JPH07160088A - Image forming device - Google Patents

Abstract

PURPOSE:To provide a simple, reliable and compact device ensuring the continuity of image formation, giving a high quality image and further ensuring the less occurrence of a failure. CONSTITUTION:The first and second image forming processes 1 and 2 are performed around a photosensitive drum 11. Cleaning devices 14 and 18, charging devices 15 and 19, exposure devices 16 and 20 and development devices 17 and 21 are respectively provided for the processes 1 and 2. The processes 1 and 2, separated from each other with the first intermediate transfer section 5 formed out of the first intermediate transfer device 3 and an image carrier 10, and the second intermediate transfer section 6 formed out of the second intermediate transfer device 4 and the image carrier 10, can independently form an image arbitrarily. Furthermore, toner images on intermediate transfer belts 30 and 40 are respectively transferred to recording paper sheets 91 and 92 paid out from paper feeding devices 9 and 10 via the first and second transfer sections 7 and 8. Thereafter, the image on the sheet 91 is fixed with a fixing device 27, when the sheet 91 is bypassed with a distributor 26, while being fixed with another fixing device 28 when not bypassed (i.e., at such a process as two-color copying process).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus (copying apparatus, laser printer) by an electrophotographic method, and it is an image forming apparatus (image forming and recording paper) for multicolor color (hereinafter, simply referred to as color). (Including records).

[0002]

2. Description of the Related Art Japanese Patent Laid-Open No. 58-23074, Japanese Patent Laid-Open No. 61-7474, in which four color four copying machines are combined with a color image forming apparatus.
79659, which uses an intermediate transfer device.
There is 95362. In addition, there is an intermediate transfer device which is disclosed in
204871 and others, such as JP-A-62-50846, have not been sufficiently satisfied.

[0003]

There is continuity of image formation,
We propose a device that is simple, reliable, has good image quality, can be copied quickly, is small, and has few failures, and is inexpensive.

[0004]

A plurality of image forming processes having one or a plurality of image carriers and image forming means around each of them are formed, and an intermediate transfer device is provided between the respective image forming processes to block the image forming processes. This is achieved by preventing interference, allowing each image forming process to function independently, and increasing the versatility of the image carrier.

[0005]

By providing a plurality of image forming steps on one image carrier, the number of image carriers is reduced, and an intermediate transfer device is interposed so that continuity of image formation can be obtained. It also enables color imaging of copies.

[0006]

1 shows an image forming apparatus 100 of the present invention. The first image carrier 10 includes a rotatable photoconductor drum (not shown, but may be a belt) 11 and a photoconductor (selenium, OPC, etc.).
13 is supported by a shaft 12 and rotates in the direction of the arrow. There are a first image forming step 1 and a second image forming step 2 having image forming means around the photosensitive drum 11, and cleaning devices 14 and 18, charging devices 15 and 19, an exposure device 16 are respectively provided as image forming means. Two
0, developing devices 17 and 21 are arranged. Then, it is partitioned by the first intermediate transfer unit 5 formed by the first intermediate transfer device 3 and the first image carrier 10 and by the second intermediate transfer device 4 and the second intermediate transfer unit 6 in the first image carrier 10. The first and second image forming steps can independently form images. The outline of each device will be described below.

The cleaning devices 14 and 18 employ a blade cleaning method using a thin rubber plate, a magnet roll cleaning method using a magnet and magnetic powder, or the like. This is because the residual toner on the photoconductor 13 after the intermediate transfer is removed so as not to hinder the subsequent image formation.

As the charging devices 15 and 19, a corona charging method using corona discharge, a contact charging method of contacting the photosensitive member with a conductive or non-conductive roller under an electric field, or the like is used. Then, static electricity is positively or negatively charged on the photoconductor 13 such as selenium or OPC. Further, the charging power source may be operated by superimposing alternating current on direct current.

The exposure devices 16 and 20 irradiate the photoconductor 13 with light to convert a document, a signal or the like to be recorded into an optical image, and to statically electrify the uniformly charged photoconductor on the photoconductor (invisible).
To the electrostatic latent image of. In order to copy ordinary originals, there are analog optical devices such as mirrors, lenses, light sources that illuminate the originals from the platen, and digital optical devices with a laser light source that handles processed digital signals. Used together.

The developer used in the developing devices 17 and 21 is composed of a toner and a carrier. There are a dry method of powder toner and a wet method of liquid toner, and a mixed toner in between, and one component (mainly toner) Only), two-component (development by mixing toner and carrier), magnetic (develop with toner that is easily magnetized), non-magnetic (develop with toner that does not have magnetism) development methods. In the case of color, red, yellow, blue, black, etc. toners are used for the developing devices of the developing devices one by one. In the case of FIG. 1, one-color or two-color toner can be used, and in the case of FIG. 2, one-color to four-color toner can be used, which will be described later.

The developing devices 17 and 21 selectively attach toner to the electrostatic latent image on the photoconductor 13 to form a toner image.
Toner is once attached to a magnetic or non-magnetic developing roll, or development is performed using a medium corresponding thereto. Then, it is roughly classified into contact and non-contact development depending on whether the developing roll or the medium is brought into contact with the photoconductor or not, but it is arbitrarily selected and used.
Furthermore, there are positive-positive development (mostly used for analog exposure) and negative-positive development (mostly used for digital exposure). The former uses toner with a polarity opposite to that of the electrostatic latent image where light does not hit, and the latter uses A toner having the same polarity as the polarity of the electrostatic latent image where the light does not hit is attached so as to be pushed out of the developing device by a bias electric field having the same polarity as the toner. In this way, the electrostatic latent image is visualized as a toner image, and the toner image is transferred onto the intermediate transfer belts 30 and 40 at the first intermediate transfer portion 5 and the second intermediate transfer portion 6, respectively, by the electric field transfer method (FIG. 1), corona. Transfer is performed by a method such as an electric discharge transfer method or an adhesive (using an adhesive intermediate transfer belt) transfer method. This is also arbitrarily selected.

The intermediate transfer is composed of a first intermediate transfer device 3 and a second intermediate transfer device 4, and belts, rolls, etc. in the respective devices are rotated or driven synchronously with respect to the photosensitive drum 11, The power is applied from the power sources 22 and 23 while the intermediate transfer belts 30 and 40 are hung on the transfer rolls 31 (shaft 32) and 41 (shaft 42) so that an electric field is applied. These rolls and belts are made of metal, rubber, plastic or the like, and a conductive or non-conductive material is selected and used. The toner images on the intermediate transfer belts 30 and 40 are fed from the paper feeding devices 9 and 90 so as to be aligned with the toner images.
92, the first transfer unit 7 and the second transfer unit 8 respectively, the power source 2
The transfer rolls 33 (shaft 34), 35 (shaft 36), which are the same as those described above, with proper bias voltage from 4 and 25, 4
3 (axis 44) and 45 (axis 46) are applied and transferred while rotating at a speed in synchronism with light pressure to form a toner image on the recording paper 91, 92. Since the untransferred toner remains on the intermediate transfer belts 30 and 40 after the transfer onto the recording paper, the belt surfaces are cleaned by the cleaners 81 and 82. This device may be substantially the same as the cleaning device 14, 18 described above.

After that, the recording paper 91 passes through the fixing device 27 only when bypassed by the distributor 26 (shown by a dotted line), and when the recording paper 91 is not passed, the heat of the fixing device 28 passes through the second transfer portion 8 (for two-color copying or the like). It is fixed on a roll.

FIG. 2 shows a second image carrier 8 rotatably supported.
0 is provided side by side with the first image carrier 10 in addition to FIG. 1, and both are rotated at a synchronized speed. Although not shown, the configuration of the second image carrier 80 may be the same as that of the photoconductor drum 11, or these photoconductor drums may have an upper layer of plastic. The contents of both the third image forming step 101 and the fourth image forming step 102 are not shown, but basically the same means as the first and second image forming steps 1 and 2 may be used.
Then, the third intermediate transfer unit 50 and the fourth intermediate transfer unit 60 are
Each is illustrated by a corona discharge transfer method (power source not shown). Further, although not shown, another transfer means, for example, a roll or plate electrode to which an electric field is applied between the intermediate transfer belts 30 and 40 and the second image holding body 80 so that the intermediate transfer belts 30 and 40 are in light contact with the second image holding body 80 is a corona. It can also be installed by replacing the dischargers 51 and 61. In this way, the toner image is transferred to the intermediate transfer belts 30 and 40, and then transferred to the recording paper.

Next, a method of using the image forming apparatus will be described. Figure 1
When the distributor 26 is a dotted line, each of the first and second image forming processes operates individually, so that they can function as two copiers or printers and can be arbitrarily operated because they do not interfere with each other.

In the case of creating a writing composite image such as one-color editing or a two-color image, the copy original and the copy signal are subjected to image processing in advance to perform image separation and color separation. For example, in the case of a two-color image, the color-separated first color image is sent to the first image forming step 1 and the second color image is sent to the second image forming step 2 to be converted into a light image and exposed. In the case of the four colors described below, the four colors are also divided and sent to the four image forming steps for processing. By the way, the distributor 26
Is in the direction of the solid line.

The toner image formed in the first image forming step 1 moves on the intermediate transfer belt 30 and is transferred onto the recording paper 91 by the first transfer section 7. Further, the toner image formed in the second image forming step 2 is transferred by the intermediate transfer belt 40, and is transferred and superposed on the recording paper 91 by the second transfer portion 8. In order to make sure that the same originals and the like are image-separated and color-separated surely combined and aligned, in the second image forming step 2, there is a deviation of the image forming start time, etc. Also, the same consideration should be taken when editing images such as multicolored writing. Of course, in this case, the paper feeding device 90 is not used.

In FIG. 2, when the distributor 26 is a dotted line, it can be used as two independent two-color copying machines and printers.
In this case, the toner image of the first image forming step 1 is the toner image of the third image forming step 101, and the toner image of the fourth image forming step 102 is the toner image of the second image forming step 2 so that they do not shift from each other. The former is transferred to the recording paper 91 and the latter is transferred to the recording paper 92. Also, when one device fails, the other can be operated independently, which is convenient. Although detailed means for the third and fourth image forming steps are not shown, they may be the same as those for the first and second image forming steps.

In the two- to four-color editing image forming, color copying machine and printer, the distributor 26 is a solid line, and the first two-color toner image (for example, red and yellow) is recorded on the recording paper 91 at the first transfer portion 7.
And the next two-color toner image (for example, blue, black)
Are combined or aligned in the second transfer portion 8 and are superposed on the recording paper 91. Note that the image-processed exposure is natural and the paper feeding device 90 is not used.

In the multicolor image formation of one color, the toners of the four colors are simply distributed from the first image formation step to the fourth image formation step, and the time is changed so that the toner images do not overlap each other during the continuous image formation. It can be done by using the normal method.

The toner spill prevention plates 83 and 84 prevent the toner from falling onto the intermediate transfer belt 40 from the developing device or the like during the image forming process, which is convenient. It will be more convenient if you leave it.

[0022]

As described above, according to the present invention, it is possible to perform various kinds of copying from one color to multiple colors, which is convenient, and since each image forming process exerts its function independently, excellent image quality can be obtained. To be It is also possible to use an apparatus having a different developing method for each image forming process, and further, a combination of the first and third image forming processes and the second and fourth image forming processes, similarly the first and the second image forming processes. The former and latter are different in each of the two image forming steps and the third and fourth image forming steps, and the former and the latter are different, for example, the former is a one-component developing method, the latter is a two-component developing method, and the former is a dry developing method. The latter can also be applied by a wet development method or the like, which can improve image quality and fixing efficiency.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an image forming apparatus.

FIG. 2 is a schematic diagram of an image forming device.

[Explanation of symbols]

 1 1st image forming process 2 2nd image forming process 3 1st intermediate transfer device 4 2nd intermediate transfer device 5 1st intermediate transfer part 6 2nd intermediate transfer part 7 1st transfer part 8 2nd transfer part 10 1st image Holder 11 Photoreceptor Drum 50 Third Intermediate Transfer Section 60 Fourth Intermediate Transfer Section 80 Second Image Holder 100 Image Forming Apparatus 101 Third Image Forming Step 102 Fourth Image Forming Step

 ─────────────────────────────────────────────────── ─── Continued Front Page (71) Applicant 593120682 Namiko Sachiko 5-71-13 Hiyoshihoncho, Kohoku-ku, Yokohama-shi, Kanagawa (71) Applicant 593120693 Akiko Namiki 5-71-13 Hiyoshimoto-cho, Kohoku-ku, Yokohama, Kanagawa Prefecture No. (72) Inventor Ryoichi Namiki 5-71-13 Hiyoshihoncho, Kohoku-ku, Yokohama-shi, Kanagawa (72) Sadako Namiki 5-71-13 Hiyoshihoncho, Kohoku-ku, Yokohama-shi, Kanagawa (72) Inventor Eiko Namiki 5-71-13, Hiyoshihoncho, Kohoku-ku, Yokohama-shi, Kanagawa (72) Inventor Sachiko Namiki 5-71-13, Hiyoshihoncho, Kohoku-ku, Yokohama-shi, Yokohama (72) Akiko Namiki Hiyoshimoto-cho, Kohoku-ku, Yokohama-shi, Kanagawa 5-chome 71-13

Claims (5)

[Claims] 1. A plurality of image forming processes having one or a plurality of image carriers and an image forming means independently formed around the image carrier, and each image forming process is isolated by an intermediate transfer device. An image forming device capable of individually transferring a toner image formed by a plurality of image forming processes onto a recording sheet. 2. The image forming apparatus according to claim 1, wherein the plurality of toner images formed in the image forming step can be combined or aligned and transferred to a recording sheet. 3. The image forming apparatus according to claim 1, wherein the plurality of toner images formed in the image forming step are individually transferred onto the recording paper, or the plurality of toner images are combined or aligned and transferred onto the recording paper. Imaging device that enables 4. The image forming apparatus according to claim 1, wherein the toner of the plurality of toner images has one color. 5. The image forming apparatus according to claim 1, wherein the toner colors of the plurality of toner images are a plurality of colors.