JPH0512189Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a sheet conveyance device such as an automatic document feeder that automatically supplies a document to a platen of an image processing device such as a copying machine or an image reader.

[Technical background of the invention]

Conventionally, an automatic document feeder attached to an image processing device, such as a copying machine, feeds documents stacked on a document tray one by one using a feeding device.
The document is sent onto the platen using the conveyor belt, and when it is set at the reference position and the copying is completed, the document is again ejected from the platen using the conveyor belt, and then stored in the paper ejection tray via the ejection roller. There is.

In such an automatic document feeder, a driving means is connected to the rotating shaft of one of a pair of rollers that support both ends of the conveyor belt, and the rotating shaft of the other roller is connected to the rotating shaft of the ejection roller. Connected to the shaft,
Some printers obtain the driving force for the paper ejection roller from a driving means for the conveyor belt.

This automatic document feeder fixes the roller on the driving means side of the conveyor belt with respect to the document conveyance direction.
The roller on the paper ejection roller side is made movable and tensioned by a spring to prevent the conveyor belt from sagging.

For this reason, when the conveyor belt's drive means operates, the roller on the paper ejection roller side that supports the conveyor belt is pulled toward the drive means, and when the conveyor belt stops, the roller on the paper ejection roller side returns to its original position due to the spring. do. That is, the distance between the rotation axis of the roller on the paper ejection roller side and the rotation axis of the paper ejection roller always changes. Therefore, the driving connection between the rotating shaft of the roller on the paper ejecting roller side and the rotating shaft of the paper ejecting roller uses pulleys attached to both rotating shafts and an elastic belt stretched between the two pulleys. ing.

[Problems with background technology]

However, when an elastic belt is attached, if the belt is stretched, the tension of the belt increases, and the radial load becomes very large.

Furthermore, if the belt is installed in a compressed state, the force that can be transmitted due to the friction between the belt and the pulley will be reduced, making it more likely that the belt will slip.

Therefore, it was extremely difficult to select a belt based on the actual load and amount of shaft movement.

[Purpose of invention]

The object of this invention is to provide a sheet conveying device that does not affect drive transmission to a conveying rotating body such as a paper ejection roller even if a rotating shaft driven by rotation of a conveying belt moves back and forth in the sheet conveying direction.

[Summary of the idea]

In order to achieve the above object, this invention has a conveyor belt stretched around it, is elastically supported in a direction opposite to the tension of the conveyor belt, and is movable in the direction of the tension of the conveyor belt in response to the tension. a conveying rotary body which is fixedly supported in a predetermined position and is pivotally supported, receives rotational power from the belt rotary body, receives and sends sheets conveyed by the conveyor belt, In order to make the distance between the axis of rotation of the belt rotation body and the rotation axis of the conveyance rotation body expandable, the rotation axis of the belt rotation body is provided between the rotation axis of the belt rotation body and the rotation axis of the conveyance rotation body. At least one intermediate rotation shaft that transmits rotational power from the rotation axis of the body is disposed, and each of the rotation shafts adjacent to each other including the intermediate rotation shaft and each rotation shaft of the belt rotation body and the conveyance rotation body, The intermediate rotating shaft is rotatably supported by a plurality of shaft spacing retaining members so as to be movable in accordance with the movement of the belt rotating body due to the tension, and the intermediate rotating shaft is connected by the shaft spacing retaining members. The rotational force transmitting means for sequentially transmitting rotational power is disposed on each of the rotating shafts.

[Example of idea]

An embodiment of this invention will be described below with reference to the drawings.

<Structure> As shown in FIG. 1, a sheet conveying device, such as an automatic document feeder 5, is placed on a platen 3 of an image forming apparatus, such as a copying machine 1.

The automatic document feeder 5 includes, for example, a document tray 7 that constitutes a part of a document storage section, a separation and feeding section 9 that separates the document set on the document tray 7 into one sheet, and sends out the document. A conveying unit 1 that conveys the original sent from the feeding unit 9 over the platen 3
1, a reversing discharge section 13 that reverses and discharges the copied original document, and a storage tray 15 that stores the document discharged from the reverse discharge section 13, and can automatically feed and discharge the original document. It's becoming like that.

Further, the conveying section 11 and the reversing ejecting section 13 are integrated with the cover C and are attached to the back of the copying machine 1 via a hinge so that they can be opened and closed. By opening it, a document can also be set on the platen 3 by manual operation.

As shown in FIG. 2, the separation feeding section 9 includes a sensor S1 that detects whether or not a document is set in the paper feed port 17, and a feed roller 19 that feeds out the document set in the paper feed port 17. , a holding guide 21 that presses the document inserted into the paper feed port 17 against the feed roller 19 , and a paper feed path 22 formed by the paper feed guides 18 and 20 . a feeding means 23 for conveying the original sent out by the feeding means 19; a separation means 25 provided opposite to the feeding means 23 for rejecting the original following the upper surface of the original conveyed by the feeding means 23; It includes a sensor S2 that detects the leading edge of the document separated and sent out by the feeding means 23 and the separating means 25, and a registration roller 27 and a pressure roller 29 that register the leading edge of the document.

The feeding roller 19 has a synthetic resin portion 33 attached to a rotating shaft 31 as shown in FIGS. 3A, B, and C.
and a rubber ring 35, and is driven by a motor M1. The synthetic resin portion 33 has flanges 37 on the left and right sides, and an arcuate portion 39 and a cutout portion 41 are formed between the flanges 37 . A rubber ring 35 is attached to the circumferential surface of the arcuate portion 39 and the cutout portion 41, and an arcuate conveying portion 42 is provided which contacts the original and sends out the original, and an arcuate conveying portion 42 is provided which is connected to the conveying portion 42 and is connected to the original without contacting the original. A cutout portion 44 is formed. Note that the surface of the flange 37 in contact with the original has a smaller coefficient of friction than the peripheral surface of the conveying section 42.

The presser guide 21 has a first arm 45 that rotates around a shaft 43 as shown in FIG. an arm 49, the tip of the first arm 21 presses the document against the feeding roller 19,
The tip of the second arm 49 holds down the tip of the document. Note that the holding guide 21 is connected to a shaft 43 and a motor M1 by a cam so as to move up and down each time an elliptical pulley 53 (described later) makes one rotation.

The feeding means 23 includes an elliptical pulley 53 attached to a rotating shaft 51 driven by a motor M1, a pulley 57 attached to a rotating shaft 55, and a pulley 56.
A feed belt (two-stage belt) 59 is provided between the rollers 3 and 57, and these are provided in three rows as shown in FIG. 4B.

The feeding belt 59 is made by stacking two different belts 59A and 59B in two stages as shown in FIG. For the inner belt 59A, use a material with a hardness of 45 or 60, which provides good tension and has little deflection.
A urethane rubber belt or a chloroprene rubber belt is used as the outer belt 59B, and a urethane rubber belt or a chloroprene rubber belt having a high coefficient of friction, for example, a hardness of 25, is used for the outer belt 59B.

As shown in FIG. 1, a backup means 61 is provided inside the feeding belt 59 to prevent the belt from sagging.

The separating means 25 is connected to a motor M1 as shown in FIG. 4A.
A pulley 65 attached to a rotating shaft 63 driven by a pulley 69 attached to a rotating shaft 67
and a separation belt 71 stretched between pulleys 65 and 69, and these are provided in two rows as shown in FIG. 4B.

In addition, as shown in FIG. 4B, the paper feed guide 20 has
Oval rollers 53 are placed on both sides of the three oval rollers 53.
is in the position shown in Figure 4A, 2
A rib 24 is provided that is slightly higher than the rubber surface of the step belt 59.

Incidentally, the speed ratio between the feeding belt 59 and the separation belt 71 is set to, for example, 10:6, and the feeding belt 59 rotates faster than the separation belt 71.

As shown in FIG. 1, the conveyance section 11 includes a conveyor belt 85 stretched between rollers 81 and 83 which are belt rotating bodies, pressure rollers 87, 89, 91, 93 that press the conveyor belt 85 against the platen 3,
A motor M3 connected to the rotating shaft of the roller 81 and rotationally driving the conveyor belt 85 is provided.

As shown in FIG. 11, the rotating shaft 105 of the roller 83 is supported by frames 107 and 109 at both ends.

A guide 11 is attached between the frames 107 and 109. As shown in FIG. 10, this guide 111 maintains a predetermined distance from the conveyor belt 85, making it difficult for sheets to enter through this gap.
Note that the guide 111 may be a metal plate or a plate-like member with a sheet of synthetic resin or the like attached thereto.

Furthermore, the frames 107 and 109 and the reversing discharge section 13
Springs 113 and 115 are tensioned between the fixed portion and the conveyor belt 85 to pull the conveyor belt 85 toward the reversing and discharging portion 13 side.

A gear 117 constituting rotational force transmission means is fixed to one end of the rotating shaft 105, as shown in FIG. Note that one end of a shaft spacing member, such as an arm 119, is rotatably attached to the rotating shaft 105. An intermediate rotating shaft 121 is provided at the other end of the arm 119, and a gear 123 constituting a rotational force transmitting means is provided in mesh with the gear 117.

The reversal discharge section 13 has a reversal path 9 formed by guides 125 and 127 as shown in FIG.
5. Conveyance rotating body, e.g. paper ejection rollers 97, 99, 1
01, 103, and a paper discharge sensor S3 are provided.

Note that one end of the guide 125 is located below the top surface of the platen 3. Further, one end of the guide 127 is provided to overlap the guide 111.

As shown in FIG. 9, a gear 131 constituting a rotational force transmitting means is fixed to the rotating shaft 129 of the paper discharge roller 99 in a state in which it meshes with the gear 123. As shown in FIG. still,
One end of a shaft spacing member, such as an arm 133, is rotatably attached to the rotary shaft 129, and the other end is rotatably attached to the rotary shaft 121.

Although not shown, the driving force transmitted to the rotating shaft 129 is also transmitted to the paper discharge roller 103 via gears or the like.

Incidentally, the gears 117, 123, and 133 constitute a rotational force transmitting means.

<Operation> With the above configuration, this device operates as follows.

In the initial state, the feeding roller 19 and the oval roller 53 are in the position shown in FIG. Further, the holding guide 21 is raised.

When a document is inserted into the paper feed port 17 with the copy side facing down, the document is detected by the sensor S1, the document rides on the rib 24, and the document is transferred to the two-stage belt 59.
It is set smoothly without hitting the rubber surface. Next, copy conditions are set by operating an operation panel (not shown).

When a print button (not shown) is pressed in this state, the motor M1 rotates. As a result, the shaft 43 of the holding guide 21 rotates clockwise in the drawing, and the holding guide 21 falls onto the document. Therefore, the tip of the first arm 45 presses the document against the feeding roller 19, and the tip of the second arm 49 presses the tip of the document.

In addition, the feed roller 1 is rotated by the operation of the motor M1.
9. The oval roller 53 and the roller 65 rotate. Therefore, the feeding roller 19 rotates in the feeding direction from a state in which the flange 37 is in contact with the bottom paper, and gradually feeds out the document. When the edge of the notch 44 comes into contact with the document, the conveyance force increases, and the document is sent out vigorously by the conveyance section 42.

At this time, as shown in FIG. 4, the amount of overlap between the feeding belt 59 and the separation belt 71 is small, and the pressure acting on the document is also weak, so the document is smoothly held between the feeding belt 59 and the separation belt 71. .

As the rotation of the elliptical roller 53 progresses and becomes as shown in FIG. 5, the overlap between the feed belt 59 and the separation belt 71 increases, the conveyance force of the feed belt 59 increases, and the separation performance of the separation belt 71 also increases. , to reliably separate documents and send only one sheet. That is, the document following the document fed by the feed belt 59 is rejected by the separation belt 71 and separated into one sheet.

When the elliptical roller 53 rotates further and becomes as shown in FIG. 6, the conditions are almost the same as in FIG. 4. The leading edge of the document passes through the separating section, and the rearward portion of the document is fed with substantially constant conveying force and separating force, with little change in the amount of overlap between the belts 59 and 71.

When the elliptical roller 53 rotates further and becomes as shown in FIG. 7, the conditions are almost the same as in FIG. 5. Even if the second and subsequent documents remain between the belts 53 and 71, the separation performance is improved, so
The second and subsequent documents are pushed out between the belts 53 and 71.

By the way, the leading edge of the separated original is detected by sensor S2.
When detected, motor M1 stops after a predetermined time T1. Here, the predetermined time T1 is from the time when the leading edge of the document passes the sensor S2 to the registration roller 27.
The time is set to be sufficient for the document to come into contact with the rolling contact portion of the pressure roller 29 and to bend the document. For this reason,
The leading edge of the bent original is registered.

Then, a predetermined time T2 after sensor S2 is turned on.
After (T2>T1), rotate motor M2 slightly,
The leading edge of the document is held between the registration roller 27 and the pressure roller 29, and the document is kept on standby with no deflection.

When copying preparations of the copying machine 1 are completed in this state, the motors M1 and M2 rotate, and the registration roller 27, feeding roller 19, and feeding belt 59 send out the original. This sent out document is sent onto the platen 3. When the trailing edge of the document is detected by the sensor S2, the motor M2 stops, and the next document is fed out in the same manner as described above by the continued rotation of the motor M1, and the registration roller 27 and the pressure roller 29 with the leading edge of the document in its mouth.

On the other hand, the motor M3 is rotated forward at the same time as the motor M2 is rotated, and the document is conveyed by the conveyor belt 85 over the platen 3 in the direction of the reversing discharge section 13.
Once the motor M3 is reversed, the document is switched back and set at the reference position. Then, a copying operation is performed.

When copying is completed, the conveyor belt 85 is rotated in the normal direction again to send the document from above the platen 3 to the reversing path 95, where it is turned over and discharged. At this time, when the trailing edge of the document is detected by the sensor S3, the first document is fed onto the platen 3. The document discharged from the reversing path 65 is stored in the storage tray 15.

By the way, since the roller 83 is tensioned by the springs 113 and 115 as shown in FIG. 11, the conveyor belt 85 is in a state without slack.

However, when the conveyor belt 85 rotates to the right in the drawing, the upper side of the conveyor belt 85 becomes the tension side and the lower side becomes the slack side, and when the conveyor belt 85 rotates to the left,
The upper side of 5 is the loose side and the lower side is the tension side.
A force acts on the roller 83 in the direction toward the motor M3.

Therefore, the rotating shaft 105 moves toward the motor M3 side together with the guide 111, and the arms 119, 13
3 opens around the shaft 121, and the rotation shafts 105, 12
9's straight line distance increases, but arms 119, 133
gears 117 and 123, gears 123 and 131
relationship remains constant.

Therefore, due to the rotation of the roller 83, the gear 11
The paper ejection roller 99 and the paper ejection roller 103 are rotated via the paper ejection rollers 7, 123, and 131.

<Effects of Example> According to this example described above, the following effects can be obtained.

A conveyor belt 85 is stretched between a pair of rollers 81 and 83, one roller 81 is driven by a motor M3, and the other roller 83 is elastically supported by springs 113 and 115 in the direction in which the conveyor belt 85 is stretched. The rotating shaft 105 of the roller 83 and the paper ejection roller 9
The rotating shafts 129 of the arms 119, 133 are connected rotatably around the rotating shafts 105, 121, 129 through the arms 119, 133, and the rotating shafts 105, 121 and the rotating shafts 121,
129 are connected by gears 117, 123, and 131, the roller 8 that follows the rotation of the conveyor belt 85
Even if the arm 3 moves back and forth in the document transport direction, the arm 11
Although the coupling angle of 9 and 131 changes, the arm 11
9, 131, the distances between the rotating shafts 105 and 121 and between the rotating shafts 121 and 129 do not change.

Therefore, even if the meshing state of the gears 117, 123, and 131 does not change, and the rotation shaft 105 driven by the rotation of the conveyance belt 85 moves back and forth in the document conveyance direction, drive can be transmitted to the paper ejection roller 99.

Further, a frame 113 supporting the rotating shaft 105,
Since the guide 111 is fixed to the guide 115 and the distance between the guide 111 and the conveyor belt 85 is constant, the distance between the guide 127 and the conveyor belt 85 changes as the rotating shaft 105 moves back and forth in the document conveyance direction. Even in this case, the distance between the guide 111 and the conveyor belt 85 remains unchanged, and the document can be prevented from entering the interior from between the guide 127 and the conveyor belt 85.

[Modified example]

Although one embodiment of this invention has been described above, this invention is not limited to the above embodiment, and, for example, the following modifications are possible.

(1) In the embodiment, three gears 117, 123,
131 and the two arms 119 and 133 transmit the driving force of the rotating shaft 105 to the rotating shaft 129, but the number of arms 119 and 133 may be greater than this. That is,
For example, four gears and three arms may be used.

(2) Although gears were shown as the drive transmission means in the above embodiments, pulleys, timing belts, etc. may also be used.

[Effect of idea]

According to the sheet conveyance device of this invention, a conveyor belt is stretched, the belt is elastically supported in a direction opposite to the tension of the conveyor belt, and is pivotally supported to be movable in the direction of tension of the conveyor belt in accordance with the tension. It consists of a rotating body, and a conveying rotary body that is fixed and supported in a predetermined position, receives rotational power from the belt rotary body, and sends sheets fed by the conveyor belt. In order to make the distance between the rotational shaft and the rotational axis expandable, at least one intermediate member is provided between the rotational axis of the belt rotational body and the rotational axis of the conveyance rotational body to transmit the rotational power from the rotational axis of the belt rotational body. A rotating shaft is provided, and each of the mutually adjacent rotating shafts, including the intermediate rotating shaft and the rotating shafts of the belt rotating body and the conveying rotating body, is rotatably supported by a plurality of shaft spacing members. and a rotational force transmitting means that makes the intermediate rotating shaft movable in accordance with the movement of the belt rotating body due to the tension, and sequentially transmits rotational power to each of the rotating shafts connected by a shaft spacing holding member. Because of this arrangement, even if the elastically supported belt rotating body moves back and forth in the tension direction of the conveyor belt and the distance between the axis and the conveying rotor changes,
There is no problem in transmitting the rotational force to the transport rotating body, and reliable power transmission is achieved.

[Brief explanation of the drawing]

1 to 11 are views showing one embodiment of this invention, in which FIG. 1 is a cross-sectional view showing the overall structure of an automatic document feeder, FIG. 2 is a cross-sectional view showing the structure of a separation and feeding section, FIGS. 3A, B, and C are cross-sectional views showing the structure of the feeding roller, and FIGS. 4A, B to 7A, B are cross-sectional views illustrating the structure and operation of the holding guide, feeding means, and separation means. Figure 8 is a sectional view of the feeding belt, Figure 9 is a sectional view of the feeding belt.
Figure 1 shows the drive transmission mechanism to the reversing and ejecting section.
FIG. 0 is a sectional view of a part of the conveying section and the reversing and discharging section, and FIG. 11 is a diagram showing the tension mechanism of the conveying belt. 5... Automatic document feeder, 9... Separation feeding unit,
11... Conveying section, 13... Reversing discharge section, 19...
Feeding roller, 21... Holding guide, 23... Feeding means, 25... Separation means, 37... Flange,
42... Conveyance section, 44... Notch section, 53... Oval pulley, 59... Feeding belt, 71... Separation belt, 81, 83... Roller, 85... Conveyance belt, 99... Paper discharge Roller, 105... Rotating shaft, 1
07,109...Frame, 111...Guide,
113, 115... Spring, 117, 123, 13
1... Gear, 119, 133... Arm, 12
1,129...Rotation axis.

Claims (1)

[Claims for Utility Model Registration] (1) A conveyor belt is stretched around it, elastically supported in a direction opposite to the tension of the conveyor belt, and movable in the direction of the tension of the conveyor belt in response to the tension. a conveying rotary body which is fixedly supported in a predetermined position and is pivotally supported, receives rotational power from the belt rotary body, receives and sends sheets conveyed by the conveyor belt, In order to make the distance between the axis of rotation of the belt rotation body and the rotation axis of the conveyance rotation body expandable, the rotation axis of the belt rotation body is provided between the rotation axis of the belt rotation body and the rotation axis of the conveyance rotation body. At least one intermediate rotation shaft that transmits rotational power from the rotation axis of the body is disposed, and each of the mutually adjacent rotation shafts including this intermediate rotation shaft and each rotation shaft of the belt rotation body and the conveyance rotation body, The intermediate rotating shaft is rotatably supported by a plurality of shaft spacing retaining members, thereby making the intermediate rotating shaft movable in accordance with the movement of the belt rotating body due to the tension, and connected by the shaft spacing retaining members. A sheet conveying device characterized in that a rotational force transmitting means for sequentially transmitting rotational power is disposed on each of the rotational shafts. (2) Utility model registration In the sheet conveying device according to claim 1, the rotational force transmitting means is fixed to each rotating shaft of the belt rotating body and the conveying rotating body, and each intermediate rotating shaft, and A sheet conveying device characterized by gears that mesh with each other. (3) In the sheet conveying device according to claim 1, the rotational force transmitting means includes a pulley fixed to each rotation shaft of the belt rotation body and the conveyance rotation body, and each intermediate rotation shaft. , a sheet conveying device characterized in that it is a timing belt drivingly connecting each of these pulleys.