JPH02297566A - Color image forming device - Google Patents

Abstract

PURPOSE:To make a device compact and to improve handling and operability by setting a process cartridge and a writing system unit to the same reference member so that they can be attached to and detached from the device and maintaining each material and member at a set position by means of opening and closing an upper case. CONSTITUTION:A printer is of a cram shell type wherein upper and lower cases 1 and 2 are devided. An image carrier 30 composing the image forming part of the printer, plural developing units 36 to 39, an electrifier 35, etc., are housed in the integral process cartridge 3 to be united. The process cartridge 3 and the laser writing system unit B are provided on the lower case 2, while a transfer and carrying part composed of a transfer belt 50 is provided on the upper case 1. The upper case 1 is opened, and a guide inserting both the process cartridge 3 and the writing system is provided on the same reference member. Consequently, the device is made compact, and the parts can be readily attached to and detached from the device main body.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a color process cartridge including a plurality of developing means containing multicolor developers and an image carrier, which can be detachably installed in an apparatus main body. The present invention relates to a compact and lightweight electrophotographic color image forming apparatus having a color process cartridge, and particularly to a color printer having a compact structure.

[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 on a photoreceptor drum according to the number of separated colors of an original image, and is transferred onto a transfer drum each time a phenomenon occurs to form a multicolor image on the transfer drum. There is a method of forming a color copy 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.

In addition, a latent image is formed on the image carrier using a dot exposure scanning writing system such as a semiconductor laser or LED.
, A-5i and other solid-state image pickup devices are used to perform so-called digital color image processing. This is causing a lot of problems.

There is also a method of repeatedly forming a W1 image on a photoreceptor drum according to the number of separated colors of an original image and developing with color toner, and then layering color powder on the photoreceptor drum and then transferring it 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. 60-7676 by the present applicant.
No. 6, No. 60-95456, No. 60-95458,
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. I am trying to obtain a color image by using

On the other hand, in terms of structure, copying machines are generally
As disclosed in Japanese Patent No. 8-54392, the photoreceptor l! Proposals have been made to integrally attach the crumb developer and cleaner to a support member to facilitate replacement and repair of each unit.

In addition, as a small and simple monochrome compatible device that can be easily handled by general users, a device that is integrated with these devices and configured in a disposable format is published in JP-A-57-1.
It is disclosed in Japanese Patent No. 54255.

Furthermore, Japanese Patent Laid-Open No. 147366/1983 discloses a printer that incorporates a laser writing system into a similar device.

Furthermore, as an apparatus for forming mono-color or full-color images, a disposable single-color process cartridge and a (color) cartridge containing multiple developing units, which are also disposable, can be exchanged, as described in Japanese Patent Application Laid-open No. A multicolor image forming apparatus disclosed in Japanese Patent No. 58-72159 has been proposed, but it is not an easy-to-operate, small, and inexpensive device, and does not necessarily provide a satisfactory image to the user when reproducing color images. This has not yet been achieved.

Furthermore, the present applicant discloses in Japanese Patent Application Laid-open No. 63-293563 various exchange forms such as a single color cartridge and a color cartridge having multiple developing devices, or provides a removable mount in the main body of the apparatus. Photoreceptor drum on the stand,
Japanese Patent Application No. 62-234493 and No. 62-239 disclose a color image forming apparatus in which multiple developing devices or cleaners can be attached and detached.
No. 748, etc., however, there is a lack of user-friendliness due to the unbalanced lifespan of consumables such as toner and developer stored in multiple developing devices, and the internal mechanism is complicated and the device is large. As a result, Funbakuto was unable to provide an inexpensive device, and there remained a major problem that would lead to loss of users.

In particular, when using the monochromatic cartridge to write an original image onto a photosensitive drum, which is an image bearing member inside the cartridge, which is directly replaceable via a lens optical system, in an analog manner, the cartridge is attached with a lens optical system. It has a structure that can be inserted and removed from the same panel, and is patented as a device that prevents image quality deterioration due to a decrease in focal resolution of the lens optical system, especially when using a cell quarter (focusing optical system) with an extremely small depth of focus. Publication No. 58-139162 discloses this.

[Problem that the invention seeks to solve]

However, in this system, a color process cartridge is used in which these multiple developing devices and image carriers are interchangeable with respect to the main body of the apparatus. 1 Odot≠, and when using a writing system such as a laser or LED that writes a latent image on the photoreceptor drum by forming dots, 1 dot/
Regarding photoresolution, it is possible to project onto a photoreceptor by correcting digital image signals such as laser beams by converging them optically or electrically, but it is possible to
Shocks caused by vibrations and load fluctuations caused by the various drive motors or drive transmission systems of the photoreceptor, developing unit, fixing unit, paper feeder, etc., can cause damage to the image forming apparatus using digital image signals.
[This results in image defects such as fluctuations in dot spacing, image blurring, continuous dots, and disappearance of donts. This is particularly noticeable in image formation using the method disclosed in Japanese Patent Application Laid-Open No. 60-75850, etc., as mentioned above, but in general, when forming color images, methods such as performing dot formation images multiple times for each color (for example, Overlap on transfer paper,
Because they are repeatedly superimposed (such as overlapping on a photoreceptor), stable mutual positioning of the photoreceptor drum and the digital image signal writing system is particularly problematic.

Furthermore, by using a color process cartridge in which multiple developing devices and image carriers are replaceable with respect to the main body of the device, it is easy to load and remove it from the main body of the device, and it is possible to easily remove toner or developer from the multiple developing devices. No color image forming apparatus, especially a compact color printer, has been proposed that has a color process cartridge that does not have to worry about leakage or collapsing, especially when dealing with transfer material jams. An object of the present invention is to solve the above problems and provide a color image forming apparatus.

[Structure of the invention]

The above object is to provide a color process cartridge with a structure that can be opened and closed into upper and lower halves, a plurality of developing devices arranged below an image carrier, and at least an image carrier and the plurality of developing devices that can be integrally converted. A system unit 7) is provided in the lower casing, and a transfer conveyance unit consisting of a transfer bell is provided in the upper casing, and the two-part casing is opened and the color process cartridge and the writing system are inserted. This is achieved by a color image forming apparatus characterized in that the guides are provided on the same reference member.

〔Example〕

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

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

The printer has a Talamusiel-type structure divided into an upper housing 1 and a lower housing 2, and the upper housing 1 is opened at a predetermined angle with the hinge IA connected to the lower housing 2 as a fulcrum. It can be held, and in the closed state, it is integrated with the lower housing 2 by a stopper A (not shown).

The image forming section of the printer includes an image carrier 30, developing devices 36, 37, 38, and 39 containing yellow, magenta, cyan, and black developers, and a cleaning device 40.
In addition, each component of the charger 35 is housed in the integrated process cartridge 3 to form a unit, and is vertically inserted into the lower housing 2 from above via a guide member to be described later, and the receiver is housed in the stand A4. .

Note that when the process cartridge 3 is inserted into and removed from the lower housing 2, a handle 5 that is movable and that is attached concentrically to the rotation axis of the image carrier 30 is used.

The handle 5 is held in each of its undulating positions by the action of a click device or the like.

The developing units housed in the process cartridge 3 have integral housings and are arranged in parallel from the rotational upstream direction below the image carrier 30 so as to face the surface thereof.

Therefore, by pulling up the handle 5, the process cartridge 3 can be easily taken out from the lower housing 2, and since each developer is maintained with its opening facing upward, the developer will not leak out and fall. Contamination with other developing devices does not occur.

Further, the printer accommodates a laser writing system unit B in a space on the side of the process cartridge 3 in the same unitized state.

That is, the optical members such as the polygon mirror 32, the fθ lens 33, each mirror, etc., which constitute the laser writing system, and their power sources are housed in a rectangular parallelepiped casing to form a unit, and a guide (to be described later) of the same type as the process cartridge 3 is installed. The receiver is inserted perpendicularly from above into the lower housing 2 via the member and housed in the stand B6.

Further, in the printer, the transfer material conveying surface is disposed in the upper part of the process cartridge 3, spanning both the upper casing 1 and the lower casing 2, and the image carrier 30 performs the laser writing from diagonally below. A system is adopted in which a color toner image formed by being subjected to laser scanning by system unit B and superimposed on the peripheral surface thereof is transferred to the lower surface of the recording paper.

In this way, the transfer material is conveyed in the horizontal direction above the process force-tridge 3 and the transfer surface is also facing downward, so even if toner falls off or scatters from the cleaning device 40 etc., the image surface It does not go so far as to cause contamination.

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 S (Fig. 3 (a)) in which 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 unit B, the laser writing unit H 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,
The image carrier 30 has its optical path bent by 34B and 34C and is charged 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 carrier 30. Therefore, a latent image corresponding to the first color is formed on the circumferential surface of the image carrier 30 by main scanning by the laser beam and sub-scanning by the rotation of the image carrier 30. This latent image is formed using yellow (Y) toner (vlAg) in the developing means.
1, medium) is developed by a developing device 36 loaded with
A toner image is formed on the drum surface. The obtained toner image, while being held on the drum surface, passes under a cleaning device 40, which is a cleaning means, which is separated from the peripheral surface of the image carrier 30, and enters the next copy cycle.

That is, the image carrier 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 I-B, and the above-mentioned first color signal is Writing is performed on the drum surface in the same manner as in the case of the drum surface, and a latent image is formed.

The latent image is developed by a developing device 37 loaded with toner of magenta (CM) as the 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 these developing units 36, 37, 38, and 39, and jumping development is performed using a two-component developer serving as a developing means, and the image carrier with a grounded base is body 30
Development is now possible without contact.

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

That is, this multicolor toner image is transferred from the paper feed cassette C to the paper feed roller 12 by bringing the transfer belt 50, which is used as a transfer means and has been rotated since the start of transfer, into contact with the image carrier 30.
The image is then transferred to a transfer material fed via the timing roller 13 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 carrier 30, and the roller 58 moves up and down to move away from or come into contact with the image carrier 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 shown by the dashed line, that is, to the position where the transfer belt 50 is brought into pressure contact with the circumferential surface of the image carrier 30, by the power of an lenoid or the like that operates at the timing of .

As the transfer belt 50, a rubber belt containing conductive cloth is used as a base, and an elastic layer with a thickness of 0.5 mm is provided on the outer periphery of the belt, and an insulating layer (dielectric layer) with a thickness of 50 μm is further provided on the outer periphery of the belt.
The one with the following is used.

The transfer belt 50 is charged by a transfer device 51, and the surface of the transfer belt 50 is charged with 1.5KV to 3.5KV. OKV
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 transferred to the image carrier 3.
The toner is separated from the circumferential surface of the sheet and conveyed to the fixing device, and after being melted and fixed by the roller 5110-ra 80, the toner is transferred to the discharge roller 90.
is discharged from the aircraft via the

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

The process cartridge 3 and the laser writing system unit B are housed in predetermined positions in the lower housing 2 via guide members as shown in FIG. 4 or 5, and accurate relative positions between them are guaranteed. .

FIG. 4 is a plan view of the lower case 2 with the lid opened, and 2A and 2B are the front and rear boards 101 installed in the lower case 2.
A and 10IB, 102A and 102B are vertical guide grooves formed at opposite positions on the inner surfaces of the front and rear substrates, and serve as insertion guides for one of the aforementioned guide members.

Further, 3A and 3B are bearing portions of the rotating shaft of the image carrier 30 protruding from the front and rear sides of the process cartridge 3, while PA and PB are guide pins installed on the front and rear sides of the laser writing system unit B. Each of the bearing portions 3A
and 3B, as well as the guide pins PA and PB, both serve as the other insertion reference for the aforementioned guide member.

The process cartridge 3 guides the bearings 3A and 3B into the guide grooves 101A and 10IB, respectively, while the writing system unit B guides the guide pins PA and PB, respectively i1! +02A and 102B are engaged with and inserted, and the respective bottom parts are placed on the stand 4 or 6 to determine the position, and therefore, the references 2A and 2B are housed in the lower housing 2 as the same reference member. .

The housed process cartridge 3 and the laser writing system unit B are held at their respective predetermined positions by the closing of the upper housing 1 and biased by the elastic members s1 and 32 included in the upper housing 1.

Note that the laser writing system unit B is indirectly biased and held via a fixing device housed above it.

Further, in order to facilitate the insertion operation into the lower housing 2, it is also possible to use a method of loosening the precision of engagement between each of the insertion standards and each of the insertion guides, and regulating each of them to the accommodated position using a separate member.

FIG. 5 shows an example of this. 20 and 2D are the front and rear boards, and the process cartridge 3 is attached to the inner surface of each board.
Guide grooves 101G and 101D are formed to engage with the bearings 3A and 3B with a slight margin, and guide grooves 102c and 102D are formed to engage the casing of the laser writing system unit B with a slight margin. .

The process cartridge 3 and the laser writing system unit B are each provided with a pair of regulation bins Pl and P2 on their bottom surfaces for mutual position determination, and one of the regulation bins PL and P2 is attached to the lower housing 2. into the round hole provided in the bottom plate 7 of the other regulation bottle PI and P2.
Similarly, it is held in a long hole provided in the bottom plate 7 and is accurately accommodated in a predetermined position.

The housed process cartridge 3 and laser writing system unit B are held at their respective predetermined positions by elastic members S1 and 32 provided in the upper housing l, as in the previous embodiment.

In this example, the fixing device also corresponds to the guide 1i1!102.
It is engaged with C and l02D and urged downward together with the laser writing system unit LB to regulate its position.

In explaining each of the embodiments described above, the directions shown in FIGS. 1 and 2 are referred to as the front side of the image forming apparatus for convenience, but from the standpoint of actually using the apparatus,
The right side in the figure is the side facing the operator, that is, the front, and therefore the front in the embodiment corresponds to the left side in use.

〔Effect of the invention〕

The present invention provides a process cartridge that accommodates a process member and a writing system unit that accommodates a writing optical system member that can be inserted into and removed from the same reference member by an extremely simple operation. It is structured so that each of the equipment and components can be accurately held in their respective set positions by closing the upper housing, and is used for digital exposure writing using dot light from semiconductor lasers, LEDs, etc. on the photoreceptor drum. The relative position can be maintained with high precision even against acceleration changes caused by internal vibrations and load fluctuations, external vibrations and shocks, etc., and good latent image formation is possible.Also, multiple developers can be used in the same cartridge. Since the image is further developed, a good image is obtained which is not affected by vibrations, etc., and is particularly effective for the above-mentioned image stability when forming dot latent images in the above-mentioned superimposition process. By making the unit insertable from the top, the process cartridge containing multiple developing devices can be inserted into the reference member centering on the photoconductor drum axis, thereby improving the connection between the photoconductor drum and the writing system unit 7. The relative position is set with high accuracy, further improving the above-mentioned effects on stability and high image quality, and as a result, a useful color image forming device that is compact, easy to handle, and always exhibits the best image processing function is provided. It was decided that

[Brief explanation of drawings]

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.
5A and 5B are a plan view and a perspective view of a main part showing a state in which a process cartridge and a writing system unit are installed in the apparatus, respectively. l... Upper case 2... Lower case 2A, 2
B... Board 3... Process cartridges 3A, 3B... Bearing parts 4, 6... The bearings are on the stand 5.
...Handle 7...Bottom plate 101A, 101
B, 101c, 101D... (for process cartridge) Guide grooves 102A, 102B, 102C, 102D.
...(For writing system unit) Guide groove B...Laser writing system unit PA, PB...Guide bin Pi, P2...Regulation bin St, S2...Elastic member

Claims (2)

[Claims] (1) A color process cartridge and writing system that has a structure that opens and closes into upper and lower halves, and has multiple developing units arranged below the image carrier, and that at least the image carrier and the multiple developing units can be converted into one unit. unit is provided in a lower casing, and a transfer conveyance unit consisting of a transfer belt is provided in the upper casing, the upper casing is opened, and an insertion guide for the color process cartridge and the writing system is provided on the same reference member. A color image forming apparatus characterized by: (2) The color image forming apparatus according to claim 1, wherein the reference member for inserting the color process cartridge into the reference member is a photosensitive drum shaft for an image carrier of the color process cartridge.