JPH02120870A - Color image forming device - Google Patents

Abstract

PURPOSE:To form full-colored, multi-colored and monochromic pictures and to reduce a color image forming device in size and weight by designing a process cartridge attachably and detachably, adopting a cram shell structure and preventing a transfer material on which a picture is transferred with monochromic developing degree from being carried again to a transfer area. CONSTITUTION:An image carrier 1, plural color developing unit groups 5 to 7, a cleaning device 16, etc., are put together in a compact form and attached to an upper case K2. The developing units 5 to 7, or an integral process cartridge 19 is incorporated into a main body removably. A lower case K provided with a transfer drum 12 and the upper case K2 are put together so that they can be opened around a shaft P1 or P2 parallel to the rotating axis of an image forming body 1. In the case of monochromic copying, the transfer material is carried to the transfer area only once. Consequently, full-colored picture and multi-colored pictures can be formed speedily, and the device can be reduced in size and weight.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color image forming apparatus such as a color electrophotographic copying machine or a color printer using a drum-shaped transfer member (hereinafter referred to as a transfer drum). In particular, the present invention relates to a color image forming apparatus that is capable of forming full-color images or functional multicolor images, as well as forming monochrome images including black at high speed, and is compact and lightweight.

[Conventional technology]

As a conventional color image forming apparatus, for example, the patent
As described in Japanese Patent No. 76766, a color toner image is formed on an image carrier by repeating color-specific writing with a color scanner using a laser beam and development with a developer containing color toner, and this is transferred. A technique is known in which color images are formed on a material by electrostatically transferring and fixing them all at once using a corona discharger. According to this technology, the toner images of each color are superimposed on the image carrier, so there are advantages such as excellent superposition accuracy, but the image forming process is different from the normal black and white image forming process and is complicated, so There are also problems such as a decrease in color quality, and problems such as the inability to obtain good color images with the conventional analog system.

For example, Japanese Patent Application Laid-open No. 123257/1983 proposes a technique in which toner images of each color are superimposed on a transfer material using a transfer drum. This publication describes writing on an image carrier with a laser beam modulated by color-coded digital signals, development with a developer containing color toner, and winding the color toner image onto a transfer drum. By repeating the transfer onto the transferred transfer material, a color toner image is formed on the transfer material, and this is fixed to form a color image.

Furthermore, as an analog color image forming apparatus using a transfer drum, for example, a technique described in Japanese Patent Application Laid-open No. 72159/1983 has been proposed. This publication discloses a color image forming apparatus having a process cartridge that integrates an image carrier, a color developing device, a cleaning device, etc., and is configured to be removably inserted into the device.

According to the technique described in Japanese Patent Application Laid-Open No. 58-72159, a cartridge is adopted which integrally houses an image carrier, a color developing device, a cleaning device, etc., and which can be inserted into and removed from the machine body. This has the advantage of making maintenance easier on the manufacturer's side and ensuring stable quality assurance at all times. Furthermore, since a process cartridge incorporating a black toner developing device is provided so as to be replaceable with the color process cartridge, it is possible to make monochrome copies, which are in high demand, and there is an advantage that the scope of use thereof is further expanded.

[Problem to be solved by the invention]

However, the color image forming apparatus using the transfer drum is a so-called console type, and when clearing jams or replacing parts, it is necessary to separate the transfer drum and various image forming devices from each other and take them out separately. Because of this, extra space was required, leading to an increase in size, and a large space was required for installation.

By the way, the field of use of copying machines and the like has been rapidly expanding in recent years, and there are many cases where they are installed and used in small spaces, making them smaller and smaller.
There has been a demand for lightweight so-called popular machines. For example, JP-A-58-192053, JP-A-59-84
No. 260, JP-A-59-192059 and JP-A-60
- Each publication of No. 19159 proposes a copying machine that is compact and lightweight by incorporating an image carrier, a black toner developing device, a cleaning device, etc. into a process cartridge body that integrally contains it, and minimizing extra space. There is. In addition, the copying machines described in each of the above-mentioned publications employ a talam shell structure in order to facilitate the insertion and removal of the process cartridge and clearing jams.

On the other hand, in offices etc., compact and lightweight color image forming apparatuses meet various demands such as single-color copying including black, two-color multi-color copying or full-color copying, etc., and single-color copying including black, which is the most in demand, is high speed. It is hoped that a color image forming apparatus that processes images will emerge.

[Means to solve the problem]

(Object of the Invention) The present invention has been proposed in view of the above-mentioned circumstances and to meet the demands of the industry. In other words, it is a color image that has many functions, such as being able to form full-color images and multi-color images, as well as monochrome images such as black, but is compact and lightweight, and is easy to remove jams, etc. An object of the present invention is to provide a forming device.

(Structure of the Invention) The above object is to attach at least an image carrier, a developer group having a plurality of color developing units, and a cleaning device to an upper housing, and to install an image carrier with an axis parallel to a rotation axis of the image carrier. The upper casing is configured to be openable to a lower casing having a drum-shaped transfer member that carries a transfer material,
When opened, at least one of the color developing devices is configured to be replaceable, and when a monochromatic image is formed by - degree development,
This is achieved by a color image forming apparatus that transfers a monochromatic developed image onto a transfer material and does not convey the transfer material onto which the monochromatic developed image has been transferred to the transfer area again.

(Specific Structure and Effects thereof) The color image forming apparatus of the present invention has an image bearing member, a plurality of groups of color developing devices, a cleaning device, etc. compactly assembled, preferably integrated, and attached to an upper housing, and the developing device Alternatively, an integrated process cartridge can be inserted into, removed from, and replaced with the machine to make the machine smaller and lighter, while ensuring the quality of color copies. In addition, by replacing the process cartridge or developing device, it is possible to form not only full-color images and multi-color images, but also mono-color images including black at high speed, making it possible to meet the diverse needs of users. It is characterized by being able to cope with the formation of monochrome images including black, which is particularly in high demand.

In addition, a transfer drum is used to facilitate the image forming process each time a transfer method is used, and the machine body has a lower housing with the transfer drum and an upper housing with the image forming device centered on an axis parallel to the rotational axis of the image forming body. The main feature is that the casing is configured to be openable, making it easy to insert and remove the developing device or process cartridge, replace parts of the machine, clear jams, etc.

In forming the full-color image, yellow (Y), magenta (M), and cyan (C) toner images are layered and mixed to reproduce a color image including intermediate colors. On the other hand, in the case of a functional multicolor image, the toner images of each color are adjacent to each other and are reproduced without color mixing.

The monochrome image including black and the functional multicolor image include a character image, a line image, an illustration image,
Used to create graphic images, etc.

Hereinafter, a specific example of the structure and operation of the color image forming apparatus of the present invention will be explained with reference to the schematic diagrams of the color image forming apparatus shown in FIGS. 1, 2, and 4, and other drawings.

In the figure, 1 is a photoreceptor drum which is an image carrier having a selenium or organic photoconductor that rotates in the direction of the arrow, 2 is a charger that applies a negative charge to the surface of the photoreceptor drum l, and 3 is shown in FIG. (
An analog image exposure device as shown in (a) or (b), or a digital image exposure device using a light source such as a laser, LED array, or LCS array as shown in Figure 5 (c) or (d). It is.

4 represents analog scanning image exposure or digital dot-like image exposure in which the image exposure device 3 forms an electrostatic latent image on the charged surface of the photoreceptor drum l, and 5 to 10
are Y, M, C, R (red), B by regular or reversal development.
This is a developing device that forms toner images of (blue), BK (black), etc. 11 is a transfer material supply means; 12 is a transfer drum that transfers the color toner image formed on the photosensitive drum l onto the transfer material fed by the supply means 11; and 12a is provided in the transfer portion of the transfer drum 12. 13 is a conveying means for sending the transferred transfer material to the fixing device 14; 15 is a pre-cleaning static eliminator for facilitating the removal of residual toner on the photosensitive drum l after the toner image has been transferred; 16 is a cleaning device that removes the residual toner from the surface of the photoreceptor drum l.

K represents the boundary between the lower casing and the upper casing of the aircraft, and axis P is 1 for the lower casing and 2 for the upper casing.

Alternatively, it is configured to be releasable centering on P2.

In this example, a transfer material supply means 11, a transfer material conveying means 13 for conveying the transfer material from the transfer drum 12 to the fixing device 14, a lower roller of the fixing device 14, etc. are incorporated in the lower housing 1, and the upper housing includes 2 incorporates an image exposure means 3, a process cartridge 19 or 20, an upper roller of a fixing device 14, and the like.

The reason why the opening axis P of the upper housing 2 or P2 is parallel to the rotation axis P of the photoreceptor drum 1 is that the upper housing can be opened easily from an ergonomic point of view, and that the process cartridge can be easily opened when opened. This is because insertion/removal, parts replacement, jam removal, etc. are facilitated.

The angle at which the upper housing 2 is opened relative to the lower housing 1 is preferably 5'' to 30°, and the locking means for regulating the position when opening is disclosed in, for example, Japanese Patent Laid-Open No. 58192059,
The means described in JP-A-58-192053 and the like can be used.

Furthermore, when the upper case 2 and the lower case 1 are closed, it is necessary to accurately align the photosensitive drum l and the transfer drum 12.
The fitting means described in Japanese Patent No. 72159 can be used.

Further, in the case of full color copying or multicolor color copying, the color image forming apparatus of the present invention prevents the transfer material supplied by the transfer material supply means 11 from being wrapped around the transfer drum 12 by the action of the gripper and electrostatic adsorption. and the transfer drum 12
The toner images of each color formed on the photoreceptor are repeatedly transferred onto the transfer material of the transfer drum 12 in a superimposed manner.

Thereafter, when the gripper is released, the transfer material is separated from the transfer drum 12 by the separating means and fixed by the fixing device 14 to form a full color image or a multicolor image.

However, the color image forming apparatus of the present invention is characterized in that it can efficiently provide copies of monochrome images including black, which are particularly in high demand. In contrast, the transfer material is conveyed to the transfer area only once. Here, the transfer area refers to a portion between the photoreceptor drum 1 and the transfer drum 12 where the transfer material contacts the photoreceptor drum 1. That is, after the monochrome image is transferred to the transfer material by the transfer pole 12a in the transfer area, the transfer material is immediately transported to the fixing device 14 via the transport member 13 and fixed thereon.

For example, the transfer material supplied by the transfer material supplying means 11 is fixed to the transfer drum 12 by a gripper and electrostatic adsorption and conveyed in the direction of the arrow, and in the transfer area, the monochrome toner image on the photoreceptor l is transferred to the transfer electrode 12a. The image is transferred onto the transfer material by the action of the printer, and immediately separated, transported, fixed, and discharged. However, in the case of a monochrome copy, unlike the case of a full-color copy or a multi-color copy, high-precision transport to obtain overlay accuracy is not required, and for example, the following transport method can be used.

(1) Eliminating the need for a gripper, the transfer material is attached to the transfer drum simply by electrostatic adsorption and conveyed in the direction of the arrow as described above, and in the transfer area, the monochrome toner on the photoconductor is transferred by the action of the transfer pole 12a. The image may be transferred onto a transfer material, immediately separated, conveyed, fixed, and discharged.

(2) Also, a transfer material supply device 11' for monochrome copying is provided outside the transfer material supply device 11 of FIG. 1, and in the case of monochrome copying, the transfer material is directly conveyed to the transfer area by the supply device 11', After the toner image on the photoreceptor is transferred by the transfer electrode 12a of the transfer drum 12, it may be separated, transported, fixed, and discharged.

(3) Japanese Patent Application Laid-Open No. 61-51178, which was previously proposed by the applicant
The transfer material may be conveyed to the transfer area by the method described in the above publication. That is, in the case of full-color copying or multi-color copying, a bias of the same polarity as the toner is applied to the transfer drum 12, and the transfer material conveyed to the transfer area is previously charged with a polarity opposite to the bias using a charging electrode. ,
The toner image of each color can be transferred, separated, and fixed to the transfer drum 12 by electrostatic adsorption without using a gripper or the like.
It is fixed to form an image. In the case of monochrome copying, the transfer material is charged with a polarity opposite to that of the toner using a charging electrode, and the monochrome toner image is directly transferred, separated, and fixed without wrapping the transfer material around the transfer drum 12, and image formation is performed. That's what I do.

With the above configuration, monochrome copying is faster than full-color copying or multicolor copying, and copying operations can be accomplished with high efficiency.

Furthermore, in the present invention, since -C uses a transfer drum, when performing full-color copying or multi-color copying, the length of the transfer material in the advancing direction should be equal to or less than the circumferential length of the transfer drum, and preferably In terms of compactness and weight reduction, it is preferable that the circumference be less than the length required for horizontal feeding of an A4 size sheet. however,
In the case of monochrome copying, there is no restriction on the circumferential length of the transfer drum.Although there is no restriction on the length of the transfer material in the advancing direction, it is preferably less than the length of an A3 plate. The reason is that
Because there is little demand for copies larger than A3 size, and from the viewpoint of making the device smaller and lighter, it is set to be A3 size or smaller.

In addition, in the case of full-color copying or multi-color copying, when a cassette larger than an A4 horizontal feed cassette is loaded in the cassette loading section, a signal C from the cassette size detection element I7 as shown in FIG. It is preferable to stop the image forming process via the CPU or the like.

FIG. 1 is a schematic diagram illustrating a color image forming apparatus that can form a full color image, a multicolor image, a monochrome image such as black, etc. by replacing the process cartridge. In the figure, reference numeral 19 denotes a process cartridge having a photosensitive drum 1, a cleaning device 16, a pre-cleaning static eliminator 15, and a group of Y, M, and C full-color developers. Alternatively, the process cartridge 20 can be replaced with a process cartridge 20 having a group of developing devices.

The process cartridge 20 includes, for example, a cartridge 20a having a BK developer 8, a cartridge 20b having a B developer 9 and an R developer 10, a B developer 9,
Cartridge 2 having an R developer lO and a BK developer 8
It consists of 0c.

Further, each cartridge is provided with marks 17, 18a, 18b, and 18c for identifying its type,
The mark is detected by the mark detection element 21 inside the machine, and the type of cartridge is determined and controlled based on the detection signal as shown in Figure 5A, and whether it is a full color image forming process or a functional image such as a monochrome image such as BK or a multicolor image. Image formation is performed by selecting one of the processes for forming an image.

FIG. 2 shows a process cartridge 22 that integrates a developing device 5 containing full-color Y toner, a photosensitive drum 11, a charger 2, a cleaning device 16, and a pre-cleaning static eliminator 15, and a BKI in place of the Y toner developing device. - A full-color M toner developer 6 and C, which has a process cartridge 23 that is replaceable with the cartridge 22, in which a toner developer 8 is incorporated, and which is not converted into a cartridge in the machine.
1 is an explanatory diagram of a color image forming apparatus having a toner developing device 7. FIG.

One reason for this configuration is Y and M.

It is used when it is desired to obtain a black-and-white copy instead of a full-color copy of C, or when a functional multicolor copy of M, C, and BK is desired instead of a full-color copy of Y, M, and C. That is, although Y toner images are indispensable for full color formation, they are rarely used for functional multicolor copying of character images, line drawings, etc. due to their low visibility. The switching between full color and functional multicolor copying is performed by detecting the marks 24 and 25 on the cartridges 22 and 23 with the sensor 26, as in the case of FIG.

As a specific example of the means for switching from full color copying to functional copying in the cartridge replaceable type, a bar code is provided on the top surface of the convex mark of each process cartridge, as shown in FIG. is read by a photoelectric reader. That is, the scanning light source of the reader is vibrated and scanned in the direction of insertion of the developer unit to obtain a pulse signal, the signal is output to the CPU, and the corresponding image forming program in the program memory is read out via the CPU. Image formation is performed by controlling the image forming equipment.

For example, in the case of the mark section 17, a signal of 1 pulse is output to the CPU, and in the case of the mark section 18G, a signal of 4 pulses is output to the CPU.
Output to PU.

Regarding the transfer material supply means shown in FIG. 1, when process cartridges 19, 20b and 20c are used, multiple rotations of the transfer drum cause multiple color toner images to be superimposed on the transfer material, so that the transfer material is not transferred. It is necessary to tightly wrap and fix the paper onto the drum 12 by mechanical fixation using a gripper, electrostatic adsorption, etc., and then transport it to the transfer area.

Next, when the process cartridge 20a is used,
The transfer material is transferred to the fixing device after only one transfer, and there is no need for superposition accuracy. Therefore, the transfer drum 12 is used only as a means for conveying the transfer material to the transfer area.

Therefore, the transfer material conveyed by the supply means 11 may be attached to the transfer drum by electrostatic adsorption or the like, and then conveyed.
Preferably, a supply means 11' is provided on the side opposite to the supply means 11 with respect to the transfer drum 12, and the transfer material is directly conveyed from there to the transfer area, where it is directly transferred and fixed to form a monochrome image such as black.

FIG. 4 is an explanatory diagram of an example of a color image forming apparatus having a photosensitive drum 1, a cleaning device 16, a pre-cleaning static eliminator 15, and the following various developing device units that can be inserted into and removed from a cartridge. Here, the developing units include Y and M.

There is a developing device unit 28 consisting of developing devices 5, 6, and 7 of C, and a developing device unit group 29 that can be replaced with this developing device unit 28. The developing device unit group 29 includes, for example, a developing device unit 29a having a BK developing device 8, an R developing device 9, and a B developing device I.
A developing unit 29b having an R developing unit 9, a B developing unit 10, and a BK developing unit 8.
It consists of Further, each developing device unit has marks 30.31a, 31b for identifying its type.
31c is provided, and the mark detection element 3 in the cartridge is
2, and the detection signal is used to determine and control the type of developing unit as shown in FIG. One of the forming processes is selected to perform image formation.

In the developer unit replaceable type, a specific example of a means for switching from full-color copying to black-and-white copying or multicolor copying is as shown in FIG. The magnetic force (Gauss) is read as the strength of the current, and after A/D conversion, the obtained digital signal is output to the CPU, and the corresponding image forming program in the program memory is read out via the CPU, and the image forming process is performed. control. A color mark may be used on the outer mark portion, or a plurality of protrusions may be provided, and the microswitch may be turned "on" or "off" by the protrusions to take out the signal.

Next, regarding the transfer material supply means, the developing unit 28.
For the developing device unit 29a, preferably, the supply means 11 is used for the developing unit 29b and 29c, and the supply means 11' is used, as in the case of the process cartridge 20a shown in FIG.

Also, the selection of the size of the transfer material is the same as in the case of FIG.

To insert and remove the developing device unit from the process cartridge 27, open the housing 2 upward, open the opening door 40 provided on the side wall of the housing with the knob 41, and remove the cartridge 27. You can go after taking out 27.
Alternatively, the process may be carried out with the cartridge 27 still attached.

For example, the cartridge 27 is provided with an opening for insertion and removal, and the developing unit is inserted and removed through the opening.

In this case, the cartridge may be contaminated with dust during transportation or storage.
It is desirable to prepare a cartridge transport case with a handle to prevent contamination with toner.

The entire developing device unit may be replaced, or each developing device within the unit may be individually pulled out and replaced using the finger hook recess shown in FIG. 6, which will be described later.

As another example, as shown in FIG. 6, a wall plate is provided on the front surface of the developing device unit, and when the unit is installed in the cartridge through the insertion/removal opening, the wall plate closes the insertion/removal opening. It may be constructed so that the section is sealed. In this case, a case for transporting the cartridge 27 is not required.

The color image forming apparatus shown in FIGS. 1 to 3 requires a door 40 for inserting and removing the cartridge because the process cartridge is built into the housing 2, but it is preferable to carry out the process described later. As shown in the example, it is preferable that the cartridge be mounted so as to be exposed downward from the upper housing. In this case, when the upper housing 2 is opened, the cartridge can be inserted and removed or the developing unit can be inserted and removed immediately.

Next, block diagrams relating to the image forming process shown in FIGS. 7(a) and (b) and FIGS. 8(c) and (d) will be explained.

As described above, the color image forming apparatus of the present invention uses a transfer drum to transfer each time, so it is possible to form images using either a digital method or an analog method.If the color image forming apparatus uses an analog method, reading, writing, etc. It has the advantage of being simple and low-cost, and there is no need to perform complicated reversal development as in the case of digital methods, and normal regular development can be used.

FIGS. 7A and 7B show an analog image forming process. Process cartridge 1 in Figure 1
The image forming process shown in FIG. 7(a) will be explained using the case where the image forming apparatus 9 is used as an example. That is, the reflected light obtained by optically scanning a color original is color-separated through a B filter, B exposure light is obtained through a reflecting mirror lens system, and a photoreceptor is uniformly charged in advance by a charger 2. An electrostatic latent image is formed by imagewise exposure on the drum 1, which is regularly developed by a Y developer 5 to form a Y toner image, which is transferred onto a transfer material wound around a transfer drum 12. . Next, color separation is performed with a C filter, and M
An M toner image is formed on the photoreceptor drum 1 in the same manner as described above, except that it is developed with the developing device 6, and this is layered and transferred onto the Y toner image. Furthermore, the C toner image obtained using the R filter and the C developing device 7 in the same manner as the Y toner image,
It is layered on the M toner image, transferred, and fixed to form a color image.

Further, the image forming process shown in FIG. 7(b) will be explained using the case where the process cartridge 20a shown in FIG. 1 is used as an example.

That is, an electrostatic latent image is formed by exposing an imagewise exposure light obtained by optically scanning a black-and-white original onto a photoreceptor drum which has been given a certain charge in advance, and this is developed by a BK developer 8. A black toner image is formed, transferred and fixed to form a black and white image.

FIGS. 8(c) and 8(d) show a digital image forming process. The image forming process shown in FIG. 8(C) will be explained using the case where the process cartridge 19 shown in FIG. 1(A) or the process cartridge 27 equipped with the developing unit 28 shown in FIG. 4 is used as an example.

That is, the reflected light obtained by optically scanning a color original is color separated through R9G and B filters, photoelectrically converted by CCD, and A/
R, G, B digitized by A/D conversion with a D converter
After obtaining the signal and performing signal processing such as shading correction, gradation correction, and color tone correction, the R, G, and B signals are
, M, and C signals, and only the Y signal is selected and extracted from among them. The Y signal causes a laser beam (L
(ED array, LCS array may be used), and the modulated laser beam is written onto the photosensitive drum l, which has been charged in a negative manner in advance, to form an electrostatic latent image. This electrostatic latent image is reversely developed by a Y developing device 5 to form a Y toner image, which is transferred onto a transfer material wound around a transfer drum 12.

Next, only the M signal is selected from the Y, M, and C signals, and an M toner image is formed on the photoreceptor drum 1 in the same manner as described above, except that it is developed in the M developing device 6, and this is transferred onto the Y toner image. Laminate and transfer.

Furthermore, only the C signal is selected from the Y, M, and C signals obtained in the same manner as above, and is developed by the C developing device 7 to form a C toner image on the photoreceptor drum l. It is layered on the M toner image, transferred, and further fixed to form a full color image.

Details of the image forming process are described in Japanese Patent Application No. 16413/1983, previously proposed by the present applicant.

Next, the functional multicolor image forming process shown in FIG. 8(d) will be described using, as an example, a case where the process cartridge 27 equipped with the process cartridge 20c shown in FIG. 1 or the developing device unit 29c shown in FIG. 4 is used. That is, the reflected light obtained by optically scanning a color original is separated into colors through R and C filters, and digitized by photoelectric conversion and A/D converters in the COD to obtain R and C digital signals, which are converted into signals. After processing, the R, B and BK multiplied signal colors are separated from the R and C signals, and only the R signal is selected and extracted. The R signal modulates the laser beam, and the modulated laser beam is written onto the photoreceptor drum l, which has been previously charged with a negative charge, thereby forming an electrostatic latent image.

This electrostatic latent image is reversely developed by an R developing device 9 to form an R toner image, which is then transferred onto a transfer material wound around a drum 12. Next, only the B signal among the R, B and BK multiplied signals obtained in the same manner as above is selected and extracted, and developed with the B developing device 10 to form a B toner image on the photoreceptor drum l. The R toner image is transferred onto the transfer material carrying the R toner image (without being laminated on the R toner image). Furthermore, R obtained in the same manner
, B and BK double signals, the BK double signal is selected and taken out, written on the photoreceptor l, and developed with a BK developer 8 to form a BK toner image, which is transferred to a transfer material carrying the R toner image and the B toner image. A functional multicolor image is formed by transferring and fixing the image onto the surface.

The details of the image forming process shown in FIG. 8(d) are described in Japanese Patent Laid-Open No. 62-26976, which was previously proposed by the present applicant. The configuration, operation, and image forming process of the color image forming apparatus of the present invention have been described above using representative examples. container unit 29
In the case of a process cartridge having one BK developer device 8, such as the process cartridge 27 having a, it is possible to replace this with the R developer device 9, B developer device 10, or other monochrome developer device to perform image formation. However, such cases are also included in the present invention.

Furthermore, instead of the process cartridge 22 having the Y developing device 5 shown in FIG. 2, a process cartridge 22' (not shown) having a Y developing device 5 and an M developing device 6 is installed, and a BK developing device corresponding to the Y developing device is installed. Process cartridge 2 with container 8
3 may be replaced by a process cartridge 23' (not shown) having a larger BK developing device 8' (not shown) corresponding to the Y developing device 5 and the M developing device 6.

Furthermore, regarding the insertion and removal of the process cartridge in the color image forming apparatus of the present invention having a talam shell structure,
■ A door 40 is provided on the side wall of the machine, and when opening the upper housing of the Talam shell structure, open the door 40 by grasping the knob 41 and pull out the process cartridge toward you (vertically upward in the drawing) to replace the cartridge. Good too. Roughly speaking, as shown in FIGS. 9 to 11 of the embodiment, the process cartridge installed in the upper case 2 of the machine body is connected to the open line of the upper case 2 with respect to 1 in the lower case of the machine body. The process cartridge may be arranged so as to protrude downward, and when the upper housing is opened, the drawer can be directly pulled out to the front for replacing the process cartridge without providing the door of item 0.

〔Example〕

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the embodiments of the present invention are not limited thereto.

(Example 1) FIG. 9 and FIG. 1θ are cross-sectional views explaining the configuration of an analog type color image forming apparatus used in this example, and FIG. Figure 1O (b) is a diagram when the upper housing 2 is closed, and Figure 1O (b) is a diagram when it is opened. The process cartridge to be incorporated is the full color process cartridge 1 previously explained in FIG.
9 and the black-and-white process cartridge 20a are used, and image formation is performed by the analog process for full-color images and the analog process for black-and-white images explained in FIGS. 7(a) and 7(b). . The drawings shown in FIGS. 9 and 10 will be explained below, and the same reference numerals will be used for the same contents as in FIG. 1. In the figure, 100 represents a color original, 101 represents an original table, and 102 represents an optical system for image exposure, which optical system includes a light source 103, reflecting mirrors 104 to 107, lenses 108, . It consists of B, G, and R filter groups 109 and a filter detection device 110.

Note that the light source 103' and the reflecting mirrors 104' to 106'
indicates the positions of the light source and reflection mirror of the optical system after they have been moved. In the case of a full-color process cartridge, the photosensitive drum 11 charger 2, Y developer 5, M developer 6, C developer 7, and pre-cleaning static eliminator 1 shown in FIG.
5. A process cartridge 19 incorporating a cleaning device 16 is installed. The process cartridge 19 is mounted on a kite rail l fixed to the upper housing.
It is slidably suspended by it and 112.

12 is a transfer drum; 121 is a transfer drum that transfers the leading edge of the transfer material to transfer drum 1;
A gripper 122 fixed to the transfer drum 20 presses the transfer material against the transfer drum by the action of a solenoid 123, and the gripper 122
12a is a transfer device, 128 and 129 are static eliminators, and 130 is a transfer material separator.

125 and 126 are cleaning devices for the surface of the transfer drum after the transfer material is separated; 131 is the gripper 121;
A cam 132 turns on and off the separating claw 130.
This is a cam that turns on and off.

Reference numeral 11 denotes a paper feeding means for the transfer material 140, in which the transfer material 140 fed by the paper feed roll 141 from the A4 size horizontal tin cassette lla is fed by the paper feed guide 145 via the transport rolls 142, 143 and the timing roll 144. It is supplied to the transfer drum 12. In the rotating drum (2), the transfer material 140 is wound and fixed by the action of the gripper 121, the presser 122, the adsorption electrode 124, etc., and is conveyed, and the photosensitive drum 1 and the transfer drum 12 are rotated by the action of the transfer pole 12a. A Y toner image, an Ml-toner image, and a C toner image are sequentially layered and transferred. The transfer material 140 carrying the toner images of each color is neutralized by neutralizing electrodes 128 and 129,
After being separated by the separation claw 130, the transfer material 140 is transported to the fixing device 14 by the transport belt 13, and the fixed transfer material 140 is discharged to a tray 147 by a paper discharge roll 146.

Next, 150 is a locking member for the lower casing of the fuselage and 2 for the upper casing, and 160 is a release position regulating member. When holding the handle 149 and releasing 2 from the lower casing to the upper casing with the shaft P2 as the rotation axis, push the knob 151 of the locking member 150 supported by 2 on the upper casing against the spring 152. and push upward. As a result, the operator 153
4 in the clockwise direction, pushing down the upper end of the interlocking element 155, and rotating the interlocking element 155 counterclockwise around the shaft 156 against the spring 157. Thus, the engagement between the lower rear end of the interlocking member 155 and the locking tool 158 is disengaged, and the upper housing can be opened upwardly by the handle, and the spring pressure of the spring 161 of the position regulating member 160 allows it to be loosened. will be opened to

The position regulating member 160 is a ring body 16 whose one end is rotatably supported by a shaft 161 provided in the lower housing.
2, and a ring body 164, one end of which is rotatably supported by a shaft 163 provided in the upper housing, and the ring body 162
and the other end of the ring body 164 is a shaft 165 that is not supported by the housing.
are rotatably coupled around a common axis. A spring 166 is provided between the shafts 161 and 163, and the casing is gently closed and opened by the spring pressure of the spring 166.

When the housing 2 is closed, the ring bodies 162 and 164 are folded, but as the upper housing 2 is opened, the position regulating member 160 resists the spring pressure of the spring 166. At the time of opening (opening angle 20°), both ring bodies extend linearly to stop the opening of 2 to the upper casing, and also support 2 to the upper casing.

When the lid is closed, the ring bodies 162 and 164 of the position regulating member 160 are folded through a process reverse to that described above.

On the other hand, the action of the locking member 150 when the lid is closed is controlled by the interlocking element 156.
The lower end of the locking tool 158 is kicked by the shoulder on the upper surface of the locking tool 158 and turns around, so that it is automatically engaged with the locking tool 158 by the action of the spring 157. Also, the process cartridge 1 is closed by the above-mentioned lid closing operation.
9 and transfer drum 12 is automatically achieved.

What has been described above is the case where the process cartridge 19 is incorporated into the machine body to form a full-color image using the analog process shown in FIG. , for example B
A process cartridge 20a having a K developing device is installed in the machine, and the mark 18a of the cartridge is placed on the sensor 21.
It is possible to identify and control the image by using the process shown in FIG. 7(b) to form a black and white image such as a character image.

However, in this case, the supply means 1 is used instead of the transfer material supply means 11.
1', the transfer material 140 is directly supplied to the transfer area.

That is, the transfer material 140 (A 3rd edition vertical feed) is placed in the cassette 11.
The sheet is fed from a' by a feed roll 141', conveyed to a transfer area via a conveyance roll 142' and a timing roll 144', and a black toner image is transferred by the action of the transfer pole 12a. Thereafter, the transfer material 140 is guided by the guide member 127, the static electricity is removed by the removal electrode 129, and the transfer material 140 is transferred to the separation member 130.
The image is separated from the transfer drum and conveyed to the fixing device 14, where a black and white image is formed.

Thus, according to this embodiment, as an advantage of adopting the process cartridge and the Talam shell configuration, by replacing the cartridge, full-color copying and multi-color copying are possible, as well as black-and-white copying of text images, etc., which are particularly in demand for copying. Effects such as being able to efficiently reproduce a large number of copies are exhibited. Furthermore, since it is a normal analog system and a regular development system, it has the advantage that the image forming process is easy.

(Example 2) FIG. 11 is a cross-sectional view illustrating the configuration of the digital image forming apparatus used in this example. As in the case of Example 1, the body is placed in the lower housing with K as the boundary. 2 is configured to be openable on the upper housing. The process cartridges to be incorporated include the developer unit 28 that integrates the Y developer 5, M developer 6, and C developer 7 described earlier in FIG. Developer 1
A developing device unit 29c in which developing devices 8 are integrated into 0 and B
The cartridge is configured such that it can be inserted into and removed from the cartridge. Further, image formation is performed by the full-color digital process and the functional multicolor digital process described in the eighth factors (c) and (d).

First, a full-color original or a functional multicolor original placed on the original platen 101 is read by the following reading system, and an image is written on the photoreceptor drum l by a laser beam modulated by the obtained reading signal. Formation takes place. In the description of the drawings, the same content as in FIG. 10 is given the same reference numeral.

Reference numeral 170 denotes a document scanning unit, which includes a rod array 108 and a same-magnification color separation line sensor 174.
-1 and an exposure lamp 103 are built in. 171 is an amplifier, 172 is a connector, 173 is a wiring cord for the document scanning unit 170, 174-2 is an actuator 174-3 and 174-4 is an actuator 174-
This is a position sensor that detects the scanning position of the document scanning unit 170 via the microswitch 2.

176 is a scanner for performing image exposure of a laser beam on the photoreceptor l, 177 is a polygon mirror 178
−〇 Lens. In the scanner 176, a laser beam is modulated by the signal obtained in the image processing 1 or 2, and the modulated laser beam is transmitted to the polygon mirror 177.
is scanned onto the photoreceptor drum l. 175 is an image processing section connected to the unit 170 through the wiring cord 173. The image processing unit 175 includes a full-color image processing system l shown in FIG. 8(c), including A/D conversion, signal processing, color conversion to Y, M, and C, and color selection, and FIG. 8(d). A of
A functional color image processing system 2 including /D conversion, signal processing, color separation into R, B, and BK, and color selection is built in so that it can be switched by replacing the developer units 28 and 29c.

In the case of full-color image formation, the photosensitive drum 1 is incorporated into a process cartridge 27 together with a charger 2, a cleaning device 16, and a developing unit 28 that integrates a Y developing device 5, an M developing device 6, and a C developing device C. ing. The Y toner image, the M toner image, and the C toner image sequentially formed on the photoreceptor drum l in the image forming process shown in FIG. The images are stacked and transferred onto a paper sheet 140, separated by a separating claw 130, transported by a conveyor belt 13, fixed by a fixing device 13 to form a full-color image, and then discharged to a paper discharge tray 147.

The configuration of the image forming section other than the reading system and writing system and the image forming process are the same as in the first embodiment, so detailed explanation will be omitted. Next, when it becomes necessary to form a functional multicolor image, the developer unit 29c, which is an integrated system of the R developer 9, the B developer IO, and the BK developer 8, is used in place of the developer unit 28. Process unit 27
The R9B and BK color toner images are sequentially transferred and fixed onto the transfer material to form a multicolor image. The switching between full color copy and multicolor copy is shown in Figure 3 (b).
As explained in FIG.
This is achieved by detecting the detection signal and switching the reading system based on the detection signal.

The switching between full-color copying and multi-color copying is described, for example, in Japanese Patent Application No. 1982-1, which was previously proposed by the applicant of the present application.
The technique described in 272033 may also be used.

Furthermore, since the color image forming apparatus of the second embodiment is of a digital type, it is possible to easily provide a variety of editing functions such as masking, color specification, area specification, etc.

For example, a specific image in a multicolor original is, for example, BK.

You can specify colors such as B and R to make a monochrome copy.

In such a case, the transfer material supply means 11' shown in FIG. 11 is used to directly convey the transfer material from the cassette 11'a to the transfer area to the paper feed roller 141', conveyance roller 142', timing roller 144', etc., and transfer the toner image. After the image is transferred, it is preferable that the image is separated, transported, and fixed by a separator 130 to form a monochrome image.

Thus, in this embodiment, in addition to the effects of the first embodiment, since the digital method is used instead of the analog method,
It is easy to control the image quality, and it is possible to obtain high-resolution full-color copies or multicolor copies with clear tones, and editing functions can be added to perform masking, color specification, area specification, etc. You can extract a specific image, specify the color, and make a monochrome copy. Furthermore, in the case of monochrome copying, the transfer material supplying means is provided in a separate system, and there are advantages such as high-speed processing.

〔Effect of the invention〕

As is clear from the above description, according to the color image forming apparatus of the present invention, ■ By employing a process cartridge having a full color developer or a functional color developer, full color copies or functional color copies including monochrome such as black can be produced. Quality guarantee is ensured, ■Using a transfer drum in the body of the machine for each transfer and using a clamshell type, it is easy to form color images, and the machine body is compact and lightweight. It is easy to insert/remove devices, replace parts, clear jams, etc. ■ It is possible to meet the needs of various users such as not only full color copying but also functional color copying including monochrome such as black, with simple operation, ■ Especially Effects such as being able to process monochrome copies including black and the like at high speed can be achieved.

[Brief explanation of drawings]

1, 2, and 4 are schematic diagrams showing various examples of color image forming apparatuses of the process cartridge replaceable type and the developer unit replaceable type, and FIG. 3 shows the identification mark portions of the process cartridge and the developer unit, and An example of a detection element that detects the mark portion, FIG. 5 is a diagram illustrating a mechanism for switching the image forming process in conjunction with replacing the process cartridge and developing unit, and FIG. FIG. 7 is a block diagram illustrating an analog image forming process;
FIG. 8 is a block diagram illustrating a digital image forming process, and FIGS. 9 to 11 are sectional views illustrating an embodiment. l... Photosensitive drum 2... Charger 5 to lO
...Developer 12...Transfer drum 16...Cleaning device 19.20a, 20b, 20c, 22, 23.27.=
Process cartridges 28, 29a, 29b, 29cm...Developer unit 102...analog optical system 150...on the lower casing, and on the locking member 2 on the upper casing, book 160...upper cylinder - *to! Position regulating member 1 when opened
70... Original scanning unit 175... Image processing section 176... Scanner Fig. 3

Claims (1)

[Scope of Claims] At least an image bearing member, a developing device group including a plurality of color developing devices, and a cleaning device are attached to an upper housing, and the image bearing member has an axis parallel to the rotational axis of the image bearing member as a center. The upper housing is configured to be openable with respect to the lower housing having a drum-shaped transfer member that carries a transfer material, and when opened, at least one of the color developing devices is replaceable, once. A color image forming apparatus characterized in that when a monochrome image is formed by development, the monochrome developed image is transferred onto a transfer material, and the transfer material to which the monochrome developed image has been transferred is not conveyed to the transfer area again. .