Image forming apparatus

Abstract

Provided is an image forming apparatus capable of suppressing movement of a fuser from an attachment position where the fuser is attached to a main body case. An image forming apparatus (1) includes a main body case (10) and a fuser (80) having a heating roller (81) and a pressure roller (82). The fuser is attachable to the main body case from one side toward the other side in the first direction. The main body case has a first recess (320A) having a shape recessed toward one side in a second direction intersecting the first direction. The fixing device has a first protrusion (120A) extending in a third direction orthogonal to both the first direction and the second direction, the first protrusion being located in the first recess in a state where the fixing device is attached to the main body housing. The image forming apparatus further includes a first spring (SP1) that presses the first protrusion located in the first recess toward one side in the first direction and one side in the second direction in a state where the fixing device is attached to the main body housing.

Description

Technical Field

[0001] The present invention relates to an image forming device. Background Art

[0002] Conventionally, there is known an image forming apparatus including a main body housing and a fuser that can be attached to and detached from the main body housing (Patent Document 1). In this technology, the image forming apparatus includes a support groove that supports a support shaft of the fuser and extends in the front-rear direction, and a wire spring that applies force to the support shaft downward and causes the support shaft to abut against the lower edge of the support groove.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2021-107852

[0006] Technical problem to be solved by the invention

[0007] However, in the conventional structure, there is a possibility that the fixing device may move forward and backward from the mounting position on the main body casing. Summary of the invention

[0008] Therefore, it is desired to suppress the fixing device from moving from the attachment position to the main body casing.

[0009] Technical means for solving technical problems

[0010] The image forming apparatus includes a main body casing and a fixing device.

[0011] The fixing device has a heating rotating body and a pressing rotating body, and can be mounted relative to the main body housing from one side toward the other side in a first direction.

[0012] The main body case has a first recessed portion having a shape recessed toward one side of a second direction intersecting the first direction.

[0013] The fixing device has a first protrusion extending in a third direction orthogonal to both the first direction and the second direction. When the fixing device is mounted on the main body housing, the first protrusion is located in the first recess.

[0014] The image forming apparatus further includes a spring that presses the first protrusion located in the first recess toward one side in the first direction and toward one side in the second direction when the fixing device is attached to the main body casing.

[0015] By providing a spring that presses the first protrusion located in the first recess toward one side in the first direction and one side in the second direction when the fixing device is attached to the main body casing, the fixing device can be prevented from moving from the attachment position to the main body casing.

[0016] The following structure may be adopted: the distance between the surface of the first recess on one side in the first direction and the surface on the other side in the first direction is larger than the size of the first protrusion in the direction orthogonal to the second direction.

[0017] In this case, the first protrusion can be configured not to contact the surface of the first recessed portion on the other side in the first direction in a state pressed by the spring.

[0018] The first protrusion does not contact the surface of the first recessed portion on the other side of the first direction when pressed by the spring, and is therefore less likely to be affected by the dimensional accuracy of the first recessed portion. Thus, the fixing device can be positioned with high accuracy relative to the main body housing.

[0019] The first projection may be configured such that, in a state pressed by a spring, the first projection contacts a surface of the first recessed portion on one side in the first direction and a surface of the first recessed portion on one side in the second direction.

[0020] The first protrusion contacts the first concave portion's surface on one side in the first direction and the first concave portion's surface on one side in the second direction while being pressed by the spring, thereby enabling the first protrusion to contact both surfaces for positioning. Thus, the fixing device can be positioned with high accuracy relative to the main body housing.

[0021] As an example, the spring is a torsion coil spring.

[0022] The spring is a torsion coil spring, whereby the pressing force and the stroke can be set well.

[0023] The main body casing may have a guide surface, and when the fixing device is mounted on the main body casing, the guide surface guides the first protrusion toward the first recessed portion.

[0024] In this case, the guide surface can be a structure having a first guide surface and a second guide surface.

[0025] The first guide surface extends along a first direction.

[0026] The second guide surface is located between the first guide surface and the first recessed portion, and is inclined so as to be located on the other side in the second direction as it moves from the one side in the first direction toward the other side.

[0027] The second guide surface located between the first guide surface and the first recess is inclined so as to be located on the other side of the second direction as it moves from one side of the first direction toward the other side, thereby making the positions of the first guide surface and the first recess in the second direction substantially the same. Thus, the posture of the fuser when the first protrusion is guided by the first guide surface can be substantially the same as the posture of the fuser after the first protrusion enters the first recess when installed.

[0028] The main body case may include a metal plate including a first portion perpendicular to the third direction, and the first recessed portion may be formed in the first portion.

[0029] The first recessed portion is formed in the metal plate, thereby enabling the fixing device to be positioned relative to the metal plate having high rigidity.

[0030] The fixing device may have a side plate that supports at least one of the heating rotator and the pressurizing rotator and is located on one side of the heating rotator and the pressurizing rotator in the third direction.

[0031] In this case, the following structure may be adopted: the first protrusion is fixed to the side plate by riveting, the metal plate is located on one side of the side plate in the third direction, and the spring presses the first protrusion on one side of the metal plate in the third direction.

[0032] The metal plate is located on one side in the third direction of the side plate to which the first protrusion is fixed by riveting, and the spring presses the first protrusion on one side in the third direction of the metal plate, thereby reducing the load applied to the riveted portion of the first protrusion.

[0033] The following structure may be adopted: the first protrusion is located on the other side in the first direction than the sandwiched position between the heating rotating body and the pressurizing rotating body.

[0034] The first protrusion is located on the other side of the sandwiched position between the heating rotator and the pressurizing rotator in the first direction, thereby enabling the fixing device to be positioned relative to the main body housing with reference to the back side in the fixing device installation direction.

[0035] The fixing device may have a second protrusion, and the main body housing may have a second recess.

[0036] The second protrusion extends along the third direction, and the second protrusion is located on one side of the first direction compared to the clamping position.

[0037] The second recessed portion is recessed toward the other side in the first direction, and the second protrusion enters therein when the fixing device is mounted on the main body housing.

[0038] The fixing device has the second protrusion, and the main body housing has the second recess, whereby the rotation of the fixing device around the first protrusion can be restricted.

[0039] The fixing device may have a protruding portion, and the main body casing may have a hole.

[0040] The protrusion protrudes toward the other side in the first direction.

[0041] The hole allows the protrusion to enter in a state where the fuser is mounted on the main body casing, and the hole restricts movement of the protrusion in the third direction.

[0042] The fixing device has a protrusion, and the main body housing has a hole for restricting movement of the protrusion in the third direction, thereby restricting movement of the fixing device in the third direction. Thus, the fixing device is positioned in the third direction.

[0043] The following structure may be adopted: a dimension of the hole in the second direction is larger than a dimension of the protrusion in the second direction.

[0044] The dimension of the hole in the second direction is larger than the dimension of the protrusion in the second direction, thereby preventing the protrusion from interfering with the main body casing even if the fixer moves in the second direction when the fixer is attached to the main body casing.

[0045] Effects of the Invention

[0046] The fixing device can be prevented from moving from the mounting position on the main body casing. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a cross-sectional view showing the image forming apparatus according to the embodiment.

[0048] Figure 2 This is a perspective view of the fixing device and the main body casing with the rear cover opened, as viewed from one side in the third direction.

[0049] Figure 3 This is a perspective view of the fuser viewed from the other side of the third direction.

[0050] Figure 4 (a) is a diagram showing a guide surface on one side of the main body housing, a first recessed portion, a second recessed portion, a first spring, and a fixing device, Figure 4 (b) is an enlarged view near the first protrusion.

[0051] Figure 5 The figure shows the side plate and boss of the fixing unit, the metal plate of the main body casing, and the spring.

[0052] Figure 6 It is a three-dimensional view showing the first protrusion and the first side plate.

[0053] Figure 7 1 is a diagram showing a force received by the first protrusion from the first spring and a force received by the first input gear of the fixing device from the first driving gear of the main body casing.

[0054] Figure 8 1 is a diagram showing one side of the third direction when the fixing unit is installed in the main body housing. Figure 8 (a) is a diagram showing a state where the first protrusion is guided by the first guide surface, Figure 8 (b) is a diagram showing a state where the first protrusion reaches the second guide surface.

[0055] Fig. 9 1 is a diagram showing one side of the third direction when the fixing unit is installed in the main body housing. Fig. 9 (a) is a diagram showing a state where the first protrusion is detached from one side guide surface, Fig. 9 (b) is a diagram showing a state where the first protrusion enters the first recess.

[0056] Fig.10 2 is a diagram showing the other side of the third direction when the fixing unit is installed in the main body housing. Fig.10 (a) is a diagram showing a state before the unit connector is connected to the main body connector. Fig.10 (b) is a diagram showing a state where the third protrusion reaches the second guide surface.

[0057] Fig.11 2 is a diagram showing the other side of the third direction when the fixing unit is installed in the main body housing. Fig.11 (a) is a diagram showing a state where the third protrusion is detached from the other side guide surface, Fig.11 (b) is a diagram showing a state where the third protrusion enters the third recess.

[0058] Explanation of symbols

[0059] 1 Image forming device

[0060] 10Main body shell

[0061] 80 Fuser

[0062] 81 Heating roller

[0063] 82 pressure roller

[0064] 120A First protrusion

[0065] 320A first recess

[0066] 321 First reference plane

[0067] 322 Second reference plane

[0068] SP1 first spring. DETAILED DESCRIPTION

[0069] Next, an embodiment will be described.

[0070] like Figure 1 As shown, the image forming apparatus 1 includes a main body casing 10 , a sheet feeding portion 20 , an image forming portion 30 , and a sheet discharging portion 90 .

[0071] The main body housing 10 includes a front cover 11 , a discharge tray 12 , and a rear cover 13 . The front cover 11 opens and closes an opening on the front side of the main body housing 10 . The rear cover 13 opens and closes an opening on the rear side of the main body housing 10 .

[0072] The sheet supply unit 20 includes a sheet tray 21 and a supply mechanism 22 . The sheet tray 21 stores sheets S such as paper. The supply mechanism 22 supplies the sheets S in the sheet tray 21 to the image forming unit 30 .

[0073] The image forming section 30 includes an exposure device 40 , a process unit PU, a transfer unit 70 , and a fixing device 80 .

[0074] The exposure device 40 is located above the process unit PU. The exposure device 40 emits a light beam to expose the surface of the photosensitive drum 51.

[0075] The process unit PU is located between the sheet tray 21 and the exposure device 40. The process unit PU is attachable to and detachable from the main body casing 10 through an opening of the main body casing 10 opened by opening the front cover 11. The process unit PU includes a drum cartridge 50 and a plurality of toner cartridges 60.

[0076] The drum cartridge 50 includes a plurality of photosensitive drums 51 , a plurality of chargers 52 corresponding to the plurality of photosensitive drums 51 , and a drum frame 53 .

[0077] The drum frame 53 supports the photosensitive drum 51 and the charger 52. The drum frame 53 is supported so as to be movable in the main body casing 10. The toner cartridge 60 is attachable to and detachable from the drum frame 53.

[0078] The plurality of toner boxes 60 contain toners of different colors and include a developing roller 61 , a supply roller 62 , a layer thickness regulating blade 63 , a toner containing portion 64 for containing toner, and an agitator 65 .

[0079] The agitator 65 agitates the toner in the toner storage section 64. The agitator 65 supplies the toner to the supply roller 62. The supply roller 62 supplies the toner to the developing roller 61. The layer thickness regulating blade 63 regulates the toner on the developing roller 61 to a certain thickness.

[0080] The transfer unit 70 is located between the sheet tray 21 and the processing unit PU. The transfer unit 70 includes a driving roller 71, a driven roller 72, a conveyor belt 73, and a plurality of transfer rollers 74. The conveyor belt 73 is an endless belt for conveying the sheet S. The driving roller 71 and the driven roller 72 rotate the conveyor belt 73. The transfer roller 74 is located inside the conveyor belt 73. The conveyor belt 73 is sandwiched between the transfer roller 74 and the photosensitive drum 51.

[0081] The fixing device 80 includes a heating roller 81 as a heating rotating body and a pressure roller 82 as a pressure rotating body. The heating roller 81 heats the sheet S. Two heaters 81A are arranged in the heating roller 81. The heating roller 81 is rotated by a driving force from a driving source (not shown).

[0082] The sheet S is sandwiched between the pressure roller 82 and the heating roller 81 . The pressure roller 82 is driven and rotated by the heating roller 81 .

[0083] The charger 52 charges the surface of the photosensitive drum 51. The exposure device 40 exposes the surface of the photosensitive drum 51. Thus, an electrostatic latent image is formed on the photosensitive drum 51. The developing roller 61 supplies toner to the photosensitive drum 51. Thus, a toner image is formed on the photosensitive drum 51.

[0084] The sheet feeding unit 20 conveys the sheet S between the photosensitive drum 51 and the transfer roller 74. The toner image on the photosensitive drum 51 is transferred to the sheet S. The sheet S to which the toner image is transferred is conveyed between the heating roller 81 and the pressure roller 82. Thus, the fixing device 80 thermally fixes the toner image to the sheet S.

[0085] The sheet discharge section 90 includes a conveying roller 91 and a discharge roller 92 . The conveying roller 91 conveys the sheet S to the discharge roller 92 . The discharge roller 92 discharges the sheet S onto the discharge tray 12 .

[0086] like Figure 2 As shown in FIG. 1 , the fixing device 80 is attachable to and detachable from the main body housing 10. Specifically, the fixing device 80 is attachable to and detachable from the main body housing 10 through the opening 10B of the main body housing 10 opened by opening the rear cover 13. In the following description, when explaining directions, the reference numeral 1 is used. Figure 2 The first direction, the second direction and the third direction are shown for explanation.

[0087] The first direction is a direction along the attachment and detachment direction of the fixing device 80 with respect to the main body housing 10. In the present embodiment, the first direction is a direction along the front-rear direction of the image forming apparatus 1. One side of the first direction corresponds to the rear side of the image forming apparatus 1, and the other side of the first direction corresponds to the front side of the image forming apparatus 1. The fixing device 80 can be mounted to the main body housing 10 from one side of the first direction toward the other side.

[0088] The second direction is a direction intersecting the first direction. In the present embodiment, the second direction is a direction orthogonal to the first direction. The second direction is a direction along the up-down direction of the image forming device 1. One side of the second direction corresponds to the lower side of the image forming device 1, and the other side of the second direction corresponds to the upper side of the image forming device 1.

[0089] The third direction is a direction orthogonal to both the first direction and the second direction. In the present embodiment, the third direction is a direction along the left-right direction of the image forming device 1. One side of the third direction corresponds to the left side of the image forming device 1, and the other side of the third direction corresponds to the right side of the image forming device 1.

[0090] The arrows indicating the directions in the drawings point to one side in the directions.

[0091] like Figure 2 and Figure 3 As shown, the fixing device 80 includes a first protrusion 120A, a second protrusion 130A, a third protrusion 120B, a fourth protrusion 130B, a protruding portion 140 , and a unit connector 170 . The image forming apparatus 1 further includes a main body connector 160 .

[0092] The first protrusion 120A and the third protrusion 120B are portions that are positioned relative to the main body casing 10 in the first direction and the second direction by contacting the main body casing 10 when the fuser 80 is mounted on the main body casing 10. The second protrusion 130A and the fourth protrusion 130B are portions that are used to stop the rotation of the fuser 80 about the protrusions 120A and 120B by contacting the main body casing 10 when the fuser 80 is mounted on the main body casing 10.

[0093] The first protrusion 120A has a cylindrical shape. The second protrusion 130A has a cylindrical shape. The second protrusion 130A is located on one side of the first direction compared to the first protrusion 120A. The second protrusion 130A is located on one side of the second direction compared to the first protrusion 120A. The first protrusion 120A and the second protrusion 130A extend along the third direction. The first protrusion 120A and the second protrusion 130A are located on one side of the third direction of the fuser 80. The first protrusion 120A and the second protrusion 130A protrude from one side of the third direction of the fuser 80 facing the third direction.

[0094] The third protrusion 120B has a structure symmetrical with the first protrusion 120A in the third direction. The fourth protrusion 130B has a structure symmetrical with the second protrusion 130A in the third direction. The third protrusion 120B and the fourth protrusion 130B are located on the other side of the third direction of the fuser 80. The third protrusion 120B and the fourth protrusion 130B protrude from the other side of the other side of the third direction of the fuser 80 facing the other side of the third direction.

[0095] The protrusion 140 is located on the surface of the other side in the first direction of the fixing device 80. The protrusion 140 is arranged on one side in the third direction and protrudes toward the other side in the first direction. The shape of the cross section of the protrusion 140 perpendicular to the first direction is a cross shape. The top end of the other side in the first direction of the protrusion 140 is thinner than the root of one side in the first direction.

[0096] The unit connector 170 is a connector connected to the main body connector 160 when the fuser 80 is mounted on the main body housing 10. The unit connector 170 is located on the other side of the third direction of the fuser 80. The main body connector 160 is a floating connector held on the main body housing 10 in a manner movable relative to the main body housing 10. When the main body connector 160 is connected to the unit connector 170, power can be supplied to the heater 81A of the heating roller 81.

[0097] like Fig.10 As shown in FIG. 1 (a), the main body connector 160 includes a main body housing 161 , a first guide pin 163 , and a second guide pin 164 .

[0098] The main housing 161 is a portion for holding the terminal. The main housing 161 is located between the first guide pin 163 and the second guide pin 164 in the second direction. The first guide pin 163 and the second guide pin 164 extend along the first direction. The top ends of the first guide pin 163 and the second guide pin 164 are located on one side of the main housing 161 in the first direction.

[0099] The unit connector 170 has a unit housing 171 , a first guide hole 173 , and a second guide hole 174 .

[0100] The unit housing 171 is a portion that holds terminals and fits with the main housing 161. The terminals of the unit connector 170 and the main connector 160 are connected by fitting the unit housing 171 with the main housing 161. The unit housing 171 is located between the first guide hole 173 and the second guide hole 174 in the second direction.

[0101] The first guide hole 173 is a hole for receiving the first guide pin 163. The second guide hole 174 is a hole for receiving the second guide pin 164. The unit housing 171, the first guide hole 173, and the second guide hole 174 are open toward the other side of the first direction.

[0102] like Figure 4 As shown in (a), the main body housing 10 has a guide surface 310A as a guide surface, a first recess 320A, and a second recess 330A. The guide surface 310A, the first recess 320A, and the second recess 330A are located on one side of the main body housing 10 in the third direction.

[0103] The first recess 320A is a recess in a shape that is recessed on one side toward the second direction. The first protrusion 120A of the fixer 80 is located in the first recess 320A when the fixer 80 is installed in the main body housing 10. The first protrusion 120A is located on the other side of the first direction than the clamping position NP between the heating roller 81 and the pressure roller 82. The main body housing 10 has a first metal plate 300A as a metal plate. The first metal plate 300A includes a first portion 301 that is orthogonal to the third direction. The first recess 320A is formed in the first portion 301 of the first metal plate 300A.

[0104] The first recessed portion 320A has a first reference surface 321 , a second reference surface 322 , and a stopper surface 323 .

[0105] The first reference surface 321 is a surface on one side of the first recess 320A in the second direction. The first reference surface 321 is orthogonal to the second direction.

[0106] The second reference surface 322 is a surface on one side of the first concave portion 320A in the first direction. The second reference surface 322 extends from an end on one side of the first reference surface 321 in the first direction toward the other side in the second direction. The second reference surface 322 intersects the first direction. In this embodiment, the second reference surface 322 is orthogonal to the first direction.

[0107] The stop surface 323 is a surface on the other side of the first direction of the first recess 320A. The stop surface 323 extends from the end of the other side of the first reference surface 321 in the first direction toward the other side of the second direction. The stop surface 323 intersects the first direction. In the present embodiment, the stop surface 323 is orthogonal to the first direction. When the stop surface 323 contacts the first protrusion 120A of the fixer 80 mounted on the main body housing 10, the fixer 80 is restrained from further moving to the other side of the first direction.

[0108] like Figure 4 As shown in (b), the interval D1 between the second reference surface 322 of the first recess 320A and the stop surface 323 is larger than the size D2 of the first protrusion 120A in the direction orthogonal to the third direction. Specifically, the interval D1 between the second reference surface 322 of the first recess 320A and the stop surface 323 is larger than the diameter D2 of the first protrusion 120A.

[0109] like Figure 4 As shown in (a) of FIG. 1 , the one side guide surface 310A is a surface that guides the first protrusion 120A toward the first recess 320A when the fixing device 80 is mounted on the main body housing 10 . The one side guide surface 310A includes a first guide surface 311 , a second guide surface 312 , and a third guide surface 313 .

[0110] The first guide surface 311 extends in the first direction. The first guide surface 311 is formed on the first side frame 14 located at one side of the main body housing 10 in the third direction.

[0111] The second guide surface 312 and the third guide surface 313 are formed on the first portion 301 of the first metal plate 300A. The second guide surface 312 is located between the first guide surface 311 and the first recess 320A. In detail, the second guide surface 312 is located between the first guide surface 311 and the third guide surface 313. The second guide surface 312 is inclined obliquely upward so as to be located on the other side of the second direction as it moves from one side of the first direction to the other side.

[0112] The third guide surface 313 is located between the second guide surface 312 and the first recess 320A. The third guide surface 313 extends from the end of the second guide surface 312 on the other side of the first direction toward the other side of the first direction. The end of the third guide surface 313 on the other side of the first direction is connected to the end of the second reference surface 322 of the first recess 320A on the other side of the second direction.

[0113] The second recess 330A is a recessed shape toward the other side of the first direction. The second recess 330A is formed in the first side frame 14 of the main body housing 10. When the fuser 80 is installed in the main body housing 10, the second protrusion 130A enters the second recess 330A. The second protrusion 130A is located on one side of the first direction compared to the clamping position NP between the heating roller 81 and the pressure roller 82. The second recess 330A opens toward one side of the first direction. The second recess 330A has a bottom surface 331, a first limiting surface 332, and a second limiting surface 333.

[0114] The bottom surface 331 is a surface on the other side in the first direction of the second recessed portion 330A.

[0115] The first limiting surface 332 and the second limiting surface 333 are surfaces for stopping the fixing device 80 from rotating around the first protrusion 120A. The first limiting surface 332 extends from the end of the bottom surface 331 on one side in the second direction toward the one side in the first direction. The second limiting surface 333 extends from the end of the bottom surface 331 on the other side in the second direction toward the one side in the first direction. The second protrusion 130A entering the second recess 330A is arranged between the first limiting surface 332 and the second limiting surface 333.

[0116] The image forming device 1 further includes a first spring SP1 as a spring. As an example, the first spring SP1 is a torsion coil spring. The first spring SP1 has a pressing arm AR. The pressing arm AR of the first spring SP1 presses the first protrusion 120A located in the first recess 320A toward one side of the first direction and one side of the second direction when the fuser 80 is mounted on the main body housing 10.

[0117] The first protrusion 120A contacts the first reference surface 321 of the first recess 320A and the second reference surface 322 of the first recess 320A while being pressed by the first spring SP1. On the other hand, the first protrusion 120A does not contact the stopper surface 323 of the first recess 320A while being pressed by the first spring SP1. In other words, there is a gap between the first protrusion 120A and the stopper surface 323 while being pressed by the first spring SP1.

[0118] like Fig.11 As shown in (b), the main body shell 10 has the other side guide surface 310B, the third recess 320B and the fourth recess 330B. The other side guide surface 310B, the third recess 320B and the fourth recess 330B are located on the other side of the third direction of the main body shell 10. In the present embodiment, the third recess 320B has a structure symmetrical with the first recess 320A in the third direction. The other side guide surface 310B has a structure symmetrical with the one side guide surface 310A in the third direction. The fourth recess 330B has a structure symmetrical with the second recess 330A in the third direction. Therefore, for parts having the same function, the same symbols are marked in the specification and the drawings and the description is omitted.

[0119] When the fuser 80 is installed in the main body housing 10, the third protrusion 120B of the fuser 80 is located in the third recess 320B. The main body housing 10 has a second metal plate 300B. In the present embodiment, the second metal plate 300B has a structure symmetrical with the first metal plate 300A in the third direction. The third recess 320B is formed in the first portion 301 of the second metal plate 300B. The stop surface 323 of the third recess 320B restrains the fuser 80 from further moving to the other side of the first direction when it contacts the third protrusion 120B of the fuser 80 installed in the main body housing 10.

[0120] The other side guide surface 310B is a surface that guides the third protrusion 120B toward the third recess 320B when the fuser 80 is mounted on the main body housing 10. The first guide surface 311 of the other side guide surface 310B is formed on the second side frame 15 located on the other side in the third direction of the main body housing 10. The second guide surface 312 and the third guide surface 313 of the other side guide surface 310B are formed on the first portion 301 of the second metal plate 300B.

[0121] The fourth recess 330B is formed in the second side frame 15 of the main body housing 10. When the fixing device 80 is installed in the main body housing 10, the fourth protrusion 130B enters the fourth recess 330B. The first limiting surface 332 and the second limiting surface 333 of the fourth recess 330B are surfaces for stopping the rotation of the fixing device 80 around the third protrusion 120B. The fourth protrusion 130B that has entered the fourth recess 330B is arranged between the first limiting surface 332 and the second limiting surface 333.

[0122] The image forming apparatus 1 further includes a second spring SP2. For example, the second spring SP2 is a torsion coil spring. When the fixing device 80 is mounted on the main body housing 10, the pressing arm AR of the second spring SP2 presses the third protrusion 120B located in the third recess 320B toward one side of the first direction and one side of the second direction.

[0123] The third projection 120B contacts the first reference surface 321 and the second reference surface 322 of the third recess 320B while being pressed by the second spring SP2. On the other hand, the third projection 120B contacts the stopper surface 323 of the third recess 320B while being pressed by the second spring SP2.

[0124] like Figure 4 (a) and Figure 5 As shown, the main body housing 10 has a long hole 340 as a hole. The long hole 340 is a bottomed hole that is longer in the second direction. The long hole 340 has a shape that is recessed toward the other side of the first direction. The long hole 340 opens toward one side of the first direction. When the fuser 80 is installed in the main body housing 10, the protrusion 140 enters the long hole 340. The protrusion 140 enters the long hole 340, thereby positioning the fuser 80 in the third direction.

[0125] The dimension of the long hole 340 in the third direction is substantially the same as the dimension of the protrusion 140 in the third direction. The protrusion 140 is fitted into the long hole 340 in the first direction. The long hole 340 restricts the movement of the protrusion 140 in the third direction. Thus, the long hole 340 restricts the movement of the fuser 80 in the third direction. The dimension of the long hole 340 in the second direction is larger than the dimension of the protrusion 140 in the second direction.

[0126] like Figure 5 As shown, the fixing device 80 has a first side plate 110A and a second side plate 110B as side plates. The first side plate 110A and the second side plate 110B are components for supporting the heating roller 81. The first side plate 110A and the second side plate 110B have circular through holes 111 (see Figure 6 ).

[0127] The first side plate 110A and the second side plate 110B are respectively formed of metal plates. The first side plate 110A is located on one side of the heating roller 81 and the pressure roller 82 in the third direction. The second side plate 110B is located on the other side of the heating roller 81 and the pressure roller 82 in the third direction. The protrusion 140 is provided on one side of the third direction compared to the portion of the first side plate 110A orthogonal to the third direction.

[0128] like Figure 5 and Figure 6 As shown, the first protrusion 120A and the third protrusion 120B are respectively formed of metal rods. The end of the first protrusion 120A on the other side of the third direction is fixed to the first side plate 110A by riveting. The end of the third protrusion 120B on one side of the third direction is fixed to the second side plate 110B by riveting. Figure 6 , the first protrusion 120A and the first side plate 110A are shown as representatives.

[0129] like Figure 5 As shown, in a state where the fuser 80 is mounted on the main body housing 10, the first metal plate 300A of the main body housing 10 is located on one side of the first side plate 110A in the third direction. The first spring SP1 presses the first protrusion 120A on one side of the first metal plate 300A in the third direction. The first spring SP1 presses the top end portion of the first protrusion 120A, which is not the portion of the first protrusion 120A located between the first metal plate 300A and the first side plate 110A, but the portion of the first protrusion 120A that is farther away from the first side plate 110A than from the first metal plate 300A.

[0130] In addition, in a state where the fuser 80 is mounted on the main body housing 10, the second metal plate 300B of the main body housing 10 is located on the other side of the second side plate 110B in the third direction. The second spring SP2 presses the third protrusion 120B on the other side of the second metal plate 300B in the third direction. The second spring SP2 presses the third protrusion 120B, which is not the portion of the third protrusion 120B located between the second metal plate 300B and the second side plate 110B, but the portion of the third protrusion 120B that is farther from the second side plate 110B than from the second metal plate 300B.

[0131] like Figure 7 As shown, the image forming apparatus 1 further includes a first driving gear R1 and a second driving gear R3. The fixing device 80 further includes a first input gear R2 and a second input gear R4.

[0132] The first drive gear R1 and the second drive gear R3 are supported by the main body housing 10. The first drive gear R1 is rotatable around a first axis 1X extending in the third direction. The second drive gear R3 is rotatable around a third axis 3X extending in the third direction.

[0133] The first input gear R2 and the second input gear R4 are located on one side of the third direction of the fuser 80. The first input gear R2 can rotate around the second axis 2X extending along the third direction. When the fuser 80 is installed in the main body housing 10, the first input gear R2 meshes with the first drive gear R1. When the first drive gear R1 receives a driving force from a driving source not shown in the figure, it moves to the first input gear R2. Figure 7 When the first input gear R2 rotates counterclockwise, the first input gear R2 rotates clockwise. As a result, the heating roller 81 rotates clockwise. The pressure roller 82 is driven by the heating roller 81 to rotate.

[0134] The first input gear R2 and the protruding portion 140 (see Figure 3 ) is arranged on the other side of the third direction compared to the first input gear R2. In other words, the protrusion 140 is arranged on one side of the third direction compared to the first input gear R2.

[0135] The second input gear R4 is rotatable around the fourth axis 4X extending in the third direction. When the fuser 80 is installed in the main body housing 10, the second input gear R4 is meshed with the second drive gear R3. The fuser 80 also has a cam 86. The cam 86 moves at least one of the heating roller 81 and the pressure roller 82 by rotating, and changes the clamping pressure of the clamped sheet S. The cam 86 is rotatable around the fourth axis 4X.

[0136] When the second drive gear R3 receives the driving force and rotates counterclockwise, the second input gear R4 rotates clockwise, thereby rotating the cam 86 clockwise. Also, when the second drive gear R3 receives the driving force and rotates clockwise, the second input gear R4 rotates counterclockwise, thereby rotating the cam 86 counterclockwise.

[0137] In the present embodiment, when viewed from the third direction, the second protrusion 130A is located on a straight line L1 passing through the first axis 1X and the second axis 2X. In addition, when viewed from the third direction, the second protrusion 130A is located on a straight line L2 passing through the third axis 3X and the fourth axis 4X. The first axis 1X and the second axis 2X are located on the other side of the straight line L2 in the first direction.

[0138] The first protrusion 120A is located on the other side of the first direction compared to the second axis 2X. The first protrusion 120A is located on one side of the second direction compared to the second axis 2X. The first input gear R2 meshes with the first drive gear R1 at a position located on the other side of the first direction compared to the second axis 2X. The first input gear R2 meshes with the first drive gear R1 at a position located on the other side of the second direction compared to the second axis 2X.

[0139] When the first drive gear R1 rotates counterclockwise by the driving force, the first input gear R2 is pressed toward the other side of the first direction and one side of the second direction by the force F3. The first spring SP1 presses the first protrusion 120A located in the first recess 320A toward one side of the first direction and one side of the second direction by the force F1. The force F11 of the first direction component of the force F1 of the first spring SP1 pressing the first protrusion 120A is greater than the force F31 of the first direction component of the force F3 of the first drive gear R1 pressing the first input gear R2.

[0140] In addition, the other side of the third direction of the fixing device 80 does not receive the force from the gear supported by the main body housing 10. Therefore, in this embodiment, the second spring SP2 (see Fig.11 (b)) The force F2 of the third protrusion 120B in the third recess 320B is smaller than the force F1 of the first spring SP1 in pressing the first protrusion 120A in the first recess 320A. The force of the second spring SP2 is smaller than the force of the first spring SP1.

[0141] Next, the operation of each part when the fixing device 80 is mounted in the main body casing 10 will be described.

[0142] like Figure 8 As shown in (a), when the fixer 80 is inserted into the main housing 10 from one side of the first direction toward the other side, on one side of the fixer 80 in the third direction, the first protrusion 120A contacts the first guide surface 311 of the one side guide surface 310A and is guided by the first guide surface 311.

[0143] In addition, if Figure 8 As shown in (b), the second protrusion 130A contacts the first limiting surface 332 of the second recess 330A and is guided by the first limiting surface 332. When the first protrusion 120A contacts the second guide surface 312, the first protrusion 120A is guided by the second guide surface 312 and moves obliquely upward from one side to the other side in the first direction.

[0144] Therefore, if Fig. 9As shown in (a), the fixing device 80 is inserted into the main body housing 10 with the surface on the other side of the first direction facing obliquely upward. After being guided by the second guide surface 312, the first protrusion 120A is guided by the third guide surface 313 in the direction along the first direction. The protrusion 140 is inserted into the long hole 340 in the middle of the first protrusion 120A being guided by the one side guide surface 310A.

[0145] When the first protrusion 120A is separated from the third guide surface 313, as shown in FIG. Fig. 9 As shown in (b), the first protrusion 120A enters the first recess 320A due to the force of the first spring SP1. Specifically, the first protrusion 120A guided by the third guide surface 313 presses the pressing arm AR of the first spring SP1, causing the pressing arm AR to elastically deform toward the other side in the first direction.

[0146] Afterwards, when the first protrusion 120A is separated from the third guide surface 313, the first protrusion 120A is pressed toward one side of the first direction and the second direction due to the restoring force of the first spring SP1 and enters the first recess 320A. At this time, the second protrusion 130A enters the second recess 330A.

[0147] On the other hand, Fig.10 As shown in (a), when the fixing device 80 is inserted into the main body housing 10, the third protrusion 120B contacts the first guide surface 311 of the other side guide surface 310B on the other side of the fixing device 80 in the third direction and is guided by the first guide surface 311.

[0148] In addition, if Fig.10 As shown in (b), the fourth protrusion 130B contacts the first limiting surface 332 of the fourth recess 330B and is guided by the first limiting surface 332. In addition, the first guide hole 173 of the unit connector 170 receives the first guide pin 163 of the main body connector 160, and the second guide hole 174 receives the second guide pin 164. When the third protrusion 120B contacts the second guide surface 312, the third protrusion 120B is guided by the second guide surface 312 and moves obliquely upward from one side to the other side in the first direction.

[0149] like Fig.11 As shown in (a), the third protrusion 120B is guided by the third guide surface 313 in the direction along the first direction after being guided by the second guide surface 312. In addition, when the unit housing 171 of the unit connector 170 is fitted with the main housing 161 of the main connector 160, the terminal of the unit connector 170 contacts the terminal of the main connector 160.

[0150] When the third protrusion 120B is separated from the third guide surface 313, as shown in FIG. Fig.11As shown in (b), the third protrusion 120B enters the third recess 320B due to the force of the second spring SP2. Specifically, the third protrusion 120B guided by the third guide surface 313 presses the pressing arm AR of the second spring SP2, causing the pressing arm AR to elastically deform toward the other side of the first direction.

[0151] Afterwards, when the third protrusion 120B is disengaged from the third guide surface 313, due to the restoring force of the second spring SP2, the third protrusion 120B is pressed toward one side of the first direction and one side of the second direction, and enters the third recess 320B. At this time, the fourth protrusion 130B enters the fourth recess 330B. In addition, the unit housing 171 is engaged with the main housing 161, thereby connecting the unit connector 170 to the main connector 160.

[0152] When the fixing device 80 is mounted on the main body housing 10, the projections 120A and 120B are pressed against the second reference surfaces 322 of the recesses 320A and 320B by the forces of the springs SP1 and SP2, and are pressed against the first reference surfaces 321 of the recesses 320A and 320B by gravity and the forces of the springs SP1 and SP2. In this way, by pressing the projections 120A and 120B against the first reference surfaces 321 and the second reference surfaces 322, the fixing device 80 is positioned in the first direction and the second direction.

[0153] In this embodiment, when the fixing device 80 is mounted on the main body housing 10, a load is applied to the end portion of the fixing device 80 on the other side of the third direction due to the friction resistance when the unit connector 170 is connected to the main body connector 160. Therefore, the force of the second spring SP2 is greater than that of the first spring SP1 (see Figure 7 ) has a small force.

[0154] As a result, the difference between the first load required to attach the fixer 80 to the main body housing 10 at the end of one side of the third direction of the fixer 80 and the second load required to attach the fixer 80 to the main body housing 10 at the end of the other side of the third direction of the fixer 80 becomes smaller. The first load is mainly the load received from the first spring SP1 when the first protrusion 120A enters the first recess 320A. In addition, the second load is mainly the sum of the load received from the second spring SP2 when the third protrusion 120B enters the third recess 320B and the load applied due to the friction resistance when the unit connector 170 is connected to the main body connector 160. It is preferred that the first load is substantially the same as the second load.

[0155] In other words, in order to determine the position of the third protrusion 120B (fixer 80) in the first direction and the second direction, the second spring SP2 needs a certain degree of force. On the other hand, due to the friction resistance when the unit connector 170 and the main body connector 160 are connected, a load is applied to the end of the other side of the third direction of the fixer 80. Therefore, in order to reduce the difference between the first load and the second load, in this embodiment, the force of the first spring SP1 is made greater than the force of the second spring SP2.

[0156] In addition, since one side in the third direction of the fixing device 80 receives a force from the first driving gear R1 supported by the main body casing 10 , the urging force of the first spring SP1 is greater than the urging force of the second spring SP2 .

[0157] In addition, if Figure 5 As shown, the protrusion 140 enters the long hole 340, whereby the fixing device 80 is positioned in the third direction.

[0158] Next, the effects of the image forming apparatus 1 will be described.

[0159] By providing the first spring SP1, when the fixing device 80 is mounted on the main body housing 10, the first spring SP1 presses the first protrusion 120A located in the first recess 320A toward one side of the first direction and one side of the second direction, thereby making it difficult for the first protrusion 120A to escape from the first recess 320A. Thus, it is possible to suppress the fixing device 80 from moving from the mounting position mounted on the main body housing 10.

[0160] In this embodiment, the first spring SP1 and the second spring SP2 are provided, the first spring SP1 presses the first protrusion 120A in the first recess 320A toward one side of the first direction and one side of the second direction, and the second spring SP2 presses the third protrusion 120B in the third recess 320B toward one side of the first direction and one side of the second direction, thereby making it difficult for the protrusions 120A and 120B to be separated from the corresponding recesses 320A and 320B. Thus, it is possible to suppress the fuser 80 from moving from the installation position.

[0161] The projections 120A and 120B do not contact the stopper surfaces 323 of the recesses 320A and 320B when pressed by the springs SP1 and SP2, and are therefore less likely to be affected by the dimensional accuracy of the recesses 320A and 320B. Thus, the fixing device 80 can be positioned with high accuracy relative to the main body housing 10.

[0162] The projections 120A and 120B contact the first reference surface 321 and the second reference surface 322 of the recesses 320A and 320B while being pressed by the springs SP1 and SP2 , so that the projections 120A and 120B can be positioned by contacting both surfaces. Thus, the fixing device 80 can be positioned with respect to the main body housing 10 with high accuracy.

[0163] The springs SP1 and SP2 are torsion coil springs, whereby the pressing force and the stroke can be set favorably.

[0164] The second guide surface 312 is inclined so as to be located on the other side of the second direction as it moves from one side of the first direction toward the other side, thereby making it possible to make the positions of the first guide surface 311 and the recesses 320A, 320B in the second direction substantially the same. Thus, the posture of the fixing device 80 during installation, in which the projections 120A, 120B are guided by the first guide surface 311, and the posture of the fixing device 80 after installation, in which the projections 120A, 120B enter the recesses 320A, 320B, can be substantially the same.

[0165] The recessed portions 320A and 320B are formed in the metal plates 300A and 300B provided in the main body casing 10 , and thereby the fixing device 80 can be positioned relative to the highly rigid metal plates 300A and 300B.

[0166] The first metal plate 300A is located on one side of the third direction of the first side plate 110A to which the first protrusion 120A is fixed by riveting, and the first spring SP1 presses the first protrusion 120A on one side of the third direction of the first metal plate 300A. Thus, compared with the case where the spring presses the first protrusion 120A between the first metal plate 300A and the first side plate 110A, the load applied to the riveted part of the first protrusion 120A can be reduced.

[0167] Similarly, the second metal plate 300B is located on the other side of the third direction of the second side plate 110B to which the third protrusion 120B is fixed by riveting, and the second spring SP2 presses the third protrusion 120B on the other side of the third direction of the second metal plate 300B, thereby reducing the load applied to the riveted part of the third protrusion 120B.

[0168] The projections 120A and 120B are located on the other side of the nip position NP between the heating roller 81 and the pressure roller 82 in the first direction, thereby positioning the fixing device 80 relative to the main body casing 10 based on the back side in the mounting direction of the fixing device 80 .

[0169] The fixing device 80 has the projections 130A and 130B, and the main body housing 10 has the recesses 330A and 330B. Therefore, the fixing device 80 can be restricted from rotating about the projections 120A and 120B in a state where the projections 130A and 130B enter the recesses 330A and 330B.

[0170] The fuser 80 has a protrusion 140, and the main body housing 10 has a long hole 340 for limiting the movement of the protrusion 140 in the third direction, thereby limiting the movement of the fuser 80 in the third direction. Thus, the fuser 80 can be positioned in the third direction. In addition, the protrusion 140 is arranged on one side in the third direction, thereby, the fuser 80 can be positioned in the third direction at a position close to the first input gear R2.

[0171] The dimension of the long hole 340 in the second direction is larger than the dimension of the protrusion 140 in the second direction, so that when the fixer 80 is mounted on the main body housing 10, even if the fixer 80 moves in the second direction, the protrusion 140 can be prevented from interfering with the main body housing 10. In addition, the top end of the protrusion 140 is tapered, so that when the fixer 80 is mounted on the main body housing 10, the protrusion 140 can be guided into the long hole 340, and the fixer 80 can be prevented from deviating greatly in the second direction.

[0172] The first spring SP1 has a force F11 in the first direction of the force F1 pressing the first protrusion 120A greater than a force F31 in the first direction of the force F3 pressing the first input gear R2. This can prevent the first protrusion 120A from moving to the other side in the first direction when the first drive gear R1 rotates.

[0173] The difference between the first load required to attach the fixer 80 to the main body housing 10 at the end of one side in the third direction of the fixer 80 and the second load required to attach the fixer 80 to the main body housing 10 at the end of the other side in the third direction of the fixer 80 is small, thereby suppressing the fixer 80 from tilting when attaching the fixer 80 to the main body housing 10. As a result, the fixer 80 is easily attached to the main body housing 10.

[0174] Although the embodiment has been described above, the image forming apparatus can be implemented in various appropriately modified forms as exemplified below.

[0175] In the above embodiment, the first spring SP1 is a torsion coil spring, but the spring for pressing the protrusion may be, for example, a leaf spring, a compression coil spring, etc. The same applies to the second spring.

[0176] In the above embodiment, the first side plate 110A of the fixing device 80 is a member that supports the heating roller 81 (heating rotating body), but the first side plate may be a member that supports the pressure roller (pressure rotating body), for example. In addition, the first side plate may be a member that supports both the heating rotating body and the pressure rotating body. The same is true for the second side plate.

[0177] In the above-mentioned embodiment, the first input gear R2 drives the heating roller 81 (heating rotating body), and the pressure roller 82 (pressure rotating body) rotates following the heating roller 81, but for example, it can also be a structure in which the first input gear drives the pressure rotating body, and the heating rotating body rotates following the pressure rotating body.

[0178] In the above embodiment, the second direction is a direction orthogonal to the first direction, but, for example, the second direction may not be orthogonal to the first direction. In other words, in the above embodiment, the first recess 320A is a shape that is recessed toward the lower side of the image forming device 1, but, for example, the first recess may be a shape that is recessed toward the oblique front and lower side. The same is true for the third recess. Furthermore, in the above embodiment, the first direction as the loading and unloading direction of the fixing device 80 is a direction along the front-to-back direction of the image forming device 1, but, for example, the first direction may be a direction that is inclined relative to the horizontal direction.

[0179] In the above embodiment, the first side plate 110A is made of metal, but the first side plate may be made of resin, for example. In addition, in the above embodiment, the first protrusion 120A is made of metal, but the first protrusion may be made of resin, for example. In addition, the first protrusion may be formed integrally with the first side plate. In addition, the fuser may not include the first side plate, and the first protrusion may be provided on the frame of the fuser, for example. The same is true for the second side plate and the third protrusion.

[0180] In the above embodiment, the first metal plate 300A is composed of the first portion 301 orthogonal to the third direction, but the first metal plate may also have a first portion and a second portion extending from the first portion in the third direction. The same is true for the second metal plate.

[0181] In the above embodiment, the first protrusion 120A is a structure that contacts the first reference surface 321 and the second reference surface 322 of the first recess 320A and does not contact the stop surface 323, but the first protrusion may also be a structure that contacts three surfaces of the first recess. The first protrusion may also be a structure that fits into the first recess. The same is true for the third protrusion and the third recess.

[0182] In the above embodiment, the long hole 340 (hole) is a hole with a bottom, but for example, a hole into which a protruding portion of the fixing device enters may be a hole penetrating in the first direction.

[0183] In the above embodiment, the heating roller 81 is exemplified as the heating rotating body, but the heating rotating body may be, for example, a heating belt, a heating film, etc. In addition, in the above embodiment, the pressing roller 82 is exemplified as the pressurizing rotating body, but the pressurizing rotating body may be, for example, an annular belt sandwiched between the heating rotating body and the elastic pad.

[0184] In the above embodiment, the image forming apparatus 1 is a printer capable of forming color images, but the image forming apparatus may be, for example, a printer capable of forming only black-and-white images. Alternatively, the image forming apparatus may be a copier, a multifunction peripheral, or the like.

[0185] The respective elements described in the above-mentioned embodiment and modified examples can be implemented in any combination.

Claims

1. An image forming device comprising a main body housing and a fixing device, wherein the fixing device has a heating rotating body and a pressurizing rotating body and can be mounted relative to the main body housing from one side toward the other side in a first direction, wherein: The main body housing has a first recessed portion, the first recessed portion being recessed toward one side of a second direction intersecting the first direction. The fixing device has a first protrusion extending in a third direction orthogonal to both the first direction and the second direction, and when the fixing device is installed in the main body housing, the first protrusion is located in the first recessed portion. The image forming apparatus further includes a spring for pressing the first protrusion located in the first recess toward one side in the first direction and one side in the second direction when the fixing device is attached to the main body housing.

2. The image forming apparatus according to claim 1, wherein: The distance between the surface of the first concave portion on one side in the first direction and the surface on the other side in the first direction is greater than the size of the first protrusion in a direction perpendicular to the third direction. The first protrusion does not contact the surface of the first recessed portion on the other side in the first direction in a state pressed by the spring.

3. The image forming apparatus according to claim 1, wherein: The first protrusion contacts a surface of the first recessed portion on one side in the first direction and a surface of the first recessed portion on one side in the second direction while being pressed by the spring.

4. The image forming apparatus according to claim 1, wherein: The spring is a torsion coil spring.

5. The image forming apparatus according to claim 1, wherein: The main body housing has a guide surface, and when the fuser is mounted on the main body housing, the guide surface guides the first protrusion toward the first recessed portion. The guide surface has: a first guiding surface extending along the first direction; as well as A second guide surface is located between the first guide surface and the first recessed portion and is inclined so as to be located on the other side in the second direction as it moves from the one side in the first direction to the other side.

6. The image forming apparatus according to claim 1, wherein: The main body housing has a metal plate including a first portion orthogonal to the third direction. The first recess is formed in the first portion.

7. The image forming apparatus according to claim 6, wherein: The fixing device includes a side plate that supports at least one of the heating rotating body and the pressurizing rotating body and is located on one side of the heating rotating body and the pressurizing rotating body in the third direction. The first protrusion is fixed to the side plate, The metal plate is located on one side of the side plate in the third direction, The spring presses the first protrusion on one side of the metal plate in the third direction.

8. The image forming apparatus according to claim 7, wherein: The side panels are made of metal plates. The first protrusion is composed of a metal rod, The first protrusion is fixed to the side plate by riveting.

9. The image forming apparatus according to claim 1, wherein: The first protrusion is located on the other side of the first direction relative to a sandwich position between the heating rotating body and the pressurizing rotating body.

10. The image forming apparatus according to claim 9, wherein: The fixing device has a second protrusion, the second protrusion extends along the third direction, and the second protrusion is located on one side of the first direction compared to the clamping position, The main body housing has a second recessed portion that is recessed toward the other side of the first direction, and the second protrusion enters the second recessed portion when the fixing device is mounted on the main body housing.

11. The image forming apparatus according to claim 1, wherein: The fixing device has a protrusion, which protrudes toward the other side of the first direction. The main body housing has a hole into which the protrusion enters when the fixing device is mounted on the main body housing, and the hole restricts movement of the protrusion in the third direction.

12. The image forming apparatus according to claim 11, wherein: A dimension of the hole in the second direction is larger than a dimension of the protrusion in the second direction.

Images