JPH0480137A - Image forming device feeding device - Google Patents

Abstract

PURPOSE:To suck a recording medium at a constant suction force regardless of its size to feed it by providing a suction means to suck the recording medium at an endless transfer means, and providing the endless transfer means with a plurality of contact means to the recording medium. CONSTITUTION:Part of an endless transfer means 53 having a suction means is pressed to get in contact with a recording medium 77 by a contact means, or a pressure means 58, for example, so the recording medium 77 is sucked at a part where it is in contact with the endless transfer means 53, and the sucked recording medium 77 is transferred by the endless transfer means 53. A plurality of such contact means 58 are provided at predetermined positions at an interval along the feed direction of the recording medium 77, so by selecting the contact means 58 to get in contact for action corresponding to the size of the recording medium, and changing the contact area of the endless transfer means 53 in contact with the recording medium 77, the suction area to the recording medium 77 is changed. The suction area is set large to the large-sized recording medium, for example.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording medium feeding and conveying device in an image forming apparatus such as a copying machine, a laser printer, and a facsimile machine.

[Prior art]

In image forming apparatuses such as copying machines, it is known that a sheet-like recording medium such as a transfer paper fed by the friction of a rubber roller is conveyed by a pair of rubber rollers or a belt to an image forming position such as a transfer position by a photoreceptor. ing.

In such conventional recording medium feeding and conveying devices, in order to prevent multiple sheets of recording media from being fed overlappingly, a friction pad is combined with the rubber feeding roller, and a rubber reverse roller is used to reverse the rotation. In addition, corner claws are provided on the cassette that houses the recording medium.

However, the conventional recording method has problems such as jams and skewing during conveyance, and in addition to double feeding, conventional apparatuses still have problems with reliability of feeding and conveyance.

Furthermore, the structure becomes more complex and the control becomes more complicated.
It is also costly, and the problems of simplifying the device and reducing costs remain unsolved.

In order to solve these conventional problems, an insulating endless belt is passed around almost all the conveyance systems in the copying machine, and the belt is charged with a charging device, and the paper stored in the paper feed tray is transferred to the belt. The paper is sent out by a paper feed roller installed coaxially with the support roll and is electrostatically attracted to the rear belt, or the belt is brought into direct contact with the paper and electrostatically adsorbed and fed, and at the same time, the paper is brought into contact with the photoreceptor. For example, JP-A-59-212856, JP-A-59-224-858, and JP-A-59-2295 disclose that conveyance by a belt to a transfer area is carried out by a belt.
This is proposed in Publication No. 85 and the like.

Also, tie the paper feed section, registration section, transfer section, fixing section, and paper ejection section of the copying machine with one endless belt in this order, and first connect the endless belt to the copy paper held in the copy paper feed section. For example, Japanese Patent Application Laid-Open No. 139846/1984 proposes that the copy paper is brought into pressure contact with the copy paper by frictional force, and is conveyed to an image forming area after registration.

In the above conventional technology, when paper of different sizes in the feeding direction is used, the position from which the paper is fed from the paper tray is always the same, so the space within the device body for the paper tray is effectively saved. The problem is that it is not available. That is, when installing a paper feed tray in the apparatus main body, a space is prepared for installing the largest size paper feed tray among a plurality of paper feed trays that accommodate sheets of different sizes. However, when the paper feed tray containing the largest size paper is not used, there is an unused space within the space for the paper feed tray, resulting in a wasted space within the apparatus main body as a whole.

If the paper feed tray is installed from outside the device, a portion of the paper feed tray will be pulled out of the device, which will substantially increase the dedicated space required to install the device and be cumbersome for operation. There is a problem with becoming.

[Problem to be solved by the invention]

The present invention solves the above-mentioned conventional problems and effectively suctions and feeds recording media of many types with a constant suction force regardless of the size in a minimum dedicated space. The objective is to provide a feeding device that is suitable for use.

[Means to solve the problem]

The present invention solves the above-mentioned problems by providing a feeding device for an image forming apparatus that includes a storage device that stores a recording medium on which an image is to be recorded, and an endless conveyance device that feeds the recording medium from the storage device to a predetermined position. In this, the endless conveyance means is provided with a suction means for sucking the recording medium, and a plurality of contact means are provided for bringing the endless conveyance means into contact with the recording medium, and each contact means is configured to release the contact as appropriate. The problem has been solved by a feeding device for an image forming apparatus that is capable of switching between contact and contact. The contact means can also be formed simply as a means for pressing the endless conveying means against the recording medium.

(Function) According to the present invention, a part of the endless conveyance means provided with the suction means is brought into pressure contact with the recording medium by the contact means, for example, the pressing means, and the recording medium is sucked at the portion in contact with the endless conveyance means, The sucked recording medium is transported by an endless transport means.

A plurality of contact means are provided at predetermined positions at intervals in the feeding direction of the recording medium, and a contact means that operates in contact is selected according to the size of the recording medium, and the contact means of the endless conveyance means that contacts the recording medium is selected. By switching the area, the suction area for the recording medium is switched. For a large size recording medium, the suction area is increased, and for a B5 size recording medium, for example, the suction area is decreased.

The contact means is not fixed in position, but is partially movable in the feeding direction, and the moving position can be selected depending on the size of the recording medium to change the area of the endless conveyance means that contacts the recording medium.

In order to suction and convey the recording medium, the endless conveyance means does not need to suction the entire recording medium, but it is sufficient to suction a part of the portion near the leading edge.

According to the present invention, the endless conveyance means can change the contact position and range of the storage means with respect to the recording medium, and the storage means of a size suitable for the maximum size is divided into several parts to accommodate multiple types of small-sized recording media. Moreover, recording media of various sizes can be fed from the stored position.

〔Example] The details of the present invention will be explained based on embodiments shown in the drawings.

In FIG. 1, a copying machine 1 as an example of an image forming apparatus according to the present invention includes a scanner device 2 for reading an image of a document;
The copying main body 3 has a built-in image forming section that forms an image based on information from the scanner device, and a paper bank device 4 that stores a large number of recording media for recording images, such as recording paper. The scanner device 2 is placed on the bank device 3, and the scanner device 2 is placed on the copying body 3.

The copying main body 3 has an image forming section 5 and a paper feeding device 6 in FIG.

As shown in FIGS. 1 and 3, the scanner device 2 placed on the copying body 3 may be configured as an integral structure, as opposed to being formed as a separate structure separated from the copying body 3. You can also do it.

The scanner device 2 includes a contact glass 1 on which a document is placed.
1, a document holder 12 for pressing and fixing a document against a contact glass 11, and an optical device. The optical device includes a lamp 13 that illuminates and scans the document on the contact glass 11, a first mirror 14 that scans together with the lamp 13 and reflects light reflected from the document, and a light reflected from the first mirror 14. A second mirror 15 and a third mirror 1 that sequentially reflect
6, and a lens 17 that images the reflected light from the third mirror 16 onto the CCD 1B. The second mirror 15 and the third mirror 1 are moved at a speed that is 1/2 of the reading scanning speed of the lamp 3.
6 is scanned.

The image forming section 5 built into the copying body 3 includes a writing optical device 7 . In FIGS. 2 and 4, the writing optical device 7 includes a semiconductor laser 21, a collimating lens 22 that converts the laser beam emitted by the single-conductor laser 21 into a parallel light beam, and an aperture that shapes the light beam into a light beam of a certain shape. 23, and a cylinder lens 24 which makes the shaped beam from the aperture 23 enter the polygon mirror 25 in a compressed form in the sub-scanning direction. A polygon mirror 25 having an accurate polygonal shape is rotated in a constant direction at a constant speed by a polygon motor 26, and the incident laser beam is deflected by the rotation of the polygon mirror 25, and the deflected laser beam is passed through fθ lenses 27a, 27b, 27c.

The rotational speed of the polygon mirror 25 is determined by the speed, writing density, and number of surfaces of the image information holding means 31 of the image forming section 5, such as the photoreceptor 31.

The fθ lenses 27a, 27b, and 27c convert the scanning light with a constant angular velocity so that it scans the photoreceptor 31 at a constant speed, forms an image on the photoreceptor 31 so that it becomes the minimum light spot, and further tilts the surface of the photoreceptor 31. It has a correction function.

The light after passing through the fθ lens 27 (27a, 27b, 27c) is reflected by the mirror 28, and the light outside the image area is guided by the synchronization detection mirror 29 to the synchronization detection sensor 30, which outputs a cue signal in the main scanning direction. emit a signal. One line of image data is output based on the image information read by the scanner device 2 after a certain period of time after the synchronization signal is output from the synchronization detection sensor 30. The light as image data is reflected by the mirror 28 and forms an image on the photoreceptor 31 at the exposure position. By repeating this process, images are sequentially exposed onto the photoreceptor 31.

The photoreceptor 31 has a drum shape and has a photosensitive layer coated on its surface. A photoconductor (OPC) is used as a photoconductor that is sensitive to the semiconductor laser wavelength of 780 nm.
Although 3i, 5e-Te, etc. are known, an organic photoreceptor is used in this embodiment.

Generally, in the case of laser writing, the light is applied to the image area.
P (negative/positive) process and P that shines on the skin
There is a /P (positive-positive) process, and in this example, N
/P process.

The charger 32 uses a scorotron system having a grid on the photoreceptor side, and charges the surface of the photoreceptor 31 uniformly (-).
A laser beam is applied to the photosensitive area to lower the potential. As a result, -750 to -800V is applied to the background part of the surface of the photoreceptor 31.
An electrostatic latent image of about -50V is formed in the image area. The electrostatic latent image is applied to the developing roller 33a by the developing device 33 at -500 to -
With a bias voltage of 600 .mu. applied, the (-) charged toner is developed and visualized.

The image visualized by the developing device 33 is transferred from the back side of the conveyor belt 53 onto a recording medium, such as a recording paper such as transfer paper, which is synchronously fed to the photoreceptor 31 by the conveyor belt 53 of the paper feeder 6. A (+) charge is applied by the transfer charger 34 and the image is transferred.

Toner remaining on the photoreceptor without being transferred to the recording paper is scraped off from the photoreceptor 31 by the cleaning device W35 and collected in a tank within the cleaning device 35. Furthermore, the potential pattern remaining on the photoreceptor 31 is erased by applying light from the discharge lamp 36.

The reflection density on the surface of the photoreceptor is measured by a photosensor 37 provided at a position immediately after the development is performed by the developer 33. The photosensor 37 consists of a combination of a light receiving element and a light emitting element. To measure the reflection density, write a certain pattern (for example, a pure black or halftone dot pattern) using the writing optical device 7 at a position corresponding to the photosensor reading position, and then develop the reflectance of the pattern area and the exposure of the area other than the pattern area. It determines the density of the image based on the ratio of body reflectance, and if it is too light, it issues a toner replenishment signal. Furthermore, it is also possible to detect an insufficient amount of toner remaining by utilizing the fact that the density does not increase even after replenishment.

The recording paper on which the image has been transferred is separated by curvature by a driving roller 54 which is applied to a conveyor belt 53, and sent to a fixing device on the third day. In the fixing device 1m3B, the toner on the surface of the recording paper is fixed by a fixing roller consisting of a pair of heat roller 39 and pressure roller 40. After fixing, the recording paper is used for normal image formation,
For example, during copying, the paper is guided to a paper ejection path 42 by a claw 41 and ejected by a paper ejection roller 43.

The paper feed device 6 has a conveyance device 51 and a storage means, such as a paper feed tray or a paper feed cassette.

The conveying device 51 has an endless conveying means, for example, an endlessly circulating conveyor belt 53, and the conveyor belt 53 has a drive roller 54, a first driven roller 55, a second driven roller 5, etc.
6 and adjustment roller 57 in sequence. The conveyor belt 53 is conveyed at a substantially constant speed by a drive roller 54. The conveyor belt 53 has a predetermined width of 2 mm between the drive roller 54 and the first driven roller 55, with the photoreceptor 31 in contact from the outside at the image forming position, for example, at the transfer position. A transfer charger 34 facing the photoreceptor 31 is arranged facing the inner surface of the conveyor belt 53.

Between the first driven roller 55 and the second driven roller 56,
An appropriate number of pickup rollers 58, for example two pickup rollers 58, are arranged at appropriate intervals inside the conveyor belt 53, and each pickup roller 58 is formed to be able to move up and down. The interval between the pickup rollers 58 can be changed as needed by moving one or more pickup rollers.

The first driven roller 55 and the adjustment roller 57 are formed to be movable in a substantially horizontal direction, and the adjustment roller 57 is formed so as to receive the tension of a spring 59 so that a predetermined tension can always be applied to the conveyance heald 53.

As shown in FIGS. 5 and 6, the first driven roller 55 has shaft portions 55a at both ends rotatably supported by bearings 60, and the cough bearing 60 is slidable on a guide shaft 62 fixed to a side plate 61. It is formed as a supported slider. The shaft portion 55a may be fixed to a bearing 60, and the first driven roller 55 may be rotatably supported by the shaft portion 55a. The first driven roller 55 , that is, the bearing 60 is reciprocated along the guide shaft 62 by a moving device 63 . The moving device 63 performs additional movement of the conveying belt 53 in addition to the conveying movement by the drive roller 54, and is used as a feeding speed change device. The drive shaft 6 is rotatably supported by the moving device 63 and the side plate 6I.
4, and a driven pulley 67 fixed to a driven shaft 66 rotatably supported by the side plate 61. The driving shaft 64 is rotationally driven by the moving motor 6B. A drive belt 69 is wound around each drive pulley 65 and driven pulley 67, and the drive heald 69 is attached to the slider 60.
is fixed by a fixing plate 7o. The drive belt 69 is moved forward and backward by the forward and reverse rotation of the moving motor 68, and the slider 60
By moving along the guide shaft 62, the first driven roller 55 is moved substantially horizontally.

When the first driven roller 55 is at the home position, which is the right end position in the figure, it is detected by the home sensor 71.

The adjusting roller 57 is also moved in accordance with the movement of the first driven roller 55, so that the conveying heald 53 can be maintained at a constant tension.

Therefore, the adjustment roller generally moves in the opposite direction to the first driven roller by a distance equal to the distance traveled by the first driven roller.

The moving speed Vs/s of the first driven roller 55 is determined by the transport heald 5.
3 conveyance speed, that is, 1/ of the circumferential speed vIIII/S
2, that is, V = v / 2, when the first driven roller 55 moves to the left in the figure, the conveyance heald 53 traveling in the direction of the arrow moves from the adjustment roller 57 to the second driven roller 56 to the first driven roller 55. In the section up to , that is, in the speed fluctuation region, the upper conveyor belt 53 is apparently shifted to a stopped state and can be maintained in a stopped state by the action of the circumferential velocity v mm/s and the moving speed V mm/s. If the recording paper is sucked from the paper feed tray 52 during the stopped state in which the feeding speed indicated by the apparent speed above is zero, it becomes possible to feed the paper without using a registration device and without shifting the leading edge registration. In addition, the suction position is always the same, so there is no deviation due to belt a feeding, and a registration stop operation using a specially installed registration device is required for image positioning. All that is required is to control the image formation start timing.

In the speed fluctuation region that is a part of the conveyor belt 53 due to the movement of the first driven roller 55, a speed change operation is performed in which the conveyor belt 53 appears to stop at the top and then returns to a predetermined speed. The driving roller 5 exits and passes through the transfer position.
4 to the adjustment roller 57, that is, in the constant speed region, the conveyance heald 53 does not appear to undergo any apparent speed fluctuations and moves at a constant speed. Therefore, the circumferential speed of the conveyor belt 53 remains unchanged while the recording paper is being transported to the transfer position and to the fixing position by the fixing device 38. This means that a part of the conveyor belt 53 appears to be in a stopped state with an upward speed change, and even while paper feeding is being performed, another recording paper is conveyed by the same conveyor belt 53, and transfer, separation, and fixing are performed in some way. This can be done without any side effects. In a constant speed region where the conveyor belt 53 always runs at a constant speed, the conveyor belt 53 can be removed from the paper feed tray 52 without causing cleaning defects by cleaning, for example, with a belt cleaner 72 provided below the drive roller 54. When the recording paper is attracted, the first driven roller 55 is moved to the right side in the figure and returned to the home position. At this time, the adjustment roller 57 is also moved.

When the first driven roller 55 returns to the home position,
The apparent speed in the speed variation region of the conveyance heald 55 increases to the upper speed, that is, the feeding speed increases to twice the speed in the constant speed region.

An upper presser roller 73 is disposed above the first driven roller 55 in FIG. 2, and a lower presser roller 74 is disposed on the lower right side of the first driven roller 55 in FIG. A guide plate 75 is provided between the presser rollers 74 and assists the conveyance of the recording paper conveyed by the conveyor belt 53 from the paper feed tray 52 so that the direction can be changed smoothly along the first driven roller 55. .

After the conveyor belt 53 is cleaned of dirt by a belt cleaner 72, a charging roller 76 disposed near the belt cleaner 72 forms a certain charge pattern on the conveyor belt 53. When a charge pattern is formed in the speed fluctuation region of the transport heald 53, such as when the charging roller 76 is disposed in circumferential contact with the second driven roller, the charge is applied in accordance with the fluctuation in the feeding speed of the transport heald 53. The transport heald 5 is controlled by changing the frequency of the charge, etc.
A certain charge pattern can be formed on 3.

The paper feed tray 52 is a front-loading recording paper stacking device, and the paper feed tray 52 is pulled out from the front of the copy vj1, recording paper 77 is set, and the paper feed tray 52 is inserted into the copy machine 1.
You can replenish recording paper by pushing it inside.

The paper feed tray 52 has a size series of recording paper (for example, A series,
B series, letter size, etc.). Although the A series will be explained here, the same applies to other series.

A center fence 7B is provided at the center of the paper feed tray 52, and a right fence 79 is provided on the right side, and the center fence 78 is foldable as shown in FIG.

When setting A4 size recording paper, use the center fence 78.
7, and put them into the two tray chambers 80 and 81 formed on the left and right sides, respectively. When setting A3 size, move the center fence 78 2 as shown in Figure 8.
The space between the two tray chambers 80.8I is opened and the recording paper is placed therein as one tray chamber.

On the lower side of the paper feed tray 52, a rising tray 8 is provided in each of tray chambers 80 and 81 formed on the left and right sides of the central fence 78.
2 is provided.

When the central fence 78 is erected, the tray consisting of the tray chamber 80 and the rising tray 82 on the right side in FIG.
2 is called a second tray 52#.

As shown in FIGS. 7 to 9, the central fence 78 has an upper face guide 83 and a lower face guide 84, and corner guides 85 are provided at both ends of the upper face guide 83 and at both ends of the lower face guide 84, respectively. This prevents the recording paper 77 from shifting laterally.

The upper face guide 83 is vertically slidably inserted into the groove of the lower face guide 84, and the spring 86 is inserted into the groove of the lower face guide 84.
3 and the lower face guide 84. A groove is formed in the improved face guide 84 to improve the lower face guide 84.
can be inserted. Due to the action of the spring 86, the upper face guide 83 is maintained at a predetermined relative position with respect to the lower face guide 84 when no load is applied.

A notch 87 is provided at the center of the upper edge of the upper face guide 83.
is formed so that the operator's hand does not touch the recording paper 77 when setting it.

The lower face guide 84 is connected to the paper feed tray 52 by a support shaft 88.
It is rotatably supported by the frame. Lower face guide 84
It has an L-shaped finger portion 89 at its lower end. The lower face guide 8 is locked by the fingers 89 locking into the protruding locking portions 90 formed on the frame portion 52a of the paper feed tray 52.
4 is stopped in a substantially vertical position when it is rotated and stands up, and is prevented from rotating any further. A claw 89a is formed on the finger portion 89, and a hook portion 9 formed on the frame portion 52a.
1, the lower face guide 84 is prevented from rotating in the direction of falling and is held in the upright position. Claw 89a
pushes the upper face guide 83 sideways with such force that the hook 91 comes off due to elastic deformation, the center fence 78 rotates clockwise in the figure and falls over, causing the right tray chamber 80 to fall as shown in FIG. The space between the left tray chamber 81 and the left tray chamber 81 is opened.

When the center fence 78 falls, the upper face guide 83 and the lower face guide 84 are arranged in four parts 92 formed on the frame 52a of the paper feed tray 52 so as not to interfere with the recording paper placed on the rising tray 82. It is formed so that it is buried inside. The center fence 78 fell and the right tray room 8
0 and the left tray chamber 81 are in communication.
The claw 89a of the fallen lower face guide 84 is detected by pressing a switch 93 serving as a paper size sensor.

A paper end sensor 94 is provided on the upper surface of the rising tray 82 to detect the presence or absence of recording paper.

The central fence 78 can also be of a removable type instead of the retractable structure shown in the figure. Size detection at this time can be performed by providing a sensor that detects the presence or absence of the central fence 78.

The right fence 79 can also be formed by a lower face guide 84 and an upper face guide 83 in the same manner as shown in FIG. In this case, there is no need to overturn the right fence 79.

The recording paper 77 in the paper feed tray 52 is transferred to the transport heald 53.
One of the Pisoqua 710-ra 58 that presses against the middle fence 78 is placed directly above the upper face guide 83 of the middle fence 78, and similarly another one is placed directly above the upper face guide 83 of the right fence 79. will be placed in

As shown in FIG. 10, one pink-up roller 58 disposed directly above each face guide 83 and one or more other pickup rollers 58 are rotatably supported as IM on, for example, a carrier plate 95. . In the illustrated example, each set of pickup rollers 58, which is supported by the carrier plate 95 as a set of two pink up rollers, is supported at the same height.

The carrier plate 95 is always pulled up to a fixed position by a tension spring 96, and the conveyor belt 53 is pulled up by the upper face guide 83.
It is located away from the top surface of. (The holding plate 95 is in contact with a push-down device 97, for example, a cam device, by the force of a spring 96. From the time when paper is not fed as shown in FIG. is pushed down, and the pickup roller 5 is pushed down as shown in FIG.
8 comes into contact with the upper face guide 83 and pushes the upper face guide 83 down. The carrier plate 95 is pushed down until the conveyance heald 53 comes into contact with the recording paper 77 and sucks it. The pressing device 97, the carrier plate 95, and the pickup roller 58 serve as pressing means for pressing the conveyance heald 53 against the recording medium, and by pressing the conveyance heald 53.
acts as a contact means for bringing a part of the recording medium into contact with the recording medium.

As shown in FIG. 12, the push-down device 97, in the case of a cam device, includes a paper feed cam 99 fixed to a shaft 98 in the same posture at a predetermined interval. As shown in the 13th example, the paper feed cam 99 has an outer peripheral shape that covers a range of 144°.
It is formed as a circular arc surface B with a radius R1, for example, 10 degrees from the center of the axis 98, and the remaining 216° range is divided into 108° increments, and the distribution is divided from the center point A to the radius R2, for example, from the center of the axis 98. As a point located at a position of 6 mm, arc surface B
and center point A are connected by a smooth curved surface.

The shaft 98 is connected via a spring clutch 100 to a drive shaft 102 to which a pulley 101 is fixed. The pulley 101 is driven by a motor via a timing heald 1.3 and a reduction gear (not shown). A stopper 104 is fixed to the shaft 98. The stopper 104 is the first
As shown in Figure 4, there are two stepped portions 105.10 on the outer periphery.
The locking bar 107 is formed of a substantially spiral-shaped claw having a diameter of 6, and the claw of the locking bar 107 engages with one step 105 to prevent the stopper 104 from rotating. The locking bar 107 is connected to the support shaft 10
8, and is always held in a locked position with respect to the stepped portion 105 or 106 by a spring 109. A plunger of a paper feed solenoid 110 is connected to the locking bar 107, and when the solenoid is energized, the locking bar 107 is rotated around the support shaft 108 against the force of the spring 109, and the step is removed. The lock on the portion 105 or 106 is released.

When the stopper 104 rotates, the angle from the first stepped portion 105 to the second stepped portion 106 is 12°.

When the locking bar 107 is unlocked at the first stepped portion 105, the stopper 104
rotates 120 degrees, and the second step 106 locks on the locking bar 107, stopping the rotation of the shaft 98. When the locking bar 107 is locked to the first stepped portion 105, the point A of the paper feed cam 99 is in contact with the support plate 95 as shown in FIG. 10, and the support plate 95 is in the raised position. .

The rotation of the pulley 101, which is driven by a motor (not shown) and transmits rotation of 12 Orpm, is caused by the spring clutch 1.
00 to the stopper 104, and when paper is fed, the paper feed solenoid 110 is energized and the stopper 104 is released, and the stopper 104, which is always receiving rotational moment, is
Since the lock was released, it started rotating for 0.25 seconds.
Afterwards, the paper feed solenoid 110 is deenergized and the locking bar 107
contacts the outer peripheral surface of the stopper 104 again. At this time, the stopper 104 has already made a half turn (180°), so
The second step portion 106 is illuminated, and the pawl of the locking bar 107 touches the first step portion 10 of the stopper 104 when it rotates once.
5 to stop the stopper 104. This operation causes the cam 99 to rotate once every 0.5 seconds. The pickup roller 58 moves 4m in 0.15sec together with the support plate 95.
Pauses for 20.2 seconds on the lower tip. At this time, the 11th
As shown in the figure, the arcuate surface B of the cam 99 contacts the support plate 95 and pushes the support plate 95 down. After stopping for 0.2 seconds, it returns to the original position in 0.15 seconds. The pick-up roller 58 and means for pushing down the pick-up roller 58, such as the push-down device 97 and the carrier plate 95, act as a suction operating means for activating the suction of the transport heald 53.

The gap between the conveyor belt 53 and the recording paper 77 in the non-feeding state is approximately 4 mm, and the gap with the upper face guide 83 is 20 mm.
It is. Therefore, when the pickup roller 58 moves downward, it descends 2■ and comes into contact with the upper face guide 83.
Further, while pushing down the upper face guide 83, 2so is lowered. At this engineer position, the conveyor belt 53 comes into contact with the recording paper 77.

At this time, the recording paper 77 is attracted to the conveyance belt 53 by an unequal electric field caused by a charge pattern formed in advance on the outer peripheral surface of the conveyance heald 53 by the charging roller 76 . The rising tray 82 is formed and controlled so that immediately after the big amplifier roller 58 moves downward, the rising tray 82 rises until the contact pressure between the recording paper 77 and the conveyance heald 53 reaches a predetermined value, and then stops. do. As a result, recording paper 7 due to paper feeding
7 can be corrected for the change in top surface position, and the paper feeding position can always be maintained at the same height.

The conveyance belt 53 has a feeding function of feeding the recording paper from the paper feed tray 52, a conveyance function of conveying it to the transfer position, and a transfer function of contributing to the transfer to the recording paper at the transfer position.

Since the conveyor belt 53 attracts and feeds the recording paper by the attraction force generated by an unequal electric field rather than by frictional force, there is no deviation of the recording paper, it has a registration function, there is no generation of paper dust during conveyance, and there is no need to remove static electricity after transfer. There is no.

The second stepped portion 106 of the stopper 104 is used when the paper feed tray 52 is replenished with recording paper, as will be described later.

As shown in FIGS. 2 and 15, rising trays 82 are individually arranged in a right tray chamber 80 and a left tray chamber 81, which are divided by the central fence 78 of the paper feed tray 52. As shown in FIG. 15 and FIG.
The wires 111 are fixed to the wires 111, respectively. Of the four wires 111, the first wire 1lla is turned by a first guide pulley 112 and a second guide pulley 113, and its end is wound around a first drive pulley 114.

The first drive pulley 114 is fixed to a shaft 115 rotatably supported by the frame 52a of the paper feed tray 52. same first
One end of the second wire 111b is wound around the drive pulley 114, and the second wire 111b is turned and guided by the second guide pulley 113 along the way.

The third wire 11 is fixed to the rising tray 82 on the opposite side from the first wire 11a and the second wire 111b.
1C and the fourth wire 11d are each wound around a second drive pulley 116 whose ends are fixed to a shaft 115. Like the first wire 11a, the third wire llc is guided by the third guide pulley 117 and fourth guide pulley 118 and wound around the second drive pulley 116, and the fourth wire 11d is guided by the third guide pulley 117 and the fourth guide pulley 118 and wound around the second drive pulley 116, like the second wire 111b. 4 guide boo 1
7118 and is guided around the second drive pulley 116.

One end of the shaft 115 is connected to the output side of the electromagnetic clutch 119, and an encoder 120 is fixed to the other end. The input side of the electromagnetic clutch 1190 is connected to the tray motor 22 via the coupling 121. The coupling 121 is a drive half 1 connected to the tray motor 122 side.
21a and the driven half 1 connected to the electromagnetic clutch 119 side
21b.

The lifting tray 82 and the lifting rod device 123 are formed in the same structure for both the right tray chamber 80 and the left tray chamber 81, but in the illustrated example, they are formed almost symmetrically with respect to the center fence 7. Rising tray 82 for right tray chamber 80 and left tray chamber 8
The No. 1 lifting tray 82 can be driven by a separate tray motor 122. If it is necessary to distinguish between the right tray chamber 80 and the left tray chamber 81, the right tray chamber 80 and the left tray chamber 80 are distinguished by adding an A after the symbol and the left tray chamber by adding a B after the symbol.

The electromagnetic clutch 119 transmits drive only when the torque on the output side is less than a predetermined value in one direction of rotation, and slips and does not transmit drive when the torque on the output side is more than a predetermined value. There is.

As a result, the rising tray 82 on which the recording paper 77 is placed rises due to the rotation of the tray motor 122, but when the top surface of the recording paper 77 comes into contact with the conveyance heald 53 and receives pressure, the electromagnetic clutch 119 is activated to slip. As a result, the rising tray 82 no longer rises, and the tray motor 122 stops after a predetermined period of time, so that the uppermost surface of the recording paper 77 is always maintained at a constant height.

When replenishing the recording paper 77, the paper feed tray 52 is pulled out from the front of the copying machine 1. At this time, the drive half 121a of the camp ring attached to the side of the copying machine 1 and the side of the paper feed tray 52 are pulled out. The driven half 121b of the coupling attached to the tray 82 comes off, and the rising tray 82 lowers to the lowest position under its own weight. At the same time, the tray open/close sensor 124 (Fig. 2)
detects that the paper feed tray 52 has been pulled out.

After replenishing the recording paper 77, when the paper feed tray 52 is pushed into the copying machine 1, the driving half 121a of the camp ring attached to the copying machine side and the driven half of the coupling attached to the paper feed tray side The bodies 121b are engaged, and at the same time, the tray opening/closing sensor 124 detects that the paper feed tray 52 is set.

The paper feed solenoid 110 operates to move the locking bar 107 to the first position.
When rotated clockwise in FIG. 4, the claw portion of the locking bar 107 is disengaged from the first stepped portion 105 of the stopper 104. The stopper 104, which has always been subjected to clockwise (rightward) rotational moment by the spring clutch 100, starts to rotate clockwise (rightward) because the regulating member is no longer present.

After 0.1 sec, the paper feed solenoid 110 is released and the locking bar 107 is again subjected to a counterclockwise rotational moment and comes into contact with the outer peripheral surface of the stopper 104. At this time, the stopper 104 has only rotated 115 times (72°), so it comes into contact with the outer circumferential surface between the first stepped portion 105 and the second stepped portion 1060.

When the stopper 104 rotates exactly 1206 times, the locking bar 10
The claw portion 7 engages with the second stepped portion 106 of the stopper 104 and stops.

At this time, eight surfaces of the cam 99 are in contact with the carrier plate 95 and are stopped, and the conveyor belt 53 is at the paper feeding position.

Next, the tray motor 122 is activated to raise the raising tray 82 together with the recording paper 77. When the top surface of the recording paper 77 comes into contact with the conveyor belt 53 and receives pressure, the electromagnetic brake 11
It is stopped by the action of 9.

After a predetermined time, the tray motor 122 stops. Then, the paper feed solenoid 110 is activated to rotate the locking knob 107 clockwise. Then, the claw portion of the locking bar 107 is removed from the second stepped portion 106 of the stopper 104. The stopper 104, which has always been subjected to clockwise (rightward) rotational moment by the spring clutch 100, starts rotating clockwise because the regulating member is no longer present.

After 0.1 sec, the paper feed solenoid 110 is released and the locking bar 107 is again applied with a counterclockwise rotational moment and comes into contact with the outer peripheral surface of the stopper 104. The stopper 104 rotates exactly 240 degrees, and the locking bar 107 again hits the first stepped portion 105 of the stopper 104 and stops.

At this time, the conveyor belt 53 returns to its non-feeding position.

As described above, the first tray 52' and the second tray 52#
It is possible to replenish recording paper individually.

When the center fence 78 is folded down and A3 size recording paper is set in the paper feed tray 52 across the first tray 52' and the second tray 52#, the above-mentioned raising tray operation and cam operation are performed on the first tray 52' and the second tray 52'. , both are performed simultaneously on the second tray 52#.

This widens the contact area of the conveyor belt 53 during paper feeding, thereby stabilizing paper feeding and conveyance.

As mentioned above, during normal image formation, the recording paper fixed by the fixing device 38 in FIG.
1 to a paper ejection path 42, and ejected by a paper ejection roller 43. During double-sided copying, in which copies are made on both the front and back sides of the recording paper, the recording paper after fixing is reversed from front to back to the transfer position by the photoreceptor 31. It is necessary to feed paper to

For this reason, after three days of the fixing device, the claw 41 closes the sheet discharge path 42.
A return guide path 44 is provided as a switchable branch path for guiding the recording paper to the paper feed tray 52.

The return guide path 44 includes a reversing path 45 as a branch path, and at the branching position, it connects directly to the paper feed tray 52 and the reversing path 45.
The first switching claw 46a can switch between the passage and the passage.

The recording paper sent to the return guide path 44 is sent to the first switching claw 46a by the feed roller 47, and the recording paper guided to the reversing path 45 is nipped by the reversing roller 48 and sent to the rear end of the recording paper. When the reversing sensor 125 detects this, the reversing roller 48 rotates in the reverse direction and the sheet is reversely fed. The recording paper that is fed backwards is the second one.
The feeding roller 4 of the return guide path 44 is controlled by the switching claw 46b.
9 and is discharged onto the paper feed tray 52.

Like A3 copy, the first tray 52' and the second tray 5
2'' at the same time, lower the raising tray 82 by a certain amount by reversing the tray motor 122 after feeding the front side copy (the landing amount (travel amount) is stored in an encoder (not shown)). After the recording paper 77 with the front side copied is inserted into the paper feed tray 52, the ascending tray 82 is returned to its original position and the rear side copy feeding operation is performed, and after the back side copy, the recording paper 77 is ejected from the paper ejection path. be done.

Like A4 copy, the first tray 52' and the second tray 5
2#, if front side copies are fed from the first tray 52', the tray motor 122 is
The ascending tray 82 of the second tray 52'' is lowered by a certain amount by the reversal of the movement (lowering M(
After the recording paper 77 on which the front side has been copied is inserted into the second tray 52'', the ascending tray 82 is returned to its original position, and the feeding operation for the back side copy is performed. The recording paper 77 is discharged from the paper discharge path.

On the other hand, when feeding the front side copy from the second tray 52'', after the feeding operation of the front side copy, the raising tray 82 of the second tray 52# is lowered by a certain amount by reversing the tray motor 122 (using an encoder not shown). After the recording paper 77 with the front side copied is inserted into the second tray 52#, the ascending tray 82 is returned to its original position, the back side copy feeding operation is performed, and the back side copy is fed. After copying, the recording paper 77 is discharged from the paper discharge path.

A recording paper upper limit sensor 126 is provided above the second tray 52#, and when in double-sided image forming mode, even if you try to lower the ascending tray 82, if it is full of recording paper, the operation panel will not allow double-sided copying. Display.

When you want to repeatedly form multiple images on the same side, such as composite copying instead of double-sided copying, the recording paper is moved to the reversing path 45.
The paper can be directly fed to the paper feed tray 52 by the first switching claw 46a without being guided by the paper feed tray 52.

In contrast to the automatic feeding of recording paper using the paper feed tray 52, there are cases where it is desired to manually feed the recording paper. For this purpose, a manual paper feeder 130 is provided.

The manual paper feed device has a manual feed door (not shown) provided in the frame of the copying body 3, a guide plate 31, 132 that guides the recording paper inserted from the core feed door, and a manual paper feed roller 133. .

When the manual feed door is opened, the manual feed mode is switched to, and the first driven roller 55 is returned to the manual feed home position.
When the manual feed sensor 134 detects that the recording paper is present in the manual paper feed device 130, a manual feed franc (not shown) is activated, and the rotation of the manual paper feed roller 133 transports the recording paper onto the conveyance heald 53.

The minimum unit of the copying machine 1 is composed of a scanner device 2 and a copying body 3, and it can function as a copying machine for nine copies.However, when using recording paper of various sizes or making multiple copies When processing, etc., a large number of containment means,
For example, it is possible to use a paper bank device 4 that can accommodate a paper feed tray or a paper feed cassette, and includes a tray that can accommodate a large number of recording sheets. In this case, the copying body 3 is placed on the paper bank device 4 as shown in FIG. The casing of the copying body 3 has a paper feed path 136 that is open at the bottom and guides the recording paper fed from the paper bank device 4.
is provided. The paper feed path 136 is formed to be able to feed the recording paper to a home position, for example, a nip position between the first driven roller 55 and the upper presser roller 74 located at the manual feed home position. A branch path 137 is provided in the paper feed path 136 so that the recording paper can be fed toward the first tray 52' of the paper feed tray 52, and a switching claw 138 is provided at the branch position to the branch path 137 to allow recording. It is possible to switch the paper feeding path. A paper bank paper feed sensor 139 is provided in the paper feed path 136 to detect that four recording papers have been fed to the paper bank device. Paper banks are abbreviated as PB as necessary.

The paper bank device 4 has a 1st PB with a maximum loading capacity of 250 sheets.
A three-stage tray consisting of a ) ray 201, a 2nd PB) ray 202, and a 3rd PB) ray 203, and a 4th PB) ray 204 with a maximum of R and M 2000 sheets are equipped. Paper is fed from each PB tray 201 to 204 by one paper feeding conveyance device 20.
5.

The paper feed conveyance device 205 has an endless conveyance means, for example, one endless heald 218, as shown in FIGS. 2 and 17. The endless heald 218 includes a driving roller 211 whose position is fixed, a tension roller 212 whose position is movable, a turning roller 213 whose position is fixed, a driven roller 214, a pickup roller 215, a pair of heald speed change rollers 216, and an auxiliary roller. It is wrapped around the entire turning roller 217.

17 to 19, guide rods 207 are vertically provided on the front side plate 205 and back side plate 206 of the paper bank device 4, respectively, and the paper feed unit 220 is vertically slidably guided by the guide rods 207. Ru. Paper feed unit 2
20 has a sheet feeding unit front side plate 222 and a sheet feeding unit back side plate 223 to which a bearing 221 that is slidably attached to a guide rod 207 is fixed. Paper feed unit front plate 2
22 and the pickup roller 2 so that both ends thereof are supported by the rear side plate 223 of the paper feed unit, respectively.
15 and an auxiliary turning roller 217 are arranged.

A pickup auxiliary roller 219 is arranged to face the driven roller 214 so as to press the conveyor belt, that is, the PB endless belt 218, and the paper feeding unit front side plate 222
The sheet feeding unit is rotatably supported by the back side plate 223. The big amplifier auxiliary roller 219 is used when changing the conveyance direction.
It serves to prevent the recording paper from peeling off from the belt 218.

A shaft 21 that rotatably supports the pickup roller 215
Both ends of the paper feed unit 5a are movably supported in an elongated hole 224 formed in the front side Fi, 222 of the paper feed unit and an elongated hole 225 formed in the back side plate 223 of the paper feed unit so as to be movable in a substantially horizontal direction.

Further, both ends of the shaft 215a of the pickup roller 215 are fixed to the timing belt 226 by fixing fittings 227, respectively. The timing heald 226 is connected to the drive pulley 22, respectively.
8 and the driven pulley 229. Drive pulley 22
8 is a common drive shaft 231 driven by a motor 230
The drive shaft 231 is fixed to the paper feed unit front plate 22.
2 and the rear side plate 223 of the sheet feeding unit. The driven pulleys 229 are rotatably supported by shafts individually attached to the paper feeding unit front plate 222 and the paper feeding unit rear side plate 223, respectively. The pickup roller 215 is reciprocated along the elongated holes 224 and 225 by driving the motor 230 in forward and reverse directions. A home position feeler 232 and a bracket 234 for mounting an upper end detection sensor 233 for detecting the upper end of the recording paper are attached to the shaft 215a of the pickup roller 215. When the home position feeler 232 activates the home position sensor 235 attached to the back side plate 223 of the paper feed unit, it is detected that the P7 quad roller 215 is at the home position. The upper edge detection sensor 233 detects when the paper feeding surface of the PB heald 218 is at a height of five decorations from the upper edge of the recording paper, and performs the paper feeding operation from this position.

The elevating device 250 that moves the paper feeding unit 220 up and down is powered by a motor 2 fixed to the back side plate 206 of the paper bank device.
51, and a drive shaft 25 rotatably supported by the back side plate 206 and the front side plate 205 and rotationally driven by the motor 251.
2, and two drive pulleys 2 fixed to the drive shaft 252.
53, a driven pulley 253 that is rotatably supported by the back side plate 206 and the front side plate 205, respectively, and a drive boob IJ 25.
2 and a driven pulley 253, respectively. timing belt 25
4 are fixed to the paper feeding unit front side plate 222 and the paper feeding unit rear side plate 223, respectively, and when the timing belt 254 moves by the forward/reverse driving of the motor 251, the paper feeding unit 220, that is, the paper feeding unit front side plate 222 and the paper feeding unit rear side plate 223 are fixed. The paper unit rear side plate 223 is moved up and down.

A bracket 237 is fixed to a front shaft 236a rotatably supported by the front side plate 222 of the paper feed unit, and a rear shaft 236b rotatably supported by the back side plate 223 of the paper feed unit, respectively. Both ends of the pair of heald speed change rollers 216 (216a, 216b) are supported. That is, the first heald speed change roller 216a and the second belt speed change roller 216b are supported by the bracket 237,
The PB runs between both heald speed change rollers 216a and 216b due to the rotation of the shaft 236 (236a, 236b).
The relative position with respect to the heald 218 is changed. Both shafts 236
(The front shaft 236a and the rear shaft 236b) are rotationally driven by a motor 238 to which the rear shaft 236b is connected. Rear shaft 23
A feeler 239 is fixed to 6b, and the feeler 239
is the sensor 240 fixed to the rear side plate 223 of the paper feed unit.
By operating the heald speed change roller 216, the home position of the heald speed change roller 216 is detected. By rotating the shaft 23G, the belt speed change roller 216 rotates the PB belt 2 before the sheet feeding operation.
18 is wound around the first belt speed change roller 216a and the second belt speed change roller 216b4, and the shaft 23G is rotated in the opposite direction during paper feeding operation to return the PB heald 218 which is the winding. The PB belt is returned to its original position and the feeding speed of the PB bevel 21B is controlled.

The transport of the PB belt 21B is driven by a transmission device having a gear 242 driven by a motor 241 attached to the back side plate 206, and a gear 244 that meshes with the gear 242 and is fixed to the shaft 243 of the drive roller 211. This is done by rotationally driving 211.

In order to adsorb and convey the recording paper, the PB health l-218 is provided with a charging roller to form a charge density pattern. In the example shown in Figure 0, the auxiliary turning roller 217 is used as the charging roller, but it may be provided separately. Good charging roller 217
An AC voltage is applied from the high voltage power supply 245 at a position before contacting the recording paper, for example: t 2 KVp-p, 26 H
2 is applied, thereby forming a striped charge density pattern on the surface of the PB belt 218 in which charge densities -σ and +σ are alternately arranged at a period of, for example, 5IIIffl.

The paper feeding unit 220 feeds paper PB) rays 201 to 20.
The driven roller 2 is moved up and down according to the position of 4.
The adjustment roller 2I2 moves in accordance with the movement of the tension roller 14 so that the tension is always kept constant. Adjustment roller 212
The end portion supported by the front side plate 205 and the end portion supported by the back side plate 206 are respectively connected to a spring 247 via a wire 246, and are pulled in a direction to apply tension to the PB heald 21B.

A first PB tray 20 is installed in the machine frame of the paper bank device 4.
Open/close sensor 26 for each of the first to fourth PB trays 204
1.262.263.264 are provided, and the opening and closing of each PB) ray 201 to 204 is detected.

For example, the 1st P as a small tray with a maximum capacity of 1250 sheets.
B) Ray 201 to 3rd PB) Ray 203 is as shown in FIG. 20 (1st PB) Ray 201 will be explained) Side fence 26 for determining the position of the recording paper to be loaded
5 and an end fence 266. The side fence 265 and end fence 266 guide the recording paper in three directions. A fence may be provided at the front end in the paper feeding direction as long as it does not interfere with paper feeding.

The side fence 265 and the end fence 266 are movable in the direction of the arrow according to the size of the paper. P.B.
There is a handle 2 on the front wall of the tray 201 for easy loading and unloading.
67 may also be provided.

In FIG. 21, for example, the 4th PBL-ray 204 as a large tray with a maximum load of M2000 sheets is the 1P in FIG.
Similar to the B tray 201, a side fence 268, an end fence 269, and a handle 267 may be provided. Since the paper capacity in the fourth PBL-ray 2°4 is large, it is preferable that the side fence 268 be formed in an L shape to guide the paper in the front, rear, left and right directions so that the paper does not shift. In this case, the cross-shaped side fence 268 is shaped so that it does not interfere with paper feeding.

The PB belt 53 in the copying body 3 attracts and conveys the recording paper with a charge density pattern formed by the charging roller 76.
In the vapor bank device 4, a charge density pattern is formed on the PB heald 218 by an auxiliary turning roller 217 acting as a charging roller, and the recording paper is attracted and conveyed. For this reason, the transport heald 53 and the PB bevel 21B are formed as endless healds having a dielectric layer 53a capable of holding charges on the surface layer and a semiconductor layer 53b on the back surface. At least one of the rollers supporting the transport heald 53.21B, for example roller 56.215, is grounded and arranged in contact with the back side of the belt.

For example, as shown in FIG. 22, an alternating electric field (AHz) is applied to the charging rollers 76 and 217 (only the charging roller 76 is shown in the figure) from the high voltage power supply 131 as opposed to the grounding roller 56. The conveyance heald 53 is the drive roller 5
4 moves in the direction of the arrow at a constant speed of U/S, and the position of the P/7 quasobro is where it contacts and attracts the recording paper.
It is located downstream of the contact position with the charging roller 76 in the moving direction of the conveyor belt 53 . Therefore, the conveyance heald 53 is connected to the high-voltage power supply 13 before the recording paper comes into contact with the surface.
An alternating current voltage is applied from 1 through a charging roller 76 .

As a result, a stripe-like charge density pattern is formed on the surface of the conveyor belt 53, in which charge densities -σ and +σ are alternately arranged at a period of U/Awn. Charges of opposite polarity are induced in the semiconductor layer on the back surface of the conveyor belt 53 due to the charge density formed on the surface of the conveyor belt.

When a charge density pattern as shown in FIG. 22 is formed, unequal charges 132 are formed near the surface of the conveyor belt 53 as shown in FIG. The force acting on a unit volume of can also be determined using Maxwell's stress tensor. The recording paper 77 is electrostatically attracted to the conveyor belt 53 by the force Fx in the direction perpendicular to the surface of the recording paper 77, that is, the surface of the sheet, and is held without shifting.
3, and the paper is fed and conveyed.

When the direction perpendicular to the sheet surface is X, the transport direction is y, and the direction within the sheet surface perpendicular to the transport direction is 2, the component force in each of the x, y, and z directions of the force acting on the unit volume of the dielectric is Fy ,Fy,
If it is F2, it will be as follows.

Maxwell's stress tensor (E-D) EY'DY 51) Z
-Sat fEqDy EyDy z'ε・D) 'EYI
)2F2ji Ez'Ctr E2D2-±(E・D
) Force acting on a unit volume This adsorption principle is different from the commonly known force that attracts charges of opposite signs, and the recording paper can be attracted using the above method without applying any charge to the recording paper. . For this reason, even if it is used in a paper feed conveyance device of an electrostatic recording device, it will not have any effect on the transfer process.

Although the example of the charge density pattern has a stripe shape, a checkerboard pattern may be used, and any appropriate pattern can be used.

As shown in Figure 24, when A3 size plain paper is fed to the conveyor belt and the contact length reaches 100 cm, a spring gauge 133 is attached to the rear end of the paper to adjust the suction force to the tensile strength. When measured as follows, the results shown in FIG. 25 were obtained. The adsorption area at this time is 300 cm''.

In FIG. 25, the amplitude of the AC voltage is constant, for example, 4KV,
, and show the results of measuring the adsorption force by changing the applied frequency. From this, in the present invention, the period of the stripe shape is set to 2(
Sufficient adsorption force was obtained when the power was set to 10 W or less, particularly 10 W or less. Further, as shown in FIG. 26, the adsorption force was measured by changing the applied voltage while keeping the applied frequency constant, for example, 26H2, and from the results, good adsorption force was obtained at 2KV□2 or more. Furthermore, it was found from measuring the surface potential that no charge density pattern was formed on the belt at the applied voltage at which no adsorption force was generated. From this, in order to generate adsorption force, at least an applied voltage equal to or higher than the charging start voltage is required.

Further, the applied voltage is the same when a DC component is superimposed on an AC voltage, or when a non-uniform alternating voltage is applied from a power source that outputs a non-uniform alternating voltage.

FIG. 22 shows the belt configuration used in the paper feeding and conveying device of the present invention. The transport heald 53 is a two-layer type, with the surface layer being a dielectric film (polyester resin 20μm, volume resistance 1016ΩCl1), and the lower layer being a semiconductor layer (polyester resin with carbon dispersed 80μm, volume resistance 101ΩC).
I+), and is rotatably supported by a drive roller and a plurality of support rollers. The charging roller 76 receives ±2KV from the high voltage power supply 131.
An alternating voltage of 24H2 is applied. Further, the conveyor belt 53 is moved at a constant speed of 120 in the direction of the arrow by the driving row.
The recording paper is moved at a speed of +nm/s, and the paper feeding position of the recording paper is downstream from the contact position of the electrode of the charging roller 76 with respect to the moving direction of the transport heald 53. Therefore, before the recording paper is fed onto the surface of the conveyor belt 53, a charge density pattern is formed on the surface of the conveyor belt in 5III11 cycles. Here, the volume resistance of the back surface of the transport heald 53 is set to 10
The reason for setting the value to 1ΩcI11 is that the resistance must be 10'Ω1 or more in order to transfer data when the transfer means is installed on the back surface. In addition, the above resistance was chosen because the adsorption force was greater when there was a difference in resistance with the surface layer.

However, the volume resistance of the back surface is actually 10'Ωcin ~ 10
■If it is within the range of Ω1, there will be no functional problem.

In FIG. 23, the PB belt 218 used in the paper feeding and conveying device of the paper bank II4 of the present invention is a two-layer type, and the surface layer is a dielectric film (PE750 μm) and the lower layer is an endless belt made of aluminum vapor deposition. It is rotatably supported by support rollers.

The volume resistance of this dielectric was set to 10I4Ω1. An alternating voltage of ±2 KV and 26 Hz is applied to the charging roller 217 from a high voltage power source B. Further, the PB belt 218 is moved by a drive roller at a constant speed of 130 trm/s in the direction of the arrow, and the paper feeding position of the recording paper is downstream of the contact position of the electrode of the charging roller 217 with respect to the moving direction of the PB belt. . Therefore, before recording paper is fed onto the surface of the PB belt, a charge density pattern is formed on the surface of the PB heald at a period of 5a.

The PB belt 218 in the paper bank device 4 is
The recording paper is sucked and fed from the PB tray 201 to the fourth PB tray 204. For this purpose, the lifting device 250 is operated, and the paper feeding unit 220 is moved to the first PB tray 201 to the third PB tray.
Move up and down in front of the PB tray 203 to load the 1st PB) Ray 2
It is stopped at the sheet feeding home position of the 01 to 3rd PB trays 203. In FIG. 17, the 4th PB) Ray 204
Before the recording paper is fed onto the surface of the PB belt, a charge density pattern is formed on the surface of the PB belt at a cycle of 511I11.

The PB belt 218 in the Haverbank device 4 is
PB) Ray 201 to 4th PB) Recording paper is sucked and fed from the ray 204. For this purpose, the lifting device 250 is operated, and the paper feeding unit 220 is
It moves up and down in front of the PBI-ray 203 and is stopped at the sheet feeding home position of the first FBI-ray 201 to the third PB tray 203. In FIG. 17, the fourth PB tray 2
04 is arranged shifted from the first PB tray 201 to the third PB tray 203, and the paper feed unit 220 is directly connected to the fourth PB tray 201 to the third PB tray 203.
PB) Can be moved onto the recording paper in the ray,
It can also be configured to be arranged in the same line as the first PB) ray 201 to the third PB) ray 203 and move up and down in front of the fourth PB) ray 204.

The paper feed home position for any PB) ray is a certain distance above the top edge of the recording paper, for example, a position above the 5th column, and when the paper feed unit 220 moves to the paper feed home position of the selected PB) ray, PB belt 218
is located 5 mm above the top edge of the recording paper.

When the PB belt 218 contacts the recording paper and feeds the recording paper by suction, the relative speed of a portion of the PB heald, that is, the contact portion with the recording paper, is changed to almost zero.

In order to change the feeding speed of a portion of the PB heald 218, that is, the relative speed with respect to the static recording paper, a feeding speed changing means;
For example, a pair of belt speed change rollers 216 (216a and 2
16b) is used.

In the 27th time, belt speed change rollers 216a, 216
For example, b is a roller with a diameter of 8M, the distance between the centers of the heald speed change rollers 216a and 216b is 12+nm, and the belt speed change roller 216a is moved by the motor 238 around the approximate center point between the axes of the belt speed change rollers 216a and 216b. , 216b are rotated, and the PB belt 218
The belt is wound around the belt speed change rollers 216a and 216b, and the winding is released. In FIG. 27, the PB belt shown in solid lines around the center 01 is rotated by an angle θ from the release position where the heald transmission rollers 216a, 216b are simply in contact.

When the PB belt 218 itself is not being conveyed, the belt speed change rollers 216a and 216b are rotated by θ (rad), thereby changing the amount of movement l of the PB belt.
is f=2rθ+12(1-cosθ) where T is the radius of the winding of the belt speed change rollers 216a and 216b.

From the relationship θ=ωL, the transition speed ■ can be expressed as a time derivative,
■-2Tω+12ωsinωt. Here, ω is the rotational angular velocity.

When the PB belt 218 is moving at a constant speed of 130 m/sec and the paper feeding unit 220 is landing at 150 wm/sec, the contact area of the PB belt 218 with the recording paper should move at 280 a/see. To become, PB
This speed must be counteracted in order to stop the belt 218 in the area of contact with the recording paper. For this purpose, if the transition speed V is set to 280III/sec,
The angular velocity ω, ie the driving speed of the motor 238 rotating the shaft 236, is obtained.

In other words, in the case of the 1st PB tray 201 to the 3rd PB tray 203, the paper feeding unit 220 moves at a speed of 150 mm/sec from the paper feeding home position shown in FIG. 28A to the position where it contacts the recording paper shown in FIG. 28B. At this time, the heald speed change roller 216 moves in the direction of unwinding the PB heald 218 from the heald speed change rollers 216a, 2+6b, as shown in FIG. 28A, for example, clockwise in the figure. The speed change rollers 216a and 216b are rotated. The part of the PB belt 218 that contacts the recording paper is almost stationary, and the recording paper is moved to the PB held 218.
Electrostatic adsorption due to the charge density pattern.

Thereafter, the paper feeding unit 220 is returned to the paper feeding home position shown in FIG. 28C.

In the case of the fourth PB tray 204, the recording paper 7 is
7 is sucked and fed. In the case of the fourth PB tray 204, the leading edge of the recording paper 77 is sucked away from the contact area of the PB belt 218, so if the recording paper is conveyed in this state, the recording paper will gradually separate from the PB belt starting from the leading edge. It will end up being put away.

Therefore, the PB belt 218 descends from the sheet feeding home position shown in FIG. 29 (A) to the position shown in FIG.
As shown in FIG. C, the paper feed unit 22G is raised and returned to the paper feed board position, and is retracted by a certain amount to a position where the leading edge of the recording paper contacts the driven roller 214 within 2 hours.

For example, if it is moved backward by 20++m+, the time Z for the nail paper unit 220 to return to the paper feeding home position is 5 (a) /150 (am/sec) = 0.
033 (see), and the linear velocity of the PB belt 218 in the opposite direction is 20 (a+) 10.033 (sec>=6
00 (ll+Il/sec>, PB belt 2
18 is conveyed at a constant speed of 130 mm/sec, so when the paper feed unit 220 moves up at 150 w/sec, the contact surface of the PB belt 218 with the recording paper is 600+130-l30-150=580/ The winding of the belt speed change roller 216 is released and rotated so as to be returned in seconds. Therefore, the above transition speed ■ is 580 k/s.
ec to control the speed of the motor 238.

PB belt 218 in the paper feeding process for the next recording paper
In preparation for the deceleration of the recording paper contact area, the heald speed change roller 216 is rotated in the range between the contacting recording papers being conveyed.

In contrast to the structure in which two rollers are rotated as in the example shown in FIGS. 27 to 29, as shown in FIGS. 30 and 31,
A structure having two fixed rollers 216' and one variable speed roller 216M disposed therebetween can be utilized. FIG. 30 shows an example of the first PB tray 210 to the third PB tray 203 as shown in FIG.
FIG. 1 shows an example used for the fourth PB) ray 204 as shown in FIG. 29. In FIG. 30, the variable speed roller 216# moves to the paper feeding home position shown by the solid line, and while descending from that position to the position where it contacts the recording paper, it moves to the left in the figure and transfers to the PB position.
The speed of the recording paper contact area of the belt is reduced or stopped, and the displacement roller 216' is displaced to the leftmost position in the figure at the position where the belt returns to the paper feeding home position.

In FIG. 31, a process of retracting the recording paper contact area of the PB belt in the opposite direction is added to the example of FIG. 30.

The paper feed unit 220 moves 150 degrees from the paper feed home position.
The time it takes to contact the 5ml landing record paper at wrt+/sec is 5 (m) / 150 (tm/sec>=0.03
3sec, PB belt 218 between Kono and 130+
In order to cancel the constant speed drive of nm/sec and the downward displacement of the sheet feeding unit 220 at a descending speed of 150 me/sec, the displacement roller 216# is displaced in the negative direction at 280 m1sec. This displacement is performed for 0.033 seconds, so the amount of displacement is 280 (m/5ec) X O,033 (see)
= 9.3 (an), for this the displacement roller 216# is 280 (m/5ec)/2 = 140
It is sufficient to move at a constant speed of 9.3 (a) /2=4.7 (■) to the left of the bamboo diagram at a speed of (am/5ec).

In FIG. 31, since the leading edge of the recording paper is further transported backward to the position of the driven roller 214, the displacement roller 216# moves at a constant speed to the left in the diagram at a speed of 290 mm/sec and a displacement of 19.7 mm. .

The speed change operation is performed until the axial center of the displacement roller 216'' moves to the left from the line connecting the axial centers of the fixed roller 216'.
The constant velocity control is performed by a total displacement of 14.4-.

[Effects] According to the present invention, it becomes possible for the endless conveyance means to suck the recording medium at an appropriate position, and the position at which feeding of the recording medium starts is not limited to a specific position. Therefore, the position of the leading edge of the recording medium accommodated in the storage means is not limited, and the same storage means can be divided into multiple chambers to store multiple types of recording media of appropriate sizes, and can be fed from the stored position. Became. Therefore, the accommodating means can be used effectively regardless of the size of the recording medium, and the exclusive space of the accommodating means within the apparatus main body can be used most efficiently, making it possible to save space.

[Brief explanation of the drawing]

1 is an overall perspective view of an example of an image forming apparatus according to the present invention, FIG. 2 is a schematic front view, FIG. 3 is a schematic view of a scanner device, and FIG. 4 is a plan view of a writing optical device. FIG. 5 is a plan view of the conveyance means transmission, FIG. 6 is a perspective view of the conveyance means transmission, FIG. 7 is a front sectional view of a part of the storage means, and FIG.
The figure is a front sectional view showing the partitioning means in FIG. 7 in a tilted state, FIG. 9 is a perspective view of the partitioning means, and FIG. 11 is a diagram corresponding to FIG. 10 showing the operating state of the conveying means contacting device, FIG. 12 is a perspective view showing the drive system of the conveying means contacting device, FIG. 13 is a front view of the cam, and FIG. The figure is an explanatory diagram of the stopper of the drive system of the conveying means contact device, the first
5 is an overall perspective view of the storage means, FIG. 16 is a perspective view showing the drive system of the raising tray of the storage means, FIG. 17 is a schematic front view of the paper bank device, and FIG. 18 is a perspective view of the paper feeding unit. 19 is a plan view of the paper feeding unit, FIG. 20 is a perspective view of an example of the storage means, FIG. 21 is a perspective view of another example of the storage means, and FIG. 22 is a perspective view illustrating the formation of an alternating electric field on the conveyance means. Figure 23 is an explanatory front view of alternating electric field formation, Figure 24 is an explanatory diagram of a method of testing attraction force using an alternating electric field, and Figure 25 is a diagram showing the relationship between the pitch of an alternating electric field and the tensile force indicating attraction force. , FIG. 26 is a diagram showing the relationship between the applied voltage of the alternating electric field and the tensile force, and FIG. 27 is an explanatory diagram of another example of the conveyance means transmission device.
FIG. 28 is an operation diagram showing the operating states of the conveying means transmission according to FIG. 27 by A, B, and C, and FIG. 29 is an example in which the relative positions of the conveying means and the storage means are different. FIG. 30 is an explanatory diagram of another example of the conveying means transmission device, and FIG. 31 is a leap corresponding to FIG. 30 of an example in which the speed change step is modified from that of FIG. 30. 52...Accommodating means 53...Endless conveying means 55...Followed roller 58...Pink up roller (contact means) 63...
Additional moving device 76...charging means 77...recording paper 95...
- Carrying plate (contact means) 97...Pushing device (contact means) 201...Accommodating means 202...Accommodating means 204...Accommodating means 216...Additional moving means 217...Charging means 203. ...Accommodating means 218... Endless conveying means 3 Fig. 4 Fig. 5 Fig. 13 Fig. 14 Fig. 20 Fig. 20 L14 Fig. 24 Fig. 25 and '-/+ [mm] Fig. 26 1P Calo 1! Manhi [Vp-pko 31st section 4.7mm (& @ Mizube) 9.7mm 4.7mm (-2 Inazumai Ga) (Mr. Ebk)

Claims (4)

[Claims] (1) A storage means for storing a recording medium on which an image is recorded;
In the feeding device of the image forming apparatus, the feeding device includes an endless conveyance means for feeding the recording medium from the storage means to a predetermined position, wherein the endless conveyance means is provided with a suction means for sucking the recording medium, and the endless conveyance means is provided with a suction means for sucking the recording medium, and the endless conveyance means A feeding device for an image forming apparatus, characterized in that a plurality of contact means are provided for bringing the shaped conveying means into contact with the recording medium, and each contact means can be switched between contact release and contact as appropriate. (2) A suction area of the endless conveying means with respect to the recording medium can be changed by changing the contacting means that operates in contact among the plurality of contacting means depending on the size of the recording medium. A feeding device for an image forming apparatus. (3) At least a part of the plurality of contact means is formed to be movable back and forth in the feeding direction of the recording medium, and a moving position is selected according to the size of the recording medium, and the endless conveyance means performs the recording. 2. The feeding device for an image forming apparatus according to claim 1, wherein a suction area for the medium is switched. (4) The contact position of the endless conveying means with the image recording medium is from the leading edge of the image recording medium of the accommodating means to a position halfway along the length of the recording medium. 3. The apparatus of the forming apparatus according to any one of 3.