JP7438710B2 - Sheet feeding device, image reading device, image forming device - Google Patents

Description

The present invention relates to a sheet feeding device suitable for image forming apparatuses such as electrophotographic copying machines and laser beam printers that form images on sheets using an electrophotographic process, and image reading apparatuses such as scanners.

An image reading device that automatically feeds a sheet and reads an image on the sheet is equipped with a sheet feeding device that feeds the sheet toward an image reading section that reads the image. In a sheet feeding device, there is a feeding roller that feeds the sheet, and a nip portion that is in pressure contact with the feeding roller and forms a nip portion with the feeding roller. A configuration is known that includes a separation roller that separates the particles into two.

When a sheet feeding device having this configuration is continuously used, paper dust generated from the sheets adheres to the separation roller, and as the separation roller wears out, it becomes necessary to replace the separation roller. Regarding this, Patent Document 1 discloses that after a cover member that guides the movement of a sheet passing through a separation roller is moved from a position that covers the mounting portion where the separation roller is mounted to a position that exposes it, the separation roller is removed and replaced. The configuration is described.

JP2009-113940A

As described above, in the configuration described in Patent Document 1, when replacing the separation roller, the operator performing the replacement needs to move the cover member. However, in order to improve the replaceability of the separation roller, it is preferable that the number of operations required when replacing the separation roller is as small as possible.

In view of the current situation, an object of the present invention is to provide a sheet feeding device that can improve the replaceability of separation rollers.

A typical configuration of a sheet feeding device according to the present invention for achieving the above object includes a feeding member that feeds a sheet , a nip portion that is in pressure contact with the feeding member, and a nip portion that is formed in contact with the feeding member . a separating member that separates the sheets fed by the feeding member one by one at the section, a holding member that removably holds the separating member, and a first position that covers at least a portion of the separating member; a cover member movable to a second position that exposes the separation member , and the cover member is moved in a direction in which the separation member is removed from the holding member while being located at the first position. At this time, the separation member is moved from the first position to the second position by coming into contact with the separation member .

According to the present invention, it is possible to improve the replaceability of the separation roller in the sheet feeding device.

FIG. 1 is a schematic cross-sectional view of an image reading device. FIG. 1 is a schematic cross-sectional view of an image reading device. FIG. 3 is a perspective view of the periphery of the separation roller. FIG. 3 is a perspective view of the periphery of the separation roller. FIG. 3 is a plan view of the periphery of the separation roller. FIG. 3 is a perspective view of the periphery of the separation roller. FIG. 3 is a plan view of the periphery of the separation roller. FIG. 3 is a perspective view of the periphery of the separation roller. FIG. 3 is a sectional view of the periphery of the separation roller. FIG. 6 is a sectional view of the ADF when replacing the separation roller.

<Image reading device>
DESCRIPTION OF THE PREFERRED EMBODIMENTS First, the overall configuration of an image reading device including a sheet feeding device according to the present invention will be described with reference to the drawings. It should be noted that the dimensions, materials, shapes, relative arrangements, etc. of the component parts described below are not intended to limit the scope of the present invention only thereto, unless otherwise specified.

1 and 2 are schematic cross-sectional views of the image reading device A. Here, FIG. 1 shows a state in which the document tray 6 is located at the standby position and the opening/closing cover 2 is located at the closed position. FIG. 2A shows a state in which the document tray 6 is located at the feeding position. FIG. 2(b) shows a state in which the open/close cover 2 is located in the open position. The detailed positions of the document tray 6 and the opening/closing cover 2 will be described later.

As shown in FIGS. 1 and 2, the image reading device A includes a reader 200 and an ADF 100. The ADF 100 is a device that reads an image of the sheet S while automatically conveying the sheet S. The ADF 100 is rotatably supported by the reader 200 by a hinge (not shown).

The reader 200 includes a first scanner unit 202 that reads an image of a sheet S that is a document, a first glass plate 201 on which the sheet S is placed, and a document table that is arranged in line with the first glass plate 201 in the sub-scanning direction. It has glass 209. The first scanner unit 202 is driven by the driving force of a motor (not shown) to move between a position below the first glass plate 201 and a position below the document table glass 209.

When reading an image with the reader 200, the sheet S is first placed on the document table glass 209. Next, while moving, the first scanner unit 202 scans the image reading surface of the sheet S with light through the document table glass 209, and the image sensor reads the image data of the sheet S by receiving the reflected light. Note that the document table glass 209 can be accessed by rotating the ADF 100 and opening it upward.

The ADF 100 includes a second scanner unit 205 (image reading unit) that reads the image of the sheet S on the downstream side of the conveyance path H along which the sheet S is conveyed, rather than the first scanner unit 202 (image reading unit). The second scanner unit 205 scans the image reading surface of the sheet S with light, receives reflected light with an image sensor, and reads image data of the sheet S. In the ADF 100, the front side of the sheet S is read by a first scanner unit 202, and the back side of the sheet S is read by a second scanner unit 205.

The ADF 100 also includes a document tray 6 (loading section) for stacking sheets S, a pick roller 41 for picking up the sheets S stacked on the document tray 6, and a feeder for feeding the sheets S picked up by the pick roller 41. A roller 42 is provided. Further, conveyance rollers 4 (4a to 4d) for conveying the sheet S fed by the feed roller 42 are provided.

The ADF 100 also includes a separation roller 5 that is in pressure contact with the feeding roller 42 to form a separation nip portion and separates the sheets S fed to the feeding roller 42 one by one at the separation nip portion. A torque limiter (not shown) is attached to the separation roller 5. Therefore, when two sheets S enter the separation nip portion, slippage occurs between the two sheets S, and the torque of the feeding roller 42 escapes, and a torque exceeding a predetermined value is not applied to the separation roller 5. The rotation of the separation roller 5 is regulated by the load of the torque limiter. As a result, the sheet S in contact with the separation roller 5 is separated from the sheet S in contact with the feeding roller 42, and the sheets S are separated one by one.

Further, when one sheet S enters the separation nip, the torque input to the feeding roller 42 is transmitted to the separation roller 5 via the frictional force of the sheet S, and a predetermined torque or more is applied to the separation roller 5. be done. As a result, torque transmission between the separation roller 5 and the torque limiter is cut off, and the separation roller 5 follows the rotation of the feeding roller 42 to rotate in the feeding direction of the sheet S, so that the sheet S is fed. In this embodiment, the separation roller 5 is configured to stop if a torque of a predetermined value or more in the feeding direction of the sheet S is not applied to the separation roller 5. However, if a drive unit is provided that rotates the separation roller 5 in the opposite direction to the feeding direction of the sheet S, and a torque of more than a predetermined value in the feeding direction of the sheet S is not applied to the separation roller 5, the separation roller 5 is rotated in the direction opposite to the feeding direction of the sheet S. It may be configured to rotate in the opposite direction to the feeding direction.

The ADF 100 also includes a separation cover 3 (cover member) that guides the movement of the sheet S passing through the separation roller 5. The detailed structure of the separation cover 3 will be described later. These document tray 6, pick roller 41, feeding roller 42, separation roller 5, and separation cover 3 are part of the sheet feeding device 300 that feeds the sheet S toward the first scanner unit 202 and the second scanner unit 205. Part of it.

The document tray 6 is rotatably supported by a tray support shaft 6a. Further, below the document tray 6, a lifter 63 (moving section) is provided which is pivotally supported by a lifter drive shaft 63a. When the lifter 63 rotates about the lifter drive shaft 63a by the driving force of a motor (not shown), the lifter 63 comes into contact with the document tray 6. Thereafter, when the lifter 63 further rotates, the document tray 6 rotates around the tray support shaft 6a, and the leading end of the document tray 6 rises. As a result, the sheets S stacked on the document tray 6 come into contact with the pick roller 41, and the sheet S can be fed by the pick roller 41. In this way, the document tray 6 has two positions: a standby position (third position) where the sheets S stacked on the document tray 6 and the pick roller 41 are separated from each other, and a standby position (third position) where the sheets S stacked on the document tray 6 are brought into contact with the pick roller 41. and the feeding position (fourth position).

The pick roller 41 is supported by a pick arm 46. The pick arm 46 is rotatably supported around the rotating shaft 45 of the feeding roller 42, and its rotational position is controlled by rotation of a cam (not shown). When the document tray 6 moves from the standby position to the feeding position, a cam (not shown) rotates, and the pick arm 46 rotates in the direction in which the pick roller 41 descends. Further, a rotating shaft 45 that supports the pick arm 46 is supported by the opening/closing cover 2. That is, the opening/closing cover 2 supports the pick roller 41 and the feeding roller 42 via the pick arm 46 and the rotating shaft 45. Further, the pick arm 46 is urged downward by a spring (not shown), so that the pick roller 41 comes into pressure contact with the sheet S on the document tray 6.

The opening/closing cover 2 is rotatably supported on a support shaft 2a of the ADF 100, and rotates between an open position relative to the main body of the ADF 100 and a closed position. The open/close cover 2 opens the transport path H when it is in the open position, and forms the transport path H when it is in the closed position. Further, when the open/close cover 2 is located in the open position, the separation cover 3 and the separation roller 5 are exposed.

When reading an image on a sheet S using the ADF 100, the sheet S loaded on the document tray 6 is first picked up by the pick roller 41, separated into one sheet by the separation roller 5, and then fed to the conveyance path H by the feed roller 42. send The sheet S fed to the transport path H is guided in movement by the upper guide 9 and the lower guide 7, and is transported onto the first glass plate 201 by the transport rollers 4a to 4c.

Next, the first scanner unit 202 irradiates the sheet S with light through the first glass plate 201 and reads the image on the surface of the sheet S. Thereafter, when the user gives an instruction to read the back side of the sheet S, the second scanner unit 205 reads the image on the back side of the sheet S. Thereafter, the sheet S is discharged to the discharge section 99 by the discharge roller 17.

<About replacing the separation roller>
A force in the feeding direction of the sheet S by the feeding roller 42 and a force in the opposite direction to the feeding direction of the sheet S by a torque limiter (not shown) act on the separation roller 5 . Therefore, it is more likely to wear out than the feed roller 42, etc., which acts only on the force in the feeding direction of the sheet S, and it is often necessary to replace it with a new one within a period shorter than the product life of the ADF 100. Therefore, next, a configuration for replacing the separation roller 5 will be explained.

FIG. 3 is a perspective view of the periphery of the separation roller 5. FIG. 4 is a perspective view of the surroundings of the separation roller 5, with a part of the conveyance guide 24 omitted from FIG. 3. 5 is a plan view of FIG. 4 viewed from the rotational axis direction of the separation roller 5. FIG.

As shown in FIGS. 3 to 5, the sheet feeding device 300 includes a separation holder 19 (holding member) that holds the separation roller 5. As shown in FIGS. The separation holder 19 is formed with a mounting groove 19a (mounting portion) into which the rotation shaft 5a of the separation roller 5 is mounted, and the rotation shaft 5a of the separation roller 5 is fitted into the mounting groove 19a and mounted. Then, the separation roller 5 is held by the separation holder 19 (see FIG. 9). Further, the separation holder 19 is biased by a spring 20 tensioned between the spring hook 23b of the frame 23 and the spring hook 19b of the separation holder 19, and this biasing force causes the separation roller 5 to come into pressure contact with the feeding roller 42. (See Figure 9). Further, a handle 18 (grip portion) is attached to one end of the rotation shaft 5a of the separation roller 5. The handle 18 (grip portion) is used to grip the rotation shaft 5a of the separation roller 5 when the rotation shaft 5a is installed in the mounting groove 19a.

The sheet feeding device 300 also includes a support member 22 that is fixed to the frame 23 with screws 95 and rotatably supports the separation holder 19, and a support member 22 that is fixed to the frame 23 and forms a conveyance path for the sheet S. It has a guide 24. A part of the conveyance guide 24 is cut out, and the guide surface 3a of the separation cover 3 is arranged in this cutout part. The guide surface 3a of the separation cover 3 is disposed upstream of the separation roller 5 in the feeding direction of the sheet S and around both ends of the separation roller 5 in the rotation axis direction of the separation roller 5, and passes through the separation roller 5. Guide the movement of the sheet S.

Further, the separation cover 3 is rotatably supported by the frame 23. Specifically, a support shaft portion 23a formed in the frame 23 is inserted into a support hole 3c formed in the separation cover 3. By rotating around the support shaft 23a, the separation cover 3 can be moved between a retracted position (first position) in which the mounting groove 19a of the separation holder 19 to which the rotation shaft 5a of the separation roller 5 is mounted is exposed, and a retracted position (first position) in which the separation holder 19 is exposed. 19 and a cover position (second position) that covers the mounting groove 19a. When the separation cover 3 is located at the cover position and the separation roller 5 is held by the separation holder 19, the separation cover 3 covers at least a portion of the rotation shaft 5a of the separation roller 5 and the handle 18 from above. The separation cover 3 is located at the cover position during normal times such as when reading an image.

Further, a toggle type spring 25 (biasing member), which is a tension spring, is stretched between the separation cover 3 and the conveyance guide 24. The spring 25 is attached to the spring hook 3b of the separation cover 3 and the spring hook 24a of the conveyance guide 24. The spring hook 3b of the separation cover 3 is located below the pivot 23a of the frame 23, which is the center of rotation of the separation cover 3, and the spring hook 24a of the conveyance guide 24 is located above the pivot 23a. , both are located on a plane perpendicular to the rotation axis of the separation cover 3.

When the spring hook 3b is located upstream of the support shaft 23a of the frame 23 with respect to the feeding direction of the sheet S, the biasing force of the spring 25 acts as a force that biases the separation cover 3 toward the cover position. do. Further, when the spring hanging portion 3b is located downstream of the support shaft portion 23a of the frame 23, the biasing force of the spring 25 acts as a force that biases the separation cover 3 toward the retracted position. In this way, when the separation cover 3 is located between the retracted position and the cover position, the spring 25 biases the separation cover 3 toward either the retracted position or the cover position, and causes the separation cover 3 to move toward the retracted position or the cover position. Position it in any position between the retracted position and the cover position.

Next, the operation of replacing the separation roller 5 will be explained. FIG. 6 is a perspective view of the area around the separation roller 5 when the separation cover 3 is located at the retracted position. 7 is a plan view of FIG. 6 viewed from the rotational axis direction of the separation roller 5. FIG. As shown in FIGS. 6 and 7, when replacing the separation roller 5, the operator first moves the opening/closing cover 2 from the closed position to the open position, and then attaches the gripping surface formed on the separation cover 3. 3d and move the separation cover 3 from the cover position to the retracted position. The gripping surface 3d is a portion extending downward from the guide surface 3a of the separation cover 3. This exposes the mounting groove 19a of the separation holder 19, into which the rotation shaft 5a of the separation roller 5 is mounted.

Next, the operator grasps the handle 18 attached to the rotating shaft 5a of the separation roller 5 and lifts it upward. As a result, the rotation shaft 5a of the separation roller 5 is disengaged from the mounting groove 19a of the separation holder 19, and the separation roller 5 is removed from the separation holder 19. Next, the operator attaches a new separation roller 5 to the attachment groove 19a of the separation holder 19, moves the separation cover 3 from the retracted position to the cover position, and then moves the opening/closing cover 2 from the open position to the closed position. . This completes the replacement work of the separation roller 5.

Further, in this embodiment, it is also possible to replace the separation roller 5 by the method described below. As shown in FIG. 8, with the separation cover 3 in the cover position, the operator grasps the handle 18 of the separation roller 5 and moves the separation roller 5 upward, which is the direction to remove it from the mounting groove 19a of the separation holder 19. move it to As a result, the handle 18 of the separation roller 5 comes into contact with the back surface of the guide surface 3a of the separation cover 3. Thereafter, when the operator continues to move the separation roller 5, the separation cover 3 is pushed up by the handle 18, and the separation cover 3 is moved from the cover position to the retracted position. In this way, the separation roller 5 is removed from the separation holder 19. Note that FIG. 9 is a cross-sectional view taken at the contact position between the handle 18 and the separation cover 3 in FIG.

As described above, according to the configuration of this embodiment, the operator who replaces the separation roller 5 can remove the separation roller 5 without moving the separation cover 3 from the cover position to the retracted position. Therefore, the number of operations required by the operator when replacing the separation roller 5 is reduced, so that the ease of replacing the separation roller 5 can be improved.

Although this embodiment describes a configuration in which the handle 18 of the separation roller 5 and the separation cover 3 come into contact with each other and the separation cover 3 is pushed up and moved from the cover position to the retracted position, the present invention is limited to this. It's not a thing. That is, in a configuration where the rotation shaft 5a of the separation roller 5 and the separation cover 3 are in contact with each other, a part of the separation roller 5 and the separation cover 3 are in contact with each other, and the separation cover 3 is pushed up and moved from the cover position to the retracted position. With this configuration, effects similar to those described above can be obtained.

<Separation cover and document tray>
After replacing the separation cover 3, it is assumed that the user forgets to move the separation cover 3 from the retracted position to the cover position. Therefore, in this embodiment, the separation cover 3 located at the retracted position is moved to the cover position in conjunction with the movement of the document tray 6 from the standby position to the feeding position. This operation will be explained below.

FIG. 10 is a cross-sectional view of the ADF 100, and shows the operation in which the separation cover 3 located in the retracted position moves to the cover position in conjunction with the operation in which the document tray 6 moves from the standby position to the feeding position. ) to FIG. 10(c).

First, as shown in FIG. 10(a), when the lifter 63 is rotated by the driving force of a motor (not shown) while the separation cover 3 is in the retracted position, the original tray 6 is moved from the standby position to the feeding position. begins to move, and the leading end of the document tray 6 rises. As a result, the leading end of the document tray 6 comes into contact with the separation cover 3.

Next, as shown in FIG. 10(b), when the tip of the document tray 6 further rises, the separation cover 3 is pressed upward by the document tray 6, and the separation cover 3 is rotated from the retracted position to the cover position. Start moving. Next, as shown in FIG. 10(c), when the tip of the document tray 6 further rises, the separation cover 3 also rotates further and is finally moved to the cover position by the biasing force of the spring 25. Note that a configuration may be adopted in which the document tray 6 presses the separation cover 3 to the cover position without using the biasing force of the spring 25. With this configuration, the separation cover 3 located at the retracted position can be moved to the cover position in conjunction with the movement of the document tray 6 from the standby position to the feeding position. Therefore, jamming of the sheet S due to forgetting to close the separation cover 3 can be suppressed.

Note that in this embodiment, the sheet feeding device 300 that feeds the sheet S toward the first scanner unit 202 and the second scanner unit 205, which are image reading sections, in the ADF 100 of the image reading device A has been described. The present invention is not limited to this. That is, in an image forming apparatus, the same effect as described above can be obtained even if the configuration of this embodiment is applied to a sheet feeding device that feeds a sheet toward an image forming section that forms an image.

3... Separation cover (cover member)
5...Separation roller 6...Document tray (loading section)
18...Handle (grip part)
19... Separation holder (holding member)
19a... Mounting groove (mounting part)
42... Feeding roller 63... Lifter (moving part)
202...First scanner unit (image reading section)
205...Second scanner unit (image reading section)
300... Sheet feeding device A... Image reading device S... Sheet

Claims (10)

a feeding member that feeds the sheet ;
a separating member that presses against the feeding member to form a nip portion and separates the sheets fed by the feeding member one by one in the nip portion;
a holding member that removably holds the separation member;
a cover member movable between a first position that covers at least a portion of the separation member and a second position that exposes the separation member ;
Equipped with
The cover member contacts the separation member and moves from the first position to the second position when the separation member is moved in a direction in which the separation member is removed from the holding member while being located at the first position. A sheet feeding device characterized by: The separating member is characterized in that it includes a separating roller that presses against the feeding member to form the nip portion, a rotating shaft of the separating roller, and a gripping portion that grips the separating member. The sheet feeding device according to claim 1. The holding member includes a mounting portion into which the rotating shaft is fitted,
The sheet feeding device according to claim 2, wherein the cover member covers the mounting portion at the first position. When the separation member is moved in a direction in which the separation member is removed from the holding member while being located at the first position, the cover member comes into contact with the gripping portion and moves from the first position to the second position. The sheet feeding device according to claim 2 or 3, wherein the sheet feeding device moves. a loading section on which sheets are loaded;
a pick roller that feeds the sheets stacked on the stacking section to the feeding member;
Movement of moving the stacking unit to a third position where the sheets stacked on the stacking unit and the pick roller are separated from each other and a fourth position where the sheets stacked on the stacking unit and the pick roller are in contact with each other. and,
When the loading section moves from the third position to the fourth position while the cover member is located at the second position, the cover member comes into contact with a part of the loading section and moves from the second position to the fourth position. The sheet feeding device according to any one of claims 1 to 4, wherein the sheet feeding device moves to one position. comprising a biasing member that biases the cover member toward either the first position or the second position when the cover member is located between the first position and the second position. The sheet feeding device according to any one of claims 1 to 5 . The sheet feeder according to any one of claims 1 to 6, wherein the cover member has a guide surface that guides the sheet to the nip portion when the cover member is located at the first position. sending device. The sheet feeding device according to any one of claims 1 to 7, wherein the cover member is rotatably supported. an image reading unit that reads the image of the sheet;
The sheet feeding device according to any one of claims 1 to 8 , which feeds the sheet toward the image reading section;
An image reading device comprising: an image forming section that forms an image;
The sheet feeding device according to any one of claims 1 to 8 , configured to feed a sheet toward the image forming section;
An image forming apparatus comprising:

Images