Image forming apparatus

Abstract

To provide an image forming apparatus capable of suppressing deviation of a sheet cutting position.SOLUTION: An image forming apparatus 1 includes: an image forming unit 3; a cutter mechanism 4; a first conveying roller pair 70 located upstream of blades 411 and 412 of the cutter mechanism 4 in a conveying direction DT1, the first conveying roller pair 70 nipping a sheet SH on which an image has been formed with a first nip 70N and conveying the sheet toward the blades 411 and 412; conveying guides 100 and 200 located downstream of the first conveying roller pair 70 in the conveying direction DT1 and having a first guide surface 101 and a second guide surface 202, respectively; and a sensor S4 configured to detect the sheet SH passing through the conveying guides 100 and 200. The sensor S4 has a detection area AS1 in which the sensor S4 detects the sheet SH between the first guide surface 101 and the second guide surface 202, and the detection area AS1 is located on a nip tangent TN1 of the first nip 70N when viewed along a cutting direction DC1.SELECTED DRAWING: Figure 24

Description

[Technical field]

[0001] The present invention relates to an image forming apparatus. [Background technology]

[0002] Patent Document 1 discloses an example of a conventional image forming apparatus. This image forming apparatus includes a cutting device. The cutting device has a cutter mechanism including a first cutting section. The guillotine blade and the counter blade of the first cutting section cut the sheet that has passed through the fixing device in a cutting direction perpendicular to the conveying direction.

[0003] The image forming apparatus also includes a pair of pre-registration rollers, a pair of registration rollers, and an entrance sensor. The pair of pre-registration rollers and the pair of registration rollers are located upstream of the guillotine blade and the opposing blade of the first cutting unit in the conveying direction, and nip the sheet that has passed through the fixing device and convey it toward the guillotine blade and the opposing blade. The entrance sensor is located upstream of the pair of pre-registration rollers in the conveying direction, and detects the sheet that has passed through the fixing device and is heading toward the pair of pre-registration rollers.

[0004] This image forming apparatus controls the timing for stopping the pair of pre-registration rollers and the pair of registration rollers based on the detection result of the entrance sensor, and cuts the stopped sheet by the first cutting unit. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2023-19469 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the conventional image forming apparatus described above, since the inlet sensor is located upstream of the pair of pre-registration rollers in the conveying direction, the leading edge of the sheet is detected at a position far away from the cutter mechanism.

[0007] Therefore, even if this image forming device controls the timing of stopping the pre-registration roller pair and the registration roller pair based on the detection results of the entrance sensor, the position of the stopped sheet tends to deviate from the expected position, making it difficult to suppress deviations in the cutting position of the sheet.

[0008] The present invention has been made in consideration of the above-mentioned conventional circumstances, and has an object to provide an image forming apparatus capable of suppressing deviation of the cutting position of the sheet. [Means for solving the problem]

[0009] The image forming apparatus of the present invention includes an image forming unit that forms an image on a sheet transported in a transport direction; a cutter mechanism having a blade for cutting the sheet on which an image is formed in a cutting direction perpendicular to the conveying direction; a first conveying roller pair that is located upstream of the blade of the cutter mechanism in the conveying direction and that nip the sheet on which an image is formed by a first nip and conveys the sheet toward the blade; a conveying guide that is located downstream of the first conveying roller pair in the conveying direction and that guides a sheet, the conveying guide having a first guide surface that guides the sheet and a second guide surface that faces the first guide surface and guides the sheet; a sensor that detects a sheet passing through the conveying guide, the sensor having a detection area that detects the sheet between the first guide surface and the second guide surface, the detection area being positioned on a nip tangent to the first nip as viewed along the cutting direction; The present invention is characterized by comprising:

[0010] In the image forming apparatus of the present invention, the detection region where the sensor detects the sheet between the first guide surface and the second guide surface of the conveying guide is, for example, a region where the leading edge of the actuator that is not swinging, which can abut against the leading edge of the sheet, extends between the first guide surface and the second guide surface if the sensor is a contact sensor having an actuator that swings when the leading edge of the sheet abuts against it. Also, if the sensor is a non-contact sensor such as a light reflection sensor or a light transmission sensor, the detection region is a region where the emitted light passes between the first guide surface and the second guide surface when the emitted light is not blocked by the sheet.

[0011] When viewed along the cutting direction, the detection area is located on a nip tangent to the first nip, so that the sheet conveyed by the first conveying roller pair and passing through the conveying guide reaches the detection area with little tendency to sag or bend, and therefore the travel distance of the leading edge of the sheet is less likely to vary.

[0012] Therefore, in this image forming apparatus, when the timing for stopping the first conveyor roller pair is controlled based on the detection result of the sensor, the position of the stopped sheet is unlikely to deviate from the expected position.

[0013] Therefore, the image forming apparatus of the present invention can suppress deviation of the cutting position of the sheet. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of an image forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a front view of the image forming apparatus according to the embodiment. [Diagram 3] FIG. 3 is a side view of the image forming apparatus according to the embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view of the image forming apparatus of the embodiment, showing a state in which the second guide is in the first guide position, the pre-cutting cover is in the first cover position, and the exterior cover is closed. [Diagram 5]FIG. 5 is a partial perspective view of the image forming apparatus of the embodiment, showing a state in which the pre-cutting cover is in the second cover position and the exterior cover is open. [Figure 6] FIG. 6 is a schematic cross-sectional view similar to FIG. 4, illustrating a state in which the second guide is in the second guide position, the pre-cutting cover is in the second cover position, and the exterior cover is open. [Figure 7] FIG. 7 is a schematic cross-sectional view similar to FIG. 4, illustrating a state in which the second guide is in the first guide position, the pre-cutting cover is in the first cover position, and the exterior cover is open. [Figure 8] FIG. 8 is an enlarged partial perspective view of the main part of FIG. [Figure 9] FIG. 9 is a perspective view showing the pre-cutting cover, the first conveyor roller, and the contact piece. [Figure 10] FIG. 10 is a perspective view showing the pre-cutting cover, the first conveyor roller, and the contact piece. [Figure 11] FIG. 11 is a perspective view showing a unit including the cutter mechanism, the first guide and the pre-cutting guide. [Figure 12] FIG. 12 is a partial schematic cross-sectional view in which a main part of FIG. 4 is enlarged. [Figure 13] FIG. 13 is a perspective view showing a unit including the cutter mechanism, the first guide and the pre-cutting guide. [Figure 14] FIG. 14 is an exploded perspective view of the cutter mechanism, the first guide, and the pre-cutting guide. [Figure 15] FIG. 15 is a front view showing a unit including the cutter mechanism, the first guide and the pre-cutting guide. [Figure 16] FIG. 16 is a front view showing the cutter mechanism. [Figure 17] FIG. 17 is a perspective view showing the pre-cutting guide. [Figure 18] FIG. 18 is a partial top view showing a unit of the cutter mechanism, the first guide and the pre-cutting guide, and the joint cover. [Figure 19] FIG. 19 is a partial perspective view mainly showing the cutter mechanism, the joint cover, and the first housing. [Figure 20] FIG. 20 is an enlarged partial perspective view of the main part of FIG. [Figure 21] FIG. 21 is a partial schematic cross-sectional view showing a state in which the biasing member applies a first biasing force to the second guide located at the first guide position. [Figure 22] FIG. 22 is a partial schematic cross-sectional view showing a state in which the biasing member applies a second biasing force to the second guide at the second guide position. [Figure 23] FIG. 23 is a perspective view showing the second guide. [Figure 24] FIG. 24 is a schematic partial cross-sectional view in which a part of FIG. 12 is simplified. [Diagram 25] FIG. 25 is a partial schematic cross-sectional view in which a main part of FIG. 4 is enlarged, illustrating the moving distance of the sheet. [Figure 26] FIG. 26 is a partial top view illustrating the folding back position of the moving blade of the cutter mechanism. [Figure 27] FIG. 27 is a partial top view showing a state in which the pre-cutting cover at the first cover position abuts against the pre-cutting guide and is thereby indirectly positioned to the cutter frame. [Figure 28] FIG. 28 is a partial perspective view of the image forming apparatus according to the embodiment, mainly showing the attachment / detachment opening. [Figure 29] FIG. 29 is a perspective view of the cutter carriage. [Diagram 30] FIG. 30 is a perspective view of the cutter carriage. [Diagram 31] FIG. 31 is an exploded perspective view of the cutter carriage. [Diagram 32] FIG. 32 is an exploded perspective view of the cutter carriage. [Diagram 33] FIG. 33 is a perspective view of the moving blade holder and the moving blade. [Diagram 34] FIG. 34 is a perspective view of the moving blade holder and the moving blade. [Diagram 35] FIG. 35 is an exploded perspective view of the moving blade holder and the moving blade. [Diagram 36]FIG. 36 is a cross-sectional view showing the AA cross section in FIG. 16, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Figure 37] FIG. 37 is a cross-sectional view showing a cross section similar to that of FIG. 36, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Figure 38] FIG. 38 is a cross-sectional view showing the cross section BB of FIG. 16, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Figure 39] FIG. 39 is a cross-sectional view showing a cross section similar to that of FIG. 36, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Diagram 40] FIG. 40 is a cross-sectional view showing a cross section similar to that of FIG. 38, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Diagram 41] FIG. 41 is a cross-sectional view showing a cross section similar to that of FIG. 36, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Diagram 42] FIG. 42 is a cross-sectional view showing a cross section similar to that of FIG. 38, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Diagram 43] FIG. 43 is a cross-sectional view showing a cross section similar to that of FIG. 36, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Diagram 44] FIG. 44 is a cross-sectional view showing a cross section similar to that of FIG. 38, illustrating the operation of mounting the moving blade holder to the cutter carriage. [Diagram 45] FIG. 45 is a flowchart when the control unit executes a print command. [Figure 46] FIG. 46 is a partial schematic cross-sectional view similar to FIG. 24, showing an image forming apparatus according to the first modified example. [Figure 47] FIG. 47 is a schematic cross-sectional view of the image forming apparatus of the second modification, showing a state in which the second guide is in the first guide position, the pre-cutting cover is in the first cover position, and the exterior cover is closed. [Figure 48]FIG. 48 is a schematic cross-sectional view similar to FIG. 47, illustrating a state in which the second guide has moved to the second guide position. [Figure 49] FIG. 49 is a flowchart of the process performed by the control unit in the image forming apparatus according to the second modification. [Figure 50] FIG. 50 is a partial schematic cross-sectional view similar to FIG. 12, showing an image forming apparatus according to the third modification. [Figure 51] FIG. 51 is a schematic cross-sectional view similar to FIG. 6, showing an image forming apparatus according to the fourth modification. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0016] (Example) 1 to 3, an image forming apparatus 1 of the embodiment is an example of a specific aspect of the image forming apparatus of the present invention. As shown in Fig. 4, the image forming apparatus 1 is a multifunction machine including an image forming section 3 and a fixing device 7 that form an image on a sheet SH by an electrophotographic method, and an image reading section 35 that reads an image of a document.

[0017] In Fig. 1, the side of the operation panel 37 of the image forming apparatus 1 is the front. The left-right direction of the image forming apparatus 1 is a direction that is perpendicular to the front-rear direction and extends horizontally. The side that is to the left when facing the operation panel 37 is the left side. The directions shown in Fig. 2 and subsequent figures are all displayed in accordance with the directions shown in Fig. 1.

[0018] <Overall composition> 1 to 4, the image forming apparatus 1 includes a first housing 10, a second housing 30, and a joint cover 50. The first housing 10, the second housing 30, and the joint cover 50 are examples of the "housing" in the present invention.

[0019] The first housing 10 is a generally box-shaped body. The second housing 30 is a generally box-shaped body with a flat shape whose vertical length is significantly smaller than that of the first housing 10. The second housing 30 is spaced upward from the first housing 10. The joint cover 50 supports the second housing 30 from below above the first housing 10.

[0020] As shown in Fig. 4, the first housing 10 accommodates a sheet cassette 10C in its lower portion. The sheet cassette 10C supports sheets SH on which images are to be formed in a stacked state. The sheets SH are paper, overhead projector sheets, etc. The first housing 10 accommodates an image forming unit 3 and a fixing unit 7 above the sheet cassette 10C.

[0021] As shown in FIGS. 4 to 7, the first housing 10 has a maintenance opening 19 and an exterior cover 90. As shown in FIG.

[0022] The maintenance opening 19 is a large, generally rectangular opening that exposes a portion of the rear surface of the first housing 10 that is located above the rear end of the sheet cassette 10C.

[0023] As shown in Fig. 4, the exterior cover 90 closes the maintenance opening 19 in an upright state, and constitutes part of the exterior surface of the rear of the first housing 10. As shown in Figs. 5 to 7, the exterior cover 90 opens the maintenance opening 19 by rotating its lower end portion as the rotation axis and moving its upper end portion rearward and downward.

[0024] 4 and 8, the joint cover 50 has a discharge tray 9. The discharge tray 9 is located in the center in the left-right direction on the top surface of the first housing 10. The discharge tray 9 extends horizontally rearward from the front end side of the top surface of the first housing 10, and then bends and slopes downward rearward.

[0025] The second housing 30 and the joint cover 50 have a discharge space AD1. The discharge space AD1 is defined between the first housing 10 and the second housing 30.

[0026] The discharge tray 9 defines the lower side of the discharge space AD1. A sheet SH on which an image is formed after passing through the image forming unit 3 and the fixing unit 7 is discharged to the discharge space AD1. The discharge tray 9 supports the sheet SH discharged to the discharge space AD1.

[0027] 1, the joint cover 50 has support parts 57L and 57R. The support part 57L is a part of the joint cover 50 that is located to the left of the discharge tray 9 and protrudes upward. The support part 57R is a part of the joint cover 50 that is located to the right of the discharge tray 9 and protrudes upward.

[0028] As shown in Fig. 8, the joint cover 50 has inner wall surfaces 58, 59. The inner wall surface 58 is a right side surface of the support portion 57L. The inner wall surface 58 defines the left side of the discharge space AD1. As shown in Figs. 4 and 8, the inner wall surface 59 is a left side surface of the support portion 57R. The inner wall surface 59 defines the right side of the discharge space AD1, i.e., one side of a cutting direction DC1 described later.

[0029] As shown in Figs. 2 and 4, the second housing 30 houses the image reading unit 35. The image reading unit 35 is located at a position spaced above the discharge tray 9. The image reading unit 35 has a well-known configuration and will not be described briefly, but as shown in Fig. 2, the image reading unit 35 has a reading sensor 35S. The image reading unit 35 reads an image of a document placed on the upper surface of the second housing 30 by the reading sensor 35S. The document is a book, a sheet, or the like.

[0030] The support portions 57L and 57R of the joint cover 50 support the second housing 30 at their upper ends above the first housing 10. In other words, the support portions 57L and 57R support the image reading unit 35 above the image forming unit 3 and a cutter mechanism 4 described later.

[0031] 4, the discharge space AD1 is formed between the image forming unit 3, the image reading unit 35, and the support units 57L and 57R. The discharge space AD1 is a space for discharging the sheet SH cut by the cutter mechanism 4 (described later) to between the image forming unit 3 and the image reading unit 35. The discharge space AD1 is also a space for discharging the sheet SH not cut by the cutter mechanism 4 to between the image forming unit 3 and the image reading unit 35.

[0032] As shown in FIGS. 1 and 2, the second housing 30 has a document cover 40 whose top surface can be opened and closed, and an automatic document feed mechanism 45 housed in the document cover 40.

[0033] The document cover 40 has a feed tray 41 and a discharge tray 42 located at the right portion thereof. The feed tray 41 is spaced apart from the discharge tray 42 above.

[0034] The automatic document feed mechanism 45 has a well-known configuration and will not be described briefly, but has an insertion opening 45H for inserting a document to be read. As shown in Fig. 2, the automatic document feed mechanism 45 conveys a sheet-like document supported by the supply tray 41 and inserted into the insertion opening 45H to a position where it can be read by the reading sensor 35S of the image reading unit 35, and then discharges the document onto the discharge tray 42. The reading sensor 35S reads the image of the document being conveyed.

[0035] 1, the operation panel 37 protrudes forward from a portion located to the left of the discharge space AD1 on the front end surface of the second housing 30. The operation panel 37 is supported from below by a front end portion of the support portion 57L of the joint cover 50.

[0036] The operation panel 37 has an operation surface that receives operation input by a user's finger, and a display unit such as an LCD located below the operation surface. The operation panel 37 displays information indicating the operating state and settings of the image forming apparatus 1, and notifies the user by displaying error messages, etc.

[0037] As shown in FIG. 4, in the image forming apparatus 1, the image forming section 3 includes a developing device 3A, a photoconductor 5, and a scanner section 8.

[0038] The image forming apparatus 1 includes a first feed roller 21, a first separation roller 22, a separation pad 22A, a conveying roller pair 23, a registration roller pair 24 and a post-fixing conveying roller pair 25 housed in a first housing 10 together with the image forming section 3 and the fixing unit 7.

[0039] A first feeding roller 21, a first separation roller 22, a separation pad 22A, and a transport roller pair 23 are located in the front portion of the first housing 10. A post-fixing transport roller pair 25 is located in the rear portion of the first housing 10.

[0040] A transport path P1 is provided inside the first housing 10. The transport path P1 is a path that starts from the front end of the sheet cassette 10C, makes a U-turn upward, passes through a first feeding roller 21, a first separation roller 22, a separation pad 22A, and a transport roller pair 23, and then proceeds approximately horizontally backward, passes through a registration roller pair 24, a photoconductor 5, and a fixing device 7, and reaches a post-fixing transport roller pair 25.

[0041] The first feeding roller 21 is located at the most upstream end of the conveying path P1. The first separation roller 22 and the separation pad 22A are located downstream of the conveying path P1 from the first feeding roller 21. The conveying roller pair 23 is located downstream of the first separation roller 22 and the separation pad 22A from the conveying path P1, midway through the portion of the conveying path P1 that makes an upward U-turn.

[0042] The registration roller pair 24 is located downstream of the transport roller pair 23 on the transport path P1 and upstream of the photoconductor 5 on the transport path P1, midway along the portion of the transport path P1 that advances substantially horizontally backward.

[0043] The first feeding roller 21 feeds the sheet SH supported by the sheet cassette 10C toward the photoconductor 5. If there are multiple sheets SH sent to the conveying path P1 by the first feeding roller 21, the first separation roller 22 and the separation pad 22A separate the sheets SH one by one. Then, the conveying roller pair 23 and the registration roller pair 24 convey the sheet SH to the photoconductor 5.

[0044] The developing device 3A has a toner storage chamber 3D that stores toner, and a developing roller 3B to which toner is supplied from the toner storage chamber 3D. The photoconductor 5 is located behind and below the developing roller 3B, and is in contact with the developing roller 3B.

[0045] The photoreceptor 5 is a cylindrical rotating body centered on a rotation axis extending in the left-right direction. A positively charged photosensitive layer is formed on the surface of the photoreceptor 5 in correspondence with the positively charged toner. Note that a negatively charged photosensitive layer may also be formed on the surface of the photoreceptor 5, in which case a negatively charged toner is used.

[0046] The photoreceptor 5 can come into contact with the sheet SH transported along a portion of the transport path P1 that moves rearward and approximately horizontally from above. A transfer roller 5A is located below the photoreceptor 5. The transfer roller 5A faces the photoreceptor 5 from below, with the transport path P1 in between.

[0047] The developing device 3A further includes a charger 3E. The charger 3E faces the rear of the photoconductor 5. The charger 3E is a well-known Scorotron charger.

[0048] The scanner unit 8 is located above the developing device 3A and the photoconductor 5. The scanner unit 8 has a laser light source, a polygon mirror, an fθ lens, a reflecting mirror, and the like, which are well-known components. The scanner unit 8 irradiates the surface of the photoconductor 5 with a laser beam.

[0049] The surface of the photoreceptor 5 is uniformly positively charged by the charger 3E as it rotates, and then exposed to high-speed scanning of a laser beam emitted from the scanner unit 8. As a result, an electrostatic latent image corresponding to the image to be formed on the sheet SH is formed on the surface of the photoreceptor 5.

[0050] Then, the developing roller 3B supplies toner to the photoreceptor 5 in accordance with the electrostatic latent image formed on the surface of the photoreceptor 5. As a result, a toner image is carried on the surface of the photoreceptor 5. The photoreceptor 5 transfers the toner image to the upward surface of the sheet SH that passes through the nip position between the photoreceptor 5 and the transfer roller 5A.

[0051] The fixing unit 7 is located behind the photoconductor 5 and in front of the post-fixing transport roller pair 25. The fixing unit 7 has a heating member 7A located above the transport path P1, and a pressure roller 7B facing the heating member 7A from below with the transport path P1 in between.

[0052] The heating member 7A has an endless belt, a guide member that supports the endless belt from the inner circumference so that it can circulate, and a heater that heats the endless belt from the inner circumference. The heating member 7A and the pressure roller 7B nip the sheet SH at the fixing nip portion 7N. The heating member 7A may be composed of a heating roller having a heater such as a halogen heater, or may be composed of a heater, a nip plate that receives radiant heat from the heater, and a heating belt that rotates around the nip plate.

[0053] The fixing unit 7 heats and presses the sheet SH onto which the toner image has been transferred, using a heating member 7A and a pressure roller 7B, thereby thermally fixing the toner image onto the sheet SH. A post-fixing transport roller pair 25 transports the sheet SH that has passed through the fixing unit 7 upward and backward. The toner image is an example of "an image formed on a sheet by the image forming unit" and "an image fixed on a sheet by the fixing unit" in the present invention.

[0054] The image forming apparatus 1 includes a control unit C1, a pre-registration sheet sensor S1, a post-registration sheet sensor S2, and a post-fixing sheet sensor S3.

[0055] The first housing 10 houses a control unit C1. The control unit C1 is an electronic circuit unit including a CPU, an interface circuit, and a storage unit (not shown). The control unit C1 performs overall control over each unit of the image forming apparatus 1.

[0056] The control unit C1 is electrically connected to the pre-registration sheet sensor S1, the post-registration sheet sensor S2, and the post-fixing sheet sensor S3.

[0057] The pre-registration sheet sensor S1 is located immediately before the pair of registration rollers 24 on the transport path P1, detects the passage of the sheet SH, and transmits the detection result to the control unit C1. The control unit C1 performs control to correct the skew of the sheet SH that reaches the pair of registration rollers 24 based on the detection result of the pre-registration sheet sensor S1.

[0058] The post-registration sheet sensor S2 is located immediately behind the pair of registration rollers 24 on the transport path P1, and detects the passage of the sheet SH and transmits the detection result to the control unit C1. The control unit C1 controls the timing of the image forming operation by the image forming unit 3 and the fixing unit 7 based on the detection result of the post-registration sheet sensor S2.

[0059] The post-fixing sheet sensor S3 is located between the fixing unit 7 and the post-fixing conveying roller pair 25 on the conveying path P1, detects the passage of the sheet SH, and transmits the detection result to the control unit C1. The control unit C1 controls the timing of a plurality of operations performed until the sheet SH that has passed through the fixing unit 7 is discharged to the discharge tray 9, based on the detection result of the post-fixing sheet sensor S3.

[0060] The pre-registration sheet sensor S1, the post-registration sheet sensor S2, and the post-fixing sheet sensor S3 may be a sensor having an actuator that swings when the sheet SH comes into contact with it, a light reflection type sensor, a light transmission type sensor, or the like.

[0061] The image forming apparatus 1 includes a flapper 26. The flapper 26 is located above the post-fixing conveying roller pair 25 and is connected to a solenoid (not shown). The control unit C1 controls the solenoid (not shown) to swing the flapper 26 between a first flapper position indicated by a solid line in Fig. 4 and a second flapper position indicated by a two-dot chain line in Fig. 4.

[0062] The image forming apparatus 1 includes a first discharge path PD1 and a second discharge path PD2. The upstream ends of the first discharge path PD1 and the second discharge path PD2 are connected to the downstream end of the transport path P1.

[0063] The first discharge path PD1 is a discharge path that is effective when the flapper 26 is in the first flapper position shown by the solid line in Fig. 4. The second discharge path PD2 is a discharge path that is effective when the flapper 26 is in the second flapper position shown by the two-dot chain line in Fig. 4.

[0064] When the flapper 26 is in the first flapper position indicated by the solid line in FIG. 4, the flapper 26 guides the sheet SH to the first discharge path PD1 while blocking the second discharge path PD2.

[0065] The first discharge path PD1 advances upward between the flapper 26, which is in the first flapper position shown by the solid line in Fig. 4, and the exterior cover 90, and discharges the sheet SH that has passed through the fixing unit 7 to the discharge space AD1 by making the conveying direction DT1 of the sheet SH face substantially horizontally forward above the flapper 26. A cutter mechanism 4, which will be described later, is disposed on the first discharge path PD1.

[0066] When the flapper 26 is in the second flapper position indicated by the two-dot chain line in FIG. 4, the flapper 26 blocks the first discharge path PD1 and guides the sheet SH to the second discharge path PD2.

[0067] The second discharge path PD2 is a path that discharges the sheet SH that has passed through the fixing unit 7 to the discharge space AD1 by guiding the sheet SH in the conveying direction DT1 of the sheet SH at the second flapper position shown by the two-dot chain line in Fig. 4 to face substantially horizontally forward. The second discharge path PD2 discharges the sheet SH to the discharge space AD1 at a position lower than the first discharge path PD1 and upstream of the first discharge path PD1 in the conveying direction DT1. The cutter mechanism 4, which will be described later, is not arranged on the second discharge path PD2.

[0068] 4, 9, and 10, the image forming apparatus 1 includes a pre-cutting cover 80 and a first conveying roller pair 70 disposed at a portion of the first discharge path PD1 where the conveying direction DT1 changes from upward to forward. The first conveying roller pair 70 includes a first conveying roller 71 and a second conveying roller 72.

[0069] As shown in Figures 4, 11 and 12, the image forming apparatus 1 includes a pre-cutting guide 300, a cutter mechanism 4, a first guide 100, a second guide 200, a sheet sensor S4 and a first discharge roller pair 29 arranged along the portion of the first discharge path PD1 where the conveying direction DT1 is substantially horizontal and forward-facing.

[0070] The pre-cutting guide 300 is an example of an "upstream guide" in the present invention. The first guide 100 and the second guide 200 are an example of a "conveying guide" in the present invention. The sheet sensor S4 is an example of a "sensor" in the present invention. The first discharge roller pair 29 is an example of a "second conveying roller pair" and a "first discharge roller pair" in the present invention.

[0071] As shown in FIG. 4, the image forming apparatus 1 includes a second discharge roller pair 28 disposed at the most downstream end of the second discharge path PD2.

[0072] The second discharge roller pair 28 is located above the upstream end 9U of the discharge tray 9 in the transport direction DT1. The discharge tray 9 has an upstream portion 9A and a downstream portion 9B. The upstream portion 9A is inclined upward from the upstream end 9U of the discharge tray 9 in the transport direction DT1 toward the downstream of the transport direction DT1. The downstream portion 9B is connected to the upstream portion 9A and extends approximately horizontally toward the downstream of the transport direction DT1. The second discharge roller pair 28 discharges the sheet SH that passes through the fixing unit 7 and is transported without passing through the cutter mechanism 4 to the discharge tray 9. The discharge tray 9 supports the sheet SH that is discharged without being cut.

[0073] As shown in FIG. 4 and FIG. 8, the first discharge roller pair 29 is located below the image reading unit 35 and above the second discharge roller pair 28. The first discharge roller pair 29 is located downstream of the second discharge roller pair 28 in the transport direction DT1. The first discharge roller pair 29 is located above the intermediate portion in the front-rear direction in the upstream portion 9A of the discharge tray 9. The first discharge roller pair 29 is located downstream of the cutter mechanism 4 in the transport direction DT1. The first discharge roller pair 29 passes through the fixing unit 7 and discharges the sheet SH (SH1) cut by the cutter mechanism 4 to the discharge tray 9. Note that the image forming apparatus 1 in this embodiment cuts the sheet SH so that the length of the side along the transport direction DT1 is halved. The discharge tray 9 supports the sheet SH that is cut by the cutter mechanism 4 and then discharged.

[0074] The first discharge roller pair 29 and the second discharge roller pair 28 discharge the sheet SH in the same direction.

[0075] 4, the sheet cassette 10C can be pulled out forward from the first housing 10 so that a user can replenish the sheets SH. The direction in which the sheet cassette 10C is pulled out from the first housing 10 is the same as the direction in which the first discharge roller pair 29 and the second discharge roller pair 28 discharge the sheets SH.

[0076] The image forming apparatus 1 includes a process cartridge 3P. The process cartridge 3P includes a toner storage chamber 3D of a developing device 3A, a developing roller 3B, and a case for accommodating these components.

[0077] 2, the first housing 10 has a front opening 10G. The front opening 10G is an example of the "housing opening" of the present invention. The front opening 10G is a large, substantially rectangular opening that opens a portion of the front surface of the first housing 10 that is located above the front end of the sheet cassette 10C.

[0078] The image forming apparatus 1 includes a front cover 10F. The front cover 10F is an example of the "cover" of the present invention. The front cover 10F closes the front opening 10G in an upright state, and constitutes a part of the front exterior surface of the first housing 10. As shown by the two-dot chain line in FIG. 4, the front cover 10F opens the front opening 10G by rotating its lower end portion as a rotation axis and moving its upper end portion forward and downward.

[0079] 4, the process cartridge 3P can be pulled out forward from the first housing 10 via the front opening 10G for the purpose of replacing consumables by a user, etc. The direction in which the process cartridge 3P is pulled out from the first housing 10 is the same as the direction in which the first discharge roller pair 29 and the second discharge roller pair 28 discharge the sheet SH.

[0080] 2 and 3, the image forming apparatus 1 includes a second motor M2. The second motor M2 drives the first conveyor roller pair 70, the first discharge roller pair 29, and the second discharge roller pair .

[0081] 4, the joint cover 50 houses the cutter mechanism 4. The second housing 30 houses the image reading unit 35 above the image forming unit 3 and the cutter mechanism 4.

[0082] <Pre-cutting cover, first conveyor roller and second conveyor roller> As shown in Figures 4 to 7, the pre-cutting cover 80 is located at the lower end of the pre-cutting cover 80 and is rotatable around a cover axis X80 parallel to the left-right direction. The left-right direction is parallel to a cutting direction DC1, which will be described later. The cross sections of the pre-cutting cover 80 shown in Figures 4, 6, and 7 show the center of the pre-cutting cover 80 in the left-right direction.

[0083] 9 and 10, the lower end of the pre-cutting cover 80 is located outside the sheet SH transported along the first discharge path PD1 in the left-right direction and extends to the cover axis X80. The pre-cutting cover 80 has a pair of left and right rotation shafts 80S at its lower end. Each rotation shaft 80S is a cylinder centered on the cover axis X80. Each rotation shaft 80S is supported by an axis hole (not shown) formed in an internal frame located on the rear side of the first housing 10, so that the pre-cutting cover 80 can rotate around the cover axis X80.

[0084] The pre-cutting cover 80 can be moved to a first cover position shown in Figures 4 and 7 and a second cover position shown in Figures 5 and 6 by rotating around the cover axis X80 with the outer cover 90 open.

[0085] The up-down direction and the front-rear direction shown in FIGS. 9 and 10 are based on a state in which the pre-cutting cover 80 is in the first cover position.

[0086] The pre-cutting cover 80 supports the first conveyor roller 71 and the second conveyor roller 72 of the first conveyor roller pair 70. The second conveyor roller 72 is located below the first conveyor roller 71 and faces the first conveyor roller 71.

[0087] 9, the first conveyor roller 71 has a rotation axis X71 extending parallel to the left-right direction, and the second conveyor roller 72 has a rotation axis X71 parallel to the rotation axis X71.

[0088] The first conveying roller 71 has a roller portion 71R. The second conveying roller 72 has a roller portion 72R. Each of the roller portions 71R and 72R has a cylindrical surface that is longer than the width of the sheet SH in the left-right direction.

[0089] 12, the first conveying roller 71 and the second conveying roller 72 form a first nip 70N. The first conveying roller 71 and the second conveying roller 72 nip the sheet SH on which an image has been formed by the first nip 70N and convey the sheet SH toward a fixed blade 411 and a movable blade 412 of the cutter mechanism 4, which will be described later.

[0090] As shown in Fig. 4, when the pre-cutting cover 80 is in the first cover position, it covers the upstream side of the cutter mechanism 4 in the conveying direction DT1 and guides the sheet SH toward the cutter mechanism 4. In this state, the first conveying roller 71 and the second conveying roller 72 are located upstream of a fixed blade 411 and a moving blade 412 (described later) of the cutter mechanism 4 in the conveying direction DT1. The fixing device 7 is located upstream of the first conveying roller 71 and the second conveying roller 72 in the conveying direction DT1. In this state, the second conveying roller 72 is rotated by a driving force transmitted from the second motor M2 via a gear train 72G shown in Fig. 10. The first conveying roller 71 is rotated by the second conveying roller 72.

[0091] 4, the first conveyor roller 71 and the second conveyor roller 72 convey the sheet SH that has passed through the fixing device 7 toward the cutter mechanism 4. The cutter mechanism 4 cuts the sheet SH that is sandwiched between the roller portions 71R and 72R of the first conveyor roller 71 and the second conveyor roller 72, respectively.

[0092] As shown in FIG. 6, the pre-cutting cover 80 rotates to the second cover position with the exterior cover 90 open and the maintenance opening 19 open, and is separated from the cutter mechanism 4, making it unable to guide the sheet SH toward the cutter mechanism 4. In this state, the first conveying roller 71 and the second conveying roller 72 also move rearward and downward away from the cutter mechanism 4. As a result, the maintenance opening 19 exposes the pre-cutting cover 80 at the second cover position to the outside of the first housing 10. At this time, the driving force transmission path between the gear train 72G and the second motor M2 is cut off, so that the first conveying roller 71 and the second conveying roller 72 can rotate by receiving a force to pull out the nipped sheet SH. As a result, the user can remove the sheet SH that is jammed around the exterior cover 90 and the pre-cutting cover 80 in the first discharge path PD1.

[0093] As shown in FIG. 4, a conveying path PD1D formed by the pre-cutting cover 80 in the first cover position is a portion from near the flapper 26 in the first discharge path PD1 to the nip position of the first conveying roller 71 and the second conveying roller 72.

[0094] The transport path formed by the exterior cover 90 with the maintenance opening 19 closed is an upstream transport path PD1U located upstream in the transport direction DT1 of the transport path PD1D formed by the pre-cutting cover 80 at the first cover position. The upstream transport path PD1U can guide the sheet SH from the fixing unit 7 toward the second discharge roller pair 28.

[0095] 7, when the pre-cutting cover 80 is in the first cover position and the exterior cover 90 opens the maintenance opening 19, the upstream conveying path PD1U is opened and the upstream side of the cutter mechanism 4 in the conveying direction DT1 remains blocked. As a result, the user can remove the sheet SH that is jammed in the second discharge path PD2.

[0096] 4, the first housing 10 has a protruding wall 17. The protruding wall 17 is located on the rear side and upper end side of the first housing 10, and covers the upper side of the pre-cutting cover 80 that is in the first cover position.

[0097] 10, the pre-cutting cover 80 has a number of ribs 87. When the pre-cutting cover 80 is in the first cover position, each rib 87 protrudes rearward from the rear surface of the pre-cutting cover 80 and extends in the up-down direction. The ribs 87 are spaced apart from each other in the left-right direction.

[0098] 6, when the maintenance opening 19 is open, the exterior cover 90 is capable of holding a sheet SH that has passed through the fixing unit 7. The method for discharging such a sheet SH is straight discharge for sheets SH such as thick paper.

[0099] During straight discharge, the pre-cutting cover 80 is in the second cover position. In this state, the ribs 87 guide the sheet SH that has passed through the fixing unit 7 toward the exterior cover 90.

[0100] <Pre-cutting guide, cutter mechanism, first guide, second guide, sheet sensor, and first discharge roller pair> As shown in Fig. 11 to Fig. 17, the pre-cutting guide 300, the cutter mechanism 4, and the first guide 100 are fastened together to form a unit. As shown in Fig. 4 and Fig. 18 to Fig. 20, the pre-cutting guide 300, the cutter mechanism 4, and the first guide 100 are assembled to the joint cover 50 as a unit and fixed to the joint cover 50. During maintenance work, etc., the pre-cutting guide 300, the cutter mechanism 4, and the first guide 100 are removed from the joint cover 50 as a unit.

[0101] As shown in Fig. 4, the pre-cutting guide 300 is located downstream in the conveying direction DT1 of the pre-cutting cover 80 at the first cover position and the first conveying roller pair 70. As shown in Fig. 12, the pre-cutting guide 300 is located upstream in the conveying direction DT1 of a fixed blade 411 and a movable blade 412 (described later) of the cutter mechanism 4. As shown in Figs. 11, 14 and 17, the pre-cutting guide 300 is a resin molded product manufactured by injection molding of a thermoplastic resin or the like.

[0102] 12, 15 and 17, the pre-cutting guide 300 has a first upstream guide surface 302 and a second upstream guide surface 301 that guide the sheet SH passing through the cutter mechanism 4. The second upstream guide surface 301 faces the first upstream guide surface 302 from above. The second upstream guide surface 301 is formed by the lower ends of a plurality of ribs that are arranged apart from each other in the left-right direction. The first upstream guide surface 302 is an upward facing surface. The second upstream guide surface 301 is a downward facing surface.

[0103] 12, the sheet SH conveyed by the first conveying roller 71 and the second conveying roller 72 toward the cutter mechanism 4 passes between the first upstream guide surface 302 and the second upstream guide surface 301, and reaches the cutter mechanism 4. The pre-cutting guide 300 guides the sheet SH between the first conveying roller pair 70 and a fixed blade 411 and a movable blade 412 of the cutter mechanism 4, which will be described later.

[0104] The cutter mechanism 4 has a cutter carriage 420 shown in Figures 11 to 14 and 16, a cutter frame 400 shown in Figures 11 to 16, a moving blade 412 shown in Figures 12 and 16, and a fixed blade 411 shown in Figures 12, 14 and 16. The fixed blade 411 and the moving blade 412 are examples of the "blade" of the present invention.

[0105] 12, the cutter carriage 420 detachably holds a moving blade holder 460. The moving blade holder 460 rotatably holds a circular moving blade 412.

[0106] Specific configurations of the cutter carriage 420 and the moving blade holder 460, and the operation of attaching and detaching the moving blade holder 460 to the cutter carriage 420 will be described later with reference to FIGS.

[0107] 12, 14, and 16, the cutter frame 400 extends in a cutting direction DC1 perpendicular to the conveying direction DT1, i.e., in the left-right direction. As shown in Fig. 18, the cutter frame 400 extends in the left-right direction even when assembled to the image forming apparatus 1.

[0108] 12, 14, and 16, a cutter frame opening 409 is formed in the cutter frame 400. The cutter frame opening 409 has an inner width in the left-right direction larger than the width of the sheet SH so that the sheet SH guided by the first upstream guide surface 302 and the second upstream guide surface 301 of the pre-cutting guide 300 can pass through.

[0109] The cutter frame 400 is made of metal, and specifically, is manufactured by pressing, punching, bending, etc. a steel plate. As shown in FIG. 12, the downstream side of the second upstream guide surface 301 in the conveying direction DT1 enters a cutter frame opening 409.

[0110] 12, 14, and 16, the cutter frame 400 has a guide portion 402 above the cutter frame opening 409 and on the opposite side to the pre-cutting guide 300. The guide portion 402 guides the cutter carriage 420 in the cutting direction DC1, i.e., in the left-right direction, and regulates the cutter carriage 420 so that it does not come off the guide portion 402. In other words, the cutter frame 400 holds the cutter carriage 420 so that it can move in the cutting direction DC1. Therefore, the cutter mechanism 4 cuts the conveyed sheet SH along the cutting direction DC1.

[0111] In this embodiment, one of the cutting directions DC1 is to the right, and the other of the cutting directions DC1 is to the left.

[0112] 11, the cutter frame 400 has a first motor M1 and a timing belt 430. The first motor M1 is located on the left end side of the cutter frame 400 and above the cutter frame opening 409.

[0113] 16, the first motor M1 is located above the cutter frame opening 409 when viewed along the conveying direction DT1, and the first motor M1 entirely overlaps with the cutter frame opening 409 in the cutting direction DC1. With this configuration, it is possible to more reliably prevent the image forming apparatus 1 from becoming larger in the cutting direction DC1, compared to a case in which the first motor M1 entirely does not overlap with the cutter frame opening 409 in the cutting direction DC1 when viewed along the conveying direction DT1.

[0114] The cutter mechanism 4 includes a drive pulley 431 , a plurality of driven pulleys 432 , 433 , 434 , a belt tensioner 435 , and a tension spring 436 .

[0115] The longitudinal direction of the cutter frame opening 409 is the same as the cutting direction DC1, i.e., the left-right direction. The drive pulley 431 is located at one end of the longitudinal direction of the cutter frame opening 409, i.e., to the left of the left end, and is rotatably supported by the cutter frame 400. The driven pulley 432 is located on the left end side of the cutter frame opening 409, below the cutter frame opening 409, and is rotatably supported by the cutter frame 400.

[0116] The driven pulley 433 is housed in an upper portion of the belt tensioner 435. In this state, the driven pulley 433 is located at the other end in the longitudinal direction of the cutter frame opening 409, i.e., to the right of the right end, and is rotatably supported by the cutter frame 400. The belt tensioner 435 is capable of swinging coaxially with the driven pulley 433. This makes it possible to achieve space saving compared to a case in which the swing shaft of the belt tensioner 435 is not coaxial with the driven pulley 433.

[0117] The driven pulley 434 is housed in a lower portion of the belt tensioner 435. The lower end of the belt tensioner 435 protrudes downward further than the driven pulley 434. The tension spring 436 is a metallic compression coil spring. One end of the tension spring 436 is engaged with a right lower corner of the cutter frame 400. The other end of the tension spring 436 is engaged with the lower end of the belt tensioner 435.

[0118] Timing belt 430 is wound around driving pulley 431 and driven pulleys 432, 433, and 434, and surrounds cutter frame opening 409. Belt tensioner 435 is biased by tension spring 436 to swing, and driven pulley 434 moves to the right, thereby applying tension to timing belt 430. As a result, even if timing belt 430 that is easily affected by heat from fixing and the like is used, the compression coil spring made of a metal with high heat resistance can stably apply appropriate tension to timing belt 430.

[0119] The cutter carriage 420 is connected to a portion of the timing belt 430 that extends in the left-right direction above the cutter frame opening 409 .

[0120] The first motor M1 drives the drive pulley 431 via a gear train to rotate it in the forward and reverse directions, whereby the cutter carriage 420, the moving blade holder 460, and the moving blade 412 move in the cutting direction DC1.

[0121] 11, the cutter carriage 420 (420A) is shown in a standby position at the right end side of the cutter frame opening 409 where it does not interfere with the right edge of the sheet SH. The standby position (420A) of the cutter carriage 420 is a position away from the sheet SH to one side in the cutting direction DC1, i.e., to the right.

[0122] The cutter carriage 420 (420B) is shown in a state in the middle of moving in the cutting direction DC1. The cutter carriage 420 (420C) is shown in a state in which it is at a folding position on the left end side of the cutter frame opening 409 and does not interfere with the left edge of the sheet SH. That is, the cutter carriage 420 can move between the position of cutter carriage 420A, which is the standby position in FIG. 11, and the position of cutter carriage 420C, which is the folding position.

[0123] The cutter carriage 420 (420A) shown in Figures 2, 13, 16, 18 to 20, and 28 is in a standby position. The cutter carriage 420 (420C) shown in Figures 13, 14, 16, and 26 is in a folded-back position.

[0124] 16 is a sensor capable of detecting whether the moving blade holder 460 and the moving blade 412 are attached to the cutter carriage 420 when the cutter carriage 420 is in the standby position. The sensor S6 goes into a state where it outputs a presence signal of the moving blade holder 460 and the moving blade 412 when the actuator is pressed down on the moving blade holder 460 held by the cutter carriage 420, and goes into a state where it outputs an absence signal otherwise. The control unit C1 can detect the presence or absence of the moving blade holder 460 and the moving blade 412 by checking the state of the sensor S6 at an appropriate timing.

[0125] 12 and 16, the fixed blade 411 is fastened to the cutter frame 400 below the lower edge of the cutter frame opening 409. The fixed blade 411 extends upward and then bends to extend downstream in the conveying direction DT1. The blade tip of the fixed blade 411 extends linearly in the cutting direction DC1. The fixed blade 411 comes into contact with the sheet SH from the first upstream guide surface 302 side, i.e., from below.

[0126] The moving blade 412 moves in the cutting direction DC1 while slidingly contacting the cutting edge of the fixed blade 411. The moving blade 412 comes into contact with the sheet SH from the second upstream guide surface 301 side, that is, from above.

[0127] The cutter mechanism 4 cuts the sheet SH that has passed through the fixing device 7 in a cutting direction DC1 with a fixed blade 411 and a moving blade 412. Since the fixed blade 411 is fixed to the cutter frame 400, the sheet SH is cut by the movement of the moving blade 412.

[0128] 16, the area in which the sheet SH exists when the cutter mechanism 4 cuts the sheet SH in the cutting direction DC1 with the fixed blade 411 and the movable blade 412 is the cut area AC1. The cut area AC1 is an area surrounded by inner peripheral edges 409E1, 409E2, 409E3, and 409E4 of the cutter frame opening 409, and is a two-dimensional area that includes the cutting positions of the fixed blade 411 and the movable blade 412 and extends in the vertical and horizontal directions.

[0129] 12, the first guide 100 is located downstream in the transport direction DT1 from the first transport roller pair 70. The first guide 100 is also located downstream in the transport direction DT1 from the fixed blade 411 and the movable blade 412 of the cutter mechanism 4.

[0130] 11 and 12, the first guide 100 has a bottom wall 105 and a plurality of ribs 107. The first guide 100 is a resin molded product manufactured by injection molding of a thermoplastic resin or the like.

[0131] The bottom wall 105 is curved and extends in the front-rear direction and in the left-right direction. Each rib 107 protrudes upward from the upper surface of the bottom wall 105 and extends in the front-rear direction. Each rib 107 is spaced apart from each other in the left-right direction.

[0132] The first guide 100 has a first guide surface 101. The first guide surface 101 is formed by the tips of the front ribs 107. The first guide 100 guides the sheet SH, which is transported from the cutter mechanism 4 to the first discharge roller pair 29, by the first guide surface 101.

[0133] 12, the first discharge roller pair 29 is located downstream in the conveying direction DT1 of the fixed blade 411 and the movable blade 412 of the cutter mechanism 4. The first discharge roller pair 29 has a first discharge roller 29A which is a driven roller, and a second discharge roller 29B which is a drive roller.

[0134] The first guide 100 rotatably supports the first discharge roller 29A. The first discharge roller 29A is rotatably supported on the downstream end 100D side of the first guide 100 in the transport direction DT1.

[0135] A pressure spring (not shown) is positioned between the first guide 100 and the first discharge roller 29A. When the first discharge roller 29A and the second discharge roller 29B are in a nip state, the pressure spring (not shown) applies a pressure force to the first discharge roller 29A to ensure a nip pressure.

[0136] 11 and 14, the first guide 100 has a left wall 106L and a right wall 106R. The left wall 106L is connected to the left end of the bottom wall 105, extends upward, and also extends in the front-to-rear direction. The right wall 106R is connected to the right end of the bottom wall 105, extends upward, and also extends in the front-to-rear direction.

[0137] As shown in Fig. 14, a shaft hole 102H is formed at a rear and lower position of the left wall 106L so as to penetrate therethrough in the left-right direction. A shaft hole 102H is also formed at a rear and lower position of the right wall 106R so as to penetrate therethrough in the left-right direction. The shaft hole 102H is a circular hole centered on a rotation axis X200 extending in the left-right direction.

[0138] 11 and 13, a substantially box-shaped biasing member accommodating portion 108 is formed at a front upper corner of each of the left wall 106L and the right wall 106R. Each biasing member accommodating portion 108 protrudes toward the center of the first guide 100 in the left-right direction.

[0139] The image forming apparatus 1 includes a biasing member 280. Each biasing member housing 108 houses a biasing member 280. The left biasing member 280 and the right biasing member 280 have the same configuration but on opposite sides. For this reason, in Figs. 12, 21, and 22, the right biasing member 280 is illustrated, and the illustration and description of the left biasing member 280 are omitted.

[0140] As shown in FIG. 21, the biasing member 280 has a metallic torsion coil spring 289 and a resin spring cover 281 that covers the torsion coil spring 289 .

[0141] The spring cover 281 is rotatably supported by a support shaft 108S located in the biasing member accommodating portion 108. The spring cover 281 protrudes rearward, and its rear portion is exposed from the biasing member accommodating portion 108.

[0142] The coil portion of the torsion coil spring 289 surrounds the support shaft 108S. One end of the torsion coil spring 289 is engaged with the spring cover 281. The other end of the spring cover 281 is engaged with a locking portion (not shown) formed around the periphery of the biasing member accommodating portion 108. The torsion coil spring 289 biases the spring cover 281 in a direction that moves the rear portion of the spring cover 281 downward.

[0143] The spring cover 281 has a pressing portion 284 and a sliding contact portion 283. The pressing portion 284 and the sliding contact portion 283 are formed separately on the rear portion of the spring cover 281.

[0144] The pressing portion 284 extends linearly in the front-rear direction while facing downward. The sliding contact portion 283 is connected to the rear end of the pressing portion 284 and is curved upward.

[0145] 11, 13, and 21, a block-shaped stopper 102S is formed at a front and lower position on the right wall 106R. Although not shown, a stopper 102S is also formed on the left wall 106L. Each stopper 102S protrudes toward the center of the first guide 100 in the left-right direction.

[0146] 8, 12, and 23, the second guide 200 has an upper wall 205. The upper wall 205 is bent so that the front portion is one step higher than the rear portion, and extends in the front-rear direction and also in the left-right direction. The second guide 200 is a resin molded product manufactured by injection molding of thermoplastic resin or the like.

[0147] 23, the second guide 200 has a pair of rotation shafts 200S provided to the left of the left end of the upper wall 205 and to the right of the right end of the upper wall 205. Each rotation shaft 200S is a cylinder centered on a rotation axis X200.

[0148] The second guide 200 is rotatable about a rotation axis X200 by inserting the rotation shafts 200S into shaft holes 102H in the left wall 106L and the right wall 106R of the first guide 100 shown in Fig. 14. The joint cover 50 to which the first guide 100 is fixed supports the second guide 200 rotatably about the rotation axis X200.

[0149] As shown in FIG. 12, the rotation axis X200 is located on the upstream end 200U side of the second guide 200 in the conveying direction DT1.

[0150] 8 and 23, the second guide 200 has a sliding surface 273 provided to the left of the left end of the upper wall 205 and to the right of the right end of the upper wall 205. The sliding surface 273 is located on the downstream end 200D side of the second guide 200 in the conveying direction DT1.

[0151] As shown in FIG. 23, the second guide 200 has a pressed portion 274 and a stopper recess 201S provided to the left of the left end of the upper wall 205 and to the right of the right end of the upper wall 205.

[0152] The left sliding surface 273, the pressed portion 274, and the stopper recess 201S and the right sliding surface 273, the pressed portion 274, and the stopper recess 201S have the same configuration but on opposite sides. For this reason, in Figures 12, 21, and 22, the right sliding surface 273, the pressed portion 274, and the stopper recess 201S are illustrated, and the illustration and description of the left sliding surface 273, the pressed portion 274, and the stopper recess 201S are omitted.

[0153] As shown in FIG. 21, the sliding surface 273 is an arc-shaped curved surface centered on the rotation axis X200, and faces outward in the radial direction of the rotation axis X200.

[0154] The pressed portion 274 is connected to the upper end of the sliding contact surface 273 and curves rearward in a small radius arc. The stopper recess 201S is recessed upward at a position slightly rearward from the lower end of the sliding contact surface 273.

[0155] The second guide 200 is movable between a first guide position in which the stopper 102S abuts the stopper recess 201S from below, as shown in FIG. 21, and a second guide position in which the stopper recess 201S moves upward away from the stopper 102S, as shown in FIG. 22.

[0156] The position of the second guide 200 shown in Figures 4, 7, 12 and 24 is the first guide position. The position of the second guide 200 shown in Figure 6 is the second guide position.

[0157] 21, the biasing member 280 applies a first biasing force FG1 to the second guide 200 at the first guide position in a direction from the second guide position to the first guide position, i.e., downward. At this time, the pressing portion 284 presses the pressed portion 274 downward, thereby applying the first biasing force FG1 to the pressed portion 274. The first biasing force FG1 makes it difficult for the stopper recess 201S to move upward from the stopper 102S, and the second guide 200 is held at the first guide position with high reliability.

[0158] 22, the biasing member 280 comes into sliding contact with the sliding contact surface 273 when the second guide 200 rotates between the first guide position and the second guide position, and applies a second biasing force FG2 to the second guide 200 in a direction toward the inside in the radial direction of the rotation axis X200. At this time, the sliding portion 283 comes into sliding contact with the sliding contact surface 273, thereby applying the second biasing force FG2 to the sliding contact surface 273. As a result, the posture of the second guide 200 can be stopped at a position that provides a desired rotation angle by the frictional force acting between the biasing member 280 and the sliding contact surface 273 of the second guide 200.

[0159] The torsion coil spring 289 and the spring cover 281 are located on the outer side of the sliding contact surface 273 in the radial direction of the rotation axis X200 with the sliding contact portion 283 in sliding contact with the sliding contact surface 273.

[0160] 12, the second guide 200 is located downstream in the conveying direction DT1 from the first conveying roller pair 70. In addition, the second guide 200 and the sheet sensor S4 are located downstream in the conveying direction DT1 from the fixed blade 411 and the movable blade 412 of the cutter mechanism 4.

[0161] 12 and 23, the second guide 200 rotatably supports the second discharge roller 29B. The second discharge roller 29B is rotatably supported on the downstream end 200D side of the second guide 200 in the transport direction DT1.

[0162] 12, when the second guide 200 is in the first guide position, the first discharge roller 29A and the second discharge roller 29B are in a nip state forming the second nip 29N. The first biasing force FG1 is set to a magnitude that can prevent the second guide 200 from escaping from the first guide position toward the second guide position due to the pressing force for ensuring the nip pressure at the second nip 29N.

[0163] 6, when the second guide 200 is in the second guide position, the first discharge roller 29A and the second discharge roller 29B are separated from each other. When the second guide 200 is in the second guide position, the position of the second discharge roller 29B is spaced upward from the discharge tray 9 further than the position of the second discharge roller 29B when the second guide 200 is in the first guide position.

[0164] 12 and 23, the second guide 200 has a plurality of ribs 207. Each rib 207 protrudes downward from the lower surface of the upper wall 205 and extends in the front-rear direction. Each rib 207 is separated from each other in the left-right direction.

[0165] The second guide 200 has a second guide surface 202. The second guide surface 202 is formed by the tip of each front rib 207. The second guide surface 202 faces the first guide surface 101 when the second guide 200 is in the first guide position. The rotation axis X200 is located between the first guide surface 101 and the second guide surface 202 when the second guide 200 is in the first guide position.

[0166] As shown in Figures 6, 12, 21 and 22, when the second guide 200 rotates between the first guide position and the second guide position, the entire second guide 200, including the upper wall 205, moves, and therefore the entire second guide surface 202 moves.

[0167] As shown in Figure 12, when the second guide 200 is in the first guide position, the upstream side 202U of the second guide surface 202 in the conveying direction DT1 is inclined away from the first guide surface 101 toward the upstream end 200U of the second guide 200, relative to the downstream side 202D of the second guide surface 202 in the conveying direction DT1.

[0168] The second guide 200 guides the sheet SH, which is transported from the cutter mechanism 4 to the first discharge roller pair 29, by the second guide surface 202.

[0169] 11 and 12, the sheet sensor S4 is provided on the first guide 100. As shown in Fig. 12, the sheet sensor S4 is located between the cutter frame 400 and the first discharge roller pair 29 in the conveying direction DT1. More specifically, the sheet sensor S4 is located downstream of the fixed blade 411 and the movable blade 412 of the cutter mechanism 4 in the conveying direction DT1, and is located upstream of the second nip 29N of the first discharge roller pair 29 in the conveying direction DT1.

[0170] The distance in the conveying direction DT1 between the sheet sensor S4 and the cutting position of the fixed blade 411 and the movable blade 412 in the cutter mechanism 4 is defined as LA2. The distance in the conveying direction DT1 between the sheet sensor S4 and the first discharge roller pair 29 is defined as LA1. The distance LA2 is shorter than the distance LA1.

[0171] The sheet sensor S4 is a contact sensor having an actuator S4A that swings when the sheet SH comes into contact with the actuator S4A. The first guide 100 supports the actuator S4A so that the actuator S4A can swing, thereby holding the sheet sensor S4. The detection area AS1 of the sheet sensor S4 will be described later.

[0172] The sheet sensor S4 detects the sheet SH that passes through the cutter mechanism 4 and the first guide 100 and the second guide 200 due to the swinging of the actuator S4A. The swinging of the actuator S4A is converted into an electric signal by a photointerrupter (not shown) and transmitted to the control unit C1. The control unit C1 controls the timing when the cutter mechanism 4 cuts the sheet SH based on the detection result of the sheet sensor S4.

[0173] Specifically, the cutter carriage 420, the moving blade holder 460, and the moving blade 412 are positioned at a standby position (420A) until the sheet SH reaches a cutting position of the fixed blade 411 and the moving blade 412.

[0174] The control unit C1 determines the timing when half the length of the sheet SH will reach the cutting position of the fixed blade 411 and the movable blade 412 based on the elapsed time since the sheet sensor S4 detected the leading edge of the sheet SH passing through the cutter mechanism 4 and the conveying speed of the sheet SH, and when that timing arrives, stops the first conveying roller 71, the second conveying roller 72, and the first discharge roller pair 29 that nip the sheet SH. Then, the control unit C1 controls the first motor M1 to move the movable blade 412 in the cutting direction DC1.

[0175] That is, when the sheet SH reaches and stops at the cutting position of the fixed blade 411 and the movable blade 412, the cutter carriage 420, the movable blade holder 460, and the movable blade 412 move in the cutting direction DC1 through the cutting area AC1. As a result, the cutter mechanism 4 cuts the stopped sheet SH, which is nipped between the first nip 70N and the second nip 29N, in half its length.

[0176] Thereafter, the control unit C1 rotates the first conveying roller 71, the second conveying roller 72, and the first discharge roller pair 29 to discharge the sheet SH (SH1) that has been cut and divided into two pieces onto the discharge tray 9. The first discharge roller pair 29 nips the cut sheet SH (SH1) with the second nip 29N and discharges it onto the discharge tray 9.

[0177] 6, when a sheet SH becomes jammed around the cutter mechanism 4, the user moves the second guide 200 from the first guide position to the second guide position. This separates the first discharge roller 29A and the second discharge roller 29B, allowing the user to easily grab and pull out the jammed sheet SH. As a result, the image forming apparatus 1 can easily remove the jammed sheet SH around the cutter mechanism 4.

[0178] <Relative positional relationship of the nip tangent of the first nip, detection area of ​​the sheet sensor, second nip, etc.> As shown in FIG. 24, a nip tangent TN1 of a first nip 70N formed by the first conveyor roller 71 and the second conveyor roller 72 extends horizontally in the front-rear direction.

[0179] A detection area AS1 where the sheet sensor S4 detects the sheet SH between the first guide surface 101 and the second guide surface 202 will be described.

[0180] When the first guide surface 101, the second guide surface 202 and the actuator S4A that is not oscillating are viewed along the cutting direction DC1, the point where the leading edge of the actuator S4A extending in the vertical direction facing upstream in the conveying direction DT1 intersects with the first guide surface 101 is designated as CP1, and the point where the leading edge intersects with the second guide surface 202 is designated as CP2.

[0181] The detection area AS1 is a linear area extending from point CP1 to point CP2 when viewed along the cutting direction DC1.

[0182] When viewed along the cutting direction DC1, the detection area AS1 of the sheet sensor S4 is located on the nip tangent line TN1 of the first nip 70N. When viewed along the cutting direction DC1, the second nip 29N is also located on the nip tangent line TN1.

[0183] When viewed along the cutting direction DC1, the first guide surface 101 and the second guide surface 202 are located away from the nip tangent line TN1 in a direction perpendicular to the conveying direction DT1 and the cutting direction DC1, i.e., in the up-down direction. The first guide surface 101 is located away below the nip tangent line TN1. The second guide surface 202 is located away above the nip tangent line TN1.

[0184] A distance LG1 between the first guide surface 101 and the second guide surface 202 facing each other in the up-down direction becomes narrower from the upstream of the detection area AS1 in the conveying direction DT1 toward the detection area AS1.

[0185] The first guide surface 101 has an overlapping portion 101Q located below the cutter carriage 420 and partially overlapping with the moving blade 412 in the conveying direction DT1. The second guide surface 202 is located downstream of the cutter carriage 420 in the conveying direction DT1.

[0186] When viewed along the cutting direction DC1, the tip 411T of the fixed blade 411 is located slightly below the nip tangent line TN1 in a direction perpendicular to the conveying direction DT1 and the cutting direction DC1, i.e., in the up-down direction. In this embodiment, as an example, the tip 411T of the fixed blade 411 is located about 0.5 mm to 1.0 mm below the nip tangent line TN1.

[0187] A distance LN1 between the nip tangent TN1 and the first upstream guide surface 302 is smaller than a distance LN2 between the nip tangent TN1 and the second upstream guide surface 301 when viewed along the cutting direction DC1.

[0188] 4, the conveying direction DT1 of the sheet SH from the fixing device 7 to the first nip 70N changes by 90° or more. In this embodiment, as an example, the conveying direction DT1 of the sheet SH from the fixing device 7 to the first nip 70N changes by about 130°.

[0189] The conveying direction DT1 of the sheet SH from the image forming unit 3 to the first nip 70N changes by 90° or more. In this embodiment, as an example, the conveying direction DT1 of the sheet SH from the image forming unit 3 to the first nip 70N changes by about 180°.

[0190] The cutter mechanism 4 is located above the second discharge roller pair 28. The first guide 100, the second guide 200, and the sheet sensor S4 are located above the second discharge roller pair 28 and downstream in the conveying direction DT1.

[0191] <Sheet movement distance> As shown in Fig. 25, the movement distance of the sheet SH from the fixing nip 7N to the nip position of the first discharge roller pair 29 (second nip 29N) is defined as LR1. The movement distance of the sheet SH from the fixing nip 7N to the nip position of the second discharge roller pair 28 is defined as LR2. The movement distance LR2 is shorter than the movement distance LR1. Note that the movement distance LR1 is the distance that the sheet SH actually moves, or a design value that is set assuming a state in which the sheet SH will ideally pass from the fixing nip 7N to the nip position of the first discharge roller pair 29 (second nip 29N). The same is true for the movement distance LR2.

[0192] As shown in Fig. 4, the maximum length of the sheet SH that the image forming apparatus 1 can accommodate is the maximum length of the sheet SH supported by the sheet cassette 10C. The maximum length of the sheet SH that the image forming apparatus 1 can accommodate is designated as LS1. More specifically, the sheet cassette 10C of the image forming apparatus 1 is configured to be capable of supporting a letter-sized (215.9 mm x 279.4 mm) sheet SH with the long side of the sheet SH aligned in the conveying direction DT1. If the maximum length of the sheet SH that the image forming apparatus 1 can accommodate is designated as LS1, then LS1 in this embodiment is 279.4 mm.

[0193] 25, the movement distance of the sheet SH from the fixing nip portion 7N to the cutting position of the fixed blade 411 and the movable blade 412 in the cutter mechanism 4 is set to LC1. The movement distance LC1 is half the maximum length LS1, i.e., longer than 139.7 mm. In other words, when the sheet SH to be cut by the cutter mechanism 4 stops, the rear end of the sheet SH is away from the fixing nip portion 7N downstream in the conveying direction DT1. Note that the image forming apparatus 1 of this embodiment can cut an A4 size (210 mm×297 mm) sheet SH and discharge two A5 size (210 mm×148 mm) sheets in addition to the letter size sheet SH.

[0194] The movement distance of the sheet SH from the fixing nip portion 7N to the nip position of the post-fixing conveying roller pair 25 is LD1. The movement distance of the sheet SH from the nip position of the post-fixing conveying roller pair 25 to the cutting position of the fixed blade 411 and the movable blade 412 in the cutter mechanism 4 is LC1-LD1. The movement distance LC1-LD1 is longer than half of the maximum length LS1. In other words, when the sheet SH to be cut by the cutter mechanism 4 stops, the rear end of the sheet SH is away from the nip position of the post-fixing conveying roller pair 25 downstream in the conveying direction DT1.

[0195] <Effect 1> In the image forming apparatus 1 of the embodiment, as shown in FIG. 24, the sheet sensor S4 is a contact sensor having an actuator S4A that swings when the leading edge of the sheet SH comes into contact with it.

[0196] The detection area AS1 in which the sheet sensor S4 detects the sheet SH between the first guide surface 101 and the second guide surface 202 of the first guide 100 and the second guide 200 is a linear area extending along the cutting direction DC1 from a point CP1 where the leading edge of the actuator S4A intersects with the first guide surface 101 to a point CP2 where the leading edge intersects with the second guide surface 202.

[0197] When viewed along the cutting direction DC1, the detection area AS1 is located on the nip tangent TN1 of the first nip 70N. For this reason, the sheet SH, which is transported by the first transport roller 71 and the second transport roller 72 of the first transport roller pair 70 and passes through the first guide 100 and the second guide 200, reaches the detection area AS1 with little tendency to bend or flex, so that the travel distance of the leading edge of the sheet SH is unlikely to vary.

[0198] Therefore, when the image forming device 1 controls the timing of stopping the first conveying roller pair 70 (first conveying roller 71 and second conveying roller 72) based on the detection result of the sheet sensor S4, the position of the stopped sheet SH is unlikely to deviate from the expected position.

[0199] Here, a comparative example will be described. If the first conveying roller 71 is at the position 71 (71C) shown by the two-dot chain line in FIG. 24, the first nip will be shifted rearward from the first nip 70N, and the nip tangent will extend along the conveying direction DT1 so as to be inclined upward from the nip tangent TN1. If the first conveying roller 71 is at the position 71 (71D) shown by the two-dot chain line in FIG. 24, the first nip will be shifted forward from the first nip 70N, and the nip tangent will extend along the conveying direction DT1 so as to be inclined downward from the nip tangent TN1. As a result, in the comparative example, the detection area AS1 is not located on the nip tangent of the first nip 70N when viewed along the cutting direction DC1. As a result, the leading edge of the sheet SH conveyed by the first conveying roller pair 70 and passing through the first guide 100 and the second guide 200 comes into contact with the first guide 100 and the second guide 200, and as a result, the sheet SH tends to bend or warp when it reaches the detection area AS1. As a result, the travel distance of the leading edge of the sheet SH until it is detected by the sheet sensor S4 is likely to vary. For this reason, in the comparative example, when the timing to stop the first conveying roller pair 70 is controlled based on the detection result of the sheet sensor S4, the position of the stopped sheet SH is likely to deviate from the expected position.

[0200] Therefore, the image forming apparatus 1 of the embodiment can suppress deviation of the cutting position of the sheet SH.

[0201] In addition, in this image forming apparatus 1, as viewed along the cutting direction DC1, the first guide surface 101 and the second guide surface 202 are located away from the nip tangent TN1 in a direction perpendicular to the conveying direction DT1 and the cutting direction DC1, i.e., in the up-down direction. With this configuration, the sheet SH conveyed by the first conveying roller pair 70 and passing through the first guide 100 and the second guide 200 is prevented from abutting against at least one of the first guide surface 101 and the second guide surface 202 and changing in the conveying direction DT1. As a result, the sheet SH conveyed by the first conveying roller pair 70 and passing through the first guide 100 and the second guide 200 reaches the detection area AS1 with even less tendency to bend or warp, so that the movement distance of the leading edge of the sheet SH is even less likely to vary.

[0202] Furthermore, in this image forming apparatus 1, a distance LG1 between the first guide surface 101 and the second guide surface 202 becomes narrower from the upstream of the detection area AS1 in the conveying direction DT1 toward the detection area AS1. With this configuration, the first guide surface 101 and the second guide surface 202 can smoothly guide the leading edge of the sheet SH, which is conveyed by the first conveying roller pair 70 and passes through the first guide 100 and the second guide 200, toward the detection area AS1, thereby preventing the sheet SH from becoming jammed around the detection area AS1.

[0203] In addition, in the image forming apparatus 1, the sheet sensor S4 has an actuator S4A that swings when the leading edge of the sheet SH comes into contact with the actuator S4A. This configuration makes it possible to reduce the component cost of the sheet sensor S4.

[0204] Furthermore, in this image forming apparatus 1, the cutter mechanism 4 cuts the sheet SH that has been nipped between the first nip 70N and the second nip 29N and stopped. When viewed along the cutting direction DC1, the second nip 29N is also located on the nip tangent TN1. With this configuration, the sheet SH that has been nipped between the first nip 70N and the second nip 29N and stopped becomes linear when viewed along the cutting direction DC1. When the cutter mechanism 4 cuts the sheet SH in this state, the sheet SH is unlikely to bend excessively, and therefore it is possible to suppress deviation of the cutting position of the sheet SH due to bending.

[0205] In addition, in this image forming apparatus 1, as shown in Fig. 4, the conveying direction DT1 of the sheet SH from the fixing device 7 to the first nip 70N changes by 90° or more. And, as shown in Fig. 24, the nip tangent TN1 extends horizontally. With this configuration, the sheet SH is guided along a curved path and then guided horizontally, thereby making it possible to suppress an increase in size in the vertical direction.

[0206] Further, in the image forming apparatus 1, as shown in FIG. 12, the first guide 100 having the first guide surface 101, the second guide 200 having the second guide surface 202, and the sheet sensor S4 are located downstream of the fixed blade 411 and the moving blade 412 of the cutter mechanism 4 in the conveying direction DT1. The first guide 100 rotatably supports the first discharge roller 29A and holds the sheet sensor S4. The second guide 200 rotatably supports the second discharge roller 29B. The second guide 200 is movable between the first guide position shown in FIG. 4 and the second guide position shown in FIG. 6. With this configuration, when a sheet SH is jammed around the cutter mechanism 4, as shown in FIG. 6, the user moves the second guide 200 from the first guide position to the second guide position. As a result, the first discharge roller 29A and the second discharge roller 29B are separated from each other, and the first guide surface 101 and the second guide surface 202 are separated from each other, so that the user can easily pick up and pull out the jammed sheet SH. As a result, the sheet SH jammed around the cutter mechanism 4 can be easily removed. In addition, since the sheet sensor S4 is not held by the movable second guide 200, a decrease in detection accuracy can be suppressed.

[0207] In addition, in this image forming apparatus 1, as shown in FIG. 12, the second guide 200 can rotate around a rotation axis X200. The rotation axis X200 is located on the upstream end 200U side of the second guide 200 in the conveying direction DT1, and is located between the first guide surface 101 and the second guide surface 202 when the second guide 200 is at the first guide position. When the second guide 200 is at the first guide position, the upstream side 202U of the second guide surface 202 in the conveying direction DT1 is inclined away from the first guide surface 101 toward the upstream end 200U side of the second guide 200 with respect to the downstream side 202D of the second guide surface 202 in the conveying direction DT1. With this configuration, as shown in FIG. 6, the second guide 200 rotated to the second guide position opens the downstream side 202D in the conveying direction DT1 more than the fixed blade 411 and the moving blade 412 of the cutter mechanism 4. Therefore, the user can easily insert his / her hand from downstream in the conveying direction DT1 into the space formed between the first guide 100 and the second guide 200 rotated to the second guide position, and can easily pick up the jammed sheet SH. In addition, even if the second guide 200 is rotated to the second guide position, the cutter mechanism 4 is prevented from being opened more than necessary, so that the user's hand inserted from downstream in the conveying direction DT1 is unlikely to reach the cutter mechanism 4. Furthermore, when the second guide 200 is rotated to the second guide position, the jammed sheet SH can be prevented from being pinched.

[0208] 6, in the image forming apparatus 1, when the second guide 200 is in the second guide position, the position of the second discharge roller 29B is located above the discharge tray 9, further away from the discharge tray 9 than the position of the second discharge roller 29B when the second guide 200 is in the first guide position. With this configuration, the second guide 200 in the second guide position opens upward and away from the discharge tray 9, and the space formed between the first guide 100 and the second guide 200 becomes larger. This makes it easier for the user to visually check the jammed sheets SH, regardless of whether or not sheets SH are stacked on the discharge tray 9, and makes it easier to remove the jammed sheets SH.

[0209] In addition, in this image forming apparatus 1, as shown in FIG. 24, the first guide 100, the second guide 200, and the sheet sensor S4 are located downstream of the fixed blade 411 and the moving blade 412 of the cutter mechanism 4 in the conveying direction DT1. The fixed blade 411 abuts against the sheet SH from below, and the moving blade 412 abuts against the sheet SH from above. The first guide surface 101 is located below the cutter carriage 420 and has an overlapping portion 101Q that partially overlaps with the moving blade 412 in the conveying direction DT1. The second guide surface 202 is located downstream of the cutter carriage 420 in the conveying direction DT1. With this configuration, the second guide surface 202 is away from the cutter carriage 420 so as not to interfere with the cutter carriage 420, but to compensate for this, the first guide surface 101 guides the sheet SH below the cutter carriage 420 and near the moving blade 412. As a result, the sheet SH can pass through the cutter mechanism 4 stably.

[0210] Furthermore, as shown in FIG. 4, the image forming apparatus 1 includes a fixing unit 7, a first discharge path PD1 in which the cutter mechanism 4 is disposed and which discharges the sheet SH that has passed through the fixing unit 7, a second discharge path PD2 in which the cutter mechanism 4 is not disposed and which discharges the sheet SH that has passed through the fixing unit 7, and a flapper 26 that is movable between a first flapper position in which the sheet SH is guided to the first discharge path PD1 while blocking the second discharge path PD2 and a second flapper position in which the first discharge path PD1 is blocked while the sheet SH is guided to the second discharge path PD2. With this configuration, when the sheet SH is discharged through the second discharge path PD2 without being cut, the flapper 26 at the second flapper position shown by the two-dot chain line in FIG. 4 blocks the path to the cutter mechanism 4, so that it is possible to suppress the influence of heat from the fixing unit 7 on the first conveying roller pair 70 and the cutter mechanism 4.

[0211] In addition, in this image forming apparatus 1, as shown in FIG. 24, the pre-cutting guide 300 has a first upstream guide surface 302 and a second upstream guide surface 301. The fixed blade 411 abuts against the sheet SH from the first upstream guide surface 302 side. The moving blade 412 abuts against the sheet SH from the second upstream guide surface 301 side. Then, as viewed along the cutting direction DC1, the distance LN1 between the nip tangent line TN1 and the first upstream guide surface 302 is smaller than the distance LN2 between the nip tangent line TN1 and the second upstream guide surface 301. If, as viewed along the cutting direction DC1, the distance LN1 between the nip tangent line TN1 and the first upstream guide surface 302 is equal to or greater than the distance LN2 between the nip tangent line TN1 and the second upstream guide surface 301, the sheet SH tends to be gradually pulled from the side where the moving blade 412 starts to press against the sheet SH, and the cut surface is likely to be wavy. In this regard, the above-described configuration can reduce the tendency for the sheet SH to be gradually pulled from the side where the moving blade 412 starts to press against the sheet SH, so that the cut surface is less likely to become wavy.

[0212] Furthermore, in this image forming apparatus 1, the first upstream guide surface 302 is an upward facing surface, and the second upstream guide surface 301 is a downward facing surface. With this configuration, the side of the sheet SH that starts to be cut by the moving blade 412 moves along the fixed blade 411 due to its own weight, so that the cut surface is less likely to ripple. In particular, in this embodiment, when viewed along the cutting direction DC1, the tip 411T of the fixed blade 411 is only located slightly below the nip tangent TN1 in the direction perpendicular to the conveying direction DT1 and the cutting direction DC1, i.e., in the up-down direction. This further weakens the tendency for the sheet SH to be gradually pulled from the side where the moving blade 412 starts to press against the sheet SH, so that the cut surface is less likely to ripple.

[0213] 4, in this image forming apparatus 1, the conveying direction DT1 of the sheet SH from the image forming unit 3 to the first nip 70N changes by 90° or more. With this configuration, the sheet SH is conveyed along a path that curves upstream of the fixed blade 411 and the movable blade 412 of the cutter mechanism 4 in the conveying direction DT1, and the sheet SH tends to curl forward along the tip 411T of the fixed blade 411 located inside the curved path, so that waving of the cut edge can be suppressed.

[0214] 25, in the image forming apparatus 1, the movement distance LR2 of the sheet SH from the fixing nip portion 7N to the nip position of the second discharge roller pair 28 is shorter than the movement distance LR1 of the sheet SH from the fixing nip portion 7N to the nip position (second nip 29N) of the first discharge roller pair 29. With this configuration, the sheet SH that does not need to be cut can be quickly discharged onto the discharge tray 9.

[0215] 4 and 25, in this image forming apparatus 1, the movement distance LC1 of the sheet SH from the fixing nip portion 7N to the cutting position of the fixed blade 411 and the movable blade 412 in the cutter mechanism 4 is longer than half the maximum length LS1 of the sheet SH that the image forming apparatus 1 can handle. With this configuration, when the cutter mechanism 4 cuts the sheet SH in half, the entire sheet SH always passes through the fixing nip portion 7N, so that the sheet SH does not become overheated in the fixing nip portion 7N.

[0216] 4, in the image forming apparatus 1, the first discharge roller pair 29 and the second discharge roller pair 28 have the same direction for discharging the sheet SH. With this configuration, the user only needs to perform substantially the same operation when collecting the sheet SH discharged by the first discharge roller pair 29 and when collecting the sheet SH discharged by the second discharge roller pair 28, which can reduce bothersomeness.

[0217] Moreover, the image forming apparatus 1 includes a discharge tray 9 that supports the sheet SH discharged by the first discharge roller pair 29 and the sheet SH discharged by the second discharge roller pair 28. With this configuration, the single discharge tray 9 can support both the cut sheet SH and the uncut sheet SH, thereby preventing the apparatus from becoming large.

[0218] Furthermore, in this image forming apparatus 1, the direction in which the sheet cassette 10C is pulled out from the first housing 10 is the same as the direction in which the first discharge roller pair 29 and the second discharge roller pair 28 discharge the sheets SH. With this configuration, the user can work on the same side of the image forming apparatus 1 when collecting the sheets SH discharged by the first discharge roller pair 29 or the second discharge roller pair 28 and when pulling out the sheet cassette 10C, thereby reducing the user's inconvenience.

[0219] Furthermore, in this image forming apparatus 1, the direction in which the process cartridge 3P is pulled out from the first housing 10 with the front cover 10F swung to open the front opening 10G is the same as the direction in which the first discharge roller pair 29 and the second discharge roller pair 28 discharge the sheet SH. With this configuration, the user can perform the work on the same side of the image forming apparatus 1 when collecting the sheet SH discharged by the first discharge roller pair 29 or the second discharge roller pair 28 and when pulling out the process cartridge 3P, thereby reducing the user's inconvenience.

[0220] Furthermore, in this image forming apparatus 1, the cutter mechanism 4 is located above the second discharge roller pair 28. The first guide 100, the second guide 200, and the sheet sensor S4 are located above the second discharge roller pair 28 and downstream in the transport direction DT1. With this configuration, the cutter mechanism 4, the first guide 100, the second guide 200, and the sheet sensor S4 can be disposed using the space above the second discharge roller pair 28, making it easy to reduce the size. Also, with this configuration, the cut sheet SH is discharged downstream in the transport direction DT1 on the discharge tray 9, making it easy to take out even short sheets SH.

[0221] 12, in this image forming apparatus 1, the first guide 100, the second guide 200, and the sheet sensor S4 are located downstream in the conveying direction DT1 of the fixed blade 411 and the moving blade 412 of the cutter mechanism 4. With this configuration, compared to a case in which the sheet sensor S4 is located upstream in the conveying direction DT1 of the fixed blade 411 and the moving blade 412 of the cutter mechanism 4, it is possible to reduce the moving distance of the sheet SH from when the sheet sensor S4 detects the leading edge of the sheet SH passing through the cutter mechanism 4 until the cutter mechanism 4 starts cutting the sheet SH, and the variation therein, so that it is possible to further suppress deviation in the cutting position of the sheet SH.

[0222] <Positioning and fastening of pre-cutting guide, cutter mechanism and first guide> In the image forming apparatus 1, in order to prevent the position at which the sheet sensor S4 provided on the first guide 100 detects the sheet SH from shifting relative to the cutter mechanism 4, and to enable the cutter frame 400 of the cutter mechanism 4 to accurately position the pre-cutting cover 80 at the first cover position via the pre-cutting guide 300, the pre-cutting guide 300, the cutter mechanism 4 and the first guide 100 as a unit, fastening and positioning are performed as follows.

[0223] As shown in FIG. 14, the first guide 100 has four fastening bosses 181, 182, 183, and 184, and two first positioning portions 191 and 192.

[0224] Each of the fastening bosses 181, 182, 183, and 184 is a cylinder that protrudes toward the upstream in the conveying direction DT1. A screw hole that is recessed from the center of the tip surface toward the downstream in the conveying direction DT1 is formed in each of the fastening bosses 181, 182, 183, and 184. The tip of the fastening boss 184 is tapered in diameter in two stages.

[0225] The fastening boss 181 is located to the left of the upper end side of the left wall 106L of the first guide part 100. The fastening boss 182 is located on the left end side of the upstream end 100U of the first guide part 100 in the conveying direction DT1. The fastening boss 183 is located on the right end side of the upstream end 100U of the first guide part 100. The fastening boss 184 is located between the fastening boss 182 and the fastening boss 183 at the upstream end 100U of the first guide part 100.

[0226] Each of the first positioning portions 191 and 192 is a convex portion made up of a cylinder that protrudes upstream in the transport direction DT1 and a truncated cone that is connected to the tip of the cylinder and protrudes upstream in the transport direction DT1.

[0227] The first positioning portion 191 is located to the right of the fastening boss 182 at the upstream end 100U of the first guide portion 100. The second positioning portion 192 is located to the left of the fastening boss 183 at the upstream end 100U of the first guide portion 100.

[0228] The cutter frame 400 of the cutter mechanism 4 has four insertion holes 481, 482, 483, and 484, two screw holes 485 and 486, and two second positioning portions 491 and 492.

[0229] The insertion hole 481 is located to the left of the first motor M1 on the cutter frame 400, and is positioned to align with the fastening boss 181. The insertion holes 482, 483, 484 are located below the cutter frame opening 409 on the cutter frame 400.

[0230] The insertion hole 482 is located at one end side in the longitudinal direction of the cutter frame opening 409 in the cutter frame 400 , that is, at the left end side, and at a position aligned with the fastening boss 182 .

[0231] The insertion hole 483 is located at the other end side in the longitudinal direction of the cutter frame opening 409 in the cutter frame 400 , that is, at the right end side, and at a position aligned with the fastening boss 183 .

[0232] The insertion hole 484 is located between the insertion holes 482 and 483 in the cutter frame 400, and is aligned with the fastening boss 184. The inner diameter of the insertion hole 484 is set to a size that allows the first reduced diameter portion at the tip of the fastening boss 184 to pass through.

[0233] The screw hole 485 is located to the right of the right end of the cutter frame opening 409 in the cutter frame 400. The screw hole 486 is located above the middle part of the cutter frame opening 409 in the left-right direction in the cutter frame 400.

[0234] Each of the second positioning portions 491 and 492 is located below the cutter frame opening 409 in the cutter frame 400 .

[0235] The second positioning portion 491 is located on the left end side of the cutter frame opening 409 and is in a position aligned with the first positioning portion 191. The second positioning portion 491 is a circular through hole into which the first positioning portion 191 fits.

[0236] The second positioning portion 492 is located at a position on the right end side of the cutter frame opening 409 and aligned with the first positioning portion 192. The second positioning portion 492 is an oval through-hole that is long in the left-right direction and fits with the first positioning portion 192.

[0237] The pre-cutting guide 300 has six insertion holes 381, 382, ​​383, 384, 385, and 386, and two third positioning portions 391 and 392.

[0238] The insertion hole 381 is located on the upper end side of the left end portion of the pre-cutting guide 300 and is positioned to align with the insertion hole 481 and the fastening boss 181. The insertion hole 382 is located on the lower end edge side of the pre-cutting guide 300 and is positioned to align with the insertion hole 482 and the fastening boss 182. The insertion hole 383 is located on the lower end edge side of the pre-cutting guide 300 and is positioned to align with the insertion hole 483 and the fastening boss 183. The insertion hole 384 is located on the lower end edge side of the pre-cutting guide 300 and is positioned to align with the insertion hole 484 and the fastening boss 184.

[0239] The insertion hole 385 is located at the right end side of the pre-cutting guide 300, at a position that aligns with the screw hole 485. The insertion hole 386 is located at the center in the left-right direction of the upper part of the pre-cutting guide 300, at a position that aligns with the screw hole 486.

[0240] As shown in FIGS. 14 and 15, the third positioning portions 391 and 392 are located below the first upstream guide surface 302 of the pre-cutting guide 300.

[0241] The third positioning portion 391 is located at a position that aligns with the first positioning portion 191 and the second positioning portion 491. The third positioning portion 391 is a circular through hole into which the first positioning portion 191 fits.

[0242] The third positioning portion 392 is located at a position that aligns with the first positioning portion 192 and the second positioning portion 492. The third positioning portion 392 is an oval through hole that is long in the left-right direction and into which the first positioning portion 192 fits.

[0243] The first positioning portions 191, 192 are fitted one-to-one with the second positioning portions 491, 492. The first positioning portions 191, 192 pass through the second positioning portions 491, 492 and are fitted one-to-one with the third positioning portions 391, 392.

[0244] The first guide 100 is positioned on the cutter frame 400 by fitting the first positioning portions 191, 192 with the second positioning portions 491, 492. The pre-cutting guide 300 is positioned on the first guide 100 and the cutter frame 400 by fitting the first positioning portions 191, 192 with the third positioning portions 391, 392.

[0245] The pre-cutting guide 300, the cutter frame 400 and the first guide 100 are fastened together by the screws 501 to 504.

[0246] Specifically, the screw 501 is inserted through the insertion holes 381 and 481 and screwed into the screw hole of the fastening boss 181. The screw 502 is inserted through the insertion holes 382 and 482 and screwed into the screw hole of the fastening boss 182. At this time, the tip surface of the fastening boss 182 is in close contact with the cutter frame 400. The screw 503 is inserted through the insertion holes 383 and 483 and screwed into the screw hole of the fastening boss 183. At this time, the tip surface of the fastening boss 183 is in close contact with the cutter frame 400. The screw 504 is inserted through the insertion holes 384 and 484 and screwed into the screw hole of the fastening boss 184. At this time, the tip surface of the fastening boss 184 has a shaft shape that reduces in diameter in two stages as shown in FIG. 14, so that it does not come into close contact with the cutter frame 400 but comes into close contact with the pre-cutting guide 300.

[0247] As shown in FIGS. 14 and 15, the pre-cutting guide 300 and the cutter frame 400 are fastened together by screws 505, 506.

[0248] Specifically, the screw 505 is inserted into the insertion hole 385 and screwed into the screw hole 485. The screw 506 is inserted into the insertion hole 386 and screwed into the screw hole 486.

[0249] In this manner, the first guide 100 and the pre-cutting guide 300 are fixed by fastening with the cutter frame 400 sandwiched between them.

[0250] <Positioning and fastening of the pre-cutting guide, cutter mechanism and first guide unit to the joint cover> As shown in FIG. 18, the unit of the pre-cutting guide 300, the cutter mechanism 4 and the first guide 100 is positioned by four positioning bosses 50M1 to 50M4 formed on the joint cover 50, and then fastened with screws at five fastening points 50N1 to 50N5.

[0251] The two positioning bosses 50M1, 50M2 position the pre-cutting guide 300 relative to the joint cover 50. The other two positioning bosses 50M3, 50M4 position the first guide 100 relative to the joint cover 50.

[0252] The two fastening points 50N1 and 50N2 fasten the pre-cut guide 300 to the joint cover 50. The other three fastening points 50N3 to 50N5 fasten the first guide 100 to the joint cover 50.

[0253] <How to determine the turnaround position and waiting position> 11, the first motor M1 is a stepping motor having an encoder M1E. A restricting protrusion 420T is formed on the left side surface of the cutter carriage 420 so as to protrude leftward by a short distance.

[0254] When the image forming apparatus 1 is powered on, the control unit C1 performs an initial operation to position the cutter carriage 420 at the standby position (420A) as follows.

[0255] The control unit C1 actuates the first motor M1 to rotate the drive pulley 431 in the forward direction, whereby the cutter carriage 420 moves leftward, that is, in a direction approaching the turning back position (420C).

[0256] As shown in FIG. 26, there is a regulating wall 120T on the left end side of the first guide 100. When the encoder M1E detects that the first motor M1 has stopped rotating, the control unit C1 determines that the regulating protrusion 420T of the cutter carriage 420 has come into contact with the regulating wall 120T and the cutter carriage 420 has reached the turn-back position (420C), and stops the first motor M1. As a result, the cutter carriage 420 is positioned at the turn-back position (420C). By using the regulating wall 120T, there is no need to provide a dedicated stopper for positioning the cutter carriage 420 at the turn-back position (420C).

[0257] Next, the control unit C1 operates the first motor M1 to rotate the drive pulley 431 in the reverse direction. This causes the cutter carriage 420 to move rightward, that is, in the direction approaching the standby position (420A). Then, when the amount of rotation detected by the encoder M1E reaches a value indicating that the cutter carriage 420 has reached the standby position (420A), the control unit C1 determines that the cutter carriage 420 has reached the standby position (420A) and stops the first motor M1. As a result, the cutter carriage 420 is accurately positioned at the standby position (420A).

[0258] <Action and effect 2> 14, in the image forming apparatus 1 of the embodiment, the sheet sensor S4 is provided on the first guide 100 made of a material constituting the cutter frame 400, that is, a material having a lower rigidity than metal, that is, a resin. The first guide 100 is positioned on the cutter frame 400.

[0259] Therefore, compared to a case in which the cutter frame 400 and the first guide 100 provided with the sheet sensor S4 are separately assembled to the image forming apparatus 1, it is possible to suppress deviation of the relative position of the first guide 100 with respect to the cutter mechanism 4. As a result, in this image forming apparatus 1, the position at which the sheet sensor S4 detects the sheet SH is less likely to deviate from the designed position with respect to the cutter mechanism 4, and a malfunction in which the cutter mechanism 4 is unable to cut the sheet SH at the target cutting position is less likely to occur when the sheet SH is transported by a transport amount to a preset cutting position of the sheet SH.

[0260] As a result, this image forming apparatus 1 does not need to perform printing with cutting several times before shipping, measure the deviation in the position where the sheet sensor S4 detects the sheet SH, and perform adjustments to control the required transport amount from when the sheet SH is detected to the position where the sheet SH is to be cut. In addition, there is no need to perform adjustments even if the cutter mechanism 4 is replaced due to deterioration over time after installation.

[0261] Therefore, the image forming apparatus 1 of the embodiment can accurately determine the position where the cutter mechanism 4 cuts the sheet SH without controlling and adjusting the cutting position of the sheet SH.

[0262] Furthermore, in this image forming apparatus 1, the first guide 100 is positioned on the cutter frame 400 by fitting the first positioning portions 191, 192 and the second positioning portions 491, 492 together. With this configuration, the first guide 100 is directly positioned on the cutter frame 400, so it is possible to highly reliably prevent the relative position of the first guide 100 with respect to the cutter mechanism 4 from shifting. As a result, in this image forming apparatus 1, the position at which the sheet sensor S4 detects the sheet SH is even less likely to shift with respect to the cutter mechanism 4, and the position at which the cutter mechanism 4 cuts the sheet SH can be determined with even greater accuracy.

[0263] Furthermore, in this image forming apparatus 1, the second positioning portion 491 is located on the left end side of the cutter frame opening 409, and the second positioning portion 492 is located on the right end side of the cutter frame opening 409, and each of the first positioning portions 191, 192 fits one-to-one with each of the second positioning portions 491, 492. With this configuration, the first guide 100 is directly positioned on the cutter frame 400 at two points, and the two points are largely separated in the longitudinal direction (left-right direction), so that it is possible to more reliably prevent the position of the first guide 100 relative to the cutter mechanism 4 from shifting.

[0264] In the image forming apparatus 1, the second positioning portions 491, 492 are through holes, and the first positioning portions 191, 192 are protrusions. With this configuration, the second positioning portions 491, 492 and the first positioning portions 191, 192 can be simplified.

[0265] 12, in this image forming apparatus 1, the first guide 100 is provided downstream of the cutter mechanism 4 in the conveying direction DT1. The movement distance of the sheet SH from when the sheet sensor S4 provided downstream of the cutter mechanism 4 in the conveying direction DT1 detects the leading edge of the sheet SH to when the cutter mechanism 4 starts cutting the sheet SH and the variation therein are smaller than the movement distance of the sheet SH from when the sheet sensor S4 provided upstream of the cutter mechanism 4 in the conveying direction DT1 detects the leading edge of the sheet SH to when the cutter mechanism 4 starts cutting the sheet SH and the variation therein. This allows the image forming apparatus 1 to more accurately determine the position at which the cutter mechanism 4 cuts the sheet SH.

[0266] 14, the pre-cutting guide 300 has two third positioning portions 391, 392, and the pre-cutting guide 300 is positioned with respect to the first guide 100 and the cutter frame 400 by fitting the first positioning portions 191, 192 with the third positioning portions 391, 392. With this configuration, the pre-cutting guide 300 is positioned together with the cutter frame 400 by the same first positioning portions 191, 192 of the first guide 100. As a result, the image forming apparatus 1 can accurately determine the relative positions of the first guide 100 and the pre-cutting guide 300 with respect to the cutter mechanism 4.

[0267] 18, in the image forming apparatus 1, the cutter frame 400 extends in a direction perpendicular to the transport direction DT1, i.e., in the left-right direction, when assembled to the image forming apparatus 1. As shown in FIG. 14, the first positioning parts 191, 192 protrude upstream in the transport direction DT1 and penetrate the second positioning parts 491, 492 to engage with the third positioning parts 391, 392. This configuration allows the relative positions of the first guide 100 and the pre-cutting guide 300 with respect to the cutter mechanism 4 to be determined with high accuracy.

[0268] In addition, in this image forming apparatus 1, the first guide 100 and the pre-cutting guide 300 are fixed by fastening with the cutter frame 400 sandwiched between them. With this configuration, the first guide 100, the cutter frame 400, and the pre-cutting guide 300 that are fastened together can be easily handled as a unit.

[0269] 11 and 18, in this image forming apparatus 1, the first guide 100, the cutter frame 400, and the pre-cutting guide 300 are attached to and detached from the image forming apparatus 1 while being fastened to one another. With this configuration, the first guide 100, the cutter frame 400, and the pre-cutting guide 300 can be easily attached to and detached from the image forming apparatus 1 as a unit, and there is no need to adjust each member separately.

[0270] 12, in the image forming apparatus 1, the sheet sensor S4 is located between the cutter frame 400 and the first discharge roller pair 29 in the conveying direction DT1. With this configuration, the sheet sensor S4 can detect the leading edge of the sheet SH in a stable state by the posture of the sheet SH passing through the cutter mechanism 4 being aligned with the first guide 100.

[0271] Furthermore, in this image forming apparatus 1, a distance LA2 between the sheet sensor S4 and the cutting positions of the fixed blade 411 and the movable blade 412 in the cutter mechanism 4 in the transport direction DT1 is shorter than a distance LA1 between the sheet sensor S4 and the first discharge roller pair 29 in the transport direction DT1. With this configuration, the sheet sensor S4 is disposed close to the cutter mechanism 4. Therefore, this image forming apparatus 1 can speed up the timing for detecting a jam of the sheet SH around the cutter mechanism 4, and as a result, the range of the jam of the sheet SH can be narrowed.

[0272] <Configuration for positioning pre-cutting cover 80 in first cover position in the transport direction> In order to prevent the relative positional relationship between the cutter mechanism 4 and the first conveying roller 71 and the second conveying roller 72 supported by the pre-cutting cover 80 from shifting when the pre-cutting cover 80 moves from the second cover position to the first cover position, the pre-cutting cover 80 at the first cover position is positioned in the conveying direction DT1 by the cutter frame 400 as follows.

[0273] As shown in FIGS. 15, 17 and 27, the pre-cutting guide 300 has a pair of left and right positioning ribs 308L, 308R.

[0274] The positioning rib 308L is located to the left of the left end of the cutter frame opening 409. The positioning rib 308L protrudes slightly toward the upstream side in the conveying direction DT1 and extends slightly in the left-right direction.

[0275] The positioning rib 308R is located to the right of the right end of the cutter frame opening 409. The positioning rib 308L protrudes slightly toward the upstream side in the conveying direction DT1 and extends slightly in the left-right direction.

[0276] 5, 9, 10 and 27, the pre-cutting cover 80 has a pair of left and right positioning protrusions 83L, 83R and a pair of left and right abutment pieces 88L, 88R. In addition, the pre-cutting cover 80 has two biasing springs 89 as shown in FIG.

[0277] As shown in FIG. 9, the positioning protrusion 83L protrudes leftward from the left ends of the roller portions 71R, 72R of the first and second conveyor rollers 71, 72, respectively, toward the rear, that is, toward the downstream in the conveying direction DT1.

[0278] The positioning protrusion 83R protrudes rearward, that is, toward the downstream in the transport direction DT1, to the right of the right ends of the roller portions 71R, 72R of the first transport roller 71 and the second transport roller 72.

[0279] The tip of each of the positioning protrusions 83L, 83R is a flat surface that faces rearward and extends long in the vertical direction and short in the left-right direction. The tip of each of the positioning protrusions 83L, 83R is located downstream of the roller parts 71R, 72R of the first conveyor roller 71 and the second conveyor roller 72 in the conveying direction DT1.

[0280] 27, the abutment piece 88L is swingably supported by a swing shaft 84L formed to protrude upward from a position rearward of the positioning protrusion 83L on the pre-cutting cover 80. The abutment piece 88L extends rearward away from the swing shaft 84L, and the left end of the protrusion protruding leftward from the rear portion thereof is curved in an arc to form a curved abutment surface 88L1.

[0281] The abutment piece 88R is supported to be able to swing on a swing shaft 84R formed to protrude upward from a position rearward of the positioning protrusion 83R on the pre-cutting cover 80. The abutment piece 88R extends rearward away from the swing shaft 84R, and the right end of the protrusion protruding rightward from the rear portion thereof is curved in an arc to form a curved abutment surface 88R1.

[0282] Each of the biasing springs 89 is a compression coil spring. The left biasing spring 89 biases the contact piece 88L to move leftward. The right biasing spring 89 biases the contact piece 88L to move leftward.

[0283] The first housing 10 has a pair of left and right abutment surfaces 18L, 18R.

[0284] The abutment surface 18L is an inclined surface formed on the left side frame of the internal frame of the first housing 10. The abutment surface 18L is located rearward and leftward away from the positioning rib 308L, and extends rearward and rightward while inclining.

[0285] The tip of the contacted surface 18L is located at a position through which the contact piece 88L can pass while swinging to the right. The contacted surface 18L can come into contact with the curved contact surface 88L1 of the contact piece 88L.

[0286] The abutment surface 18R is an inclined surface formed on the right side frame of the internal frame of the first housing 10. The abutment surface 18R is located rearward and to the right away from the positioning rib 308R, and extends rearward and leftward while inclining.

[0287] The tip of the contacted surface 18R is located at a position through which the contact piece 88R can pass while swinging leftward. The contacted surface 18R can come into contact with the curved contact surface 88R1 of the contact piece 88R.

[0288] When the pre-cutting cover 80 moves from the second cover position toward the first cover position, the positioning protrusions 83L, 83R of the pre-cutting cover 80 approach the positioning ribs 308L, 308R of the pre-cutting guide 300.

[0289] Then, after the abutment pieces 88L, 88R of the pre-cutting cover 80 pass the tips of the abutted surfaces 18L, 18R, the abutted surfaces 18L, 18R abut against the curved abutment surfaces 88L1, 88R1 of the abutment pieces 88L, 88R which are biased by the biasing spring 89, thereby applying a pressing force FC1 to the pre-cutting cover 80, pressing the pre-cutting cover 80 towards the first cover position.

[0290] The pressing force FC1 biases the positioning protrusions 83L, 83R downstream in the transport direction DT1, As a result, the tips of the positioning protrusions 83L, 83R come into contact with the positioning ribs 308L, 308R, and the pre-cutting cover 80 reaches the first cover position.

[0291] The pre-cutting cover 80 comes into contact with the pre-cutting guide 300 on the outer side of the sheet SH in the cutting direction DC1, that is, in the left-right direction.

[0292] In this way, the pre-cutting cover 80 at the first cover position is positioned in the conveying direction DT1 by the cutter frame 400. At this time, the pre-cutting cover 80 at the first cover position abuts against the pre-cutting guide 300, and is thereby indirectly positioned by the cutter frame 400.

[0293] <Effect 3> 27, in the image forming apparatus 1 of the embodiment, the pre-cutting cover 80 in the first cover position is positioned in the conveying direction DT1 by the cutter frame 400 by abutting against the pre-cutting guide 300. This makes it difficult for the relative positional relationship between the cutter mechanism 4 and the first conveying roller 71 supported by the pre-cutting cover 80 to shift when the pre-cutting cover 80 moves from the second cover position to the first cover position.

[0294] As a result, the direction in which the rotation axis X71 of the first conveying roller 71 supported by the pre-cutting cover 80 extends is likely to be parallel to the cutting direction DC1 as it should be, and the sheet SH is unlikely to be obliquely shifted relative to the cutting direction DC1. As a result, the sheet SH conveyed by the first conveying roller 71 is unlikely to be skewed.

[0295] Therefore, the image forming apparatus 1 of the embodiment can prevent the cutter mechanism 4 from cutting the sheet SH obliquely.

[0296] 12, in the image forming apparatus 1, the fixed blade 411 is fixed to the cutter frame 400 and extends in the cutting direction DC1. With this configuration, the cutting position of the sheet SH is determined by the fixed blade 411, and the relative positional relationship between the fixed blade 411 and the pre-cutting cover 80 is determined by the cutter frame 400. This improves the positional accuracy of the first conveyor roller 71 supported by the pre-cutting cover 80 with respect to the fixed blade 411, so that the cutter mechanism 4 can cut the sheet SH at the desired cutting position.

[0297] Furthermore, in this image forming apparatus 1, the moving blade 412 is guided in the cutting direction DC1 by the cutter frame 400, and moves while sliding against the fixed blade 411. With this configuration, the cutting position of the sheet SH is determined by the fixed blade 411, and the relative positional relationship between the fixed blade 411 and the moving blade 412 is determined by the cutter frame 400. This improves the positional accuracy when the moving blade 412 slides against the fixed blade 411.

[0298] 6, in the image forming apparatus 1, the pre-cutting cover 80 supports the first conveying roller 71 and the second conveying roller 72. With this configuration, when the pre-cutting cover 80 is moved to the second cover position, both the first conveying roller 71 and the second conveying roller 72 move together with the pre-cutting cover 80. As a result, the sheet SH that is jammed upstream of the cutter mechanism 4 in the conveying direction DT1 moves together with the first conveying roller 71 and the second conveying roller 72, making it easy to remove the jammed sheet SH.

[0299] 13 and 14, in the image forming apparatus 1, the pre-cutting guide 300 is fixed to the cutter frame 400. Then, as shown in Fig. 27, the pre-cutting cover 80 in the first cover position is indirectly positioned to the cutter frame 400 by abutting against the pre-cutting guide 300. This configuration can improve design freedom compared to a configuration in which the pre-cutting cover 80 is positioned by directly abutting against the cutter frame 400.

[0300] Furthermore, in this image forming apparatus 1, the contact surfaces 18L, 18R of the first housing 10 come into contact with the curved contact surfaces 88L1, 88R1 of the contact pieces 88L, 88R biased by the biasing spring 89, thereby applying a pressing force FC1 to the pre-cutting cover 80, pressing the pre-cutting cover 80 toward the first cover position. With this configuration, when the pre-cutting cover 80 is moved to the first cover position, the pre-cutting cover 80 can be positioned at the first cover position with high reliability.

[0301] Furthermore, in this image forming apparatus 1, as shown in Fig. 9, the first conveyor roller 71 and the second conveyor roller 72 each have a roller portion 71R, 72R formed with a cylindrical surface longer than the sheet SH in the cutting direction DC1. Then, as shown in Fig. 4, the cutter mechanism 4 cuts the sheet SH held between the roller portions 71R, 72R of the first conveyor roller 71 and the second conveyor roller 72. With this configuration, it is possible to prevent the sheet SH from rippling when the cutter mechanism 4 cuts the sheet SH.

[0302] 5, the first housing 10 has a maintenance opening 19 that exposes the pre-cutting cover 80 to the outside of the first housing 10, and an exterior cover 90 that opens and closes the maintenance opening 19. With this configuration, the pre-cutting cover 80 does not also serve as the exterior cover 90. As shown in FIG. 7, by keeping the pre-cutting cover 80 closed when opening the exterior cover 90 to remove the sheet SH that has become clogged around the fixing unit 7 or in the second discharge path PD2, it is possible to prevent the user's hand from reaching the cutter mechanism 4 via the maintenance opening 19.

[0303] 4, in the image forming apparatus 1, the first housing 10 has a protruding wall 17 that covers the upper part of the pre-cutting cover 80 in the first cover position. The presence of the protruding wall 17 above the pre-cutting cover 80 can prevent the user from accidentally putting his / her hand on the pre-cutting cover 80 from above, thereby preventing excessive force from being applied to the pre-cutting cover 80.

[0304] 4 and 6, in the image forming apparatus 1, the pre-cutting cover 80 moves to the first cover position and the second cover position by rotating about the cover axis X80. With this configuration, rattling when the pre-cutting cover 80 moves to the first cover position and the second cover position can be suppressed compared to a case in which the pre-cutting cover 80 moves linearly.

[0305] Further, in the image forming apparatus 1, as shown in FIG. 4, when the exterior cover 90 closes the maintenance opening 19, the exterior cover 90 forms an upstream conveying path PD1U that is located upstream in the conveying direction DT1 from the conveying path PD1D formed by the pre-cutting cover 80 in the first cover position, and that can guide the sheet SH from the fixing device 7 toward the second discharge roller pair 28. As shown in FIG. 7, when the pre-cutting cover 80 is in the first cover position and the exterior cover 90 opens the maintenance opening 19, the upstream conveying path PD1U is opened, and the upstream side of the cutter mechanism 4 in the conveying direction DT1 remains blocked. With this configuration, when the exterior cover 90 is opened to remove the sheet SH that has become jammed around the second discharge roller pair 28, the pre-cutting cover 80 is in the first cover position, so that it is possible to prevent the user's hand from reaching the cutter mechanism 4 via the maintenance opening 19.

[0306] 6, in the image forming apparatus 1, the exterior cover 90 with the maintenance opening 19 open can accommodate a sheet SH that has passed through the fixing unit 7. The multiple ribs 87 of the pre-cutting cover 80 guide the sheet SH that has passed through the fixing unit 7 toward the exterior cover 90 when the pre-cutting cover 80 is in the second cover position. With this configuration, when the sheet SH that has passed through the fixing unit 7 is discharged in a straight manner, the ribs 87 of the pre-cutting cover 80 allow the sheet SH to be smoothly placed on the exterior cover 90.

[0307] 27, in the image forming apparatus 1, the pre-cutting cover 80 abuts against the pre-cutting guide 300 on the outer side of the sheet SH in the cutting direction DC1. With this configuration, the problem of the direction in which the rotation axis X71 of the first conveying roller 71 supported by the pre-cutting cover 80 extends being obliquely shifted with respect to the cutting direction DC1 is less likely to occur compared to the case in which the pre-cutting cover 80 abuts against the pre-cutting guide 300 on the inner side of the sheet SH in the cutting direction DC1.

[0308] <First Edge and Second Edge of Image Forming Apparatus> 2, one edge in the cutting direction DC1, i.e., the right edge, of the image forming apparatus 1 is a first edge 1E1. The other edge in the cutting direction DC1, i.e., the left edge, of the image forming apparatus 1 is a second edge 1E2.

[0309] On the first edge 1E1 side of the image forming apparatus 1, a first length by which the second housing 30 protrudes rightward relative to the first housing 10 is defined as LP1. The first length LP1 is equal to or greater than zero. In this embodiment, the first length LP1 is zero.

[0310] At the second end edge 1E2 side of the image forming apparatus 1, the second length by which the second housing 30 protrudes leftward relative to the first housing 10 is defined as LP2. The second length LP2 is longer than the first length LP1. In this embodiment, the second length LP2 is approximately 10 to 15% of the length of the first housing 10 in the left-right direction.

[0311] An insertion port 45H of the automatic document feeder mechanism 45 opens in a direction facing the first edge 1E1 side of the image forming apparatus 1, that is, in the right direction.

[0312] <Joint cover storage recess> 18 to 20, the joint cover 50 has an accommodating recess 55. The accommodating recess 55 is recessed so as to accommodate a portion of the joint cover 50 located on one side in the cutting direction DC1 from the cutting area AC1, i.e., the cutter carriage 420, the moving blade holder 460, and the moving blade 412 when the support portion 57R is in the standby position (420A). The accommodating recess 55 is recessed rightward from the inner wall surface 59 of the support portion 57R.

[0313] As shown in FIGS. 20 and 28, the support portion 57R has a first support portion 51, a second support portion 52, and a connecting wall 53.

[0314] 20, the first support part 51 is located to the right of the discharge tray 9 and is located downstream in the conveying direction DT1 of the moving blade holder 460 and the moving blade 412. The first support part 51 supports a part of the first edge 1E1 side (right side surface side) of the second housing 30 from below.

[0315] The second support portion 52 is located to the right of the discharge tray 9 and is located upstream in the conveying direction DT1 of the moving blade holder 460 and the moving blade 412. The second support portion 52 supports another part of the first edge 1E1 side (right side surface side) of the second housing 30 from below.

[0316] The connecting wall 53 connects the first support part 51 and the second support part 52. The connecting wall 53 is located at a position retreated to the right from the cutting area AC1 relative to the first support part 51 and the second support part 52 so as to be able to accommodate the cutter carriage 420, the moving blade holder 460, and the moving blade 412.

[0317] The accommodating recess 55 is defined by the first support portion 51, the second support portion 52, and the connecting wall 53. In other words, the joint cover 50 forms the accommodating recess 55 by reducing the thickness of the connecting wall 53 in the left-right direction between the first support portion 51 and the second support portion 52.

[0318] As shown in FIG. 16, when the cutter carriage 420, the movable blade holder 460 and the movable blade 412 are in the standby position (420A), the end 420E of the cutter carriage 420 on the cutting area AC1 side is positioned above the cutting area AC1 when viewed along the conveying direction DT1, and protrudes toward the cutting area AC1 side more than the inner wall surface 59.

[0319] When the cutter carriage 420, the moving blade holder 460, and the moving blade 412 are in the standby position (420A), a part of the cutter carriage 420, i.e., an end 420E of the cutter carriage 420 on the cutting area AC1 side, is located above the cutter frame opening 409 when viewed along the conveying direction DT1, and overlaps with the cutter frame opening 409 in the cutting direction DC1. Furthermore, when viewed along the conveying direction DT1, most of the cutter carriage 420A in the standby position, except for the end 420E, overlaps with the first support part 51. Since the second guide 200 is located in front of the cutter mechanism 4, i.e., downstream of the conveying direction DT1, the cutter carriage 420 is covered by the second guide 200 and the joint cover 50 and cannot be seen from the outside when viewed from the front of the device along the conveying direction DT1.

[0320] <Detachable opening of joint cover and detachable opening cover> 1, 5, and 28, the joint cover 50 has a side wall 56. The side wall 56 is made up of a right wall of the first support part 51, a right wall of the second support part 52, and the connecting wall 53. The right surface of the side wall 56 constitutes the right design surface of the joint cover 50.

[0321] As shown in FIG. 20, the side wall 56 is located on one side of the cutter frame 400 in the cutting direction DC1.

[0322] 1, 5, 20 and 28, the joint cover 50 has a detachable opening 54. The detachable opening 54 penetrates the connecting wall 53, which is a part of the side wall 56, in the left-right direction.

[0323] In other words, the connecting wall 53 has an attachment / detachment opening 54. The attachment / detachment opening 54 is located on the first edge 1E1 side of the image forming apparatus 1.

[0324] 28, the attachment / detachment opening 54 is an opening sized to allow the moving blade holder 460 and the moving blade 412 to pass through in order to attach and detach the moving blade holder 460 and the moving blade 412 to and from the cutter carriage 420 in the standby position. The lower portion of the attachment / detachment opening 54 is smaller than the upper portion of the attachment / detachment opening 54. The front edge of the lower portion of the attachment / detachment opening 54 and the front edge of the upper portion of the attachment / detachment opening 54 extend continuously in the vertical direction.

[0325] The moving blade holder 460 has a handle 469. The handle 469 protrudes rightward from the upper end of the moving blade holder 460, i.e., toward the attachment / detachment opening 54.

[0326] 12 shows the relative positional relationship between the attachment / detachment opening 54, the cutter carriage 420, the moving blade holder 460, and the moving blade 412 when viewed along the cutting direction DC1. The attachment / detachment opening 54 is a part of the moving blade holder 460 held by the cutter carriage 420, and overlaps with a part including the handle 469 when viewed along the cutting direction DC1.

[0327] 18 and 20, the attachment / detachment opening 54 is located on one side in the cutting direction DC1, i.e., to the right, of the discharge tray 9. The attachment / detachment opening 54 is located in the support part 57R, which is on one side in the cutting direction DC1 of the support parts 57L and 57R, of the discharge space AD1.

[0328] 1, 5, 18 to 20, and 28, the joint cover 50 has a detachable opening cover 54C. The detachable opening cover 54C is supported by a connection portion of the side wall 56 between the connecting wall 53 and the second support portion 52, and is capable of opening and closing the detachable opening 54.

[0329] The detachable opening cover 54C can swing between a position in which the detachable opening 54 is closed as shown in Figures 1, 5, and 18 to 20, and a position in which the detachable opening 54 is open as shown in Figure 28. The detachable opening cover 54C is generally rectangular and larger than the detachable opening 54.

[0330] 28, a rib 54R is formed on the lower end side of the detachable opening cover 54C. A rib insertion hole 53R is formed in the connecting wall 53 at a position spaced downward from the front lower corner of the detachable opening 54. The rib insertion hole 53R penetrates the connecting wall 53 in the left-right direction.

[0331] When the removable opening cover 54C opens the removable opening 54, the rib 54R is separated to the right and rear from the rib insertion hole 53R. Although not shown, when the removable opening cover 54C moves to a position where the removable opening 54 is closed, the rib 54R is inserted into the rib insertion hole 53R and its tip protrudes leftward beyond the rib insertion hole 53R.

[0332] As shown in Figures 11 and 13, the image forming apparatus 1 includes an open / close sensor S7. The open / close sensor S7 is a sensor capable of detecting the open / close state of the removable opening cover 54C. When the removable opening cover 54C closes the removable opening 54 and the tip of the rib 54R presses the actuator of the open / close sensor S7, the open / close sensor S7 goes into a state where it outputs a close signal for the removable opening cover 54C, and goes into a state where it outputs an open signal for the removable opening cover 54C in any other case. The control unit C1 can detect the open / close state of the removable opening cover 54C by checking the state of the open / close sensor S7 at an appropriate timing.

[0333] As shown in FIG. 28, the cutter carriage 420 is capable of attaching and detaching the moving blade holder 460 and the moving blade 412 while the moving blade holder 460 and the moving blade 412 are in the standby position.

[0334] With the cutter carriage 420, the moving blade holder 460, and the moving blade 412 in the standby position (420A), the attachment / detachment opening cover 54C is opened, and then the upper end of the carriage cover 450 of the cutter carriage 420, which will be described later, is moved forward and downward from the position shown in Fig. 28. This allows the moving blade holder 460 and the moving blade 412 to be removed from the cutter carriage 420 by holding the handle 469 and pulling the moving blade holder 460 and the moving blade 412 to the right while lifting them upward. Also, by performing the reverse operation, the moving blade holder 460 and the moving blade 412 can be attached to the cutter carriage 420.

[0335] <Arrangement of the first motor and the second motor> As shown in FIG. 2, the first motor M1 and the second motor M2 are located on the second edge 1E2 side of the image forming apparatus 1.

[0336] As shown in FIG. 3, almost the entire first motor M1 except for its upper end portion overlaps with the joint cover 50 when viewed in the cutting direction DC1, that is, the left-right direction.

[0337] The entire second motor M2 overlaps with the joint cover 50 when viewed along the cutting direction DC1, that is, the left-right direction.

[0338] <Layout of control board, communication board, speaker, exhaust vent and exhaust fan> As shown in FIGS. 2 and 3, the image forming apparatus 1 includes a control board 60 and a communication board 61.

[0339] The control board 60 has an electronic circuit that constitutes the main part of the control unit C1, and controls the operation of the image forming apparatus 1.

[0340] The communication board 61 has a communication circuit for the image forming apparatus 1 to communicate with the outside, and is connected to the control board 60. The communication board 61 performs short-range wireless communication, such as Wi-Fi (registered trademark), Bluetooth (registered trademark), or NFC.

[0341] The control board 60 and the communication board 61 are located on the second edge 1E2 side of the image forming apparatus 1, and are arranged along the inner wall surface of the left wall of the first housing .

[0342] As shown in FIG. 2, the first housing 10 has a speaker 64, an exhaust port 63H, and an exhaust fan 63.

[0343] The speaker 64 is controlled by the control unit C1 to emit sounds such as voice messages, warning sounds, etc. The speaker 64 is located on the second edge 1E2 side of the image forming apparatus 1 and is attached to the inner wall surface of the left wall of the first housing 10.

[0344] As shown in FIG. 3, a plurality of small holes 10H are formed in the left wall of the first housing 10 at positions facing the speaker 64 for diffusing sound emitted by the speaker 64 to the outside of the first housing 10.

[0345] The exhaust port 63H is located on the first edge 1E1 side of the image forming apparatus 1. The exhaust port 63H has an opening formed in the right wall of the first housing 10 and a lattice connected to the inner peripheral edge of the opening. The exhaust port 63H connects the inside and outside of the first housing 10.

[0346] The exhaust fan 63 is attached to the inner wall surface of the right wall of the first housing 10, and faces the exhaust port 63H. The exhaust fan 63 exhausts the air inside the first housing 10 through the exhaust port 63H.

[0347] <Effect 4> As shown in FIG. 20, in the image forming apparatus 1 of the embodiment, space can be secured to accommodate the moving blade 412 in the standby position simply by partially recessing the joint cover 50 for supporting the second housing 30 from below to form an accommodating recess 55.

[0348] Therefore, the image forming apparatus 1 of the embodiment can suppress an increase in size in the cutting direction DC1.

[0349] In addition, in this image forming apparatus 1, as shown in FIG. 8, the joint cover 50 has an inner wall surface 59 that defines one side of the cutting direction DC1 of the discharge space AD1. As shown in FIG. 20, the accommodation recess 55 is recessed from the inner wall surface 59 to one side of the cutting direction DC1, that is, to the right, and accommodates the moving blade 412 together with the cutter carriage 420. As shown in FIG. 16, when the cutter carriage 420, the moving blade holder 460, and the moving blade 412 are in the standby position (420A), the end 420E of the cutter carriage 420 on the cutting area AC1 side is located above the cutting area AC1 as viewed along the conveying direction DT1, and protrudes toward the cutting area AC1 side from the inner wall surface 59. With this configuration, it is possible to reliably suppress the enlargement of the cutting direction DC1 of the image forming apparatus 1, compared to a case in which the accommodation recess 55 is recessed to accommodate the entire cutter carriage 420. Furthermore, with this configuration, the empty space above the cutting area AC1 can be effectively utilized for the end 420E of the cutter carriage 420 on the cutting area AC1 side.

[0350] 28, in the image forming apparatus 1, when the cutter carriage 420, the moving blade holder 460, and the moving blade 412 are in the standby position (420A), the cutter carriage 420 can detachably mount the moving blade holder 460 and the moving blade 412. With this configuration, the worn moving blade 412 can be replaced, so that the cutter mechanism 4 can provide stable cutting performance for a long period of time.

[0351] In addition, in this image forming apparatus 1, as shown in Fig. 12, the cutter carriage 420 detachably holds the moving blade holder 460 and the moving blade 412. Then, as shown in Fig. 28, the joint cover 50 has an attachment / detachment opening 54 for attaching and detaching the moving blade holder 460 and the moving blade 412 to and from the cutter carriage 420 when the cutter carriage 420 is in the standby position (420A). With this configuration, the worn moving blade 412 can be easily replaced via the attachment / detachment opening 54, so that the cutter mechanism 4 can exhibit stable cutting performance for a long period of time.

[0352] Further, in this image forming apparatus 1, as shown in FIG. 20, the joint cover 50 has a first support portion 51, a second support portion 52, and a connecting wall 53 connecting the first support portion 51 and the second support portion 52. The connecting wall 53 is located in a position retreated from the cutting area AC1 to one side in the cutting direction DC1 from the first support portion 51 and the second support portion 52 so as to be able to accommodate the cutter carriage 420, the moving blade holder 460, and the moving blade 412. The storage recess 55 is defined by the first support portion 51, the second support portion 52, and the connecting wall 53. With this configuration, the joint cover 50 supports the second housing 30 from below by the first support portion 51 and the second support portion 52, and the storage recess 55 can be largely defined by the first support portion 51, the second support portion 52, and the connecting wall 53.

[0353] In addition, in this image forming apparatus 1, as shown in Fig. 12, the cutter carriage 420 detachably holds the moving blade holder 460 and the moving blade 412. Then, as shown in Fig. 28, the connecting wall 53 has an attachment / detachment opening 54 for attaching and detaching the moving blade holder 460 and the moving blade 412 to and from the cutter carriage 420 when the cutter carriage 420 is in the standby position (420A). With this configuration, the worn moving blade 412 can be easily replaced via the attachment / detachment opening 54, so that the cutter mechanism 4 can exhibit stable cutting performance for a long period of time.

[0354] 16, in the image forming apparatus 1, when the cutter carriage 420, the moving blade holder 460, and the moving blade 412 are in the standby position (420A), a part of the cutter carriage 420, i.e., the end 420E of the cutter carriage 420 on the cutting area AC1 side, is located above the cutter frame opening 409 when viewed along the conveying direction DT1, and overlaps with the cutter frame opening 409 in the cutting direction DC1. With this configuration, it is possible to reliably suppress an increase in size of the cutting direction DC1 of the image forming apparatus 1, compared to a case in which the entire cutter carriage 420 when the cutter carriage 420 and the moving blade 412 are in the standby position does not overlap with the cutter frame opening 409 in the cutting direction DC1 when viewed along the conveying direction DT1.

[0355] 16, the first motor M1 is located above the cutter frame opening 409 when viewed along the conveying direction DT1, and the entire motor M1 overlaps with the cutter frame opening 409 in the cutting direction DC1. This configuration makes it possible to more reliably prevent the image forming apparatus 1 from becoming larger in the cutting direction DC1, compared to a case in which the entire first motor M1 does not overlap with the cutter frame opening 409 in the cutting direction DC1 when viewed along the conveying direction DT1.

[0356] Further, in this image forming apparatus 1, as shown in FIG. 1, the attachment / detachment opening 54 is located on the first edge 1E1 side, which is one edge of the image forming apparatus 1 in the cutting direction DC1, and as shown in FIG. 2, the control board 60 is located on the second edge 1E2 side of the image forming apparatus 1. A large number of connection cables for connecting to the image forming unit 3, the fixing unit 7, the cutter mechanism 4, and the image reading unit 35 are wired to the control board 60. For this reason, the design freedom for arranging the attachment / detachment opening 54 on the second edge 1E2 side where the control board 60 is located tends to be low. In this regard, by the configuration in which the attachment / detachment opening 54 is located on the first edge 1E1 side opposite to the second edge 1E2, it is not necessary to consider interference between the attachment / detachment opening 54, the control board 60, and the connection cables, so that the design freedom for arranging the attachment / detachment opening 54 can be improved.

[0357] Moreover, in this image forming device 1, the communication board 61 is located on the second edge 1E2 side and is connected to the control board 60. With this configuration, the communication board 61 can be disposed in a position close to the control board 60, and the connection cable for connecting the communication board 61 and the control board 60 can be shortened.

[0358] 3, the entire second motor M2 overlaps with the joint cover 50 when viewed along the cutting direction DC1, i.e., the left-right direction. With this configuration, the empty space within the joint cover 50 can be effectively used as a storage space for the second motor M2, thereby realizing a reduction in size in the vertical direction.

[0359] In addition, in this image forming apparatus 1, almost the entire first motor M1 except for its upper end portion overlaps with the joint cover 50 when viewed along the cutting direction DC1, i.e., the left-right direction. With this configuration, the empty space within the joint cover 50 can be effectively used as a storage space for the first motor M1, thereby achieving a reduction in size in the vertical direction.

[0360] 1, the attachment / detachment opening 54 is located on the first edge 1E1 side of the image forming device 1, and as shown in Fig. 2, the first motor M1 and the second motor M2 are located on the second edge 1E2 side of the image forming device 1. With this configuration, it is possible to prevent the driving sounds of the first motor M1 and the second motor M2 from leaking to the outside via the attachment / detachment opening 54.

[0361] 2, in the image forming device 1, the first length LP1 by which the second housing 30 protrudes in one direction in the cutting direction DC1 from the first housing 10 at the first edge 1E1 side of the image forming device 1 is equal to or greater than zero. The second length LP2 by which the second housing 30 protrudes in the other direction in the cutting direction DC1 from the first housing 10 at the second edge 1E2 side of the image forming device 1 is greater than the first length LP1. The attachment / detachment opening 54 is located on the first edge 1E1 side. With this configuration, when replacing the moving blade 412 through the attachment / detachment opening 54, one side of the second housing 30 in the cutting direction DC1, i.e., the right side, is unlikely to get in the way.

[0362] 1, the attachment / detachment opening and the exhaust port 63H are located on the first edge 1E1 side of the image forming apparatus 1. With this configuration, when the image forming apparatus 1 is installed, the first edge 1E1 side where the exhaust port 63H is located is placed away from the wall surface. Therefore, the user can easily reach the attachment / detachment opening 54, and the moving blade 412 can be easily replaced.

[0363] In addition, in this image forming apparatus 1, the attachment / detachment opening 54 is located on the first edge 1E1 side of the image forming apparatus 1, and as shown in FIG. 2, the speaker 64 is located on the second edge 1E2 side of the image forming apparatus 1. The side on which the speaker 64 is located needs to have a relatively large wall for reverberating sound. For this reason, the degree of freedom in designing to place the attachment / detachment opening 54 on the second edge 1E2 side on which the speaker 64 is located tends to be low. In this regard, by using a configuration in which the attachment / detachment opening 54 is located on the first edge 1E1 side opposite to the second edge 1E2, it is easy to ensure a large wall for reverberating sound, and therefore the degree of freedom in designing to place the attachment / detachment opening 54 can be improved.

[0364] 1, in this image forming apparatus 1, the attachment / detachment opening 54 is located on the first edge 1E1 side of the image forming apparatus 1, and the insertion opening 45H of the automatic document feeder mechanism 45 opens in a direction facing the first edge 1E1 side of the image forming apparatus 1. With this configuration, when the image forming apparatus 1 is installed, a space is secured on the first edge 1E1 side for a user to insert a document into the insertion opening 45H. This space makes it easy for the user to reach the attachment / detachment opening 54, so that the moving blade 412 can be easily replaced.

[0365] <Specific configuration of cutter carriage> As shown in FIGS. 29 to 32, the cutter carriage 420 has a carriage base 440 and a carriage cover 450. As shown in FIG.

[0366] As shown in Figures 31 and 32, the carriage base 440 has a holder holding portion 446, a shaft hole 447, an engaging protrusion 448, a guided portion 442, and a belt engaging portion 443 which are integrally formed to form a single resin molded product.

[0367] The holder holding portion 446 has a first holding wall 446A and a pair of left and right second holding walls 446B.

[0368] The first retaining wall 446A extends in the left-right and up-down directions and has a plurality of protrusions and recesses. As shown in FIG. 32, a left-right positioning recess 446H is formed in the left-right center of the first retaining wall 446A so as to be recessed rearward. A front-rear positioning protrusion 446T is formed on the right edge side of the first retaining wall 446A. The upper and lower ends of the front-rear positioning protrusion 446T bulge forward above the left-right positioning recess 446H. Although not shown in the drawings, a front-rear positioning protrusion 446T is also formed on the left edge side of the first retaining wall 446A.

[0369] The second retaining walls 446B are connected to the left and right side edges of the first retaining wall 446A, protrude forward, and extend in the vertical direction.

[0370] As shown in FIGS. 43 and 44, the holder holding portion 446 holds the moving blade holder 460 by surrounding the moving blade holder 460 from the left, right, and rear with a first holding wall 446A and second holding walls 446B.

[0371] 31 and 32, a pair of left and right shaft holes 447 are formed at the lower end of each second holding wall 446B so as to penetrate in the left-right direction. The shaft holes 447 are circular holes centered on a swing axis X450 extending in the left-right direction. A notch is formed at the lower end side of the shaft hole 447 to allow a swing shaft 457 (described later) to enter therein.

[0372] A pair of left and right engaging protrusions 448 are formed so as to protrude upward and forward from upper and front corners of each of the second holding walls 446B.

[0373] The guided portion 442 is formed rearward of the first holding wall 446 A. The belt engaging portion 443 is formed rearward of the first holding wall 446 A and below the guided portion 442.

[0374] 36, the guided portion 442 is supported by the guide portion 402 of the cutter frame 400 so as to be movable in the cutting direction DC1. The belt engagement portion 443 is connected to a portion of the timing belt 430 that extends in the left-right direction above the cutter frame opening 409. As a result, the driving force of the first motor M1 is transmitted to the carriage base 440 by the timing belt 430, and the carriage base 440 is guided in the cutting direction DC1 by the guide portion 402.

[0375] As shown in Fig. 30, the carriage base 440 holds a pair of left and right elastic beams 445, which are metal leaf springs. As shown in Fig. 31 and Fig. 32, each elastic beam 445 is connected by a beam connector 445J. Each elastic beam 445 and the beam connector 445J are manufactured by punching, bending, etc., a single spring steel plate.

[0376] 36, the beam connecting portion 445J engages with the upper portion of the first retaining wall 446A, so that each elastic beam 445 is held by the first retaining wall 446A. The elastic beam 445 extends downward and forward so as to enter the holder retaining portion 446, i.e., to enter the space surrounded by the first retaining wall 446A and each second retaining wall 446B, when the holder retaining portion 446 is not retaining the moving blade holder 460.

[0377] As shown in FIGS. 31 and 32, the carriage cover 450 has a cover body 456, a swing shaft 457, a protrusion 458, a surrounding portion 459, and an operation protrusion 459T, which are integrally formed to constitute a single resin molded product.

[0378] The cover body 456 has a cover main wall 456A and a pair of left and right cover side walls 456B.

[0379] 31, the cover main wall 456A extends in the left-right and up-down directions and has a plurality of protrusions and recesses. A pair of left and right pressing protrusions 456T are formed at the lower end of the cover main wall 456A so as to protrude rearward.

[0380] The cover side walls 456B are connected to the left and right side edges of the cover main wall 456A, protrude rearward, and extend in the vertical direction. The lower ends of the cover side walls 456B are located lower and forward of the lower end of the cover main wall 456A.

[0381] A pair of left and right swing shafts 457 are formed at the lower end of each cover side wall 456B. Each swing shaft 457 is a cylinder that protrudes toward each other and is centered on a swing axis X450 parallel to the cutting direction DC1. A part of the outer circumferential surface of the swing shaft 457 is made flat so that it passes through the notch and is inserted into the shaft hole 447.

[0382] As shown in Figures 31 and 32, a pair of left and right protrusions 458 are formed integrally with each oscillation shaft 457 centered on the oscillation axis X450. Each protrusion 458 has a smaller diameter than each oscillation shaft 457. As shown in Figure 31, the left protrusion 458 is connected to the right surface of the left oscillation shaft 457 and protrudes to the right. As shown in Figure 32, the right protrusion 458 is connected to the left surface of the right oscillation shaft 457 and protrudes to the left.

[0383] 29 and 30, each pivot shaft 457 is inserted into each shaft hole 447 of the carriage base 440, whereby each shaft hole 447 pivotably supports each pivot shaft 457. As a result, as shown in FIGS. 36 to 44, the carriage cover 450 is supported by the carriage base 440 so as to be pivotable around the pivot axis X450.

[0384] The carriage cover 450 swings between an unlocked position shown in FIGS. 36 to 42 and a locked position shown in FIGS.

[0385] When the carriage cover 450 is in the unlocked position shown in Figure 36 etc., it allows the moving blade holder 460 to be attached to and detached from the holder holding portion 446. When the carriage cover 450 is in the locked position shown in Figure 43 etc., it fixes the moving blade holder 460 to the holder holding portion 446.

[0386] 29, the surrounding portion 459 and the operation protrusion 459T are located in the upper portion of the right cover side wall 456B. The operation protrusion 459T protrudes rightward from the upper end portion of the right cover side wall 456B, that is, toward the attachment / detachment opening 54. The surrounding portion 459 has a notch 459C recessed forward below the operation protrusion 459T.

[0387] 28, the enclosing portion 459 encloses the handle 469 when the carriage cover 450 is in the locked position. The cutout 459C exposes a part of the right end side of the handle 469 when the carriage cover 450 is in the locked position.

[0388] 29 and 31, the carriage cover 450 holds a pair of first springs 455 on the left and right. Each first spring 455 is a metal leaf spring. The left first spring 455 is held on the rear side of the lower part of the cover main wall 456A at a position adjacent to the left cover side wall 456B. The right first spring 455 is held on the rear side of the lower part of the cover main wall 456A at a position adjacent to the right cover side wall 456B.

[0389] Each of the first springs 455 has a curved portion 455C. The curved portion 455C is a portion of each of the first springs 455 that is above a portion that is held by the cover main wall 456A. ​​The curved portion 455C extends rearward and upward, and then curves downward while continuing to extend rearward, and further curves upward while continuing to extend rearward.

[0390] As shown in FIG. 29, when the carriage cover 450 moves to the locked position, each curved portion 455C engages with each engaging protrusion 448 of the carriage base 440 to maintain the carriage cover 450 in the locked position.

[0391] <Specific configuration of moving blade holder> 33 to 35, the moving blade holder 460 has a holder frame 461. The holder frame 461 has a holder main body 461A and a holder cover 461B.

[0392] Engagement pieces 461B1 and 461B2 of holder cover 461B engage with engagement claws 461A1 and 461A2 of holder body 461A, and holder body 461A and holder cover 461B are fastened together by screw 461F, whereby holder body 461A and holder cover 461B are integrated together. Holder body 461A and holder cover 461B are each a resin molded product.

[0393] Handle 469 is formed integrally with holder body 461A. Handle 469 is connected to a left-right intermediate portion of the upper end surface of holder body 461A, extends forward and upward, and then protrudes in an elongated shape to the right.

[0394] As shown in FIGS. 35 and 36, the moving blade holder 460 has a support shaft 462 and a second spring 465.

[0395] The support shaft 462 extends in the front-rear direction along the conveying direction DT1. The support shaft 462 is inserted into a multi-stage cylinder 412A fixed to the center of the moving blade 412. The front end of the support shaft 462 fits into the lower part of the holder main body 461A. The rear end of the support shaft 462 fits into the lower part of the holder cover 461B. In this way, the holder frame 461 holds the support shaft 462 therein, and the support shaft 462 rotatably supports the moving blade 412.

[0396] The lower end of the moving blade 412 protrudes downward from the gap between the lower end of the holder frame 461 and the lower end of the holder cover 461B.

[0397] The second spring 465 is a torsion coil spring, and is located between the moving blade 412 and the holder frame 461. The second spring 465 is compressed and deformed with its front end abutting against the inner wall surface of the holder frame 461 and its rear end abutting against the large diameter portion of the multi-stage cylinder 412A, and stores a restoring force. As a result, the second spring 465 biases the moving blade 412 toward the fixed blade 411 along the conveying direction DT1, that is, backward.

[0398] As shown in FIGS. 33 to 35, the holder main body 461A has a pair of grooves 468 on the left and right sides.

[0399] As shown in Fig. 33, the left groove 468 is formed on the lower end side of the left side surface of the holder main body 461A and is recessed rightward from the left side surface of the holder main body 461A. Figs. 38, 40, 42 and 44 show the left groove 468.

[0400] As shown in FIGS. 34 and 35, the right groove 468 is formed on the lower end side of the right side surface of the holder main body 461A and is recessed leftward from the right side surface of the holder main body 461A.

[0401] When viewed along the cutting direction DC1, the left groove 468 and the right groove 468 have the same shape and are in the same position.

[0402] As shown in FIGS. 33 to 35, one end 468A of each groove 468 is located at the lower end of the left and right side surfaces of the holder main body 461A and opens downward.

[0403] Each groove 468 extends upward from one end 468A in a direction perpendicular to the conveying direction DT1 and the cutting direction DC1, i.e., along the up-down direction, away from the fixed blade 411. Each groove 468 is bent at a bent portion 468B, and further extends forward from the bent portion 468B along the conveying direction DT1, away from the fixed blade 411, to reach the other end 468C. The other end 468C of each groove 468 is closed.

[0404] 34, a left / right positioning protrusion 461T is formed at approximately the center of the rear surface of the holder cover 461B so as to protrude rearward. A pair of left and right beam abutment surfaces 461U are formed at the lower end side of the rear surface of the holder cover 461B. When the tip of each elastic beam 445 abuts against each beam abutment surface 461U, each elastic beam 445 urges the moving blade holder 460 forward.

[0405] <Attachment and detachment of the moving blade holder to the cutter carriage> A user can attach the moving blade holder 460 and the moving blade 412 to the cutter carriage 420 by the following actions.

[0406] As shown in Figure 28, the description will begin with the state in which the attachment / detachment opening cover 54C opens the attachment / detachment opening 54, and as shown in Figure 36, the carriage cover 450 is in the unlocked position and the holder holding portion 446 is not holding the moving blade holder 460.

[0407] The user grasps the handle 469 of the moving blade holder 460 and moves the moving blade holder 460 to above the holder holding portion 446 of the cutter carriage 420 via the attachment / detachment opening 54 .

[0408] 37 and 38, the user lowers the moving blade holder 460 to enter the holder holding portion 446. At this time, each pressing protrusion 456T of the carriage cover 450 abuts against the front surface of the holder main body 461A to guide the moving blade holder 460 toward the holder holding portion 446. The moving blade 412 is spaced upward and forward from the tip of the fixed blade 411.

[0409] 39 and 40, the user further lowers the moving blade holder 460 to make it enter deeper inside the holder holding part 446. At this time, the tip of each elastic beam 445 contacts the moving blade holder 460 and elastically deforms backward to store a restoring force, thereby biasing the moving blade holder 460 forward so as to move the moving blade 412 away from the fixed blade 411 along the conveying direction DT1. This maintains the state in which each pressing protrusion 456T abuts against the front surface of the holder main body 461A.

[0410] 40, each protrusion 458 of the carriage cover 450 enters each groove 468 from one end 468A of each groove 468. In this state, the lower end of the moving blade 412 is located forward and away from the tip of the fixed blade 411 along the conveying direction DT1, and is at approximately the same height as the tip of the fixed blade 411 in the vertical direction.

[0411] 41 and 42, the user further lowers the moving blade holder 460. Then, as shown in Fig. 42, each groove 468 is guided by each protrusion 458, and the lowering of the moving blade holder 460 stops when each protrusion 458 is positioned at the bent portion 468B of each groove 468. In this state, the lower end of the moving blade 412 is located forward and away from the tip of the fixed blade 411 along the conveying direction DT1, and is located lower than the tip of the fixed blade 411 in the up-down direction.

[0412] In this state, the front and rear positioning protrusions 446T of the carriage base 440 face the moving blade holder 460. The left and right positioning recesses 446H of the carriage base 440 face the left and right positioning protrusions 461T of the moving blade holder 460, as shown in FIG.

[0413] 43 and 44, the user pinches the operation protrusion 459T and moves the carriage cover 450 from the unlocked position to the locked position, causing each pressing protrusion 456T of the carriage cover 450 to press the moving blade holder 460 and move it backward.

[0414] 44, in the process of the carriage cover 450 swinging from the unlocked position to the locked position, each protrusion 458 moves from the bent portion 468B of each groove 468 to the other end 468C, thereby guiding the moving blade holder 460. Accordingly, the moving blade 412 moves backward along the conveying direction DT1 so as to approach the fixed blade 411 and comes into contact with the fixed blade 411. Thereafter, the second spring 465 is compressed and deformed while pressing the moving blade 412 against the fixed blade 411.

[0415] At this time, as shown in Fig. 43, the left and right positioning protrusions 461T fit into the left and right positioning recesses 446H, so that the moving blade holder 460 is positioned in the left and right direction on the cutter carriage 420. Also, as shown in Fig. 44, the front and rear positioning protrusions 446T come into contact with the moving blade holder 460, and the protrusions 458 come into contact with the other ends 468C of the grooves 468, so that the moving blade holder 460 is positioned in the front and rear direction on the cutter carriage 420. As a result, the moving blade holder 460 is fixed to the holder holding portion 446.

[0416] 29, the carriage cover 450 is maintained in the locked position with high reliability by the engagement between the curved portions 455C of the first springs 455 and the engaging protrusions 448. As shown in FIG 1, the user closes the attachment / detachment opening cover 54C.

[0417] Moreover, the user can remove the moving blade holder 460 and the moving blade 412 from the cutter carriage 420 by performing the above-mentioned operations in reverse.

[0418] When the moving blade holder 460 is attached to or detached from the cutter carriage 420 , the protrusions 458 guide the moving blade holder 460 through the grooves 468 .

[0419] <Effect 5> 28, when performing the operation of attaching or detaching the moving blade holder 460 to or from the cutter carriage 420 in the image forming apparatus 1 of the embodiment, the hand can reach the moving blade holder 460 attached to the cutter carriage 420 in the cutting direction DC1, i.e., in the left-right direction, via the attachment / detachment opening 54 penetrating the connecting wall 53 that is a part of the side wall 56. At this time, even if a plurality of cut sheets SH are stacked on the discharge tray 9 downstream of the cutter mechanism 4 in the conveying direction DT1, the hand attempting to reach the moving blade holder 460 is unlikely to be obstructed by the sheets SH.

[0420] Furthermore, in this image forming apparatus 1, the moving blade holder 460 is not attached to or detached from the cutter carriage 420 from above, so the problem of the entire apparatus becoming larger is unlikely to occur.

[0421] Therefore, in the image forming apparatus 1 of the embodiment, the moving blade holder 460 can be easily attached to and detached from the cutter carriage 420 without increasing the size of the apparatus.

[0422] In addition, in the image forming apparatus 1, as shown in FIG. 4, the discharge tray 9 has an upstream portion 9A that is inclined upward and a downstream portion 9B that extends substantially horizontally. As shown in FIG. 20, the attachment / detachment opening 54 is located on one side of the discharge tray 9 in the cutting direction DC1. In this configuration, if a user attempts to reach the moving blade holder 460 attached to the cutter carriage 420 along the conveying direction DT1, the user is likely to be obstructed by the downstream portion 9B that is raised higher than the upstream portion 9A of the discharge tray 9. In this regard, according to the image forming apparatus 1, the user is unlikely to be obstructed by the downstream portion 9B of the discharge tray 9 when the user attempts to reach the moving blade holder 460 attached to the cutter carriage 420 along the cutting direction DC1 via the attachment / detachment opening 54.

[0423] Furthermore, this image forming apparatus 1 is a multifunction machine. As shown in Figs. 18 to 20, the second housing 30 and the joint cover 50 have a discharge space AD1 formed between the image forming unit 3, the image reading unit 35, and the support units 57L and 57R. The attachment / detachment opening 54 is located on one side of the discharge space AD1 in the cutting direction DC1. In other words, the attachment / detachment opening 54 is located on the support unit 57R, which is on one side of the discharge space AD1 in the cutting direction DC1, among the support units 57L and 57R. According to this configuration, the cutter mechanism 4 is located deeper than the discharge space AD1 in the joint cover 50, and the image reading unit 35 is located above the cutter mechanism 4. In this configuration, if one tries to reach the moving blade holder 460 attached to the cutter carriage 420 along the conveying direction DT1, it is likely to be obstructed by the sheets SH that have been cut and stacked in the discharge space AD1, and the image reading unit 35 and the support units 57L and 57R that surround the discharge space AD1. In this respect, according to the image forming apparatus 1, the hand can reach the moving blade holder 460 attached to the cutter carriage 420 along the cutting direction DC1 via the attachment / detachment opening 54. At this time, the hand trying to reach the moving blade holder 460 is unlikely to be obstructed by the cut sheets SH stacked in the discharge space AD1, or the image reading unit 35 and the support units 57L and 57R that form the discharge space AD1. In addition, since the image forming apparatus 1 does not attach or detach the moving blade holder 460 to or from the cutter carriage 420 from above, the problem of the entire apparatus becoming larger is unlikely to occur. Therefore, the image forming apparatus 1, which is a multifunction machine, can easily attach and detach the moving blade holder 460 to or from the cutter carriage 420 without increasing the size of the apparatus.

[0424] 28, the joint cover 50 has the detachable opening cover 54C. With this configuration, the closed detachable opening cover 54C can prevent foreign matter from entering the inside of the joint cover 50 through the detachable opening 54.

[0425] Furthermore, as shown in Fig. 11, the image forming apparatus 1 includes an open / close sensor S7. As shown in Fig. 28, if the cutter mechanism 4 were operable when the removable opening cover 54C is open, the user may accidentally touch the cutter carriage 420 or the moving blade holder 460 during operation. In this regard, the image forming apparatus 1 can detect the state of the removable opening cover 54C by the open / close sensor S7, and therefore can control the cutter mechanism 4 not to operate when the cover is open.

[0426] Furthermore, in this image forming apparatus 1, the moving blade holder 460 has a handle 469 that protrudes toward the attachment / detachment opening 54. With this configuration, the user's hand can easily reach the handle 469 of the moving blade holder 460 via the attachment / detachment opening 54, making it even easier to attach and detach the moving blade holder 460 to and from the cutter carriage 420.

[0427] Furthermore, in this image forming apparatus 1, as shown in Fig. 31, the carriage cover 450 has each protrusion 458. As shown in Fig. 33 and Fig. 34, the holder main body 461A has each groove 468. With this configuration, as shown in Fig. 40, Fig. 42 and Fig. 44, the each protrusion 458 guides each groove 468, so that the operation of attaching and detaching the moving blade holder 460 to and from the cutter carriage 420 can be performed more easily.

[0428] In addition, in this image forming apparatus 1, as shown in Fig. 31, the guiding portions are the protrusions 458, and as shown in Fig. 33 and Fig. 34, the guided portions are the grooves 468. With this configuration, the guided portions of the moving blade holder 460, which is a replacement unit, are the grooves 468 and do not protrude, so that even if the moving blade holder 460 is dropped, damage to the grooves 468 can be suppressed.

[0429] Furthermore, in this image forming apparatus 1, as shown in Figures 40, 42, and 44, one end 468A of each groove 468 is open, and the other end 468C of each groove 468 is closed. When the moving blade holder 460 is attached to the cutter carriage 420, each protrusion 458 enters each groove 468 from one end 468A of each groove 468 and guides each groove 468. Then, in a state in which the moving blade holder 460 is attached to the cutter carriage 420, each protrusion 458 abuts against the other end 468C to position the moving blade holder 460 in the front-rear direction. With this configuration in which each protrusion 458 abuts against the other end 468C of each groove 468, the moving blade holder 460 attached to the cutter carriage 420 can be easily positioned.

[0430] Also, in this image forming apparatus 1, the carriage cover 450 swings between an unlocked position, which allows the moving blade holder 460 to be attached and detached to the holder holding portion 446 of the carriage base 440, as shown in Fig. 36, and a locked position, which fixes the moving blade holder 460 to the holder holding portion 446, as shown in Fig. 43. With the carriage cover 450 swung to the unlocked position, this image forming apparatus 1 can easily attach and detach the moving blade holder 460, and with the carriage cover 450 swung to the locked position, the moving blade holder 460 can be fixed with high reliability.

[0431] 31 and 32, in the image forming apparatus 1, the carriage cover 450 has each swing shaft 457, and each protrusion 458 is formed integrally with each swing shaft 457 centered on the swing axis center X450. With this configuration, each protrusion 458 that positions the moving blade holder 460 is formed on the carriage cover 450 coaxially with each swing shaft 457, thereby realizing space saving.

[0432] In addition, in this image forming apparatus 1, as shown in FIG. 41, when the moving blade holder 460 is attached to the holder holding portion 446 with the carriage cover 450 in the unlocked position, the tip of each elastic beam 445 contacts the moving blade holder 460 and elastically deforms, and biases the moving blade holder 460 forward so as to move the moving blade 412 away from the fixed blade 411 along the conveying direction DT1. With this configuration, the tip of each elastic beam 445 guides the moving blade holder 460 attached to the holder holding portion 446 during the mounting of the moving blade holder 460. Also, due to the biasing force of each elastic beam 445, the moving blade 412 supported by the moving blade holder 460 moves forward away from the fixed blade 411 along the conveying direction DT1. As a result, the moving blade 412 can be prevented from contacting the fixed blade 411 during the mounting of the moving blade holder 460.

[0433] 29, in the image forming apparatus 1, the carriage cover 450 holds the first springs 455, and the carriage base 440 has the engaging protrusions 448. With this configuration, when the carriage cover 450 moves to the locked position, the curved portions 455C of the first springs 455 engage with the engaging protrusions 448, so that the carriage cover 450 is reliably maintained in the locked position. As a result, the image forming apparatus 1 can prevent the moving blade holder 460 held by the holder holding portion 446 from rattling relative to the cutter carriage 420.

[0434] 28, in this image forming apparatus 1, the moving blade holder 460 has a handle 469, and the carriage cover 450 has an enclosing portion 459 that surrounds the handle 469 when the carriage cover 450 is in the locked position. With this configuration, the handle 469 of the moving blade holder 460 cannot be grasped unless the carriage cover 450 is first swung to the unlocked position, so that it is possible to prevent the moving blade holder 460 from being forcibly removed.

[0435] Furthermore, in this image forming apparatus 1, the enclosure 459 has a notch 459C that exposes a part of the right end side of the handle 469 when the carriage cover 450 is in the locked position. With this configuration, the user can visually check the handle 469 through the attachment / detachment opening 54, which makes it possible to prevent the user from forgetting to attach the moving blade holder 460.

[0436] Furthermore, in this image forming apparatus 1, the carriage cover 450 has an operation protrusion 459T that protrudes toward the attachment / detachment opening 54. With this configuration, the user can easily swing the carriage cover 450 by pinching the operation protrusion 459T.

[0437] Further, in this image forming apparatus 1, as shown in Fig. 42, when the carriage cover 450 is in the unlocked position and each protrusion 458 is located at the bent portion 468B of each groove 468, the moving blade 412 is away from the fixed blade 411 forward along the conveying direction DT1. Then, as shown in Fig. 44, in the process of the carriage cover 450 swinging from the unlocked position to the locked position, each protrusion 458 moves from the bent portion 468B of each groove 468 to the other end 468C, so that the moving blade 412 moves backward along the conveying direction DT1 so as to approach the fixed blade 411 and comes into contact with the fixed blade 411, and then the second spring 465 compresses and deforms the moving blade 412 while pressing it against the fixed blade 411. With this configuration, a force is generated to press the moving blade 412 against the fixed blade 411 in the process of the carriage cover 450 swinging to the locked position. This prevents the carriage cover 450 from closing when the moving blade holder 460 is not properly held by the cutter carriage 420, thereby preventing the moving blade 412 from being pressed against the fixed blade 411 in an undesired position. Also, when the carriage cover 450 is in the locked position, the biasing force of the second spring 465 prevents the moving blade 412 from moving away from the fixed blade 411 during cutting.

[0438] <Second guide handle> 8 and 23, the second guide 200 has a handle 260. The handle 260 is integrally formed with the second guide 200. The handle 260 has a plate shape extending in the conveying direction DT1 from a downstream end 200D of the second guide 200 in the conveying direction DT1. A user can move the second guide 200 between the first guide position and the second guide position by holding the handle 260 and moving it up and down.

[0439] As shown in FIG. 12, the handle 260 is located downstream of the nip position (second nip 29N) between the first discharge roller 29A and the second discharge roller 29B in the transport direction DT1 and above the nip position (second nip 29N).

[0440] The downstream end 260D of the handle 260 in the conveying direction DT1 is located above the sheet SH (SH1) discharged by the first discharge roller pair 29 when the second guide 200 is in the first guide position, and above the upper surface SHm of the maximum number of sheets SH that can be loaded on the discharge tray 9.

[0441] <Second guide sensor and control operation in response to print command> 11 and 21, the image forming apparatus 1 includes a second guide sensor S5. The second guide sensor S5 is a microswitch in which an internal contact is connected or disconnected by the swinging of a detection lever.

[0442] The second guide sensor S5 is held at a portion of the right wall 106R of the first guide 100, spaced rearward and downward from the stopper 102S.

[0443] As shown in FIG. 21, the detection lever is pushed down by the second guide 200 at the first guide position, so that the second guide sensor S5 detects that the second guide 200 is at the first guide position.

[0444] As shown in FIG. 22, when the second guide 200 rotates to the second guide position and moves upward away from the detection lever, the second guide sensor S5 detects that the second guide 200 is not at the first guide position.

[0445] The second guide sensor S5 transmits the detection result to the control unit C1. The control unit C1 performs a control operation for a print command based on the detection result of the second guide sensor S5. Specifically, the control unit C1 executes the process of the flowchart shown in FIG.

[0446] First, in step S101, the control unit C1 determines whether or not a print command has been received. The control unit C1 receives a print command by a user's operation input to the operation panel 37, or receives a print command from an information processing terminal or the like via a network.

[0447] The control unit C1 repeats step S101 until it receives a print command. When the control unit C1 receives a print command and the determination in step S101 is "Yes," the control unit C1 proceeds to step S102.

[0448] When the control section C1 proceeds to step S102, it determines whether or not a printing with cutting command for cutting the sheet SH on which an image has been formed by the cutter mechanism 4 has been received.

[0449] If the answer is "No" in step S102, the control unit C1 proceeds to step S103 and executes a no-cut printing command that does not cut the sheet SH on which an image has been formed by the cutter mechanism 4. That is, when the control unit C1 receives a no-cut printing command, it starts the no-cut printing command regardless of the detection result of the second guide 200. Then, the control unit C1 moves the flapper 26 to the second flapper position shown by the two-dot chain line in FIG. 4 to enable the second discharge path PD2, and forms an image on the sheet SH by the image forming unit 3 and the fixing unit 7, and discharges the sheet SH to the discharge tray 9 by the second discharge roller pair 28. Thereafter, the control unit C1 ends the flowchart shown in FIG. 45 and repeats the process from the beginning.

[0450] If "Yes" in step S102, the control section C1 proceeds to step S104, and determines whether or not the second guide 200 is in the first guide position based on the detection result of the second guide sensor S5.

[0451] If the answer is "Yes" in step S104, the control unit C1 proceeds to step S105 and executes the print with cutting command. Then, the control unit C1 moves the flapper 26 to the first flapper position shown by the solid line in Fig. 4 to enable the first discharge path PD1, and forms an image on the sheet SH by the image forming unit 3 and the fixing unit 7. Then, the control unit C1 cuts the sheet SH in half length by the cutter mechanism 4, and discharges it onto the discharge tray 9 by the first discharge roller pair 29. Thereafter, the control unit C1 ends the flowchart shown in Fig. 45 and repeats the process from the beginning.

[0452] If the result in step S104 is "No," the control unit C1 proceeds to step S106, does not start the print with cut command, notifies the user that the second guide 200 is not at the first guide position, and starts timing. The notification is made by displaying an error message on the operation panel 37 or by transmitting an error message via the network to the information processing terminal that issued the print command.

[0453] Next, the control section C1 proceeds to step S107, and determines whether or not the second guide 200 is at the first guide position based on the detection result of the second guide sensor S5.

[0454] If the user who has received the notification moves the second guide 200 to the first guide position, the result in step S107 becomes "Yes", and the control unit C1 proceeds to step S105. The process from step S105 onwards is as described above.

[0455] If the result in step S107 is “No”, the control unit C1 proceeds to step S108 and determines whether the elapsed time is equal to or greater than a threshold value. The threshold value is set in consideration of the time required for the user who has received the notification to move the second guide 200 to the first guide position.

[0456] If step S108 is "No", the control unit C1 repeats steps S107 and S108. If step S108 is "Yes", the control unit C1 determines that the cut-off print command cannot be executed and proceeds to step S109, where it executes error processing to cancel the print command. After that, the control unit C1 ends the flowchart shown in FIG. 45 and repeats the process from the beginning.

[0457] <Effect 6> As shown in Fig. 21, the image forming apparatus 1 of the embodiment includes a biasing member 280 that applies a first biasing force FG1 to the second guide 200 at the first guide position. With this configuration, when the first discharge roller 29A and the second discharge roller 29B are in a nip state, a pressing force for ensuring the nip pressure acts from the first discharge roller 29A to the second discharge roller 29B, but the first biasing force FG1 of the biasing member 280 can suppress the second guide 200 from escaping from the first guide position to the second guide position due to the pressing force. As a result, the image forming apparatus 1 can suppress the variation in the nip pressure between the first discharge roller 29A and the second discharge roller 29B.

[0458] 22, in the image forming apparatus 1, the biasing member 280 comes into sliding contact with the sliding contact surface 273 when the second guide 200 rotates between the first guide position and the second guide position, and applies a second biasing force FG2 to the second guide 200. With this configuration, the posture of the second guide 200 can be stopped at a position where the desired rotation angle is achieved by the frictional force acting between the biasing member 280 and the sliding contact surface 273 of the second guide 200. As a result, the image forming apparatus 1 can suppress rattling of the second guide 200, and can improve the operability when rotating the second guide 200.

[0459] 21 and 22, in the image forming apparatus 1, the second guide 200 has a pressed portion 274 on which the first biasing force FG1 acts, and the pressed portion 274 and the sliding surface 273 are continuously connected. With this configuration, there is no step between the pressed portion 274 and the sliding surface 273, so that the biasing member 280 can smoothly transition between a state in which the first biasing force FG1 acts on the pressed portion 274 and a state in which the second biasing force FG2 acts on the sliding surface 273.

[0460] 21, the biasing member 280 has a torsion coil spring 289 and a spring cover 281, and the spring cover 281 has a sliding portion 283 that slides against the sliding surface 273 when the biasing member 280 applies the second biasing force FG2 to the second guide 200. With this configuration, the sliding portion 283 of the spring cover 281 that covers the torsion coil spring 289 slides against the sliding surface 273, so that the contact surface pressure can be reduced compared to a case in which the torsion coil spring 289, which has a small contact area, directly slides against the sliding surface 273. As a result, the image forming apparatus 1 can suppress wear of the sliding surface 273 and improve durability.

[0461] Furthermore, in this image forming apparatus 1, the spring cover 281 has, in addition to the sliding contact portion 283, a pressing portion 284 that presses the pressed portion 274 when the biasing member 280 applies the first biasing force FG1 to the second guide 200. With this configuration, the direction in which the biasing member 280 applies the first biasing force FG1 can be easily changed from the direction in which the biasing member 280 applies the second biasing force FG2 to the second guide 200.

[0462] Furthermore, in this image forming apparatus 1, the torsion coil spring 289 makes it easier to reduce the space required for arranging the urging member 280 compared to a tension coil spring or a compression coil spring.

[0463] 22, in the image forming apparatus 1, the torsion coil spring 289 and the spring cover 281 are located radially outward of the sliding surface 273 with the sliding portion 283 in sliding contact with the sliding surface 273. This configuration prevents the torsion coil spring 289 and the spring cover 281 from protruding outward in the direction of the rotation axis X200 from the second guide 200. As a result, the image forming apparatus 1 can be prevented from becoming large in size in the direction of the rotation axis X200.

[0464] 12, in the image forming apparatus 1, the first guide surface 101 is formed by the tips of a plurality of ribs 107, and the second guide surface 202 is formed by the tips of a plurality of ribs 207. This configuration can reduce the conveying resistance when the first guide surface 101 and the second guide surface 202 guide the sheet SH.

[0465] 6, in the image forming apparatus 1, when the second guide 200 rotates between the first guide position and the second guide position, the entire second guide surface 202 moves. With this configuration, the entire width of the second guide surface 202 moves, so that a user can easily reach the jammed sheet SH, compared to a case in which only a part of the range of the second guide surface 202 in the direction of the rotation axis X200 moves when the second guide 200 rotates between the first guide position and the second guide position.

[0466] 4, in the image forming apparatus 1, the second discharge roller pair 28 is located above the upstream end 9U of the discharge tray 9 in the transport direction DT1, and the first discharge roller pair 29 is located downstream of the second discharge roller pair 28 in the transport direction DT1. With this configuration, the cut sheet SH discharged by the first discharge roller pair 29 is discharged downstream of the uncut sheet SH discharged by the second discharge roller pair 28 in the transport direction DT1 on the discharge tray 9. This makes it easier for the user to reach the small cut sheet SH (SH1) while it is supported on the discharge tray 9. With this configuration, the user's hand can also easily reach the second guide 200, making it easier to rotate the second guide 200.

[0467] Furthermore, in this image forming apparatus 1, the first discharge roller pair 29 is located below the image reading unit 35 and above the second discharge roller pair 28. With this configuration, even if uncut sheets SH are stacked in a fully loaded state on the discharge tray 9, this does not affect the discharge of the cut sheets SH.

[0468] 12, the second guide 200 has a handle 260 located downstream of the nip position (second nip 29N) between the first discharge roller 29A and the second discharge roller 29B in the conveying direction DT1 and above the nip position (second nip 29N). This configuration allows the user to rotate the second guide 200 by holding the handle 260, improving the operability when rotating the second guide 200.

[0469] Furthermore, in this image forming apparatus 1, the handle 260 has a plate shape extending in the transport direction DT1 from the second guide 200. A downstream end 260D of the handle 260 in the transport direction DT1 is located above the sheets SH (SH1) discharged by the first discharge roller pair 29 when the second guide 200 is at the first guide position, and is located above the upper surface SHm of the maximum number of sheets SH that can be stacked on the discharge tray 9. This configuration makes it possible to prevent the handle 260 from interfering with the cut sheets SH (SH1) discharged by the first discharge roller pair 29, and also to prevent the handle 260 from interfering with the uncut sheets SH stacked on the discharge tray 9.

[0470] 45, in the image forming apparatus 1, when the control unit C1 receives a print with cutting command and the second guide sensor S5 does not detect that the second guide 200 is at the first guide position in step S104, the control unit C1 proceeds to step S106, does not start the print with cutting command, and causes the operation panel 37 to notify that the second guide 200 is not at the first guide position. With this configuration, the user can recognize that the second guide 200 is not at the first guide position, and can rotate the second guide 200 to the first guide position.

[0471] Furthermore, in this image forming apparatus 1, when the control unit C1 receives a no-cut printing command, it starts the no-cut printing command in step S103 regardless of the detection result of the second guide 200. With this configuration, even if the second guide 200 is not at the first guide position, there is no problem in starting the no-cut printing command, so that it is possible to suppress a decrease in convenience for the user.

[0472] Although the present invention has been described above with reference to the embodiments, it goes without saying that the present invention is not limited to the above embodiments and can be modified as appropriate without departing from the spirit of the present invention.

[0473] (Variation 1) As shown in FIG. 46, in the image forming apparatus of the first modified example, a tip 411T of the fixed blade 411 in the image forming apparatus 1 of the embodiment is changed.

[0474] That is, when viewed along the cutting direction DC1, the tip 411T of the fixed blade 411 is located on the nip tangent line TN1 in a direction perpendicular to the conveying direction DT1 and the cutting direction DC1, i.e., in the up-down direction. In the first modification, as an example, the tip 411T of the fixed blade 411 protrudes upward from the nip tangent line TN1 by about several tenths of a millimeter to 1.0 mm.

[0475] This configuration can further reduce the tendency for the sheet SH to be gradually pulled from the side where the moving blade 412 begins to press against the sheet SH, making the cut surface even less likely to become wavy.

[0476] (Variation 2) As shown in FIGS. 47 and 48, the image forming apparatus of the second modified example includes a first guide 1100 and a second guide 1200 instead of the first guide 100 and the second guide 200 of the image forming apparatus 1 of the embodiment.

[0477] The first guide 1100 is located above the second guide 1200 and is fixed to the joint cover 50. The second guide 1200 is movable between a first guide position shown in FIG. 47 and a second guide position shown in FIG.

[0478] In the second modification, the vertical relationship between the first discharge roller 29A and the second discharge roller 29B is reversed from that of the embodiment. The first guide 1100 rotatably supports the first discharge roller 29A. The second guide 1200 rotatably supports the second discharge roller 29B.

[0479] As shown in FIG. 47, when the second guide 1200 is in the first guide position, the first discharge roller 29A and the second discharge roller 29B are in a nip state.

[0480] 48, when the second guide 1200 is in the second guide position, the first discharge roller 29A and the second discharge roller 29B are separated from each other. When the second guide 1200 is in the second guide position, the position of the second discharge roller 29B is closer to the discharge tray 9 than the position of the second discharge roller 29B when the second guide 1200 is in the first guide position.

[0481] In the second modification, a second guide sensor S5B is provided instead of the second guide sensor S5 according to the embodiment. The second guide sensor S5B detects whether or not the second guide 1200 is at the first guide position.

[0482] The second guide sensor S5B transmits the detection result to the control unit C1. The control unit C1 performs control operations for a print command based on the detection result of the second guide sensor S5B. Specifically, the control unit C1 executes the process of the flowchart shown in FIG.

[0483] Other configurations of the modified example 2 are the same as those of the embodiment, so the same reference numerals are used for the same configurations as those of the embodiment, and the description thereof will be omitted.

[0484] When the control unit C1 executes the process of the flowchart shown in Fig. 49, it first determines in step S201 whether or not a print command has been received. The control unit C1 receives a print command by an operation input performed by a user on the operation panel 37, or receives a print command from an information processing terminal or the like via a network.

[0485] The control unit C1 repeats step S201 until it receives a print command. When the control unit C1 receives a print command and the answer is "Yes" in step S201, the control unit C1 proceeds to step S202.

[0486] When the control unit C1 proceeds to step S202, it determines whether or not the second guide 1200 is at the first guide position based on the detection result of the second guide sensor S5B.

[0487] If the answer is "Yes" in step S202, the control unit C1 proceeds to step S207. The process after step S207 will be described later.

[0488] If the result in step S202 is "No," the control unit C1 proceeds to step S203, does not start the print command, notifies the user that the second guide 1200 is not at the first guide position, and starts timing. The notification is made by displaying an error message on the operation panel 37 or by transmitting an error message via the network to the information processing terminal that issued the print command.

[0489] Next, the control section C1 proceeds to step S204, and determines whether or not the second guide 1200 is at the first guide position based on the detection result of the second guide sensor S5B.

[0490] If the user who has received the notification moves the second guide 1200 to the first guide position, the result in step S204 becomes "Yes", and the control unit C1 proceeds to step S207. The process after step S207 will be described later.

[0491] If the answer is "No" in step S204, the control unit C1 proceeds to step S205 and determines whether the elapsed time is equal to or greater than a threshold value. The threshold value is set in consideration of the time required for the user who has received the notification to move the second guide 1200 to the first guide position.

[0492] If the result in step S205 is "No", the control unit C1 repeats steps S204 and S205. If the result in step S205 is "Yes", the control unit C1 determines that the print command cannot be executed and proceeds to step S206, where it executes an error process to cancel the print command. After that, the control unit C1 ends the flowchart shown in FIG. 49 and repeats the process from the beginning.

[0493] When the process proceeds from step S202 or step S204 to step S207, the control section C1 determines whether or not a command for printing with cutting has been received.

[0494] If the answer is "Yes" in step S207, the control unit C1 proceeds to step S208 and executes the print with cutting command. Then, the control unit C1 moves the flapper 26 to the first flapper position shown by the solid line in Fig. 4 to enable the first discharge path PD1, and forms an image on the sheet SH by the image forming unit 3 and the fixing unit 7. Then, the control unit C1 cuts the sheet SH in half length by the cutter mechanism 4, and discharges it onto the discharge tray 9 by the first discharge roller pair 29. Thereafter, the control unit C1 ends the flowchart shown in Fig. 49 and repeats the process from the beginning.

[0495] If the answer is "No" in step S207, the control unit C1 proceeds to step S209 and executes the no-cut printing command. Then, the control unit C1 moves the flapper 26 to the second flapper position shown by the two-dot chain line in Fig. 4 to enable the second discharge path PD2, and causes the image forming unit 3 and the fixing unit 7 to form an image on the sheet SH, and discharges the sheet SH onto the discharge tray 9 by the second discharge roller pair 28. Thereafter, the control unit C1 ends the flowchart shown in Fig. 49 and repeats the process from the beginning.

[0496] In the image forming apparatus of the second modified example, like the image forming apparatus 1 of the embodiment, the operation of removing the sheet SH that has become jammed around the cutter mechanism 4 can be easily performed.

[0497] 48, in this image forming apparatus, the position of the second discharge roller 29B when the second guide 1200 is in the second guide position is closer to the discharge tray 9 than the position of the second discharge roller 29B when the second guide 1200 is in the first guide position. With this configuration, the second guide 1200 in the second guide position opens downward and approaches the discharge tray 9, and the space formed between the first guide 1100 and the second guide 1200 becomes larger. As a result, the jammed sheet SH tends to fall due to gravity, making it easier for the user to remove the jammed sheet SH.

[0498] 49, in this image forming apparatus, when the control unit C1 receives a print with cutting command and the second guide sensor S5B cannot detect that the second guide 1200 is at the first guide position, the control unit C1 proceeds to step S203, does not start the print with cutting command, and causes the operation panel 37 to notify that the second guide 1200 is not at the first guide position. With this configuration, the user can recognize that the second guide 1200 is not at the first guide position, and can rotate the second guide 1200 to the first guide position.

[0499] Furthermore, in this image forming apparatus, when the control unit C1 receives a no-cut printing command and the second guide sensor S5B cannot detect that the second guide 1200 is at the first guide position, the control unit C1 proceeds to step S203, does not start the no-cut printing command, and causes the operation panel 37 to notify that the second guide 1200 is not at the first guide position. With this configuration, if the no-cut printing command is started, there is a risk that the second guide 1200 at the second guide position or the handle of the second guide 1200 may interfere with the sheet SH discharged by the second discharge roller pair 28. In this regard, with the above configuration, it is possible to suppress a problem in which the sheet SH becomes jammed due to interference from the second guide 1200 at the second guide position, etc.

[0500] (Variation 3) In the embodiment, the distance LA2 is shorter than the distance LA1, but as in Modification 3 shown in FIG. 50, the distance LA2 may be longer than the distance LA1.

[0501] In the image forming apparatus of the third modified example, the sheet sensor S4 is disposed away from the cutter mechanism 4. Therefore, this image forming apparatus can reduce the movement distance and the variation thereof of the sheet SH from when the leading edge of the sheet SH passing through the cutter mechanism 4 is detected until the cutter mechanism 4 starts cutting the sheet SH, and can more accurately determine the position at which the cutter mechanism 4 cuts the sheet SH.

[0502] (Variation 4) In the embodiment, the pre-cutting cover 80 supports the first conveying roller 71 and the second conveying roller 72, but the present invention also includes a configuration in which the pre-cutting cover 80 supports the first conveying roller 71 and the pre-cutting guide 300 supports the second conveying roller 72, as in variant example 4 shown in Figure 51.

[0503] In the image forming apparatus of the fourth modified example, when the pre-cutting cover 80 is moved to the second cover position, the first conveying roller 71 and the second conveying roller 72 are separated from each other. As a result, the sheet SH that is jammed upstream of the cutter mechanism 4 in the conveying direction DT1 is no longer nipped between the first conveying roller 71 and the second conveying roller 72, and the jammed sheet SH can be easily removed.

[0504] (others) In the embodiment, the image forming apparatus of the present invention is embodied as the image forming apparatus 1, which is a multifunction machine equipped with an image reading device on the upper side, but the present invention is not limited to this configuration. For example, the configuration of the present invention may be applied to an image forming apparatus that is not a multifunction machine. Furthermore, the configuration of the present invention may be applied not only to a monochrome electrophotographic image forming apparatus as in the present embodiment, but also to a color electrophotographic image forming apparatus or a printing apparatus of another printing method, such as an inkjet method or a thermal method.

[0505] In the embodiment, the sheet sensor S4 is a contact sensor having an actuator S4A, but the present invention is not limited to this configuration. For example, the sensor that detects the sheet passing through the conveying guide may be a non-contact sensor such as a light reflection sensor or a light transmission sensor. In this case, the detection area is the area through which the emitted light from the sensor passes between the first guide surface and the second guide surface when the emitted light is not blocked by the sheet SH.

[0506] In the embodiment, the first conveying roller pair 70 has two rollers, i.e., the first conveying roller 71 and the second conveying roller 72, but the present invention is not limited to this configuration. For example, the present invention also includes a configuration in which at least one of the first conveying roller 71 and the second conveying roller 72 of the first conveying roller pair 70 is changed to one using an endless belt. In this case, the nip tangent is the nip tangent at the downstream end in the conveying direction of the first nip that is long in the conveying direction.

[0507] In the embodiment, the first discharge roller pair 29 is an example of the "second conveyor roller pair" and the "first discharge roller pair" of the present invention, but the present invention is not limited to this configuration. For example, the present invention also includes a configuration in which the embodiment is modified so that a second conveyor roller pair is provided between the fixed blade 411 and the moving blade 412 of the cutter mechanism 4 and the first discharge roller pair 29.

[0508] In the embodiment, the first guide 100, the second guide 200, and the sheet sensor S4, which are examples of the conveying guide and the sensor, are located downstream of the fixed blade 411 and the movable blade 412 of the cutter mechanism 4 in the conveying direction DT1, but the present invention is not limited to this configuration. For example, the present invention also includes a configuration in which the conveying guide and the sensor are located downstream of the first conveying roller pair in the conveying direction and upstream of the blade of the cutter mechanism in the conveying direction.

[0509] In the embodiment, each of the second positioning portions 491, 492 is a through hole, but the present invention is not limited to this configuration. For example, the second positioning portions may be recesses.

[0510] In the embodiment, the pre-cutting cover 80 in the first cover position is indirectly positioned on the cutter frame 400 by abutting against the pre-cutting guide 300, but the present invention is not limited to this configuration. For example, the present invention also includes a configuration in which the pre-cutting cover in the first cover position is directly positioned on the cutter frame.

[0511] In the embodiment, the pre-cutting cover 80 in the first cover position is positioned in the conveying direction DT1 by the cutter frame 400, but the present invention is not limited to this configuration. For example, the pre-cutting cover 80 in the first cover position may be positioned in the conveying direction DT1 and the vertical direction by the cutter frame 400, may be positioned in the conveying direction DT1 and the cutting direction DC1 (left-right direction), or may be positioned in the conveying direction DT1, the vertical direction, and the cutting direction DC1.

[0512] In the embodiment, the cutter mechanism 4 is configured with the fixed blade 411 and the movable blade 412, but the present invention is not limited to this configuration. For example, a sheet may be cut by sandwiching it between two movable blades without a fixed blade, or the movable blade itself may extend in the cutting direction like the fixed blade, and the movable blade may move in the vertical direction to sandwich the sheet between the fixed blade and the movable blade to cut the sheet. Also, a sheet may be cut with a single blade. [Explanation of symbols]

[0513] 1...Image forming device DT1: Transport direction SH…Sheet 3...Image forming section DC1…Cutting direction 411, 412...Blade (411...Fixed blade, 412...Moving blade) 4…Cutter mechanism 70N…First nip 70...First conveying roller pair 100, 200...Transport guide (100...1st guide, 200...2nd guide) 101…First guide surface 202…Second guide surface S4…Sensor (seat sensor) AS1…detection area TN1…Nip tangent LG1: Distance between the first guide surface and the second guide surface S4A…Actuator 29N…Second nip 29...Second conveying roller pair (first discharge roller pair) 7. Fixing unit 29...First discharge roller pair 29A…First discharge roller 29B…Second discharge roller X200…Rotation axis center 200U: upstream end of the second guide in the conveying direction 202U: upstream side of the second guide surface in the conveying direction 202D...downstream side of the second guide surface in the conveying direction 9…Outlet tray 420…Cutter carriage 101Q…Duplicate part of the first guide surface PD1…First excretion pathway PD2: Secondary discharge route 26...Flapper 300...Upstream guide (guide before cutting) 302…First upstream guide surface 301…Second upstream guide surface LN1: Distance between the nip tangent and the first upstream guide surface LN2: Distance between the nip tangent and the second upstream guide surface 411T…fixed blade tip 28...Second discharge roller pair 7N…Fixing nip LR2: Distance traveled by the sheet from the fixing nip to the second pair of discharge rollers LR1: Distance traveled by the sheet from the fixing nip to the first pair of discharge rollers LC1: Sheet travel distance from the fixing nip to the cutter mechanism LS1: Maximum sheet length that the image forming device can handle 10, 30, 50...Housing (10...First housing, 30...Second housing, 50...Joint cover) 10C…Seat cassette 10G…Housing opening (front opening) 3P...Process cartridge 10F…Cover (front cover)

Claims

1. an image forming section for forming an image on a sheet conveyed in a conveying direction; a cutter mechanism having a blade for cutting the sheet on which an image is formed in a cutting direction perpendicular to the conveying direction; a first conveying roller pair that is located upstream of the blade of the cutter mechanism in the conveying direction and that conveys the sheet on which an image is formed toward the blade by nipping the sheet with a first nip; a conveying guide that is located downstream of the first conveying roller pair in the conveying direction and that guides a sheet, the conveying guide having a first guide surface that guides the sheet and a second guide surface that is opposed to the first guide surface and guides the sheet; a sensor that detects a sheet passing through the conveying guide, the sensor having a detection area that detects the sheet between the first guide surface and the second guide surface, the detection area being positioned on a nip tangent to the first nip as viewed along the cutting direction; An image forming apparatus comprising:

2. 2. The image forming apparatus according to claim 1, wherein, as viewed along the cutting direction, the first guide surface and the second guide surface are located away from the nip tangent line in a direction perpendicular to the conveying direction and the cutting direction.

3. 3. The image forming apparatus according to claim 2, wherein a distance between the first guide surface and the second guide surface becomes narrower from an upstream side of the detection area in the transport direction toward the detection area.

4. 2. The image forming apparatus according to claim 1, wherein the sensor has an actuator that swings when the leading edge of the sheet comes into contact with the sensor.

5. a second conveying roller pair that is located downstream of the blade of the cutter mechanism in the conveying direction and that conveys the sheet on which an image is formed by nipping the sheet with a second nip, The cutter mechanism cuts the sheet that is nipped and stopped by the first nip and the second nip, 5. The image forming apparatus according to claim 1, wherein the second nip is also located on a tangent line to the nip when viewed along the cutting direction.

6. a fixing unit that is located upstream of the first conveying roller pair in the conveying direction and fixes the image on the sheet that has passed through the image forming unit; the conveying direction of the sheet changes by 90° or more from the time when the sheet passes through the fixing device to the time when the sheet reaches the first nip, 6. An image forming apparatus according to claim 5, wherein said nip tangent line extends horizontally.

7. a first discharge roller pair that nips the sheet cut by the cutter mechanism with a second nip and discharges the sheet; the conveying guide and the sensor are located downstream of the blade of the cutter mechanism in the conveying direction, the first discharge roller pair includes the first discharge roller and a second discharge roller that form the second nip, the conveying guide includes a first guide that rotatably supports the first discharge roller and has the first guide surface, and a second guide that rotatably supports the second discharge roller and has the second guide surface, The first guide holds the sensor, 5. An image forming apparatus according to claim 1, wherein the second guide is movable between a first guide position where the first discharge roller and the second discharge roller are in a nipped state and a second guide position where the first discharge roller and the second discharge roller are in a separated state.

8. The second guide is rotatable about a rotation axis, the rotation axis is located on an upstream end side of the second guide in the conveying direction, and is located between the first guide surface and the second guide surface when the second guide is at the first guide position, An image forming device as described in claim 7, wherein the upstream side of the second guide surface in the transport direction is inclined away from the first guide surface relative to the downstream side of the second guide surface in the transport direction when the second guide is in the first guide position, the upstream end side of the second guide being inclined away from the first guide surface.

9. a discharge tray for supporting the sheet discharged by the first discharge roller pair; 9. An image forming apparatus according to claim 8, wherein the position of the second discharge roller when the second guide is in the second guide position is farther from the discharge tray than the position of the second discharge roller when the second guide is in the first guide position.

10. the conveying guide and the sensor are located downstream of the blade of the cutter mechanism in the conveying direction, The blade has a fixed blade extending in the cutting direction and a movable blade that moves while in sliding contact with the fixed blade, the cutter mechanism has a cutter carriage that holds the moving blade and moves in the cutting direction, The fixed blade abuts against the sheet from below, The moving blade abuts against the sheet from above, the first guide surface has an overlapping portion that is located below the cutter carriage and partially overlaps with the moving blade in the conveying direction, 5. The image forming apparatus according to claim 1, wherein the second guide surface is located downstream of the cutter carriage in the transport direction.

11. a fixing unit that is located upstream of the first conveying roller pair in the conveying direction and fixes the image on the sheet that has passed through the image forming unit; a first discharge path in which the cutter mechanism is disposed and which discharges the sheet that has passed through the fixing unit; a second discharge path in which the cutter mechanism is not disposed and through which the sheet that has passed through the fixing unit is discharged; a flapper movable to a first flapper position where the sheet is guided to the first discharge path while blocking the second discharge path, and a second flapper position where the sheet is guided to the second discharge path while blocking the first discharge path; 5. The image forming apparatus according to claim 1, further comprising:

12. an upstream guide that is located downstream of the first conveying roller pair in the conveying direction and upstream of the blade of the cutter mechanism in the conveying direction and that guides a sheet between the first conveying roller pair and the blade of the cutter mechanism; the conveying guide and the sensor are located downstream of the blade of the cutter mechanism in the conveying direction, the upstream guide has a first upstream guide surface that guides a sheet, and a second upstream guide surface that faces the first upstream guide surface and guides the sheet, The blade has a fixed blade extending in the cutting direction and a movable blade that moves while in sliding contact with the fixed blade, The fixed blade contacts the sheet from the first upstream guide surface side, The moving blade contacts the sheet from the second upstream guide surface side, 5. The image forming apparatus according to claim 1, wherein, as viewed along the cutting direction, a distance between the nip tangent and the first upstream guiding surface is smaller than a distance between the nip tangent and the second upstream guiding surface.

13. 13. The image forming apparatus according to claim 12, wherein, as viewed along the cutting direction, a tip of the fixed blade is positioned on a tangent to the nip in a direction perpendicular to the conveying direction and the cutting direction.

14. 14. The image forming apparatus according to claim 13, wherein the first upstream guide surface is an upward facing surface, and the second upstream guide surface is a downward facing surface.

15. 15. The image forming apparatus according to claim 14, wherein the conveying direction of the sheet changes by 90 degrees or more from the time when the sheet passes through the image forming section until the sheet reaches the first nip.

16. a fixing unit that is located upstream of the first conveying roller pair in the conveying direction and fixes the image on the sheet that has passed through the image forming unit; a first discharge roller pair that discharges the sheet that has passed through the fixing unit and been cut by the cutter mechanism; a second discharge roller pair that discharges the sheet that passes through the fixing unit and is conveyed without passing through the cutter mechanism; Equipped with 5. An image forming apparatus according to claim 1, wherein a moving distance of the sheet from a fixing nip portion that nips the sheet in the fixing unit to the second pair of discharge rollers is shorter than a moving distance of the sheet from the fixing nip portion to the first pair of discharge rollers.

17. a fixing unit that is located upstream of the first conveying roller pair in the conveying direction and fixes the image on the sheet that has passed through the image forming unit; 5. The image forming apparatus according to claim 1, wherein a moving distance of the sheet from a fixing nip portion in the fixing unit that nips the sheet to the cutter mechanism is longer than half a maximum length of the sheet that the image forming apparatus can accommodate.

18. a fixing unit that is located upstream of the first conveying roller pair in the conveying direction and fixes the image on the sheet that has passed through the image forming unit; a first discharge roller pair that nips and discharges the sheet that has passed through the fixing unit and been cut by the cutter mechanism with a second nip; a second discharge roller pair that discharges the sheet that passes through the fixing unit and is conveyed without passing through the cutter mechanism; Equipped with 5. The image forming apparatus according to claim 1, wherein the first discharge roller pair and the second discharge roller pair discharge the sheet in the same direction.

19. 19. The image forming apparatus according to claim 18, further comprising a discharge tray that supports the sheet discharged by the first discharge roller pair and the sheet discharged by the second discharge roller pair.

20. A housing and a sheet cassette for supporting a sheet on which an image is to be formed, the sheet cassette being capable of being pulled out from the housing; Equipped with 19. The image forming apparatus according to claim 18, wherein a direction in which the sheet cassette is pulled out from the housing is the same as a direction in which the first discharge roller pair and the second discharge roller pair discharge the sheets.

21. A housing having an opening; a process cartridge constituting at least a part of the image forming unit, the process cartridge being removable from the housing through the opening; a cover capable of opening and closing the opening; Equipped with 19. The image forming apparatus according to claim 18, wherein a direction in which the process cartridge is pulled out from the housing is the same as a direction in which the first discharge roller pair and the second discharge roller pair discharge the sheet.

22. a fixing unit that is located upstream of the first conveying roller pair in the conveying direction and fixes the image on the sheet that has passed through the image forming unit; a first discharge roller pair that nips and discharges the sheet that has passed through the fixing unit and been cut by the cutter mechanism with a second nip; a second discharge roller pair that discharges the sheet that passes through the fixing unit and is conveyed without passing through the cutter mechanism; Equipped with the cutter mechanism is located above the second discharge roller pair, 5. The image forming apparatus according to claim 1, wherein the transport guide and the sensor are located above the second discharge roller pair and downstream in the transport direction.

23. 5. The image forming apparatus according to claim 1, wherein the transport guide and the sensor are located downstream of the blade of the cutter mechanism in the transport direction.

Images