Sheet conveyance device and image forming device

Abstract

To provide a sheet conveyance device which allows a sheet conveyance guide to be arranged close to a sheet conveyance roller.SOLUTION: A sheet conveyance device (70) includes: an opening / closing member provided at a device body; a sheet conveyance roller (72) provided at the device body; a sheet conveyance guide (82c) provided at the opening / closing member; a holding member (84) for holding the sheet conveyance guide at a tip part, and provided at the opening / closing member in an oscillable manner with a base end part being a fulcrum; and positioning guides (72b, 84b) for oscillating the holding member so that the sheet conveyance guide moves avoiding interference with a roller shaft (72b) of the sheet conveyance roller, during the opening / closing of the opening / closing member.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present disclosure relates to a paper transport device and an image forming apparatus, and in particular to a paper transport device and an image forming apparatus that are provided in a device body and have an opening / closing member that opens a paper transport path by rotating one end of the opening / closing member around a fulcrum. [Background technology]

[0002] An example of a conventional paper transport device is disclosed in Patent Document 1. In the technology of Patent Document 1, the switching flapper and the holder arm swing in conjunction with the swing of the rear cover when it swings from the closed position to the open position, so that the angle between the switching flapper and the holder arm changes and the connecting part displaces toward the rear cover. As a result, when the rear cover swings from the closed position to the open position, the holder arm and the switching flapper rotate around the connecting part while changing the angle they form, and move away from the rear cover. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-228842 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology of Patent Document 1, the paper transport path is opened by opening the rear cover (opening / closing member) provided on the device body. When opening and closing the rear cover, the paper transport roller is left on the device body side, while the paper transport guide fixed on the rear cover side moves together with the rear cover. At this time, it is necessary to avoid interference between the paper transport guide and the roller shaft of the paper transport roller, so in the technology of Patent Document 1, the paper transport guide cannot be positioned close to the paper transport roller.

[0005] Therefore, a primary object of this disclosure is to provide a novel paper transport device and image forming apparatus.

[0006] Another object of this disclosure is to provide a paper transport device and an image forming apparatus that can position a paper transport guide close to the paper transport roller while avoiding interference between the paper transport guide and the roller shaft of the paper transport roller when the opening / closing member is opened or closed. [Means for solving the problem]

[0007] The first disclosure is a paper transport device having a paper transport path within the device main body, comprising: an opening / closing member provided in the device main body that opens the paper transport path by rotating and opening one end as a fulcrum; a paper transport roller provided in the device main body that provides a propulsive force to paper transported along the paper transport path; a paper transport guide provided on the opening / closing member at a position corresponding to the paper transport roller and forming the paper transport path; a holding member that holds the paper transport guide at its tip and is provided on the opening / closing member so that it can swing around its base end as a fulcrum; and a positioning guide that swings the holding member so that the paper transport guide moves while avoiding interference with the roller shaft of the paper transport roller when the opening / closing member is opened or closed.

[0008] According to the first disclosure, the paper transport guide can be disposed close to the paper transport roller while avoiding interference between the paper transport guide and the roller shaft of the paper transport roller when the opening / closing member is opened or closed.

[0009] The second disclosure is dependent on the first disclosure, and when the opening and closing member is closed, the positioning guide restricts the swinging of the holding member.

[0010] The third disclosure is dependent on the first or second disclosure, and the positioning guide includes a first guide portion and a second guide portion that are slidably engaged with each other, and one of the first guide portion and the second guide portion is provided on the device body, and the other is provided on the holding member.

[0011] The fourth disclosure is dependent on the third disclosure, and the first guide portion is a guide groove provided in the holding member, and the second guide portion is a roller shaft of a paper transport roller.

[0012] The fifth disclosure is dependent on the third disclosure, and the first guide portion is a guide groove provided in the device body, and the second guide portion is a guide protrusion provided in the holding member.

[0013] A sixth disclosure is an image forming apparatus including the paper transport device according to the first disclosure. Effect of the Invention

[0014] According to this disclosure, the paper transport guide can be disposed close to the paper transport roller while avoiding interference between the paper transport guide and the roller shaft of the paper transport roller when the opening / closing member is opened or closed.

[0015] The above and other objects, features and advantages of the present disclosure will become more apparent from the following detailed description of the embodiments, which proceeds with reference to the drawings. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic cross-sectional view showing an internal structure of an image forming apparatus including a paper transport device according to a first embodiment of the present disclosure. [Diagram 2] FIG. 1 is a perspective view showing an external appearance of an image forming apparatus. [Diagram 3] FIG. 2 is a perspective view showing the image forming apparatus with the right door open. [Figure 4] FIG. 2 is a perspective view showing a portion around a paper transport roller provided in the main body of the apparatus. [Diagram 5] FIG. 4 is a perspective view showing the inner side of the right door. [Figure 6] FIG. 4 is a perspective view showing a portion around a first guide member of the right door. [Figure 7] FIG. 4 is a perspective view showing a first guide member. [Figure 8] 13 is a perspective view showing the area around the paper transport roller when the right door is closed. FIG. [Figure 9] FIG. 11 is a perspective view showing the operation of the first guide member when the right door is opened. [Figure 10] FIG. 11 is a perspective view showing a portion around a paper transport roller of a paper transport device according to a second embodiment of the present disclosure. [Figure 11] FIG. 11 is a perspective view showing a portion around a first guide member of a right door in a second embodiment. [Figure 12] FIG. 11 is a perspective view showing the operation of the first guide member when the right door is opened in the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] [First Example] 1 and 2, a paper transport device 70 according to a first embodiment of the present disclosure is used in an image forming apparatus 10. As will be described in detail later, the paper transport device 70 includes a paper transport roller (post-fixing roller 72) and a paper transport guide (roller front guide 82c) provided downstream of the fixing device 44 in the paper transport direction, and transports paper after image formation toward the paper discharge tray 48. The paper transport device 70 is incorporated into the image forming apparatus 10 and forms a part of it. That is, the device body 12 of the image forming apparatus 10 is also the device body of the paper transport device 70. In addition, an opening / closing member (right door 62) provided in the device body 12 is also an opening / closing member of the paper transport device 70, and a paper transport path (first paper transport path L1) provided in the device body 12 is also a paper transport path of the paper transport device 70.

[0018] First, the configuration of the image forming apparatus 10 will be described briefly. In this embodiment, the front side (front) is defined as the surface facing the user's standing position, that is, the surface on which the operation panel 28 is provided, and the front-rear direction (depth direction) of the image forming apparatus 10 and its components are defined, and the left-right direction (horizontal direction) of the image forming apparatus 10 and its components are defined based on the state in which the image forming apparatus 10 is viewed from the user. In addition, in Fig. 2 and Fig. 3, the document pressing cover 18 is omitted for the sake of simplicity of the drawings.

[0019] 1 and 2, the image forming apparatus 10 is a multifunction machine having a copying function, a printer function, a scanner function, a facsimile function, etc., and forms an image on a sheet (recording medium) by an electrophotographic method. The image forming apparatus 10 includes an apparatus main body 12 equipped with an image forming section 30, and an image reading device 14 disposed above the apparatus main body 12.

[0020] The image reading device 14 includes a document placement platform 16 formed of a transparent material. A document pressing cover 18 is attached above the document placement platform 16 via a hinge or the like so as to be freely opened and closed. A document supply tray 20 is provided on the top surface of the document pressing cover 18, and an ADF (automatic document feeder) is provided inside the document pressing cover 18. The ADF automatically supplies documents placed on the document supply tray 20 one by one to an image reading position 22 and discharges them to a document discharge tray 24.

[0021] The image reading unit 26 built into the image reading device 14 includes a light source, multiple mirrors, an imaging lens, a line sensor, etc. The image reading unit 26 exposes the surface of the document to the light source, and guides the reflected light from the document surface to the imaging lens by multiple mirrors. The imaging lens then forms an image of the reflected light on the light receiving element of the line sensor. The line sensor detects the luminance and chromaticity of the reflected light imaged on the light receiving element, and generates image data based on the image of the document surface. The line sensor may be a CCD (Charge Coupled Device) or a CIS (Contact Image Sensor), etc.

[0022] An operation panel 28 that accepts input operations such as print instructions from a user is provided on the front side of the image reading device 14. A display with a touch panel, a plurality of operation buttons, and the like are provided on the upper surface of the operation panel 28.

[0023] A control unit (not shown) including a CPU, memory, etc., and an image forming unit 30 are provided inside the housing 60 of the device main body 12. The control unit transmits control signals to each part of the image forming device 10 in response to input operations on the operation panel 28, etc., and causes the image forming device 10 to perform various operations.

[0024] The image forming section 30 includes an exposure unit 32, a developing device 34, a photoconductor drum 36, a cleaner unit 38, a charger 40, a transfer device 42, and a fixing device 44, and forms an image on paper transported from a paper feed cassette 46 or the like, and discharges the paper on which the image has been formed onto a paper discharge tray 48. As image data for forming an image on the paper, image data read by the image reading section 26 or image data transmitted from an external computer, etc., are used.

[0025] The image data handled by the image forming apparatus 10 corresponds to color images of four colors: black (K), cyan (C), magenta (M), and yellow (Y). For this reason, four of each of the developing device 34, the photoconductor drum 36, the cleaner unit 38, and the charger 40 are provided so as to form four types of latent images corresponding to each color, and these constitute four image stations.

[0026] The photoconductor drum 36 is an image carrier in which a photosensitive layer is formed on the surface of a cylindrical base body having electrical conductivity, and the charger 40 is a member that charges the surface of the photoconductor drum 36 to a predetermined potential. The exposure unit 32 is configured as a laser scanning unit (LSU) equipped with a laser emission section and a reflecting mirror, and exposes the charged surface of the photoconductor drum 36 to light, thereby forming an electrostatic latent image on the surface of the photoconductor drum 36 according to image data. The developer 34 visualizes the electrostatic latent image formed on the surface of the photoconductor drum 36 with four-color (YMCK) toners. The cleaner unit 38 removes toner remaining on the surface of the photoconductor drum 36 after development and image transfer.

[0027] The transfer device 42 is a device for transferring the toner image formed on the photosensitive drum 36 onto paper, and includes an intermediate transfer unit 50 and a transfer unit (secondary transfer unit) 52. However, the transfer device 42 does not necessarily have to be of an intermediate transfer type equipped with the intermediate transfer unit 50, and a configuration in which the toner image on the photosensitive drum 36 is directly transferred onto paper by the transfer unit can also be adopted.

[0028] The intermediate transfer unit 50 includes an intermediate transfer belt, a suspension roller, and four intermediate transfer rollers, and is disposed above the photosensitive drum 36. During image formation, a transfer electric field is formed between the photosensitive drum 36 and the intermediate transfer belt by applying a predetermined voltage to the intermediate transfer roller. Then, due to the action of this transfer electric field, the toner image formed on the outer circumferential surface of the photosensitive drum 36 is sequentially transferred to the outer circumferential surface of the circulating intermediate transfer belt.

[0029] The transfer unit 52 includes a transfer roller that is arranged to press the intermediate transfer belt. During image formation, a predetermined voltage is applied to the transfer roller, forming a transfer electric field between the intermediate transfer belt and the transfer roller. Then, due to the action of this transfer electric field, the toner image formed on the outer circumferential surface of the intermediate transfer belt is transferred to the paper as the paper passes through the transfer nip between the intermediate transfer belt and the transfer roller.

[0030] Fixing device 44 includes a fixing roller (heat roller) and a pressure roller, and is disposed above transfer unit 52. The fixing roller is set to a predetermined fixing temperature, and when paper passes through a fixing nip between the fixing roller and the pressure roller, the toner image transferred to the paper is melted, mixed and pressed against the paper, and the toner image is thermally fixed to the paper.

[0031] In the device main body 12, a first paper transport path L1 (one example of a paper transport path) is formed for sending paper transported from a paper feed cassette 46 or the like to a paper output tray 48 via a registration roller 56, a transfer device 42, and a fixing device 44. In addition, when performing double-sided printing on a paper, a second paper transport path L2 is formed for returning the paper after single-sided printing is completed and the paper has passed through the fixing device 44 to the first paper transport path L1 upstream of the transfer unit 52 in the paper transport direction. In the first paper transport path L1 and the second paper transport path L2, a plurality of paper transport rollers 58 for providing auxiliary propulsion force to the paper are appropriately provided.

[0032] 2 and 3, a right door 62, which is an example of an opening / closing member, is provided on the right side of the device body 12. Specifically, an opening 60a is formed on the right side of the housing 60 of the device body 12, and the right door 62 is provided in the opening 60a so as to be freely opened and closed by a hinge or the like. The right door 62 is an upward-opening door that opens at the top by rotating rightward about a lower end (one end) as a fulcrum, and is used to remove paper that has stopped midway along the paper transport paths L1 and L2. By opening the right door 62, the first paper transport path L1 is opened (exposed) on the device body 12 side, and the second paper transport path L2 is opened on the right door 62 side.

[0033] Next, the configuration of the paper transport device 70 will be described with reference to Figures 3 to 8 as well as Figure 1. As shown in Figures 1 and 3 to 5, the paper transport device 70 includes a right door 62, a post-fixing roller 72 provided in the apparatus body 12, and a first guide member 74 provided in the right door 62, and is disposed on the right side of the image forming apparatus 10.

[0034] The post-fixing roller 72 is an example of a paper transport roller provided in the paper transport device 70. Note that the post-fixing roller 72 is given a special reference symbol (72) to distinguish it from the paper transport rollers 58 provided in other areas of the paper transport paths L1 and L2.

[0035] 4, the post-fixing rollers 72 are a pair of rollers provided in the first paper transport path L1 downstream of the fixing device 44 in the paper transport direction, and each of the pair of rollers includes two roller portions 72a and a roller shaft 72b. The roller shaft 72b of the post-fixing roller 72 is provided to extend in the front-rear direction (the paper width direction, which is a direction perpendicular to the paper transport direction), and the two roller portions 72a are provided to be aligned at a predetermined interval in the front-rear direction. Both ends of the roller shaft 72b are rotatably supported by bearings provided in the main body frame 78, and a driving source is connected to the rear end of the roller shaft 72b via a gear 80 or the like.

[0036] Further, a second guide member 76 that forms a pair with a first guide member 74 described later is provided around the post-fixing roller 72. When the right door 62 is closed, a part of the first paper transport path L1 (a paper transport path after fixing) is formed between the first guide member 74 and the second guide member 76. Note that this second guide member 76 is provided in the device body 12, and remains on the device body 12 side even when the right door 62 is opened.

[0037] 5 to 7, the first guide member 74 is provided at the upper end portion (at a position corresponding to the post-fixing roller 72) on the inner surface side of the right door 62. The first guide member 74 includes a guide body 82 extending in the front-rear direction, and holding members 84 provided at both ends of the guide body 82. The holding members 84 are members for attaching the guide body 82 to the right door 62, and the guide body 82 is held (fixed) between the two holding members 84.

[0038] On the left side surface (surface on the side of the post-fixing roller 72) of the guide body 82, a roller housing portion 82a that houses the roller portion 72a of the post-fixing roller 72 and a shaft housing portion 82b that houses the roller shaft 72b are formed when the right door 62 is closed. In addition, on the left side surface of the guide body 82, a roller front guide 82c is provided below the roller housing portion 82a and the shaft housing portion 82b (upstream side in the paper transport direction). A plurality of notches 82d are formed in the lower half of the roller front guide 82c, which are arranged at predetermined intervals in the front-rear direction. This roller front guide 82c is an example of a paper transport guide provided in the paper transport device 70, and forms a paper transport path (an introduction path to the post-fixing roller 72) that guides the paper to the post-fixing roller 72 between the roller front guide 82c and the second guide member 76. Furthermore, on the left side surface of the guide body 82, a roller rear guide 82e is formed above the roller housing portion 82a and the shaft housing portion 82b (downstream side in the paper transport direction).

[0039] In such a paper transport device 70, as described above, when the right door 62 is opened or closed, the post-fixing roller 72 and the second guide member 76 are left on the device body 12 side, while the first guide member 74 provided on the right door 62 side moves together with the right door 62. Since the right door 62 rotates about its lower end as a fulcrum, the first guide member 74 provided on the inner side of the upper end of the right door 62 moves diagonally in the upper right direction as the right door 62 opens. At this time, it is necessary to avoid interference between the pre-roller guide 82c and the roller shaft 72b of the post-fixing roller 72, so that in this state, the pre-roller guide 82c cannot be positioned up to a position close to the post-fixing roller 72 (immediately before the position in the paper transport direction).

[0040] Therefore, in this first embodiment, a holding member 84 (and therefore the entire first guide member 74) is provided to be swingable relative to the right door 62, and a positioning guide is provided that is composed of a first guide portion and a second guide portion that are slidably fitted together. When the right door 62 is opened or closed, the holding member 84 is swung by the positioning guide so that the pre-roller guide 82c moves while avoiding interference with the roller shaft 72b of the post-fixing roller 72, thereby making it possible to position the pre-roller guide 82c to a position close to the post-fixing roller 72. This will be described in detail below.

[0041] As shown in FIG. 5 to FIG. 7, the holding member 84 is provided to be able to swing with respect to the door frame 86 of the right door 62, with the base end serving as a fulcrum 84a. The guide body 82 is held (fixed) at the tip end of the holding member 84. That is, the roller front guide 82c is held at the tip end of the holding member 84, and swings with the swinging of the holding member 84. The tip end of the holding member 84 is formed with a guide groove 84b that opens toward the left side (the post-fixing roller 72 side) and extends in the left-right direction. The opening 84c (left end) of the guide groove 84b is an inclined surface that gradually widens toward the opening end. This guide groove 84b is an example of a first guide portion that is one of the positioning guides.

[0042] Further, a cylindrical stopper 88 extending in the front-rear direction is provided on the outer surface side of the holding member 84. This stopper 88 is engaged with a locking portion 86a formed on the door frame 86, thereby restricting the downward swing of the holding member 84. As a result, when the right door 62 is in the open state, the holding member 84 is held in this reference position (swing position shown in FIGS. 6 and 7) where the stopper 88 is engaged with the locking portion 86a.

[0043] 8, when the right door 62 is closed, the roller shaft 72b of the post-fixing roller 72 is slidably fitted into the guide groove 84b of the holding member 84. That is, in this first embodiment, the roller shaft 72b of the post-fixing roller 72 is used as a second guide portion, which is the other of the positioning guides.

[0044] As described above, when the right door 62 is closed, the roller portion 72a of the post-fixing roller 72 is received in the roller housing portion 82a of the first guide member 74, and the roller shaft 72b is received in the shaft housing portion 82b. In addition, a part of the first paper transport path L1 is formed between the second guide member 76 and the front-roller guide 82c and rear-roller guide 82e of the first guide member 74.

[0045] Next, with reference to FIG. 9, the operation of the first guide member 74 (the holding member 84 and the roller front guide 82c) when opening and closing the right door 62 will be described.

[0046] As shown in the upper part of Figure 9, when the right door 62 is closed, the roller shaft 72b of the post-fixing roller 72 is fitted into the deepest part (right end) of the guide groove 84b of the holding member 84, and the oscillation of the holding member 84 (up and down movement of the tip) is regulated by these positioning guides (roller shaft 72b and guide groove 84b).

[0047] 9, when the right door 62 starts to open, the first guide member 74 moves diagonally to the upper right as the right door 62 opens, but the holding member 84 swings so that its tip is lowered by the positioning guide. That is, the front-roller guide 82c held at the tip of the holding member 84 moves to take a movement trajectory that avoids interference with the roller shaft 72b of the post-fixing roller 72. This makes it possible to position the front-roller guide 82c close to the post-fixing roller 72.

[0048] 9, when the right door 62 is further opened, the engagement between the roller shaft 72b and the guide groove 84b is released. At this time, the weight of the first guide member 74 causes the tip of the holding member 84 to move down a little, but as described above, the stopper 88 is engaged with the engaging portion 86a, thereby restricting the downward swing of the holding member 84.

[0049] When the right door 62 is closed, the first guide member 74 operates in the opposite manner to that described above. That is, as shown in the lower part of FIG. 9, when the right door 62 is closed, the roller shaft 72b comes into contact with the upper side of the opening 84c of the guide groove 84b, so that the roller shaft 72b is guided into the guide groove 84b. As shown in the middle part of FIG. 9, when the right door 62 is further closed, the positioning guide swings the holding member 84 so that the roller front guide 82c moves while avoiding interference with the roller shaft 72b of the post-fixing roller 72. Then, when the right door 62 is completely closed, the roller shaft 72b is fitted into the inner part of the guide groove 84b, so that the swinging of the holding member 84 is restricted.

[0050] As described above, according to this first embodiment, the holding member 84 is provided so as to be able to swing relative to the right door 62, and a positioning guide (roller shaft 72b and guide groove 84b) is provided which swings the holding member 84 so that the pre-roller guide 82c moves while avoiding interference with the roller shaft 72b of the post-fixing roller 72. Therefore, the pre-roller guide 82c can be positioned close to the post-fixing roller 72 while avoiding interference between the pre-roller guide 82c and the roller shaft 72b of the post-fixing roller 72 when the right door 62 is opened or closed.

[0051] [Second Example] Next, a paper transport device 70 according to a second embodiment of this disclosure will be described with reference to Figures 10-12. In this second embodiment, the configuration of the positioning guide is different from that of the first embodiment. Since the other parts are similar, the same reference numbers are used for parts common to the first embodiment, and duplicated descriptions are omitted or simplified.

[0052] As shown in FIG. 10, in the second embodiment, a groove member 90 is provided on the main body frame 78 of the apparatus main body 12 that supports the roller shaft 72b of the post-fixing roller 72. A guide groove 90a is formed on the inner surface of the groove member 90, which opens toward the right side (the right door 62 side) and extends in the left-right direction along the lower outer peripheral surface of the roller shaft 72b. An opening 90b (right end) of the guide groove 90a is an inclined surface that gradually widens toward the opening end. This guide groove 90a is an example of a first guide portion that is one of the positioning guides. On the other hand, as shown in FIG. 11, a cylindrical guide protrusion 92 extending in the front-rear direction is provided on the outer surface side of the holding member 84. This guide protrusion 92 is an example of a second guide portion that is the other of the positioning guides.

[0053] Next, a brief description will be given of the operation of the first guide member 74 when opening and closing the right door 62 with reference to Fig. 12. Note that, in Fig. 12, the post-fixing roller 72 and the roller front guide 82c are omitted for the sake of simplicity.

[0054] As shown in the upper part of FIG. 12, when the right door 62 is closed, the guide protrusion 92 is fitted into the inner part (left end) of the guide groove 90a, and the swing of the holding member 84 is restricted by these positioning guides (the guide groove 90a and the guide protrusion 92). Also, as shown in the middle part of FIG. 12, when the right door 62 starts to be opened, the first guide member 74 moves diagonally to the upper right in accordance with the opening operation of the right door 62, but the holding member 84 swings so that its tip is lowered by the positioning guide. That is, the roller front guide 82c held at the tip of the holding member 84 moves to take a movement trajectory that avoids interference with the roller shaft 72b of the post-fixing roller 72. This makes it possible to position the roller front guide 82c up to a position near the post-fixing roller 72. Then, as shown in the lower part of FIG. 12, when the right door 62 is further opened, the engagement between the guide groove 90a and the guide protrusion 92 is released. When the right door 62 is closed, the first guide member 74 operates in the opposite manner to that described above.

[0055] As described above, according to the second embodiment, the retaining member 84 is arranged to be swingable relative to the right door 62, and is provided with a positioning guide (guide groove 90a and guide protrusion 92). As a result, as in the first embodiment, the roller front guide 82c can be positioned close to the post-fixing roller 72 while avoiding interference between the roller front guide 82c and the roller shaft 72b of the post-fixing roller 72 when the right door 62 is opened or closed.

[0056] In the above-mentioned embodiments, a multifunction machine combining a copier, a facsimile, a printer, etc., is exemplified as the image forming apparatus, but the image forming apparatus may be any one of a copier, a facsimile, a printer, etc., or a multifunction machine combining at least two of them. The image forming apparatus may also be a monochrome machine that forms a single-color image on a print medium. Furthermore, the image forming unit of the image forming apparatus is not limited to an electrophotographic type, and may be, for example, an inkjet type. Furthermore, the paper transport device according to this disclosure may also be applied to a document feeder that transports paper (document) from which an image is read, a post-processing device, a relay device, etc.

[0057] Furthermore, in each of the above-described embodiments, a right door provided on the right side of the device body is given as an example of an opening / closing member, but this is not limited to this, and the opening / closing member may be provided on other surfaces (other sides or top surfaces) of the device body.

[0058] It should be noted that the specific numerical values ​​and part shapes given above are merely examples and can be changed as appropriate according to the needs of product specifications, etc. [Explanation of symbols]

[0059] 10...Image forming device 12 ... Device body 30...Image forming section 44... Fixing device 60…Housing 62 ... Right door (opening and closing part) 72 ... Post-fuser roller (paper transport roller) 72b ... Roller shaft (the other of the positioning guides, the second guide portion) 74 ... First guide member 82 ... Guide body 82c ... Roller front guide (paper transport guide) 84 ... Retaining member 84b ... Guide groove (one of the positioning guides, first guide portion) 90a ... Guide groove (one of the positioning guides, first guide portion) 92 ... Guide protrusion (the other of the positioning guide, the second guide portion)

Claims

1. A paper transport device having a paper transport path inside a device body, an opening / closing member that is provided in the device body and opens the paper transport path by rotating around one end of the opening / closing member; a paper transport roller provided in the device body and configured to provide a propulsive force to the paper transported along the paper transport path; a paper transport guide provided on the opening / closing member at a position corresponding to the paper transport roller, the paper transport guide forming the paper transport path; a holding member that holds the paper transport guide at a tip portion and is provided on the opening / closing member so as to be swingable about a base end portion of the holding member; a positioning guide that swings the holding member so that the paper transport guide moves while avoiding interference with a roller shaft of the paper transport roller when the opening / closing member is opened or closed.

2. 2. The paper transport device according to claim 1, wherein when the opening / closing member is closed, the positioning guide restricts the pivoting of the holding member.

3. The positioning guide includes a first guide portion and a second guide portion that are slidably fitted together, 3. The paper transport device according to claim 1, wherein one of the first guide portion and the second guide portion is provided on the device body, and the other is provided on the holding member.

4. the first guide portion is a guide groove provided in the holding member, The paper transport device according to claim 3 , wherein the second guide portion is the roller shaft of the paper transport roller.

5. the first guide portion is a guide groove provided in the device body, The paper transport device according to claim 3 , wherein the second guide portion is a guide protrusion provided on the holding member.

6. An image forming apparatus comprising the paper transport device according to claim 1.

Images