Media transport device and image forming apparatus

Abstract

To prevent damage to components in media transport devices. [Solution] The media transport device 10 comprises a feed roller 42, a retard roller 43, a mounting plate 12, an opening / closing lever 20, a side guide 13, and an insertion prevention member 30. The feed roller 42 transports the media P, and the retard roller 43 provides transport resistance to the media P. The mounting plate 12 is positioned upstream of the retard roller 43 in the media transport direction, and the media P is placed on it. The opening / closing lever 20 is movable between a closed position facing the mounting plate 12 and an open position where the distance between the lever and the mounting plate 12 is increased. The side guide 13 guides the side edge of the media P on the mounting plate 12. The insertion prevention member 30 is provided on the opening / closing lever 20. When the opening / closing lever 20 is in the closed position, the insertion prevention member 30 contacts the surface of the mounting plate 12 (or the surface of the media P on the mounting plate 12) downstream of the upstream end of the side guide 13 in the media transport direction.

Description

Technical Field

[0001] The present disclosure relates to a medium conveyance device for conveying a medium and an image forming apparatus including the medium conveyance device.

Background Art

[0002] Generally, a medium conveyance device of an image forming apparatus includes a mounting plate, a pickup roller, a feed roller, and a retard roller. A medium is placed on the mounting plate, and the pickup roller feeds out the medium placed on the mounting plate. The feed roller conveys the medium fed out by the pickup roller toward an image forming unit. The retard roller applies conveyance resistance to the conveyed medium.

[0003] The mounting plate is vertically movable and can change the distance from the pickup roller. The user sets the medium in a state where the mounting plate is pushed down, and then raises the mounting plate to bring the surface of the medium into contact with the pickup roller (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, when the mounting plate is not pushed down, the user may accidentally insert a medium between the pickup roller and the mounting plate. In this case, the leading end of the medium may pass through the pickup roller and reach the contact portion between the feed roller and the retard roller. If the medium is pulled out from this state, there is a possibility that components holding the retard roller may be damaged.

[0006] This disclosure was made to solve the above-mentioned problems and aims to prevent damage to components in a media transport device. [Means for solving the problem]

[0007] The media transport device of this disclosure comprises a transport roller for transporting a medium in the medium transport direction, a separation roller that provides transport resistance to the medium transported by the transport roller, a mounting plate positioned upstream of the separation roller in the medium transport direction on which the medium is placed, a movable member that can move between a closed position facing the mounting plate and an open position in which the distance between the mounting plate and the movable member is wider than the closed position, a side guide that guides the side end of the medium placed on the mounting plate, and an insertion prevention member provided on the movable member. When the movable member is in the closed position, the insertion prevention member contacts the surface of the mounting plate or the surface of the medium placed on the mounting plate downstream of the upstream end of the side guide in the medium transport direction.

[0008] The image forming apparatus disclosed herein comprises a media transport device and an image forming unit that forms an image on the medium transported by the media transport device. [Effects of the Invention]

[0009] In this disclosure, when the movable member is in the closed position, the insertion prevention member contacts the surface of the mounting plate (or the surface of the medium if a medium is placed on the mounting plate), thereby preventing accidentally inserted medium from reaching the separation roller. This prevents damage to components in the medium conveying device (for example, components that hold the separation roller). [Brief explanation of the drawing]

[0010] [Figure 1] This diagram shows the basic configuration of the image forming apparatus according to the embodiment. [Figure 2] This is a perspective view showing the external appearance of the image forming apparatus according to the embodiment. [Figure 3]These are cross-sectional views (A) and (B) showing the manual feed tray of the image forming apparatus of the embodiment in a closed state. [Figure 4] This is a cross-sectional view showing the manual feed tray of the image forming apparatus of the embodiment in an open state. [Figure 5] This is a cross-sectional view showing the manual feed tray of the image forming apparatus of the embodiment opened and the lever rotated to the open position. [Figure 6] These are a cross-sectional view (A) and a perspective view (B) showing the configuration for linking the lever and the manual feed tray in the embodiment. [Figure 7] These are a cross-sectional view (A) and a perspective view (B) showing the support structure of the mounting plate in the manual feed tray of the embodiment. [Figure 8] This is a perspective view showing the manual feed tray of the image forming apparatus of the embodiment in an open state. [Figure 9] This is a perspective view showing the manual feed tray of the image forming apparatus of the embodiment opened and the lever rotated to the open position. [Figure 10] These are perspective views (A) to (C) showing the retard roller and its support structure according to the embodiment. [Figure 11] These are cross-sectional views (A) and (B) showing the lever and insertion prevention member of the embodiment. [Figure 12] These are perspective view (A) and side view (B) showing the insertion prevention member of the embodiment. [Figure 13] This is a front view of the tray cover, mounting plate, lever, and insertion prevention member of the embodiment. [Figure 14] This is a perspective view showing the tray cover, mounting plate, lever, and insertion prevention member of the embodiment. [Figure 15] Figures (A) and (B) illustrate the operation of the insertion prevention member of Embodiment 1. [Modes for carrying out the invention]

[0011] Embodiment. <Configuration of Image Forming Apparatus 1> First, the image forming apparatus 1 provided with the manual feed tray 10 as a medium conveyance device in the embodiment will be described. FIG. 1 is a diagram showing the image forming apparatus 1 of the embodiment. The image forming apparatus 1 forms an image using an electrophotographic method and is, for example, a printer.

[0012] The image forming apparatus 1 includes a manual feed tray 10 that supplies a medium P, a medium cassette 50 that houses a medium Q, a feeding unit 51 that feeds out the medium Q from the medium cassette 50, an image forming unit 60 that forms a toner image (developer image) on the medium P, a fixing device 70 that fixes the toner image on the medium P, a medium discharging unit 80 that discharges the medium P from the discharge port 84, and a housing 100 that houses these components.

[0013] In the image forming apparatus 1, as conveyance paths for the medium P (Q), a paper feeding conveyance path R1 from the medium cassette 50 to the image forming unit 60, an image forming conveyance path R2 that passes through the image forming unit 60 and the fixing device 70, and a discharging conveyance path R3 from the fixing device 70 to the discharge port 84 are provided. The medium P supplied from the manual feed tray 10 merges in the middle of the paper feeding conveyance path R1.

[0014] The housing 100 of the image forming apparatus 1 has a front panel 101, a rear panel 102, and side panels 103, 104 (FIG. 2). An openable top cover 105 is provided at the upper part of the housing 100.

[0015] The medium cassette 50 is detachably attached to the lower part of the housing 100. Media Q such as printing paper is loaded and housed in the medium cassette 50. The feeding unit 51 is disposed in front of the medium cassette 50 (on the side of the front panel 101). The feeding unit 51 has a pickup roller 52, a feed roller 53, and a retard roller 54.

[0016] The pickup roller 52 feeds out the media Q contained in the media cassette 50. The feed roller 53 feeds the media Q fed out by the pickup roller 52 to the paper feed path R1. The retard roller 54 provides transport resistance to the media Q being transported by the feed roller 53, separating the media Q one sheet at a time.

[0017] The paper feed transport path R1 is provided with a transport roller pair 55 and a transport roller pair 56. The transport roller pair 55 consists of a drive roller that rotates with the driving force of a transport motor (not shown) and a pinch roller that is pressed by the drive roller. The transport roller pair 55 transports the medium Q from the feed roller 53 along the paper feed transport path R1.

[0018] The transport roller pair 56 consists of a drive roller that rotates with the driving force of a transport motor (not shown) and a pinch roller that is pressed by the drive roller. The transport roller pair 56 transports the medium P from the manual feed tray 10, or the medium Q from the transport roller pair 55, toward the image forming unit 60.

[0019] The manual feed tray 10 is mounted on the front panel 101 of the image forming apparatus 1 so as to be openable and closable. The manual feed tray 10 is also called a multi-purpose tray (MPT). The manual feed tray 10 has a tray cover 11 and a mounting plate 12. The tray cover 11 holds the mounting plate 12 so as to be rotatable. A medium P such as printing paper is loaded onto the mounting plate 12.

[0020] The manual feed tray 10 also includes a pickup roller 41 as a paper feed roller (or third roller), a feed roller 42 as a transport roller (or first roller), and a retard roller 43 as a separation roller (or second roller).

[0021] The pickup roller 41 feeds the media P placed on the mounting plate 12 toward the feed roller 42. The feed roller 42 transports the media P fed by the pickup roller 41 toward the paper feed transport path R1. The retard roller 43 provides transport resistance to the media P being transported by the feed roller 42, separating them one sheet at a time.

[0022] Note that Figure 1 shows only some of the components of the manual feed tray 10. The other components of the manual feed tray 10 will be described later.

[0023] The image forming unit 60 includes a photoreceptor drum 61 as an image carrier, a charging roller 62 as a charging member, an exposure head 63 as an exposure device, a developing roller 64 as a developer carrier, a supply roller 65 as a supply member, and a toner cartridge 66 as a developer container.

[0024] The photoreceptor drum 61 has a photosensitive layer formed on the surface of a cylindrical conductive support, with a charge transport layer and a charge generation layer laminated on top of it. The charging roller 62 is supplied with a charging voltage from a power supply unit (not shown) to uniformly charge the surface of the photoreceptor drum 61. The exposure head 63 irradiates light onto the surface of the photoreceptor drum 61 to form an electrostatic latent image.

[0025] The developing roller 64 receives a developing voltage from a power supply unit (not shown) and develops the electrostatic latent image on the photoreceptor drum 61 with toner (developer). The supply roller 65 receives a supply voltage from a power supply unit (not shown) and supplies toner to the developing roller 64. The toner cartridge 66 replenishes toner to the developing roller 64 and the supply roller 65.

[0026] Furthermore, a transfer roller 67, which serves as a transfer member, is provided on the lower side of the photoreceptor drum 61. The transfer roller 67 receives a transfer voltage from a power supply unit (not shown) and transfers the toner image formed on the photoreceptor drum 61 to the medium P.

[0027] The fixing device 70 includes a fixing roller 71 and a pressure roller 72. The fixing roller 71 has a built-in heat source and rotates with the driving force of a fixing motor (not shown). The pressure roller 72 is pressed against the fixing roller 71 to form a fixing nip. The fixing roller 71 and the pressure roller 72 apply heat and pressure to the medium P through which the fixing nip passes, fixing the toner image to the medium P.

[0028] The media discharge section 80 has pairs of discharge rollers 81, 82, and 83 arranged along the discharge transport path R3. Each of the discharge roller pairs 81, 82, and 83 consists of a drive roller that rotates due to rotational transmission from the fixing roller 71 and a pinch roller that is pressed by the drive roller. The discharge roller pairs 81, 82, and 83 transport the media P that has passed through the fixing device 70 along the discharge transport path R3 and discharge it from the discharge port 84. The top cover 105 of the image forming apparatus 1 is provided with a stacker section 85 for stacking the media P discharged from the discharge port 84.

[0029] If the image forming apparatus 1 has a double-sided printing function, a re-transport mechanism 90 is also provided. In addition to the transport paths R1 to R3 described above, a retraction path R4 adjacent to the discharge transport path R3 and a return transport path R5 extending from the entrance of the retraction path R4 to the paper feed transport path R1 are also provided.

[0030] The re-transport mechanism 90 includes a selector 91 provided on the discharge side of the fixing device 70, transport rollers 92 and 93 arranged along the retraction path R4, and transport rollers 94, 95, and 96 arranged along the return transport path R5.

[0031] The selector 91 guides the medium P(Q) that has passed through the fixing device 70 to the discharge transport path R3 or the escape path R4. The transport rollers 92 and 93 pull the medium P(Q) that has been guided from the selector 91 to the escape path R4 into the escape path R4 for a predetermined distance, and then pull it back in the reverse direction. The transport rollers 94, 95, and 96 transport the medium P(Q) that has been pulled back from the escape path R4 along the return transport path R5. Details of the re-transport mechanism 90 are omitted from the explanation.

[0032] The image forming apparatus 1 is equipped with media sensors S1, S2, and S3 for detecting the passage of the medium P(Q). Media sensor S1 is located upstream of the transport roller pair 56, and media sensor S2 is located downstream of the transport roller pair 56. Media sensor S3 is located downstream of the fixing device 70. The detection signals from media sensors S1, S2, and S3 are used for transport control of the medium P(Q).

[0033] In Figure 1, the XY plane is defined as the horizontal plane, and the Z direction is defined as the vertical direction. The direction of the rotation axis of the photoreceptor drum 61 is defined as the X direction. The X direction is also the axial direction of each roller in the image forming apparatus 1, and is also the width direction of the medium P(Q).

[0034] Regarding the Y direction, the front panel 101 side of the housing 100 is considered the front (-Y direction), and the rear panel 102 side is considered the rear (+Y direction). The direction of movement of the medium P(Q) as it passes through the image forming unit 60 and the fixing device 70 is approximately the +Y direction. However, these X, Y, and Z directions do not limit the orientation of the image forming apparatus 1.

[0035] <Configuration of manual feed tray 10> Figure 2 is a perspective view showing the external appearance of the image forming apparatus 1. The housing 100 of the image forming apparatus 1 has a front panel 101, a rear panel 102, and side panels 103 and 104, as described above. The top of the housing 100 is covered by a top cover 105. The front panel 101 is provided with an openable and closable manual feed tray 10.

[0036] An operating section 11c is formed at the upper end of the manual feed tray 10 for the user to operate when opening the manual feed tray 10. The operating section 11c is formed in the center of the manual feed tray 10 in the X direction.

[0037] Figures 3(A) and 3(B) are cross-sectional views showing the manual feed tray 10 of the image forming apparatus 1 in the closed position. Figure 4 is a cross-sectional view showing the manual feed tray 10 of the image forming apparatus 1 in the open position. Figure 5 is a cross-sectional view showing the manual feed tray 10 of the image forming apparatus 1 in the open position, with the opening / closing lever 20 (described later) rotated to the open position.

[0038] Figures 3(A), 4, and 5 are cross-sectional views of the manual feed tray 10 passing through its X-center. Figure 3(B) is a cross-sectional view of the manual feed tray 10 at a position displaced from its X-center. As shown in Figures 3(A) and 4, the manual feed tray 10 is supported on the housing 100 so as to be rotatable about a pivot axis C1 in the X direction.

[0039] Specifically, a bearing portion 17 (Figures 6(A), (B)) is formed on the wall portion 11a of the tray cover 11, which will be described later, and engages with a support shaft 106 provided on the housing 100. The engagement between the support shaft 106 and the bearing portion 17 allows the manual feed tray 10 to rotate around the pivot axis C1.

[0040] As shown in Figure 3(B), the end of the tray cover 11 away from the pivot axis C1 (i.e., the tip) is provided with an engaging claw 11d that can engage with a groove 108 provided in the housing 100, and a spring 11e that biases the engaging claw 11d in the direction of engagement with the groove 108 (upward). The engaging claws 11d are arranged on both sides in the X direction of the operating section 11c shown in Figure 2. The spring 11e is, for example, a compression coil spring. The engagement of the engaging claws 11d with the groove 108 locks the manual feed tray 10 in the closed position.

[0041] Furthermore, the engaging claw 11d is connected to the operating section 11c (Figure 2) of the manual feed tray 10. When the user pushes the operating section 11c downward (in the -Z direction), the engaging claw 11d moves downward against the biasing force of the spring 11e, releasing its engagement with the groove 108. This releases the lock on the manual feed tray 10 in the closed position, allowing it to rotate toward the open position.

[0042] The rotational range of the manual feed tray 10 around its pivot axis C1 is limited by a rotating frame 110 (Figure 6(A)) provided on the housing 100. The rotating frame 110 is rotatable around a pivot axis coaxial with the rotation axis of the feed roller 42. The tip of the rotating frame 110 engages with a guide groove (not shown) formed in the wall portion 11a of the tray cover 11, thereby limiting the rotational range of the manual feed tray 10.

[0043] The mounting plate 12 is provided on the tray cover 11. The mounting plate 12 is also supported at the end of the tray cover 11 away from the pivot axis C1 (i.e., the tip) so as to be rotatable about the pivot axis C4 in the X direction (Figures 7(A), (B)).

[0044] <Configuration of the opening / closing lever 20> The manual feed tray 10 has an opening / closing lever 20 as a movable member that rotates the mounting plate 12. The opening / closing lever 20 is located above the mounting plate 12 and is supported so as to be rotatable about a pivot axis C2 (second pivot axis) in the X direction.

[0045] The opening / closing lever 20 is supported so as to be rotatable between the closed position shown in Figure 4 and the open position shown in Figure 5. The pivot axis C2 of the opening / closing lever 20 is coaxial with the rotation axis of the pickup roller 41.

[0046] The opening / closing lever 20 has a plate-shaped cover plate 21 (see Figure 8) that covers a portion of the mounting plate 12 from above in the state shown in Figure 4. The cover plate 21 is long in the X direction and has a width in the approximately radial direction centered on the pivot axis C2.

[0047] A recessed portion 22 is formed in the center of the cover plate 21 in the X direction, serving as a storage area recessed towards the mounting plate 12 (see Figure 8). The recessed portion 22 is the part where the user places their hand when operating the opening / closing lever 20. The recessed portion 22 has walls 23 on both sides in the X direction (see Figure 13) and a bottom portion 24 facing the mounting plate 12.

[0048] Figure 6(A) is a cross-sectional view showing the interlocking state between the opening / closing lever 20 and the mounting plate 12, and is a cross-sectional view near the -X end of the manual feed tray 10. As shown in Figure 6(A), arms 27 are provided on both sides of the cover plate 21 in the X direction (only one side is shown in Figure 6(A)). The arms 27 extend such that the angle around the pivot axis C2 is within the range of 90° to 180° with respect to the cover plate 21.

[0049] Figure 6(B) is a magnified perspective view showing the engagement portion between the arm 27 of the opening / closing lever 20 and the mounting plate 12. As shown in Figure 6(B), arm opposing portions 12a are formed along both ends of the mounting plate 12 in the X direction (only one end is shown in Figure 6(B)) that face the arm 27.

[0050] An inclined surface 12b is formed on the side of the arm-facing portion 12a closest to the pivot axis C1, inclined with respect to the extending direction of the tray cover 11. A groove 12c is formed at the end of the inclined surface 12b (i.e., the end away from the pivot axis C1).

[0051] As the opening / closing lever 20 rotates from the closed position in Figure 4 to the open position in Figure 5, the tip of the arm 27 of the opening / closing lever 20 contacts the inclined surface 12b of the arm opposing part 12a, pushing the mounting plate 12 downward. When the tip of the arm 27 reaches the groove 12c, it holds the mounting plate 12 in the lowered position.

[0052] <Support structure of mounting plate 12> Figure 7(A) is a cross-sectional view illustrating the support structure of the mounting plate 12 in the tray cover 11, and is a cross-sectional view near the -X end of the manual feed tray 10. Figure 7(B) is a perspective view showing an enlarged view of the engagement portion between the tray cover 11 and the mounting plate 12.

[0053] As shown in Figure 7(A), the mounting plate 12 extends from the vicinity of the pivot axis C1 to the vicinity of the tip of the tray cover 11 (the end on the side away from the pivot axis C1). The tip of the mounting plate 12 has support shafts 12d that protrude on both sides in the X direction.

[0054] As shown in Figure 7(B), the tray cover 11 has wall portions 11a on both sides of the mounting plate 12 in the X direction (only one side is shown in Figure 7(B)). On the side of the wall portion 11a facing the mounting plate 12, a groove portion 11b is formed that engages with the support shaft 12d of the mounting plate 12.

[0055] The mounting plate 12 is supported so as to be rotatable around a pivot axis C4 in the X direction relative to the tray cover 11 by the engagement of the support shaft 12d of the mounting plate 12 with the groove 11b of the tray cover 11.

[0056] Furthermore, a spring 14 (Figure 4) is positioned near the pivot axis C1 of the tray cover 11 as a biasing member. The spring 14 is, for example, a coil spring. The spring 14 is positioned between the tray cover 11 and the mounting plate 12 and biases the mounting plate 12 upward, that is, away from the tray cover 11.

[0057] Therefore, when the opening / closing lever 20 is rotated from the closed position shown in Figure 4 to the open position shown in Figure 6(A), the tip of the arm 27 of the opening / closing lever 20 presses against the inclined surface 12b of the mounting plate 12, causing the mounting plate 12 to rotate downward around the pivot axis C4 while compressing the spring 14 (Figure 5).

[0058] Furthermore, when the opening / closing lever 20 reaches the open position shown in Figure 6(A), the tip of the arm 27 of the opening / closing lever 20 engages with the groove 12c of the mounting plate 12, and the engagement between the tip of the arm 27 and the groove 12c holds the mounting plate 12 in a position separated downward from the pickup roller 41.

[0059] Figure 8 is a perspective view showing the manual feed tray 10 of the image forming apparatus 1 in the open position and the opening / closing lever 20 in the closed position. Figure 9 is a perspective view showing the manual feed tray 10 of the image forming apparatus 1 in the open position and the opening / closing lever 20 in the open position.

[0060] As shown in Figure 8, when the manual feed tray 10 is opened, the opening / closing lever 20 is exposed to the outside, allowing the user to operate it. As shown in Figure 9, when the opening / closing lever 20 is rotated to the open position, the mounting plate 12 is pushed down in conjunction with the rotation of the opening / closing lever 20, securing a large space on the mounting plate 12 for setting the media P.

[0061] <Configuration of pickup roller 41 and feed roller 42> As shown in Figure 4, the pickup roller 41 is positioned on the opposite side of the spring 14 from the mounting plate 12. The pickup roller 41 is supported by the aforementioned rotating frame 110 (Figure 6(A)) so as to be rotatable about the rotation axis C2 in the X direction.

[0062] The feed roller 42 is positioned adjacent to the conveying roller pair 56 of the pickup roller 41. The feed roller 42 is rotatably supported about an axis of rotation in the X direction by a frame (not shown) provided within the housing 100.

[0063] The pickup roller 41 and the feed roller 42 are rotated by the driving force of a paper feed motor (not shown) of the image forming apparatus 1. The pickup roller 41, the feed roller 42, and the retard roller 43 are located inside the housing 100 of the image forming apparatus 1, but they form part of the manual feed tray 10 (media transport device).

[0064] <Retard Roller 43> Figure 10(A) is a perspective view showing a retard roller 43 and a retard holder 45 that holds it. The retard roller 43 has a shaft 43a with the X direction as its axis, a torque limiter 43b provided on the outer circumference of the shaft 43a, and a roller portion 43c provided on the outer circumference of the torque limiter 43b. The shaft 43a has a circular cross-section, but D-cut portions 43d are formed at both ends in the axial direction (only one end is shown in Figure 10(A)).

[0065] The retard holder 45 has a pair of side plates 45a located on both sides of the retard roller 43 in the X direction, a connecting portion 45b that connects these side plates 45a, and arm portions 45d that extend from each side plate 45a. Each side plate 45a has a fitting hole 45c into which the shaft 43a of the retard roller 43 fits. The arm portion 45d has a hole 45e into which a shaft portion, which will be described later, is inserted.

[0066] The side plate 45a has a contact piece 45f that abuts against the D-cut portion 43d of the shaft 43a, which passes through the fitting hole portion 45c. In addition, a protrusion 45g is formed in the center of the connecting portion 45b to which one end of a spring 47, which will be described later, is fixed.

[0067] Figure 10(B) is a perspective view showing a retard frame 48 that holds the retard holder 45. Figure 10(C) is a cross-sectional view showing the retard frame 48. The retard frame 48 is mounted inside the housing 100 of the image forming apparatus 1.

[0068] As shown in Figure 10(B), the retard frame 48 has a pair of side walls 48a located on both sides of the retard holder 45 in the X direction, and a front wall 48b connecting these side walls 48a. Between the pair of side walls 48a is a shaft (not shown) which is inserted into the hole 45e of the retard holder 45 (defining a rotation axis C5 in the X direction).

[0069] As shown in Figure 10(C), a spring 47 is provided as a biasing member between the front wall 48b of the retard frame 48 and the protrusion 45g of the retard holder 45. The spring 47 is, for example, a tension coil spring. The spring 47 biases the retard holder 45 to rotate about the pivot axis C5 in the direction in which the retard roller 43 rises.

[0070] Because of this configuration, the retard roller 43 is pressed against the feed roller 42 by the biasing force of the spring 47.

[0071] Furthermore, the shaft 43a of the retard roller 43 does not rotate because its D-cut portion 43d is in contact with the contact piece 45f of the retard holder 45. Therefore, when the roller portion 43c of the retard roller 43 receives a rotational force from the outside, the roller portion 43c rotates in the direction of the rotational force around the rotation axis Ax in the X direction, while the torque limiter 43b generates a predetermined rotational load.

[0072] <Configuration of the insertion prevention member 30> Next, the configuration of the insertion prevention member 30 will be described. Figure 11(A) is a cross-sectional view showing the opening / closing lever 20 and its surroundings. The insertion prevention member 30 is provided in the recessed portion 22 of the opening / closing lever 20. The insertion prevention member 30 is also called a passage prevention member.

[0073] The insertion prevention member 30 has a pair of arm portions 32 (see Figure 12(A)) that are rotatably supported inside the recess 22 of the opening / closing lever 20 around a pivot axis C3 (first pivot axis) in the X direction, and a plate-like portion 31 provided at the lower end of the arm portions 32.

[0074] The insertion prevention member 30 (more specifically, the portion including the middle of the arm portion 32 up to the plate-shaped portion 31) protrudes downward, i.e., toward the mounting plate 12, through an opening 25 formed in the bottom portion 24 of the recess portion 22 of the opening / closing lever 20.

[0075] Figure 11(B) is a cross-sectional view showing the opening / closing lever 20 and the insertion prevention member 30. As shown in Figure 11(B), the rotation range of the insertion prevention member 30 around the pivot axis C3 is restricted by the front (-X direction) end 25a and the rear (+X direction) end 25b of the opening 25. The ends 25a and 25b of the opening 25 correspond to the restricting portion.

[0076] Figure 12(A) is a perspective view showing the insertion prevention member 30. Figure 12(B) is a side view showing the insertion prevention member 30. For convenience of illustration, the XYZ coordinates shown in Figures 12(A) and (B) are shown assuming that the plate-shaped portion 31 of the insertion prevention member 30 is placed horizontally.

[0077] As shown in Figure 12(A), the pair of arms 32 of the insertion prevention member 30 are formed at both ends in the X direction and at the rear (+Y direction) of the plate-shaped portion 31. The arms 32 have holes 33 that engage with a support shaft 26 (Figure 13) provided in the recess 22 of the opening / closing lever 20. The engagement of the support shaft 26 and the holes 33 allows the insertion prevention member 30 to rotate about the pivot axis C3.

[0078] An end face 31c is formed at the front end (the end in the -Y direction) of the plate-like portion 31. The end face 31c is formed in the center of the plate-like portion 31 in the X direction. On both sides of the end face 31c in the X direction, inclined end faces 31d are formed, which are inclined with respect to the X direction. The inclined end faces 31d are inclined such that the width of the plate-like portion 31 in the X direction becomes narrower towards the front (-Y direction).

[0079] As shown in Figure 12(B), the plate-like portion 31 has a bottom surface 31a facing the mounting plate 12 and a top surface 31e opposite to the bottom surface 31a. In addition, an inclined surface 31b is formed on the front side of the bottom surface 31a, i.e., on the end surface 31c side. The inclined surface 31b is inclined by an angle R with respect to the bottom surface 31a such that the thickness of the plate-like portion 31 becomes thinner as it approaches the end surface 31c.

[0080] As shown in Figure 4, when the opening / closing lever 20 is in the closed position and the mounting plate 12 is not being pushed down, the plate-shaped portion 31 of the insertion prevention member 30 contacts the surface of the mounting plate 12 (or the surface of the medium P if the medium P is placed on the mounting plate 12) due to its own weight.

[0081] <Side Guide 13> Figure 13 is a view of the tray cover 11, mounting plate 12, side guides 13, opening / closing lever 20, and insertion prevention member 30 from the front (-Y direction). A pair of side guides 13 are provided on the mounting plate 12 to regulate the widthwise position of the medium P. Each side guide 13 is supported so as to be slidable in the X direction by a guide groove 12g (Figure 14) provided on the mounting plate 12.

[0082] Each side guide 13 has a bottom portion 13a supported on the mounting plate 12 and a wall portion 13b extending vertically from the bottom portion 13a. The bottom portion 13a has an engaging portion (not shown) that engages with the guide groove 12g of the mounting plate 12.

[0083] Each wall portion 13b is formed at the opposite ends of a pair of bottom portions 13a (i.e., the ends facing outward in the X direction). Each wall portion 13b faces the widthwise end of the medium P and restricts the widthwise position of the medium P. The surface of the bottom portion 13a is slightly higher than the surface 12e of the mounting plate 12 (i.e., further away from the tray cover 11).

[0084] The pair of side guides 13 slide symmetrically with respect to the X-center of the mounting plate 12 by an interlocking mechanism (not shown). The range of movement of each side guide 13 is restricted by the engagement portion of the bottom 13a contacting the end of the guide groove 12g.

[0085] In Figure 13, the pair of side guides 13 are in their minimum distance from each other (for example, guiding a medium P of the minimum expected width). Also, the opening / closing lever 20 is in the closed position (Figure 4), and the mounting plate 12 is not pressed down.

[0086] In this state, the wall portion 13b of the side guide 13 faces the wall portion 23 of the recess 22 of the opening / closing lever 20 with a gap in the X direction. That is, even when the distance between the pair of side guides 13 is minimized, the wall portion 13b of the side guide 13 does not interfere with the recess 22 of the opening / closing lever 20.

[0087] Furthermore, in the state shown in Figure 13, the plate-shaped portion 31 of the insertion prevention member 30 is located above the bottom portion 13a of the side guide 13. However, since the plate-shaped portion 31 is inclined with respect to the mounting plate 12 (see Figure 4), and inclined end faces 31d are formed on both sides in the X direction of the end face 31c of the plate-shaped portion 31, the insertion prevention member 30 does not interfere with the bottom portion 13a of the side guide 13.

[0088] Figure 14 is a perspective view showing the tray cover 11, mounting plate 12, side guide 13, opening / closing lever 20, and insertion prevention member 30. In Figure 14, as in Figure 13, the pair of side guides 13 are in their closest position to each other. Also, the opening / closing lever 20 is in the closed position (Figure 4), and the mounting plate 12 is not pressed down.

[0089] As shown in Figure 14, the plate-shaped portion 31 of the insertion prevention member 30 is located behind the front end (-Y direction end) 13e of the side guide 13 (+Y direction). That is, the insertion prevention member 30 is located behind the front end 13e of the side guide 13 and is in contact with the surface of the mounting plate 12 (or the surface of the medium P placed on the mounting plate 12).

[0090] Here, the direction in which the medium P is transported by the pickup roller 41 and feed roller 42 (Figure 4) that contact the surface of the mounting plate 12 (or the surface of the medium P placed on the mounting plate 12) is referred to as the "medium transport direction." The front end 13e of the side guide 13 corresponds to the upstream end in the medium transport direction. Therefore, the insertion prevention member 30 can be said to contact the surface of the mounting plate 12 (or the surface of the medium P placed on the mounting plate 12) downstream of the upstream end (front end 13e) of the side guide 13 in the medium transport direction, and upstream of the pickup roller 41 that contacts the surface of the mounting plate 12 (or the surface of the medium P placed on the mounting plate 12).

[0091] Furthermore, the insertion prevention member 30 contacts the surface of the mounting plate 12 (or the surface of the medium P placed on the mounting plate 12) in front of the rear end 13f (Figure 5) of the side guide 13. Using the expression "medium transport direction," it can be said that the insertion prevention member 30 contacts the surface of the mounting plate 12 (or the surface of the medium P placed on the mounting plate 12) upstream of the downstream end (rear end 13f) of the side guide 13 in the medium transport direction.

[0092] <Operation of the image forming apparatus> Next, the operation of the image forming apparatus 1 will be explained with reference to Figures 1, 3, and 4. When the control unit of the image forming apparatus 1 receives a print command and print data from the host device, it starts the image forming operation, i.e., the printing operation.

[0093] This section describes the case where media P is transported from the manual feed tray 10 based on a print command. When setting media P in the manual feed tray 10, the user rotates the manual feed tray 10 from the closed position shown in Figure 3(A) to the open position shown in Figure 4.

[0094] When the manual feed tray 10 is rotated to the open position, the opening / closing lever 20 is exposed to the outside, allowing the user to operate it. The user rotates the opening / closing lever 20 from the closed position shown in Figure 4 to the open position shown in Figure 5.

[0095] When the opening / closing lever 20 is rotated from the closed position to the open position, the arm 27 (Figure 6(A), (B)) provided on the opening / closing lever 20 comes into contact with the inclined surface 12b of the mounting plate 12, pushing the mounting plate 12 down. The mounting plate 12 rotates downward around the pivot axis C4 against the biasing force of the spring 14.

[0096] When the opening / closing lever 20 reaches the open position shown in Figure 5, the tip of the arm 27 engages with the groove 12c of the mounting plate 12, and the mounting plate 12 is held in a depressed position. This creates a gap between the mounting plate 12 and the pickup roller 41. In this state, the user sets the bundle of media P on the mounting plate 12.

[0097] After the bundle of media P is placed on the mounting plate 12, when the user rotates the opening / closing lever 20 toward the closed position shown in Figure 4, the tip of the arm 27 disengages from the groove 12c of the mounting plate 12 and moves along the inclined surface 12b. Consequently, the mounting plate 12 rotates upward around the pivot axis C4 due to the biasing force of the spring 14.

[0098] When the opening / closing lever 20 reaches the closed position shown in Figure 4, the bundle of media P on the mounting plate 12 comes into contact with the pickup roller 41, enabling the supply (transportation) of media P from the manual feed tray 10.

[0099] In this state, the control unit of the image forming apparatus 1 rotates the pickup roller 41 and the feed roller 42 based on the print job. The rotation of the pickup roller 41 feeds out the medium P that is pressed against the pickup roller 41 and sends it between the feed roller 42 and the retard roller 43. The feed roller 42 transports the medium P toward the transport roller pair 56, and the retard roller 43 provides transport resistance to the medium P.

[0100] The medium P, having passed through the feed roller 42 and the retard roller 43, passes through the medium sensor S1 and reaches the transport roller pair 56. The transport roller pair 56 starts rotating in accordance with the timing of when the medium P passes through the medium sensor S1. The transport roller pair 56 transports the medium P toward the image forming unit 60.

[0101] In the image forming unit 60, the charging voltage, developing voltage, and supply voltage are applied to the charging roller 62, developing roller 64, and supply roller 65, respectively. The photoreceptor drum 61 also rotates, and the charging roller 62, developing roller 64, and supply roller 65 rotate in conjunction with it.

[0102] The charging roller 62 uniformly charges the surface of the photoreceptor drum 61. The exposure head 63 exposes the surface of the photoreceptor drum 61, forming an electrostatic latent image. The electrostatic latent image formed on the surface of the photoreceptor drum 61 is developed by the toner adhering to the developing roller 64, forming a toner image.

[0103] The toner image formed on the surface of the photoreceptor drum 61 is transferred to the medium P that passes between the photoreceptor drum 61 and the transfer roller 67 by a transfer voltage applied to the transfer roller 67.

[0104] The medium P onto which the toner image has been transferred reaches the fuser unit 70. In the fuser unit 70, the fuser roller 71 is heated to a predetermined fixing temperature. As the medium P passes through the fuser nip between the fuser roller 71 and the pressure roller 72, it is heated and pressurized, and the toner image is fixed to the medium P.

[0105] The media P on which the toner image has been fixed is transported along the discharge transport path R3 by the discharge roller pairs 81, 82, and 83 of the media discharge unit 80 and discharged from the discharge port 84. The media P discharged from the discharge port 84 is stacked on the stacker unit 85. This completes the image formation on the media P.

[0106] <effect> Next, the operation of the embodiment will be described. As described above, when setting media P in the manual feed tray 10, it is necessary to rotate the opening / closing lever 20 to the open position in advance and push down the mounting plate 12. However, there is a possibility that the user may forget to operate the opening / closing lever 20 and insert the bundle of media P between the pickup roller 41 and the mounting plate 12 without pushing down the mounting plate 12.

[0107] If the insertion prevention member 30 is not provided, and the user inserts the bundle of media P with sufficient force, the bundle of media P may pass between the pickup roller 41 and the mounting plate 12 and reach the space between the feed roller 42 and the retard roller 43.

[0108] As shown in Figure 10(C), the retard roller 43 is held in a state where the D-cut portion 43d of the shaft 43a is in contact with the contact piece 45f of the retard holder 45. When the user attempts to pull out the medium P, the force applied to the roller portion 43c of the retard roller 43 is transmitted to the shaft 43a via the torque limiter 43b.

[0109] Therefore, if the thickness of the media P bundle is thick, a large force is applied to the contact piece 45f of the retard holder 45 that is in contact with the D cut portion 43d, which may cause the contact piece 45f to break.

[0110] In contrast, in Embodiment 1, when the mounting plate 12 is not pressed down, the plate-shaped portion 31 of the insertion prevention member 30 contacts the surface of the mounting plate 12 due to its own weight, as shown in Figure 15(A). As a result, the bundle of media P inserted by the user is guided onto the plate-shaped portion 31 of the insertion prevention member 30, as indicated by the arrow. This prevents the media P from reaching the space between the feed roller 42 and the retard roller 43.

[0111] In particular, since the plate-shaped portion 31 of the insertion prevention member 30 contacts the surface of the mounting plate 12 behind the front end portion 13e of the pair of side guides 13, the effect of preventing the passage of the medium P by the insertion prevention member 30 can be enhanced.

[0112] Furthermore, the insertion prevention member 30 stops the insertion of the medium P midway, allowing the user to recognize any operational error.

[0113] Furthermore, by setting the angle R of the inclined surface 31b of the insertion prevention member 30 (Figure 12(B)), if the thickness of the bundle of media P is 1.0 mm or less, the bundle of media P may be guided into the gap between the insertion prevention member 30 and the mounting plate 12. This is because if the thickness of the bundle of media P is 1.0 mm or less, even if it reaches the space between the feed roller 42 and the retard roller 43, damage to the holding part of the retard roller 43 when pulling out the bundle of media P is less likely to occur.

[0114] Furthermore, as shown in Figure 15(B), after pressing down the mounting plate 12 to set the medium P (indicated by the symbol P1), and returning the mounting plate 12 to its original position (Figure 4), the user may insert an additional bundle of medium P (indicated by the symbol P2).

[0115] In this case as well, the plate-shaped portion 31 of the insertion prevention member 30 comes into contact with the surface of the medium P1 placed on the mounting plate 12, so the bundle of additionally inserted medium P2 is guided onto the plate-shaped portion 31 of the insertion prevention member 30 as indicated by the arrow. Therefore, the medium P2 is prevented from reaching the space between the feed roller 42 and the retard roller 43.

[0116] In both cases shown in Figures 15(A) and (B), the medium P is prevented from reaching the space between the feed roller 42 and the retard roller 43, thereby preventing damage to the retaining portion of the retard roller 43 (for example, the contact piece 45f of the retard holder 45) when the medium P is withdrawn.

[0117] Furthermore, the insertion prevention member 30 is provided on the opening / closing lever 20, and when the opening / closing lever 20 is rotated to the open position, the gap between the insertion prevention member 30 and the mounting plate 12 widens. Therefore, when the user sets the medium P on the mounting plate 12, or when removing a jammed medium P from the mounting plate 12, the insertion prevention member 30 does not get in the way of the work.

[0118] Furthermore, since the insertion prevention member 30 is rotatable around the pivot axis C3 (first pivot axis), it contacts the surface of the mounting plate 12 when no medium P is placed on the mounting plate 12 (see Figure 15(A)), and contacts the surface of the medium P when medium P is placed on the mounting plate 12 (see Figure 15(B)). In either case, damage to the holding portion of the retard roller 43 can be prevented.

[0119] Furthermore, since the pivot axis C3 (first pivot axis) of the insertion prevention member 30 is located upstream of the pivot axis C2 (second pivot axis) of the opening / closing lever 20 in the media transport direction, when the opening / closing lever 20 is rotated to the open position (see Figure 5), a large gap is created between the insertion prevention member 30 and the mounting plate 12. This makes it easier for the user to set the media P on the mounting plate 12 or to remove jammed media P from the mounting plate 12.

[0120] Furthermore, since the range of motion of the insertion prevention member 30 is restricted by the opening 25 (restricting portion) of the opening / closing lever 20 (see Figure 11(B)), interference between the insertion prevention member 30 and surrounding parts can be prevented during the rotational operation of the opening / closing lever 20.

[0121] Furthermore, since the insertion prevention member 30 is located in the center of the mounting plate 12 in the X direction (see Figure 8), interference between the insertion prevention member 30 and the side guides 13 can be prevented even when the distance between the pair of side guides 13 is narrowed to the minimum distance.

[0122] Furthermore, the insertion prevention member 30 is supported on the inside in the X direction of the recessed portion 22 (housing portion) that protrudes toward the mounting plate 12 side of the opening / closing lever 20 (see Figure 13), and the wall portion 23 of the recessed portion 22 is interposed between the insertion prevention member 30 and the wall portion 13b of the side guide 13. Therefore, regardless of the rotational positions of the opening / closing lever 20 and the insertion prevention member 30 or the X direction position of the side guide 13, interference between the insertion prevention member 30 and the side guide 13 can be prevented.

[0123] Furthermore, since the width of the recessed portion 22 of the opening / closing lever 20 in the X direction is narrower than the minimum distance between the wall portions 13b of the pair of side guides 13 (see Figure 13), even when the distance between the side guides 13 is narrowed to the minimum distance, contact between the recessed portion 22 and the wall portions 13b of the side guides 13 can be prevented.

[0124] Furthermore, since the width of the plate-shaped portion 31 of the insertion prevention member 30 narrows as it approaches the tip (end face 31c) of the plate-shaped portion 31, interference between the insertion prevention member 30 and the bottom 13a of the side guides 13 can be prevented even when the bottom 13a of the pair of side guides 13 are inserted below the insertion prevention member 30 (see Figure 13).

[0125] Furthermore, when the opening / closing lever 20 is in the closed position (when the mounting plate 12 is not being pressed down), the opening / closing lever 20 covers the insertion prevention member 30 from above (see Figure 4), thus preventing the user from touching the insertion prevention member 30.

[0126] Furthermore, by moving the opening / closing lever 20 to the closed position, the mounting plate 12 approaches the pickup roller 41, and by moving the opening / closing lever 20 to the open position, the mounting plate 12 moves away from the pickup roller 41 (see Figures 4 and 5), making it easy to switch between setting the media P on the mounting plate 12 and feeding the paper with the pickup roller 41.

[0127] Furthermore, although the surface of the bottom 13a of the side guide 13 is slightly higher than the surface 12e of the mounting plate 12 (see Figure 13), the tip (end face 31c) of the plate-shaped portion 31 of the insertion prevention member 30 is higher than the bottom 13a of the side guide 13, so that the bundle of media P can be reliably guided onto the insertion prevention member 30.

[0128] <Effects of the Embodiment> As described above, the manual feed tray 10 as a media transport device of this embodiment includes a feed roller 42 as a transport roller for transporting media P, a retard roller 43 as a separation roller that provides transport resistance to the media P transported by the feed roller 42, a mounting plate 12 positioned upstream of the retard roller 43 in the media transport direction on which the media P is placed, an opening / closing lever 20 as a movable member that can move between a closed position facing the mounting plate 12 and an open position where the distance to the mounting plate 12 is wider than the closed position, a side guide 13 that guides the side end of the media P placed on the mounting plate 12, and an insertion prevention member 30 provided on the opening / closing lever 20. When the opening / closing lever 20 is in the closed position, the insertion prevention member 30 is in contact with the surface of the mounting plate 12 or the surface of the media P placed on the mounting plate 12, downstream of the upstream end (front end) 13e of the side guide 13 in the media transport direction in the media transport direction.

[0129] Therefore, the insertion prevention member 30 can prevent a bundle of media P that has been mistakenly inserted onto the mounting plate 12 from reaching the retard roller 43, and damage to the retaining parts of the retard roller 43 (for example, the contact piece 45f of the retard holder 45) when the bundle of media P is pulled out can be prevented.

[0130] Although this explanation describes the case where a bundle of media P is set on the mounting plate 12 (see Figures 15(A) and (B)), it is also possible to set only one media P on the mounting plate 12.

[0131] The image forming apparatus 1 (Figure 1) described above was configured to form a monochrome image using an image forming unit 60, but it may also be configured to form a color image using multiple image forming units.

[0132] Furthermore, although the image forming apparatus 1 described above (Figure 1) had a manual feed tray 10 and a media cassette 50, it is sufficient to have at least a manual feed tray 10.

[0133] Furthermore, this disclosure can be used, for example, in image forming apparatuses (e.g., photocopiers, facsimile machines, printers, multifunction devices, etc.) and their fixing devices that form images on a medium using an electrophotographic method.

[0134] The various aspects of this disclosure are summarized below as an appendix. (Note 1) A conveyor roller that transports the medium in the medium transport direction, A separation roller that provides transport resistance to the medium transported by the transport roller, A mounting plate is positioned upstream of the separation roller in the media transport direction, on which the media is placed, A movable member that can move between a closed position facing the mounting plate and an open position in which the distance between the mounting plate and the movable member is wider than that of the closed position, Side guides that guide the side edges of the medium placed on the mounting plate, The insertion prevention member provided on the movable member and Equipped with, When the movable member is in the closed position, the insertion prevention member contacts the surface of the aforementioned mounting plate or the surface of the medium placed on the aforementioned mounting plate, downstream of the upstream end of the side guide in the medium transport direction. A media transport device characterized by the following features. (Note 2) The insertion prevention member is supported by the movable member so as to be rotatable about the first pivot axis. A media transport device as described in Appendix 1, characterized by the features described herein. (Note 3) The movable member is rotatable about the second pivot axis, The first pivot axis is located upstream of the second pivot axis in the media transport direction. The media transport device described in Appendix 2, characterized by the features described herein. (Note 4) The movable member has a restricting portion that restricts the rotation range of the insertion prevention member. A media transport device as described in Appendix 2 or 3, characterized by the features described herein. (Note 5) The insertion prevention member is positioned in the width direction of the medium at a location corresponding to the center of the aforementioned mounting plate. A media transport device as described in any one of the appendices 1 to 4, characterized by the above. (Note 6) The movable member has a housing portion that protrudes in a direction approaching the aforementioned mounting plate when the movable member is in the closed position, The insertion prevention member is supported inside the housing portion in the width direction of the medium. A media transport device as described in any one of the appendices 1 to 5, characterized by the above. (Note 7) The aforementioned side guides are a pair of side guides provided on the aforementioned mounting plate so as to be positionable in the width direction of the medium, and each of the pair of side guides has a wall portion facing the side end of the medium. The width dimension of the media in the housing section is narrower than the minimum distance between the walls of the pair of side guides. A media transport device as described in Appendix 6, characterized by the features described herein. (Note 8) The insertion prevention member has the tip surface closest to the aforementioned mounting plate when the movable member is in the closed position, The width dimension of the insertion prevention member of the medium decreases as it approaches the tip. A media transport device as described in any one of the appendices 1 to 7, characterized by the above. (Note 9) When the movable member is in the closed position, the movable member covers at least a portion of the insertion prevention member. A media transport device as described in any one of the appendices 1 to 8, characterized by the above. (Note 10) The system includes a paper feed roller that feeds the medium placed on the mounting plate toward the transport roller, The aforementioned movable member is linked to the previously described mounting plate, By moving the movable member to the open position, the aforementioned mounting plate moves in a direction away from the paper feed roller, By moving the movable member to the closed position, the aforementioned mounting plate moves in a direction that approaches the paper feed roller. A media transport device as described in any one of the appendices 1 to 9, characterized by the above. (Note 11) A media transport device described in any one of the items 1 to 10 of the appendix, An image forming unit that forms an image on the medium conveyed by the medium transport device. An image forming apparatus equipped with [a specific feature]. [Explanation of Symbols]

[0135] 1 Image forming apparatus, 10 Manual feed tray (media transport device), 11 Tray cover, 12 Mounting plate, 13 Side guide, 13e End, 14 Spring (biasing member), 20 Lever, 21 Cover part, 22 Recessed part, 23 Wall part, 24 Bottom part, 25 Opening, 25a, 25b End (regulating part), 27 Arm, 30 Insertion prevention member, 31 Plate-shaped part, 31a Bottom surface, 31b Inclined surface, 31c End surface (tip part), 31d Inclined end surface, 32 Arm part, 41 Pickup roller (paper feed roller), 42 Feed roller (transport roller), 43 Retard roller (separation roller), 45 Retard holder (holder), 47 Spring (biasing member), 48 Retard frame (frame), 50 Media cassette, 51 Feeding unit, 55 Transport roller pair, 56 Transport roller pair, 60 Image forming unit, 61 Photoreceptor drum (image carrier), 62 Charging roller (charging member), 63 Exposure head (exposure device), 64 Developer roller (developer carrier), 65 Supply roller (supply member), 66 Toner cartridge (developer carrier), 67 Transfer roller (transfer unit), 70 Fixing unit, 80 Media discharge unit, 100 Housing, 101 Front panel.

Claims

1. A conveyor roller that transports the medium in the medium transport direction, A separation roller that provides transport resistance to the medium transported by the transport roller, A mounting plate is positioned upstream of the separation roller in the media transport direction, on which the media is placed, A movable member that can move between a closed position facing the mounting plate and an open position in which the distance between the mounting plate and the movable member is wider than that of the closed position, Side guides that guide the side edges of the medium placed on the mounting plate, The insertion prevention member provided on the movable member and Equipped with, When the movable member is in the closed position, the insertion prevention member contacts the surface of the aforementioned mounting plate or the surface of the medium placed on the aforementioned mounting plate, downstream of the upstream end of the side guide in the medium transport direction. A media transport device characterized by the following features.

2. The insertion prevention member is supported by the movable member so as to be rotatable about the first pivot axis. The media transport device according to feature 1.

3. The movable member is rotatable about the second pivot axis, The first pivot axis is located upstream of the second pivot axis in the media transport direction. The media transport device according to feature 2.

4. The movable member has a restricting portion that restricts the rotation range of the insertion prevention member. The media transport device according to feature 2.

5. The insertion prevention member is positioned in the width direction of the medium at a location corresponding to the center of the aforementioned mounting plate. A media transport device according to any one of claims 1 to 4.

6. The movable member has a housing portion that protrudes in a direction approaching the aforementioned mounting plate when the movable member is in the closed position, The insertion prevention member is supported inside the housing portion in the width direction of the medium. A media transport device according to any one of claims 1 to 4.

7. The aforementioned side guides are a pair of side guides provided on the aforementioned mounting plate so as to be positionable in the width direction of the medium, and each of the pair of side guides has a wall portion facing the side end of the medium. The width dimension of the media in the housing section is narrower than the minimum distance between the walls of the pair of side guides. The media transport device according to feature 6.

8. The insertion prevention member has the tip surface closest to the aforementioned mounting plate when the movable member is in the closed position, The width dimension of the insertion prevention member of the medium decreases as it approaches the tip surface. A media transport device according to any one of claims 1 to 4.

9. When the movable member is in the closed position, the movable member covers at least a portion of the insertion prevention member. A media transport device according to any one of claims 1 to 4.

10. The system includes a paper feed roller that feeds the medium placed on the mounting plate toward the transport roller, The aforementioned movable member is linked to the previously described mounting plate, By moving the movable member to the open position, the aforementioned mounting plate moves in a direction away from the paper feed roller, By moving the movable member to the closed position, the aforementioned mounting plate moves in a direction that approaches the paper feed roller. A media transport device according to any one of claims 1 to 4.

11. A media transport device according to any one of claims 1 to 4, An image forming unit that forms an image on the medium conveyed by the medium transport device. An image forming apparatus equipped with [a specific feature].

Images