MEDIUM CONVEYING DEVICE AND IMAGE FORMING APPARATUS

Abstract

To provide a conveying apparatus that improves operability of an operator while preventing a plurality of rollers from being slipped out by using a guide member attachable / detachable in a thrust direction with respect to each of roller axes of the plurality of rollers.SOLUTION: According to a medium conveying apparatus provided with a pair of rollers arranged in a conveyance direction of a medium, the medium conveying apparatus comprises a rotational shaft for rotatably supporting a second roller for constituting the pair of rollers; an arm member for supporting a first roller paired with the second roller, that is rotatable with respect to the rotational shaft; and a guide member for positioning in an axial direction of the first roller and the second roller by engaging with the rotation axis and the arm member. The arm member comprising an engagement part for engaging the guide member with a shaft-shaped tip for rotatably supporting one of the pair of rollers.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a medium transport device and an image forming apparatus. [Background technology]

[0002] There is known a medium transport device that transports a sheet-like medium using multiple roller pairs. The roller pairs are supported so that their relative positions in the medium transport direction are fixed. This structure often employs a method in which a guide member that determines and fixes the relative positions of the roller pairs arranged in the medium transport direction is inserted from the axial direction of each roller to fix the axial position of each roller.

[0003] It is desirable for the roller pair used in the media transport device to be maintained in a state where it can transport media reliably so that the media transport device can continue to operate normally. However, each roller that makes up the roller pair is one of the components that wears out with use, and the condition of the roller surface deteriorates over time and is consumed. Therefore, although replacement is required depending on the deterioration level, it is necessary to reliably prevent the roller from coming off the shaft except when performing the replacement work.

[0004] A known technology for the structure of roller pairs provided in a media transport device is to utilize the elasticity of a leaf spring provided on a guide member to engage a claw shape provided on the guide member with a groove provided on the roller shaft, preventing each roller that makes up multiple roller pairs from coming off the shaft (see Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0005] In the structure disclosed in Patent Document 1, when assembling the medium transport device or replacing the pair of transport rollers due to wear (roller replacement), it is necessary to move the claw shape in a direction against the biasing force of the leaf spring while avoiding the rollers, to remove the claw shape from the roller shaft, and to remove the guide member. Also, when replacing and reattaching the rollers with new ones, it is necessary to attach the guide member while operating the claw biased by the leaf spring while avoiding the rollers.

[0006] That is, in the conventional technology, when assembling or maintaining the pair of transport rollers in the media transport device, the leaf spring structure is placed in the space between the rollers, making it difficult to attach and detach the rollers to and from the guide member for fixing them. In addition, there is a possibility that the guide member may scratch the rollers, especially when reinstalling them after replacing them with new rollers. In other words, there are problems with the structure for attaching and detaching the pair of transport rollers in the media transport device to and from the device body.

[0007] The present invention aims to improve operability for an operator while preventing multiple rollers from coming loose by using a guide member that is detachable in the thrust direction from each roller shaft of multiple rollers provided in a medium transport device. [Means for solving the problem]

[0008] In order to achieve the above object, the present invention provides a medium transport device having a pair of rollers arranged in a transport direction of a medium, the medium transport device including: a rotation shaft that rotatably supports a second roller that constitutes the pair of rollers; an arm member that is rotatable about the rotation shaft and supports a first roller that forms a pair with the second roller; and a guide member that determines axial positions of the first roller and the second roller by engaging with the rotation shaft and the arm member. first low Ra The guide member is supported by a locking portion at a tip of the shaft shape that rotatably supports the guide member. guide Department Material includes a claw portion and a first insertion hole, the claw portion being made of a resin material, beforeThe first insertion hole is an elliptical long hole whose major axis is the conveying direction, and after the claw portion moves to a position where it can be inserted according to the circumference of the first insertion hole, the arm member engages the guide member by getting caught in the first insertion hole. Effect of the Invention

[0009] According to the present invention, by using a guide member that is detachable in the thrust direction to each roller shaft of a plurality of rollers provided in a medium transport device, it is possible to prevent the plurality of rollers from coming loose while improving operability for an operator. [Brief description of the drawings]

[0010] [Figure 1] 1 is a diagram showing the overall configuration of an image forming apparatus according to an embodiment of the present invention. [Diagram 2] 1 is a schematic front sectional view of a sheet conveying device according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic cross-sectional view of the sheet processing apparatus according to the embodiment, as viewed from above. [Figure 4] 1 is a partially enlarged front cross-sectional view of a sheet conveying device according to an embodiment of the present invention. [Diagram 5] FIG. 2 is an enlarged partial cross-sectional view of the sheet processing apparatus according to the embodiment, as viewed from above. [Figure 6] FIG. 2 is an enlarged partial cross-sectional view showing one state of the sheet processing apparatus according to the embodiment. [Figure 7] FIG. 11 is an enlarged partial cross-sectional view showing another state of the sheet processing apparatus according to the embodiment. [Figure 8] FIG. 13 is an enlarged partial cross-sectional view showing one state of a sheet processing apparatus as a comparative example. [Figure 9] FIG. 13 is an enlarged partial cross-sectional view showing another state of the sheet processing apparatus as a comparative example. [Figure 10] FIG. 4 is a partially enlarged front cross-sectional view of a sheet conveying device as a comparative example. [Figure 11] 13 is a schematic front sectional view of a sheet conveying device according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] [Embodiment of Image Forming Apparatus] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an overall configuration diagram of an MFP 10 as an embodiment of an image processing device according to the present invention. The MFP 10 is a device that forms an image (toner image) by electrophotography, for example, and transfers the toner image onto a sheet-like medium P. The MFP 10 includes a paper feed section 2 as a sheet storage space that stores the sheet-like medium P, a sheet transport device 100 that configures a part of the transport section, an image forming section 3, a transfer section 4, a fixing section 5, a discharge section 6, an automatic document feeder 40, and a scanner section 50.

[0012] The paper feed section 2 includes a first paper feed tray 11 and a second paper feed tray 12 as placement sections on which the media P are placed.

[0013] A sheet transport device 100 as an embodiment of a medium transport device according to the present invention takes out a medium P from each of a first paper feed tray 11 and a second paper feed tray 12 and transports it downstream.

[0014] The image forming unit 3 forms an image to be transferred onto the medium P. The image forming unit 3 includes a drum-shaped photoconductor 14 as an image carrier on whose surface a latent image is formed when exposure light is irradiated from the optical writing unit 13, a developing unit 15 that supplies toner as a developer to the latent image on the photoconductor 14 to develop and visualize it, and a cleaning unit 18 that cleans the photoconductor 14 after transfer.

[0015] Further, a belt transfer unit 17 is disposed opposite to the photoconductor 14 so as to form a transfer portion 4 as a transfer nip between the belt transfer unit 17 and the photoconductor 14 .

[0016] The transfer unit 4 transfers the formed image onto the medium P. The fixing unit 5 fixes the image transferred onto the medium P onto the medium P. The discharge unit 6 discharges the medium P onto which the image has been fixed.

[0017] An automatic document feeder (hereinafter simply referred to as "ADF") 40, as an embodiment of a media transport device, separates and feeds a stack of paper Pb placed on an ADF paper feed tray 41 one sheet at a time, transports the separated documents to an image reading position of the scanner unit 50, and discharges them onto an ADF paper output tray 42.

[0018] Scanner unit 50, which serves as an image reading device, reads the surface of medium P transported from ADF paper feed tray 41 to obtain image data. The read medium P is discharged to ADF paper discharge tray 42. Scanner unit 50 reads images formed on medium P passing through an image reading position, converts them into electrical signals, and outputs them. Based on the electrical signals converted by scanner unit 50, image forming unit 3 forms an image on the transported medium P, generating a medium P that is a copy of the read image.

[0019] [Image formation operation overview] The medium P sent out from the paper feed unit 2 is transported toward the transfer unit 4 by a plurality of transport roller pairs 16 provided on the transport path. The toner image is transferred onto the medium P transported to the transfer unit 4, and the medium P is transported to the fixing unit 5 by the operation of the belt transfer unit 17. After the image (toner image) is fixed to the medium P by the fixing unit 5, the transported medium P is transported to the discharge unit 6 by a discharge roller pair 20 arranged between the fixing unit 5 and the discharge unit 6, and is discharged outside the apparatus.

[0020] Furthermore, in order to accommodate printing on a small number of sheets of medium P or a size that cannot be accommodated in the first paper feed tray 11 and the second paper feed tray 12, the MFP 10 is equipped with a manual feed tray 300 that enables medium P to be supplied by manual feeding, and a manual feed unit 301 that feeds and transports medium P from the manual feed tray 300.

[0021] Also, the user can optionally connect an external large-capacity paper feeder capable of feeding a large amount of media P to the MFP 10. Note that the large-capacity paper feeder is not shown.

[0022] 1 is an example of an electrophotographic image forming apparatus, the above configuration is of course not limited to this configuration as long as it has a similar function. For example, the image forming unit 3 may be an inkjet type.

[0023] [Embodiment of medium conveying device] An embodiment of a medium conveying device according to the present invention will be described below with reference to Fig. 2. Fig. 2 is a schematic front cross-sectional view of a sheet conveying device 100 according to this embodiment. As shown in Fig. 2, the sheet conveying device 100 includes a pickup roller 101 as a first roller constituting a roller pair for conveying a medium P, a paper feed roller 102 as a second roller, and a separation roller 103 arranged to face the paper feed roller 102 and form a nip for clamping the medium P.

[0024] The pickup roller 101 as the first roller is a roller for feeding the medium P from the paper feed unit 2 and the ADF paper feed tray 41. The pickup roller 101 is disposed so as to abut against the upper surface 1a (see FIG. 1) of the medium P placed on the first paper feed tray 11 and the second paper feed tray 12.

[0025] The paper feed roller 102 as the second roller is disposed downstream of the first roller in the sheet conveying direction, and is a roller for feeding the medium P from the paper feed unit 2 or the ADF paper feed tray 41. When there are multiple sheets of the medium P fed by the pickup roller 101, the paper feed roller 102 separates the sheets into one sheet between the pickup roller 101 and the separation roller 103 and feeds the sheets from the paper feed unit 2.

[0026] As a separating member, separation roller 103 is disposed opposite paper feed roller 102 to form a nip. Medium P picked up from paper feed unit 2 by pickup roller 101 is sent toward the nip between separation roller 103 and paper feed roller 102, and at that time, medium P is separated and sent out one by one by the nip between separation roller 103 and paper feed roller 102 so that medium P is transported one by one downstream in the transport direction. Note that separation roller 103 may be a plate-shaped separation plate.

[0027] In the following description, arrow A in Fig. 2 indicates the transport direction of medium P. Then, as shown in Fig. 3, arrow B indicates a direction perpendicular to the transport direction and corresponding to the width direction of medium P being transported. Also, as shown in Fig. 4, arrow C indicates a medium thickness direction perpendicular to arrows A and B, in which medium P is stacked in paper feeder 2.

[0028] 2, the direction in which medium P is transported from sheet transport device 100 is inclined with respect to the Y direction (see FIG. 1) which is parallel to the placement surface on which MFP 10 equipped with sheet transport device 100 is placed. That is, sheet transport device 100 transports medium P in an upward direction relative to the horizontal from the state in which it is placed on paper feed section 2. Along the transport direction of medium P, a pickup roller 101 as a first roller and a paper feed roller 102 as a second roller are arranged.

[0029] [First embodiment] Next, a first embodiment of the sheet conveying device 100 will be described in detail. FIG. 3 is a diagram for explaining a schematic cross-sectional view of the sheet conveying device 100 when viewed from above. FIG. 4 is a schematic front view of the sheet conveying device 100, viewed in the direction of the arrow A in FIG. 3. FIGS. 5 to 7 are cross-sectional views viewed from above similar to FIG. 3, and are enlarged views of the main parts of this embodiment. With reference to FIGS. 5 to 7, the engagement and disengagement states of the claw portion 104b constituting the locking portion and the first insertion hole 130a as the main parts of this embodiment will be described.

[0030] First, as shown in FIG. 3, the pickup roller 101, which is disposed at a position closest to the first paper feed tray 11 and the second paper feed tray 12, is rotatably mounted on a pickup shaft 104a provided on a pickup arm 104 and supported in a cantilever manner.

[0031] Furthermore, the pickup shaft 104a is provided on the pickup arm 104 so as to protrude in the direction of the arrow B, which is the roller axis direction. The paper feed roller 102 is a drive roller configured to rotate integrally with the feed shaft 105, which is rotated by a drive motor serving as a drive source, and is prevented from rotating. The feed shaft 105 is rotatably held by the pickup arm 104 so as to protrude in the direction of the arrow B, which is the roller axis direction. The sheet conveying device 100 is configured so that the feed shaft 105 rotates in the paper feed direction by the drive source.

[0032] That is, pickup arm 104 as an arm member has a holding portion into which feed shaft 105 as a rotating shaft is inserted. Pickup arm 104 also has pickup shaft 104a as a shaft shape, and rotatably supports pickup roller 101 as a first roller.

[0033] A one-way clutch 106 with teeth is attached to the feed shaft 105, which engages with the one-way clutch 106 to transmit a driving force in a rotation direction corresponding to the paper feed direction and rotates idly when rotating in the opposite direction. A toothed pulley 107 is provided on the pickup roller 101. A timing belt 108 with teeth is wound between the one-way clutch 106 and the pulley 107. Therefore, when a driving force is transmitted to the feed shaft 105 and the feed shaft 105 rotates, the rotation is transmitted to the timing belt 108 and the pulley 107 via the one-way clutch 106, and the pickup roller 101 rotates in the rotation direction of the pulley 107. In other words, the pickup roller 101 is a driven roller rotatably supported by the pickup shaft 104a, which is a non-rotating shaft.

[0034] The sheet conveying device 100 also includes a guide member 130. As illustrated in Fig. 4, the guide member 130 has a second insertion hole 130b for inserting the feed shaft 105, which is a rotating shaft, a first insertion hole 130a for inserting the pickup shaft 104a, which is a non-rotating shaft, and a guide portion 130c that serves as a surface against which the leading end of the medium P being conveyed abuts.

[0035] Guide portion 130c is formed on an inclined surface that slopes downward toward the medium transport direction (arrow A direction), and is disposed so as to overlap with paper feed roller 102 in the roller axial direction (arrow B direction). This prevents medium P transported from pickup roller 101 in the medium transport direction (arrow A direction) from excessively floating upward from the transport path and hitting against members around the transport path, thereby preventing jamming.

[0036] As shown in Fig. 4, an elastically deformable claw portion 104b is formed at the end of the pickup shaft 104a. The claw portion 104b can change between an engaged state where it is hooked into the first insertion hole 130a and a disengaged state where it is disengaged from the first insertion hole 130a. In other words, the claw portion 104b is formed so as to be movable from the engaged state to a state where it can be disengaged from the first insertion hole 130a. In this embodiment, the engagement and disengagement direction of the claw portion 104b is the same direction as the direction of the arrow C, which is the medium thickness direction of the medium P.

[0037] Moreover, the first insertion hole 130a is an elliptical long hole, and the medium transport direction (arrow A direction) is the long axis direction. In other words, the direction in which the claw portion 104b engages with and disengages from the first insertion hole 130a is the short axis direction. Since the short axis direction of the first insertion hole 130a is the engaging and disengaging direction, the claw portion 104b can be pushed against the inner wall of the first insertion hole 130a and reliably fixed. Furthermore, since the long axis of the first insertion hole 130a is the medium transport direction (arrow A direction), even if the pickup roller 101 is slightly displaced toward the transport direction due to friction with the medium P when the medium P is transported, the external force can be released, and transport failure can be suppressed.

[0038] In FIG. 5, the direction indicated by the arrow C1 corresponds to the disengagement direction, and the direction indicated by the arrow C2 corresponds to the engagement direction.

[0039] The second insertion hole 130b determines a position other than the roller axial direction (arrow B direction) by inserting and engaging the feed shaft 105. The first insertion hole 130a is a hole that can be inserted / detached in the roller axial direction (arrow B direction) relative to the pickup shaft 104a, and is configured to determine the positions of the first insertion hole 130a and the pickup shaft 104a by having a dimensional accuracy that does not allow movement in the medium thickness direction (arrow C direction).

[0040] For example, when removing the pickup roller 101, the worker moves the claw portion 104b in the direction of the arrow C1 as a disengagement direction from the engaged state shown in Fig. 5. This operation releases the engagement state between the claw portion 104b and the first insertion hole 130a, and the restriction of the pickup shaft 104a in the roller axis direction (arrow B1 direction) is removed (see Fig. 6).

[0041] Therefore, by moving the guide member 130 to the front side (in the direction of the arrow B1), the guide member 130 can be removed from the sheet conveying device 100 (the pickup shaft 104a and the feed shaft 105).

[0042] To attach the removed guide member 130, the feed shaft 105 and the pickup shaft 104a are inserted from the front side (arrow B1 direction) into the second insertion hole 130b and the first insertion hole 130a and pushed in the rear side (arrow B2 direction). When the guide member 130 is pushed in the rear side (arrow B2 direction), the inclined portion 104c at the tip of the claw portion 104b abuts against the first insertion hole 130a and is pushed in the arrow C1 direction. This state is illustrated in FIG. 7. That is, the tip of the claw portion 104b is deformed in the direction perpendicular to the long hole direction of the first insertion hole 130a.

[0043] Thereafter, when the claw portion 104b penetrates the first insertion hole 130a, the claw portion 104b itself returns to its original position due to its restoring force. As a result, the return-shaped portion 104d at the tip of the claw portion 104b engages with the first insertion hole 130a, and the movement of the guide member 130 in the roller axis direction (arrow B direction) is restricted (see FIG. 5). As described above, the guide member 130 becomes detachable from the sheet conveying device 100.

[0044] The pickup arm 104 is formed, for example, from an elastic resin material. Therefore, the claw portion 104b formed at the tip of the pickup shaft 104a is also a portion that elastically deforms in the C direction. As a result, as shown in Fig. 7, when the claw portion 104b is inserted into the first insertion hole 130a of the guide member 170, the claw portion 104b comes into contact with the circumference of the first insertion hole 130a and is displaced, becoming insertable.

[0045] As described above, by providing a portion for engaging guide member 130 at the tip of pickup shaft 104a, which serves as a non-rotating shaft, the roller pair can be easily and reliably supported at a predetermined position without being affected by the rotation of the rollers.

[0046] Also, an elastic member may be disposed between the pickup roller 101 and the pulley 107 to bias the pickup shaft 104a in the axial direction. In this case, when the claw portion 104b is pressed down to attach or detach the pickup roller 101, the elastic member causes the pickup roller 101 to move in the axial direction, making removal even easier. In this case, it is preferable that the biasing force of the elastic member is such that it does not impede the rotation of the pickup roller 101.

[0047] [Explanation of Comparative Example] Hereinafter, a structure configured by a conventional technique will be illustrated as a comparative example to more clearly explain the effect of the sheet conveying device 100 according to the present embodiment. Note that the same components as those of the sheet conveying device 100 are denoted by the same reference numerals.

[0048] 8 and 9 are schematic cross-sectional top views illustrating an engaged state and a disengaged state of a guide member 131 that determines the axial directions of the pickup roller 101 and the paper feed roller 102 in a conventional configuration. FIG. 10 is a schematic front view of a conventional configuration similar to FIG.

[0049] In the conventional configuration as a comparative example, a groove 104f is formed in the pickup shaft 104a, and a claw 131a that elastically deforms and engages with the pickup shaft 104a is provided on the guide member 131. Furthermore, a leaf spring 132 is attached to the guide member 131 as an elastic member.

[0050] Leaf spring 132 has a U-shaped outer shape and functions to apply a biasing force to claw portion 131a in the engagement direction (arrow A1 direction). However, in order to mount leaf spring 132, the shape and dimensions are required to be such that it can be positioned in the space between feed shaft 105 and pickup shaft 104a when guide member 131 is mounted.

[0051] Therefore, when removing or attaching the guide member 131 or replacing the rollers, there is a possibility that the guide member 131 may come into contact with the pickup roller 101 or the paper feed roller 102, and if this is done aggressively, there is a possibility that the surfaces of the pickup roller 101 or the paper feed roller 102 may be scratched.

[0052] Therefore, when installing or removing the guide member 131 or replacing the rollers, the worker must work carefully to prevent the guide member 131 from coming into contact with the pickup roller 101 or the paper feed roller 102. As a result, the efficiency of the maintenance work tends to decrease, and damage to the members (rollers) (such as scratches on the surface) may occur.

[0053] In contrast to the conventional configuration described above, the sheet conveying device 100 according to this embodiment is configured such that an elastically deformable claw portion 104b is formed at the end of the pickup shaft 104a, and is configured to engage with a guide member 130 to regulate the position of the pickup shaft 104a in the roller axis direction (direction of arrow B).

[0054] Therefore, in the sheet transport device 100, there is no need to provide a shape for preventing the feed shaft 105 and the pickup shaft 104a from coming off in the space between them. This makes it possible to prevent the guide member 131 from coming into contact with the pickup roller 101 or the paper feed roller 102 when the guide member 131 is attached or detached or when the rollers are replaced, and the surfaces of the pickup roller 101 and the paper feed roller 102 are not scratched during maintenance work.

[0055] That is, the sheet conveying device 100 can improve the operability of the worker when installing the guide member 130 or replacing the rollers, and can improve the efficiency of maintenance work by shortening the time required for the work, etc. In addition, since it is not necessary to install the leaf spring 132 on the guide member 130, it is possible to reduce the number of parts and thereby reduce costs.

[0056] [Second embodiment] Next, a second embodiment of the sheet transport device 100 will be described in detail. As already described, in the configuration of the sheet transport device 100, a space is provided between the pickup roller 101 and the paper feed roller 102. Therefore, as shown in FIG. 11 showing the second embodiment, for example, a first gear 101a is provided on the pickup roller 101, and a second gear 102a is provided on the paper feed roller 102. An idler gear 133 is disposed between the first gear 101a and the second gear 102a, which is a gap in the direction of the arrow A. It is also possible to adopt a configuration in which a shaft shape 104e that rotatably supports the idler gear 133 is provided on the pickup arm 104.

[0057] With the above configuration, second gear 102a rotates with the rotation of feed shaft 105, which is driven to rotate by the drive motor, and first gear 101a rotates with second gear 102a via idler gear 133. With this configuration, the number of parts can be further reduced compared to the configuration described with reference to Fig. 4 etc. (pulley with one-way clutch, idler pulley, timing belt), thereby achieving further cost reduction.

[0058] In the embodiment, a sheet conveying device 100 is used as an example of a device that picks up medium P from the paper feed section 2 in order to form an image on medium P on the main body side of MFP 10, but it goes without saying that the present invention is not limited to this configuration as long as the configuration has a similar function.

[0059] For example, it is possible to apply the present invention to the manual feed unit 301, the ADF feed unit 43, or an external large-capacity feed unit.

[0060] [effect] According to the sheet conveying device 100 of this embodiment described above, rollers are attached to a rotatable shaft (feed shaft 105) and a non-rotating shaft (pickup shaft 104a) with a claw-shaped tip, respectively, a guide member is inserted in the thrust direction of each shaft, and the guide member 130 is fixed by the claw of the pickup shaft 104a. This structure makes it possible to prevent the rollers constituting the roller pair from coming off. Also, it is possible to secure a large space for an operator to operate to remove the guide member when replacing the roller, as in the conventional technology. Furthermore, it is not necessary to provide an elastic member such as a leaf spring to the member for removing the guide member during the operation.

[0061] This eliminates the difficulty in assembling the roller pair and the possibility of damaging the rollers, which are present in the conventional technology. In addition, the number of parts is reduced because, while the conventional configuration (comparative example) requires two members to determine and hold the relative positions of the rollers, this embodiment requires only one member (only the guide member 130), which reduces the number of parts.

[0062] In addition, because there is space between the roller pairs, it is possible to provide gears on the two rollers and provide an idler gear between the gears. This configuration eliminates the need for a one-way clutch pulley, an idler pulley, and a belt connecting them, as in the conventional configuration, further reducing costs.

[0063] The present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the technical gist of the present invention. The present invention covers all technical matters included in the technical ideas described in the claims. The above-described embodiments are preferred examples, but a person skilled in the art can realize various modifications from the disclosed contents. Such modifications are also included in the technical scope described in the claims. [Explanation of symbols]

[0064] 10:MFP 11: First paper feed tray 12: Second paper feed tray 30: Guide member 30a: Insertion hole 30b: Insertion hole 30c: Guide section 31: Guide member 31a: Claw part 32: Leaf spring 33: Idler gear 40: Automatic document feeder 41: ADF paper feed tray 42: ADF output tray 43: ADF paper feed unit 50: Scanner section 100: Sheet conveying device 101: Pickup roller 101a: First gear 102: Paper feed roller 102a: Second gear 103: Separation roller 104: Pickup arm 104a: Pickup shaft 104b: Claw part 104c: Inclined part 104d: Return shape part 104e: Shaft shape 104f:Groove 105: Feed shaft 106: One-way clutch 107: Pulley 108: Timing belt 300: Manual feed tray 301: Manual feed unit [Prior art documents] [Patent documents]

[0065] [Patent Document 1] JP 2019-094211 A

Claims

1. A medium transport device including a pair of rollers arranged in a transport direction of a medium, a rotation shaft that rotatably supports a second roller that constitutes the roller pair; an arm member that is rotatable about the rotation shaft and supports a first roller that is paired with the second roller; a guide member that determines axial positions of the first roller and the second roller by engaging with the rotation shaft and the arm member; Equipped with the arm member has a locking portion that locks the guide member at a tip end of a shaft shape that rotatably supports the first roller, The guide member includes a claw portion and a first insertion hole, The claw portion is made of a resin material, The first insertion hole is an elliptical long hole whose major axis is in the conveying direction, After the claw portion moves to a position where it can be inserted according to the circumference of the first insertion hole, the arm member engages with the guide member by being caught in the first insertion hole. A medium transport device comprising:

2. an image forming unit that forms an image on a medium; An image forming apparatus having a loading section for loading a medium, and a transport section for removing the medium from the loading section and transporting it to the image forming section, 2. An image forming apparatus, comprising: a pair of transport rollers disposed at a position for removing the medium from the placement portion; the pair of transport rollers being the medium transport device according to claim 1.

Images