Image forming device

Abstract

Provided is an image forming device with which it is possible to suppress a displacement of the cutting position of a sheet. An image forming device 1 comprises: an image forming part 3; a cutter mechanism 4; a first conveyance roller pair 70 which is located upstream from blades 411, 412 of the cutter mechanism 4 in a conveyance direction DT1, nips a sheet SH on which an image is formed by a first nip 70N, and conveys the sheet toward the blades 411, 412; conveyance guides 100, 200 which are located downstream from the first conveyance roller pair 70 in the conveyance direction DT1 and have a first guide surface 101 and a second guide surface 202; and a sensor S4 which detects the sheet SH passing the conveyance guides 100, 200, and in which a detection area AS1 where the sensor S4 detects the sheet SH between the first guide surface 101 and the second guide surface 202 is located on a nip tangent TN1 of the first nip 70N when viewed along a cutting direction DC1.

Description

Image forming device

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

[0002] Patent Document 1 discloses an example of a conventional image forming apparatus. This image forming apparatus is equipped with a cutting device. The cutting device has a cutter mechanism consisting of a first cutting unit and the like. The guillotine blade and counter blade of the first cutting unit cut the sheet that has passed through the fixing device in a cutting direction perpendicular to the conveyance direction.

[0003] The image forming apparatus further 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 to stop 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.

[0005] JP 2023-19469 A

[0006] However, in the conventional image forming apparatus described above, the entrance sensor is located upstream of the pair of pre-registration rollers in the conveying direction, so 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 is likely to deviate from the expected position, making it difficult to prevent the sheet cutting position from shifting.

[0008] The present invention has been made in view of the above-described conventional situation, and has an object to provide an image forming apparatus that can suppress deviation of the cutting position of a sheet.

[0009] The image forming apparatus of the present invention is characterized by comprising: an image forming unit that forms an image on a sheet transported in a transport direction; a cutter mechanism having a blade that cuts the sheet on which the image has been formed in a cutting direction perpendicular to the transport direction; a first pair of transport rollers that are located upstream of the blade of the cutter mechanism in the transport direction and nip the sheet on which the image has been formed with a first nip and transport it toward the blade; a transport guide that is located downstream of the first pair of transport rollers in the transport direction and guides the sheet, the transport guide having a first guide surface that guides the sheet and a second guide surface that is opposite to the first guide surface and guides the sheet; and a sensor that detects a sheet passing through the transport guide, the sensor having a detection area where the sensor detects the sheet between the first guide surface and the second guide surface that is located on a nip tangent to the first nip when viewed along the cutting direction.

[0010] In the image forming apparatus of the present invention, the detection area where the sensor detects the sheet between the first guide surface and the second guide surface of the conveying guide is, for example, if the sensor is a contact sensor having an actuator that swings when the leading edge of the sheet comes into contact with it, an area where the leading edge of the actuator that is not swinging can abut against the leading edge of the sheet extends between the first guide surface and the second guide surface. Also, if the sensor is a non-contact sensor such as a light reflective sensor or a light transmissive sensor, the detection area is an area 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 movement distance of the leading edge of the sheet is less likely to vary.

[0012] Therefore, when the image forming apparatus controls the timing for stopping the first conveying roller pair 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.

[0014] FIG. 1 is a perspective view of an image forming apparatus according to an embodiment. FIG. 2 is a front view of the image forming apparatus according to an embodiment. FIG. 3 is a side view of the image forming apparatus according to an embodiment. FIG. 4 is a schematic cross-sectional view of the image forming apparatus according to an 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. FIG. 5 is a partial perspective view of the image forming apparatus according to an embodiment, showing a state in which the pre-cutting cover is in the second cover position and the exterior cover is open. FIG. 6 is a schematic cross-sectional view similar to FIG. 4, showing 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. FIG. 7 is a schematic cross-sectional view similar to FIG. 4, 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 open. FIG. 8 is a partial perspective view of an enlarged portion of FIG. 1. FIG. 9 is a perspective view showing the pre-cutting cover, the first conveying roller, and the abutting piece. FIG. 10 is a perspective view showing the pre-cutting cover, the first conveying roller, and the abutting piece. FIG. 11 is a perspective view showing a unit including a cutter mechanism, a first guide, and a pre-cutting guide. FIG. 12 is a partial schematic cross-sectional view enlarging the main parts of FIG. 4. FIG. 13 is a perspective view showing a unit including a cutter mechanism, a first guide, and a pre-cutting guide. FIG. 14 is an exploded perspective view of the cutter mechanism, the first guide, and the pre-cutting guide. FIG. 15 is a front view showing a unit including a cutter mechanism, a first guide, and a pre-cutting guide. FIG. 16 is a front view showing the cutter mechanism. FIG. 17 is a perspective view showing the pre-cutting guide. FIG. 18 is a partial top view showing a unit including a cutter mechanism, a first guide, and a pre-cutting guide, and a joint cover. FIG. 19 is a partial perspective view mainly showing the cutter mechanism, the joint cover, and the first housing. FIG. 20 is a partial perspective view enlarging the main parts of FIG. 19. 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 in the first guide position. 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. Fig. 23 is a perspective view showing the second guide. Fig. 24 is a partial schematic cross-sectional view that simplifies a part of Fig. 12. Fig. 25 is a partial schematic cross-sectional view that enlarges a main part of Fig. 4 and explains the moving distance of the sheet.FIG. 26 is a partial top view illustrating the folded-back position of the moving blade of the cutter mechanism. FIG. 27 is a partial top view illustrating a state in which the pre-cutting cover in the first cover position is indirectly positioned on the cutter frame by abutting against the pre-cutting guide. FIG. 28 is a partial perspective view of the image forming apparatus of the embodiment, mainly illustrating the attachment / detachment opening. FIG. 29 is a perspective view of the cutter carriage. FIG. 30 is a perspective view of the cutter carriage. FIG. 31 is an exploded perspective view of the cutter carriage. FIG. 32 is an exploded perspective view of the cutter carriage. FIG. 33 is a perspective view of the moving blade holder and the moving blade. FIG. 34 is a perspective view of the moving blade holder and the moving blade. FIG. 35 is an exploded perspective view of the moving blade holder and the moving blade. FIG. 36 is a cross-sectional view showing the A-A cross section of FIG. 16, illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 37 is a cross-sectional view similar to FIG. 36, illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 38 is a cross-sectional view showing the B-B cross section in FIG. 16 and is a view illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 39 is a cross-sectional view showing a cross section similar to FIG. 36 and is a view illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 40 is a cross-sectional view showing a cross section similar to FIG. 38 and is a view illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 41 is a cross-sectional view showing a cross section similar to FIG. 36 and is a view illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 42 is a cross-sectional view showing a cross section similar to FIG. 38 and is a view illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 43 is a cross-sectional view showing a cross section similar to FIG. 36 and is a view illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 44 is a cross-sectional view showing a cross section similar to FIG. 38 and is a view illustrating the operation of attaching the moving blade holder to the cutter carriage. FIG. 45 is a flowchart when the control unit executes a print command. Fig. 46 is a partial schematic cross-sectional view similar to Fig. 24 of the image forming apparatus of Modification 1. Fig. 47 is a schematic cross-sectional view of the image forming apparatus of Modification 2, 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.Fig. 48 is a schematic cross-sectional view similar to Fig. 47, showing a state in which the second guide has moved to the second guide position. Fig. 49 is a flowchart showing the image forming apparatus of Modification 2 when the control unit executes a print command. Fig. 50 is a partial schematic cross-sectional view similar to Fig. 12, showing the image forming apparatus of Modification 3. Fig. 51 is a schematic cross-sectional view similar to Fig. 6, showing the image forming apparatus of Modification 4.

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

[0016] 1 to 3, an image forming apparatus 1 according to 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 unit 3 and a fixing unit 7 that form an image on a sheet SH by electrophotography, and an image reading unit 35 that reads an image of a document.

[0017] In Fig. 1, the operation panel 37 side 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 correspondence with the directions shown in Fig. 1.

[0018] 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 above the first housing 10. The joint cover 50 supports the second housing 30 from below above the first housing 10.

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

[0022] The maintenance opening 19 is a large, substantially 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 as the rotation axis and moving its upper end backward 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, 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 has been formed after passing through the image forming unit 3 and the fixing device 7 is discharged into the discharge space AD1. The discharge tray 9 supports the sheet SH discharged into the discharge space AD1.

[0027] 1, the joint cover 50 has support portions 57L and 57R. The support portion 57L is a portion of the joint cover 50 that is located to the left of the discharge tray 9 and protrudes upward. The support portion 57R is a portion 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 the 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 the 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 in the cutting direction DC1 described below.

[0029] 2 and 4, the second housing 30 houses the image reading unit 35. The image reading unit 35 is located above and spaced apart from 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 top surface of the second housing 30 using 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 the cutter mechanism 4 described below.

[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) 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 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 an original cover 40 whose top surface can be opened and closed, and an automatic original feeder mechanism 45 housed in the original cover 40 .

[0033] The document cover 40 has a supply tray 41 and a discharge tray 42 located on the right side thereof. The supply tray 41 is spaced apart above the discharge tray 42.

[0034] The automatic document feeder 45 has a well-known configuration and will not be described briefly, but has an insertion slot 45H for inserting a document to be read. As shown in Fig. 2, the automatic document feeder 45 transports a sheet-like document supported by the supply tray 41 and inserted into the insertion slot 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 transported.

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

[0036] The operation panel 37 has an operation surface that receives operation inputs by the 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 status and settings of the image forming apparatus 1, and notifies the user by displaying error messages and the like. The operation panel 37 is an example of the "notification unit" of the present invention.

[0037] As shown in FIG. 4, in the image forming apparatus 1, the image forming section 3 has a developing device 3A, a photosensitive member 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 pair of conveying rollers 23, a pair of registration rollers 24, and a pair of post-fixing conveying rollers 25 housed in a first housing 10 together with the image forming unit 3 and the fixing unit 7.

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

[0040] A transport path P1 is provided within the first housing 10. The transport path P1 makes a U-turn upward from the front end of the sheet cassette 10C, passes through a first feed roller 21, a first separation roller 22, a separation pad 22A, and a transport roller pair 23, then proceeds rearward in a substantially horizontal direction, passes through a registration roller pair 24, a photosensitive member 5, and a fixing unit 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 separation pad 22A are located downstream of the first feeding roller 21 on the conveying path P1. The conveying roller pair 23 is located downstream of the first separation roller 22 and separation pad 22A on the conveying path P1, midway along the portion of the conveying path P1 where the conveying path P1 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 photosensitive member 5 on the transport path P1, midway along the portion of the transport path P1 that moves substantially horizontally backward.

[0043] The first feed roller 21 feeds the sheet SH supported by the sheet cassette 10C toward the photosensitive member 5. If there are multiple sheets SH sent to the transport path P1 by the first feed roller 21, the first separation roller 22 and separation pad 22A separate the sheets SH one by one. Then, the transport roller pair 23 and the registration roller pair 24 transport the sheets SH to the photosensitive member 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 having a rotation axis extending in the left-right direction as its center. A positively charged photosensitive layer is formed on the surface of the photoreceptor 5 in correspondence with positively charged toner. Note that a negatively charged photosensitive layer may also be formed on the surface of the photoreceptor 5, in which case negatively charged toner is used.

[0046] The photosensitive element 5 can come into contact from above with the sheet SH that is transported along the portion of the transport path P1 that moves rearward and approximately horizontally. A transfer roller 5A is located below the photosensitive element 5. The transfer roller 5A faces the photosensitive element 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 photosensitive member 5. The charger 3E is a well-known scorotron charger.

[0048] The scanner unit 8 is located above the developing device 3A and the photosensitive member 5. The scanner unit 8 has a known configuration including a laser light source, a polygon mirror, an fθ lens, and a reflecting mirror. The scanner unit 8 irradiates the surface of the photosensitive member 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 device 7 is located behind the photosensitive member 5 and in front of the post-fixing transport roller pair 25. The fixing device 7 has a heating member 7A located above the transport path P1, and a pressure roller 7B facing the heating member 7A from below across the transport path P1.

[0052] The heating member 7A includes an endless belt, a guide member that supports the endless belt from its inner periphery so that it can circulate, and a heater that heats the endless belt from its inner periphery. The heating member 7A and the pressure roller 7B nip the sheet SH at the fixing nip 7N. The heating member 7A may be configured as a heating roller having a heater such as a halogen heater, or may be configured as 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, which has passed through the fixing unit 7, upward and backward. The toner image is an example of the "image formed on the sheet by the image forming unit" and the "image fixed on the sheet by the fixing unit" of 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 section 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 conveying path P1, detects the passage of the sheet SH, and transmits the detection result to the control unit C1. Based on the detection result of the pre-registration sheet sensor S1, the control unit C1 performs control such as correcting skew of the sheet SH that reaches the pair of registration rollers 24.

[0058] The post-registration sheet sensor S2 is located immediately after 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 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. Based on the detection result of the post-fixing sheet sensor S3, the control unit C1 controls the timing of a plurality of operations that are performed until the sheet SH that has passed through the fixing unit 7 is discharged onto the discharge tray 9.

[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 sensor, a light transmission 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 shown by the solid line in FIG. 4, it guides the sheet SH to the first discharge path PD1 while blocking the second discharge path PD2.

[0065] 4, the first discharge path PD1 advances upward between the flapper 26 at 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 into the discharge space AD1 by making the conveyance 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, it 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 into the discharge space AD1 while being guided by the flapper 26 in the second flapper position shown by the two-dot chain line in Fig. 4 so that the sheet SH faces forward in the conveying direction DT1, which is substantially horizontal. The second discharge path PD2 discharges the sheet SH into 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 that are 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] 4, 11, and 12, the image forming apparatus 1 includes a pre-cutting guide 300 arranged along a portion of the first discharge path PD1 where the conveying direction DT1 faces forward and is substantially horizontal, a cutter mechanism 4, a first guide 100, a second guide 200, a sheet sensor S4, and a first discharge roller pair 29. Furthermore, the first guide 100 is an example of the "sheet guide" of the present invention.

[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 in the transport direction DT1. The downstream portion 9B is connected to the upstream portion 9A and extends approximately horizontally toward the downstream in 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 onto the discharge tray 9. The discharge tray 9 supports the sheet SH that is discharged without being cut.

[0073] As shown in FIGS. 4 and 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 middle portion of the upstream portion 9A of the discharge tray 9 in the front-to-rear direction. 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 discharged after being cut by the cutter mechanism 4.

[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 the user can replenish the sheets SH, etc. 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 is equipped with a process cartridge 3P. The process cartridge 3P has a toner storage chamber 3D of a developing device 3A, a developing roller 3B, etc., and a case that houses them, and constitutes a part of the image forming unit 3.

[0077] 2, the first housing 10 has a front opening 10G. The front opening 10G is an example of the "housing opening" in the present invention. The front opening 10G is a large, generally rectangular opening that exposes 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 position and constitutes a part of the exterior surface of the front 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 as a rotation axis and moving its upper end forward and downward.

[0079] 4, the process cartridge 3P can be pulled out forward from the first housing 10 through the front opening 10G for the user to replace consumables, 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 that drives the first conveying roller pair 70, the first discharge roller pair 29, and the second discharge roller pair 28.

[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 conveying roller, and second conveying 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 that is parallel to the left-right direction. The left-right direction is parallel to the 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 positioned outward in the left-right direction from the sheet SH transported along the first discharge path PD1 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 in a shaft hole (not shown) formed in an internal frame located on the rear side of the first housing 10, allowing the pre-cutting cover 80 to 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 the state in which the pre-cutting cover 80 is in the first cover position.

[0086] The pre-cutting cover 80 supports the first conveying roller 71 and the second conveying roller 72 of the first conveying roller pair 70. The second conveying roller 72 is located below the first conveying roller 71 and faces the first conveying 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 that is parallel to the rotation axis X71.

[0088] The first conveying roller 71 has a roller portion 71 R. The second conveying roller 72 has a roller portion 72 R. Each of the roller portions 71 R and 72 R 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 at the first nip 70N and convey the sheet SH toward a fixed blade 411 and a movable blade 412 (described later) of the cutter mechanism 4.

[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 in the conveying direction DT1 of a fixed blade 411 and a movable blade 412 (described later) of the cutter mechanism 4. The fuser 7 is located upstream in the conveying direction DT1 of the first conveying roller 71 and the second conveying roller 72. 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 conveying roller 71 and the second conveying 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 conveying roller 71 and the second conveying roller 72, respectively.

[0092] As shown in FIG. 6 , when the pre-cutting cover 80 rotates to the second cover position with the exterior cover 90 open and the maintenance opening 19 open, it moves away from the cutter mechanism 4 and is unable to guide the sheet SH toward the cutter mechanism 4. In this state, the first conveyor roller 71 and the second conveyor roller 72 also move rearward and downward away from the cutter mechanism 4. This causes the maintenance opening 19 to expose the pre-cutting cover 80, which is in 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 interrupted, allowing the first conveyor roller 71 and the second conveyor roller 72 to rotate by receiving a force that pulls out the nipped sheet SH. As a result, the user can remove the sheet SH that has become jammed around the exterior cover 90 and the pre-cutting cover 80 in the first discharge path PD1.

[0093] As shown in Figure 4, the conveying path PD1D formed by the pre-cutting cover 80 in the first cover position is the portion from near the flapper 26 on 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 from 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 closed. 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 plurality 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 can hold a sheet SH that has passed through the fixing unit 7. The discharge method for such a sheet SH is straight discharge for a sheet SH such as cardboard.

[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 Figures 11 to 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 Figures 4 and 18 to 20, the pre-cutting guide 300, the cutter mechanism 4, and the first guide 100 are assembled as a unit to the joint cover 50 and fixed to the joint cover 50. Furthermore, during maintenance work, etc., the pre-cutting guide 300, the cutter mechanism 4, and the first guide 100 are removed as a unit from the joint cover 50.

[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, which is in 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, which will be 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 multiple ribs that are spaced 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 (described later) of the cutter mechanism 4.

[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" in 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] The 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 that is 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 Figure 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 from the pre-cutting guide 300. The guide portion 402 guides the cutter carriage 420 in the cutting direction DC1, i.e., the left-right direction, and prevents the cutter carriage 420 from coming 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 its entirety 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 where the first motor M1 does not entirely 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 of the cutter frame opening 409 in the longitudinal direction, i.e., to the right of the right end, and is rotatably supported by the cutter frame 400. The belt tensioner 435 is able to swing coaxially with the driven pulley 433. This makes it possible to save space compared to when 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 below the driven pulley 434. The tension spring 436 is a metal compression coil spring. One end of the tension spring 436 is engaged with the lower right 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 drive 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 a timing belt 430 that is easily affected by heat from fixing and the like is used, the heat-resistant metal compression coil spring allows appropriate tension to be applied stably 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, thereby moving the cutter carriage 420, the moving blade holder 460, and the moving blade 412 in the cutting direction DC1.

[0121] 11, the cutter carriage 420 (420A) is shown in a standby position on the right side of the cutter frame opening 409 so as not to 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. In other words, the cutter carriage 420 can move between the position of cutter carriage 420A, which is the standby position in Figure 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 shown in a state where it is in the standby position. The cutter carriage 420 (420C) shown in Figures 13, 14, 16, and 26 is shown in a state where it is in the folded-back position.

[0124] 16 is a sensor that can detect 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 is in a state where it outputs a presence signal for 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 is in a state where it outputs an absence signal in any other case. 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 cutting edge of the fixed blade 411 extends linearly in the cutting direction DC1. The fixed blade 411 contacts the sheet SH from the first upstream guide surface 302 side, i.e., from below.

[0126] The movable blade 412 moves in the cutting direction DC1 while sliding against the cutting edge of the fixed blade 411. The movable 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 using a fixed blade 411 and a movable blade 412. Because the fixed blade 411 is fixed to the cutter frame 400, the sheet SH is cut by the movement of the movable blade 412.

[0128] 16 , the area where 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 extends in the vertical and horizontal directions and includes the cutting positions of the fixed blade 411 and the movable blade 412.

[0129] 12, the first guide 100 is located downstream in the conveying direction DT1 from the first conveying roller pair 70. The first guide 100 is also located downstream in the conveying 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 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. The ribs 107 are 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 tip of each front rib 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 from 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 to the first discharge roller 29A to ensure 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 and extends upward and in the front-to-rear direction. The right wall 106R is connected to the right end of the bottom wall 105 and extends upward and in the front-to-rear direction.

[0137] 14, a shaft hole 102H is formed at a rear and lower position in 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 in 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 generally box-shaped biasing member accommodating portion 108 is formed in the 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 is equipped with 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 are opposite each other. For this reason, in Figures 12, 21, and 22, the right biasing member 280 is shown, and the illustration and description of the left biasing member 280 are omitted.

[0140] 21, the biasing member 280 has a metal torsion coil spring 289 and a resin spring cover 281 that covers the torsion coil spring 289. The torsion coil spring 289 is an example of the "spring" of the present invention.

[0141] The spring cover 281 is rotatably supported by a support shaft 108S located inside 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 an engaging portion (not shown) formed around the periphery of the biasing member housing 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 at 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 curves 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 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 at X200.

[0148] The second guide 200 is rotatable about the rotation axis X200 by inserting the rotation shafts 200S into the shaft holes 102H in the left wall 106L and the right wall 106R of the first guide 100 shown in Figure 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 sliding surfaces 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 surfaces 273 are 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, pressed portion 274, and stopper recess 201S and the right sliding surface 273, pressed portion 274, and 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, pressed portion 274, and stopper recess 201S are shown, and the left sliding surface 273, pressed portion 274, and stopper recess 201S are not shown or described.

[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 an arc shape with a small radius. 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 Figure 21, and a second guide position in which the stopper recess 201S moves upward away from the stopper 102S, as shown in Figure 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, which is located at the first guide position, in a direction from the second guide position toward the first guide position, i.e., a downward biasing force FG1. 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 away from the stopper 102S, and the second guide 200 is held in the first guide position with high reliability.

[0158] 22 , when the second guide 200 rotates between the first guide position and the second guide position, the biasing member 280 comes into sliding contact with the sliding contact surface 273, 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 contact 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 frictional force acting between the biasing member 280 and the sliding contact surface 273 of the second guide 200 can stop the orientation of the second guide 200 at a position that achieves a desired rotation angle.

[0159] The torsion coil spring 289 and the spring cover 281 are positioned radially outward of the sliding contact surface 273 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 conveying 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 where they form a 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 spaced apart. 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 more 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. The ribs 207 are spaced apart 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 the entire second guide surface 202 moves accordingly.

[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, relative to the downstream side 202D of the second guide surface 202 in the conveying direction DT1, as it approaches the upstream end 200U of the second guide 200.

[0168] The second guide 200 guides the sheet SH conveyed 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 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 positions 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 sensor. The first guide 100 swingably supports the actuator S4A to hold 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 passing through the cutter mechanism 4 and the first guide 100 and 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 ( 420 A) until the sheet SH reaches the 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 has been nipped between the first nip 70N and the second nip 29N, in half.

[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), which has been cut 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 grasp and pull out the jammed sheet SH. As a result, the image forming apparatus 1 makes it easy to remove the jammed sheet SH around the cutter mechanism 4.

[0178] <Relative positional relationship between nip tangent of first nip, detection area of ​​sheet sensor, second nip, etc.> As shown in Figure 24, the nip tangent TN1 of the first nip 70N formed by the first conveying roller 71 and the second conveying roller 72 extends horizontally in the front-to-back 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 swinging 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 positioned 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 positioned downward away from the nip tangent line TN1. The second guide surface 202 is positioned upward away from 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 vertical direction becomes narrower from the upstream side 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 that is located below the cutter carriage 420 and 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.

[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 the 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 below the nip tangent line TN1 by about several tenths of a millimeter to 1.0 mm.

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

[0188] 4, the conveyance direction DT1 of the sheet SH changes by 90° or more from the time it passes through the fixing device 7 until it reaches the first nip 70N. In this embodiment, as an example, the conveyance direction DT1 of the sheet SH changes by about 130° from the time it passes through the post-fixing conveying roller pair 25 of the fixing device 7 until it reaches the first nip 70N.

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

[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 Figure 25, the movement distance of the sheet SH from the fixing nip 7N to the nip position (second nip 29N) of the first discharge roller pair 29 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 actual movement distance of the sheet SH, or a design value set assuming the ideal state in which the sheet SH will pass from the fixing nip 7N to the nip position (second nip 29N) of the first discharge roller pair 29. The same is true for the movement distance LR2.

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

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

[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 defined as 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 trailing edge 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] <First Function and Effect> 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 where 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, when viewed along the cutting direction DC1, from the point CP1 where the leading edge of the actuator S4A intersects with the first guide surface 101 to the 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 line TN1 of the first nip 70N. Therefore, the sheet SH that is conveyed by the first conveying roller 71 and the second conveying roller 72 of the first conveying roller pair 70 and passes through the first guide 100 and the second guide 200 reaches the detection area AS1 with little tendency to sag or bend, and therefore the movement distance of the leading edge of the sheet SH is less likely to vary.

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

[0199] A comparative example will now be described. If the first conveyor 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 at an upward inclination relative to the nip tangent TN1. Furthermore, if the first conveyor 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 at an upward inclination relative to the nip tangent TN1. As a result, in the comparative example, the detection area AS1 will not be 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 or the second guide 200, which increases the tendency for the sheet SH to sag or bend before reaching the detection area AS1. This causes the travel distance of the leading edge of the sheet SH until it is detected by the sheet sensor S4 to vary. Therefore, 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] Furthermore, in this image forming apparatus 1, 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. 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 sag or bend, and therefore 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, the 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] Furthermore, in this image forming apparatus 1, the sheet sensor S4 has an actuator S4A that swings when the leading edge of the sheet SH abuts against it. 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 stopped after being nipped between the first nip 70N and the second nip 29N. When viewed along the cutting direction DC1, the second nip 29N is also located on the nip tangent line TN1. With this configuration, the sheet SH that has stopped after being nipped between the first nip 70N and the second nip 29N is aligned in a straight line when viewed along the cutting direction DC1. When the cutter mechanism 4 cuts the sheet SH in this state, the sheet SH is less likely to bend excessively, which can prevent the cutting position of the sheet SH from shifting due to the bend.

[0205] In addition, in this image forming apparatus 1, as shown in Fig. 4, the conveying direction DT1 of the sheet SH changes by 90° or more from the time it passes through the fixing device 7 until it reaches the first nip 70N. Furthermore, 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 preventing the sheet SH from becoming larger in the vertical direction.

[0206] Furthermore, in this 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 movable blade 412 of the cutter mechanism 4 in the conveying direction DT1. The first guide 100 rotatably supports the first discharge roller 29A and also 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, as shown in FIG. 6 , if a sheet SH jams 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 from the second discharge roller 29B, and separates the first guide surface 101 from the second guide surface 202, allowing the user to easily grasp 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, because the sheet sensor S4 is not held by the movable second guide 200, a decrease in detection accuracy can be suppressed.

[0207] In the image forming apparatus 1, the second guide 200 is rotatable about a rotation axis X200, 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, 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 with respect to the downstream side 202D of the second guide surface 202 in the conveying direction DT1, as the second guide 200 approaches the upstream end 200U of the second guide 200. 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 beyond the fixed blade 411 and the movable blade 412 of the cutter mechanism 4. Therefore, a user can easily insert their 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 easily grab the jammed sheet SH. Furthermore, even when 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 a user who inserts their hand from downstream in the conveying direction DT1 has difficulty reaching the cutter mechanism 4. Furthermore, when the second guide 200 rotates to the second guide position, it is possible to prevent the jammed sheet SH from being pinched.

[0208] 6, in this image forming apparatus 1, when the second guide 200 is in the second guide position, the position of the second discharge roller 29B is higher and 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, when the second guide 200 is in the second guide position, it opens upward and moves 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 for jammed sheets SH, regardless of whether or not sheets SH are stacked on the discharge tray 9, and makes it even easier to remove 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 in the conveying direction DT1 from the fixed blade 411 and the movable blade 412 of the cutter mechanism 4. The fixed blade 411 contacts the sheet SH from below, and the movable blade 412 contacts 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 movable blade 412 in the conveying direction DT1. The second guide surface 202 is located downstream in the conveying direction DT1 from the cutter carriage 420. With this configuration, the second guide surface 202 is spaced from the cutter carriage 420 so as not to interfere with the cutter carriage 420. To compensate for this, the first guide surface 101 guides the sheet SH below the cutter carriage 420 and near the movable blade 412. As a result, the sheet SH can pass through the cutter mechanism 4 stably.

[0210] 4, the image forming apparatus 1 further includes a fuser 7, a first discharge path PD1 on which the cutter mechanism 4 is disposed and which discharges the sheet SH that has passed through the fuser 7, a second discharge path PD2 on which the cutter mechanism 4 is not disposed and which discharges the sheet SH that has passed through the fuser 7, and a flapper 26 that is movable between a first flapper position where the sheet SH is guided to the first discharge path PD1 while blocking the second discharge path PD2, and a second flapper position where the flapper 26 blocks the first discharge path PD1 while guiding the sheet SH to the second discharge path PD2. With this configuration, when the sheet SH is discharged by the second discharge path PD2 without being cut, the flapper 26 in the second flapper position shown by the two-dot chain line in FIG. 4 blocks the path leading to the cutter mechanism 4, thereby suppressing the heat from the fuser 7 from affecting the first conveying roller pair 70 and the cutter mechanism 4.

[0211] 24 , the pre-cutting guide 300 has a first upstream guide surface 302 and a second upstream guide surface 301. The fixed blade 411 contacts the sheet SH from the first upstream guide surface 302 side. The movable blade 412 contacts the sheet SH from the second upstream guide surface 301 side. When 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, when 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 will be gradually pulled from the side where the movable blade 412 begins to press against the sheet SH, which will make the cut surface more likely to ripple. In this regard, the above-described configuration can weaken 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, making it difficult for the cut surface to become wavy.

[0212] Furthermore, in this image forming apparatus 1, the first upstream guide surface 302 faces upward, and the second upstream guide surface 301 faces downward. With this configuration, the side of the sheet SH that begins to be cut by the moving blade 412 moves along the fixed blade 411 due to its own weight, making the cut surface even 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 slightly below the nip tangent line TN1 in the direction perpendicular to the conveying direction DT1 and the cutting direction DC1, i.e., in the up-down direction. This further reduces 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 ripple.

[0213] 4, in this image forming apparatus 1, the conveying direction DT1 of the sheet SH changes by 90° or more as it passes through the image forming unit 3 and reaches the first nip 70N. With this configuration, the sheet SH is conveyed along a path that curves upstream in the conveying direction DT1 from the fixed blade 411 and the movable blade 412 of the cutter mechanism 4, and the sheet SH tends to curl forward along the tip 411T of the fixed blade 411, which is located inside the curved path, thereby suppressing wavy cut edges.

[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 accommodate. 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 the problem of the sheet SH being overheated in the fixing nip portion 7N does not occur.

[0216] 4, the first pair of discharge rollers 29 and the second pair of discharge rollers 28 discharge the sheets SH in the same direction. With this configuration, the user only needs to perform approximately the same operations when collecting the sheets SH discharged by the first pair of discharge rollers 29 and when collecting the sheets SH discharged by the second pair of discharge rollers 28, thereby reducing the user's inconvenience.

[0217] The image forming apparatus 1 also includes a discharge tray 9 that supports the sheets SH discharged by the first discharge roller pair 29 and the sheets SH discharged by the second discharge roller pair 28. With this configuration, the single discharge tray 9 can support both cut sheets SH and uncut sheets SH, thereby preventing the apparatus from becoming too 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 use the same side of the image forming apparatus 1 to collect the sheets SH discharged by the first discharge roller pair 29 or the second discharge roller pair 28 and to pull 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 use the same side of the image forming apparatus 1 to collect the sheet SH discharged by the first discharge roller pair 29 or the second discharge roller pair 28 and to pull 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. This configuration makes it possible to utilize the space above the second discharge roller pair 28 to arrange the cutter mechanism 4, the first guide 100, the second guide 200, and the sheet sensor S4, thereby facilitating miniaturization. Furthermore, this configuration allows the cut sheet SH to be discharged downstream in the transport direction DT1 on the discharge tray 9, making it easy to remove 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 from the fixed blade 411 and the movable 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 from the fixed blade 411 and the movable blade 412 of the cutter mechanism 4, the movement 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 can be reduced, thereby further suppressing 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, when the pre-cutting guide 300, cutter mechanism 4 and first guide 100 are unitized, fastening and positioning are performed as follows 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.

[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 upstream in the conveying direction DT1. A threaded hole that is recessed from the center of the tip surface of each of the fastening bosses 181, 182, 183, and 184 toward the downstream in the conveying direction DT1 is formed. The tip of the fastening boss 184 has a diameter that is reduced in two stages.

[0225] The fastening boss 181 is located to the left of the upper end of the left wall 106L of the first guide portion 100. The fastening boss 182 is located on the left end side of the upstream end 100U of the first guide portion 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 portion 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 portion 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 conveying direction DT1 and a truncated cone that is connected to the tip of the cylinder and protrudes upstream in the conveying 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 aligned 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 is positioned to align 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 is positioned to align 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-stage 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 aligned with the first positioning portion 191. The second positioning portion 491 is a circular through-hole that fits into the first positioning portion 191.

[0236] The second positioning portion 492 is located on the right end side of the cutter frame opening 409 and is 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 into 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 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 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 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 of the pre-cutting guide 300, in a position that aligns with the screw hole 485. The insertion hole 386 is located at the center in the left-right direction in the upper part of the pre-cutting guide 300, in 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 that fits into the first positioning portion 191.

[0242] The third positioning portion 392 is located in 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 fits into the first positioning portion 192.

[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 threaded hole of the fastening boss 181. The screw 502 is inserted through the insertion holes 382 and 482 and screwed into the threaded 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 threaded 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 threaded hole of the fastening boss 184. At this time, the tip surface of the fastening boss 184 has a shaft shape that narrows in diameter in two stages as shown in FIG. 14 , so 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 and 506 .

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

[0249] In this way, the first guide 100 and the pre-cutting guide 300 are fastened together with the cutter frame 400 sandwiched therebetween.

[0250] <Positioning and fastening of the pre-cutting guide, cutter mechanism and first guide unit to the joint cover> As shown in Figure 18, the pre-cutting guide 300, cutter mechanism 4 and first guide 100 unit are 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 and 50M2 position the pre-cutting guide 300 relative to the joint cover 50. The other two positioning bosses 50M3 and 50M4 position the first guide 100 relative to the joint cover 50.

[0252] The two fastening points 50N1 and 50N2 fasten the pre-cutting 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] 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 slightly leftward.

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

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

[0256] As shown in FIG. 26 , a restricting wall 120T is located 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 restricting protrusion 420T of the cutter carriage 420 has come into contact with the restricting wall 120T and that 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 restricting 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 activates 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, toward the standby position (420A). 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] 14 , in the image forming apparatus 1 of the embodiment, the sheet sensor S4 is provided on the first guide 100 made of the same material as that of the cutter frame 400, that is, a material less rigid than metal, i.e., resin. The first guide 100 is positioned relative to the cutter frame 400.

[0259] Therefore, compared to a case where 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 when the sheet SH is transported by a predetermined transport amount to the cutting position of the sheet SH, a problem is less likely to occur in which the cutter mechanism 4 is unable to cut the sheet SH at the target cutting position.

[0260] As a result, this image forming device 1 does not need to perform printing with cutting several times before shipping the product, measure the positional deviation at which the sheet sensor S4 detects the sheet SH, and perform adjustments to control the required transport amount from detecting the sheet SH to the position at which the sheet SH is to be cut, and also does not need to perform adjustments when 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 with the second positioning portions 491, 492. With this configuration, the first guide 100 is positioned directly on the cutter frame 400, which highly reliably prevents the first guide 100 from shifting in position relative 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 shift relative to the cutter mechanism 4, and the position at which the cutter mechanism 4 cuts the sheet SH can be determined with 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, 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 these two points are widely spaced apart in the longitudinal direction (left-right direction), so that it is possible to more reliably prevent the position of the first guide 100 from shifting relative to the cutter mechanism 4.

[0264] In the image forming apparatus 1, the second positioning portions 491 and 492 are through holes, and the first positioning portions 191 and 192 are protrusions. This configuration simplifies the second positioning portions 491 and 492 and the first positioning portions 191 and 192.

[0265] 12, in this image forming apparatus 1, the first guide 100 is provided downstream in the conveying direction DT1 from the cutter mechanism 4. The movement distance of the sheet SH from when the sheet sensor S4 provided downstream in the conveying direction DT1 from the cutter mechanism 4 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 in the conveying direction DT1 from the cutter mechanism 4 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 relative to the first guide 100 and the cutter frame 400 by fitting the first positioning portions 191, 192 into 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 portions 191, 192 protrude upstream in the transport direction DT1 and penetrate the second positioning portions 491, 492 to engage with the third positioning portions 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 precision.

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

[0269] 11 and 18, the first guide 100, the cutter frame 400, and the pre-cutting guide 300 are fastened together when they are assembled to and removed from the image forming apparatus 1. With this configuration, the first guide 100, the cutter frame 400, and the pre-cutting guide 300 can be easily assembled to and removed from the image forming apparatus 1 as a unit, and there is no need to adjust each component individually.

[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 because the orientation of the sheet SH passing through the cutter mechanism 4 is aligned with the first guide 100.

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

[0272] <Configuration for positioning the pre-cutting cover 80 at the first cover position in the conveying 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 and 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 a short distance upstream in the conveying direction DT1 and extends a short distance 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 a short distance upstream in the conveying direction DT1 and extends a short distance 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 Figure 9, the positioning protrusion 83L protrudes rearward, i.e., downstream in the conveying direction DT1, to the left of the left ends of the roller portions 71R and 72R of the first conveying roller 71 and the second conveying roller 72, respectively.

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

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

[0280] 27, the abutment piece 88L is swingably supported on a swing shaft 84L that is 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 that protrudes leftward from the rear portion thereof forms a curved abutment surface 88L1 that is curved in an arc shape.

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

[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, and 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 and 18R.

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

[0285] The tip of the contacted surface 18L is located at a position where 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 contact surface 18R is an inclined surface formed on the right side frame of the internal frame of the first housing 10. The contact surface 18R is located rearward and to the right away from the positioning rib 308R, and extends rearward and to the left while sloping.

[0287] The tip of the contacted surface 18R is located at a position where 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 and 83R of the pre-cutting cover 80 approach the positioning ribs 308L and 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 toward the first cover position.

[0290] The pressing force FC1 biases the positioning protrusions 83L, 83R downstream in the transport direction DT1, causing the tips of the positioning protrusions 83L, 83R to abut against the positioning ribs 308L, 308R, and the pre-cutting cover 80 reaches the first cover position.

[0291] 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, i.e., 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 is indirectly positioned relative to the cutter frame 400 by abutting against the pre-cutting guide 300. The pre-cutting cover 80 is an example of the "upstream cover" of the present invention.

[0293] 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. As a result, when the pre-cutting cover 80 moves from the second cover position to the first cover position, the relative positional relationship between the cutter mechanism 4 and the first conveying roller 71 supported by the pre-cutting cover 80 is less likely to shift.

[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 tends to be parallel to the cutting direction DC1 as it should be, and the sheet SH is less likely to be displaced obliquely relative to the cutting direction DC1. As a result, the sheet SH conveyed by the first conveying roller 71 is less likely 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 conveying roller 71 supported by the pre-cutting cover 80 with respect to the fixed blade 411, allowing the cutter mechanism 4 to cut the sheet SH at the desired cutting position.

[0297] Furthermore, in this image forming apparatus 1, movable blade 412 is guided in cutting direction DC1 by cutter frame 400 and moves while sliding against fixed blade 411. With this configuration, the cutting position of sheet SH is determined by fixed blade 411, and the relative positional relationship between fixed blade 411 and movable blade 412 is determined by cutter frame 400. This improves the positional accuracy when movable blade 412 slides against 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, a 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. As shown in Fig. 27, the pre-cutting cover 80 in the first cover position is indirectly positioned relative to the cutter frame 400 by abutting against the pre-cutting guide 300. This configuration allows for greater 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 conveying roller 71 and the second conveying roller 72 each have roller portions 71R and 72R formed with cylindrical surfaces that are longer than the sheet SH in the cutting direction DC1. Then, as shown in Fig. 4, the cutter mechanism 4 cuts the sheet SH that is held between the roller portions 71R and 72R of the first conveying roller 71 and the second conveying 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 of the image forming apparatus 1 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 a sheet SH that has become jammed around the fixing unit 7 or in the second discharge path PD2, it is possible to prevent a user's hand from reaching the cutter mechanism 4 via the maintenance opening 19.

[0303] 4, the first housing 10 of the image forming apparatus 1 has a protruding wall 17 that covers the top of the pre-cutting cover 80 in the first cover position. The presence of the protruding wall 17 above the pre-cutting cover 80 prevents the user from accidentally putting their 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 between the first cover position and the second cover position by rotating about the cover axis X80. This configuration can reduce rattling when the pre-cutting cover 80 moves between the first cover position and the second cover position, compared to when the pre-cutting cover 80 moves linearly.

[0305] Furthermore, in this image forming apparatus 1, as shown in FIG. 4 , when the exterior cover 90 closes the maintenance opening 19, it forms an upstream transport path PD1U that is located upstream in the transport direction DT1 from the transport path PD1D formed by the pre-cutting cover 80 in the first cover position, and that can guide the sheet SH from the fuser 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 transport path PD1U is opened, and the upstream side of the cutter mechanism 4 in the transport direction DT1 remains closed. With this configuration, when the exterior cover 90 is opened to remove the sheet SH that has jammed around the second discharge roller pair 28, by placing the pre-cutting cover 80 in the first cover position, it is possible to prevent a 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 can receive a sheet SH that has passed through the fuser 7 when the maintenance opening 19 is open. The multiple ribs 87 of the pre-cutting cover 80 guide the sheet SH that has passed through the fuser 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 fuser 7 is discharged straight, the ribs 87 of the pre-cutting cover 80 allow the sheet SH to be smoothly received 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, compared to a case where 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, 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 even less likely to occur.

[0308] 2, one edge of the image forming apparatus 1 in the cutting direction DC1, i.e., the right edge, is a first edge 1E1. The other edge of the image forming apparatus 1 in the cutting direction DC1, i.e., the left edge, is a second edge 1E2.

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

[0310] A second length LP2 is defined as the length by which the second housing 30 protrudes leftward relative to the first housing 10 on the second edge 1E2 side of the image forming apparatus 1. The second length LP2 is greater 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] The insertion port 45H of the automatic document feeder mechanism 45 opens in a direction facing the first edge 1E1 of the image forming apparatus 1, that is, to the right.

[0312] 18 to 20 , the joint cover 50 has a storage recess 55. The storage recess 55 is recessed so as to accommodate a portion of the joint cover 50 that is located on one side of the cutting area AC1 in the cutting direction DC1, 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 storage recess 55 is recessed to the right 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 portion 51 is located to the right of the discharge tray 9 and downstream in the conveying direction DT1 of the moving blade holder 460 and the moving blade 412. The first support portion 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 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 Figure 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 located above the cutting area AC1 when viewed along the conveying direction DT1, and protrudes toward the cutting area AC1 more than the inner wall surface 59.

[0319] When the cutter carriage 420, moving blade holder 460, and moving blade 412 are in the standby position (420A), a portion 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 portion 51. Note that because the second guide 200 is located in front of the cutter mechanism 4, i.e., downstream in 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] 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 portion 51, a right wall of the second support portion 52, and a connecting wall 53. The right surface of the side wall 56 forms 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 an attachment / detachment opening 54. The attachment / detachment 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. 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.

[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 located on one side in the cutting direction DC1 of the discharge space AD1 of the support parts 57L and 57R.

[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 the 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 downwardly spaced 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 detachable opening cover 54C opens the detachable opening 54, the rib 54R is spaced to the right and rearward from the rib insertion hole 53R. Although not shown, when the detachable opening cover 54C moves to a position where it closes the detachable opening 54, the rib 54R is inserted into the rib insertion hole 53R and its tip protrudes leftward beyond the rib insertion hole 53R.

[0332] 11 and 13, the image forming apparatus 1 is equipped with 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 outputs a closed signal for the removable opening cover 54C. In all other cases, the open / close sensor S7 outputs an open signal for the removable opening cover 54C. 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 the appropriate time.

[0333] As shown in FIG. 28, the cutter carriage 420 can detachably mount 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, moving blade holder 460, and moving blade 412 in the standby position (420A), after opening the attachment / detachment opening cover 54C, the upper end of the carriage cover 450 (described later) of the cutter carriage 420 is moved forward and downward from the position shown in Figure 28. This makes it possible to remove the moving blade holder 460 and moving blade 412 from the cutter carriage 420 by grasping the handle 469 and pulling the moving blade holder 460 and moving blade 412 upward and to the right. Furthermore, by performing the reverse operation, the moving blade holder 460 and moving blade 412 can be attached to the cutter carriage 420.

[0335] <Arrangement of First Motor and 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 overlaps with the joint cover 50 when viewed in the cutting direction DC1, i.e., the left-right direction.

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

[0338] <Arrangement of Control Board, Communication Board, Speaker, Exhaust Port, 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), and 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 10.

[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 and warning sounds. 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 Figure 3, a plurality of small holes 10H are formed in the left wall of the first housing 10 at a position facing the speaker 64 to diffuse the 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 air from inside the first housing 10 through the exhaust port 63H.

[0347] <Fourth effect> As shown in FIG. 20 , in the image forming apparatus 1 of the embodiment, the joint cover 50 for supporting the second housing 30 from below is partially recessed to form the storage recess 55, thereby making it possible to secure space for storing the moving blade 412 in the standby position.

[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 discharge space AD1 in the cutting direction DC1. As shown in FIG. 20 , the storage recess 55 is recessed from the inner wall surface 59 to one side in the cutting direction DC1, i.e., to the right, to store 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 conveyance direction DT1 and protrudes toward the cutting area AC1 beyond the inner wall surface 59. This configuration reliably prevents the image forming apparatus 1 from becoming larger in the cutting direction DC1, compared to when the storage recess 55 is recessed to store 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 this 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 attach the moving blade holder 460 and the moving blade 412. With this configuration, worn moving blade 412 can be replaced, allowing the cutter mechanism 4 to provide stable cutting performance for a long period of time.

[0351] 12, the cutter carriage 420 detachably holds the moving blade holder 460 and the moving blade 412. 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, worn moving blade 412 can be easily replaced via the attachment / detachment opening 54, allowing the cutter mechanism 4 to provide stable cutting performance over a long period of time.

[0352] 20 , the joint cover 50 of the image forming apparatus 1 includes 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 further back in the cutting direction DC1 from the cutting area AC1 than the first support portion 51 and the second support portion 52 so that the cutter carriage 420, the moving blade holder 460, and the moving blade 412 can be accommodated therein. 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 with the first support portion 51 and the second support portion 52, and the first support portion 51, the second support portion 52, and the connecting wall 53 can define a large storage recess 55.

[0353] 12, the cutter carriage 420 detachably holds the moving blade holder 460 and the moving blade 412. 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, worn moving blade 412 can be easily replaced via the attachment / detachment opening 54, allowing the cutter mechanism 4 to provide stable cutting performance over a long period of time.

[0354] 16 , when the cutter carriage 420, the moving blade holder 460, and the moving blade 412 are in the standby position (420A), a portion 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. This configuration makes it possible to more reliably prevent the image forming apparatus 1 from becoming larger in size in the cutting direction DC1, compared to a case where 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, in the image forming apparatus 1, the first motor M1 is located above the cutter frame opening 409 when viewed along the conveying direction DT1, and its entirety 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 size in the cutting direction DC1, compared to a case where 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] Furthermore, 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. As shown in FIG. 2 , the control board 60 is located on the second edge 1E2 side of the image forming apparatus 1. Numerous connection cables are wired to the control board 60 for connecting the image forming unit 3, the fuser 7, the cutter mechanism 4, and the image reading unit 35. Therefore, the design freedom for locating the attachment / detachment opening 54 on the second edge 1E2 side where the control board 60 is located tends to be limited. In this regard, by locating the attachment / detachment opening 54 on the first edge 1E1 side, opposite the second edge 1E2, there is no need to consider interference between the attachment / detachment opening 54, the control board 60, and the connection cables, which improves the design freedom for locating the attachment / detachment opening 54.

[0357] In addition, in this image forming apparatus 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 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 of the image forming apparatus 1 overlaps with the joint cover 50 when viewed in the cutting direction DC1, i.e., the left-right direction. This configuration allows the free space within the joint cover 50 to be effectively used as a space for accommodating the second motor M2, thereby achieving a more compact size in the vertical direction.

[0359] Furthermore, in this image forming apparatus 1, almost the entire first motor M1, except for its upper end, overlaps with the joint cover 50 when viewed in the cutting direction DC1, i.e., the left-right direction. This configuration allows the empty space within the joint cover 50 to be effectively used as a storage space for the first motor M1, thereby achieving a more compact 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. This configuration makes it 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 this image forming device 1, at the first edge 1E1 side of the image forming device 1, the second housing 30 protrudes from the first housing 10 in one direction in the cutting direction DC1 by a first length LP1 that is equal to or greater than zero. At the second edge 1E2 side of the image forming device 1, the second housing 30 protrudes from the first housing 10 in the other direction in the cutting direction DC1 by a second length LP2 that 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 less likely to get in the way.

[0362] 1, the attachment / detachment opening 54 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 positioned away from the wall surface. This allows the user to easily reach the attachment / detachment opening 54, making it easy to replace the moving blade 412.

[0363] Furthermore, 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 where the speaker 64 is located needs to have a relatively large wall for reverberating sound. Therefore, the design freedom for arranging the attachment / detachment opening 54 on the second edge 1E2 side where the speaker 64 is located tends to be limited. In this regard, by positioning the attachment / detachment opening 54 on the first edge 1E1 side, opposite the second edge 1E2, it is easier to ensure a large wall for reverberating sound, thereby improving the design freedom for arranging the attachment / detachment opening 54.

[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 the 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, making it easy to replace the moving blade 412.

[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.

[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 multiple 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 of the first retaining wall 446A. The upper and lower ends of the front-rear positioning protrusion 446T bulge forward above the left-rear positioning recess 446H. Although not shown, a front-rear positioning protrusion 446T is also formed on the left edge 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 Figures 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 in 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 the swing axis X450 extending in the left-right direction. A notch is formed in the lower end of the shaft holes 447 to allow the insertion of a swing shaft 457 (described later).

[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 second holding wall 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 engaging 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, the elastic beams 445 are connected by beam connectors 445J. Each elastic beam 445 and the beam connectors 445J are manufactured by punching and bending a single spring steel plate.

[0376] 36 , the beam connecting portions 445J engage with the upper portions of the first retaining walls 446A, thereby holding each elastic beam 445 to the first retaining walls 446A. When the holder retaining portion 446 is not holding the moving blade holder 460, the elastic beams 445 extend downward and forward so as to enter the holder retaining portion 446, i.e., so as to enter the space surrounded by the first retaining wall 446A and each second retaining wall 446B.

[0377] As shown in FIGS. 31 and 32, the carriage cover 450 has a cover body 456, a swing shaft 457, a protrusion 458, an enclosing portion 459, and an operating protrusion 459T, which are integrally formed to form 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 vertically. The lower ends of the cover side walls 456B are located lower and forward than 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. The swing shafts 457 are cylindrical columns that protrude toward each other and are centered on a swing axis X450 that is parallel to the cutting direction DC1. A portion of the outer circumferential surface of the swing shafts 457 is flat so that it can pass through the notch and be inserted into the shaft hole 447.

[0382] As shown in Figures 31 and 32, a pair of left and right protrusions 458 are integrally formed on each swing shaft 457 with the swing axis X450 as the center. Each protrusion 458 has a smaller diameter than each swing shaft 457. As shown in Figure 31, the left protrusion 458 is connected to the right surface of the left swing 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 swing 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 pivotally 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] 36 and the like, the carriage cover 450 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 FIG. 43 and the like, the carriage cover 450 fixes the moving blade holder 460 to the holder holding portion 446.

[0386] 29 , the enclosure 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 of the right cover side wall 456B, i.e., toward the attachment / detachment opening 54. The enclosure 459 has a notch 459C recessed forward below the operation protrusion 459T.

[0387] 28, the enclosing portion 459 surrounds the handle 469 when the carriage cover 450 is in the locked position. The notch 459C exposes a portion 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 left and right first springs 455. Each first spring 455 is a metal leaf spring. The left first spring 455 is held on the rear side of the lower portion of the main cover 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 portion of the main cover wall 456A at a position adjacent to the right cover side wall 456B.

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

[0390] As shown in FIG. 29, when the carriage cover 450 is moved to the locked position, the curved portions 455C and the engaging protrusions 448 of the carriage base 440 engage with each other to maintain the carriage cover 450 in the locked position.

[0391] 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] The holder body 461A and the holder cover 461B are integrated by engaging the engagement pieces 461B1 and 461B2 of the holder cover 461B with the engagement claws 461A1 and 461A2 of the holder body 461A and fastening the holder body 461A and the holder cover 461B with the screw 461F. The holder body 461A and the holder cover 461B are each a resin molded product.

[0393] The handle 469 is formed integrally with the holder main body 461 A. The handle 469 is connected to the upper end surface of the holder main body 461 A at the middle portion in the left-right direction, 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-to-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 is fitted into the lower part of the holder main body 461A. The rear end of the support shaft 462 is fitted 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 the inner wall surface of the holder frame 461 and its rear end abutting 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 conveyance direction DT1, i.e., backward.

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

[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. The left groove 468 is shown in Figs. 38, 40, 42, and 44.

[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 located at 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., in the up-and-down direction, away from the fixed blade 411. Each groove 468 bends 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 is formed at the lower end 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] <Attaching and Detaching the Moving Blade Holder to the Cutter Carriage> The user can attach the moving blade holder 460 and the moving blade 412 to the cutter carriage 420 by the following operation.

[0406] As shown in Figure 28, the detachable opening cover 54C is in the state where the detachable opening 54 is open, 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 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, the pressing protrusions 456T of the carriage cover 450 come into contact with 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 above and forward from the tip of the fixed blade 411.

[0409] 39 and 40, the user further lowers the moving blade holder 460 to penetrate deeper into the holder holding portion 446. At this time, the tip of each elastic beam 445 comes into contact with the moving blade holder 460, elastically deforming backward and storing restoring force, thereby urging the moving blade holder 460 forward so as to move the moving blade 412 away from the fixed blade 411 along the conveyance 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 the corresponding 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, the grooves 468 are guided by the protrusions 458, and the lowering of the moving blade holder 460 stops when the protrusions 458 are positioned at the bent portions 468B of the grooves 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 in the conveying direction DT1, and is located below 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 operating protrusions 459T and moves the carriage cover 450 from the unlocked position to the locked position, causing the pressing protrusions 456T of the carriage cover 450 to press the moving blade holder 460 and move it rearward.

[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 rearward along the conveying direction DT1 to approach the fixed blade 411 and come into contact with the fixed blade 411. Thereafter, the second spring 465 is compressed and deformed while still pressing the moving blade 412 against the fixed blade 411.

[0415] At this time, as shown in Figure 43, the left and right positioning protrusions 461T fit into the left and right positioning recesses 446H, thereby positioning the moving blade holder 460 in the left and right direction on the cutter carriage 420. Also, as shown in Figure 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, thereby positioning the moving blade holder 460 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 reliably maintained in the locked position 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] The user can also remove the moving blade holder 460 and the moving blade 412 from the cutter carriage 420 by performing the above-described 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 by guiding the grooves 468 .

[0419] 28 , when 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 moving blade holder 460 attached to the cutter carriage 420 can be reached in the cutting direction DC1, i.e., in the left-right direction, via the attachment / detachment opening 54 that penetrates the connecting wall 53 that is part of the side wall 56. At this time, even if a plurality of cut sheets SH are stacked on the discharge tray 9 that is downstream of the cutter mechanism 4 in the conveying direction DT1, the sheets SH are unlikely to obstruct the hand attempting to reach the moving blade holder 460.

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

[0423] Furthermore, this image forming apparatus 1 is a multifunction peripheral. 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 portions 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 portion 57R of the support portions 57L and 57R, which is on the other side of the discharge space AD1 in the cutting direction DC1. With this configuration, the cutter mechanism 4 is located further back 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 a user attempts to reach the moving blade holder 460 attached to the cutter carriage 420 along the conveyance direction DT1, the user's hand is likely to be obstructed by the cut sheets SH stacked in the discharge space AD1, as well as by the image reading unit 35 and support members 57L and 57R that surround the discharge space AD1. In this regard, the image forming apparatus 1 allows the user to 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 user's hand attempting to reach the moving blade holder 460 is unlikely to be obstructed by the cut sheets SH stacked in the discharge space AD1, as well as by the image reading unit 35 and support members 57L and 57R that form the discharge space AD1. Furthermore, because the moving blade holder 460 is not attached to or detached from the cutter carriage 420 from above, the image forming apparatus 1 is less likely to become bulky. Therefore, the image forming apparatus 1, which is a multifunction device, can easily attach and detach the moving blade holder 460 to and from the cutter carriage 420 without increasing the size of the apparatus.

[0424] 28, the joint cover 50 has a 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 is equipped with 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, there is a risk that the user may accidentally come into contact with 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 using 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 Figure 31, the carriage cover 450 has protrusions 458. As shown in Figures 33 and 34, the holder main body 461A has grooves 468. With this configuration, as shown in Figures 40, 42 and 44, the protrusions 458 guide the grooves 468, making it even easier to attach and detach the moving blade holder 460 to and from the cutter carriage 420.

[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 34, the guided portions are the grooves 468. With this configuration, the guided portions of the moving blade holder 460, which is the replacement unit, are the grooves 468 and do not protrude, so even if the moving blade holder 460 were to fall, 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 the groove 468 from one end 468A and guides the groove 468. Then, with the moving blade holder 460 attached to the cutter carriage 420, each protrusion 458 abuts against the other end 468C, positioning the moving blade holder 460 in the front-to-rear direction. This configuration in which each protrusion 458 abuts against the other end 468C of each groove 468 makes it easy to position the moving blade holder 460 attached to the cutter carriage 420.

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

[0431] 31 and 32, the carriage cover 450 of the image forming apparatus 1 has swing shafts 457, and the projections 458 are formed integrally with the swing shafts 457, with the swing shaft center X450 as the center. With this configuration, the projections 458 that position the moving blade holder 460 are formed on the carriage cover 450 coaxially with the swing shafts 457, thereby realizing space saving.

[0432] 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 tips of the elastic beams 445 contact the moving blade holder 460 and elastically deform, 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. With this configuration, the tips of the elastic beams 445 guide the moving blade holder 460 attached to the holder holding portion 446 during attachment. The biasing force of the elastic beams 445 also causes the moving blade 412 supported by the moving blade holder 460 to move forward from the fixed blade 411 along the conveying direction DT1. As a result, the moving blade 412 can be prevented from coming into contact with the fixed blade 411 during attachment of the moving blade holder 460.

[0433] 29, 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, thereby maintaining the carriage cover 450 in the locked position with high reliability. 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 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 portion of the right end of the handle 469 when the carriage cover 450 is in the locked position. With this configuration, the user can see the handle 469 through the attachment / detachment opening 54, which reduces the likelihood of 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] Furthermore, 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 positioned at the bent portion 468B of each groove 468, the moving blade 412 is spaced forward from the fixed blade 411 along the conveying direction DT1. Then, as shown in FIG. 44 , as the carriage cover 450 swings 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, causing the moving blade 412 to move rearward along the conveying direction DT1 toward the fixed blade 411 and come into contact with the fixed blade 411. After that, 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 that presses the moving blade 412 against the fixed blade 411 as the carriage cover 450 swings 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. Furthermore, when the carriage cover 450 is in the locked position, the biasing force of the second spring 465 prevents the moving blade 412 from separating from the fixed blade 411 during cutting.

[0438] 8 and 23 , the second guide 200 has a handle 260. The handle 260 is integrally molded with the second guide 200. The handle 260 has a plate shape that extends 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 grasping 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 conveying 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 stacked on the discharge tray 9.

[0441] 11 and 21, the image forming apparatus 1 includes a second guide sensor S5. The second guide sensor S5 is a microswitch whose internal contacts are connected and disconnected by the swinging of the detection lever.

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

[0443] As shown in FIG. 21, the second guide sensor S5 detects that the second guide 200 is in the first guide position when the detection lever is pushed down by the second guide 200 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 control operations in response to print commands 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 through 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.

[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 command with cutting for cutting the sheet SH on which the 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. In other words, when the control unit C1 receives the 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 indicated by the two-dot chain line in FIG. 4 to enable the second discharge path PD2, and then forms an image on the sheet SH by the image forming unit 3 and the fixing unit 7, 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. 45 and repeats the process from the beginning.

[0450] If the answer is "Yes" in step S102, the control unit C1 proceeds to step S104, where it determines whether the second guide 200 is at 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 using 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 then discharges the sheet SH 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 answer is "No" in step S104, the control unit C1 proceeds to step S106, does not start the print command with cutting, 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 determination in step S107 becomes "Yes," and the control unit C1 proceeds to step S105. The processing from step S105 onward is as described above.

[0455] If the determination in step S107 is "No," the control unit C1 proceeds to step S108, where it 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 returns "No," the control unit C1 repeats steps S107 and S108. If step S108 returns "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. The control unit C1 then ends the flowchart shown in FIG. 45 and starts again from the beginning.

[0457] 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 nip pressure acts from the first discharge roller 29A to the second discharge roller 29B. However, the first biasing force FG1 of the biasing member 280 can prevent the second guide 200 from moving away from the first guide position toward the second guide position due to this pressing force. As a result, the image forming apparatus 1 can prevent variations in the nip pressure between the first discharge roller 29A and the second discharge roller 29B.

[0458] 22 , in this 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 frictional force acting between the biasing member 280 and the sliding contact surface 273 of the second guide 200 can stop the orientation of the second guide 200 at a position that achieves a desired rotation angle. As a result, the image forming apparatus 1 can suppress rattling of the second guide 200, improving the operability when rotating the second guide 200.

[0459] 21 and 22 , the second guide 200 has a pressed portion 274 on which the first biasing force FG1 acts, and the pressed portion 274 is continuously connected to the sliding surface 273. With this configuration, there is no step between the pressed portion 274 and the sliding surface 273, so 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 in the image forming apparatus 1 includes a torsion coil spring 289 and a spring cover 281. The spring cover 281 has a sliding portion 283 that comes into sliding contact with 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 comes into sliding contact with the sliding surface 273, thereby reducing the contact surface pressure compared to when the torsion coil spring 289, which has a small contact area, comes into direct sliding contact with the sliding surface 273. As a result, the image forming apparatus 1 can suppress wear on the sliding surface 273 and improve durability.

[0461] Furthermore, in this image forming apparatus 1, spring cover 281 has, in addition to sliding contact portion 283, pressing portion 284 that presses pressed portion 274 when biasing member 280 applies first biasing force FG1 to second guide 200. With this configuration, the direction in which biasing member 280 applies first biasing force FG1 can be easily changed from the direction in which biasing member 280 applies second biasing force FG2 to 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 biasing 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 positioned radially outward of the sliding contact surface 273 in the direction of the rotation axis X200 with the sliding contact portion 283 in sliding contact with the sliding contact surface 273. This configuration prevents the torsion coil spring 289 and the spring cover 281 from protruding outward from the second guide 200 in the direction of the rotation axis X200. As a result, the image forming apparatus 1 can be prevented from becoming larger 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 conveyance resistance when the first guide surface 101 and the second guide surface 202 guide the sheet SH.

[0465] 6, 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 a user can more easily reach a jammed sheet SH compared to when only a portion of the second guide surface 202 moves in the direction of the rotation axis X200 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. Furthermore, with this configuration, the user's hand can 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 the discharge tray 9 is full of uncut sheets SH, this does not affect the discharge of the cut sheets SH.

[0468] 12, the second guide 200 has a handle 260 located downstream in the conveying direction DT1 from the nip position (second nip 29N) between the first discharge roller 29A and the second discharge roller 29B and above the nip position (second nip 29N). This configuration allows the user to rotate the second guide 200 by gripping 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 surfaces 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 this image forming apparatus 1, when a print with cutting command is received and the second guide sensor S5 does not detect in step S104 that the second guide 200 is at the first guide position, the control unit C1 proceeds to step S106, does not start the print with cutting command, and causes the operation panel 37 to notify the user 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, which prevents a decrease in user convenience.

[0472] Although the present invention has been described above with reference to the examples, it goes without saying that the present invention is not limited to the above examples and can be modified and applied as appropriate within the scope of the invention.

[0473] (Modification 1) As shown in FIG. 46, in the image forming apparatus of Modification 1, the 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 modified example, as an example, the tip 411T of the fixed blade 411 protrudes upward from the nip tangent line TN1 by about 0.5 mm 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 starts to press against the sheet SH, making it even less likely for the cut surface to become wavy.

[0476] (Variant 2) As shown in Figures 47 and 48, the image forming apparatus of variant 2 has 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 Figure 47 and a second guide position shown in Figure 48.

[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 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 in response to print commands based on the detection result of the second guide sensor S5B. Specifically, the control unit C1 executes the process shown in the flowchart in FIG.

[0483] Other configurations of the modified example 2 are the same as those of the embodiment, so the same components as those of the embodiment will be denoted by the same reference numerals 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 through 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 determination in step S201 is "Yes," 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 from step S207 onwards will be described later.

[0488] If the answer is "No" in step S202, the control unit C1 proceeds to step S203, does not start issuing a 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 unit 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 of step S204 becomes "Yes," and the control unit C1 proceeds to step S207. The processing from step S207 onwards will be described later.

[0491] If the determination in step S204 is "No," the control unit C1 proceeds to step S205, where it 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 step S205 is "No," the control unit C1 repeats steps S204 and S205. If step S205 is "Yes," the control unit C1 determines that the print command cannot be executed, proceeds to step S206, and executes error processing to cancel the print command. Thereafter, 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 cutting-with-print command 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 using 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 then discharges the sheet SH 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 then forms an image on the sheet SH using the image forming unit 3 and the fixing unit 7, and discharges the sheet SH onto the discharge tray 9 using 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 modification, similarly to 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, 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. With this configuration, when the second guide 1200 is in the second guide position, the second guide 1200 opens downward and approaches the discharge tray 9, and the space formed between the first guide 1100 and the second guide 1200 becomes larger. This causes the jammed sheet SH to tend 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 does not 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 the user 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 controller C1 receives a no-cut printing command and the second guide sensor S5B does not detect that the second guide 1200 is in the first guide position, the controller C1 proceeds to step S203, does not initiate the no-cut printing command, and causes the operation panel 37 to notify that the second guide 1200 is not in the first guide position. With this configuration, if the no-cut printing command were initiated, there is a risk that the second guide 1200 in the second guide position or the handle of the second guide 1200 may interfere with the sheet SH being discharged by the second discharge roller pair 28. In this regard, the above configuration makes it possible to prevent the sheet SH from jamming due to interference from the second guide 1200 in the second guide position.

[0500] (Modification 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 modification, the sheet sensor S4 is disposed away from the cutter mechanism 4. Therefore, this image forming apparatus can reduce the movement distance 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 the variation in the movement distance, and can more accurately determine the position at which the cutter mechanism 4 cuts the sheet SH.

[0502] (Variant 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 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, making it easier to remove the jammed sheet SH.

[0504] (Other) In the embodiment, the image forming apparatus of the present invention is embodied as the image forming apparatus 1, which is a multifunction peripheral equipped with an image reading device above, 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 peripheral. 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 using 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 a sheet passing through the conveying guide may be a non-contact sensor such as a light reflective sensor or a light transmissive 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 replaced with 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, which is long in the conveying direction.

[0507] In the embodiment, the first discharge roller pair 29 is an example of the "second conveying 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 second conveying 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 in the conveying direction DT1 from the fixed blade 411 and the movable blade 412 of the cutter mechanism 4, 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 in the conveying direction from the first conveying roller pair and upstream in the conveying direction from the blade of the cutter mechanism.

[0509] In the embodiment, each of the second positioning portions 491 and 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 at 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 at 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 up-down direction by the cutter frame 400, or 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 up-down 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 up and down to sandwich the sheet between the fixed blade and the movable blade and cut the sheet. Also, a sheet may be cut with a single blade.

[0513] [Example 1-1] A discharge tray may be provided to support the sheet discharged by the first discharge roller pair and the sheet discharged by the second discharge roller pair. [Example 1-2] A fixing device located upstream of the first conveying roller pair in the conveying direction and configured to fix 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 device and been cut by the cutter mechanism at a second nip, and a second discharge roller pair that discharges the sheet that has passed through the fixing device and been conveyed without passing through the cutter mechanism, wherein the cutter mechanism is located above the second discharge roller pair, and the conveying guide and the sensor may be located above the second discharge roller pair and downstream in the conveying direction. [Example 1-3] The conveying guide and the sensor may be located downstream of the blade of the cutter mechanism in the conveying direction. [Second Example-1] An image forming unit that forms an image by transferring a toner image onto a sheet transported in a transport direction; a fuser that fuses the toner image onto the sheet that has passed through the image forming unit; a cutter mechanism that cuts the sheet that has passed through the fuser; a first discharge roller pair having a first discharge roller and a second discharge roller that discharges the sheet cut by the cutter mechanism; an output tray that supports the sheet discharged by the first discharge roller pair; a first guide that rotatably supports the first discharge roller and guides the sheet transported from the cutter mechanism to the first discharge roller pair; and a second guide that rotatably supports the second discharge roller and guides the sheet transported from the cutter mechanism to the first discharge roller pair, and the second guide may be movable between a first guide position where the first discharge roller and the second discharge roller are nipped together and a second guide position where the first discharge roller and the second discharge roller are separated from each other.[Second Example-2] The first guide may be fixed to a housing that supports the second guide rotatably about a rotation axis, the first discharge roller may be rotatably supported at the downstream end of the first guide in the conveying direction, the second discharge roller may be rotatably supported at the downstream end of the second guide in the conveying direction, and the rotation axis may be located at the upstream end of the second guide in the conveying direction. [Second Example-3] The second guide may be provided with a biasing member that applies a first biasing force to the second guide in the direction from the second guide position toward the first guide position when the second guide is at the first guide position. [Second Example-4] The second guide may have an arc-shaped sliding surface centered on the rotation axis, and the biasing member may be in sliding contact with the sliding surface when the second guide rotates between the first guide position and the second guide position, and may apply a second biasing force to the second guide in a direction radially inward of the rotation axis. [Example 2-5] The second guide may have a pressed portion on which the first biasing force acts, and the pressed portion and the sliding contact surface may be continuously connected. [Example 2-6] The image forming apparatus of claim 28, wherein the biasing member has a spring and a spring cover covering the spring, and the spring cover has a sliding contact portion that slides against the sliding contact surface when the biasing member applies the second biasing force to the second guide. [Example 2-7] The spring cover may have a pressing portion, separate from the sliding contact portion, that presses the pressed portion when the biasing member applies the first biasing force to the second guide. [Example 2-8] The spring may be a torsion coil spring. [Example 2-9] The spring and the spring cover may be located radially outward of the sliding contact surface with respect to the rotation axis when the sliding contact portion slides against the sliding contact surface. [Example 2-10] The first guide has a first guide surface that guides the sheet, the second guide has a second guide surface that faces the first guide surface and guides the sheet when the second guide is at the first guide position, and the rotation axis may be located between the first guide surface and the second guide surface when the second guide is at the first guide position.[Example 2-11] The upstream side of the second guide surface in the conveying direction may be inclined away from the first guide surface relative to the downstream side of the second guide surface in the conveying direction when the second guide is at the first guide position, such that the upstream end of the second guide is more distant from the first guide surface. [Example 2-12] The first guide surface may be formed by tips of multiple ribs formed on the first guide, and the second guide surface may be formed by tips of multiple ribs formed on the second guide. [Example 2-13] The entire second guide surface may move when the second guide rotates between the first guide position and the second guide position. [Example 2-14] A second discharge roller pair may be provided that discharges a sheet that passes through the fixing unit and is conveyed without passing through the cutter mechanism onto the discharge tray, and the movement distance of the sheet from a fixing nip portion that nips the sheet in the fixing unit to the second discharge roller pair may be shorter than the movement distance of the sheet from the fixing nip portion to the first discharge roller pair. [Example 2-15] The second pair of discharge rollers may be located above the upstream end of the discharge tray in the transport direction, and the first pair of discharge rollers may be located downstream of the second pair of discharge rollers in the transport direction. [Example 2-16] An image reading unit may be located above the discharge tray and spaced apart from the discharge tray to read an image of a document, and the first pair of discharge rollers may be located below the image reading unit and above the second pair of discharge rollers. [Example 2-17] The second guide may have a handle located downstream of a nip position between the first and second discharge rollers in the transport direction and above the nip position. [Example 2-18] The handle may be plate-shaped extending from the second guide in the transport direction, and the downstream end of the handle in the transport direction may be located above the sheets discharged by the first pair of discharge rollers when the second guide is at the first guide position and above the top surface of the maximum number of sheets that can be stacked on the discharge tray.[Second Example-19] The position of the second discharge roller when the second guide is in the second guide position may be farther from the discharge tray than the position of the second discharge roller when the second guide is in the first guide position. [Second Example-20] An image forming apparatus includes: a second guide sensor that detects whether the second guide is in the first guide position; a control unit that controls the image forming apparatus; and a notification unit that issues a notification, wherein when a cutting printing command is received in which a sheet on which an image is formed is cut by the cutter mechanism, and the second guide sensor does not detect that the second guide is in the first guide position, the control unit may not initiate the cutting printing command and may cause the notification unit to notify that the second guide is not in the first guide position. [Second Example-21] When a non-cutting printing command is received in which a sheet on which an image is formed is not cut by the cutter mechanism, the control unit may initiate the non-cutting printing command regardless of the detection result of the second guide. [Second Example-22] The position of the second discharge roller when the second guide is in the second guide position may be closer to the discharge tray than the position of the second discharge roller when the second guide is in the first guide position. [Second Example-23] An image forming apparatus including: a second guide sensor that detects whether the second guide is in the first guide position; a control unit that controls the image forming apparatus; and a notification unit that issues a notification; wherein, when a cutting printing command is received in which a sheet on which an image is formed is cut by the cutter mechanism, and the second guide sensor does not detect that the second guide is in the first guide position, the control unit may not initiate the cutting printing command and cause the notification unit to notify that the second guide is not in the first guide position. [Second Example-24] When a non-cutting printing command is received in which a sheet on which an image is formed is not cut by the cutter mechanism, and the second guide sensor does not detect that the second guide is in the first guide position, the control unit may not initiate the non-cutting printing command and cause the notification unit to notify that the second guide is not in the first guide position.[Second Example-25] The distance the sheet moves from the fixing nip portion that nips the sheet in the fixing unit to the cutter mechanism may be longer than half the maximum length of the sheet that the image forming apparatus can accommodate. [Third Example-1] An image forming unit that transfers a toner image to a sheet transported in a transport direction to form an image, a fixing unit that fixes the toner image to the sheet that has passed through the image forming unit, a cutter mechanism having a movable blade that cuts the sheet that has passed through the fixer and a cutter frame that movably holds the movable blade, a sheet guide that is located upstream or downstream of the cutter mechanism in the transport direction and guides the sheet that passes through the cutter mechanism, and a sheet sensor that is located on the sheet guide and detects the sheet that passes through the cutter mechanism, wherein the sheet guide may be positioned on the cutter frame. [Third Example-2] The sheet guide may have a first positioning portion, and the cutter frame may have a second positioning portion, and the sheet guide may be positioned on the cutter frame by engaging the first positioning portion with the second positioning portion. [Example 3-3] The cutter frame may have a plurality of second positioning portions and a cutter frame opening through which a sheet passes, wherein one of the second positioning portions is located at one end of the cutter frame opening in the longitudinal direction, and another of the second positioning portions is located at the other end of the cutter frame opening in the longitudinal direction, and the sheet guide may have a plurality of first positioning portions that fit one-to-one with the second positioning portions. [Example 3-4] Each of the second positioning portions may be a recess or a through hole, and each of the first positioning portions may be a protrusion. [Example 3-5] The sheet guide may be a first guide provided downstream of the cutter mechanism in the conveying direction. [Example 3-6] The sheet guide may include a pre-cutting guide that is provided upstream of the cutter mechanism in the conveying direction and guides a sheet passing through the cutter mechanism, and the pre-cutting guide may have a third positioning portion, and the first positioning portion may be fitted into the third positioning portion, thereby positioning the pre-cutting guide with respect to the first guide and the cutter frame.[Example 3-7] The cutter frame may extend in a direction perpendicular to the conveying direction when assembled to the image forming apparatus, and the first positioning portion may protrude toward the upstream side in the conveying direction, penetrate the second positioning portion, and engage with the third positioning portion. [Example 3-8] The first guide and the pre-cutting guide may be fastened together with the cutter frame sandwiched therebetween. [Example 3-9] The first guide, the cutter frame, and the pre-cutting guide may be assembled to and removed from the image forming apparatus while fastened to each other. [Example 3-10] A first pair of discharge rollers may be located downstream of the cutter mechanism in the conveying direction and discharge a sheet that has passed through the cutter mechanism, and the sheet sensor may be located between the cutter frame and the first pair of discharge rollers in the conveying direction. [Example 3-11] The distance between the sheet sensor and the cutter mechanism in the conveying direction may be shorter than the distance between the sheet sensor and the first pair of discharge rollers in the conveying direction. [Third Example-12] The distance between the sheet sensor and the cutter mechanism in the transport direction may be longer than the distance between the sheet sensor and the first discharge roller pair in the transport direction.[Example 4-1] An image forming unit that forms an image by transferring a toner image onto a sheet transported in a transport direction, a fuser that fuses the toner image onto the sheet that has passed through the image forming unit, a cutter mechanism having a blade that cuts the sheet that has passed the fuser in a cutting direction perpendicular to the transport direction and a cutter frame that holds the blade, a first transport roller whose rotation axis extends parallel to the cutting direction, the first transport roller being located upstream of the cutter mechanism in the transport direction and transporting the sheet that has passed the fuser toward the cutter mechanism, and an upstream cover that is movable between a first position that covers the upstream side of the cutter mechanism in the transport direction and guides the sheet toward the cutter mechanism, and a second position that is separated from the cutter mechanism and cannot guide the sheet toward the cutter mechanism, and supports the first transport roller, wherein the upstream cover in the first position is positioned at least in the transport direction by the cutter frame. [Example 4-2] The blade may be a fixed blade fixed to the cutter frame and extending in the cutting direction. [Example 4-3] The blade may be guided in the cutting direction by the cutter frame and may have a movable blade that moves while sliding against the fixed blade. [Example 4-4] A second conveyance roller facing the first conveyance roller may be provided, and the cover may support the second conveyance roller. [Example 4-5] A second conveyance roller facing the first conveyance roller, and an upstream guide that is provided downstream in the conveyance direction of the upstream cover at the first position and upstream in the conveyance direction of the cutter mechanism, and that guides a sheet passing through the cutter mechanism, the upstream guide being fixed to the cutter frame, and the upstream guide may support the second conveyance roller.[Example 4-6] An upstream guide may be provided downstream in the conveying direction of the upstream cover at the first position and upstream in the conveying direction of the cutter mechanism, the upstream guide guiding a sheet passing through the cutter mechanism, the upstream guide being fixed to the cutter frame, the upstream cover at the first position being indirectly positioned to the cutter frame by abutting against the upstream guide. [Example 4-7] A first housing accommodating the image forming unit and the fixing unit, the upstream cover having a contact piece capable of abutting against the first housing and a biasing spring that biases the contact piece, the first housing having a contact surface that is abutted by the contact piece biased by the biasing spring to apply a pressing force to the upstream cover to press the upstream cover toward the first position. [Example 4-8] The printer may include a second conveyor roller facing the first conveyor roller, wherein the first conveyor roller and the second conveyor roller each have a roller portion formed with a cylindrical surface longer than the sheet in the cutting direction, and the cutter mechanism may cut the sheet held between the roller portions of the first conveyor roller and the second conveyor roller. [Example 4-9] The printer may include a first housing that houses the image forming unit and the fixing unit, wherein the first housing may have a maintenance opening that exposes the upstream cover to the outside of the first housing and an exterior cover that opens and closes the maintenance opening. [Example 4-10] The printer may include a first housing that houses the image forming unit and the fixing unit, wherein the first housing may have a protruding wall that covers the top of the cover in the first position. [Example 4-11] The cover may be located at the lower end of the cover and may be moved between the first position and the second position by rotating about a cover axis parallel to the cutting direction. [Example 4-12] A first pair of discharge rollers that discharges a sheet cut by the cutter mechanism, and a second pair of discharge rollers that discharges a sheet that passes through the fixing device and is transported without passing through the cutter mechanism, wherein the distance the sheet moves from a fixing nip portion that nips the sheet in the fixing device to the second pair of discharge rollers may be shorter than the distance the sheet moves from the fixing nip portion to the first pair of discharge rollers.[4th Example-13] The moving distance of the sheet from the fixing nip portion in the fixing unit that nips the sheet to the cutter mechanism may be longer than half the maximum length of the sheet that the image forming apparatus can accommodate. [Example 4-14] An image forming apparatus comprising: a first pair of discharge rollers that discharges a sheet cut by the cutter mechanism; a second pair of discharge rollers that discharges a sheet that passes through the fuser unit and is transported without passing through the cutter mechanism; and a first housing that houses the image forming unit and the fuser unit, wherein the first housing has a maintenance opening that exposes the upstream cover to the outside of the first housing and an exterior cover that opens and closes the maintenance opening, and when the exterior cover closes the maintenance opening, an upstream transport path is formed that is located upstream in the transport direction from a transport path formed by the upstream cover at the first position, and that can guide a sheet from the fuser unit toward the second pair of discharge rollers, and when the upstream cover is at the first position and the exterior cover opens the maintenance opening, the upstream transport path is opened, and the upstream side of the cutter mechanism in the transport direction may remain blocked. [Example 4-15] The exterior cover may be capable of placing a sheet that has passed through the fixing unit when the maintenance opening is open, and the upstream cover may have a rib that guides the sheet that has passed through the fixing unit toward the exterior cover when the upstream cover is in the second position. [Example 4-16] The upstream cover may abut against the upstream guide on the outer side of the sheet in the cutting direction.[Example 5-1] An image forming unit that forms an image by transferring a toner image onto a sheet transported in a transport direction; a fixing unit that fixes the toner image to the sheet that has passed through the image forming unit; a first housing that accommodates the image forming unit and the fixing unit; a cutter mechanism that cuts the sheet that has passed through the fixing unit in a cutting direction perpendicular to the transport direction, the cutter mechanism being located in a standby position away from the sheet on one side in the cutting direction until the sheet reaches a cutting position, and having a movable blade that moves in the cutting direction through a cutting area in which the sheet is present when the sheet reaches the cutting position and stops; an image reading unit that has a reading sensor that reads an image of a document; a second housing that accommodates the image reading unit; and a joint cover that supports the second housing from below above the first housing, the joint cover having a recessed portion that is located on the one side in the cutting direction relative to the cutting area so as to accommodate the movable blade that is at the standby position. [Fifth Example-2] A sheet cut by the cutter mechanism may be discharged into a discharge space between the first housing and the second housing by a first discharge roller pair, the cutter mechanism having a cutter carriage that holds the movable blade and a cutter frame that guides the cutter carriage in the cutting direction, the joint cover having an inner wall surface that defines one side of the discharge space in the cutting direction, the recessed portion being recessed from the inner wall surface toward the one side in the cutting direction to accommodate the movable blade together with the cutter carriage, and the end of the cutter carriage on the cutting area side when the movable blade is in the standby position may be located above the cutting area as viewed along the conveying direction and protrude further toward the cutting area than the inner wall surface. [Fifth Example-3] The cutter mechanism may have a cutter carriage that holds the movable blade, and the cutter carriage may be detachable from the movable blade when the movable blade is in the standby position. [5th ​​Example-4] The cutter mechanism may have a cutter carriage that detachably holds the moving blade, and the joint cover may have an attachment / detachment opening for attaching and detaching the moving blade in the standby position to and from the cutter carriage.[Fifth Example-5] The joint cover may have: an ejection tray that supports sheets that are cut by the cutter mechanism and ejected; a first support portion that is located on one side of the cutting direction relative to the ejection tray and downstream of the moving blade in the conveying direction and supports a portion of the second housing from below; a second support portion that is located on one side of the cutting direction relative to the ejection tray and upstream of the moving blade in the conveying direction and supports another portion of the second housing from below; and a connecting wall that connects the first support portion and the second support portion, the connecting wall being located further back from the cutting area toward one side of the cutting direction than the first support portion and the second support portion so as to accommodate the moving blade; and the recess may be defined by the first support portion, the second support portion, and the connecting wall. [Fifth Example-6] The cutter mechanism may have a cutter carriage that detachably holds the moving blade, and the connecting wall may have an attachment / detachment opening for attaching and detaching the moving blade to and from the cutter carriage in the standby position. [5th ​​Example-7] The cutter mechanism includes a cutter carriage that holds the moving blade, a timing belt connected to the cutter carriage, a drive pulley and a driven pulley around which the timing belt is wound, a first motor that drives the drive pulley, and a cutter frame that has a guide portion that guides the cutter carriage in the cutting direction and in which a cutter frame opening is formed, the cutting area is an area surrounded by the inner periphery of the cutter frame opening, and when the moving blade is in the standby position, a part of the cutter carriage may be located above the cutter frame opening when viewed along the conveying direction and may overlap with the cutter frame opening in the cutting direction. [5th Example-8] The first motor may be located above the cutter frame opening when viewed along the conveying direction and may overlap with the cutter frame opening in the cutting direction.[Example 5-9] The image forming apparatus may include a control board for controlling the operation of the image forming apparatus, wherein the attachment / detachment opening is located on a first edge side, which is one edge of the image forming apparatus in the cutting direction, and the control board may be located on a second edge side, which is the other edge of the image forming apparatus in the cutting direction. [Example 5-10] The image forming apparatus may include a communication board for communicating with the outside, wherein the communication board is located on the second edge side and connected to the control board. [Example 5-11] The image forming apparatus according to claim 77 includes: a first discharge roller pair that discharges the sheet cut by the cutter mechanism into a discharge space between the first housing and the second housing; and a second motor that drives the first discharge roller pair, wherein at least a portion of the second motor overlaps the joint cover when viewed along the cutting direction. [Example 5-12] The cutter mechanism may include a first motor for moving the moving blade, and at least a portion of the first motor may overlap the joint cover when viewed along the cutting direction. [Example 5-13] A sheet cutting device may include a first discharge roller pair that discharges the sheet cut by the cutter mechanism into a discharge space between the first housing and the second housing, and a second motor that drives the first discharge roller pair, wherein the cutter mechanism has a first motor for moving the movable blade, and the attachment / detachment opening is located on a first edge side that is one edge in the cutting direction of the image forming device, and the first motor and the second motor are located on a second edge side that is the other edge in the cutting direction of the image forming device. [Example 5-14] At the first edge side that is one edge in the cutting direction of the image forming device, a first length by which the second housing protrudes from the first housing in one direction in the cutting direction is zero or more, and at the second edge side that is the other edge in the cutting direction of the image forming device, a second length by which the second housing protrudes from the first housing in the other direction in the cutting direction is greater than the first length, and the attachment / detachment opening may be located on the first edge side.[Example 5-15] The first housing may have an exhaust port that connects the inside and outside of the first housing, and an exhaust fan that exhausts air from inside the first housing via the exhaust port, and the attachment / detachment opening and the exhaust port may be located on a first edge side that is one of the edges in the cutting direction of the image forming device. [Example 5-16] The first housing may have a speaker that emits sound, and the attachment / detachment opening may be located on a first edge side that is one of the edges in the cutting direction of the image forming device, and the speaker may be located on a second edge side that is the other edge of the image forming device in the cutting direction. [Example 5-17] The second housing may be an automatic document feeder having an insertion port for inserting a document to be read, the automatic document feeder transporting the document inserted in the insertion port to a position where it can be read by the reading sensor, the attachment / detachment opening may be located on a first edge side that is one edge in the cutting direction of the image forming device, and the insertion port may open in a direction facing the first edge side. [Example 5-18] The image forming apparatus may include a first discharge roller pair that discharges a sheet cut by the cutter mechanism, and a second discharge roller pair that discharges a sheet that passes through the fuser and is transported without passing through the cutter mechanism, and the distance the sheet moves from a fixing nip portion that nips the sheet in the fuser to the second discharge roller pair may be shorter than the distance the sheet moves from the fixing nip portion to the first discharge roller pair. [Fifth Example-19] The moving distance of the sheet from the fixing nip portion in the fixing unit that nips the sheet to the cutter mechanism may be longer than half the maximum length of the sheet that the image forming apparatus can accommodate.

[0514] 1...Image forming apparatus DT1...Conveying direction SH...Sheet 3...Image forming unit DC1...Cutting direction 411, 412...Blade (411...Fixed blade, 412...Moving blade) 4...Cutter mechanism 70N...First nip 70...First pair of conveying rollers 100, 200...Conveying guides (100...First guide, 200...Second guide) 101...First guide surface 202...Second guide surface S4...Sensor (sheet sensor) AS1...Detection area TN1...Nip tangent LG1...Gap between the first guide surface and the second guide surface S4A...Actuator 29N...Second nip 29...Second pair of conveying rollers (First discharge roller pair) 7...Fuser 29...First pair of discharge rollers 29A...First discharge roller 29B...Second discharge roller X200...Pivoting axis 200U...Upstream end of second guide in the conveying direction 202U...Upstream side of second guide surface in the conveying direction 202D...Downstream side of second guide surface in the conveying direction 9...Discharge tray 420...Cutter carriage 101Q...Overlapping portion of first guide surface PD1...First discharge path PD2...Second discharge path 26...Flapper 300...Upstream guide (pre-cutting guide) 302...First upstream guide surface 301...Second upstream guide surface LN1...Distance between nip tangent and first upstream guide surface LN2...Distance between nip tangent and second upstream guide surface 411T...Tip of fixed blade 28...Second discharge roller pair 7N...Fusing nip portion LR2...Movement distance of sheet from fixing nip portion to second discharge roller pair LR1...Movement distance of sheet from fixing nip portion to first discharge roller pair LC1...Movement distance of sheet from fixing nip portion to cutter mechanism LS1: Maximum length of sheets supported by the image forming apparatus 10, 30, 50: Housing (10: First housing, 30: Second housing, 50: Joint cover) 10C: Sheet cassette 10G: Housing opening (front opening) 3P: Process cartridge 10F: Cover (front cover)

Claims

1. An image forming apparatus comprising: an image forming unit that forms an image on a sheet transported in a transport direction; a cutter mechanism having a blade that cuts the sheet on which the image has been formed in a cutting direction perpendicular to the transport direction; a first pair of transport rollers that are located upstream of the blade of the cutter mechanism in the transport direction and nip the sheet on which the image has been formed with a first nip and transport it toward the blade; a transport guide that is located downstream of the first pair of transport rollers in the transport direction and guides the sheet, the transport 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; and a sensor that detects a sheet passing through the transport guide, the sensor having a detection area where the sensor detects the sheet between the first guide surface and the second guide surface when viewed along the cutting direction and is located on a nip tangent to the first nip.

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

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

5. An image forming apparatus as described in any one of claims 1 to 4, further comprising a second pair of conveying rollers located downstream of the blade of the cutter mechanism in the conveying direction and nipping and conveying the sheet on which an image has been formed with a second nip, the cutter mechanism cuts the sheet that has been nipped and stopped between the first nip and the second nip, and the second nip is also located on the tangent to the nip when viewed along the cutting direction.

6. An image forming apparatus as described in claim 5, further comprising a fixing device located upstream of the first conveying roller pair in the conveying direction for fixing the image onto the sheet that has passed through the image forming section, wherein the conveying direction of the sheet from the fixing device to the first nip changes by 90° or more, and the nip tangent line extends horizontally.

7. An image forming apparatus as described in any one of claims 1 to 4, further comprising a first pair of discharge rollers which nip the sheet cut by the cutter mechanism with a second nip and discharge the sheet, the transport guide and the sensor being located downstream of the blade of the cutter mechanism in the transport direction, the first pair of discharge rollers having the first discharge roller and a second discharge roller which form the second nip, the transport guide having a first guide which rotatably supports the first discharge roller and has the first guide surface, and a second guide which rotatably supports the second discharge roller and has the second guide surface, the first guide holds the sensor, and the second guide is movable between a first guide position where the first discharge roller and the second discharge roller are in a nip state, and a second guide position where the first discharge roller and the second discharge roller are in a separated state.

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

9. An image forming apparatus as described in claim 8, further comprising an ejection tray for supporting a sheet ejected by the first ejection roller pair, wherein the position of the second ejection roller when the second guide is in the second guide position is farther away from the ejection tray than the position of the second ejection roller when the second guide is in the first guide position.

10. An image forming apparatus as described in any one of claims 1 to 4, wherein the transport guide and the sensor are located downstream of the blade of the cutter mechanism in the transport direction, the blade has a fixed blade extending in the cutting direction and a movable blade that moves while sliding against the fixed blade, the cutter mechanism has a cutter carriage that holds the movable blade and moves in the cutting direction, the fixed blade abuts the sheet from below, and the movable blade abuts the sheet from above, the first guide surface is located below the cutter carriage and has an overlapping portion that partially overlaps with the moving blade in the transport direction, and the second guide surface is located downstream of the cutter carriage in the transport direction.

11. An image forming apparatus as claimed in any one of claims 1 to 4, comprising: a fixing unit located upstream of the first pair of conveying rollers in the conveying direction, fixing the image onto the sheet that has passed through the image forming section; a first discharge path in which the cutter mechanism is located and which discharges the sheet that has passed through the fixing unit; a second discharge path in which the cutter mechanism is not located and which discharges the sheet that has passed through the fixing unit; and a flapper that can be moved between a first flapper position which guides the sheet to the first discharge path while blocking the second discharge path, and a second flapper position which blocks the first discharge path while guiding the sheet to the second discharge path.

12. An image forming apparatus as described in any one of claims 1 to 4, further comprising an upstream guide located downstream of the first pair of conveying rollers in the conveying direction and upstream of the blade of the cutter mechanism in the conveying direction, guiding a sheet between the first pair of conveying rollers and the blade of the cutter mechanism, wherein 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 the 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 sliding against the fixed blade, the fixed blade abuts against the sheet from the first upstream guide surface side, and the movable blade abuts against the sheet from the second upstream guide surface side, and when viewed along the cutting direction, the distance between the nip tangent and the first upstream guide surface is smaller than the distance between the nip tangent and the second upstream guide surface.

13. The image forming apparatus according to claim 12, wherein, as viewed along the cutting direction, the 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. The image forming apparatus according to claim 13, wherein said first upstream guide surface is an upward facing surface, and said second upstream guide surface is a downward facing surface.

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

16. An image forming apparatus as described in any one of claims 1 to 4, comprising: a fixing unit located upstream of the first conveying roller pair in the conveying direction, fixing the image onto 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; and a second discharge roller pair that discharges the sheet that has passed through the fixing unit and is conveyed without passing through the cutter mechanism, wherein the distance the sheet moves from a fixing nip portion that nips the sheet in the fixing unit to the second discharge roller pair is shorter than the distance the sheet moves from the fixing nip portion to the first discharge roller pair.

17. An image forming apparatus as claimed in any one of claims 1 to 4, further comprising a fixing device located upstream of the first pair of conveying rollers in the conveying direction and fixing the image onto the sheet that has passed through the image forming section, wherein the travel distance of the sheet from the fixing nip portion that nips the sheet in the fixing device to the cutter mechanism is longer than half the maximum length of the sheet that the image forming apparatus can accommodate.

18. An image forming device as claimed in any one of claims 1 to 4, comprising: a fixing unit located upstream of the first pair of conveying rollers in the conveying direction, fixing the image onto the sheet that has passed through the image forming unit; a first pair of discharge rollers that nips and discharges the sheet that has passed through the fixing unit and been cut by the cutter mechanism with a second nip; and a second pair of discharge rollers that discharges the sheet that has passed through the fixing unit and is conveyed without passing through the cutter mechanism, wherein the first pair of discharge rollers and the second pair of discharge rollers have the same direction in which the sheet is discharged.

19. An image forming device as described in claim 18, comprising: a housing; and a sheet cassette supporting a sheet on which an image is to be formed, the sheet cassette being removable from the housing, wherein the direction in which the sheet cassette is removed from the housing is the same as the direction in which the first pair of discharge rollers and the second pair of discharge rollers discharge the sheet.

20. An image forming apparatus as described in claim 18, comprising: a housing having an opening; a process cartridge constituting at least a part of the image forming unit, the process cartridge being capable of being pulled out of the housing via the opening; and a cover capable of opening and closing the opening, wherein the direction in which the process cartridge is pulled out of the housing is the same as the direction in which the first pair of discharge rollers and the second pair of discharge rollers discharge sheets.

Images