JPS62247379A - Method for forming digital image and its image formed body - Google Patents

Abstract

PURPOSE:To stabilize the formation of image by transferring the multi-colored image, which is formed by repeating a step of forming a color toner image by developing an electrostatic image with a non-magnetic developer composed of one component, and a rotation of the image forming body at a plural times, to a transfer material. CONSTITUTION:The electrostatic image is formed by writing a chrominance signal on the image forming body and the colored toner image corresponding to the chrominance signal is formed by developing the electrostatic image with the non- magnetic developer composed of one component. The multicolored image is transferred to the transfer material by forming the multi-color toner image on the image forming body by repeating a step of forming the color toner, and a rotation of an image forming body at a plural times followed by transferring the multicolor toner to the transfer material. The non-magnetic insulating toner which is the main component of the image forming developer is composed of, for example, particles which disperse a coloring matter, an electrostatic charge controlling agent and an offset-resisting agent in the insulating binder resin. The means particle size of the particle is 1-20mum, preferably, 3-15mum, and if necessary, the particle is granulated by heat treating the particles.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for forming a multicolor image, and particularly to a method for forming a multicolor image using a digital method and a developer used therein.

[Conventional technology]

In recent years, in the copying industry, there has been a demand for color copies with a larger amount of information in place of monochrome copies. The reason for this is that many of the documents being processed are multicolored graphic images, or achromatic documents have various colored marks and annotations, and it is necessary to identify the content based on the type of color. be. Analog multicolor recording devices such as the Xerox 6500 manufactured by Xerox Corporation, the NP-Color T manufactured by Canon Corporation, and the Ref-Color 5000 manufactured by Ricoh Corporation are known as devices for obtaining the color copies. The image forming process in such a multicolor recording device is as follows:
For example, after corona charging a photoreceptor, an original image is exposed through a green (G) filter, and developed with a magenta (M) developer.
The obtained magenta visible image is once transferred onto a copy paper. 6. Next, the photoreceptor is exposed through a blue (B) filter in the same manner as above, and after development with a yellow (Y) developer, the obtained yellow visible image is transferred. The image is transferred in accordance with the magenta image already transferred onto the transfer paper. Furthermore, the same process as above is repeated using a red (R) filter and cyan (C) developer, and the cyan visible image is transferred in line with the previous two images, and the resulting three-color image is fixed and finalized. Obtain a color copy image. That is, according to this method, the original image is subjected to BGR color separation, and each color is exposed to a photoreceptor separately to produce MMC (black if necessary).
After development, toner images are transferred one color at a time onto a transfer paper on a transfer drum to obtain a color copy image. However, in the above-mentioned analog type multicolor recording device, each color toner image is transferred each time an image is formed, so transfer misalignment occurs, resulting in poor resolution and color balance of the multicolor toner image after transfer. There's a problem. In addition, since the toner images of each color are superimposed, chromatic toner is mixed into the black image, and the pure black expression required for documents is lost.Also, it is difficult to achieve a highly accurate registration layer, so the sharpness of black line images etc. There are problems such as loss of information. By the way, in recent years, color CRT displays have been introduced for combiators! Ili
! With the spread of color image devices such as , Videotex terminal devices, techniques for obtaining color copies directly from such devices in a digital manner are being considered. In such a digital method, optical information obtained by optically scanning a document is color separated, and the obtained color separation information is subjected to photoelectric conversion and A/D@
After converting, the colors are separated according to a predetermined method, and based on the obtained color signals, multicolor printing is performed using various recording methods such as wire tod matrix recording method, ink jet recording method, thermal transfer recording method, electrostatic recording method, or electrophotographic method. An image is formed. According to such a digital method, black can be expressed as pure black by separating it from other chromatic colors without relying on color mixture. Generally, office color copies often include black line drawings, and it is always desired that the black line drawings be clear and free from color turbidity. Conventionally, the digital multicolor image forming method was proposed by Mr. Tajiri of Nippon Telegraph and Telephone Public Corporation and Yokosuka Electric Telegraph Research Institute at the 1981 General Meeting of the Institute of Electronics and Communication Engineers, for example.
Research report titled ``Multicolor reading method using contact image sensor'', JP-A-56-162755, JP-A-57-44825, and JP-A-56-144452.
There are publications etc. In the research report of the Institute of Electronics and Communication Engineers, there are seven green LEDs and a red LED on the side of the contact image sensor on the manuscript.
An array is arranged, and the LED array light of each color is projected onto a document, and the reflected light is received by an image sensor to obtain respective image signals. A technique has been disclosed in which, after A/D conversion, these image signals are subjected to comparison calculations in an arithmetic circuit to be separated into red and black color signals, and the signals are output to a photocopy type two-color recording device for recording. . Furthermore, in JP-A-56-162755, when a document with a black image and a cautionary note for the black image written in red and blue is used, the black image is first processed using an electrophotographic method using an ordinary photoreceptor. A black toner image is formed on a transfer paper using a digital copying method, and a color toner image is formed by copying only the part of the cautionary note using a digital copying method. I try to print color copies. In the above-mentioned digital copying, the reflected light from the original is color-separated using blue and red filters, and the resulting color separation information is photoelectrically converted via an image sensor to obtain image signals of each color. /D conversion conversion calculation process A red or blue recording signal from which the black component has been removed is obtained. After converting this recording signal into an optical signal, an electrostatic image is formed on the photoconductor by the optical signal, and then developed with a developer containing color toner to form a color toner image, which is then converted into the black toner image. is transferred onto a transfer paper carrying These image forming methods may be an inkjet method or an electrostatic recording method using a pin electrode. Furthermore, in Japanese Patent Application Laid-Open No. 57-44825, optical character information from a color original is color-separated by charging conversion means having different spectral characteristics to obtain two types of color separation information, which is then photoelectrically converted. The image signals of each color are obtained, and after ^/D conversion, the image signals of each color are calculated, the sum of the image signals of each color is calculated, and the brightness is determined from the sum signal. Separately, a logarithmic operation is performed on each of the color image signals, the hue is determined by a combination of the difference signal and the sum signal, and the signals from each of these determination means are output to the inkjet head to record a color image. ing. Furthermore, Japanese Patent Application Laid-Open No. 144452/1983 discloses an electrophotographic color printer. The image forming process by this printer involves uniformly charging the drum-shaped photoreceptor with a corona charger, then performing a first image exposure to form an electrostatic image, which is then charged with a first color. A developing device containing toner performs reversal development, followed by second image exposure, and non-contact reversal development and third image exposure using the second color toner.
(@ Exposure, with the third color toner, reversal development is repeated in a non-contact manner to form a multicolor toner image on the photoreceptor with one rotation of the photoreceptor, which is then transferred at once. This technology is considered to be applicable to, for example, a digital color printer that uses a laser beam modulated by a video signal for image exposure.In the above-mentioned known technology, there is a recording method that forms a multicolor image by digital copying. As described above, there are various methods such as inkjet, thermal transfer, and electrostatic recording, but the electrophotographic method is preferable from the points of view of recording speed, cost, recording accuracy, ILJ+ of maintenance management, etc.

[Problems to be Solved by the Invention] As described above, it is desirable to use a digital method and an electrophotographic method as a multicolor image forming method, and furthermore, a multicolor toner image is formed on an image forming body. However, it is preferable to transfer this to a transfer material all at once. However, it is preferable to arrange a plurality of image exposure systems and developing systems around the image forming body, as in the prior art described above, to form a multicolor toner image by one rotation of the image forming body. When forming an image forming apparatus, there are problems in that a large number of image forming devices are placed close to each other, resulting in a complex and expensive structure, resulting in a very large apparatus. Furthermore, in the known electrophotographic method, a two-component developer mainly consisting of carrier and toner is used. However, in general, a two-component developer has a complex composition, which increases the complexity and cost of production. Furthermore, it is difficult to maintain a constant developing performance by controlling variations in the component ratio of toner and carrier. Furthermore, in denotal image formation, the toner image is structured as an aggregate of dots, and toner and anti-Nfii are distributed around the outer periphery of the dots.
Fine carrier particles adhere to the image and reduce resolution. For the above reasons, a one-component developer is desired for developing digital images. Developers made of magnetic toner are known as such one-component developers, but magnetic toners have drawbacks such as undesirable turbidity in the hue of chromatic toner images when forming multicolor images. [Means for Solving the Problems] As a result of intensive studies, the present inventors discovered an image forming method suitable for digital image formation and a developer suitable for the image forming method, and completed the present invention. That's what I came to do.

[Purpose of the invention]

The purpose of the present invention is to ensure that when forming multicolor images using an electrostatic recording method, particularly a photoelectronic method, the developer composition is purified, there is no variation in developing performance, and stable image formation is always achieved. Another object of the present invention is to provide an image forming method and a developer which can provide a reproduced image with high resolution, excellent black image reproducibility, and clear hue.

[Structure of the invention]

The digital image forming method of the present invention achieves the above object by photoelectrically converting and digitally converting a plurality of color separation information obtained by color separation of optical information, and converting the obtained plurality of digital signals into a predetermined color separation map. The first step is to output a color signal based on color separation, convert the color signal into light and write the obtained optical signal on an image forming body to form an electrostatic image, and convert the electrostatic image into one component. a second step of developing with a non-magnetic developer to form a color toner image corresponding to the color signal, and repeating at least the second step and rotation of the image forming body a plurality of times to form a color toner image corresponding to the color signal; The method is characterized in that after forming a multicolor toner image on a forming body, the multicolor toner image is applied to a transfer material. Furthermore, the development array for forming a digital image according to the present invention performs photoelectric conversion and digital conversion of a plurality of color separation information obtained by color separation of optical information, and converts a predetermined color separation map from a plurality of obtained digital signals. The first step is to perform color separation and output a color signal based on the color signal, convert the color signal into light and write the obtained optical signal to an image forming body to form an electrostatic image, and transfer the electrostatic image to a developer. a twelfth step of developing a color toner image corresponding to the color signal; The developer used in the image forming method of forming a multicolor toner image thereon and then transferring the multicolor toner image to a transfer material is a one-component nonmagnetic developer.

[Effect] In addition to the effects described in the object of the invention, there are advantages such as no need for complicated control to stabilize development characteristics. In addition, when the developing method is non-contact development in which toner is transferred and developed, when multicolor image formation is preferred, the toner image developed first may be damaged by subsequent development, or the adjacent developing device may be damaged. This prevents problems such as contamination of the developer due to the contamination of toner of different colors, and provides multicolor images with clear hues and no color turbidity. Furthermore, when the development method is antipine development, the toner adheres only to the exposed area, so it is suitable for forming a dectal multicolor image in which dot-shaped toner images of each color are superimposed, and moreover, the toner does not adhere to the background area. Since it is difficult for the toner to adhere, there are advantages such as less toner consumption. [Invention! Explanation of R/&]

As shown in the image forming system block diagram of FIG. 1, the image forming method of the present invention includes an image processing section including a reading system and a writing system, and a recording section. In the reading system, optical information obtained by optically scanning a color original is separated into two colors using two types of filters, cyan (C) and red (R), a guichroic mirror, a guicroic prism, etc. Alternatively, color separation information can be obtained by separating the colors into three colors using a combination of three types of filters, blue (B), green (G), and red (R), or a guichroic mirror, a guichroic prism, etc. obtain. This color separation information is photoelectrically converted by a photoelectric conversion element such as a CCD image sensor to obtain an image signal, which is then A/D converted into a digital signal. These digital signals are processed in the arithmetic unit, and based on the results, the colors are separated and color signals are output. This color signal is for example if optical fiber tube (OFT>, liquid crystal (L)
CD), light emitting diode (LED), laser light, etc., preferably by a semiconductor laser device r)'! It is optically converted into an optical signal. This optical signal is, for example, Zr+O
Alternatively, an electrostatic image is formed by writing on an image forming body such as a photoconductor in which CdS or the like is dispersed in a pine resin, an organic photoconductor, a selenium-based photoconductor, or a 7 mol 77 silicon or amorphous dermanitum photoconductor. This electrostatic image can be developed, preferably in a non-contact manner, by a developing method such as a magnetic brush method, a seven-arbrush method, or a Balagu-Cloud method using a developer whose main component is a conductive color toner corresponding to the color signal. It is developed to form a color toner image. The non-magnetic toner includes a non-magnetic conductive toner and a non-magnetic insulating toner, but it is preferable to use a non-magnetic insulating toner suitable for non-contact development. It may also be used as a toner. The above-described steps including reading, writing, and one development are repeated for the number of color-separated signals to form a multicolor toner image in which toner images of each color are superimposed on the image forming body. This multicolor toner image is transferred by electrostatic transfer or the like, and fixed by heating or, in the case of capsule toner, by pressure. Note that the dectal image forming member method of the present invention is not necessarily limited to multicolor toner images; for example, a single toner image of black, blue, or red may be formed using the same pine of the image forming member,
This also includes the case of transferring and fixing to form a black, blue or red image. The non-magnetic insulating toner, which is the main component of the image-forming developer, contains, for example, an insulating binding resin containing a colorant, a charge control agent,
Consisting of particles containing dispersed anti-offset agents, etc., such particles are obtained by thoroughly mixing a composition containing the above-mentioned materials, adding a solvent, kneading, cooling, and classifying the particles to obtain an average particle size of 1 to 20 μl, preferably 3 μl.
~15μR, and can be obtained by spheroidizing by heating etc. if necessary. Examples of the buying resin used in the toner include addition polymerization resins such as styrene resin, styrene-acrylic resin, styrene-butadiene resin, and 7-acrylic resin, condensation polymerization resins such as polyester resin and polyamide resin, and epoxy resin. can be exemplified. Among these resins, monomers for forming addition polymerization type resins include styrenes such as styrene, 0-methylstyrene, r-methylstyrene, p-methylstyrene, and 3,4-nochlorostyrene; ethylene, propylene; Ethylenically unsaturated monoolefins such as , butylene, and isobutylene; Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; Vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and vinyl acetate. Class; methyl acrylate, methyl acrylate,
Aphryl n-butyl, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, lauryl acrylate, acrylic IIi! 2-ethylhexyl, methacrylic I! ! n-octyl, dodecyl methacrylate, lauryl methacrylate, methacrylic! ! ! 2-Ethylhexyl, stearyl methacrylate, methacrylic Il! ! Phenyl, trimethylaminoethyl methacrylate, trimethylaminoethyl methacrylate, tono-alpha-ren aliphatic monocarboxylic acid ester; acrylic acid or methacrylic acid derivatives such as 7-acrylonitrile, methacrylonitrile, acrylamide; vinyl Vinyl ethers such as methyl ether, vinyl ethyl ether, and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone: N-vinylvirol, N-vinylcarbazole, N-vinylindole, N-vinylpyrrolidone Examples of the N-vinyl compound include monoolefin monomers such as vinylnaphthalenes; monoolefin monomers such as propadiene, pugdiene, isoprene, chloroprene, pentanoene, and hexanoene. These monomers can be used alone or in combination of two or more. In addition, monomers for forming the condensation type resin include ethylene glycol, triethylene glycol, 1,3-
Examples include propylene glycol. In addition, colorants include black dyes or pigments such as dicarbon black, aniline black, lamp black, blue dyes or pigments such as niathalocyanine blue, methylene blue, Victoria blue, methyl violet, 7-niline blue, red dyes or pigments: rhodamine 6G lake, Examples include Watching Red, Rose Bengal, Rhodamine B1 Alizarin Lake, etc., and are contained in the toner in an amount of 0 to 20 wt%. In addition, examples of charge control agents include azo dyes, quinone dyes,
Anthraquinone dyes, anone dyes, etc. are used, and among these, for positive charging, 7ETSIE BALTZ HB
N (C,1No26150), nigrosine (C11,
No50415), Sugunchi-7 Schwarz BB (C,
I. No. 26150), Brilliant Spirit Spartz TN, and Zabon Yubarz. In addition, for positive charging, compounds having a quaternary ammonium group, a substituted or unsubstituted amide group, a vinylpyridine group, a vinylpiperazine group, a vinylpyridine group, a vinylveranonium group, etc.
Resin etc. are used. Also, for negative band use, Ceressie Walz (R)G. C,I,No1
．． 4645) There are dyes such as 7-zooyl black and 7-talocyanine blue. Compound resins having an external electric charge changing group such as a chlorine atom, a cyano group, a nitro group, etc. are used. Such a charge control agent is contained in the toner in an amount of 90 to 5 wt%. Further, when a toner image is fixed using a heat roll, an offset preventing agent can be contained on the roll to prevent part of the fixed toner from being offset. A typical example of anti-offset agent is one with a softening point of 100.
There are polyolefins (polyethylene, polypropylene, polybutylene, etc.) with a temperature of ~180°C, especially 130~160°C, and in addition, there are fatty acid metal salts, paraffin necks, higher alcohols, higher fatty acids, etc. In addition to producing a toner by mixing, using a solvent, kneading, and pulverizing as described above, for example, reactive monomers (such as vinyl monomers containing a polymerization initiator or polybasic acids and polyvalent furfurs) may be used. It may also be produced by dispersing a coloring agent and, if necessary, an anti-offset agent, etc. in a monomer (monomer), mixing and suspending the dispersion in water containing a dispersant such as polyvinyl alcohol, and polymerizing the mixture while heating and stirring. In addition, in order to fix the toner image by applying pressure without using a heat source, a capsule toner may be used. Such a capsule toner includes a core material having adhesiveness and a comparative material coated on the core material. Consisting of a hard capsule coating,
The capsule is broken by pressure fixing, and the core material inside the capsule is pushed out and fixed. As the core material, waxes, vegetable oils, oligomers, etc. are usually used, and as the capsule coating material, the above-mentioned toner binder resin, preferably a thermosetting resin, is used. The specific resistance of the non-magnetic insulating toner preferably used in the present invention is more than 10 Ωell, preferably 10
The specific resistance of the toner is determined by placing the particles in a perforator with a cross-sectional area of 0.5 cz, tapping them, and then applying a load of 1 kg/cm2 on the packed particles. 102~10'V/c between and the bottom electrode
It is determined by applying a voltage that produces an electric field of z, reading the current value or voltage conversion value flowing at that time, and performing a predetermined calculation. Next, develop using a overcasting developer.i
[li! For example, there is a cloud developing device in which a powder box-shaped developer is brought into contact with an image forming body for development. In this developing device, the developer is made into a powder box shape by air flow, ultrasonic vibration, mechanical vibration, electrical vibration, etc. and is supplied to the surface of the image forming body. In addition, 7-aplas development involves bringing 7-aplash containing developer into contact with the surface of the image forming body! There is an IC location. In this developing device, the developer is supplied from a hopper, or the developer M is supplied into the inside of the 7 appla cylinder, and is further supplied through the jet holes of a cylindrical member having a large number of jet holes to which the brush 77 is fixed. It is made to supply to the outer 7 abrasions through it. Furthermore, there is an apparatus in which a thin developer layer is formed on the surface of a cylindrical roll, and this developer layer is brought into contact with the surface of an image forming member for development. In these developing devices, various methods can be used to impart a charge to the developer, such as triboelectric charging, charge injection from a conductive electrode such as a blade, screen, or needle electrode, and charge attachment by corona discharge. . Representative examples of such a developing device will be explained with reference to FIGS. 1 to 3. Figure 2 is a sectional view of a 7-abrush developing device, and Figure 3 is a sectional view of a powder n developing device. Figure ly's4 is a sectional view of a non-contact developing device using screen electrodes. In Fig. 2, 1 is an image forming body, 2 is a hopper, 3 is a developer made of non-magnetic insulating toner, 4 is a 7-abrush developing roll rotating in the direction of the arrow, 5 is a 7T brush, and 6 is rotating in the direction of the arrow. The supply roller 7 rubs the developer with a coating blade to apply an electric charge. Further, 8 is a sealing member. In this developing device, when the developer in the hopper 2 is conveyed by the supply roll 6, it is rubbed by the applicator blade 7, is positively or negatively charged, and is quantitatively supplied to the upper brush roll 4. The developer supplied here is Den! ! The electrostatic image on the image forming member 1 is developed under the application of a bias supplied from the image forming member 9. Next, FIG. 3 shows an apparatus for developing a powder box with a developer made of non-magnetic insulating toner using an air flow, and 10 is a developing chamber;
11 is a hopper, 12 is a circulation conveyance path, 13 is a pump, 14
1 is a filter, 15 is a rotating shaft of the filter 14, 16 is a brush that cleans the developer attached to the filter when the filter 4 is rotated, and 17 is a bypass conveyance path. In the apparatus shown in FIG. 3, the developer in the hopper 11 is made into a powder box shape by an air flow sent by a pump 13, and this is brought into contact with the image forming body 1 for development. After the developer is collected and removed by the filter 14, the latter air flow is sent to powder box development via the pump 13, but a portion of the air flow enters the pump 13 through a bypass branched off from the air flow. The developer is passed through the conveyance path 17 and is subjected to powder development while still containing the developer (or including the developer obtained by rotating the filter 15 and scraping off the developer attached to the filter 15 with the brush 16). In this way, if the developer after development is used effectively, there are advantages such as the pump 13 is not contaminated by the developer after development.
The film is triboelectrically charged inside and developed under the application of bias from the electric fi 18. Figure 4 shows non-contact reversal development using flying developer made of non-magnetic insulating toner! il is shown. In I2I, 21 is a developing drum rotating in the direction of the arrow, 21 is its rotating shaft, and 22 is a guide 7M/! on the surface of the developing drum. to form a sleeve for transporting the developer. i3 is a power source that applies alternating current and direct current bias to the sleeve 22, 24 is a screen grid electrode, 25 is a power source that applies a direct current bias to the screen electrode 24, 26 is a hopper, and 27 is a blade. In the developing device shown in FIG. 4, the developer in the hopper 26 is conveyed by the sleeve 22, but the amount of conveyance is regulated by the blade 26 and the developer is charged by friction. The developer being conveyed is blown from the screen electrode to the image forming body by the action of AC and DC biases from the electrode 23, and develops in a puffer cloud manner without contact. Reversal development is performed by a DC bias of the same polarity as the electrostatic image applied from 25. The toner image on the image forming body developed as described above is usually produced by electrostatic processing using corona discharge. The image is transferred onto a recording paper using a full-length copying method, and fixed by pressure in the case of a heated roll or capsule toner, as shown in FIG. 5 or 6. tIS 5 and 6, 28 is a heat roll type fixing wfc device, 29 is a heat roll, 30 is a vinyl roll,
31 is a transfer 1 [by corona discharge]; 32 is a pressure fixing system; 33 and 34 are upper and lower rollers for pressure fixing; 35 and 36 are arms that hold these; 37 is a support that connects the arms; 38 and 39 are the rollers 33
Cleaner for cleaning F-ner stains and 11734, 40
is a ring passing through the arm, 41 is a ring inserted in the port 40, and 7
- A spring for moving the rollers 33 and 34 to press them against each other. Regarding the fixing device in Figure #45, please note! i
The toner image on the paper P is heated to around the melting point of the toner and fixed, and in the fixing 51cr11 in FIG. It is extruded and fixed. Further, in the pressure fixing, heating may be used in combination to ensure fixing, and the image forming body after transfer is made easy to clean by a pre-cleaning static eliminator, and then is further cleaned by a cleaning blade or an auxiliary cleaning brush. etc., and is used for the next image formation. Next, the image forming method having the step of developing with the non-magnetic component developer will be explained in more detail using a specific image forming apparatus. 7 to 10 are diagrams for explaining the image forming apparatus, and FIG. 7 shows the image forming f! Cross-sectional view showing the configuration of position c, f:
IS8 diagram is a partial side view showing the color separation and photoelectric conversion device,
tpJ9 is a cross-sectional view showing the laser beam optical system for writing, and FIG. 10 is a graph showing the spectral characteristics of the original scanning light gyroic mirror and the CCD color scanner. In FIG. 7, A is a reading unit, B is a writing unit, C is an image forming section, and D is a paper feeding section. In reading unit A, 90 is a drum-shaped image forming body, 51 is a platen glass, and the original 52 is placed on the second platen plus 51. The original 52 is placed on the slide rail 5
Fluorescent lamp 55 installed on the carrier horn 54 that moves above 3.
and 56. Movable mirror unit 58
A second mirror 59^ and a third mirror 59B are provided, which move on the slide rail 53, and in combination with the first mirror 5 provided on the carriage 54, image the optical image of the document 52 on the platen plus 51. Lens reading unit 7
Derived to page 70. The carriage 54 and movable mirror unit 58 are mounted on a stand. Pulleys 61, 62, 63, 64 . driven by a ping motor 60 via a wire 65. are driven in the same direction at speeds of 1 and 172\l, respectively. Standard white plates 66 and 67 are provided on the back side of both ends of the platen plus 51, and are configured so that a standard white signal can be obtained before the start of document reading scan and after the end of one scan. The lens reading unit 70 includes a lens 71 and a prism 7.
2. It is composed of a first reading board 74, a CCD 75 for red light, a second reading board 76, and a CCD 77 for cyan light. The original light image transmitted by the third mirror 59B through the first mirror 5F, the second mirror 59^, and the third mirror 59B is bundled by the lens 71, and is focused on the prism 72a constituting the prism 72.
and 72b are separated into a red light image and a cyan light image by a gicroic mirror 73 provided at the joint between fj
Red light CCD 7 provided on Si reading board 74
5 and the second reading board 76, respectively, are imaged on the light receiving surfaces of the CCD 77 for cyan light. The fluorescent lamps 55 and 56 are commercially available warm white fluorescent lamps used as a light source to prevent emphasis or deterioration of specific colors when reading color originals, and are powered by a 40 KHz high frequency power source to prevent flickering. In order to maintain a constant temperature of the tube wall or to promote ohm heating, it is kept warm by a heater using a POSISTOR. The CCD 75 for red light and C0D77 for cyan light
The image signal outputted from the color separation unit is subjected to signal processing in a color separation unit, which will be described later. In the color division #1 section, color signals separated according to the toner colors to be described later are outputted and inputted to the writing unit B. The writing unit) B is constructed as shown in FIG. 9, in which a laser beam generated by a semiconductor laser 81 is rotated up and scanned by a polygon mirror 82 rotated by a drive motor 80, passes through an Fθ lens 83, and is reflected by a reflection fi 87 on an optical path. The light is bent and projected onto the surface of the photoreceptor drum 90 to form a bright line 89 . 84 is an index sensor for detecting the start of beam scanning, and 85 and 86 are cylindrical lenses for negative tilt correction. 88a, 88b, 88c
forms a beam scanning optical path and a beam detection optical path with a reflecting mirror. When scanning is started, the beam is detected by the index sensor 84, and Iil adjustment of the beam using the first color signal is started. The modulated beam goes up to a charger 91 and scans over a photoreceptor drum 90 that has been uniformly charged in advance. A latent image corresponding to the first color is formed on the drum surface by the main scanning by the laser beam and the sub-scanning by the rotation of the photosensitive drum 90. This latent image is developed by a developing device 93 loaded with red toner, for example, and a toner image is formed on the drum surface (
(FIG. 5), the obtained toner image passes under a cleaning device 96 held on the drum surface and separated from the photosensitive drum surface, and enters the next copy cycle. The photosensitive drum 90 is charged again by the charger 91. Next, the second color signal output from the color separation section is input to writing unit B, and is written on the drum surface in the same manner as the first color signal to form an electrostatic image. Ru. The electrostatic image is developed by a developer 94 loaded with toner of a second color, for example blue. This blue toner image is formed to overlap the already formed red toner image. 95 is a developing device having black toner, and a signal path Fl! A black toner image is formed on the drum surface based on control signals generated by the drum. These developing devices 93, 94, and 95 are all 7-arbrush developing devices having the structure shown in FIG.
, 94a, 95a are 7T-brush developing rolls, 93b. Reference numerals 94b and 95b are supply rollers for supplying a fixed amount of developer to each of the developing rolls. Reference numeral 92 denotes a bias power supply that applies an AC bias and a DC bias to the developing roll to cause the non-magnetic insulating toner in the developing device to fly toward the image forming body 90 for non-contact and anti-conductive development. Here, the voltage and frequency of AC bias for non-contact development of conductive toner is 100V.
-5KV (P-P) and C/ 100Hz -20KHz
It is said that Also, the DC bias for reversal development is s? ! !
The voltage is set to have the same polarity as the image and close to the potential of the electrostatic image (for example, a voltage 50 to 200 V lower than the same voltage). The multicolor toner image developed in this way, in which a red toner image, for example, based on the first color signal, a blue toner image, based on the second color signal, and a black toner image based on the third signal are superimposed, is: After e':f1 is transferred by the transfer fixing device previously explained with reference to FIGS. 5 and 6, it is fixed using a heated roll or under pressure. In the image forming body device shown in FIG. 7, the multicolor toner image formed on the image forming body is transferred from a cassette 111 in a paper feeding section to a recording paper P fed at the same timing by a paper feeding device 112. , are electrically transferred by the eaves 100, separated by the separator 101, heated and fixed by the heat roll fixing device 102, and discharged. A cleaning device 87 comes into contact with the photosensitive drum 80 after the transfer, and performs cleaning with a blade 88 to remove unnecessary toner from the drum surface. The roller 89 of the cleaning device is used to remove a small amount of toner that is left behind between the drum surface and the blade when the blade 88 leaves the drum surface in preparation for the next exposure and development after cleaning. While rotating in the reverse or forward direction, the contact portion with the drum surface is rubbed to collect residual toner. The spectral characteristics of the light sources 55 and 56 that optically scan the original are shown in FIG.
), the vertical axis represents the relative intensity (%), and the spectral characteristics of the guichroic mirror 73 for pre-color separation are shown in Figure 10 (b).
The horizontal axis of the figure represents wavelength (nm), and the vertical line represents transmittance (%). Furthermore, the spectral characteristics of the CCD image sensor for photoelectric conversion are shown in FIG. 16(c), in which the horizontal axis represents wavelength (nm) and the vertical axis represents relative sensitivity (%). Note that the order of development by the developing units 93, 94, and 95 does not necessarily have to be in the order of this numerical sequence; for example, the developing unit RA 94 is activated by the first color signal to form a blue toner image, and then the second color signal is activated to form a blue toner image. A red toner image may be formed on the growing toner image by activating the developing VTRA 93 based on the color signal, and finally a black toner image may be formed by activating the developing device fi 95. Furthermore, the black toner image may be formed first. It may be formed. Next, the image formation Wtf! shown in FIG. The reading section ^ in I (see reading system in Figure 1) will be described in more detail. FIGS. 11 to 16 are diagrams explaining the reading section A, FIG. 11 is a color separation map, and ff112 is a ROM
Figures showing examples of tables, Figures 13, 14, and 16
The figure is a block diagram showing the reading process of the reading section A, and FIG. 15 shows the color separation map introduced into each color ROM table in the process. Read said! The reading process of IsA is the 13th rXJ,
Although shown in FIGS. 14 and 16, an example of a color separation means suitable for the present invention will be explained with reference to FIGS. 11 and 12 before explaining the color separation means. In the optical information obtained by optically scanning the color original 52 shown in FIG. 7 with the light sources 55 and 56, the red light component is transmitted through the guichroic mirror 73 and emitted from the prism 72m.
On the other hand, the cyan color light component is reflected and emitted from the prism 2b. The obtained color separation information is photoelectrically converted by the C0D75 for red and CCD7 for cyan color light, normalized so that the output value when optically scanning the standard white plates 66 and 67 is 1.0, and the red and A cyan image signal is obtained. These normalized red and cyan image signals are designated as VR and Vc, respectively, and are converted into, for example, 6-bit digital signals by a ^/D converter to facilitate subsequent arithmetic processing. Each color digital signal V thus obtained
A preferred coordinate system for color separation is constructed using , and Ve, and the created color separation map is used as a color separation means. ■In order to express halftones, information on the emissivity (reflection density) of the document, which corresponds to the brightness signal of the TV, is taken in. ■Colors M such as red and cyan (including hue and saturation) are used. ). From the above, it is preferable to use the following as the luminance signal information and color difference signal information. 117ffi (Fr! Information 11 (5 hits) ) = V * + V
c (1) V pt , V c (0≦V,≦1.0
, O≦Vc≦1.0) sum Vp+Ve (0≦V+
Ve≦Z, 0) it black level (=O), white level (=2
．． 0), and all colors exist in the range 0 to 2.0. Color difference signal information 11t (5 focus) = VR/ (VR+Vc) or Vc/(V*+Vc)
(2) In the case of achromatic color, the whole (VR+'/c
) The ratio of vR acid component (■) and c component contained in (1) is constant. Therefore, VFI/(VR+Vc)=0.5 Vc/<Vp+Vc)=0.5. On the other hand, in the case of chromatic colors, VR/(VR+
The value of Vc) or Vc/(VR+VC) is one measure of the hue and saturation of the original. That is, (1) red color 0.5<VJ(VR+Vc)≦1.00;, VC/
(VR+Vc)<0.5(2) Cyan color O≦VFI/(VR+Vc)<0.50.5<V
It can be expressed as c/(Vp+Vc)≦1.0. From this, the coordinate axes are VB+Ve and VR/(VR+
Vc) Another 1! By using a two-wheel toss coordinate system of Ve/('/to+Vc), it becomes possible to clearly separate chromatic colors (red colors, cyan colors) and achromatic colors. FIG. 14 is a diagram showing an example of a color separation map in which color gamut is divided according to the color separation method described above. In FIG. 6, the horizontal axis represents color difference signal information Ve/(V*+Ve), and the left vertical axis represents The brightness signal information VH + Vc is displayed in the vicinity of 0 color difference signal information = 0.5 (for example, a width of 0.70 to 0.30) and the area where the brightness signal information is small, where the right vertical pongee shows the reflection density due to achromatic color. There is coloring (the shaded area in the figure), with the color gamut smaller than 0.5 being red-ish colors, and the area larger than 0.5 being cyan-ish colors. In addition, since there is a correspondence relationship between the reflection density and the luminance signal information VH+Vc as shown in the figure, in the example shown in Figure 1, which is easily connected directly to the output value, the horizontal axis shows the color difference signal information Ve.
/(V*+ We), but vR/(VR+
The effect is the same even if Ve) is used. FIG. 12 shows an example of a ROM table in which the color separation map is set, and this has a capacity of 1024 words x 4 bits (assuming 1 word is 4 bits). is line address X (VR+
Vc) 5t' y column address X (Vc/Vp+ We
)51:' yt. This ROM table stores quantized hexadecimal density correspondence values (4-bit pattern) obtained from the reflection density of the original. Actual image processing! It! In the following, fjS1
The black color separation map in Figure 5(a), the cyan color separation map in Figure 15(b), and the red color separation layer map in Figure 15(e) are used, and these are the black ROM table and the cyan color separation map, respectively. It is set in the ROM table and red ROM table. Note that the red and cyan ROM tables are integrated into a red-cyan ROM table due to the nature of the color separation method and for the purpose of reducing the cost of the device. The luminance signal VR+Vc and the color difference signal Vc/(VR
+VC! ) as an address, the density corresponding values stored in the corresponding area are read out, and the read density corresponding values are binarized using the threshold specified for each color gamut by the color select signal, and the result is output data. . It should be noted that the output does not necessarily have to be a binary output, and may be a multi-value output. Figure 13 shows the reading device l! FIG. 3 is a configuration block diagram showing an example of a reading process in A. In the figure, 121
receives red color optical information f:trJl no CCD, 1
22 is a second CCD that receives cyan-based optical information;
31 amplifies the photoelectric conversion output of the first CCD 121 fJ' = 177) Increase @W, 132 Ha! l*2 CCD
This is an fjS2 amplifier that amplifies the 122-wavelength rL conversion output. The first and second CCDs 121 and 122 constitute a photoelectric conversion means 120, and fjSl and the second amplification 31
31 and 132 constitute the amplifying section 130. 141 is a first ^/D converter that converts the output of the first linear amplifier 131 into digital data at equal intervals; 142
is a second ^/D converter that similarly converts the output of the second linear amplifier 132, and the ^10 of these first and NS2
Converters 141 and 142 constitute a ^/D conversion WI 140. The number of bits used for the ^/D converters 141 and 142 is, for example, about 6 bits. 151 is the first ^/D1! An arithmetic processing circuit 152 receives the output of the converter W141 and the output of the second ^/D converter 142 and performs arithmetic processing to normalize them.
Digital ii of red and cyan colors with e-memory!
ii a Pt%1 memory in which νζ+Vc is calculated in advance based on the image signals vFI and Vc and the result is stored;
153 is a Vc/(V*10Vc) memory, and a second memory 153 in which the calculation result of Vc/(VH+Vc) is similarly stored in advance.
memory, and V11L+ corresponds to the input address.
Vc and 1/Vc/(% +Vc) (7) 411 are output. 161 is a third memory (red-cyan ROM table) which outputs chromatic color (red, cyan) data using the outputs of the first and second cargo notes 152 and 153 as addresses, +6
2 is a fourth memory (black ROM table) which outputs density-corresponding values of achromatic colors (black, gray, white) using the outputs of the first and second memories 152 and 153 as addresses. and the second memories 152 and 153 for color separation lI#
The information creating means 150 is constituted, and the memories 161 and 162 of the NS3 and PIS4 constitute the concentration information storing means 160. 123 is a tpJl buffer that temporarily stores the output of the memo 17161 of fjS3; 124 is the fourth memory 16;
This is a second buffer that temporarily stores the output of step 2. 1
25 is a color selection circuit that receives B (black/black), 8 (blue/blue), R (red/red) selection signals, and its output is applied to ml and second buffers 123 and 124. The output of either the first or PIS2 buffers 123, 124 becomes the output of the device shown in the figure.The numbers in the figure indicate the number of bits of the signal line.The operation of the device configured in this way will be explained. Then, the optical information of the color original is incident on the optical means shown in figure fJS8 and is decomposed into red and cyan components.The optical information of the decomposed red and cyan components are each CO
The light enters D 121 and 122 and is converted into an electrical signal. The converted image signals are each sent to an intensifier 131.1.
After entering 32 and being amplified to a predetermined level, it continues ^/
The data is converted into digital data by D converters 141 and 142. The arithmetic processing circuit 151 receives the red and cyan image data converted into digital data and normalizes it using the output value of the reference color (white). That is, the reference color Wl image data is set to 1.0, and the red and cyan H image data are normalized. The image data normalized in this way are respectively designated as V**Ve. These normalized image data VyHVc are already vR
The input address is input to the first memory and the second memory in which data of 10Vc (sum) and Vc/(VR ratio) are stored, and the corresponding sum and ratio data are output. Then, these ml and (/second memory 15
2. The output of 153 is the third and fourth memory 161, 16
2 as an address signal. Third. The fourth memories 161 and 162 output density corresponding values stored at addresses corresponding to the input addresses, and are held in buffers 123 and 124, respectively. On the other hand, the color select circuit 125 receives the B, B, and R signals and supplies a select signal to either one of the first and C/second buffers 123 and 124. For example, when the first buffer 123 is selected, When the second buffer 124 is selected, the density corresponding value of red or cyan is output, and when the second buffer 124 is selected, the density corresponding value of the black system (white, gray, black) is output. The output density-corresponding data is converted into binary data (or multi-value data in some cases) by a z-value converting circuit (not shown) using threshold values set for each color gamut. This binary data is input to the i-insertion section B, and written on the image forming body by a laser beam modulated by the data, thereby forming an electrostatic image. This electrostatic image is developed with a developer corresponding to the selected color signal to form a color toner image. The above operations are performed using CCD 121.
and 122 are repeated each time optical information is received. FIG. 14 shows a block configuration diagram in which the first memory (sum memory) and second memory (ratio memory) of the PtSi3 diagram are removed to simplify the process. That is, the denotalized red and cyan image data is normalized and the sum and ratio calculations are performed in the arithmetic processing circuit 151, and the obtained data is converted into a red-cyan image data for which a red-cyan color separation map has been set. The ROM table 161 is input to the black ROM table 162 in which the black color separation map is set, and the density corresponding values of each color stored at the address corresponding to the address are output and sent to the buffers 123 and 162, respectively.
It is held at 124. Thereafter, the held color density corresponding values are selectively outputted by the select signal, and after binarization, writing and recording on the image forming body are performed to form a multicolor image. In the above description, the color separation pine 7' shown in FIG.
(r) MA M niVc/(V*+Vc) It may be R/(vR+VC). or,
A similar effect for horizontal narrowing is (VR-VC)/(VR+Vc
) or by using (Vc-VR)/(VR+Vc) as a horizontally thin line. For example, horizontally (VR-V(ri/(VR
+ Vc), then (VFl-Vc)/(V*+Vc) = 0. For example, in the vicinity of ±0.3, it becomes an achromatic color〉O red-ish 0 cyan-based. Furthermore, in the above explanation, a red transmitting and cyan reflective type was used as the spectral characteristics of the guichroic mirror.
The present invention is not limited to this. Further, the color separation means is not limited to a guichroic mirror, but may be any device that can separate colors. For example, it may be a spectral filter or the like, and the color separation map need not be limited to the T-shaped one shown in FIG. 11, but may be of any kind. In the above description, the arithmetic processing circuit 151 is required, and the VF
The case where the I+Vc and (/V(!/(VFI+Vc) operation and the normalization operation of the output of the 1 or ^/D converter 141, 142 are performed is taken as an example. However, the present invention is not limited to this. Memo 17152.153 may be addressed immediately with the output of ^/D conversion N141, 142. In this case, memories 152, 153 correspond to the input address vFtt Vc, respectively.
In addition to using a ROM in which data having Vc, Vc/(V*+Ve) characteristics are written, the ^/D converter 141
．． Full scale 11 is set in advance inside the ^/D converter so that full scale (FS) data of 1.0 is output when the image data of the reference white plate 66 and 67 is input.
%, the arithmetic processing circuit 151 becomes unnecessary. The reading process of such a configuration is shown in FIG. In other words, the normalized digital signal from the ^/D converter 140 does not pass through an arithmetic circuit as shown in the PtSi2 figure, and is converted into the presum (VR+Vc) and the ratio (Vc/V*+Vc) Noah' -F fi 'Written Vp+Ve memory 15
2 (first memory) and 1/c/(VR+Vc)15
3 (second/mo 17-) 27 address is input, and data corresponding to the address is output. The output data is input into a red-cyan ROM table 161 (third memory) in which chromatic color density corresponding values are stored and a black ROM table 162 (fourth memory) in which black density corresponding values are stored, and is color-separated. Ru. The density data stored in the address corresponding to the input address is output from each of the ROM chips and pulls.
-F#L buffer 123 (buffer yl), buffer 12
4 (buffer 2). On the other hand, the color select circuit 125 receives the B, B, and R signals and provides a select signal to one of the first and second buffers 123 and 124. for example,! When the #1 buffer 123 is selected, data corresponding to red or cyan density is output, and when the second buffer 124 is selected, data corresponding to black density (white, gray, black) is output. be done. The output density correspondence data enters the comparison circuit 126. On the other hand, a threshold circuit 127 provides a threshold value to the comparison circuit 126.
The color selection signal and the density regulation signal from the color selection circuit 125 are inputted to the color selection circuit 125, and a threshold value corresponding to the color gamut and density value is outputted. The comparison circuit 126 converts the density-corresponding data into binary data (multi-value data in some cases) using the threshold value and density-corresponding value set for each color gamut. By using this binary data as input data to a printer, copying machine, etc., it can be output and displayed externally. It should be noted that in a normal analog copying machine, the ability of fluorescent markers for writing instruments to be expressed is limited by comprehensive characteristics such as the illumination system and the sensitivity of the photoreceptor, regardless of the user's will. However, within the coordinate system of the present invention, the areas where the red and cyan markers are located are known, so it is possible to erase the markers or, conversely, to output them. Here, the output value is, for example, an optical fiber W (OFT>
An electrostatic image is written on the image forming body through a liquid crystal display (LCD), laser, etc., especially a semiconductor laser, and is developed with a developer corresponding to the selected color signal to form a color toner image. Ru. The above process is repeated for the required number of color signals (2 toner images of each color are superimposed on the two forming bodies) to form a multicolor toner image.This multicolor toner image is usually electrostatically transferred to the recording paper. The image is transferred and fixed by heating or pressure, and the image forming body after the transfer is Q-cleaned using a blade and/or a fur brush, etc., in preparation for the next image formation.In the above explanation, the color original is optically scanned. The obtained optical TN information is separated into red and cyan, and the obtained color separation information is processed by a color separation means after digital conversion,
Red, blue, and black color signals are obtained, and writing is performed on the image forming body using these color signals, but the image forming method of the present invention is not limited to this. It can also be used as a signal, such as green, red, cyan, magenta,
It may also be possible to receive multicolor signals such as yellow. EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the embodiments of the present invention are not limited thereto. (Example 1) Using the image forming apparatus and its image forming process shown in FIG. 7 described above, and following the step described in FIG. A three-color multicolor image of black (B), blue (B), and red (R) was formed using the developer described above based on the image forming conditions shown in Tables 1 to #IJS. (Production method of developer) Production method of blue toner: Styrene-butyl methacrylate (75:25) copolymer resin 100 parts by weight tR79a cyanine 8!1f 1 part Paris 77st (
Orient Kagaku Co., Ltd. 91) 0.2 parts by weight Softening point 120°C polypropylene 2 parts 1 part The above materials were thoroughly mixed in a ball mill for 5 hours, then kneaded with two rolls at 150°C.Then, this was left to cool naturally and then milled in a cutter mill. The powder was coarsely pulverized using a pulverizer using a jet stream, further pulverized using a pulverizer using a jet stream, and further classified using a wind classifier to obtain a non-magnetic insulating blue toner having an average particle size of 10 μm. 0.5f for this toner
Hydrophobic silica in the "IT" portion was added externally to form a developer. Further, red toner and black toner were obtained in the same manner as the blue toner using Rogue Gummy B and carbon black as colorants. Table 1 Table 2 Table 3 Table 4 As in the case of Example 1, a color image with high resolution and excellent reproducibility of the black m image and clear hue was obtained. Manufacturing method of developer: Blue toner styrene 70 parts by weight n-butyl methacrylate) 30 parts by weight 1 part benzoyl peroxide
1 part by weight steel phtaxyanin 8
Parts by weight Low molecular weight 1 polyethylene "6A" 3 parts by weight (manufactured by Allied Chemical Co., Ltd.) 0.2 parts by weight or more of Bali 7 Foust (Orient Chemical Co.! 1) were dispersed using a sand grinder, and copper 7-lysyanine Create a well-dispersed polymeric composition,
The polymer composition was added to a three-lore 2 bath of volume F111 containing distilled water containing 0.6% by weight of polyvinyl alcohol, and after being suspended and dispersed, the gas phase was replaced with nitrogen gas, and the reaction system was heated to a temperature of Heat to 80℃ and keep at that temperature for 10 hours.
Polymerization was completed. Thereafter, it is cooled, dehydrated and washed repeatedly, and dried to obtain a coarse solid material, which is crushed to obtain a toner having an average particle size of about 10 microns. In addition, red toner and black toner Ni v. were obtained in the same manner as the blue toner except that Rhodamine B and carbon black were used as colorants.

【Effect of the invention】

As is clear from the above description, according to the image forming method and the developer used therefor of the present invention, the developer and the developing device are simplified, and stable image formation without variation in development characteristics is possible. Moreover, effects such as high resolution, excellent reproducibility of black images, and multicolor images with clear hues can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the multicolor image forming system, FIGS. 2 to 4 are cross-sectional views of various developing devices, and FIGS. Figure #6 is a cross-sectional view of the heat roll fixing device and pressure fixing device, Figure 7 is the image forming device according to the present invention, Figure @8 is a side view of the chromatic dispersion and photoelectric conversion device, and Figure 9 is the laser beam. Optical system, FIG. 10 is a graph showing the spectral characteristics of the light source for scanning the original, the guichroic mirror, and the COD image sensor, FIGS. 11 and 15 are color separation maps according to the present invention, and FIG. 12 is the RO
M table, FIG. 13, FIG. 14, and FIG. 16 are process diagrams showing the reading process. l, 90... Image forming body 4. 93a, 94a, 95a... 7 Arbrush developing roll 6. 93b, 94b, 95b... Supply roll 6.
18, 23.92...Bias power supply 7.27...Developer layer thickness and pressure regulating member 22...Sleeve 31.32, 100...Transfer device 52...Original 55.58-...Light source 57.59.59'...Reflection mirror 70...Lens reading unit 71...Lens 72.72a, 72b--Prism 73...Guiroi 7 mirror 75.77.121,122...CCD image Sensor 81...Semiconductor laser 82...Polygon mirror 83...Rθ lens, 91...Charger 87...Reflector 93
．． 94, 95...Developing device 96...Cleaning device 102...Fixing device a111...Paper feed cassette 112
...Paper feeding device ^...Reading section, B...
・Writing section, C... Image forming section D... Paper feeding section, 120... Photoelectric conversion section, 130... Amplifying section 1
40...^/D conversion section 150... Color separation information creation means 160... Density information storage means

Claims (6)

[Claims] (1) A plurality of color separation information obtained by color separation of optical information is subjected to photoelectric conversion and digital conversion, and color separation is performed based on a predetermined color separation map from the obtained plurality of digital signals, and a color signal is output. The first step is to electro-optically convert the color signal, write the obtained optical signal on an image forming body to form an electrostatic image, and develop the electrostatic image with a one-component non-magnetic developer to convert the color signal into the color signal. and a second step of forming a corresponding color toner image, and after repeating at least the second step and rotation of the image forming member a plurality of times to form a multicolor toner image on the image forming member. . A digital image forming method, comprising transferring the multicolor toner image to a transfer material. (2) Digital image formation according to claim 1, wherein the formation of the multicolor toner image is performed by repeating the first step, the second step, and the rotation of the image forming body a plurality of times. Method. (3) The digital image forming method according to claim 1, wherein the electrostatic image is developed in a non-contact manner using a reversal development method. (4) Photoelectrically converting and digitally converting a plurality of color separation information obtained by color separation of optical information, performing color separation based on a predetermined color separation map from the obtained plurality of digital signals, and outputting a color signal. The first step is to electro-optically convert the color signal, write the obtained optical signal on an image forming body to form an electrostatic image, and develop the electrostatic image with a developer to create a color toner corresponding to the color signal. a second step of forming an image, and after repeating at least the second step and rotation of the image forming body a plurality of times to form a multicolor toner image on the image forming body, the multicolor toner image is formed on the image forming body; A developer for digital image formation, characterized in that the developer used in an image forming method for transferring a toner image onto a transfer material is a one-component non-magnetic developer. (5) The digital image forming device according to claim 4, wherein the multicolor toner image is formed by repeating the first step, the second step, and the rotation of the image forming body a plurality of times. developer. (6) The digital image forming developer according to claim 4, wherein the electrostatic image is developed in a non-contact manner using a reversal development method.