JPH0139115B2 - - Google Patents

Description

Detailed Description of the Invention <Technical Field> The present invention relates to a photosensitive drum mounting structure in an electrostatic copying machine for rotatably and detachably mounting a photosensitive drum having a photosensitive layer on at least a portion of its peripheral surface. Regarding.

<Prior art and its problems> As is well known to those skilled in the art, a so-called transfer electrostatic copying machine generally uses a photosensitive drum having a photosensitive layer on at least a portion of its peripheral surface. An image (an electrostatic latent image or a toner image obtained by developing the image) corresponding to the original is formed on the layer, and then this image is transferred to copy paper. Since the photosensitive layer becomes contaminated and also deteriorates through repeated use, it is necessary to clean and replace the photosensitive drum from time to time. In addition to being rotatably mounted at a predetermined position within the electrostatic copying machine, it is also necessary to be detachably mounted.

As a structure for rotatably and detachably mounting a photosensitive drum, a so-called shaft insertion type has been proposed. In such a shaft insertion type, a front support opening and a rear support opening whose centers are aligned with each other are formed in the front side plate and the rear side plate, which are spaced apart from each other. Also,
The photosensitive drum has an insertion hole extending along its central axis. Then, the photosensitive drum is positioned at a predetermined position between the front side plate and the rear side plate, and the insertion hole is aligned with the front support opening and the rear support opening, and the front support opening, the insertion hole, and the The shaft is removably inserted through the rear support openings in sequence. In this way, the photosensitive drum is mounted on the shaft supported by the front side plate and the rear side plate.

However, the conventional shaft insertion type has the following problems. First, when mounting the photosensitive drum at a desired position, the photosensitive drum is positioned at a predetermined position between the front side plate and the rear side plate, and the insertion hole is inserted into the front support opening and the rear support opening. The shaft must be inserted into the front support opening, the insertion hole, and the rear support opening while aligning with and maintaining this state. Therefore, it is extremely difficult, if not impossible, to perform a photosensitive drum mounting operation by only one operator, and typically requires an operator to hold the photosensitive drum in place and a shaft to be inserted. It is necessary to carry out the photosensitive drum mounting operation by two people including the operator. Second
In addition, if you accidentally pull out the shaft without holding the photosensitive drum by hand when removing the photosensitive drum, the photosensitive drum will fall downward, and this will cause damage to the photosensitive drum itself or to the area below the photosensitive drum. There is a high risk of damaging other structural elements installed.

In order to solve the above problem,
The publication discloses that a holding member is provided on the rear surface of the front side plate and the front side of the rear side plate for holding the protruding small diameter portions formed at both ends of the photosensitive drum, more specifically, at both ends of the photosensitive drum. A photosensitive drum mounting structure has been proposed. In such a structure, when both ends of the photosensitive drum are placed on the holding member, the front support opening and the rear support opening formed in the front side plate and the rear side plate are filled with the space between the front side plate and the rear side plate. The insertion holes formed in the positioned photosensitive drums are aligned. Therefore, when mounting the photosensitive drum, both ends of the photosensitive drum are first placed on the holding member and then aligned with each other. It is only necessary to insert the shaft through the front support opening, the insertion hole, and the rear support opening, and the photosensitive drum mounting operation can be carried out easily enough by only one operator. Moreover, even if the shaft is pulled out to remove the photosensitive drum, the photosensitive drum continues to be held by the holding member, and therefore the photosensitive drum will not fall by mistake.

However, the photosensitive drum mounting structure disclosed in the above-mentioned Japanese Utility Model Publication No. 53-20041 is still not fully satisfactory and has the following problems. That is, even when the shaft is inserted into the front support opening, the insertion hole, and the rear support opening and the photosensitive drum is installed as required, both ends of the photosensitive drum continue to be supported by the support member, and the photosensitive drum is Both ends remain in contact with the support member. Therefore, in order to ensure smooth rotation of the photosensitive drum during the copying process, it is necessary to manufacture the outer circumferential surface of both ends of the photosensitive drum and the inner circumferential surface of the support member with sufficient precision. Yes, with an increase in production costs. Furthermore, when the photosensitive drum is rotated, a relative movement is generated between both ends of the photosensitive drum and the above-mentioned holding member, which are inevitably brought into contact with each other. in time,
There is also a tendency for smooth rotation of the photosensitive drum to be hindered.

On the other hand, Japanese Utility Model Application Publication No. 51-22444 discloses a photosensitive drum of a type in which the front end and the rear end of the photosensitive drum are rotatably attached to a front side plate and a rear side plate, respectively, rather than the so-called shaft insertion type. A mounting structure is disclosed. Furthermore, in this type of photosensitive drum mounting structure, the rear surface of the front side plate and the rear surface of the rear side plate are each provided with a certain distance below both ends of the photosensitive drum mounted at a predetermined position. It is disclosed to provide a retaining member that is positioned at a distance.

In such a photosensitive drum mounting structure, when the photosensitive drum is mounted at a desired position, both ends of the photosensitive drum are separated from the holding member. The problem is avoided. However, in 1977-
The photosensitive drum mounting structure disclosed in Japanese Patent No. 22444 has a separate problem in that the photosensitive drum mounting operation is quite complicated. That is, when mounting the photosensitive drum at a desired position, after placing both ends of the photosensitive drum on the holding member, the photosensitive drum is lifted up by hand a little to position it at the desired position, and while maintaining this state, It is necessary to rotatably attach the front end to the front plate and the rear end to the rear plate, and therefore it is very difficult to carry out the photosensitive drum mounting operation by only one operator. .
In addition, since the photosensitive drum is supported separately at its front end and rear end in a so-called cantilever manner, there is a problem in that the photosensitive drum cannot be mounted stably.

<Object of the Invention> The present invention has been made in view of the above-mentioned facts, and its main purpose is to easily and easily allow only one operator to drop the photosensitive drum without fear of accidentally dropping the photosensitive drum. A new and superior shaft-insertion type photosensitive drum in an electrostatic copying machine that can carry out loading and unloading operations of the photosensitive drum, and also reliably solves problems caused by contact between the photosensitive drum and the holding member. Another object of the present invention is to provide a drum mounting structure.

<Summary of the Invention> As a result of extensive studies, the inventors of the present invention have determined that the position of the holding means on which both ends of the photosensitive drum are placed at the time of mounting is set at the center of the photosensitive drum placed on the holding means. The axes are set to be somewhat lower than the rotation axis connecting the centers of the front support opening and the rear support opening formed in the front side plate and the rear side plate, respectively, and in addition, the front support opening and the photosensitive drum are When the shaft is inserted through the formed insertion hole and the rear support opening,
The above object can be achieved if the photosensitive drum is automatically raised to some extent only by such shaft insertion operation, thereby causing the central axis of the photosensitive drum to substantially coincide with the rotational axis. I discovered that.

That is, according to the present invention, a photosensitive drum having a photosensitive layer on at least a portion of its circumferential surface is rotatably and removably mounted between a front plate and a rear plate that are spaced apart from each other. In the photosensitive drum mounting structure for an electrostatic copying machine, the front side plate and the rear side plate are respectively formed with a front support opening and a rear support opening whose centers are aligned with each other. The photosensitive drum has an insertion hole extending along its central axis, and holding means on which both ends of the photosensitive drum are placed are disposed between the front plate and the rear plate. When both ends of the photosensitive drum are placed on the holding means, the central axis of the photosensitive drum is located at a position several times smaller than the rotational axis connecting the centers of the front support opening and the rear support opening. a shaft for supporting the photosensitive drum and being supported by the front side plate and the rear side plate by being sequentially inserted into the front support opening, the insertion opening and the rear support opening; is provided, and when both ends of the photosensitive drum are placed on the holding means and the shaft is inserted into the front support opening, the insertion hole, and the rear support opening in sequence, the front side plate and by supporting the photosensitive drum on the shaft supported by the rear side plate, the photosensitive drum is raised somewhat, and the central axis of the photosensitive drum is substantially aligned with the rotational axis. A photosensitive drum mounting structure is provided.

<Preferred Specific Examples of the Invention> Hereinafter, a more detailed description will be given with reference to the accompanying drawings.

Overview of the entire electrostatic copying machine FIGS. 1 and 2 illustrate an example of an electrostatic copying machine to which a specific example of the photosensitive drum mounting structure constructed according to the present invention is applied.

Basically, in the electrostatic copying machine shown in the figure, a part of an optical device including an exposure lamp moves back and forth to form an image corresponding to the original on the photosensitive layer of the photosensitive drum. Forms an electrostatic image corresponding to
It has the function of developing an electrostatic image using a two-component developer consisting of carrier and toner, transferring this toner image onto copy paper, and fixing it by heating. A transparent plate 4 on which a document is placed horizontally is provided at the top of the body 2 of the copying machine. The body 2 is provided with a document holding plate 6 for pressing the document onto the transparent plate 4. A paper feed cassette 8 for storing copy paper is detachably attached to the right end of the machine body 2. This paper feed cassette 8 can be pulled out from the machine body 2 to the right. After copying is completed, the copy paper is discharged onto a copy tray 10 provided at the left end of the machine body 2. The number of consecutive copies of each document is set by a copy number setting button 12 provided at the upper front of the machine body 2. For copying operations, press the main switch 14.
After inputting the number of copies, set the number of copies using the number of copies setting button 12, and then press the print button 16. The amount of exposure of an original image onto a photosensitive layer 24 of a photosensitive drum 26, which will be described later, by an optical device is adjusted by an exposure amount adjustment knob 18. Also, adjust the toner supply amount adjustment knob 20 according to the degree of darkness of the original,
The mixing ratio of toner and carrier can be manually adjusted to a predetermined value.

Approximately in the center of the body 2 is a photosensitive drum 26, which is formed by providing a photosensitive layer 24 on the entire circumferential surface of a cylindrical base 22.
is rotatably mounted. Around the photosensitive drum 26, there are charging corona dischargers 30 that sequentially charge the photosensitive layer 24 along the rotation direction 28 of the photosensitive drum 26.
A developing device 32 that visualizes the electrostatic latent image formed on the photosensitive layer 24 into a toner image and also has a cleaning function, and a transfer device that transfers the toner image formed on the photosensitive layer 24 onto copy paper. a corona discharger 34 for use as well as a photosensitive layer 24 after the transfer process.
A static eliminating corona discharger 36 and a static eliminating lamp 38 are arranged to remove residual charges remaining on the battery.

An optical device 40 is provided above the photosensitive drum 26 for projecting an image of the document onto the photosensitive layer 24 between the charging corona discharger 30 and the developing device 32 as shown in the second figure. In this optical device 40,
Light projecting means 42 for projecting light onto the original through transparent plate 4 includes an exposure lamp 44 and a reflecting mirror 46. The light projected onto the document from the light projecting means 42 and reflected is transmitted to the photosensitive layer 20 through a movable reflecting mirror 50, a lens 52 having an in-mirror, and a reflecting mirror 54.
The image of the document is projected onto the photosensitive layer 24, and an electrostatic image is formed on the photosensitive layer 24.

The copy sheets stacked and stored in the paper feed cassette 8 are fed from the paper feed cassette 8 by a paper feed roller 58. The copy paper is transported by a pair of transport rollers 60,
61 and a guide plate 62, the transfer corona discharger 3 is transferred by a pair of feed conveyance rollers 64 and 65.
The photosensitive layer 24 of the photosensitive drum 26 facing the photosensitive drum 4 is fed into close contact with the photosensitive layer 24 of the photosensitive drum 26 . After the transfer is completed, the copy paper is
One axial end of the copy paper is held between a peeling roller 66 and a conveyance roller 68, peeled off from the photosensitive layer 24, and sent to a heat fixing device 72 via a guide plate 70, where the toner image on the copy paper is heat-fixed. Ru. The copy paper after being heated and fixed is transported by a pair of transport rollers 74, 7.
5. Guide plate 76 and pair of discharge rollers 78, 7
9 and is discharged onto a copy tray 10. A cooling blower 80 is further provided within the fuselage 2. This cooling blower 80 sucks air from outside and blows it below the transparent plate 4 . The transparent plate 4 is cooled by this air. Air is exhausted from the outlet 84.

The above-described configuration of the illustrated electrostatic copying machine does not constitute a new feature of the present invention, but merely represents an example of the configuration of an electrostatic copying machine to which the present invention is applied. Therefore, detailed explanation of the above-mentioned configuration will be omitted.

Photosensitive Drum Mounting Structure Next, a specific example of a photosensitive drum mounting structure constructed according to the present invention will be described.

Referring to FIG. 3 together with FIGS. 1 and 2, in the illustrated example, a support 290 is attached to the fuselage 2 so as to be movable forward and backward (direction perpendicular to the plane of the paper in FIG. 2). The developing device 32 and the photosensitive drum 26 are attached to the support 290. Referring to FIG. 3, which shows the state in which the support body 290 is pulled forward from the fuselage 2, the support body 290, which is attached so as to be slidable in the front and rear directions via an appropriate attachment mechanism, is It has a front side plate 292 and a rear side plate 294 arranged parallel to each other with a predetermined interval. Front side plate 29
A gripping piece 302 is provided on the front surface of 2.
Referring to FIGS. 4 and 6 as well as FIG. 3, the front side plate 292 and the rear side plate 294 include:
A front support aperture and a rear support aperture are formed whose centers are aligned with each other, and bearing members 306 and 308 are mounted in the front and rear support apertures, respectively. A front holding member 310 and a rear holding member 312 are fixed to the rear surface of the front side plate 292 and the front side of the rear side plate 294, respectively. As will be described later, each of the front holding member 310 and the rear holding member 312, which constitute holding means for temporarily holding both ends of the photosensitive drum 26, has a shape of approximately U.
It is composed of a letter-shaped member and has upwardly facing arcuate receiving surfaces 310a and 312a.

On the other hand, as shown in FIG.
The base 22 is provided at both ends with end plates 314 and 316 interconnected by stay bolts 318. And such end plates 314 and 31
6 are provided with bosses 320 and 322, respectively. Each of the bosses 320 and 322 projects axially outwardly beyond the base body 22;
The axially protruding end portions of the bosses 320 and 322 constitute protruding small diameter portions that are placed on the arcuate trays 310a and 312a of the front holding member 310 and the rear holding member 312. The bosses 320 and 322 have holes extending through their centers in the axial direction. In addition, a guide tube 324 is fixed between the bosses 320 and 322. boss 32
The holes formed at 0 and 322 and the inner hole of the guide tube 324 extend along the central axis of the photosensitive drum 26, and constitute an insertion hole into which a shaft is inserted, as will be described later. The arcuate receiving surfaces 310a and 312a of the front holding member 310 and the rear holding member 312, and the arcuate receiving surfaces 310a and 312
bosses 320 and 322 placed on a
The axially protruding ends of the bosses 320 and 322
When the outer end of the photosensitive drum 26 is inserted from above into the front holding member 310 and the rear holding member 312 and placed on the arcuate receiving surfaces 310a and 312a, the central axis of the photosensitive drum 26 is aligned with the center of the bearings 306 and 308. It is important that the relative position and dimensions are such that it is located somewhat below the axis or axis of rotation.

Continuing the explanation with reference to Figures 4 and 6,
The illustrated photosensitive drum mounting structure further includes a shaft 326. This shaft 326 is sequentially inserted from the front through the bearing 306, the insertion hole of the photosensitive drum 26, and the bearing 308, and is thus inserted into the bearings 306 and 308 (therefore, the front side plate 292 and the rear side plate 29).
4) It is rotatably supported and supports the photosensitive drum 26. The tip of the shaft 326 is connected to the fuselage 2.
The drive connection means 328 is connected to a drive connection means 328 disposed at a predetermined position. A female thread 330 is carved into the hole formed in the boss 320 of the photosensitive drum 26, and the hole formed in the boss 322 has an introduction cone tapered outward in the axial direction. 332 and a supporting cylindrical portion 336 following this. On the other hand, the shaft 326 includes a tip portion 338, a small diameter shaft portion 340, and a conical portion 3, which are sequentially located when viewed in the axial direction.
42, a large diameter shaft portion 344, a male thread portion 346, a large diameter end portion 348, and a knob 350. Tip 338
has a substantially conical shape tapered toward the free end. The male thread formed in the male thread portion 346 is screwed into the female thread 330. The screwing direction is the rotational drive direction of the shaft 326, that is, the direction indicated by the arrow 28 in FIG.
6 and the photosensitive drum 26 attached thereto will not loosen the screw connection.

To explain with reference to FIG.
6, a drive shaft 360 rotatably fitted into the holding member 354 via bearings 356, 358, and a sprocket wheel 100 fixed to the outer periphery of the drive shaft 360. include. The drive shaft 360 is formed with a fitting hole 362 that opens on the insertion side, and the tip portion 338 of the shaft 326 and the small diameter shaft portion 340 are inserted into the fitting hole 362 via a one-way clutch 364 as a shaft coupling.
is inserted. holding member 354, drive shaft 360,
Sprocket wheel 100 and mating hole 362
have the same axis. sprocket wheel 10
0 is drivingly connected by a chain 94 to a drive source (not shown), which may be a motor disposed within the fuselage 2. Referring to FIG. 5, which shows a portion of one-way clutch 364, an input end member 366 is secured to drive shaft 360. The input end member 366 is formed with a recess having an inclined surface 370 in a direction radially outwardly away from the rotary shaft 326 toward the rotary drive direction 368 at intervals in the circumferential direction. A roller 372 is interposed between the inclined surface 370 and the outer peripheral surface of the small diameter shaft portion 340.
The spring 374 provides rotational drive direction 3 to the roller 372.
It gives an elastic force along the rear of 68. drive shaft 360
When the input end member 366 is rotated in the rotational driving direction 368, the spring 37 is rotated as shown in FIG.
4, the roller 372 moves to the inclined surface 370.
It bites in between the inclined surface 370 and the outer circumferential surface of the small diameter shaft portion 340 along. Therefore, the rotational power from the input end member 366 is transmitted to the small diameter shaft portion 340 via the roller 372, the shaft 326 is rotationally driven integrally with the drive shaft 360, and the rotation of the shaft 326 rotates the photosensitive drum 26. be done. When the drive shaft 360 and therefore the input end member 366 are at rest, the rollers 372 move toward the inclined surface 3, as shown in FIG. 5b.
70 and the outer circumferential surface of the small diameter shaft portion 340.

The photosensitive drum mounting operation procedure in the photosensitive drum mounting structure as described above will be summarized as follows. When mounting the photosensitive drum 26, the support body 290 is pulled out forward from inside the body 2, as shown in FIG. Then, the axially projecting ends of the bosses 320 and 322 of the photosensitive drum 26 are inserted into the front holding member 310 and the rear holding member 312 from above, and the arcuate receiving surface 310 is inserted into the front holding member 310 and the rear holding member 312.
a and 312a. Then the shaft 326
are inserted into the bearing 306, boss 320, guide tube 324, and boss 322 in order from the front side. At this time, the tip 338 of the shaft 326 is moved from the guide tube 324 to the boss 322 by the conical surface 332 of the boss 322.
can be smoothly inserted into the support surface 336 of. Then, turn the knob 350 to screw the male thread of the male thread portion 346 of the shaft 326 into the female thread 330 of the boss 320, and turn the shaft 326 rearward (that is, to the left in FIG. 4). towards) The distal end 338 of the shaft 326 is then smoothly fitted into the bearing 308 and advanced toward the one-way clutch 364. At this time, since the conical portion 342 is formed continuously to the small diameter shaft portion 340 of the shaft 326, as the shaft 326 advances, the large diameter shaft portion 344 is connected to the bearing 340.
08 fits smoothly. The tip portion 338 and small diameter shaft portion 340 of the shaft 326 protrude outward from the bearing 308 in the axial direction.

As described above, the shaft 326 is attached to the bearings 306 and 308, and the photosensitive drum 2 is attached to the shaft 326.
6 is installed, the shaft 326 moves the photosensitive drum 2
6 is raised somewhat, so that the center axis of the photosensitive drum 26 is substantially aligned with the center axis of the bearings 306 and 308, that is, the axis of rotation. The axially protruding ends of the bosses 320 and 322 of the photosensitive drum 26 are connected to the front holding member 310 and the rear holding member 310.
It is spaced upwardly from the arcuate receiving surfaces 310a and 312a.

The photosensitive drum 2 is attached to the support 290 as described above.
6 is finished, the support body 290 is slid rearward and positioned within the body 2. In this way, the small diameter shaft portion 340 of the shaft 326 protruding from the bearing 308 is fitted into the one-way clutch 364 provided in the fitting hole 362 of the drive shaft 360. Axis 3
26 is formed into a conical shape, so that the small diameter shaft portion 340 of the rotating shaft 326 can be smoothly fitted into the one-way clutch 364.

In order to detach the photosensitive drum 26 from the body 2, the mounting operation described above may be performed in reverse.

<Effects of the Invention> As described above in detail, the photosensitive drum mounting structure according to the present invention can be easily operated by only one operator without fear of accidentally dropping the photosensitive drum. In addition, when the shaft is inserted and the photosensitive drum is installed as desired, the photosensitive drum is raised somewhat upwards, thereby causing the photosensitive drum to move upward. An excellent effect is achieved in that the light emitting drum is separated upward from the holding means (front holding member and rear holding member), and therefore problems caused by contact between the light emitting drum and the holding means do not occur.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway perspective view showing an example of an electrostatic copying machine to which a specific example of a photosensitive drum mounting structure constructed according to the present invention is applied. Figure 2 shows
2 is a simplified cross-sectional view of the electrostatic copying machine of FIG. 1. FIG. FIG. 3 is a partial perspective view showing a specific example of a photosensitive drum mounting structure constructed according to the present invention, which is applied to the electrostatic copying machine of FIG. 1. FIG. 4 is a partial cross-sectional view showing the photosensitive drum mounting structure shown in FIG. 3. FIG. 5 is a partial cross-sectional view of the one-way clutch used in the electrostatic copying machine of FIG. FIG. 6 is a partially exploded sectional view showing the photosensitive drum mounting structure shown in FIG. 3. 2... Body, 26... Photosensitive drum, 290... Support body, 292... Front side plate, 294... Rear side plate, 306 and 308... Bearing member, 310... Front holding member (holding means), 312... Rear holding member (holding means) , 310
a and 312a... arcuate receiving surface, 326... shaft, 328
...drive coupling means.

Claims (1)

[Scope of Claims] 1. A photosensitive drum having a photosensitive layer on at least a portion of its circumferential surface is rotatably and removably mounted between a front plate and a rear plate that are spaced apart from each other. In the photosensitive drum mounting structure for an electrostatic copying machine, the front side plate and the rear side plate are respectively formed with a front support opening and a rear support opening whose centers are aligned with each other, The photosensitive drum has an insertion hole extending along its central axis, and holding means on which both ends of the photosensitive drum are placed is provided between the front plate and the rear plate. When both ends of the photosensitive drum are placed on the holding means, the central axis of the photosensitive drum is slightly longer than the rotational axis connecting the centers of the front support opening and the rear support opening. By sequentially inserting the shaft into the front support opening, the insertion opening and the rear support opening, the shaft is supported by the front side plate and the rear side plate and supports the photosensitive drum. When both ends of the photosensitive drum are placed on the holding means and the shaft is sequentially inserted into the front support opening, the insertion hole, and the rear support opening, the front side plate and the By supporting the photosensitive drum on the shaft supported by the rear plate, the photosensitive drum is raised somewhat, and the central axis of the photosensitive drum is substantially aligned with the rotational axis. Features a photosensitive drum mounting structure. 2. The photosensitive drum mounting structure according to claim 1, wherein the tip of the shaft has a tapered shape. 3. Each of the front support opening and the rear support opening has a
A bearing member is disposed, the shaft is rotatably supported by the front plate and the rear plate via the bearing member, and the shaft and the photosensitive drum are mutually connected so that they can rotate as a unit. 3. The photosensitive drum mounting structure according to claim 1 or 2, wherein the shaft is coupled to a shaft and driven to rotate. 4 A female thread is formed on the inner peripheral surface of the insertion hole of the photosensitive drum, and a male thread is formed on the outer peripheral surface of the shaft, and the female thread and the male thread are screwed together. The shaft and the photosensitive drum are interconnected by screwing, and the screwing direction of the female thread and the male thread is the same as the direction of rotation of the shaft. The photosensitive drum mounting structure described in item 3. 5. Any one of claims 1 to 4, wherein a drive connection means is provided at the rear of the rear side plate to receive the tip of the shaft and drive the shaft to a drive source. The photosensitive drum mounting structure described above. 6. The holding means is composed of a front holding member fixed to or integrally formed with the rear surface of the front side plate, and a rear holding member fixed on or integrally formed with the front surface of the rear side plate. , a photosensitive drum mounting structure according to any one of claims 1 to 5. 7. A protruding small diameter portion is formed at each of both ends of the photosensitive drum, and the protruding small diameter portion is placed on the front holding member and the rear holding member. photosensitive drum mounting structure. 8 Each of the front holding member and the rear holding member,
The photosensitive drum mounting structure according to claim 7, wherein an upwardly facing arcuate receiving surface is formed. 9. The photosensitive drum mounting structure according to claim 8, wherein the arcuate receiving surface has a semicircular arc shape having substantially the same radius as the radius of the protruding small diameter portion. 10. Claims 1 to 1, wherein the front side plate and the rear side plate are the front side plate and the rear side plate of a support body that is detachably installed in the electrostatic copying machine housing in the direction of the rotation axis. The photosensitive drum mounting structure according to item 9.