JPH0326518Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an electrophotographic photosensitive film that forms color images, for example.

When forming color images on electrophotographic paper using the capacitive imaging method, for example, cyan, magenta, yellow,
It is sufficient to sequentially form black color images, but at this time, a problem occurs that does not occur in the xerographic transfer process.

That is, the first problem is the "edge effect" in which when toner adheres to a colored area, the distribution of charge in the colored area is not uniform, so the peripheral area of the colored area becomes darker. .

The second problem is the "trapping phenomenon".
This is a phenomenon in which when the first development is performed, the toner adhering to the surface of the photoreceptor changes the photosensitive characteristics for the second and subsequent exposures.

This is because normal dry toner contains an insulating resin, so it retains its charge during the first charging and exposure, which results in correct color images for the second and subsequent colors. This is a phenomenon in which it is no longer possible to obtain

The third problem is a phenomenon called the "filter effect." This is because the transparency of the toner is not sufficient, so when the first phenomenon is carried out, toner adhesion is already present during the second exposure. As a result, the correct color image cannot be obtained for the second and subsequent colors.

Furthermore, the fourth problem is that in subtractive color mixing methods such as printing, the photoreceptor itself is the recording medium, so it must have good whiteness. In other words,
It is impossible to increase the sensitivity of photosensitive materials such as ZnO by dye sensitization to all color lights.

This idea addresses the first of these problems.
The purpose is to provide a photosensitive film that solves the problem of the "edge effect".

Let's explain one example below.

In FIGS. 1 and 2, 1 indicates a photosensitive film according to this invention, and 2 indicates a film serving as a transparent support, which is made of Mylar, polyester, etc. and has a uniform thickness, for example, 100 μm. is formed. Then, on one surface of the film 2, a transparent electrode layer 3, a photoconductor layer 4, and a dielectric layer 5 are formed in this order to each have a uniform thickness.

In this case, the electrode layer 3 is formed by depositing, for example, In ₂ O ₃ on the support 2 to a thickness of, for example, 0.05 to 0.1 μm using an evaporation method or the like. Further, the photoconductor layer 4 is a transparent or white photoreceptor layer, which is different from the support 2 on which the electrode layer 3 is formed.
Photosensitive materials used in ordinary electrophotography, e.g.
For example, apply ZnO, CdS, PVK-TNF using a sprayer, coater, wire bar, etc.
It is formed by adhering to a thickness of 30 μm, and at this time, a binder such as acrylic resin is mixed in to improve bonding with other layers 3 and 5, if necessary.

Further, the dielectric layer 5 is made of an insulating material with a thickness of 5 to 8 μm, for example, to the support 2 on which the two layers 3 and 4 are formed.
At this time, the insulating material of the dielectric layer 5 must (i) have high resistance and be able to retain static electricity, and (ii) the photoconductor layer 3 must not be white. Sometimes, it is said to satisfy the conditions of being white and opaque (iii) that the toner has good fixing characteristics, for example, zinc white or oxidized white pigment is added to acrylic resin, epoxy resin, polyester resin, silicone resin, etc. It is made by dispersing titanium, lithon, etc.

Further, at this time, the dielectric layer 5 is formed into a mesh shape with an area ratio of about 70% by, for example, a gravure printing method.

Note that color images can be recorded on this photosensitive film 1 using a process that is almost the same as that used in general capacitive imaging, but as shown in FIG.
Exposure is performed from the support 2 side, and toner is applied to the dielectric layer 5.

That is, in FIG. 3, 11 is the original, 12
indicates the imaging lens, and the image of the original 11 is captured on the film 1.
The light is projected onto the dielectric layer 4 from the surface on the support 2 side through the support body 2 and exposed. A developing device 13 containing toner and a charging device 14 are provided on the dielectric layer 5 side of the film 1, and these move along the film 1 to perform development. The above-described processing and fixing are then performed for each color to fix a color image on the film 1.

In this case, according to this invention, since the dielectric layer 5 has a mesh shape, charges are locally concentrated and no edge effect occurs when toner is attached. Further, when the resistance of the toner is large, the toner adheres in proportion to the magnitude of the potential gradient of the film 1, so that a high density can be obtained. Furthermore, it is also possible to eliminate moiré caused by pixel shift in color images.

In addition, since exposure is performed from the support 2 side and the toner is attached to the dielectric layer 5, there is no trapping phenomenon, fog-free development is possible, and there is no filter effect. As a result, a high-quality color image with high color purity and no turbidity can be obtained.

Further, since it is a capacitive image method, the photoconductor layer 4, that is, the photoreceptor layer 4, may have a low specific resistance, and therefore, the sensitivity can be increased.

In addition, in the above description, the photoconductor layer 4 may have a mesh shape. Furthermore, the image obtained on the film 1 may be transferred to another device, and some of the meshes may be connected to adjacent ones.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an example of this invention, FIG. 2 is a plan view thereof, and FIG. 3 is a diagram for explaining the same. 2 is a support, 3 is an electrode layer, 4 is a photoconductor layer, 5
is a dielectric layer.

Claims (1)

[Claims for Utility Model Registration] A transparent film-like support, a transparent electrode layer formed on one surface of this support, a photoconductor layer formed on the upper surface of this transparent electrode layer, and a dielectric layer formed on the upper surface of the photoconductor layer, the support is exposed to light from the other surface, and toner is attached to the dielectric layer in accordance with the exposure. A photosensitive film for capacitive imaging, wherein the dielectric layer or the photoconductor layer is white and opaque, and the dielectric layer or the photoconductor layer is formed in a mesh shape.