JP2000019889A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which eliminates surely with a simple structure, even in the case the number of the kinds of photoreceptor drums is increased, such a problem that the device is damaged or the original performance of the device is not achieved due to the integration of the quite different photoreceptor drum. SOLUTION: In the image forming device 1 having the photoreceptor drum 41 which has a flange 41a on each end, a drum fixing member 500 which engages with the flange 41a, and a drum shaft 700 which supports the photoreceptor drum 41, specific engagement parts are provided between the flange 41a of the photoreceptor drum 41 and the drum fixing member 500, between the drum shaft 700 and the drum fixing member 500, and between the flange 41a of the photoreceptor drum 41 and the drum shaft 400. Only the flange 41a, drum fixing member 500, and drum shaft 700 of the specific photoreceptor drum 41 are engageable with each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus capable of forming an image on transfer paper.

[0002]

2. Description of the Related Art In an image forming apparatus such as a copying machine, for example, an electrostatic latent image is formed on a photosensitive drum, and this electrostatic latent image is developed to form a toner image, which is transferred by rotating the photosensitive drum. Some transfer a toner image to paper. The photosensitive drum is attached, for example, by engaging a flange of the photosensitive drum with a drum fixing member, or penetrating the photosensitive drum through a drum shaft, and engaging the flange of the photosensitive drum with the drum fixing member.

[0003]

In such an image forming apparatus, the photoconductor drum may be damaged by use, so that a serviceman replaces the photoconductor drum. By the way, as shown in FIG. 6, there is a case where the photosensitive drums have the same or similar shapes and different drum performances. For example, if the photosensitive drum for the image forming apparatus B is erroneously incorporated into the image forming apparatus A, there is a problem that the image forming apparatus does not function or the apparatus is damaged.

[0004] In some cases, photosensitive drums have the same or similar shapes, and further have similar drum performance. For example, an inexpensive photosensitive drum for the image forming apparatus C may be intentionally incorporated and used. In this case, the original performance (image quality or the like) of the image forming apparatus is not exhibited.

For this reason, in Japanese Patent Application No. 9-174415, specific engagement portions are provided on the flange of the photosensitive drum and the drum fixing member, respectively, as shown in FIG. Each has a specific engaging portion, and even if there is a photosensitive drum having the same or similar diameter or length, by providing the specific engaging portion, a different photosensitive drum is erroneously Alternatively, an image forming apparatus capable of preventing intentional incorporation has been proposed.

However, when the number of types of photosensitive drums having the same or similar diameters and lengths increases, the conventional technology has a limit. That is, even if the photoconductor drum has the same or similar shape in diameter and length, if the original performance of the photoconductor drum is different, if the photoconductor drum is erroneously installed, it functions as an image forming apparatus. Or damage to the device.

In the case where the photosensitive drums have the same or similar diameters and lengths, and further have similar inherent performances and are inexpensive, the photosensitive drums may be intentionally incorporated and used. There is a problem that the original performance of the image forming apparatus is not exhibited.

The present invention has been made in view of the above point, and even if the number of types of photosensitive drums is increased, the structure of the photosensitive drum can be reliably reduced by a simple structure, and the inherent performance of the apparatus can be reduced. It is an object of the present invention to provide an image forming apparatus capable of solving the problem of not being exhibited.

[0009]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention has the following constitution.

According to a first aspect of the present invention, there is provided an image forming apparatus comprising: a photosensitive drum having a flange at an end; a drum fixing member engaging with the flange; and a drum shaft supporting the photosensitive drum. A specific engagement portion is provided between the flange of the photoconductor drum and the drum fixing member, between the drum shaft and the drum fixing member, and between the flange of the photoconductor drum and the drum shaft, respectively.
An image forming apparatus wherein only a flange of a specific photosensitive drum, a drum fixing member, and a drum shaft can be engaged. ].

According to the first aspect of the present invention, even if there are photosensitive drums having the same or similar diameters and lengths, the flange of the photosensitive drum and the drum fixing member and the drum shaft and the drum fixing are fixed. By providing the member and the engaging portions at three places of the flange of the photosensitive drum and the drum shaft,
Inadvertent or intentional incorporation of a different drum can be prevented. Thus, even if the number of types of photoconductor drums increases, it is possible to solve the problem that the device is damaged due to the incorporation of a different photoconductor drum and the original performance of the device is not exhibited with a simple structure.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an image forming apparatus according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a configuration diagram of the image forming apparatus.

In this embodiment, a copying machine is shown as the image forming apparatus 1. The image forming apparatus 1 includes an automatic document feeder 2. The automatic document feeder 2 includes a document tray 3, a feed roller 4, a takeout table 5, and the like. The document set on the document tray 3 is automatically driven one by one by the driving of the feeding roller 4.
Then, the document whose image has been read is sent out onto the take-out table 5.

Further, the image forming apparatus 1 is provided with an image information reading section 20 for reading image information of a fed document. The image information reading unit 20 includes a light source 21 and a mirror 2
2 to 24, a lens 25 and a CCD 26 are provided. The light source 21 and the mirrors 22 to 24 are reciprocally arranged below the document placing glass 10 so that the light source 21 irradiates the document on the document placing glass 10. I do. The reflected light is mirror 22
Through an optical system consisting of a lens 25 and a CCD 26
Is read optically. Position detection sensors S1 and S2 for reciprocating the light source 21 are arranged below both ends of the document placing glass 10, and the position detection sensors S
When 1, S2 detects the light source 21, the light source 21 is moved in the opposite direction. The CCD 26 is controlled by the control unit 30 and stores the read image signal in the image storage unit 27.

The image forming apparatus 1 includes an image carrying unit 40, a fixing unit 50, a paper feeding unit 60, a registration control unit 70, and an automatic reversing and re-conveying unit (ADU) 80 as a reversing unit.
Further, a transfer conveyance path A for conveying the transfer paper to the image carrier 40, a discharge path B for discharging the transfer paper on which the image is formed out of the apparatus, and an automatic reversal of the transfer paper on which the image is formed by the image carrier 40 A circulation reversing sheet feeding path C for circulating to the re-conveying unit (ADU) 80, an automatic reversing re-conveying unit (ADU) 8
And a return path D from 0.

A photosensitive drum 41 as an image bearing member is disposed in the image bearing portion 40, and the photosensitive drum 41 is uniformly charged by a charging electrode 42, and is charged by an image information writing portion 43. Is irradiated on the peripheral surface of the photosensitive drum 41 to form an electrostatic latent image. Image information writing unit 43
Is configured to write the image information stored in the image storage unit 27 by laser on the peripheral surface of the photosensitive drum 41.

The electrostatic latent image is developed by the developing unit 44 to form a toner image. The transfer paper is sent to the transfer unit 45 in synchronization with the rotation of the photosensitive drum 41, and the toner image is transferred. Thereafter, the transfer paper is separated from the photosensitive drum 41, and is conveyed to the fixing unit 50 in the next step via the conveyance belt 300. A cleaning unit 46 is provided around the photosensitive drum 41.
The surface of the photoconductive drum 41 after the transfer is cleaned and charged again by the charging electrode 42 for the next image formation.

The fixing section 50 has a pair of rollers 51 and 52, and fixes the toner image on the transfer paper heated and pressed by the transfer paper. Switching gate 10 arranged after fixing unit 50
By 0, the transfer path of the transfer sheet is switched between the discharge side and the re-conveyance side. The switching of the switching gate 100 is performed according to the timing of sending the transfer paper from the registration control unit 70.

The paper feed section 60 includes a plurality of paper feed step sections 61 and 6.
2 are provided, and in this embodiment, they are arranged at the upper stage and the lower stage. The upper paper feed stage 61 and the lower paper feed stage 62 include:
Trays 63 and 64 for storing transfer papers are arranged. Paper feed rollers 65 and 66 are arranged on the upper surface of the transfer paper of the upper paper feed step 61 and the lower paper feed step 62, respectively, and intermittently feed the transfer paper. Each paper feed roller 65, 6
6, a double feed prevention roller pair 67, 68 is disposed in front of
The transfer paper is transported to the transport path A one by one. Transport path A
Is provided with a transport roller pair 101.

The automatic inversion re-transport unit (ADU) 80 includes:
Loading roller pair 81, reversing roller pair 82, transport roller pair 2
02, 203, 204, 205 and sensors S3, S4
S5, S6, and S7 are provided. The transfer paper sent from the reversing paper feed path C is carried in by the forward rotation of the carry-in roller pair 81 and the reverse roller pair 82, and the reverse of the reverse roller pair 82 and the driving of the transport roller pairs 202, 203, 204, 205. To return to the transport path D.

The conveying roller pair 2
00 and 201 are arranged. The registration control unit 70 includes a registration roller pair 71 and a sensor S8. The registration roller pair 71 is independently driven by a motor 73. The transferred transfer paper is a pair of registration rollers 71.
, The position of the image on the image carrier and the transfer sheet are aligned, and a spool is forcibly formed in order to correct the skew of the transfer sheet.

In the image forming apparatus 1, a re-conveying path E is formed so as to surround a sheet feeding section 60 for sending a transfer sheet to the image carrying section 40. The re-conveying path E has a circulation reversing sheet feeding path C and a return conveying path D. In the re-conveying path E, an automatic reversing re-conveying device (AD
U) 80 are provided.

FIG. 2 is a view showing an embodiment in which the photosensitive drum and the drum fixing member are assembled in the image forming apparatus.

Drum shaft 70 assembled to image forming apparatus 1
0, the photosensitive drum 41 incorporated in the drum cartridge is penetrated and mounted. The drum fixing member 500 is engaged with the flange 41a of the photosensitive drum 41 and the drum shaft 700 and tightened with the tightening bolt 510. The photosensitive drum 41 is positioned and stopped by attaching the drum fixing member 500.

An uneven engaging portion 4 is provided between a flange 41 a provided at an end of the photosensitive drum 41 and the drum fixing member 500.
1a1 and 500a are provided, and uneven engagement portions 700a and 500 are provided between the drum shaft 700 and the drum fixing member 500.
b, and a flange 41 of the photosensitive drum 41
a and a specific engagement portion 41a2,
700b is provided. Engaging part 700 of drum shaft 700
b is formed with the shaft portion having a small diameter while the flange 41a is formed.
The engaging portion 41a2 is formed to have a diameter such that the shaft hole fits into the engaging portion 700b. Thus, only the flange 41a of the specific photosensitive drum 41, the drum fixing member 500, and the drum shaft 700 can be engaged.

FIG. 3 is a diagram showing a state in which the photosensitive drum and the drum fixing member are assembled in the image forming apparatus.

As shown in FIG. 3A, the photosensitive drum 41 is passed through and mounted on the drum shaft 700 assembled in the image forming apparatus 1, and is fixed to the flange 41a of the photosensitive drum 41 and the drum shaft 700. In this embodiment, only the flange 41a of the specific photosensitive drum 41, the drum fixing member 500, and the drum shaft 700 can be engaged with each other, as shown in FIG. .

Therefore, as shown in FIG. 3B, even if the photosensitive drums 600 having the same or similar diameters and lengths exist, for example, the flanges 600a of the photosensitive drums 600 can be used.
Since the engaging portion 600a1 formed in the above-mentioned portion does not engage with the engaging portion 500a of the drum fixing member 500, it is possible to prevent a different photosensitive drum 600 from being erroneously or intentionally incorporated.

Further, as shown in FIG. 3C, even if the photosensitive drums 600 having the same or similar diameters and lengths exist, the engaging portion 700b of the drum shaft 700 and the photosensitive drum 600 Does not engage with the first photosensitive drum 600a, it is possible to prevent a wrong photosensitive drum 600 from being erroneously or intentionally incorporated.

Next, specific embodiments of the drum shaft, the drum fixing member, and the engaging portion of the photosensitive drum will be described.

FIG. 4 shows the drum shaft, the drum fixing member and the engaging portion of the photosensitive drum of the first embodiment. FIG. 4 (a),
In the drum shaft 700 of (b), a key groove is formed at one place as an engaging portion 700a, and the engaging portion 700b is formed with a small diameter shaft portion. In the drum fixing member 500 shown in FIG. 4C, two convex portions are formed as the engaging portions 500a, and the key is engaged with the key groove of the engaging portion 700a at one position as the engaging portion 500b. Is formed. In the flange 41a of the photosensitive drum 41 in FIGS. 4D and 4E, two concave portions are formed as engaging portions 41a1 so as to engage with the convex portions of the engaging portion 500a. The shaft hole 41a2 is formed to have a diameter that fits into the engagement portion 700b.

FIG. 5 shows a drum shaft, a drum fixing member and an engaging portion of a photosensitive drum according to a second embodiment. FIG. 5 (a),
In the drum shaft 700 of (b), key grooves are formed at two places as engaging portions 700a, and the engaging portions 700b are formed with a small diameter shaft portion. In the drum fixing member 500 of FIG. 5C, three convex portions are formed as the engaging portions 500a, and two keys are engaged with the key groove of the engaging portion 700a as the engaging portions 500b. Is formed. In the flange 41a of the photosensitive drum 41 in FIGS. 5D and 5E, three concave portions are formed as engaging portions 41a1 so as to engage with the convex portions of the engaging portion 500a. The shaft hole 41a2 is formed to have a diameter that fits into the engagement portion 700b.

[0033]

As described above, according to the first aspect of the present invention, even if there are photosensitive drums having the same or similar diameters and lengths, the flanges of the photosensitive drums and the drum fixing members, the drums, and the like. Since the engaging portions are provided at the shaft and the drum fixing member, and at the three positions of the photosensitive drum flange and the drum shaft, it is possible to prevent a different drum from being erroneously or intentionally incorporated. Even if the number of types increases, it is possible to solve the problem that the device is damaged due to the incorporation of a different photoconductor drum and that the original performance of the device is not exhibited with a simple structure.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an image forming apparatus.

FIG. 2 is a diagram illustrating an embodiment in which a photosensitive drum and a drum fixing member are assembled to an image forming apparatus.

FIG. 3 is a diagram illustrating a state in which a photosensitive drum and a drum fixing member are assembled to the image forming apparatus.

FIG. 4 is a diagram illustrating a drum shaft, a drum fixing member, and an engaging portion of a photosensitive drum according to the first embodiment.

FIG. 5 is a diagram illustrating a drum shaft, a drum fixing member, and an engaging portion of a photosensitive drum according to a second embodiment.

FIG. 6 is a diagram illustrating a state where a photosensitive drum is assembled in a conventional image forming apparatus.

FIG. 7 is a diagram illustrating a state where a photosensitive drum and a drum fixing member are assembled to a conventional image forming apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image forming apparatus 41 Photoreceptor drum 41a Flange 500 Drum fixing member 500a Engaging part 700 Drum shaft

Claims (1)

[Claims] A photosensitive drum having a flange at an end;
In an image forming apparatus having a drum fixing member that engages with the flange, and a drum shaft that supports the photosensitive drum, between the flange of the photosensitive drum and the drum fixing member, the drum shaft and the drum fixing member And a specific engagement portion is provided between the flange of the photosensitive drum and the drum shaft so that only the flange of the specific photosensitive drum, the drum fixing member, and the drum shaft can be engaged. An image forming apparatus comprising: