Image forming apparatus

Abstract

There is provided an image forming apparatus configured to form an image on a sheet, the image forming apparatus including an apparatus body and a detachable unit. The detachable unit includes a first positioned portion and a second positioned portion. The device body includes a frame member having a first positioning portion and a second positioning portion that engage with the first positioned portion and the second positioned portion, respectively, such that the detachable unit is positioned in the attachment direction and the first direction with respect to the frame member. The second positioning portion is disposed closer to a central portion of the detachable unit in the second direction than the first positioning portion.

Description

[0001] This application is a divisional application of the patent application with application number 202210549480.1, titled "Image forming apparatus", filed on May 20, 2022. TECHNICAL FIELD

[0002] The present application relates to an image forming apparatus for forming an image on a sheet. BACKGROUND

[0003] Hitherto, an image forming apparatus has been proposed which has a process cartridge detachably supported on an apparatus body, wherein the process cartridge is replaceable (see Japanese Patent Application Laid-Open No. 2020-112731). The apparatus body of the above-described image forming apparatus includes a pair of side plates arranged on right and left sides, wherein two rail-like grooves are formed on each side plate. The process cartridge is positioned by engaging a first positioning portion and a second positioning portion of the process cartridge with end portion portions of the grooves.

[0004] However, according to the side plates disclosed in Japanese Patent Application Laid-Open No. 2020-112731, two large rail-like grooves are formed on the same plane, thereby possibly reducing the rigidity of the side plates. If the rigidity of the side plates supporting the process cartridge is reduced, the positioning accuracy of the process cartridge can be degraded.

[0005] Therefore, the present application provides an image forming apparatus which improves the positioning accuracy of a detachable unit with respect to an apparatus body. SUMMARY

[0006] According to a first aspect of the present application, there is provided an image forming apparatus configured to form an image on a sheet, the image forming apparatus including an apparatus body and a detachable unit detachably attached to the apparatus body in an attachment direction. The detachable unit includes a first positioned portion and a second positioned portion provided in an end portion of the detachable unit in a second direction perpendicular to the attachment direction and a first direction, the second positioned portion being provided downstream of the first positioned portion in the attachment direction. The apparatus body includes a frame member provided on a side of the end portion of the detachable unit in the second direction and having a first positioning portion and a second positioning portion engaged with the first positioned portion and the second positioned portion, respectively, to position the detachable unit with respect to the frame member in the attachment direction and the first direction. At least a portion of the second positioning portion is aligned with the first positioning portion in the attachment direction when viewed in the second direction. The second positioning portion is arranged closer to a central portion of the detachable unit in the second direction than the first positioning portion.

[0007] According to a second aspect of the present application, there is provided an image forming apparatus configured to form an image on a sheet, the image forming apparatus including an apparatus main body and a detachable unit detachably attached to the apparatus main body in an attachment direction. The detachable unit includes a first positioned portion and a second positioned portion provided in an end portion of the detachable unit in a second direction perpendicular to the attachment direction and a first direction, the second positioned portion being provided downstream of the first positioned portion in the attachment direction. The apparatus main body includes a metal plate provided on a side of the end portion of the detachable unit in the second direction and including a first surface and a second surface extending in the attachment direction and the first direction, the second surface being formed by stretching so that the second surface is positioned closer to a center portion of the detachable unit in the second direction than the first surface. The first surface and the second surface have a first positioned portion and a second positioned portion which respectively engage with the first positioned portion and the second positioned portion of the detachable unit to position the detachable unit with respect to the metal plate in the attachment direction and the first direction. The second positioned portion is provided closer to the center portion of the detachable unit in the second direction than the first positioned portion.

[0008] Further features of the present application will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF DRAWINGS

[0009] Figure 1 is a whole schematic view showing an image forming apparatus according to a first embodiment.

[0010] Figure 2 is a cross-sectional view showing a configuration of the image forming apparatus.

[0011] Figure 3A is a perspective view of the image forming apparatus with the rear cover closed.

[0012] Figure 3B is a perspective view of the image forming apparatus with the rear cover opened.

[0013] Figure 4 is a perspective view showing a state of the image forming apparatus before the attachment of the processing unit.

[0014] Figure 5A is a rear view and an enlarged view showing a positioning configuration in which the processing unit is positioned by the left side plate frame.

[0015] Figure 5B is a rear view and an enlarged view showing a positioning configuration in which the processing unit is positioned by the right side plate frame.

[0016] Figure 6Ais a perspective view showing an image forming apparatus to which a processing unit is attached.

[0017] Figure 6B is an enlarged view showing a left positioning portion and a left rotation control portion.

[0018] Figure 6C is an enlarged view showing a left positioning portion and a left rotation control portion according to a modification of the first embodiment.

[0019] Figure 7A is a cross-sectional view parallel to the XY plane showing a positioning configuration in which the processing unit is positioned by a left side plate frame.

[0020] Figure 7B is a cross-sectional view parallel to the XY plane showing a positioning configuration in which the processing unit is positioned by a right side plate frame.

[0021] Figure 8 is a left side view showing the positioning configuration in which the processing unit is positioned by the left side plate frame.

[0022] Figure 9 is a perspective view of an image forming apparatus according to a second embodiment.

[0023] Figure 10A is a rear view and an enlarged view showing the positioning configuration in which the processing unit is positioned by the left side plate frame.

[0024] Figure 10B is a rear side view and an enlarged view showing the positioning configuration in which the processing unit is positioned by the right side plate frame.

[0025] Figure 11 is a perspective view showing an image forming apparatus to which a processing unit is attached.

[0026] Figure 12 is a perspective view showing an image forming apparatus according to a third embodiment.

[0027] Figure 13 is a left side view showing the positioning configuration in which the processing unit is positioned by the left side plate frame. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments for carrying out the present technology will be explained in detail based on examples with reference to the drawings. Note that the size, material, shape, and relative arrangement of components described in the embodiments are arbitrarily changed according to the configuration of an apparatus to which the technology is applied and various conditions. In other words, the following explanation of the embodiments is not intended to limit the scope of the present application.

[0029] First Embodiment

[0030] Figure 1is a perspective view showing the image forming apparatus 1 according to the first embodiment. Figure 2 1 is a cross-sectional view illustrating the configuration of an image forming apparatus 1. The image forming apparatus 1 is a monochrome printer for forming an image on a recording material based on image information input from an external device. The recording material may be a sheet formed of various materials, including paper such as plain paper and thick paper, plastic film such as OHP sheets, specially shaped sheets such as envelopes and index paper, and cloth.

[0031] In the following description, in a state where the image forming apparatus 1 is arranged on a horizontal plane, the height direction of the image forming apparatus 1 (i.e., the direction opposite to the vertical direction) is referred to as the Z direction. The direction intersecting the Z direction and being parallel to the direction of the rotation axis of the photosensitive drum 11 described later (i.e., the main scanning direction) is referred to as the X direction. The direction intersecting the X direction and the Z direction is referred to as the Y direction. The X direction, the Y direction, and the Z direction preferably intersect each other perpendicularly. In addition, for convenience, the positive side in the X direction is referred to as the right side and the negative side in the X direction is referred to as the left side, the positive side in the Y direction is referred to as the front side and the negative side in the Y direction is referred to as the rear side, the positive side in the Z direction is referred to as the upper side, and the negative side in the Z direction is referred to as the lower side.

[0032] Overall configuration

[0033] like Figure 1 and Figure 2 As shown, the image forming apparatus 1 includes an image forming unit 40 for forming a toner image on a recording material, a feeding unit 30 for feeding the recording material P, a fixing unit 9 for fixing the toner image formed by the image forming unit 40 on the recording material, and a sheet discharge roller pair 10.

[0034] The image forming unit 40 includes a scanner unit 50, a process unit 20 employing an electrophotographic system, and a transfer roller 7 for transferring a toner image formed on a photosensitive drum 11 of the process unit 20 onto a recording material P serving as a sheet. The process unit 20 includes the photosensitive drum 11, a cleaning unit 13 disposed around the photosensitive drum 11, a charging roller 17, a developing roller 12, and a storage portion 18 for storing toner. The process unit 20 can be attached to the apparatus body 2 of the image forming apparatus 1 using screws and can be removed by a service person.

[0035] The photosensitive drum 11 serving as an image bearing member is a photosensitive body formed into a cylindrical shape. The photosensitive drum 11 according to the present embodiment includes a photosensitive layer formed of a negatively charged organic photosensitive body on a drum-shaped base formed of aluminum. In addition, the photosensitive drum 11 serving as a rotatable member is driven by a motor to rotate in a predetermined direction (R direction in the figure) at a predetermined process speed around a longitudinal direction LD (see FIG. 1 ). Figure 4 ) extends along an axis of rotation.

[0036] The charging roller 17 is pressed against the photosensitive drum 11 at a predetermined contact pressure to form a charging portion. In addition, by applying a desired charging voltage from a charging high-voltage power supply to the charging roller 17, the surface of the photosensitive drum 11 is uniformly charged to a predetermined potential. According to the present embodiment, the photosensitive drum 11 is charged to a negative polarity by the charging roller 17.

[0037] The scanner unit 50 performs a scan exposure to the surface of the photosensitive drum 11 by irradiating the photosensitive drum 11 with laser light in response to image information input from an external device, using a polygon mirror. By the exposure, an electrostatic latent image corresponding to the image information is formed on the surface of the photosensitive drum 11. The scanner unit 50 is not limited to a laser scanner device, and for example, an LED exposure unit including an LED array in which a plurality of LEDs are arranged along the longitudinal direction of the photosensitive drum 11 can be employed.

[0038] The developing roller 12 is rotatably supported by a storage portion 18 serving as a toner storage portion. In addition, the developing roller 12 is arranged opposite the photosensitive drum 11. In addition, a feed roller for applying toner serving as a developer stored in the storage portion 18 to the surface of the developing roller 12 can be provided in the storage portion 18.

[0039] According to the present embodiment, the processing unit 20 serving as a detachable unit employs a contact developing system as a developing system. That is, a toner layer carried on the developing roller 12 contacts the photosensitive drum 11 at a developing portion (i.e., a developing area) in which the photosensitive drum 11 and the developing roller 12 are opposite each other. A developing voltage is applied to the developing roller 12 from a developing high-voltage power supply. Under the developing voltage, the toner carried on the developing roller 12 is transferred from the developing roller 12 to the drum surface according to the potential distribution on the surface of the photosensitive drum 11, thereby developing the electrostatic latent image into a toner image.

[0040] The toner according to the present embodiment is a so-called one-component developer that does not include a magnetic component, and the toner is carried on the developing roller 12 mainly by intermolecular forces and electrostatic forces (i.e., image forces). A one-component developer containing a magnetic component can also be used. In addition to toner particles, the one-component developer can include additives (e.g., wax and silica particles) for adjusting flowability and charging performance. In addition, a two-component developer composed of a non-magnetic toner serving as a developer and a magnetic carrier can also be used. For example, if a magnetic developer is used, a cylindrical developing sleeve in which a magnet is arranged on the inner side can be used as a developer carrying member.

[0041] The fixing unit 9 employs a heat fixing system for fixing an image by heating and melting the toner on the recording material while applying pressure. The fixing unit 9 includes a heating roller 9a including a fixing heater 9c and a pressure roller 9b in pressure contact with the heating roller 9a. Each of the heating roller 9a and the pressure roller 9b is a rotatable member configured to rotate around a rotation axis extending in the longitudinal direction LD (see Figure 4 ),

[0042] The feeding unit 30 includes the cartridge 4 on which the recording material P is placed, the pickup roller 3, the feeding roller 5a, and the separation roller 5b. The front cover 70 is provided at a portion of an end surface of the front side of the image forming apparatus 1, and the front cover 70 covers the circuit board 100. The device body 2 of the image forming apparatus 1 includes a housing 72. The housing 72 includes the front cover 70, the sheet discharge tray 14, the rear cover 75 (see Figure 3A and 3B ), and an outer cover 71 constituting the exterior of the image forming apparatus 1 other than the front cover 70, the sheet discharge tray 14, and the rear cover 75. The sheet discharge port 15 through which the sheet is discharged to the sheet discharge tray 14 is formed in the housing 72.

[0043] Further, the supply port 200 (see Figure 4 ) serving as an inlet for receiving the toner supplied from the outside of the processing unit 20 is formed in the processing unit 20. The supply port 200 communicates with the storage portion 18, and the supply port 200 is exposed by opening the sheet discharge tray 14 upward in a state where the processing unit 20 is attached to the device body 2. The user can attach the toner container for replenishment to the exposed supply port 200 so as to replenish the toner to the storage portion 18 via the supply port 200. That is, the toner is supplied into the storage portion 18 through the supply port 200. As described above, the processing unit 20 according to the present embodiment is capable of supplying the toner to the storage portion 18 when the storage portion 18 is attached to the device body 2.

[0044] As shown in Figure 2 , the image forming apparatus 1 includes the circuit board 100. The circuit board 100 includes a wiring board 101 formed of an insulator and electronic components 111 and 121 soldered to the wiring board 101. A conductor wiring is arranged on a surface and inside of the wiring board 101, and the electronic components 111 and 121 are electrically connected by the conductor wiring. The circuit board 100 has a function of converting an AC current supplied from the outside of the image forming apparatus 1 into a direct current, or converting an input voltage to obtain a predetermined voltage required for the image forming process.

[0045] The circuit board 100 is arranged such that the surface of the wiring board 101 on which the electronic components 111 and 121 are mounted is disposed along a direction that intersects the discharge direction. Further, the wiring board 101 is arranged between the front cover 70 and the scanner unit 50 along the discharge direction. The electronic components 111 and 121 are disposed on the side of the wiring board 101 that is opposite the scanner unit 50.

[0046] Next, the image forming operation of the image forming apparatus 1 will be described. When an image forming instruction is input to the image forming apparatus 1, the image forming process of the image forming unit 40 will start based on image information input from an external computer connected to the image forming apparatus 1. The scanner unit 50 irradiates the photosensitive drum 11 with laser light based on the input image information. In this state, the photosensitive drum 11 is pre-charged by the charging roller 17, and an electrostatic latent image is formed on the photosensitive drum 11 by causing the laser light to be irradiated on the photosensitive drum 11. Thereafter, the electrostatic latent image is developed by the developing roller 12, and a toner image is formed on the photosensitive drum 11.

[0047] In parallel with the above-described image forming process, the pickup roller 3 of the feeding unit 30 feeds the recording material P supported on the cassette 4. The recording material P is separated one by one by the feeding roller 5a and the separation roller 5b and is conveyed to the conveying roller pair 5c. Then, the recording material P is conveyed to the transfer nip N1 formed by the transfer roller 7 and the photosensitive drum 11 by the conveying roller pair 5c serving as a conveying portion.

[0048] A transfer voltage is applied to the transfer roller 7 from a transfer high-voltage power supply, and the toner image carried on the photosensitive drum 11 is transferred to the recording material P conveyed by the conveying roller pair 5c. The recording material P on which the toner image has been transferred is conveyed to the fixing unit 9, and the toner image is heated and pressed when passing through the nip portion formed between the heating roller 9a and the pressure roller 9b of the fixing unit 9. Thereby, the toner particles are fused and then solidified, thereby fixing the toner image to the recording material P. The recording material P that has passed through the fixing unit 9 is discharged from the sheet discharge port 15 to the outside of the image forming apparatus 1 (i.e., the outside of the apparatus) by the sheet discharge roller pair 10, and is supported on the sheet discharge tray 14.

[0049] When an image is formed on both sides of the recording material P, the sheet discharge roller pair 10 turns the recording material P on which an image is formed on the first side, thereby guiding the recording material P to the double-sided conveying path 16. The recording material P guided to the double-sided conveying path 16 is conveyed again toward the transfer roller 7 by the double-sided conveying roller pair 5d. An image is formed on the second side of the recording material P by the transfer roller 7, and then the sheet is discharged to the outside of the apparatus by the sheet discharge roller pair 10. After the toner image has been transferred to the recording material P, the toner remaining on the photosensitive drum 11 is cleaned by the cleaning unit 13.

[0050] AsFigure 3A and 3B As shown, a rear cover 75 supported in an openable and closable manner is provided on the rear side of the image forming apparatus 1. The rear cover 75 serving as an opening and closing member covers the process unit 20 when in a closed state and exposes the process unit 20 when opened. In a state where the rear cover 75 is open, the process unit 20 can be opened and closed along the rear side of the image forming apparatus 1. Figure 4 The device is attached to the apparatus body 2 in the attachment direction AD shown, and can be detached in a detachment direction opposite to the attachment direction AD. The attachment direction AD is a direction along the Y direction.

[0051] By opening the rear cover 75, the double-sided conveying path 16 is exposed (see Figure 2 ). That is, the rear cover 75 can be moved between a closed position in which the double-sided conveying path 16 is covered and an open position in which the double-sided conveying path 16 is exposed to the outside. Thus, sheet jamming that occurs in the double-sided conveying path 16 can be resolved. In addition, by opening the transfer unit (not shown) in a state in which the double-sided conveying path 16 is in the open position, the conveying path 19 (see Figure 2 ) is opened, and the sheet conveyed by the conveying roller pair 5 c passes through the conveying path 19.

[0052] Positioning configuration of processing units

[0053] Next, we will refer to Figure 4 to Figure 8 The positioning configuration of the processing unit 20 is described. Figure 4 is a perspective view showing the image forming apparatus 1 in a state before the process unit 20 is attached. Figure 5A is a rear view and an enlarged view of the positioning configuration of the processing unit 20 positioned by the left side plate frame 73, Figure 5B It is a rear view and an enlarged view of the positioning configuration in which the processing unit 20 is positioned by the right side plate frame 74.

[0054] like Figure 4 As shown, the processing unit 20 includes a left side surface 30L and a right side surface 30R, which serve as end portions in the longitudinal direction LD parallel to the X direction. The left side surface 30L includes a left positioning boss 21L serving as a first positioned portion and a left rotation regulating boss 22L serving as a second positioned portion, while the right side surface 30R includes a right positioning boss 21R and a right rotation regulating boss 22R (see Figure 7B The left positioning boss 21L and the right positioning boss 21R are respectively arranged upstream of the left rotation regulating boss 22L and the right rotation regulating boss 22R in the attachment direction AD of the processing unit 20. In other words, the left rotation regulating boss 22L and the right rotation regulating boss 22R are respectively arranged downstream of the left positioning boss 21L and the right positioning boss 21R in the attachment direction AD.

[0055] The apparatus body 2 of the image forming apparatus 1 includes a left side plate frame 73 and a right side plate frame 74 formed of sheet metal members, wherein the left side plate frame 73 and the right side plate frame 74 are opposed to each other in the longitudinal direction LD serving as the second direction with a gap therebetween. Note that the left side plate frame 73 is provided on the left side surface 30L side of the process unit 20 in the longitudinal direction LD.

[0056] like Figure 4 and Figure 5A As shown, the left side plate frame 73 serving as a frame member includes a first left surface 81Lf and a second left surface 82Lf, which extend in the direction along the attachment direction AD (i.e., the Y direction) and the Z direction. By stretching the first left surface 81Lf serving as the first surface, the second left surface 82Lf is arranged to be spaced apart from the first left surface 81Lf at a distance X1 on the inner side of the device body 2 along the longitudinal direction LD. In other words, the second left surface 82Lf is arranged to be closer to the center part of the processing unit 20 in the longitudinal direction LD than the first left surface 81Lf. That is, the first left surface 81Lf and the second left surface 82Lf are not coplanar. In this embodiment, the second left surface 82Lf serving as the second surface is composed of surfaces parallel to the attachment direction AD (i.e., the Y direction) and the Z direction, but the present technology is not limited to this. For example, the second left surface 82Lf can be a curved surface along the attachment direction AD (i.e., the Y direction) and the Z direction.

[0057] The left positioning portion 81L (with which the left positioning boss 21L can engage) is formed on the first left surface 81Lf, wherein the left positioning portion 81L serving as the first positioning portion is a cutout that is open on the upstream side in the attachment direction AD. In other words, the left positioning portion 81L is a first opening. Or the left positioning portion 81L is part of a slit extending from the upstream edge of the left side plate frame 73 along the attachment direction AD. The left rotation control portion 82L (with which the left rotation control boss 22L can engage) is formed on the second left surface 82Lf, wherein the left rotation control portion 82L serving as the second positioning portion is a U-shaped cutout that is open on the upstream side in the attachment direction AD. In other words, the left rotation control portion 82L is a second opening provided on the second left surface 82Lf of the left side plate frame 73. Since the second left surface 82Lf is formed by stretching, an inclined surface can be formed for guiding the left positioning boss 21L toward the left positioning portion 81L.

[0058] Since the first left surface 81Lf and the second left surface 82Lf are positioned a distance X1 from each other in the longitudinal direction LD, the left rotation regulating portion 82L is also positioned a distance X1 from the left positioning portion 81L in the longitudinal direction LD. In other words, the left rotation regulating portion 82L is positioned at a different position in the longitudinal direction LD than the left positioning portion 81L. In other words, the left rotation regulating portion 82L is positioned closer to the center of the process unit 20 in the longitudinal direction LD than the left positioning portion 81L.

[0059] Similarly, if Figure 4 and 5B As shown, the right side plate frame 74 includes a first right surface 81Rf and a second right surface 82Rf extending along the attachment direction AD (i.e., the Y direction) and the Z direction. By stretching the first right surface 81Rf, the second right surface 82Rf is arranged to be separated from the first right surface 81Rf by a distance X2 on the inner side of the device body 2 along the longitudinal direction LD. In other words, the first right surface 81Rf and the second right surface 82Rf are not coplanar. In this embodiment, the first right surface 81Rf and the second right surface 82Rf are composed of surfaces parallel to the attachment direction AD (i.e., the Y direction) and the Z direction, but the present technology is not limited to this. For example, the second right surface 82Rf can be a curved surface along the attachment direction AD (i.e., the Y direction) and the Z direction.

[0060] The right positioning portion 81R (with which the right positioning boss 21R can engage) is formed on the first right surface 81Rf. The right positioning portion 81R is a cutout that opens upstream in the attachment direction AD. The right rotation regulating portion 82R (with which the right rotation regulating boss 22R can engage) is formed on the second right surface 82Rf. The right rotation regulating portion 82R is a U-shaped cutout that opens upstream in the attachment direction AD. Since the second right surface 82Rf is formed by stretching, it can form an inclined surface for guiding the right positioning boss 21R toward the right positioning portion 81R.

[0061] Since the first right surface 81Rf and the second right surface 82Rf are positioned to be spaced apart from each other by a distance X2 in the longitudinal direction LD, the right rotation regulating portion 82R is also arranged to be spaced apart from the right positioning portion 81R by a distance X2 in the longitudinal direction LD. In other words, the right rotation regulating portion 82R is arranged at a position different from the right positioning portion 81R in the longitudinal direction LD.

[0062] Figure 6A is a schematic diagram showing the image forming apparatus 1 in a state where the processing unit 20 is attached, Figure 6B 81L and the left rotation control portion 82L. Figure 5A to 6BAs shown, when the process unit 20 is attached to the device body 2, the process unit 20 is pushed from the rear side toward the front side by an unillustrated pushing mechanism. When the process unit 20 is attached to the device body 2, the left positioning boss 21L and the left rotation regulating boss 22L of the process unit 20 respectively engage with the left positioning portion 81L and the left rotation regulating portion 82L of the left side plate frame 73. Similarly, when the process unit 20 is attached to the device body 2, the right positioning boss 21R and the right rotation regulating boss 22R of the process unit 20 respectively engage with the right positioning portion 81R and the right rotation regulating portion 82R of the right side plate frame 74.

[0063] By engaging the left positioning boss 21L and the right positioning boss 21R with the left positioning portion 81L and the right positioning portion 81R, respectively, the processing unit 20 is positioned relative to the left plate frame 73 and the right plate frame 74 in the attachment direction AD. In addition, by engaging the left rotation control boss 22L and the right rotation control boss 22R with the left rotation control portion 82L and the right rotation control portion 82R, respectively, the rotational movement of the processing unit 20 around the left positioning boss 21L and the right positioning boss 21R is controlled. In other words, the processing unit 20 is positioned relative to the left plate frame 73 and the right plate frame 74 in the Z direction serving as the first direction. The rotation axis serving as the center of the left positioning boss 21L and the right positioning boss 21R extends in the longitudinal direction LD and overlaps with the left rotation control portion 82L and the right rotation control portion 82R when viewed along the longitudinal direction LD.

[0064] In more detail, if Figure 6B As shown, the left positioning portion 81L includes protrusions 51, 52, and 53 against which the left positioning boss 21L abuts. When the process unit 20 is attached to the apparatus body 2, the left positioning boss 21L abuts against the protrusions 51 and 52 in the attachment direction AD, thereby positioning the process unit 20. In this state, the left positioning boss 21L abuts against the protrusions 51, 52, and 53 in the Z direction, thereby positioning the process unit 20 in the Z direction. In other words, the left positioning portion 81L, together with the left rotation control portion 82L, positions the process unit 20 in the Z direction.

[0065] Furthermore, when the process unit 20 is attached to the apparatus body 2, that is, when the left positioning boss 21L abuts against the protruding portions 51, 52, and 53, a gap G is formed between the left rotation regulating boss 22L and the left rotation regulating portion 82L along the attachment direction AD. In other words, when the process unit 20 is positioned along the attachment direction AD by the left positioning portion 81L, the left rotation regulating portion 82L is configured so as not to position the process unit 20 in the attachment direction AD. Therefore, the process unit 20 can be reliably positioned in the attachment direction AD by the left positioning portion 81L, and the positioning accuracy of the process unit 20 can be improved.

[0066] The right positioning portion 81R and the right rotation control portion 82R adopt a similar configuration to the left positioning portion 81L and the left rotation control portion 82L, and thus the description thereof is omitted.

[0067] Figure 6C is an enlarged view showing the left positioning portion 281L and the left rotation control portion 282L according to a variant of the first embodiment. According to the present embodiment shown in Figure 6B The left positioning portion 81L is arranged upstream of the left rotation control portion 82L in the attachment direction AD, but the present technology is not limited thereto. For example, as shown in Figure 6C The left positioning portion 281L serving as the first positioning portion can be arranged downstream of the left rotation control portion 282L serving as the second positioning portion in the attachment direction AD.

[0068] The left positioning portion 281L has faces 251, 252, and 253, of which the faces 251 and 253 oppose each other in the Z direction. In a state in which the processing unit 20 is attached to the device body 2, the left positioning boss 221L serving as the first positioned portion abuts against the face 252 of the left positioning portion 281L and is positioned in the attachment direction AD. Also at this time, the left positioning boss 221L abuts against the faces 251 and 253 in the Z direction, whereby it is also positioned in the Z direction.

[0069] The left rotation control portion 282L includes protruding portions 261 and 262. In a state in which the processing unit 20 is positioned by the left positioning portion 81L in the attachment direction AD, the left rotation control boss 222L serving as the second positioned portion is positioned in the Z direction by abutting against the protruding portions 261 and 262. Further, in this state, a gap G2 is formed between the left rotation control boss 222L and the left rotation control portion 282L in the attachment direction AD. In other words, in a state in which the processing unit 20 is positioned in the attachment direction AD by the left positioning portion 281L, the left rotation control portion 282L is configured not to position the processing unit 20 in the attachment direction AD. Thereby, the processing unit 20 can be reliably positioned in the attachment direction AD by the left positioning portion 281L, and the positioning accuracy of the processing unit 20 can be improved.

[0070] Figure 7A is a cross-sectional view taken parallel to the XY plane of a positioning configuration in which the processing unit 20 is positioned by the left side plate frame 73, Figure 7B is a cross-sectional view taken parallel to the XY plane of a positioning configuration of the processing unit 20 positioned by the right side plate frame 74.

[0071] As Figure 7AAs shown, the second left surface 82Lf (on which the left rotation control portion 82L is formed) is arranged on the inner side of the device body 2 in the longitudinal direction LD with respect to the first left surface 81Lf (on which the left positioning portion 81L is formed). Further, the left rotation control boss 22L is also arranged on the inner side of the device body 2 in the longitudinal direction LD with respect to the left positioning boss 21L. Thereby, the shape of the cutout constituting the left rotation control portion 82L formed on the second left surface 82Lf can be formed in a relatively small area. Since the left positioning portion 81L is arranged upstream of the left rotation control portion 82L in the attachment direction AD, the shape of the cutout constituting the left positioning portion 81L formed on the first left surface 81Lf can also be formed in a relatively small area. As described above, by reducing the area of the cutout formed on the left side plate frame 73, the rigidity of the left side plate frame 73 can be ensured.

[0072] Similarly, as Figure 7B shown, the second right surface 82Rf (on which the right rotation control portion 82R is formed) is arranged on the inner side of the device body 2 in the longitudinal direction LD with respect to the first right surface 81Rf (on which the right positioning portion 81R is formed). Further, the right rotation control boss 22R is also arranged on the inner side of the device body 2 in the longitudinal direction LD with respect to the right positioning boss 21R. Thereby, the shape of the cutout constituting the right rotation control portion 82R formed on the second right surface 82Rf can be formed in a relatively small area. Further, since the right positioning portion 81R is arranged upstream of the right rotation control portion 82R in the attachment direction AD, the shape of the cutout constituting the right positioning portion 81R formed on the first right surface 81Rf can also be formed in a relatively small area. As described above, by reducing the area of the cutout formed on the right side plate frame 74, the rigidity of the right side plate frame 74 can be ensured.

[0073] By maintaining the rigidity of the left side plate frame 73 and the right side plate frame 74, the positioning accuracy of the processing unit 20 with respect to the device body 2 can be improved. Further, since it is not necessary to increase the thickness of the left side plate frame 73 and the right side plate frame 74 in order to enhance the rigidity of the left side plate frame 73 and the right side plate frame 74, the weight and cost of the device can be reduced.

[0074] Figure 8 is a left side view showing a positioning configuration in which the processing unit 20 is positioned by the left side plate frame 73. As Figure 8 shown, the left positioning portion 81L has side portions 81La and 81Lc opposite to each other in the Z direction, and a side portion 81Lb connecting the side portions 81La and 81Lc and opposite to the left positioning boss 21L in the attachment direction AD. Further, the left rotation control portion 82L has side portions 82La and 82Lb opposite to each other in the Z direction.

[0075] The width of the left positioning portion 81L in the Z direction (i.e., the distance between the side portions 81La and 81Lc) is width Z1. The width of the left rotation control portion 82L in the Z direction (i.e., the distance between the side portions 82La and 82Lb) is width Z2. Accordingly, the left rotation control portion 82L is arranged so that at least a portion thereof overlaps with the left positioning portion 81L in the Z direction. In other words, when viewed along the longitudinal direction LD, at least a portion of the left rotation control portion 82L is aligned with the left positioning portion 81L in the attachment direction AD. Thus, when the processing unit 20 is attached to the device body 2, the movement trajectories of the left positioning boss 21L and the left rotation control boss 22L in the Z direction overlap, and the area within the device body 2 that avoids the movement trajectory can be suppressed. Thus, the space within the device body 2 can be effectively utilized, and the image forming device 1 can be miniaturized.

[0076] Furthermore, since the left positioning portion 81L and the left rotation regulating portion 82L are both provided on the single left side plate frame 73 composed of a sheet metal member, it is possible to improve the positioning accuracy of the process unit 20 while suppressing component intersection.

[0077] The right side plate frame 74 adopts the same Figure 8 Further according to the present embodiment, the axial centers of the left positioning boss 21L and the left rotation regulating boss 22L are at the same position in the Z direction, but the present technology is not limited thereto.

[0078] Second embodiment

[0079] Next, a second embodiment of the present technology will be described, wherein according to the second embodiment, the configurations of the second left surface 82Lf and the second right surface 82Rf of the first embodiment are changed. Therefore, in the drawings, configurations similar to those of the first embodiment are not shown or denoted by the same reference numerals.

[0080] Figure 9 1 is a schematic diagram showing the image forming apparatus 1B according to the second embodiment in a state before the process unit 20B serving as a detachable unit is attached. Figure 10A 20B is a rear view and an enlarged view showing a positioning configuration in which the processing unit 20B is positioned by the left side plate frame 73B, Figure 10B 1 and 2 are a rear view and an enlarged view showing a positioning configuration in which the process unit 20B is positioned according to the right side plate frame 74B.

[0081] like Figure 9As shown, the processing unit 20B includes left and right side surfaces 30L and 30R serving as end surfaces in the longitudinal direction LD, and surfaces 31L and 31R facing the downstream side in the attachment direction AD. The surface 31L includes the left rotation control boss 22BL serving as a second positioning portion, and the surface 31R includes the right rotation control boss 22BR. The left and right rotation control bosses 22BL and 22BR extend downstream in the attachment direction AD. The left and right positioning bosses 21BL and 21BR are arranged upstream of the left and right rotation control bosses 22BL and 22BR, respectively, in the attachment direction AD.

[0082] The device main body 2B of the image forming apparatus 1B includes left and right side plate frames 73B and 74B composed of sheet metal members, which oppose each other with a gap therebetween in the longitudinal direction LD.

[0083] As shown in Figure 9 and 10A , the left side plate frame 73B includes a first left surface 81Lf extending in the direction along the attachment direction AD (i.e., the Y direction) and the Z direction, and a second left surface 82BLf extending in the direction along the longitudinal direction LD and the Z direction. The second left surface 82BLf serving as a second surface is arranged inside the device main body 2 from the first left surface 81Lf in the longitudinal direction LD by stretch working the first left surface 81Lf. That is, the first left surface 81Lf and the second left surface 82BLf are not coplanar. In the present embodiment, the second left surface 82BLf is composed of a surface parallel to the longitudinal direction LD and the Z direction, but the present technology is not limited thereto. For example, the second left surface 82Lf can be a curved surface along the longitudinal direction LD and the Z direction.

[0084] A left rotation control portion 82BL (with which the left rotation control boss 22BL is engageable) is formed on the second left surface 82BLf, which is composed of a hole portion penetrating in the attachment direction AD, serving as a second positioning portion. Further, the left rotation control portion 82BL includes surfaces 82BLa and 82BLb engageable with the left rotation control boss 22BL in the Z direction. Since the second left surface 82BLf is arranged inside the device main body 2 from the first left surface 81Lf in the longitudinal direction LD, the left rotation control portion 82BL is arranged at a position different from the left positioning portion 81BL in the longitudinal direction LD.

[0085] Similarly, as shown in Figure 9 and 10BAs shown, the right side plate frame 74B includes a first right surface 81Rf extending along the attachment direction AD (i.e., the Y direction) and the Z direction, and a second right surface 82BRf extending along the longitudinal direction LD and the Z direction. By stretching the first right surface 81Rf, the second right surface 82BRf is arranged on the inner side of the device body 2 along the longitudinal direction LD from the first right surface 81Rf. That is, the first right surface 81Rf and the second right surface 82Rf are not coplanar. In this embodiment, the first right surface 81Rf and the second right surface 82Rf are composed of surfaces parallel to the attachment direction AD (i.e., the Y direction) and the Z direction, but the present technology is not limited to this. For example, the second right surface 82Rf can be a curved surface along the attachment direction AD (i.e., the Y direction) and the Z direction.

[0086] A right rotation control portion 82BR (with which the right rotation control boss 22BR can engage) is formed on the second right surface 82BRf, wherein the right rotation control portion 82BR is composed of a hole portion extending therethrough in the attachment direction AD. Furthermore, the right rotation control portion 82BR includes surfaces 82BRa and 82BRb that can engage with the right rotation control boss 22BR in the Z direction. Since the second right surface 82BRf is arranged on the inner side of the device body 2 along the longitudinal direction LD from the first right surface 81Rf, the right rotation control portion 82BR is arranged at a different position along the longitudinal direction LD from the right positioning portion 81BR.

[0087] Figure 10A to Figure 11 FIG is a schematic diagram illustrating the image forming apparatus 1B in a state where the process unit 20B is mounted. Figure 11 As shown, when the processing unit 20B is attached to the device body 2B, the processing unit 20B is pushed from the rear side to the front side by a pushing mechanism (not shown). When the processing unit 20B is attached to the device body 2B, the left positioning boss 21L and the left rotation control boss 22BL of the processing unit 20B are respectively engaged with the left positioning portion 81L and the left rotation control portion 82BL of the left side plate frame 73B. Similarly, when the processing unit 20B is attached to the device body 2B, the right positioning boss 21R and the right rotation control boss 22BR of the processing unit 20B are respectively engaged with the right positioning portion 81R and the right rotation control portion 82BR of the right side plate frame 74B.

[0088] By engaging the left and right positioning bosses 21L and 21R with the left and right positioning portions 81L and 81R, respectively, the process unit 20B is positioned in the attachment direction AD. Furthermore, by engaging the left and right rotation control bosses 22BL and 22BR with the left and right rotation control portions 82BL and 82BR, respectively, the rotational movement of the process unit 20B about the left and right positioning bosses 21L and 21R is controlled. In other words, the process unit 20B is positioned in the Z direction.

[0089] Similarly to the first embodiment, the second left surface 82BLf (on which the left rotation control portion 82BL is formed) is arranged on the inner side of the device body 2 in the longitudinal direction LD with respect to the first left surface 81Lf (on which the left positioning portion 81L is formed). Further, the left rotation control boss 22BL is also arranged on the inner side of the device body 2 in the longitudinal direction LD with respect to the left positioning boss 21L. Thereby, the shape of the hole constituting the left rotation control portion 82BL formed on the second left surface 82BLf can be formed in a relatively small area. Since the left positioning portion 81L is arranged upstream of the left rotation control portion 82BL in the attachment direction AD, the shape of the cutout constituting the left positioning portion 81L formed on the first left surface 81Lf can also be formed in a relatively small area. As described above, by reducing the area of the cutout or hole formed on the left side plate frame 73B serving as a frame member, the rigidity of the left side plate frame 73B can be ensured.

[0090] Similarly, by reducing the area of the cutout or hole formed on the right side plate frame 74B, the rigidity of the right side plate frame 74B can be ensured. By ensuring the rigidity of the left side plate frame 73B and the right side plate frame 74B, the positioning accuracy of the processing unit 20B with respect to the device body 2B can be improved. Further, since it is not necessary to increase the thickness of the left side plate frame 73B and the right side plate frame 74B in order to enhance the rigidity of the left side plate frame 73B and the right side plate frame 74B, the weight and cost of the device can be reduced.

[0091] Third Embodiment

[0092] Next, a third embodiment of the present technology will be described. Instead of the processing unit 20 described according to the first embodiment, the fixing unit 9 described according to the third embodiment is configured to be detachably attached to the device body 2C. Therefore, configurations similar to the first embodiment are not shown or denoted with the same reference numerals.

[0093] Figure 12 is a schematic view showing the image forming device 1C according to the third embodiment in a state before the fixing unit 9 serving as a detachable unit and a fixing unit is attached. As shown in Figure 12 , the fixing unit 9 includes a left side surface 41L and a right side surface 41R serving as end surfaces in a longitudinal direction LD parallel to the X direction. The left side surface 41L includes the left positioning boss 21L and the left rotation control boss 22L, and the right side surface 41R similarly includes the right positioning boss 21R and the right rotation control boss 22R (see Figure 7B ).

[0094] Figure 13 is a left side view showing a positioning configuration in which the fixing unit 9 is positioned by the left side plate frame 73. As shown in Figure 13As shown, when the fixing unit 9 is attached to the apparatus body 2, the fixing unit 9 is urged from the rear side toward the front side by an unillustrated urging mechanism. When the fixing unit 9 is attached to the apparatus body 2C, the left positioning boss 21L and the left rotation regulating boss 22L of the fixing unit 9 engage with the left positioning portion 81L and the left rotation regulating portion 82L of the left side plate frame 73, respectively. Similarly, when the fixing unit 9 is attached to the apparatus body 2, the right positioning boss 21R and the right rotation regulating boss 22R of the fixing unit 9 engage with the right positioning portion 81R and the right rotation regulating portion 82R of the right side plate frame 74, respectively.

[0095] By engaging the left and right positioning bosses 21L and 21R with the left and right positioning portions 81L and 81R, respectively, the fixing unit 9 is positioned in the attachment direction AD. Furthermore, by engaging the left and right rotation regulating bosses 22L and 22R with the left and right rotation regulating portions 82L and 82R, respectively, the rotational movement of the fixing unit 9 about the left and right positioning bosses 21L and 21R is regulated. In other words, the fixing unit 9 is positioned in the Z direction.

[0096] The left positioning boss 21L, the left rotation regulating boss 22L, the right positioning boss 21R, and the right rotation regulating boss 22R adopt similar configurations to those of the first embodiment, and thus descriptions thereof are omitted.

[0097] Other embodiments

[0098] According to all the above embodiments, the process unit 20, 20B or the fixing unit 9 is attached from the rear side to the front side of the apparatus body 2, 2B or 2C, but the present technology is not limited thereto. In other words, the attachment direction AD is not limited to the direction along the Y direction.

[0099] In all of the above embodiments, the boss-shaped positioning boss and the rotation regulating boss are provided on the process unit 20, 20B or the fixing unit 9, but the present technology is not limited thereto. In other words, a non-boss-shaped positioning member and a rotation regulating member may be provided on the process unit 20, 20B or the fixing unit 9.

[0100] Furthermore, according to the first and second embodiments, the process unit 20 or 20B including the photosensitive drum 11, the developing roller 12, and the storage portion 18 is configured to be detachably attached to the apparatus body 2 or 2B, but the present technology is not limited thereto. For example, instead of the process unit, only the storage portion 18 for storing toner, or a developing unit including the developing roller 12 and the storage portion 18 but not the photosensitive drum 11 can be positioned on the apparatus body 2 using the above-described positioning configuration.

[0101] According to all of the above-described embodiments, the left positioning portion 81L is arranged upstream of the left rotation control portion 82L or 82BL in terms of the attachment direction AD, but the present technology is not limited thereto. For example, the left positioning portion 81L can be arranged downstream of the left rotation control portion 82L or 82BL in terms of the attachment direction AD. In this case, the left positioning portion 81L is preferably arranged on the second left surface 82Lf or 82BLf, and the left rotation control portion 82L is preferably arranged on the first left surface 81Lf.

[0102] According to all of the above-described embodiments, the image forming apparatus 1, 1B, or 1C employing an electrophotographic system has been described, but the present technology is not limited thereto. For example, the present technology can be applied to an image forming apparatus employing an inkjet system in which liquid ink is discharged through a nozzle to form an image on a sheet.

[0103] While the present technology has been described with reference to example embodiments, it is to be understood that the technology is not limited to the disclosed example embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all the variations and equivalents.

Claims

1. An image forming apparatus for forming an image on a recording material, the image forming apparatus comprising: Unit, the unit comprising: a photosensitive drum rotatable about a rotation axis extending in a rotation axis direction intersecting the direction of gravity; a developing roller configured to supply toner to the photosensitive drum; a first contact portion that projects relative to an end surface portion of the unit in the direction of the rotation axis; as well as a second contact portion that projects relative to the end surface portion of the unit, the second contact portion being provided inside relative to the first contact portion in the rotation axis direction, and an apparatus body to which the unit is attachable along an attachment direction intersecting both the rotation axis and the gravity direction, the apparatus body including a side frame portion disposed so as to face the unit, wherein the side frame portion of the device body is provided with a first contacted portion and a second contacted portion, the first contacted portion and the second contacted portion being configured to contact the first contacting portion and the second contacting portion of the unit, respectively, and The second contacted portion is disposed downstream of the first contacted portion in the attachment direction and is disposed inside the first contacted portion in the rotation axis direction.

2. An image forming device according to claim 1, wherein the side frame portion includes a sheet metal component, the sheet metal component having a stretched portion recessed toward the inner side of the device body in the direction of the rotation axis, so that the second contacted portion can be positioned on the inner side relative to the first contacted portion in the direction of the rotation axis.

3. The image forming apparatus according to claim 2, wherein the sheet metal member includes a portion formed as a first cutout, and a second cutout, the first contact portion is exposed from the sheet metal member through the portion formed as the first cutout, and the second contact portion is exposed from the sheet metal member through the second cutout.

4. The image forming apparatus according to any one of claims 1 to 3, wherein The image forming apparatus further includes a fixing unit for fixing the image on the recording material, and the first contact portion and the second contact portion are located below the fixing unit.

Images