JPH02300768A - Color image forming device - Google Patents

Abstract

PURPOSE:To easily take out a color process cartridge to above and to preclude flawing by opening and closing a protection cover as a grip which is rotatable around the shaft of a photosensitive drum is operated between a grip position and a storage position. CONSTITUTION:When the process cartridge 3 is inserted into and extracted from a lower housing 2, the grip 5 which is fitted coaxially with the rotary shaft of an image carrier 30 and can be raised is utilized. Further, the arcuate protection cover 6 which is slidable in engagement with a guide rail 3A engages the grip 5 at a cut formed provided at its side edge part, then moves to a position off above the image carrier by the rotation or returns through the operation of a torsion spring 5A to cover a peripheral surface above the image carrier 30, thereby protecting the image carrier from flawing and damaging. Consequently, the process cartridge is easily inserted into and detached from above its center of gravity, and the image carrier is neither stained nor damaged carelessly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a small-sized color process cartridge having a plurality of developing means containing multicolor developers and an image carrier that are detachably attached to an apparatus main body. - It relates to a lightweight electrophotographic color image forming apparatus, especially a color printer with a compact structure.

[Background of the invention]

There are many ways to obtain color images using electrophotography.
A device has been proposed. For example, Japanese Patent Application Publication No. 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 each time the development is performed, the latent image is transferred onto a transfer drum 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 an image carrier using a dot/dot exposure scanning writing system such as a semiconductor laser or LED, or a CCD
, A-5i and other solid-state image pickup devices are used to perform so-called digital color image processing. This is causing a similar problem.

Another method is to repeatedly form a latent image on a photoreceptor drum in accordance with the number of separated colors of an original image and develop it with color toner, and then layer color powder on the photoreceptor drum and then transfer it to obtain a color image. The basic process of forming a multicolor image is disclosed in Japanese Patent Application Laid-open Nos. 60-75850 and 60-76766 by the present applicant.
No. 60-95456, No. 60-95458, No. 60-158475, etc.

In a multicolor image forming apparatus that obtains a color image through such superposition, a plurality of developing devices containing different colored 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.

On the other hand, in terms of structure, copying machines are generally
As disclosed in Japanese Patent No. 8-54392, a proposal has been made in which a photosensitive drum, a developer, and a cleaner are integrally attached 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, there is a device that is integrated with these devices and configured in a disposable format.
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 1-ridge containing a plurality of developing units, which are also disposable, are replaceable. A multicolor image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 58-72159 has been proposed, but it is not easy to operate, small, and inexpensive, and does not necessarily produce images that satisfy the user when reproducing color images. It has not yet been provided.

Furthermore, the present applicant has disclosed various types of replacement such as a single color cartridge and a color cartridge having multiple developing units in Japanese Patent Laid-Open No. 63-293563.

In addition, a color image forming apparatus is provided with a removable mount in the main body of the apparatus, on which a photoreceptor drum, multiple developing units, cleaners, etc. can be attached and removed.
No. 239748, etc., there is a lack of ease of use for the user due to an unbalance in the lifespan of consumables such as toner or developer stored in multiple developing devices, and the internal mechanism is complicated and the device is large. Therefore, it was not possible to provide a compact and inexpensive device, and there remained a large problem that led to loss of users.

In particular, Japanese Patent Laid-Open Nos. 58-108552 and 1983 disclose the relationship between the handle and the center of gravity of the single-color cartridge, which prevents toner agglomeration in the cartridge run and facilitates handling. -5844
Proposals have been made in Publication No. 4, etc. Additionally, regarding protective covers for photoreceptor drums, etc., please refer to JP-A-58-181.
This is disclosed in Publication No. 062 and the like.

[Problem that the invention seeks to solve]

The above-mentioned Japanese Patent Application Laid-open No. 58-181062 discloses that the image bearing member is divided into upper and lower halves in order to prevent the surface of the image bearing member from being deteriorated by wave light during jam processing, etc., and to prevent scratches, dirt, etc. from being caused to the surface due to careless handling during processing. A safety measure has been proposed in which the protective cover automatically opens and closes when the bottom is opened.

However, in the color process cartridge in which the plurality of developing devices and image carriers mentioned above are replaceable with respect to the apparatus main body, loading and unloading operations into the apparatus main body are easy to handle.
In addition, there is no need to worry about toner or developer leaking or collapsing from multiple developing units, and the color image forming apparatus has a color process cartridge that does not have these problems, especially when dealing with transfer material jams, etc. It is especially small and easy to handle. Color process cartridges that are suitable for easy-to-use color printers are not available, and it is necessary to make the handling of such cartridges easy and to deal with the above-mentioned concerns such as toner collapsing, and to organically ensure safe and secure mounting of the cartridges through complex operations in relation to the equipment. No configuration has been proposed in which the removal means (handle) and the prevention of light waves, scratches, etc. on the photoreceptor are integrated.

An object of the present invention is to provide a color image forming apparatus that solves the above problems.

[Structure of the invention]

The above object is to provide a color image forming apparatus having a structure that can be opened and closed into upper and lower halves, in which a plurality of developing devices are disposed below an image carrier, and at least the image carrier and the plurality of developing devices can be replaced integrally. A process cartridge and a laser writing system unit are provided in a lower casing, and a transfer conveyance section consisting of a transfer belt is provided in an upper casing. A rotatable handle is provided, and the handle is operated between a gripping position and a storage position, and a color process cartridge is provided that opens and closes a protective cover for a photoreceptor drum, etc. according to the operation of the handle. Achieved by a color image forming device.

[Explanation of configuration]

The handling means (handle) and the protective cover that prevents scratches on the photoconductor are operated in a complex and integral manner, and at least the image carrier and multiple developing devices provided in the lower housing can be replaced integrally from the main body of the device. In a color process cartridge, multiple developing devices are arranged at the bottom of the image carrier, and the color process cartridge can be easily taken out from the top through the opening of the upper housing, and at the same time, it has a multifunctional structure that solves the problems such as preventing scratches mentioned above. This is what I did.

〔Example〕

An embodiment of the present invention is shown in FIGS. 1 to 7.

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

The printer has a thalamusiel-type structure divided into an upper housing 1 and a lower housing 2, and the upper housing 1 is tilted at a predetermined angle with the hinge IA connected to the lower housing 2 as a fulcrum. It can be held at an open angle, and in the closed state, it is integrated with the lower housing 2 by a metal fitting (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 an 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 4. It will be done. 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.

When the upper housing 1 is closed with respect to the lower housing 2, the handle 5 is held in a substantially horizontal position against the bias of the torsion spring 5A as shown in FIG. When the lid is opened, as shown in FIG. 2, the torsion spring 5A stands up almost upright.

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 circumferential surface thereof.

Therefore, by pulling up the handle 5, the process car I/ridge 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 flow out. This prevents the developer from falling or getting mixed into other developing devices.

The printer has a laser writing system unit I-B in a space on the side of the process cartridge 3, and a transfer surface that straddles both the upper housing 1 and the lower housing 2 above the process cartridge 3. The image carrier 30 receives laser scanning from the laser writing system unit l-B from diagonally below, and superimposes a color 1-ner image on the circumferential surface of the recording paper. A method is used to transfer the image to the bottom surface.

In this way, the transfer material is conveyed horizontally over the top of the process cartridge 3, and the transfer surface is also facing downward, so even if toner spills or scatters from the cleaning device 40 or the like, the image surface will be contaminated. I never get to the point where I do it.

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 carrier 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 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 developed by a developing device 36 loaded with yellow (Y) toner (developing medium) of the developing means, and 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 B, and the above-mentioned first color signal Writing is performed on the drum surface in the same manner as in the case of , and a latent image is formed.

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 these developing units 36, 37, 38, and 39, and jumping development is performed using a two-component developer serving as a developing means. body 30
Development is not possible without contact.

The color image thus formed on the circumferential surface of the image carrier 30 is transferred to the paper feed roller from the paper feed force sensor 1-0 in the transfer section.
The image is transferred to the lower surface of the transfer unit fed through the paper feed guide.

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,
It is rotated in synchronization with the circumferential speed of the image carrier 30 by rotation of the roller 60, and is moved away from or in contact with the image carrier 30 by moving the roller 58 up and down.

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, or is held in the upper position shown by the solid line, or is The transfer belt 50 is moved downward as indicated by a dashed line by the power of a solenoid or the like that operates at the appropriate timing, that is, to a position where the transfer belt 50 is brought into pressure contact with the circumferential surface of the image carrier 30 .

As the transfer plates 1 to 50, a rubber belt with conductive cloth is used as the base, and an elastic layer with a thickness of 5 mm is provided on the outer periphery of the belt, and an insulator layer (dielectric layer) with a thickness of 50 μm is further provided on the outer periphery of the belt. It will be done.

The transfer heald 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.
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 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 is shown in FIGS. 4 and 6 (a).
), the handle 5 is guided to and removed from the lower housing 2, and at the same time, the handle 5 is raised and lowered. Here the 6th
Figure (a) shows a cross section taken along arrow AA in Figure 4.

In the figure, 2 people and 2B are the front and rear boards installed in the lower housing 2, and 10IA and 10IB are guide members forming vertical guide grooves provided at opposing positions on the inner surface of each board. Therefore, the guide members 101A and l
OIB guides the insertion and removal of the process cartridge 3 into and out of the lower housing 2 by engaging the bearing portion of the image carrier 30 protruding from the process cartridge 3 . The support stand 4 is supported between the substrates 2A and 2B, and determines the vertical position of the inserted process cartridge 3.

Reference numeral 3A denotes an arcuate guide rail formed opposite to each other on a part of the side edge of the process cartridge 3, and 3B denotes a vertical guide groove formed on the front surface of the process cartridge 3, with the guide groove 3B extending downward. is provided with an abutment part.

Reference numeral 6 denotes an arc-shaped protective cover that can be slid by engaging with the guide rail 3A, and has a notch provided on the side edge that engages with the handle 5, and when it rotates, it can be slid as shown in FIG. It moves to a position evacuated from the upper part of the image carrier 30 or returns to the position shown in FIG. 2 by the action of the torsion spring 5A to cover the circumferential surface of the upper part of the image carrier 30 and protect it from dirt and damage. It looks like this.

Although FIG. 4 shows an example in which the protective cover 6 moves and retracts along the circumferential surface of the image carrier 30 while maintaining an equal distance, the curvature and direction of the guide rail 3A can be appropriately selected as shown in FIG. As shown in (a), it is also possible to move and retreat to a position that is far away from the circumferential surface, thereby making it possible to additionally install a pre-transfer charger or the like facing the image carrier 30.

Furthermore, even if a handle 500 is used whose center of rotation is at a position other than the rotation axis of the image carrier 30 as shown in FIGS. Similarly, it can be moved along the circumferential surface of the image carrier 3o or moved and retreated at a large distance.

Note that when the protective cover 6 is moved and retracted along the circumferential surface by the handle 5 whose center of rotation is the rotation axis of the image carrier 30, the protective cover 6 may be supported by being fixed to the handle 5. If possible, the guide rail 3A can also be omitted.

Reference numeral 70 denotes a waste toner box that accommodates the collected I/toner collected in the cleaning device 4o, and is attached to the process cartridge 3 by inserting and engaging a guide pin 71 provided on the back side into the guide groove 3B. A toner transport pipe 4OA connected to the cleaning device 40 is attached to and detached from the upper part of the waste toner box 70 via a bayonet mechanism or the like, so that it can be removed from the process cartridge 3 at any time and the collected toner can be disposed of. It becomes.

After the process cartridge 3 is housed in the lower housing 2, the handle 5 is automatically rotated counterclockwise by the operation of closing the upper housing l, and at the same time, the position relative to the lower housing 2 is adjusted. Fixed.

1B is a cam member whose lower edge is a curved surface, and is attached to the upper housing 1.
As shown in FIGS. 4 and 6(a), a pair of handles 5 are attached in front and rear inside the upper housing 1 so as to press both ends of the handle 5 when the lid is closed.

The cam member IB guides the handle 5 counterclockwise by pressing it with its curved surface during the process of closing the upper housing l, and further rotates to hold the handle 5 in a substantially horizontal position in the closed state. It has the effect of enlarging.

The handle 5 is also provided with an operating pin 5B that is inserted through the long side walls 3C of the front and rear sides of the process cartridge 3, and operates a locking device installed on each inner surface of the substrates 2A and 2B of the lower housing 2. 3 is locked and fixed in its storage position.

FIG. 7(a) shows the locking device provided on the front side with the board 2A removed.

Reference numerals 102 and 105 indicate an operating lever and a lock lever that are both attached to the inner surfaces of the two substrates, and when the handle 5 rotates, the operating lever 102 rotates, and the lock lever 105 slides. The lock lever 105 engages with the locking portion 3D of the process cartridge 3 to fix the position.

That is, the operating lever 102 has a rather strong torsion spring 1.
03, the support shaft 102A is used as a fulcrum and is biased clockwise so as to come into contact with the stop pin 104 on the board 2A.

On the other hand, the lock lever 105 has a slightly weak tension spring 106.
is urged to slide rightward under the guidance of the guide pin 107.

The figure shows a state in which the handle 5 is rotated to a horizontal position by closing the lid of the upper housing 1, and is rotated counterclockwise by pressing the operating pin 5B or the operating lever 102.

The lock lever 105 is rotated by the rotation of the operating lever 102.
The upper regulating pin 108 follows, and the lock lever 105 is slid to the right by the action of the tension spring 106, and the distal end 105A is engaged with the locking part 3D of the process cartridge 3, and the process cartridge 3 is moved to the substrate 2A, i.e. It is fixed to the lower housing 2.

Further, when the upper case l is opened and the handle 5 is raised, the operating lever 102 is rotated counterclockwise by the action of the torsion spring 103 until it comes into contact with the stop pin 104, so that the lock lever 105 is pulled by the action of the torsion spring 103. spring 106
The distal end portion 105A slides to the left against the bias of the locking portion 3D, and the engagement is released.

On the other hand, on the rear board B side, the process cartridge 3
In conjunction with the action of the locking device due to the attachment, the driven gear G1 on the rotating shaft of the image carrier 30 meshes and connects with the driving gear G2 on the substrate 2B side from the arrow direction in FIG. 7(b). The joints and connections of each power transmission system and electrical system are performed at the same time.

Regarding the laser writing system unit I-B and the fixing device located above it, as shown in FIG.
0A, and one contact is mounted vertically to the lower housing 2 from above in the same way as the process cartridge 3, using guide grooves 110B formed slightly outside the guide grooves 110A as guides.

On the other hand, regarding the vertical position of the laser writing system unit B, the bottom support is placed on the stand 4 (not shown), and the fixing device is placed on the laser writing system unit I-B and then placed on the top when the lid is closed. It is regulated by the urging force of an elastic member on the casing l.

In explaining this embodiment, the direction shown in FIGS. 1 and 2 is 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 FIGS. The side surface facing the operator, that is, the front surface, and thus the front surface in this embodiment corresponds to the left side surface in use.

〔Effect of the invention〕

The present invention not only opens the conveyance path of the transfer material by opening the upper casing to facilitate work such as clearing jams, but also works in conjunction with the raising of the handle to lift up the cartridge of the unitized process equipment. The exposed surface of the image bearing member is covered with a protective cover, and by arranging multiple developing devices symmetrically and in parallel under the photoreceptor drum, the center of gravity of the process cartridge is stabilized. It has a new configuration with a handle that can operate reliably and stably during insertion, attachment and removal, or handling operations, and also has a handle that can be positioned in the operating and non-operating positions (opening and closing in two parts) of the transfer conveyor belt provided on the upper housing. On the other hand, the handle can be automatically or manually set to the used or unused state as described above, and the cover of the process cartridge, which also contributes to fatigue of the photoreceptor toner transport tube, is also used or not used. By cooperating and integrally performing complex operations under the conditions of Thus, a color image forming apparatus has been provided which is easy to handle and can always produce high-quality color images without inadvertently staining or damaging the image carrier.

[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.
The figures are explanatory diagrams showing the relationship between the upper housing and the process cartridge, Fig. 5 is an explanatory diagram showing the direction of movement of the protective cover, and Fig. 6 is an explanatory diagram showing the relationship between the upper case and the process cartridge.
Figures (a) and (b) are a sectional view and a plan view of the main part of Fig. 4, and Fig. 7 is a front view of the main part. ■... Upper housing IA... Hinge 2... Lower housing 2A, 2B... Board 3... Process cartridge 3A... Guide rail 3B... Guide groove 3D.
...Locking part 4...Base is 5.500...
・Handle 5A...Torsion spring 5B...Operating pin 6...Protective cover 30...Image carrier
40...Cleaning device 40A/toner conveying pipe 70...waste l/napo/cus 1.02...operating lever 105...lock lever-105A/
... Tip s G1 ... Driven gear G2 ... Drive gear

Claims (3)

[Claims] (1) In a color image forming apparatus having a structure that opens and closes into upper and lower halves, a color process in which a plurality of developing devices are arranged below an image carrier, and at least the image carrier and the plurality of developing devices can be replaced integrally. A cartridge and a laser writing system unit are provided in a lower casing, and a transfer conveyance section consisting of a transfer belt is provided in an upper casing. A color image forming apparatus comprising a color process cartridge that is provided with a movable handle, the handle is operated between a gripping position and a storage position, and a protective cover for a photoreceptor drum, etc. is opened and closed according to the operation of the handle. . (2) The rotating operation of the handle is performed in conjunction with the opening/closing operation of the casing.
The color image forming apparatus described in 1. (3) The color image forming apparatus according to claim 1, wherein the handle is interlocked with a locking mechanism for the color cartridge with respect to the main body of the apparatus.