JPH04107471A - Color image forming device - Google Patents

Abstract

PURPOSE:To miniaturize the whole of a process cartridge and to enhance the maintenance of a device by providing a developer housing means in addition to the process cartridge which integrally houses plural developing units. CONSTITUTION:Respective image forming means such as a photosensitive belt 31, a scorotron electrostatic charger 33, respective developing devices and a cleaning device 32 are integrated in the process cartridge 30 to be attached and detached with respect to a device main body. A toner housing container unit 40 where respective toner housing containers are serially connected is attached to the cleaning device 32 and respective toner such as black, cyan, magenta and yellow is housed in the respective toner housing containers corresponding to the arrangement of the respective developing devices. Besides, the developing device of the cartridge 30 is provided under the belt 31 and arranged at a position where the belt 31 is easily exchanged by loosing the tension of turning rollers 31A and 31B. Thus, the maintenance of the device is facilitated by easily exchanging the belt 31 in the case that the durability or the maintenance term of the cartridge 30 is different.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color image in which a toner image is formed on a belt-like image forming member by an electrophotographic method and transferred onto a transfer material to obtain an image. The present invention relates to a forming device.

[Background of the invention]

There are many ways to obtain color images using electrophotography.
A device has been proposed. For example, Japanese Patent Publication No. 61100770
As disclosed in the publication, a latent image is formed and developed in accordance with the number of separated colors of the original image on a photosensitive drum serving as an image forming member, and is transferred onto a transfer drum each time it is developed. There is a method of forming a multicolor image and then transferring it onto recording paper to obtain a color copy. A device using this method requires a transfer drum large enough to transfer one sheet of image onto its circumferential surface in addition to the photoreceptor drum, and the device does not have a large and complicated structure. Inevitable.

For example, as disclosed in Japanese Patent Application Laid-Open No. 149972/1983, a latent image is formed and developed on a photosensitive drum according to the number of separated colors of the original image, and is transferred onto a transfer material each time it is developed. This is a method of obtaining multicolor copies. With this method, it is difficult to overlay multicolor images with high precision, and high-quality color copies cannot be obtained.

Another method is to repeatedly form a latent image on a photoreceptor drum according to the number of separated colors of an original image and develop it with color toner, and then overlap the color toner images on the photoreceptor drum and then transfer the images to obtain a color image. The basic process of forming a multicolor image is disclosed in Japanese Patent Application Laid-open No. 6075850 and No. 60-767 by the present applicant.
No. 66, No. 60-95456, No. 6095458,
This is disclosed in Japanese Patent Publication No. 60-158475.

In a multicolor image forming apparatus that obtains a color image through such superimposition, a plurality of developing units containing different color toners are arranged around the periphery of the photoreceptor drum. The photoreceptor drum is rotated multiple times to develop the latent image on the photoreceptor drum to obtain a color image.

Regarding the image forming body, as explained above, there are a photosensitive drum in which a photoconductor is coated or deposited on the drum circumference, and a belt-like image forming body in which a photoconductor is coated or mounted on a visible belt. The body is also suggested. The shape of the belt-shaped image forming body (hereinafter also referred to as a photoconductor belt) is determined by stretching it between rotating rollers including a drive roller, so it is possible to effectively utilize space and create a compact color image forming apparatus. It is effective when configured. Furthermore, since the photoreceptor belt can run along a small curvature, it is possible to prevent poor separation of the transfer material by using a rotating roller with a small diameter and utilizing this curvature to separate the transfer material. can.

In an image forming apparatus using a photoreceptor, each image forming means such as a charging means, an image exposure means, a plurality of developing device groups, and a cleaning means mainly faces the lower circumferential surface of the outer peripheral surface of the photoreceptor belt. However, it is known that each of these image forming means, including the photoreceptor belt, is housed in a unitized process cartridge that can be freely attached to and detached from the main body of the apparatus.

Therefore, the toner storage container that stores the toner to be replenished to the developing device and the sealed storage box that stores the waste toner collected by the cleaning device must also be installed in a position that can be easily linked functionally to the process cartridge. Integrating them with a developing device and a cleaning device increases the size and also poses problems in terms of maintenance work.

This becomes a greater problem in more complex process configurations such as color image forming apparatuses. Furthermore, the problem becomes even more complicated due to differences in the frequency of use of multiple developing devices.

[Purpose of the invention]

As a result of solving this problem and making improvements, the present invention aims to provide a color image forming apparatus in which the sealed storage box of the toner storage container for replenishment, etc., can be easily connected and separated from the process cartridge as necessary. This is what I did.

[Structure of the invention]

The object is to provide an apparatus having a belt-like image forming member stretched between a plurality of rotating rollers, and a plurality of developing units located adjacent to each other at the peripheral edge of the belt-like image forming member. At least the belt-shaped image forming body and the plurality of developing devices constitute a cartridge that is removably mountable to the main body of the apparatus, and includes a plurality of toner storage containers that replenish toner to the developing devices]-
This is achieved by a color image forming apparatus characterized in that the supply path of the color image forming container unit is separated so that the cartridge can be attached to and removed from the apparatus main body.

Furthermore, the object is further achieved by a color image forming apparatus characterized in that the arrangement of the plurality of developing units and the arrangement of the plurality of toner containers corresponding thereto are perpendicular to each other.

Furthermore, the purpose is further achieved by making the replenishment path lengths substantially equal for each color.

〔Example〕

An embodiment of the color image forming apparatus of the present invention is shown in FIGS. 1 to 6.

In FIG. 1, 31 is a flexible photoreceptor belt which is a belt-like image forming member, and the photoreceptor belt 31 is a rotating roller 3].
A and 31B, and is conveyed clockwise by the rotation roller 31A.

31C is a guide member inscribed in the photoreceptor belt 1-3, 1, and the photoreceptor belt 31A is brought into a tensioned state by the action of the tension roller 31d, so that its inner peripheral surface slides on the guide member 31C. Let it rub.

Therefore, the photoreceptors on the outer circumferential surface of the photoreceptor belt 31 are always maintained at a constant position relative to the surface of the guide member 31C even during conveyance, making it possible to form a stable image forming surface.

33 is a Scoro I/Ron charger which is a charging means, 10 is a laser writing system unit which is an image exposure means, and 34 to 37 are developing devices which are a plurality of developing means each containing a developer of a specific color. The image forming means is a photoreceptor bell)3
It is arranged at a position opposite to the first guide member 31C. In order to maintain a gap without interfering with the movement of the photoreceptor belt 31, the kite member 3 is placed on the outside of the photoreceptor belt 31.
1C with a gap holding means.

In addition to the illustrated optical system, the laser writing system unit 10 may also include an optical system that integrates a light emitting section and a convergent light transmission body.

Each of the developing units 34 to 37 has yellow, magenta,
Each developing sleeve 3 accommodates cyan and black developers and maintains a predetermined gap with the photoreceptor belt 31.
4A, 35A, 36A, and 37A, and has a function of visualizing the latent image on the photoreceptor belt 31 by a non-contact development method. Unlike contact development, this non-contact development has the advantage of not interfering with the movement of the photoreceptor belt.

24 is a transfer device, 32 is a cleaning device which is a cleaning means, and blades 13A and 1 of the cleaning device 32 are connected to each other.
- The toner conveying roller 13B is kept at a position apart from the surface of the photoreceptor belt 31 during image formation, and is pressed against the surface of the photoreceptor belt 31 as shown in the figure only during cleaning after image transfer.

The image forming apparatus 100 opens the retractable casing 102 and removes the process cartridge 30 as shown by the dotted line in FIG.
This allows you to pull out the photoreceptor and replace the photoreceptor.

The process of forming a color image by the color image forming apparatus is performed as follows.

First, the formation of a multicolor image according to this embodiment is performed according to the image forming system shown in FIG. That is, the data obtained by the color image data input section a, in which the image sensor scans the original image, is processed by the image data processing section equipped with a calculation function to create image data, which is then transferred to the image memo IJ.
Stored in C.

The image memory is then taken out during recording and inputted into the recording section d, for example, the color image forming apparatus shown in the embodiment of FIG.

That is, when a color signal output from an image reading device separate from the printer is input to the laser writing system unit 10, the laser writing system unit 10 outputs a laser beam generated by a semiconductor laser (not shown). is rotated and scanned by a polygon mirror 12 rotated by a drive motor 11, and then passes through an fθ lens 13 to mirrors 14 and 1.
5, the optical path is bent by the charger 3, which is a pre-charging means.
3 onto the circumferential surface of the photoreceptor belt 310 to which the electric charge is applied, forming a bright line.

On the other hand, when scanning starts, the beam is detected by an index sensor (not shown), modulation of the beam by the first color signal is started, and the modulated beam scans the circumferential surface of the photoreceptor belt 31. do. Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the photoreceptor belt 31 by main scanning by the laser beam and sub-scanning by the conveyance of the photoreceptor belt 31. This latent image is yellow (
The developing device 34 loaded with the toner (developing medium) of Y) forms a toner image on the belt surface. The obtained toner image, while being held on the belt surface, passes under a cleaning device 32, which is a cleaning means, which is separated from the circumferential surface of the photoreceptor belt 31, and enters the next copy cycle.

That is, the photoreceptor belt 31 is charged again by the charger 33, and then the second
The color signal is input to the writing system unit 1-10, and writing is performed on the belt surface to form a latent image in the same manner as in the case of the first color signal described above. The latent image is developed by a developer 35 loaded with magenta (M) toner as a second color.

This magenta (M) toner image is formed in the presence of the previously formed yellow (Y) toner image.

A developing device 36 has cyan (C) toner, and forms a cyan (C) toner image on the belt surface based on a control signal generated by a signal processing section.

Furthermore, 37 is a developing device having black toner, which forms a black toner image superimposed on the drum surface by the same process. These developing devices 34, 35, 36 and 37
A direct current or even alternating current bias is applied to each sleeve, and jumping development is performed using a two-component developer, which is a developing means, and development is performed without contacting the photoreceptor belt 31, which is grounded to the substrate. It looks like this.

The color toner image thus formed on the circumferential surface of the photoreceptor belt 31 is transferred to a transfer material fed from the paper feed cassette 21 via the paper feed guide 25 at the transfer section.

That is, the transfer material housed in the paper feed center 21 is conveyed by the rotation of the paper feed roller 22, and the top layer is carried out via the timing roller 23 and transferred to the transfer device in synchronization with the image formation on the photoreceptor belt 31. 24.

The transfer material on which the image has been transferred is reliably separated from the photoreceptor belt 31, which suddenly changes direction along the rotating roller 31A, and heads upward, and after the image is fixed by the fixing roller 26, it is transferred to the paper ejection roller. 27 and is discharged onto a tray 28.

On the other hand, the photoreceptor belt 31, which has completed the transfer to the transfer material, continues to be conveyed to the blade 32A and the rotating toner conveyance roller 3.
The remaining toner is removed in the cleaning device 32 with the blade 2B in pressure contact, and after the cleaning is finished, the blade 32A is separated again, and a little later, the toner conveying roller 32B is separated and a new image forming process begins.

The photoreceptor belt 31 guide member 31C, the scorotron charger 33, each developing device, and the cleaning device 3
As shown in FIG. 1, each of the image forming means 2 is incorporated into a cartridge 30 and is attached to and detached from the main body of the apparatus as a unit.

That is, the cartridge 30 holds each of the image forming means and is vertically inserted and stored from above the apparatus main body via a total of three guide rails (not shown) attached to the front and back sides. .

The kite rail has a convex rail, and the main body of the apparatus is provided with a guide rail (not shown) having a concave rail. For power transmission with the device main body side, a power supply is connected.

The main body of the apparatus is constructed so that it can be opened together with the fixing roller 26 and the paper ejection roller 27 using a hinge 103 shown in FIG.

A toner storage container unit 40 is attached to the right side of the cleaning device 32, which is an integrated toner storage container unit 40 in which toner storage containers are connected in series. The toner storage container unit 4
0 stores toners of black, cyan, magenta, and yellow in the order of black, cyan, magenta, and yellow from the front to the back in accordance with the arrangement of the developing devices described above.

FIG. 3 is a plan view showing the main parts of the process cartridge provided in the image forming apparatus of this embodiment, and FIG. 4 is a vertical cross-section showing the developing unit i constituting the developing device.

In the process cartridge 30, the developing device is provided below the photoreceptor belt 31, and includes rotating rollers 31A,
The tension of the photoreceptor belt 31B is loosened and the photoreceptor belt 31 is placed in a position where it can be easily replaced. Figure 3 shows the photoreceptor belt 31.
FIG. 3 is a plan view showing the process cartridge 30 with the cartridge removed. The developing device is the developing unit 34~
37 are arranged in parallel.

Since the developing units 34 to 37 have a substantially concave configuration,
The developing unit 34 will be explained as a representative example.

As shown in FIGS. 3 and 4, the developing unit 34 has a substantially rectangular developing chamber formed in the casing 34, and the developing chamber has an opening for toner replenishment at the bottom. . A connecting portion 52 of a screw pipe 51, which will be described later, is fitted into the opening of the developing unit 34. Further, a developing sleeve 34A is provided near the opening of the developing chamber, and a screw-shaped stirring member 34B is provided at the bottom.

34C is provided. The stirring member 34C transports the toner supplied from the toner supply opening to the center of the developing chamber while stirring it. Each of the developing units 34 to 37 is loaded with two-component developers of different colors, in this case black, yellow, magenta, and cyan. This allows full-color images to be reproduced. Developing unit 3
4 is a developing sleeve 34A1 stirring member 34B, 34
The diameter of C is made as small as possible, and a replenishment chamber for storing toner and replenishing toner as needed is omitted to reduce the capacity, thereby making the toner compact and lightweight.

The toner storage container units 40 are connected and arranged in series in the order of yellow, magenta, cyan, and black toner from the drive side in the longitudinal direction of the developing sleeve shaft, and are perpendicular to the arrangement of the developing unit units 34 to 37. Further, the toner supply path portion 41 is separated at a connecting portion 42.

In addition, as shown in FIG. 3, the toner replenishment openings of each developing unit are different so that it does not get in the way when the process cartridge 30 is inserted and removed in the direction of the arrow shown in FIG. 3 and the connection part of the screw pipe is fitted. It is provided in the position.

As described above, in the image forming apparatus 100 of the present embodiment, the developer storage means 40 that accumulates a large amount of toner is provided outside the process cartridge 30, and replenishes toner to the developing unit as necessary. With this configuration, the toner chamber can be omitted from the developing unit, and the capacity of the developing unit can be further reduced.

With the above configuration, the process cartridges 1 to 30 employed in the image forming apparatus 100 of the present embodiment can be made small and lightweight, so that the process cartridge 30 can be easily taken in and out, and the photoreceptor The belt 31 could be easily replaced.

FIG. 5 shows the front side of the cartridge 30 with the toner storage container unit set therein. A supply port 43 communicating with each developing device is opened.

Each of the toner replenishing ports 43 houses an extension of one of a pair of stirring screws built into each developing device, and the toner that has fallen into each of the toner replenishing ports 43 is transferred to each developing device by rotation of the stirring screw. It is designed to be transported inside. The extended stirring screws include stirring screws 34C, 35G, 36C, and 37C located on the rotational upstream side of each developing sleeve due to the stirring effect.
is given.

When the toner storage container unit 40 is set in the toner replenishment path section 41, the toner sent by the rotation of the supply spiral built in each toner storage container falls into the toner replenishment path section.

FIG. 6(a) and FIG. 6(b) will be explained.

Toner supply path section 4 integrated with the cartridge
FIG. 6(a) shows a state in which the toner storage container section 1 and the toner storage container section 40 (in which the toner replenishment path section 40' is integrated) are in a connected state.

FIG. 6(b) shows a state in which it is in a divided state. In this state, the cartridge can be removed from the main body of the device.

Needless to say, each connection port of the toner supply path section 41 is closed by a shutter.

The merging spiral in each toner storage container is controlled by a toner replenishment signal by an independent motor (not shown) and rotates only when necessary.

Each spiral in the toner replenishment path section 41 is connected to the stirring spiral of each developing device through a gear so as to rotate.

The toner storage container unit 40 also has a structure that automatically closes the connection port 51 by operating a shutter plate to prevent toner from flowing out or scattering when it is not set in the toner replenishing section 40. Be taken.

The cartridge 30 may be physically configured including a developing device and made detachable, or may be configured such that a guide member, a belt-shaped image forming body, a cleaning device, etc. excluding the developing device are integrally configured and made detachable. You can also. In this way, maintenance of the apparatus is made possible by easily replacing elements of the cartridge that have a short or different service life or maintenance period.

〔Effect of the invention〕

As described above, the present invention provides an image forming apparatus in which a process cartridge in which a belt photoreceptor and at least a plurality of developing units are integrally housed is provided in a main body casing, and a developer storage means is provided outside the process cartridge. Because it can accommodate a large amount of developer of each color,
Since a large number of images can be continuously formed for a long time and the entire process cartridge 1-ridge can be downsized, an image forming apparatus with improved maintainability can be provided.

The present invention also provides a color image forming apparatus that uses a belt-like image forming member and houses each image forming means including a plurality of developing devices in an integrated cartridge, in which the cartridge is integrated into a unit so that the operation is extremely simple and easy. A toner storage container for storing supplementary and replenishing toner is realized which can be attached to and detached from the image forming means, and as a result, each image forming means can be replaced individually according to its service life. As a result, a color image forming apparatus has been provided which is extremely useful in terms of maintenance and management as well as economically.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus of the present invention, FIG. 2 is a block diagram showing an image forming system, and FIGS. 3 and 5 are front and rear configuration diagrams of a cartridge accommodated in the apparatus. , FIG. 4 is a longitudinal cross-sectional view showing a developing unit constituting the developing unit, and FIGS. 6(a) and 6(b) are perspective views showing the state of connection between the toner storage container unit and the toner supply path. be. 1... Photoreceptor belt 4... Guide member 6...
Band device (scorotron) 8.9.10.11...Developer 8B, 9B, IOB, IIB...Stirring screw 13...Cleaning device 30...Cartridge 30A, 30B...Substrate 40 ... Toner replenishment section 41 ... Replenishment port 42
- Rotating plate 50... Toner storage container unit 51... Drop opening 52... Supply roller 53
・・・Shatter board

Claims (3)

[Claims] (1) In an apparatus having a belt-like image forming member stretched between a plurality of rotating rollers, and a plurality of developing units located adjacent to each other at the peripheral edge of the belt-like image forming member, at least The belt-like image forming body and the plurality of developing devices constitute a cartridge that is removably attached to the main body of the apparatus, and a replenishment path of a toner storage container unit consisting of a plurality of toner storage containers that replenishes toner to the developing devices is separated. . A color image forming apparatus, wherein the cartridge is removable from the apparatus main body. (2) The color image forming apparatus according to claim 1, wherein the arrangement of the plurality of developing devices and the arrangement of the plurality of toner storage containers corresponding thereto are perpendicular to each other. (3) The color image forming apparatus according to claim 1 or 2, wherein the supply path length is approximately equal for each color.