JPS6156362A - Image forming method - Google Patents

Abstract

PURPOSE:To obtain a distinct image consisting of a chromatic color and an anchromatic 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 positive 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 positive and negative, respectively. In this state, when a positive 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 positive image information, and a latent image is synthesized newly. Accordingly, the latent image separated into a chromatic color level of the first group of positive and a chromatic color level of the second group of positive 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 in particular to an image reading method and printer copying method for simple color discrimination between chromatic colors and achromatic colors, or between chromatic colors. 2. Prior 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 to light using a green filter in the same manner as in step 1 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, 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. Okay, I'm making color corrections.

A technique in which the masking method used in printing is applied to electrophotography is disclosed in Japanese Patent Application Laid-Open No. 52-3430. According to this known technique, a technique is known in which a photoreceptor is irradiated with a charge flow having a polarity opposite to that of the first electrostatic charge image, thereby correcting the first electrostatic charge image.

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 colored 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 these image information, and separates the latent image potential of a chromatic color from the potential level of an achromatic color. A negative electrostatic charge image formed on the image carrier is used as first image information,
The present invention is characterized in that a positive ion flow that passes through an ion flow control screen and has the same polarity as the electrostatic charge image is used as second image information.

5. Examples Hereinafter, embodiments of the present invention will be described in detail 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 is a fixed lens, 47 is a predetermined chromatic color,!
[.

Colors that reflect light and are complementary to this chromatic color
It is a movable dichroic filter that allows one light to pass through, and can be moved in and out of the optical path.
A photosensitive layer 56 and an insulating layer 57 are provided on the surface of a drum-shaped photosensitive body, and when the photosensitive body 1 rotates clockwise, the photosensitive layer 56 and the insulating layer 57 are uniformly charged by the primary charger 24 and the secondary charger 25. is charged with electricity.

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

Around the photoreceptor 10, a negative charger 24 and a secondary charger 25 are installed.
, developing devices 48, 49, each containing toner of each color, respectively.
・・・・・・・・・ (However, actually GXY, R, M,
BXC.

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.

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.
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. Figure 2A and 3rd
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. Furthermore, other known layer configurations may also be employed.

FIG. 3 shows a process of selectively depositing charges on the photosensitive drum 1 through the photosensitive screen 17 to form a positive latent image. First, as shown in FIG. 3A, the photoconductive layer 15 is negatively charged over the entire photosensitive screen 1)-717 by the charger 28, and then, as shown in FIG. Selectively eliminate or reduce negative charges. Next, as shown in FIG. 3C, positive ion particles are applied to the photosensitive screen 1 from the charged particle source 19 described above.
7, positive ion particles pass through the negatively charged area of the screen 7L7 and adhere in a predetermined amount in a predetermined pattern on the insulating layer 57, forming a positive electrostatic latent image. In addition, vl in FIG. 3C 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) increases, the amount of passing ions increases, and the more positive ion particles reach the photoreceptor drum 1. It will increase.

? Next, an image forming process using the photosensitive screen 17, for example the screen IJ-7f 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 positively charged and then secondarily entirely negatively charged.
Thereafter, image exposure is performed using light from the original 44. On this occasion,
As the above-mentioned dichroic mirror 47, one having the function of reflecting G component light (i.e., as a green filter) and transmitting B and R component light (i.e., as a magenta filter) of the reflected light from the original is used. do. As a result, a predetermined amount of charge is left 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 amount of light irradiated, and the internal charges disappear more often in areas where the amount of light is large (particularly in the magenta image area). Here, as the photoreceptor 1, one having the following configuration was used.

Photosensitive layer 56: Cadmium sulfide (layer thickness: 50 μm, relative dielectric constant: 6) Insulating layer 57: 1-” polyethylene tere 7 tallate film (layer thickness: 50 μm, relative dielectric constant: 3) As a result, as shown in FIG. charge pairs through an insulating layer;
The contribution rate of charge pairs via the photosensitive layer to the surface potential of the photoreceptor is approximately 5 if the former is +1, and the surface potential of the photoreceptor 10 after exposure in FIG. 5 is as shown in the figure.
Negative image information). And next, charged particle source 19
When positive ion particles are projected from the screen (■projection), these positive ion particles pass through the negatively charged area of the photosensitive screen 17 and are transferred to the insulating layer 57 as positive image information.
A new combined electrostatic charge image is formed by the charges on the photoreceptor 1 and the positive 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 are selectively left on the photoreceptor 1 with a predetermined charge amount according to the profile shown in the figure, and a positive first group chromatic color level and a positive first group chromatic color level are placed on both sides of the achromatic color levels W and b. An electrostatic latent image is formed in which two groups of chromatic color levels are separated. Therefore, in the next development, any chromatic color can be visualized.

In this process, when the charge image on the photoreceptor 1 after image exposure (image information [M]) and the charge image on the photosensitive screen 17 (image information [G]) are combined, a particle source 19 The polarity of the image information (G) is reversed by the positive ion particles (i.e., the negative image information [G] on the screen 17 is
] is positive inversion information (G) due to the passage of positive ion particles.
is equivalent to the existence of ), composite information (CM) + CG
)) becomes.

FIG. 7 shows the surface potential of the photoreceptor according to each stage of the process.

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 midge, the optical path can be separated using a half mirror.
A color filter may be inserted into each optical path. 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. Furthermore, an electrostatic charge image on a photoreceptor drum and a photosensitive screen,
The polarity of the ionic particles may be reversed from that in the rows described above. Further, three or more types of image information to be combined may be used, and the optical means may be variously changed for this purpose.

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

Therefore, a desired image can be reproduced clearly, with high precision, and with easy control.

[Brief explanation of the drawing]

The drawings show the implementation of the present invention, and FIG. 1 is a schematic diagram of an image forming apparatus, FIGS. 2A and 2B are enlarged sectional views of a part of a photosensitive screen, and FIGS. 3A and 3B. Fig. 3C is a process diagram of an image forming process using a photosensitive screen, Fig. 4 is a graph showing the amount of ions passing through the screen depending on the surface potential of the photosensitive screen, and Fig. 5 is an image obtained using the apparatus shown in Fig. 1. 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 each stage. Figure 8 is the process of forming a latent image using another method. FIG. In addition, in the reference numerals shown in the drawings, 1...........Photosensitive drum. 17・・・・・・・・・・・・・・・Photosensitive screen ~19 ・・・・
・・・・・・－・・・・・・Charged particle source required・・・・・・−
・・・・・・・・・Original image or manuscript 47・
・・・・・・・・・・・・・・・Dichroic mirror 56・・・・・・・・・・・・・・・Photosensitive layer 57・・・・・・・・・......It is an insulating layer. Agent Patent Attorney Hirodai Bezaka 1 @ Figure 3A m Figure 3B Figure 3C Figure 4 Figure 6 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, the negative electrostatic charge image formed on the image carrier is An image forming method characterized in that the first image information is a positive ion flow that passes through an ion flow control screen and has the same polarity as the electrostatic charge image as the second image information.