JPH02302763A - Color image forming device - Google Patents

Abstract

PURPOSE:To simply attach and detach each equipment and material constituting an image forming part by dividing the device into upper and bottom enclosures attaching plural processing units which perform image formation in the bottom enclosure and opening the upper enclosure so that the processing units can be independently taken out. CONSTITUTION:A printer is structured in a clamshell type divided into the upper and bottom enclosures 1 and 2. The upper enclosure 1 can be held at the prescribed value of an angle in an opening direction with a hinge 1A which couples it with the bottom enclosure 2 as a fulcrum and is incorporated with the bottom enclosure 2 by a fastening plate in a closed condition. Then the plural processing units which perform image formation are attached in the bottom enclosure 2 and the upper enclosure 1 is opened so that the processing units are separately and upward taken out. Thus units which highly frequently requires maintenance and inspection are readily and preferentially attached and detached.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming apparatus using an electrophotographic method, and relates to a color image forming apparatus that is miniaturized and unitized to improve maintenance performance.

[Background of the invention]

An electrophotographic image forming apparatus that forms full-color or monochrome images includes a charger that charges a photoreceptor drum, which is an image forming member, a developer that develops an electrostatic latent image on the photoreceptor drum with toner, and a photoreceptor drum. A transfer device or the like that transfers the upper toner image onto recording paper is disposed at the peripheral edge of the photoreceptor drum.

Among these, there are three or four developing units in an electrophotographic image forming apparatus for full-color images, each containing yellow (Y), magenta (M), cyan (C) toner, and sometimes black (BK) toner. It consists of a developing device, and while the photosensitive drum rotates 3 or 4 times,
Toner images of yellow, magenta, and black in the case of cyan are formed on a photoreceptor drum, and the toner images are transferred to a transfer material to obtain a full-color image. When such an image forming method is used, the color image forming apparatus can be made into a combined color image forming apparatus by making three or four developing units thin and arranging them close to each other.

Japanese Patent Application Laid-open No. 61-55661 proposes a color image forming apparatus using such an image forming method, in which latent images are formed by three exposure devices using lasers, etc. corresponding to three developing units. , the photosensitive drum, the developing device, and the cleaning means are integrated into a unit and can be taken out from the main body of the apparatus.

Further, an image forming apparatus has been proposed in which a visible transfer belt is used as a means for transferring an image onto a transfer material, and the transfer portion thereof is arranged above a photosensitive drum.

When this device adopts a clamshell structure in which the device is divided into upper and lower halves, the upper casing can be made relatively lightweight, and the conveyance surface of the transfer material can be left wide open as necessary. This has the advantage of making jam removal and maintenance work extremely easy.

[Problem that the invention seeks to solve]

However, in such an image forming apparatus, if a method is adopted in which the photoreceptor drum, developing device, and cleaning means described above are integrated into one cartridge, the cartridge containing them will inevitably be vertically disposed from above with respect to the lower housing. The format is to insert it into

Therefore, when inspecting or cleaning the equipment, the operator has to pull up and remove the cartridge, which has increased in weight due to the integration, and is also forced to remove equipment that is not subject to maintenance from the equipment. .

An object of the present invention is to provide a color image forming apparatus that solves this problem and improves the color image forming apparatus so that units that require frequent maintenance and inspection can be easily and preferentially attached and detached.

[Means for solving problems]

The above object is divided into an upper casing and a lower casing, the lower casing is equipped with a plurality of process units that perform image formation, and the upper casing is opened to independently move the process units upward. This is achieved by a color image forming apparatus that is characterized by being removable.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 to 6.

1 and 2 show a printer to which the present invention is applied.

The printer has a structure in which a Talam shell is divided into an upper casing 1 and a lower casing 2, and the upper casing 1 is opened at a predetermined angle using a hinge IA connected to the lower casing 2 as a fulcrum. It can be held at an angle, and in the closed state, it is integrated with the lower housing 2 by a locking fitting (not shown).

The image forming section of the printer has an image forming body 30, yellow,
Developing unit 3 containing magenta, cyan, and black developers
6.37, 38, 39, cleaning device 40, charger 35, pre-transfer charger 9, toner collection box 70
It consists of various equipment, all of which are mounted on the lower casing 2 side.

The developing units have an integral housing and are arranged in parallel from the rotational upstream direction below the image forming body 30 so as to face the surface thereof. Therefore, each developing unit has an opening. Since the developer is kept in an upward position, the developer does not leak out and fall or get mixed into other developing units.

The printer has a laser writing system unit B in a space to the side of the image forming section, and a transfer material conveyance surface in both the upper housing 1 and the lower housing 2 above the image forming body 30. The image forming body 30 receives laser scanning from the laser writing system unit B from diagonally downward, and a color toner image formed by overlapping the circumferential surface of the image forming body 30 is applied to the lower surface of the transfer material. We use a method of transcription.

In this way, the transfer material is conveyed over the image forming body 30 in a substantially horizontal direction, and the transfer surface is also facing downward, so even if the toner spills or scatters from the cleaning device 140 or the like, the image surface It does not go so far as to contaminate the material.

In addition, this device has the following advantages: (1) The paper feeding system is located below, and the center of gravity is set further below, which has great advantages in terms of the structure of the machine.

(2) The transport system can be easily opened in the event of a jam.

Benefits include:

The process of color image copying by the printer 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 color image data input section (Fig. 3 (a)) where the image sensor scans the original image.
) is processed by an image data processing unit equipped with a computer (Figure 3 (B)) to create image data, which is temporarily stored in the image memory (Figure 3 (C)). be done. Then, the image memory is taken out during recording and stored in the recording section (
For example, the color image forming apparatus shown in FIG. 1 is inputted as shown in FIG. 3(d)).

That is, when a color signal output from an image reading device separate from the printer is input to the laser writing system unit B, the laser writing system unit B outputs a laser beam generated by a semiconductor laser (not shown). is rotated and scanned by a polygon mirror 32 rotated by a drive motor 31, and passes through an fθ lens 33 to three mirrors 34A,
An image forming body 30 whose optical path is bent by 34B and 34C and to which a charge is applied in advance by a charger 35 serving as a charging means.
is projected onto the circumferential surface 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 the circumferential surface of the image forming body 30. Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the image forming body 30 by the main scanning by the laser beam and the sub scanning by the rotation of the image forming body 30. This latent image is developed by a developing device 36 loaded with yellow (Y) toner (M image medium) of the developing means, and a toner image is formed on the drum surface. The obtained toner image passes under a cleaning device 40, which is a cleaning means, which is separated from the peripheral surface of the image forming body 30 while being held on the drum surface, and enters the next copy cycle.

That is, the image forming body 30 is charged again by the charger 35, and then the second color signal output from the signal processing section is input to the writing system unit B, and the second color signal is inputted to the writing system unit B, and the second color signal is inputted to the writing system unit B. In the same manner, writing is performed on the drum surface to form a latent image.

The latent image is developed by a developer 37 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 38 has cyan (C) toner, and forms a cyan (C) toner image on the drum surface based on a control signal generated by a signal processing section.

Furthermore, 39 is a developing device having black toner, and a black toner image is superimposed and formed on the drum surface by the same process. Direct current or even alternating current bias is applied to each sleeve of each of these developing devices 36, 37, 38 and 39, and jumping development is performed using a two-component developer serving as a developing means to form an image with the substrate grounded. body 30
Development is now possible without contact.

The color image thus formed on the circumferential surface of the image forming body 30 is sent from the paper feed cassette C via the paper feed roller and the paper feed guide to the transfer section and is transferred onto the lower surface of the transfer material.

That is, after this multicolor toner image is charged by the pre-transfer charger 9 to be easily transferred, the transfer belt 50 used as a transfer means, which has been rotated since the start of transfer, is brought into contact with the image forming body 30 and fed. Paper feed roller 1 from paper cassette C
2 and the timing roller 13, the image is transferred onto the supplied recording paper in synchronization with the image formation.

The transfer belt 50 is stretched between rollers 59 and 60,
The roller 60 is rotated in synchronization with the circumferential speed of the image forming body 30, and as the roller 58 moves up and down, it is moved away from or in contact with the image forming body 30.

The roller 58 is attached to a lever 57 that can swing around the axis of the roller 60 as a fulcrum, and is held in the upper position shown by the solid line by an elastic member that biases the lever 57. The transfer belt 50 is moved downward as indicated by the dashed line by the power of a solenoid or the like that operates at the timing of , that is, to a position where the transfer belt 50 is brought into pressure contact with the circumferential surface of the image forming body 300 .

As the transfer belt 50, a rubber belt containing a conductive cloth is used as a base, and a high resistance layer or an insulating layer having an elastic body with a thickness of 0.5 mm is provided on the outer periphery of the belt.

The transfer belt 50 is charged by a transfer device 51, and a transfer charge having a polarity opposite to that of the toner is applied to perform the transfer. Note that the toner adhering to the transfer belt 50 is removed and cleaned by a transfer belt cleaning device 50A.

The transfer material to which the multicolor toner image has been transferred in this way is an image forming body 3.
It is separated from the circumferential surface of the fixing roller 8 and transported to the fixing device.
After the toner is melted and fixed by 0, the toner is discharged to the outside of the machine via the paper discharge roller 90.

On the other hand, the image forming body 30 from which the transfer material has been separated is cleaned by the cleaning device 40 to remove residual toner.

The image forming body 30, the cleaning device, and each developing device are constructed by integrating the related equipment and forming an independent cleaning unit I, image forming body unit ①, and developing device unit ②, and a lower casing with the lid opened. The developing device unit m, the image forming unit 2, and the cleaning unit I are stored in the body 2 in this order, and are removed in the reverse order.

FIG. 4 shows the cleaning unit I, in which the cleaning device 40 is integrated with a toner collection box 70 placed at a position sandwiching the image forming body 30 via front and rear relay plates 40A as shown with dashed lines, for example. Both are connected by a toner transport pipe 70A and supported by front and rear substrates fixed to the lower housing 2 as an independent process unit.

Further, FIG. 5 shows the image forming unit (2), in which the image forming unit 30 is provided with a charger 35 and a pre-transfer charger 9 installed facing the circumferential surface of the image forming unit 30, which are shown by front and rear support plates with dashed lines, for example. It is integrated via 3OA and supported by the above-mentioned front and rear substrates as an independent process unit.

On the other hand, FIG. 6 shows the developing device unit III, in which toner supply boxes 36A to 39A for each developing device are mounted and supported on the front surface of each integrated developing device, and the cleaning device l-1 and image forming It is also supported by the front and rear substrates as an independent process unit similar to body unit (2).

It should be noted that the shape of the relay plate 40A1 and the support plate 30A may be any shape or form other than that shown in the drawings due to structural or handling considerations.

Each of the process units described above is inserted into the guide portions provided on the front and rear substrates, and when the developing unit (Ill), image forming unit (I), and cleaning unit I are stored in this order, the drive system on the lower housing 2 side is simultaneously inserted. It is also connected to a power supply and functions as an image forming process unit.

〔Effect of the invention〕

According to the present invention, it is extremely easy to attach and detach each component of the image forming section to the main body of the apparatus, and as a result, maintenance inspections and various types of maintenance are thorough, and the best performance is always exhibited, resulting in copies with excellent image quality. A color image forming apparatus that provides the following will be realized.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of the color image forming apparatus of the present invention, FIG. 3 is a block diagram showing the image forming system, and FIG.
6 through 6 are perspective views of each process unit constituting the image forming section of the apparatus. l... Upper housing IA... Hinge 2... Lower housing 9... Pre-transfer charger 30... Image forming body 35... Charger 36-39... Developer device 36A- 39A...Toner supply box 40...Cleaning device 70...Toner collection box 70A...Toner transport pipe■...Cleaning unit■...Image forming body unit■...Phenomenon unit

Claims (3)

[Claims] (1) Divided into an upper housing and a lower housing, the lower housing is equipped with a plurality of process units that perform image formation, and the upper housing is opened to take out the process units independently upwards. A color image forming apparatus characterized by the following features: (2) The color image forming apparatus according to claim 1, wherein the process unit includes an image forming body unit and a cleaning unit that performs cleaning. (3) The color image forming apparatus according to claim 1, wherein the process unit includes a plurality of individual developer units or a developer unit in which a plurality of developers are integrated.