Drum Unit and Cartridge

Abstract

The coupling member and the drive transmission member of the device body are engaged. The drum unit has a photosensitive drum and a coupling member disposed near the end of the photosensitive drum and connected to the photosensitive drum so as to be drive-transmittable. The coupling member is inclined with respect to the rotation axis of the photosensitive drum and is configured to reduce the angle of inclination with respect to the photosensitive drum as it is driven by rotation.

Description

Technology Field

[0001] The present invention relates to a drum unit, a drive transmission unit, a cartridge, and an electrophotographic image forming device.

[0002] An electronic photographic image forming device (image forming device) is a device that forms an image on a recording medium using an electronic photographic image forming process. Examples include electronic photocopiers, electronic photo printers (LED printers, laser beam printers, etc.), facsimile devices, and word processors.

[0003] The cartridge is detachably mounted to the main body of the electrophotographic image forming device. Additionally, the drum unit is a unit having a photosensitive drum. The drive transmission unit is a unit having a coupling member. Background Technology

[0004] In an electrophotographic image forming device (hereinafter also simply referred to as an "image forming device"), an electrophotographic photosensitive material, which is generally in the form of a drum, i.e., a photosensitive drum (electrophotographic photosensitive drum), is uniformly charged. Subsequently, an electrostatic latent image (electrostatic image) is formed on the photosensitive drum by selectively exposing the charged photosensitive drum to light. Subsequently, the electrostatic latent image formed on the photosensitive drum is developed into a toner image using toner as a developer. Then, the toner image formed on the photosensitive drum is transferred to a recording material such as a recording paper or a plastic sheet. Furthermore, image recording is performed by applying heat or pressure to the toner image transferred onto the recording material to fix the toner image onto the recording material.

[0005] Such image forming devices generally require toner replenishment and maintenance of various process means. To facilitate this toner replenishment and maintenance, a photosensitive drum, charging means, developing means, cleaning means, etc. are unitized together within a frame and made into a cartridge that can be attached to and detached from the main body of the image forming device, which has been put into practical use.

[0006] By making a unit of the image forming device detachable from the main body, as with this cartridge, users can perform some of the device's maintenance themselves without relying on after-sales service technicians. This significantly improves the operability of the device, allowing for the provision of an image forming device with excellent usability. For this reason, this cartridge method is widely used in image forming devices.

[0007] As an example of a cartridge that is a detachable unit, a process cartridge is known in which a photosensitive drum and a process means acting on the photosensitive drum are integrated (cartridge-ized). In the process cartridge, a configuration in which a coupling member is installed at the tip of the photosensitive drum to transmit driving force from the main body of the device to the photosensitive drum is widely used (Japanese Patent Publication No. 2017-223802). The problem to be solved

[0008] The present invention further develops the aforementioned prior art. means of solving the problem

[0009] The representative composition disclosed herein is,

[0010] In a drum unit used in a cartridge,

[0011] photosensitive drum and,

[0012] It has a coupling member disposed near the end of the photosensitive drum and connected to the photosensitive drum so as to be driveable,

[0013] The coupling member is a drum unit configured to be inclined with respect to the rotation axis of the photosensitive drum and to reduce the angle of inclination with respect to the rotation axis of the photosensitive drum as it is driven by rotation.

[0014] Other representative configurations disclosed herein are,

[0015] As a drive transmission unit mountable to the device body of an electronic photo image forming device,

[0016] Absence of coupling and,

[0017] It has a support member that supports the above coupling member, and

[0018] The coupling member is a drive transmission unit configured to be inclined with respect to the rotational axis of the support member and, as it is driven, to reduce the angle of inclination with respect to the rotational axis of the support member.

[0019] In addition, another representative configuration disclosed herein is a cartridge equipped with the drum unit or drive transmission unit, or an electrophotographic image forming device. Effects of the invention

[0020] It is possible to advance conventional technology. Brief explanation of the drawing

[0021] Figure 1 is a diagram illustrating the configuration of the image forming device body and process cartridge. Figure 2 is a cross-sectional view of the image forming device body and process cartridge. Figure 3 is a cross-sectional view of a process cartridge. Figure 4 is an exploded perspective view of a process cartridge. Figure 5 is an exploded perspective view of a process cartridge. Figure 6 is a cross-sectional view of the image forming device body and process cartridge. Figure 7 is an explanatory diagram of the main body of the image forming device. Fig. 8 is an exploded perspective view of the drum unit. Figure 9 is a perspective view of a process cartridge. FIG. 10 is a cross-sectional view of the image forming device body and process cartridge. Figure 11 is an explanatory diagram of a coupling unit. FIG. 12 is a perspective view of the main body of an image forming device. Fig. 13 is an exploded perspective view of a drum flange unit. FIG. 14 is a cross-sectional view of the image forming device body and process cartridge. Figure 15 is an explanatory diagram of a coupling unit. FIG. 16 is a cross-sectional view of the driving transmission section and the non-driving transmission section. Specific details for implementing the invention

[0022] <Example 1>

[0023] Hereinafter, a first embodiment will be described in detail based on the drawings.

[0024] Meanwhile, the rotation axis direction of the electrophotographic photosensitive drum is set to the length direction.

[0025] In addition, in the longitudinal direction, the side where the electrophotographic photosensitive drum receives driving force from the main body of the image forming device is designated as the driving side, and the opposite side is designated as the non-driving side.

[0026] The overall configuration and image formation process are described using Figures 2 and 3.

[0027] FIG. 2 is a cross-sectional view of the device body (electronic photographic image forming device body, image forming device body) (A) and the process cartridge (hereinafter referred to as cartridge (B)) of the first embodiment of the electronic photographic image forming device.

[0028] Figure 3 is a cross-sectional view of the cartridge (B).

[0029] Here, the device body (A) is the part of the electronic photo image forming device excluding the cartridge (B).

[0030] <Overall Configuration of Electronic Photographic Image Forming Device>

[0031] The electronic photograph image forming device (image forming device) shown in FIG. 2 is a laser beam printer utilizing electronic photograph technology in which a cartridge (B) is detachably attached to the device body (A). When the cartridge (B) is mounted on the device body (A), an exposure device (3) (laser scanner unit) is arranged to form a latent image on an electronic photograph sensitizer drum (62) which serves as a storage body for the cartridge (B). Additionally, a sheet tray (4) containing a recording medium (hereinafter referred to as a sheet material (PA)) to be used for image formation is arranged on the lower side of the cartridge (B). The electronic photograph sensitizer drum (62) is a photograph (electrophotograph sensitizer) used for electronic photograph image formation.

[0032] Furthermore, in the main body (A), a pickup roller (5a), a pair of feed rollers (5b), a transfer guide (6), a transfer roller (7), a conveying guide (8), a fixing device (9), a pair of discharge rollers (10), a discharge tray (11), etc. are sequentially arranged along the conveying direction (C) of the sheet material (PA). Meanwhile, the fixing device (9) is composed of a heating roller (9a) and a pressure roller (9b).

[0033] Image Formation Process

[0034] Next, an overview of the image formation process is described. Based on a print start signal, the electrophotographic photosensitive drum (hereinafter referred to as the photosensitive drum (62) or simply the drum (62)) is driven to rotate at a predetermined peripheral speed (process speed) in the direction of the arrow (R).

[0035] The charging roller (charging member) (66) to which a bias voltage is applied contacts the outer surface of the drum (62) and uniformly charges the outer surface of the drum (62).

[0036] The exposure device (3) outputs laser light (L) according to image information. The laser light (L) passes through a laser aperture (61h) installed in the cleaning frame (61) of the cartridge (B) and scans and exposes the outer surface of the drum (62). By doing so, an electrostatic latent image corresponding to the image information is formed on the outer surface of the drum (62).

[0037] Meanwhile, as shown in FIG. 3, in a developing unit (20) as a developing device, the toner (T) in the toner chamber (28) is stirred and conveyed by the rotation of a conveying member (stirring member) (30) and sent to the toner supply chamber (29).

[0038] The toner (T) is supported on the surface of the developing roller (23) by the magnetic force of the magnet roller (24) (fixed magnet). The developing roller (23) is a developer carrier that supports the developer (toner (T)) on its surface to develop the latent image formed on the drum (62).

[0039] The toner (T) is tribocharged by the developing blade (25), and the thickness of the layer on the peripheral surface of the developing roller (23) as a developer carrier is regulated.

[0040] The toner (T) is supplied to the drum (62) according to the electrostatic latent image and develops the latent image. As a result, the latent image becomes visible as a toner image. The drum (62) is a storage body that holds the latent image or the image formed by the toner (toner image, developer image) on its surface. In addition, as shown in FIG. 2, a sheet material (PA) stored in the lower part of the device body (A) is sent from the sheet tray (4) by the pickup roller (5a) and the feed roller pair (5b) in accordance with the output timing of the laser light (L). Then, the sheet material (PA) is conveyed to a transfer position between the drum (62) and the transfer roller (7) via the transfer guide (6). At this transfer position, the toner image is sequentially transferred from the drum (62) to the sheet material (PA).

[0041] The sheet material (PA) on which the toner image has been transferred is separated from the drum (62) and conveyed along the conveying guide (8) to the fixing device (9). The sheet material (PA) then passes through the nip portions of the heating roller (9a) and the pressure roller (9b) constituting the fixing device (9). At these nip portions, a pressure and heating fixing process is performed so that the toner image is fixed to the sheet material (PA). The sheet material (PA) that has undergone the toner image fixing process is conveyed to the discharge roller pair (10) and discharged into the discharge tray (11).

[0042] Meanwhile, as shown in FIG. 3, the drum (62) after transfer has residual toner removed from its outer surface by a cleaning member (65) and is then used again in an image formation process. The toner removed from the drum (62) is stored in the waste toner chamber (61b) of the cleaning unit (60). The cleaning unit (60) is a unit having a photosensitive drum (62).

[0043] In the above, the charging roller (66), developing roller (23), transfer roller (7), and cleaning member (65) are process means acting on the drum (62).

[0044] <Complete composition of the cartridge>

[0045] Next, the overall configuration of the cartridge (B) will be explained using FIGS. 3, 4, and 5. FIGS. 3 is a cross-sectional view of the cartridge (B), and FIGS. 4 and 5 are perspective views explaining the configuration of the cartridge (B). Meanwhile, in this embodiment, the screws used to connect each part will be omitted from the description.

[0046] In addition, the description of the action member unit including the lever member will be provided later, so the description is omitted here.

[0047] The cartridge (B) has a cleaning unit.

[0048] As shown in FIG. 3, the cleaning unit (60) has a drum (62), a charging roller (66), a cleaning member (65), and a cleaning frame (61) that supports them. On the driving side of the drum (62), the driving side drum flange (71) installed on the driving side is rotatably supported by the hole portion (69a) of the drum bearing (69). In a broader sense, the drum bearing (69) and the cleaning frame (61) may be collectively referred to as a cleaning frame.

[0049] In the non-driven side, as shown in FIG. 4, the hole portion (63a) (see FIG. 8 (e)) of the non-driven side drum flange (63) is rotatably supported by a drum shaft (64) that is pressed into a hole portion (61c) installed in the cleaning frame (61).

[0050] In the cleaning unit (60), the charging roller (66) and the cleaning member (65) are each positioned in contact with the outer surface of the drum (62).

[0051] The cleaning member (65) has a rubber blade (65a), which is a blade-shaped elastic member formed of rubber as an elastic material, and a support member (65b) that supports the rubber blade. The rubber blade (65a) is in contact with the drum (62) in a counter-direction with respect to the rotational direction of the drum (62). That is, the rubber blade (65a) is in contact with the drum (62) such that its tip faces upstream of the rotational direction of the drum (62).

[0052] As shown in FIG. 3, waste toner removed from the surface of the drum (62) by the cleaning member (65) is collected in the waste toner chamber (61b) formed by the cleaning frame (61) and the cleaning member (65).

[0053] In addition, as shown in FIG. 3, a scooping sheet (34) to prevent waste toner from leaking from the cleaning frame (61) is installed at the edge of the cleaning frame (61) so as to come into contact with the drum (62).

[0054] The electric roller (66) is rotatably mounted to the cleaning unit (60) via electric roller bearings (not shown) at both ends in the longitudinal direction of the cleaning frame (61).

[0055] Meanwhile, the longitudinal direction of the cleaning frame (61) (the longitudinal direction of the cartridge (B)) is a direction parallel to the rotational axis of the drum (62) (the axial direction). Therefore, in the following cases where the longitudinal direction or the axial direction is simply referred to without further mention, the axial direction of the drum (62) is intended.

[0056] The charging roller (66) is pressed against the drum (62) by the charging roller bearing (67) being pressed toward the drum (62) by the charging roller pressing member (68). The charging roller (66) rotates in response to the rotation of the drum (62).

[0057] As shown in FIG. 3, the developing unit (20) has a developing roller (23), a developing container (21) that supports the developing roller (23), and a developing blade (25), etc. The developing roller (23) is rotatably mounted in the developing container (21) by means of a driving side bearing member (26) and a non-driving side bearing member (27) installed at both ends.

[0058] Additionally, a magnet roller (24) is installed within the developing roller (23). In the developing unit (20), a developing blade (25) is arranged to regulate the toner layer on the developing roller (23). As shown in FIG. 4, a gap maintaining member (31) is mounted on both ends of the developing roller (23), and by the gap maintaining member (31) and the drum (62) coming into contact, the developing roller (23) is held and supported with a small gap from the drum (62). Additionally, as shown in FIG. 3, an ejection prevention sheet (33) to prevent toner from leaking from the developing unit (20) is installed on the edge of the bottom member (22) so as to come into contact with the developing roller (23). Furthermore, a return member (30) is installed in the toner chamber (28) formed by the developing container (21) and the bottom member (22). The return member (30) returns toner to the toner supply chamber (29) while stirring the toner contained in the toner chamber (28).

[0059] As shown in FIGS. 4 and 5, the cartridge (B) is formed by combining a cleaning unit (60) and a developing unit (20).

[0060] First, a support boss (26a) installed on the driving side bearing member (26) with respect to the first hanging hole (61i) on the driving side of the cleaning frame (61), and a support boss (27a) installed on the non-driving side bearing member (27) with respect to the second hanging hole (61j) on the non-driving side are each fitted together. By doing so, the developing unit (20) is connected to the cleaning unit (60) so that it can rotate (rotatably). Then, a cartridge (B) is formed by combining a drum bearing (69) with the cleaning unit (60).

[0061] In this embodiment, the driving side pressure member (32L) and the non-driving side pressure member (32R) are formed as compression springs. Due to the pressure of these springs, the developing unit (20) is pressed against the cleaning unit (60), and the developing roller (23) is reliably pressed in the direction of the drum (62). Then, the developing roller (23) is maintained at a predetermined distance from the drum (62) by the spacing member (31) mounted on both ends of the developing roller (23).

[0062] Cartridge Installation Operation

[0063] In this embodiment, the operation of mounting a cartridge (B) to the device body (A) is explained using FIG. 1(a), FIG. 6, and FIG. 7. FIG. 1(a) is a cross-sectional view showing the state of the drive transmission member (drive shaft, drive output member) (1) and the drive-side drum flange unit (drive transmission unit) (70) when the cartridge (B) is mounted to the device body (A) and is not being driven. FIG. 6(a) is a cross-sectional view showing the state of mounting the cartridge (B) to the device body (A). FIG. 6(b) is a cross-sectional view showing the state of the cartridge (B) being mounted to the device body (A). FIG. 7 is an explanatory diagram showing the state of the drive transmission member (1) before the cartridge (B) is mounted to the device body (A).

[0064] As shown in FIG. 6(a), mounting of the cartridge (B) onto the device body (A) is first opened by rotating the opening / closing door (13) of the device body (A) around a rotation center not shown. Next, the guide portion (69d, 69e) of the cartridge (B) is inserted along the guide rail (15d, 15e) (only the driving side is shown). Then, as shown in FIG. 6(b), mounting of the cartridge (B) is completed by inserting the positioning portion (69b, 69c) installed on the drum bearing member (69) into or near the device body positioning portion (15b, 15c).

[0065] Two cartridge pressing members (17) are each rotatably mounted near both ends of the opening / closing door (13) in the axial direction. Two cartridge pressing springs (19) are mounted at both ends in the longitudinal direction of the device body (A). On the cleaning frame (61), cartridge pressing portions (61e) serving as receiving portions for the pressure of the cartridge pressing springs (19) are installed at both ends in the longitudinal direction. By completely closing the opening / closing door (13), a predetermined force is applied to the cartridge pressing portions (61e) from the cartridge pressing springs (19). Accordingly, the positioning portions (69b, 69c) remain in contact with the device body positioning portions (15b, 15c), and the cartridge (B) is positioned at a location where an image can be formed (Fig. 6 (b)).

[0066] Here, the mounting and positioning configuration of the cartridge (B) and the pressing configuration have been described for the driving side, but the same configuration applies to the non-driving side.

[0067] In this embodiment, as shown in FIG. 7, one end of the drive transmission member (1) is temporarily supported in the hole portion (15a) of the drive-side plate (15). Before mounting the cartridge (B), the drive transmission member is tilted by its own weight within the range of play (gap) created between the hole portion (15a) and the drive transmission member (1). Additionally, the first coupling portion (72) is tilted in approximately the same direction as the drive transmission member (1) by the pressure of the third pressure member (76) (coupling pressure member, third elastic member, third spring) (Fig. 9) in order to engage with the drive transmission member (1). At this time, since the rotational axes of the drive transmission member (1) and the first coupling portion (72) each have an angle, the axis of the drive transmission member (1) is offset from the axis of the drum (62) (see FIG. 1 (a)). In this case, for the drum (62) to rotate stably during driving, it is necessary for the drum (62) to rotate while the rotation axis of the driving transmission member (1) and the rotation axis of the drum (62) coincide.

[0068] <Configuration of the driving side drum flange unit and engagement operation of the coupling>

[0069] Next, the operation is described in which, after the cartridge (B) is installed, the axis of the drive transmission member (1) is inclined with respect to the axis of the drum (62), and a driving force is applied so that the drive transmission member (1) engages with the first coupling part (72) and becomes coaxial with the axis of the drum (62).

[0070] First, the configuration of the driving side drum flange unit (drive transmission unit) (70) will be explained using FIGS. 8, 9, and 10. FIGS. 8(a), FIGS. 8(b), and FIGS. 8(c) are drawings explaining the assembly method of the coupling unit (79). FIGS. 8(d) is a drawing explaining the assembly method of the driving side drum flange unit (70). FIGS. 8(e) is a drawing explaining the assembly method of the drum unit.

[0071] FIG. 9 is a perspective view showing the configuration of the first coupling part (72) and the third pressing member (third elastic member, third spring) (76). FIG. 10 is a cross-sectional view showing the state of the drive transmission member (1) and the drive-side drum flange unit (70) when the cartridge (B) is mounted on the device body (A) and is not being driven.

[0072] Each member that rotates together with the photosensitive drum (62) is unitized and called a drum unit. The drum unit has a photosensitive drum (62), a driving side drum flange unit (70), and a non-driving side drum flange (63). A driving side drum flange unit (70) is fixed to one end of the photosensitive drum, and a non-driving side drum flange (63) is fixed to the other end (second end) of the photosensitive drum opposite to this end.

[0073] The driving side drum flange unit (70) is composed of a driving side drum flange (71), a first coupling part (72), a second coupling part (73), a first pressure member (74) (a first elastic member, a first spring, an axial pressure member), a second pressure member (75) (a second elastic member, a second spring, a radial pressure member), a pin (78), and a lid member (77).

[0074] The first coupling part (72) is equipped with a driven transmission part (driving force receiving part) (72a) to which driving force is transmitted from the driving transmission member (1) of the device body (A). The first coupling part (72) transmits driving force to the second coupling part (73) through a pin (78) (second contact part). The first coupling part (72) and the pin (78) may be integral. The second coupling part (73) is equipped with a driven transmission part (73a) (second contact part) to which driving force is transmitted from the first coupling part (72), and a driving transmission part (73b) (first contact part) to which driving is transmitted to the lid member (77). The lid member (77) is equipped with a driven transmission part (77a) (first contact part) to which driving force is transmitted from the second coupling part (73).

[0075] As shown in FIG. 8 (a), the first coupling part (72) and the second coupling part (73) have a shaft part (72k) inserted into a hole part (73k), and the second coupling part (73) is supported so as to be rotatable relative to the first coupling part (72). Additionally, as shown in FIG. 8 (b), a second pressing member (75) that applies pressure in a rotational direction is disposed between the first coupling part (72) and the second coupling part (73). In this embodiment, the second pressing member (75) is made of a torsion coil spring, and both ends of the spring are respectively in contact with the spring catch part (72h) of the first coupling part (72) and the spring catch part (73h) of the second coupling part (73) to restrict movement in the rotational direction. And, as shown in Fig. 8 (c), a coupling unit (coupling member) (79) is formed by passing a pin (78) through each pin insertion hole (72d, 73d).

[0076] Next, as shown in FIG. 8 (d), after the coupling unit (79) is inserted into the interior of the driving side drum flange (71), a first pressing member (74) for pressing the coupling unit (79) toward the driving side is inserted. Then, the driving side drum flange unit (70) is formed by fixing the lid member (77) to the driving side drum flange (71) by means such as welding. As shown in FIG. 8 (e), the driving side drum flange unit (70) and the non-driving side drum flange (63) are inserted into the drum (62) and fixed by means such as press-fitting or clamping.

[0077] The drum unit (62, 70, 63) configured in this manner is rotatably supported by the frame (drum bearing (69)) of the cartridge (B). The drum unit (62, 70, 73) can be mounted on the device body (A) as part of the cartridge (B).

[0078] The pin (78), the first coupling part (72), and the second coupling part (73) of the drum unit are collectively referred to as coupling members. These coupling members (72, 73, 78) are connected to a drive transmission member (described later) of the device body (A) and are members for transmitting driving force (rotational force) from the device body (A) toward the drum (62). In this embodiment, the coupling member is a unit that can be disassembled into a plurality of members (78, 72, 73), but it is not limited to this configuration and may be composed of a single unit. For example, the first coupling part (72) and the second coupling part (73) are not connected by the pin (78), and the first coupling part (72) and the second coupling part (73) may originally be composed of a single part. Such a configuration will be described later. Additionally, the lid member (77) and the driving side drum flange (71) may be collectively referred to as the flange member, or the lid member (77) may be considered as part of the driving side drum flange (71).

[0079] The flange members (71, 77) are fixed to one end of the drum (62) and connect the drum (62) and the coupling members (72, 73, 78) so as to enable driving transmission. The flange members are end members mounted on the end of the drum (62). The coupling members (72, 73, 78) are positioned near the end of the photosensitive drum (62) by being supported by the flange members.

[0080] The flange members (71, 77) transmit driving force from the coupling members (72, 73, 78) to the drum (62). The flange members (71, 77) are the cartridge-side transmission members (driving force transmission members) that transmit driving force.

[0081] Additionally, the flange members (71, 77) are also connecting members that connect the coupling members (72, 73, 78) to the drum (62). The coupling members (72, 73, 78) are indirectly connected to the drum (62) through the flange members (71, 77). As described above, the coupling members are connected to the drum (62) so as to be drive-transmittable. In other words, the coupling members (72, 73, 78) are operationally connected to the drum (62). That is, the two are connected so that as the coupling members (72, 73, 78) are rotated, the drum (62) is also rotated (operated).

[0082] Although details will be described later, the coupling member (72, 73, 78) is supported by the flange member (71, 77) so as to be tiltable. The flange member (71, 77) is also a supporting member that supports the coupling member.

[0083] In this embodiment, the driven transmission part (driving force receiving part, driving input part) (72a) of the first coupling part (72) adopts a shape in which the cross-section is substantially triangular and convex (see FIG. 16). Specifically, a shape in which the cross-section of substantially triangular shape is twisted counterclockwise along the axis of the drum (62) from the driving side to the non-driving side is adopted.

[0084] As shown in FIG. 9, a triangular ridge at the driving end of the first coupling member (72) has a chamfered portion (72e) inclined in the longitudinal direction. Additionally, as shown in FIG. 10, the size of the chamfered portion (72e) is such that, in a state where the driving transmission member (1) is inclined in the V direction due to its own weight, a part of the chamfered portion (72e) is located within the driving transmission section (1a) of the driving transmission member (1) in the diameter direction. Specifically, as shown in FIG. 10, the minimum distance (D1) of the chamfered portion (72e) from the center axis of the drum is configured to be smaller than the distance (D2) from the center axis of the drum to the entrance of the driving transmission section of the driving transmission member (1).

[0085] Additionally, the driving transmission part (73b) of the second coupling part (73) and the driven transmission part (driving force receiving part) (77a) of the lid member (77) engage with each other, and the cross-section of the driving transmission part (73b) is substantially triangular in shape.

[0086] Furthermore, as shown in FIG. 10, the first coupling part (72) is deviated toward the longitudinal driving side (direction of arrow (G)) by the first pressing member (74). Accordingly, the spherical regulated part (72c) of the first coupling part (72) strikes the conical regulated part (71c) of the driving side drum flange (71). As a result, when the cartridge (B) is mounted, a part of the first coupling part (72) is positioned to be securely positioned within the drive transmission part (1a) in the longitudinal direction (see FIG. 1 (a)). Here, the driving transmission part (73b) and the driven transmission part (77a) correspond to a pivoting part having a pivoting action that aligns the rotation axis of the second coupling part (73) with the rotation axis of the lid member (77) (drum (62)). That is, when the second coupling part (73) rotates relative to the lid member (77), the driving transmission part (73b) and the driven transmission part (77a) press the second coupling part (73) in a direction that reduces the angle of inclination of the second coupling part (73) relative to the lid member (77).

[0087] Next, the engagement operation of the first coupling part (72) and the second coupling part (73) will be explained using FIG. 1 and FIG. 11. FIG. 1 is a drawing illustrating the engagement operation of the drive transmission member (1), the first coupling part (72), and the second coupling part (73). FIG. 11 is a drawing showing the relative positional relationship of the first coupling part (72) to the second coupling part (73).

[0088] FIG. 1(a) shows a state where the phases of the drive transmission part (1a) of the drive transmission member (1) and the driven transmission part (72a) of the first coupling part (72) are misaligned after the cartridge (B) is mounted on the device body (A). Here, when the drive transmission member (1) is rotated, the drive transmission member (1) oscillates in a direction (direction of arrow (W) in FIG. 1(a)) that reduces the inclination angle of the drive transmission member (1) which is inclined in the direction of arrow (V) (Fig. 10) due to its own weight, by means of the chamfered part (72e) of the first coupling part (72). At the same time, the drive transmission member (1) is pulled toward the non-drive side (direction of arrow (N)) due to its twisted shape, and as shown in FIG. 1(b), the surface (1f) of the drive transmission member (1) strikes the end surface (72f) of the first coupling part (72). Here, the surface (1f) of the drive transmission member (1) and the end surface (72f) of the first coupling member (72) are each surfaces perpendicular to the rotational axis of the drive transmission member (1) and the first coupling member (72). At this time, the driven transmission part (72a) of the first coupling member (72) and the drive transmission part (1a) of the drive transmission member (1) are configured to secure a longitudinal engagement amount necessary for stable drive transmission. Furthermore, as the phases of the triangular shapes coincide, the centers of the triangles coincide, and as the surfaces perpendicular to the rotational axis collide, the rotational axes of the drive transmission member (1) and the first coupling member (72) coincide. Then, the engagement between the drive transmission member (1) and the first coupling member (72) is completed.

[0089] In this embodiment, the inclination direction of the drive transmission member (1) is the direction of gravity, but the inclination direction is not limited to the direction of gravity; as described above, if the condition is satisfied that a part of the chamfered portion (72e) is located within the drive transmission member (1a), engagement is possible even if the inclination direction is any direction. Furthermore, even in the case where the rotational axis of the first coupling member (72) and the drive transmission member (1) are parallel and not coaxial, if the condition is likewise satisfied, the first coupling member (72) can engage with the drive transmission member (1).

[0090] In the above description, the drive transmission member (1) and the first coupling member (72) are engaged, and a state is achieved where drive transmission from the device body (A) to the cartridge (B) is possible. At this time, the drive transmission member (1) and the first coupling member (72) are both coaxial, but are still inclined with respect to the drum (62). Next, a configuration is described in which the drive transmission member (1) and the first coupling member (72), which are in a state where the rotation axis is inclined with respect to the rotation axis of the drum (62), become aligned with the rotation axis.

[0091] Inside the driving side drum flange (71), a second coupling part (73) is arranged to be rotatably supported and coaxial with respect to the first coupling part (72). Between the first coupling part (72) and the second coupling part (73), there is a degree of freedom in the rotational direction of 120° or more through a pin insertion hole (73d). Before rotation begins, the first coupling part (72) is located at a first position (see FIG. 11 (a)) where it is pressed in the direction opposite to the rotational direction during driving (direction of arrow (F)) by the second pressing member (75) relative to the second coupling part (73). Then, when the first coupling part (72) rotates 120° or more, it moves to a second position (see FIG. 11 (b)) where the pin (78) strikes the non-driving transmission part (73a). Here, the second coupling part (73) has a pin (78) that strikes the non-driven transmission part (73a). Accordingly, since it receives driving force from the first coupling part (72), the second coupling part (73) does not rotate while the first coupling part (72) moves from the first position to the second position.

[0092] Continuing, when the second coupling part (73) reaches the second position (see (b) in FIG. 11), the pin (78) strikes the driven transmission part (73a), so the driving force of the first coupling part (72) is transmitted, and the second coupling part (73) becomes rotatable. Furthermore, when the second coupling part (73) rotates, as in FIG. 1 (c), the driving transmission part (73b) of the second coupling part (73) engages with the driven transmission part (77a) of the lid member (77), and the lid member (77) becomes rotatable. At this time, the phases of the triangular shapes of the driving transmission part (73b) and the driven transmission part (77a) coincide, and the second coupling part (73) is pulled toward the non-driving side (direction of arrow (N)) by the twisted shape, so that the end surface (73f) comes into contact with the surface (77f) of the lid member (77). Here, the end surface (73f) of the second coupling part (73) and the surface (77f) of the lid member (77) are each surfaces perpendicular to the rotational axis of the second coupling part (73) and the lid member (77), respectively. As the phases of the triangular shapes coincide, the centers of the triangles coincide, and as the surfaces perpendicular to the rotational axis collide, their rotational axes become parallel to each other. Therefore, the rotational axes of the second coupling part (73) and the lid member (77) coincide. Since the lid member (77) is fixed to the driving side drum flange (71) and the driving side drum flange (71) is fixed to the drum (62), the second coupling member (73) has a rotation axis that coincides with the drum (62).

[0093] Here, the rotational axes of the drive transmission member (1), the first coupling part (72), the second coupling part (73), and the drum (62) are aligned. And, since the first coupling part (72) and the second coupling part (73) are coaxial, as a result, the rotational axes of the drive transmission member (1) and the drum (62) can also be rotated in a state where they are aligned.

[0094] As described above, in this embodiment, a first coupling member (72) is engaged with a drive transmission member (1) having an axis inclined with respect to the axis of the drum (62) so as to be coaxial with the drum (62). With this configuration, the precision of drive transmission from the device body (A) to the cartridge (B) can be improved.

[0095] Meanwhile, in the present embodiment, the coupling member has a first coupling part (72) and a second coupling part (73), and they are configured to be relatively movable. This provides the advantages described below.

[0096] In the stage where the drive transmission member (1) begins to rotate, there may be cases where the first coupling part (72) of the coupling member is not engaged with the drive transmission member (1). Even in this state, frictional force is generated between the first coupling part (72) and the drive transmission member (1), so there is a risk that the first coupling part (72) will rotate slightly before engaging with the drive transmission member (1) due to this frictional force. If rotation is transmitted from the first coupling part (72) to the second coupling part (73) while the first coupling part (72) is not engaged with the drive transmission member (1), the aforementioned cautionary action is unintendedly created between the second coupling part (73) and the flange member (lid member (77)). That is, as the second coupling part (73) engages with the lid member (77) of the flange member, the angle of inclination of the second coupling part (73) relative to the drum (62) decreases. Accordingly, the inclination angle of the first coupling part (72) with respect to the drum (62) is also reduced. If the inclination angle is reduced before the first coupling part (72) engages with the drive transmission member (1), there is a risk that the first coupling part (72) will move away from the drive transmission member (1) and thus the first coupling part (72) will not be able to engage with the drive transmission member (1).

[0097] Accordingly, in this embodiment, the first coupling part (72) is configured to rotate relatively within a certain range relative to the second coupling part (73). Therefore, even if the first coupling part (72) rotates slightly unintentionally before engaging with the drive transmission member (1), the rotation is not transmitted to the second coupling part (73). The rotation is configured to be transmitted from the first coupling part (72) to the second coupling part (73) only after the drive transmission member (1) and the first coupling part (72) are securely engaged. Therefore, there is no unintentional accidental action occurring before the first coupling part (72) and the drive transmission member (1) engage.

[0098] In particular, in this embodiment, as described above, the angle (phase difference) at which the first coupling part (72) can rotate relative to the second coupling part (73) from the first position to the second position is set to 120 degrees or more.

[0099] 120 degrees is the angle θ = 120° between the straight lines connecting each vertex from the center of an equilateral triangle (see FIG. 16). When the cartridge is mounted on the device body, even if the phases of the triangular shapes of the drive transmission member (1) and the first coupling member (72) are different, the phase difference is 120 degrees or less. That is, typically, when the drive transmission member (1) rotates up to 120 degrees, the triangular shapes of the drive transmission member (1) and the first coupling member (72) can engage. Even if the first coupling member (72) rotates slightly due to the frictional force before this engagement, the rotation angle is less than 120 degrees, and the second coupling member (73) does not start rotating due to this rotation of the first coupling member (72).

[0100] As a result, the first coupling part (72) first engages with the drive transmission member (1) and rotates, after which the second coupling part (73) begins to rotate, and subsequently the drum (62) becomes rotatable.

[0101] By means of the adjusting force generated between the second coupling part (72) and the flange member (77), the tilt of the first coupling part (72) can be prevented from being corrected before the first coupling part (72) and the drive transmission member (1) engage. As a result, the occurrence of a failure in engagement between the drive transmission member (1) and the first coupling part (72) can be prevented.

[0102] However, the coupling member of the coupling unit (79) does not necessarily have to be divided into a first coupling part (72) and a second coupling part (73) as described above. For example, if the first coupling part (72) rarely rotates before engaging with the drive transmission member (1) (for example, if the frictional force between the first coupling part (72) and the drive transmission member (1) is sufficiently small), such a configuration is unnecessary. In this case, the coupling part does not need to be divided into a first coupling part (72) and a second coupling part (73), and they may be integrated. Furthermore, even if the coupling member is divided into a first coupling part (72) and a second coupling part (73), the rotatable angle of the first coupling part (72) relative to the second coupling part (73) may be less than 120 degrees.

[0103] As described above, in order to enable engagement between the driving transmission part (1a) of the driving transmission member (1) and the driven transmission part (72a) of the first coupling part (72), and between the driving transmission part (73b) of the second coupling part (73) and the driven transmission part (77a) of the lid member (77), each has a characteristic shape. In this embodiment, a triangular shape of the cross-section perpendicular to the rotation axis is an equilateral triangle, and a shape in which each vertex is chamfered into an arc shape (see FIG. 16) is adopted. To obtain the same effect as in this embodiment, it is not necessarily limited to this shape.

[0104] Cartridge Removal Action

[0105] Next, the operation of releasing the engagement between the drive transmission member (1) and the first coupling part (72) in the engaged state and removing the cartridge (B) from the device body (A) is described.

[0106] When the cartridge (B) is withdrawn to the outside, as the opening / closing door (13) is opened, the connecting member (2) (Fig. 12) linked to the opening / closing door (13) rotates, and the connecting member (2) moves toward the driving side (direction of arrow (G)) along the inclined portion (not shown) installed on the driving side plate (15). Accordingly, the driving transmission member (1) moves toward the driving side. As a result, the driving transmission member (1) moves while rotating in the opposite direction due to the twisted shape of the triangle, and the engagement with the first coupling portion (72) is released. When the engagement is released, the driving transmission member (1) and the first coupling portion (72) return to an inclined state.

[0107] The configuration of the embodiment described so far can be briefly summarized as follows. The drum unit of the embodiment has a coupling member (79) that can receive driving force (rotational force) by engaging and connecting with a driving transmission member (1) (see FIG. 8). The coupling member (79) is supported so as to be tiltable by flange members (71, 77) fixed to the photosensitive drum (1). That is, the angle formed by the rotation axis of the coupling member (79) and the rotation axis of the photosensitive drum (62) varies.

[0108] The drive transmission member (1) is inclined inside the device body (A) (see FIG. 4). In order to engage with this drive transmission member (1), the coupling member (79) is also inclined relative to the photosensitive drum (62) (Fig. 4). In particular, in this embodiment, a pressure member (elastic member, spring) (76) is installed in the cartridge (B) to incline the coupling member (79) in a predetermined direction to engage with the drive transmission member (1) (see FIG. 9). When the coupling member (79) is in an inclined state, the coupling member (79) receives a driving force from the drive transmission member (1) and rotates (see FIG. 1). When the coupling member (79) rotates relative to the flange members (71, 79), a force is applied to the coupling member (79) to reduce its inclination angle by the action of the pivot member (drive transmission member (73b), driven transmission member (77a): see FIG. 8) installed between the coupling member (79) and the flange members (71, 79). As a result, the inclination angle of the coupling member (79) and the drive transmission member (1) connected thereto is reduced. Consequently, the driving force can be stably transmitted from the drive transmission member (1) to the photosensitive drum (62) through the coupling member (72, 73) and the flange members (71, 77). In this embodiment, the drive transmission member (1), the coupling member (72, 73), and the photosensitive drum (62) are arranged in an approximately coaxial shape during drive transmission, but they do not necessarily have to be in a coaxial shape. That is, if the angle of inclination of the drive transmission member (1) or coupling member (72, 73) is reduced, there is an effect of improving the precision of the drive transmission.

[0109] As described above, the drive transmission member (1) may tilt or become inclinable inside the main body of the electrophotographic image forming device depending on the support configuration that supports it. In terms of engaging and connecting the coupling members (72, 73) to such a drive transmission member (1) to facilitate drive transmission, the drive transmission configuration including the coupling members described in this embodiment is preferred.

[0110] In addition, a support configuration can be conceived in which the drive transmission member (1) is intentionally inclined so that it does not interfere with the attachment or detachment of the drum unit or cartridge. The drive transmission configuration of the present embodiment is also useful for such a support configuration.

[0111] In addition, the driving side drum flange unit (driving transmission unit) (70) of the present embodiment was integrally formed with the photosensitive drum to form a drum unit. That is, the driving transmission unit (70) was detachable from the main body of the image forming device as part of the drum unit or a cartridge equipped with it. However, the driving transmission unit (70) does not necessarily have to be integrated with the photosensitive drum, and the driving transmission unit (70) does not have to be part of the drum unit or part of the cartridge.

[0112] That is, the drive transmission unit (70) may be a unit (detachable unit, attachment) or a part thereof that can be mounted on the main body of the electronic image forming device by a user. That is, the drive transmission unit (70) may be capable of receiving driving force by connecting to the drive transmission member (1) when mounted on the main body of the electronic image forming device. The object to which the drive transmission unit (70) transmits driving force may be other members, such as a developing roller (23), rather than the photosensitive drum (62). Furthermore, the drive transmission unit (70) does not need to be directly connected to the object to which the drive force is transmitted (the photosensitive drum in this embodiment). For example, a configuration may be conceived in which a cartridge has the drive transmission unit (70) and the photosensitive drum (62), while the two are arranged separately and the two are indirectly connected through a gear or the like. In this case as well, the coupling member of the drive transmission unit (70) may be connected to the photosensitive drum (62) in a drive-transmittable manner, that is, operationally.

[0113] Alternatively, a configuration in which the drive transmission unit (70) is detachable from the drum unit or cartridge can be considered. In this case, the user first mounts the drive transmission unit (70) to the main body of the image forming device. After that, the user mounts the cartridge or drum unit to the main body of the image forming device and connects them to the drive transmission unit (70).

[0114] In this embodiment, one of the driving transmission part (73b) and the driven transmission part (77a) is a convex shape (protrusion, convex part), and the other is a concave shape (indentation, concave part) that can engage with this protrusion. As the driving transmission part (73b) rotates relative to the driven transmission part (77a), one of the convex shape and the concave shape rotates relative to the other and engages. Since at least one of the convex shape and the concave shape is twisted, when one of the convex shape and the concave shape rotates relative to the other and engages, the axes of the convex shape and the concave shape coincide due to the action of this twisting. As a result, the angle of inclination of the flange members (71, 77) relative to the coupling member (79) is reduced, and the angle of inclination of the coupling member (79) relative to the drum (62) is also reduced. As a result, the rotational axis of the coupling member (79) and the drum (62) roughly coincide. In this embodiment, the driving transmission part (73b) is made convex, and the driven transmission part (77a) is made concave. Additionally, twisting is applied to both the convex shape and the concave shape.

[0115] The cross-sectional shape of the driving transmission part (73b) and the driven transmission part (77a) is substantially triangular. That is, the cross-section is shaped such that the area near the vertex of an equilateral triangle is an arc. However, the cross-section may have a different shape.

[0116] <Example 2>

[0117] Next, a second embodiment is described. In this embodiment as well, the drive transmission member (1) is configured to be tiltable (inclinable). In Embodiment 2, the attachment and detachment operation of the cartridge (B) and the engagement between the drive transmission member (1) and the first coupling member (82) are the same as in Embodiment 1, so the description is omitted. Embodiment 2 is a modified example of the configuration of the drive-side drum flange unit (80) to convert the rotation axis of the first coupling member (82) and the rotation axis of the drum (62) from a misaligned state to a coaxial state. Accordingly, the following description uses FIGS. 13, 14, and 15 to explain the configuration in which the drive transmission member (1) and the first coupling member (82) become coaxial with the rotation axis of the drum (62) after engagement. FIGS. 13 is a drawing illustrating the assembly method of the coupling unit (89) and the drive-side drum flange unit (80).

[0118] FIG. 14 is a drawing illustrating the engagement operation of the drive transmission member (1), the first coupling part (82), and the second coupling part (83). FIG. 15 is a drawing showing the relative positional relationship of the first coupling part (82) to the second coupling part (83).

[0119] As shown in FIG. 13 (a), the coupling unit (89) is composed of a first coupling part (82), a second coupling part (83), a second pressing member (85), and a pin (88). As shown in FIG. 13 (b), the driving side drum flange unit (80) is composed of a driving side drum flange (81), a coupling unit (89), a first pressing member (84), and a lid member (87).

[0120] The drum unit in this embodiment corresponds to the driving side drum flange unit (70) (see FIG. 8 (e)) of the drum unit in Example 1 being replaced with a driving side drum flange unit. That is, the drum unit in this embodiment has a driving side drum flange unit (80), a photosensitive drum (62), and a driven side drum flange (63) (see FIG. 8 (e)).

[0121] Additionally, the driving side drum flange (81) and the lid member (87) may be collectively referred to as the flange member, or the lid member (87) may be considered as part of the driving side drum flange (81). The first coupling part (82) has a driven transmission part (82a) that receives driving force by engaging with the driving transmission member (1) and a shaft part (82k), and is inclined by a third pressurizing member (86) (not shown). The second coupling part (83) has a hole part (83k) into which the shaft part (82k) is inserted and which supports rotational movement coaxially with the first coupling part (82), and a driving transmission part (83b) that transmits driving force by engaging with the driven transmission part (81a) of the driving side drum flange (81). The first pressing member (first elastic member, first spring) (84) presses the first coupling part (82) and the second coupling part (83) in the longitudinal driving direction (direction of arrow (G) in FIG. 14). The second pressing member (85) presses the first coupling part (82) in the rotational direction relative to the second coupling part (83), just as in Example 1.

[0122] Additionally, the first coupling part (82) and the second coupling part (83) are provided with inclined portions (82g, 83g) that come into contact with each other, and the first coupling part (82) is enabled to move in the longitudinal direction by rotating. When the first coupling part (82) is not being driven, the first coupling part (82) is pressed in the rotational direction by the second pressing member (85), and the pin (88) is positioned at a first position (see FIG. 15 (a)) that comes into contact with the end surface of the pin insertion hole (83d) of the second coupling part (83). As in Example 1, the pin insertion hole (83d) of the second coupling part (83) has a rotational degree of freedom of 120° or more. Therefore, when the first coupling part (82) rotates more than 120°, the pin (88) strikes the driven transmission part (83a) in a second position (see (b) of FIG. 15). Then, the driving force of the first coupling part (82) is transmitted, and the second coupling part (83) becomes rotatable. At the same time, in the second position, the second coupling part (83) moves along the inclined part (82g, 83g) toward the non-driven side (direction of arrow (N)), and the spherical regulated part (83c) (second regulated part) comes into contact with the conical regulated part (87c) (second regulated part) of the lid member (87).

[0123] A drive transmission unit (83b) is installed in the second coupling unit (83), and a driven transmission unit (81a) corresponding to the drive transmission unit (83b) is installed in the drive-side drum flange (81), and the second coupling unit (83) is movable in the longitudinal direction relative to the drive-side drum flange (81). When the second coupling unit (83) rotates, the drive-side drum flange (81) and the drum (62) can rotate.

[0124] The first coupling part (82), the second coupling part (83), and the pin (88) are collectively referred to as coupling members. The coupling members (82, 83, 88) are configured to transmit driving force (rotational force) to the photosensitive drum (62) through the flange members (81, 87).

[0125] Next, the engagement operation of the first coupling part (82) and the second coupling part (83) is described.

[0126] As shown in FIG. 14 (a), after the cartridge (B) is fully mounted, the drive transmission member is inclined and is not engaged with the first coupling member (82). At this time, the first coupling member (82) has a spherical regulated part (82c) (first regulated part) that is in contact with the conical regulated part (81c) (first regulated part) of the drive-side drum flange (81) by the first pressurizing member (84). Next, as shown in FIG. 14 (b), when the drive transmission member (1) rotates, the triangular phases of the drive transmission part (1a) and the driven transmission part (82a) coincide, just like in Example 1, and the surface (1f) of the drive transmission member (1) collides with the end surface (82f) of the first coupling member (82) and rotates. Therefore, the first coupling part (82) rotates in a state where the rotation axis of the drive transmission member (1) coincides with the rotation axis of the first coupling part (82). Then, the inclined part (83g) of the second coupling part (83) moves along the inclined part (82g) toward the non-driven side in the longitudinal direction (direction of the arrow (N)). At this time, while moving along the inclined part (82g), the second coupling part (83) does not rotate because there is a degree of freedom in the rotational direction of 120° or more between the first coupling part (82) and the second coupling part (83) due to the hole part (83d). When rotated to a predetermined angle of 120° or more, as in FIG. 14 (c), the second coupling part (83) moves along the inclined part (82g) to a second position on the non-driving side (see FIG. 15 (b)), and the spherical regulated part (83c) strikes the conical regulated part (87c) of the lid member (87). At the same time, the second coupling part (83) rotates so that the driving transmission part (83b) of the second coupling part (83) comes into contact with the driven transmission part (81a) of the driving side drum flange (81) and rotates the drum (62).

[0127] Here, the first coupling part (82) is in contact with the regulating part (81c) of the driving side drum flange (81), and the second coupling part (83) is in contact with the regulating part (87c) of the lid member (87). Accordingly, as shown in (c) of FIG. 14, the positions of the centers (Q1, Q2) of the regulated part (82c) of the first coupling part (82) and the regulated part (83c) of the second coupling part (83) are determined. Here, the conical center axis in the regulating part (81c) of the driving side drum flange (81) and the conical center axis in the regulating part (87c) of the lid member (87) are both set to be coaxial with the rotation axis of the drum (62). In addition, the centers (Q1 and Q2) are set to be located on the rotation axis of the first coupling part (82) and the second coupling part (83), respectively. Therefore, since the first coupling part (82) and the second coupling part (83) are coaxial, the straight line connecting the centers (Q1 and Q2), that is, the rotation axis of the first coupling part (82) and the second coupling part (83), coincides with the rotation axis of the drum (62).

[0128] From the above, all rotation axes of the drive transmission member (1), the first coupling part (82), the second coupling part (83), the lid member (88), the drive side drum flange (81), and the drum (62) can be rotated in a state where they coincide.

[0129] Similar to Example 1, the first coupling member (82) in this embodiment can engage even if the driving transmission member (1) is configured such that the rotation axis prior to engagement is inclined relative to the first coupling member (82). Furthermore, even if the rotation axes of the first coupling member (82) and the driving transmission member (1) prior to engagement are parallel and not coaxial, the first coupling member (82) of this embodiment can engage with the driving transmission member (1).

[0130] In this embodiment, the regulating portion (81c) of the driving side drum flange (81) and the regulated portion (82c) of the first coupling portion (82) each adopt a concave shape having a conical surface and a convex shape having a spherical surface. Similarly, the regulating portion (87c) of the lid member (87) and the regulated portion (83c) of the second coupling portion (83) each adopt a concave shape having a conical surface and a convex shape having a spherical surface. To obtain the same effect as in this embodiment, the relationship between the concave shape having a conical surface and the convex shape having a spherical surface may be reversed.

[0131] The regulated portion (81c, 87c) and the regulated portion (82c, 83c) are the cautionary portions in Example 2.

[0132] As described above, in Example 2, just like in Example 1, a first coupling member (82) can be coupled to a drive transmission member (1) having an axis inclined with respect to the axis of the drum (62) so as to be coaxial with the drum (62). With this configuration, the precision of drive transmission from the device body (A) to the cartridge (B) can be improved.

[0133] The embodiments described so far are summarized as follows.

[0134] Regarding the coupling member of the present embodiment, the first coupling part (82) and the second coupling part (83) are configured to be relatively movable. As shown in FIG. 14 (b), the first coupling part (82) rotates by engaging with the drive transmission member (1). Then, one of the first coupling part (82) and the second coupling member (83) moves in the axial direction relative to the other. That is, the second coupling part (83) moves in the axial direction of the drum (the direction of the arrow (N) in FIG. 14 (c)) relative to the first coupling part (82).

[0135] As a result, the regulated portion (82c) installed in the first coupling portion (82) comes into contact (is pressed) with the regulated portion (81c) installed in the flange member (drive-side drum flange (81)). Also, the regulated portion (83c) installed in the second coupling portion (83) comes into contact (is pressed) with the regulated portion (87c) installed in the flange member (lid member (77)). Due to the action of these contacts, the coupling members (first coupling portion (82), second coupling portion (83)) are aligned. That is, the angle of inclination of the coupling members (82, 83) with respect to the photosensitive drum (62) is reduced. As a result, as shown in FIG. 14 (c), the drive transmission member (1), the coupling members (82, 83), and the photosensitive drum (62) are arranged in a roughly coaxial shape, and the precision of the drive transmission is improved.

[0136] The first coupling part (82) and the second coupling part (83) have an inclined part (82g, 83g) as a cam mechanism (see FIG. 13 (a)). Therefore, when the first coupling part (82) rotates relative to the second coupling part (83), the relative position of the first coupling part (82) and the second coupling part (83) is configured to change along this inclined part (82g, 83g) in the axial direction.

[0137] Additionally, one of the regulated portion (82c) installed on the first coupling portion (82) and the regulated portion (81c) installed on the flange member (drive-side drum flange (81)) is a spherical convex shape, and the other is a spherical or conical concave shape. Additionally, one of the regulated portion (83c) installed on the second coupling portion (83) and the regulated portion (87c) installed on the flange member (lid member (77)) is a spherical convex shape, and the other is a spherical or conical concave shape.

[0138] The concave and convex shapes described above engage to create a stabilizing effect.

[0139] Industrial applicability

[0140] According to the present invention, a drum unit, a drive transmission unit, a cartridge, and an electronic photographic image forming device suitable for use in an image forming device such as an electronic photographic image forming device are provided.

[0141] The present invention is not limited to the above embodiments, and various changes and modifications are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to disclose the scope of the present invention.

[0142] The present application claims priority based on Japanese patent application No. 2019-109671 filed on June 12, 2019, and incorporates all of the contents of the application herein by reference.

Claims

Claim 1 A drum unit for a cartridge comprises: a photosensitive drum; a flange coaxial with the photosensitive drum and provided at the end of the photosensitive drum and configured to transmit a driving force to the photosensitive drum; a first coupling supported by the flange and inclined with respect to the flange, wherein at least a portion of the first coupling is exposed from the flange to receive the driving force; and a second coupling operatively connected to the first coupling and the flange and configured to transmit the driving force from the first coupling to the flange, wherein the first coupling is partially rotatable with respect to the second coupling around the rotational axis of the first coupling by receiving the driving force, and the first coupling and the second coupling are configured to move apart from each other in the direction of the rotational axis of the first coupling as the first coupling rotates relative to the second coupling, and the flange is such that as the first coupling rotates relative to the second coupling, the inclination of the first coupling with respect to the flange A drum unit configured to be reduced. Claim 2 A drum unit according to claim 1, wherein the second coupling is inclined relative to the flange, and the flange is configured such that the inclination of the second coupling is reduced as the first coupling rotates relative to the second coupling. Claim 3 A drum unit according to claim 1, wherein the flange, the first coupling, and the second coupling are moved away from each other in the direction of the rotational axis of the first coupling, so that the first coupling and the second coupling come into contact with the flange, thereby reducing the inclination of the first coupling with respect to the flange. Claim 4 A drum unit according to claim 1, wherein one of the first coupling and the flange has a convex curved surface and the other of the first coupling and the flange has a concave curved surface, and the convex curved surface and the concave curved surface are configured to come into contact with each other as the first coupling and the second coupling move away from each other in the direction of the rotation axis of the first coupling. Claim 5 A drum unit according to claim 1, wherein one of the second coupling and the flange has a convex curved surface and the other of the second coupling and the flange has a concave curved surface, and the convex curved surface and the concave curved surface are configured to come into contact with each other as the first coupling and the second coupling move away from each other in the direction of the rotation axis of the first coupling. Claim 6 A drum unit according to claim 1, wherein the first coupling has a curved surface, and the curved surface is configured to come into contact with the flange as the first coupling and the second coupling move away from each other in the direction of the rotation axis of the first coupling. Claim 7 A drum unit according to claim 1, wherein the second coupling has a curved surface, and the curved surface is configured to come into contact with the flange as the first coupling and the second coupling move away from each other in the direction of the rotation axis of the first coupling. Claim 8 A drum unit according to claim 1, wherein at least one of the first coupling and the second coupling comprises an inclined surface configured to move the first coupling and the second coupling away from each other in the direction of the rotation axis of the first coupling as the first coupling rotates relative to the second coupling. Claim 9 A drum unit according to claim 1, further comprising a spring, wherein the first coupling is configured to move relative to the second coupling by receiving the driving force while resisting the elastic force of the spring. Claim 10 A drum unit according to claim 1, wherein the first coupling is rotatable relative to the second coupling at an angle of 120° or more. Claim 11 A cartridge comprising: a photosensitive drum; a support member operatively connected to the photosensitive drum; a first coupling supported by the support member and inclined relative to the support member, wherein at least a portion of the first coupling is exposed from the support member to receive a driving force; and a second coupling operatively connected to the first coupling and the support member and configured to transmit the driving force from the first coupling to the support member, wherein the first coupling is partially rotatable relative to the second coupling around the rotational axis of the first coupling by receiving the driving force, and the first coupling and the second coupling are configured to move apart from each other in the direction of the rotational axis of the first coupling as the first coupling rotates relative to the second coupling, and the support member is configured such that the inclination of the first coupling relative to the support member is reduced as the first coupling rotates relative to the second coupling. Claim 12 A cartridge according to claim 11, wherein the second coupling is inclined relative to the support member, and the support member is configured such that the inclination of the second coupling is reduced as the first coupling rotates relative to the second coupling. Claim 13 A cartridge according to claim 11, wherein the support member, the first coupling, and the second coupling are such that as the first coupling and the second coupling move away from each other in the direction of the rotational axis of the first coupling, the first coupling and the second coupling come into contact with the support member, thereby reducing the inclination of the first coupling with respect to the support member. Claim 14 A cartridge according to claim 11, wherein one of the first coupling and the support member has a convex curved surface and the other of the first coupling and the support member has a concave curved surface, and the convex curved surface and the concave curved surface are configured to come into contact with each other as the first coupling and the second coupling move away from each other in the direction of the rotation axis of the first coupling. Claim 15 A cartridge according to claim 11, wherein one of the second coupling and the support member has a convex curved surface and the other of the second coupling and the support member has a concave curved surface, and the convex curved surface and the concave curved surface are configured to come into contact with each other as the first coupling and the second coupling move away from each other in the direction of the rotation axis of the first coupling. Claim 16 In claim 11, the first coupling has a curved surface, and the curved surface is configured to come into contact with the support member as the first coupling and the second coupling move away from each other in the direction of the rotation axis of the first coupling. Claim 17 In claim 11, the second coupling has a curved surface, said curved surface is configured to come into contact with said support member as the first coupling and said second coupling move away from each other in the direction of said rotational axis of the first coupling, a cartridge. Claim 18 A cartridge according to claim 11, wherein at least one of the first coupling and the second coupling comprises an inclined surface configured to move the first coupling and the second coupling away from each other in the direction of the rotation axis of the first coupling as the first coupling rotates relative to the second coupling. Claim 19 A cartridge according to claim 11, further comprising a spring, wherein the first coupling is configured to move relative to the second coupling by receiving the driving force while resisting the elastic force of the spring. Claim 20 In claim 11, the cartridge is such that the first coupling is rotatable relative to the second coupling at an angle of 120° or more.

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