JPS6156365A - Image forming method - Google Patents

Abstract

PURPOSE:To obtain a distinct image by dividing an original image into a cyan component and a red component, carrying the first image information of the cyan component by a photosensitive drum, projecting the second image information of the red component of an ion 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 the mirror 47, a red component is reflected, and a cyan component is made to transmit. Subsequently, the cyan component is advanced to a photosensitive drum 1 and the first image information is carried. Also, the reflected red component is advanced to a photosensitive screen drum 17 and the second image information is carried. Next, for instance, a photosensitive layer 56 of the photosensitive drum 1, and the screen drum 17 are electrified to negative. In this state, a negative ion particle is projected from a charged particle source 19 of the screen drum 17, and it passes through the drum 17, negative image information reaches the photosensitive layer 56, and a latent image is synthesized newly. Accordingly, the latent image separated into a chromatic color level of the first group of negative and a chromatic color level of the second group 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 tangible colors and achromatic colors, or between chromatic colors. BACKGROUND ART Conventionally, as color image processing, image signal processing for color printing, electrophotography, 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 B1 Green G Rud 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 the resulting cyan visible image is once placed on copy paper. Transfer to. Next, the photoreceptor is exposed with a green filter in the same manner as above, and after development with a magenta developer, a magenta visible image is transferred onto the same copy paper in alignment with the cyan image. Further, the same process as above is repeated using a blue filter and a yellow developer, and the image is transferred to match the previous two images. Then, if necessary, the final color image of the print is fixed.

On the other hand, as image processing based on two color information, a masking technique using a color correction method in color printing is known. For example, according to the positive masking method, at the platemaking stage for each color, an uncorrected color separation negative image is superimposed with a separation positive image of the required density created from another color separation negative image. , making color 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, magenta color can be reproduced by this, but this is only based on the premise of color correction. Therefore, it is not intended to separate chromatic colors from achromatic colors, and in particular it is not possible to separate chromatic color levels on either side of an achromatic color level.

3. Purpose of the Invention The purpose of the present invention is to sharply produce images consisting of chromatic colors and achromatic colors.
The object of the present 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 image information, and separates the latent image potential of a chromatic color from the potential level of an achromatic color. A positive first electrostatic charge image formed on the image carrier through a process including exposure to a cyan component is used as first image information, and a second electrostatic charge image formed on an ion flow control screen through a process including exposure to a red component is used as the first image information. It is characterized in that a negative ion flow that passes through this ion flow control screen and has the same polarity as the first electrostatic charge image is used as second image information in accordance with the image.

5. Examples Hereinafter, examples of the present invention will be explained in detail with reference to the drawings. 6.

! 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 a document 44 placed on the document table 61 is illuminated by an illumination lamp 62. 63.64 is mirror,
39 is a fixed lens, 47. is a movable dichroic filter that reflects a predetermined chromatic color light and allows light of a complementary color to the chromatic color to pass, and can be moved in and out of the optical path. A photosensitive layer 56 is provided on the surface of the drum-shaped photoreceptor 1, and when the photoreceptor 1 rotates clockwise, the photosensitive layer 56 is uniformly charged by a corona charger. The photosensitive layer 56 is made of selenium, an organic semiconductor, or the like.

Around the photoreceptor 1, there are a charger for uniformly charging the photoreceptor layer 56, and developers 48, 49, and 49 for storing toner of each color.
・・・・・・・・・ (However, actually G, YXR, M, B
.

The developer of the desired color is placed in C1b, but in the drawing, 2
One developing device is shown as an example. ) 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.

Also, around the outside of the drum 17, there is a screen charger path and an EL (electroluminescent) plate or A for removing the charge remaining on the photosensitive screen drum 17.
Screen static eliminator 69 made from C corona static eliminator etc.
A charged particle source (corona discharger) 19 that projects charged particles is provided inside the photosensitive screen drum 17 at a position facing the photoreceptor 1 .

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 side of the conductive screen, a bias conductive layer 14 made of M or the like provided on this insulating layer by vapor deposition, etc. The photoconductive layer 15 is made of 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 cloth IJ-/17 to form a positive latent image. First, as shown in FIG. 3A, the photoconductive layer 15 is negatively charged over the entire multi-photosensitive screen 17 by the charging path, and then, as shown in FIG. 3B, the photoconductive layer 15 is negatively charged by the image exposure 32. Selectively eliminate or reduce charges. 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 areas of the screen 17 where there is no negative charge, and are deposited on the photosensitive layer 56. A predetermined amount is deposited on a predetermined pattern to form a negative electrostatic latent image. In addition, Vl in FIG. 30 is a bias power supply, v2 is a discharge power supply, and V3 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 l 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. 5. However, in this figure, the screen is shown schematically.

First, the entire surface of the photosensitive screen 17 and the photosensitive layer 56 are negatively charged, and then imagewise exposed to light from the original 44 . At this time, the dichroic mirror 47 has the function of reflecting the R component light of the light reflected from the original (i.e., as a red filter) and transmitting the B and G component lights (i.e., as a cyan filter). use. 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 The negative charge on 56 and the
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 [C]) on the photosensitive layer 56 after image exposure and the charge image (image information [R]) on the photosensitive screen 17 are combined,
The positive image information (R) is inverted to negative by the negative ion particles from 9 (that is, the negative ion particles pass through an area on the screen 17 where no negative image information (R) exists, This is equivalent to the existence of the inverted information [R] of (C) (however, the dynamic range is changed), and the composite information ((C)+(RE)).

In this process, when exposing the photosensitive drum 1 and the photosensitive screen 17, a dichroic mirror 47 having both cyan filter and red filter functions is used. Since the spectral characteristics are the closest, the reproducibility of the red image after synthesis is extremely good.

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 the above example, when cyan and red chromatic lights are applied to the photosensitive drum and the photosensitive screen, respective color filters may be used in place of the above dichroic mirror.

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.

However, the number of image information to be combined may be three or more, and the optical means may be variously modified for this purpose. A positive first electrostatic charge image is used as first image information, a negative ion flow that passes through the ion flow control screen and has the same polarity as the electrostatic charge image is used as second image information, and these image information are synthesized. Since the latent image potential of the chromatic color is separated from the potential level of the achromatic color, each individual can be formed in a state where the chromatic color and the achromatic color are clearly separated. Therefore, a desired image can be reproduced clearly and with high precision and with easy control. Moreover, when exposing an image carrier such as a photoreceptor drum and an ion flow control screen such as a photosensitive screen, exposure to cyan and red components is applied respectively, and the spectral characteristics of general red are the same as those of ideal red. Since it is closest to the spectral characteristics of Q, the reproducibility of the red image after synthesis is extremely good.

[Brief explanation of drawings]

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...
......Photosensitive screen 19...
...Charged particle source 44...Original image or manuscript 47...
Dichroic mirror 56 is a photosensitive layer. ,! Agent Patent Attorney Hiroshi Aisaka Figure 1 Figure 2A Figure 2B Figure 2C Figure 3A Figure 3B Figure 3C; 9 Figure 4 Figure 6 Figure 17 Figure 5

Claims (1)

[Claims] 1. When obtaining multiple pieces of image information from the original image and synthesizing these image information to separate the chromatic latent image potential from the achromatic potential level, a process that includes exposure to cyan components is performed on the image carrier. The formed positive first electrostatic charge image is used as first image information, and the ion flow control screen is passed through in response to a second electrostatic charge image formed on the ion flow control screen by a process including exposure with a red component. An image forming method characterized in that a negative ion flow having the same polarity as the first electrostatic charge image is used as second image information.