JPS60202454A - Analog/digital color image forming apparatus - Google Patents

Abstract

PURPOSE:To obtain inexpensive and multifunctional analog/digital color image- forming apparatus suitable for personal use by arranging a photosensitive drum for forming an analog electrostatic latent image and an electrostatic recording head above a transfer drum, and horizontally movable color developing devices below the transfer drum. CONSTITUTION:One of developing devices 9 contg. each developing soln. for each color corresponding to each electrostatic latent image formed by color separating an original 3 approaches a transfer drum 6 to develop the first latent image, and moves to alternate with the developing device 9 of another color till the next electrostatic latent image comes. An electrostatic recording paper 7 on the transfer drum 6 is dried after the end of development to fix a toner. A sheet of an analog color image is completed by repeating said process in three times. Further, to overlay a digital image, a digital latent image is formed on a part of the electrostatic recording paper 7 free from the color images with an electrostatic recording head 8 at the time of the fourth roration of the drum 6, and finally, it is developed with a black developing soln. to obtain a black digital image.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a color copying device and an electrostatic recording device.

] Month 1 Conventionally known color electrophotographic copying device, for example,
As stated in Japanese Patent Publication No. 5-26466 and Japanese Patent Publication No. 51-35460, when a belt-shaped photoreceptor is used, the entire apparatus becomes large, the copying speed is slow, and the mechanical damage of the belt-shaped photoreceptor is large. , the transfer rate is also poor.

Further, although electronic copying apparatuses having both a copy function and a printer function are known, there have been no inexpensive ones suitable for use in color copying apparatuses.

1. The present invention aims to provide a multifunctional copying machine that is suitable for personal use, is inexpensive, and is capable of color copying and digital recording.

1 ridge The present invention will be explained according to embodiments shown in the drawings.

FIG. 1 is a schematic diagram of the apparatus of the present invention, in which above the transfer drum,
A photoreceptor drum that forms an analog electrostatic latent image and an electrostatic recording head for digital signals are arranged, and a horizontally movable color (yellow, magenta, cyan, black) developing device is installed below the transfer drum. ing.

That is, a charger 2, an exposure device 4 for projecting a color original 3 onto the photoreceptor drum 1, and a static eliminator 5 are provided around the photoreceptor drum 1. A transfer drum 6 is provided, and an electrostatic recording paper 7 is fed between the photosensitive drum 1 and the transfer drum 6 from the right side, and is transported while being wrapped around the transfer drum 6. Incidentally, an electrostatic recording head 8 is provided facing the transfer head 61, and digital recording is thereby performed on the electrostatic recording paper 7.

In addition, since the electrostatic latent image formed on the photoreceptor drum 1 is transferred to the electrostatic recording paper 7 that is transported while being wrapped around the transfer drum 6 at the contact position, the transfer drum is used to develop the latent image. 6 Color developer that can be moved downward horizontally @
9 are installed, squeeze roller] 0, static eliminator (A
C, lamp) 11 is also provided subsequently.

The developed electrostatic recording paper 7 is sent out to the left after repeating color development a necessary number of times.

The photosensitive drum 1 has a small diameter (20 to 60φ), is endless (seamless), and has a dielectric thickness D=d/ε (d: film thickness, E: dielectric constant) of the photosensitive layer of 77 zm or less, and is transparent in the entire visible light range. Sensitive materials such as various OPC photoreceptors, a-8i photoreceptors, As2 Se3, CdS, and dye-sensitized ZnO photoreceptors are suitable. The transfer driver 6 has an elastic surface and has the function of pressing the dielectric layer of the transfer paper, the surface of the photosensitive drum 1, and the electrostatic recording head 8 while holding the transfer paper (electrostatic recording paper). Furthermore, by positioning the transfer paper on the transfer drum 6-H and rotating it at the same linear speed as the photoconductor l (ram), a color analyzer with no color misregistration or misalignment can be achieved.
The purpose is to obtain digital images. In this case, the return time tO of the exposure system, the passage time t1 of the portion of the transfer drum where there is no transfer paper. It is necessary to design the developing units so that the moving time t2 is equal. Further, as shown in FIG. 2, the transfer drum and the base (base paper) of the electrostatic recording paper 7 are grounded, and the conductive substrate of the photosensitive drum 1 is insulated from the ground, so that the photosensitive layer is not affected. It can be maintained at a potential (200 to 400 V) with the same polarity as the corona charge by an external power source. Note that the reference numeral indicates the digital electrostatic latent image (charge) already formed by discharge from the electrostatic recording head 8, and A indicates the state in which the analog electrostatic latent image on the photosensitive layer is transferred onto the dielectric layer. . In this way, the transfer rate of the electrostatic latent image on the photosensitive layer to the dielectric layer is improved, and leakage can also be prevented when the digital latent image already formed on the dielectric layer by the recording head comes into contact with the photosensitive drum. Helpful.

Next, an embodiment in which a digital image is overlaid in black on an analog color image of a color document and a margin area will be described based on the apparatus shown in FIG.

The photosensitive drum 1 is a 40φ OPC drum, and a charger 2 applies a dark potential of -750 cm and a DC voltage of -250 V to the photosensitive drum base. A color original 3 is separated into three colors using blue, green, and red filters, and an analog latent image formed by exposure to blue light is first transferred to an electrostatic recording paper 7 positioned on a transfer drum 6 ( Transfer voltage 1000V). The surface of the photosensitive drum after electrostatic transfer is passed through a static eliminator 5 and used many times.

4- On the other hand, in order to develop the transferred static image on electrostatic recording paper, dry method-
Component, two-component, wet development, etc. are used, but the color is good as a color toner, and when attached as an image to electrostatic recording paper, the electrical properties are not much different from the dielectric layer of electrostatic recording paper. It does not affect the subsequent latent image transfer, and furthermore, it is easy to fix the toner after development.

Therefore, magnetic 1-ner is not preferred and wet development is appropriate.

Among the developing devices containing yellow, magenta, cyan, and black developing solutions, the developing device for the color that corresponds to the electrostatic latent image created by color-separating the original is located close to the transfer drum. ), move until the next electrostatic latent image arrives,
Replace with a developer of another color (in this case, magenta).

After the development is completed, the electrostatic recording paper on the transfer drum is dried by a squeeze roller 10 and hot air (not shown), and the toner is fixed thereon. Furthermore, if any latent image charge remains, it will affect the next latent image transfer, so it is removed by the static eliminator 11.

AC corona is generally used, but
As described in Publication No. 1, if a photoconductor is dispersed in the dielectric layer of a positive recording paper, optical static elimination becomes possible.

By repeating the above-described electrostatic latent image formation, latent image transfer, development, and fixing (electrostatic elimination) steps as many times as the document is color-separated (three times in this case), one sheet of analog color image is completed.

Further, in order to overlay a digital image, a digital latent image is formed by the electrostatic recording head 8 on the portion of the electrostatic recording paper where there is no color image at the fourth rotation of the transfer ram. Even if this portion comes into contact with the photoreceptor drum, the digital latent image will not leak because the photoreceptor drum is not grounded. The image is developed with a black developer by a developing device 9 to obtain a black digital image.

The embodiments of image formation in which a digital image is overlaid on the margin of an analog color image that is faithful to a color original have been described above, but according to the apparatus of the present invention, (1) an analog color image; (2) an analog color image;

Digital color image, (3) Digital color image, (4
) Various composite images such as analog image digital color image and (5) analog digital image can be obtained.

Alternatively, all colors may be produced by a combination of yellow, magenta, and cyan without using black development.

According to the present invention, by using an endless small-diameter drum as a photoreceptor, the entire device can be made smaller, and it is also possible to create an inexpensive and multifunctional analog/digital device suitable for personal use.
A digital color image creation device is obtained.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the apparatus of the present invention, and FIG. 2 is an explanatory diagram showing a state in which a latent image is transferred from a photosensitive drum to electrostatic recording paper. 1... Photosensitive drum, 2... Charger, 3... Color original, 4... Exposure device, 5... Static eliminator, 6...
・Transfer drum, 7... Electrostatic recording paper, 8... Electrostatic recording head, 9... Developer, 10... Squeeze roller, 11... Static eliminator, t□... Exposure system return time, tl... time for passing through the area on the transfer drum where there is no recording paper, t2... time for moving the developing device. Agent Patent Attorney Makoto Kon

Claims (1)

[Claims] The process of forming an analog latent image on the uniformly corona-charged surface of the photoreceptor drum by color-separating the color original and exposing the monochrome original as it is to form an analog latent image. A step of transferring a latent image to an electrostatic recording paper positioned on a transfer drum, a step of forming a digital electrostatic latent image from a recording head provided close to the electrostatic recording paper, and a plurality of horizontally movable A step of bringing one of the color developing devices close to the transfer drum to develop the latent image on the electrostatic recording paper, a step of fixing the toner image on the electrostatic recording paper, and a step of removing the latent image charge. An analog/digital color image creation device characterized by repeating the process multiple times.