TWI798600B - Drum unit, cartridge, electrophotographic image forming apparatus and coupling member - Google Patents

Abstract

The photodrum unit has a photosensitive drum and a coupling member. The coupling member has an engaging member having a driving force receiving portion configured to receive a driving force for rotating the photoreceptor drum by entering into the concave portion of the drive shaft. Furthermore, the coupling member has a holding member configured to hold the engaging member slidably at least in the radial direction of the photodrum unit, and an urging member configured to urge the engaging member.

Description

Photodrum unit, cassette, electrophotographic image forming device, and coupling member

The present invention relates to an electrophotographic image forming apparatus using an electrophotographic method, and a photoelectric drum unit, a cassette, a coupling member, and the like using the electrophotographic method.

In an electrophotographic image forming device, elements such as a photosensitive drum or a developing roller as a rotating body related to image formation are integrated as a cassette, and can be attached to and detached from the image forming device body (hereinafter referred to as the device body) The genus is known. In such a configuration, the configuration in which the device main body receives the driving force for rotating the photosensitive drum in the cassette has been adopted in many devices. At this time, a configuration in which a coupling member is engaged with a driving force transmission portion such as a driving pin on the device main body side on the cassette side to transmit the driving force is also known.

For example, Patent Document 1 discloses a cassette provided with a coupling member capable of obliquely moving with respect to the rotation axis of the photoreceptor drum at the end of the photoreceptor drum.

The subject of the present invention is to develop the aforementioned prior art.

A representative configuration is a photodrum unit that can be attached to and detached from an electrophotographic image forming device body provided with a drive shaft having a concave portion, and has: (1) a photosensitive drum, (2) ) is provided on the coupling member of the photosensitive drum, and (2-1) has a driving force receiving portion configured to receive a driving force for rotating the photosensitive drum by entering into the concave portion The engagement member is composed of (2-2) a holding member configured to hold the engagement member so as to be slidable at least in the radial direction of the photodrum unit, and (2-3) and the engagement member respectively. And the spring pushing member is constituted by spring pushing the above-mentioned engagement member.

The present invention advances the aforementioned prior art.

1: photoreceptor drum

2: Charging roller

3: Scanner unit

4: Developing unit

5: Intermediate transfer belt

6: Clean the scraper

7: Dealing with the cassette

8: Primary transfer roller

9:Secondary transfer roller

10: Fixing device

11:Intermediate transfer belt cleaning device

12: Recording material

13: Cleaning unit

14a: waste toner storage unit

14b: opening

15: Charger roller bearing

16: Compression spring

17: Developing roller

18: Development frame

19: Bearing components

20: Toner supply roller

51: Drive roller

52:Secondary transfer counter roller

53: driven roller

100: image forming device

100A: image forming device body

FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 .

FIG. 2 is a perspective view of the appearance of the processing cassette 7 .

FIG. 3 is a schematic sectional view of the processing cassette 7 .

FIG. 4 is a sectional view of the processing cassette 7 .

FIG. 5 is a cross-sectional view of the processing cassette 7 .

FIG. 6 is an outline view of the drive shaft 101 of the main body.

FIG. 7 is a cross-sectional view of the body drive shaft 101 .

FIG. 8 is a perspective view of the main body drive shaft 101 .

FIG. 9 is a cross-sectional view of the coupler 28 and the body drive shaft 101 .

FIG. 10 is a cross-sectional view perpendicular to the rotation axis of the coupling unit 28 and the main body drive shaft 101 .

FIG. 11 is a perspective view of the driving side of the photodrum unit 30 .

FIG. 12 is a driving side sectional view of the photodrum unit 30 .

FIG. 13 is a perspective view of the engagement member 65 .

FIG. 14 is a perspective view of members constituting the coupling unit 28 .

FIG. 15 is a cross-sectional view of the coupling unit 28 in the vertical direction of the rotation axis.

FIG. 16 is a perspective view showing the installation of the cassette 7 to the image forming apparatus main body 100A.

FIG. 17 is a sectional view showing the installation of the cassette 7 to the image forming apparatus main body 100A.

FIG. 18 is a sectional view showing the installation of the cassette 7 to the image forming apparatus main body 100A.

FIG. 19 is a sectional view showing the installation of the cassette 7 to the image forming apparatus main body 100A.

Figure 20 shows the drive shaft 101 of the coupling unit 28 towards the main body Sectional drawing of the installation.

FIG. 21 is a sectional view showing the installation of the coupling unit 28 to the main body drive shaft 101 .

FIG. 22 is a sectional view showing the installation of the coupling unit 28 to the main body drive shaft 101 .

FIG. 23 is a cross-sectional view perpendicular to the rotation axis of the coupling unit 28 and the main body drive shaft 101 .

FIG. 24 is a cross-sectional view perpendicular to the rotation axis of the coupling unit 28 and the main body drive shaft 101 .

FIG. 25 is a cross-sectional view perpendicular to the rotation axis of the coupling unit 28 and the main body drive shaft 101 .

FIG. 26 is a cross-sectional view of the drive transmission engagement surface of the engagement member 65 and the main body drive shaft 101 .

FIG. 27 is a schematic cross-sectional view of image forming apparatus 4100A.

FIG. 28 is a perspective view of the appearance of the drum cassette 4013.

FIG. 29 is a sectional view of the drum cassette 4013.

FIG. 30 is a perspective view of the appearance of the developing cassette 4004.

FIG. 31 is a sectional view of the developing cassette 4004.

FIG. 32 is a perspective view of the drive shaft 4101 of the body.

FIG. 33 is a cross-sectional view of the main body drive shaft 4101.

FIG. 34 is a perspective view of the coupling unit 4028.

FIG. 35 is a perspective view of the engaging member 4065 .

FIG. 36 is a perspective view of members constituting the coupling unit 4028 .

FIG. 37 is a perspective view of the coupling unit 4028 and the toner supply roller 4020 .

FIG. 38 is a cross-sectional view of the coupling unit 4028 and the rotation axis of the main body drive shaft 4101 in a vertical direction.

FIG. 39 is a sectional view of the developing cassette 4004.

FIG. 40 is a perspective view showing the installation of the developing cassette 4004 to the image forming apparatus body 4100. FIG.

FIG. 41 is a cross-sectional view showing the installation of the developing cartridge 4004 to the image forming apparatus body 4100. FIG.

FIG. 42 is a cross-sectional view showing the installation of the developing cartridge 4004 to the image forming apparatus body 4100. FIG.

FIG. 43 is a sectional view showing the installation of the developing cartridge 4004 to the image forming apparatus main body 4100. FIG.

FIG. 44 is a cross-sectional view showing the installation of the coupling unit 4028 to the body drive shaft 4101.

FIG. 45 is a cross-sectional view showing the installation of the coupling unit 4028 to the main body drive shaft 4101.

FIG. 46 is a sectional view showing the installation of the coupling unit 4028 to the body drive shaft 4101.

FIG. 47 is a cross-sectional view showing the installation of the coupling unit 4028 to the body drive shaft 4101.

Fig. 48 is an explanatory diagram showing an engaging member.

Fig. 49 is a sectional view of the coupling unit.

Fig. 50 is an explanatory view showing an engaging member.

Fig. 51 is a sectional view of the coupling unit.

Fig. 52 is a sectional view of the coupling unit.

Fig. 53 is a sectional view of the coupling unit.

Fig. 54 is a sectional view of the coupling unit.

Fig. 55 is a sectional view of the coupling unit.

Fig. 56 is a sectional view of the coupling unit.

Fig. 57 is a sectional view of the coupling unit.

Hereinafter, the image forming apparatus and the process cassette of this embodiment will be described using the drawings. Also, the so-called image forming device is, for example, one that forms an image on a recording medium using electrophotographic image forming processing. For example, electrophotographic copiers, electrophotographic printers (for example, LED printers, laser printers, etc.), electrophotographic facsimile devices, and the like are included. In addition, the term "cassette" refers to one that can be attached to and detached from the image forming apparatus body (device body). Among the cartridges, those that integrate the photoreceptor or the processing means acting on the photoreceptor are called process cartridges.

In addition, a photoreceptor drum integrated with a coupling member is called a photodrum unit.

In addition, in the following embodiments, a full-color image forming apparatus in which four process cassettes can be attached and detached is exemplified. However, the number of process cassettes installed in the image forming apparatus is not limited thereto. In addition, similarly, the materials, arrangement, dimensions, other numerical values, etc. of each structure disclosed in the embodiment are not limited unless otherwise specified. In addition, without When there is a special note, the term "upper side" refers to the upper side in the direction of gravity when the image forming device is installed.

<Example 1>

[Overview of Electrophotographic Image Forming Device]

First, the overall configuration of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) related to this embodiment will be described with reference to FIG. 1 .

FIG. 1 is a schematic cross-sectional view of an image forming apparatus 100 of this embodiment.

As shown in FIG. 1 , the image forming apparatus 100 has, as a plurality of image forming units, first, second, and second color images for forming images of yellow (Y), magenta (M), cyan (C), and black (K). The third and fourth image forming units SY, SM, SC, and SK. In the present embodiment, the first to fourth image forming sections SY, SM, SC, and SK are arranged in a row substantially in the horizontal direction.

Also, in this embodiment, the configuration and operation of the processing cassettes 7 (7Y, 7M, 7C, 7K) are substantially the same except that the colors of the images formed are different. That is, in the following, where there is no need to specifically distinguish, Y, M, C, and K will be collectively described without omitting.

In this embodiment, the image forming apparatus 100 has, as a plurality of image carriers, four cylinders (cylinders) having a photosensitive layer (hereinafter referred to as photosensitive drums) arranged side by side in a direction slightly inclined to the vertical direction. 1. The scanner unit is arranged below the direction of gravity of the processing cassette 7 (Exposure device) 3. In addition, around the photosensitive drum 1, a charging roller 2 and the like are disposed as processing means (processing means, processing means) acting on the photosensitive layer.

The charging roller 2 is a charging means (charging device, charging member) for uniformly charging the surface of the photosensitive drum 1 . Next, the scanner unit (exposure device) 3 is an exposure means (exposure device, exposure member) for forming an electrostatic image (electrostatic latent image) on the photosensitive drum 1 by irradiating laser light based on image information. Around the photoreceptor drum 1, a cleaning blade 6 serving as a developing device (hereinafter referred to as developing unit) 4 and cleaning means (cleaning device, cleaning member) is arranged.

Furthermore, facing the four photoreceptor drums 1, an intermediate transfer member serving as an intermediate transfer body for transferring the toner image on the photoreceptor drum 1 to the recording material (sheet, recording medium) 12 is arranged. Print belt 5.

The developing unit 4 of this embodiment uses a non-magnetic single-component developer (hereinafter referred to as toner) as a developer, and adopts contact development in which the developing roller 17 as a developer carrier is brought into contact with the photosensitive drum 1. Way.

In the aforementioned configuration, the toner image formed on the photoreceptor drum 1 is transferred to the sheet (paper) 12, and the toner image transferred to the sheet is fixed. In addition, as a processing means acting on the photosensitive drum 1, the processing cartridge includes a charging roller 2 for charging the photosensitive drum 1, and a cleaning device for cleaning remaining toner that has not been transferred to the photosensitive drum 1. scraper6. The transfer residual toner remaining on the photoreceptor drum 1 without being transferred onto the sheet 12 is collected by the cleaning blade 6 . In addition, by cleaning the scraping The transfer residual toner recovered by the plate 6 is stored in the developer removal container (hereinafter referred to as waste toner container) 14a through the opening 14b. The waste toner storage portion 14 a and the cleaning blade 6 constitute an integrated cleaning unit (photoreceptor unit, image carrier unit) 13 .

Moreover, the process cassette 7 is comprised by integrating the developing unit 4 and the cleaning unit 13 into a unit (cassette). The image forming apparatus 100 includes guides (positioning means) such as mounting guides and positioning members (not shown) in the main body housing. The process cassette 7 is guided by the above-mentioned guide, and is configured so as to be attachable and detachable to the image forming apparatus main body (electrophotographic image forming apparatus main body) 100A.

In the processing cassette 7 for each color, toners of yellow (Y), magenta (M), cyan (C) and black (K) are accommodated respectively.

The intermediate transfer belt 5 comes into contact with the photoreceptor drum 1 provided in each process cassette, and rotates (moves) in the direction of arrow B in FIG. 1 . The intermediate transfer belt 5 is stretched over a plurality of supporting members (a driving roller 51 , a secondary transfer counter roller 52 , and a driven roller 53 ). On the inner peripheral surface side of the intermediate transfer belt 5 , four primary transfer rollers 8 are arranged side by side as primary transfer means so as to face the respective photosensitive drums 1 . In addition, a secondary transfer roller 9 as a secondary transfer means is disposed on the outer peripheral surface side of the intermediate transfer belt 5 at a position facing the secondary transfer counter roller 52 .

When forming an image, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2 . Then, the surface of the charged photosensitive drum 1 is scanned and exposed by the laser light corresponding to the image information emitted by the scanner unit 3 . Thereby, a corresponding image is formed on the photosensitive drum 1 The electrostatic latent image of information. The electrostatic latent image formed on the photosensitive drum 1 is developed as a toner image by the developing unit 4 .

The photoreceptor drum is a rotating body (image carrier) that rotates while supporting an image (developer image, toner image) formed by a developer (toner) on its surface.

The toner image formed on the photosensitive drum 1 is transferred (primary transfer) to the intermediate transfer belt 5 by the action of the primary transfer roller 8 .

For example, when forming a full-color image, the aforementioned processing is sequentially performed in the four processing cassettes 7 (7Y, 7M, 7C, 7K). Next, the toner images of the respective colors formed on the photoreceptor drums 1 of the process cassettes 7 are sequentially primary-transferred so as to overlap on the intermediate transfer belt 5 . Thereafter, the recording material 12 is conveyed to the secondary transfer unit in synchronization with the movement of the intermediate transfer belt 5 . Next, the four-color toner images on the intermediate transfer belt 5 are collectively transferred onto the recording material 12 conveyed to the secondary transfer section formed by the intermediate transfer belt 5 and the secondary transfer roller 9 .

The recording material 12 to which the toner image has been transferred is conveyed to a fixing device 10 as a fixing means. The fixing device 10 fixes the toner image on the recording material 12 by applying heat and pressure to the recording material 12 . In addition, the primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer step is removed by the cleaning blade 6 and recovered as waste toner. In addition, the secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11 .

Also, the image forming apparatus 100 may use a desired One or several (not all) image forming units form monochrome or multicolor images.

〔Overview of handling cassettes〕

Next, an overview of the process cassette 7 (cassette 7 ) mounted on the image forming apparatus main body 100A of this embodiment will be described using FIGS. 2 , 3 , 4 , and 5 .

The cassette 7a for storing yellow toner, the cassette 7b for storing magenta toner, the cassette 7c for storing cyan toner, and the cassette 7d for storing black toner have the same configuration. That is, in the following description, each cassette 7a, 7b, 7c, 7d is collectively referred to as cassette 7, and it demonstrates. The respective cassette constituent members will also be described using generic terms in the same manner.

FIG. 2 is a perspective view of the appearance of the processing cassette 7 . Here, as shown in FIG. 2, the rotation axis direction of the photoreceptor drum 1 is taken as the Z direction (arrow Z1, arrow Z2), and the horizontal direction of FIG. 1 is taken as the X direction (arrow X1, arrow X2). The vertical direction is taken as the Y direction (arrow Y1, arrow Y2).

3 is a schematic cross-sectional view of the process cartridge 7 in a state (posture) in which the photoreceptor drum 1 is in contact with the developing roller 17 as seen along the Z direction, installed in the image forming apparatus 100 .

The process cassette 7 is composed of two units: a cleaning unit 13 which unitizes the photoreceptor drum 1, charging roller 2, and cleaning blade 6, and a developing unit 4 having developing members such as a developing roller 17.

The developing unit 4 has various requirements for supporting the developing unit 4. The development frame body 18 of element. The developing unit 4 is provided with a developing roller 17 as a developer carrier that is in contact with the photoreceptor drum 1 and rotates in the direction of arrow D (counterclockwise) in the drawing. The developing roller 17 is rotatably supported by the developing frame 18 via developing bearings 19 ( 19R, 19L) at both end portions in the longitudinal direction (rotation axis direction). Here, the developing bearings 19 ( 19R, 19L) are attached to both sides of the developing frame 18 , respectively.

Further, the developing unit 4 has a developer storage chamber (hereinafter referred to as a toner storage chamber) 18 a and a development chamber 18 b in which the development roller 17 is arranged.

In the developing chamber 18b, a developing blade for restricting the toner layer of the developing roller 17 and the toner supplying roller 20 serving as a developer supplying member that contacts the developing roller 17 and rotates in the direction of the arrow E is disposed. plate 21. The developing blade 21 is fixed and integrated by welding the fixing member 22 or the like.

Further, in the toner storage chamber 18 a of the developing frame 18 , an agitating member 23 for agitating the stored toner and conveying the toner to the toner supply roller 20 is provided.

Next, the developing unit 4 is rotatably coupled to the cleaning unit 13 around the fitting shafts 24 ( 24R, 24L) provided in the bearing members 19R, 19L and fitted in the holes 19Ra and 19La. Further, in the developing unit 4 , the developing roller 17 is elastically pushed in the direction of abutting against the photosensitive drum 1 by the biasing springs 25 ( 25R, 25L). Therefore, when the image of the processing cassette 7 is formed, the developing unit 4 reverses (rotates) in the direction of the arrow F around the fitting shaft 24, and the photoreceptor drum 1 and the developing roller 17 abutments.

The cleaning unit 13 has a cleaning frame 14 as a frame supporting various elements in the cleaning unit 13 .

4 and 5 are cross-sectional views cut along an imaginary plane along the rotation axis of the photosensitive drum 1 of the process cartridge 7 .

Also, in FIG. 4, the side where the coupling unit (coupling member) 28 receives the driving force from the main body of the image forming apparatus (the side in the Z1 direction) is referred to as the driving side of the process cartridge 7. In addition, in FIG. 5 , the side opposite to the driving side (the side in the Z2 direction) is referred to as the non-driving side of the process cartridge 7 .

When the cassette 7 is inserted into the mounting portion of the main body of the image forming apparatus, the driving side of the cassette 7 is arranged on the rear side of the mounting portion, and the non-driving side of the cassette 7 is disposed on the front side of the mounting portion.

At the end opposite to the coupling unit 28 (the end of the non-driving side of the process cassette), there is an electrode (electrode portion) in contact with the inner surface of the photoreceptor drum 1, and the electrode is connected to the image forming apparatus body. Contact to play the role of grounding.

A coupling unit 28 is attached to one end of the photoreceptor drum 1 , and a non-driving side flange member 29 is attached to the other end of the photoreceptor drum 1 to form a photoreceptor drum unit 30 . The photoreceptor drum unit 30 receives a driving force from a main body driving shaft 101 provided on the main body 100A of the image forming apparatus (the driving force is transmitted by the main body driving shaft 101 ) via the coupling unit 28 . As described later in detail, the coupling unit 28 can be engaged with the main body drive shaft 101 along with the installation of the cassette 7 of the device main body 100A. Accompanied by removing the cassette 7 from the device body 100A, the coupling unit 28 can be separated from the body drive shaft 101.

The coupling unit 28 is configured in such a way that it can be combined with and detached from the main body drive shaft 101 .

The coupling unit 28 has a flange member 71 (drive-side flange member) attached to the drive-side end portion of the photoreceptor drum 1 .

As shown in FIG. 4 , the Z1 side of the coupling unit 28 has a cylindrical shape (cylindrical portion 71 a ). The cylindrical portion 71 a protrudes toward the Z1 side (outer side in the axial direction) than the end portion of the photosensitive drum 1 . The portion near the tip on the Z1 side of the cylindrical portion 71a is a bearing portion 71c. The bearing portion 71c is rotatably supported by a bearing portion provided on the optical drum unit bearing member 39R. In short, the photoreceptor drum unit 30 is made rotatable by being supported by the bearing portion 71c via the bearing portion of the drum unit bearing member 39R.

Similarly in FIG. 5 , the non-driving side flange member 29 provided on the non-driving side of the photoreceptor drum unit 30 is rotatably supported by the photodrum unit bearing member 39L. The non-driving side flange member 29 has a cylindrical portion (cylindrical portion) protruding from the end of the photosensitive drum 1, and the outer peripheral surface of the cylindrical portion 29a is rotatably supported by the photodrum unit bearing member. 39L.

In addition, the photodrum unit bearing member 39R is arranged on the driving side of the process cartridge 7 , and the photodrum unit bearing member 39L is arranged on the non-driving side of the process cartridge 7 .

When the process cassette 7 is mounted on the apparatus main body 100A, as shown in FIG. 4 , the photodrum unit bearing member 39R is in contact with the rear cassette positioning portion 108 provided on the image forming apparatus main body 100A. In addition, the photodrum unit bearing member 39L interferes with the front side of the image forming apparatus main body 100A. Cassette positioning part 110 . Thereby, the cassette 7 is positioned in the image forming apparatus 100A.

In the Z direction of this embodiment, as shown in FIG. 4 , the photodrum unit bearing member 39R is disposed at a position supporting the bearing portion 71c, and the photodrum unit bearing member 39R is disposed near the cassette positioning portion positioned on the rear side. The location of the 108 location. By doing so, when the process cassette 7 is mounted on the apparatus main body 100A, it is possible to suppress the inclination of the coupling unit 28 .

The bearing member 39R is disposed at a position supporting the bearing portion 71c, and the bearing member 39R is disposed at a position close to a position positioned at the rear cassette positioning portion 108, and the bearing portion 71c is disposed. In short, the bearing-received portion 71c is disposed on the tip side (Z1 direction side) of the outer peripheral surface of the cylindrical portion 71a provided in the coupling unit 28 .

Similarly, as shown in FIG. 5 , in the Z direction, the photodrum unit bearing member 39L is disposed at a place where the non-driving side flange member 29 is rotatably supported, and the photodrum unit bearing member 39L is disposed close to the card positioned on the front side. The position of the position of the cassette positioning part 110. Thereby, the inclination of the non-driving side flange member 29 is suppressed.

The photodrum unit bearing members 39R, 39L are attached to both sides of the cleaning frame 14, respectively, and support the photosensitive drum unit 30, respectively. Accordingly, the photosensitive drum unit 30 is rotatably supported by the cleaning frame 14 .

In addition, the charging roller 2 and the cleaning blade 6 are attached to the cleaning frame 14 , and these are arranged so as to be in contact with the surface of the photoreceptor drum 1 . In addition, charging roller bearings 15 ( 15R, 15L) are attached to the cleaning frame 14 . The charging roller bearing 15 is a shaft for supporting the shaft of the charging roller 2 Inheritance.

Here, the charging roller bearings 15 ( 15R, 15L) are attached so as to be movable in the direction of arrow C shown in FIG. 3 . The rotating shaft 2 a of the charging roller 2 is rotatably attached to the charging roller bearings 15 ( 15R, 15L). Next, the charging roller bearing 15 is urged toward the photosensitive drum 1 by the pressure spring 16 as the urging means. Thereby, the charging roller 2 comes into contact with the photosensitive drum 1 and rotates along with the photosensitive drum 1 .

The cleaning frame 14 is provided with a cleaning blade 6 as cleaning means for removing toner remaining on the surface of the photosensitive drum 1 . The cleaning blade 6 is a scraper-shaped rubber (elastic member) 6a that abuts against the photosensitive drum 1 to remove toner on the photosensitive drum 1, and a support plate 6b that supports it is integrated. In this embodiment, the support plate 6b is fixed on the cleaning frame 14 by screws.

As mentioned above, the cleaning frame 14 has an opening 14 b for recovering the residual toner recovered by the cleaning blade 6 . The opening 14b is provided with a blow-out preventing plate 26 which abuts against the photosensitive drum 1 and seals between the photosensitive drum 1 and the opening 14b, and suppresses leakage of toner in the upper direction of the opening 14b.

In this way, the ease of maintenance is improved by adopting the structure of integrating the elements related to the image formation of the cassette which can be attached and detached from the main body of the device. In other words, the user can easily maintain the device by attaching and detaching the processing cassette to the device body. Therefore, it is possible to provide a device in which not only service personnel but also users can easily perform maintenance work.

〔Configuration of the drive shaft of the main body〕

The structure of the main body drive shaft 101 is demonstrated using FIG.6, FIG.7, FIG.8, FIG.9, FIG.10.

Figure 6 is the outline drawing of the main body drive shaft.

FIG. 7 is a sectional view cut along the rotation axis (rotation axis) of the main body drive shaft 101 in a state where the main body of the image forming apparatus is installed.

Figure 8 is a perspective view of the drive shaft of the body.

FIG. 9 is a sectional view of the coupler 28 and the main body drive shaft 101 cut along the rotation axis (rotation axis).

FIG. 10 is a cross-sectional view of the coupling unit 28 and the main body drive shaft 101 cut along the vertical direction of the rotation axis.

As shown in FIG. 6, the main body drive shaft 101 has a gear part 101e, a shaft part 101f, a rough guide part 101g, and a bearing part 101d.

A motor (not shown) as a driving source is provided in the image forming apparatus main body 100A. The gear part 101e is rotationally driven by this motor and the body drive shaft 101 is rotated. Further, the main body drive shaft 101 includes a rotatable protrusion-shaped shaft portion 101f that protrudes toward the cassette side more than the gear portion 101e along the rotation axis. Then, the rotational driving force received by the motor is transmitted to the cassette 7 side through the groove-shaped drive transmission groove 101a (recessed portion, drive transmission portion) provided in the shaft portion 101f. In addition, the shaft portion 101f has a hemispherical shape 101c at its tip.

This main body drive transmission groove 101a is shaped so that a part of the engaging portion 65a of the coupling unit 28 described later can enter. Specifically, a driving force receiving surface (driving force receiving portion) 65b with the coupling unit 28 is provided. contact with the main body driving transmission surface 101b which is a surface transmitting the driving force.

In addition, as shown in FIG. 6 , the body drive transmission surface 101 b is not a flat surface, but has a twisted shape around the rotation axis of the body drive shaft 101 . The twisting direction is the direction from the Z1 direction side of the main body drive shaft 101 to the Z2 direction side, and is arranged upstream in the rotation direction of the main body drive shaft 101 . In this embodiment, the amount of twist along the rotation axis of the cylinder of the engaging portion 65 a is about 1° per 1 mm. The reason for taking the shape of the twisted body drive transmission surface 101b will be described in detail later.

In addition, on the Z2-direction side surface of the main body drive transmission groove 101a, a main body side pull-off gradient 101i is provided. The body-side removal gradient 101i is a gradient (inclined surface, inclined portion) for assisting the removal of the engaging portion 65a from the drive transmission groove 101a when the process cartridge 7 is detached from the apparatus body 100A. See below for details.

Here, when driving is transmitted to the engaging portion 65a through the driving transmission groove 101a, it is preferable that the main body driving transmission surface 101b and the driving force receiving surface (driving force receiving portion) 65b are in reliable contact. Here, the main body drive transmission groove 101a has gaps ( G) The structure (refer to FIG. 9, FIG. 10).

In addition, in the axial direction of the main body drive shaft 101, the center 101h of the hemispherical shape 101c is arranged within the range of the main body drive transmission groove 101a (see FIG. 7). In other words, if the center 101h and the main body drive transmission groove 101a are projected on the axis of the main body drive shaft 101, the center is arranged inside the projected area of the main body drive transmission groove 101a on the axis. The projection area of 101h.

Here, the main body drive shaft or the axis of the drum unit (rotation axis, rotation center line) means an imaginary line extending through the rotation center of the shaft. In addition, the axis direction (rotation axis direction) means the direction in which the axis extends. Next, the axial direction of the photodrum unit 30 is synonymous with the longitudinal direction (Z direction) of the photodrum unit 30 .

Furthermore, the so-called "X and Y overlap in the A direction" means that when X and Y are projected on a straight line extending parallel to the A direction, at least a part of the projected area of X and the projected area of Y on the straight line At least a portion of overlaps.

Also, when something is projected onto a line, unless otherwise specified, the projected direction is a direction perpendicular to the line. For example, "project A onto the axis" means "project A on the axis in a direction perpendicular to the axis".

The rough guide portion 101g of the main body drive shaft 101 is provided between the shaft portion 101f and the gear portion 101e in the axial direction (see FIG. 6 ). The rough guide portion 101g has a gradient shape at the tip of the shaft portion 101f side, and the outer diameter D6 of the thick guide portion 101g is, as shown in FIG. The inner diameter D2 is even smaller. In addition, the outer diameter D6 of the rough guide portion 101g is larger than the outer diameter D5 of the shaft portion 101f as shown in FIG. 6 . Thereby, when the cassette 7 is inserted into the image forming apparatus main body 100A, it is possible to make the main body drive shaft 101 follow the example of the coupling unit in such a manner that the axis deviation between the rotation center of the cylindrical portion 71 and the rotation center of the shaft portion 101f is reduced. 28 way to guide (guide). Therefore, the rough guide portion 101g can be renamed as an insertion guide.

Moreover, after the attachment of the cassette 7 to the image forming apparatus main body 100A is completed, the dimensional relationship is set so that the rough guide portion 101g does not come into contact with the inner peripheral surface 71b.

The bearing part 101d of the main body drive shaft 101 is arrange|positioned on the opposite side of the rough guide part 101g with the gear part 101e interposed, as shown in FIG. Next, the bearing portion 101d is rotatably supported (bolted) by the bearing member 102 provided in the image forming apparatus main body 100A.

In addition, the main body drive shaft 101, as shown in FIG. 7, is spring-loaded toward the cassette 7 side by the spring member 103 of the image forming apparatus main body 100A. However, the movable amount (play) of the main body drive shaft 101 in the Z direction is about 1 mm, which is sufficiently smaller than the width of the driving force receiving surface 65b in the Z direction described later.

As mentioned above, the main body drive transmission groove 101a is provided on the main body drive shaft 101, and the engaging portion 65a is provided on the coupling unit 28, so that the drive is transmitted from the device main body 100A to the cassette 7 (photoconductive drum unit 30).

Also, the details will be described later, but the engaging portion 65a is pushed by the pushing member constituted by an elastic and stretchable compression spring. Therefore, when the cassette 7 is mounted on the apparatus main body 100A, the engaging portion 65a can at least move outward in the radial direction of the photodrum unit 30 (the second position). Thereby, as the cassette 7 is inserted into the device main body 100A, the engaging portion 65a enters the driving transmission groove 101a, and the engaging portion 65a can be engaged with the main body driving transmission groove 101a.

In addition, in the following description, the diameter direction of the photodrum unit 30 will also be referred to simply as the diameter direction. In addition, the radial direction of the photodrum unit 30 refers to the radial direction of the photosensitive drum 1 and also the radial direction of the coupling unit 28 .

〔Composition of the coupling unit〕

Next, the coupling unit 28 of this embodiment will be described in detail using FIG. 11 , FIG. 12 , FIG. 13 , FIG. 14 , and FIG. 15 .

FIG. 11 is a perspective view of the driving side of the drum unit 30 in which the coupling unit 28 is mounted on the photosensitive drum 1 .

FIG. 12 is a driving side sectional view of the photodrum unit 30 .

Fig. 13 is a perspective view of the engaging member 65, Fig. 13(a) is a perspective view seen from the upper left, and Fig. 13(b) is a perspective view seen from the upper right.

FIG. 14 is a perspective view of members constituting the coupling unit 28 .

FIG. 15 is a cross-sectional view of the coupling unit 28 perpendicular to the rotation axis.

In the coupling unit 28 , as shown in FIG. 11 , three engaging portions 65 a engaging with the main body drive shaft 101 are provided. This engagement portion 65a enters the groove portion 101a of the main body drive shaft 101 as shown in FIG. Carry out drive transmission.

FIG. 12 is a cross-sectional view of a state where the coupling unit 28 is mounted on the photosensitive drum 1 . An engaging member 65 having an engaging portion 65a, in the coupling unit 28 , it is supported in a state of being pushed by the pushing member 66 toward the inner side of the coupling unit 28 in the radial direction (the first position).

Hereinafter, the configuration of the coupling unit 28 will be described in detail. The coupling unit 28 is composed of a flange member 71 , a flange cover member 72 , an engaging member 65 , and a spring pushing member 66 as shown in the cross-sectional view of FIG.

The flange member 71 is attached to the inner periphery of the photosensitive drum 1 and is fixed to the photosensitive drum 1 . The flange member 71 has a substantially cylindrical shape and has a hollow portion. The flange member 71 opens toward the outside in the axial direction of the photo drum unit.

The flange cover member 72 is attached to the inner surface of the hollow portion of the flange member 71 . The flange cover member 72 plugs the inner side (bottom side) of the flange member 71 in the axial direction of the photodrum unit.

The flange cover member 72 is fixed to the photosensitive drum 1 through the flange member 71 .

The engagement member 65 is movably (slidably) held by the flange cover member 72 , and is configured to be movable (slidable) with respect to the flange cover member 72 . The urging member 66 is an elastic member (spring member) configured to urge the engagement member 65 at least toward the inner side in the radial direction of the photodrum unit.

In this embodiment, the flange member 71 , the flange cover member 72 , the engagement member 65 , and the urging member 66 are configured as separate entities (different members) from each other. In addition, in this embodiment, the engagement member 65 is configured to be movable along the diameter direction of the coupling unit (approximately parallel to the diameter direction). In addition, the engaging member 65 and the pushing member 66 are arranged along the diameter direction. In short, it is configured such that both the engaging member 65 and the urging member 66 are arranged on an imaginary line parallel to the radial direction of the coupling unit.

As shown in FIG. 11 , three engaging members 65 are arranged at equal intervals in the circumferential direction of the coupling unit 28 (120° intervals, approximately equal intervals). Furthermore, as shown in FIG. 13 , the engagement member 65 has an engagement portion 65a protruding inward in the radial direction, and a driving force receiving surface 65b formed on the engagement member 65a. Furthermore, the engagement member 65 is formed adjacent to the driving force receiving surface 65b, and has a drive shaft abutting surface (drive shaft abutting portion) 65c formed in an arc shape so as to abut against the outer peripheral surface 101f of the main body drive shaft. The driving force receiving surface 65b is a driving force receiving portion that receives a driving force from the main body drive shaft 101 by being in contact with the driving groove 101a. In addition, the engaging portion 65 a is a protrusion (protruding portion) protruding from the surface of the engaging member 65 .

The engaging member 65 is a driving force receiving member provided with a driving force receiving portion (driving force receiving surface 65 b ), and is also a supporting member for supporting the driving force receiving surface 65 b.

Moreover, the engagement member 65 has the 1st to-be-guided surface 65d and the 2nd to-be-guided surface 65e so that it may be movably guided in the coupling unit. The first guided surface 65d is a restricted position portion for restricting the engaging member 65 in the circumferential direction, and is arranged near the engaging portion 65a. The second to-be-guided surface 65e is also a restricted position portion for restricting the engagement member 65 in the circumferential direction, and is arranged on the far side relative to the engagement portion 65a.

The 1st to-be-guided surface 65d and the 2nd to-be-guided surface 65e are the to-be-guided parts guided by the flange cover member 72 mentioned later. In addition, the first to-be-guided surface 65d and the second to-be-guided surface 65e are regulated portions where the position of the photodrum unit in the rotational direction (circumferential direction) is regulated by the flange cover member 72 . The 1st to-be-guided surface 65d is an upstream to-be-guided part (and an upstream-side to-be-regulated part) located on the downstream side of the engagement member 65 with respect to the rotation direction of the coupling unit. The second to-be-guided surface 65e is a downstream-side to-be-guided portion (and a downstream-side to-be-regulated portion) located on the upstream side of the engagement member 65 in the rotational direction.

The 1st to-be-guided surface 65d and the 2nd to-be-guided surface 65e are mutually substantially parallel.

Moreover, it has the 3rd to-be-guided surface 65f and the 4th guide surface 65g for regulating the position of the engaging member 65 in an axial direction. The 3rd to-be-guided surface 65f and 65 g of 4th guide surfaces are to-be-guided parts guided by the flange cover member 72 mentioned later. In addition, the third to-be-guided surface 65f and the second to-be-guided surface 65g are regulated portions where the position in the axial direction (longitudinal direction) of the photodrum unit is regulated by the flange cover member 72 . The third to-be-guided surface 65f is an outer to-be-guided portion (and also an outer to-be-regulated portion) located outside the engaging member 65 in the axial direction of the photodrum unit. The 4th guide surface 65g is a downstream side to-be-guided part located on the upstream side of the engaging member 65 in an axial direction (it is also a downstream side to-be-regulated part).

The 3rd to-be-guided surface 65f and the 4th guide surface 65e are mutually substantially parallel.

Furthermore, in the engaging member 65, it has the function of receiving the elastic push member 66. The abutting surface (part to be pushed, surface to be pushed) 65h (Fig. 10) for the purpose of raw elastic thrust. Furthermore, the engagement member 65 abuts against the flange cover member 72 by the biasing force of the biasing member 66 , and has a position regulating protrusion 65 i for regulating the position of the engaging member 65 . In particular, the elastic thrust position regulating surface (locked portion) 65 j formed on the position regulating protrusion is brought into contact with the flange cover member 72 . The position limiting protrusion 65i is provided on both sides of the engagement member 65 with the abutting surface 65h with the urging member 66 sandwiched.

Further, the engaging member 65 has an insertion inclined surface 65k on the outer side (Z1 direction side) of the photoreceptor drum unit 30 in the Z direction. The insertion inclined surface 65k is an inclined portion facing outward in the axial direction. The insertion inclined surface 65k is a mounting force receiving portion that receives a force for retracting the engagement member 65 in the radial direction when the cassette is mounted. In addition, the engaging member 65 has a pull-out inclined portion 651 as a force receiving portion for detachment on the inner side (Z2 direction side) of the photoreceptor drum unit 30 in the Z direction. The pull-out inclined surface 65l is a force receiving portion for receiving the force for retracting the engagement member 65 in the radial direction when the cassette is removed.

The flange cover member 72 has a coupling hole 72a through which the main body drive shaft 101 passes, and an attachment hole 72b for supporting the engagement member 65 movably in the radial direction. In order to engage the engaging member with the main body drive shaft, the engaging portion 65a of the engaging member 65 is exposed from the coupling hole portion 72a. The mounting hole portion 72b has a first guide surface 72d in contact with the first guided surface 65d on the surface that restricts the position of the engagement member 65 in the circumferential direction, and abuts with the second guided surface 65e. The second guide surface 72e. In addition, in the mounting hole portion 72b, there is a mechanism for restricting the position of the engaging member 65. The 3rd guide surface 72f abutting against the 3rd guided surface 65f of the surface placed in the axial direction, and the 4th guide surface 72f abutting against the 4th guide surface 65g of the surface facing the 3rd guided surface. Guide surface 72g.

The 1st guide surface 72d, the 2nd guide surface 72e, the 3rd guide surface 72f, the 4th guide surface 72g are the guide parts for guiding the usefulness of the engaging member 65 respectively, and also limit the engaging member. A restricting part for position (position restricting part).

The first guide surface 72d guides the upstream side of the engaging member 65 in the rotational direction of the photodrum unit, and is an upstream side guide (upstream restricting portion) for restricting the position. Similarly, the 2nd guide surface 72e is a downstream side guide (downstream regulation part) which guides the downstream side of the engaging member 65. As shown in FIG.

The engagement member 65 and the urging member 66 are arranged in the space between the first guide surface 72d and the second guide surface 72e.

In addition, the third guide surface 72f guides the outside of the engagement member 65 in the axial direction of the photodrum unit, and serves as an outer guide portion (outer restricting portion) for restricting the position. Similarly, the fourth guide surface 72g guides the inner side of the engagement member 65 in the axial direction and is an inner guide portion (inner restricting portion) for restricting the position.

The flange cover member 72 guides the engagement member 65 by these guide portions (the first guide surface 72d, the second guide surface 72e, the third guide surface 72f, and the fourth guide surface 72g). guide member. In addition, the flange cover member 72 is a holding member that movably (guideably) holds the engaging member 65 .

The first guide surface 72d and the second guide surface 72e are mutually solid quality parallel. 72 f of 3rd guide surfaces and 72 g of 4th guide surfaces are mutually substantially parallel.

In addition, the engaging member 65 is a moving member movably held by the flange cover member 72 and is also a sliding member slidable on the flange cover member 72 .

In addition, the flange cover member 72 has a regulating surface (locking portion) 72 j in order to restrict the position of the engaging member 65 against the biasing force of the biasing member 66 .

The restricting surface (locking portion) 72j abuts against the elastic thrust position restricting surface (radially stopped portion) 65j to restrict the engagement member 65 from moving inwardly in the radial direction. In short, the limiting surface (locking portion) 72j locks the locking member 65 against the elastic thrust of the elastic pushing member 66 . The cassette 7 is in the state of being installed on the device body (the natural state in which no force is applied to the cassette 7 from the outside), and the locking member 65 is pushed/pressed toward the restricting surface 72j by the pushing force of the pushing member 66 .

In addition, the flange cover member 72 has a fitting surface 72k fitted to the inner peripheral surface of the flange member 71 and a position regulating groove 72l for regulating the position of the flange member 71 in the rotational direction. Furthermore, the flange cover member 72 has a conical surface 72m for positioning the main body drive shaft 101 with respect to the flange cover member 72 in contact with the hemispherical shape 101c of the main body drive shaft 101 .

Also, the positioning portion does not have to be a conical depression like the conical surface 72m. When the diameter direction positioning part and the longitudinal direction positioning part are in contact with the tip (hemispherical shape 101c) of the main body drive shaft 101, only As long as the position of the photosensitive drum unit 30 can be determined with respect to the main body drive shaft 101, its shape is not required. These are suitable, for example, depressions (recesses) that narrow toward the bottom. As such, a pyramid shape other than a cone such as a pyramid (square pyramid, etc.) may be used. However, as long as it is a conical concave portion symmetrical to the axis of the coupling unit 28 like the conical shape 72m of the present embodiment, the position of the coupling unit 28 can be held particularly accurately.

In addition, the conical shape 72m may be any shape as long as it is a region for contact with the main body drive shaft 101, and the non-contact region may be any shape. For example, the portion not in contact with the main body drive shaft 101 does not need to have the bottom of the conical shape 72m, and the conical shape 72m may be a recess without a bottom.

The flange member 71 has a fitting portion 71d to the photoreceptor drum, and a flange portion 71e formed at an axial end portion of the fitting portion. Furthermore, the flange member 71 has the cylindrical part 71a extended in the axial direction from the flange part 71e. In the cylindrical portion 71a, an inner peripheral surface 71b through which the main body drive shaft 101 passes, and a bearing portion 71c supported by a bearing member are formed. The flange portion 71e is, as shown in FIG. 14 , a shape protruding outward in the radial direction from the fitting portion 71d. When the coupling unit 28 is assembled to the photosensitive drum 1 , the position of the photosensitive drum 1 and the coupling unit 28 in the Z direction is determined by contacting the end surface of the collar portion 71 e against the end surface of the photosensitive drum 1 .

The fitting portion 71d of the flange member 71 is pressed into the inner diameter of the cylinder of the photosensitive drum 1 as shown in FIG. 12 . Make the flange The member 71 presses the fitting portion 71d into the photosensitive drum 1 by entering into the inside of the cylinder until the collar portion 71e of the flange member 71 abuts against the end surface of the photosensitive drum in the axial direction. , so that the coupling unit 28 is correctly positioned on the photoreceptor drum 1 . Specifically, a dimension is employed such that the inner diameter of the cylinder of the photoreceptor drum 1 and the outer shape of the fitting portion 71 d are in a press fitting relationship.

In this way, after the flange member 71 is attached to the photosensitive drum 1, the flange member 71 and the photosensitive drum 1 are fixed by a temporary locking method. Specifically, in the groove (not shown) formed in the fitting portion 71d of the flange member 71, the end portion of the cylinder (cylinder) of the photoreceptor drum 1 is inserted into the portion where plastic deformation is made, and the photoreceptor is firmly bonded. The photoconductive drum 1 and the flange member 71. Here, the term "temporary locking" refers to an action of plastically forming and joining a part of a plurality of components.

Also, according to the fixing method of the temporary lock, as an example of the means for firmly fixing the flange member 71 on the photoreceptor drum 1, the inner diameter of the cylinder (cylinder) and the fitting portion 71d are fixed by adhesion, etc., using Other fixing means are also available.

The cylindrical part 71a of the flange member 71 has the bearing part 71c (shown in FIG. 4, FIG. 9) at the tip side (Z1 direction side) of the outer peripheral surface as mentioned above. In other words, the coupling unit has a bearing portion 71c having a cylindrical outer shape on the side in the Z1 direction (outside in the axial direction) of the engaging member. By employing such a shape, the engaging portion 65 a is not exposed to the outside of the cassette 7 . Therefore, the engaging portion 65a of the engaging member 65 can be protected by the photodrum unit bearing member 39R or the bearing portion 71c. In this way, it is possible to suppress the The user accidentally touches the engaging portion 65a, or prevents something from hitting the engaging portion 65a directly when the cassette 7 falls. In addition, as shown in FIG. 14, the inner peripheral surface 71b of the cylindrical portion 71 has a gradient shape 71g at the tip of the front side (Z1 direction). This gradient shape 71g is an inclined portion (inclined surface) for guiding the body drive shaft 101 inserted into the cylindrical portion 71 .

The elastic pushing member 66 is an elastic and stretchable compression coil spring, which resists the external force of the compression spring in the direction of contraction, and oppositely has the reaction force of the compression spring in the direction of extension. In addition, the spring pushing member 66, in addition to the compression coil spring of this embodiment, can be configured so as to apply a spring pushing force to the inside of the engagement member 65 in the radial direction. For example, a leaf spring or a torsion coil spring can also be used. Such an elastic push member (elastic member, spring member).

Alternatively, the push member 66 may be integrated with the engaging member 65 or the flange cover member 72 . However, in this embodiment, the push member 66 is configured as a separate body from the engaging member 65 or the flange cover member 72 . By doing so, the degree of freedom of selection of the pushing member 66 can be increased, and it is easy to select a suitable one as the pushing member 66 . For example, it is easy to select the snapping member 66 having an appropriate snapping force (elastic force) for the snapping engaging member 65 .

Regarding the coupling unit 28 configured as described above, the supporting structure of the engaging member 65 will be described in detail. Fig. 15 is a sectional view perpendicular to the axial direction of the coupling unit.

The first guided surface 65d and the second guided surface 65e of the engagement member 65 contact and are guided to the first guide surface 72d and the second guide surface 72e of the flange cover member 72, respectively. Next, as shown in FIG. 12 , the third guided surface 65f and the fourth guide surface 65g of the engagement member 65 respectively abut against and guide the third guide surface 72f and the fourth guide surface 72f of the flange cover member 72 . The leading surface is 72g. By the abutment of these guide surfaces, the engaging member 65 is guided and supported so as to be movable at least in the radial direction with respect to the flange cover member 72 . In short, the vector along the direction in which the engaging member 65 moves has at least a component in the diameter direction of the photodrum unit. In this embodiment, the engaging member 65 is movable almost parallel to the diametrical direction.

The engaging member 65 is pushed toward the radially inner side (first position) of the coupling unit 28 by the pushing member 66 . The push member 66 is compressed in a state where it is pinched by the abutting surface 65h of the engagement member 65 and the inner peripheral surface of the flange member 71, so the push force of the push member 66 in the direction in which the push member 66 extends pushes the card. Composite member 65.

The position of the engaging member 65 is regulated by contacting the position regulating surface 65j of the engaging member 65 with the regulating surface 72j of the flange cover member 72 against the elastic thrust force.

The engaging member 65 is supported by the flange cover member 72 in a state where the engaging portion 65 a of the engaging member 65 is exposed from the hole 72 a of the flange cover member 72 . In addition, the drive shaft abutting surface 65 c formed in an arcuate shape on the engagement member 65 is similarly exposed from the hole 72 a of the flange cover member 72 . The engaging portion 65 a of the engaging member 65 protrudes further inward in the radial direction from the inner peripheral surface of the hole portion 72 a of the flange cover member 72 .

The protrusion amount of the engaging portion 65a protruding from the drive shaft abutting surface 65c of the engaging member 65 is such that the engaging portion 65a surely enters the groove 101a of the drive shaft. Also, this amount of protrusion is only a snap that has to be formed in the The driving force receiving surface 65b of the portion 65a corresponds to the intensity of the load moment of the photosensitive drum unit 30 of the member to be rotated. In short, the driving force receiving surface 65 b of the engaging portion 65 a should only be able to stably transmit the driving force from the main body drive shaft 101 . In the case of this embodiment, if the distance from the inner surface of the flange cover member 72 to the tip of the engaging portion 65a is measured along the diameter direction of the coupling unit, the engaging portion 65a is defined so that the distance becomes 1 mm to 3 mm. the amount of prominence.

Also, the drive shaft abutting surface 65c of the engaging member 65 protrudes further radially inward from the inner peripheral surface of the hole portion (hollow portion) 72a of the flange cover member 72 . The protruding amount (exposed amount) of the driving shaft abutting surface 65c from the inner peripheral surface of the hole portion 72a, in the case where the dimensions of each part are uneven, the driving shaft abutting surface 65c can also be sure to protrude from the inner peripheral surface of the hole portion 72a. Those who stand out are better. In the present embodiment, the protrusion amount of the drive shaft contact surface 65c from the inner peripheral surface of the hole portion 72a is preferably 0.3 mm to 1 mm. In short, when the distance from the inner surface of the flange cover member 72 to the drive shaft abutting surface 65c is measured along the diameter direction of the coupling unit, the distance is 0.3 mm to 1 mm.

In this way, the engaging portion 65a and the drive shaft abutting surface 65c of the engaging member 65 are exposed through the hole portion 72a, and can be engaged with and abutted against the main body drive shaft 101 . The configuration in which the engaging member 65 is engaged with the main body drive shaft 101 to be driven and communicated will be described in detail later.

〔Installation of the cassette to the main body of the image forming device〕

Attachment and detachment of the process cassette 7 to the main body of the image forming apparatus will be described using FIG. 16, FIG. 17, FIG. 18, and FIG. 19.

FIG. 16 is a perspective view for explaining the installation of the cassette 7 to the image forming apparatus main body 100A.

17, 18, and 19 are cross-sectional views for explaining the installation operation of the cassette 7 to the image forming apparatus main body 100A.

The main body 100A of the image forming apparatus of the present embodiment is configured so that a cassette can be mounted in a substantially horizontal direction. Specifically, the image forming apparatus main body 100A has a space in which a cassette can be installed. Next, a cassette door 104 (front door) for inserting cassettes into the aforementioned space is provided on the front side of the image forming apparatus main body 100A (the direction in which the user stands during use).

As shown in FIG. 16 , the cassette door 104 of the main body 100A of the image forming apparatus is configured to be openable and closable. When the cassette door 104 is opened, the cassette lower guide rail 105 guiding the cassette 7 is arranged on the bottom surface of the space, and the cassette upper guide rail 106 is arranged on the upper surface. The cassette 7 is guided to the installation position by the upper and lower guide rails (105, 106) arranged above and below the space. The cassette 7 is inserted into the installation position roughly along the axis of the photosensitive drum unit 30 .

Hereinafter, attachment and detachment of the cassette to the image forming apparatus main body 100A will be described with reference to FIGS. 17 , 18 , and 19 .

As shown in FIG. 17 , when the cassette 7 is initially inserted, the photo-drum unit bearing member 39R and the photoreceptor drum 1 are not in contact with the intermediate transfer belt 5 . In other words, in a state where the end portion on the deep side in the insertion direction of the cassette 7 is supported by the cassette lower rail 105 , there is a dimensional relationship in which the photoreceptor drum 1 and the intermediate transfer belt 5 do not come into contact.

Next, as shown in FIG. 18 , the image forming apparatus main body 100A includes a deep cassette lower guide 107 protruding upward in the gravity direction from the cassette lower guide 105 on the deep side in the insertion direction of the cassette lower guide 105 . This deep-side cassette lower guide 107 has an inclined surface 107 a on the front side in the insertion direction of the cassette 7 . Accompanying the insertion, the cassette 7 is guided to the installation position astride the inclined surface 107a.

Also, the position and shape of the deep side cassette lower guide 107 may be set so that a part of the cassette does not slip against the image forming area 5A of the intermediate transfer belt 5 when the cassette is inserted into the device main body 100A. Here, the image forming area 5A refers to an area of the intermediate transfer belt 5 that holds the toner image transferred to the recording material 12 . In addition, in the present embodiment, among the cassettes maintaining the mounting posture, the unit bearing member 39R provided on the deep side in the insertion direction of the cassette 7 protrudes most upward in the direction of gravity. Therefore, it is only necessary to appropriately select the arrangement of the individual elements so that the track (hereinafter referred to as the insertion track) drawn by the end portion of the photo drum unit bearing member 39R on the deepest side in the insertion direction during insertion does not interfere with the image forming area 5A. and the shape can be.

Next, the cassette 7 is inserted into the deep side of the image forming apparatus main body 100A from the state of straddling the deep side cassette lower guide 107 . In this way, the photodrum unit bearing member 39R is in contact with the deep side cassette positioning portion 108 provided on the main body 100A of the image forming apparatus. At this time, the cassette 7 (photosensitive drum unit 30 ) is inclined by about 0.5° to 2° from the state ( FIG. 17( d )) when it has been mounted on the image forming apparatus main body 100A. In short, in the insertion direction of the cassette 7, it becomes the cassette 7 (photosensitive drum unit 30) A state in which the downstream side of the is more lifted than the upstream side.

FIG. 19 is a diagram showing the state of the device body and the cassette in a state where the cassette door 104 is closed. The image forming apparatus 100A has a front cassette lower guide 109 on the front side in the insertion direction of the cassette lower guide rail 105 . The front side cassette lower guide 109 is configured to move up and down in conjunction with the opening and closing of the cassette door (front door) 104 .

When the user closes the cassette door 104, the front cassette lower guide 109 rises. Next, the photodrum unit bearing member 39L abuts against the front cassette positioning portion 110 of the image forming apparatus main body 100A, and the cassette 7 is positioned with respect to the image forming apparatus main body 100A.

Through the above operations, the attachment of the cassette 7 to the image forming apparatus main body 100A is completed.

In addition, pulling out the cassette 7 from the main body 100A of the image forming apparatus is the reverse sequence of the insertion operation described above.

As mentioned above, since the oblique mounting structure is adopted, when the cassette 7 is mounted on the device main body 100A, the friction between the photoreceptor drum 1 and the intermediate transfer belt 5 can be suppressed. Therefore, it is possible to suppress the occurrence of minute scratches (scratches) on the surface of the photoreceptor drum 1 or the surface of the intermediate transfer belt 5 .

In addition, the configuration disclosed in this embodiment can simplify the configuration of the image forming apparatus main body 100A compared to the configuration in which the entire cassette is lifted after the cassette 7 is installed by moving the main body 100A in the horizontal direction.

〔The process of engaging the drive shaft of the coupling unit to the main body〕

Next, the process of engaging the coupling unit 28 and the main body drive shaft 101 will be described in detail using FIGS. 20 , 21 , 22 , 23 , 24 , 25 , and 26 .

20, 21, and 22 are sectional views for explaining the installation of the coupling unit 28 to the drive shaft 101 of the main body.

Figure 23 and Figure 24 are for explaining the coupling of the main body drive shaft 101 when the main body drive transmission groove 101a and the engaging portion 65 (driving force receiving surface 65b) are out of phase and start to rotate the main body drive shaft 101 when the phases are matched. A sectional view for the installation operation of the unit 28.

Fig. 25 is a cross-sectional view showing the relationship of forces acting on the engaging member.

Fig. 26 is a sectional view in the axial direction of the engagement surface showing the drive transmission between the engagement member and the drive shaft of the main body.

In addition, FIG. 21 and FIG. 23 are diagrams for explaining a state in which the main body drive transmission groove 101a and the engaging portion 65 (driving force receiving surface 65b) are out of phase.

Install the cassette 7 into the device body 100A as described above. In this way, along with the installation of the cassette, the hemispherical shape 101c formed at the tip of the main body drive shaft 101 and the inclined surface of the end face of the rough guide portion 101g formed on the main body drive shaft are pressed against by the coupling unit. catch. By this, the body drive shaft 101 is guided to the inner face 71b of the flange member 71 of the coupling unit.

FIG. 20 shows a state where the main body drive shaft 101 guided in this way abuts against the engaging member 65 of the coupling unit. Hemispherical shape of body drive shaft The shape 101c abuts against the insertion inclined surface 65k formed on the engagement member 65 .

From this state, a force is applied in the direction in which the cassette 7 is installed deeply. In this way, the force in the cassette installation direction is applied to the direction in which the engagement member 65 retracts radially outward (the second position) by inserting the inclined surface 65k. Therefore, the cassette 7 can be further moved to the depth of the device body in a state where the tip end of the body drive shaft 101 is in contact with the insertion inclined surface 65k.

Fig. 21 and Fig. 23 show the state in which the cassette 7 is moved deep and the installation of the cassette 7 to the device body 100A is completed. In this state, the hemispherical shape 101c of the main body drive shaft abuts against the conical surface 72m of the coupling unit, and the main body drive shaft 101 is positioned in the axial direction and the radial direction with respect to the coupling unit 28 .

The engaging member 65, as described above, guides the first, second, third, and fourth guided surfaces of the engaging member 65 by the first, second, third, and fourth guide surfaces of the flange cover member 72. In this way, the tip of the engaging portion retracts in the radial direction until it abuts against the outer peripheral surface of the shaft portion 101f of the drive shaft of the main body. At this time, as shown in FIG. 23 , the regulating surface 72j of the flange cover member is separated from the regulating surface 65j of the elastic thrust of the engaging member 65 . In addition, the pushing member 66 is in a shortened state further compressed than the state of FIG. 15 in which the main body drive shaft 101 is not inserted into the coupling unit 28 .

Thereafter, when the main body of the image forming apparatus is activated, or when the image forming operation starts, the main body drive shaft 101 rotates. In this way, as shown in FIGS. 22 and 24 , the engaging portion 65 a of the engaging member enters the groove 101 a of the main body drive shaft. Thereby, the drive shaft contact surface 65c of the engaging member The engagement member 65 moves to the inner side in the radial direction (the first position) until it comes into contact with the outer peripheral surface of the shaft portion 101f of the main body drive shaft. In addition, FIG. 24 shows a state where the position regulating surface 65j of the engaging member is also in contact with the regulating surface 72j of the flange cover member.

However, in order to make the drive shaft abutting surface 65c of the engagement member abut against the outer peripheral surface of the shaft portion 101f of the main body drive shaft more reliably, a certain gap is always set between the position limiting surface 65j and the limiting surface 72j. The dimensional relationship in an open state is preferable. In short, even if the dimensions are discrete, in the state where the drive shaft contact surface 65c of the engaging member is in contact with the outer peripheral surface of the shaft portion 101f of the drive shaft of the main body, a gap between the position regulating surface 65j and the regulating surface 72j will surely occur. gap.

Next, if the main body drive shaft 101 is rotated from the state shown in FIG. 24, as shown in FIG. The status of volume photodrum 1. As described above, the engaging portion 65 a of the engaging member is engaged with the main body drive shaft 101 .

In FIG. 22 , in the Z direction, the distance L1 from the front end surface of the cylindrical portion 71 to the front end surface of the engaging portion 65a is carried out so that the length L2 of the driving force receiving surface 65b becomes L1>L2. The engaging portion 65a is arranged.

As shown in FIG. 22 , the center 101h of the hemispherical shape 101c is arranged in the conical shape 72m so as to enter the range L2 of the driving force receiving surface 65b of the engaging member 65 in the Z direction. When the engaging portion 65a and the center 101h are projected onto the axis of the photodrum unit 30, the center of the center 101h is arranged inside the projected area L2 of the driving force receiving surface 65b of the engaging portion 65a. By establishing such an arrangement relationship, the following effects can be obtained.

As shown in FIG. 4 , FIG. 5 , and FIG. 19 , the photodrum unit bearing member 39R and the photodrum unit bearing member 39L are in contact with the deep cassette positioning portion 108 and the front cassette positioning portion 110 respectively. Accordingly, the position of the cassette 7 relative to the main body 100A of the image forming apparatus is determined. Here, the relative position of the body drive shaft 101 and the coupling unit 28 is affected by the tolerance of the parts. Specifically, the positions are shifted due to the tolerances of parts from the photodrum unit bearing member 39R to the coupling unit 28 , and the tolerances of parts from the deep side cassette positioning portion 108 to the main body drive shaft 101 .

As shown in FIG. 6 and FIG. 22 , the main body drive shaft 101 has a hemispherical shape 101c that interferes with the inverse conical shape 533a and is supported by two points of the bearing portion 101d and the hemispherical shape 101c. That is, the main body driving shaft 101 is viewed from the coupling unit 28, and the main body driving shaft 101 inclines the center 101h of the hemispherical shape 101c. The position at the same position as the center 101h in the Z-axis direction is the position least affected by this inclination. The driving force receiving surface 65b is arranged at the same position as the center 101h in the Z-axis direction, but it is also a position where the influence of positional displacement can be minimized. That is, it becomes a position where the photosensitive drum 1 can be stably driven.

Also, in this embodiment, a protrusion for receiving the driving force is provided on the side of the engaging member 65, but it is also possible to provide a groove for receiving the driving on the engaging member, and a groove for receiving the driving force may be provided on the side of the main body drive shaft 101 by moving the A movable protrusion that engages with the groove in the diameter direction. However, the image forming apparatus main body 100A requires higher durability than the cassette 7 . As in this embodiment, the movable It is preferable to provide the movable portion (engagement portion 65 ) in the radial direction on the side of the coupling unit 28 of the cassette 7 in order to improve the durability of the image forming apparatus main body 100A.

〔Driven by the coupling unit of the drive shaft of the main body〕

The configuration concerning the transmission of the rotational driving force to the coupling unit 28 will be described with reference to FIGS. 25 and 26 .

First, the supporting structure of the engaging member 65 at the time of coupling driving will be described in detail. As shown in FIG. 25 , when the main body drive shaft 101 is rotationally driven in the direction of the arrow R, the drive transmission surface 101b formed in the groove 101a of the main body drive shaft abuts against the driving force formed on the engaging portion 65a of the engaging member. On the receiving surface 65b, the force F acts on the normal direction of the driving force receiving surface 65b. When the driving force F acts on the driving force receiving surface, the first guided surface 65d of the engaging member is brought into contact with the first guiding surface 72d of the flange cover by this force. In addition, it is more preferable that the drive shaft abutting surface 65c of the engagement member abuts against the outer peripheral surface of the shaft portion 101f of the main body drive shaft. Thereby, the engaging member 65 is firmly supported between the flange cover member 72 and the main body drive shaft 101 .

Next, when the engaging member 65 generates force, the supporting structure of the engaging member 65 utilizing this force will be described.

The driving force receiving surface 65 b is inclined to the moving direction S of the engaging member 65 , and faces at least the outer side in the diameter direction. In short, the normal vector of the driving force receiving surface 65b (the vector extending perpendicular to the driving force receiving surface 65b toward the side facing the driving force receiving surface 65b) has an outward component in the radial direction of the coupling unit.

In other words, the inner side in the radial direction of the driving force receiving surface 65b (the front end side of the engaging portion 65a) is closer to the rotation direction of the photodrum unit than the outer side in the radial direction of the driving force receiving surface 65b (the rear end side of the engaging portion 65a ). on the upstream side.

When the driving force F is applied perpendicularly to the driving force receiving surface 65b of the engaging portion, the direction in which the driving force F is generated is inclined so as to be radially inward with respect to the circumferential direction (circumferential direction) of the coupling unit. In other words, if an imaginary circle passing through the driving force receiving surface 65b is drawn concentrically with the coupling unit, the line of the imaginary circle with respect to the driving force F is inclined so as to be radially inward.

Therefore, the driving force F can be decomposed into the force F1 of the line direction component (circumferential direction component, rotation direction component) along the line of the virtual circle mentioned above, and the force F2 which is the radial direction component toward the inner side of the radial direction.

By this force F2 acting on the driving force receiving surface 65b, the driving force receiving surface 65b of the engaging member is spring-pushed radially inward. Since the driving force receiving surface 65b can be restrained from moving radially outward, it is also possible to prevent the contact state between the driving force receiving surface 65b and the drive transmission surface 101b of the main body drive shaft from being released.

In addition, the direction of the force F acting in the normal direction on the driving force receiving surface is a direction inclined only by an angle θ relative to the movement direction S in which the flange cover member is guided radially inward so that the engaging member can move. Thus, the force F acting on the driving force receiving surface generates a component FS acting in the moving direction S of the engaging member as shown in FIG. 25( b ). By this force FS, the movement of the engaging member 65 to the opposite side of the moving direction S is prevented, It is possible to prevent the driving force receiving surface 65b of the engaging member from detaching from the driving transmission surface 101b of the drive shaft of the main body and falling to the outside. To briefly explain this, it can be said that the direction of the driving force receiving surface 65b is inclined toward the direction in which the driving force receiving surface 65b bites into the drive transmission surface 101b of the main body drive shaft with respect to the moving direction of the engaging member 65 .

In addition, it is more preferable that the drive shaft abutting surface 65c of the engagement member abuts against the outer peripheral surface of the shaft portion 101f of the main body drive shaft.

As shown in FIG. 25, the drive shaft contact surface 65c is provided on the side opposite to the direction of the drive force F with respect to the drive force receiving surface 65b. Thereby, the rotational moment M generated in the engagement member 65 by the force F acting on the driving force receiving surface is supported by the drive shaft contact surface 65c, and the engagement member 65 can be supported more firmly. The drive shaft contact surface 65c of the engagement member protrudes radially inward from the hole inner peripheral surface 72a of the flange cover member. Thereby, even when the dimensions of each part and the assembly accuracy vary, the drive shaft contact surface 65c can be reliably brought into contact with the outer peripheral surface of the drive shaft 101f. In short, it is preferable that at least a part of the drive shaft abutting surface 65c is arranged on the upstream side of the driving force receiving surface 65b in the rotational direction of the photodrum unit.

As described above, the engaging member 65 is firmly supported between the flange cover member 72 and the body drive shaft 101 . Thereby, the engaging member 65 is prevented from being detached or dropped from the main body drive shaft 101 , and the driving force from the main body drive shaft 101 can be stably transmitted to the engaging member 65 . Next, the driving stability of the photosensitive drum 1 can be improved, and the image quality can be improved.

Next, the axial direction of the driving force receiving surface 65b of the engaging portion will be described. tilt. FIG. 26 is a cross-sectional view of the engaging portion 65a of the engaging member taken along a plane extending along the normal direction of the driving force receiving surface 65b. In short, it is a sectional view cut in the direction of the arrow of the force F in FIG. 25 . Here, the body drive transmission surface 101b formed in the drive transmission groove 101a of the body drive shaft 101 abuts against the drive force receiving surface 65b formed in the engagement portion 65a of the engagement member, and the drive force of the body drive shaft 101 is transmitted to the engaging member 65 .

As mentioned above, the main body drive transmission surface 101b has a shape in which the axis of the coupling unit 28 is twisted at the center. In the sectional view of FIG. The driving force receiving surface 65b of the engaging portion is in contact with the main body drive transmission surface 101b, so it has a twisted shape as well, and the driving force receiving surface 65b is inclined with respect to the rotation axis of the main body drive shaft 101 . More specifically, the driving force receiving surface 65b is arranged on the outer side in the axial direction of the photodrum unit than on the inner side in the upstream side in the rotation direction of the photodrum unit.

Therefore, the force F in the normal direction acting from the main body drive transmission surface 101b to the drive force receiving surface 65b has a force F3 as a component in the direction of the rotation axis. That is, a force F3 for springing and pushing the engaging member 65 and the coupling unit 28 outward in the longitudinal direction of the photosensitive drum is generated. Thereby, it is possible to prevent force from being applied to the main body drive shaft 101 in a direction in which the coupling unit 28 deviates from the axial direction. Next, as shown in FIG. 21 , a force is generated to push the hemispherical shape 101c formed at the tip of the main body drive shaft in a direction in which the conical shape 72m formed on the flange cover member interferes. Thereby, the hemispherical shape 101c, which becomes the drive shaft of the main body, definitely interferes with the conical shape 72m of the flange cover member, For the coupling unit 28, a more correct positioning of the body drive shaft 101 can be achieved.

The driving force received by the driving force receiving surface 65 b is transmitted from the engaging member 65 to the flange cover member 72 . That is, the driving force is transmitted from the first guided surface 65 d of the engagement member 65 to the first guide surface 72 d of the flange cover member 72 . The first guide surface 72d is a transmitted portion to which the driving force is transmitted, and the flange cover member 72 is a transmitted member. In addition, the first guide surface 72d is also a backup portion that prevents the engaging portion 65a from moving to the downstream side in the rotation direction of the photodrum unit when a driving force is applied to the engaging member 65 . In addition, the first guided surface 65 d is a transmission portion for transmitting a driving force to the flange cover member 72 .

In addition, the first guide surface 72d is inclined with respect to the driving force receiving surface 65b. Therefore, the driving force F applied perpendicularly to the driving force receiving surface 65d has a component directed inward in the radial direction along the first guide surface 72d.

By the component of the driving force F, the engaging portion 65a is guided toward the radially inner side of the coupling unit 28 along the ground 1 guiding surface 72d. In short, the first guide surface 72d faces a direction in which the engaging portion 65a or the driving force receiving surface 65b is elastically pushed radially inward (that is, the deep side of the driving transmission groove 101a) when the driving force F is transmitted.

In FIG. 25 , when extending the wiring of the first guide surface 72d and the wiring of the driving force receiving surface 65d, the two wirings intersect at a radially outer side than the first guiding surface 72d or the driving force receiving surface 65d. way constituted.

In addition, in the rotational direction R of the photodrum unit, the radially inner side of the first guide surface 72d is arranged more downstream than the radially outer side (refer to FIG. 25).

The driving force transmitted from the engaging member 65 to the flange cover member 72 is transmitted to the photosensitive drum 1 through the flange member 71 . As a result, the photoreceptor drum 1 rotates together with the coupling unit 28 .

That is, as shown in FIG. 14 , the flange cover member 72 has a position regulating groove 72 l (an engaging portion, a recessed portion) for engaging with a convex portion provided on the flange member 71 . In addition, it also has a fitting surface 72k fitted to the inner periphery of the flange member 71 . The driving force is transmitted to the flange member 71 via these fitting surfaces 72k or the position regulating groove 72l. The flange member 71 is attached to the inner periphery of the photoreceptor drum 1 , so the flange member 71 finally transmits the driving force to the photoreceptor drum 1 .

In addition, the flange member 71 is provided with a convex portion, and the flange cover member 72 is provided with a concave portion (position regulating groove 72l) for engagement therewith, but the configuration is not limited to this. For example, the flange member 71 may be provided with a concave portion, and the flange cover member 72 may be provided with a convex portion engaged therewith, so that the driving force may be transmitted from the flange cover member 72 to the flange member 71 .

Also, as described above, by making the driving force receiving surface 65b a twisted surface, the optical drum unit 30 is spring-pushed outward in the axial direction when the driving force F is applied to the driving force receiving surface 65b. That is, when the driving force is applied to the driving force receiving surface 65b by the main body driving shaft 101, the photodrum unit 30 and the main body driving shaft 101 are configured to be drawn closer to each other. Also, the driving force receiving surface 65b may be configured as long as it has a function equivalent to that of a twisted surface, and does not necessarily have to have a twisted shape. The driving force receiving surface 65b may be any surface inclined in the direction in which the elastic thrust force Fc2 is generated with respect to the aforementioned driving force F, and the shape of the surface is, for example, Can be flat or curved.

In addition, as shown in FIG. 10 and FIG. 12 , on the flange member 71, for the radially inner spring force received by the spring push member 66 on the engaging member 65, there is provided a radially outer force spring that bears the reaction force thereof. 71 f of the abutment surface (spring push member abutment part) of a push member. The contact surface 71f is a pressing force receiving portion (an elastic thrust receiving portion) that is pressed/elastically pushed by an elastic pushing member. In addition, it is an elastic push member supporting part for supporting the elastic push member.

As shown in FIG. 12, the abutting surface 71f of the flange member 71 is disposed so that at least a part of the abutting surface 71f and a part of the photosensitive drum 1 are in the longitudinal direction of the photosensitive drum 1. overlapping positions. In short, when the abutting surface 71f and the photoreceptor drum 1 are perpendicularly projected on the axis of the photoreceptor drum, at least a part of the mutual projection area overlaps. Furthermore, in other words, at least a part of the contact surface 71f is arranged inside the photoreceptor drum 1 . In particular, in this embodiment, the entire contact surface 71 f is arranged inside the photosensitive drum 1 . This should be due to the following reasons.

The contact surface 71f of the flange member 71 is arranged on the thin-walled portion of the flange member in consideration of space in the radial direction. The photoreceptor drum 1, which is generally made of aluminum alloy, which has a higher strength than the flange member, bears the radially outward elastic force from the elastic member 66 generated on the abutment surface 71f, thereby suppressing Deformation of the periphery of the contact surface 71f of the flange member 71 . By suppressing the deformation of the flange member 71, the deformation of the bearing portion 71c formed on the flange member 71 for rotatably supporting the photosensitive drum 1 is suppressed, and the photosensitive drum can be rotatably supported with high precision. Body light drum1.

In order to arrange at least a part of the contact surface 71 f inside the photosensitive drum 1 , at least a part of the urging member 66 is arranged inside the photosensitive drum 1 .

More precisely, at least a part of the abutting portion (urging portion) of the urging member 66 abutting against the abutting surface 71 f is arranged inside the photosensitive drum 1 . Especially in this embodiment, the entirety of the urging member 66 is arranged inside the photosensitive drum 1 .

In addition, the engaging member 65 , or at least a part of the engaging portion 65 a and the driving force receiving surface 65 b is also disposed inside the photoreceptor drum 1 . In short, especially in this embodiment, the entire engagement member 65 is arranged inside the photosensitive drum 1 .

By arranging the movable engaging member 65 or the elastically deformable pushing member 66 inside the photoreceptor drum 1, it is not easy for the user's hands to touch these. It is also suitable for protecting the snapping member 65 or the snap-on member 66 .

In addition, disposing at least a part of the engaging member 65 inside the photoreceptor drum also has the following effects.

That is, if the engaging member 65 is disposed inside the photosensitive drum 1, when the cassette 7 is mounted on the device body, the shaft portion 101f formed with the driving transmission groove 101a also enters the inside of the photosensitive drum 1 (refer to Figure 8, Figure 9). Next, since the drive transmission shaft 101 is supported at two places, the bearing portion 101d and the shaft portion 101f, the farther the distance between the bearing portion 101d and the shaft portion 101f is, the more the inclination of the drive transmission shaft 101 to the photodrum unit is suppressed. appropriate. When the shaft portion 101f enters the photoreceptor drum 1, the device body can be kept compact, and the distance between the bearing portion 101d and the shaft portion 101f can be easily ensured.

〔Pull out the coupling unit from the drive shaft of the main body〕

10, FIG. 20, FIG. 21, and FIG. 22 will be used to describe the action of pulling out the coupling unit 28 from the main body drive shaft 101.

As shown in FIG. 10 , when the rotational drive of the main body drive shaft 101 is stopped, the driving force receiving surface 65 b is in contact with the main body drive transmission surface 101 b. In this state, the engaging portion 65a enters the main body driving communication groove 101a.

When the cassette 7 is initially removed from the main body 100A of the image forming apparatus, as shown in FIG. 22 , the inclined surface 65l for removal of the engagement portion 65a interferes with the removal gradient 101i on the main body side. When the inclined surface 65l is pulled out, because it interferes with the body-side pull-out gradient 101i, the spring pushing member 66 begins to shorten, so that the engaging member 65 moves radially outward along the body-side pull-out gradient 101i (the second position).

Furthermore, when the coupling unit 28 is pulled out from the main body drive shaft 101, it will be in the same state as in FIG. By moving the engaging portion 65 a to the outer diameter of the shaft portion 101 f , the coupling unit 28 can be pulled out from the main body drive shaft 101 .

Furthermore, when the coupling unit 28 is pulled out from the main body drive shaft 101, as shown in FIG. 20 and FIG. The connection position is limited to the state of the push direction.

Through the above actions, the coupling unit 28 can be pulled out from the main body drive shaft 101 .

Also, as described above, the driving force receiving surface 65 b has a twisted shape around the rotation axis of the flange member 71 . The twisting direction is from the outside (Z1 direction side) to the inside (Z2 direction side) of the photoreceptor drum unit 30 of the driving force receiving surface 65b, and is arranged on the upstream side of the rotation direction of the photoreceptor drum 1 .

If it is desired to remove the coupling unit 28 from the main body drive shaft 101 in this state, the driving force receiving surface 65b is arranged in a direction that hinders the removal operation. In short, as shown in FIG. 26, the outer side (Z1 direction side) of the driving force receiving surface 65b is arranged on the inner side (Z2 direction side) on the upstream side in the rotation direction, so the coupling unit 28 is pulled out from the main body drive shaft 101 by a pulling action. When I go, the unplugging load increases to the plugging load.

In contrast, the main body drive shaft 101 may be rotated in the reverse direction until the cassette 7 is pulled out from the image forming apparatus main body 100A while the rotation of the main body drive shaft 101 is stopped. Thereby, the cassette 7 can be pulled out from the image forming apparatus main body 100A after the driving force receiving surface 65b is released from abutting against the driving transmission surface 101b, so that the pulling load can be reduced.

As a method of reverse rotation, it can also be linked with the opening action of the cassette door 104, and the main body drive shaft 101 can be reversely rotated by a link mechanism, etc., and the motor of the driving source of the main body drive shaft 101 can be reversely rotated. .

In the embodiment described above, the functions related to the present invention are collectively described. and effects.

In this embodiment, since the engagement member 65 movable in the radial direction is provided in the coupling unit 28, it is not necessary to use a mechanism for retracting the main body drive shaft 101 in the axial direction, and the cassette 7 can be attached and detached well, and According to the driving transmission of the coupling unit 28 .

The engagement portion 65 a formed in the engagement member 65 protrudes radially inward from the hole portion 72 a of the coupling unit 28 . Thereby, the protection of the engagement part 65a can be achieved in the cassette 7 comprised detachably from 100 A of apparatus main bodies.

In addition, the driving force receiving surface 65b formed on the engaging portion extends radially inward. Therefore, after the engagement portion enters the groove portion 101a of the main body drive shaft, the driving force receiving surface 65b abuts against the drive transmission surface 101b formed in the groove portion 101a to perform good drive transmission.

In addition, when the coupling unit 28 is driven, the direction of the driving force F received by the driving force receiving surface 65b in the normal direction is directed toward the photoreceptor light with respect to the connection direction of an imaginary circle centered on the rotation axis of the photoreceptor drum 1 . The radially inner side of the drum 1 is inclined. Furthermore, the direction of the driving force F is inclined to the direction in which the engaging member 65 is movably guided so that the angle formed is an acute angle. This prevents force from being applied to the engagement member 65 outward in the radial direction, and prevents the driving force receiving surface 65b from detaching or falling off from the drive transmission surface 101b. At the same time, the driving force from the main body drive shaft 101 can be stably transmitted to the engagement member 65. . Next, the driving stability of the photosensitive drum 1 can be improved, and the image quality can be improved.

In addition, the engagement member 65 is provided with a shaft that abuts against the main body drive shaft. The drive shaft contact surface 65c on the outer peripheral surface of the portion 101f. Thereby, the rotational moment M generated in the engaging member 65 is supported by the drive shaft abutting surface 65c, and the engaging member 65 can be supported more firmly, thereby improving driving stability.

Further, the direction of the driving force F received by the driving force receiving surface 65b in the normal direction is inclined toward the outside in the longitudinal direction of the photosensitive drum 1 with respect to the direction of the rotation axis of the photosensitive drum 1 . Thereby, it is possible to prevent force from being applied to the main body drive shaft 101 in a direction in which the coupling unit 28 deviates from the axial direction.

In addition, in the engagement portion 65a, an insertion inclined surface 65k is formed at one end portion outside the longitudinal direction of the photosensitive drum 1, and an insertion inclined surface 65l is formed at the other end portion opposite to the end portion having the insertion inclined surface 65k. . Thereby, when the cassette is attached or detached, by abutting the insertion inclined surface 65k or the extraction inclined surface 65l against the groove 101a of the main body drive shaft, the cassette 7 can be attached and detached smoothly without being stuck.

In addition, at least a part of the abutting surface 71 f of the urging member provided on the flange member 71 is arranged at a position overlapping the longitudinal direction of the photosensitive drum 1 . The engagement member 65 receives a radially inner biasing force from the biasing member 66 , while the contact portion 71 f receives a radially outer force of the reaction force of the biasing force. By arranging the contact surface 71f inside the photosensitive drum 1 in this way, deformation of the bearing portion 71c formed on the flange member 71 can be suppressed, and the photosensitive drum 1 can be rotatably supported with high precision.

<Example 2>

The second embodiment will be described using Fig. 27 to Fig. 47 . Elements corresponding to the above-mentioned embodiments are given the same names, and explanations for the same points as the above-mentioned elements may be omitted. About these, it demonstrates centering on the difference from the above-mentioned element.

The coupling unit disclosed in the foregoing embodiments is a member that transmits a driving force for rotating the photosensitive drum 1 . However, in order to rotate members other than the photoreceptor drum 1, the aforementioned coupling unit can also be used.

As an example of such a configuration, the present embodiment discloses a coupling unit 4028 for transmitting a driving force for rotating the developing roller and the toner supply roller.

In addition, the photoreceptor drum 1, the developing roller 4017, and the toner supply roller 4020 are all rotating bodies configured to rotate while holding the developer (toner) on their surfaces.

[Overview of Electrophotographic Image Forming Device]

First, the overall configuration of an embodiment of an electrophotographic image forming apparatus (image forming apparatus) related to this embodiment will be described with reference to FIG. 27 .

Fig. 27 is a schematic cross-sectional view of an image forming apparatus 4100A of this embodiment.

As shown in FIG. 27, image forming apparatus 4100A has, as a plurality of image forming units, first, second, The third and fourth image forming units SY, SM, SC, and SK. In this embodiment, the first to the first 4. The image forming units SY, SM, SC, and SK are arranged in a row substantially in the horizontal direction.

Also, in this embodiment, the configuration and operation of the drum cassettes 4013 (4013Y, 4013M, 4013C, 4013K) are substantially the same except that the colors of the images to be formed are different. Similarly, the configuration and operation of each developing cartridge 4004 (4004Y, 4004M, 4004C, 4004K) are substantially the same except that the color of the formed image is different. That is, below, where there is no need to specifically distinguish, Y, M, C, and K will be omitted, and the photodrum cassette 4013 and the developing cassette 4004 will be collectively described.

In this embodiment, image forming apparatus 4100A has four cylinders (cylinders) having photosensitive layers (hereinafter referred to as photosensitive drums) arranged side by side in a direction slightly inclined to the vertical direction as a plurality of image carriers. 1. A scanner unit (exposure device) 3 is disposed below the drum cassette 4013 and the developing cassette 4004 in the direction of gravity. In addition, around the photosensitive drum 1, a charging roller 2 and the like are disposed as processing means (processing means, processing means) acting on the photosensitive layer.

The charging roller 2 is a charging means (charging device, charging member) for uniformly charging the surface of the photosensitive drum 1 . Next, the scanner unit (exposure device) 3 is an exposure means (exposure device, exposure member) for forming an electrostatic image (electrostatic latent image) on the photosensitive drum 1 by irradiating laser light based on image information. Around the photoreceptor drum 1, a cleaning blade 6 and a developing cartridge 4004 are arranged as cleaning means (cleaning means, cleaning member).

Furthermore, for the four photoreceptor drums 1, the work is arranged The intermediate transfer belt 5 is an intermediate transfer body for transferring the toner image on the photosensitive drum 1 to the recording material (sheet, recording medium) 12 .

In the developing cartridge 4004 of this embodiment, a non-magnetic single-component developer (hereinafter referred to as toner) is used as a developer, and a contact method in which the developing roller 4017 as a developer carrier is brought into contact with the photosensitive drum 1 is adopted. Developing method.

In the aforementioned configuration, the toner image formed on the photoreceptor drum 1 is transferred to the sheet (paper) 12, and the toner image transferred to the sheet is fixed. In addition, as processing means acting on the photosensitive drum 1 , the photosensitive drum cassette 4013 includes a charging roller 2 for charging the photosensitive drum 1 , and cleaning of remaining toner that has not been transferred to the photosensitive drum 1 . The cleaning scraper 6. The transfer residual toner remaining on the photoreceptor drum 1 without being transferred onto the sheet 12 is collected by the cleaning blade 6 . In addition, the residual transfer toner recovered by the cleaning blade 6 is stored in the removed developer storage portion (hereinafter referred to as the waste toner storage portion) 4014a through the opening 4014b. The waste toner storage portion 4014a and the cleaning blade 6 constitute an integrated photodrum cassette (photoreceptor unit, photodrum unit, image carrier unit) 4013 .

In addition, image forming apparatus 4100A includes guides (positioning means) such as attachment guides and positioning members (not shown) in the main body housing. The developing cassette 4004 and the photoconductive drum cassette 4013 are guided by the above-mentioned guides, and are constructed so as to be detachable from the image forming apparatus main body 4100A.

Toners of yellow (Y), magenta (M), cyan (C) and black (K) are stored in the developing cartridges 4004 for each color.

The intermediate transfer belt 5 abuts against each photoconductive drum cassette 4013 tools The prepared photosensitive drum 1 rotates (moves) in the direction of arrow B in FIG. 1 . The intermediate transfer belt 5 is stretched over a plurality of supporting members (a driving roller 51 , a secondary transfer counter roller 52 , and a driven roller 53 ). On the inner peripheral surface side of the intermediate transfer belt 5 , four primary transfer rollers 8 are arranged side by side as primary transfer means so as to face the respective photosensitive drums 1 . In addition, a secondary transfer roller 9 as a secondary transfer means is disposed on the outer peripheral surface side of the intermediate transfer belt 5 at a position facing the secondary transfer counter roller 52 .

When forming an image, first, the surface of the photosensitive drum 1 is uniformly charged by the charging roller 2 . Then, the surface of the charged photosensitive drum 1 is scanned and exposed by the laser light corresponding to the image information emitted by the scanner unit 3 . Thereby, an electrostatic latent image corresponding to image information is formed on the photosensitive drum 1 . The electrostatic latent image formed on the photosensitive drum 1 is developed as a toner image by the developing cartridge 4004 . The toner image formed on the photosensitive drum 1 is transferred (primary transfer) to the intermediate transfer belt 5 by the action of the primary transfer roller 8 .

For example, when forming a full-color image, the aforementioned processing is sequentially carried out in the four drum cassettes 4013 (4013Y, 4013M, 4013C, 4013K) and the developing cassette 4004 (4004Y, 4004M, 4004C, 4004K). Next, the toner images of the respective colors formed on the photosensitive drums 1 of the respective drum cassettes 4013 are sequentially primary-transferred so as to overlap on the intermediate transfer belt 5 . Thereafter, the recording material 12 is conveyed to the secondary transfer unit in synchronization with the movement of the intermediate transfer belt 5 . Next, the four-color toner images on the intermediate transfer belt 5 are collectively transferred onto the recording material 12 conveyed to the secondary transfer section formed by the intermediate transfer belt 5 and the secondary transfer roller 9 .

The recording material 12 to which the toner image has been transferred is conveyed to a fixing device 10 as a fixing means. The fixing device 10 fixes the toner image on the recording material 12 by applying heat and pressure to the recording material 12 . In addition, the primary transfer residual toner remaining on the photosensitive drum 1 after the primary transfer step is removed by the cleaning blade 6 and recovered as waste toner. In addition, the secondary transfer residual toner remaining on the intermediate transfer belt 5 after the secondary transfer step is removed by the intermediate transfer belt cleaning device 11 .

In addition, image forming apparatus 4100A may use a single or several (not all) image forming units as desired to form monochrome or multicolor images.

〔Overview of handling cassettes〕

Next, the drum cassettes 4013 (4013Y, 4013M, 4013C, 4013K) and the developing cassettes 4004 (4004Y, 4004M, 4004C, 4004K) summary.

Also, the drum cassette 4013Y, the drum cassette 4013M, the drum cassette 4013C, and the drum cassette 4013K have the same configuration. In addition, the development cassette 4004Y for storing yellow toner, the development cassette 4004M for storing magenta toner, the development cassette 4004C for storing cyan toner, and the development cassette 4004K for storing black toner have the same configuration. That is, in the following description, the drum cassettes 4013Y, 4013M, 4013C, and 4013K are collectively referred to as the drum cassette 4013 , and the developing cassettes 4004Y, 4004M, 4004C, and 4004K are collectively referred to as the developing cassette 4004 . The same applies to each cassette constituent member as a whole called for explanation.

FIG. 28 is a perspective view of the appearance of the drum cassette 4013. Here, as shown in FIG. 28, the rotation axis direction of the photoreceptor drum 1 is taken as the Z direction (arrow Z1, arrow Z2), and the horizontal direction of FIG. 27 is taken as the X direction (arrow X1, arrow X2). The vertical direction is taken as the Y direction (arrow Y1, arrow Y2).

Photodrum unit bearing members 4039R and 4039L are mounted on both sides of the cleaning frame 4014, respectively, and support the photosensitive drum unit 4030, respectively. Accordingly, the photosensitive drum unit 4030 is rotatably supported by the cleaning frame 4014 .

In addition, the charging roller 2 and the cleaning blade 6 are attached to the cleaning frame 4014 , and these are arranged so as to be in contact with the surface of the photosensitive drum 1 . In addition, the charging roller bearing 15 is attached to the cleaning frame 4014 . The charging roller bearing 15 is a bearing for supporting the shaft of the charging roller 2 .

Here, the charging roller bearings 15 ( 15R, 15L) are mounted so as to be movable in the direction of arrow C shown in FIG. 29 . The rotating shaft 2 a of the charging roller 2 is rotatably attached to the charging roller bearings 15 ( 15R, 15L). Next, the charging roller bearing 15 is urged toward the photosensitive drum 1 by the pressure spring 16 as the urging means. Thereby, the charging roller 2 comes into contact with the photosensitive drum 1 and rotates along with the photosensitive drum 1 .

The cleaning frame 4014 is provided with a cleaning blade 6 as cleaning means for removing toner remaining on the surface of the photoreceptor drum 1 . The cleaning scraper 6 is in contact with the photoreceptor drum 1 to remove the carbon on the photoreceptor drum 1 Powdered scraper-like rubber (elastic member) 6a is integrated with support plate 6b supporting it. In this embodiment, the support plate 6b is fixed on the cleaning frame 4014 by screws.

As mentioned above, the cleaning frame 4014 has an opening 4014b for recovering the transfer residual toner collected by the cleaning blade 6 . The opening 4014b is provided with a blow-out prevention plate 26 that is in contact with the photosensitive drum 1 and sealed between the photosensitive drum 1 and the opening 4014b to prevent leakage of toner in the upper direction of the opening 4014b.

FIG. 30 is a perspective view of the appearance of the developing cassette 4004.

The development cassette 4004 has a development frame 4018 that supports various elements. The developing cartridge 4004 is provided with a developing roller 4017 as a developer carrier that is in contact with the photoreceptor drum 1 and rotates in the arrow D direction (counterclockwise direction) shown in FIG. 31 . The developing roller 4017 is rotatably supported by the developing frame 4018 via developing bearings 4019 (4019R, 4019L) at both ends in the longitudinal direction (rotation axis direction). Here, the developing bearings 4019 (4019R, 4019L) are attached to both sides of the developing frame 4018, respectively.

In addition, the development cartridge 4004 has a developer storage chamber (hereinafter referred to as a toner storage chamber) 4018a and a development chamber 4018b in which a development roller 4017 is disposed, as shown in FIG. 31 .

In the developing chamber 4018b, a developing blade of a developer restricting member for restricting the toner layer of the developing roller 4017 and the toner supplying roller 4020, which is a developer supplying member that is in contact with the developing roller 4017 and rotates in the direction of arrow E, is disposed. plate 21. The developing blade 21, by performing the fixing member 22 Fixed and integrated by welding and so on.

In addition, in the toner storage chamber 4018 a of the developing frame 4018 , an agitating member 23 for agitating the stored toner and conveying the toner to the toner supply roller 4020 is provided.

〔Configuration of the drive shaft of the main body〕

The structure of the main body drive shaft 4101 is demonstrated using FIG.32, FIG.33.

FIG. 32 is an outline view of the main body drive shaft 4101.

Fig. 33 is a sectional view cut along the rotation axis (rotation axis) of the main body drive shaft 4101 in a state where the main body of the image forming apparatus is installed.

As shown in Fig. 32, the main body drive shaft 4101 is composed of a gear member 4101e, an intermediate body 4101p, an output member 4101q, and a drive transmission member 4101r.

A motor (not shown) as a driving source is provided in the image forming apparatus main body 4100A. The gear member 4101e is rotationally driven by this motor, the intermediate body 4101p, the output member 4101q, and the drive transmission member 4101r are sequentially driven, and the main body drive shaft 4101 rotates. In addition, the gear member 4101e, the intermediate body 4101p, and the output member 4101q have the mechanism of the Oldham coupling, and can move a certain distance in the X direction and the Y direction. Therefore, the drive transmission member 4101r provided on the cassette side of the main body drive shaft 4101 via the Oldham coupling can also move a certain distance in the X direction and the Y direction. Next, the drive transmitting member 4101r has The rotatable shaft portion 4101f transmits the rotational driving force received by the motor to the developer cartridge 4004 side through a groove-shaped drive transmission groove 4101a (recess, drive transmission portion) provided on the shaft portion 4101f. In addition, the shaft portion 4101f has a conical shape 4101c at its tip.

The main body drive communication groove 4101a is shaped so that the engaging portion 4065a described later can enter. Specifically, it includes a main body drive transmission surface 4101b as a surface that transmits a driving force in contact with a driving force receiving surface (driving force receiving portion) 4065b of the coupling unit 4028 .

In addition, as shown in FIG. 32 , the main body drive transmission surface 4101b is not a flat surface, but has a twisted shape at the center of the rotation axis of the main body drive shaft 4101 . The twisting direction is from the Z1 direction side of the main body drive shaft 4101 to the Z2 direction side, and is arranged upstream in the rotation direction of the main body drive shaft 4101 . In this embodiment, the amount of twist along the rotation axis of the cylinder of the engaging portion 4065 a is about 1° per 1 mm. The reason for taking the shape of the twisted body drive transmission surface 4101b will be described in detail later.

In addition, on the Z2-direction side surface of the main body drive communication groove 4101a, a main body side pulling gradient 4101i is provided. The body-side pull-out gradient 4101i is a gradient (inclined surface, sloped portion) for assisting the pull-out of the engagement portion 4065b from the driving transmission groove 4101a when the developing cassette 4004 is detached from the apparatus body 4100A.

As shown in FIG. 33 , the bearing portion 4101d provided on the gear member 4101e is rotatably supported (bolted) by the bearing member 4102 provided on the image forming apparatus main body 4100A. Next, the output member 4101q, The coupler holder 4101s is rotatably supported. In addition, the drive transmission member 4101r is supported by the output member 4101q so as to be movable in the Z direction, and is pushed by the spring member 4103 to the developing cartridge 4004 side (Z2 direction). However, the movable amount (play) in the Z direction of the drive transmission member 4101q is about 1 mm, which is sufficiently smaller than the Z direction width of the driving force receiving surface 4065a described later.

Further, the coupler holding frame 4101s is pushed in approximately the Y2 direction by the push spring 4101t. Therefore, as will be described later, when the developing cartridge 4004 is mounted, the axis of the drive transmission member 4101r relative to the gear member 4101e is located at a position substantially shifted in the Y2 direction.

As described above, the drive transmission member 4101r is provided with the main body drive transmission groove 4101a, and the coupling unit 4028 is provided with the engaging portion (protrusion, protruding portion) 4065a, and the drive is transmitted from the device main body 4100A to the developing cartridge 4004. When the driving force is transmitted to the coupling unit 4028, the developing roller or the supply roller rotates.

The details will be described later, but the engaging portion 4065a is formed on an engaging member (sliding member, moving member, driving force receiving member) 4065 that is movable in a state of being pushed by an urging member. Therefore, the engaging portion 4065a is configured to be movable at least radially outward when the developing cartridge 4004 is mounted on the apparatus main body 4100A. Thereby, as the developing cartridge 4004 is inserted into the device main body 4100A, the engaging portion 4065a enters the driving transmission groove 4101a, and the engaging portion 4065a can engage with the main body driving transmission groove 4101a.

〔Composition of the coupling unit〕

Next, the coupling unit 4028 of this embodiment will be described in detail using FIG. 34 , FIG. 35 , FIG. 36 , FIG. 37 , FIG. 38 , and FIG. 39 .

FIG. 34 is a perspective view of installing the coupling unit 4028 on the toner supply roller 4020 .

Figure 35 is a perspective view of the engaging member 4065, Figure 35(a) is a perspective view seen from the upper left, and Figure 35(b) is a perspective view seen from the upper right.

FIG. 36 is a perspective view of members constituting the coupling unit 4028 .

FIG. 37 is a perspective view of the coupling unit 4028 and the toner supply roller 4020 .

FIG. 38 is a cross-sectional view of a state where the coupling unit 4028 is engaged with the drive transmission member 4101r.

FIG. 39 is a sectional view of the developing cassette 4004.

The coupling unit 4028 of this embodiment is different from the coupling unit 28 of the first embodiment in that the driving member is the toner supply roller 4020, and the others have similar configurations.

In the coupling unit 4028, as shown in FIG. 34, three engaging portions 4065a that engage with the drive transmission member 4101r are provided. This engagement portion 4065a is fitted into the groove portion 4101a of the drive transmission member 4101r as shown in FIG. 38 to perform drive transmission.

Hereinafter, the configuration of the coupling unit (coupling member) 4028 will be specifically described. Coupling unit 4028, as shown in the perspective view of Figure 36, or the cross-section of Figure 38 As shown in the figure, it is composed of a coupling cover member 4071 , a coupling clamping frame member 4072 , an engaging member 4065 , and a spring pushing member 4066 .

The coupling covering member 4071 is a cylindrical member having a hollow portion, and the coupling holder 4072 is disposed in the inner space of the coupling covering member 4071 .

The coupling holder 4072 is a holding member for slidably holding the engaging member 4065 .

As shown in FIG. 38 , the engaging member 4065 having the engaging portion 4065 a is supported in the coupling unit 4028 in a state of being elastically pushed by the urging member 4066 toward the inner side of the coupling unit 4028 in the radial direction.

As shown in FIG. 35 , the engagement member 4065 has a first guided surface 4065d and a second guided surface 4065e in such a manner that it is movably guided in the coupling unit. Moreover, it has the 3rd to-be-guided surface 4065f and the 4th guide surface 4065g for regulating the position of the engaging member 4065 in an axial direction.

Similar to Embodiment 1, the first to fourth guided surfaces (4065d, 4065e, 4065f, 4065g) are guided to the guided portion of the coupling holder 4072, and are also limited by the coupling holder 4072. The restricted position part (restricted part) of the position. The coupling clamping frame 4072 has the first to fourth guiding surfaces corresponding to the first to fourth guided surfaces as in the first embodiment.

The engagement member 4065 has an abutment surface (portion to be pushed, surface to be pressed) 4065h for receiving the push force generated by the push member 4066 . In addition, the engaging member 4065 is coupled with the spring force of the spring pushing member 66. The holder member 4072 abuts, has a position limiting protrusion 4065i for limiting the position of the engaging member 4065, and an elastic thrust position limiting surface 4065j formed on the position limiting protrusion. Similar to Embodiment 1, the elastic thrust position limiting surface 4065j is a locked portion that is limited/locked by the coupling clamp member 4072 and moves radially inward.

Furthermore, the engaging member 4065 has an insertion inclined surface 4065k.

The coupling holder member 4072 has a coupling hole 4072a through which the drive transmission member 4101r passes, and an attachment hole 4072b for supporting the engagement member 4065 movably in the radial direction.

The coupling cover member 4071 has a cylindrical shape as shown in FIG. 36 and is attached to an outer peripheral surface 4072k of the coupling holder member 4072 .

The elastic pushing member 4066 is an elastic stretchable elastic member (compression coil spring). For the external force of the compression spring in the direction of contraction, there is a reaction force of the compression spring in the direction of extension on the contrary.

The engaging member 4065 is pushed toward at least the inner side (the inner side in the radial direction) of the coupling unit 4028 by the pushing member 4066 . The push member 4066 is compressed under the state of being pinched by the abutting surface 4065h of the engaging member 4065 and the inner peripheral surface of the coupling cover member 4071, so the push card is pushed by the push force of the push member 4066 in the extending direction. Composite member 65.

The engaging member 4065 is supported by the coupling holder member 4072 in a state where the engaging portion 4065 a of the engaging member 4065 is exposed from the hole 4072 a of the coupling holder member 4072 . In addition, the drive shaft abutting surface 4065c of the engaging member 4065 formed in an arc shape is similarly formed by The hole portion 4072a of the coupling holder member 4072 is exposed.

The engaging portion 4065a of the engaging member 4065 protrudes further inward in the radial direction from the inner peripheral surface coupled to the hole portion 4072a of the holder member 4072 . The amount of protrusion is such that the engaging portion 4065a surely enters the groove 4101a of the drive shaft. In addition, this amount of protrusion is only the strength of the driving force receiving surface 4065b formed on the engaging portion 4065a corresponding to the load moment of the toner supply roller 4020 of the rotating member. By setting the amount of protrusion in this way, it is only necessary that the engaging portion 4065a can stably transmit the driving force from the main body drive shaft 4101 .

In this embodiment, the protrusion amount of the engaging portion 4065a is preferably 1 mm to 3 mm. In short, when the distance from the inner surface of the coupling holder member 4072 to the tip of the engaging portion 4065a is measured along the diameter direction of the coupling member, the distance is 1 mm to 3 mm.

Also, the drive shaft contact surface 4065c of the engagement member 4065 protrudes further inward in the radial direction from the inner peripheral surface of the hole portion 4072a of the flange cover member 4072 in the same manner. The protrusion amount is preferably 0.3 mm to 1 mm in this embodiment so that the drive shaft abutting surface 4065c protrudes from the inner peripheral surface of the hole portion 4072a even if the dimensions of each part are uneven.

In addition, in the coupling holder member 4072, as shown in FIG. 37, a hole portion 4072h through which the shaft portion (shaft) 4020a of the toner supply roller 4020 is passed is formed. The toner supply roller 4020 and the coupling unit 4028 rotate integrally by the stop shape formed in the hole portion 4072h and the shaft portion 4020a. In short, in this embodiment, different from Embodiment 1, the coupling unit 4028 is fixed to the shaft (shaft portion 4020a) of the rotating body (toner supply roller). The coupling unit 4028 is arranged coaxially with the toner supply roller 4020 .

Also, the distance from the axis (center) of the coupling unit 4028 to the driving force receiving portion (driving force receiving surface 4065b) is longer than the radius of the shaft portion 4020a. By doing so, the load moment required to rotate the shaft portion 4020a of the toner supply roller 4020 can be made smaller than the force applied to the driving force receiving surface 4065b.

Also, as shown in FIG. 39, the toner supply roller 4020 has a gear 4098 on the opposite side (non-driving side) to the driving side to which the coupling unit 4028 is mounted. This gear meshes with a gear 4099 attached to the shaft of the developing roller 4017 .

When the toner supply roller 4020 is rotated by the driving force transmitted from the coupling unit 4028, the developing roller 4017 is also rotated by the aforementioned two gears.

〔Installation of the cassette to the main body of the image forming device〕

Using Fig. 40, Fig. 41, Fig. 42, and Fig. 43, the attachment and detachment of the developing cassette 4004 to the main body of the image forming apparatus will be described.

FIG. 40 is a perspective view for illustrating the installation of the developer cassette 4004 to the image forming apparatus main body 4100A.

41, 42, and 43 are cross-sectional views for explaining the mounting operation of the developer cassette 4004 to the image forming apparatus main body 4100A.

The image forming apparatus main body 4100A of this embodiment adopts The development cassette 4004 and the photo drum cassette 4013 are installed approximately horizontally. Specifically, the image forming apparatus main body 4100A has a space in which the developing cassette 4004 and the photo drum cassette 4013 can be installed. Next, there is a cassette door 4104 (front door) on the front side of the image forming apparatus body 4100A (the direction in which the user stands during use) for inserting the developing cassette 4004 and the photoconductive drum cassette 4013 into the aforementioned space.

As shown in FIG. 40 , the cassette door 4104 of the main body 4100A of the image forming apparatus is configured to be openable and closable. When the cassette door 4104 is opened, the cassette lower guide rail 4105 guiding the development cassette 4004 is arranged on the bottom surface of the space, and the cassette upper guide rail 4106 is arranged on the upper surface. The developing cassette 4004 is guided to the installation position by the upper and lower guide rails (4105, 4106) arranged above and below the space. The developing cartridge 4004 is inserted into the installation position approximately along the axis of the developing roller 4020 .

Next, the attachment and detachment of the developer cassette 4004 to the image forming apparatus main body 4100A will be described with reference to FIGS. 41, 42, and 43. FIG.

As shown in Figure 41, the development cassette 4004 is supported/guided by the lower end of the deep side in the insertion direction as the lower guide rail 4105 of the cassette, and the upper end of the deep side in the insertion direction is the upper guide rail 4016 of the cassette (not shown in the figure). shown) is inserted. At this time, the developing frame 4018 and the developing bearing 4019 have a dimensional relationship in which the intermediate transfer belt 5 does not come into contact with each other.

Next, as shown in FIG. 42 , the developing cassette 4004 is inserted horizontally while being supported by the lower cassette guide rail 4105 until it reaches the deep side cassette positioning portion 4108 provided on the image forming apparatus body 4100A.

In addition, when the development cassette 4004 is mounted, the drive transmission member 4101r of the image forming apparatus main body 4100A is engaged with the coupling unit 4028 in a state of being pushed in the roughly Y2 direction as described above.

FIG. 43 is a diagram showing a state of the image forming apparatus main body 4100A and the developing cassette 4004 in a state where the cassette door 4104 is closed. The lower cassette rail 4105 of the image forming apparatus main body 4100A is configured to move up and down in conjunction with the opening and closing of the cassette door (front door) 4104 .

When the user closes the cassette door 4104, the cassette lower rail 4105 rises. Next, both ends of the developing cassette 4004 abut against the cassette positioning portion (4108·4110) of the image forming apparatus main body 4100A, and the developing cassette 4004 is positioned against the image forming apparatus main body 4100A. In addition, the drive transmission member 4101r of the image forming apparatus main body 4100A also rises following the developing cartridge 4004 .

Through the above operations, the attachment of the developing cassette 4004 to the image forming apparatus main body 4100A is completed.

In addition, pulling out the developing cartridge 4004 from the main body 4100A of the image forming apparatus is the reverse sequence of the aforementioned inserting operation.

〔The process of engaging the drive shaft of the coupling unit to the main body〕

Next, the engaging process of the coupling unit 4028 and the main body drive shaft 4101 will be described in detail using FIG. 44 , FIG. 45 , FIG. 46 , and FIG. 47 .

Fig. 44, Fig. 45, Fig. 46 and Fig. 47 are sectional views for explaining the installation action of the coupling unit 4028 to the main body drive shaft 4101.

Figure 44 shows that the coupling unit 4028 starts to communicate with the drive A diagram of the engaged state of member 4101r. In addition, FIG. 47 shows a state in which the developing cassette 4004 is installed in the image forming apparatus main body 4100A. In particular, FIG. 47 shows a state in which the cassette lower rail 4105 is raised as the cassette door 4104 is closed, and the developing cassette 4004 is positioned with respect to the image forming apparatus main body 4100A.

Here, Fig. 45 and Fig. 46 are diagrams for explaining the installation process of the coupling unit 4028 and the drive transmission member 4101r between Fig. 44 and Fig. 47 . Also, the drive transmission member 4101r is pushed in the roughly Y2 direction by the spring 4101t, and the axis of the drive transmission member 4101r is pushed until it is offset from the axis of the coupling unit 4028 in the Y2 direction.

In the development cassette 4004 , as described using FIG. 40 , the image forming apparatus main body 4100A is inserted in the horizontal direction while being supported by the cassette lower rail 4105 .

FIG. 44 is a diagram showing a state before the driving transmission member 4101r is engaged with the coupling unit 4028 . As mentioned above, in this state, the axis of the drive transmission member 4101r is deviated from the axis of the coupling unit 4028 . Therefore, first, the inclined surface 4072p of the coupling unit 4028 formed at the entrance of the hole 4072a of the coupling holder member 4072 comes into contact with the conical shape 4101c of the drive transmission member 4101r.

As shown in FIG. 45, from FIG. 44, the coupling unit 4028 is inserted toward the deep side of the drive transmission member 4101r. In this way, the conical shape 4101c of the drive transmission member 4101r is guided on the insertion inclined surface 4065k of the engagement member 4065, and the axis of the coupling unit 4028 is aligned with the drive transmission. The axes of the members 4101r are approximately the same.

As shown in FIG. 46, from FIG. 45, the coupling unit 4028 is inserted toward the deep side of the drive transmission member 4101r. In this way, the coupling unit 4028 is inserted into the driving transmission member 4101r until the pull-out inclined surface 4065l of the engaging member 4065 is closer to the deep side in the Z direction than the body-side pull-out gradient 4101i of the drive transmission member 4101r.

Furthermore, the coupling unit 4028 is inserted into the drive transmission member 4101r. In this way, the conical recess 4072m formed in the positioning portion of the coupling holder member 4072 of the coupling unit 4028 comes into contact with the conical shape 4101c of the drive transmission member 4101r.

Thereafter, as described above, when the developing cassette 4004 is lifted up by the cassette lower guide rail 4105, the developing cassette 4004 becomes a state of being positioned relative to the image forming apparatus body 4100A (as shown in FIG. 43 ). At this time, as shown in FIG. 47 , the drive transmission member 4101 r is also raised along with the raising of the developing cartridge 4004 .

As described above, as the developing cassette 4004 is attached to the apparatus main body 4100A, the main body drive communication groove 4101a and the engaging portion 4065a are brought into an engageable state. Therefore, there is no need to move the main body drive shaft 4101 to engage with the coupling unit 4028 . In short, there is no need to provide a mechanism for moving the main body drive shaft 4101 so as to engage with the coupling unit 4028 on the device main body 4100A of the image forming apparatus.

In short, there is no mechanism for moving the main body drive shaft 4101 so as to engage with the coupling unit 4028 after the developing cassette 4004 is installed in the image forming apparatus 4100A.

Also, when the developing cartridge 4004 is mounted on the device main body 4100A, the engagement member 4065 of the coupling unit 4028 retracts radially outward (second position) by contacting the main body drive shaft 4101 . Next, when the engaging member 4065 moves radially inward (first position), it is configured to engage with the groove of the main body drive shaft 4101 (main body drive communication groove 4101a).

Here, a groove for receiving driving may be provided on the coupling unit side, and a movable protrusion capable of engaging with the groove by moving in the radial direction may be provided on the main body drive shaft 4101 side. However, the image forming apparatus main body 4100A requires higher durability than the developing cartridge 4004 . It is preferable to provide the movable portion (engagement member 4065 ) movable in the radial direction on the side of the coupling unit 4028 of the developing cartridge 4004 as in this embodiment, because it improves the durability of the image forming apparatus main body 4100A.

Also, the engagement member 4065 provided in the coupling unit 4028 of this embodiment has almost the same configuration as that provided in the coupling unit 28 described in the first embodiment. In short, the coupling unit 4028 of this embodiment is a partly modified configuration in which the coupling unit 28 described in the first embodiment is applied to the developing cartridge (developing device) 4004 . Therefore, the coupling unit 4028 of this embodiment also has the same functions and effects related to the present invention as the coupling unit 28 described in the first embodiment.

Also, the configuration of the coupling unit shown in this embodiment may be used as a coupling unit for rotating the photosensitive drum 1 .

<Example 3>

A third embodiment will be described using FIGS. 48 to 50 . This implementation For example, compared to the aforementioned embodiments, the shape of the engaging portion of the engaging member is different. The description will focus on the shape of this engaging portion.

In addition, the present embodiment is described by taking the coupling unit provided in the photoconductive drum cassette as an example in the same manner as in the first embodiment, but it can also be used for the coupling unit provided in the developing cassette.

[Engaging part of engaging member]

Fig. 48(a) and Fig. 48(b) are perspective views of the engaging member 5065 of this embodiment, and Fig. 48(c) is a front view. Fig. 49 is a sectional view of the coupling unit. FIG. 49 is a diagram showing the state of the driving force generated from the main body drive shaft 101 to the coupling unit 5028, and the cross-sectional view of the coupling unit 5028 is partially enlarged. More specifically, FIG. 49 is a sectional view perpendicular to the axis of the coupling unit 5028 (axis of the photodrum unit).

As shown in FIGS. 48 and 49 , as in the case of the first embodiment, the engaging member 5065 is provided with an engaging portion 5065 a protruding radially inward of the photosensitive drum 1 . The leading end side of this engaging portion 5065a is rounded, and expands (protrudes) toward the upstream side in the rotation direction of the photodrum unit.

More specifically, in the engaging portion 5065a, a convex portion (expansion portion) 5065m having a semicircular shape protruding in the circumferential direction toward the side where the drive shaft abutting surface 5065c is formed is formed, and the convex portion 5065m is engaged with the convex portion 5065m. The base of the portion 5065a is formed with a concave portion 5065n. In short, the convex portion 5065m is a portion that protrudes (expands) toward the upstream side in the rotational direction of the photodrum unit with respect to the concave portion 5065n. Conversely, the concave portion 5065n is facing toward the convex portion 5065m. The part that is depressed toward the downstream side in the direction of rotation.

FIG. 49 shows a state where the driving force F is generated from the drive transmission surface 101b of the main body drive shaft 101 in the engaging portion 5065a having such a shape. Since the base of the engaging portion 5065a protruding from the engaging member 5065 is formed with a concave portion 5065n, the groove 101a of the main body drive shaft 101 and the entrance-side corner 101j on the drive transmission surface 101b side can enter the concave portion 5065n. Thereby, the engaging part 5065a receives the driving force F acting on the normal direction of the driving transmission surface 101b, and can perform driving transmission.

In short, the driving force receiving portion 5065r for receiving the driving force from the driving transmission surface 101b faces at least radially outward of the coupling unit. Therefore, the driving force F received by the driving force receiving portion 5065r from the driving transmission surface 101b acts radially inward of the coupling unit. The engaging portion 5065a or the driving force receiving portion 5065r is elastically pushed at least radially inward (that is, the deep side of the driving transmission groove 101a).

As a result, the engaging portion 5065a or the driving force receiving portion 5065r can be stably engaged with the driving transmission groove 101a.

Further, the shape of the engaging portion 5065a will be described in detail. As shown in FIG. 49 , when the wire T parallel to the moving direction S of the engaging member 5065 is drawn from the convex portion 5065m, there is a vertex 5065p as a contact point between the wire T and the convex portion 5065m. The apex 5065p protrudes from the base 5065q of the engaging portion 5065a along the moving direction S of the engaging member 5065, and is arranged at a distance L3 apart.

Between the apex 5065p and the root 5065q is formed a concave portion 5065n that is concave to the line T. Enter the recess by the corner 101j of the drive shaft 5065n, the engaging portion 5065a, can receive the driving force F at the contact portion (driving force receiving portion 5065r) with the driving transmission surface 101b disposed in the concave portion 5065n.

The surface on which the driving force receiving portion 5065r is provided (the curved surface between the apex 5065p and the root 5065q) is inclined to the moving direction of the engaging member 5065, and faces at least outward in the radial direction of the coupling unit. In short, the normal vector of the driving force receiving portion 5065r (the vector extending perpendicularly to the driving force receiving portion 5065r toward the direction in which the driving force receiving portion 5065r faces) has a radially outward component. Next, as shown in FIGS. 49( a ) and ( b ), the driving force F is a force acting perpendicularly to the driving transmission surface 101 b or the driving force receiving portion 5065 r. Therefore, the driving force F has a radially inward component.

In addition, the driving force F is a force acting in a direction inclined only by the angle θ with respect to the moving direction S of the engaging member 5065 . Accordingly, as shown in FIG. 49( b ), the driving force F has a force FS as a component of the moving direction S of the engaging member. This force FS prevents the engaging member 5065 from moving to the opposite side of the moving direction S, and prevents the driving force receiving portion 5065r of the engaging member from detaching from the drive transmission surface 101b of the main body drive shaft and falling to the outside.

Also, in FIG. 49, a circular shape is exemplified as one of the shapes of the convex portion (expansion portion) 5065m. way to form. That is, the position where the butt wire T protrudes from the base 5065q of the engaging portion has an apex 5065p as a contact point, and between the apex 5065p and the root 5065q, a recess 5065n in which the butt wire T is recessed may be formed.

The cross-sectional shape of the convex portion (expanded portion) 5065m may be swollen for engagement with the driving transmission groove 101a. For example, a substantially circular polygon (pentagon, etc.) can also be used as the expansion part. In addition, the cross-sectional shape may be an ellipse or the like. Such an example will be described in FIG. 55 of the fourth embodiment.

Also, as described above, in this embodiment, the contact portion (driving force receiving portion) 5065r that contacts the drive transmission surface 101b is preferably disposed between the apex 5065p and the root portion 5065q of the convex portion (expansion portion) 5065m.

In order to surely contact the driving transmission surface 101b at the contact portion 5065r arranged in this way, at least the engaging member 5065 is preferably movable beyond the distance from the center of the section of the convex portion 5065m to the surface. That is, it is preferable that the engagement member 5065 is larger than or equal to the radius of the cross-sectional shape of the movable convex portion 5065m. It is more preferable to have a margin so that the width of the movable convex portion 5065m or more (that is, more than the diameter) is provided.

Also, when the movement amount of the engaging member 5065 is small, the convex portion 5065m contacts the drive transmission groove 101a on the tip side of the convex portion 5065m closer to the apex 5065p. In this case, when the convex portion 5065m receives a driving force, a force in a direction in which the oil drives the transmission groove 101a to separate may be applied to the engaging member 5065 . That is, in order to make the engaging state of the engaging member 5065 and the driving transmission groove 101a more reliable, the elastic thrust of the elastic pushing member that pushes the engaging member 5065 is increased, or the force generated between the convex portion 5065m and the driving transmission groove 101a is increased. The frictional force between the grooves 101a is better. If these countermeasures are taken, the engagement member 6065 becomes less likely to be driven by the transmission channel. 101a retreats.

Next, Figs. 50 and 51 show modifications of the third embodiment. As shown in FIG. 50 , the entire engagement portion 6065a may be a substantially circular expansion portion. By forming such a simple shape, it is possible to easily manage the dimensional accuracy of the engaging portion 6065a.

The engaging portion 6065a also has a vertex 6065p that is a contact point of a wire T parallel to the moving direction S of the engaging member 6065 . In addition, the apex 6065p protrudes and is arranged at a position separated by a distance L4 along the moving direction S from the base 6065q of the engaging portion. Next, between the apex 6065p and the base 6065q of the engaging portion, a recess 6065n in which the line T is recessed is formed. Between the apex 6065p and the base 6065q of the engaging portion, a contact portion (driving force receiving portion 6065r) for contacting the drive transmission surface 101b is also arranged. This contact portion (driving force receiving portion) 6065r faces a direction in which a force FS, which is a component generated in the direction opposite to the moving direction S of the engaging member, is generated with respect to the driving force F. As shown in FIG. As a result, it is possible to prevent the engagement member 6065 from coming off from the drive transmission surface 101b of the main body drive shaft, and falling off to the outside.

The surface (the curved surface between the apex 6065p and the base 6065q of the engaging portion) on which the abutting portion (driving force receiving portion) 6065r is provided is inclined with respect to the moving direction S of the engaging member 6065 . More specifically, the wiring of the driving force receiving portion 6065r is inclined to the moving direction S. As shown in FIG.

Next, the driving force receiving portion 6065r faces outward at least in the radial direction of the coupling unit. In short, the normal vector of the driving force receiving portion 6065r toward the side facing the driving force receiving portion 6065r has at least a direction toward the coupling Composition on the outer side of the cell diameter.

In addition, the cross-sectional shape of the engagement portion (expansion portion) convex portion 6065a does not necessarily have to be arcuate, and only needs to be a bulge for engagement with the driving transmission groove 101a. For example, a substantially circular polygon (pentagon, etc.) is also suitable for use as the expansion part. In addition, the cross-sectional shape may be an ellipse or the like.

Furthermore, in order to make the contact portion (driving force receiving portion) 6065r disposed between the apex 6065p and the root portion 6065q reliably contact the drive transmission surface 101b, the amount of movement of the engagement member 6065 preferably satisfies the following conditions. In short, it is preferable that the engaging member 6065 is movable beyond the distance from the center of the cross section of the engaging portion 6065a to the surface. That is, it is preferable that the engaging member 6065 (engaging portion 6065a) is equal to or larger than the radius of the cross-sectional shape of the movable engaging portion 6065a.

More preferably, the engaging part 6065a can move the engaging member. It is more preferable that the cross-sectional shape of the engaging part 6065a is wider (that is, diameter).

<Example 4>

A fourth embodiment will be described using FIGS. 52 to 57 . In the present embodiment, the structure corresponding to the structure of the engaging member and the urging member integrated with resin will be described. Also, the present embodiment is described by taking the coupling unit provided in the drum cassette as an example like the first or third embodiment, but it can also be used for the coupling unit provided in the developing cassette.

Figure 52 (a), (b) is a sectional view of the photodrum unit. Figure 52 (a) shows a state where the engaging portion 565a is engaged with the driving transmission groove 101a and receives a driving force. Fig. 52(b) shows the state before the engaging portion 565a is engaged with the drive transmission groove 101a.

Like the first or third embodiment, a flange member 571 is mounted inside the photoreceptor drum 1 . This flange member 571 is the coupling unit (coupling member) of this embodiment.

In the flange member 571 , a support portion 565 for movably supporting the driving force receiving portion 565 r is integrally formed with the flange member 571 . Three support portions 565 are provided on the flange member 571 . Each of these supporting parts 565 has an extension part 565t, an expansion part (engaging part 565a) provided at the tip of the extending part, and a connecting part 565s for connecting the extending part 565t and the engaging part 565a.

The extension portion 565t continues to the inner periphery of the flange member 571 . In short, the fixed end 565 of the extension portion 565t is provided on the inner periphery of the flange member 571 . Next, the extension portion 565t is a portion extending from the fixed end 565t thereof toward the inside of the hollow portion of the flange member 571 . Details will be described later, but the extension portion 565t is an elastic portion that can be elastically deformed.

In addition, the free end side of the extension part 565t (that is, the side where the connecting part 565s is provided) is located on the downstream side in the rotation direction R of the photodrum unit (coupling unit) than the fixed end 565t1 of the extension part 575t. In short, the extension portion 565t is a portion extending from the fixed end 565t1 toward the free end at least toward the downstream side of the rotation direction R. As shown in FIG. In addition, the free end of the extension portion 575t (that is, the connecting portion 565s or the engaging portion 565a ) is located on the inner side in the radial direction than the fixed end 565t1 of the extension portion 575t.

In addition, the engagement portion 565a is an expansion portion provided at the tip of the extension portion 565t, and is a portion for entering the drive transmission groove 101a of the main body drive shaft 101 . The engaging part 565a is connected by the connection part 575s provided at the tip of the extension part 575t. The continuation portion 575s is a portion formed by bending the tip side of the extension portion 565t. Moreover, the engagement part 565a and the connection part 565s are protrusion parts (protrusion part) which protrude toward the direction which intersects from the extension direction of the extension part 565t.

The engaging portion 565a is provided with a driving force receiving portion 565r. As shown in FIG. 52( a ), the driving force receiving portion 565r is in contact with the driving transmission groove 101a to receive the driving force. When the driving force receiving portion 565r receives the driving force, the driving force is transmitted to the flange member 571 through the fixed end 565t1 of the supporting portion 565 . The flange member 571 is fixed to the photosensitive drum 1 so that the flange member 571 rotates integrally with the photosensitive drum 1 .

The extension portion 575t and the engagement portion 565a are integrally formed on the flange member 570 . The extension part 575t and the engaging part 565a are part of the support part 565 which movably supports the driving force receiving part 565r.

The extension part 565t can be elastically deformed as mentioned above. That is, as shown in FIG. 52( b ), during the process of inserting the cartridge 7 into the device body, the engaging portion 565 a contacts the outer peripheral surface of the body drive shaft 101 . In this way, the engaging portion 565a moves at least radially outward of the coupling unit by the elastic deformation of the extending portion 565a.

Here, the extension part 565t is deformed so as to incline with its fixed end 565t as a fulcrum. As a result, the engaging portion 565a moves in a direction intersecting the direction in which the extending portion 565t extends.

After the cassette 7 is inserted into the device body, when the body drive shaft 101 is rotationally driven, the engaging portion 565a enters the driving transmission groove 101a when the phase of the engaging portion 565a matches the drive transmission groove 101a.

In a word, at least part of the elastic deformation of the extension part 565t is released, and the engaging part 565a is pushed to the inside of the driving transmission groove 101a. The extension portion 565t can also be regarded as a springing portion that pushes the engaging portion 565a at least radially inward.

In short, the engaging portion 565a is elastically pushed toward the inside of the drive transmission groove 101a by the elastic force (elastic force) of the extension portion 565t. The extension part 565t functions as the pushing member 72 of the first embodiment. In short, the support portion 565 is a part that has both the function of the pushing member 72 and the function of the engaging member 65 of the first embodiment.

At least a part of the support portion 565 or at least a portion of the driving force receiving portion 565r provided on the support portion 565 is arranged inside the photosensitive drum 1 (see FIG. 52 ). This is the same as the pushing member 72 or the engaging member 65 of the first embodiment.

In addition, since the flange member 571 is held by the photoreceptor drum 1 inside the photoreceptor drum 1, the flange member 571 is not easily deformed. In particular, if at least a part of the fixed end 565t of the support portion 565 is arranged inside the photoreceptor drum 1, even if the driving force is transmitted to the flange member 571 through the fixed end 565t, deformation of the flange member 571 can be suppressed, so it is suitable. of.

Also, the extension part is made of resin, but in the Elastic metal (such as leaf springs) may be inserted into the resin to increase the elastic force or strength of the extension.

When the engaging portion 565a enters the inside of the drive transmission groove 101a, the driving force receiving portion 565r provided on the engagement portion 565a receives the force from the inside of the drive transmission groove 101a. Also, when the drive transmission shaft 101a is driven, to ensure the engagement state between the drive transmission shaft 101a and the engagement portion 565a, it is better that more than half of the engagement portion 565a enters the interior of the drive transmission shaft.

That is, the engaging portion 565a is preferably more than the radius (the distance from the center of the engaging portion to the surface) that can move from the cross section of the engaging portion 565a. More preferably, the engaging portion 565a is movable by 2 times the distance from the center of the engaging portion to the surface from the diameter of the cross section of the engaging portion 565a (more than the width of the cross section of the engaging portion 565a). double or more) is better.

In addition, in FIG. 53 , a state in which the driving force receiving portion 565r receives the driving force F is shown. In addition, a straight line LN1 is drawn in the normal direction of the driving force receiving portion 565r. The straight line LN1 extends toward the side facing the driving force receiving portion 565r, and is also a straight line along the vector indicating the driving force F. As shown in FIG.

Next, the fixed end 565t1 of the extension portion 565t is arranged on the upstream side in the rotation direction R of the straight line LN1. That is, the supporting portion 565 is arranged to straddle the straight line L1.

In this case, when the driving force receiving portion 565r receives the driving force F, a moment M1 is generated on the extending portion 565t in the same direction (counterclockwise in the drawing) as the rotation direction of the photodrum unit with the fixed end 565t as a fulcrum. this The moment M1 acts to make the supporting portion 565 approach the main body driving shaft 101 . That is, the moment M1 acts to spring the engaging portion 565a toward the depth of the drive transmission groove 101a. Thereby, the engagement state of the engagement part 565a and the drive transmission groove 101a can be stabilized. In this embodiment, since the support portion 565 can be molded as a part of the flange member 571, the flange member 571 having the support portion 565 can be easily manufactured.

Hereinafter, a modified example of the fourth embodiment will be described using FIGS. 54 to 58 . 54 to 58 are cross-sectional views of the coupling unit (flange member).

First, in the modified example shown in FIG. 54, the extension part (665t, 665s) is bent, and the extension part has a first extension part 665s and a second extension part 665t extending in different directions. The boundary between the first extending portion 665s and the second extending portion 665t is a curved portion. The first extension portion 665s of this modification corresponds to the connection portion 565s shown in FIG. 52 . That is, the one extending the connecting portion 565s ( FIG. 52 ) is the first extending portion 665s ( FIG. 54 ), and the first extending portion 665s is also a connecting portion connecting the second extending portion 665t and the engaging portion 665a. Conversely, the connecting portion 565s shown in FIG. 52 may be regarded as the first extending portion, and the extending portion 565t may be regarded as the second extending portion.

The engagement portion 665a shown in FIG. 54 is an expansion portion provided at the tip of the extension portion (first extension portion 665s). The 1st extension part 665s and the engaging part 665a can also be considered as the protrusion part (protrusion part) which protrudes in the direction which intersects with the 2nd extension part 665t.

Compared with the connection part 565s shown in FIG. 52, the 1st extension part 665s of this modification is long. Therefore, the flange member 671 of this modified example becomes thinner (thickness becomes smaller) corresponding to this part.

Next, Fig. 55 shows another modified example. Fig. 55 shows the person whose shape of the expansion part (engagement part) has been changed. This is as described in Embodiment 3, and the expansion part may be polygonal or the like. The cross-sectional shape of the engaging portion 765a in FIG. 55 is approximately hexagonal. Such a cross-sectional shape can also be regarded as a substantially circular shape. In addition, the cross-sectional shape of the engaging portion (expansion portion) may be polygonal in the modified examples (see FIG. 56 and FIG. 57 ) shown below.

Fig. 56 shows another modified example. In the structure shown in FIG. 56, the extension part 865t is directly connected to the expansion part (engagement part 865a) at the extension part 865t without bending. However, the center of the engaging portion 865a with respect to the extension of the extension portion 865t is shifted, and the engaging portion 865a becomes a protruding portion protruding in a direction intersecting with the extending portion 865t. In this modified example, the position of the fixed end 856t1 of the extension portion 865t is changed from the configuration shown in FIG. 52 . In short, the fixed end 865t1 is located on the downstream side in the rotation direction R with respect to the straight line L1 extending in the normal direction of the driving force receiving portion 865r.

With such a configuration, when the support portion 865 receives a driving force, there is a possibility that a moment in the clockwise direction in the figure is applied to the support portion 865 with the fixed end 865t1 as a fulcrum. This moment acts to keep the engaging portion 865a away from the driving transmission groove 101a.

In this case, it is preferable to increase the elastic force by the extension part 865t (that is, to make the extension part 865t difficult to deform) so that the engagement between the engagement part 865a and the drive transmission groove 101a is not released. Or it is better to generate a large frictional force between the engaging portion 865a and the drive transmission groove 101a.

Another modified example is further described in FIG. 57 . In the aforementioned Figure 56 According to the configuration, the engaging portion is arranged at a position deviated from the extension line of the extending portion. On the other hand, the present modified example shown in FIG. 57 is configured such that the center of the engaging portion 965a is arranged on the extension line of the extension portion 965t.

The engagement portion 965a is a protruding portion provided at the tip of the extension portion 965t, and protrudes (protrudes) toward the entire circumference of the extension portion 965t.

In this modified example shown in FIG. 57 , the fixed end 965t1 of the support portion 965 is further arranged on the downstream side in the rotation direction R compared with the above-mentioned configuration shown in FIG. 56 . That is, when the driving force receiving portion of the engaging portion 965a receives the driving force, a moment may be applied to the supporting portion 965 in a direction in which the engaging portion 965a is separated from the drive transmission groove 101a.

Here, in order to make the engaging state of the engaging portion 965a and the driving transmission groove 101a more reliable, as mentioned above, the elastic force of the extension portion 965t is further increased, or the friction coefficient of the surface of the engaging portion 965a is increased. Waiting for countermeasures is better.

However, if the elastic force of the extension part 965t is increased so that the extension part 965t is not easy to bend, the force required to mount the cassette 7 to the device body will increase. In short, in order to attach the cassette 7, it is necessary to bend the extension part 965t, so the load becomes large. Therefore, considering the mountability of the cassette 7, it is preferable to set a sufficient and necessary elastic force as the extension portion 965t.

[industrial availability]

According to the present invention, there is provided a photodrum unit that can be attached to and detached from the main body of an electrophotographic image forming apparatus.

1: photoreceptor drum

65: Fastening member

65a: engaging part

65b: driving force receiving surface

65h: contact surface

66: spring push member

71: Flange member

71f: contact surface

72: Flange cover member

101: Body drive shaft

101a: Drive communication channel

101b: ontology drive communication surface

G: Gap

Claims (48)

A photosensitive drum unit for a cassette, the photosensitive drum unit comprising: photoreceptor drums; and A coupling member operatively connected to the aforementioned photoreceptor drum, the coupling member comprising: a snapping member including a protrusion; a holding member including a cylindrical portion configured to movably hold the engaging member so that the engaging member can move relative to the holding member between a first position and a second position; and an elastic push member configured to push the engaging member to the first position, wherein one end of the protrusion is disposed closer to the axis of rotation of the coupling member when the engaging member is in the first position than when the engaging member is in the second position, wherein when the engaging member is in the first position, the end of the protruding portion is disposed inside the cylindrical portion, and Wherein the coupling member is configured to transmit the driving force from the protrusion to the photosensitive drum via the holding member. The optical drum unit according to claim 1, wherein the holding member has a locking portion for restricting movement of the engaging member relative to the holding member when the engaging member is at the first position. The optical drum unit according to claim 2, wherein the engaging member is pushed on the locking portion by the pushing member. The optical drum unit as claimed in claim 1, wherein when the protrusion is at the first position, the protrusion protrudes inward in a radial direction of the optical drum unit. The photodrum unit according to claim 1, wherein at least a part of the engaging member is disposed inside the photosensitive drum. The optical drum unit according to claim 1, wherein the pushing member is a coil spring. The photodrum unit according to claim 1, wherein at least a part of the urging member is disposed inside the photosensitive drum. The photodrum unit as claimed in claim 1, wherein the holding member is fixed to the photosensitive drum. The optical drum unit according to claim 1, wherein the pushing member and the holding member are formed separately. The optical drum unit according to claim 1, wherein the pushing member and the engaging member are formed separately. The optical drum unit as claimed in claim 1, wherein the coupling member is formed with an open space between the end of the protrusion and the rotation shaft of the coupling member. The optical drum unit as claimed in claim 6, wherein the coil spring is a torsion coil spring. The optical drum unit as claimed in claim 6, wherein the coil spring is a compressed coil spring. The photodrum unit as claimed in claim 1, wherein a part of the cylindrical part is disposed inside the photosensitive drum, and a part of the cylindrical part A portion is disposed outside the photosensitive drum. The optical drum unit as claimed in claim 1, wherein the cylindrical portion comprises (i) a first portion having a first outer diameter, and (ii) a second portion having a second outer diameter, the second outer diameter being larger than the first outer diameter, and Wherein at least a part of the first part is configured outside the photosensitive drum, and at least a part of the second part is configured inside the photosensitive drum. The photodrum unit according to claim 1, wherein the cylindrical portion includes (i) a first end disposed outside the photosensitive drum, and (ii) a second end disposed inside the photosensitive drum, and Wherein the retaining member includes a cover portion attached to the second end of the cylindrical portion. The optical drum unit according to claim 16, wherein the cover portion includes a surface facing the protruding portion. A cassette comprising: frame; and A photodrum unit that may be rotatably supported by the frame, the photodrum unit including (i) a photosensitive drum, and (ii) a coupling member operatively connected to the photosensitive drum, the coupling member including: a snapping member including a protrusion; a retaining member including a cylindrical portion configured to movably retain the engaging member such that the engaging member is movable relative to the retaining member between a first position and a second position; and a snap member configured to snap the snapping member to the first position place, wherein one end of the protrusion is disposed closer to the axis of rotation of the coupling member when the engaging member is in the first position than when the engaging member is in the second position, wherein when the engaging member is in the first position, the end of the protruding portion is disposed inside the cylindrical portion, and Wherein the coupling member is configured to transmit the driving force from the protrusion to the photosensitive drum via the holding member. The cassette according to claim 18, wherein the retaining member has a locking portion for restricting movement of the engaging member relative to the retaining member when the engaging member is at the first position. The cassette according to claim 19, wherein the engaging member is pushed to the locking portion by the aforementioned pushing member. The cassette according to claim 18, wherein when the engaging member is at the first position, the protruding portion protrudes inward along the diameter direction of the photodrum unit. The cassette according to claim 18, wherein at least a part of the engaging member is disposed inside the photosensitive drum. The cassette according to claim 18, wherein the pushing member is a coil spring. The cassette according to claim 18, wherein at least a part of the pushing member is disposed inside the photosensitive drum. The cassette according to claim 18, wherein the holding member is fixed to the photosensitive drum. The cassette according to claim 18, wherein the pushing member and the holding member are formed separately. The cassette according to claim 18, wherein the pushing member and the engaging member are formed separately. The cassette according to claim 18, wherein the coupling member forms an open space between the end of the protrusion and the rotation shaft of the coupling member. The cassette according to claim 23, wherein the coil spring is a torsion coil spring. The cassette according to claim 23, wherein the coil spring is a compression coil spring. The cassette according to claim 18, wherein a part of the cylindrical part is arranged inside the photosensitive drum, and a part of the cylindrical part is arranged outside the photosensitive drum. The cassette of claim 18, wherein the cylindrical portion includes (i) a first portion with a first outer diameter, and (ii) a second portion with a second outer diameter, the second outer diameter being larger than the first outer diameter, and Wherein at least a part of the first part is configured outside the photosensitive drum, and at least a part of the second part is configured inside the photosensitive drum. The cassette according to claim 18, wherein the cylindrical portion includes (i) a first end disposed outside the photosensitive drum, and (ii) a second end disposed inside the photosensitive drum, and Wherein the holding member includes a cover portion, the second attached to the cylindrical portion end. The cassette according to claim 33, wherein the cover portion includes a surface facing the protruding portion. A cassette comprising: framework; a developing roller that may be rotatably supported by the frame; and a coupling member operatively connected to the developer roller, the coupling member comprising: a snapping member including a protrusion; a retaining member including a cylindrical portion configured to movably retain the engaging member such that the engaging member is movable relative to the retaining member between a first position and a second position; and an elastic push member configured to push the engaging member to the first position, wherein one end of the protrusion is disposed closer to the axis of rotation of the coupling member when the engaging member is in the first position than when the engaging member is in the second position, wherein when the engaging member is in the first position, the end of the protruding portion is disposed inside the cylindrical portion, and Wherein the coupling member is configured to transmit the driving force from the protrusion to the developing roller via the holding member. The cassette according to claim 35, wherein the retaining member has a locking portion for restricting movement of the engaging member relative to the retaining member when the engaging member is at the first position. The cassette according to claim 36, wherein the engaging member is pushed to the locking portion by the aforementioned pushing member. The cassette according to claim 35, wherein when the engaging member is at the first position, the protruding portion protrudes inward along the diameter direction of the photodrum unit. As in the cassette according to claim 35, wherein the pushing member is a coil spring. The cassette according to claim 35, wherein at least a part of the pushing member is arranged inside the photosensitive drum. As claimed in item 35, the cassette further includes a supply roller configured to supply toner to the developing roller, Wherein the coupling member is configured to transmit the driving force to the developing roller via the supply roller. The cassette according to claim 41 further includes a gear configured to transmit the driving force from the supply roller to the developing roller. The cassette of claim 42, wherein the supply roller includes a shaft portion, and the retaining member is fixed to the shaft portion of the supply roller. The cassette according to claim 35, wherein the pushing member and the holding member are formed separately. The cassette according to claim 35, wherein the pushing member and the engaging member are formed separately. The cassette according to claim 35, wherein the coupling member forms an open space between the end of the protrusion and the rotation shaft of the coupling member. The cassette according to claim 39, wherein the coil spring is a torsion coil spring. The cassette according to claim 39, wherein the coil spring is a compression coil spring.

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