JPH0437771A - Color image forming device - Google Patents

Abstract

PURPOSE:To prevent the clogging of toner from occurring by providing a means for turning a developer regulating roller by a specified angle. CONSTITUTION:The developer regulating rollers 8c, 9c, 10c and 11c are provided near the respective developing rollers 8a, 9a, 10a and 11a of a developing device, so that the quantity of the developer stuck to a rotating sleeve K is regulated. At the time of ordinary operation (in the case of developing), the developer on the surface of the developing rollers 8a-11a which advances in a gap G is regulated so that its height may be a specified one to supply nearly fixed quantity of developer. A turning means X is provided for the regulating rollers 8c-11c to turn them by the specified angle at the time of non-operation (in the case of maintenance or non-developing), so that the opposed surfaces thereof to the developing rollers 8a-11a are changed to eliminate the clogging.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a color image forming apparatus that forms a toner image on a photoreceptor belt using an electrophotographic method and then transfers it to transfer paper to obtain a color image. It is.

[Conventional technology]

Generally, the image forming principle of this type of color image forming apparatus is as follows: ■Photoreceptor drum method ■Photoreceptor belt method It is broadly divided into two methods.

Among these, the photoreceptor drum method forms a multicolor image on a photoreceptor drum with a photoconductor formed on its surface by repeating latent image formation and development according to the number of separated colors of the original image. A color copy is obtained by transferring a multicolor image onto recording paper (for example, Japanese Patent Laid-Open No. 75850/1983). This method has the advantage of stabilizing latent image formation and making it easy to transfer onto recording paper. However, as the original image becomes larger, the diameter of the photoreceptor drum also becomes larger, and the transfer paper from the drum becomes larger. Separation performance is poor (in addition, there is a drawback that the overall size and complexity of the device cannot be avoided.In addition, repeated development according to the number of separated colors may cause misalignment during transfer to recording paper. Easy,
Another drawback is that precise multicolor copying is difficult.

Therefore, the basic process of a method in which a color toner image is superimposed on the drum by rotating the photoreceptor drum multiple times to form an electrostatic latent image, and then transferred to recording paper one at a time is as follows.
Disclosed by the present applicant (Japanese Unexamined Patent Publication No. 60-7585
No. 0, No. 60-76766, No. 60-95456,
No. 60-95458, No. 60-158475). In a color image forming apparatus that uses such superimposed images, a plurality of developing units containing color toner of each color are arranged in parallel around the periphery of the photosensitive drum.

On the other hand, in the photoconductor belt method, a photoconductor is coated on the surface of a flexible belt stretched between rotating rollers, and an electrostatic latent image is formed on the belt. It has the advantage that space can be used more effectively and a compact color image forming apparatus can be constructed compared to the conventional method. In addition, this method has the advantage that the transfer paper can be separated using a small-diameter rotary roller traveling section, and that separation performance is excellent.

[Problem to be solved by the invention]

The conventional belt-type color image forming apparatus described above has a problem in that the toner regulating section of each developing device is easily clogged.

That is, the conventional device includes a photoreceptor belt stretched between rotating rollers, and a group of developing devices arranged in parallel to face the lower running surface of the belt, and each of the developing devices is connected to a developing roller. Although the structure includes a developer regulating roller near the developing roller, toner lumps and foreign matter may adhere between the developing roller and the developer regulating roller, causing clogging and preventing the proper toner from adhering. .

In view of the above-mentioned points, it is an object of the present invention to provide a color image forming apparatus that is free from clogging in the developer regulating section.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a color image forming apparatus comprising a photoreceptor belt stretched between rotating rollers, and a group of developing units arranged in parallel to face the lower running surface of the belt. In the forming device, a developer regulating roller is provided near each developing roller of the developing device group, and means for rotating the regulating roller by a predetermined angle is provided, and the working surface of the regulating roller facing the developing roller is appropriately changed. This prevents clogging from occurring.

This problem is especially true when the light emitter and the developer group are integrated and configured as a cartridge that can be attached to and detached from the main body.
This is important as a means to prevent clogging.

Further, the rotating means is constructed by providing a one-way clutch on each regulating roller of the developing device group and mounting an arm member that can drive the clutch group all at once, so that all the developing devices can be moved. This allows the clogging to be cleared at once.

Further, the arm member is linked to the cartridge attachment/detachment mechanism, so that clogging can be automatically cleared when the cartridge is opened and closed during periodic maintenance work.

〔Example〕

The present invention will be described below based on an embodiment shown in the accompanying drawings.

FIG. 1 is a sectional view showing the overall configuration of the color image forming apparatus of the present application, FIG. 2 is a principle configuration diagram showing the configuration of the developing device, FIG. 3 is a principle diagram showing the relationship between the clutch group and arm members, and FIG. 4 FIG. 2 is an explanatory diagram showing the direction of developer reflux.

In FIG. 1, ``■'' is a flexible photoconductor belt having a photoconductor formed on its surface 1a. It is configured so that it can run clockwise (in the direction of the arrow).

Reference numeral 4 denotes a guide member, and the guide member 4 is inscribed in the photoreceptor belt 1, and is arranged so that a predetermined tension can be applied by a tension roller 5. Thus, the surface 1a of the photoreceptor belt 10 is maintained in a constant positional relationship with respect to the surface of the guide member 4, allowing stable image formation.

6 is a charger, and 7 is a laser writing unit serving as an image exposure means. The writing unit 7 writes optical information of the original image separated into each primary color to a polygon mirror 7a, an fθ lens 7b, and a reflection mirror 7c.

The light is focused and scanned on the surface 1a of the photoreceptor belt 1 via the photosensitive member 7d, etc., so that an electrostatic latent image can be formed.

8.9.10 are C (cyan) and M (magenta) respectively.
, developing device corresponding to Y (yellow), 11 is Bk (black)
The developing devices 8 to 11 are arranged in parallel to face the lower running surface of the photoreceptor belt 1.

The developing units 8 to 11 each include a magnetic developing roller 8a,
9a, LOa.

11a, and developer storage boxes 8b, 9b, fob, and 11b that store developer Z (a mixture of resin-coated ferrite carrier and color toner) below.

Reference numeral 30 denotes a cartridge formed by integrating the photoreceptor belt 1 and the developing devices 8 to 11;
It is constructed so that it can be opened/closed or attached/detached with respect to 0.

The structure of the developing device is shown in FIGS. 2 and 4.

Each of the developing rollers 8a to lla consists of a rotating sleeve (moving in the direction of the arrow) that is in almost contact with the surface 1a of the photoreceptor belt 1, and a magnetic roll J housed inside the sleeve, and is developed by the magnetic attraction force of the magnetic roll J. In addition to adsorbing the developer Z, the rotary sleeve K can supply the developer to the belt surface 1a. Then, the electrostatic latent image on the belt surface 1a is converted into a toner image via the rotating sleeve K by a non-contact development method.

Further, the developer boxes 8b to llb are connected to the developing rollers 8a to 8b.
The developer replenishing chamber H and the developer adhering chamber F are each divided by a scraping plate R in contact with the lower side of the lla. In addition, stirring screws St and St are provided in the developer replenishment chamber H and the developer adhesion chamber F, respectively, so that the replenishment toner and carrier, which are the constituent components of the developer Z, are scraped off by the scraping plate R. The used toner can be stirred and refluxed between the replenishment chamber H and the deposition chamber F while being uniformly mixed. That is, the toner flowing from the toner supply ports 8d, 9d, 10d, and lid is mixed with the carrier and the used toner, as shown in FIG. 4, and then stirred to become the developer Z.
The toner flows from the replenishment chamber H to the developer adhesion chamber F, and after the toner is adhered, it circulates again from the toner supply port 8d to the lid side.

Note that the toner supply port 8d provided at the upper part of the end of the developing device
~lid is used to supply developer in advance, while developer discharge ports 8e~lie provided at the bottom are outlets for discharging used developer when replacing it. .

Each developing roller 8a, 9a of the developing units 8-11.

Near lQa and lla, developer regulating rollers 8° and 9
c, 10c, and llc are provided so that the amount of developer adhering to the rotating sleeve K can be regulated. here,
The regulating rollers 8c to llc are provided to face the developing roller 8a=11a through a small gap G, and during normal operation (during development), the developing roller 8 enters the gap G.
The developer Z on the surfaces of a to lla is regulated to a predetermined height, so that a fairly constant amount of developer can be supplied. still,
The distance between the gaps G is extremely close to zero.

On the other hand, the regulating rollers 8c to llc are provided with a rotating means X, and are rotated by a predetermined angle during non-operation (during maintenance or non-development) to change the surface facing the developing rollers 8a to lla. It is designed to eliminate clogging.

Although various embodiments of the rotating means X can be considered, the rotating means
~ 11a is provided with a one-way clutch C, and a common arm member A is provided for each clutch C, and by driving the arm member A, all the regulating rollers 8
c~llc can be rotated all at once.

Further, the arm member A is configured to be linked to the attachment/detachment mechanism of the cartridge 30 via the protrusion 101. For example, during maintenance and inspection, when the cartridge 3o is opened and closed, the developing rollers 8a to fla are automatically rotated.
It is configured to eliminate clogging of the regulating rollers 8C to 11c.

12 is a transfer device, and 12a is a charge eliminating bar. The transfer device 12
Thus, the toner image on the photoreceptor belt 1 is transferred onto the recording paper P fed from the paper feed cassette 13, and the charge can be removed by the rear charge removal bar 12a. Reference numeral 14 denotes a cleaning device. The cleaning device 14 is for removing a slight amount of toner remaining on the surface 1a of the photoreceptor belt 1 after development, and is composed of a scraping blade 14a and a toner conveying roller 14b. It is provided near the rotating roller 3 inside the cartridge 30.

18 is a fixing device for thermally fixing the toner image on the recording paper P;
9 is a paper discharge roller, and 20 is a paper discharge tray.

In the above embodiment, the color original image data taken in from the image input section is sent to the polygon mirror 7a and fθ lens 7b of the laser writing unit 7.

The photoreceptor belt l is
After the original image is focused and scanned on the surface 1a to form an electrostatic latent image, color toner of each color is applied to the latent image by the developing devices 8 to 11. At this time, developer storage boxes 8b to llb
The developer Z inside is circulated between the replenishment chamber H and the adhesion chamber F while being stirred by the stirring screws S, , S, and in the adhesion chamber F, the amount is regulated by the regulating rollers 8C to llc, and the amount is regulated by the developing rollers 8a to lla. to form a toner image using a non-contact development method. In the vicinity of the rotating roller 2,
The toner image is transferred onto the recording paper P by the transfer device 12, fixed by the fixing device 18, and discharged onto the paper discharge tray 20 by the paper discharge roller 19. Here, when the cartridge 30 is opened and closed with respect to the main body 100 during regular maintenance work, the arm member A of the rotating means The regulation rollers 8C to llc rotate. Then, while removing toner lumps and foreign matter near the gap G, the new surfaces of the regulating rollers 8C to llc are removed from the developing rollers 8a to llc.
The clogging will be automatically cleared.

In the present invention, a two-component developer is used as the developer, but a -component developer may also be used.

In the present invention, the protrusion 101 may be partially exposed from the apparatus, and the user may press the protrusion 101 from the outside as appropriate while checking the printing state of the image to perform the clogging removal operation. Of course.

〔Effect of the invention〕

As described above, the present invention particularly provides a cartridge that is detachably attached to a main body, and includes a photoconductor belt stretched between rotating rollers, and a photoconductor belt that is arranged in parallel to face the lower running surface of the belt. A color image forming apparatus comprising a group of developing devices, characterized in that a developer regulating roller is provided near each developing roller of the group of developing devices, and means for rotating the regulating roller by a predetermined angle is provided. Therefore, clogging between the developing roller and the developer regulating roller can be prevented with extremely simple means.

Further, the rotating means is provided with a one-way clutch for each regulating roller of the developing roller group, and the clutch group includes:
It is constructed of an arm member that can drive each regulation roller at the same time, and can prevent clogging of all developing device groups at once.

Further, by linking the arm member to the cartridge attachment/detachment mechanism, clogging can be automatically cleared every time the developing cartridge is opened or closed for maintenance work or the like.

As a result, it is possible to provide a color image forming apparatus that is free from the risk of image deterioration due to clogging of the developer slot even during long-term operation.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the overall configuration of the color image forming apparatus of the present application, FIG. 2 is a principle configuration diagram showing the arrangement of the photoreceptor belt and the developing device group, and FIG. 3 is the principle showing the relationship between the clutch group and the arm member. FIG. 4 is an explanatory view showing the reflux direction of the developer. 1-Photosensitive belt 1a-Belt surface 2.3-Rotating roller 4-Guide member 5-Tension roller 6-Charger 7--Laser writing unit 8.9.10.11-Developing device 8a, 9a, 10a , 11a-Developing rollers 8b, 9b
, 10b, llb--Developer storage box 8c, 9c, 10c
, 11 c-regulating roller 12-transfer device 12a--static elimination bar 13-paper feed cassette 14-cleaning device 18 constant adhering device 19-paper discharge roller 20--paper discharge tray 20 30-cartridge 100-main body 101- m - projection A - arm member B - spring c - clutch F - developer adhesion chamber G... - gap H - developer supply chamber J, - one magnetic roll K one rotation sleeve P - recording paper R - - Scraping plate

Claims (3)

[Claims] (1) In a color image forming apparatus comprising a photoreceptor belt stretched between rotating rollers, and a group of developing devices arranged in parallel facing the lower running surface of the belt, the developing device group is A color image forming apparatus comprising: a developer regulating roller provided near each developing roller; and means for rotating the regulating roller by a predetermined angle. (2) The rotating means is provided with a one-way clutch for each regulating roller of the developing device group, and an arm member that can drive the clutch group all at once is installed. Color image forming device. (3) The color image forming apparatus according to claim 2, wherein the arm member is linked to a cartridge attachment/detachment mechanism.