JPS6156361A - Image forming method - Google Patents

Abstract

PURPOSE:To obtain a distinct image consisting of a chromatic color and an achromatic color by dividing an original image into each hue, carrying the first image information by a photosensitive drum, projecting the second image information of an iron current of negative of the same polarity, to said image information, and synthesizing a latent image. CONSTITUTION:An image of an original 44 is reflected by mirrors 62, 64, and made incident on a dichroic mirror 47. By its mirror 47, a chromatic color light is reflected, and its complementary color light is made to transmit. Subsequently, the complementary color light is advanced to a photosensitive drum 1 and the first image information is carried. Also, the reflected chromatic color light is advanced to a photosensitive screen drum 17 and the second image information is carried. Next, a photosensitive layer 56 of the photosensitive drum 1, and the screen drum 17 are electrified, for instance, to negative. In this state, when a negative ion particle is projected from a charged particle source 19 of the screen drum 17, it passes through the drum 17, reaches the photosensitive layer 56 as negative image information, and a latent image is synthesized newly. Accordingly, the latent image separated into the first group chromatic color level of negative and the second group chromatic color level of negative is formed on both sides of an achromatic color potential level, therefore, a distinct image can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Field of Industrial Application The present invention relates to an image forming method, particularly an image reading method and printer copying method for simple color discrimination between chromatic colors and achromatic colors, or between chromatic colors. be.

2. Prior Art Conventionally, as color image processing, for example, color printing, electrophotography, image signal processing of color scanners, etc. are known. In all of these, it is necessary to obtain three color information by color separation of three primary colors (Blue 81 Green G, Red R) for image formation. For example, according to a known full-color process electrophotographic copying machine, for example, after a photoreceptor is charged with corona, an original image is exposed through a red filter;
Developed with a cyan developer, and transferred the resulting cyan visible image onto copy paper. Next, expose the photoreceptor to light using a green filter in the same way as above, develop with a magenta developer, and then transfer the same visible image onto copy paper. Transfer the magenta visible image to the copy paper in accordance with the cyan image.Furthermore, repeat the same process as above using a blue filter and yellow developer to transfer it in accordance with the previous two images.Then, as necessary, Accordingly, the final color image of the print is fixed.

On the other hand, masking technology, which is a color correction method in color printing, is known as image processing based on two color information. For example, according to the positive masking method, at the stage of plate making for each color, an uncorrected color separation negative image is overlaid with a separation positive image of the required density created from another color separation negative image. We are making corrections.

A technique in which such a masking method in printing is applied to electrophotography is disclosed in Japanese Patent Application Laid-Open No. 52-3430. According to this known technique, a first electrostatic charge image is formed on a photoreceptor, a second electrostatic charge image is formed on a photosensitive screen, and a first electrostatic charge image is formed in accordance with the second electrostatic charge image. A technique is known in which a first electrostatic charge image is modified by applying a charge flow of opposite polarity. For example, it is possible to reproduce the color magenta, but this is only based on the premise of color correction. Therefore, the purpose is not to separate chromatic colors from achromatic colors. In particular, it is not possible to separate chromatic levels on either side of an achromatic level.

36 Purpose of the Invention The purpose of the present invention is to sharply produce images consisting of chromatic colors and achromatic colors.
The purpose of this invention is to provide a method that is highly accurate, controllable, and easily reproducible.

4. Structure of the invention, that is, the image forming method according to the present invention obtains a plurality of image information from an original image, synthesizes these single image information, and separates the latent image potential of a chromatic color from the potential level of an intangible color. , a positive electrostatic charge image formed on the image carrier is used as first image information, and a negative ion flow passing through an ion flow control screen and having the same polarity as the electrostatic charge image is used as second image information. It is characterized by:

5. Examples Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an image forming apparatus using a photosensitive screen.

A reciprocating document table 61 is provided at the top of the main body of the apparatus, and the document 44 placed on the document table 61 is illuminated by an illumination lamp 62 . 63.64 is mirror, 39
47 is a fixed lens, and 47 is a movable guichroic mirror that reflects a predetermined chromatic color light and allows light of a color complementary to this chromatic color to pass through, and can be moved in and out of the optical path. There is. (Rum-shaped photoreceptor 1
A photosensitive layer 56 is provided on the surface of the photosensitive member 1 , and when the photosensitive member 1 rotates clockwise, the photosensitive layer 56 is uniformly charged by the corona charger 24 . Photosensitive layer 56
is made from selenium or organic semiconductors.

Around the photoreceptor 1, there are a charger 24 that uniformly charges the photoreceptor layer 56, and developing devices 48 and 49 containing toner of each color.
・・・・・・(However, actually G, Y, R, M, B, c,
A developing device for a desired color is arranged in the drawing, and two developing devices are shown as an example in the drawing. ) etc. are arranged.

On the other hand, a cylindrical photosensitive screen drum 17 is disposed on the outside of the photosensitive drum 1 so that the photoconductive layer faces, and this drum 17 is rotated counterclockwise in synchronization with the document table 61 and the photosensitive layer 56. It is arranged so that it can rotate in the direction.

Further, around the outside of the drum 17, a screen charger 28 and a screen charger 69 made of an EL (electroluminescence) plate or an AC corona charger for removing charges remaining on the photosensitive screen drum 17 are provided. A charged particle source (corona discharger) 19 that projects charged particles to a position facing the photoreceptor 1 inside the photosensitive screen drum 17 is provided.

A portion of the photosensitive screen 17 is shown in FIGS. 2A and 3.
As shown in Figure A, a conductive screen 11 made of stainless steel or the like has a large number of fine openings 10 and has one side exposed;
An insulating layer 13 made of methacrylic resin or the like provided on the other surface of the conductive screen, a conductive layer 14 for biasing such as β β provided on this insulating layer by vapor deposition, an azo dye,
The photoconductive layer 15 is made of selenium, amorphous silicon, cadmium sulfide, zinc oxide, or the like.

Note that the photosensitive screen 17 may have another structure, for example, it may have a layered structure as shown in FIG. 2B. Additionally, other known layer configurations may be employed, such as an NP photosensitive screen as shown in FIG. 2C.

FIG. 3 shows a process of selectively depositing charges on the photosensitive drum 1 using the photosensitive screen 17 to form a negative latent image. First, as shown in FIG. 3A, the photoconductive layer 15 is negatively charged over the entire photosensitive screen 17 by the charger 28, and then, as shown in FIG. 3B, the negative charge is selectively removed by image exposure 32. disappear or decrease. Next, as shown in FIG. 3C, when negative ion particles are projected onto the photosensitive screen 17 from the charged particle source 19 described above, the negative ion particles pass through the area of the screen 17 that has no negative charge, and are deposited on the photosensitive layer 56. A predetermined amount is deposited in a predetermined pattern to form a negative electrostatic latent image. Note that (1) in FIG. 30 is a bias power supply, (2) is a discharge power supply, and (2) is a DC power supply.

FIG. 4 shows the relationship between the amount of passing ion particles and the surface potential of the photosensitive screen 17. As the surface potential (negative) is small, the amount of passing ions increases, and the number of negative ion particles reaching the photosensitive drum 1 increases accordingly. It will increase.

Next, an image forming process using the photosensitive screen 17, for example the screen shown in FIG. 3, will be explained with reference to FIG. However, in this figure, the screen is shown schematically.

The photosensitive screen 17 and the photosensitive layer 56 are first coated with a surface quality of 1.
After being charged, image exposure is performed using light from the original 44. At this time, the dichroic mirror 47 is a mirror from the original! Among the 11 lights, a filter having the function of reflecting B component light (ie, as a blue filter) and transmitting G and R component lights (ie, as a yellow filter) is used. As a result, a predetermined amount of negative charge is left on the photosensitive screen 17 and the photosensitive layer 56 as positive image information, as shown. Next, when negative ion particles are projected from the charged particle source 19, these negative ion particles pass through the area of the photosensitive screen 17 that is not negatively charged, reach the photosensitive layer 56 as negative image information, and the photosensitive layer 56 and the negative charge on
A new combined electrostatic charge image is formed by the negative charges that have passed through the photosensitive screen 17 (the bias of the photosensitive screen 17 is omitted in the drawing). As a result, charges of negative polarity are selectively left on the photosensitive layer 56 with a predetermined charge amount, and a negative first group chromatic color level and a negative chromatic color level are left on both sides of the achromatic color levels W and b. An electrostatic latent image is formed in which the chromatic color levels of the second group are separated. Therefore, in the next development, any chromatic color can be visualized.
! In this process, when the charge image (image information [Y]) on the photosensitive layer 56 after image exposure and the charge image (image information [B]) on the photosensitive screen 17 are combined, the particle source 19 The positive image information (B) is inverted into a negative by the negative ion particles from It is equivalent to the existence of inverted information CB)), and composite information ((
Y) + (100).

Although the present invention has been illustrated above, the embodiments described above can be further modified based on the technical idea of the present invention.

For example, in addition to the blue-yellow combinations mentioned above, the combinations of colored lights irradiated on the photosensitive drum and the photosensitive screen include red-yellow, red-yellow,
A wide variety of colors can be used, such as magenta-cyan, green-blue, red-white (white light), and magenta-white (white light). If it is not possible to obtain two colored lights using a dichroic mirror, the optical path may be separated using a half mirror and a color filter may be inserted into each optical path. Further, the polarities of the electrostatic charge image and ionic particles on the photosensitive drum and the photosensitive screen may be reversed from those in the above-mentioned example. As shown in FIG. 6, when a known NP photoreceptor is used as a photosensitive screen, positive ion particles pass through the light irradiation area on the screen, and a positive electrostatic charge image (not shown) is formed on the photoreceptor drum 1. can be synthesized in the same manner as described above. Furthermore, three or more types of image information to be combined may be used.
For this purpose, the optical means may be varied in various ways.

6. Effects of the Invention As described above, the present invention uses a positive electrostatic charge image formed on an image carrier as the first image information, passes through an ion flow control screen, and has the same polarity as the electrostatic charge image. The negative ion flow is used as second image information, and this image information is combined to separate the latent image potential of chromatic colors from the potential level of achromatic colors, so chromatic colors and achromatic colors can be clearly separated. Each image can be formed in the same state. Therefore, a desired image can be reproduced clearly and with high precision and with easy control.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a schematic diagram of an image forming apparatus, FIGS. 2A, 2B, and 2C are enlarged sectional views of a part of a photosensitive screen, and FIG. 3A is a schematic diagram of an image forming apparatus. Figures 3B and 3C are process diagrams of the image forming process using a photosensitive screen, Figure 4 is a graph showing the amount of ions passing through the screen depending on the surface potential of the photosensitive screen, and Figure 5 is the apparatus shown in Figure 1. FIG. 6 is a process diagram of another example of image formation. In addition, in the symbols shown in the drawings, 1--Photosensitive drum 17--2 Photosensitive screen 19--Charged particle source 44--Original image or original 47--・
-・Guicroic mirror 56・・・・・It is a photosensitive layer town.

Claims (1)

[Claims] 1. When obtaining multiple image information from the original image and synthesizing these image information to separate the chromatic latent image potential from the achromatic potential level, the positive electrostatic charge image formed on the image carrier is An image forming method characterized in that a negative ion flow passing through an ion flow control screen and having the same polarity as the electrostatic charge image is used as first image information and second image information.