JPS6156368A - 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 opposite 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 incidnet on a dichroic mirror 47. By its 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 rectified 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 positive and negative, respectively. In this state, a negative ion particle is projected from a charged particle source 19 of the screen drum 17, and its passes through the drum 17, negative image information reaches the photosensitive layer 56, and a latent image is synthesized. Accordingly, the latent image separated into a positive chromatic color level and a negative chromatic color level 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, and particularly to an image reading method and printer copying method for simple color discrimination between chromatic colors and achromatic colors, or between chromatic colors. I can buy things.

λ Prior Art Conventionally, as color image processing, for example, image signal processing for color printing, electrophotography, color scanners, etc. is known. In all of these, it is necessary to obtain three color information by color separation of three primary colors (blue B1 green G1 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 the resulting cyan visible image is once placed on copy paper. Transfer to. Next, the photoreceptor is exposed to light using a green filter in the same manner as described 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 an image processing process based on two color information, a masking technique which is a color δ positive method in color printing is known. For example, according to the positive masking method, at the stage of plate making 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. Color corrections are being made.

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, an Ml electrostatic charge image is formed on a photoreceptor, a second electrostatic charge image is formed on a photosensitive screen, and the second electrostatic charge image is inverted with respect to the first electrostatic charge image. Techniques are known for modifying the GL electrostatic charge image by applying a polar charge flow. This makes it possible to reproduce magenta, for example, but kneading is best used only for color correction. Therefore, 5 chromatic colors are
It is not intended to separate chromatic from chromatic levels, and in particular it is not possible to separate chromatic levels on either side of an achromatic 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 the multiple image information, and separates the chromatic latent image potential from the achromatic potential level. , a negative first electrostatic charge image formed on the image carrier by a process including exposure to a cyan component is used as first image information, and a second static charge image formed on an ion flow control screen by a process including exposure to a red component is used as first image information. The ion flow control screen is characterized in that a negative ion flow that passes through this ion flow control screen and has a polarity opposite to that of the first electrostatic charge image is used as second image information in accordance with the charge image.

5. Examples Hereinafter, examples of the present invention will be explained in detail with reference to the drawings.
) to clarify.
1 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 placed on the document table 61 is illuminated by an illumination lamp 62. Hammer, 64
is a mirror, 39 is a fixed lens, and 47 is a movable dichroic filter that reflects a predetermined chromatic color light and passes light of a complementary color to this chromatic color, so that it can enter and exit the optical path. It has become. A photoconductor layer 56 and an insulating layer 57 are provided on the surface of the drum-shaped photoconductor 1, and when the photoconductor 1 rotates clockwise, the photoconductor layer 56 and the insulating layer 57 are charged by a primary strain charger and a secondary charger 25. Evenly charged.

The photoreceptor 1 is a so-called NP photoreceptor shown in Japanese Patent Publication No. 42-23910, and has an insulating layer 57 (
(see Fig. 5).

Around the photoreceptor 1, there are a negative-order distortion electric device 24, a secondary electric power device 25, and developing devices 48 and 49 containing toner of each color.
・・・・・・・・・(However, actually G%Y, R, M, B
,C.

A developing device of a desired color is arranged among those of b, 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.

Also, there is a screen around the outside of this drum 17! electric appliance 28 and a screen static eliminator 6 made of an EL (electroluminescence) plate or an AC corona static eliminator that removes the electric charge remaining on the photosensitive screen drum 17.
9, and a charged particle source (corona discharger) 19 that projects charged particles to a position facing the photoreceptor 1 inside the photosensitive screen drum 17.

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 N/l 13 made of methacrylic resin or the like provided on the other side of this 23 conductive screen, a bias conducting tli layer 14 such as A1 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 the NP photosensitive screen 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 photosensitive layer 15 is negatively charged over the entire photosensitive screen 17 by the electric device 28, and then the negative charge is removed by image exposure 32 as shown in FIG. 3B. selectively eliminate or reduce. Next, as shown in FIG. 3C, when negative ion particles are projected from the charged particle source 19 onto the photosensitive screen 17, the negative ion particles pass through the area of the screen 17 where there is no negative charge, and are deposited on the insulating layer m. A certain amount is deposited in a predetermined pattern to form a negative electrostatic latent image. In addition, in FIG. 3C, the or bias power supply, the pigeon is the power supply for discharging, and the symbol ■ is the DC power supply.

FIG. 4 shows the relationship between the amount of passing ion particles and the surface potential of the photosensitive fleece 1. As the surface potential (negative) becomes smaller, the amount of passing ions increases, and the more negative ion particles reach the photoreceptor drum 1. 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 entire surface of the photosensitive screen 17 is negatively charged, while the entire surface of the photoreceptor 1 is firstly charged positively, and then the entire surface is negatively charged.
Thereafter, image exposure is performed using light from the document material. On this occasion,
The dichroic mirror 47 has the function of reflecting R component light of the light reflected from the original (i.e., as a red filter) and transmitting B and G component light (i.e., as a cyan filter). use. As a result, a predetermined amount of charge remains on the photosensitive screen 17 and the photoreceptor 1 in a predetermined pattern as shown.

In this case, the distribution of charges on the photoreceptor 1 changes as shown in the figure depending on the irradiated scene, and the internal charges disappear more often in areas where the amount of light is large (particularly in the cyan image area). Here, as the photoreceptor 1, one having the following configuration was used.

Photosensitive layer 56: Cadmium sulfide (layer thickness: 50 μm, dielectric constant: 6) Insulating layer 57: polyethylene terephthalate film (layer thickness: 50 μm, dielectric constant: 3) As a result, as shown in FIG. and the charge pair of
The contribution rate of the charge pair via the photosensitive layer to the surface potential of the photoreceptor is, if the former is +1, the latter is approximately -Q, 5, and the 5th
In the figure, the surface potential of the photoreceptor 1 after exposure is as shown in the figure (
Negative image information).

Then, when negative ion particles are irradiated from the charged particle source 19 (◯ projection), the negative ion particles pass through a region of the photosensitive screen 17 that is not negatively charged,
Negative image information reaches the insulating layer 57, and a new composite electrostatic charge image is formed by the charges on the photoreceptor 1 and the negative charges that have passed through the photosensitive screen 17 (in the drawing, the bias of the photosensitive screen 17 is are omitted). As a result, charges are selectively left on the photoreceptor 1 with a predetermined amount of charge according to the profile shown in the figure, and positive chromatic levels G, B, and C and negative chromatic levels G, B, and C are formed on both sides of the achromatic color levels W and b. An electrostatic latent image is formed in which chromatic color levels Y, R, and M are separated. Therefore, in the next development, these chromatic colors can be visualized.

In this process, when the charge image on the photoreceptor 1 after image exposure (image information [C]) and the charge image on the photosensitive screen 17 (image information [R]) are combined, the particle source 1
The positive image information [G] is inverted to negative by the negative ion particles from This is equivalent to the existence of the inverted information CR) (however, the dynamic range is changed), and the composite information (2CC) + 3 CRY). The surface potential of the body is shown.

In this process, when exposing the photosensitive drum 1 and the photosensitive screen 17, the dichroic mirror 47
Although a filter having both a cyan filter and a red filter function is used as the filter, since the general red spectral characteristics are closest to the ideal red spectral characteristics, 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.

In addition to the method described above, to form a negative latent image on the photoreceptor drum, a constant charge charging method using a charger 26 as shown in FIG. 8 using an ordinary photoreceptor 1 may be adopted. It's fine. 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 Figure 9, NP, which is known as a photosensitive screen,
When a photoreceptor is used, positive ion particles can pass through the light irradiation area on the screen and be combined with a negative electrostatic charge image (not shown) on the photoreceptor drum 1 in the same manner as described above.
Further, there may be three or more types of image information to be combined, and the optical means may be variously changed for this purpose.

6. Effects of the Invention As described above, the present invention uses the first negative electrostatic charge image formed on the image carrier as the first image information, passes through the ion flow control screen and is inversely to the electrostatic charge image. The polar negative ion flow is used as the 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, making it possible to clearly distinguish between chromatic colors and achromatic colors. Six images can be formed in a separated state. Therefore, a desired image can be reproduced clearly and with high precision and with easy control. Furthermore, 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 different from those of ideal red. The reproducibility of the red image after synthesis is said to be extremely good, as the spectral characteristics are the closest to that of the spectral characteristics.

[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 an image forming process using a photosensitive screen, Figure 4 is a graph showing the amount of ions passing through the screen depending on the photosensitive screen's shinshield potential, and Figure 5 is the apparatus shown in Figure 81. Figure 6 is a schematic diagram showing the contribution rate of the latent image to the surface potential, Figure 7 is a graph showing the surface potential at multiple stages, Figures 8 and 9 are FIG. 7 is a diagram illustrating a latent image forming process using another method. 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 5
6......Photosensitive layer 57...
・・・・・・・・・・・・It is an insulating layer. Agent Patent Attorney Hiroshi Aisaka Figure 1 Figure 2A Figure 2B Figure 20 Figure 3A Figure 38

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 negative first electrostatic charge image is used as first image information, and an ion flow control screen is passed through the ion flow control screen in accordance with 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 a polarity opposite to that of the first electrostatic charge image is used as second image information.