JPS6175366A - Formation of polychromatic image - Google Patents

Abstract

PURPOSE:To easily obtain a polychromatic image through single-time exposure by exposing a photosensitive body equipped with filters which transmit visible light in a short-wavelength, an intermediate-wavelength, and the entire wavelength range to an image, executing an entire-surface exposure using light passed through only one kind of filter and a development, and repeating this process for other filters. CONSTITUTION:The photosensitive body consists of a conductive base 1, photoconductive layer 2, and a transparent insulating layer 3 including the filters which transmit visible light in the long-wavelength range (R), intermediate-wavelength ragne (G), and short-wavelength area (B). When the entire surface is charged electrostatically and positively by an electrostatic charging electrode 4, a positive charge is generated on the surface of the layer 3 and a negative charge is induced at the boundary between the layers 2 and 3. Image exposure is carried out while negative discharging is performed by an electrostatic charging electrode 5. Then, the charge in the layer 2 of a white image part W disappears. Then the entire surface is exposed to light L1 transmitted through only the R filter part to form a potential pattern on the surface of the R filter part. This is developed with cyan toner. Then, discharging is performed by the electrostatic charging electrode, and then entire-surface development using light transmitted through the G or R filter part and development are carried out repeatedly to form the polychromatic image.

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention provides a novel method for forming multicolor images using electrophotography. [Prior Art] Many methods and devices used therefor have been proposed in the past for the purpose of obtaining this, but they can generally be classified into the following types. One method is to repeatedly form a latent image using a photoreceptor according to the number of separated colors and develop it with color toner, overlapping the colors on the photoreceptor, or to transfer it to a transfer material each time it is developed. This is a method of layering colors. Another method uses a device having multiple photoconductors corresponding to the number of separated colors, and simultaneously exposes each photoconductor with a light image of each color.The latent image formed on each photoconductor is then colored with color toner. The image is developed and sequentially transferred onto a transfer material, and the colors are superimposed to obtain a multicolor image. However, these methods have various drawbacks as described below and have not yet achieved sufficient practicality. [Problems to be Solved by the Invention] That is, in the first method, multiple latent image formation and development processes are required. The major disadvantages are that it has to be repeated, it takes time to record images, and it is extremely difficult to improve its sophistication. In addition, the second method uses multiple photoreceptors in parallel, which is advantageous in terms of high speed, but requires multiple photoreceptors, an optical system, a developing means, etc., making the device complicated, large, and expensive. Practicality is low due to the price. In addition, both types have a major drawback in that it is difficult to align the image when image formation and transfer are repeated multiple times, and it is impossible to completely prevent color misregistration of the image. In order to fundamentally solve these problems, it is sufficient to record a multicolor image on a single photoreceptor with one exposure, but the reality is that such a system has not yet been developed. The present invention attempts to solve the above-mentioned problem by providing a method for forming multicolor images on the same photoreceptor with one exposure and a simple process. [Means for solving the problem] The above problem can be solved by using a filter that transmits the short wavelength range of visible light.
A photosensitive material comprising an insulating layer carrying a filter that transmits the intermediate wavelength range of visible light and a filter that transmits the long wavelength range of visible light, a photoconductive layer that has spectral sensitivity over at least the entire wavelength range of visible light, and a conductive substrate. (1) perform image exposure while applying a charge, and (2) apply any filter Fl among the three types of filters to the body.

[A first electrostatic image is formed by uniformly exposing the entire surface of the photoreceptor to the first light Ll, which contains a component that passes through the filter and does not substantially contain a component that passes through the other two types of filters. After at least developing with the first color toner, the surface potential of the photoreceptor is made uniform; A second electrostatic image is formed by uniformly exposing the entire surface of the photoreceptor with light (L2) that does not substantially contain components that pass through the filter F3. After forming and developing with the second color toner, the surface potential e of the photoreceptor is again made uniform, and (4) the entire surface of the photoreceptor is covered with the third light L3 containing the component 3 that passes through at least one of the remaining filters F3. The problem was solved by a multicolor image forming method in which a third electrostatic image is formed by exposure and this is developed with a third color toner. In the following, the term "free from components" refers to "substantially no components". [Operation] The process of forming a multicolor image by the method of the present invention described above will be explained below. The photoreceptor used in the present invention has a photoconductive layer on a conductive substrate, and fine color separation filters arranged in a striped or mosaic pattern on the photoconductive layer, that is, visible light in the long wavelength region, intermediate wavelength region, A transparent insulating layer having three types of filters each transmitting a short wavelength region is provided, and FIGS. 1A to 1D schematically show cross sections thereof. 1 in the diagram
is a conductive substrate, 2 is a photoconductive i! Layer 3 is an insulating layer and %R
%G%B is a filter section (hereinafter simply referred to as a three-color separation filter, or (referred to as R filter, G filter, and B filter). The conductive substrate 1 may be made of metals such as aluminum, iron, nickel, copper, or alloys thereof, and may have an appropriate shape and structure as necessary, such as a cylindrical shape or an endless belt shape. The photoconductive layer is sulfur, selenium, amorphous silicon or sulfur,
Photoconductors such as alloys containing selenium, tellurium, arsenic, antimony, etc., or inorganic photoconductors of oxides, iodides, sulfides, and selenides of metals such as zinc, aluminum, antimony, bismuth, cadmium, molybdenum, etc. material,
Organic photoconductive substances such as vinylcarbazole, anthracetate, trinitrofluorenone, polyvinylcarbazole, polyvinylanthracene, polyvinylpyrene, polystyrene, polyester, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, polycarbonate, etc. It can be composed of a material dispersed in an insulating binder resin such as acrylic resin, silicone resin, fluororesin, or epoxy resin. The insulation 11J3 can be made of a transparent insulating material, such as various polymers, resins, etc., and has a colored portion on its surface or inside thereof that functions as a color separation filter. Is the filter part made of an insulating material colored with a coloring agent such as a dye having the desired color as shown in Figure 1A? It is deposited in a predetermined pattern on the photoconductive layer by means such as printing, or by means such as printing or vapor deposition on a colorless insulating layer with a coloring agent uniformly formed on the photoconductive layer in advance as shown in FIG. 1B. It can be formed by adhering it in a predetermined pattern. Alternatively, the surface of the formed colored portion may be further covered with an insulating material to obtain a structure as shown in FIG. 1C. Also the first
As shown in the figure, a predetermined noiturn pattern may be applied to the photoconductive layer by direct printing or vapor deposition of a coloring agent, and the surface thereof may be covered with an insulating material. Furthermore, a photoreceptor having the same structure as the CSD shown in FIG. 1B can be constructed by attaching a film-like insulating material on which a filter portion is previously formed on the photoconductor. The shape and arrangement of the multiple types of minute color separation filters are not particularly limited, but may be linear as shown in FIG. Examples include those that are perpendicular to each other, those that are parallel to each other, those that are arranged so as to densely surround the drum-shaped photoreceptor in a spiral shape), or those that are arranged in a mosaic shape as shown in Fig. 2 B and C. It will be done. The size of each filter is
It is preferable that the color repetition width (1 in FIG. 2) is from 蜀 to 300 远. If the filter is undersized,
A strong edge effect appears during development, or it becomes easily influenced by adjacent areas of other colors, and it becomes difficult to create a filter if the width of one unit of the filter is equal to or smaller than the particle size of the toner particles. . Furthermore, if the size of the filter becomes too large, the resolution and color mixing properties of the image will decrease, resulting in deterioration of the image quality. FIG. 3 shows an example of the spectral transmittance curve of each filter, and shows λ. , λ1, and λ4 represent the short wavelength end transmission wavelengths of the blue, green, and red filters, respectively, and λ1, λ8, and λ represent the long wavelength end transmission wavelengths of each filter. Next, the process of forming a multicolor image in the method of the present invention will be explained with reference to FIG. FIG. 4 schematically shows a portion of a photoreceptor using an n-type semiconductor such as cadmium sulfide as a photoconductive layer, and the image forming process therein. In the figure, numerals 1 and 2 are a conductive substrate and a photoconductive layer, respectively, as in FIG. 1, and numeral 3 is an insulating layer containing a three-color separation filter. The graphs at the bottom of each of the figures above show the potential P on the surface of each part of the photoreceptor. First obi 1! ! When a positive corona discharge is applied to the entire surface by the L pole 4, a positive charge is generated on the surface of the insulating layer 3, and a corresponding negative charge is induced at the interface between the photoconductive layer 2 and the insulating layer N3, as shown in FIG. ). Next, image exposure is applied to the strip provided with the exposure slit while applying alternating current or negative discharge through the pole 5. In the figure, W is a white image area, and BK is a black image area. FIG. 4 shows the state P after image exposure. In the white image area, the image exposure light passes through each filter and the light guide i! Due to the conductivity of the layer 2, the charges in the photoconductive layer 2 are dissipated. On the other hand, in the black image area, each filter section is not exposed to light, so the negative charges on the photoconductive layer 2 remain as they are. Further, due to the action of the charger 5, positive charges are distributed on both sides of the insulating layer 3 and the conductive substrate 1 so that the surface potential of the photoreceptor becomes uniform. The state shown in FIG. 4 [2] is hereinafter referred to as a primary latent image. This is because the surface of the photoreceptor has the same potential not only in the white image area where the charge has been erased but also in the black image area where the charge remains, and therefore does not function as an electrostatic image. A full exposure is then provided with light that passes only through a specific filter. FIG. 4 [3] shows a case where the entire surface is exposed using the light LIE generated by the light source 6 and the filter F that transmits only the R filter section. The light LL is transmitted only through the R filter section, and the photoconductive layer under the R filter becomes conductive. As a result, the potential changes in areas where charges exist in the photoconductive layer 2, and does not change in areas where there are no charges. In this way, a potential pattern is formed on the surface of the R filter section. In other filter sections, the primary latent image is maintained as it is. The state P shown in FIG. 4 [3] is called a second-state latent image. When this is developed with cyan toner T (J: loaded developing device 7), a cyan toner image is formed on the IR: filter section (Fig. 4, 8)). (Fig. 4 [5]). This potential uniformization may be achieved by discharging negative charges using a sufrotron!j!I'rL device.Then, as the second light L2, for example, a G filter The entire surface is exposed using light that passes through ξ and does not pass through the R filter P, and a second latent image is formed on the G filter section in the same way.This is developed with magenta toner.Furthermore, the potential on the surface of the photoreceptor is increased. Uniform bales, B as third light L3
The entire surface is exposed using light that passes through the filter, and a second latent image is formed on the B filter portion and developed with yellow toner. As a result, a three-color image consisting of cyan, magenta, and yellow toners is formed on the insulating layer 2. According to the example in FIG. 4, toner of three colors adheres to the mosaic in the black image portion indicated by BK in the figure, forming a black image by the additive coloring method, and toner does not adhere to the portion W. When transferred to paper, etc., it becomes white. Regarding the dimensional color portion of the original image, although it is not shown in the figure, the density of the toner image formed on the B, G, and R color filter portions changes depending on the color selection of the original image, and the dimensional color by the additive coloring method. Needless to say, the image is reproduced. When peeled off, image exposure (#! 4 [ff1
By step (2)), the charges on the photoconductive layer in the R filter part of the mosaic filter are erased, and a second blown latent image is formed in the B filter part and the G filter part. Therefore R
Full-surface exposure with light L1 that passes only through the filter section (Fig. 4)
A secondary latent image is not formed even if the second latent image is carried out, and cyan toner does not adhere even after development. However, when the entire surface is exposed by light L2, a secondary latent image is formed on the G filter part, and magenta toner is removed by development. Further, a secondary latent image is formed on the B filter portion by full exposure with light L3, yellow toner is attached, and a red image consisting of magenta and yellow toner is reproduced. As is clear from the above explanation, the key point of the method of the present invention is to sequentially form a secondary latent image on each color filter portion by exposing the entire surface with light having a specific spectral distribution after image exposure. Therefore, the spectral components of the light used for full-surface exposure are used to change only the primary latent image formed on the target filter section into a secondary latent image, without affecting the primary latent images on other filter sections. It is necessary to choose appropriately. Most simply, light consisting of wavelength components that pass only through each color separation filter, λ4 to λ5 shown in FIG. For the filter section, light of λ0 to λ1 may be used. However, in practice, the bandwidth is so narrow that
In order to obtain a sufficient amount of colored light, various restrictions are imposed on the selection of filter materials, which is undesirable. The method of the present invention is intended to more easily achieve the same objective, and in the above process, once the image formation has been completed, the entire surface is exposed. This is based on the fact that there is no problem even when exposed to light. In other words, the light used for the first full-surface exposure must consist only of wavelength components that pass through one of the three color separation filters (F1);
For the second full exposure, use the second filter F2'E-
The filter FI' which has already completed image formation outside of the transmitted wavelength
f: May include a wavelength component that is transmitted. However, it must not contain any components that pass through the remaining third filter F3. Also, the light L used for the third, final full-surface exposure
3 includes a wavelength component that passes through the third filter F3, other restrictions are unnecessary, and white light, which can be easily obtained, is most preferable in practice. Specifically, for example, first, red light consisting of long wavelength components of wavelength 24 or more is applied to the three types of filters shown in Fig. 3.
A second latent image is formed on the R filter area and developed in cyan, and then yellow light consisting of components with wavelengths of 22 or more that passes through filter F2 and filter F1 is used as L2 for second exposure. The entire surface is exposed to light to form a second latent image on the G filter section, developed magenta, and then the entire surface is exposed with white light to form a second latent image on the B filter section. By forming the image and developing it with yellow toner, the desired multicolor image can be obtained. Figure 6 shows the spectral distribution L1 of the entire surface exposure light in this case.
, L2, L3 and the spectral transmittance B, G, R of the color separation filter
This shows the relationship between Furthermore, the order of color image formation and the components of the light used therein are not limited to the above example, but may be of any order as long as it satisfies the above conditions. Preferred examples are shown in Table 1. As the light source for full-surface exposure, it is preferable to use a known white light source such as a tungsten lamp or a fluorescent lamp, or one provided with a filter that transmits the required wavelength light P. When a filter is used as a light source for full-surface exposure, it is advantageous to use a red or yellow filter, since it is easy to obtain a filter with a sharp rise in spectral distribution and high transmittance. Practically speaking, it is most preferable to take Further, if the spectral sensitivity of the light guide 'f& layer extends beyond the visible range of ultraviolet or infrared radiation, ultraviolet light or infrared light may be used for the entire surface exposure. In this process, the entire surface exposure light Ll (or L2
) If the amount of light reaching the photoconductive layer is not sufficient, the charge on the photoconductive layer may not be completely erased. In this case, in the subsequent full-surface exposure step, the remaining charge disappears, the surface potential of that area changes, and there is a risk that toner will adhere and color becomes cloudy. To prevent this, charge remaining in the photoconductive layer before the next full exposure? It is desirable to irradiate light for erasing. It is desirable that this light has the same or similar spectral characteristics as the entire surface exposure light Ll (or L2). Also, this exposure
It is preferable to carry out the charging simultaneously with the charging to uniformize the surface potential P of the photoreceptor by the charger 8. The developer used in the present invention can be used as either a so-called partial developer using a magnetic toner or a so-called two-component developer containing a mixture of toner and a magnetic carrier such as iron powder. For development, a method of directly rubbing with a magnetic brush may be used, but in order to avoid damage to the formed toner image, especially after the second development, a developing method in which the developer layer does not come into contact with the photoreceptor surface. A developing method in which the gap with the body surface is set larger than the developer layer on the developing sleeve (provided there is no potential difference between the two), for example, U.S. Pat. -1
Publication No. 8656, Japanese Patent Application No. 58-57446, Japanese Patent Application No. 1983
Particularly preferred is the method 'f:F@' as described in the specifications of Japanese Patent Application No. 8-238295 and Japanese Patent Application No. 58-238296. Are these methods non-magnetic toners that allow you to freely choose the coloring? Using a one-component or two-component developer with an electrostatic image support and developer layer, an alternating electric field is created in the development zone. Development is performed without contact. The color toner used for development is prepared using known techniques, consisting of known binding resins, organic and inorganic pigments, dyes, chromatic and achromatic colorants, and various magnetic additives, which are commonly used in toners. The prepared toner for developing electrostatic images can be used, and the carrier can be iron powder, ferrite powder, which are usually used for electrostatic images, resin-coated materials thereof, or materials with magnetic material dispersed in resin, etc. Various known carriers such as magnetic carriers can be used. In addition, the applicant filed the patent application No. 58-24966 earlier.
The one-image method described in the specifications of No. 9 and No. 240066 may be used. The method of the present invention will be specifically explained below with reference to Examples. [Embodiment 1] FIG. 5 is a schematic diagram of an image forming section of a color copying machine suitable for carrying out the method of the present invention. In the figure, reference numeral 11 denotes a photosensitive drum having the configuration shown in FIG. Insulating layer containing? It was established. The spectral transmittance of each of the B, G, and R filters included in the insulating layer on the surface of the photosensitive drum is shown in Figure 3, and the transmission wavelength range of each filter is B λo < 360 nm λ, = 530
nmG At = 460 nm λs =
650 nmRλ4 = 570 ntn λa
) 750 nm. During the copying operation, the photosensitive drum 11 is rotated in the direction of arrow a, and the entire surface of the photosensitive drum 11 is given a positive charge by the shuttle 12.
j! equipped with the next exposure slit! ! [Negative belt than 13!
(which may be an alternating current), the exposure optical system (consisting of mirrors M1 to M4, lenses L, lamps Lp, etc.) applies image exposure to the scanned document, and the surface of the document is exposed to the primary latent light. An image is formed. The entire surface is then exposed to light L1 from the light source 14 that has passed through the filter F1. The spectral distribution of the light L1 is as shown in FIG. 6, and it has a component of 630 nm or more, and only passes through the R filter section on the photosensitive drum 11, while the components that pass through the B filter section and the G filter section are Not included. The primary latent image on the R filter portion on the photosensitive drum is converted into a static latent image (secondary latent image) by full exposure, and is developed by the developing device 15A loaded with a developer containing cyan toner to form a cyan image. However, the primary latent images under the G and B filters do not change. The drum 1 which has undergone cyan development is subjected to a negative discharge from the electrode 16, and is irradiated with light from the light source 17 that has passed through the filter F 11, and the potential on the surface is made uniform, and the light guide 1 below the R filter The charge on the layer is erased. Filter F11 has the same spectral transmittance as filter FI. After that, the light 1fIi! passed through the filter F2!
The entire surface is exposed to light L2 from 17. The spectral characteristics of the light L2 are as shown in Figure 3, and the spectral characteristics are 520nyn.
This is yellow light that passes through the above light, and passes through the G filter section and the R filter section on the photosensitive drum 11, but does not include a component that passes through the B filter section. Therefore, the primary latent image on the photosensitive drum G filter portion becomes an electrostatic image. By developing with the developing device 15B loaded with developer P containing a magenta toner image, a magenta image is formed to be superimposed on the previously obtained cyan image. Further, the photosensitive drum 11 is negatively discharged by the electrode 18 and is irradiated with the light from the light source 19 that has passed through the filter F217i, which has the same spectral transmission characteristics as the filter F2, and as a result, the surface potential is made uniform. The charge on the photoconductive layer under the G filter is dissipated. Next, the entire surface of the photosensitive drum 11 is illuminated with white light from the light ri 19, and the first latent image in the B filter section becomes static 1! The resulting image is developed by a developing device 15C loaded with a developer containing yellow toner, and a yellow toner image is formed superimposed on the cyan and magenta toner images that have already been formed, completing the formation of a full-color image. The obtained color toner image is electrostatically transferred to a transfer paper fed by a paper feeding device (the feeding path is indicated by a chain line p) after being charged again with a charging electrode, and heated by a fixing device 21. It is fixed and becomes a completed copy, which is then ejected from the machine. In the figure, the transfer electrode path for transferring the toner image is a separation electrode for separating the transfer paper from the photosensitive drum surface. After the transfer, the photosensitive drum 11 is neutralized under light irradiation by a removing electrode equipped with a light source, and the cleaning blade 5
After the toner remaining on the surface is removed, it is reused. Parameters regarding development and other matters in this example were as shown in Table 2. Further, a halogen lamp was used as a light source for each exposure. When a multicolor image copying test was carried out under the conditions shown in Table 2, it was possible to obtain a copied image with good color reproduction and no color turbidity or color shift. [Example 2] Filters F1, Fi1, F2, F2 of the device of Example 1
1 were changed to filters F3, F3], F1, and Fll, respectively. As a result, the spectral distributions of the first whole surface exposure light L1 and the second whole surface exposure light L2 become as shown in FIG. In addition,
The filters F3 and F31 have the same spectral transmittance characteristics. Further, developing devices 15A and 15B. 15 C was loaded with yellow, cyan, and magenta developers respectively, and a multicolor image copying test was conducted under the same conditions as in Example 1. As in Example 1, a good copied image 'JE: I was able to do PJ. The present invention has been described in detail with reference to embodiments of a color copying machine using an n-type photoconductive photoreceptor. It is also possible to apply this method by reversing the polarity of the charging, and it can be applied not only to color copying machines but also to a wide range of applications such as multicolor image recording devices and color photo printers. [Effects of the Invention] According to the method of the present invention, a high-quality multicolor image with no color shift can be obtained by a simple process of one exposure using an apparatus using easily manufactured or available filters.

[Brief explanation of the drawing]

1A-D are cross-sectional views of the photoreceptor used in the method of the present invention, FIGS. 2A-C are the shapes of the three-color separation filters on the photoreceptor, and FIG. 3 is the three-color separation filters B, G, 4 [1] to [5] are explanatory diagrams of the image forming process in the present invention, FIG. 5 is a schematic diagram of a color copying machine suitable for carrying out the method of the present invention, and FIG. 7 are spectral transmittance curves of color separation filter section B, GSR, and full-surface exposure filters F1, F2, and F3 used in Examples 1 and 2, respectively. 1... Conductive substrate 2... Photoconductive layer 3...
Insulating layer 11... Photosensitive drum 4.12...
・Charging electrode 5.13...Charging electrode 6.14 with an exposure slit.
17.19... Light source 8.16.18... Electrode for charge uniformity 7.15
A, 15B, 15e...Developer F, F1, Fi1, F
2, F21...filter agent patent attorney No 1)
Yoshichika Figure 2 Figure 3 j Yunaga (ji) 13+' (lrBflBR F3 に(=ry R@BR Figure 5 Figure 6 + o6 "Ugdo" Figure 7 Shidago Procedures Amendment Book 1982) October 258 2. Name of the invention Multi-color image forming method 3. Relationship with the person who made the supplement 2 Patent applicant address 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Name (1271 Konishiroku Photo Industry) Konishiroku Photo Industry Co., Ltd. 6, "Detailed explanation of the invention" column 7 of the specification subject to amendment, Contents of the amendment (1) Specification 8, page S, line 18, "10 Ω or more" Amended to "1-Ω tan or more." Procedural amendment March 29, 1985 Patent application No. 198127 of 1988 2 Title of the invention Multicolor image forming method 3 Relationship with the case if the amendment is made Patent applicant's address Konishiroku Photo Industry Co., Ltd., 1-26-2, Nishi!frjuku, Shinjuku-ku, Tokyo, Sakura-machi Koko, Hino-shi, Tokyo (Telephone: 0425-83-152)
1) Patent Section 5, the entire text of the specification to be amended and drawing 6, each of the amendments (1) The entire text of the specification shall be amended in a separate document. (2) Add Figures 8, 9, and 10. Amendment Statement 1, Name of the Invention Multicolor Image Forming Method 2, Claims (II) Filter that transmits short wavelength range of visible light, filter that transmits intermediate wavelength range of visible light, and long wavelength of visible light Image exposure was performed while applying electric charges to an insulating layer including a filter that transmits the light, a photoreceptor layer that has spectral sensitivity over at least the entire wavelength range, and a photoreceptor such as a conductive substrate. After that, 1i - sudden 1st character (
A first electrostatic image is formed by uniformly exposing the entire surface of the photoreceptor with first light (L1) that contains a component that passes through F1) and does not substantially contain components that pass through the other two types of filters. After forming and developing this with a first color toner, the potential on the surface of the photoreceptor is made uniform, and the remaining one contains at least a component that passes through another filter (F2) different from the filter F1. The entire surface of the photoreceptor is uniformly exposed to the second light (L2), which does not substantially contain components that pass through the two filters (F3), to form a second electrostatic image, and the second color toner is used to form a second electrostatic image. After development, the potential on the surface of the photoreceptor is made uniform again, and the entire surface of the photoreceptor is exposed to light with tertiary element (L3), which contains a component that passes through the filter F3, which is at least a type of residual electrostatic material. A multicolor image forming method that forms an image and develops it with a third color toner. (2) The multicolor image forming method according to claim 1, wherein the third light L3 is white light. (3) The filters F1, F2, and F3 are filters that transmit visible light in the long wavelength range, intermediate wavelength range, and short wavelength range, respectively, and the light L1 and L2 that are used for full-surface exposure are transmitted through the filter F1, respectively. Red light, filter F3
3. The multicolor image forming method according to claim 2, wherein the yellow light does not pass through the yellow light. 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a novel image forming method for forming multicolor images using electrophotography. [Prior Art] Many methods and devices useful for the method have been proposed in the past for the purpose of obtaining multicolor MTV using electrophotography, but they are generally classified into the following types. be able to. One of them is 4i!, which uses a U photoconductor to separate colors and repeatedly forms an IS image and develops with color toner on the photoconductor. This is done by transferring the color onto a transfer material and then overlapping the colors on the transfer material. if
cAnother method is to use a device having multiple photoreceptors according to the number of separated colors, expose each color light image to each photoreceptor at Ioi, and convert the l\iF image formed on each photoreceptor. A multicolor image is obtained by developing with color toner and sequentially transferring the colors onto a transfer material. However, these methods have various drawbacks as described below, and have not yet reached the point of practical use. [Problems to be solved by the invention] That is, in the first method, a plurality of m-image formation and development processes must be repeated, time is imitated in image recording, and the sophistication thereof is extremely difficult. This is a major drawback. In addition, in the second method, multi-ridged photoreceptors are used in parallel, so there is a problem with high speed. has become more complex and larger;
Since it is a market price, it is difficult to see how practical it is. Also, with the field method, multiple I[! Il image formation, it is difficult to align images that are repeatedly transferred, and it is not possible to prevent image misalignment. In order to do this, it would be possible to record a multicolor image on a single photoreceptor in one exposure, but the reality is that such a system has not yet been developed. The present invention seeks to solve the above-mentioned problems by providing a method for forming multicolor images on the same photoreceptor through a single exposure and a simple process. [Means for solving the problem] The problem of the previous ≧ r2 is to pass through a filter that transmits the short wavelength range of -raJ congratulatory light, a filter that transmits the intermediate wavelength range of visible light, and a filter that transmits the visible light projection mounting. Insulation carrying filter)
ψ and M
To the photoreceptor consisting of the photoconductive j- and the spring dragon body, image processing is performed while applying (1 + mJ), (2)
Any filter F' 1 among the 381 filters
It passes through the filter of the other two wolves; #
b1, the entire surface of the photoreceptor is uniformly exposed to the first light L1 that is not substantially enriched in the amount of light L1 to form a first electrostatic image, which is developed with a first color toner, and then exposed to light. (3) Next, the light contains at least a component that passes through another filter F2 different from the filter F1, and substantially does not contain a component that passes through the remaining filter F3. In (L2), the entire surface of the photoconductor is uniformly exposed to light to form a second electrostatic image and developed with a second color toner, and then the surface potential of the photoconductor is made uniform again. Forming a multicolor image by exposing the entire surface of the photoreceptor with tertiary element L3 containing at least a component that passes through the remaining uniform filter F3 to form a third electrostatic image, and developing this with a third color toner. solved by the method. In the following, the word "not containing acid content" means "not containing any acid content". The photoreceptor used in the present invention has a layer formed on a conductive substrate, on which fine color separation filters arranged in a spiral or mosaic pattern are used, i.e., in the long wavelength region of visible light, intermediate It is equipped with a transparent insulating layer that carries the entire 3aI filter that transmits the wavelength range and short wavelength range, respectively, and FIGS. 1A to 1D schematically show the cross section of the filter. 1 is a specialized substrate, 2 is an original 4'lkL layer, 3 is an insulating layer 9, and RlGXB are long wavelength ranges of visible light (and).
, a filter section that transmits the intermediate wavelength range (green) and the short wavelength range (evening) (hereinafter simply referred to as a three-color separation filter, or R filter,
(referred to as G filter and B filter). The conductive substrate 1 may be made of gold #4 such as aluminum, iron, nickel, copper, etc. or an alloy thereof, and may have an appropriate shape and structure, such as a cylindrical shape or an endless belt shape, depending on the needs of the woman. The light guide layer is made of a photoconductor such as sulfur, selenium, amorphous silicon or an alloy containing sulfur, selenium, tellurium, arsenic, antimony, etc., or a metal such as zinc, aluminum, antimony, bismuth, cadmium, molybdenum, etc. Inorganic photoconductivity of oxides, iodides, sulfides, and selenides! 12!7, organic photoconductive substances such as vinylcarbazole, anthracenephthalocyanine, trinitrofluorenone, polyvinylcarbazole, polyvinylanthracene, polyvinylpyrene, etc. are combined with polyethylene, polyester, polyvinyl pyrene, polystyrene, polyvinyl chloride, polyvinyl acetate, It can be made of a material dispersed in an insulating binder resin such as polycarbonate, acrylic resin, silicone resin, fluororesin, or epoxy resin. The insulating layer 3 is made of a transparent insulating material, such as Meishin's polymer.
It can be made of resin or the like, and has a colored portion on its surface or inside that can be used as a color separation filter. As shown in FIG. 1A, the filter section is made of an insulating material colored by adding a coloring agent such as a dye having a desired color. A predetermined pattern is applied to the photoconductive layer by means such as printing, and then a coloring agent is printed or vapor-deposited on a colorless layer that has been uniformly formed on the photoconductive layer in advance, as shown in FIG. 1B. It is possible to form the adhesive awn in a predetermined pattern by means such as the above. Alternatively, the surface of the formed colored portion may be covered with an insulating material to form a structure as shown in FIG. 1C. Also the first
As shown in the figure, a predetermined pattern may be applied to the photoconductive layer by applying a coloring agent to the photoconductive layer by surface printing, vapor deposition, or the like, and the surface thereof may be further covered with an insulating material. Alternatively, a photoreceptor having the same structure as that shown in FIGS. 1B, C, and D can be constructed by attaching a film-like insulating material on which a filter portion is previously formed on the photoconductor. The shape and arrangement of the fine color separation filters made of gradient glaze are not particularly limited, but the shape and arrangement of the minute color separation filters made of gradient glaze are not particularly limited. A mosaic like the one shown in Figure 2 B and C is a mosaic that is closely arranged in a spiral shape around a drum-shaped photoreceptor. As an example, the size of the filter configured in the form of ``J''L0 is 3 as the color repetition rl] (Fig. 2 A t).
It is best to set it to 0 to 300 Ha. If the size of the filter is too small, there will be a strong edge effect at the boundary, it will be susceptible to the shadows of other adjacent color areas, and the filter's size will be affected by toner particles. If the diameter is the same or smaller, it will be difficult to create. Furthermore, if the size of the filter becomes too large, the resolution and color mixing properties of the image will decrease, resulting in poor image quality. Figure 3 shows an example of the spectral transmittance curve of each filter, and is λ. , A2, and A4 indicate the short and long side transmission terminal wavelengths of the blue, green, and red filters, respectively, and A1, A3, and λS indicate the transmission terminal wavelengths on the long wavelength side of each filter. Next, the process of forming a multicolor image in the method of the present invention will be explained with reference to FIG. FIG. 4 schematically shows a part of a photoreceptor using an n-type semiconducting material such as cadmium sulfide with light 4 as a layer, and the image forming process therein. In the figure, numerals 1 and 2 are a conductive substrate and a light guide, respectively, as in FIG. 1, and numeral 3 is an insulating layer containing a three-color separation filter. Further, the graph at the bottom of each figure shows the potential of the bottom surface of each part of the photoreceptor. First, when a positive corona discharge is applied to the entire surface by charging 44, a positive charge is generated on the surface of the insulating J@3, and correspondingly, a photoconductor J-2 and an absolute Pt! 1. Negative charges are induced at the interface of the layer 3, resulting in the state shown in FIG. 4 [1]. Next, image exposure is applied while applying alternating current or negative discharge using a charging electrode 5 equipped with an exposure slit. In the figure, W is a white image portion, and BK is a black image portion. FIG. 4 [2] shows the state after image exposure. In the white image area, the image exposure light passes through each filter and makes the photoconductive layer 2 below it conductive, so that the charge in the photoconductive layer 2 disappears. On the other hand, in the black image area, each filter area is not exposed to light, so the negative charge on the photoconductive layer 2 is reduced to ! I will remain. Further, due to the action of the charger 5, positive charges are distributed on both sides of the insulating layer 3 and the conductive substrate 1 so that the surface potential of the photoreceptor becomes uniform. The state shown in Figure 4 [2] is hereinafter referred to as the primary latent image.
This is because the white image part has been erased! Since the surface of the photoreceptor has the same potential in the black image area where the load remains, it does not function as a cage, and is fully exposed to light that passes only through a specific filter. FIG. 4 [3] shows the case where the entire surface is exposed using the light L1 produced by the light source 6 and the filter P' which passes only through the R filter section. Light L1 is transmitted only through R7 (ruter section), and the photoconductive layer under the R filter becomes conductive.As a result, the potential changes in the area where photoconductor 1-2 had charge, and the charge The potential does not change in the area without .In this way, a potential pattern is formed on the surface of the R filter section.The primary latent image is maintained as it is in other filter sections.As shown in Figure 4 [3] This state is hereinafter referred to as a second latent image.This state is developed by the imager 7 loaded with cyan toner TC.
'': A cyan toner image is formed on the tR filter section (Fig. 4 [4]). Next, the potential on the surface of the photoreceptor is made uniform by the father flow discharge by tk8 (Fig. 4 [5]). The potential may be made uniform by discharging a negative charge using a scorotron discharger.Then, the second light L2 is transmitted through, for example, a G filter.
The entire surface is exposed using light that does not pass through the R filter, and a second latent image is formed on the G filter portion in a regular manner. It is developed with magenta toner. Furthermore, after making the potential on the surface of the photoreceptor uniform, the entire surface is exposed using light that can pass through the B filter as the third light L3, and a second latent image is formed on the B filter section, and the yellow toner is used to form a second latent image on the B filter. develop. As a result, a three-color image consisting of cyan, magenta, and yellow toners is formed on the insulating layer 2. According to the example in FIG. 4, toner of three colors adheres to the mosaic in the black image portion indicated by BK in the figure, forming a black image by the additive coloring method, and in the WLv portion, no toner adheres to the paper. If you transfer it to something like this, it will become white. Although the chromatic color mK of the original image is not shown in the figure, the density of the toner image formed on the B, G, and R color filters changes depending on the color of the original image, and a chromatic color image is reproduced by the additive color method. Needless to say. For example, in the red part of the original image, the charge of the photovoltaic layer in the R filter part of the mosaic filter is erased by image exposure (the process shown in Figure 4 [2]), and the charge in the photovoltaic layer in the B filter part and the G filter part is erased. Therefore, even if the entire surface is exposed with the light L1 that passes only through the R filter section (the process shown in Fig. 4 [3]), a second latent image will not be formed, and the developer will not be able to use the cyan toner. However, when the entire surface is exposed to light L2, a secondary latent image is formed on the G filter section, and magenta toner adheres to it through development.Furthermore, when the entire surface is exposed to light L3, a secondary latent image is formed on the filter section of B7 (yellow). The toner adheres, and a red image consisting of magenta and yellow toner is reproduced.As the above explanation makes clear, the key point of the method of the present invention is to expose the entire surface with light having a specific spectral distribution after image exposure. Therefore, the spectral components of the light used for full-surface exposure are formed on the target filter section, and only the primary latent image is formed. It is necessary to change it to a second-order m-image and to select it appropriately so as not to affect the second-order images of other filter sections.To put it simply, the light consists of wavelength components that only pass through each color separation filter. , that is, λ4 to λS shown in FIG. 3 to make the latent image visible in the F filter section, and λ2 for the G filter section.
For the B filter section, light of λ0 to λl may be used. However, in practice, the bandwidth is extremely narrow, and in order to obtain a sufficient amount of colored light, severe restrictions are imposed on the selection of filter materials, which is undesirable. The method of the present invention is intended to achieve the same purpose more easily, and in the above process, - the area where the formation of the figurine image has been completed will not be disturbed by the subsequent exposure of the entire surface; It is based on the fact that there is no In other words, the light used for the first full-surface exposure needs to consist only of wavelength components that pass through any one type of filter (F'1) among the three color separation filters;
The second full-surface exposure may include a wavelength component that is transmitted through the filter Fl on which image formation has already been performed, in addition to the wavelength that is transmitted through the second target filter F2. However, it must not contain any components that pass through the remaining third filter F3. Also, the light L used for the third, final full-surface exposure
3 includes wavelength components that pass through the third filter F3, other restrictions are unnecessary, and white light, which can be easily obtained, is the brightest in practice. Specifically, for example, first, red light consisting of long wavelength components of wavelength 24 or more is applied to the three filters shown in FIG.
A second latent image is formed on the R filter area and developed in cyan, and then yellow light consisting of components with wavelengths of 22 or more that passes through filter F2 and filter F1 is used as L2 to expose the entire surface for a second time. Exposure is performed to form a secondary latent image on the G filter area, and then magenta development is performed.Furthermore, the entire surface is exposed to white light to form a secondary latent image on the B filter area, and then developed with yellow toner. A desired multicolor image can be obtained. Figure 6 shows the spectral distribution L of the entire surface exposure light in this case.
1, L2, L3 and the spectral transmittance of the color separation filter B, G,
This shows the relationship between R. Furthermore, the order of color image formation and the components of the light used therein are not limited to the above examples, but may be of any order as long as all of the above requirements are met. The preferred columns are shown in Table 1. Table 1 As the light source for full-surface fog light, it is preferable to use a known white light source such as a tungsten lamp or a fluorescent lamp as it is, or one provided with a filter that transmits light of a necessary wavelength. When using a filter as a light source for full-surface exposure, it is advantageous to use a red or yellow filter because it is easy to obtain a sharp rise in the spectral distribution and a high transmittance. Practically speaking, it is most preferable to take Further, if the spectral sensitivity of the original tetraelectric layer extends beyond the visible range of ultraviolet or infrared, ultraviolet light or infrared light may be used for the entire surface exposure. In this process, if the amount of the entire surface exposure light Ll (or L2) reaching the photoconductive layer is not sufficient, the charge on the photoconductive layer may not be completely erased. In this case, in the subsequent full-surface exposure step, the remaining charge disappears, the surface potential of that area changes, and there is a risk that toner will adhere and muddy color will occur. In order to prevent this, it is desirable to irradiate the photoconductive layer with light to erase the charges remaining in the photoconductive layer before the next full-surface fogging. It is desirable that this light has the same or similar spectral characteristics as the entire surface exposure light Ll (or L2). Moreover, it is preferable to carry out this charging at the same time as the charger 8 is used to make the surface potentials of the crystals the same. The developer used in the present invention can be used either as a so-called partial developer using a magnetic toner or as a so-called two-component developer containing a mixture of toner and a magnetic carrier such as iron powder. For dust 15J, a method of directly grinding it with a magnetic brush may be used, but in particular, the 2v) developing body is a developing method in which the developer layer does not come into contact with the 1vi light body surface in order to avoid sifting the formed toner image. A developing method in which the gap between the sleeve and the surface of the photoreceptor is set to be larger than the developer layer on the developing sleeve (provided that there is no potential difference between the two), for example, U.S. Pat. No. 3,893.418 No. specification,
% Publication No. 18656/1982, Patent Application No. 5744/1983
No. 6, Patent Application No. 1982-238295, % Application No. 1983-238
The method f! as described in each specification of No. 8296!
: It is particularly preferable to use it. These methods use a partial or two-component developer carrying non-magnetic toner, which can be colored freely, and create an alternating electric field in the development area to perform development without contact between the electrostatic image support and the developer layer. It is something to do. The color toner used for development consists of chromatic and achromatic coloring agents such as street resin, organic and inorganic pigments, dyes, and various magnetic additives that are commonly used in toners. Toners for electrostatic image development made by known techniques can be used, and the carrier is usually Ta! Various known carriers can be used, such as iron powder, ferrite powder, magnetic carriers such as carriers with flank coatings, and magnetic carriers with magnetic material dispersed in resin. Patent application No. 58-24966 filed earlier by the applicant
The developing methods described in the specifications of No. 9 and No. 240066 may be used. Among the above-mentioned developing methods, in the embodiment described below, a two-component developer using a non-magnetic toner is used, and development is performed without bringing the photoreceptor and the developer layer into contact in an alternating current electric field formed in the development area. A two-component non-contact development method has many advantages, as described below, and is most preferred for the method of the present invention. The advantages of two-component non-contact development are: (1) There is no need to add a magnetic substance (usually a dark color such as black) to the toner; only a small amount is required, and toner with vivid colors can be used; (2) The size of the mosaic filter used in the method of the present invention is 50μ? FIs and IIL, and in order to faithfully develop them, extremely fine particles,
For example, it is preferable to use a fine toner with a particle size of 10 μm or less; however, in the case of fractional toner, if the toner particles are made fine, the fluidity decreases and the toner particles become less likely to vibrate under an oscillating electric field. problem occurs. On the other hand, with two-component developers, these "
(3) In the method of the present invention, color development is performed by an additive method, so in order to obtain a high density image, a sufficient amount of toner is attached to each mosaic filter image. However, such development can be easily performed by using a two-component developer that can increase the amount of toner band and increase the amount of toner conveyance and delivery to the development area. ( 4) - Overlay development can be performed by applying a voltage at a lower voltage than when using a component developer, and the charge distribution of the toner is more stable than that of a partial developer, making it easier to set false overlay conditions. The temple is said to be stable. Regarding appropriate conditions for two-component non-contact development preferably used in the method of the present invention, % Application No. 58-183152
No. 3, No. 58-184381, No. 58-187000
No., Et.
This is also described in *, but this will be explained below.0 First, speaking of the carrier, it is preferable that the carrier is spherical.The fact that the magnetic carrier particles are spherical means that they are different from the toner. The inertia of the carrier and the transportability of the developer are improved, and the charge controllability of the toner is improved, thereby preventing aggregation of toner particles and toner particles and carrier particles. However, if the average particle size of the magnetic carrier particles is large, (1) the ears of the magnetic brush formed on the developer transport carrier are rough, and the electrostatic image is developed while giving vibration to the electric field. Also, unevenness tends to appear in the toner image, and problems such as high density development cannot be performed because the toner # degree in the ears becomes low can occur. In order to solve this problem (2), the average particle size of the carrier particles can be made smaller, and as a result of trial experiments, the effect begins to appear when the average particle size is 50 μm or less, and especially when the particle size is 30 μm or less, the effect of (2) is substantially reduced. Problems will no longer arise. Also, the problem of ■ is
This problem can be solved by making the magnetic carrier into fine particles, which increases the toner concentration in the spikes 9 and enables high-density development. However, if the carrier particles are too fine, they tend to adhere to the photoreceptor surface together with O toner particles, and (2) they tend to scatter. These phenomena are related to the strength of the magnetic field acting on the carrier particles and the resulting magnetization strength K of the carrier particles, but when the average particle size of the carrier particles becomes 15 μm or less, a tendency gradually begins to appear, and when the average particle size of the carrier particles becomes 15 μm or less,
This will become more apparent below. The carrier particles are usually black or a dark color close to black, and the carrier adhering to the surface of the photoreceptor transfers onto the recording paper together with the toner, significantly deteriorating the tone of the image. As mentioned above, the magnetic carrier has an average particle size of 50 μm or less, 5
The particle size is preferably 15 μm or more, particularly 30 μm or less and 15 μm or more, and the shape is preferably spherical.
This is the weight average particle diameter determined using Omnicon Alpha (manufactured by Bossierom).・Such magnetic carrier particles may contain metals such as iron, chromium, nickel, cobalt, etc., or compounds or alloys thereof, such as triiron tetroxide or γ-oxide, as in conventional magnetic carrier particles. Ferric iron, chromium dioxide, manganese oxide, ferrite, manganese-copper alloy,
The particles of a ferromagnetic or paramagnetic material such as It can be coated in a spherical shape with a zero resin such as acrylic resin, polyamide resin, epoxy resin, or polyester resin, or fatty acid wax such as valmic acid or stearic acid, or more preferably, it can be coated with a resin containing dispersed magnetic particles. The particles obtained by pulverizing or JFLM-combining fatty acid wax particles to preferably form spherical particles are subjected to 'EL' using conventionally known means for determining the average particle size.
It is prayed for by sorting the diameter. In addition to the above-mentioned effects, forming the carrier particles into a spherical shape using a resin or the like as described above makes the developer layer formed on the developer transport carrier uniform, and also makes the developer transport carrier highly spherical. It also has the effect of making it possible to apply a bias voltage. That is, the fact that the carrier particles are made spherical by a resin or the like is because (1) Generally, carrier particles tend to be magnetized and attracted in the long axis direction, but by making them spherical, this directionality is lost; (2) In addition to the high resistance of the carrier particles, there are no edges found in conventional carrier particles. As a result, even if a high bias pressure is applied to the developer transport carrier, the electric field will not be concentrated on the edge portion, and the static TM image will be disturbed due to discharge on the photoreceptor surface, or the bias voltage will break down. It gives the effect that nothing you do will happen. Applying this bias voltage means that when the development under an oscillating electric field in a preferred embodiment of the present invention is performed by applying an oscillating bias voltage, the effects described below can be sufficiently obtained. This means that you can make the most of it. As mentioned above, wax is also used as the carrier particle that produces the above effects, but,
From the viewpoint of the durability of the carrier, it is preferable to use a resin such as the one described above, and further, to form insulating magnetic particles so that the resistivity of the carrier particles is 1080 (7) or more, particularly 1013 Ωα or more. is preferred. This resistivity is calculated by placing the particles in a container containing a cross-sectional area of 0.50 and tapping, then applying I Kg/
Apply a load of cd and apply 100OV between the load l and the bottom electrode.
It is a clay that can be served by reading the current value when applying a voltage that generates an electric field of /σ (at this time, the particle layer thickness u
1 m8K), if this resistivity is low, when a bias voltage is applied to the developer transport carrier, charge is injected into each carrier particle, making it easy for carrier particles to be deposited on the surface of the photoreceptor, or when the bias voltage is lowered. Breakdown may occur more easily. In summary, the magnetic carrier particles are spherical so that the ratio of the major axis to the minor axis is at least 3 times or less, there are no protrusions such as needles or edges, and the resistivity is 108Ω. A suitable condition is to cut the weight by 10,130 or more, preferably 10,130 or more. For such magnetic carrier particles, for spherical magnetic particles with high resistance or resin-coated carriers, it is necessary to select magnetic particles as spherical as possible and coat them with resin, or to use a magnetic fine particle dispersion system. The carrier is manufactured by using fine particles of magnetic material as much as possible, by subjecting the dispersed resin particles to a spheroidizing treatment after forming them, or by obtaining the dispersed resin particles by a spray drying method. Next, you can carry about the toner. In the multicolor image forming method of the present invention, as described above, 50μ? It is particularly preferable to use a fine toner because it is safe to faithfully develop fine mosaic filter particles of PI level. When the average particle size of the toner exceeds 20 μm, it becomes difficult to faithfully reproduce a simosaic filter image with severe image roughness. In general, when the average particle size of toner particles in a two-component image agent becomes smaller, the amount decreases as compared to the particle size, and the adhesion force, such as Van der Waals force, decreases. The toner particles may become small and difficult to separate from the carrier, or once the toner particles are removed from the non-image area on the photoreceptor surface.
Once K is deposited, it cannot be easily removed by rubbing with a conventional hunting brush, resulting in a fog (7), but this can be solved by performing development under an alternating current electric field. The toner particles attached to the agent layer are
Due to the vibration given by the electric voltage, it is easy to separate from the developer layer and move to the image area and non-image area of the photoreceptor surface, and it becomes easy to separate from the developer layer. Also, toner particles with a low charge amount are 1! ! II
There is almost no migration to the image area or non-image area, and since there is no friction with the photoconductor surface, there is no possibility of adhesion to the image carrier due to frictional charging, and toner particles with a particle size of 1 μm in diameter are eliminated. It comes to be used. Therefore, i#
You can attend the P + dusty and clear toner that faithfully stares at the statue of Kamehiro. Since the wJ electric field of one oscillation weakens the bond between toner particles and carrier particles, adhesion of carrier particles accompanying toner particles to the image carrier surface is also reduced. Song J image section and non-II! ! + In the mound region, toner particles with a large central chamber vibrate under the oscillating electric field, and depending on the strength of the electric field, the carrier particles also vibrate, so that the toner particles selectively form an image on the photoreceptor surface. Therefore, the adhesion of carrier particles to the surface of the image bearing member is greatly reduced. According to Rida above, the appropriate condition for the particle size of the toner is that the average particle size is 20 μm or less, preferably 10 μm or less. Furthermore, in order for the toner particles to follow the electric field, it is desirable that the charge amount of the toner particles be greater than 1 to 3 μC/f (preferably 3 to 100 μC/P). Particularly when the particle size is small, a high charge a: is inevitable. Also, the resistivity is 1 (JS
It is preferable that Ωcn is 1 or more, preferably 101jΩα or more. So, the solid toner can be obtained by the same method as the milled toner. That is, it is possible to use a toner in which the toner particles of conventional toners such as cypress, irregular j, or magnetic toner particles are sorted according to the average y and the diameter El-=yield. In the case of A, it is preferable that the toner particles are magnetic particles containing magnetic particles, and in particular, it is preferable that the amount of magnetic particles is less than 60 wt%, but in order to obtain vivid colors, it is preferable that the toner particles are magnetic particles containing magnetic particles. A small amount of wt% or less is preferable. When the toner particles contain magnetic particles, the toner particles are influenced by the magnetic force of the magnet included in the developer carrying carrier, which further improves the uniform formation of the magnetic plano. This prevents fogging, smearing, and scattering of toner particles. However, if the amount of magnetic material contained is too large, the magnetic force between the carrier particles and the carrier particles becomes too large, making it impossible to obtain a sufficient developing density. As a result, it becomes difficult to control triboelectrification, and the toner particles become easily damaged or agglomerated with the carrier particles. In summary, the preferable toner in the method of forming urine of the present invention is to use fine particles of a resin and a magnetic material that can be carried on a carrier, and to add a coloring component such as carbon and a fluorophore depending on safety. Toner particles having an average particle diameter of 20 μm or less, particularly preferably 10 μm, which can be produced by a conventionally known method for producing toner particles and a shell-like method by adding a bulking agent, etc.
It consists of particles smaller than μm. In the image forming method of the present invention, a developer in which the above-mentioned spherical carrier particles and toner particles are mixed in the same ratio as in a conventional two-component developer is preferably used. If necessary, a fluidizing agent to improve the fluidity and sliding of the particles, a cleaning agent to clean the surface of the photoreceptor, and the like are mixed. As a fluidizing agent,
Colloidal silica, silicon face, metal soap, nonionic surfactants, etc. can be used, and as cleaning agents, surfactants such as fatty acid metal salts, organic group-substituted silicones, or fluorine, etc. can be used. The above are the conditions regarding the developer. By using such a developer, it is possible to prevent color variations between the mosaic filters. Next, conditions regarding a developer transporting carrier that forms a developer layer with such a developer and controls the image on the photoreceptor will be described. A developer transport carrier similar to that used in conventional development methods to which a bias voltage can be applied is used as the developer transport carrier, but in particular, a developer transport carrier having a plurality of magnetic poles inside a sleeve on which a developer layer is formed on the surface. A structure in which a rotating magnet is provided is preferably used. In such a developer transport carrier, the rotation of the rotating magnet causes the developer layer formed on the surface of the sleeve to move in an undulating manner, so that new developer is successively supplied and the sleeve Even if there is some degree of non-uniformity in the layer thickness of the developer layer on the surface, the effect of this is sufficiently covered by the above-mentioned wavy undulations so that it does not become a problem in practice. It is preferable that the developer transport speed due to the rotation of the rotating magnet or the rotation of the sleeve is almost the same as or faster than the moving speed of the photoreceptor. Also, the t! of the rotating magnet body! It is preferable that the conveyance direction by the 21 rotation and the rotation of the sleeve be the same direction. The image is better in the concave direction than in the opposite direction! + Excellent practicality. However, it is not limited to these. In addition, the thickness of the developer layer formed on the developer transport carrier is
It is preferable that the thickness is such that the adhered developer is sufficiently scraped off by the thickness regulating blade to form a uniform layer.
The gap between the developer transport carrier and the image carrier is several tens to
2000 μm is preferred. If the surface gap between the developer transport carrier and the photoconductor is too narrow (less than several tens of micrometers), it will be difficult to form magnetic brush ears that will uniformly develop the gap). It became impossible to supply it to the developing section,
Stable development will not be possible and the gap will be 2000 μm.
If it greatly exceeds this, the counter electrode effect decreases, making it impossible to obtain a sufficient 7J degree of development, and the edge effect that more toner adheres to the contours than the center of the electrostatic image occurs. Become. In this way, if the gap between the developer transport carrier and the photoreceptor becomes extreme, it becomes impossible to make the thickness of the developer layer on the developer transport carrier appropriate. Within this range, the developer layer can be formed to an appropriate thickness. Therefore, the gap and the thickness of the developer layer were determined to have a gap of 10 to 500 μm so that the tip of the magnetic brush does not come into contact with the surface of the image carrier and comes close to it under conditions where no vibration field is applied. It is particularly preferable to set This is because the toner development of the latent image is prevented from having scratches or fog caused by the rubbing of the magnetic brush. Further, development under an oscillating electric field is preferably carried out by applying an oscillating bias voltage to the sleeve of the developer transport carrier. The bias voltage is a DC voltage that prevents toner particles from adhering to non-image areas and an AC voltage that makes it easier for toner particles to separate from carrier particles.
Preferably, a voltage is used. However, the present invention is not limited to the method of applying an image dynamic pressure to the sleeve or the method of applying a superimposed DC and AC voltage. The developing method of the present invention as described above is shown in FIGS.
This is implemented by an apparatus such as that illustrated in FIG. 8 to 10, reference numeral 81 denotes a drum-shaped image bearing member made of the photoreceptor of the present invention, which rotates in the direction of the arrow and has a static image formed on its surface by a charging exposure device that does not have any markings; 8
2 is a sleeve made of non-magnetic material such as aluminum; 8
3 is provided inside the nose 52 and has a plurality of N on the surface.
, this sleeve 82 is a magnet body having S magnetic poles in the circumferential direction.
and the magnet body 83 constitute a developer transport carrier. The sleeve 82 and the magnet body 83 can rotate relative to each other, and the figure shows a case where the sleeve 2 rotates in the direction of the arrow. In addition, the N and S magnetic poles of the magnet body 3 are normally magnetized to a magnetic flux density of 500 to 1500 Gauss, and the magnetic force causes the surface of the sleeve 82 to form a layer of developer as described above. That is, a magnetic brush is formed. 84 is a regulating blade made of magnetic or non-magnetic material that regulates the height and amount of the magnetic brush; 85 is a regulating blade that controls the magnetic brush that has passed through the developing area A;
2. This is a cleaning blade that removes from above. The surface of the sleeve 82 comes into contact with the developer reservoir in the developer reservoir 86, thereby supplying the developer reservoir. This is a Pjt stirring screen. When development is performed, the toner particles at the top of the developer tank at the bottom of the developer tank are consumed, so 88 is a toner hopper for replenishing the toner particles T as described above, 89 is a supply roller having a concave portion on its surface that drops the toner particles T into the developer reservoir p85. 90 is a bias power supply that applies a bias voltage to the sleeve 82 via a protection resistor 91. The difference between the devices shown in FIGS. 8 to 10 is that in the device shown in FIG. 8, the sleeve 82 rotates in the direction of the arrow;
The magnet body 83 rotates in the opposite direction of the arrow to 200
The magnetic flux densities of the N and S magnetic poles, which are preferably from rpm to 2000 rpm, are approximately equal.In the device shown in FIG. 9, the sleeve 82 rotates in the direction of the arrow, but the magnet body 53 is fixed. In the apparatus shown in FIG. 10, the magnetic fluxes of the fixed magnet body 83 are not the same, and the magnetic flux density of the N magnetic pole facing the image carrier 1 is different from that of the other N, S magnetic poles. It is greater than the magnetic flux @ degrees. As for the poles facing the image carrier 81, it goes without saying that the N& poles may be arranged and facing each other as shown in FIG. 10, or the N and S magnetic poles may be arranged and opposed. By arranging a plurality of magnetic poles to face each other in this way, it is possible to obtain an effect that development is more stable than when a single pole is made to face each other. In the above-described apparatus, the sleeve 82 is attached to the image carrier 8.
When the electrostatic image on the image carrier 1 is developed with the surface gap set to be in the range of several tens to 2000 μm, the magnetic brush formed on the surface of the sleeve 82 will As the magnetic flux density on the surface of the magnet 83 changes as it rotates, it moves on the sleeve 82 while vibrating, thereby stably and smoothly passing through the gap with the image carrier 81. At this time, a uniform developing effect is imparted to the surface of the image carrier 81, making it possible to stably develop with a high toner density. In order to prevent the occurrence and origin of fog and to improve the developing effect, a bias voltage having an alternating current component that vibrates from a bias power source 90 is applied to the sleeve 82 on the image carrier 51 to which it is grounded.
The voltage is applied between the base body 81a and the base body 81a. As mentioned earlier, this bias voltage uses a preferable N-fold voltage of DC voltage and AC voltage.The DC component prevents the occurrence of fogging, and the AC component vibrates the magnetic brush to produce a developing effect. improve. Note that the DC voltage component usually has a voltage of 50 to 60, which is approximately equal to or higher than the valve surface potential.
0■ voltage is used, and the AC voltage component is 100Hz~
A frequency of 10 KHz, preferably 1 to 5 KHz is used. Note that, when the toner particles contain a magnetic substance, the DC voltage component may be lower than the valve surface potential. However, in order to maintain the clarity of colors, it is better to use less magnetic material. If the frequency of the AC voltage component is too low, the effect of imparting vibration cannot be obtained, and even if it is too high, the developer will not be able to follow the vibrations of the electric field, resulting in a decrease in developer density and the ability to obtain clear, high-quality images. There is a tendency to disappear. Also, the voltage value (ri) of the AC voltage component (frequency is also related, but the higher it is, the more effective it becomes as VC vibrates the magnetic brush, but on the other hand, the higher it is, the more likely it is to cause vibrations, and lightning strikes. Dielectric breakdown during development is also likely to occur.However, the fact that the carrier particles in the developer are made spherical by a resin or the like prevents dielectric breakdown, and the occurrence of fog can also be prevented by the continuous voltage component. Note that the surface of the sleeve 82 to which this alternating voltage is applied may be insulated or semi-insulated by resin or oxide film pressure.As shown in FIGS. Although an example in which a voltage is applied is shown, the developing method of the present invention is not limited to this. For example, several electrode wires may be stretched around the developing area between the developer transport carrier and the image bearing member, and the electrode wires may be vibrated. Even if a voltage is applied, the magnetic brush Km
It is possible to improve the developing effect by adding motion. In that case, the full DC bias voltage is applied to the developer carrying carrier,
Alternatively, oscillating voltages with different cycle times may be applied. The inventive method will be specifically explained below with reference to Examples. [Tenkawa Example 1] FIG. 5 is a schematic diagram of a color copying machine that was destroyed to carry out the method of the present invention. In the figure, reference numeral 11 denotes a photosensitive drum having the structure shown in FIG. 1B, and on a drum-shaped metal base, there is an insulating layer containing a cadmium sulfide photoconductive layer having sensitivity over the entire visible light range and a mosaic-shaped BXGXR three-color separation filter. It has been established. B, GX contained in the insulating layer on the surface of the photosensitive drum [The spectral transmittance of each filter is as shown in Figure 3, and the transmission wavelength range of each filter is B λr) (360 nm λ1 = 530 nm
G λ2 = 460 nm λ3 = 650
nmRλ4: 570 nm λ5) 750
It's nm. During the copying operation, the photosensitive drum 11 is not rotated in the direction of the arrow a and is given a positive charge over its entire surface by the electric charger 12.
X equipped with the next exposure slit
The image exposure of the eroded Ryokusugi is given by the Fukimoto optical system (consisting of mirrors M1 to M4, lenses, lamps Lp, etc.), and its surface is A primary latent image is formed. The entire surface is then exposed to light L1 from the light source 14 that has passed through the filter F1. The spectral distribution of the lights 1 and 1 is as shown in FIG. 6, and they have a component of 630 nm or more, and they only pass through the R filter section on the photosensitive drum 11, but they also pass through the B and G filter sections. Contains no ingredients. The primary latent image on the R filter portion on the photosensitive drum is converted into an electrostatic image (secondary latent image) by full-surface exposure, and is developed into a cyan image by a developing device 15AK loaded with a developer containing cyan toner. Although an image is formed, the primary latent images on the G and B filter sections do not change. The drum 11 after cyan development is subjected to a negative discharge (from the electrode 16), and is irradiated with light from the light source 17 that has passed through the filter Fll, which equalizes the potential on the surface and also increases the photoconductive layer under the R filter. charge is erased. Filter F11 has the same spectral transmittance as filter F1. After that, the entire surface can be exposed with the source L2 from the light source 17 which has passed fL through the filter F2. The spectral characteristics of the light L2 are as shown in FIG.
It passes through the filter section and the R filter section, but does not include any components that pass through the B filter section. The primary latent image on the filter portion of the photosensitive drum G becomes an electrostatic image. By developing with the developing device 15B loaded with a developer containing magenta toner, a magenta image is formed superimposed on the previously obtained 77-color image. Further, the photosensitive drum 11 is negatively discharged by the electrode 18 and is irradiated with light from a light source 19 that has passed through a filter F21 having the same spectral transmission characteristics as the filter F2.
As a result, the potential on the surface is made uniform and the charge on the photoconductive layer under the G filter is erased. Next, the entire surface of the photosensitive drum 11 is exposed to white light from the light source 19, and the first latent image on the B filter section becomes an electrostatic image, and the photosensitive drum 11 is loaded with a developer containing yellow toner! A yellow toner image is formed on top of the cyan and magenta toner images that have already been formed, and a full color image is formed by photons. The obtained color toner image is electrostatically transferred to a transfer paper fed by the device (its feeding path is indicated by @p) after the band is charged again with a brush 20. It is thermally controlled by the gradual device 21, becomes a light-formed copy, and is discharged outside the facility. In the top view, a transfer electrode 23 for transferring a toner image is a separation electrode for separating the transfer paper from the photosensitive drum surface. After the transfer, the photosensitive drum 11 is placed in a static neutralizer equipped with a light source.
4, the charge is removed under light irradiation, and the toner remaining on the surface is removed by a cleaning blade 25 before being reused. The parameters for development and other matters in this example were as shown in Table 2. Further, a halogen lamp was used as a light source for each exposure. When a multicolor image copying test was conducted under the conditions described above, it was possible to obtain a verification image with good color reproduction and no color shift. [Example 2] Filters F1, Fi1, F2, and F12 of the device of Example 1
1 to filters F3, F31, F i , F'l, respectively
Changed to l. As a result, the spectral distributions of the first whole surface exposure light L1 and the second whole surface exposure light L2 become as shown in FIG. In addition, the spectral transmittance of filters F3 and F31 is custom-made as 1=i
− is. Further, developing devices 15A and 15B. 15C was loaded with yellow, cyan, and magenta developers, and a multicolor image copying test was conducted under the same conditions as in Example 1. As a result, a good image was obtained as in Example 1. was completed. The present invention has been described in detail above with reference to an embodiment of a color copying machine using an n-type photoconductive photoreceptor. It can also be applied when using a body by reversing the polarity of the band 1°, and can be applied not only to color copiers but also to a wide range of applications such as multicolor image recording devices and color photo printers. . [Effects of the Invention] By the method of the present invention, it is possible to obtain a pre-quality multicolor image with no color shift through a simple process of one exposure using an apparatus using a filter manufactured or available at each station. I can do it. 4. Brief description of the drawings Figures 1A-D are cross-sectional views of the photoreceptor used in the method of the present invention, Figures 2A-C are the shapes of the three-color separation filter on the photoreceptor, and Figure 3 is the cross-sectional view of the three-color separation filter used in the method of the present invention. The spectral transmittance curve of the color separation filter BXGXR, Figures 4 [1] to [5] are explanatory diagrams of the image forming process in the present invention, and Figure 5 is a schematic diagram of a color copying machine suitable for implementing the method of the present invention. , FIGS. 6 and 7 are the spectral transmission small curves of the color separation filter sections BXG, R and the full-surface exposure filters F1, F2, and F3 used in Examples 1 and 2, respectively, and FIGS. 8 to 10 are the spectral transmission small curves. 1 is a schematic diagram of a developing device preferably used in the method of the present invention. 1...4 is a sexual substrate 2...photoconductivity increase 3...
Insulating layer 11... Photosensitive drum 4.12...
@ Electrode 5.13... Charged electrode with an exposure slit 6.14.
17.19...Light source 8.16.18..."RL pole for charge uniformity7.
15A, 15B, 15C...Developer fi', F 1
, F'l1, F''2, F21...filter agent
Patent Attorney No 1) Father-in-law Figure 10

Claims (3)

[Claims] (1) An insulating layer including a filter that transmits the short wavelength range of visible light, a filter that transmits the intermediate wavelength range of visible light, and a filter that transmits the long wavelength range of visible light, and spectral sensitivity over at least the entire visible wavelength range. After performing imagewise exposure while applying a charge to a photoreceptor consisting of a photoconductive layer having a photoconductive layer and a conductive substrate, a component that transmits through any one of the three types of filters (F1), and the other The entire surface of the photoreceptor is uniformly exposed to first light (L1) that does not substantially contain components that pass through the two types of filters, forming a first electrostatic image, which is used as a first color toner. After development, the potential on the surface of the photoreceptor is made uniform, and then at least a component that passes through another filter (F2) different from the filter F1 is included, and a component that passes through the remaining one filter (F3) is A second electrostatic image is formed by uniformly exposing the entire surface of the photoreceptor to the second light (L2) that does not substantially contain it, and is developed with a second color toner. The entire surface of the photoreceptor is exposed to third light (L3) containing a component that passes through at least one of the remaining filters F3 to form a third electrostatic image, which is developed with a third color toner. A multicolor image forming method. (2) The multicolor image forming method according to claim 1, wherein the third light L3 is white light. (3) The filters F1, F2, and F3 are filters that transmit visible light in the long wavelength range, intermediate wavelength range, and short wavelength range, respectively, and the lights L1 and L2 used for full-surface exposure are red light that passes through the filter F1, respectively. 3. The multicolor image forming method according to claim 2, wherein the light is yellow light that does not pass through the filter F3.