Process cartridge and electrophotographic image forming apparatus

Abstract

The present invention relates to a process cartridge and an electrophotographic image forming apparatus so as to provide a structure for a process cartridge for receiving an input of driving force from an outside of the process cartridge. A main assembly of the electrophotographic image forming apparatus includes a driving output member provided with an output gear portion and an output coupling portion. A process cartridge capable of being mounted to and detached from the main assembly of the electrophotographic image forming apparatus includes a photosensitive member, an input coupling portion provided at an end portion of the photosensitive member and capable of being coupled with the output coupling portion, and an input gear portion capable of being engaged with the output gear portion.

Description

[0001] This application is a divisional application. The direct parent application of this application is the invention patent application with the invention name of “Process cartridge and electrophotographic image forming apparatus”, the filing date of June 14, 2017, and the national application number of 202111358283.3. The original parent application of this application is the invention patent application with the invention name of “Process cartridge and electrophotographic image forming apparatus”, the international filing date of June 14, 2017, the international application number of PCT / JP2017 / 022763, and the national application number of 201780036685.7. TECHNICAL FIELD

[0002] The present application relates to a process cartridge and an electrophotographic image forming apparatus using the process cartridge.

[0003] Here, the process cartridge is a cartridge integrally formed with a photosensitive member and a process means capable of acting on the photosensitive member, and detachably mounted to a main assembly of the electrophotographic image forming apparatus.

[0004] For example, the photosensitive member is integrally formed with at least one of a developing means, a charging means, and a cleaning means as the process means as a cartridge. Also, the electrophotographic image forming apparatus forms an image on a recording material using an electrophotographic image forming process.

[0005] Examples of the electrophotographic image forming apparatus include an electrophotographic copier, an electrophotographic printer (LED printer, laser beam printer, etc.), a facsimile machine, a word processor, and the like. BACKGROUND

[0006] In the electrophotographic image forming apparatus (hereinafter, also simply referred to as “image forming apparatus”), a drum-type electrophotographic photosensitive member, i.e., a photosensitive drum (electrophotographic photosensitive drum) as an image bearing member is uniformly charged. Subsequently, the charged photosensitive drum is selectively exposed to light to form an electrostatic latent image (electrostatic image) on the photosensitive drum. Next, the electrostatic latent image formed on the photosensitive drum is developed into a toner image with toner as a developer. Then, the toner image formed on the photosensitive drum is transferred onto a recording material (e.g., recording sheet, plastic sheet, etc.), and the toner image transferred onto the recording material is heated and pressed to fix the toner image on the recording material, thereby performing image recording.

[0007] Such an image forming apparatus generally requires replenishment of toner and maintenance of various process means. In order to facilitate the replenishment of toner and the maintenance, a process cartridge in which a photosensitive drum, a charging means, a developing means, a cleaning means, and the like are integrated in a frame and can be detachably mounted to a main assembly of the image forming apparatus has been put into practical use.

[0008] With this process cartridge system, a part of the maintenance operation of the device can be performed by the user himself without having to rely on service personnel responsible for after-sales service. Thus, the availability of the device can be significantly improved, and an imaging device of excellent availability can be provided. Therefore, the process cartridge system is widely used for imaging devices.

[0009] As described in JP H08-328449 (page 20, Figure 16 ), the known imaging device of the above type includes a drive transmission member having a coupling at its free end for transmitting a drive to the process cartridge from a main assembly of the imaging device which is spring-biased toward the process cartridge.

[0010] When the opening and closing door of the main assembly of the imaging device is closed, the drive transmission member of the imaging device is pressurized by the spring and moves toward the process cartridge. By doing so, the drive transmission member engages (couples) with the coupling of the process cartridge and the transmission of the drive to the process cartridge can be achieved. Also, when the opening and closing door of the main assembly of the imaging device is opened, the drive transmission member moves in a direction away from the process cartridge against the spring by a cam. Thereby, the drive transmission member disengages (uncouples) from the coupling of the process cartridge, so that the process cartridge can be detached from the main assembly of the imaging device. SUMMARY

[0011] [Problems to be Solved by the Invention]

[0012] It is an object of the present invention to further develop the prior art described above.

[0013] [Means for Solving the Problems]

[0014] One typical structure of the invention in this application is:

[0015] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge comprising: a photosensitive member; a coupling portion provided at an end portion of the photosensitive member and including a drive force receiving portion for receiving a drive force for rotating the photosensitive member from outside of the process cartridge; and a gear portion including a gear tooth for receiving a drive force from outside of the process cartridge independently of the coupling portion, wherein the gear tooth includes an exposed portion exposed to outside of the process cartridge, wherein at least a part of the exposed portion (a) faces an axis of the photosensitive member, (b) is disposed outside of the drive force receiving portion in an axial direction of the photosensitive member, and (c) is in the vicinity of a peripheral surface of the photosensitive member.

[0016] Another structure is:

[0017] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the main assembly including a drive output member having an output gear portion and an output coupling portion coaxial with each other, the process cartridge including: a photosensitive member; an input coupling portion provided at an end portion of the photosensitive member and couplable with the output coupling portion; and an input gear portion engageable with the output gear portion; wherein the input gear portion is configured such that the input gear portion and the output gear portion are attracted to each other by their rotations in a state where the input gear portion and the output gear portion are engaged with each other.

[0018] A further configuration is:

[0019] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including: a photosensitive member; a coupling portion provided at an end portion of the photosensitive member and including a drive force receiving portion for receiving a drive force for rotating the photosensitive member from outside of the process cartridge; and a gear portion including gear teeth for receiving a drive force from outside of the process cartridge independently of the coupling portion; wherein the gear teeth are helical gear teeth, and include an exposed portion exposed to outside of the process cartridge, wherein at least a portion of the exposed portion is disposed outside of the drive force receiving portion in an axial direction of the photosensitive member and faces an axis of the photosensitive member.

[0020] A further configuration is:

[0021] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including: a photosensitive member; a coupling portion provided at an end portion of the photosensitive member and including a drive force receiving portion configured to receive a drive force for rotating the photosensitive member from outside of the process cartridge; a gear portion including gear teeth for receiving a drive force from outside of the process cartridge independently of the coupling portion; and a developer bearing member configured to bear a developer to develop a latent image formed on the photosensitive member, the developer bearing member being rotatable in a clockwise direction as seen in a direction in which the gear portion rotates clockwise; wherein the gear teeth include an exposed portion exposed to outside of the process cartridge, wherein at least a portion of the exposed portion faces an axis of the photosensitive member and is disposed outside of the drive force receiving portion in an axial direction of the photosensitive member.

[0022] A further configuration is:

[0023] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including: a photosensitive member; an alignment portion coaxially disposed with the photosensitive member; and a gear portion including a gear tooth for receiving a driving force from outside of the process cartridge; wherein the gear tooth includes an exposed portion exposed to outside of the process cartridge, wherein at least a portion of the exposed portion (a) faces an axis of the photosensitive member, (b) is disposed outside of the alignment portion in an axial direction of the photosensitive member, and (c) is disposed adjacent to a peripheral surface of the photosensitive member in a plane perpendicular to the axis of the photosensitive member.

[0024] A further structure is:

[0025] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the main assembly including a driving output member having an output gear portion and a main assembly side alignment portion coaxial with each other, the process cartridge including: a photosensitive member; a cartridge side alignment portion engageable with the main assembly side alignment portion to achieve alignment between the photosensitive member and the driving output member; and an input gear portion engageable with the output gear portion; wherein the input gear portion is configured such that the input gear portion and the output gear portion are attracted to each other by their rotation in a state where the input gear portion and the output gear portion are engaged with each other.

[0026] A further structure is:

[0027] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including: a photosensitive member; an alignment portion coaxially disposed with the photosensitive member; and a gear portion including a gear tooth for receiving a driving force from outside of the process cartridge, wherein the gear tooth is a helical gear tooth, and includes an exposed portion exposed to outside of the process cartridge, wherein at least a portion of the exposed portion is disposed outside of the alignment portion in an axial direction of the photosensitive member and faces an axis of the photosensitive member.

[0028] A further structure is:

[0029] A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge including: a photosensitive member; an alignment portion coaxially disposed with the photosensitive member; a gear portion including a gear tooth configured to receive a driving force from outside of the process cartridge; and a developer bearing member configured to bear a developer to develop a latent image formed on the photosensitive member, the developer bearing member being rotatable in a clockwise direction as viewed in a direction in which the gear portion rotates clockwise, wherein the gear tooth includes an exposed portion exposed to outside of the process cartridge, and wherein at least a portion of the exposed portion faces an axis of the photosensitive member and is disposed outside of the alignment portion in an axial direction of the photosensitive member.

[0030] [Effects of Invention]

[0031] The above-described prior art can be further developed. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is a view of a drive transmission portion of the process cartridge according to Embodiment 1.

[0033] Figure 2 is a cross-sectional view of an image forming apparatus main assembly and the process cartridge according to Embodiment 1.

[0034] Figure 3 is a cross-sectional view of the process cartridge according to Embodiment 1.

[0035] Figure 4 is a perspective view of the image forming apparatus main assembly in a state in which an opening and closing door of the electrophotographic image forming apparatus according to Embodiment 1 is open.

[0036] Figure 5 is a perspective view of the process cartridge and a drive side positioning portion of the image forming apparatus main assembly in a state in which the process cartridge is mounted on the electrophotographic image forming apparatus main assembly according to Embodiment 1.

[0037] Figure 6 is a view of a link portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0038] Figure 7 is a view of a link portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0039] Figure 8 is a cross-sectional view of a guide portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0040] Figure 9 is a view of a drive chain of the electrophotographic image forming apparatus according to Embodiment 1.

[0041] Figure 10 is an illustration of a positioning portion for positioning in a longitudinal direction in the electrophotographic image forming apparatus according to Embodiment 1.

[0042] Figure 11 is an illustration of a positioning portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0043] Figure 12 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0044] Figure 13 is a perspective view of a drive transmission portion on the electrophotographic image forming apparatus according to Embodiment 1.

[0045] Figure 14 is a perspective view of a developing roller gear of the electrophotographic image forming apparatus according to Embodiment 1.

[0046] Figure 15 is a perspective view of a drive transmission portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0047] Figure 16 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0048] Figure 17 is a cross-sectional view of a drum surrounding of the electrophotographic image forming apparatus according to Embodiment 1.

[0049] Figure 18 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0050] Figure 19 is a perspective view of a drive transmission portion of the process cartridge according to Embodiment 1.

[0051] Figure 20 is a cross-sectional view of a drive transmission portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0052] Figure 21 is a perspective view of a developing roller gear of the process cartridge according to Embodiment 1.

[0053] Figure 22 is an illustration of a drive chain of the process cartridge according to Embodiment 1.

[0054] Figure 23 is an illustration of a drive transmission portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0055] Figure 24 is an illustration of a control portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0056] Figure 25 is a cross-sectional view of a drive transmission portion of the process cartridge according to Embodiment 1.

[0057] Figure 26 is a perspective view of a management portion of the process cartridge according to Embodiment 1.

[0058] Figure 27 is an illustration of the management portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0059] Figure 28 is an illustration of the drive transmission portion of the electrophotographic image forming apparatus according to Embodiment 1.

[0060] Figure 29 is a perspective view of a management portion of the electrophotographic image forming apparatus according to Embodiment 2.

[0061] Figure 30 is an illustration of the management portion of the electrophotographic image forming apparatus according to Embodiment 2.

[0062] Figure 31 is an illustration of the management portion of the electrophotographic image forming apparatus according to Embodiment 2.

[0063] Figure 32 is an illustration of the management portion of the electrophotographic image forming apparatus according to Embodiment 2.

[0064] Figure 33 is an illustration of the process cartridge according to Embodiment 1.

[0065] Figure 34 is an illustration of the process cartridge according to Embodiment 1.

[0066] Figure 35 is an illustration of a modification of Embodiment 1.

[0067] Figure 36 is an illustration of a modification of Embodiment 1.

[0068] Figure 37 is a perspective view showing a gear portion and a coupling portion in Embodiment 1.

[0069] Figure 38 is a perspective view showing a modification of Embodiment 1.

[0070] Figure 39 is an illustration of the apparatus according to Embodiment 2. DETAILED DESCRIPTION

[0071] <EMBODIMENT 1>

[0072] Embodiments of the present application will be described in detail with reference to the accompanying drawings.

[0073] The direction of the rotation axis of the electrophotographic photosensitive drum is defined as a longitudinal direction.

[0074] In the longitudinal direction, the side of the electrophotographic photosensitive drum from which driving force is received from the main assembly of the image forming apparatus is a driving side, and the opposite side thereof is a non-driving side.

[0075] Reference Figure 2 and Figure 3 The overall structure and the image forming process will be described.

[0076] Figure 2 is a cross-sectional view of a main assembly of an electrophotographic image forming apparatus (electrophotographic image forming apparatus main assembly, image forming apparatus main assembly) A and a process cartridge (hereinafter referred to as a cartridge B) according to an embodiment of the present application.

[0077] Figure 3 is a cross-sectional view of the cartridge B.

[0078] Here, the apparatus main assembly A is a portion of the electrophotographic image forming apparatus other than the cartridge B.

[0079] <Overall configuration of the electrophotographic image forming apparatus>

[0080] Figure 2 The illustrated electrophotographic image forming apparatus (image forming apparatus) is a laser beam printer using electrophotographic processing, in which the cartridge B is detachably mounted to the apparatus main assembly A. An exposure device 3 (laser scanner unit) is provided for forming a latent image on an electrophotographic photosensitive drum 62 that is an image bearing member of the cartridge B when the cartridge B is mounted in the apparatus main assembly A. Also, below the cartridge B, a sheet tray 4 containing a recording material (hereinafter referred to as a sheet PA) to be subjected to image formation is provided. The electrophotographic photosensitive drum 62 is a photosensitive member (electrophotographic photosensitive member) for forming an electrophotographic image.

[0081] Further, in the apparatus main assembly A, a pickup roller 5a, a pair of feed rollers 5b, a pair of feed rollers 5c, a transfer guide 6, a transfer roller 7, a feed guide 8, a fixing device 9, a pair of discharge rollers 10, a discharge tray 11, and the like are arranged in this order. In addition, the fixing device 9 includes a heating roller 9a and a pressure roller 9b.

[0082] <Image forming process>

[0083] Next, the image forming process will be briefly explained. Based on a print start signal, the electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum 62 or simply a drum 62) is rotationally driven in the direction of the arrow R at a predetermined circumferential speed (process speed).

[0084] A charging roller (charging member) 66 to which a bias voltage is applied is brought into contact with the outer peripheral surface of the drum 62 to uniformly charge the outer peripheral surface of the drum 62.

[0085] Exposure apparatus 3 outputs a laser beam L based on image information. The laser beam L passes through a laser opening 71h provided in the cleaning frame 71 of housing B and scans and incident on the outer peripheral surface of drum 62. As a result, an electrostatic latent image corresponding to the image information is formed on the outer peripheral surface of drum 62.

[0086] On the other hand, such as Figure 3 As shown, in the developing unit 20, which is a developing apparatus, the toner T in the toner chamber 29 is stirred by the rotation of the feeding member (stirring member) 43 and fed into the toner supply chamber 28.

[0087] The toner T is carried on the surface of the developing roller 32 by the magnetic force of the magnetic roller 34 (fixed magnet). The developing roller 32 is a developer-carrying component that carries developer (toner T) on its surface to develop the latent image formed on the drum 62.

[0088] When the toner T becomes energized by friction through the developing blade 42, the layer thickness on the peripheral surface of the developing roller 32, which serves as the developer carrier, is controlled.

[0089] Toner T is supplied to drum 62 according to the electrostatic latent image to develop the latent image. Thus, the latent image is visualized as a toner image. Drum 62 is an image-carrying component for carrying the latent image and the image (toner image, developer image) formed on its surface using toner. Furthermore, as... Figure 2 As shown, in a timing relationship with the output of the laser beam L, the sheet PA stored in the lower part of the main assembly A is fed from the sheet tray 4 by the pickup roller 5a, the feed roller pair 5b, and the feed roller pair 5c. The sheet PA is then fed along the transfer guide 6 to the transfer position between the drum 62 and the transfer roller 7. At this transfer position, the toner image is sequentially transferred from the drum 62 to the sheet PA.

[0090] The sheet PA, with the toner image transferred onto it, is separated from the drum 62 and fed along the conveying guide 8 to the fixing unit 9. The sheet PA then passes through a clamping section between the heating roller 9a and the pressure roller 9b, which constitute the fixing unit 9. Pressure and heat fixing are performed in this clamping section, fixing the toner image onto the sheet PA. The sheet PA, having undergone the toner image fixing process, is fed to the discharge roller pair 10 and discharged onto the discharge tray 11.

[0091] On the other hand, such as Figure 3 As shown, after image transfer, residual toner remaining on the outer peripheral surface of drum 62 is removed by cleaning blade 77 and reused for imaging processing. The toner removed from drum 62 is stored in waste toner chamber 71b of cleaning unit 60. Cleaning unit 60 is a unit that includes photosensitive drum 62.

[0092] In the above description, the charging roller 66, the developing roller 32, the transfer roller 7, and the cleaning blade 77 serve as processing devices that act on the drum 62.

[0093] <Overall cartridge structure>

[0094] Next, the overall structure of the cartridge B will be described with reference to Figure 3 , 4 and 5. Figure 3 is a cross-sectional view of the cartridge B, and Figure 4 and Figure 5 are perspective views showing the structure of the cartridge B. In the description of this embodiment, screws for joining the components are omitted.

[0095] The cartridge B includes a cleaning unit (photosensitive member holding unit, drum holding unit, image bearing member holding unit, first unit) 60 and a developing unit (developer bearing member holding unit, second unit) 20.

[0096] Generally, a process cartridge is a cartridge in which at least one of an electrophotographic photosensitive member and a processing device that acts thereon is integrally formed as a cartridge, and the process cartridge is capable of being attached to and detached from a main assembly (device main assembly) of an electrophotographic image forming apparatus. Examples of the processing device include a charging device, a developing device, and a cleaning device.

[0097] As shown in Figure 3 , the cleaning unit 60 includes the drum 62, the charging roller 66, the cleaning member 77, and a cleaning frame 71 for supporting them. On the drive side of the drum 62, a drive-side drum flange 63 provided on the drive side is rotatably supported by a hole 73a of a drum bearing 73. Broadly speaking, the drum bearing 73 plus the cleaning frame 71 can be referred to as a cleaning frame.

[0098] As shown in Figure 5 , on the non-drive side, a hole portion (not shown) of the non-drive-side drum flange is rotatably supported by and configured to be supported by a drum shaft 78 press-fitted in a hole portion 71c provided in the cleaning frame 71.

[0099] Each drum flange is a supported portion that is rotatably supported by a bearing portion.

[0100] In the cleaning unit 60, the charging roller 66 and the cleaning member 77 are arranged in contact with the outer peripheral surface of the drum 62.

[0101] The cleaning member 77 includes a rubber blade 77a, which is a blade-shaped elastic member formed of rubber as an elastic material, and a support member 77b that supports the rubber blade. The rubber blade 77a is in reverse contact with the drum 62 with respect to the rotation direction of the drum 62. In other words, the rubber blade 77a is in contact with the drum 62 so that the tip end portion thereof faces the upstream side of the drum 62 in the rotation direction.

[0102] As Figure 3 shown, the waste toner removed from the surface of the drum 62 by the cleaning member 77 is stored in a waste toner chamber 71b formed by the cleaning frame 71 and the cleaning member 77.

[0103] Also, as Figure 3 shown, a scooping sheet 65 for preventing the waste toner from leaking from the cleaning frame 71 is provided in contact with the drum 62 at the edge of the cleaning frame 71.

[0104] The charging roller 66 is rotatably installed in the cleaning unit 60 by charging roller bearings (not shown) at the opposite ends in the longitudinal direction of the cleaning frame 71.

[0105] Further, the longitudinal direction of the cleaning frame 71 (the longitudinal direction of the cartridge B) extends in a direction substantially parallel to the rotation axis of the drum 62 (an axial direction). Therefore, in the case of simply referring to the longitudinal direction or only referring to the axial direction without a specific description, it means the axial direction of the drum 62.

[0106] The charging roller 66 is pressed against the drum 62 by the biasing member 68 pressing the charging roller bearing 67 toward the drum 62. The charging roller 66 is rotationally driven by the drum 62.

[0107] As Figure 3 shown, the developing unit 20 includes a developing roller 32, a developing container 23 that supports the developing roller 32, a developing blade 42, and the like. The developing roller 32 is rotatably installed in the developing container 23 by bearing members 27 Figure 5 and 37 Figure 4 provided at the opposite ends.

[0108] Also, inside the developing roller 32, a magnetic roller 34 is provided. In the developing unit 20, the developing blade 42 for controlling the toner layer on the developing roller 32 is provided. As Figure 4 and Figure 5 shown, a gap maintaining member 38 is installed to the developing roller 32 at the opposite ends of the developing roller 32, and the gap maintaining member 38 and the drum 62 are in contact with each other so that the developing roller 32 is maintained with a small gap from the drum 62. Also, as Figure 3As shown, a blowing prevention sheet 33 for preventing toner from leaking from the developing unit 20 is provided in contact with the developing roller 32 at the edge of the bottom member 22. In addition, in the toner chamber 29 formed by the developing container 23 and the bottom member 22, a feeding member 43 is provided. The feeding member 43 stirs the toner accommodated in the toner chamber 29 and conveys the toner to the toner supply chamber 28.

[0109] As shown in Figure 4 and Figure 5 , the cartridge B is formed by combining the cleaning unit 60 and the developing unit 20.

[0110] In a first step of joining the developing unit and the cleaning unit to each other, the center of the developing first support lug 26a of the developing container 23 is aligned with the first suspension hole 71i on the drive side of the cleaning frame 71 and the center of the developing second support lug 23b is aligned with the second suspension hole 71j on the non-drive side of the cleaning frame 71. More particularly, by moving the developing unit 20 in the direction of arrow G, the developing first support lug 26a and the developing second support lug 23b are fitted in the first suspension hole 71i and the second suspension hole 71j. Thereby, the developing unit 20 is movably connected to the cleaning unit 60. More specifically, the developing unit 20 is rotatably connected to the cleaning unit 60. Thereafter, the cartridge B is constructed by assembling the drum bearing 73 to the cleaning unit 60.

[0111] Furthermore, the first end portion 46La of the drive side biasing member 46L is fixed to the surface 23c of the developing container 23 and the second end portion 46Lb abuts against the surface 71k which is part of the cleaning unit.

[0112] Furthermore, the first end portion 46Ra of the non-drive side biasing member 46R is fixed to the surface 23k of the developing container 23 and the second end portion 46Rb is in contact with the surface 71 1 which is part of the cleaning unit.

[0113] In this embodiment, the drive side push member 46L ( Figure 5 ) and the non-drive side push member 46R ( Figure 4 ) each comprise a compression spring. The pushing force of these springs presses the developing unit 20 against the cleaning unit 60 to reliably push the developing roller 32 toward the drum 62 by the drive side push member 46L and the non-drive side push member 46R. Then, the developing roller 32 is held at a predetermined distance from the drum 62 by the gap holding member 38 mounted to the opposite end portion of the developing roller 32.

[0114] <Installation of Cartridge>

[0115] Next, reference is made to parts (a) and Figure 1 of Fig. 6.Figure 1 Part (b) Figure 6 Part (a) Figure 6 Part (b) Figure 6 Part (c) Figure 7 Part (a) Figure 7 Part (b) Figure 8 Part (a) Figure 8 Part (b) Figure 9 , Figure 10 Part (a) and Figure 10 Part (b) Figure 11 Part (a) and Figure 11 Part (b) Figure 12 Part (a) and part (b) Figure 13 Part (a) Figure 13 Part (b) Figure 14 , Figure 15 , Figure 16 and Figure 17 The installation of the box will be described in detail. Figure 1 Parts (a) and (b) are perspective views of the box used to illustrate the shape around the drive transmission components. Figure 6 Part (a) is a perspective view of a cylindrical cam. Figure 6 Part (b) is a perspective view of the drive side panel as seen from the outside of the main assembly A of the device, and Figure 6 Part (c) is a cross-sectional view of a cylindrical cam mounted on the drive side plate. Figure 6 (The direction indicated by the arrow in part (b)). Figure 7 Part (a) is a cross-sectional view of the imaging device linkage, used to illustrate the linkage structure; and Figure 7 Part (b) is a cross-sectional view of the imaging device drive unit, used to illustrate the movement of the drive transmission components. Figure 8 Part (a) is a cross-sectional view of the drive-side guide portion of the imaging device, used to illustrate the installation of the box; and Figure 8 Part (b) is a cross-sectional view of the non-drive side guide portion of the imaging device, used to illustrate the installation of the box. Figure 9 This is a diagram of the drive chain of the imaging device, used to illustrate the positional relationship of the drive chain before the opening and closing door is closed. Figure 10 Part (a) is a diagram just before the imaging device positioning part is engaged, used to illustrate the positioning of the processing box B in the longitudinal direction. Figure 10 Part (b) is a diagram after the imaging device positioning part is joined, used to illustrate the positioning of the processing box B in the longitudinal direction. Figure 11 Part (a) is a cross-sectional view of the driving side of the imaging device, used to illustrate the positioning of the box. Figure 11Part (b) of FIG. 1 is a non-drive side cross-sectional view of the imaging device for explaining the positioning of the cartridge. Figure 12 Part (a) of FIG. 2 is a cross-sectional view of the imaging device link portion for explaining the link structure; and Figure 12 Part (b) of FIG. 2 is a drive side cross-sectional view of the imaging device for explaining the movement of the drive transmission member. Figure 13 Part (a) of FIG. 3 is a perspective view of the drive transmission member for explaining the shape of the drive transmission member. Figure 13 Part (b) of FIG. 3 is a diagram of the drive transmission portion of the main assembly A for explaining the drive transmission portion. Figure 15 FIG. 4 is a perspective view of the drive unit of the imaging device for explaining the engagement space of the drive transmission portion. Figure 16 FIG. 5 is a cross-sectional view of the drive transmission member for explaining the engagement space of the drive transmission member. Figure 17 FIG. 6 is a cross-sectional view around the drum 62 of the device main assembly A for explaining the arrangement of the developing roller gear. Figure 18 FIG. 7 is a cross-sectional view of the drive transmission member for explaining the engagement of the drive transmission member.

[0116] First, the state in which the opening and closing door of the device main assembly A is opened will be described. As shown in Figure 7 Part (a) of FIG. 1, in the device main assembly A, an opening and closing door 13, a cylindrical cam link 85, a cylindrical cam 86, a cartridge pressurizing member 1, 2, a cartridge pressurizing spring 19, 21, and a front plate 18 are provided. Further, as shown in Figure 7 Part (b) of FIG. 1, in the device main assembly A, a drive transmission member bearing 83, a drive transmission member 81, a drive transmission member biasing spring 84, a drive side plate 15, and a non-drive side plate 16 are provided (FIG. 2, Part (a)). Figure 10

[0117] The opening and closing door 13 is rotatably mounted on the drive side plate 15 and the non-drive side plate 16. As shown in Figure 6 Part (a) of FIG. 1, Figure 6 Part (b) of FIG. 1, and Figure 6 Part (c) of FIG. 1, the cylindrical cam 86 is rotatable on the drive side plate 15 and is movable in the longitudinal direction AM, and it has two ramp portions 86a, 86b, and further, it has one end portion 86c which is continuous with the ramp on the non-drive side in the longitudinal direction. The drive side plate 15 has two ramp portions 15d and 15e which are opposed to the two ramp portions 86a and 86b of the cylindrical cam 86, and an end face 15f which is opposed to the one end portion 86c of the cylindrical cam 86. As shown in Figure 7 ​As shown in part (a), the cylindrical cam link 85 has lugs 85a and 85b at opposite ends. Lugs 85a and 85b are rotatably mounted to mounting holes 13a in the opening / closing door 13 and 86e in the cylindrical cam 86, respectively. When the opening / closing door 13 rotates and opens, the rotating cam link 85 moves in association with the opening / closing door 13. The cylindrical cam 86 rotates due to the movement of the rotating cam link 85, and the inclined surfaces 86a and 86b first contact the inclined surfaces 15d and 15e provided on the drive side plate 15. As the cylindrical cam 86 rotates further, the inclined surfaces 86a and 86b slide along the inclined surfaces 15d and 15e, thereby moving the cylindrical cam 86 longitudinally toward the drive side. Finally, the cylindrical cam 86 moves until one end 86c of the cylindrical cam 86 abuts against the end face 15f of the drive side plate 15.

[0118] Here, as Figure 7 As shown in part (b), the drive transmission component 81 is fitted to the drive transmission component bearing 83 at one end (fixed end 81c) located on the drive side along the axial direction, and is supported to be able to rotate and move in the axial direction. Furthermore, in the drive transmission component 81, the central portion 81d in the longitudinal direction has a gap M relative to the drive side plate 15. Moreover, the drive transmission component 81 has an abutment surface 81e, and the cylindrical cam 86 has another end 86d opposite to the abutment surface 81e. The drive transmission component spring 84 is a compression spring, with one end 84a contacting a spring seat 83a provided on the drive transmission component bearing 83, and the other end 84b contacting a spring seat 81f provided on the drive transmission component 81. Thus, the drive transmission component 81 is directed towards the non-drive side along the axial direction ( Figure 7 The left side of part (b) is pushed. Through this push, the abutment surface 81e of the drive transmission component 81 and the other end 86d of the cylindrical cam 86 come into contact with each other.

[0119] When the cylindrical cam 86 is facing the drive side in the longitudinal direction ( Figure 7 When the right side of part (b) moves, the drive transmission member 81 is pushed by the cylindrical cam 86 and moves toward the drive side, as described above. This puts the drive transmission member 81 in the retracted position. In other words, the drive transmission member 81 retracts from the movement path of the cartridge B, thereby securing the space for mounting the cartridge B in the main assembly A of the imaging device.

[0120] Next, the installation of box B will be described. For example... Figure 8 Part (a) and Figure 8As shown in part (b), the drive side plate 15 has an upper guide rail 15g and a guide rail 15h as guide devices, and the non-drive side plate 16 has a guide rail 16d and a guide rail 16e. Furthermore, the drum bearing 73 provided on the drive side of the housing B has a guided portion 73g and an anti-rotation portion 73c. ​​Along the mounting direction of the housing B (arrow C), the guided portion 73g and the anti-rotation portion 73c are arranged upstream of the axis of the connecting protrusion 63b (see [reference]). Figure 1 Part (a), details will be described later. Figure 16 (Arrow AO side in the middle).

[0121] The direction of mounting box B is approximately perpendicular to the axis of drum 62. When referring to upstream or downstream of the mounting direction, it means the upstream and downstream defined by the direction of movement of box B just before the installation of box B to the main assembly A of the device is completed.

[0122] Furthermore, the cleaning frame 71 has a positioned portion (to be positioned) 71d and an anti-rotation portion 71g on the non-drive side along the longitudinal direction. When the box B is installed through the box insertion port 17 of the main assembly A, the guided portion 73g and the anti-rotation portion 73c on the driven side of the box B are guided by the guide rails 15g and 15h of the main assembly A. On the non-drive side of the box B, the positioned portion 71d and the anti-rotation portion 71g are guided by the guide rails 16d and 16e of the main assembly A. Thus, the box B is installed in the main assembly A.

[0123] Here, the developing roller gear (developing gear) 30 is located at the end of the developing roller 32. Figure 9 and Figure 13 Part (b)). That is, the developing roller gear 30 is mounted on the shaft portion (shaft) of the developing roller 32.

[0124] The developing roller 32 and the developing roller gear 30 are coaxial with each other and surround each other. Figure 9 The axis Ax2 shown rotates. The developing roller 32 is arranged such that its axis Ax2 is approximately parallel to the axis Ax1 of the drum 62. Therefore, the axial direction of the developing roller 32 (developing roller gear 30) is approximately the same as the axial direction of the drum 62.

[0125] The developing roller gear 30 is a drive input gear (cassette-side gear, drive input component), and the driving force is input to the drive input gear from outside the cassette B (i.e., the main assembly A of the device). The developing roller 32 rotates by the driving force received by the developing roller gear 30.

[0126] like Figure 1 As shown in parts (a) and (b), an open space 87 is provided on the side of the developing roller gear 30 on the drum 62 side and on the drive side of the cartridge B, so that the developing roller gear 30 and the connecting protrusion 63b are exposed to the outside.

[0127] A coupling protrusion 63b is formed on a drive side drum flange 63 mounted on the end portion of the drum Figure 9 ). The coupling protrusion 63b is a coupling portion (drum side coupling portion, cartridge side coupling portion, photosensitive member side coupling portion, input coupling portion, drive input portion) Figure 9 from which a drive force is input from the outside of the cartridge B (i.e., the device main assembly A). The coupling protrusion 63b is arranged coaxially with the drum 62. In other words, the coupling protrusion 63b rotates around the axis Ax1.

[0128] The drive side drum flange 63 including the coupling protrusion 63b can be referred to as a coupling member (drum side coupling member, cartridge side coupling member, photosensitive member side coupling member, drive input coupling member, input coupling member).

[0129] Also, in the longitudinal direction of the cartridge B, the side on which the coupling protrusion 63b is provided is the drive side, and the opposite side corresponds to the non-drive side.

[0130] Also, as Figure 9 indicated, the developing roller gear 30 has a gear portion (input gear portion, cartridge side gear portion, developing side gear portion) 30a and an end face 30a1 on the drive side of the gear portion Figure 1 part (a), part (b), and Figure 9 ). The teeth (gear teeth) formed on the outer periphery of the gear portion 30a are helical teeth inclined with respect to the axis of the developing roller gear 30. In other words, the developing roller gear 30 is a helical toothed gear Figure 1 part (a) in the foregoing).

[0131] Here, the helical teeth also include a shape in which a plurality of protrusions 232a are arranged along a line inclined with respect to the axis of the gear to substantially form a helical tooth portion 232b Figure 14 ). In the structure shown in Figure 14 , the gear 232 has a large number of protrusions 232b on its circumferential surface. And a group of five protrusions 232b can be regarded as forming a column inclined with respect to the axis of the gear. Each column formed of such five protrusions 232b corresponds to the teeth of the aforementioned gear portion 30a.

[0132] The drive transmission member (drive output member, main assembly side drive member) 81 has a gear portion (main assembly side gear portion, output gear portion) 81a for driving the gear portion (cartridge side gear portion, developing side gear portion) 30a of the developing roller gear 30. The gear portion 81a has an end face 81a1 at the end portion on the non-drive side Figure 13 part (a), part (b) of the foregoing).

[0133] The teeth (gear teeth) formed on the gear portion 81a are also helical teeth inclined with respect to the axis of the drive transmission member 81. In other words, a helical gear portion is also provided on the drive transmission member 81.

[0134] Further, the drive transmission member 81 is provided with a coupling recess 81b. The coupling recess 81b is a coupling portion provided on the device main assembly side (main assembly side coupling portion, output coupling portion). The coupling recess 81b is formed by forming a recess capable of being coupled with the coupling protrusion 63b provided on the drum side in a protrusion (cylindrical portion) provided at the free end portion of the drive transmission member 81.

[0135] A space (space) 87 configured to expose the gear portion 30a and the coupling protrusion 63b Figure 1 permits the gear portion 81a of the drive transmission member 81 to be disposed when the cartridge B is installed in the device main assembly A. Therefore, the space 87 is larger than the gear portion 81a of the drive transmission member 81 Figure 15 .

[0136] More specifically, in a cross section of the cartridge B passing through the gear portion 30a and perpendicular to the axis of the drum 62 (axis of the coupling protrusion 63b), an imaginary circle having the same radius as the gear portion 81a is drawn around the axis of the drum 62 (axis of the coupling protrusion 63b). Accordingly, the inside of this imaginary circle is a space in which constituent elements of the cartridge B are not present. The space defined by this imaginary circle is included in the above-described space 87. That is, the space 87 is larger than the space defined by this imaginary circle.

[0137] The following is an explanation of this in another way. In the above-described cross section, an imaginary circle concentric with the drum 62 (coaxial) is drawn, the radius of which is the distance from the axis of the drum 62 to the tooth tip of the gear portion 30a of the developing roller 30. Accordingly, the inside of this imaginary circle is a space (space) in which constituent elements of the cartridge B are not present.

[0138] Because of the presence of the space 87, the drive transmission member 81 does not interfere with the cartridge B when the cartridge B is installed to the device main assembly A. As Figure 15 indicated, the space 87 permits the cartridge B to be installed to the device main assembly A by disposing the drive transmission member 81 therein.

[0139] Furthermore, when the cartridge B is viewed along the axis of the drum 62 (axis of the coupling protrusion 63b), the gear teeth formed in the gear portion 30a are disposed at a position close to the peripheral surface of the drum 62.

[0140] As Figure 16As shown, the distance AV (distance along the direction perpendicular to the axis) from the axis of drum 62 to the free end (tooth end) of the gear tooth of gear part 30a is more than 90% and less than 110% of the radius of drum 62.

[0141] Specifically, in this embodiment, the radius of the drum 62 is 12 mm, and the distance from the axis of the drum 62 to the free end (tooth tip) of the gear tooth of the gear portion 30a is more than 11.165 mm and less than 12.74 mm. In other words, the distance from the axis of the drum 62 to the free end (tooth tip) of the gear tooth of the gear portion 30a is in the range of 93% to 107% of the radius of the drum.

[0142] In the longitudinal direction, the end face 30a1 of the gear portion 30a of the developing roller gear 30 is positioned closer to the drive side (outside of cartridge B) than the front end 63b1 of the connecting protrusion 63b of the drive-side drum flange 63. Figure 9 , Figure 33 ).

[0143] Therefore, in the axial direction of the developing roller gear 30, the gear teeth of the gear portion 30a have exposed portions that are exposed from the cartridge B. Figure 1 Especially in this embodiment, such as Figure 16 As shown, the gear portion 30a is exposed at a range of 64° or more. In other words, taking the line connecting the center of the drum 62 and the center of the developing roller gear 30 as a reference line, when viewing cartridge B from the drive side, both sides of the developing roller gear 30 are exposed at least 32 degrees or more relative to this reference line. Figure 16 In the context of the developing roller gear 30, the angle AW indicates the angle from the reference line to the position where the gear portion 30a is covered by the driving-side developing side component 26 with the center (axis) of the developing roller gear 30 as the origin, and satisfies AW ≥ 32°.

[0144] The total exposure angle of the gear section 30a can be expressed as 2AW, and as described above, it satisfies the relationship 2AW≥64°.

[0145] If the gear portion 30a of the developing roller gear 30 is exposed from the driving-side developing-side component 26 in a manner that satisfies the above relationship, then the gear portion 81a meshes with the gear portion 30a without interfering with the driving-side developing-side component 26, and therefore drive transmission is feasible.

[0146] Furthermore, at least a portion of the exposed portion of the gear section 30a is positioned further outward (drive side) of the housing B than the front end 63b1 of the connecting protrusion 63b and faces the axis of the drum. Figure 1 , Figure 9 , Figure 33 ).exist Figure 9 and33 In this case, the gear tooth surface of the gear portion 30a arranged on the exposed portion 30a3 of the gear portion 30a faces the rotation axis Ax1 of the drum 62 (the rotation axis Ax1 of the coupling portion 63b). In Figure 33 In this case, the axis Ax1 of the drum 62 is located above the exposed portion 30a3 of the gear portion 30a.

[0147] In Figure 9 In this case, at least a portion of the gear portion 30a protrudes toward the driving side beyond the coupling protrusion 63b along the axial direction, so that the gear portion 30a overlaps the gear portion 81a of the driving transmission member 81 in the axial direction. Also, a portion of the gear portion 30a is exposed in a manner facing the axis Ax1 of the drum 62, and thus the gear portion 30a and the gear portion 81a of the driving transmission member 81 can contact each other during insertion of the cartridge B into the device main assembly A.

[0148] Figure 33 An arrow D1 side of the free end 63b1 of the coupling protrusion 63b is shown in a state in which the outer side end portion 30a1 of the gear portion 30a is arranged. The arrow D1 extends toward the outer side along the axial direction.

[0149] Due to the above-described arrangement relationship, the gear portion 30a of the developing roller gear 30 and the gear portion 81a of the driving transmission member 81 can mesh with each other during installation of the above-described cartridge B to the device main assembly A.

[0150] Further, in the installation direction C of the cartridge B, the center (axis) of the gear portion 30a is arranged on the upstream side of the center (axis) of the drum 62 (the Figure 16 side of the arrow AO in FIG. 12).

[0151] The arrangement of the developing roller gear 30 will be described in more detail. As Figure 17 shown, this drawing is a cross-sectional view seen from the non-driving side, and a line connecting between the center of the drum 62 and the center of the charging roller 66 is defined as a reference line (origin line) that provides an angular reference (0°). At this time, the center (axis) of the developing roller gear 30 is in an angular range of 64° to 190° from the reference line toward the downstream side of the rotation direction of the drum 62 (the clockwise direction in Figure 17 FIG. 12).

[0152] Strictly speaking, a half straight line that takes the center of the drum 62 as an origin, extends from the center of the drum 62 to the center of the charging roller 66 is taken as the origin line, and the rotation direction of the drum is taken as the positive direction of the angle. Accordingly, the angle on the polar coordinates formed with respect to the center of the developing roller satisfies the following relational expression.

[0153] 64° ≤ the angle on the polar coordinates formed with respect to the center of the developing roller ≤ 190°.

[0154] There is a certain degree of freedom in the arrangement of the charging roller 66 and the developing roller gear 30. The angle when the charging roller 66 and the developing roller gear 30 are closest to each other is indicated by arrow BM, and as mentioned above, it is 64° in this embodiment. On the other hand, the angle when they are furthest apart is indicated by arrow BN, which is 190° in this embodiment.

[0155] Furthermore, as described above, the unit (developing unit 20) equipped with the developing roller gear 30 can move relative to the unit (cleaning unit 60) equipped with the drum 62 and the connecting protrusion 63b. That is, the developing unit 20 can move relative to the cleaning unit 60 around the developing first support lug 26a and the developing second support lug 23b, which serve as the rotation center (rotation axis). Figure 4 , 5 The developing roller gear 30 rotates. Therefore, the distance between the center of the developing roller gear 30 and the center of the drum 62 (the distance between the axes) is variable, and the developing roller gear 30 can move within a certain range relative to the axis of the drum 62 (the axis of the connecting protrusion 63b).

[0156] like Figure 9 As shown, when gear portion 30a and gear portion 81a come into contact with each other during the insertion process into box B, gear portion 30a is pushed away from the axis of drum 62 (the axis of connecting protrusion 63b) by gear portion 81a. This reduces the impact of the contact between gear portion 30a and gear portion 81a.

[0157] like Figure 10 Part (a) and Figure 10 As shown in part (b), the drum bearing 73 is provided with a part to be joined 73h (part to be joined) as a part to be positioned in the longitudinal direction (axial direction) (axial alignment part).

[0158] The drive side plate 15 of the main assembly A has a engagement portion 15j capable of engaging with the engagement portion 73h. During the aforementioned installation process, the engagement portion 73h of the box B engages with the engagement portion 15j of the main assembly A, thereby determining the position of the box B in the longitudinal direction (axial direction). Figure 10 Part (b)). Additionally, in this embodiment, the joined portion 73h is in the form of a slit (groove). Figure 1 Part (b)). The slit communicates with space 87. That is, the slit (the joined part 73h) forms a space that is open to space 87.

[0159] refer to Figure 33 The location of the joined portion 73h will be described in detail. Figure 33 This is a diagram (schematic diagram) showing the arrangement of the engaged portion 73h relative to the gear portion 30a or the connecting protrusion 63b.Figure 33 As shown in FIG. 7, the slit (engaged portion 73h) is a space formed between two portions (an outer side portion 73hl and an inner side portion 73h2 of the engaged portion 73h) arranged along the axial direction. In the axial direction, the inner side end portion (inner side portion 73h2) of the engaged portion 73h is arranged inside the outer side end portion 30al of the gear portion 30a (arrow D2 side). In the axial direction, the outer side end portion (outer side portion 73hl) of the engaged portion 73h is arranged on the side further outside than the free end portion 63b of the coupling protrusion 63b (arrow Dl side).

[0160] Next, the state of the closing door 13 will be described. As shown in FIG. 8, the closing door 13 is in the closed state. Figure 8 Part (a) of FIG. 9, Figure 8 Part (b) of FIG. 9, Figure 11 Part (a) of FIG. 10, Figure 11 Part (b) of FIG. 10, the drive side plate 15 has an upper positioning portion 15a, a lower positioning portion 15b, and a rotation-stopping portion 15c. As the positioning portion, the non-drive side plate 16 has a positioning portion 16a and a rotation-stopping portion 16c. The drum bearing 73 includes an upper portion to be positioned (positioned portion) (first portion to be positioned (positioned portion), first protrusion, first protruding portion) 73d and a lower portion to be positioned (positioned portion) (second portion to be positioned (positioned portion), second protrusion, second protruding portion) 73f.

[0161] Furthermore, the cartridge pressing members 1 and 2 are rotatably attached to opposite axial end portions of the closing door 13. The cartridge pressing springs 19 and 21 are attached to opposite end portions in the longitudinal direction of a front plate provided in the image forming apparatus A. The drum bearing 73 is provided with a portion to be pressed 73e (pressed portion) as a push pressure receiving portion, and the cleaning frame 71 has a portion to be pressed 71o (pressed portion) on the non-drive side as a push pressure receiving portion. Figure 3 By the closing door 13, the pressed portions 73e and 71o of the cartridge B are pressed by the cartridge pressing members 1 and 2 pushed by the cartridge pressing springs 19 and 21 of the apparatus main assembly A.

[0162] Thus, on the drive side, the upper positioned portion 73d, the lower positioned portion 73f, and the rotation-stopping portion 73c of the cartridge B respectively contact the upper positioning portion 15a, the lower positioning portion 15b, and the rotation-stopping portion 15c. Thus, the cartridge B and the drum 62 are positioned relative to each other on the drive side. Furthermore, on the non-drive side, the positioned portion 71d and the rotation-stopping portion 71g of the cartridge B respectively contact the positioning portion 16a and the rotation-stopping portion 16c of the apparatus main assembly A. Thus, the cartridge B and the drum 62 are positioned relative to each other on the non-drive side.

[0163] As shown in FIG. 11, Figure 1The upper positioned part 73d and the lower positioned part 73f are disposed near the drum 62 as shown in part (a) and part (b) of FIG. 7. Also, the upper positioned part 73d and the lower positioned part 73f are aligned in the rotation direction of the drum 62.

[0164] Also, in the drum bearing 73, it is necessary to secure a space (arc-shaped recess) 73l for arranging the transfer roller 7 (see FIG. 1) between the upper positioned part 73d and the lower positioned part 73f. Therefore, the upper positioned part 73d and the lower positioned part 73f are arranged to be separated from each other. Figure 11

[0165] Also, the upper positioned part 73d and the lower positioned part 73f are protrusions that protrude inward in the axial direction from the drum bearing 73. As described above, it is necessary to secure the space 87 around the coupling protrusion 63b. Therefore, the upper positioned part 73d and the lower positioned part 73f do not protrude outward in the axial direction, but they protrude inward to secure the space 87.

[0166] The upper positioned part 73d and the lower positioned part 73f are protrusions that are arranged to partially cover the photosensitive drum 62. In other words, the positioned parts 73d, 73f are projecting parts that protrude inward in the axial direction of the photosensitive drum 62. When the upper positioned part 73d and the photosensitive drum 62 are projected onto the axis of the drum 62, the projected areas of at least portions of the upper positioned part 73d and the photosensitive drum 62 overlap each other. In this regard, the lower positioned part 73f is the same as the upper positioned part 73d.

[0167] Also, the upper positioned part 73d and the lower positioned part 73f are arranged to partially cover the drive-side drum flange 63 provided at the end portion of the photosensitive drum 62. When the upper positioned part 73d and the drive-side drum flange 63 are projected onto the axis of the drum 62, the projected areas of at least portions of the upper positioned part 73d and the drive-side drum flange 63 overlap each other. In this regard, the lower positioned part 73f is the same as the upper positioned part 73d.

[0168] The pressurized parts 73e and 71o are projecting parts of the frames of the cleaning units arranged on the one end side (drive side) and the other end side (non-drive side) of the cartridge B with respect to the longitudinal direction, respectively. Specifically, the pressurized part 73e is provided on the drum bearing 73. The pressurized parts 73e and 71o protrude in a direction that intersects the axial direction of the drum 62 and is separate from the drum 62.

[0169] On the other hand, as shown in part (a) and part (b) of FIG. 7, the upper positioned part 73d and the lower positioned part 73f are arranged near the drum 62. Figure 12 Figure 12 ​​portion 86a, 86b of the cylindrical cam 86 rotates along the inclined portions 15d, 15e of the drive-side plate 15 (toward the side close to the cartridge B) by the rotation of the cam link 85. Thereby, the drive transmission member 81 in the retracted position moves along the longitudinal direction to the non-drive side (the side close to the cartridge B) by the drive transmission member spring 84. Since the gear teeth of the gear portion 81a and the gear portion 30a are inclined with respect to the moving direction of the drive transmission member 81, the gear teeth of the gear portion 81a abut the gear teeth of the gear portion 30a by the movement of the drive transmission member 81. At this time, the movement of the drive transmission member 81 to the non-drive side is stopped.

[0170] Even after the drive transmission member 81 stops, the cylindrical cam 86 further moves to the non-drive side, and the drive transmission member 81 and the cylindrical cam 86 are separated.

[0171] Next, as shown in Figure 1 portion (a) and Figure 13 , Figure 18 portion (b) of FIG. 8, the drive-side drum flange 63 has a coupling protrusion 63b on the drive side, and the coupling protrusion 63b has a free end 63b1 at a free end thereof. The drive transmission member 81 has a coupling recess 81b and a free end 81b1 of the coupling recess 81b on the non-drive side. By closing the opening and closing door 13, the inclined portions 86a, 86b of the cylindrical cam 86 rotate along the inclined portions 15d, 15e of the drive-side plate 15 (toward the side close to the cartridge B) by the rotation of the cam link 85. Thereby, the drive transmission member 81 in the retracted position moves along the longitudinal direction to the non-drive side (the side close to the cartridge B) by the drive transmission member spring 84. Since the gear teeth of the gear portion 81a and the gear portion 30a are inclined with respect to the moving direction of the drive transmission member 81, the gear teeth of the gear portion 81a abut the gear teeth of the gear portion 30a by the movement of the drive transmission member 81. At this time, the movement of the drive transmission member 81 to the non-drive side is stopped.

[0172] The gear portion 81a and the coupling recess 81b are arranged on the axis of the drive transmission member 81 so that the axis of the gear portion 81a and the axis of the coupling recess 81b overlap each other. In other words, the gear portion 81a and the coupling recess 81b are coaxially (concentrically) arranged.

[0173] The coupling protrusion 63b of the drive-side drum flange 63 has a substantially triangular cross section and has a protrusion shape (protrusion, protrusion). The coupling protrusion 63b twists in the counterclockwise direction O from the drive side (the end side of the coupling protrusion 63b) toward the non-drive side (the bottom side of the coupling protrusion 63b)Figure 37 In other words, the coupling protrusion 63b is inclined (twisted) in the counterclockwise direction (the rotation direction of the drum) as it moves away from the outside of the cartridge toward the inside in the axial direction.

[0174] Further, in the coupling protrusion 63b, the portion (ridge line) that forms the corner portion (the apex of the triangle) of the triangular prism is a driving force receiving portion that actually receives the driving force from the coupling recess 81b. The driving force receiving portion is inclined in the rotation direction of the drum from the outside of the cartridge toward the inside in the axial direction. Also, the inner surface (inner circumferential surface) of the coupling recess 81b functions as a driving force applying portion for applying the driving force to the coupling protrusion 63b.

[0175] Further, since the corner portion is chamfered or rounded, the shape of the cross section of the coupling protrusion 63b and the coupling recess 81b is not a strict triangle (polygon), but is referred to as a substantially triangular (polygonal) shape. In other words, the coupling protrusion 63b has a substantially twisted triangular prism (polygonal prism) shape. However, the shape of the coupling protrusion 63b is not limited to such a shape. The shape of the coupling protrusion 63b can be changed as long as the coupling protrusion 63b can be coupled with the coupling recess 81b, that is, as long as the coupling protrusion can be engaged with and driven by the coupling recess. For example, three lugs 163a can be disposed at the apexes of the triangle, where each lug 163a is twisted (inclined) with respect to the axial direction of the drum 62, and the coupling protrusion 63b is formed in a substantially triangular prism shape. Figure 19 .

[0176] The gear portion 30a of the developing roller gear 30 is a helical gear, and has a shape that is twisted (inclined) in the clockwise direction P from the driving side toward the non-driving side Figure 37 In other words, the gear teeth (helical teeth) of the gear portion 30a are inclined (twisted) in the clockwise direction P (the rotation direction of the developing roller or the developing roller gear) from the outside of the cartridge toward the inside in the axial direction of the gear portion 30a. That is, the gear 30a is inclined (twisted) in the axial direction from the outside toward the inside in the direction opposite to the rotation direction of the drum 62.

[0177] As shown in FIG. 13, from the non-driving side (the cartridge side), the driving transmission member 81 is rotated in the counterclockwise direction CW (the direction opposite to the arrow N in FIG. 12) by a motor (not shown). Then, a thrust force (a force generated in the axial direction) is generated by the meshing between the helical teeth of the gear portion 81a of the driving transmission member 81 and the gear portion 30a of the developing roller gear 30. The force FA in the axial direction (the longitudinal direction) is applied to the driving transmission member 81, and the driving transmission member 81 tends to move in the longitudinal direction toward the non-driving side (closer to the cartridge). In other words, the driving transmission member 81 approaches and contacts the coupling protrusion 63b. Figure 13 Figure 13 In other words, the gear teeth (helical teeth) of the gear portion 30a are inclined (twisted) in the clockwise direction P (the rotation direction of the developing roller or the developing roller gear) from the outside of the cartridge toward the inside in the axial direction of the gear portion 30a. That is, the gear 30a is inclined (twisted) in the axial direction from the outside toward the inside in the direction opposite to the rotation direction of the drum 62. ​

[0178] In particular, in this embodiment, the helix of the teeth of the gear portion 81a of the drive transmission member 81 is such that each tooth moves 5 to 8.7 mm in the axial direction (longitudinal direction) (see FIG. 6). Figure 13 This corresponds to a helix angle of 15° to 30° for the gear portion 81a. Also, the helix angle of the developing roller gear 30 (gear portion 30a) is also 15° to 30°. In this embodiment, the helix angle between the gear portion 81a and the gear portion 30a is selected to be 20°.

[0179] Correspondingly, when the phases of the triangular portions of the coupling recess 81b and the coupling protrusion 63b are matched by the rotation of the drive transmission member 81, the coupling protrusion 63b and the coupling recess 81b engage with each other (couple).

[0180] Correspondingly, when the coupling protrusion 63b and the coupling recess 81b engage, an additional thrust force FC is generated, since both the coupling recess 81b and the coupling protrusion 63b are twisted (tilted) with respect to the axis.

[0181] That is, a force FC directed toward the non-drive side (toward the side of the cassette) in the longitudinal direction is applied to the drive transmission member 81. This force FC, together with the force FA described above, causes the drive transmission member 81 to move further in the longitudinal direction toward the non-drive side (toward the cassette). In other words, the coupling protrusion 63 causes the drive transmission member 81 to approach the coupling protrusion 63b of the cassette B.

[0182] The drive transmission member 81 attracted by the coupling protrusion 63b is positioned in the longitudinal direction (axial direction) by the free end portion 81b1 of the drive transmission member 81 contacting the concave bottom surface 73i of the drum bearing 73.

[0183] Moreover, a reaction force FB of the force FC acts on the drum 62, and due to this reaction force (resisting force) FB, the drum 62 moves in the longitudinal direction toward the drive side (toward the outside of the drive transmission member 81, the cassette B). In other words, the drum 62 and the coupling protrusion 63b are attracted toward the drive transmission member 81 side. As a result, the free end portion 63b1 of the coupling protrusion 63b of the drum 62 abuts against the bottom 81b2 of the coupling recess 81b. As a result, the drum 62 is also positioned in the axial direction (longitudinal direction).

[0184] That is, the coupling protrusion 63b and the coupling recess 81b attract each other, thereby determining the position of the drum 62 and the drive transmission member 81 in the axial direction.

[0185] In this state, the drive transmission member 81 is in the drive position. In other words, the drive transmission member 81 is in a position for transmitting the drive force to the coupling protrusion 63b and the gear portion 30b, respectively.

[0186] Moreover, the position of the center at the free end of the drive transmission member 81 is determined with respect to the drive-side drum flange 63 by the triangular alignment action of the coupling recess 81b. In other words, the drive transmission member 81 is aligned with the drum flange 63, and the drive transmission member 81 and the photosensitive member are coaxial. Thereby, the drive is transmitted from the drive transmission member 81 to the developing roller gear 30 and the drive-side drum flange 63 with high accuracy.

[0187] The coupling recess 81b and the coupling protrusion 63b engaged with the coupling recess 81b can also be regarded as alignment portions. That is, the engagement between the coupling recess 81b and the coupling protrusion 63b makes the drive transmission member 81 and the drum coaxial with each other. Specifically, the coupling recess 81b is referred to as a main assembly side alignment portion (an alignment portion on the image forming apparatus side), and the coupling protrusion 63b is referred to as a cartridge side alignment portion.

[0188] As described above, the engagement of the coupling is assisted by the force FA and the force FC acting on the drive transmission member 81 toward the non-drive side.

[0189] Moreover, by positioning the drive transmission member 81 by the drum bearing (bearing member) 73 provided in the cartridge B, the positional accuracy of the drive transmission member 81 with respect to the cartridge B can be improved.

[0190] The positional accuracy in the longitudinal direction between the gear portion 30a of the developing roller gear 30 and the gear portion 81a of the drive transmission member 81 is improved, and therefore, the width of the gear portion 30a of the developing roller gear 30 can be reduced. The cartridge B and the device main assembly A for mounting the cartridge B can be miniaturized.

[0191] In summary, in this embodiment, the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 have helical teeth. The helical teeth provide a higher gear contact ratio than straight teeth. Thereby, the rotational accuracy of the developing roller 30 is improved, and the developing roller 30 can rotate smoothly.

[0192] Furthermore, the direction of the helical teeth of gear portion 30a and gear portion 81a is selected to generate forces (force FA and force FB) that attract gear portion 30a and gear portion 81a to each other. In other words, by rotating gear portion 30a and gear portion 81a in a meshed state, a force is generated that brings the connecting recess 81b provided in the drive transmission member 81 and the connecting protrusion 63b provided in the end of the photosensitive drum 62A closer to each other. As a result, the drive transmission member 81 moves toward the cartridge B side, and the connecting recess 81b approaches the connecting protrusion 63b. This facilitates the connection (coupling) between the connecting recess 81b and the connecting protrusion 63b. In other words, by rotating gear portion 30a and gear portion 81a in a meshed state, the generated force brings the connecting recess 81b provided in the drive transmission member 81 and the connecting protrusion 63b provided in the end of the photosensitive drum 62 closer to each other. As a result, the drive transmission member 81 moves toward the cartridge B side, and the connecting recess 81b approaches the connecting protrusion 63b. This facilitates the connection between the connecting recess 81b and the connecting protrusion 63b.

[0193] Furthermore, the direction in which the connecting protrusion 63b (driving force receiving portion) is inclined relative to the axis of the drum and the direction in which the helical teeth of the gear portion 30a of the developing roller gear 30 are inclined relative to the axis of the gear portion 30a are opposite to each other. Figure 38 Therefore, the movement of the transmission member 81 is aided not only by the force generated by the engagement (meshing) of the gear portion 30a and the gear portion 81a, but also by the force generated by the engagement (connection engagement) of the connecting protrusion 63b and the connecting recess 81b. In other words, the connecting protrusion 63b and the connecting recess 81b attract each other through rotation in their connected state. As a result, the connecting protrusion 63b and the connecting recess 81b are stably engaged (connected) with each other.

[0194] The elastic component (drive transmission component spring 84) pushes the drive transmission component 81 towards the connecting protrusion 63b. Figure 7 Part (a)). According to this embodiment, the force of the drive transmission component spring 84 can be reduced corresponding to force FA and force FC ( Figure 13 (b) Accordingly, the frictional force between the drive transmission member spring 84 and the drive transmission member 81 generated when the drive transmission member 81 rotates is also reduced, and therefore, the torque required to rotate the drive transmission member 81 is reduced. In addition, the load applied to the motor used to rotate the drive transmission member 81 can also be reduced. Moreover, the sliding noise generated between the drive transmission member 81 and the drive transmission member spring 84 can also be reduced.

[0195] Further, in this embodiment, the drive transmission member 81 is biased by an elastic member (spring 84), but the elastic member is not essential. In other words, if the gear portion 81a and the gear portion 30a at least partially overlap in the axial direction, and the gear portion 81a and the gear portion 30a engage with each other when the cartridge is mounted on the device main assembly, the elastic member can be eliminated. In other words, in this case, when the gear portion 81a rotates, a force that attracts the coupling protrusion 63b and the coupling recess 81b to each other is generated by the engagement between the gear portion 81a and the gear portion 30a. That is, even without the elastic member (spring 84), the drive transmission member 81 approaches the cartridge B due to the force generated by the engagement between the gears. This establishes the engagement of the coupling recess 81b and the coupling protrusion 63b.

[0196] Without such an elastic member, a frictional force between the elastic member and the drive transmission member 81 is not generated, and therefore, the rotational torque of the drive transmission member 81 is further reduced. Also, a sound generated by the sliding between the drive transmission member 81 and the elastic member can be eliminated. Also, the number of components of the image forming device can be reduced, and therefore, the structure of the image forming device can be simplified and the cost can be reduced.

[0197] Also, the coupling protrusion 63b of the drive-side drum flange 63 is coupled with the recess 81b of the drive transmission member 81 in a state where the drive transmission member 81 rotates. Here, the coupling protrusion 63b is inclined (twisted) in the rotational direction of the photosensitive drum from the outside to the inside of the cartridge with respect to the axial direction of the drum 62. In other words, the coupling protrusion 63b is inclined (twisted) in the rotational direction of the drive transmission member 81, and therefore, the coupling protrusion 63b is easily connected with the rotating recess 81b.

[0198] Further, in this embodiment, a helical gear is used as the developing roller gear 30 that engages with the drive transmission member 81. However, another gear can be used as long as drive transmission is possible. For example, a thin spur gear 230 that can enter the tooth gap 81e of the drive transmission member 81 can be used. The thickness of the spur gear is set to 1 mm or less. Likewise, in this case, the gear portion 81a of the drive transmission member 81 has a helical tooth, and therefore, a force for guiding the drive transmission member 81 toward the non-drive side is generated by the engagement between the gear portion 81a and the spur gear 230 Figure 21 .

[0199] Further, in this embodiment, as shown in Figure 1 part (a) and part (b), when the cartridge B is viewed from the drive side, the coupling protrusion 63b (drum 62) rotates in the counterclockwise direction O so that the developing roller gear 30 (developing roller 32) rotates in the clockwise direction P.

[0200] However, a structure can also be adopted in which, when the cartridge B is viewed from the non-driving side, the coupling protrusion 63b (the drum 62) rotates in the counterclockwise direction and the developing roller gear 30 (the developing roller 32) rotates in the clockwise direction. In other words, the layout of the main assembly A and the cartridge B can be modified so that the rotation directions of the coupling protrusion 63b (the drum 62) and the developing roller gear 30 are reversed from those in this embodiment. In any case, the coupling protrusion 63b and the developing roller gear 30 rotate in opposite directions when viewed in the same direction. One rotates clockwise and the other counterclockwise.

[0201] In other words, when the cartridge B is viewed in the direction in which the rotation direction of the coupling protrusion 63b becomes the counterclockwise direction (from the driving side in this embodiment), the rotation direction of the developing roller gear 30 is clockwise.

[0202] Further, in this embodiment, the developing roller gear 30 functions as a driving input gear that engages with the driving transmission member 81, but another gear can be used as the driving input gear.

[0203] Figure 22 A driving input gear 88 that meshes with the driving transmission member 81, a developing roller gear 80 provided on the developing roller, idler gears 101 and 102, and a feed gear (stirring gear, developer feed gear) 103 are shown.

[0204] In Figure 22 , the driving force is transmitted from the driving input gear 88 to the developing roller gear 80 through one idler gear 101. The idler gear 101 and the developing roller gear 80 are driving transmission mechanisms (cartridge-side driving transmission mechanisms, developing-side driving transmission mechanisms) for transmitting the driving force from the driving input gear 88 to the developing roller 32.

[0205] On the other hand, the idler gear 102 is a gear for transmitting the driving force from the driving input gear 88 to the stirring gear 103. The feed gear 103 is mounted to the feed member 43 Figure 3 , and the feed member 43 is rotated by the driving force received by the feed gear 103.

[0206] Further, a plurality of gears can also be used for transmitting the driving force between the driving input gear 88 and the developing roller gear 80. At this time, in order to set the rotation direction of the developing roller 32 in the direction of the arrow P Figure 1 , it is preferable to make the number of idler gears that transmit the driving force between the driving input gear 88 and the developing roller gear 80 odd. In Figure 22 , one structure of the idler gears is shown in order to simplify the structure of the gear train.

[0207] Furthermore, in other words, regarding the number of gears, in order to set the rotation direction of the developing roller 32 as indicated by arrow P ( Figure 1 The drive is transmitted in the direction of the developing roller 32, and cartridge B is provided with an odd number of gears. Figure 22 In the structure shown, there are three gears used to transmit drive to the developing roller 32: the developing roller gear 80, the idler gear 101, and the drive input gear 88. On the other hand, in... Figure 1 In the structure shown, there is only one gear used to transmit drive to the developing roller 32, that is, only the developing roller gear 32.

[0208] In other words, it is sufficient as long as cartridge B is equipped with a drive transmission mechanism (cassette-side drive transmission mechanism, developer-side drive transmission mechanism) for rotating the developing roller 32 in the same rotational direction as the drive input gear 88.

[0209] In other words, when viewing cartridge B in a direction that causes the drive input gear 88 to rotate clockwise, the developing roller 32 also rotates clockwise. Figure 22 In the structure shown, when viewing cartridge B from the drive side, the drive input gear 88 and the developing roller 32 rotate clockwise.

[0210] In addition, Figure 1 The structure shown or Figure 22 In the structure shown, the drive input gears (30, 88) receive driving force from the drive transmission member 81 independently of the connecting protrusion 63b. In other words, cartridge B has two input portions (drive input portions) for receiving driving force from the outside of cartridge B (i.e., the main assembly A of the device), one for the cleaning unit and one for the developing unit.

[0211] In a structure where the photosensitive drum (cleaning unit) and the developing roller (developing unit) independently receive driving force from the drive transmission component 81, there is an advantage in enhancing the rotational stability of the photosensitive drum. This is because there is no need to transmit driving force (rotational force) between the photosensitive drum and other components (such as the developing roller), and therefore, when these different components (such as the developing roller) experience uneven rotation, their uneven rotation is unlikely to affect the rotation of the photosensitive drum.

[0212] In addition, Figure 22 In the structure of arrow FA ( Figure 13 A force in the direction of part (b) is applied to the drive transmission member 81 to assist in the connection between the connecting recess 81b and the connecting protrusion 63b. For this purpose, a load (torque) needs to be generated when the drive input gear 88 rotates. In other words, as long as a load is generated to make the drive input gear 88 rotate, the drive input gear 88 does not need to be configured to receive the driving force for rotating the developing roller 32.

[0213] For example, the driving force received by the drive input gear 88 can be transmitted only to the feed component 43. Figure 3 However, in this configuration where the cartridge includes a developing roller 32, the driving force must be transmitted to the developing roller 32 independently. For example, cartridge B requires gears, etc., to transmit the driving force from drum 62 to the developing roller 32.

[0214] <Connector engagement conditions>

[0215] Next, we will refer to Figure 1 , Figure 18 Part (a) Figure 24 Part (b) Figure 25 Part (a) Figure 25 Part (b) and Figure 27 To describe the conditions under which the connecting parts engage. Figure 24 Part (a) is a cross-sectional view of the imaging device drive section as seen from the direction opposite to the mounting direction of box B, used to illustrate the distance of the drive transmission section. Figure 24 Part (b) is a cross-sectional view of the imaging device drive section as seen from the drive side, used to illustrate the distance of the drive transmission section. Figure 25 Part (a) is a cross-sectional view of the imaging device drive section as seen from the drive side, used to illustrate the gap of the connecting parts. Figure 25 Part (b) is a cross-sectional view of the imaging device drive section as seen from the drive side, used to illustrate the gap of the connecting parts. Figure 27 This is a cross-sectional view of the imaging device as seen from the drive side, used to illustrate the scope of the control section (stop).

[0216] like Figure 1 , Figure 24 Part (a) and Figure 24 As shown in part (b), the drum bearing 73 is provided with a tilt control part (movement control part, position control part, stop) 73j for controlling the movement of the drive transmission part 81, thereby limiting (suppressing) the tilt of the drive transmission part 81.

[0217] The drive transmission component 81 has a cylindrical portion 81i on the non-drive side (the side closer to box B). Figure 24 Part (a)). The cylindrical part 81i is a cylindrical part (protrusion) in which the connecting recess 81b is formed.

[0218] As described above, during the initial rotation phase of the drive transmission member 81, the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 mesh with each other, such as... Figure 9The coupling recess 81b and the coupling protrusion 63b are not yet coupled, or the coupling therebetween is insufficient. Therefore, when the gear portion 81a transmits a driving force to the gear portion 30a, a meshing force FD is generated in the gear portion 81a by engagement between the gears Figure 24 part (b) of FIG. 12.

[0219] The driving force transmission member 81 is tilted by the meshing force FD applied thereto. That is, as described above, only the fixed end portion 81c of the driving force transmission member 81 supporting the end portion on the driving side (see Figure 24 part (a) of FIG. 12: the end portion away from the cartridge B), and thus the driving force transmission member 81 tilts with the driving side end portion 81c (the fixed end portion) as a fulcrum. Accordingly, the end portion (the free end portion, the tip end) of the driving force transmission member 81 on the side where the coupling recess 81b is provided moves.

[0220] If the driving force transmission member 81 is greatly tilted, the coupling recess 81b cannot be coupled with the coupling protrusion 63b. To avoid this, the regulation portion 73j is provided in the cartridge B so that the tilt of the driving force transmission member 81 is regulated within a certain range. That is, when the driving force transmission member 81 is tilted, the regulation portion 73j supports the driving force transmission member 81, thereby suppressing an increase in the degree of tilt thereof.

[0221] The regulation portion 73j of the drum bearing 73 has an arc-shaped curved surface portion provided so as to face the axis of the drum 62 (the axis of the coupling protrusion 63b). The regulation portion 73j can also be regarded as a protruding portion protruding so as to cover the drum axis. This structure makes it possible to provide a space in which no constituent element of the process cartridge B is arranged between the regulation portion 73i and the drum axis, and in which the driving force transmission member 81 is arranged. The regulation portion 73i faces Figure 1 the space 87 shown in FIG. 12, and the regulation portion 73i forms an edge (an outer edge) of the space 87.

[0222] The regulation portion 73j is arranged at a position at which movement (tilt) of the driving force transmission member 81 can be suppressed by the meshing force FD.

[0223] The direction in which the meshing force FD is generated is determined by the transverse pressure angle a of the gear portion 81a (i.e., the transverse pressure angle a of the developing roller gear 30). The direction in which the meshing force FD is generated is inclined (90+a) degrees toward the upstream AK of the direction of rotation of the photosensitive drum 62 with respect to a direction (a semi-straight line) LN extending from the center 62a of the photosensitive drum (i.e., the center of the driving force transmission member 81) toward the center 30b of the developing roller gear 30.

[0224] In the wrap angle helical gear in which the wrap angle is 20°, the standard angle a is 21.2°. The transverse pressure angle a of the gear portion 81a and the gear portion 30a of this embodiment is also 21.2°. In this case, the inclination of the meshing force FD with respect to the arrow LN is 111.2°. However, another value can be used as the transverse pressure angle of the gear portion 81a and the gear portion 30a, and in this case, the direction of the meshing force FD also differs. The transverse pressure angle a also varies depending on the wrap angle of the helical gear, and the transverse pressure angle a is preferably 20.6 degrees or more and 22.8 degrees or less.

[0225] In Figure 24 portion (b), when a half straight line FDa extending in the same direction as the direction of the meshing force FD is extended with the center 62a of the photosensitive drum as a starting point, the control portion 73j is disposed to cross the half straight line FDa. Here, the half straight line FDa is a line provided by tilting (rotating) the half straight line LN by 90 + a degrees toward the upstream side with respect to the direction of rotation of the drum 62 with the center of the drum 62 as the origin (axis, fulcrum). In this embodiment, the half straight line FDa is tilted by 111.2 degrees with respect to the half straight line LN.

[0226] The control portion 73j does not necessarily have to be disposed on this half straight line FDa, and the control portion 73j is preferably disposed adjacent to the half straight line FDa. More specifically, it is desirable to dispose at least a portion of the control portion 73j somewhere within a range of plus or minus 15° with respect to the half straight line FDa. The half straight line FDa is a line obtained by rotating the half straight line LN by (90 + a) degrees toward the upstream side of the direction of rotation of the drum 62. Therefore, the control portion 73j is preferably within a range of (75 + a) degrees to (105 + a) degrees on the upstream side of the direction of rotation of the drum with respect to the half straight line LN with the center of the drum 62 as the origin. Considering that the preferable value of the transverse pressure angle a is 20.6 degrees or more and 22.8 degrees or less, the preferable range in which the control portion 73j is disposed is 95.6 degrees or more and 127.8 degrees or less with respect to the half straight line LN. In this embodiment, the transverse pressure angle a is 21.2 degrees, and therefore, the preferable range of the control portion 73j is 96.2 degrees or more and 126.2 degrees or less.

[0227] As another example of the preferable disposition of the control portion 73j, a plurality of control portions 73j can be provided so that they are independently disposed on respective sides of the half straight line FDa with the half straight line FDa interposed therebetween (not shown). Figure 26 In this case, it can also be considered that the control portions 73j are disposed across the line FDa.

[0228] Furthermore, it is preferable that the control portion 73j be disposed on the upstream side AO of the center (axis) of the coupling protrusion 63b in the cartridge mounting direction C (arrow C) of portion (a). Figure 11 Figure 16 ​). This is to prevent the control portion 73j from interfering with the mounting of the cartridge B.

[0229] The range (region) in which the control portion 73j is disposed in the drum bearing 73 can also be described as follows.

[0230] In a plane perpendicular to the axis of the drum 62 (the direction of the arrow AK), a straight line LA passing through the center 62a of the drum 62 and the center 30b of the gear portion 30a of the developing roller gear 30 is drawn. At this time, the control portion 73j is disposed on the side on which the charging roller is disposed with respect to the straight line LA (i.e., the side indicated by the arrow AL). Figure 24

[0231] Alternatively, the control portion 73j is disposed in the region AL opposite the side on which the drum 62 is exposed (the side on which the drum 62 faces the transfer roller 7) with respect to the line LA passing through the drum center 62a and the gear center 30b. Here, in the case where a cover or a baffle for covering the drum 62 is provided in the cartridge B before the cartridge B is mounted in the device main assembly A, and the drum 62 can not be exposed. However, in such a case, the side on which the drum 62 is exposed refers to the side on which the drum 62 is exposed when the cover, the baffle, or the like is removed.

[0232] Further, in a plane perpendicular to the axis of the photosensitive drum 62, the range (region AL) in which the control portion 73j is disposed can also be described using the circumferential direction (direction of rotation) of the photosensitive drum 62 as follows.

[0233] A half straight line (primitive line) LN extending from the center 62a of the drum 62 toward the center 30b of the gear portion 30a of the developing roller gear 30 is drawn. The region AL is a range (region) of more than 0° and not more than 180° toward the upstream side (the side of the arrow AK) in the drum rotation direction with respect to the half straight line LN.

[0234] Further, in other words, the range AL is on the upstream side (the side of the arrow AK) with respect to the drum rotation direction O of the center point MA between the drum center 62a and the developing roller gear center 30b, and does not exceed the straight line (extension line) LA passing through the center 62a of the drum 62 and the center 30b of the gear portion 30a of the developing roller gear 30.

[0235] Further, in the state where the opening and closing door 13 is open and the drive transmission member 81 is moved to the drive side, the control portion 73j is in a position overlapping the gear portion 81a of the drive transmission member 81 in the longitudinal direction. That is, the control portion 73j also overlaps the developing roller gear 30 in the longitudinal direction. As Figure 34 ​As shown, when the developing roller gear 30 and the control portion 73j are projected on the axis Ax2 of the developing roller gear 30, their projected regions at least partially overlap each other. That is, the control portion 73j is close to the gear portion 81a (the gear portion 30a) that generates the meshing force. Therefore, when the drive transmission member 81 that receives the meshing force is supported by the control portion 73j, the bending of the drive transmission member 81 is suppressed.

[0236] Moreover, in the axial direction, at least a portion of the control portion 73j is on the outside of the coupling protrusion 63b (the arrow D1 side in FIG. 6). Figure 34

[0237] Next, the radial position of the control portion 73j with respect to the drum 62 will be described with reference to FIG. 7. Figure 24

[0238] The distance shown below is a distance measured in a direction perpendicular to the axial direction of the drum 62 (a distance in the radial direction of the drum 62). Let S be the distance from the axis (center 62a) of the drum 62 to the control portion 73j. Let U be the radius of the tooth tip of the gear portion 81a of the drive transmission member 81. Let AC be the distance from the center 81j of the drive transmission member 81 to the radially outermost portion of the coupling recess. Let AD be the distance from the center 63d of the drive-side drum flange 63 to the radially outermost portion of the coupling protrusion 63b. Let AA be the distance between the control portion 73j and the tooth tip of the gear portion 81a of the drive transmission member 81. And let AB be the amount of deviation between the center of the coupling protrusion 63b and the center of the coupling recess 81b when the drive transmission member 81 is tilted by an amount of play with respect to the control portion 73j (when the drive transmission member 81 is tilted and the gear portion 81a is in contact with the control portion 73j). Figure 25

[0239] Correspondingly, the gap AA between the gear portion 81a of the drive transmission member 81 and the control portion 73j of the drum bearing 73 is as shown in the following equation.

[0240] AA = S - U.

[0241] In the following description, the distance is measured in the axial direction of the drive transmission member 81 from the fixed end portion 81c that is the fulcrum of the tilt of the drive transmission member 81. Let X be the distance in the axial direction from one end portion 81c of the drive transmission member 81 to the gear portion 81a. Also, let W be the distance in the axial direction from one end portion 81c of the drive transmission member 81 to the coupling recess 81b.

[0242] The distance X and the distance W satisfy W > X.

[0243] ​​​Therefore, when the drive transmission member 81 is tilted by the gap AA, the misalignment amount AB between the control portion 73j and the gear portion 81a is longer than the gap AA and is expressed by the following equation.

[0244] AB = AA x (W / X)

[0245] Further, let V be the gap between the coupling protrusion 63b of the drive side drum flange 63 and the coupling recess 81a of the drive transmission member 81 in a state where there is no misalignment. Here, the gap V is the minimum value (distance measured in a direction perpendicular to the axis of the drum 62 and radial distance) of the surface-to-surface distance of the two coupling portions.

[0246] In a state where the phase of the coupling portions is aligned, the shortest gap V is expressed by the following equation.

[0247] V = AC - AD

[0248] In order for the coupling portions to be engaged even in a case where the drive transmission member 81 is tilted by the gap AA and misalignment of an amount AB occurs between the coupling portions, the gap V between the coupling portions can satisfy the following equation.

[0249] V = AC - AD > AB

[0250] That is, as long as the misalignment amount AB is smaller than the shortest gap V between the coupling protrusion 63b and the coupling recess 81b, the coupling protrusion 63b and the coupling recess 81b can accommodate the misalignment amount AB and be engaged.

[0251] If the phase of the coupling recess 81b differs with respect to the coupling protrusion 63b, the shortest gap V between the coupling portions also differs. That is, if the phases of the coupling portions are not aligned, the shortest gap V between the coupling protrusion 63b and the coupling recess 81b is smaller than (AC - AD). Depending on the situation, the gap V can be smaller than the misalignment amount AB.

[0252] However, as long as there is at least one phase relationship between the two coupling portions that satisfies "V > AB", the coupling protrusion 63b and the coupling recess 81b can be engaged. This is because the coupling recess 81b will contact the coupling protrusion 63b upon rotation. When the coupling recess 81b rotates to an angle that satisfies "V > AB", it can engage (couple) with the coupling protrusion 63b.

[0253] Further, when measuring the distance S from the center 62a of the drum 62 to the control portion 73i in the radial direction of the drum 62:

[0254] S = AA + U

[0255] Substituting "AB = AA x (W / X)" and "AA = S - U" into "V > AB" gives:

[0256] V > (S - U) x (W / X)

[0257] It is sufficient that there is at least one phase relationship between the coupling protrusion 63b and the coupling recess 81b that satisfies the formula.

[0258] Furthermore, the above formula is further modified, and the condition for the distance S is shown in the following formula.

[0259] S < U + V x (X / W)

[0260] In addition, it is preferable that the control portion 73j not contact the gear portion 81a when the drive transmission member 81 is rotated, and thus, it is preferable that the control portion 73j be separated from the tooth end of the gear portion 81a. This is expressed in the following formula.

[0261] S > U

[0262] Combining with the above relational expression gives:

[0263] U < S < U + V x (X / W)

[0264] If the cross-sectional shape of the coupling protrusion 63b and the cross-sectional shape of the coupling recess 81b are substantially equilateral triangles, as in this embodiment, the gap V is largest when the phases of the coupling portions are aligned. By substituting the value of V at this time into the above expression, the necessary S range is obtained.

[0265] The operation when the coupling members are engaged will be described. Before the coupling recess 81b of the drive transmission member 81 and the coupling protrusion 63b of the drive-side drum flange 63 engage with each other, the engagement force FD is applied to the drive transmission member 81. The engagement force FD is a force that is generated by engagement between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30, as described above.

[0266] By the engagement force FD, the drive transmission member 81 tilts in the direction FD in which the engagement force is applied, by the amount of the gap AA between the control portion 73j of the drum bearing 73 and the gear portion 81a, with the drive transmission member bearing 83 as a fulcrum. The amount of misalignment AB of the coupling recess 81b and the coupling protrusion 63b provided by this tilt is smaller than the gap V between the coupling recess 81b and the coupling protrusion 63b in the predetermined phase. Thus, when the drive transmission member 81 is rotated and the triangular phases of the coupling recess 81b and the coupling protrusion 63b align with each other, the end surfaces of the coupling members do not interfere with each other, so that the coupling recess 81b fits around the coupling protrusion 63b, and they engage with each other.

[0267] Here, an example of the dimensions that satisfy the above condition expression when the radius of the drum 62 is 12 mm will be described below.

[0268] In this embodiment, the dimensions of each portion of the drive transmission member 81 that is adapted for a drum 62 having a radius of 12 mm are as follows. The distance AC from the center of the coupling recess 81b to the vertex of the substantially equilateral triangle shape of the coupling recess 81b is 6.5 mm, and the radius AE of the inscribed circle of the substantially equilateral triangle shape of the coupling recess 81b is 4.65 mm. The substantially equilateral triangle shape of the coupling recess 81b is not a strict equilateral triangle, but rather the vertexes (corners) thereof are chamfered into an arc shape. The radius AF of the thinning portion 81b3 of the coupling recess is 4.8 mm, the radius U of the end circle of the gear portion 81a of the coupling recess is 12.715 mm, the distance X from one end portion 81c to the non-drive side end face 81a1 is 30.25 mm, and the distance W from one end portion 81c to the free end portion 81b1 of the coupling recess is 33.25 mm.

[0269] The shortest distance V between the coupling recess 81b and the coupling protrusion 63b satisfies the following relationship:

[0270] 0 < V < 1.7

[0271] The lower limit of V occurs when the dimension of the triangle shape of the coupling recess 81b is equal to the dimension of the triangle shape of the coupling protrusion 63b, and the lower limit value of V is “0”. On the other hand, the upper limit of V occurs when the distance AC from the center of the coupling protrusion 63b to the vertex is 4.8 mm, which is equal to the radius AF of the thinning portion of the coupling recess 81b. At this time, the clearance V (mm) between the coupling protrusion 63b and the coupling recess 81b is found to be “1.7 = 6.5 - 4.8”.

[0272] Substituting each value and V = 1.7 into the formula “U < S < U + V x (X / W)” given previously results in:

[0273] “12.715 < S < 14.262” (in mm).

[0274] The satisfaction of the above condition will be confirmed using two examples below.

[0275] First, in the first example, the dimensions are shown when the coupling protrusion 63b is as large as possible within the range that can be engaged with the coupling recess 81b. At this time, the clearance V between the coupling protrusion 63b and the coupling recess 81b is the smallest, and therefore, the allowable inclination of the drive transmission member 81 is small. Therefore, in order to reduce the inclination of the drive transmission member 81, the tube control portion 73j must be made closer to the normal position of the gear portion 81a.

[0276] On the other hand, in the second example, the size of the coupling protrusion 63b is shown when it is as small as possible within a range in which it can be engaged with the coupling recess 81b. At this time, the gap V between the coupling protrusion 63b and the coupling recess 81b is the largest, and thus, even if the drive transmission member 81 is relatively greatly inclined, the coupling protrusion 63b and the coupling recess 81b can be engaged with each other. That is, the control portion 73j can relatively greatly allow the inclination of the drive transmission member 81, and thus, the control portion 73j can be relatively greatly spaced apart from the normal position of the gear portion 81a.

[0277] In the first example, the size of the coupling protrusion 63b is closest to the maximum value, and the amount of engagement in the radial direction (the area in which both are engaged) between the coupling protrusion 63b and the coupling recess 81b is maximized. At this time, V (the gap between the couplings) is close to the lower limit (the minimum value), and thus, S (the distance from the center of the drum 62 to the control portion 73j) needs to be close to the lower limit (12.715 mm).

[0278] The distance AD from the center of the coupling protrusion 63b of the drive-side drum flange 63 to the apex of the triangle is 6.498 mm. As described above, when the coupling protrusion 63b has a size slightly smaller than the distance of 6.5 mm from the center of the coupling recess 81b to the apex of the triangle, the value of the amount of engagement in the radial direction between the coupling portions is substantially the maximum value. The radius AG of the inscribed circle inscribed in the triangle constituting the coupling protrusion 63b of the drive-side drum flange 63 is 4.648 mm. Here, the substantially triangular shape that the coupling protrusion 63b has is not a strict equilateral triangle, but the apexes (corners) are chamfered into an arc shape.

[0279] At this time, the distance S from the center 62a of the drum 62 to the control portion 73j of the drum bearing is 12.716 mm, which is slightly larger than the radius U of the addendum circle of the gear portion 81a.

[0280] By this, the gap AA between the control portion 73j of the drum bearing and the gear portion 81a of the drive transmission member is 0.001 mm (= 12.716 - 12.715). Here, when the drive transmission member 81 is inclined with respect to the control portion 73j by the gap AA, the amount of misalignment AB between the coupling portions is amplified due to the difference between the positions of the control portion 73j and the coupling portions in the longitudinal direction. The amount of misalignment AB is 0.0011 mm (= 0.001 multiplied by 33.25 / 30.25). In addition, the shortest gap V between the coupling protrusion 63b and the coupling recess 81b when the phases of the coupling portions are aligned is 0.002 mm (“6.5 - 6.498” or “4.65 - 4.648”, whichever is smaller).

[0281] Therefore, even if the drive transmission member 81 is inclined due to the engagement force, the gap V between the coupling members is larger than the misalignment amount AB between the coupling portions, so that the coupling can be performed.

[0282] As can be understood from the above description, the radial distance from the center of the drum 62 to the outermost portion of the coupling portion is preferably greater than 4.8 mm, and the radial distance from the center of the drum 62 to the control portion 73j is preferably greater than 12.715 mm.

[0283] In the second example, as described above, the size of the coupling protrusion 63b is made as small as possible, and the radial engagement amount (the area where both are engaged) between the coupling protrusion 61b and the coupling recess 81b is made as small as possible. At this time, V (the gap between the coupling members) approaches the maximum value (the upper limit), and S (the distance from the center of the drum 62 to the control portion 73j) can approach the upper limit.

[0284] The distance AD between the center and the apex of the coupling protrusion 63b of the drive side drum flange 63 is 4.801 mm. This is a value slightly larger than the radius of 4.8 mm of the thinned portion 81b3 of the coupling recess 81b, and is the diameter at which the radial engagement amount between the coupling members is almost the smallest. If this distance AD of the coupling protrusion 63b is shorter than the radius of the thinned portion 81b3, the tip end of the coupling protrusion 63b cannot engage with the coupling recess 81b, as a result of which drive transmission cannot be performed.

[0285] At this time, the radius AG of the inscribed circle of the triangle of the coupling protrusion 63b is 2.951 mm.

[0286] The distance S between the center 62a of the drum 62 and the control portion 73j of the drum bearing is 14.259 mm.

[0287] As a result, the gap AA between the control portion 73j of the drum bearing 73 and the gear portion 81a of the drive transmission member 81 is 1.544 mm (= 14.259 - 12.715). Here, when the drive transmission member 81 is inclined with respect to the control portion 73j by the amount of the gap AA, the misalignment amount AB between the coupling portions is amplified due to the difference in position in the longitudinal direction between the control portion 73j and the coupling portions, and this misalignment amount is 1.697 mm (= 1.544 x 33.25 / 30.25). In addition, the gap V between the coupling protrusion 63b and the coupling recess 81b when the phases of the coupling portions are aligned with each other is 1.699 mm ("6.5 - 4.801" or "4.65 - 2.951", whichever is smaller). Therefore, even if the drive transmission member 81 is inclined by the engagement force FD, the gap V between the coupling members is larger than the misalignment amount AB between the coupling portions, so that the coupling protrusion 63b and the coupling recess 81b can be engaged.

[0288] It can be understood from the second example that it is preferable that the radial distance from the center of the drum 62 to the outermost portion of the coupling protrusion 63b be greater than 4.8 mm, and that the radial distance from the center of the drum 62 to the regulated portion 73j be less than 14.262 mm.

[0289] Summarizing the first and second examples, in this embodiment, the radial distance S from the center 62a of the drum 62 to the regulated portion 73j of the drum bearing is preferably greater than 12.715 mm and less than 14.262 mm.

[0290] Next, a case in which the coupling protrusion 363b has a more general shape will be used as an example without limiting the shape of the coupling protrusion to a substantially equilateral triangle, and the preferred arrangement with respect to the regulated portion 73j will be described generally. Here, for ease of explanation, it is assumed that the shape of the coupling recess is substantially a strict equilateral triangle.

[0291] First, in Figure 28 Examples of coupling protrusions including a general shape are shown in part (a) and part (b) of FIG. 36. Figure 28 The coupling protrusion 363b shown in part (a) and part (b) of FIG. 36 has a substantially cylindrical shape, and also has a protrusion 363b1 provided on the outer periphery of the cylinder. The coupling protrusion 363b receives a driving force through the protrusion 363b1.

[0292] Referring to Figure 27 A case in which the regulated portion is positioned farthest from the center of the drum will be described.

[0293] First, consider the smallest equilateral triangle BD circumscribing the coupling protrusion 363b, and take this equilateral triangle BD as a hypothetical coupling protrusion. Here, the center of gravity of the equilateral triangle BD is made to coincide with the center of the coupling protrusion 363b (the center of the drum 62), and the size of the equilateral triangle BD is minimized. Thereafter, the arrangement of the regulated portion 73j corresponding to this hypothetical coupling protrusion (equilateral triangle DB) will be considered.

[0294] The circle inscribed in the hypothetical coupling protrusion (equilateral triangle BD) is circle BE, and the radius thereof is BA.

[0295] When the coupling recess has an equilateral triangle shape, the coupling recess needs to be greater than the equilateral triangle BD in order to engage the coupling recess with the hypothetical coupling protrusion (equilateral triangle BD). That is, the size of the equilateral triangle BD can also be considered as a lower limit of the size that the coupling recess can have.

[0296] Next, the maximum shape that the coupling recess can have will be considered. First, consider a circle BU circumscribing an imaginary coupling convex portion (equilateral triangle BD), and its radius is AZ. Also, draw an equilateral triangle BQ that has this circle BU as an inscribed circle. When the coupling recess has the shape of an equilateral triangle, the equilateral triangle BQ is the largest (upper limit) among the equilateral triangle shapes that can be selected as the coupling recess. If the coupling recess becomes larger than the equilateral triangle BQ, the coupling recess cannot come into contact with the imaginary coupling convex portion BD, and thus, drive transmission cannot be performed. This equilateral triangle BQ is taken as the maximum coupling recess.

[0297] Let AY be the shortest distance between the two equilateral triangles BD and BQ when they are in the same phase. The distance AY corresponds to the difference between the radius of the inscribed circle BU inscribed in the equilateral triangle BQ (AZ) and the radius of the inscribed circle BE inscribed in the equilateral triangle BD (BA). That is, AY = AZ - BA.

[0298] When the coupling recess is an equilateral triangle, the distance between the imaginary coupling convex portion and the coupling recess is the above-described distance AY that is the upper limit. If the misalignment distance of the coupling recess with respect to the imaginary coupling convex portion is smaller than AY, the coupling recess can engage with the imaginary coupling convex portion.

[0299] The misalignment distance between the couplings is equal to or greater than the gap BC between the tooth tip of the gear portion 81a of the drive transmission member and the control portion 73j. Therefore, in order for the coupling recess to engage with the imaginary coupling convex portion BD, the gap BC between the gear portion 81a of the drive transmission member and the control portion 73j needs to be at least smaller than the distance AY. This is shown in the following equation:

[0300] BC < AY

[0301] The gap BC is the difference between the distance BB from the center of the drum to the control portion 73j and the radius of the addendum circle of the gear portion 81a. As for the radius of the addendum circle of the gear portion 81a, the tooth tip of the gear portion 81a of the drive transmission member can extend to the bottom of the gear portion 30a of the developing roller gear 30. That is, the tooth tip of the gear portion 81a can extend to such an extent that it does not touch the bottom. If the shortest distance from the center of the drum to the bottom of the developing roller gear 30a is AX, the upper limit of the radius of the addendum circle 81a of the gear portion 81a is also AX.

[0302] Therefore, the gap BC between the tooth tip of the gear portion 81a and the control portion 73j is always greater than "BB - AX", that is, BC > BB - AX. Using the relationship "BC > BB - AX" and the above-described "BC < AY", it can be seen that the distance BB from the center of the drum to the control portion 73j satisfies the following condition:

[0303] BB - AX < AY

[0304] BB < AY + AX

[0305] Here,

[0306] AY = AZ - BA = BA (1 / sin 30° - 1) = BA

[0307] Therefore,

[0308] BB < BA + AX

[0309] As a condition required for the coupling to engage when the drive transmission member 81 is tilted by the meshing force between the gears, "BB < BA + AX" can be derived with respect to the distance BB of the drum center of the control portion 73j.

[0310] Next, a case where the control portion is positioned closest to the drum center will be described. In order for the gear portion 81a of the drive transmission member 81 to mesh with the gear portion 30a, the radius of the addendum circle of the gear portion 81a needs to be greater than the distance BF (distance measured in a direction perpendicular to the drum axis) from the center of the drum 62 to the addendum end of the gear portion 30a of the developing roller. In addition, the addendum end of the control portion 73j and the drive transmission member 81a must not contact each other during imaging. That is, the distance BB (distance measured in a direction perpendicular to the drum axis) from the center of the drum 62 to the control portion 73j needs to be greater than the distance BF (distance measured in a direction perpendicular to the drum axis) from the center of the drum 62 to the addendum end of the gear portion 30a of the developing roller. From the above two conditions, it is necessary to satisfy the following condition:

[0311] BB > BF

[0312] In combination with the above "BB < BA + AX", it is preferable to arrange the control portion 73j in a range that satisfies the following relational expression with respect to the center of the drum (drum axis, axis of the input coupling):

[0313] BF < BB < AX + BA

[0314] The definition of each value is summarized as follows.

[0315] BB: distance measured from the center of the photosensitive member (axis of the photosensitive member, axis of the coupling protrusion) to the control portion 73j in a direction perpendicular to the axis of the photosensitive member;

[0316] BA: radius of the inscribed circle in the smallest equilateral triangle that circumscribes the coupling protrusion, while aligning the center of gravity of the equilateral triangle with the axis of the drum (axis of the coupling protrusion);

[0317] AX: distance from the center of the photosensitive member (rotation axis of the coupling protrusion) to the bottom of the developing roller gear (bottom of the input gear) measured in the direction perpendicular to the axis of the photosensitive member; and

[0318] BF: minimum distance measured from the rotation center (axis) of the photosensitive member to the end of the teeth of the input gear portion (gear portion 30a) measured in the direction perpendicular to the axis of the photosensitive member.

[0319] In this embodiment, the control portion 73j is formed by a continuous surface. More specifically, the control portion 73j is a curved surface (circular arc surface) that opens toward the axis of the drum 62 and is curved in an arc shape. In other words, it is a bay (bight) that opens toward the axis of the drum 62.

[0320] However, as shown in the perspective view of the cartridge in Figure 26 , the control portion 89j can be formed by a plurality of portions (a plurality of surfaces 89j) that are discontinuous in the rotation direction of the drum 62. Likewise, in this case, by connecting the plurality of discontinuous portions, the control portion can be considered to form a bay (bight) that opens toward the axis of the drum 62.

[0321] That is, there is a difference in whether the control portion is one continuous portion or a plurality of discontinuous portions, but, Figure 1 the control portion shown in Figure 26 both can be considered to have an arc shape (bay, curved surface portion, curved portion) that opens toward the axis of the drum 62.

[0322] In addition, in this embodiment, as a means for aligning the center of the drive transmission member 81 with the center of the drum 62, the triangular alignment action of the coupling protrusion 63b and the coupling recess 81b is utilized. That is, the coupling protrusion 63b and the coupling recess 81b contact at three points so that the axis of the coupling protrusion 63b and the axis of the coupling recess 81b align with each other. By coaxially aligning the drive transmission member 81 and the photosensitive drum, it is possible to easily maintain the precision of the center-to-center distance (distance between axes) between the gear portion 81a and the gear portion 30a, and the drive is stably transmitted to the developing roller gear 30.

[0323] However, one of the drive transmission member 81 and the drive-side drum flange 63 can be provided with a cylindrical lug (projection), and the other can be provided with a hole that cooperates with the lug. Even with such a structure, the axis of the drive transmission member 81 and the axis of the drum 62 can overlap. Figure 38 Such a modification is shown. Figure 38The illustrated drive transmission member 181 has a protrusion (lug) 181c at the center of the coupling recess 181b. The protrusion 181c is disposed so as to overlap the axis of the drive transmission member 181, and is a protrusion projecting along the axis. On the other hand, Figure 38 The illustrated coupling protrusion has a recess (recessed portion) for engaging with the protrusion 181c at the center thereof. The recess is disposed so as to overlap the rotational axis of the drum 62, and is a recessed portion recessed along the axis. By coaxially arranging the drive transmission member 81 and the photosensitive drum, it is possible to easily maintain the accuracy of the center-to-center distance (distance between axes) between the gear portion 81a and the gear portion 30a, and the drive is stably transmitted to the developing roller gear 30.

[0324] Next, the arrangement of the coupling protrusion 63b in the longitudinal direction (axial direction of the drum) will be described. As Figure 18 As illustrated, the drive-side drum flange 63 has a flange portion 63c. The cleaning frame 71 is provided with a drum control rib 71m (drum control portion, drum longitudinal position control portion, drum axial position control portion).

[0325] The drum control rib 71m is disposed on the non-drive side of the flange portion 63c of the drive-side drum flange 63 with respect to the longitudinal direction, and faces the flange portion 63c with a gap therebetween.

[0326] When the amount by which the drum 62 moves toward the non-drive side exceeds the gap, the flange 63c and the drum control rib 71m come into contact with each other, and the movement of the drum 62 is restricted. That is, the movement of the drum 62 in the longitudinal direction (axial direction) does not exceed a predetermined range. Thereby, the positional accuracy of the coupling protrusion 63b of the drive-side drum flange 63 in the longitudinal direction is improved before the coupling protrusion 63b of the drive-side drum flange 63 engages with the coupling recess 81b. Therefore, even if the amount of movement of the drive transmission member 81 in the longitudinal direction is reduced, the coupling protrusion 63b and the coupling recess 81b can engage with each other. By reducing the amount of movement of the drive transmission member 81 in the longitudinal direction, it is possible to downsize the device main assembly A.

[0327] Next, the arrangement of the gear portion 30a of the developing roller gear 30 in the longitudinal direction (axial direction of the drum) will be described. As Figure 18 As illustrated, the developing roller gear 30 has an end surface 30a2 on the non-drive side of the gear portion 30a. The developing container 23 is provided with a developing roller gear control rib 23d (gear control portion, gear longitudinal position control portion, gear axial position control portion).

[0328] The developing roller gear control rib 23d is disposed on the non-drive side in the axial direction with respect to the non-drive side end surface 30a2 of the gear portion 30a, and faces the non-drive side end surface 30a2a with a gap therebetween.

[0329] Thus, the developing roller gear tube control rib 23d arranged on the drive side of the cartridge B restricts the developing roller gear 30 from moving in the longitudinal direction toward the non-drive side. Thus, the axial position accuracy of the gear portion 30a of the developing roller gear 30 is improved before the gear portion 30a of the developing roller gear 30 engages with the gear portion 81a of the drive transmission member 81. Therefore, the gear width of the gear portion 30a of the developing roller gear 30 can be reduced. Thus, the cartridge B and the device main assembly A in which the cartridge B is installed can be downsized.

[0330] <Removal of Cartridge>

[0331] The removal of the cartridge B from the device main assembly A will be described with reference to Figure 7 , 24 and 25.

[0332] As shown in Figure 7 , when the opening and closing door 13 is turned and opened, the cylindrical cam 86 moves while rotating along the inclined surface portions 86a and 86b by the rotating cam link 85 until the end surface portion 86c of the cylindrical cam 86 and the end surface portion 15f of the drive side plate 15 abut on the drive side in the axial direction. Also, when the cylindrical cam 86 moves, the drive transmission member 81 can move to the drive side (the side away from the cartridge B) in the axial direction.

[0333] Here, as shown in parts (a) and (b) of Figure 24 and part (a) of Figure 25 , the engagement amount of the radial teeth of the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 is referred to as the engagement amount AH.

[0334] In order to break the engagement between the gear portion 81a and the gear portion 30a, the amount by which the gear portion 81a moves in the direction away from the gear portion 30a must be equal to or greater than the engagement amount AH between the gear portions. Therefore, the control portion 73j of the drum bearing 73 is provided so as not to hinder the movement of the drive transmission member 81 when the gear portion 81a is separated from the gear portion 30a. The direction in which the gear portion 81a of the drive transmission member 81 moves away from the gear portion 30a of the developing roller gear 30 is indicated by an arrow AI in the direction extending along the line connecting the center 81j of the drive transmission member 81 and the center 30b of the developing roller gear 30. It is preferable that the control portion 73j is not provided in the direction of the arrow AI. That is, it is preferable that the control portion 73j is not arranged to cross the straight line LA, and that the drive transmission member 81 does not contact the control portion 73j when the gear portion 81a is disengaged from the gear portion 30a.

[0335] It is preferable that the drive transmission member 81 not contact the concave peripheral surface 73k of the drum bearing 73 when the gear portion 81a is disengaged from the gear portion 30a. In this state where the door 13 is open (Figs. 10 and 11) Figure 7 The drive transmission member 81 is retracted to a position where it does not contact the concave peripheral surface 73k of the drum bearing 73 in the portions (a) and (b) of Fig. 9.

[0336] That is, as shown in the portion (a) of Fig. 9, the position where the drive transmission member 81 is retracted to the extent that the coupling with the coupling protrusion 63b is broken. Therefore, in the longitudinal direction of the drive transmission member 81, the free end portion of the drive transmission member 81 is at approximately the same position as the free end portion of the concave peripheral surface 73k or is on the left side of the free end portion of the concave peripheral surface 73k. Figure 24

[0337] In this state, even if the drive transmission member 81 is tilted in an attempt to break the meshing between the gear portion 81a and the gear portion 30a, the drive transmission member 81 and the concave peripheral surface 73k do not contact each other.

[0338] It is also conceivable that the amount of movement of the drive transmission member 81 when retracted is short and that the free end portion of the drive transmission member 81 in the retracted position is disposed on the right side of the free end portion of the concave peripheral surface 73k. In such a case, as long as the following conditions are satisfied, contact between the drive transmission member 81 and the concave peripheral surface 73k can be avoided.

[0339] Let Z be the distance in the radial direction from the center 62a of the drum 62 to the concave peripheral surface 73k of the drum bearing 73. Let Y be the radial distance from the center 81j of the drive transmission member 81 to the outer peripheral surface of the cylindrical portion 81i of the drive transmission member 81. Let AJ be the radial distance at the gap between the concave peripheral surface 73k and the cylindrical portion 81i.

[0340] At this time, the gap AJ satisfies the following relational expression.

[0341] AJ = Z - Y

[0342] AJ>AH

[0343] That is, a recess is provided around the drum 62. Also, the drive transmission member 81 can move in a range where the inner peripheral surface of the recess (the concave peripheral surface 73k) does not contact the gear portion 81a.

[0344] The radial position of the concave peripheral surface 73k of the drum bearing 73 can be such that the distance Z from the center 62a of the drum 62 satisfies the following expression:

[0345] Z>AH + Y

[0346] ​With the above structure, when the cartridge B is taken out from the main assembly A of the apparatus, the drive transmission member 81 can tilt in the distancing direction AD by an amount exceeding the engagement amount AH between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30. Also, disengagement between the gear portion 81a of the drive transmission member 81 and the gear portion 30a of the developing roller gear 30 is achieved, so that the cartridge B can be smoothly taken out from the main assembly A of the apparatus.

[0347] As described above, the drive transmission member 81 moves toward the coupling portion on the cartridge side due to the thrust caused by the engagement of the helical gears with each other.

[0348] Further, the drive transmission member 81 moves (tilts) by the force generated by the gear engagement, but the amount of movement (tilt amount) is regulated by the regulating portion provided on the cartridge side. Thereby, engagement (coupling) between the drive transmission member 81 and the coupling portion on the cartridge side is ensured, so that reliable drive transmission is ensured.

[0349] Further, since the drive transmission member 81 is provided so as to leave a gap to allow the drive transmission member 81 to move in the radial direction beyond the engagement height of the gears, disengagement between the gears is smoothly performed when the cartridge B is removed from the main assembly of the apparatus. That is, the cartridge can be easily taken out.

[0350] Further, in this embodiment, the coupling protrusion 63b is fixed to the drum 62, but a movable coupling protrusion can be provided. For example, Figure 20 The coupling member 263b shown is movable in the axial direction with respect to the drum 62, and is urged toward the drive side by the spring 94 in a state where it does not receive an external force. When the cartridge B is installed in the main assembly A, the end portion 263a of the coupling member 263b comes into contact with the drive transmission member 81. The coupling protrusion 263b can be retracted to the non-drive side (the side distanced from the drive transmission member 81), at which time the spring 94 is retracted by the force received from the drive transmission member 81. With such a structure, it is not absolutely necessary to retract the drive transmission member 81 to the extent that it does not contact the coupling protrusion 263b. That is, the amount of retraction of the drive transmission member 81 associated with the opening of the opening and closing door 13 ( Figure 2 ) can be reduced by the amount by which the coupling protrusion 263b can be retracted. That is, the main assembly A can be downsized.

[0351] The end portion 263a of the coupling protrusion 263b is a tilted portion (bevel, chamfered surface). With such a structure, when the end portion 263a contacts the drive transmission member 81 in the case of installation and removal of the cartridge, the end portion 263a tends to receive a force in the direction of retracting the coupling protrusion 263b. However, the present application is not limited to such a structure. For example, the contact portion on the drive transmission member 81 side that contacts the coupling protrusion 263b can be a tilted portion.

[0352] Another modification is shown in Figure 23 In this embodiment, the drum 62 is driven by engagement between the driving transmission member 81 and the coupling protrusion 63b. However, as Figure 23 shown, the driving of the drum 62 can be performed by the gears 330b, 95b.

[0353] In the structure shown in Figure 23 The drum flange 95 fixed to the end portion of the drum 62 has a gear portion 95b (input gear portion) for receiving the driving force from the gear portion 330b instead of including the coupling protrusion. Further, the drum flange 95 has a cylindrical portion 95a.

[0354] In this case, the cylindrical portion 95a provided at the end portion of the drum 62 serves as a positioning portion for positioning the driving transmission member 81 by engagement with the coupling recess 81b provided at the tip end of the driving transmission member 81.

[0355] Both the recess 81b and the cylindrical portion 95a serve as alignment portions for aligning the axes of the driving transmission member recess 81 and the drum 62 with each other. When the coupling recess 81b and the cylindrical portion 95a engage with each other, the axes of the drum 62 and the driving transmission member 81 substantially overlap, and both are coaxially arranged. Here, the coupling recess 81b can be referred to as a main assembly side alignment portion (alignment recess), and the cylindrical portion 95a can be referred to as a cartridge side alignment portion (alignment protrusion).

[0356] Strictly speaking, the outer peripheral surface of the cylindrical portion 95a corresponds to the cartridge side alignment portion. In addition, the thinned portion 81b3 of the coupling protrusion 81b corresponds to the main assembly side alignment portion. The circular thinned portion 81b3 engages with the outer peripheral surface of the cylindrical portion 95a, thereby aligning the drum 62 and the driving transmission member 81 with each other.

[0357] In the cartridge shown in Figure 23 In the cartridge shown in Figure 23The part (b) of the coupling recess 81b is provided on the edge of the tip of the cylindrical portion 95a, so that the coupling recess 81b and the cylindrical portion 95a easily engage with each other. That is, the diameter of the cylindrical portion 95a is reduced toward the tip thereof.

[0358] As described above, when the coupling protrusion 63b is provided at the end of the drum 62, the coupling recess 81b functions as an output coupling for transmitting a driving force to the coupling protrusion 63b. In addition, in the case where the coupling protrusion 63b is substantially triangular, the driving transmission member 81 is centered by being coupled to the coupling protrusion 63b through the coupling recess 81b. Therefore, the coupling recess 81b also functions as a centering portion.

[0359] On the other hand, in the case where the cylindrical portion 95a is provided at the end of the drum 62 in the structure shown in the part (a) of the figure, Figure 23 the coupling recess 81b does not function as a coupling portion (output coupling), but only as a centering recess (main assembly side alignment portion).

[0360] That is, the coupling recess 81b can function as both an output coupling and a main assembly side alignment portion (alignment recess), and the function of the coupling recess 81b provided by the structure of the drum 62 is to have both functions of a coupling recess and a centering portion or to have either one of them.

[0361] In addition, although Figure 23 the outer periphery of the alignment portion on the cassette side is a cylindrical portion 95a forming a complete circle, the present application is not limited to such a structure. Figure 35 The shape of the alignment portion is schematically shown as an example.

[0362] Figure 35 The part (a) of the figure shows Figure 23 the state in which the cylindrical portion 95a shown in the part (a) of the figure is provided on the drum flange 63. In contrast, in the part (b) of the figure, Figure 35 the shape of the alignment portion 95b constitutes only a part of a circle. As long as the circular arc portion of the alignment portion 95b is sufficiently larger than the circular arc shape of the thinned portion 81b3, the alignment portion 95b has a centering effect.

[0363] The distance (radius) from the center of the drum to the outermost portion of the alignment portion 95a, 95b corresponds to the radius of the thinned portion 81b3. The radius of the thinned portion 81b3 is 4.8 mm, and therefore, the distance (radius) from the center of the drum to the outermost portion of the alignment portion 95a, 95b, 95c is 4.8 mm or less, and the closer to 4.8 mm, the better the alignment effect.

[0364] In this embodiment, the coupling recess 81b as the main assembly side alignment portion has a substantially triangular shape so as to transmit drive when engaged with the coupling protrusion 63b, and an arc-shaped thin portion 81b3 is provided on a part of the side of the triangle. However, the main assembly side alignment portion can take another shape when the main assembly side alignment unit does not need to transmit drive to the drum 62. For example, the main assembly side alignment portion can be a substantially circular recess. In the case of such a main assembly side alignment portion, as Figure 35 The alignment portion 95c shown in part (c) can be used as the cartridge side alignment portion. Figure 35 The centering portion shown in part (c) has a structure in which a plurality of protrusions 95c are arranged in a circle. That is, a circumscribed circle (a circle shown by a broken line) of the protrusions 95c is a circle coaxial with the drum. In addition, the size of this circumscribed circle corresponds to the recess of the main assembly side alignment portion. That is, the radius of the circumscribed circle is not greater than 4.8 mm.

[0365] Figure 35 Any of the structures shown in part (a), part (b), and part (c) can be regarded as an alignment portion substantially coaxial with the drum. That is, each of the alignment portions 95a, 95b, 95c is arranged so as to be centered on the axis of the drum.

[0366] Strictly speaking, the outer peripheral surface of the alignment portion 95a, 95b, 95c, that is, the portion facing the opposite side of the drum axis (in other words, the portion facing the outer side in the radial direction of the drum) functions as the alignment portion. The outer peripheral surface functioning as the alignment portion extends in a manner surrounding the axis of the drum.

[0367] Each of the alignment portions 95a, 95b, 95c is exposed toward the outside of the cartridge in the axial direction.

[0368] In addition, it is preferable that the structure of the cartridge shown in Figure 23 has the tube control portion 73j as described above. In addition, the positional relationship (dimensional relationship) between the developing roller gear 30 and the tube control portion 73j with respect to the alignment portion can be considered similar to the relationship (dimensional relationship) between the developing roller gear 30 and the tube control portion 73j with respect to the cartridge protrusion 63b.

[0369] For the reasons as described above, for example, for the lower limit of the distance BB from the center of the drum to the center of the tube control portion 73j, the following relational expression holds.

[0370] BF < BB

[0371] BB: The distance measured from the center of the photosensitive member (the axis of the photosensitive member, the axis of the coupling protrusion) to the tube control portion 73j in a direction perpendicular to the axis of the photosensitive member.

[0372] BF: the minimum distance measured in the direction perpendicular to the axis of the photosensitive member from the rotation center (axis) of the photosensitive member to the end of the teeth of the input gear portion (gear portion 30a).

[0373] The upper limit of the distance BB will be considered. It is preferable that the amount of misalignment generated between the coupling recess 81b and the alignment portion 95a when the moving transmission member 81 is tilted until the gear portion 81a comes into contact with the control portion 73j satisfies the following relationship. That is, it is preferable that the tilt portion 95al (part (a) of the portion) be provided at the end of the alignment portion 95a, but when the width of the tilt portion 95a is measured in the radial direction of the drum, the width of the tilt portion 95a is greater than the amount of misalignment. As long as this relationship is satisfied, even if misalignment occurs, the tilt portion 95al of the alignment portion 95a will come into contact with the edge of the coupling recess 81b to assist in the engagement between the coupling recess 81b and the alignment portion 95a. Figure 23

[0374] The difference between the distance BB and the radius U of the end circle of the gear portion 81a is "BB - U", and the amount of misalignment becomes greater than "BB - U".

[0375] Therefore, the width BX of the tilt portion 95a needs to be at least greater than "BB - U". In addition, the radius U of the addendum circle of the gear portion 81a is smaller than the distance AX from the center of the drum to the root of the developing roller gear. Therefore, the width BX of the tilt portion 95a is greater than "BB - AX".

[0376] BX > BB - AX

[0377] This formula is modified as follows:

[0378] BB < BX + AX

[0379] BB: the distance measured in the direction perpendicular to the axis of the photosensitive member from the center of the photosensitive member (axis of the photosensitive member, axis of the coupling convex portion) to the control portion 73j.

[0380] BX: the width of the tilt portion 95a measured in the radial direction of the photosensitive member.

[0381] AX: the distance measured in the direction perpendicular to the axis of the photosensitive member from the axis of the photosensitive member to the root of the developing roller gear.

[0382] In summary, "BF < BB < BX + AX" holds.

[0383] In Figure 23 ​In the illustrated structure, the cylindrical portion 95a is provided on the drum 62. Alternatively, an alignment portion such as the cylindrical portion 95a can be provided on the frame of the cleaning unit 60 (i.e., the drum bearing 73). That is, it is also conceivable that the drum bearing 73 covers the end portion of the drum 62, and the drum bearing 73 is provided with an alignment portion. In addition, a structure in which a portion (a) of the driving transmission member 81 (see FIG. 6) is engaged with, instead of the recess 81b of the driving transmission member 81, can be used as the alignment portion on the cartridge side. Figure 13

[0384] In Figure 36 In the illustrated modification, a circular-arc-shaped protrusion 173a for contacting the periphery of the cylindrical portion 81i is provided on the drum bearing 173. Figure 36 Figure 36

[0385] The alignment portion is provided in the drum bearing 173, instead of being provided in the drum flange 195. Therefore, the drum flange 195 has a gear portion 195a for receiving a driving force from the developing roller gear, but does not have an alignment portion.

[0386] The center of the alignment portion is arranged to overlap the axis of the drum. That is, the protrusion 173a is arranged to be substantially coaxial with the drum. In other words, the inner peripheral surface of the protrusion 173a facing the axis side of the drum is arranged to surround the axis of the drum. A tapered portion (inclined portion) is provided on the edge of the tip of the protrusion 173a, so that when the tip of the protrusion 173a hits the cylindrical portion 81i, the cylindrical portion 81i can be easily introduced into the inner space of the protrusion 173a.

[0387] The distance (radius) from the axis of the drum to the alignment portion (protrusion 173a) corresponds to the radius of the cylindrical portion 81i. If the radius of the cylindrical portion 81i is 7.05 mm, the radius of the protrusion 173a is preferably 7.05 mm or more.

[0388] The protrusion 173a also functions as a regulation portion (stopper) for suppressing the inclination and movement of the driving transmission member 81 by contacting the cylindrical portion 81i. That is, the protrusion 173a can also function as the regulation portion 73j (see FIG. 5) of the drum bearing 73. Figure 24 ​​​). The structure of the control portion configured to be in contact with the cylindrical portion 81i will be described later in Embodiment 2. Here, an inclined portion (tapered portion, chamfered portion) is provided at the tip of the protrusion 173a, and when the drive transmission member 81 is inclined, the tip of the cylindrical portion 81i comes in contact with the inclined portion, thereby facilitating the engagement between the cylindrical portion 81i and the protrusion 173a. That is, the inner peripheral surface of the protrusion 173a has a diameter that increases toward the tip of the protrusion 173a.

[0389] The functions, materials, shapes, and relative arrangements of the components described in connection with this embodiment and each of the above-described modification examples should not be understood as limiting the scope of the present application to only this unless otherwise specified.

[0390] <Embodiment 2>

[0391] Next, embodiments of Embodiment 2 of the present application will be described with reference to Figure 29 , Figure 30 part (a) of FIG. 8, Figure 30 part (b) of FIG. 8, Figure 30 part (c) of FIG. 8, Figure 31 part (a) of FIG. 9, and Figure 31 part (b) of FIG. 9. Figure 29 is a perspective view of a cartridge for illustrating the control of the drive transmission member. Figure 30 part (a) of FIG. 8 is a cross-sectional view of a drive portion of an image forming apparatus seen from the opposite direction of the cartridge mounting direction for illustrating the control of the drive transmission member. Figure 30 part (b) of FIG. 8 is a cross-sectional view of a drive portion of an image forming apparatus seen from the drive side for illustrating the control of the drive transmission member. Figure 30 part (c) of FIG. 8 is a cross-sectional view of a drive portion of an image forming apparatus seen from the drive side for illustrating the control of the drive transmission member. Figure 31 part (a) of FIG. 9 is a cross-sectional view of a drive portion of an image forming apparatus seen from the drive side for illustrating the control of the drive transmission member. Figure 31 part (b) of FIG. 9 is a cross-sectional view of a drive portion of an image forming apparatus seen from the upstream side of the cartridge mounting direction for illustrating the control of the drive transmission member.

[0392] In this embodiment, the parts different from the above-described embodiment will be described in detail. In particular, the materials, shapes, and the like are the same as in the above-described embodiment unless otherwise specified. For these parts, the same reference numerals will be given and detailed description thereof will be omitted.

[0393] As Figure 29 and Figure 30 part (a) of FIG. 8, Figure 30 part (b) of FIG. 8, and Figure 30As shown in part (c), the drum bearing 90 is provided with a recess surrounding the protrusion of the connecting part. Furthermore, the control portion 90k1 for controlling the movement of the drive transmission component 91 is a small-diameter portion within the concave peripheral surface 90k (the inner peripheral surface of the recess) (the inner diameter of the recess is smaller than that of other portions). The control portion 90k1 is an arc-shaped curved surface portion facing the axial side of the drum.

[0394] The control section 90k1 is a control section (stop) used to suppress the movement and tilting of the drive transmission component 91, and is the same as the control section 73j in Embodiment 1. Figure 1 , Figure 24 The part corresponding to (etc.). In the following, the control part 90k1 in this embodiment will be described in detail, especially the part that is different from the control part 73j in embodiment 1.

[0395] The inclined portion of the drive transmission member 91 controlled by the control section 90k1 is a cylindrical portion (cylindrical portion) 91i provided at the free end on the non-drive side along the axial direction of the drive transmission member. The cylindrical portion 91i corresponds to a cylindrical protrusion in which a connecting recess is formed.

[0396] When the opening / closing door 13 is open and the drive transmission member 91 is moving along the drive side (away from the box side), the control portion 90k1 overlaps with the cylindrical portion 91i of the drive transmission member 91 in the axial direction.

[0397] like Figure 39 As shown, in this embodiment, at least a portion of the control portion 90k1 in the axial direction is located outside the outer peripheral surface 63b2 of the input connection portion (connection protrusion 63b) (arrow D1 side). Here, the outer peripheral surface 63b2 is the portion that receives driving force from the connection recess (drive receiving portion). In particular, at least a portion of the control portion 90k1 is arranged outside the front end 63b1 of the connection protrusion 63b.

[0398] Furthermore, at least a portion of the control portion 90k1 is arranged to overlap with the input connection portion (connecting protrusion 63b) in the axial direction. That is, when the connecting protrusion 63b and the control portion 90k1 are projected onto the axis Ax1 of the drum, at least a portion of their projection areas overlap each other. In other words, at least a portion of the control portion 90k1 is arranged to face the input connection portion (connecting protrusion 63b) located at the end of the drum.

[0399] The control section 90k1 can also be considered a protruding section, which protrudes to cover the axis of the drum.

[0400] Here, it has been explained in Example 1 ( Figure 24 Part (a) and part (b) Figure 25the following relational expression in part (a) of the above equation holds.

[0401] AB = AA x (W / X)

[0402] S = AA + U

[0403] V > AB

[0404] V > (S - U) x (W / X)

[0405] U < S < U + V x (X / W)

[0406] In this embodiment, in the dimensions shown in part (a), part (b), and part (c) of the above equation, AU corresponds to V and AS corresponds to S. Figure 30

[0407] In addition, AT corresponds to AA, and AP corresponds to U.

[0408] In addition, W = X, and (W / X) = 1.

[0409] Accordingly, in this embodiment, according to the same analysis as in Embodiment 1, the conditions under which the coupling protrusions 63b and the coupling recesses are able to be coupled to each other when the drive transmission member 91 is tilted until it comes into contact with the control portion 90k1 are as follows.

[0410] AB = AT

[0411] AS = AT + AP

[0412] AU > AT

[0413] AU > (AS - AP)

[0414] AP < AS < AP + AU

[0415] In other words, as long as there is at least one phase relationship between the coupling protrusions and the coupling recesses that satisfies "AU > AT = AS - AP", the coupling portions are able to be engaged (coupled) with each other.

[0416] Here,

[0417] AB: amount of misalignment between the couplings measured in a direction perpendicular to the drum axis.

[0418] AT: distance from the drive transmission member 91 (cylindrical portion 91i) to the control portion 90k1 measured in a direction perpendicular to the drum axis.

[0419] AS: distance from the drum axis (axis of the coupling protrusion) to the control portion 90k1 measured in a direction perpendicular to the drum axis.

[0420] ​AP: radius of the cylindrical portion 91i of the drive transmission member 91.

[0421] In Embodiment 1, the gear portion 81a of the drive transmission member 81 is regulated by the regulating portion 73j.

[0422] In contrast, in this embodiment, the cylindrical portion 91i that forms the outer peripheral surface of the coupling recess 91b is regulated by the regulating portion 90k1.

[0423] Therefore, the positions of the regulating portion 90k1 and the coupling recess 91b in the axial direction are substantially the same.

[0424] In contrast to the case where the gear portion 81a of the drive transmission member 81 is regulated by the regulating portion (part (a) of Figure 24 In this embodiment, the inclination of the drive transmission member 91 can be accurately regulated.

[0425] Thus, even if the gap between the coupling recess 91 and the coupling protrusion 63b is small, they can engage with each other. Since the sizes of the coupling recess 91 and the coupling protrusion 63b are close to each other, the accuracy of the drive transmission is improved.

[0426] Here, an example of the dimensions established when the radius of the drum 62 is 12 mm will be described below. First, the dimensions of the respective portions of the drive transmission member 91 that are applicable to the drum 62 having a radius of 12 mm in this embodiment are the same as those of the drive transmission member 81 in Embodiment 1, and are as follows: the distance AJ from the center of the coupling recess 91b to the apex of the substantially equilateral triangle of the recess 91b is 6.5 mm, and the radius AK of the inscribed circle of the substantially triangular shape of the coupling recess 91b is 4.65 mm. Here, the substantially equilateral triangular shape of the recess 91b is not a pure equilateral triangle, but the apex angles are chamfered into an arc shape. In addition, the radius AN of the thinned portion 91b3 of the coupling recess 91b is 4.8 mm, and the radius AP of the cylindrical portion 91i of the drive transmission member 91 is 7.05 mm.

[0427] The shortest distance AU between the coupling recess 91b and the coupling protrusion 63b satisfies the following relationship:

[0428] 0 < AU < 1.7

[0429] AU is the lower limit when the dimensions of the triangular shape of the coupling recess 91b are equal to the dimensions of the triangular shape of the coupling protrusion 63b. On the other hand, AU is the upper limit when the distance from the center to the apex of the coupling protrusion 63b is 4.8 mm, which is equal to the radius AC of the thinned portion of the coupling recess 91b. At this time, the gap AU between the coupling protrusion 63b and the coupling recess 81b is "1.7 = 6.5 - 4.8".

[0430] Therefore, substituting each value and AU = 1.7 into the expression "AP < AS < AP + AU" shown above gives:

[0431] "7.05 < S < 8.75".

[0432] Two examples will be used to verify the fact that the above formula is established.

[0433] In the first example, the size when the coupling protrusion 63b is enlarged to the maximum within the range in which it can be engaged with the coupling recess 91b is shown. In this case, the gap AU between the coupling protrusion 63b and the coupling recess 91b approaches the lower limit, and therefore, the allowable inclination of the drive transmission member 81 becomes small. Therefore, in order to reduce the inclination of the drive transmission member 91, it is necessary to make the normal position of the pipe control portion 90k1 closest to the cylindrical portion 91i.

[0434] In the second example, the size when the coupling protrusion 63b is the smallest within the range in which it can be engaged with the coupling recess 91b is shown. The gap AU between the coupling protrusion 63b and the coupling recess 91b approaches the upper limit, and therefore, even if the drive transmission member 81 is relatively greatly inclined, the coupling protrusion 63b and the coupling recess 91b can be engaged with each other. That is, the pipe control portion 73j can relatively significantly allow the inclination of the drive transmission member 91, and therefore, the pipe control portion 93j can relatively greatly depart from the normal position of the cylindrical portion 91i.

[0435] In the first example, the coupling protrusion 63b is maximized to maximize the radial coupling amount between the coupling portions.

[0436] The distance AQ from the center of the coupling protrusion 63b of the drive side drum flange 63 to the apex thereof, which is 6.498 mm, is slightly smaller than the distance AJ from the center of the coupling recess to the apex of the triangle, which is 6.5 mm. At this time, the radius AR of the incircle of the triangle of the coupling protrusion 63b of the drive side drum flange 63 is 4.648 mm.

[0437] Also, the radius AP of the cylindrical portion 91i of the drive transmission member 91 is 7.05 mm, and therefore, the distance AS from the center of the drum 62 to the pipe control portion 90k1 of the drum bearing is 7.051 mm, which is slightly larger than the radius AP.

[0438] As a result, the gap AT between the tub control portion 90k1 of the drum bearing and the cylindrical portion 91i of the drive transmission member is 0.001 mm (= 7.051 - 7.05). Also, the gap AU between the coupling protrusion 63b and the coupling recess 91b when the phases of the coupling portions are aligned is 0.002 mm ("6.5 - 6.498" or "4.65 - 4.648", whichever is smaller). Therefore, even if the drive transmission member 91 is tilted due to the meshing force, the gap AU between the coupling members is larger than the misalignment amount AT between the coupling portions, and thus, the coupling protrusion 63b and the coupling recess 91b can be coupled to each other.

[0439] In the first example, it is preferable that the distance in the radial direction from the center of the drum 62 to the tub control portion 90k1 be greater than 7.05 mm.

[0440] In the second example, the coupling protrusion 63b is minimized so that the amount of engagement between the coupling portions is minimized.

[0441] The distance AQ from the center of the coupling protrusion 63b provided on the drive side drum flange 63 to the apex is set to 4.801 mm, which is slightly greater than the radius AN of the thinned portion 91b3 of the coupling recess (i.e., 4.8 mm). At this time, the radius AR of the inscribed circle inscribed in the triangular shape of the coupling protrusion is 2.951 mm.

[0442] The distance AS of the tub control portion 90k1 of the drum bearing from the center of the drum 62 is 8.749 mm. As a result, the gap AT between the tub control portion 90k1 of the drum bearing 90 and the gear portion 91a of the drive transmission member 91 is 1.698 mm (= 8.748 - 7.05). Also, the gap AU between the coupling protrusion 63b and the coupling recess 91b when the phases of the coupling portions are aligned is 1.699 mm ("6.5 - 4.801" and "4.65 - 2.951", whichever is smaller). Therefore, even if the drive transmission member 91 is tilted due to the meshing force, the gap AU between the coupling members is larger than the misalignment amount AT between the coupling portions, and thus, the coupling portions can be engaged with each other.

[0443] According to the second example, it can be understood that the radial distance from the center of the drum 62 to the tub control portion 90k1 of the drum bearing is preferably less than 8.75 mm.

[0444] In other words, it is preferable that the distance in the radial direction from the center of the drum 62 to the tub control portion 90k1 of the drum bearing be greater than 7.05 mm and less than 8.75 mm.

[0445] The shape of the connecting protrusion provided on the drum 62 is not limited to an approximately equilateral triangle, and a preferred arrangement of the control portion in the case of a more general shape will be considered. Here, for convenience, it is assumed that the shape of the connecting recess is an equilateral triangle. Here, the connecting protrusion 363b described above ( Figure 27 and 28 It is used as a connecting protrusion with a general shape.

[0446] First, use Figure 31 The control section 90k1 and drive transmission component 191 shown are used to consider the upper limit of the distance from the drum axis to the control section 90k1.

[0447] The position of the control section 90k1 depends on the radius of the cylindrical portion 191i of the drive transmission component 191. That is, as the radius of the cylindrical portion 191i increases, the control section 90k1 must be moved away from the axis of the drum. Firstly, as... Figure 31 As shown, it is assumed that the diameter of the cylindrical portion 191i of the drive transmission member 191 is larger than the diameter of the gear portion (output gear portion) 191a of the drive transmission member 191. In this case, the cylindrical portion 191i is arranged to be sandwiched between the roller portion 132a of the developing roller 132 and the developing roller gear 30, and the cylindrical portion 191i faces the shaft portion 132b of the developing roller 132.

[0448] The distance from the center (axis) of drum 62 to the control section 90k1 is distance BG (the distance measured in the direction perpendicular to the axis of the drum). The distance from the center of drum 62 to the axis of the developing roller is taken as distance BK (the distance taken in the direction perpendicular to the axis of the drum).

[0449] Here, preferably, when the drive transmission member 191 tilts so that the cylindrical portion 191i contacts the control portion 90k1, the cylindrical portion 191i does not interfere with the shaft portion 32b of the developing roller. That is, ideally, the movement of the cylindrical portion 191i is controlled by the control portion 90k1 so that at least the cylindrical portion 191i does not tilt beyond the axis of the developing roller. Therefore, preferably, the distance BG from the drum center to the control portion 90k1 is less than the distance BK from the drum center to the axis of the developing roller 132, i.e.:

[0450] BG <BK

[0451] Next, refer to Figure 31 The lower limit of the distance from the center of the drum to the control section 90k1 will be considered. The external connecting protrusion 363b ( Figure 28 The smallest equilateral triangle BO is used as the imaginary connecting protrusion. The centroid of the equilateral triangle BO is set at the center of the connecting protrusion 363b.

[0452] The circle inscribed in the imaginary connecting protrusion (equilateral triangle BO) is circle BP, and its radius is radius BH. Here, in order for the imaginary connecting protrusion BO to engage with the connecting recess provided in the cylindrical portion 191i, the cylindrical portion 191i of the drive transmission member needs to be larger than the inscribed circle BP. This is because if the cylindrical portion 191i is smaller than the inscribed circle BP of the imaginary connecting protrusion BO, then an output connection portion for transmitting drive to the imaginary connecting protrusion BO cannot be formed in the cylindrical portion 191i.

[0453] The distance BG from the center of the drum to the control section 90k1 is greater than the radius of the cylindrical section 191i, and therefore, the distance BG is greater than the radius BH of the inscribed circle BP.

[0454] Therefore, the distance BG from the center of the drum at 90k1 in the control section satisfies:

[0455] BH <BG

[0456] In other words, the preferred range for the 90k1 control section is as follows:

[0457] BH <BG<BK

[0458] Next, it will be used in the following text. Figure 32 The drive transmission component 291 shown is used to describe a further preferred range of the control section 90k1.

[0459] exist Figure 32 In the drive transmission component 291, the cylindrical portion 291i is smaller in diameter than the gear portion 291a and is arranged to face the developing roller gear 30. If the diameter of the cylindrical portion 191i is as... Figure 31 If the cylindrical portion 191i is enlarged as shown, it cannot be arranged in front of the developing roller gear 30, and the cylindrical portion 191i needs to be arranged facing the shaft portion of the developing roller. In this case, the length of the shaft portion of the developing roller or the length of the drive transmission component must be increased. In contrast, if the cylindrical portion 291i of the drive transmission component is as shown... Figure 32 The arrangement shown is on the front side of the developing roller gear 30, so there is no need to increase the length of the shaft portion 232b of the developing roller 232 and the drive transmission component 291, and therefore, the cartridge and imaging device can be miniaturized.

[0460] First, refer to Figure 32 Consider the upper limit of the distance from the center of the drum to the control section 90k1.

[0461] The distance from the center of the drum 162 to the control portion 90k1 is the distance BG (a distance measured in a direction perpendicular to the axis of the drum). The shortest distance from the center of the drum 162 to the tooth end of the gear portion of the developing roller gear 30 is the distance BJ (a distance measured in a direction perpendicular to the axis of the drum). When the control portion 90k1 contacts the cylindrical portion 291i, in order to prevent the cylindrical portion 291i from interfering with the gear 30 of the developing roller, it is preferable that the distance BG from the center of the drum to the control portion 90k1 be smaller than the distance BJ from the center of the drum to the tooth end of the developing roller gear.

[0462] Therefore, BG > BJ.

[0463] Next, the lower limit of the distance from the center of the drum to the control portion 90k1 will be considered. The smallest circle that circumscribes the coupling protrusion 163a is BS, and the radius thereof is the radius BL.

[0464] Here, the circle BS is provided concentrically (on the same axis) with the drum 162.

[0465] Here, if the cylindrical portion 291i of the drive transmission member 291 is larger than the circle BS, a coupling recess portion that surrounds the entire periphery of the coupling protrusion 163a can be formed in the cylindrical portion 291i.

[0466] By this, the strength of the output coupling portion (coupling recess portion) can be increased, and the engagement between the coupling members can be stabilized.

[0467] When the radius of the cylindrical portion 291i is larger than the radius BL of the circle BS, the distance BG from the center of the drum to the control portion 90k1 is also larger than the radius BL, and therefore:

[0468] BG < BL

[0469] That is, the range of the control portion 90j is as follows:

[0470] BJ < BG < BL

[0471] Combining this "BJ < BG < BL" with the above-described "BH < BG < BK", the preferable range of the control portion can be defined as follows:

[0472] BH < BJ < BG < BL < BK

[0473] The definition of each value is summarized as follows:

[0474] BH: The radius of the inscribed circle that is inscribed in the equilateral triangle when the smallest equilateral triangle that circumscribes the coupling protrusion (input coupling portion) is drawn with the center of gravity of the equilateral triangle aligned with the axis of the drum (the axis of the coupling protrusion).

[0475] BJ: The shortest distance from the axis of the drum to the end of the teeth of the gear portion (input gear portion) 30a measured in a direction perpendicular to the axis of the drum.

[0476] BG: The distance from the center of the drum to the tube control portion measured in a direction perpendicular to the axis of the drum.

[0477] BL: The radius of the circumscribed circle when the minimum circumscribed circle of the externally tangent coupling protrusion (input coupling portion) is drawn coaxially with the drum.

[0478] BK: The distance from the axis of the drum to the axis of the developing roller gear (axis of the developing roller) measured in a direction perpendicular to the axis of the drum.

[0479] The functions, materials, shapes, and relative arrangements of components described in the embodiments or variations thereof should not be understood as limiting the scope of the present application to only this unless otherwise specified.

[0480] [Industrial applicability]

[0481] An image forming cartridge is provided which includes a structure for receiving a driving force input from the outside.

[0482] [Reference signs]

[0483] 30: Developing roller gear

[0484] 30a: Gear portion

[0485] 32: Developing roller (developer bearing member)

[0486] 62: Drum (electrophotographic photosensitive drum)

[0487] 62a: Drum center

[0488] 63: Drive-side drum flange (driven transmission member)

[0489] 63b: Coupling protrusion

Claims

1. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, the process cartridge comprising: a photosensitive member; a coupling portion provided at an end portion of the photosensitive member and including a drive force receiving portion for receiving a drive force for rotating the photosensitive member from outside of the process cartridge; and a gear portion including gear teeth for receiving a drive force from outside of the process cartridge independently of the coupling portion, wherein the gear teeth include an exposed portion exposed to outside of the process cartridge, wherein at least a portion of the exposed portion is disposed outside of the drive force receiving portion in an axial direction of the photosensitive member, faces an axis of the photosensitive member, and gear teeth of the at least a portion of the exposed portion are in proximity to a peripheral surface of the photosensitive member when viewed along the axis of the photosensitive member, and wherein a shortest distance from the axis of the photosensitive member to a tip end of the gear portion measured in a direction perpendicular to the axis of the photosensitive member is not less than 90% of a radius of the photosensitive member and not more than 110% of the radius of the photosensitive member.

2. The process cartridge according to claim 1, further comprising a developer bearing member configured to bear a developer to develop a latent image formed on the photosensitive member.

3. The process cartridge according to claim 2, wherein the gear portion and the developer bearing member are coaxially disposed to each other.

4. The process cartridge according to claim 2, wherein the gear portion and the developer bearing member are configured to rotate clockwise when viewed in a direction of counterclockwise rotation of the photosensitive member.

5. The process cartridge according to claim 2, further comprising a gap maintaining member mounted to the developer bearing member at opposite end portions of the developer bearing member, the gap maintaining member configured to maintain a gap between the developer bearing member and the photosensitive member by contact with the photosensitive member. Another gear transmits a drive force from the photosensitive member to a developer bearing member.

6. The process cartridge of claim 2, wherein, 7. The process cartridge according to claim 6, wherein the gear portion is a helical gear portion.

8. The process cartridge according to claim 7, wherein each of the gear teeth is inclined in a clockwise direction as extending in an axial direction of the photosensitive member from outside of the photosensitive member toward an inside thereof when viewed in a direction of counterclockwise rotation of the photosensitive member.

9. The process cartridge according to any one of claims 7-8, wherein each of the gear teeth is inclined toward a direction of rotational movement of the gear portion as extending in an axial direction of the photosensitive member from outside of the photosensitive member toward an inside thereof.

10. The process cartridge according to any one of claims 1-6, wherein the gear portion is a thin spur gear portion that allows a force for guiding a corresponding gear having helical teeth on a main assembly side toward a non-drive side to be generated by engagement with the corresponding gear. ​ 11. The process cartridge according to claim 10, wherein the gear teeth are flat teeth having a thickness of 1 mm or less in an axial direction of the spur gear portion.

12. The process cartridge according to any one of claims 1-8, wherein the process cartridge is configured to be mounted to and demounted from the main assembly of the electrophotographic image forming apparatus in a direction substantially perpendicular to an axis of the photosensitive member.

13. The process cartridge according to any one of claims 1-8, wherein a distance between an axis of the gear portion and an axis of the coupling portion is variable.

14. The process cartridge of claim 13, further comprising: a first unit including the coupling portion; and a second unit including the gear portion, wherein the distance between the axis of the gear portion and the axis of the coupling portion is changed by movement of the second unit relative to the first unit.

15. The process cartridge according to claim 14, wherein the second unit is rotatably connected with the first unit.

16. The process cartridge according to any one of claims 1-8, further comprising a stopper disposed on a same side of the coupling portion as in an axial direction, the stopper facing the axis of the photosensitive member and projecting outward in the axial direction.

17. The process cartridge according to claim 16, wherein at least a portion of the stopper is disposed outside a free end of the coupling portion in the axial direction of the photosensitive member.

18. The process cartridge according to claim 16, wherein in a plane perpendicular to the axis of the photosensitive member, the stopper is disposed within an angular range of 0° to 180° about the axis of the photosensitive member on an upstream side of a direction of rotational movement of the photosensitive member from a half-line extending from the axis of the photosensitive member toward the axis of the gear portion.

19. The process cartridge according to claim 17, wherein in a plane perpendicular to the axis of the photosensitive member, the stopper is disposed within an angular range of 0° to 180° about the axis of the photosensitive member on an upstream side of a direction of rotational movement of the photosensitive member from a half-line extending from the axis of the photosensitive member toward the axis of the gear portion.

20. The process cartridge according to claim 16, wherein in a plane perpendicular to the axis of the photosensitive member, the stopper is disposed on a side opposite a side from which the photosensitive member is exposed, with respect to a line passing through the axis of the photosensitive member and the axis of the gear portion.

21. The process cartridge according to claim 17, wherein in a plane perpendicular to the axis of the photosensitive member, the stopper is disposed on a side opposite a side from which the photosensitive member is exposed, with respect to a line passing through the axis of the photosensitive member and the axis of the gear portion.

22. The process cartridge according to claim 16, further comprising a charging member for charging the photosensitive member, wherein in a plane perpendicular to the axis of the photosensitive member, the stopper is disposed on a side on which the charging member is disposed, with respect to a line passing through the axis of the photosensitive member and the axis of the gear portion.

23. The process cartridge of claim 17, further comprising a charging member for charging the photosensitive member, wherein in a plane perpendicular to an axis of the photosensitive member, the stop is disposed on a side on which the charging member is disposed relative to a line passing through the axis of the photosensitive member and the axis of the gear portion.

24. The process cartridge of claim 16, wherein in a plane perpendicular to an axis of the photosensitive member, a distance from the axis of the photosensitive member to the stop is greater than the shortest distance from the axis of the photosensitive member to the tooth tip of the gear portion and is less than a distance from the axis of the photosensitive member to the axis of the gear portion.

25. The process cartridge of claim 17, wherein in a plane perpendicular to an axis of the photosensitive member, a distance from the axis of the photosensitive member to the stop is greater than the shortest distance from the axis of the photosensitive member to the tooth tip of the gear portion and is less than a distance from the axis of the photosensitive member to the axis of the gear portion.

26. The process cartridge of claim 16, wherein the stop defines a bay that is open toward the axis of the photosensitive member.

27. The process cartridge of claim 17, wherein the stop defines a bay that is open toward the axis of the photosensitive member.

28. The process cartridge of claim 16, wherein the stop has a curved surface that is open toward the axis of the photosensitive member.

29. The process cartridge of claim 17, wherein the stop has a curved surface that is open toward the axis of the photosensitive member.

30. The process cartridge of claim 16, wherein the stop comprises a plurality of discrete portions.

31. The process cartridge of claim 17, wherein the stop comprises a plurality of discrete portions.

32. The process cartridge of any one of claims 1-8, wherein the coupling portion is in the form of a protrusion.

33. The process cartridge of any one of claims 1-8, wherein the coupling portion is in the form of a twisted substantially triangular prism.

34. The process cartridge of any one of claims 1-8, further comprising a slit disposed on a side of the process cartridge on which the coupling portion is disposed relative to an axial direction of the photosensitive member.

35. The process cartridge of claim 34, wherein the slit is configured to engage the main assembly of the electrophotographic image forming apparatus to thereby position the process cartridge in the axial direction of the photosensitive member.

36. The process cartridge of any one of claims 1-8, wherein the shortest distance from the axis of the photosensitive member to the tooth tip of the gear portion measured along a direction perpendicular to the axis of the photosensitive member is not less than 93% of a radius of the photosensitive member and not more than 107% of the radius of the photosensitive member.

37. An electrophotographic image forming apparatus comprising: main assembly; and the process cartridge of any one of claims 1-36.

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