor 101 for paper ejection alignment (dlejct3). When the paper discharge counter is finished (dlejct4), the reversing motor 101 is turned off (dlejct5), and the paper discharge drop timer that starts an interval until the document falls on the document tray is started (dle).
jct6) and after completion (dlejct7), a closed-loop discharge jogging process is performed to align the discharged originals (d).
lejct8), and the continuous feeding intermittent paper discharge process is ended.

(Original Flowing Reading Process) The original flow reading process will be described with reference to FIG.

In the original flow reading process, in order to read the image of the original by the optical system of the copying machine main body which is fixed, the conveyance motor 104 is turned on in synchronization with (constant speed) the speed of the belt motor 102 for the flow reading, and at the same time. The belt motor 102 also starts constant speed control by outputting an excitation clock signal based on the flow reading speed data (v) received from the copying machine main body (draftsq1). After that, the image sensor 18
At the same time that the leading edge of the document is detected by (drafts
q2), the image destination signal is transmitted to the main body of the copying machine, and the process ends (draftsq3). The copying machine main body performs actual image reading by calculating and controlling the time until the leading edge of the original arrives at the fixed position of the optical system at the time of the above-described flow reading after receiving the image destination signal.

Also, the flow reading speed data (v) is
It may be equal to or different from the reading speed (v1) when the optical system moves. Particularly, when v> v1 is set, the reading of the original image is completed in a shorter time than the normal optical system moving reading, so that the copying speed is improved by using the original feeding device of the present invention.

(Continuous Paper Discharge Processing) The continuous paper discharge processing will be described with reference to FIG.

In the continuous paper discharge process, in order to discharge the original onto the platen, the reversing motor 101 is turned on in synchronization with (constant speed) the speed of the belt motor 102 which is flowing and reading (reject1). When the trailing edge of the document is detected by the reversing sensor 26 (reject2), the reversing motor 101 is speeded up to the maximum speed (rejct3) in order to secure a space between the document and the next document, and the document passes from the sheet path (d) When the trailing edge of the original is detected by the paper discharge sensor 27 (rejct4) after being conveyed to the path (f), the original is discharged onto the original tray while the speed of the reversing motor 101 is controlled for discharging alignment. The paper discharge counter for determining the distance is started (rejct5). When the paper discharge counter is finished (reject6), the reversing motor 101 is turned off (reject5), and a paper discharge timer that starts an interval until the document falls on the document tray is started (r
ejct8) and after completion (reject9), a closed-loop discharge jogging process is performed to align the discharged originals (r
ejct10), and the continuous feeding intermittent paper discharge process is ended.

(Left Side Separation Processing) The left side separation processing will be described with reference to FIG.

In the left separation processing, if the first document is the first document (lsepa1), the partition member motor 1 is operated to operate the partition member for detecting the partition of the document bundle P.
At the same time when 05 is turned on, the first separation motor 100 is turned on to separate the document stack P (lsepa2). Further, a jogging process, which will be described later, is performed to align the document bundle P in the axial direction (lsepa3). After that, when the jogging process is completed, the stopper solenoid 108 is turned on (lsepa4) in order to lower the paper feed stopper so that only the lowermost original of the original bundle is separated (lsepa4), and the sheet path (a) is advanced. When the first paper feed sensor 25 detects the leading edge of the document (lsepa5), the first separation motor 10
While starting the speed control to drive 0 at low speed,
The separation loop timer is started (lsepa6), and after this set time is completed (lsepa7), the first separation motor 1
By turning off 00 (lsepa8), the leading edge of the original can be abutted against the nip portion of the feeding roller pair at a low speed.
It is possible to prevent damage to the leading edge of the document and reduce the collision noise. Further, the document stops with a predetermined amount of loops formed. As a result, even if skewing occurs at the time of separation, the skewing is corrected. If it is not the first original in (lsepa1), the first separation motor is turned on in (lsepa2 ') and the process proceeds to (lsepa7).

(Left Side Paper Feeding Processing) The left paper feeding processing will be described with reference to FIG.

In the left side sheet feeding process, the pair of feeding rollers,
And drive the full-face feed belt to pass the document through the sheet path (a).
In order to convey the belt motor 102 from the reverse direction to the sheet path (C), the belt motor 102 is turned on in the forward direction and the reverse motor is turned on.
t1). Then, the size check counter is stopped at the same time when the document is conveyed and its trailing edge passes the first paper feed sensor 25 (lent2), and the size of the document is determined by the size check process shown in FIG. 38 based on the data. Then, the reversing motor is turned off, and further, the registration counter that is counted by the belt excitation clock is started to stop the document at a predetermined position on the platen (the rear end of the document is the position of FIG. 4D) (lent3). When the above-mentioned started registration counter ends (len
t4), the belt motor is turned off.

(Intermittent Paper Ejection Processing) The intermittent paper ejection processing will be described with reference to FIG.

In the intermittent paper discharge process, the belt motor 112 is reversely turned on and the reverse motor is turned on (lejct1) to discharge the original on the platen, and the original is moved from the sheet path (d) to the sheet path (f). When the trailing edge of the document is detected by the discharge sensor 27 (lejct2),
Turn off the belt motor and turn the motor 1
While performing the speed control of 01, the paper discharge counter for determining the distance for discharging the document onto the document tray is started (lejct3). When the discharge counter is finished (l
ejct4), the reversing motor 101 is turned off (lejct
5) Start the drop timer that takes an interval until the document falls on the document tray (lejct6), and after the end (lejct7), perform the paper ejection jogging process to align the ejected documents (lejct8), and intermittently. The paper discharge process ends.

(Size Check Processing 1) The size check subroutine 1 will be described with reference to FIG.

In this size check subroutine 1, the size check counter data from the nip position of the large roller to the first paper feed sensor 25 is used as the document size determination means.
The true original size is corrected by adding the distance up to. At this time, the original is conveyed by the feeding roller and the entire belt, and the feeding amount and the count value based on the belt excitation clock surely coincide with each other. After that, A5, B5, A4, B5R, and A4 are corrected according to the corrected size data.
Size determination of R, B4, A3, etc. is performed.

(Size Check Processing 2) The size check subroutine 2 will be described with reference to FIG.

In the size check subroutine 2, the true document size is obtained by correcting the size check counter data by adding the distance from the nip position of the large roller 16 to the second paper feed sensor 30 as the document size determining means. Become. At this time, the original is conveyed by the feeding roller and the entire belt, and the feeding amount and the count value based on the belt excitation clock surely coincide with each other. After that, according to the corrected size data, A5, B5, A4, B5R, A
4R, B4, A3, etc. size determination is performed.

(Jogging Process) The flow of the jogging process will be described with reference to the flowchart shown in FIG.

In the jogging process, JOG-CN for determining the number of times of jogging is first initialized (jog-CN).
1) At the same time as turning on the jogging solenoid 132 for pushing out the jogging guide of the width regulating member, at the same time, start a timer JOG-TM that can be arbitrarily set (jo).
g2), when the timer JOG-TM has finished the set time (jog3), the jogging solenoid 132 is turned off to return the jogging guide to the initial state, and the timer JOG-TM is started (jog4) in the same manner as above, and the timer When the set time ends, the number of times jogging is performed is increased (jog5), and the process returns to (jog2) and is repeated until the reciprocating path of the jogging guide ends three times (jog6). As a result, the document stack P is aligned in the width direction, and skewing, lateral registration, etc. can be prevented.

(Paper Discharge Jogging Processing) The flow of the paper discharge jogging processing will be described with reference to the flowchart shown in FIG.

The discharge jogging process is performed by the jogging solenoid 1 for pushing out the jogging guide of the width regulating member.
Timer EJ that can be set at the same time when 32 is turned on
When CT_JOG_TM is started (ejog1) and the timer EJCT_JOG-TM ends the set time (ejog2), the jogging solenoid 132 is turned off to return the jogging guide to the initial state (ejog).
3). As a result, the document stack P is aligned in the width direction, and skewing, lateral registration, etc. can be prevented.

(Closed Loop Discharge Jogging Processing) The flow of the closed loop discharge jogging processing will be described with reference to the flow chart shown in FIG.

In the closed loop sheet discharge jogging process, the jogging solenoid 132 for pushing out the jogging guide of the width regulating member is turned on, and the stopper slide motor 106 is turned on in order to improve the alignment in the feeding direction, and at the same time, arbitrarily set. Possible timer DEJCT_JOG_T
Start M (dejog1), timer DEJC
Bundle sensor HP sensor 45 while waiting for the end of T_JOG_TM
Monitor and returns to the home position, the stopper slide motor 132 is turned off (dejog2.
3, 4). When the set time is finished (dejog5), the jogging solenoid 132 is turned off to return the jogging guide to the initial state (dejog6). As a result, the document stack P is aligned in the width direction, and skewing, lateral registration, etc. can be prevented. In addition, this DEJCT_JOG_
TM is set to a time sufficient for the stopper unit to make one rotation.

As described above, by using the stepping motor to drive the wide belt of the document feeder, it is possible to reduce noise, reduce costs, improve stopping accuracy, and cope with flow-reading copying.

[0288]

According to the present invention, the following effects can be obtained.

The drive means rating can be reduced by the control according to the drive means load detection.

When the load of the driving means is small (this is the case in most cases), the replacement time can be shortened even with the driving means having a small rating.

Optimal drive means current can be set and vibration noise can be reduced.

Also, the temperature rise can be suppressed at the same time.

Even if a step-out occurs, the control parameter can be automatically changed according to the cause of the step-out, and the recovery process can be performed without lowering the productivity. Further, depending on the cause, the productivity is lowered, but the jam / error does not occur.

Furthermore, since the cause of the problem is estimated, the service person can easily find the cause of the problem.

An alarm can be output to a service person without taking down the system.

As described above, it is possible to estimate the cause of step-out from the timing of occurrence of step-out and change the belt motor control accordingly. As a result, depending on the cause, it is only necessary to perform temporary parameter processing for overdriving, and the restoration processing can be performed without sacrificing the document replacement time (document moving time). If the cause is relatively serious, the document replacement time is sacrificed, but the operation can be continued without stopping the system. At this time, it is possible to inform the serviceman by an alarm or the like that the operation parameter has been changed. Further, even if the system is stopped due to an error or the like, the cause of the error can be identified and appropriate service can be promptly performed.

Further, the paper thickness of the paper can be detected by using the existing sensor and the driving means, and the low-cost paper thickness detection sensor can be realized, and the control which has not been carried out up to now depending on the paper thickness is performed. It will be possible.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention.

FIG. 3 is a diagram showing a bundle conveying state according to the embodiment of the present invention.

FIG. 4 is a diagram illustrating a paper path according to the embodiment of this invention.

FIG. 5 is a layout view of a drive system according to an embodiment of the present invention.

FIG. 6 is a detailed view of the tray section.

FIG. 7 shows an acceleration / deceleration pattern of a belt motor, (a)
FIG. 6A is a diagram showing a case where acceleration is increased, FIG. 8B is a diagram showing a case where steady speed is increased, and FIG. 8C is a diagram showing a case where pulse rate for start-up is increased.

FIG. 8 is a flowchart of a step-out recovery process for the belt motor.

FIG. 9 is a detailed block diagram of a reversing motor control unit.

FIG. 10 is a detailed block diagram of a carry motor controller.

FIG. 11 is a detailed block diagram of a separation motor control unit.

FIG. 12 is a relational diagram between separation current and document thickness.

FIG. 13 is a relationship diagram between a reversing motor and a document thickness.

FIG. 14 is a detailed block diagram of another example of the reversing motor control unit.

FIG. 15 is a detailed top view of the recycle lever.

FIG. 16 is a block diagram of an embodiment of the present invention.

FIG. 17 is a detailed block diagram of an optical document thickness detection unit.

FIG. 18 is a detailed block diagram of a second example of the optical document thickness detection unit.

FIG. 19 is a sensor output characteristic diagram with respect to a document basis weight.

FIG. 20 is a diagram showing measurement results of temperature-humidity characteristics of friction coefficient.

FIG. 21 is an operational flowchart of the embodiment of the present invention.

FIG. 22 is another operational flowchart of the embodiment of the present invention.

FIG. 23 is another operational flowchart of the embodiment of the present invention.

FIG. 24 is a further operational flowchart of the embodiment of the present invention.

FIG. 25 is a further operational flowchart of the embodiment of the present invention.

FIG. 26 is still another operation flowchart of the embodiment of the present invention.

FIG. 27 is still another operational flowchart of the embodiment of the present invention.

FIG. 28 is a further operational flowchart of the embodiment of the present invention.

FIG. 29 is a further operational flowchart of the embodiment of the present invention.

FIG. 30 is a still another operational flowchart of the embodiment of the present invention.

FIG. 31 is still another operational flowchart of the embodiment of the present invention.

FIG. 32 is a further operational flowchart of the embodiment of the present invention.

FIG. 33 is another operational flowchart of the embodiment of the present invention.

FIG. 34 is a further operational flowchart of the embodiment of the present invention.

FIG. 35 is a flowchart showing yet another operation of the example of the present invention.

FIG. 36 is a further operational flowchart of the embodiment of the present invention.

FIG. 37 is a further operational flowchart of the embodiment of the present invention.

FIG. 38 is a further operational flowchart of the embodiment of the present invention.

FIG. 39 is a further operational flowchart of the embodiment of the present invention.

FIG. 40 is a further operational flowchart of the embodiment of the present invention.

FIG. 41 is a further operational flowchart of the embodiment of the present invention.

FIG. 42 is a schematic block diagram relating to speed control.

FIG. 43 is a schematic block diagram relating to stepping motor control.

FIG. 44 is a diagram showing changes in the rising speed of the conveyance system with respect to the acceleration profile of the belt motor.

[Explanation of symbols]

 1 Image Forming Device 2 Automatic Document Feeding Device 3 Platen Glass 4 Sheet Document Tray 6,38 First Separation Means 14, 15 Second Separation Means 7 Conveyor Belt 11 Paper Ejection Roller 19 Sheet Manuscript Stopper 21 Stopper

Claims (55)

[Claims] 1. A first transport unit located on a first transport path for transporting a sheet, a second transport unit located on a second transport path adjacent to the first transport path, and the first transport unit. A first drive means for driving the first transport means, a second drive means for driving the second transport means, and the first transport means when the first transport path is on the upstream side. The second conveying means operates in synchronization with the speed of
When the second transport path is on the upstream side, the first drive means and the second drive means are arranged so that the first transport means operates in synchronization with the speed of the second transport means. A sheet conveying device comprising: a control unit that controls a driving unit. 2. The first drive means is a pulse motor, the second drive means is a DC motor controlled in synchronization with a reference clock, and the control means is the first motor. A sheet conveying device, wherein a reference clock of the second driving means when the first conveying means operates in a reverse direction is controlled to become an excitation clock of the first driving means. 3. The control unit according to claim 1, wherein the first driving unit is the drive shaft of the second conveying unit or the first conveying unit is in the normal rotation direction when the first conveying unit operates in the normal direction. The speed of the second drive means is controlled by the encoder clock from the driven shaft of the second transport means,
A sheet conveying device characterized in that speed control is performed so that the driving means can follow. 4. The first transporting means according to claim 1, wherein the first transporting means is a transporting means capable of normal rotation and reverse rotation, and the second transport path is forward rotation and reverse rotation by the first transporting means. A sheet conveying device having the same conveying path regardless of the operation. 5. The first transport means according to claim 1, wherein the first transport means is a transport means capable of normal rotation and reversal operations, and the second transport means.
The sheet conveying device is characterized in that the conveying path of the first conveying means is different from that of the first conveying means when the first conveying means is rotating normally. 6. A first driving means for driving a first carrying means, a second driving means for driving a second carrying means, a first driving means and a second driving means at the same time. When activated, a control unit that controls the first drive unit and the second drive unit so that the transport distance by the first transport unit and the transport distance by the second transport unit are synchronized. A sheet conveying device having. 7. The control means according to claim 6, wherein when the first transport means and the second transport means reach a steady speed region, the transport speeds of the two transport means match each other. A sheet conveying device, characterized in that the first driving means and the second driving means are controlled as described above. 8. The sheet conveying apparatus according to claim 6, wherein the first driving unit is a DC motor and the second driving unit is a pulse motor. 9. The sheet conveying apparatus according to claim 6, wherein the control unit controls the acceleration pattern of the second driving unit to have a mechanical time constant of the first driving unit. 10. The control means according to claim 6,
A sheet conveying apparatus, wherein the control signal of the second driving means is controlled to be generated from the rotary encoder clock of the first driving means. 11. A document conveying apparatus for separating a document loaded on a tray one by one and feeding the document onto a platen for reading an image of the document and discharging the document from the platen. An original document conveying apparatus comprising: a judgment unit for making a judgment; and a conveyance control unit for changing a torque for conveying an original document based on a judgment result of the judgment unit. 12. The document feeder according to claim 11, wherein the determination unit determines the number of documents placed on the platen in advance. 13. The document feeder according to claim 11, wherein the determination unit determines the temperature on the platen. 14. The document feeder according to claim 11, wherein the determination unit determines the humidity on the platen. 15. A document transporting device for separating a document loaded on a tray one by one and transporting the document onto a platen for reading an image of the document and discharging the document from the platen. An original document conveying device comprising: a judgment unit for making a judgment; and a conveyance control unit for changing a conveyance speed for conveying an original document based on the judgment result of the judgment unit. 16. The document feeder according to claim 15, wherein the feeding control unit controls a maximum speed at the time of feeding a document. 17. The document transport apparatus according to claim 15, wherein the transport control unit controls acceleration during document transport. 18. The document transport apparatus according to claim 15, wherein the transport control unit controls an initial speed at the start of document transport. 19. A document conveying device for separating a document placed on a tray one by one, conveying the document onto a platen for reading an image of the document, and discharging the document from the platen, a motor for conveying the document. And a control unit for controlling the torque of the motor based on the monitoring result of the monitoring unit. 20. The original document conveying device according to claim 19, wherein the motor for conveying the original document is a pulse motor. 21. The document feeder according to claim 19, wherein the monitoring means monitors a motor stop and a motor stop timing. 22. The document feeder according to claim 19, wherein the control unit controls the torque of the motor based on the motor stop timing information from the monitoring unit. 23. A document conveying device for separating a document placed on a tray one by one and feeding the document onto a platen for reading an image of the document and discharging the document from the platen. And a control unit that controls the speed of the motor based on the monitoring result by the monitoring unit. 24. The original document conveying device according to claim 23, wherein the motor for conveying the original document is a pulse motor. 25. The pre-control means according to claim 23,
An original conveying apparatus, wherein the acceleration of the motor is controlled based on the timing information of the motor stop from the monitoring means. 26. The front control means according to claim 23,
An original conveying apparatus, wherein the maximum speed of the motor is controlled based on the motor stop timing information from the monitoring means. 27. The front control means according to claim 23,
An original conveying apparatus, wherein the motor starting speed is controlled based on the motor stop timing information from the monitoring means. 28. Conveying means for conveying a sheet, driving means for driving the conveying means, and thickness detecting means for detecting the thickness of the sheet conveyed by the conveying means from a load torque applied to the driving means. A paper transport device characterized by. 29. The paper feeding device according to claim 28, wherein the conveying device also serves as a separating device for separating the paper, and the thickness detecting device detects the thickness of the paper from a current of the driving device when the separating device separates. A paper transport device characterized by the above. 30. The transport means according to claim 28, wherein the transport means is on a transport path downstream of the separation means for separating the sheets,
The sheet conveying device, wherein the thickness detecting unit detects the thickness of the sheet from the current of a driving unit that drives the conveying unit when the sheet is being separated by the separating unit. 31. A transmissive sensor including a light emitting portion and a light receiving portion, which are arranged so as to face the paper transport path, and a setting means for setting the transmissive sensor in a first operation mode and a second operation mode. Causing the transmissive sensor to be set to the first operating mode,
Detection for detecting the thickness of the paper on the conveyance path from the response of the control means for setting the paper on the conveyance path to the second operation mode and the transmission type sensor in the second operation mode A sheet conveying device comprising: 32. The control unit according to claim 31, wherein the switching between the first mode and the second mode is performed by a light amount of a light emitting portion of the transmissive sensor, and the detection unit is configured to perform the first mode. The sheet conveying apparatus is characterized in that the thickness of the document is detected based on the output of the light receiving section in the above mode and the output of the light receiving section. 33. The control device according to claim 31, wherein the control unit performs switching between the first mode and the second mode by a load of a light receiving unit of the transmissive sensor, and the detection unit includes the first unit. The sheet conveying apparatus is characterized in that the thickness of the document is detected from the output of the light receiving section in the mode 2 and the output of the light receiving section. 34. The control unit according to claim 31, regardless of the presence / absence of a sheet on the transmissive sensor,
A sensor correction operation that keeps the detection level of the light receiving unit constant is possible, and in the first mode and the second mode,
A sheet conveying apparatus, wherein the detecting unit detects the thickness of a document based on the correction value while the correction operation is activated. 35. A paper thickness detecting means for detecting a thickness of a paper, a carrying means for carrying the paper, a speed control means for controlling a speed of the carrying means for carrying the paper, and a paper thickness detecting means. And a setting unit that sets a control constant of the speed control unit based on a detection result. 36. The sheet according to claim 35, wherein the drive source of the conveying means controlled by the speed control means is a DC motor, and the setting means sets an initial drive voltage of the DC motor. Transport device. 37. The speed control means according to claim 35 forms a speed control loop, and the setting means comprises:
A sheet conveying device, wherein a control gain of the speed control loop is set. 38. The sheet according to claim 35, wherein the speed control means forms a speed control loop, and the setting means sets the detection sensitivity of the speed detection means in the speed control loop. Transport device. 39. Paper thickness detecting means for detecting the thickness of paper, conveying means for conveying the paper, and control means for controlling the conveying speed of the conveying means based on the detection result from the paper thickness detecting means. A sheet conveying device having. 40. The sheet conveying apparatus according to claim 39, wherein the conveying control unit controls acceleration of the conveying unit. 41. The sheet conveying apparatus according to claim 39, wherein the conveying control unit controls a maximum speed of the conveying unit. 42. The sheet conveying apparatus according to claim 39, wherein the driving source of the conveying unit is a pulse motor, and the conveying control unit controls a starting speed of the driving source of the conveying unit. 43. Separation means for sequentially separating the sheets stacked on the tray one by one, conveyance means for pulling the separated sheets out of the separation means, and conveyance load determination means for determining a conveyance load of the conveyance means. And a control unit that controls the transport torque of the transport unit based on the determination result of the transport load determination unit. 44. The driving source of the carrying means is a pulse motor, and the carrying load determining means includes a thickness detecting means for detecting a thickness of a document to be carried.
It is composed of a calculation means for calculating the transport load from the detection result from the thickness detection means, the control means has a setting means for setting the drive current of the pulse motor from the calculation result by the calculation means. Paper transport device. 45. The drive source of the carrying means is a pulse motor, and the carrying load determining means comprises a paper detecting sensor provided downstream of the separating means in the paper carrying direction, and the paper detecting sensor. From the pulling-out determination means for determining whether or not the conveying means is pulling out the sheet from the separating means, and the control means sets the drive current of the pulse motor from the determination result by the pulling-out determination means. A sheet conveying device comprising a setting unit. 46. A separating means for sequentially separating the sheets stacked on the tray one by one, a first conveying means for pulling the separated sheets out of the separating means, and a downstream arrangement of the first conveying means. The conveying speeds of the second conveying means and the first conveying means are made equal to the conveying speed of the separating means during sheet conveyance by the separating means and the first conveying means, and the first conveying means A sheet conveying device, characterized in that the sheet conveying device has a controller and a control unit that follows the conveying speed of the second conveying unit when the sheet is conveyed by the second conveying unit. 47. The separating means according to claim 46, further comprising a first clock generating means for generating a clock frequency proportional to a carrying speed of the separating means, and the control means for controlling the first clock generating means. A paper transporting device, characterized in that the transport speed of the first transporting means is controlled by a clock from. 48. The second transport mechanism according to claim 46, wherein the first transport means controls a transport speed of the first transport means.
Clock generating means, the second conveying means has third clock generating means for controlling the conveying speed of the second conveying means, and the first conveying means and the second conveying means. When the paper is conveyed in the
The ratio between the clock from the second clock generating means and the clock from the third clock generating means is controlled so that the speeds of the second conveying means and the second conveying means are the same. Paper transport device. 49. A method for carrying out image formation by transporting a document stacked on a tray of a document transport device to a platen of the image forming device and placing the document at a predetermined position, and then scanning an optical system of the image forming device. An image forming mode of No. 1 and a second image forming mode in which an optical system of the image forming apparatus is fixed at an arbitrary position and an image is formed while an original on the tray is transferred to a platen of the image forming apparatus. In the image forming system, a selecting means for selecting one of the first image forming mode and the second image forming mode, a transferring means for transferring an original, and a selecting means for selecting the image forming mode. An image forming apparatus comprising a document transfer control means for controlling the starting operation of the transfer means based on a selection result. 50. The original transfer control means according to claim 49, when the selection result by the selection means is the first image forming mode, a starting speed of the transfer means,
Alternatively, the image forming apparatus is controlled so that the startup acceleration is maximized. 51. The original transfer control means according to claim 49, when the selection result by the selection means is the second image forming mode, a starting speed of the transfer means,
Alternatively, the image forming apparatus is controlled so that the startup acceleration is minimized. 52. The document transfer control means according to claim 49, when the selection result by the selection means is the second image forming mode, the drive torque of the transfer means is controlled to be minimum. An image forming apparatus characterized by the above. 53. A motor stop detection means for detecting a stop of a motor for conveying a sheet, a parameter setting means for estimating a cause of the motor stop and resetting a control parameter of the motor from the estimation result, and the setting means. And a control means for continuing the conveyance of the sheet while driving the motor on the basis of the control parameter. 54. The motor stop detection means according to claim 53, further comprising movement distance detection means for detecting a movement distance of the sheet from the start-up to the stop of the motor, and the parameter setting means from the movement distance detection means. The cause of the motor stop is estimated based on the sheet transport distance data, and the control means has a determining means for automatically determining whether or not to continue the sheet transport based on the sheet transport distance data. Transport device. 55. The motor stop detection means according to claim 53, further comprising movement time detection means for detecting a movement time of the paper from starting to stopping of the motor, and the parameter setting means is the movement distance time detection means. The cause of the motor stop is estimated based on the paper transport time data from the above, and the control means has a determination means for automatically determining whether or not to continue the paper transport from the paper transport distance data. Paper transport device.