JPH0339764A - Color image forming device - Google Patents

Abstract

PURPOSE:To singly replace each image forming means according to its serving life by forming each image forming means containing plural developing devices into a unit with respect to an integrated cartridge through the use of a belt-like image forming body. CONSTITUTION:The cartridge attachable/detachable to/from a device main body is constituted of the belt-like image forming body 1 and a toner container unit 50, and the toner container unit 50 can be attached/detached while the cartridge is removed. Consequently, when the cartridge is attached/detached to/from the device main body, a tray 20 is opened counterclockwise centering on a hinge 21 as a supporting point together with a fixing roller 18 and a paper ejecting roller 19, whereby the cartridge is vertically pulled upward and the engagement of the guide rail 32 is released. Thus, the components of the cartridge can be easily replaced when their serving lives and maintenance periods are short or different each other, and the maintenance of the device can be facilitated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention involves forming a toner image on a belt-like image forming member using an electrophotographic method and transferring it onto a transfer material to obtain an image. The present invention relates to a color image forming apparatus.

[Background of the invention]

There are many ways to obtain color images using electrophotography.
A device has been proposed. For example, JP-A-61-10077
As disclosed in Publication No. 0, a latent image is formed and developed in accordance with the number of separated colors of an original image on a photoreceptor drum serving as an image forming member, and is transferred onto a transfer drum each time the development is performed. There is a method of forming a multicolor image on a paper 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 Unexamined Patent Publication 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 to obtain multicolor copies. With this method, it is difficult to overlay multicolored images with high precision.
It is not possible to obtain a good quality color copy.

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. 60-75850 and No. 60-7 by the present applicant.
No. 6766, No. 60-95456, No. 60-9545
No. 8, No. 60-158475, etc.

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.

As for image forming bodies, as explained above, there are photosensitive drums with a photoconductor coated or vapor-deposited on the circumferential surface of the drum, and belt-shaped image forming bodies with a photoconductor coated or mounted on a flexible belt. has also been proposed. 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. Also, since the photoreceptor belt can run along a small curvature,
By using a rotating roller with a small diameter and separating the transfer material using this curvature, it is also possible to prevent poor separation of the transfer material.

[Purpose of the invention]

In a color image forming apparatus using such a photoreceptor belt, each image forming means such as a charging means, an image exposure means, a plurality of developing unit groups, and a cleaning means is mainly located on the lower circumferential surface of the outer peripheral surface of the photoreceptor belt. Each of these image forming means, including the photoreceptor belt, is housed as a unitized process cartridge, which 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 each 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 facilitates functional linkage with the process cartridge. However, integrating them with the developing device and the cleaning device poses problems in terms of the difference in service life and maintenance work.

The present invention solves this problem and improves it, thereby providing a color image forming apparatus in which the replenishment toner storage container, the sealed storage box for collected toner, etc. can be easily connected to and separated from the process cartridge as necessary. The purpose is to

[Structure of the invention]

The above purpose is to provide a belt-like image forming body stretched between two rotating rollers, a plurality of developing devices located adjacent to each other on the peripheral edge of the belt-like image forming body, and supplying toner to the developing devices. In an apparatus comprising a plurality of toner storage containers, at least the belt-shaped image forming member and the toner storage container unit constitute a cartridge that is removably attached to the apparatus main body, and the toner storage container unit is removed with the cartridge removed. This is achieved by a color image forming apparatus characterized by being detachable.

〔Example〕

An embodiment of the color image forming apparatus of the present invention is shown in FIGS. 1 to 5.

In FIG. 1, reference numeral 1 denotes a flexible photoreceptor belt which is a belt-like image forming member, and the photoreceptor belt is installed between rotary rollers 2 and 3, and is rotated clockwise by the drive of rotary roller 2. transported to.

Reference numeral 4 denotes a guide member inscribed on the photoreceptor belt, and the photoreceptor bell 171 is brought into a tensioned state by the action of the tension roller 5, so that its inner circumferential surface slides against the guide member 4.

Therefore, the photoreceptor on the outer peripheral surface of the photoreceptor belt is always maintained at a constant relative position with respect to the surface of the guide member 4 even during conveyance, making it possible to form a stable image forming surface.

6 is a scorotron charger which is a charging means; 7 is a laser writing system unit which is an image exposure means; and 8 to 11 are developing devices which are a plurality of developing means each containing a developer of a specific color. is disposed on the photoreceptor belt 1 at a position facing the guide member 4 . Then, in order to maintain a gap without interfering with movement on the photoreceptor belt, the guide member 4 is brought into contact with the guide member 4 on the outside of the photoreceptor belt 1 with a gap retaining means.

In addition to the optical system shown in the drawings, the laser writing system unit 7 may also include an optical system that integrates a light emitting section and a convergent light transmission body.

Each of the developing units 8.9.10.11 accommodates, for example, yellow magenta, cyan, and black developers, respectively, and each of the developing sleeves 8A, 9A, and IOA maintains a predetermined gap with the photoreceptor bell l-1. , IIA, and has a function of visualizing the latent image on the photoreceptor belt l 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.

12 is a transfer device, 12A is a static elimination bar, and 13 is a cleaning device as a cleaning means.
The blade 13A and the toner conveying roller 13B are kept at a position apart from the surface of the photoreceptor belt 1 during image formation, and are brought into pressure contact with the surface of the photoreceptor belt 1 as shown only during cleaning after image transfer.

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. In other words, the color image data input section (Figure 2 (a)) where the image sensor scans the original image.
) is processed by the image data processing unit (Figure 2 (b)) to create image data, which is then stored in the image memory (Figure 2 (c)). . Then, the image memory is taken out during recording and stored in the recording section (FIG. 2(d)).
) is input to the color image forming apparatus shown in the embodiment of FIG. 1, for example.

That is, when a color signal output from an image reading device separate from the printer is input to the laser writing system unit 7, the laser writing system unit 7 outputs a laser beam generated by a semiconductor laser (not shown). is rotated and scanned by the polygon mirror 7B rotated by the drive motor 7At2, and is scanned by the mirrors 7D and 7 via the fθ lens 7C.
The optical path is bent by E, and a charger 6, which is a pre-charging means,
The light is projected onto the circumferential surface of the photoreceptor bell l-1, which is charged with a charge, to form a bright line.

On the other hand, when scanning is started, the beam is detected by the index sensor, modulation of the beam by the first color signal is started, and the modulated beam scans over the circumferential surface of the photoreceptor bell)l. Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the photoreceptor belt l by the main scanning by the laser beam and the sub-scanning by the conveyance of the photoreceptor belt l. This latent image is developed by a developing device 8 loaded with yellow (Y) toner (developing medium) of the developing means, and a toner image is formed on the belt surface. The obtained toner image passes under a cleaning device 13, which is a cleaning means, which is separated from the peripheral surface of the photoreceptor belt 1 while being held on the belt surface, and enters the next copy cycle.

That is, the photoreceptor pel I-1 is charged again by the charger 6, and then the second color signal output from the signal processing section is input to the writing system unit 7, and the above-mentioned first color signal is Writing is performed on the belt surface in the same manner as in the case of the above example, and a latent image is formed. The latent image is developed by a developer 9 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 10 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.

Further, numeral 11 denotes a developing device having black toner, which forms a black toner image superimposed on the drum surface by the same process. These developing devices 8, 9゜lO and 11
A direct current or even alternating current bias is applied to each sleeve, and jumping development is performed using a one- or two-step developer, which is a developing means, and a non-contact is applied to the photoreceptor bell whose base is grounded. Development is now done.

The color toner image thus formed on the circumferential surface of the photoreceptor bell I-1 is transferred to a transfer material fed from the paper feed cassette 14 via the paper feed guide 15 in the transfer section.

That is, the top layer of the transfer material stored in the paper feed cassette 14 is carried out by the rotation of the paper feed roller 16, and transferred to the transfer device 12 via the timing roller 17 in synchronization with the image formation on the photoreceptor belt l. supplied to.

The transfer material on which the image has been transferred is reliably separated from the photoreceptor bell (1) which suddenly changes direction along the rotation roller 2, moves upward, and after the image is fused by the fixing roller 18, the paper is discharged. It passes through rollers 19 and is discharged onto tray 20 .

On the other hand, the photoreceptor belt l, which has completed the transfer to the transfer material, continues to be conveyed and is brought into pressure contact with the blade 13A and the rotating toner conveyance roller 13B.
After removing the remaining toner, the blade 13A is removed again after the removal, and a little later, the toner conveying roller 13B is removed to begin a new image forming process.

The image forming means of the photoreceptor belt 1, guide member 4, scorotron charger 6, developing devices, and cleaning device 13 are composed of front and rear substrates 30A and 30B, as shown in FIG. The cartridge 30 is assembled into a cartridge 30 that is attached to and detached from the main body of the apparatus as a unit.

That is, the cartridge 30 integrates the front and rear substrates 30A and 30B with four stays 31, and holds each of the image forming means between them through a total of three guide rails 32 attached to the front and back surfaces. It is inserted and stored vertically from above the device main body.

The guide rail 327 is provided with a convex rail 32A, while a guide rail (not shown) having a concave rail is provided on the main body of the apparatus, and by engagement of these guide rails, each of the above-mentioned images is formed. The means is connected to the main body of the device for power transmission or power supply.

FIG. 4 shows the back side of the cartridge 30. The cartridge 30 has a toner replenishing section 40 protruding from the back side of the substrate 30B, which connects to each developing device, and a replenishing port 41 communicating with each developing device on the top surface thereof. I'm letting you do it.

Each of the toner replenishing ports 41 houses an extension of one of a pair of stirring screws internally controlled by each developing device, and the toner that has fallen into each of the toner replenishing ports 41 is transferred to each developing device by rotation of the stirring screw. It is designed to be transported inside. Stirring screws 8B, 9B, IOB, and IIB located on the rotationally upstream side of each developing sleeve are applied to the extended stirring screws in view of the stirring effect.

On the other hand, the toner storage containers attached to the toner replenishing section 40 are connected in series and integrated as a toner storage container unit 50, which is mounted on the upper part of the toner replenishing section 40.

The toner storage container unit 50 stores yellow, magenta, cyan, and black toners from the left toward each toner storage container, and each drop port 51 corresponds to the replenishment port 41 of the toner replenishment section 40 .

When the toner storage container unit 50 is attached, the rotary plate 42 attached to the end face of the toner replenishing section 40 is used as a guide, and the attachment position is further regulated thereby. At the same time, a gear G coaxially integrated with the supply roller 52
1 meshes with the gear G2 on the toner replenishing section 40 side, and a power transmission system is also connected.

The operation of replenishing toner to each developing device by the toner storage container unit 1-50 will be explained in the case of the developing device 9.

FIG. 5(A) shows a cross section taken along arrow AA in FIG. The rotation starts and the magenta toner stored in the container is dropped into the supply port 41 from the drop port 51.

The magenta toner that has fallen into the replenishment port 41 is conveyed into the developing device 9 by the rotation of the stirring screw 9B, and further stirred and mixed in the developing device 9 by the reverse feeding action of the other stirring screw, and then transferred to the developing sleeve. 9A to restore the image density.

After the image density is restored, the rotation of the gear G2 is stopped in response to a signal from the control section based on the detection result, and toner replenishment is completed, and this action is performed intermittently during the development process.

FIG. 5(B) shows the state in which the toner storage container unit 50 is removed from the toner supply section 40, and the cough toner storage container unit 50 can be easily pulled out upward by releasing the locking device (not shown). It can be removed by

When the toner storage container unit 50 is removed, the shutter plate 53 operates to close the drop opening 51, and the toner replenishing section 40 rotates the rotary plate 42 counterclockwise about its support shaft 42A as a fulcrum. The replenishment port 41 is shielded to prevent toner from flowing out or scattering or from entering foreign matter.

When attaching and detaching the cartridge 30 to the main body of the apparatus, the tray 20 is opened counterclockwise together with the fixing roller 18 and the paper ejection roller 19 using the hinge 21 shown in FIG. The guide rail 32 is disengaged by being pulled up vertically.

Although the cartridge 30 including the belt-shaped image forming body and the developing unit is configured to be integrally removable, it is also possible to configure the toner replenishment container and the belt-shaped image forming body to be integrally configured to be removable. This allows maintenance of the device by easily replacing elements of the cartridge with short or different service life or maintenance periods.

〔Effect of the invention〕

The present invention provides a color image forming apparatus that uses a belt-like image forming body and houses image forming means including a plurality of developing devices in an integrated cartridge, which can be easily attached to and detached from the cartridge by an extremely simple operation. As a result, each image forming means can be replaced individually according to its service life, which reduces maintenance and management issues. A color image forming apparatus that is economically extremely useful has now been provided.

[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 4 are front and rear configuration diagrams of a cartridge accommodated in the apparatus. , FIG. 5 is a sectional view of a main part of the cartridge. l...Photoreceptor belt 4...Guide member 6...
- Band ttl (scorotron) 8.9.10.11...Developer 8B, 9B, 1OB, 11B...Stirring screw 13
... Cleaning device 30 ... Cartridge 30
A, 30B... Board 40... Toner supply section 41... Supply port 42... Rotating plate 50.
... Toner storage container unit 51 ... Falling port 52 ... Supply roller 5
3...Shatter board

Claims (1)

[Claims] A belt-like image forming member stretched between two rotating rollers, a plurality of developing devices located adjacent to each other on the peripheral edge of the belt-like image forming member, and a plurality of developing devices that supply toner to the developing devices. In an apparatus comprising a toner storage container, at least the belt-shaped image forming body and the toner storage container unit constitute a cartridge that is removable from the apparatus main body, and the toner storage container unit is removable with the cartridge removed. A color image forming apparatus characterized by: