JPH09190131A - Color image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily exchange an electrostatic charger and a developing unit whose frequency in use is high, to exchange them without damaging them and to easily clean them by arranging an image exposure means in the interior of an image forming body and integrally unitizing the electrostatic charger and the developing unit for forming an identical toner image so that they can be loaded and unloaded with respect to a color image forming device main body. SOLUTION: An exposure unit 12 being as the image exposure means of every color is arranged so that the exposure position thereof on a photoreceptor drum 10 is set on an upstream side in the rotating direction of the drum 10 with respect to a developing sleeve 131 between the corona electric discharge electrode 101 of the scorotron electric charger 100 and the developing position of the developing unit 13. The unit 12 is fitted to a fixing member 20 holding the unit 12 provided by being included in the drum 10. Then, the image data of the respective colors stored in a memory is successively read out from the memory and respectively inputted to the unit 12 of every color as an electric signal.

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 such as a copying machine, a printer, and a FAX, in which a plurality of chargers, an image exposing unit and a developing unit are arranged around the image forming body. The present invention relates to an electrophotographic color image forming apparatus that forms a color image by superimposing toner images while rotating.

[0002]

2. Description of the Related Art Conventionally, as a method for forming a multicolor image, a single color formed on each image forming body is provided with image exposing means, chargers, developing devices, etc., in the same number as the colors necessary for forming an image. The toner image of is superposed on the transfer material to form a color image, and the color image forming apparatus and the image forming body are rotated a plurality of times,
A color image forming apparatus that forms a color image by repeating charging, image exposure, and development for each color, or a color image that forms a color image by sequentially performing charging, image exposure, and development within one rotation of the image forming body. Forming devices and the like are known.

However, each of the above-mentioned image forming apparatuses is provided with the same number of image exposing means, charging devices, developing devices and the like as the colors required for image formation, and the monochromatic toner images formed on the photoconductor are superposed on the transfer material. A color image forming apparatus for forming a color image has a drawback that the volume of the apparatus is increased because a plurality of image forming bodies and transfer materials need to be conveyed. On the other hand, by rotating the image forming body a plurality of times, each color A color image forming apparatus that forms a color image by repeating charging, image exposure and development is
Although the volume is reduced, there is a restriction that the size of the formed image is limited to the surface area of the photoconductor or less.

In view of this, a color image forming apparatus which forms a color image by sequentially performing charging, image exposure and development within one rotation of the image forming body has no restriction on the size of the image and is capable of high speed image formation. There are advantages such as Furthermore,
For example, JP-A-5-307307 proposes a device in which a transparent substrate is used as a substrate of an image forming body and an image exposing means is arranged inside the image forming body to downsize the apparatus.

[0005]

However, in the apparatus according to the above-mentioned proposal, the charger and the developer are arranged close to the outside with respect to the image exposure means arranged inside the image forming body. It is necessary to perform a lot of replacement and cleaning work of the charging device that is extremely dirty and requires stable corona discharge, and the developing device and the like for changing the developer.
Poor workability when replacing or cleaning the charger or developer.
In particular, when forming a color image, a specific color is often used to form the same toner image, and it is necessary to replace or clean a charging device or a developing device of a frequently used color. There is also a problem that the charging device and the developing device are easily damaged during replacement or cleaning.

The present invention solves this problem and makes it easy to replace a charging device or a developing device that is frequently used, without causing damage during replacement, and to easily clean dirt on the charging device or the developing device. A color image forming apparatus is provided.

[0007]

The object of the present invention is to provide a charger for charging an image forming body around a rotating image forming body,
A plurality of sets of image exposing means for exposing a charged image forming body to form a latent image and a developing device for developing the latent image formed on the image forming body to form a toner image are arranged, and the image forming is performed. A plurality of toner images are formed on the image forming body by sequentially repeating charging of the image forming body by the charging device, image exposure by the image exposing means, and development by the developing device during one rotation of the body. In the color image forming apparatus for superimposing the toner images of the above, the image exposing unit is arranged inside the image forming body, and a charger and a developing unit for forming the same toner image can be attached to and detached from the main body of the color image forming apparatus. And a color image forming apparatus.

In the second and fourth aspects, the protective cover for protecting the charging device and the developing device includes at least a sharp electrode of the charging device, a corona discharge electrode such as a corona wire, a developing sleeve of the developing device, a development control electrode, and the like. It is for protection, and it is not necessary to protect the frame of the charger or the developing device.

In the third and fourth aspects, the cleaning member for cleaning the charging device and the developing device means at least a corona discharge electrode such as a sharp electrode or a corona wire that directly contributes to the charging of the charging device, or the development of the developing device. This is to clean the development control electrode and the like that contribute to the above, and it is not necessary to clean the frame of the charging device and the developing device.

[0010]

Embodiments of the present invention will be described below. Note that the description in this column does not limit the technical scope of the claims and the meaning of terms. Also, the following assertive description in the embodiment of the present invention indicates the best mode, and does not limit the meaning of the terms of the present invention or the technical scope.

Embodiment 1 An image forming process and each mechanism of a color image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional configuration diagram of a color image forming apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of an essential part of FIG. 1, and FIG. 3 is an enlarged view of an essential part of FIG. And
FIG. 4 is a diagram showing a corona discharge electrode, and FIG. 5 is a diagram showing a development control electrode.

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

The photosensitive drum 10, which is an image forming body, is provided with a cylindrical substrate formed of a transparent member of transparent acrylic resin inside, and a transparent conductive layer, an a-Si layer or an organic photosensitive layer (OPC). ) Is formed on the outer circumference of the substrate, and is rotated clockwise in the state of being grounded as shown by the arrow in FIG.

In the present embodiment, it is sufficient that the photoconductive layer of the photosensitive drum has an exposure light amount capable of imparting an appropriate contrast. 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 translucent substrate, an acrylic resin, particularly one polymerized using methyl methacrylate monomer, has transparency, strength, accuracy,
Acrylic, fluorine used for other general optical members, etc.
Various translucent resins such as polyester, polycarbonate, and polyethylene terephthalate can be used. The light-transmitting conductive layer was made of indium tin oxide (ITO), tin oxide, lead oxide, indium oxide, copper iodide, Au, Ag, Ni, Al, etc. A metal thin film is used, and as a film forming method, a vacuum vapor deposition method, an active reaction vapor deposition method, various sputtering methods, various CVs.
D method, dip coating method, spray coating method and the like are used.
Further, as the photoconductor layer, amorphous silicon (a
-Si) alloy photosensitive layer, amorphous selenium alloy photosensitive layer, and various organic photosensitive layers (OPC) can be used.

Scorotron charger 100 as a charger
Is used in the image forming process of each color of yellow (Y), magenta (M), cyan (C) and black (K), and is held at a predetermined potential with respect to the above-described organic photoconductor layer of the photoconductor drum 10. The control grid and the corona discharge by the discharge electrode perform a charging action to give a uniform potential to the photosensitive drum 10.

A sharp electrode 112, which serves as a plurality of discharge electrodes, is formed at one end of the strip-shaped plate portion 111, for example, a serrated electrode or a needle-shaped electrode at a constant pitch L (mm). The corona discharge electrode 101 is formed by attaching 110 to an insulating substrate 115, for example, ceramics.

The sharpened electrode plate 110 has, for example, a plate thickness of 0.
It is made by etching a 1 mm stainless steel plate, and the curvature of the tip 113 of the sharpened electrode 112 is R.
= 40 μm or less. The control grid 105 is made by etching a stainless plate having a plate thickness of 0.1 mm, and has a mesh width of 1 mm.

The corona discharge electrode 101 is attached and fixed to the groove of the rectangular support member 102 made of an insulating resin, for example, ABS resin, with an adhesive, for example. The shield member 103 and the control grid 105 are attached and fixed to the support member 102 in parallel with the longitudinal direction of the sharpened electrode plate 110 with, for example, resin screws not shown, and the scorotron charger 10 is attached.
0 is formed.

The above scorotron charger 100 is mounted facing the photoconductor drum 10 in a direction orthogonal to the moving direction of the photoconductor drum 10, which is an image forming body. It is preferable that the drum 10 is mounted on the downstream side in the rotational direction of the drum 10 because the discharge spreads in the rotational direction of the photoconductor drum so that the charging is stable.

As shown in FIGS. 2 and 3, the exposure unit 12 as an image exposing means for each color is provided with a photosensitive drum 10.
The exposure position above is between the corona discharge electrode 101 of the scorotron charger 100 and the development position of the developing device 13 (in this embodiment, the control grid 105 provided on the scorotron charger 100 or the end of the shield member 103 is Between the tip of the development control electrode 133 provided in the developing device 13)
The developing sleeve 131 is disposed upstream of the developing sleeve 131 in the rotation direction of the photosensitive drum.

The exposure unit 12 is a light emitting element L arranged in the main scanning direction in parallel with the axis of the photosensitive drum 10.
A linear exposure element 12a in which a plurality of EDs (light emitting diodes) are arranged in an array and a SELFOC lens 12b as an equal-magnification imaging element are configured as an exposure unit attached to a holder (not shown). . The exposure unit 12 is
Exposure unit 1 included in the photosensitive drum 10
The image data of each color stored in the memory is sequentially read out from the memory and is input to the exposure unit 12 for each color as an electric signal.

As the exposure element, other linear elements in which a plurality of light emitting elements such as FL (fluorescent substance light emission), EL (electroluminescence), PL (plasma discharge), LED (light emitting diode) are arranged in an array are used. Used. The emission wavelength of the light emitting element used in this embodiment is usually Y,
Although it is in the range of 780 to 900 nm where M and C toners have high transparency, a shorter wavelength may be used since image exposure is performed from the back surface.

The developing device 13 for each color is yellow (Y),
One-component or two-component developers of magenta (M), cyan (C), and black (K) are contained respectively, and a predetermined gap is maintained between the peripheral surface of the photoconductor drum 10 and the photoconductor drum 10 at the developing position. And a developing sleeve 131 that rotates in the same direction as that of the developing sleeve 1.
31 or the developing sleeve 13 than the developing area
A development control electrode 133 provided in contact with the developer layer on the developing sleeve 131 is provided on the upstream side in the rotation direction of No. 1.

The developing control electrode 133 is the developing sleeve 131.
Is arranged parallel to the longitudinal direction of the developing casing 132.
Insulating electrode plate 1 which is a plate-shaped member attached to the
33b and a strip-shaped electrode portion 133a provided in contact with the developer layer at the tip of the electrode plate 133b. By providing the development control electrode 133, the developability is improved.

The developing device 13 for each of the above-mentioned colors is the charging and exposure unit 12 by the scorotron charger 100 described above.
The electrostatic latent image formed on the photosensitive drum 10 by the image exposure by and is reverse-developed in a non-contact state by a non-contact developing method by applying a developing bias voltage and a voltage to the developing control electrode.

In the present embodiment, the rotation of the photosensitive drum 10 indicated by the arrow in FIG. 1 is performed according to the color order in which images are formed and the arrangement of the developing devices provided on the rotated photosensitive drum according to the color order. Y, M developing unit 1 with respect to direction
3 is arranged on the left side of the photosensitive drum 10, and the C and K developing devices 13 are arranged on the right side of the photosensitive drum 10, so that Y, M
Of the Y and M scorotron charger 100 on the lower surface 132a of the developing casing 132 of the developing device 13 of FIG. 1, and the C and K scorotron charger 100 of the upper surface 132b of the developing casing 132 of the C and K developing device 13, for example. The charging / developing unit 130 is an integral unit that is fixed by screws. As shown in FIG. 3, the charging / developing unit 130 is detachably provided on the apparatus body by using rails R1 and R2 provided on the lower side of the developing device 13 as guides T1 and T2 provided on the apparatus body. .

Since the developing device of a specific color for forming the same toner image and the scorotron charging device as the charging device are configured as an integrated unit, replacement and cleaning of the charging device and the developing device are facilitated. .

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

At the start of image recording, a photoconductor drive motor (not shown) is rotated to rotate the photoconductor drum 10 in the clockwise direction shown by the arrow in FIG. 1, and at the same time, the left side of the photoconductor drum 10 is colored yellow (Y). The charging action of the Y scorotron charger 100, which is integrated with the developing device 13 and arranged on the lower surface 132a of the developing casing 132, starts to apply a potential to the photosensitive drum 10.

After the electric potential is applied to the photosensitive drum 10, the exposure of the first color signal, that is, the electric signal corresponding to the Y image data is started in the Y exposure unit 12, and the surface of the photosensitive drum 10 is exposed by the rotational scanning of the drum. An electrostatic latent image corresponding to the Y image of the original image is formed on the layer.

The latent image is reversely developed by the Y developing device 13 in a state where the developer on the developing sleeve is 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 placed on the yellow (Y) toner image, and further on the left side of the photoconductor drum 10 and above the yellow (Y) image, the magenta (M) developing device 1 is provided.
3 and a magenta (M) scorotron charger 100 which is disposed on the lower surface 132a of the developing casing 132.
Potential is given by the charging action of M, and the exposure unit 1 of M
The exposure is performed by the second second color signal, that is, the electric signal corresponding to the image data of M, and the non-contact reversal development by the developing unit 13 of M causes magenta (M) on the toner image of yellow (Y). ) Toner images are sequentially superposed and formed.

By the same process, cyan (C) is integrated with the developing device 13 for cyan (C) on the right side of the photosensitive drum 10 and is arranged on the upper surface 132b of the developing casing 132.
By the scorotron charger 100, the exposure unit 12 of C and the developing device 13 of C, a cyan (C) toner image corresponding to the third color signal is also generated.
To the right, under C, the black (K) scorotron charger 100 integrated with the black (K) developing device 13 and disposed on the upper surface 132b of the developing casing 132, the exposure unit 1
2 and the developing unit 13 sequentially form a black (K) toner image corresponding to the fourth color signal, and a color toner image is formed on the peripheral surface of the photosensitive drum 10 within one rotation. It

These Y, M, C and K exposure units 1
Exposure of the organic photosensitive layer of the photosensitive drum 10 by 2 is performed from the inside of the drum through the transparent substrate described above. 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 the same exposure as the image corresponding to the first color signal is performed. It is possible to form an electrostatic latent image.

The developing device 13 is kept in non-contact with the photoconductor drum 10 with a gap of a predetermined value by an abutting roller (not shown), and when developing 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 and a direct current voltage is applied to the electrode portion 133a of the developing control electrode 133, respectively, and jumping development is performed by a one-component or two-component developer accommodated in the developing device. And a photosensitive drum 10 for grounding a transparent conductive layer
, A non-contact reversal development is performed in which a DC bias having the same polarity as the toner is applied to adhere the toner to the exposed portion.

A transfer sheet P, which is a transfer material, is sent out from a paper feed cassette 15 which is a transfer material storage 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 onto a transfer paper P which is a transfer material that is fed in synchronization with the above toner image.

The transfer paper P on which the toner image has been transferred is discharged from the drum peripheral surface in the static eliminator 14b and separated from the peripheral surface of the drum, and is then transported to the fixing device 17 by the transport belt 14e which is a transport unit. After being heated and pressed in the fixing device 17 to fuse and fix the toner on the transfer paper P, the toner is discharged from the fixing device 17, conveyed by a pair of discharge conveyance rollers 18 a, and is transferred to the upper tray of the apparatus via the discharge rollers 18. Is discharged with the toner image surface facing down.

On the other hand, the photosensitive drum 10 from which the transfer paper is separated
Is rubbed against the surface of the photoconductor drum 10 by the cleaning blade 19a in the cleaning device 19 to remove and clean the residual toner and continue to form the toner image of the original image, or temporarily stop the toner image of a new original image. Formation. The waste toner scraped off by the cleaning blade 19a and the cleaning roller 19b is discharged to a waste toner container (not shown) by the toner conveying screw 19c. After the cleaning is completed, the cleaning blade 19a and the cleaning roller 19b are kept apart from the photoconductor drum 10 in order to prevent damage to the photoconductor drum 10.

Embodiment 2 A second embodiment will be described with reference to FIG. FIG.
FIG. 3 is a diagram showing a protective cover of a charging / developing unit.

The color image forming process, the mechanism, the scorotron charger as a charger, and the developing device are the same as those described in the first embodiment, and the same reference numerals are given to members having the same function and structure. Attach.

In this embodiment, a protective cover 301 is provided on a charging / developing unit 130 in which a scorotron charger 100 as a charger and a developing device 13 are integrated, and a developing casing 132 and a scorotron charger 100 are provided.
A protective cover 301 is rotatably provided on the charging / developing unit 130 with a shaft 302 provided on the shield member 103, a casing (not shown) of the charging / developing unit 130, or the like as a spindle. When the charging / developing unit 130 is pulled out from the main body of the apparatus, the protective cover 301 at the position indicated by the alternate long and short dash line when attached to the main body is closed by the spring or the like (not shown) as shown by the solid line in FIG. , The control grid 105 or the sharpened electrode 112 provided in the opening of the scorotron charger 100, or the development control electrode 133 or the developing sleeve 131 provided in the opening of the developing device 13.
To prevent damage to the charger and developer during maintenance and replacement.

When the charging / developing unit 130 is mounted on the apparatus main body by using the rails R1 and R2 provided on the lower side of the developing device 13 as guides T1 and T2 provided on the apparatus main body, for example. The charging / developing unit 130 is mounted with the protective cover 301 in the open state shown by the one-dot chain line in FIG.

Third Embodiment A third embodiment will be described with reference to FIG. Figure 7
7A and 7B are views showing a charging / developing unit provided with a cleaning member, and FIG. 7A is a side sectional view of the charging / developing unit according to the third embodiment.
FIG. 7B is a perspective view of FIG.

The color image forming process, the mechanism, the scorotron charger as a charger, and the developing device are the same as those described in the first embodiment, and the members having the same functions and structures are designated by the same reference numerals. Attach.

In this embodiment, a cleaning member 201 for cleaning the sharpened electrode 112 and the development control electrode 133 is provided in the charging / developing unit 130 in which the scorotron charger 100 as a charger and the developing device 13 are integrated. A handle 203 is provided at one end of a slide member 202 of the scorotron charger 100 that fits with a guide groove 103a provided in the shield member 103, for example.
By moving the grip 203 in the direction shown by the arrow in FIG. 7B, the cleaning member 201 provided on the other end of the slide member 202 is connected to the sharp electrode 112 of the scorotron charger 100 and the development control electrode 133 of the developing device 13. The sharpened electrode 112 and the development control electrode 133 are slid, especially the electrode portion 1.
33a is cleaned. Since the structure is such that cleaning can be performed by closing the protective cover 301, the charger and the developing device are not accidentally damaged during cleaning.

The sharpened electrode of the charging device and the development control electrode of the developing device, especially the electrode portion are easily cleaned, and stable charging performance and developing performance are maintained for a long time.

Fourth Embodiment A fourth embodiment will be described with reference to FIG. FIG.
FIG. 8 is a diagram showing a charging / developing unit protective cover provided with a cleaning member. FIG.
FIG. 8B is a side sectional view of the developing unit according to the fourth embodiment, and FIG. 8B is a perspective view of FIG. 8A.

The color image forming process, the mechanism, and the scorotron charger and the developing device as the charger are the same as those described in the first embodiment, and the members having the same functions and structures are designated by the same reference numerals. Attach.

In this embodiment, the protective cover 301 described in the second embodiment is provided with the cleaning member 201 for cleaning the sharpened electrode 12 and the development control electrode 133 described in the third embodiment. Yes, the cleaning by the cleaning member 201 is performed with the charging / developing unit 130 removed from the mounting body.

When the charging / developing unit 130 is removed from the mounting body by the rails R1 and R2 using the guide members T1 and T2 as guides, the protection cover 301 is closed by a spring (not shown) as shown in FIG. 8 (A). The protective cover 301 has the control grid 105 and the sharpened electrode 112 provided in the opening of the scorotron charger 100, or the development control electrode 133 and the development sleeve 13 provided in the opening of the developing device 13.
1 to prevent damage to the charging device and developing device during maintenance and replacement.

With the protective cover 301 closed, the handle 203 provided at one end of the slide member 202 is shown in FIG. 8 (B).
Move in the direction indicated by the arrow to indicate the charging / developing unit 13
0 through the notch 130b of the casing 130a, the cleaning member 201 provided at the other end of the slide member 202 is moved into the charging / developing unit 130 by using the guide groove 301a provided in the protective cover 301 as a guide. 201 is slid on the sharp electrode 112 of the scorotron charger 100 and the development control electrode 133 of the developing device 13, and the sharp electrode 112 and the development control electrode 1
33, especially the electrode part 133a is cleaned.

Although the protective cover 301 is opened when the cleaning member 201 is attached, as shown in FIG.
Is retracted to the side end of the protective cover 301 that does not interfere with the charging / developing unit 130 of 301, and is opened.

It is possible to prevent damage to the charging device and the developing device during maintenance and replacement of the charging device and the developing device, and to clean the sharpened electrode of the charging device and the development control electrode of the developing device, especially the electrode portion. It is easily performed, and stable charging performance and developing performance are maintained for a long time.

Embodiment 4 A fifth embodiment will be described with reference to FIG. FIG.
FIG. 13 is a side sectional view according to a fifth embodiment of a charging / developing unit.

The color image forming process, the mechanism, the scorotron charger as a charger, and the developing device are the same as those described in the first embodiment, and the members having the same functions and structures are designated by the same reference numerals. Attach.

In this embodiment, the scorotron charger 100 as a charger charges the developing device 13 so that it can be opened and closed.
The developing unit 130 is configured, and the developing device 1
The end 103b of the shield member 103 of the scorotron charger 100 is rotatably supported by the shaft 103c provided on the upper surface 132b of the developing casing 132 of No. 3, and the scorotron charger 100 is rotatably provided around the shaft 103c.

As shown by the solid line in FIG. 9, the scorotron charger 100 is opened and mounted on the apparatus main body, and the charging / developing unit 130 is guided from the mounting main body to the guide members T1, T.
When the rail 2 is removed using the rails R1 and R2 as a guide, the scorotron charger 100 is closed by a spring (not shown) as shown by the alternate long and short dash line in FIG.

With the charging / developing unit 130 removed, the opening of the scorotron charger 100 and the opening of the developing device 13 are closed, and the scorotron charger 1
Control grid 105 and sharpened electrode 11
2 and the developing control electrode 133 and the developing sleeve 131 provided on the developing device 13 are prevented from being damaged.

[0059]

According to the first aspect of the present invention, it becomes easy to replace or clean the charging device or the developing device of a specific color that is frequently used.

According to the second aspect, it is possible to prevent the charging device and the developing device from being damaged during maintenance and replacement of the charging device and the developing device.

According to the third aspect, the charging device and the developing device are easily cleaned, and stable charging performance and developing performance are maintained for a long period of time.

According to the present invention, the charging device and the developing device are prevented from being damaged during maintenance and replacement of the charging device and the developing device, and the charging device and the developing device are easily cleaned. Stable charging performance and developing performance are maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is a diagram showing a corona discharge electrode.

FIG. 5 is a diagram showing a development control electrode.

FIG. 6 is a diagram showing a protective cover of the charging / developing unit.

FIG. 7 is a diagram showing a charging / developing unit provided with a cleaning member.

FIG. 8 is a diagram showing a protective cover of the charging / developing unit provided with a cleaning member.

FIG. 9 is a side sectional view of a charging / developing unit according to a fifth embodiment.

[Explanation of symbols]

 10 Photoreceptor Drum 13 Developer 100 Scorotron Charger 101 Corona Discharge Electrode 105 Control Grid 112 Sharp Electrode 130 Charging / Developing Unit 131 Developing Sleeve 132 Developing Casing 133 Developing Control Electrode 201 Cleaning Member 301 Protective Cover R1, R2 Rails T1, T2 Guide member

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Komatsu 2970 Ishikawa-cho, Hachioji-shi, Tokyo Konica Stock Company

Claims (4)

[Claims] 1. A charging device for charging the image forming body around the rotating image forming body, an image exposing means for exposing the charged image forming body to form a latent image, and an image forming means formed on the image forming body. A plurality of sets of developing devices for developing the formed latent image to form a toner image are arranged, and during one rotation of the image forming body, the image forming body is charged by the charger and the image is formed by the image exposing means. In a color image forming apparatus in which a plurality of toner images are superposed on the image forming body by sequentially repeating the formation of a toner image by exposure and development by the developing device, the image exposing means is arranged inside the image forming body. However, the color image forming apparatus is characterized in that the charging device and the developing device for forming the same toner image are formed as an integral unit that can be attached to and detached from the main body of the color image forming device. 2. The color image forming apparatus according to claim 1, wherein the unit is provided with a protective cover that can be opened and closed to protect the charging device and the developing device. 3. The color image forming apparatus according to claim 1, wherein the unit is provided with a cleaning member for cleaning the charging device and the developing device. 4. The cleaning member is provided on the openable / closable protective cover.
3. The color image forming apparatus according to 1.