JPH02181759A - Color image forming device - Google Patents

Abstract

PURPOSE:To form various images by attaching a processing unit, which integrates a photosensitive drum with a multiple number of developers, and a processing unit, which includes a developing device, separable from the photosensitive drum, compatibly. CONSTITUTION:A multi color processing unit is formed from a cartridge containing a photosensitive drum, a three color developing device, and a cleaning device etc., and is attached to the device main body by a pair of guiding members. On the other hand, a single color processing unit 3B is formed from a cartridge containing a photosensitive drum 130, a developing device 100, and the cleaning device 139, and is attached to the device main body by the railings of a pair of guiding members 104A. The developing device 100 of a unit 3B has the facility of easily exchanging and attaching/detaching the developing device with toner of specified color. Thus color or monochrome image can be selected arbitrarily, obtaining various images, and at the same time various monochrome images can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color image forming apparatus that can be used by switching between two types of image processing: monochrome and color.

[Background of the invention]

Color image forming apparatuses using electrophotography, even in the so-called image overlapping type color image forming method, develop the image using at least three developing units each having developer of three colors: yellow, magenta, and cyan. A method of composing a recolor image by compositing is used.

These developing devices require high precision in image overlaying, and to facilitate inspection and maintenance, they are usually housed in a stacked state together with the photoreceptor drum, which serves as an image forming body, in a cartridge, and are collectively used as a process unit for image formation. The structure is such that it can be attached to and removed from the main body of the device.

For example, when monochrome image processing using a black developer is continuously performed using such a color image forming apparatus, a monochrome process is performed in which only one developer containing a large amount of black developer is housed in a cartridge of the same type. The unit is used by replacing it with the multicolor process unit described above.

[Problem that the invention seeks to solve]

Regarding the processing of color images, all color images can be processed by a combination of developing devices each containing yellow, magenta, and cyan developers, so one multicolor process equipped with each of these developing devices can be used. It is sufficient to prepare a unit, but since developers other than black are often used when processing monochrome images, multiple units each containing developers of other colors such as red and blue are installed. Seven single color process units are prepared and used by replacing them depending on the color to be processed.

Therefore, for monochrome image processing, multiple photoconductor drums, cleaning devices, etc., and cartridges to accommodate them are required, which not only increases manufacturing costs but also places a heavy burden on users in terms of maintenance and management. It becomes.

The present invention has been made to solve this problem, and as a result, it is an object of the present invention to provide a color image forming apparatus that can process monochrome images using a plurality of processing colors by simply preparing one monochrome processing unit.

[Means for solving problems]

The above purpose is to compatibilityly install a process unit that includes a photoconductor drum and a plurality of color developing devices, and a process unit that includes a photoconductor drum and one developer that is separable. This is achieved by a color image forming apparatus characterized in that it is possible.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 to 5.

The color image forming apparatus of this embodiment uses a multicolor image forming method using a toner overlapping development method disclosed by the present applicant in Japanese Patent Laid-Open No. 60-75850.

Figure 1 shows the main configuration of a color image forming apparatus. A is an image reading system, B is a laser writing system unit, C is an image forming section, and D is a paper feeding section. An image is now formed.

In the reading system A, 11 is a document table;
The document stored in the holder is illuminated by a halogen lamp 13 attached to a carriage 12 that slides in the horizontal direction. Mirrors 16 and 17 are attached to the movable mirror unit 15, which also slide in the horizontal direction, and in combination with the mirror 14 attached to the carriage 12 guide the optical image of the document to the image reading section 22. do.

The carriage 12 and the movable mirror unit 15 are connected to a stepping motor by wires (both not shown).
, and are slid in the same direction at speeds of V and 1/2V, respectively.

When a color image is to be copied by the color image forming apparatus of this embodiment, a multicolor process unit, which will be described later, is used, and when the multicolor process unit is installed, the copy mode switching device of the apparatus is activated, and the image processing by the apparatus is performed in color. The process is switched to

When the image reading unit 22 reads the document placed on the platen glass 11, color separation is performed via the filter 9. The filter 9 is, for example, filter R1 filter G1 filter B1 filter N.
When reading a document, the document is read after passing through one of the filters R1 and 7 (Luther B1 and ND).

The selection of filter R1, filter G, filter B1, and filter ND is achieved by moving filter 9 in a direction perpendicular to the plane of the paper in FIG. 1 using a filter selection device.

Note that filter R1, filter G1, and filter B are filters that pass red light, green light, and blue light, respectively, and filter ND is a neutral filter that passes all three color lights.

The image signal output from the image reading section 22 is subjected to signal processing in a signal processing section. In the signal processing section,
Color signals are separated according to the toner colors, and color signals are output and input to the laser writing system unit B, which is an exposure means.

In the laser writing system unit B, 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, passes through an fθ lens 33, and has an optical path bent by a mirror 34. The circumferential surface of the photosensitive drum 30 to which a charge has been applied in advance by a charger 35 serving as a charging means is scanned.

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 is transferred to the photoreceptor drum 30.
scan the circumferential surface of the Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the photoreceptor drum 30 by main scanning by the laser beam and sub-scanning by the rotation of the photoreceptor drum 30. This latent image is developed by a developing device 36 loaded with yellow (Y) toner (a image medium) of the developing means, and a toner image is formed on the drum surface. The obtained toner image is separated from the surface of the photosensitive drum 30 while being held on the drum surface.A cleaning device 3 serves as a cleaning means.
9 and enters the next copy cycle.

That is, the photosensitive drum 30 is charged again by the charger 35, and then the second
The color signal is input to the writing system unit B, and writing is performed on the drum 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 37 loaded with magenta (M) toner as a second color.

This magenta (M) toner image has already been formed6.
It is formed in the presence of the yellow (Y) toner image described above.

A developing device 38 has cyan (C) toner, and forms a cyan (C) toner image on the drum surface based on an image signal generated by a signal processing section. Each of these developing devices 36,
AC and DC biases are applied to the sleeves 37 and 38, and development is performed without contacting the photoreceptor drum 30 with a two-component developer serving as a developing means.

The color image thus formed on the circumferential surface of the photosensitive drum 30 is transferred to the transfer pole 40 provided as a transfer means.
The paper feed belt 41. The image is transferred onto recording paper, which is a recording medium, fed by the feeding roller 42. The recording paper onto which the toner image has been transferred is separated from the drum surface by a separation pole 43 and transferred to a fixing device 45 via a conveyor belt 44.
The image will be fixed.

On the other hand, the photosensitive drum 3 with the recording paper separated from the drum circumferential surface
At 0, the blade 39A of the cleaning device 39 comes into contact and removes the remaining toner, and at the end of the process, the drum is again separated from the circumferential surface of the drum by a barrel, and a new color image forming process begins.

Next, the layout of each of the main components mentioned above will be explained. As shown in FIG. There is.

The main body 2 incorporates an image recording system consisting of the writing system B1, image forming section C1, paper feeding section, etc., and receives data from the image reading system A via a group of flexible cables connected to the housing 1. It is designed to receive color signals.

In the main body portion 2, the photosensitive drum 30 is located approximately in the middle, and facing the right peripheral surface thereof, each of the developing units 36°37.3
8 are arranged horizontally, while the charger 35 and the cleaning device 39 are arranged on the left peripheral surface.

The photosensitive drum 30, the charger 35, the developing devices 36, 37, 38, and the cleaning device 39 are all housed in the multicolor process unit 3A and are removably attached to the main body 2 in an integrated state. It will be done.

As shown in FIG. 2, the multicolor process unit 3A is composed of cartridges that can house the photosensitive drum 30, each developing device 36, 37, 38, a cleaning device 39, etc. The guide member allows for easy removal and installation.

That is, rails 4A are provided on the left and right edges of the multicolor process unit 3A, and guide rails 4B are provided inside the main body 2 corresponding to the rails 4A, and the rails 4A are slidably engaged with the guide rails 4B. So, main body 2
will be installed on the

When each of the developing units 36, 37, and 38 is housed in the respective storage space in the cartridge, it is pressed in the direction of the photosensitive drum 30 by the action of the pressing and urging means, and is coaxially aligned with the developing sleeves 36A, 37A, and 38A. By pressing the provided abutting rollers against the drum surface, the gap (Dsd) between the drum surface and each of the developing sleeves is maintained at a specified value.

When mounted on the main body 2, the multicolor process unit 3A is latched by a member (not shown) to accurately place each piece of equipment to be accommodated in each set position, and at the same time connects to the drive section and power supply section on the main body 2 side. be done.

On the other hand, when copying a monochrome image using the color image forming apparatus, a monochrome process unit 3B shown in FIG. 3 is used, and when it is installed, the process of the apparatus I is switched to a monochrome copy mode.

The monochrome process unit 3B houses a photoreceptor drum 130, a charger 135, and a cleaning device 139 as in the case of the multicolor process unit 3A, but the blade 139A of the cleaning device 139 constantly touches the circumferential surface of the photoreceptor drum 130. They are in pressure contact.

Furthermore, one developing device 100, which has a function of storing a large amount of toner of a specific color and replenishing it according to changes in the density of a developed image, is incorporated in the monochrome process unit 3B in a freely replaceable manner.

That is, the developing device 100 is located in a fourth position relative to the cartridge.
It is incorporated so that it can be easily attached and detached using the attachment mechanism shown in the figure.

A pair of upper and lower guide bins 51 fitted with compression springs are installed on the rear surface of the developing device 100 between a fixed handle 50A and a holding piece 52, and are slidably fitted to each of the guide pins 51. The movable handle 50B is biased rightward.

The movable handle 50B has a pair of upper and lower boss portions 50G.
A pressing lever 54, which is urged counterclockwise by a torsion spring 53, is pivoted to the lower boss portion 50C.

On the other hand, a guide plate 37A on which the developing device 100 is mounted is fixed to the cartridge, and a "hook-shaped" notch 60 is provided at the side end portion thereof corresponding to the press lever 54.

When the developing device 100 is attached to the cartridge, the pressing lever 54 is pressed against the straight portion 6 of the notch 60.
1 and is pressed slightly clockwise,
By the action of the pressing and urging means constructed in this manner, the developing device 100 is pressed in the direction of the photosensitive drum 130, so that the developing sleeve 100A located at the tip is brought into pressure contact with the circumferential surface of the drum.

On the other hand, in order to remove the developing device 100 from the cartridge, the movable handle 50B is slid to the left against the action of the compression spring so as to grasp the movable handle 50B relative to the fixed handle 50A. It returns clockwise, and in the process, the protrusion 54A comes into contact with the movable handle 50B and stops.

Therefore, when the handles 50A and 50B are simultaneously pulled at the position where the boss portion 50C has completely pushed the compression spring, the pressing lever 54 escapes from the opening of the notch 60 and the developing device lO
O can be taken out and separated from the cartridge.

When installing the developing device 100 into the cartridge, place the front end of the developing device 100 on the guide plate 37A, and hold the fixed handle 5.
When pushed in by 0A, the pressing piece 54 on the movable handle 50B located at the right end of the guide pin 51 comes into contact with the slope part 63 on the front side due to the action of the compression spring, and due to the inclination angle, the pressing piece 54 on the movable handle 50B is pushed together with the movable handle 50B. Slide on the guide bin 51 to the left.

When the pressing lever 54 reaches the opening of the notch 60 and the developing device 100 is further pushed in, the movable handle 50B slides to the right due to the action of the compression spring, and the pressing lever 5
4 comes into sliding contact with the slope part 62 and is rotated slightly clockwise until it reaches the straight part 61, as described above.
A biased state of 0 is obtained. Note that other developing units containing developers of different colors are also attached to and detached from the cartridge using a similar attachment mechanism. As explained above, the handle members (50A, 50B) are used for release and release when pushing in and out.
Since it includes a locking mechanism and can also be used to hold a small and lightweight developing device, its operability is further improved.

The position of the handle is not limited to the position of the embodiment, depending on the state when the cartridge is pulled out or the weight balance of the developing device, and it may be provided in the center, or two handles may be provided, one on each side.

Furthermore, when installing each developing device to the cartridge, it depends on the dimensions such as length, depth, and width, or the relative position, and the combination of grooves, holes, notches, etc., and protrusions such as dowels and rails. By combining one or more of the mechanical elements and selecting the above-mentioned specifications, a fool-proof mechanism is provided that prevents a developing device of another type from being accidentally attached to the multicolor process unit 3A. There is.

FIG. 5 shows the right side of the cartridge in a state in which the developing device 100 is accommodated.

When installing the developing device, as shown in the example of the developing device 100, guide rails 100B formed on the left and right side surfaces engage with guide members provided on the cartridge and slide in the horizontal direction while being regulated in the vertical position. It is installed.

Each developing device is attached to the cartridge and is urged against the circumferential surface of the photosensitive drum 130 by the action of a locking device provided in the cartridge to maintain the developing sleeve 100A in pressure contact.

Therefore, in the single-color process unit 3B, the developing device used can be freely replaced and installed at a predetermined mounting position, so it can accommodate various developers such as red, blue, green, etc. in addition to black. By preparing and installing multiple developing devices, it becomes possible to organize multiple single-color process units dedicated to each specific color by sharing them in one cartridge, and as a result, it is possible to create multiple single-color process units dedicated to each specific color with a simple equipment configuration. This makes it possible to process monochrome images.

At this time, the positions of the developing devices are set to be the same so that the developing device drive system can be used in common. Further, the color multicolor process unit may be configured to include four developing devices including a developing device having Y, M, and C toners and a developing device having black toner.

When using the monochrome process unit 3B, a filter corresponding to the color of the target image is selected in conjunction with the above-mentioned copy mode switching. For example, in the case of a black image, the filter ND is placed on the optical path of the image reading system A. Set.

Although this embodiment describes a color image forming apparatus using a toner overlapping development method, the present invention can also be applied to a color image forming apparatus that uses a transfer drum to directly overlay images on recording paper. It is something.

〔Effect of the invention〕

By configuring each equipment for color and monochrome image formation as a compatible process unit, the present invention enables the formation of various images by arbitrarily selecting color or monochrome images with extremely simple operations. In addition, it is possible to process a plurality of monochrome monochrome images using one process unit, thereby providing a color image forming device that can obtain a variety of monochrome images with a simple device configuration. It became a thing.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional configuration diagram of a color image forming apparatus of the present invention, FIGS. 2 and 3 are cross-sectional views of a multicolor process unit and a monochrome process unit used in the apparatus, and FIG.
The figure is a perspective view of the monochrome process unit, and FIG. 5 is a side view of its main parts. 3A...Multicolor floss unit 7) 3B...Single color floss unit 4A, 104A...Rail 5...Handle 30
．． 130...Photosensitive drum 35.135...Charger 36.37.38...(For color) Developer 39.1
39...Cleaning device 39A, 139A...Blade 100...(monochrome) developer

Claims (1)

[Claims] A process unit that is integrated with a photoreceptor drum and multiple color developing devices, and a unit that is separable from the photoreceptor drum.
A color image forming apparatus characterized in that a process unit including a developing device on a stand can be attached interchangeably.