Post-processing apparatus and image forming apparatus

Abstract

In a post-processing device installed in the internal space of an image forming apparatus, the mechanism for moving the binding unit is made smaller than in conventional devices. [Solution] The post-processing device 5 installed in the internal space 6 of the image forming apparatus 1 includes a binding unit 50 that performs binding on a sheet 9, and a moving mechanism 60 that moves the binding unit 50 in a direction perpendicular to the sheet transport direction. The moving mechanism 60 includes a rail 61 that extends in the direction of movement and supports the binding unit 50 so that it can move, pulleys 65 provided at both ends of the rail 61, and a timing belt 66 that is stretched over the pulleys 65 and moves the binding unit 50 along the rail 61. The rotation axis 65a of the pulley 65 is set at an angle θ of 45 degrees or less with respect to the horizontal axis.

Description

Technical Field

[0001] The present invention relates to a post-processing device and an image forming apparatus.

Background Art

[0002] In an image forming apparatus such as an MFP (Multifunction Peripheral), generally, a scanner unit is provided above the apparatus main body, and a printer unit is provided below the apparatus main body. An inner body space is formed between the scanner unit and the printer unit in the height direction of the apparatus main body, and the printer unit discharges a sheet on which an image is formed into the inner body space. In this type of image forming apparatus, a post-processing device installed in the inner body space is known (for example, Patent Document 1). The post-processing device performs post-processing on the sheets discharged from the printer unit. As post-processing by the post-processing device, for example, there is a process of binding a plurality of sheets.

[0003] The post-processing device has an alignment tray for aligning a plurality of sheets. The post-processing device aligns each sheet sequentially discharged from the printer unit onto the alignment tray. The alignment tray is inclined with respect to the sheet conveyance direction in order to align the rear ends of a plurality of sheets. That is, the alignment tray is inclined such that the downstream side in the sheet conveyance direction is at a higher position and the upstream side in the sheet conveyance direction is at a lower position. Above the alignment tray, an alignment member is provided. The alignment member conveys the sheet that has fallen onto the alignment tray to the rear end side (upstream side in the sheet conveyance direction) and aligns the rear ends of the sheets at a predetermined position.

[0004] Further, the post-processing device has a binding unit at a position close to the alignment tray. The binding unit is a unit that binds the rear ends of a plurality of sheets with staples or the like. The binding unit is movable in a direction orthogonal to the sheet conveyance direction and can bind the rear ends of the sheets at an arbitrary position.

[0005] Conventionally, a known mechanism for moving a binding unit in a direction perpendicular to the sheet transport direction comprises a base, rails, a timing belt, and a pair of pulleys (for example, Patent Document 2). The base supports the bottom surface of the binding unit. The rails extend in a direction perpendicular to the sheet transport direction and move the base in that direction. The timing belt is an endless belt stretched over a pair of pulleys. The base is connected to a predetermined point on the timing belt. The pair of pulleys stretch the timing belt parallel to the rails, and rotational force from a motor is applied to one of the pulleys, causing the timing belt to circulate between the pair of pulleys. The motor rotates the pulleys in both forward and reverse directions. As a result, the timing belt reciprocates along the extension direction of the rails, moving the binding unit supported by the base in the direction of movement.

[0006] Incidentally, the moving mechanism disclosed in Patent Document 2 has the rotation axes of a pair of pulleys that tension the timing belt oriented vertically. In other words, the timing belt is configured to circulate within the horizontal plane. In such a configuration, the timing belt occupies a certain area adjacent to the rail, making it difficult to miniaturize the moving mechanism. If the moving mechanism cannot be miniaturized, the size of the post-processing device will also increase. Therefore, it becomes difficult to install the post-processing device in the space inside the cylinder of the image forming apparatus.

[0007] On the other hand, by installing the timing belt inside the rail, the installation area of ​​the timing belt overlaps with the installation area of ​​the rail, enabling space saving in the horizontal plane. However, adopting such a configuration requires housing a pair of pulleys and the timing belt inside the rail, which increases the rail height and thus the height of the moving mechanism. As a result, the overall height of the post-processing device also increases, making it difficult to install it in the internal space of the image forming apparatus. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2020-168808 [Patent Document 2] Japanese Patent Application Publication No. 9-86778 [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention was made to solve the above-mentioned conventional problems. Specifically, the present invention aims to provide a post-processing device that allows for a smaller-than-conventional-sized moving mechanism for moving a binding unit in a post-processing device installed in the internal space of an image forming apparatus, and an image forming apparatus equipped with such a post-processing device. [Means for solving the problem]

[0010] To achieve the above objective, the invention according to claim 1 is a post-processing device installed in the internal space of an image forming apparatus, comprising: a binding unit that performs binding on a sheet; and a moving mechanism that moves the binding unit in a direction perpendicular to the sheet transport direction, wherein the moving mechanism comprises: a rail extending in the direction of movement and supporting the binding unit so as to be movable in the direction of movement; pulleys provided at both ends of the rail in the direction of movement; and a timing belt stretched over the pulleys and rotatingly driving the pulleys to move the binding unit along the rail in the direction of movement, wherein the pulleys are configured such that their axis of rotation is set at an angle of 45 degrees or less with respect to the horizontal axis.

[0011] The invention according to claim 2 is a post-processing device according to claim 1, characterized in that the length of the moving mechanism in the sheet transport direction is shorter than the length of the binding unit.

[0012] The invention according to claim 3 is a post-processing device according to claim 1, characterized in that the pulley is installed so that the rotating shaft is horizontal.

[0013] The invention according to claim 4 is characterized in that, in the post-processing device of claim 1, the binding unit is provided at the rear end position of an inclined alignment tray for aligning the rear end of a sheet, the rail has an inclined surface that supports the binding unit in an inclined state parallel to the inclination of the alignment tray, and the pulley is provided outside the highest position of the inclined surface.

[0014] The invention according to claim 5 is a post-processing device according to claim 4, characterized in that the diameter of the pulley is smaller than the height of the inclined surface.

[0015] The invention according to claim 6 is a post-processing device according to claim 4, characterized in that a wall portion is provided at the highest end of the inclined surface, and the rotation axis of the pulley is provided at the wall portion.

[0016] The invention according to claim 7 is a post-processing device according to claim 6, characterized in that the wall portion is formed perpendicular to the inclined surface.

[0017] The invention according to claim 8 is a post-processing device according to claim 6, characterized in that the wall portion is formed in the vertical direction.

[0018] The invention according to claim 9 is an image forming apparatus having a scanner unit and a printer unit, wherein an internal space is formed between the scanner unit and the printer unit, and the post-processing device according to any one of claims 1 to 8 is installed in the internal space. [Effects of the Invention]

[0019] According to the present invention, the mechanism for moving the binding unit can be made smaller than in the conventional method. As a result, the post-processing device can be made smaller, making it possible to install the post-processing device in the space inside the cylinder of the image forming apparatus. [Brief explanation of the drawing]

[0020] [Figure 1] It is a diagram showing a configuration example of an image forming apparatus. [Figure 2] It is a diagram showing a configuration example of a post-processing apparatus. [Figure 3] It is a plan view of the collation tray seen from above. [Figure 4] It is a perspective view showing details of the binding unit and the moving mechanism. [Figure 5] It is a side view showing details of the binding unit and the moving mechanism. [Figure 6] It is a diagram showing a moving mechanism in which the wall portion of the rail is erected in the vertical direction. [Figure 7] It is a diagram showing a preferable relationship between the height of the inclined surface of the rail and the diameter of the pulley.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, preferred embodiments of the present invention will be described in detail while referring to the drawings. In the embodiments described below, elements common to each other are denoted by the same reference numerals, and redundant descriptions thereof are omitted.

[0022] FIG. 1 is a conceptual diagram showing an image forming apparatus 1 according to an embodiment of the present invention. The XYZ three-dimensional coordinate system shown in FIG. 1 is a coordinate system in which the XY plane is a horizontal plane and the Z direction is a vertical direction, and is a coordinate system common to other figures. This image forming apparatus 1 is configured as an MFP and has a plurality of functions such as a scan function, a print function, and a copy function.

[0023] The image forming apparatus 1 has a scanner unit 2 at the top of the apparatus body 1a and a printer unit 4 at the bottom of the apparatus body 1a. The scanner unit 2 operates when a job related to scanning or copying is executed, optically reading the image of a document set by the user and generating image data. The printer unit 4 operates when a job related to printing or copying is executed, forming and outputting an image on a sheet such as printing paper. The image forming apparatus 1 also has an operation panel 3 on the front side of the apparatus body 1a that can be operated by the user. The operation panel 3 is a user interface that displays a screen that can be operated by the user and accepts user input.

[0024] The image forming apparatus 1 has an internal space 6 between the scanner unit 2 and the printer unit 4 in the vertical direction. The printer unit 4 discharges the image-formed sheet into the internal space 6. The image forming apparatus 1 has a post-processing device 5 installed in the internal space 6. The post-processing device 5 receives the sheet discharged from the printer unit 4, performs post-processing on the sheet, and then discharges it. Post-processing performed in the post-processing device 5 is, for example, the process of binding multiple sheets together.

[0025] Figure 1 shows the internal structure of the printer unit 4. As shown in Figure 1, the printer unit 4 comprises a paper feed and transport unit 10 and an image forming unit 20. The printer unit 4 also includes a control unit 7 that comprehensively controls the operation of the image forming apparatus 1.

[0026] The paper feed and transport unit 10 feeds sheets 9 from one of the multiple paper feed trays 10a, 10b, and 10c, and transports the sheets 9 along a transport path 13 formed inside the printer unit 4. The multiple paper feed trays 10a, 10b, and 10c may each contain different types of sheets 9, or they may each contain the same type of sheet 9. Each paper feed tray 10a, 10b, and 10c is provided with a pickup roller 11 and a paper feed roller 12. The paper feed and transport unit 10 drives the pickup roller 11 and paper feed roller 12 provided on one of the paper feed trays designated by the user, and feeds the sheets 9 toward the transport path 13. The paper feed and transport unit 10 transports the sheets 9 that have been sent toward the transport path 13 along the direction of arrow F1.

[0027] The transport path 13 is equipped with a sheet detection unit 14, a timing roller 15, a secondary transfer roller 16, a fixing unit 17, and an discharge roller 18.

[0028] The sheet detection unit 14 is installed at a predetermined position in the transport path 13 and detects the sheet 9 as it passes through that predetermined position. For example, the sheet detection unit 14 has the function of a media sensor and can detect the type of sheet 9, such as its thickness and basis weight. The detection result from the sheet detection unit 14 is output to the control unit 7. The control unit 7 controls the fixing temperature in the fixing unit 17, etc., based on the type of sheet 9 detected by the sheet detection unit 14.

[0029] The timing roller 15 is composed of a pair of rollers. The timing roller 15 is a roller that adjusts the timing for feeding the sheet 9 to the secondary transfer position by the secondary transfer roller 16. When the leading edge of the sheet 9 fed from the paper trays 10a, 10b, and 10c reaches the position of the timing roller 15, the paper feed transport unit 10 temporarily stops transporting the sheet 9. Then, the paper feed transport unit 10 drives the timing roller 15 in accordance with the timing when the image that has been primary transferred to the intermediate transfer belt 22 in the image forming unit 20 is transported to the secondary transfer position, and transports the sheet 9 toward the secondary transfer roller 16.

[0030] The sheet 9, fed out by the timing roller 15, has its image transferred to it as it passes the secondary transfer position by the secondary transfer roller 16. The sheet 9 with the image transferred to it is then transported to the fixing unit 17.

[0031] The image forming unit 20 includes image forming units 21Y, 21M, 21C, and 21K corresponding to yellow (Y), magenta (M), cyan (C), and black (K), respectively, and an intermediate transfer belt 22.

[0032] The image forming unit 21Y is a unit that forms an image of a color corresponding to Y. The image forming unit 21Y comprises an image carrier 25 composed of a photosensitive drum and the like, a charger 26, an exposure unit 27, and a developer unit 28. The image carrier 25 has a photosensitive layer on the surface of a cylindrical body and rotates in a predetermined direction (clockwise). The charger 26, exposure unit 27, and developer unit 28 are arranged around the image carrier 25. The charger 26 charges the surface of the image carrier 25 to a predetermined charge. The exposure unit 27 exposes the surface of the charged image carrier 25 based on image data, thereby forming an electrostatic latent image on the surface of the image carrier 25. The developer unit 28 supplies toner to the surface of the image carrier 25 and develops the electrostatic latent image with toner. As a result, an image (toner image) corresponding to the image data is formed on the surface of the image carrier 25.

[0033] The other image forming units 21M, 21C, and 21K have the same configuration as image forming unit 21Y, differing only in the color of the toner supplied to the image carrier 25. In other words, multiple image forming units 21Y, 21M, 21C, and 21K, each with the same configuration, are arranged horizontally at predetermined intervals.

[0034] The intermediate transfer belt 22 is an endless belt positioned above the image forming units 21Y, 21M, 21C, and 21K. The intermediate transfer belt 22 is stretched over a drive roller 23 positioned opposite the secondary transfer roller 16 and a driven roller 24 positioned at a predetermined distance from the drive roller 23. As the drive roller 23 is rotated counterclockwise, the intermediate transfer belt 22 moves in a circular motion in the direction indicated by arrow F2. The intermediate transfer belt 22 contacts the secondary transfer roller 16 at the position of the drive roller 23.

[0035] Inside the intermediate transfer belt 22, primary transfer rollers 29 are provided at positions facing each image forming unit 21Y, 21M, 21C, and 21K. The primary transfer rollers 29 are operated by applying a predetermined voltage while the intermediate transfer belt 22 is pressed against the image carriers 25 of each image forming unit 21Y, 21M, 21C, and 21K, thereby primary transferring the image (toner image) formed on the image carriers 25 to the intermediate transfer belt 22. Each image forming unit 21Y, 21M, 21C, and 21K performs primary transfer, sequentially superimposing the Y, M, C, and K images onto the intermediate transfer belt 22. As a result, a color image is formed on the surface of the intermediate transfer belt 22. The image transferred to the intermediate transfer belt 22 is then secondary transferred to the sheet 9 at the position of the secondary transfer roller 16.

[0036] The fixing unit 17 fixes the image onto the sheet 9 by applying heat and pressure to the sheet on which the image has been formed. For example, the fixing unit 17 has a heating roller and a pressure roller, and heat and pressure are applied to the sheet 9 at the nip between the heating roller and the pressure roller. The surface temperature of the heating roller is controlled by the control unit 7 to a temperature suitable for the type of sheet 9. The sheet 9 on which the image has been fixed in the fixing unit 17 is discharged into the cylinder space 6 via the discharge roller 18.

[0037] The post-processing device 5 sequentially receives the sheets 9 discharged from the printer unit 4 as described above. The post-processing device 5 aligns the multiple sheets 9 in the internal space 6 of the image forming apparatus 1 and performs post-processing such as binding on the multiple sheets 9. The post-processing device 5 then discharges the post-processed sheets 9 from the internal space 6.

[0038] Figure 2 shows an example configuration of the post-processing device 5. The post-processing device 5 comprises a housing 30, a transport path 31, transport rollers 32 and 33, an alignment tray 34, a binding unit 50, and a paper output tray 41. An inlet 30a for receiving sheets 9 is provided on the right side wall of the housing 30. The post-processing device 5 receives the sheets 9 discharged from the printer unit 4 through the inlet 30a and transports them inside the housing 30 along the transport path 31. The transport rollers 32 and 33 are a pair of rollers arranged above and below the transport path 31, and transport the sheets 9 upwards towards the alignment tray 34. That is, the transport direction of the sheets 9 in the post-processing device 5 corresponds to the Y direction shown in Figure 2.

[0039] The alignment tray 34 is a tray that aligns multiple sheets 9 on its upper surface. The alignment tray 34 is inclined with respect to the conveying direction of the sheets 9. That is, the alignment tray 34 is inclined such that the downstream side of the sheets 9 in the conveying direction is at a higher position, and the upstream side of the sheets 9 in the conveying direction is at a lower position. A stopper 35 is provided at the lower end of the alignment tray 34. The stopper 35 is for aligning the rear end of the sheets 9 to a predetermined position.

[0040] A first alignment member 36 is provided above the alignment tray 34. The first alignment member 36 is a member that aligns the sheet 9 in the direction of transport on the alignment tray 34. The first alignment member 36 is rotatable around a rotation axis 36a, and a rotating member 36b provided at its tip can swing forward and backward toward the upper surface of the alignment tray 34. The rotating member 36b is provided with a paddle 36c formed of an elastic material. When a sheet 9 is discharged from the transport roller 33, the first alignment member 36 lowers the rotating member 36b, pressing down on the sheet 9 and causing it to fall onto the upper surface of the alignment tray 34. At this time, the first alignment member 36 rotates the rotating member 36b in a predetermined direction (counterclockwise), causing the paddle 36c to rotate. The paddle 36c rotates while in contact with the sheet 9 that has fallen onto the upper surface of the alignment tray 34, transporting the sheet 9 toward the stopper 35. In other words, the paddle 36c transports the sheet 9 toward the lower side of the inclined alignment tray 34, allowing the sheet 9 to move smoothly. This aligns the rear end of the sheet 9 to the stopper 35. The first alignment member 36 then raises the rotating member 36b and waits until the next sheet 9 is discharged.

[0041] A second alignment member 37 is provided on the side of the alignment tray 34. The second alignment member 37 is a member that aligns the sheet 9 in the alignment tray 34 in a direction perpendicular to the conveying direction of the sheet 9. Figure 3 is a plan view of the alignment tray 34 as seen from above. As shown in Figure 3, the second alignment members 37 are provided on both sides of the alignment tray 34 in a direction perpendicular to the conveying direction of the sheet 9. The pair of second alignment members 37 arranged on both sides of the alignment tray 34 move back and forth in the X1 direction shown in Figure 3, aligning the sheet 9 that has fallen onto the alignment tray 34 to the center of the alignment tray 34 in a direction perpendicular to the conveying direction of the sheet 9.

[0042] Furthermore, a transport mechanism 38 is provided below the alignment tray 34 to transport the sheets 9 bound by the binding unit 50 toward the output tray 41. The transport mechanism 38 has a locking piece (not shown). The transport mechanism 38 locks its locking piece to the rear end of the sheet 9 and moves along the inclined surface of the alignment tray 34, thereby transporting the sheet bundle, of multiple sheets 9 bound together, toward the output tray 41. As a result, the processed sheets 9 are discharged into the output tray 41. Further below the transport mechanism 38, a first alignment member 36, a second alignment member 37, and a control board 39 for controlling the operation of the transport mechanism 38 are provided.

[0043] The stapling unit 50 is positioned adjacent to the alignment tray 34. Specifically, the stapling unit 50 is positioned close to the lowest point of the alignment tray 34 on the upstream side in the conveying direction of the sheets 9. The stapling unit 50 is a unit that staples the rear ends of multiple sheets 9 aligned by the stopper 35. This stapling unit 50 has a movable part 51 that clamps and staples the rear ends of multiple sheets 9. For example, by operating its movable part 51, the stapling unit 50 drives staples into the rear ends of multiple sheets 9 aligned on the alignment tray 34, thereby stapling the multiple sheets 9. The stapling unit 50 is movable in a direction perpendicular to the conveying direction of the sheets 9 (X direction), and the stapling position at the rear end of the sheets 9 can be adjusted.

[0044] The post-processing device 5 includes a moving mechanism 60 that moves the binding unit 50 in a direction perpendicular to the conveying direction of the sheet 9 (the X direction). The moving mechanism 60 engages with a base 52 that supports the binding unit 50, and moves the base 52 in the X direction, thereby moving the binding unit 50 in the X direction. The moving mechanism 60 moves the binding unit 50 to the binding position specified in the job settings.

[0045] As shown in Figure 3, the moving mechanism 60 includes a rail 61 that guides the movement of the stapling unit 50. The stapling unit 50 moves in the X direction along the rail 61. When the stapling unit 50 moves along the center of the rail 61 extending in the X direction, it maintains a frontal orientation relative to the alignment tray 34 (see dashed line in Figure 3). Therefore, when the stapling unit 50 drives staples into the center of the rear end of the sheet 9, it can drive staples parallel to the rear edge of the sheet 9. In contrast, near the end of the rail 61, the stapling unit 50 changes from a frontal orientation relative to the alignment tray 34 to an oblique orientation (see solid line in Figure 3). Therefore, when the stapling unit 50 drives staples into the corners of the sheet 9, it can drive staples in an oblique direction.

[0046] Figure 4 is a perspective view showing details of the binding unit 50 and the moving mechanism 60. Figure 5 is a side view showing details of the binding unit 50 and the moving mechanism 60. As shown in Figures 4 and 5, the rail 61 supports the binding unit 50 at a predetermined angle of inclination in order to align it with the inclined alignment tray 34. The inclination angle of the binding unit 50 matches the inclination angle of the alignment tray 34. Therefore, the rail 61 has an inclined surface 62 that is parallel to the inclination of the alignment tray 34. The inclined surface 62 gradually increases in height from the upstream side to the downstream side in the direction of sheet 9 transport. This inclined surface 62 supports the binding unit 50 in an inclined position parallel to the alignment tray 34. A wall portion 63 is provided at the highest point of the inclined surface 62. The wall portion 63 is erected from the installation surface of the moving mechanism 60 and supports the end of the inclined surface 62, thereby holding the inclined surface 62 inclined at the same angle as the alignment tray 34. In the example shown in Figure 5, the wall portion 63 is formed perpendicular to the inclined surface 62.

[0047] The moving mechanism 60 also includes a pair of pulleys 65, 65 and a timing belt 66. The pair of pulleys 65, 65 are provided at both ends of the rail 61. As shown in Figure 5, the rotation axis 65a of the pulleys 65 is mounted perpendicular to the wall portion 63 of the rail 61. A motor 67 is connected to the rotation axis 65a of one of the two pulleys 65, 65, and it rotates in both forward and reverse directions by the rotational force of the motor 67. The other pulley 65 is rotatably mounted relative to the rotation axis 65a.

[0048] The timing belt 66 is an endless belt stretched between a pair of pulleys 65, 65. In other words, the timing belt 66 is stretched in a direction perpendicular to the conveying direction of the sheet 9 (the X direction). As one pulley 65 rotates due to the motor 67, the timing belt 66 circulates between the pair of pulleys 65, 65. The direction of this movement is perpendicular to the conveying direction of the sheet 9 (the X direction). One pulley 65 is rotated in both forward and reverse directions by the motor 67. Therefore, the timing belt 66 circulates in a direction corresponding to the direction of rotation by the motor 67.

[0049] The base 52 of the binding unit 50 is provided with a locking portion 59 that engages with the timing belt 66. For example, the locking portion 59 is fixed to a predetermined position on the timing belt 66 by screws or the like. As a result, the timing belt 66 is driven by the rotation of the pulley 65, which moves the binding unit 50 along the rail 61 in a direction of movement (X direction) perpendicular to the sheet transport direction.

[0050] As shown in Figure 5, the base 52 comprises a first base 53 and a second base 54. The first base 53 supports the bottom surface of the binding unit 50. The second base 54 is positioned on the underside of the first base 53 and rotatably supports the first base 53 that supports the binding unit 50. When the binding unit 50 is driven in the X direction and moves from near the end of the rail 61 towards the end, the first base 53 rotates relative to the second base 54, changing the orientation of the binding unit 50 relative to the alignment tray 34 from a frontal orientation to an oblique orientation. The locking portion 59 that connects the base 52 to the timing belt 66 is attached to the second base 54. That is, the locking portion 59 is attached to the second base 54, which does not change the orientation relative to the alignment tray 34.

[0051] Engagement pins 55 and 56 protrude from the lower surface of the base 52. These engagement pins 55 and 56 extend downward at an angle perpendicular to the lower surface of the second base 54. These engagement pins 55 and 56 are inserted into guide portions 62a and 62b provided on the inclined surface 62 of the rail 61 and engage with the guide portions 62a and 62b. The guide portions 62a and 62b are formed along the longitudinal direction (X direction) of the rail 61 and allow the binding unit 50 to move along the rail 61 in the X direction. The guide portions 62a and 62b may be slit-shaped holes or grooves.

[0052] Furthermore, rollers 57 and 58 are provided on the underside of the base 52, which are joined to and roll on the upper surface of the rail 61. These rollers 57 and 58 extend downward from, for example, the underside of the second base 54 and are placed on the upper surface of the rail 61. The rollers 57 and 58 roll on the rail 61 when the binding unit 50 moves. Therefore, the binding unit 50 can move smoothly on the rail 61 when the timing belt 66 is driven.

[0053] As described above, the rotation shafts 65a of the pair of pulleys 65, 65 are mounted perpendicular to the wall portion 63. The wall portion 63 is mounted perpendicular to the inclined surface 62, as shown in Figure 5. Therefore, the rotation shafts 65a of the pulleys 65, 65 are inclined at an angle θ equal to that of the inclined surface 62. In other words, the moving mechanism 60 mounts the rotation shafts 65a of the pulleys 65, 65 at a predetermined angle θ with respect to the horizontal axis. In this embodiment, the mounting angle θ of the rotation shafts 65a is set to 45 degrees or less (0°≦θ≦45°). As a result, the pair of pulleys 65, 65 tension the timing belt 66 not in a horizontal plane, but in an upright position in an oblique vertical direction. Therefore, the area occupied by the pair of pulleys 65, 65 and the timing belt 66 in the horizontal plane is smaller than in conventional designs. This has the advantage of allowing for a reduction in the size of the moving mechanism 60 in the sheet transport direction (Y direction).

[0054] Furthermore, the pair of pulleys 65, 65 are positioned on the outside of the rail 61, close to the wall 63. Therefore, the moving mechanism 60 can install the pair of pulleys 65, 65 and the timing belt 66 on the rail 61 without increasing the height of the rail 61. Thus, the moving mechanism 60 can be made to minimize an increase in its height, and the overall height of the post-processing device 5 can also be made to minimize an increase in its height. For this reason, the post-processing device 5, by being equipped with the moving mechanism 60 described above, can be properly installed in the internal space 6 of the image forming apparatus 1.

[0055] Furthermore, as shown in Figure 5, the length Y2 of the moving mechanism 60 in the sheet transport direction is shorter than the length Y1 of the binding unit 50. Therefore, the moving mechanism 60 fits on the underside of the binding unit 50 in the sheet transport direction. Consequently, the moving mechanism 60 contributes to miniaturization of the post-processing device 5 in the sheet transport direction.

[0056] Furthermore, the angle θ of the rotation axis 65a should be as small as possible within the range of 45 degrees or less. Figure 6 shows a moving mechanism 60 in which the wall portion 63 of the rail 61 is erected in the vertical direction (Z direction). In the moving mechanism 60 shown in Figure 6, the wall portion 63 of the rail 61 is erected in the vertical direction. The rotation axis 65a of the pulley 65 is attached to the erected wall portion 63. Therefore, the rotation axis 65a of the pulley 65 is held in a horizontal state parallel to the Y axis. In this case, the pair of pulleys 65, 65 are stretched in the XZ plane in which the timing belt 66 is erected in the vertical direction. Therefore, the area occupied by the pair of pulleys 65, 65 and the timing belt 66 in the horizontal plane is even smaller than that of the moving mechanism 60 shown in Figure 5. This has the advantage of further reducing the size of the moving mechanism 60 in the sheet transport direction (Y direction).

[0057] Furthermore, the moving mechanism 60 shown in Figure 6, like the one in Figure 5, has a length Y2 in the sheet transport direction that is shorter than the length Y1 of the binding unit 50. Therefore, the moving mechanism 60 fits on the underside of the binding unit 50 in the sheet transport direction. Consequently, the moving mechanism 60 contributes to miniaturization of the post-processing device 5 in the sheet transport direction.

[0058] As shown in Figure 6, if the rotation axis 65a of the pulley 65 is installed parallel to the horizontal axis, the mounting angle θ of the rotation axis 65a becomes 0 degrees. Therefore, the area occupied by the pair of pulleys 65, 65 and the timing belt 66 in the horizontal plane is minimized, and the size of the moving mechanism 60 can be minimized. However, if it is difficult to install the rotation axis 65a of the pulley 65 parallel to the horizontal axis, the rotation axis 65a can be set to be approximately horizontal.

[0059] When the rotation axis 65a of the pulley 65 is installed approximately horizontally, it is preferable that the pulley 65 be formed with a diameter corresponding to the height of the inclined surface 62 of the rail 61. Figure 7 shows a preferred relationship between the height H of the inclined surface 62 of the rail 61 and the diameter D of the pulley 65. In the moving mechanism 60 shown in Figure 7, the diameter D of the pulley 65 is formed to be smaller than the height H of the inclined surface 62. Therefore, even when the rotation axis 65a is installed approximately horizontally, the amount of protrusion of the upper end of the pulley 65 from the upper end of the inclined surface 62 can be reduced. For example, it is also possible to configure the upper end of the pulley 65 so that it does not protrude from the upper end of the inclined surface 62. Consequently, the height dimension of the moving mechanism 60 can be kept small, which also contributes to reducing the height dimension of the post-processing device 5.

[0060] As described above, the post-processing device 5 of this embodiment is equipped with a moving mechanism 60 that moves the binding unit 50 in a direction perpendicular to the sheet transport direction. The moving mechanism 60 has a rail 61, pulleys 65 provided at both ends of the rail 61, and a timing belt 66 stretched over the pulleys 65. The rotation axis 65a of the pulleys 65 is set at an angle of 45 degrees or less with respect to the horizontal axis. With this configuration, the post-processing device 5 can reduce the area occupied by the pulleys 65 and the timing belt 66 in the horizontal plane, thus reducing the size in the sheet transport direction compared to conventional devices. Furthermore, by setting the rotation axis 65a of the pulleys 65 to be approximately horizontal, it is possible to further reduce the size in the sheet transport direction.

[0061] Furthermore, by positioning the pulley 65 on the outside of the highest point of the inclined surface 62, the moving mechanism 60 can be installed with the pulley 65 and timing belt 66 without increasing the height of the rail 61. Therefore, the moving mechanism 60 can be made smaller not only in the sheet transport direction but also in the height direction.

[0062] The post-processing device 5, equipped with the above-described moving mechanism 60, can be made smaller in size in the sheet transport direction and height direction, and can therefore be realized in a size that can be installed in the internal space 6 of the image forming apparatus 1.

[0063] Preferred embodiments of the present invention have been described above. However, the present invention is not limited to those described in the above embodiments, and various modifications are applicable.

[0064] For example, in the above embodiment, a configuration was described in which the rotation shaft 65a of the pulley 65 is attached to the wall portion 63 of the rail 61. However, the rotation shaft 65a of the pulley 65 is not limited to being attached to the wall portion 63 of the rail 61. For example, the rotation shaft 65a of the pulley 65 may be attached to a member other than the wall portion 63. [Explanation of Symbols]

[0065] 1. Image forming apparatus 2. Scanner section 4. Printer section 5. Post-processing equipment 6 Interior space 34 Alignment Trays 50 binding units 60 Moving mechanism 61 rails 62 Slope 63 Wall 65 Pulley 65a Rotating shaft 66 Timing belt

Claims

1. A post-processing device installed in the internal space of an image forming apparatus, A binding unit that performs binding on sheets, A moving mechanism for moving the binding unit in a direction perpendicular to the sheet transport direction, Equipped with, The aforementioned moving mechanism is A rail extending in the direction of movement and supporting the binding unit so as to be movable in the direction of movement, Pulleys provided at both ends of the rail in the aforementioned direction of movement, A timing belt stretched over the pulley, which rotates the pulley, thereby moving the binding unit along the rail in the direction of movement; It has, The post-processing device is characterized in that the pulley is installed at an angle of 45 degrees or less with respect to the horizontal axis.

2. The post-processing device according to claim 1, characterized in that the length of the moving mechanism in the sheet transport direction is shorter than the length of the binding unit.

3. The post-processing device according to claim 1, characterized in that the pulley is installed so that the rotating shaft is horizontal.

4. The binding unit is provided at the rear end position of an inclined alignment tray to align the rear end of the sheet. The rail has an inclined surface that supports the binding unit in an inclined state parallel to the inclination of the alignment tray. The post-processing apparatus according to claim 1, characterized in that the pulley is provided on the outside of the highest position of the inclined surface.

5. The post-processing device according to claim 4, characterized in that the diameter of the pulley is smaller than the height of the inclined surface.

6. A wall is provided at the highest point of the inclined surface. The post-processing device according to claim 4, characterized in that the rotation axis of the pulley is provided on the wall portion.

7. The post-processing apparatus according to claim 6, characterized in that the wall portion is formed perpendicular to the inclined surface.

8. The post-processing apparatus according to claim 6, characterized in that the wall portion is formed in the vertical direction.

9. An image forming apparatus having a scanner unit and a printer unit, wherein an internal space is formed between the scanner unit and the printer unit, An image forming apparatus characterized in that a post-processing device according to any one of claims 1 to 8 is installed in the internal space of the body.

Images