JPS63175866A - Electrophotographic sensitive body and image forming method - Google Patents

Abstract

PURPOSE:To prevent color slurring by forming an insulating layer having color sepn. filters to a recessed shape in the regions between filter elements and directing the recessed surfaces toward a photosensitive layer. CONSTITUTION:This photosensitive body has opaque parts 52 constituting mask patterns on a transparent substrate 51 and the opaque parts 52 are made of vapor deposited chromium films. A thin protective film 53 is formed thereon. A liquid mixture layer 54 composed of a color material and UV curing resin is formed on a transparent intermediate layer 50 consisting of a polyester film or the like and is brought into tight contact with the surface of said protective film. The resin layer 54 in the regions except the opaque parts 52 is cured by UV rays and the other parts where the light is shut off are not cured when the UV rays are exposed to the resin layer from the transparent substrate 51 side. The layer of the 1st color is, therefore, formed when said parts are removed by a solvent. This formation is similarly repeated for each of the color sepn. filters to form the recessed shape in the boundary parts, by which the color sepn. filter layer is formed. Bulging by overlapping is thus eliminated, by which the color slurring is prevented.

Description

[Detailed Description of the Invention] [Industrial Applicability] The present invention provides an electrophotographic photoreceptor for forming a multicolor image using the electrophotographic 3'% method, and an image forming method using the photoreceptor. Concerning this, it can be used for multicolor image formation, color photography, color blinking, etc. of the six gods.

(Prior Art) Several methods and devices have been proposed for forming multicolor images using electrophotography.

For example, there is a multicolor image forming method and apparatus (former) that performs image exposure and development according to each color separated light on an electrophotographic photoreceptor and transfers each color toner image to recording paper each time. A method of using a device equipped with a plurality of photoreceptors corresponding to the number of photoreceptors, exposing and developing images of each color on each of the photoreceptors to form l/toner images of each color, and sequentially transferring these to recording paper; and There is a device (the latter).

However, in the former case, the photoreceptor is rotated multiple times to form toner images of each color, so it takes a long time to record the image.
There are drawbacks such as difficulty in increasing the speed. In the latter case, multiple photoreceptors f! - Since it is used in an OFF row, it is advantageous in terms of high speed, but it has drawbacks such as the use of a plurality of photoreceptors, which makes the device large and expensive. Furthermore, since transfer is repeated multiple times for both the former and the latter, there is a problem in that it is difficult to align the images.

The title of the present invention is based on Japanese Patent Application Laid-open No. 61-63858, Japanese Patent Application No. 61-65262, and Japanese Patent Application No. 5
No. 9-199547, etc., a composite filter layer in which multiple types of microscopic filters of different colors are arranged in a mosaic pattern is placed on the upper side (the side to which toner adheres during development) or the lower side (the side to which toner adheres during development) of the photosensitive layer. We have proposed an image forming method using a photoreceptor with a photoreceptor on the non-adhering side. In this method, image exposure is applied through a composite filter bonded to a photoreceptor, and then the entire surface is exposed to specific light, and the portion of the composite filter corresponding to the specific filter has a potential corresponding to the light transmitted through the filter. This process of forming an image, developing it using toner of a specific color, and smoothing it by recharging is repeated for each type of filter to form a multicolor image on the photoreceptor. It has the advantage of requiring only a few times and no need for alignment, making it possible to easily obtain high-quality multicolor images.

However, in the color separation filter, a difference in level occurs at the boundary between each region due to the overlapping of color layers, so the filter portion is formed slightly lower. (Second figure shown) Therefore, when a color separation filter is adhered to the surface of a photoreceptor, a stepped portion is generated, resulting in non-uniform adhesion and air bubbles remaining in the stepped portion. This makes the light transmittance and potential pattern unstable, which is a problem especially when the color separation filter is used in a multicolor electrophotographic photoreceptor.

[Problems to be Solved by the Invention] The present invention is a result of many years of research by the inventors and others, and is intended to provide a multicolor image forming method that does not require positioning by imagewise exposure. The present invention provides an electrophotographic photoreceptor that eliminates bulges due to overlap and is resistant to color shift at the boundaries of color layer regions of a filter, and an image forming method for forming a multicolor image using the photoreceptor. It is something to do.

[Means for Solving the Problems] The above objects of the present invention are achieved by an electrophotographic photoreceptor in which the insulating layer having color separation filters is concave in the region between the filter elements, with the concave surface facing the photosensitive layer. We were able to.

The electrophotographic photoreceptor of the present invention is composed of an insulating layer of a color separation filter having depressions on its surface. For a photoreceptor with a concave surface in the photosensitive layer, the surface is charged by corona discharge or the like and imagewise exposed as described below, and then the entire surface is exposed to a specific light and a specific development process is repeated to form a multicolor image on the photoreceptor. A picture can be formed.

An example of a method for manufacturing a color separation filter according to the present invention will be described below with reference to the drawings.

First, the color separation filter according to the present invention will be explained in detail with reference to FIG. The membrane is dyed to form a layer 2 of the first color of the color separation filter, then a layer 3 of the second color, and finally a layer 4 of the third color, and then the whole is made transparent. It is coated with protective H5 to form a color separation filter.

Also, as with conventional color separation filters, the overlapping portions of each color layer (see Figure 2) may be selectively removed to form concave portions. There are various methods for forming the concave portions. After forming the color layers, the entire structure can be easily constructed by removing the overlapping portions by plasma etching or the like.

Further, a second manufacturing method of a color separation filter will be explained as an example with reference to FIGS. 3(^) to (D). For simplicity, the detailed structure of the color separation filter is omitted in the figure. No. 3111(^) is provided with an opaque part 52 forming a mask pattern on a transparent substrate 51, the opaque part 52 is made of a chromium vapor deposited film, and a thin protection M53 is formed thereon. As shown in FIG. 3(B), a mixed liquid layer 54 of a coloring material and an ultraviolet curing resin is applied on a transparent intermediate layer 50 such as a polyester film. Figure 3 (
In C), when UV exposure is applied from the transparent substrate 51 side, the resin [54] in the area other than the opaque area 52 is cured by the ultraviolet light, and the part where the low light is blocked is not cured, so by removing it with a solvent. , a first color layer is formed as shown in FIG. 3(D). The same process is repeated for each color separation filter to form a concave shape at the boundary portion to form a color separation filter layer.

FIG. 4A is a sectional view showing the structure of an electrophotographic photoreceptor having a color separation filter formed according to the present invention.

When a transparent substrate such as a plastic film is used as the substrate, a color separation filter can be applied to the electrophotographic photoreceptor with good illumination on the substrate formed by the above manufacturing method.
The electrophotographic photoreceptor of the present invention can be obtained by adhering. The color separation filter can also be provided after the transparent insulating layer 1, which is a protective layer, is provided on the photosensitive layer 10 in advance.

In Figure 4A, 1 is the above transparent substrate, and 5 is Figure 3A.
9 is a color separation filter layer, and 9 is an adhesive layer having adhesive properties for adhering the color separation filter layer 5 onto the photosensitive layer 10.

According to the present invention, any known bonding method can be used as the bonding method, such as a method of bonding the color separation filter made of a vapor-deposited layer and the photoreceptor through a laminator, and There is a method of temporarily adhering the photoconductor, placing it under negative pressure and applying atmospheric pressure, and a method of adhering it by continuing to apply compressed air after the temporary adhesion as described above.

In the above method of bonding through a laminator,
Adhesion is performed by applying an adhesive to the sheet-like photoreceptor side or the color separation filter side, and passing the adhesive together with the color separation filter through a laminator roller, applying pressure and heating with a force of U.

Furthermore, in the latter method, that is, in the method of bonding by applying atmospheric pressure after being placed under negative pressure, and in the method of bonding by blowing compressed air, bonding is performed through an adhesive layer.

The adhesion direction in the above adhesion may be such that the surface of the transparent substrate of the color separation filter is adhered to the surface of the photoreceptor, and there are no particular restrictions on the adhesive used to adhere the photoreceptor and the color separation filter. Various adhesives and pressure-sensitive adhesives can be used, but silicone oil (for example, Shin-Etsu Silicone KF-96 ), silicone oil (for example, Shin-Etsu Silicone KRIOI-10) is particularly preferably used for purposes requiring tackiness.

Next, referring to the shape and arrangement of the color separation filter according to the present invention, the shape and arrangement of the color separation filter useful in the present invention are not particularly limited, but are as shown in FIG. 4B. If the photoreceptor is in the form of a drum, for example, a linear shape may be used, such as one in which the lines are perpendicular to the direction of rotation, or one in which the lines are parallel to the direction of rotation.

However, usually a mosaic structure as shown in Figure 4 C and D is used, and the size of each filter is 30 to 500 μm as the color repetition width (1., i'2 in Figure 4). is preferable. If the size of the filter is too small, it will be susceptible to the influence of other adjacent color parts, and if the width of one filter is equal to or less than the particle size of the toner particles, it will be difficult to fabricate. 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. Note that FIGS. 4A, B to D all show the case where so-called three-color separation filters of red, green, and blue are provided. In the figure, R indicates red, G indicates green, and B indicates blue filters; however, the coloring of the color separation filter according to the present invention is not limited to these three colors (but can be freely changed as needed). A single layer of color filters can be formed.

The electrophotographic photoreceptor of the present invention is one in which a photoconductive photosensitive layer is provided on a conductive substrate-L as described in 111N.

The conductive Jλ plate II may be made of metals such as aluminum, iron, nickel, copper, or alloys thereof, and may have an appropriate shape and structure as required, such as a cylindrical endless belt shape. The photosensitive layer 10 is a photoconductor such as an alloy containing (1), selenium, amorphous cedar silicon, acid 6'11 selenium, tellurium, arsenic, γ-antimony, etc., or II [lead, lead,
Oxides of metals such as mercury, cadmium, molybdenum, etc.
111-organic electroconductive substances such as trifluoride, sulfide, selenide, azo type, diazo type, tris gamma-zo yarn, lid [J cyanine, etc. dye pigments and vinyl carbazole, trinide [j fluorenone, polyvinyl carbazole, It is formed by dispersing a resin and a 6:7'rQ4 transporting substance such as an oxadiazole, a hydrazone compound, a stilbene derivative, or a styryl 64 compound, and then applying the resin.

Examples of such binder resin include insulating resins such as polyethylene, polyester, polypropylene, polystyrene, polyvinyl chloride, polyvinyl acetate, polycarbonate, acrylic resin, silicone resin, fluororesin, and epoxy resin.

Further, a photoconductor having a functional structure divided into a charge generation layer and a charge transfer layer is also used.

According to this process, a photoreceptor is used, in which a photoreceptor layer having photosensitivity over the entire visible light range and a plurality of color separation filters arranged in a fine linear or mosaic pattern is first subjected to image exposure. A first-order latent image corresponding to the resolved image density is formed on the photosensitive layer below each filter, and then the photoreceptor is entirely exposed to a specific light (the same color as the filter color in this embodiment) to obtain the corresponding color. A second latent image is formed only on the filter, and a potential pattern is formed according to the light intensity of the first latent image forming process. Then, it is printed with a color toner of a color corresponding to the color of the filter, preferably a color that is complementary to the color that passes through the filter.

Thereafter, recharging is performed to smooth the surface potential, and the entire surface is exposed to specific light to form a potential pattern in the next decomposition filter section.
A multicolor image is formed on the photoreceptor by repeating the development process using toner having a complementary color to that of the filter. These multicolor images are superimposed and transferred onto the recording paper in only one transfer.

Figures 5 [1] to [8] show a portion of a photoreceptor using an n-type semiconductor such as cadmium sulfide as a photosensitive layer, and schematically represent the image forming process there. As in FIG.
, R) is a decomposition filter.

The graphs at the bottom of each figure in FIG. 5 show the potential on the surface of each part of the photoreceptor.

First, a positive charge is generated on the surface of the color separation filter 5 by the charger 14, which applies a positive corona discharge to the entire surface.

Correspondingly, negative charges are induced at the interface between the photosensitive layer 10 and the filter 5, resulting in the state shown in FIG. 5 [1].

Next, alternating current or negative discharge is applied by a charger 15 equipped with an exposure slit to erase the charges on the surface of the color separation filter 5 while imagewise exposing the multicolor original.

In the photoreceptor of the present invention, red, green,
Image formation is performed by exposing a blue multicolor image, but for the sake of clarity, the image formation process will be described using an original having only a red image as an example.

FIG. 5 [2] shows the poor condition of the portion subjected to image exposure (arrow Lr) from the red image. Since it is conductive, most of the positive charges on the filter 5 are erased, and the negative charges induced in the photosensitive layer 10 are also erased, so that the surface potential becomes close to zero potential.

On the other hand, since the green and blue separation filters 5G and 5B do not transmit the red light Lr, some of the positive charges on the filter 5 are erased, but the negative charges in the photosensitive layer 10 remain as they are, and Charges corresponding to the partially erased positive charges are induced in the conductive substrate 11. In such a charge arrangement, the surface potentials on the green and blue screen filter sections 5G and 5B are close to zero potential. However, the charger 15 may be a scorotron charger and the polarity may be reversed by controlling the grid voltage to provide a uniform surface potential of, for example, -200V. Therefore, although the filter has an inherent charge pattern as a primary latent image, a toner image cannot be formed because no surface potential difference is generated.

Next, the entire surface is exposed to specific light that produces a potential pattern only in a part of the decomposition filter, for example, blue light (arrow LB) obtained by the light source 16 and the blue filter FB. In this case, the decomposition filter transmits the blue light LB. A part of the negative charges on the photosensitive layer 10 under the photosensitive layer 10 and the positive charges on the conductive substrate 11 are neutralized, and a positive and negative charge is created between the portion of the decomposition filter 5B and the photosensitive layer 10 as shown in FIG. 5 [3]. The charges remain and a positive surface potential is applied to the color separation filter 5. By developing this with the developing device 17 carrying negative yellow toner Ty as shown in FIG. 5 [4], a partial yellow toner image of the separation filter 5B is formed. In the area of the separation filter 5B where this yellow toner is formed, the surface potential remains unsaturated by the toner, so as shown in the lower graph, a relatively high surface potential remains, and the next step is to There is still room for another toner to adhere during the development process.

Therefore, the surface of the filter 5 is recharged with alternating current or negative direct current.
Preferably, a negative corona discharge is applied by the scorotron charger 18 to attribute a flat surface potential state of 1M as shown in the lower graph of FIG. 5 [5], and the surface potential as shown in FIG. 5 [2] is It is best to make it equal to .

Next, by exposing the entire surface to green light (arrow LG) obtained by the light source 16 and the green filter FC, the negative charges in the photosensitive layer 10 and the conductive substrate 11 are removed as shown in FIG. The positive charges of are neutralized, and a high surface potential in the lower graph is obtained in the 5G region of the filter 5. The developing device 19 which shared this with the magenta toner TM in Fig. 5 [7]
A magenta toner image is obtained in the 5G region by developing the image.After zero-order recharging (Fig. 5 [8]), the entire surface is exposed to red light obtained by the red filter FR. No potential pattern occurs and cyan toner T
No development with C is carried out, thus the yellow 1
~ When a toner image and a magenta toner image are transferred and fixed onto a recording paper, a red image in which yellow and magenta are superimposed is visually observed on the recording paper.

The above explanation is based on the case where the original is a red image, but the same applies to cases where the original is a white, green, blue, yellow, magenta, cyan, or black image. Color reproduction is performed by matching. FIG. 6 is a diagram illustrating the process of color reproduction when such originals of each color are used. In FIG. 6, the horizontal axis represents the color tone of the original, and the vertical axis represents the process at each stage leading to toner image formation when each color original is used.

The symbol "r:, -, %" represents the formation of a -order latent image, the symbol "○" represents the formation of a secondary latent image, and the symbol "ri" represents the process of each stage of toner image formation. Further, the symbol "↓" indicates that the state in the upper column is maintained as it is, and the blank column indicates a portion where no latent image is formed.

Note that in the above description, a mouth-type semiconductor is used as the photoreceptor, but a photoreceptor using a p-type semiconductor such as selenium may also be used. Of course, there is no difference between the two types of photoreceptors, which can be used as either n-type or p-type photoreceptors.

As is clear from the above description, the photoreceptor according to the present invention is
This is a photoreceptor in which an insulating color separation filter is provided on the photoreceptor layer, and an image forming method using the photoreceptor is [1l
After a primary latent image is formed by one exposure, a secondary latent image is formed for each color of the color separation filter by full exposure using the three-color separation method, and developed with toner of the corresponding color. A multicolor image is obtained through a step of recharging.

For example, the NP method is used, which utilizes charges induced in the photosensitive layer as described above, but when forming a secondary latent image by second and subsequent full-surface exposures, it eliminates the negative effects caused by the residual latent image potential from the first exposure. Therefore, recharging is required. This recharging is effected by an alternating current or negative direct current discharge, preferably by a negative corona discharge with a scorotron charger. Note that "charging" as used in the method of the present invention includes cases in which the surface potential obtained when charging becomes 0 or the surface charge disappears.

The present invention also provides -order charging, secondary charging with a polarity substantially opposite to the -order charge, recharging for smoothing the potential pattern after image exposure, full-surface exposure with specific light, and specific color toner. It can also be applied to an image forming method in which development is repeated.

(Japanese Patent Application No. 60-229524) The development in the present invention is preferably carried out by a magnetic brush method, and the developer is a so-called one-component developer using a non-magnetic toner or a magnetic I-toner, or a toner and a magnetic carrier such as iron. It can be used with any of the so-called two-component developers that are mixed with. 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 surface of the 3-photo element is used. A developing method in which the gap between the developing sleeve and the photoreceptor is set to be larger than the thickness of the developer layer on the sleeve (provided there is no potential difference between the two), for example, U.S. Pat.
, No. 893,418, Mei 44, JP-A-55-186.
Publication No. 56, Japanese Patent Application No. 58-57446, Japanese Patent Application No. 58-
It is particularly preferable to use the methods described in the specifications of No. 238295 and Japanese Patent Application No. 58-238296. In this method, a one-component developer consisting of only non-magnetic toner and a two-component developer containing non-magnetic toner are used, and an alternating current electric field is formed in the development area, and the electrostatic image support and developer are A developer that performs development without contacting the layers is preferred, although a developer using a magnetic 1-ner may also be used.

The color toner used for development is made using known techniques and consists of known binder resins, organic and inorganic pigments, various chromatic colors such as dyes, and various additives such as charge control agents, which are commonly used in toners. A toner for developing a statically charged image can be used, and the carrier can be iron or ferrite powder, which is usually used for electrostatic images, more preferably iron or ferrite coated with a resin, or finely powdered magnetic particles in the resin. Various known carriers can be used, such as high-resistance magnetic carriers in which particles are dispersed.

Further, the developing methods described in Japanese Patent Application No. 58-249669 and Japanese Patent Application No. 58-240066 previously filed by the applicant may be used.

[Examples] The present invention will be specifically explained below with reference to Examples, but the embodiments of the present invention are not limited thereto.

(Image Formation Using the Photoreceptor of the Present Invention) FIG. 7 is a sectional view of essential parts of a multicolor image forming apparatus for copying a multicolor image using the photoreceptor described above obtained by the method according to the present invention. It is. SD is a photosensitive drum in which the film photoreceptor 40 is mounted on a metal drum, 41 is a positive direct current primary charger, 42 is a negative direct current corona discharge scorotron charger having a slit for image exposure, and 43B is a negative direct current corona discharge scorotron charger. Blue filter F[! a light source that emits blue light LC, 44
Y is a developing device containing yellow toner. 45 is a scorotron charger for negative DC corona discharge, 46G is a light source that has a green filter FC and emits green light LG, 47M
48 is a negative DC corona discharge scorotron charger; 49R is a light source having a red filter PR and emits red light Lll; and 50 is a modern device containing cyan toner. P is a recording paper, 51 is a transfer electrode, 52 is a separation To pole, 53 is a static eliminator for removing residual charges that removes static electricity while exposing the electrode to white light, 54
is a cleaning blade for removing residual toner.

First, the photoreceptor 40 having the above structure is uniformly positively charged by the charger 41, and then the charger 42 having negative polarity is applied to the photoreceptor 40, and at the same time, f-elevation exposure is performed from the three primary color originals of blue, green, and red. scan and expose. A primary latent image is formed on the photoreceptor 40 by color-separating the document corresponding to the intensity of f-quadrant exposure from the document for each color separation filter of the composite filter. Next, the entire surface is exposed LB by a white light source 43B equipped with an interference filter that transmits blue light and a glass filter FD, and an electrostatic charge image corresponding to the above-mentioned next layer ('l) is formed in the region of the blue separation filter. Yellow is developed by the yellow developing device 44Y.

Next, after erasing the electrostatic charge image remaining in the area of the blue separation filter using a negative scorotron charger 45, the entire surface is exposed LG using a white light source 46G equipped with an interference filter that transmits green light and a glass filter FC, and magenta Developing device 4
7M gives 1 momme of magenta.

Next, after erasing the remaining electrostatic image with a negative scorotron charger 48, a white light 149 equipped with a red filter FR is used.
Full-surface exposure LR is performed using R, and cyan development is performed using a cyan developer 50. In this way, a multicolor toner image corresponding to the original is formed on the photoreceptor, and is then transferred to the fed recording paper P at the same timing by the action of the transfer electrode 51, and is also transferred to the recording paper P fed at the same timing. After being separated by the action of the electrode 52, the toner image on the recording paper is fixed by a fixing device (not shown).

On the other hand, after the transfer, the photoreceptor 40 is neutralized by a static eliminator 53, and then residual toner is cleaned by a cleaning blade 54, and the photoreceptor 40 is prepared for the next image formation.

All of the above explanations have been made regarding embodiments of a color copying machine using so-called three-color separation filters and three primary colors 1 to 3, but embodiments of the present invention are not limited to this, and various multicolor images can be printed. It can be widely used in photo recording devices, color photo printers, etc.

It goes without saying that the combination of the color of the separation filter and the color of the toner corresponding thereto can be arbitrarily selected depending on the purpose.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a color separation filter formed according to the present invention, FIG. 2 is a sectional view of a conventional color separation filter, and FIG.
4A is a cross-sectional view showing the structure of an electrophotographic photoreceptor having the above-mentioned color separation filter, and FIGS. 1
) Schematic configuration diagram showing the shape and arrangement of the η two-color separation filter,
FIG. 5 is a diagram explaining the image forming process from a colored original, FIG. 6 is a diagram explaining the image forming process from various colored originals, and FIG. 7 is a multicolor image forming apparatus using a photoreceptor according to the present invention. FIG. 5... Color separation filter 5R... Red filter 5
G...Green filter 5B...Blue filter 9.
... Adhesive layer 10... Photosensitive layer 11... Conductive substrate Applicant: Roku Konishi Photo Industry Co., Ltd. Figure 1 Figure 2 Figure 3 111 volumes-'-55

Claims (1)

Claims: 1) An electrophotographic photoreceptor, characterized in that an insulating layer having a color separation filter is concave in the region between the filter elements, with the concave surface facing the photosensitive layer. 2) Charging and imagewise exposing the photoreceptor using an electrophotographic photoreceptor in which the insulating layer with color separation filters is concave in the areas between said filter elements, with the concave side facing the photosensitive layer. After that, the entire surface is exposed to specific light and a specific development process is repeated to form a multicolor image on the photoreceptor.