JPS60198563A - Bicolor electrophotographic device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (a) Technical Field The present invention relates to an electrophotographic apparatus, particularly an electrophotographic apparatus that exposes and develops a plurality of images on a drum or belt-like photoreceptor and transfers them to a transfer material such as paper. For example, it is used in a multicolor electrophotographic device.

(b) Prior art In conventional electrophotographic equipment, for one image exposure,
This method uses one light source and a photoreceptor. Therefore, when multicolor electrophotography is required, it is necessary to prepare as many light sources and photoreceptors as there are colors and apply the colors one after another, or to expose and develop the photoreceptors and transfer them to the transfer material. By repeating the process a necessary number of times, the colors are applied over and over to obtain a desired multicolor electrophotograph. However, the former method has the disadvantage that the equipment is larger and has more parts, which requires more effort to maintain, while the latter method makes it difficult to accurately superimpose the jM images and takes longer processing time. Given these drawbacks, there has been a demand to obtain multicolor electrophotography with fewer light sources and photoreceptors.

The applicants, etc. are able to comply with such requests.
First, patent application No. 59-005323 was filed. This consists of an electrophotographic section and a scanning optical system. A second exposure section, a first developing device, an entire surface exposure section, and a second developing device are sequentially provided, and in the scanning optical system, one laser beam emitted from a laser transmitter is converted into two different images using a modulator. This laser beam is divided into two light beams by a deflector, and these light beams are then scanned by a scanning device to print the first image on the photoreceptor. and the second exposure section, respectively.

However, color bleeding and color mixing occur during exposure and development using this device, making it difficult to obtain clear, multicolored electronic and photographic images.
It turned out that it had the drawback of being extremely difficult.

(C) Purpose of the Invention The present invention provides a multicolor electronic photograph that can obtain clear multicolor electronic photographs with almost no color bleeding or color mixing when exposing and developing two or more colors using one photoreceptor. The purpose is to provide photographic equipment.

(d) Configuration of Embodiments The present invention will now be described in detail based on embodiments and drawings. In FIG. 1, 1 is a photoreceptor, and 2 is a pre-exposure section, which provides uniform light onto the photoreceptor 1 and eliminates potential irregularities. A first charger 3 charges the photoreceptor 1 with one polarity, and a direct current type is generally used. A second charger 4 charges the photoreceptor 1 with an opposite polarity, and in the embodiment, a type that superimposes a direct current on an alternating current is used.

Reference numeral 5 denotes a first exposure section that has an optical axis passing through the second charger 4 and exposes an image signal of a first color, and numeral 6 indicates a second exposure section that exposes an image signal of a second color. 7 is a first developing device for developing the image signal of the second color; 8 is a full exposure area that gives a hazy glow on the photoreceptor 1; and 9 is a second developing device for developing the image signal of the first color. Therefore, it is desirable to use a so-called jump developer, which performs development without contacting the photoreceptor 1. These devices are numbered in this order. 10A110B are both side walls 4A of the second charger 4,
4B is an electrically insulating shield attached to each. The shields 10A and 10B are preferably arranged so that they lightly touch the photoreceptor 1, but they may also be provided with a small gap to the extent that interference between the beams does not occur.

(e) Effects of the examples Next, I will explain its effect.

When the photoreceptor body 1 is rotated by a photoreceptor (not shown), the surface of the photoreceptor 1 is mechanically cleaned by a cleaning mechanism (not shown), and then the photoreceptor 1 is exposed to the pre-exposure section 2. By being exposed to light, the remaining charged parts are erased and electrically wiped away. At this time, the light beam emitted from the pre-exposure section 2 interferes with one laser beam 5A of the first exposure section 5, which will be described later, due to the shield 10Δ attached to one side wall 4A of the second charger 4. There isn't. The potential of the photosensitive layer of the photoreceptor 1 in this state is shown by curve 0 in FIG.

The photoreceptor 1 is charged to one polarity by the first charger 3. For example, in the case of a photoreceptor having an N-type photoreceptor layer,
The surface of the photosensitive layer is positively charged, as shown by curve a in FIG.
It becomes like this. Subsequently, exposure is performed, and this light source uses a laser beam that is modulated and polarized by a scanning optical system (not shown) and then split into two color signals. That is, one laser beam 5 A
The lfi first exposure section 5 and the other laser beam 6A are introduced into the second exposure section 6, respectively.

At this time, the beams do not interfere with each other due to the shield 10B attached to the other side wall 4B of the second charger 4. The photoreceptor 1 is charged to the opposite polarity by the second charger 4 while being exposed by the first exposure section 5 . At this time, the potential of the surface of the photosensitive layer on the receiving side irradiated with one laser beam 5A is uniform regardless of the optical image, and becomes as shown by the curve in FIG. 2. Next, the surface potential of the photoreceptor 1 irradiated with the other radar beam 6A in the second exposure section 6 changes in potential as shown by the curve C in FIG. At this time, the potential of the dark part of the optical image remains unchanged and changes as shown by curve d in FIG.

Next, in the first current FQ device 7, the other laser beam 6
Toner of the other color (not shown) adheres only to the area hit by A, and only the image showing a positive potential is visualized. That is, the toner of the other color, which is negatively charged, is attached to only the positive potential area along with the Kyrelia.

Next, the entire surface of the photoreceptor 1 is uniformly exposed by the entire surface exposure section 8, and the area not irradiated with the laser beam 5A changes to the potential shown by the curve e in FIG. 2, and the area where the irradiation is alternately applied Only the voltage becomes the negative potential shown by the curve @f. Therefore, the second developing device 9 is used.

The positively charged colors 1 to 1 to toner of one color adhere only to the negative potential portion of the photoreceptor 1, and the two colors of 1 to toner are simultaneously transferred to a transfer material (not shown).

In addition, if necessary, such a two-color electrophotographic device can be
It is clear that by further modulating and splitting the beam, multicolor electrophotography can be obtained with one light source and two photoreceptors.

(F) Structure of the Present Invention As described above, the two-color electrophotographic apparatus of the present invention comprises a photoreceptor and an exposure and development device installed at a position 1i opposite to the photoreceptor. The equipment includes a pre-exposure section, etc.
A first charger charges the photoreceptor to one polarity, a second charger charges the photoreceptor to the opposite polarity, and an optical axis passes through the side wall of the second charger. A first exposure section that exposes an image signal of a first color, a second exposure section that exposes an image signal of a second color, a first developer that develops an image signal of a second color, and a photoreceptor. an entire exposed area exposed to 4-;
A second developing device for feeding the image signal of the first color is sequentially installed to form a CL-C WJ, and electrically insulating shields are provided on both side walls of the second charger. .

(g) Effects of the present invention

Claims (1)

[Claims] It consists of a photoconductor, and an exposure and development device provided at a position opposite to the photoconductor, and the exposure and development device includes a pre-exposure section, a first charger that charges the photoconductor to one polarity, and a second charger that prevents the body from being charged to an opposite polarity; a first exposure section that has an optical axis passing through a side wall of the second charger and exposes an image signal of a first color; and an image signal of a second color. a second exposure section that exposes the signal; a first development device that develops the second color image signal; a full surface exposure section that exposes the entire surface of the photoreceptor; and a second development device that develops the first color image signal. A two-color electrophotographic apparatus characterized in that the two-color electrophotographic apparatus is configured by sequentially providing the following, and electrically insulating shields are provided on both side walls of the second charger.