JP2022077929A - Sheet conveying device and image reading device - Google Patents

Abstract

To provide a sheet conveying device capable of reducing conveying failure without increasing cost, and to provide an image reader equipped with the same.SOLUTION: A sheet conveying device of the invention comprises: a loading unit, in which sheets are loaded; a conveyance rotor, which by rotating in a first rotation direction, conveys the sheet in a sheet conveyance direction; a separation rotor, which forms a separation nip together with the conveyance rotor and can separate the sheets one by one in the separation nip; a drive motor; and a transmission mechanism, wherein the transmission mechanism transmits a drive force from the drive motor to the conveyance rotor so that the conveyance rotor rotates in the first rotation direction in a separated conveying mode, and transmits a drive force from the drive motor to the separation rotor so that the separation rotor rotates in a second rotation direction in a non-separated conveying mode.SELECTED DRAWING: Figure 8

Description

The present invention relates to a sheet transport device for transporting sheets and an image reading device including the same.

Generally, an image forming apparatus such as a printer capable of transporting a folded sheet (hereinafter referred to as a folded sheet) along the direction of the fold is known. Conventionally, an image forming apparatus that feeds a folded sheet in a state where a part including a part of the crease is pressed by a pressing member so that the sheet on the upper surface side and the sheet on the lower surface side do not overlap with each other is used. It has been proposed (see Patent Document 1).

Further, conventionally, an inserter has been proposed in which sheets fed by a pickup roller are separated one by one by a pair of separation rollers (see Patent Document 2). The pickup roller is driven by a pickup motor. The separation roller pair is composed of a separation transfer roller driven by a progressive motor and a friction roller driven by a separation motor or a folding sheet motor. When transporting an unfolded sheet, the friction roller is driven by a separation motor so as to transport the sheet in the direction opposite to the sheet transport direction. Further, when transporting the folded sheet, the friction roller is driven by a folding sheet motor so as to transport the folded sheet in the sheet transporting direction.

Japanese Unexamined Patent Publication No. 2014-15305 Japanese Unexamined Patent Publication No. 2007-302376

However, in the image forming apparatus described in Patent Document 1, when the fold of the double-folded sheet is pressed by the pressing member, the transport load is biased to the side where the crease is present, and the image forming apparatus is skewed or the upper surface side of the double-folded sheet and the lower surface side. Transport defects such as misalignment with the sheet will occur. Further, the inserter described in Patent Document 2 requires four motors, a pickup motor, a progressive motor, a separation motor, and a folding sheet motor, in order to drive the pickup roller, the separation transfer roller, and the friction roller. Therefore, the cost has increased.

Therefore, an object of the present invention is to provide a sheet transfer device capable of reducing transfer defects without increasing the cost and an image reading device provided with the sheet transfer device.

The present invention comprises a loading section on which a sheet is loaded, a transport rotating body that transports a sheet taken in from the loading section in the sheet transport direction by rotating in the first rotation direction, and the transport rotating body in the sheet transport device. A separated rotating body that forms a separated nip together with the rotating body and can separate the sheets one by one at the separated nip when the transport rotating body is driven in the first rotation direction, one drive motor, and the like. The transmission mechanism is provided with a transmission mechanism capable of transmitting the driving force from the drive motor to the transfer rotating body and the separation rotating body, and the transmission mechanism separates and conveys the sheets one by one by the separation nip. In the mode, a non-separable transfer mode in which the driving force from the drive motor is transmitted to the transfer rotating body so that the transfer rotating body rotates in the first rotation direction, and the sheet is conveyed without being separated by the separation nip. The separated rotating body is characterized in that the driving force from the driving motor is transmitted to the separated rotating body so as to rotate in the second rotation direction in which the sheet is conveyed in the sheet conveying direction.

According to the present invention, transport defects can be reduced without increasing the cost.

The whole schematic which shows the image reader which concerns on this embodiment. The whole schematic which shows the image reader. (A) is a cross-sectional view showing a reading unit located at a document reading position, and (b) is a cross-sectional view showing a reading unit located at a shading position. The perspective view which shows the image reader. (A) is a perspective view showing a transmission mechanism of a separate transfer mode, (b) is a perspective view showing a transmission mechanism of a non-separable transfer mode, and (c) is a perspective view for explaining drive transmission of a pickup roller. (A) is a plan view showing a transmission mechanism of a separate transfer mode, and (b) is a plan view showing a transmission mechanism of a non-separate transfer mode. (A) is a side view showing a transmission mechanism of a separate transfer mode, and (b) is a side view showing a transmission mechanism of a non-separable transfer mode. (A) is a diagram showing the rotation direction of each roller when the transmission mechanism is in the separate transfer mode, (b) is a diagram showing the rotation direction of each roller when the transmission mechanism 400 is in the non-separable transfer mode, (c) is a diagram. The figure which shows the rotation direction of each roller when the transmission mechanism 400 is in a non-separable transfer mode which concerns on another embodiment.

〔overall structure〕
FIG. 1 is an overall schematic view showing an image reading device 200, and FIG. 2 is a schematic diagram for explaining a drive transmission path of each roller of the image reading device 200. As shown in FIGS. 1 and 2, the image reading device 200 controls a sheet transporting device 101 that transports a sheet as a document and reading units 14 and 15 that read an image of the sheet conveyed by the sheet transporting device 101. It has a device 45 and. The image reading device 200 is applied to, for example, an automatic feeding mechanism (Auto Document Feeder: ADF) mounted on an image reading device such as an image scanner, a copying machine, a facsimile, or a character recognition device, or an image forming device such as a printer. Will be done. Further, the sheet in the present embodiment includes various sheets such as thin paper, thick paper, coated paper, uncoated paper, two-fold sheet, three-fold sheet, and a printed original.

The sheet transport device 101 includes a seat loading platform 1 as a loading unit, a pickup roller 4 as a feeding and rotating body, and a separation roller pair 42. The sheet loading platform 1 has a sheet loading surface 1a on which the sheet is loaded, and a regulating plate 1b that regulates the positions of both ends of the sheet loaded on the sheet loading surface 1a in the width direction. The width direction of the sheet is a direction orthogonal to the sheet transport direction D1.

The seat loading platform 1 is configured to be able to move up and down by the loading platform drive motor 2. When the sheet transport device 101 starts transporting the sheets, the seat loading platform 1 rises, and the highest-level sheet loaded on the sheet loading platform 1 is detected by the sheet detection sensor 3. When the uppermost seat is detected by the seat detection sensor 3, the seat loading platform 1 stops ascending. Further, whether or not the seat is loaded on the seat loading table 1 is detected by the seat loading detection sensor 12.

The highest-level sheet loaded on the sheet loading platform 1 is fed into the device of the image reading device 200 by the pickup roller 4. Then, the sheet is guided to the separation roller pair 42 by the upper guide plate 40 and the lower guide plate 41 constituting the transport path. The separation roller pair 42 is composed of a feeding roller 6 and a separating roller 7 forming a separation nip N together with the feeding roller 6, and the sheets can be separated one by one. The feeding roller 6 and the separating roller 7 are driven by the drive motor 10.

The feed roller 6 as a transport rotating body is rotated in the first rotation direction R1 by the drive motor 10 so as to transport the sheet taken in from the seat loading platform 1 in the seat transport direction D1. The separation roller 7 as a separation rotating body has a drive motor 10 via a torque limiter 9 in a direction opposite to the sheet transport direction D1, that is, a third rotation direction R3 so as to return the sheet to the sheet loading platform 1. It is receiving rotational force.

When there is no sheet or only one sheet in the separation nip N, the separation roller 7 receives a load from the feeding roller 6 that is equal to or greater than the limit value of the torque limiter 9, and the torque limiter 9 spins. As a result, the separation roller 7 is driven to rotate according to the feeding roller 6. Further, when a plurality of sheets are present in the separation nip N, the frictional force acting between the plurality of sheets is lower than the limit value of the torque limiter 9, so that the separation roller 7 rotates in the third rotation direction R3 and separates. The plurality of sheets that have entered the nip N are separated into one sheet at a time.

In the present embodiment, the separation roller pair 42 is composed of a roller pair, but one or both rollers of the roller pair may be replaced with another rotating body such as a belt.

Further, in the present embodiment, in order to further improve the sheet separation performance, a separation pad 37 is provided upstream of the sheet transfer direction D1 of the separation roller 7. By making the separation pad 37 abut on the sheet before the sheet is separated by the separation nip N, the separability of the sheet is improved and the sheet can be more reliably prevented from being double-fed and conveyed. can.

A double feed detection sensor 32 for detecting whether or not the sheet is double feed is arranged downstream of the separation nip N in the sheet transport direction D1. The double feed detection sensor 32 has, for example, an ultrasonic transmission unit and a reception unit, and can detect double transmission by the amount of ultrasonic wave attenuation between the transmission unit and the reception unit arranged across the transport path. can. For example, when the sheets are double-fed, the amount of ultrasonic wave attenuation is larger than when the sheets are separated one by one.

The pre-resist sensor 30 is arranged upstream of the double feed detection sensor 32 and downstream of the separation roller pair 42 in the sheet transport direction D1. The resist in-resist sensor 33 is arranged downstream of the transfer rollers 17 and 18 and upstream of the transfer rollers 20 and 21 in the sheet transfer direction D1. A post-resist sensor 34 is arranged downstream of the transfer rollers 20 and 21 in the sheet transfer direction D1. The pre-resist sensor 30, the in-resist sensor 33, and the post-resist sensor 34 are composed of a photo sensor, a flag sensor, and the like, and can detect the position of the sheet to be conveyed.

The drive force of the transfer rollers 17 and 18 is transmitted from the drive motor 10 via a clutch 19 such as an electromagnetic clutch, and the drive force is also transmitted from the drive motor 10 to the transfer rollers 20 and 21. The clutch 19 is engaged and disconnected based on the sheet detection timing of the pre-resist sensor 30, and the sheet transfer timing is adjusted by the transfer rollers 17 and 18.

When the tip of the sheet to be conveyed is detected by the post-resist sensor 34, the control device 45 issues an image reading instruction to the reading units 14 and 15, and the reading units 14 and 15 read the image of the sheet. Then, the sheet is conveyed in a U-shaped transfer path by the transfer rollers 22 and 23 driven by the drive motor 10 and the transfer rollers 24 and 25, and is discharged to the discharge tray 44.

The control device 45 has a CPU, a ROM, and a RAM, and controls the entire image reading device 200. The CPU controls each part while reading a program corresponding to the control procedure stored in the ROM. Further, work data and input data are stored in the RAM, and the CPU controls by referring to the data stored in the RAM based on the above program or the like. The image of the sheet read by the reading units 14 and 15 is transmitted to an external device such as an information processing device via an interface unit (not shown). The control device 45 controls the loading platform drive motor 2 and the drive motor 10. The drive motor 10 can change the drive speed according to the setting such as the optimum speed for reading the sheet and the resolution of the sheet. By changing the drive speed of the drive motor 10, the sheet transfer speed of each roller can be changed. Be changed.

The housing of the image reader 200 is composed of an upper unit 200a and a lower unit 200b, and the upper unit 200a opens and closes with respect to the lower unit 200b centering on a hinge provided near the seat ejection port. It is supported as much as possible. The transport path through which the sheet passes is formed between the upper unit 200a and the lower unit 200b, and the transport path is opened by opening the upper unit 200a.

[Reading unit]
Next, the configurations of the reading units 14 and 15 as the reading unit will be described. As shown in FIG. 1, the reading units 14 and 15 are arranged so as to sandwich a transport path through which the sheet is conveyed. As shown in FIG. 2, a platen roller 14a as a pressing member is arranged on the opposite side of the reading unit 14 across the transport path, and as a pressing member on the opposite side of the reading unit 15 across the transport path. A platen roller 15a is arranged. The reading units 14 and 15 read images on both sides or one side of the sheet while urging the sheet from the transport path side with respect to the contact glass 54 (see FIG. 3).

The reading units 14 and 15 may be arranged so that different surfaces of the sheets transported along the transport path can be read. That is, the reading units 14 and 15 are provided on one of the upper unit 200a and the lower unit 200b of the image reading device 200, respectively. The platen rollers 14a and 15a corresponding to the respective reading units are provided on the other side of the upper unit 200a and the lower unit 200b.

In the following description, the reading unit 15 basically has the same structure as the reading unit 14. Therefore, the reading unit 15 will be described only in terms of differences from the reading unit 14, and duplicated description will be omitted.

FIG. 3 is a cross-sectional view of the reading unit 14 in a plane perpendicular to the longitudinal direction. FIG. 3A shows a state when the document is read (the document reading position), and FIG. 3B shows a state when the color reference member is read (shading position).

The reading unit 14 has a line image sensor 50 capable of reading an image of a sheet (original) conveyed by the transfer rollers 20 and 21, and a sensor box 51 movably accommodating the line image sensor 50. .. Further, the reading unit 14 includes a glass holding unit including a contact glass 54, a glass holding member 55, a color reference member 56, and a protective member 57, and a moving mechanism 58 that movably supports the line image sensor 50.

The line image sensor 50 is movable within the sensor box 51, and is therefore movable relative to the sensor box 51 and is connected to the control device 45 by a cable 53. The input / output signals of the line image sensor 50 are transmitted to and received from the control device 45 via the cable 53.

The image reading device 200 having such reading units 14, 15 transports the sheet (original) by the transport rollers 20, 21 and the like, and reads the image. Specifically, the conveyed sheet is irradiated with a light source included in the reading units 14 and 15, and the reflected light from the sheet is collected on the sensor surface of the line image sensor 50 by a rod lens array or the like. After that, the reflected light received by the line image sensor 50 is photoelectrically converted and output to the control device 45, and the control device 45 generates original image data based on the output signal of the line image sensor 50. The photoelectrically converted image data may be subjected to image processing or various conversions before being output to the control device 45.

[Transmission mechanism]
As shown in FIGS. 4 to 7B, the image reader 200 has a transmission mechanism 400 capable of transmitting the driving force from the drive motor 10 to the feed roller 6, the separation roller 7, and the pickup roller 4. There is. The transmission mechanism 400 has a switching means 201 for switching the drive transmission path from the drive motor 10 to the feed roller 6, the separation roller 7, and the pickup roller 4, and the switching means 201 has the first switching means 201 shown in FIG. 5A. It can be moved to one position and the second position shown in FIG. 5 (b).

When the switching means 201 is located at the first position, the transmission mechanism 400 is in the separate transfer mode as shown in FIGS. 5 (a), 6 (a) and 7 (a), and the switching means 201 is second. When it is located at the position, it becomes a non-separable transfer mode as shown in FIGS. 5 (b), 6 (b) and 7 (b). The drive transmission path is switched by selecting either the separate transfer mode or the non-separate transfer mode. In the drive motor 10, the transmission mechanism 400 rotates in one direction in both the separate transfer mode and the non-separate transfer mode, and the rotation direction is the same.

[Separate transport mode]
First, the drive transmission configuration of the transmission mechanism 400 in the separate transfer mode will be described. As shown in FIGS. 5 (a), 6 (a) and 7 (a), the drive motor 10 rotationally drives the motor pulley 301, and the timing belt 302 is attached to the pulley portion 303a of the motor pulley 301 and the gear 303. It is wrapped. The gear 303 driven by the timing belt 302 has a gear portion 303b that rotates integrally with the pulley portion 303a, and the gear portion 303b meshes with the large diameter gear 304a of the gear 304. The gear 304 has a large-diameter gear 304a and a small-diameter gear 304b that rotates integrally with the large-diameter gear 304a.

The large-diameter gear 304a meshes with the small-diameter gear 305a of the gear 305. The gear 305 has a small diameter gear 305a and a large diameter gear 305b that rotates integrally with the small diameter gear 305a. As shown in FIG. 5C, the large-diameter gear 305b meshes with the gear 203a fixed to one end of the feeding shaft 203 in the axial direction. In this way, the driving force of the drive motor 10 is transmitted to the feed shaft 203 via the motor pulley 301, the timing belt 302, and the gears 303, 304, 305, 203a. A feeding roller 6 is fixed to the other end of the feeding shaft 203 in the axial direction, and the rotation of the feeding roller 6 is transmitted to the pickup roller 4 via the gear 205.

Further, as shown in FIGS. 5A, 6A and 7A, the small diameter gear 304b of the gear 304 is meshed with the gear 306, and the gear 306 is meshed with the gear 307. is doing. Although the gears 305 and 306 are arranged coaxially, they are not driven and connected to each other. The gear 307 is fixed to one end in the axial direction of the separation shaft 204, and the separation roller 7 is fixed to the other end in the axial direction of the separation shaft 204. In the present embodiment, the torque limiter 9 (see FIG. 2) is built in the gear 307, but is not limited thereto. For example, the torque limiter 9 may be provided between the separation roller 7 and the separation shaft 204, or may be built in the gear 306. The torque limiter 9 receives a load of a predetermined value (limit value) or more in the second rotation direction R2 (see FIG. 8B) by the feed roller 6 driven by the separation roller 7 in the first rotation direction R1. In addition, the separation roller 7 is allowed to rotate in a driven manner of the feeding roller 6.

In this way, the driving force of the drive motor 10 is transmitted to the separation roller 7 via the motor pulley 301, the timing belt 302, the gears 303, 304, 306, 307, and the separation shaft 204.

As shown in FIG. 8A, when the transmission mechanism 400 is in the separate transfer mode, the pickup roller 4 receives a driving force that rotates in the fourth rotation direction R4 from the drive motor 10, and the feed roller 6 is driven. It receives a driving force that rotates in the first rotation direction R1 from the motor 10. Further, the separation roller 7 receives a driving force that rotates in the third rotation direction R3 from the drive motor 10. The pickup roller 4 rotating in the fourth rotation direction R4 and the feeding roller 6 rotating in the first rotation direction R1 exert a force on the sheet on the transfer path so as to be conveyed in the sheet transfer direction D1. The separation roller 7 rotating in the third rotation direction R3 exerts a force on the sheet on the transfer path so that the sheet is conveyed in the direction opposite to the sheet transfer direction D1.

The separate transport mode of the transmission mechanism 400 is suitable for transporting unfolded sheets (hereinafter referred to as non-folded sheets) while separating them one by one. As described above, the non-folded sheet is fed by the pickup roller 4, separated one by one by the separation nip N, and transported in the sheet transport direction D1.

[Non-separable transport mode]
Next, the drive transmission configuration of the transmission mechanism 400 in the non-separable transfer mode will be described. As shown in FIGS. 5A (b), 6 (a) (b) and 7 (a) (b), the switching means 201 can swing about the rotation shaft 303c of the gear 303. , The gear 304 is rotatably supported. That is, when the switching means 201 moves from the first position to the second position, the gear 304 swings around the rotation shaft 303c. Therefore, the gear 304 meshes with the gear portion 303b of the gear 303 at both the first position and the second position of the switching means 201.

As shown in FIGS. 5 (b), 6 (b) and 7 (b), when the switching means 201 moves from the first position to the second position, the gear 304 swings about the rotation shaft 303c. , The large-diameter gear 304a of the gear 304 is separated from the small-diameter gear 305a of the gear 305. Further, the small diameter gear 304b of the gear 304 is separated from the gear 306 and meshes with the small diameter gear 308a of the gear 308. The gear 308 has a small diameter gear 308a and a large diameter gear 308b that rotates integrally with the small diameter gear 308a, and the large diameter gear 308b meshes with the small diameter gear 309a of the gear 309. The gear 309 has a small diameter gear 309a and a large diameter gear 309b that rotates integrally with the small diameter gear 309a, and the large diameter gear 309b meshes with the gear 307.

By moving the switching means 201 to the second position in this way, the drive connection between the gear 304 and the gear 305 is released, so that the driving force of the drive motor 10 is not transmitted to the feed roller 6. Then, the driving force of the drive motor 10 is transmitted to the separation roller 7 via the motor pulley 301, the timing belt 302, the gears 303, 304, 308, 309, 307 and the separation shaft 204.

Then, as shown in FIG. 8B, when the transmission mechanism 400 is in the non-separable transfer mode, the separation roller 7 moves from the drive motor 10 to the second rotation direction R2 opposite to the third rotation direction R3. Upon receiving the rotating driving force, the feeding roller 6 is driven to rotate via the sheet.

Further, as shown in FIGS. 5A and 5B, the switching means 201 is connected to the holder 8 that rotatably holds the pickup roller 4 by the connecting member 202, and the holder 8 is connected to the feeding shaft 203. It is supported so that it can rotate relative to the relative. When the switching means 201 moves from the first position to the second position, the holder 8 swings around the feed shaft 203, and the pickup roller 4 rotatably supported by the holder 8 is shown in FIG. 8 (b). As such, it is separated from the sheet conveyed by the separation nip N. In this case, the pickup roller 4 does not exert a conveying force on the seat, but the user can convey the seat by manually inserting the folded sheet or the like into the separation nip N. By separating the pickup roller 4 from the seat, the frontage for inserting the seat into the separation nip N can be widened, and the operability can be improved.

In the present embodiment, the switching means 201 is moved between the first position and the second position by driving a solenoid (not shown) by the control device 45, but is not limited thereto. For example, the user may manually move the switching means 201.

As described above, in the present embodiment, when the transmission mechanism 400 is set to the separate transfer mode, as shown in FIG. 8A, the pickup roller 4 rotating in the fourth rotation direction R4 and the first rotation direction The sheet is transported in the sheet transport direction D1 by the feed roller 6 that rotates in R1. Further, since the driving force for rotating in the third rotation direction R3 is input to the separation roller 7, the sheet can be satisfactorily separated by the separation nip N, and transfer defects such as double feeding can be reduced. In particular, the separate transport mode is preferably set when transporting the non-folded sheet.

Further, when the transmission mechanism 400 is set to the non-separable transfer mode, as shown in FIG. 8B, no driving force is input from the drive motor 10 to the feed roller 6, and the separation roller 7 has a second position. A driving force that rotates in the two rotation directions R2 is input. The feeding roller 6 is driven to rotate in the first rotation direction R1 by the separation roller 7 rotating in the second rotation direction R2 via the sheet to which the separation nip N is conveyed. As a result, the sheet is conveyed in the sheet transfer direction D1 by the separation nip N.

In particular, the non-separable transport mode is preferably set when transporting a folded sheet such as a folded sheet. That is, when the feeding roller 6 is driven in the first rotation direction R1 and the separation roller 7 is driven in the third rotation direction R3 as when the transmission mechanism 400 is set to the separation transfer mode, the folded sheet is folded in half. The sheet shifts between the upper surface side and the lower surface side. On the other hand, when the transmission mechanism 400 is set to the non-separable transfer mode, the separation roller 7 is driven in the second rotation direction R2, so that the feed roller 6 is driven to rotate with respect to the separation roller 7, so that the separation roller 7 is folded in half. The sheet can be transported in the sheet transport direction D1 without the upper surface side and the lower surface side being displaced. As a result, transfer defects can be reduced, and images can be read satisfactorily by the reading units 14 and 15.

Further, when the transmission mechanism 400 is in the non-separable transfer mode, the pickup roller 4 is separated from the sheet transferred in the sheet transfer direction D1 by the separation nip N, so that the load on the sheet is reduced and transfer defects can be reduced. .. Further, in the present embodiment, since the pickup roller 4, the feeding roller 6, and the separation roller 7 are driven by one drive motor 10, the number of motors can be suppressed and the cost can be reduced. Therefore, it is possible to provide a sheet transfer device 101 capable of reducing transfer defects while reducing costs and an image reading device 200 provided with the sheet transfer device 101.

It should be noted that the present invention is preferably applied to a sheet transfer device as shown in FIG. 1, in which the uppermost sheet of the sheet loading platform 1 is fed by the pickup roller 4. In such a sheet transporting device, since the separation roller 7 is located at the lower part of the sheet to be transported, the folded sheet can be smoothly transported by the transporting force of the separation roller 7.

<Other embodiments>
In the above-described embodiment, when the switching means 201 is located at the second position and the transmission mechanism 400 is in the non-separable transfer mode, the driving force from the drive motor 10 is not transmitted to the feed roller 6. However, as shown in FIG. 8C, the driving force from the drive motor 10 is transmitted to the feeding roller 6 via the transmission mechanism 400 in the non-separable transfer mode, and the feeding roller 6 moves to the first rotation direction R1. It may be configured to rotate. At this time, it is preferable that the peripheral speed of the feeding roller 6 is set to be the same as the peripheral speed of the separating roller 7. As a result, the deviation between the upper surface side and the lower surface side of the folded sheet can be reduced. Specifically, when the switching means 201 moves to the second position, the gear 304 may mesh with a gear (not shown), and further mesh with the gear 305 via an odd number of gears. At this time, the reduction ratio of the gear between the gear 304 and the gear 305 can be adjusted so that the peripheral speeds of the feed roller 6 and the separation roller 7 are the same.

Further, in the above-described embodiment, the switching means 201 is supported so as to be swingable around the rotation shaft 303c of the gear 303, but the present invention is not limited to this. For example, the switching means 201 may be swingably supported by a rotation shaft of another gear or another component of the lower unit 200b.

Further, in the above-described embodiment, the separation roller 7 is limited to the drive input to the third rotation direction R3 when the transmission mechanism 400 is in the separation / transfer mode (see FIG. 8A). Not done. For example, the separation roller 7 does not have to be driven by the drive motor 10 when the transmission mechanism 400 is in the separation / transfer mode. Even in such a configuration, since the torque limiter 9 is connected to the separation roller 7, the sheets can be separated one by one at the separation nip N by the separation roller 7 in the rotation stopped state.

Further, in the above-described embodiment, the seat loaded on the seat loading platform 1 is fed by the pickup roller 4, but the present invention is not limited to this. For example, instead of the pickup roller 4, the sheet may be fed by a belt or the like, or the pickup roller 4 may be omitted and the sheet loaded on the seat loading platform 1 by the feeding roller 6 may be fed. ..

Further, in the above-described embodiment, in the drive motor 10, the transmission mechanism 400 rotates in one direction, that is, in the same direction in both the separate transfer mode and the non-separate transfer mode, but the drive motor 10 is not limited to this. For example, the driving force of the drive motor 10 that drives in the forward rotation direction is transmitted to the pickup roller 4, the feeding roller 6, and the separation roller 7 via the transmission mechanism 400 in the separation and transfer mode, so that FIG. 8A shows. Each roller is configured to rotate in the indicated rotation direction, and the driving force of the drive motor 10 that drives in the reverse direction is applied to the pickup roller 4, the feeding roller 6, and the separation roller 7 via the transmission mechanism 400 in the non-separable transfer mode. Each roller may be configured to rotate in the rotation direction shown in FIG. 8 (b) or FIG. 8 (c) by being transmitted or cut off.

Further, in the above-described embodiment, the image reading device 200 having the sheet transporting device 101 has been described, but the present invention is not limited thereto. For example, it is possible to adopt the sheet transfer device 101 to which the present invention is applied to other image forming devices such as an electrophotographic printer, an inkjet printer, a facsimile, and a multifunction device. Further, the present invention may be applied to an optional feeder or a large-capacity feeding deck connected to a printer or the like.

1: Loading unit (seat loading platform) / 4 :: Feeding rotating body (pickup roller) / 6: Transporting rotating body (feeding roller) / 7: Separation rotating body (separation roller) / 10: Drive motor / 14, 15: Reading unit (reading unit) / 101: Sheet transporting device / 200: Image reading device / 201: Switching means / 400: Transmission mechanism / D1: Sheet transporting direction / N: Separation nip / R1: First rotation direction / R2 : Second rotation direction

Claims (10)

The loading section where the seats are loaded and
A transport rotating body that transports the sheet taken in from the loading unit in the sheet transport direction by rotating in the first rotation direction, and a transport rotating body.
A separation rotating body that forms a separation nip together with the transfer rotating body and can separate sheets one by one at the separation nip when the transport rotating body is driven in the first rotation direction.
One drive motor and
A transmission mechanism capable of transmitting the driving force from the drive motor to the transport rotating body and the separated rotating body is provided.
The transmission mechanism is
In the separate transport mode in which the sheets are separated and transported one by one by the separation nip, the driving force from the drive motor is transmitted to the transport rotating body so that the transport rotating body rotates in the first rotation direction. ,
In the non-separable transfer mode in which the sheet is conveyed without being separated by the separation nip, the separated rotating body is subjected to the driving motor to the separated rotating body so as to rotate in the second rotation direction in which the sheet is conveyed in the sheet conveying direction. To transmit the driving force of
A sheet transfer device characterized by this. The transmission mechanism has a switching means for switching a drive transmission path from the drive motor to the transport rotating body and the separated rotating body, and when the switching means is located at the first position, the separated transport mode is set. When the switching means is located at a second position different from the first position, the non-separable transfer mode is set.
The sheet transport device according to claim 1. Further provided with a feeding rotating body that feeds the sheet loaded on the loading portion toward the separation nip.
The feed rotating body is separated from the sheet conveyed by the separation nip when the switching means is located at the second position.
The sheet transport device according to claim 2, wherein the sheet transport device is characterized by the above. The transport rotating body is described by the separated rotating body that rotates in the second rotation direction without transmitting the driving force from the drive motor by the transmission mechanism when the transmission mechanism is in the non-separable transport mode. Driven rotation in the first rotation direction,
The sheet transport device according to any one of claims 1 to 3, wherein the sheet transport device is characterized by the above. In the transport rotating body, a driving force is transmitted from the drive motor so that the transmission mechanism rotates in the first rotation direction when the transmission mechanism is in the non-separable transport mode.
The sheet transport device according to any one of claims 1 to 3, wherein the sheet transport device is characterized by the above. When the transmission mechanism is in the non-separable transport mode, the peripheral speed of the transport rotating body rotating in the first rotation direction and the peripheral speed of the separated rotating body rotating in the second rotation direction are the same.
The sheet transporting apparatus according to claim 5. The transmission mechanism receives a load of a predetermined value or more in the second rotation direction by the transfer rotation body driven in the first rotation direction in the separation transfer mode. It has a torque limiter that allows the separated rotating body to rotate in a driven manner.
The sheet transport device according to any one of claims 1 to 6, wherein the sheet transport device is characterized by the above. In the drive motor, the transmission mechanism rotates in one direction in both the separate transfer mode and the non-separate transfer mode.
The sheet transport device according to any one of claims 1 to 7, wherein the sheet transport device is characterized by the above. Sheets include folded sheets,
The sheet transport device according to any one of claims 1 to 8, wherein the sheet transport device is characterized by the above. The sheet transport device according to any one of claims 1 to 9,
A reading unit for reading an image of a sheet conveyed by the sheet conveying device is provided.
An image reader characterized by this.

Images