JPH0926741A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent image in which toner and dust or the like are prevented form entering and an image forming body is not soiled by providing a fixing rod at a panel member and attaching the image forming body and an image exposure means through the fixing rod. SOLUTION: In a state where the holding member 20 provided with an exposure optical system 12 is included in a photoreceptor drum 10, the holding member 20 is fitted in having a supporting shaft 50 as the guide for the center hole of the holding member 20, and the falling preventing part 24 of a bearing provided at a disk part 22 is fitted in the receiving part 102a of a front side plate 102. Then, the exposure optical system 12 is aligned with respect to the photoreceptor drum 10 where a screw 53 provided at the front side plate 102 is aligned and fitted in a hole provided at the disk part 22 of the holding member 20. A processing unit 100 is constituted by respectively tightening nuts 52a and 53a on a screw 52 provided at the left end part of the supporting shaft 50 and the screw 53 provided on the front side plate 102 and fixing the holding member 20 at a housing 101.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a copying machine, a printer, an F
In an image forming apparatus such as AX, charging means is provided on the peripheral surface of the image forming body,
The present invention relates to an electrophotographic image forming apparatus that forms an image by arranging an image exposing unit and a developing unit, and particularly, a plurality of charging units, an image exposing unit and a developing unit arranged on the peripheral surface of the image forming member. The present invention relates to an electrophotographic color image forming apparatus that forms a color image by superposing toner images during one rotation.

[0002]

2. Description of the Related Art Conventionally, as one method for forming a multicolor image, a color image is formed by sequentially performing charging, image exposure and development for each color within one rotation of one photoconductor. Forming devices are known.

However, although the above-mentioned color image forming apparatus enables high-speed image formation as a method of forming a multicolor image, a charging device, an image exposing means and a developing device are provided within one rotation of the photoconductor. It is necessary to dispose a plurality of sets, and the image exposure optical system may be contaminated with toner leaking from the developing device in the vicinity, which may impair the image quality. To avoid this, the distance between the image exposing means and the developing device should be increased. Since it is necessary, there is a contradiction that the diameter of the photoreceptor is inevitably increased and the apparatus is enlarged. For the purpose of avoiding this drawback, the substrate of the image forming body is formed of a transparent material, and a plurality of image exposing means are housed therein, and the image is exposed through the substrate to the photosensitive layer formed on the outer periphery thereof. An apparatus of the form is proposed, for example, by Japanese Patent Laid-Open No. 5-307307.

[0004]

However, in the apparatus according to the above-mentioned proposal, the structure is complicated because a large number of image exposing means are arranged inside the image forming body, and a large number of chargers and developing units are arranged outside the image forming body. There are drawbacks in that the attachment / detachment operation of the exposure means becomes complicated, the handleability deteriorates, and it is difficult to maintain the positional accuracy between the respective equipments. Further, it is difficult to dispose the exposure optical system, which is the image exposure means fixed inside, to rotate the image forming body or to attach or detach the image exposing means or the image forming body.

The distance between the exposure optical system and the image forming body must be coaxially positioned and maintained with a high accuracy of ± 50 μm. In the case where the exposure optical system is detachable, the image exposure can be performed depending on the attachment / detachment method. The resist or image formation position of the image changes and a good image cannot be obtained, and especially when the exposure optical system inside the image forming body is attached or detached, the image forming body may come into contact with and damage the image forming body. If the image forming body is damaged or damaged, or comes into contact with a member inside the apparatus when the image forming body is attached or detached, the image forming body is damaged or damaged, and a good image cannot be obtained. Further, when the exposure optical system is attached or detached, toner or dust from the outside enters the inside of the image forming body and adheres to the inner surface of the image forming body to stain the image forming body, resulting in a problem that a good image cannot be obtained. .

As a result of solving and improving this point, the present invention provides
When the exposure optical system or the image forming body disposed inside the image forming body is attached or detached, the image forming body is not damaged or damaged, and when the exposure optical system is attached or detached, An object of the present invention is to provide an image forming apparatus capable of preventing the entry of toner, dust and the like and obtaining a good image without contaminating the image forming body, particularly a color image forming apparatus capable of obtaining a good color image for superimposing toner images. It was done.

[0007]

An object of the present invention is to provide an image forming apparatus having an image forming body for forming a latent image and an image exposing means along the inner peripheral surface of the image forming body, the panel of the image forming apparatus. This is achieved by an image forming apparatus characterized in that a fixing rod is provided on a member, and the image forming body and the image exposing means are mounted through the fixing rod (first invention).

Further, the above-mentioned object is to provide an image forming body for forming a latent image and an image forming device provided with an image exposing means along an inner peripheral surface of the image forming body, the image forming body and the image exposing means. A process unit that includes a process unit that is detachable from the image forming apparatus and a fixing rod that is fixed to a housing of the process unit are provided, and the image forming body and the image exposure unit are mounted through the fixing rod. This is achieved by a characteristic image forming apparatus (second invention).

Further, the above-mentioned object is to dispose a charging means and a developing means outside the image forming body for forming a latent image and an image exposing means inside and to charge the image forming body by the charging means. An image forming apparatus that forms an image on the image forming body by forming an image on the image forming body by developing the image forming body by exposing the image forming body by the image exposing means, This is achieved by an image forming apparatus characterized in that a panel member of the image forming apparatus is provided with a protective cover for the image forming body which can be opened and closed when the image exposing means is attached and detached (third invention).

Further, the above-mentioned object is to arrange a charging means and a developing means on the outside of an image forming body for forming a latent image and an image exposing means on the inside, and charge the image forming body by the charging means. An image forming apparatus that forms an image on the image forming body by forming an image on the image forming body by developing the image forming body by exposing the image forming body by the image exposing means, A process unit that includes the image forming body and the image exposing unit and is detachable from the image forming apparatus is provided, and a protective cover of the image forming unit that can be opened and closed when the image exposing unit is attached and detached is provided in a housing of the process unit. This is achieved by an image forming apparatus characterized by being provided (fourth invention).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The image forming process and each mechanism of a color image forming apparatus, which is an example of an image forming apparatus suitable as an example of the present invention, and the main configuration of the color image forming apparatus are suitable for applying the present invention. This will be described with reference to FIGS. FIG. 1 is a sectional view of a color image forming apparatus as an embodiment of an image forming apparatus suitable for carrying out the present invention, and FIG. 2 is a sectional view of a process unit provided in a main part of FIG. Yes, FIG. 3 is a schematic configuration diagram showing the assembly configuration of the process unit.
FIG. 3 is a schematic cross-sectional view taken along the line AA of the process unit of FIG.

In the color image forming apparatus of this embodiment, the base of the photosensitive drum, which is an image forming body, is formed of a transparent material, and the conductive base and the photosensitive layer are provided on the outer peripheral surface of the transparent base. This is a structure in which a drum is used, and an image exposure unit is arranged inside the photosensitive drum, and an image forming process unit such as a charger, a developing unit, a transfer unit, a static eliminator, and a cleaning unit is arranged outside the drum.

The photosensitive drum 10, which is an image forming body, is provided with, for example, a cylindrical base body formed of a transparent member such as optical glass or a transparent acrylic resin inside, and a transparent conductive layer, a, on the outer periphery of the base body. A photosensitive layer such as a Si layer or an organic photosensitive layer (OPC) is formed on a drum, and is driven and rotated clockwise in a grounded state.

In this embodiment, in the photoconductor layer of the photoconductor drum, which is the image forming point of the exposure beam for image exposure, an appropriate contrast is obtained with respect to the light attenuation characteristics (photocarrier generation) of the photoconductor layer. It suffices that the exposure light amount has a wavelength that can be applied. Therefore, the light transmittance of the transparent substrate of the photosensitive drum in the present embodiment does not need to be 100%, and may have a characteristic that some light is absorbed when the exposure beam is transmitted. As the material of the light-transmitting substrate, acrylic, fluorine, polyester, polycarbonate, polyethylene terephthalate, which is used for soda glass, Pyrex glass, borosilicate glass and general optical members,
Various translucent resins such as can be used. In addition, as a transparent conductive layer, indium tin oxide (IT
O), tin oxide, lead oxide, indium oxide, copper iodide,
A light-transmissive metal thin film made of Au, Ag, Ni, Al, or the like is used. As a film forming method, a vacuum deposition method, an active reaction deposition method, various sputtering methods, various CVD methods,
A dip coating method, a spray coating method, or the like is used. Also,
As the photoconductor layer, amorphous silicon (a-S
i) An alloy photosensitive layer, an amorphous selenium alloy photosensitive layer, or various organic photosensitive layers (OPC) can be used.

The scorotron charger 11, which is a charging means, is used in the image forming process of each color of yellow (Y), magenta (M), cyan (C) and black (K), and the above-described organic photosensitive member of the photosensitive drum 10 is used. The body layer is charged by a control grid held at a predetermined potential and a corona discharge by a discharge wire to give a uniform potential to the photoconductor drum 10.

An exposure optical system 12 which is an image exposure means for each color.
Is a linear FL (phosphor emission), EL (electroluminescence), PL (plasma discharge), LE in which light emitting elements arranged in the axial direction of the photoconductor drum 10 are arranged in an array.
D (light emitting diode), linear LISA (photomagnetic effect optical shutter array) in which elements having an optical shutter function are arranged, PLZT (transmissive piezoelectric element shutter array), L
An exposure element such as a CS (liquid crystal shutter) and a SELFOC lens as an equal-magnification imaging element are configured as a unit, and are attached to a holding member 20 that holds an exposure optical system provided inside the photosensitive drum 10. The image signal of each color read by a separate image reading device is sequentially taken out from the memory, and the exposure optical system 1 for each color is provided.
2 are respectively input as electric signals. The emission wavelength of the light emitting device used in this example is in the range of 600 to 900 nm.

Development which is a developing means for each color using a non-contact developing method in which one-component or two-component developers of yellow (Y), magenta (M), cyan (C) and black (K) are respectively contained. Each of the containers 13 includes a developing sleeve 131 that rotates in the same direction with a predetermined gap from the peripheral surface of the photosensitive drum 10.

The developing device 13 for each color described above applies an electrostatic latent image on the photosensitive drum 10 formed by the charging by the scorotron charger 11 and the image exposure by the exposure optical system 12 by applying a developing bias voltage. Reverse development in a non-contact state.

The original image is temporarily read as an image signal for each color of Y, M, C and K from an image read by an image pickup device or an image edited by a computer in an image reading apparatus separate from this apparatus. Store and store in memory.

When image recording is started, a photoconductor drive motor (not shown) is rotated to rotate the photoconductor drum 10 in the clockwise direction, and at the same time, a Y scorotron charger is arranged at the lower left part of the photoconductor drum 10. The charging action of 11 starts the application of the potential to the photoconductor drum 10.

After a potential is applied to the photoconductor drum 10, exposure by an electric signal corresponding to a first color signal, that is, a Y image signal is started in the Y exposure optical system 12, and the surface of the photoconductor drum 10 is rotated by scanning the drum. Y of the original image on the photosensitive layer
To form an electrostatic latent image corresponding to the image of.

The latent image is reversal-developed by the Y developing device 13 with the developer on the developing sleeve in a non-contact state, and a yellow (Y) toner image is formed according to the rotation of the photosensitive drum 10.

Next, the photoconductor drum 10 is charged on the yellow (Y) toner image and further by a charging action of a magenta (M) scorotron charger 11 arranged on the left side of the photoconductor drum 10 and above Y. Exposure is performed by an electric signal corresponding to the second color signal of the M exposure optical system 12, that is, the image signal of M, and the yellow (Y) is produced by non-contact reversal development by the developing device 13 of M. A toner image of magenta (M) is sequentially superposed on the toner image of 1.

A cyan (C) scorotron charger 1 disposed on the photosensitive drum 10 by the same process.
Further, a cyan (C) toner image corresponding to the third color signal is generated by the exposure optical system 12 for C and the developing device 13 for C, and a black (C) toner image is disposed on the right side of the photosensitive drum 10 and below C. K) Scorotron charger 11, exposure optical system 12
A black (K) toner image corresponding to the fourth color signal is sequentially superimposed and formed by the developing device 13, and a color toner image is formed on the peripheral surface of the photosensitive drum 10 within one rotation. .

These Y, M, C and K exposure optical systems 12
The exposure of the organic photosensitive layer of the photoconductor drum 10 is performed through the transparent substrate described above from the inside of the drum.
Therefore, the exposure of the images corresponding to the second, third, and fourth color signals is performed without any influence from the previously formed toner image, and is equivalent to the image corresponding to the first color signal. It is possible to form an electrostatic latent image. In order to stabilize the temperature inside the photosensitive drum 10 and prevent the temperature from rising due to the heat generated by the exposure optical system 12, a material having good thermal conductivity is used for the holding member 20, a heater is used for low temperature, and a high temperature is used for high temperature. Can be suppressed to the extent that it does not interfere by taking measures such as air cooling and heat radiation to the outside.

In addition, the replenishing developer for each color is supplied to the replenishing tank 81.
Further, the toner is supplied to the developing device 13 of a corresponding color, stirred by the two stirring rollers 136 and 137, and then supplied to the developing sleeve 131 by the toner supply roller 135. Abutting rollers 138 and 139, which are rotated by the photosensitive drum 10, are provided at both ends of the developing sleeve 131 outside the image area.

The developing device 13 is pressed by a pressing member (not shown), for example, a pressing spring, and the abutting rollers 138 and 139 as gap holding members press the photosensitive drum 10 into pressure contact. The developing sleeve 131 is brought into contact with the photosensitive drum 10 by the abutting rollers 138 and 139.
And a predetermined value, for example, a gap of 100 to 1000 μm, is kept in a non-contact state, and during the developing action by the developing device 13 for each color, a developing bias in which a direct current or an alternating current is applied to the developing sleeve 131 is applied, Jumping development is performed by a one-component or two-component developer housed in the developing unit, and a DC bias having the same polarity as the toner is applied to the photosensitive drum 10 that grounds the conductive layer to adhere the toner to the exposed portion. Non-contact reversal development is performed. The developer on the developing sleeve 131 after development is scraped off by a scraping plate (not shown).

A transfer sheet P, which is a transfer material, is sent out from a sheet feeding cassette 15 which is a transfer material storing means, and is conveyed to a timing roller 16. The color toner image formed on the peripheral surface of the photoconductor drum 10 is transferred to the photoconductor drum 10 by driving the timing roller 16 in the transfer device 14a.
It is transferred to the transfer paper P that is fed in synchronization with the toner image above.

The transfer paper P, on which the toner image has been transferred, is separated from the peripheral surface of the drum by removing the charge in the static eliminator 14b, and is then transferred to the fixing device 17 by the transfer belt 14e which is a transfer unit. Fixing device 17 as fixing means
After being heated and pressure-bonded to fuse and fix the toner on the transfer paper P, the toner is ejected from the fixing device 17 and is conveyed by the paper ejection conveyance roller pair 18 a and is ejected via the paper ejection rollers 18 onto the tray on the upper part of the apparatus. It is discharged with the surface facing down.

On the other hand, the photosensitive drum 10 from which the transfer paper is separated
In the cleaning device 19 which is a cleaning unit, the photosensitive drum 1 is moved by the cleaning blade 19a.
The 0th surface is rubbed to remove and clean residual toner, and the toner image of the original image is continuously formed or is temporarily stopped to form a new toner image of the original image. The waste toner scraped off by the cleaning blade 19a and the cleaning roller 19b is removed by the toner transport screw 19
It is discharged to the waste toner container 82 through the c and the toner transport pipe 19d. After the cleaning is completed, the cleaning blade 19a and the cleaning roller 19b are provided on the photosensitive drum 1 in order to prevent damage to the photosensitive drum 10.
It is kept apart from 0.

The front and rear side plates 102 and 103 and the left and right side plates 104 and 105, which are frame bodies, are used to form the process unit 10.
The housing 101 of 0 is framed. Rear plate 1 of housing 101
A bearing 141 as one bearing member of the photosensitive drum 10 is press-fitted into the receiving portion 103a of No. 03. Further, a screw hole 103b provided at the center of the receiving portion 103a of the rear side plate 103 is provided with a screw portion 5 provided at the right end portion of the support shaft 50.
1 is screwed in, and the support shaft 50 is fixed to the rear side plate 103.

The photosensitive drum 10 has a front flange 111,
A photoreceptor drum driving gear 10g is provided at the end, and is held by a flange 112. Photoconductor drum 1
The bearing 142 as one bearing member is press-fitted onto the inner peripheral surface of the receiving portion 112a of the rear flange 112 of 0,
Further, the bearing 143 as the other bearing member is press-fitted onto the outer peripheral surface of the receiving portion 111a of the front flange 111, and the retaining ring 113 is further fitted.

The holding member 20 of the photosensitive drum is the cylindrical portion 2
1, the disc portion 22, and the central hole 23 of the cylindrical portion, and the exposure optical system 12 for each color is fixed to each position of the cylindrical portion 21 with the axis of the holding member 20 aligned.

The inner peripheral surface of the bearing 142 is fitted into the support shaft 50 through the hole of the receiving portion 102a provided on the front side plate 102 of the housing 101, so that the photosensitive drum 10 becomes the housing 101.
The outer peripheral surface of the receiving portion 112a of the rear flange 112 of the photosensitive drum 10 is inserted into the inner peripheral surface of the bearing 141 provided on the rear side plate 103 of the housing 101, and the front flange 111 of the photosensitive drum 10 is received. The outer peripheral surface of the bearing 143 press-fitted into the portion 111a is fitted into the receiving portion 102a of the front side plate 102 of the housing 101, and the housing 101 and the photosensitive drum 10 are coupled. Since the photosensitive drum is inserted using the spindle as a guide, the photosensitive drum is attached and detached without coming into contact with the housing and damaging or damaging the photosensitive drum.

Further, with the holding member 20 provided with the exposure optical system 12 being housed in the photosensitive drum 10, the support shaft 5 is
The holding member 20 is fitted by using 0 as a guide for the center hole 23 of the holding member 20, and the retaining portion 24 of the bearing provided on the disk portion 22 is fitted into the receiving portion 102a of the front side plate 102. At this time, the screws 53 provided on the front side plate 102
A hole 25 provided in the disk portion of the holding member 20 is aligned and fitted into the optical disk to position the exposure optical system 12 with respect to the photosensitive drum 10. The nuts 52a and 53a are respectively tightened into the screw portion 52 provided on the left end portion of the support shaft 50 and the screw 53 provided on the front side plate 102, the holding member 20 is fixed to the housing 101, and the process unit 10
0 is configured. Since the holding member provided with the exposure optical system using the support shaft as a guide is inserted into the photosensitive drum, the holding member and the exposure optical system come into contact with the photosensitive drum to damage or damage the inner surface of the photosensitive drum. It is attached and removed without doing.

In this state, the photosensitive drum 10 and the holding member 20 having the exposure optical system 12 for each color are supported by the support shaft 5.
It is positioned and attached with the axis centered around 0. Therefore, high-precision positioning is performed between the exposure optical system and the photoconductor drum that is the image forming body, the positional relationship between the exposure optical system and the photoconductor drum is maintained even during assembly or use, and the high-precision positioning of the exposure optical system is ensured. An image forming apparatus capable of obtaining a good image in which the resist is retained can be realized. In particular, a color image forming apparatus capable of forming a good color image of a superimposed toner image can be provided.

Further, as a main part of the above-described image forming process, a cleaning device 19 is provided around the photosensitive drum 10, and Y and M developing devices 13 and a replenishing tank 81 are provided on the left side of the photosensitive drum 10. C and K developing device 13 on the right side,
The replenishment tank 81 is attached, and the process unit 1
00, a waste toner container 82, and a scorotron charger 11 for each color, which is a charging unit, on the outside of the photosensitive drum 10.
Are attached, and the process unit 100 is configured.

When the photoconductor drum 10 or the holding member 20 is attached or detached, the cleaning device 19 and the developing device 13 are separated from the photoconductor drum 10 by a contacting / separating mechanism (not shown). With the holding member 20 provided with the photoconductor drum 10 and the exposure optical system 12 mounted, the abutting rollers 138 and 139 provided at both ends of the developing device 13 are attached to the photoconductor drum 1 respectively.
It is in contact with both ends of 0.

The process unit 100 has two guide members T1 and T2 provided in the color image forming apparatus, and guide rails R provided on both sides of the process unit 100.
When R1 and R2 are inserted and mounted in the color image forming apparatus, the gear 10g for driving the photoconductor drum, which is provided on the rear flange 112 of the photoconductor drum 10, is the gear G1 provided in the process unit 100. Through, the photosensitive drum 10 is driven by being coupled to a drive motor provided in the apparatus main body (not shown). When the process unit 100 is attached to or detached from the apparatus main body, the transfer device 14a, the static eliminator 14b, the transfer belt 14e, etc. are separated from the photoconductor drum 10.

During maintenance and replacement of the exposure optical system and the photosensitive drum, the holding member 20 to which the exposure optical system 12 is fixed and the photosensitive drum 1 with the nuts 52a and 53a removed.
0 and 0 are held by the spindle 50 and are attached and detached. Therefore, when the holding member 20 is attached or detached, the holding member 20 makes the photosensitive drum 1
No contact with the inner surface of the photosensitive drum 10 to damage the inner surface of the photosensitive drum 10 or damage the photosensitive drum 10, and when the photosensitive drum 10 is attached or detached, The holding member 20 and the photoconductor drum 10 are kept in contact with the housing 101 and the scorotron charger 11 without damaging or damaging the photoconductor drum 10.
Is attached and detached.

In the above embodiments, the method of holding and attaching / detaching the photosensitive drum, which is the image forming body, and the supporting member provided with the exposure optical system, using the support shaft, has been described using the process unit. However, the configuration of the present invention is not necessarily limited to the process unit, and is also used, for example, when the photosensitive drum and the exposure optical system are attached to front and rear side plates as panel members provided in the apparatus main body. Of course. Further, in the above embodiment, the bearing 141 does not necessarily have to be used.

A color image forming apparatus which is another embodiment of the image forming apparatus of the present invention is shown in FIGS. FIG. 5 is a diagram showing an assembled configuration of a main part of a color image forming apparatus according to another embodiment, and FIG. 6 is a schematic sectional view of a main part of a color image forming apparatus according to another embodiment. The image forming process and each mechanism of the color image forming apparatus are the same as those in the above-described embodiment, and the members having the same structure and function are denoted by the same reference numerals.

In this embodiment, the support shaft 50 has a screw portion 51 provided at the right end portion fixed to the rear panel 4 as a panel member of the color image forming apparatus main body by a nut 51a. And a cleaning device 19, a developing device 12, and a replenishing tank 8 on the outer periphery of the photosensitive drum 10.
1. The process unit 100, to which the waste toner container 82 and the scorotron charger 11 are attached, processes the support shaft 50 on the inner circumference of the bearing 142 and the two guide members T1 and T2 provided in the color image forming apparatus. The guide rails R1 and R2 provided on both sides of the unit 100 are inserted and mounted on the color image forming apparatus through the hole 3a of the front panel 3 as a panel member of the mounting body.

Subsequently, with the holding member 20 provided with the exposure optical system 12 being contained in the photosensitive drum 10, the holding member 20 is fitted by using the support shaft 50 as a guide of the center hole 23 of the holding member 20, The bearing retaining portion 24 provided on the disk portion 22 is fitted into the receiving portion 102a of the front side plate 102. At this time, the screws 5 provided on the front side plate 102
A hole 25 provided in the disk portion of the holding member 20 is aligned and fitted into the positioning member 3 to position the exposure optical system 12 with respect to the photosensitive drum 10. A screw portion 52 provided on the left end of the support shaft 50 and a screw 53 provided on the front side plate 102.
The nuts 52a and 53a are respectively tightened in and, and the holding member 20 is fixed to the housing 101.

Since the holding member provided with the exposure optical system using the spindle as a guide is inserted into the photosensitive drum, the holding member and the exposure optical system come into contact with the photosensitive drum to damage the inner surface of the photosensitive drum. It can be attached and removed without being damaged.

A gear 10g for driving the photoconductor drum, which is provided on the rear flange 112 of the photoconductor drum 10, is connected to a drive motor M1 provided on the main body of the apparatus through a gear G1 provided on the process unit 100, The photoconductor drum 10 is driven.

When the process unit 100 is attached to or detached from the apparatus main body, the transfer unit 14a, the static eliminator 14b, the transfer belt 14e, etc. are separated from the photosensitive drum 10.

During maintenance and replacement of the exposure optical system and the photosensitive drum, the holding member 20 to which the exposure optical system 12 is fixed and the photosensitive drum 10 are supported with the nuts 52a and 53a removed. The process unit 100 is held by the shaft 50.
More removable. Therefore, when attaching and detaching the holding member 20,
The holding member 20 does not contact the inner surface of the photoconductor drum 10 to damage the inner surface of the photoconductor drum 10 or damage the photoconductor drum 10, and also when the photoconductor drum 10 is attached or detached. The drum 10 is the process unit 100
The holding member 20 and the photoconductor drum 10 are attached and detached without coming into contact with the housing 101 or the scorotron charger 11 to damage or damage the photoconductor drum 10.

When the photosensitive drum 10 is attached or detached, the developing device 12 and the cleaning device 19 are operated by a contacting / separating mechanism (not shown).
The photoconductor drum 10 is attached and detached in a state in which are separated from each other.

Next, FIG. 7 shows an embodiment of a protective cover for preventing toner, dust, and the like from entering from the outside when the exposure optical system is attached or detached. The image forming process of the color image forming apparatus and each mechanism and process unit are the same as those in the embodiment described in FIG. 1, and members having the same structure and function are denoted by the same reference numerals.

FIG. 7A shows a front plate 102 of a housing 101 of a process unit 100 provided with a protective cover 60 which is rotated around a fulcrum 61. The protective cover 60 is opened and the exposure optical system 12 is opened. The holding member 20 holding is attached and detached. As shown in FIG. 7B, a protective cover 60a opened by the rotating shaft 61a may be provided. Holding member 2
When 0 is pulled out and is removed from the process unit 100 or after the holding member 20 is attached, the protective covers 60, 60a
Is closed by a spring (not shown) that acts in the closing direction, and is locked to the front side plate 102 by an unillustrated locking member such as a click when opening.

Another embodiment of the protective cover is shown in FIG. Four guide pins 62a that fit into four holes provided in the front side plate 102 of the housing 101 of the process unit 100,
The holding member 20 is attached and detached in a state where the protective cover 60b that can be pulled out by 62b, 62c, and 62d is pulled out.

FIG. 9 shows an embodiment in which the protective cover is used as a guide for inserting the holding member. A protective cover 60c opened forward by the rotating shafts 63a and 63b is provided on the front side plate 102 of the process unit 100. The holding member 20 is attached / detached using the arcuate portion 64 of the protective cover 60c as a guide when the holding member 20 is attached / detached.

In the above embodiment, the mounting of the protective cover was described using the process unit, but the structure of the present invention is not necessarily limited to the process unit, and for example, a side plate as a panel member of the apparatus main body. It goes without saying that the present invention is also applied to the case where the protective cover is provided on the.

By providing the above-mentioned protective cover and closing the protective cover during maintenance and inspection of the exposure optical system,
Toner, dust, and the like from the outside do not enter through the take-out hole of the holding member of the front plate and stain the inner surface of the photosensitive drum.

[0056]

According to the first or second aspect of the present invention, the holding member to which the exposure optical system is fixed and the photosensitive drum are held by the support shaft during maintenance and replacement of the exposure optical system and the photosensitive drum. Detachable. Therefore, when the holding member is attached or detached, the holding member does not come into contact with the photoconductor drum to damage or damage the inner surface of the photoconductor drum, and also when the photoconductor drum is attached or detached. The holding member and the photosensitive drum can be attached and detached without damaging or damaging the photosensitive drum by contacting with the housing or the scorotron charger.

According to the third or fourth aspect of the present invention, by providing the protective cover, toner and dust from the outside enter through the take-out hole of the holding member of the front side plate at the time of maintenance and inspection of the exposure optical system. Does not stain the inner surface of the body drum.

According to the fifth aspect, the holding member to which the exposure optical system is fixed can be easily attached and detached without damaging the exposure optical system.

[Brief description of drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus which is an example of an image forming apparatus suitable for carrying out the present invention.

FIG. 2 is a sectional view of a process unit provided in a main part of FIG.

FIG. 3 is a schematic configuration diagram showing an assembly configuration of a process unit.

FIG. 4 is a schematic cross-sectional view taken along the line AA of the process unit of FIG.

FIG. 5 is a diagram showing an assembly configuration of main parts of a color image forming apparatus according to another embodiment.

FIG. 6 is a schematic cross-sectional view of a main part of a color image forming apparatus according to another embodiment.

FIG. 7 is a diagram showing an example of a protective cover.

FIG. 8 is a view showing another embodiment of the protective cover.

FIG. 9 is a diagram showing an example in which a protective cover is used as an insertion guide for a holding member.

[Explanation of symbols]

 3 Front Panel 4 Rear Panel 10 Photosensitive Drum 12 Exposure Optical System 20 Holding Member 50 Spindle 60, 60a, 60b, 60c Protective Cover 100 Process Unit 101 Housing 102 Front Side Plate 103 Rear Side Plate 141, 142, 143 Bearing R1, R2 Guide Rail T1, T2 guide member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Hama ▼ Tauta Takata 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Company

Claims (5)

[Claims] 1. An image forming apparatus comprising an image forming body for forming a latent image and an image exposing means along an inner peripheral surface of the image forming body, wherein a fixing rod is provided on a panel member of the image forming apparatus.
An image forming apparatus, wherein the image forming body and the image exposing means are mounted through the fixing rod. 2. An image forming apparatus comprising an image forming body for forming a latent image and an image exposing means along an inner peripheral surface of the image forming body, the image forming body and the image exposing means being included in the image forming apparatus. The image forming apparatus is provided with a detachable process unit and a fixing rod fixed to a housing of the process unit, and the image forming body and the image exposing unit are attached through the fixing rod. Forming equipment. 3. A charging means and a developing means are provided outside an image forming body for forming a latent image, and an image exposing means is provided inside the latent image, and the image forming body is charged by the charging means, and the image exposing means is provided. An image forming apparatus for forming an image on the image forming body by exposing the image forming body to image exposure by the developing means to form a toner image on the image forming body by development. An image forming apparatus, wherein the panel member is provided with a protective cover for the image forming body which can be opened and closed when the image exposing means is attached and detached. 4. A charging means and a developing means are provided outside an image forming body for forming a latent image, and an image exposing means is provided inside the latent image, and the image forming body is charged by the charging means, and the image exposing means is provided. In the image forming apparatus, an image is formed on the image forming body by exposing the image forming body to image exposure by the developing means to form a toner image on the image forming body. And a process unit that includes the image exposure unit and is detachably attached to the image forming apparatus, and a protective cover of the image formation unit that can be opened and closed when the image exposure unit is attached and detached is provided in a housing of the process unit. A characteristic image forming apparatus. 5. The image forming apparatus according to claim 3, wherein the protective cover serves as a guide when the image exposing unit is attached and detached.