JPH0792855A - Photoreceptor drum - Google Patents

Abstract

PURPOSE:To provide a photoreceptor drum capable of easily exchanging only a photoreceptor without damaging the photoreceptor and a peripheral unit in the case of exchanging the photoreceptor. CONSTITUTION:This photoreceptor drum is constituted of a belt stay 2 supporting the photoreceptor 1, the photoreceptor 1 carrying an electrostatic latent image and a toner image and attached to/detached from the belt stay 2, a fixing plate 5 attaching the photoreceptor 1 to the belt stay 2, a shaft 4 being the center of the rotation of the photoreceptor drum and transmitting hydraulic pressure for adjusting the length of a movable shaft 3 to the movable shaft 3, the movable shaft 3 capable of varying a distance between the shaft 14 and the belt stay 2 and a hydraulic pressure controller 8 making the length of the movable shaft 3 small by the hydraulic pressure at the time of exchanging the photoreceptor drum so that the bulk of the photoreceptor drum is made small, and making the length of the movable shaft 3 long enough to form the image after finishing the exchange of the photoreceptor drum.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive drum which carries an electrostatic latent image or a toner image in an electrostatic recording apparatus, and more particularly to a photosensitive drum which can be easily maintained.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 2, a photosensitive drum has a cylindrical drum 101, which is a supporting member, on the surface thereof.
It is configured by applying a photoconductive material 102 that is a photoconductor. The photoconductor is a member that requires a relatively short service life and needs to be replaced. In order to replace the photoconductor, the first conventional method is to first install a developing unit, a charger, a transfer body, a cleaner, etc. (hereinafter referred to as a peripheral unit), which are arranged in proximity to the photoconductor drum, to the photoconductor drum. Removed away from. Then, the photosensitive drum is removed from the electrostatic recording device and replaced, and then the peripheral unit is attached. According to the second conventional method, a fixed shaft is provided inside the electrostatic recording device in which the photosensitive drum is horizontally movable with respect to the peripheral unit, and the fixed shaft is extended outside the electrostatic recording device during replacement. The axis is connected. Then, the photosensitive drum was moved horizontally along a fixed shaft and taken out, and the entire photosensitive drum was replaced. In the third conventional method, the photosensitive drum and the peripheral unit are combined into one unit and the unit is replaced.

[0003]

However, in the conventional replacement method, since the entire photosensitive drum is replaced, the supporting member for the photosensitive member, which has a considerably long service life with respect to the photosensitive member, is also replaced. Therefore, there is a problem that the maintenance cost becomes high. Further, in the first conventional method, since the peripheral unit is removed, maintenance is troublesome, and in the second conventional method, since the photosensitive drum and the peripheral unit are very close to each other, the photosensitive drum may be damaged. There was a problem that was high. Further, the third conventional method has a problem that the maintenance cost is increased because the peripheral unit, which has a long life of the photosensitive member, is also replaced.

Therefore, in order to solve the conventional problems as described above, the object of the present invention is to make the photosensitive member attachable to and detachable from the supporting member, and at the time of exchanging the photosensitive member, the bulkiness of the photosensitive drum can be reduced, and the replacement It is to obtain a photoconductor drum that returns to the bulk before replacement.

[0005]

In order to solve the above-mentioned problems, the present invention relates to a photosensitive drum having a photosensitive member carrying an electrostatic latent image and a toner image, and a plurality of belt stays for supporting the photosensitive member. , A belt stay and a detachable photoconductor, a fixing plate for attaching the belt stay and the photoconductor, a shaft serving as a rotation shaft of the photoconductor drum, a movable shaft capable of varying a distance between the belt stay and the shaft, and a movable shaft. And a controller for controlling the length of the.

[0006]

In the photoconductor drum configured as described above, the photoconductor can be attached to and detached from the support member, and the bulkiness of the photoconductor drum becomes small when the photoconductor is replaced.
Return to the original volume.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a photosensitive drum of the present invention. The photoreceptor 1 of FIG. 1 carries an electrostatic latent image and a toner image, and has a belt shape that can be easily deformed.

FIG. 6 is a perspective view showing the structure of the photosensitive member 1. As shown in FIG. 6, the photoconductor 1 overlaps with the photoconductive layer 41, the conductive layer 42, and the belt support layer 43 in a belt shape. The belt support layer 43 is a deformable belt-shaped insulator, and is, for example, silicon rubber having a thickness of about 0.3 mm. The conductive layer 42 is adhered to the belt support layer 43 with a conductive resin having a thickness of about 0.1 mm, for example, polystyrene having conductivity. The photoconductive layer 41 is formed by applying a photoconductor, for example, a phthalocyanine-based OPC (organic photoconductor) whose binder is polyvinylcarbazole, to the conductive layer 42 to a thickness of about 0.1 mm.

Belt stays 2a, 2b, ..., 2f of FIG.
The belt stay 2 (hereinafter abbreviated as belt stay) supports the photoconductor 1. FIG. 5 is a side view showing the shape of the photosensitive drum of the present invention during image formation. As shown in FIG. 5, the shape of the belt stay 2 is a plate having a curved surface obtained by dividing a cylinder, for example, an aluminum plate having a thickness of about 2 mm. The support surface of the photoconductor 1 is formed by the combination of the belt stays 2.

Fixing plates 5a, 5b, ..., 5f (hereinafter abbreviated as fixing plate 5) in FIG. 1 are members for fixing the photosensitive member 1 to the belt stay 2. The photoreceptor 1 is fixed by attaching the fixing plate 5 to the belt stay 2 with screws. FIG. 7 is an explanatory view showing a mounting structure of the fixing plate 5. FIG. 7A shows a structure in which the belt stays 2b, 2d, 2f are fixed by fixing plates 5b, 5d, 5f, and FIG. 7B shows the belt stay 2a.
2C and 2e show a structure in which the fixing plates 5a, 5c and 5e are used for fixing. As shown in FIG. 7A, fixing plates 5b, 5d, 5 for fixing the belt stays 2b, 2d, 2f.
f is such that the width M of the fixing plate is about 10% of the length L of the belt stay 2 in the curved surface direction. Belt stays 2a, 2c, 2
The width M of the fixing plates 5a, 5c and 5e for fixing e is shown in FIG.
As shown in (b), about 90% of the width L of the belt stay 2
To a degree. The fixing plate is made of a conductor, for example, an aluminum plate, and electrically connects the conductive layer 42 of the photoconductor 1 and the belt stay 2. The belt stay 2 is connected to the ground, and the potential of the conductive layer 42 of the photoconductor 1 is always 0.

The movable shafts 3a, 3b, ..., 3f (hereinafter abbreviated as movable shaft 3) in FIG. 1 connect the belt stay 2 and the shaft 4 and change the length of the movable shaft 3 by changing the length thereof. It is the axis to adjust. FIG. 8 shows the movable shaft 3 and the shaft 4.
It is a side view showing a detailed structure of. As shown in FIG.
The inside of the movable shaft 3 is hollow and filled with oil 52, and the movable shafts 3a, 3a, 3a, and 3a slide and move by hydraulic pressure, and the distance between the belt stay 2 and the shaft 4 is adjusted. Specifically, the hydraulic pressure is adjusted by the valve 51 and the valve controller 53, and the length of the movable shaft 3 is controlled. The length of the movable shaft 3 is adjusted when the photosensitive drum is replaced, which will be described later.

The shaft 4 in FIG. 1 is the center of rotation of the photosensitive drum and is a hydraulic pressure transmission portion for adjusting the movable shaft length. As shown in FIG. 8, the shaft 4 has a bearing 55 into which the shaft center of the rotary drum in the electrostatic recording device is inserted. A gear 6 is attached to the shaft 4 in FIG. 1, and the rotation of the gear 6 causes the shaft 4 to rotate, thereby rotating the entire photosensitive drum. The shaft 4 is filled with oil in the hollow 54 of FIG. 8, and transmits the hydraulic pressure controlled by the hydraulic controller 8 of FIG. 1 to the movable shaft 3.

The shaft receiving portion 7 of FIG. 1 injects oil for oil pressure adjustment into and out of the shaft. FIG. 9 is an explanatory diagram of the shaft receiving portion 7 and the tip portion of the shaft 4. Figure 9
As shown in, the shaft receiving portion 7 has a protrusion 63.
The tip of the shaft 4 has an oil fence 61 and a spring 62 to prevent oil from leaking from the shaft. When the shaft receiving portion 7 is inserted into the tip portion of the shaft, the protrusion 63 opens the oil fence 61 to inject and discharge the oil into the shaft.

The hydraulic controller 8 in FIG. 1 controls the hydraulic pressure of the oil filled in the shaft when the photosensitive drum is replaced. The hydraulic control is performed when the photoconductor drum is replaced.
This will be described later. The replacement method when the photosensitive drum of the present invention is used will be described.

When the photosensitive drum is mounted in the electrostatic recording device and is used during image formation such as charging, exposure, development, transfer, etc., the photosensitive drum has a cylindrical shape as shown in FIG. Therefore, the surface of the photosensitive drum and the peripheral unit are in contact with or close to each other. At this time,
The movable shaft 3 has a maximum length. A method of replacing the photosensitive drum in this state will be described. To replace the photoconductor 1 with the photoconductor drum of the present invention, the bulkiness of the photoconductor drum is reduced, the photoconductor drum is pulled out from the electrostatic recording device, and the photoconductor 1 is replaced. Then, with the bulkiness being small, the photoconductor drum is re-installed in the electrostatic recording device, and the bulkiness of the photoconductor drum is returned to the state at the time of image formation.

Next, a method of reducing the bulkiness of the photosensitive drum will be described. Insert the shaft receiving portion 7 into the shaft 4 shown in FIG.
Reduce the oil pressure inside. At this time, all the valves 51 in each movable shaft 3 in FIG. 8 are closed. Next, the movable shaft 3b,
The valves 51 of 3d and 3f are opened by the valve controller 53.
As a result, the length of the movable shafts 3b, 3d, 3f becomes shorter.
The length of the movable shafts 3b, 3d, 3f is about 80 to the maximum length.
When it reaches about 90%, the valve 51 in the movable shafts 3a, 3c, 3e is opened to shorten the length of the movable shaft. Movable axis 3
When the length of b, 3d, 3f is about 50 to 60% of the maximum length, and the length of the movable shafts 3a, 3c, 3e is about 30 to 40% of the maximum length, each valve 51 is closed to move. Fix the shaft length. As a result, the bulkiness of the photosensitive drum is reduced.

FIG. 4 is a side view showing the shape of the photoconductor drum when the photoconductor is replaced. As shown in FIG. 4, the belt stays 2 have different structures, and the bulkiness of the photosensitive drum is reduced. As shown in FIG. 4, when the bulkiness of the photosensitive drum decreases, the distance between the peripheral unit and the photosensitive drum surface increases. Therefore, the photosensitive drum can be easily pulled out from the electrostatic recording device and removed.

FIG. 3 is an explanatory view showing a method of replacing the photoconductor. To replace the photoconductor 1, the shaft receiving portion 7 of FIG. 1 is removed from the shaft 4, all the fixing plates 5 are removed, and the photoconductor 1 is pulled out from the photoconductor drum as shown in FIG. Then, as shown in FIG.
The photosensitive drum is mounted on the belt stay 2 in a state where the bulkiness of the photosensitive drum is small.

After replacing the photoconductor 1, the photoconductor drum is set in the electrostatic recording apparatus, the shaft receiving portion 7 of FIG. 1 is inserted into the tip of the shaft, and the hydraulic pressure in the shaft is raised by the hydraulic controller 8. And the valve 5 of the movable shaft 3
1 is opened and the length of the movable shaft 3 is maximized, the valve 5
1 is closed and the movable shaft is fixed. As a result, the surface of the photosensitive drum and the peripheral unit come close to or come into contact with each other, and the photosensitive drum returns to the state at the time of image formation.

[0020]

As described above, according to the present invention, the photoconductor can be attached to and detached from the support member, and the bulkiness of the photoconductor drum becomes small when the photoconductor is replaced. Since it is configured to return, only the photoconductor can be replaced, and it can be easily replaced without damaging the photoconductor or peripheral units. Therefore, there is an effect of reducing maintenance cost and labor.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a photosensitive drum of the present invention.

FIG. 2 is an explanatory diagram of a conventional photosensitive drum.

FIG. 3 is an explanatory diagram showing a method for replacing a photoconductor according to the present invention.

FIG. 4 is an explanatory view showing the shape of the photosensitive drum when the photosensitive member is replaced in the present invention.

FIG. 5 is an explanatory diagram showing the shape of a photosensitive drum during image formation in the present invention.

FIG. 6 is an explanatory view showing a structure of a photoconductor in the photoconductor drum of the present invention.

FIG. 7 is an explanatory view showing a mounting structure of a fixing plate in the photosensitive drum of the present invention.

FIG. 8 is an explanatory diagram showing a side surface of a shaft of a movable shaft in the photosensitive drum of the present invention.

FIG. 9 is an explanatory diagram showing a side surface of a shaft tip portion and a shaft receiving portion in the photosensitive drum of the present invention.

[Explanation of symbols]

 1 Photoconductor 2 Belt stay 3 Movable shaft 4 Shaft 5 Fixed plate 6 Gear 7 Shaft receiving part 8 Hydraulic controller 41 Photoconductive layer 42 Conductive layer 43 Belt support layer 51 Valve 52 Oil 53 Valve controller 54 Hollow 55 Bearing 61 Oil fence 62 Spring 63 protrusions

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Koji Kawaguchi 6-31-1 Kameido, Koto-ku, Tokyo Seiko Denshi Kogyo (72) Inventor Shino Koiwa 6-31-1 Kameido, Koto-ku, Tokyo No. Seiko Electronics Industry Co., Ltd.

Claims (1)

[Claims] 1. A photoconductor drum having a photoconductor carrying an electrostatic latent image and a toner image, wherein a plurality of belt stays having a substantially cylindrical shape when combined are provided, and a photoconductor detachable from the belt stays. A fixing plate to which the belt stay and the photoconductor are attached; a shaft that serves as a rotation shaft of the photoconductor drum; a movable shaft that can change the distance between the belt stay and the shaft; and a length of the movable shaft. And a controller for controlling the photosensitive drum.