JPH06148962A - Color image recorder - Google Patents

Abstract

PURPOSE:To provide a color image recorder whose photosensitive belt, four developing devices or the like can be easily exchanged or maintained, whose developing devices can be independently renewed and which uses the photosensitive belt realizing the constitution of the recorder more compact. CONSTITUTION:The photosensitive belt 41, the developing devices which are faced to the upper surface of the belt 41 and which respectively use the toner of black, yellow, magenta and cyan for developer and a cleaning device on the outer circumferential surface of the belt 41 are integrally combined as a process cartridge 4 so that they can be loaded and unloaded. Besides, the respective developing devices can be loaded and unloaded in/from the cartridge 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color image recording apparatus such as a copying machine or a facsimile, and more particularly to a color image formed by superposing a yellow toner image, a magenta toner image and a cyan toner image on a photosensitive belt. The present invention relates to a color image recording device to be formed.

[0002]

2. Description of the Related Art An image recording apparatus using a photosensitive belt is
It is suitable for recording color images because it is easy to arrange a plurality of developing devices in almost the same state with respect to the photoconductor belt, and it is easy to configure the recording device compactly. It is also known that four developing devices using magenta, cyan and black toners as developers are provided to record a black toner image and a color image.

In the conventional color image recording apparatus as described above, the four developing devices are arranged together with the photoconductor belt or as the photoconductor belt so that the four developing devices can be easily replaced and their toners can be easily replenished. Separately, it can be detachably attached to the image recording device, and when recording only the black toner image, the developing device other than the black toner becomes completely redundant, and the development of the black toner frequently used As described above, when the apparatus is renewed, the other color developing apparatus must be renewed as well, and thus there is a problem that it tends to be wasteful.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the replacement and maintenance of the photoconductor belt, the four developing devices, etc. can be easily performed, and the developing device can be renewed. It is also an object of the present invention to provide a color image recording apparatus using a photoconductor belt, which enables the recording apparatus to be configured more compactly.

[0005]

SUMMARY OF THE INVENTION In the present invention, charging, image exposure and development are repeated on a surface of a rotating photosensitive member to form a color image composed of a superposition of a plurality of toner images, and the color image is transferred and fixed on a recording material. In a color image recording apparatus, a photoconductor belt, a developing device that uses black, yellow, magenta, and cyan toners as a developer and a cleaning device that cleans the outer circumferential surface of the photoconductor belt, which face the upward surface of the photoconductor belt, are used as process cartridges. The color image recording apparatus is characterized by being integrally detachably combined with each other, and each of the developing devices can be attached to and detached from the process cartridge. With this configuration, the above object is achieved.

[0006]

That is, in the color image recording apparatus of the present invention, since the photosensitive belt and the four developing devices and the like can be integrally attached and detached as the process cartridge, they can be easily replaced and maintained, and the process cartridge can be used. On the other hand, since each developing device can be individually attached and detached, the developing device can be individually updated. Further, since each developing device faces the upper surface of the photosensitive belt, the developing roller is provided below. Therefore, the developer supplying means to the developing roller can be simplified, the developing device can be downsized, and the charging device and the transfer device can be shared without deteriorating the image quality. It can be made more compact than the recording device.

[0007]

The present invention will be described below with reference to the illustrated examples.

FIGS. 1 and 2 are sectional views showing the construction of an example of the color image recording apparatus of the present invention, FIG. 3 is a partial sectional view showing the process cartridge of FIG. 1, and FIG. 4 is an arrow XX of FIG. FIG. 5 and FIG. 5 are control operation flowcharts of the control device until the recording operation of the color image recording apparatus of the present invention can be started.

1 and 2, reference numeral 1 is an apparatus frame of a color image recording apparatus, reference numeral 2 in FIG. 1 is a document placing portion provided with a platen glass 21, a platen cover 22, an exposure lamp 23, a first mirror 24, A scanning optical system consisting of a V mirror 25 and an imaging lens 26, a dichroic prism 27, and three CCs for each color.
A document reading unit 3 having an image reading unit composed of D28a, 28b, and 28c is denoted by 3 in FIG.
In FIG. 2, scanning deflection of a laser light source and a rotating polygon mirror, etc., in which a laser beam carrying image information for each color based on an image signal for each color inputted from an external computer or image reading means is incident on a photosensitive member. Means and a known laser beam scanner composed of an f-θ lens, a cylindrical lens, and the like, and a laser writing unit 4;
And a developing device 4 using black (B), yellow (Y), magenta (M), and cyan (C) toners as developers, respectively.
Developing device accommodating portion 42 for disposing B, 4Y, 4M, and 4C so as to face the upward surface of the photosensitive belt 41 and the photosensitive belt.
A process cartridge in which the cleaning device 43 of 41 is integrally configured.

In each of the developing devices 4B and the like shown in FIGS. 1 to 4, both side walls of the developing device are arranged so that the developing roller 4a does not come into contact with the developing roller 4a even if the developing roller 4b is placed on a table surface or the like. It extends below the lower surface of the developing roller 4a, and the lower surfaces of both side walls come into contact with the table surface. Further, each developing device accommodating chamber 42 of the developing device accommodating portion 42 of the process cartridge 4 shown in FIG. 1, FIG. 3 and FIG.
B, 42Y, 42M, and 42C each have a door 42a that is urged by an elastic member such as a spring (not shown) to a position where the entrance is closed, and the developing device 4B and the like are dropped into the developing device accommodating chamber 42B and the like. At that time, the door 42a is pushed and rotated by about 90 °,
As shown in FIG. 4, the developing device 4B or the like dropped in receives the lower surfaces of both side walls at the stepped portions of the inner surfaces of both side walls of the process cartridge 4 so that the lower surface of the developing roller 4a and the upper surface of the photoconductor belt 41 are fixed. It is installed at a position where the developing gap d is maintained.

The developing gap d is adjusted by the developing rollers 4a on both side walls of the developing device and both side walls of the process cartridge 4.
A slit for developing gap measurement is provided at a position facing the lower surface and the upper surface of the photosensitive belt 41, and the developing position guides 41B, 41Y, 41M of the photosensitive belt 41 are measured while measuring the developing gap d from the slit. 41C is adjusted and moved up and down and fixed to both side walls of the process cartridge 4 with screws or the like. Not limited to that, the developing device 4
A lower part of the process cartridge 4 which is received by the step part on both side walls of the process cartridge 4 is fixed to the both side walls such as B by a screw or the like as a hood that can be adjusted up and down, and the developing gap is set by the fixing position of the hood. Good. In that case,
The positions of the developing position guide 41B and the like of the photoconductor belt 41 may not be adjustable.

Further, as shown in FIG. 2, the developing device 4B
Have flange portions on both side walls or outside of the front and rear walls, and a screw for adjusting the developing gap provided on the flange portion abuts on the upper surface of the inlet peripheral wall of the developing device accommodating chamber 42B of the process cartridge 4 and the like. Or the front and rear corners of the bottom surface where the developing device 4B or the like makes the lower surface of the developing roller 4a look downward, the inner surface steps of the front and rear walls of the developing device accommodating chamber 42B of the process cartridge 4 or the like. Alternatively, it may be installed at a position where it is received by a section and maintains a developing gap. In the latter case, a mounting frame is required to prevent the developing roller 4a from coming into contact with the table surface when the developing device 4B or the like is placed on the table or the like. Further, it is better not to provide an entrance door for the developing device accommodating chamber 42B. Even if there is no entrance door, the developing device accommodating chamber 42B and the like prevent an object from coming into contact with the surface of the photosensitive belt 41.

The cleaning device 43 is provided with a waste toner storage chamber 43a extending below the photosensitive belt 41. A toner conveyor 43b is provided in the waste toner storage chamber 43a, and a bar-shaped toner scraping and feeding bar is attached to the waste toner storing chamber 43a to rotate in the direction of the arrow to feed the toner to the left.

The photoconductor belt 41 and the toner conveyor 43b may be driven by a common motor, but since the toner conveyor 42b may be intermittently driven with respect to the photoconductor belt 41, they are independently driven. It is preferable to use a direct drive motor. It is preferable to drive the developing roller and the like of the developing device 4B and the like by direct coupling motors. Therefore, although not shown, when the developing device 4B and the like are housed in the developing device housing chamber 42B and the like of the process cartridge 4, the developing device 3B and the like are electrically connected to the process cartridge 4. This connection may be made at the same time when the connection is made in the developing device 3B, or may be made by inserting a separate connector. Note that the positions of the developing roller 4a and the photosensitive belt 41 in FIG. 4 are deviated to one side wall side because the direct coupling motor is provided on the opposite side.

Reference numeral 51 in FIGS. 1 and 2 denotes a delivery roller 52 for sequentially delivering one sheet from the uppermost one of the stacked recording sheets housed in the recording sheet cassette 50 inserted in the apparatus frame 1.
Is a conveying roller for gripping and sending the recording paper sent out by the sending roller 51, and 53 is a corona functioning both as a transfer device and a charging device at the timing when the toner image formed on the photosensitive belt 41 is transferred onto the recording paper. A timing roller for feeding the discharger 5 so as to come into contact with the surface of the photosensitive belt 41 facing the discharger 6, a fixing roller 6 for melting and fixing the toner image on the recording paper, and 54 for removing the recording paper on which the toner image is fixed out of the apparatus. It is a discharge roller for discharging.

The color image recording apparatus shown in FIG. 1 has the original reading unit 2 mounted on the upper portion thereof so that the color image recording apparatus shown in FIG. The side wall door 11 on the insertion port side of the paper cassette 50 is opened so that the process cartridge 4 can be inserted and removed in the direction of the arrow. The side wall door 11 is provided with an elastic member 11a for pushing the process cartridge 4 into a predetermined position. The above-described mounting and demounting of the developing devices 4B and the like with respect to the process cartridge 4 is performed with the process cartridge 4 taken out. Even if the laser writing unit 3 opens and closes the door provided on the top plate of the device frame 1 on which the document reading unit 2 is not placed, the laser writing unit 3 can be installed on the side plate on the front side or the back side of the paper of the device frame 1. The door provided may be opened and put in or taken out from it, or may be fixed to the device frame 1.

In the color image recording apparatus shown in FIG. 2, the laser writing unit 3 is a top plate door which can rotate the top plate of the apparatus frame 1 to open.
It is also possible to take out the developing device 4B and the like upward from the process cartridge 4 attached to the image recording apparatus main body by attaching the top plate door 12 to the opening 12 as shown by the chain double-dashed line. Alternatively, the entire process cartridge 4 can be taken out upward.

In any of the color image recording apparatuses described above, a sensor (not shown) for moving the developing device 4B or the like to or from the developing device housing chamber 42B of the process cartridge 4 to detect whether the developing device is mounted or not is mounted. S1 to S4 are provided, and in these sensors S1 to S4, the process cartridge 4 is attached to the apparatus frame 1, the process cartridge 4 and the apparatus frame 1 are electrically connected, and a power switch (not shown) is provided. It will be in the operating state when it is turned on.
On the other hand, for example, the process cartridge 4 is moved by the attaching / detaching operation of the process cartridge in FIG.
The sensor S for detecting whether or not the device is mounted is provided in the device frame 1 and is activated by turning on the power switch.

Further, the sending roller 51, the conveying roller 52 on the mounting side of the process cartridge 4, the timing roller 53, the fixing roller 6, the fixing device cover, the paper discharge roller 54 and the recording paper guide are arranged in the device frame 1, and The conveyance roller 52, the timing roller 53, the transfer device 5, the fixing roller 6, the fixing device cover, the paper discharge roller 54, and the recording paper guide, which are on the outer side of the cartridge 4 on the opposite side to the jammed paper when the recording paper is jammed, are In order to facilitate the removal, in the example of FIG. 1, the axis of the paper discharge roller 54 is centered, and in the example of FIG. 2, the axis of the transport roller 52 is centered, as shown by the two-dot chain line.
It is arranged on a rotating frame 10 which can be opened and rotated.

In the color image recording apparatus described above, if the process cartridge 4 is not installed, the image cannot be recorded and the absence of the process cartridge is displayed. Even if the process cartridge 4 is installed, the developing device 4B is installed in the process cartridge 4. Otherwise, the image recording is not possible, the image recording is not possible, or the absence of the developing device 4B is displayed, and the developing device 4B is mounted and the developing devices 4Y, 4 are not installed.
If either M or 4C is not installed, the monochrome mode display and the absence of the developing device not installed are displayed.
If all developing devices are installed, a mode selection request display indicating that either monochrome mode or color mode should be selected is displayed, and if mode selection is performed, monochrome mode or color mode is displayed. When the monochrome mode is displayed, a monochrome image is recorded, and when the color mode is displayed, a color image is recorded.

The flowchart of FIG. 5 shows the above control operation by the control device.

The image recording in the black and white mode is carried out by the photosensitive belt.
41 rotates in the direction of the arrow, and its surface is cleaned by the cleaning device 43.
Removes residual toner on the surface, the corona discharger 5 uniformly charges the surface positively or negatively, and the laser writing unit 3 makes image exposure 31 of a black-and-white image incident on the charged surface and low potential. An electrostatic latent image having a spot distribution is formed, the developing device 4B develops the electrostatic latent image with black toner by non-contact reversal development, and the black toner image formed thereby is switched to the inoperative state. When the recording paper cassette 50 has passed the position of the cleaning device 43 and reached the position of the corona discharger 5, the recording paper fed from the recording paper cassette 50 to the position of the corona discharger 5 by the feed roller 51, the conveyance roller 52 and the timing roller 53. The transfer is performed by the corona discharger 5, the fixing roller 6 fixes the recording paper on the recording paper, and the discharging roller 54 discharges the recording paper to the outside of the machine.

To record an image in the color mode, the developing device 4Y forms an electrostatic latent image formed by the laser writing unit 3 which is exposed to the image exposure 31 of, for example, a yellow image on the charged surface of the photosensitive belt 41 as described above. The yellow toner image is developed by non-contact reversal development, and the toner image forming surface passes through the positions of the other developing devices 4M and 4C and the cleaning device 43 which are in the inoperative state like the developing device 4B, and the corona discharger 5 is used. It is uniformly charged again, and the laser writing unit 3 is attached to the charged surface.
Then, for example, the developing device 4M similarly develops the electrostatic latent image formed by incident the image exposure 31 of the magenta image into the magenta toner image, whereby the surface on which the yellow and magenta toner images are formed is again corona. The electrostatic latent image is uniformly charged by the discharger 5, and the electrostatic latent image formed by the laser writing unit 3 entering the cyan image exposure 31 on the charged surface is developed by the developing device 4.
C similarly develops a cyan toner image, and the charging, image exposure and developing device 4B is formed on the three-color image forming surface composed of the yellow, magenta and cyan toner images formed thereby.
The four-color image formed of the toner images of yellow, magenta, cyan, and black formed by performing the development by is transferred and fixed on the recording paper like a black-and-white image.

The order of forming the toner images of the respective colors in the color image forming step is not limited to the above example. It is also possible to record a three-color image except for the step of forming a black toner image. In that case, even if the developing device 4B is absent, that is, the sensor S1 is not turned on, the sensors S2 to S4 are
Of all of the sensors are turned on, and when all of them are turned on, the color mode is displayed so that a color image is recorded, and when none of the sensors S2 to S4 is turned on, the image cannot be recorded. Display and prohibit the image forming process.

Further, in the present invention, even if the charging device and the transfer device are separately provided, the developing device is not limited to the one using the one-component magnetic toner, but may use the two-component developer in which the toner and the carrier are mixed. .

[0026]

In the color image recording apparatus of the present invention, the photoreceptor belt and the four developing devices can be easily replaced and maintained, and the four developing devices can be renewed and toners can be replenished individually. Therefore, it is possible to simplify the means for supplying the developer to the developing roller of those developing devices, to use the charging device and the transfer device in common without deteriorating the image quality, and to make the recording device more compact. can get.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing the configuration of an example of a color image recording apparatus of the present invention.

FIG. 2 is a schematic structural sectional view showing an example of a color image recording apparatus of the present invention.

FIG. 3 is a partial cross-sectional view showing the process cartridge of FIG.

FIG. 4 is a view on arrow XX in FIG.

FIG. 5 is a control operation flowchart of the control apparatus until the recording operation of the color image recording apparatus of the present invention can be started.

[Explanation of symbols] 1 device frame 10 rotating frame 11 side wall door 12 top plate door 2 original reading unit 3 laser writing unit 4 process cartridge 41 photoconductor belt 42 developing device accommodating section 42B, 42Y, 42M, 42C developing device accommodating chamber 4B, 4Y, 4M, 4C Developing device 43 Cleaning device 43a Waste toner storage chamber 43b Toner conveyor 5 Corona discharger 50 Recording paper cassette 51 Sending roller 6 Fixing roller

Claims (4)

[Claims] 1. A color image recording apparatus for forming a color image comprising superposition of a plurality of toner images by repeating charging, image exposure and development on a surface of a rotating photoreceptor and transferring and fixing the color image on a recording material. A developing device that uses black, yellow, magenta, and cyan toners as a developer and a cleaning device for the outer peripheral surface of the photoconductor belt, which face the upward surface of the belt and the photoconductor belt, are detachably combined as a process cartridge. A color image recording apparatus, wherein each of the developing devices can be attached to and detached from the process cartridge. 2. The color image recording apparatus according to claim 1, wherein each of the developing devices can be attached to and detached from the process cartridge even when the process cartridge is attached. 3. The developing device is mounted on the process cartridge by pressing a door provided at each developing device insertion opening of the process cartridge and having a spring biasing force to rotate to the insertion opening closed position by the developing device. 3. The color image recording apparatus according to claim 1, wherein the color image recording apparatus is inserted into the insertion opening until it stops. 4. The color image recording apparatus according to claim 1, wherein a common corona discharge field is used for the charging and the transfer.