JPS58139160A - Image forming element and image forming method using this element - Google Patents

Abstract

PURPOSE:To obtain an image forming element capable of copying repetitively by only once exposing, by forming primary and secondary electrodes on an insulating support, coating them with a persistent photoconductive layer, forming an isolated conductor having light-transmitting parts and shading parts. CONSTITUTION:Comb-shaped primary and secondary electrodes 3, 4 are formed on a support 2 of glass or the like, and coated with a persistent photoconductive layer 5 contg. ZnO or the like together with a sensitizing dye or a sensitizer, such as acid, dispersed into an acrylic resin or the like. The layer 5 retains photoconductivity for >=30sec after light irradiation, and when heated to >=about 60 deg.C, conductivity returns to the initial state before the irradiation. The layer 5 is coated with an isolated conductor 10 having light-transmitting parts 11 and shading parts 12 to obtain an image element 1. The element 1 is exposed to a light past and image 8 from the conductor 10 side, an at the same time or after that, voltage is applied to the electrodes 3, 4, causing difference betwen distributed voltage of the exposed and unexposed parts. The unexposed parts are developed by attaching toner, and the toner image is transferred to transfer paper. A plurality of copies can be made by exposing the layer 5 only once, and the image is erased by heating the element 1 to about 100 deg.C after the copying.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming element, particularly an ll1i fine-forming element for forming a potential image by utilizing a difference in distributed voltage due to a resistance change of a persistent photoconductive layer, and an lli image using the element. Regarding the forming method. Furthermore, the present invention relates to an 1iif11 forming element and an image forming method that can make a plurality of copies with one exposure and can be used repeatedly.

Conventionally, the most common method for copying books, documents, etc. is the xerography method, in which an electrostatic latent image is formed by charging and exposing a photoconductive photoreceptor, then developed with toner, and then transferred and fixed onto transfer paper. is known. The photoreceptor used in this method has a photoconductive layer provided on a conductive support. The photoconductive layer is formed by vacuum deposition of an alloy such as S@ and S., T., Muhata, etc., or an inorganic photoconductor such as Zoo, Cam% TI%, etc. with an insulating binder. It is dispersed and formed by Ikl. An electrostatic latent image is generally formed by charging the surface of the photoreceptor by corona discharge and then selectively eliminating the charge in the exposed area using a stirrup. This electrostatic fII is a toner charged with a polarity opposite to that of the latent image.
After that, the toner image is transferred and fixed onto transfer paper. This type of electrophotography requires a corona wire, a shield case, a high-voltage power source for corona discharge, etc. for corona charging, and therefore it is difficult to miniaturize the apparatus. Furthermore, contamination of the corona wire deteriorates image quality and reduces reliability.

In order to improve these drawbacks of conventional electrophotography, a photoreceptor that does not require corona charging was developed in Japanese Patent Application Laid-Open No. 48-6823.
8, Japanese Patent Application Laid-Open No. 51-150342, 4I Publication No. 53-1027, Japanese Patent Application Laid-Open No. 54-61534, Japanese Patent Application Publication No. 54-61537, etc.

These photoreceptors are capable of forming a potential image that can be developed with charged toner without requiring continuous charging. A potential image is formed by applying a voltage to a photoconductive layer provided with an electrode and performing an exposure of 51 m1 to create a difference in distributed voltage between exposed and non-exposed areas. In this method of forming a potential image, a millable 1:' potential image is formed by changing the resistance of the photoconductive layer.
It is necessary to perform i-image exposure and S-image exposure at the same time, which is accompanied by restrictions.

The present invention eliminates the drawbacks of the conventional electrophotographic method as described above,
An object of the present invention is to provide an image forming element and an image forming method that do not require corona charging and can perform kit imaging after exposure with a voltage applied. Broadly speaking, it is an object of the present invention to provide a Lii square forming element and an image forming method that can be used repeatedly. A further object of the present invention is to provide a III* forming element and an image forming method that do not require a transparent support and allow exposure and development to be performed from the same side of the III image forming element.

The object of the present invention is to provide a layer that forms a pixel-forming light-shielding part and a light-shielding part with a strong isolated conductor, a layer whose conductivity changes upon irradiation with light, and whose change persists even after irradiation with light, that is, a persistent photoconductive layer. Im image forming element characterized by having an electrode,
and a step of applying a voltage to the electrodes of this image forming element, 1
This is achieved by a 1mfI & forming method characterized by comprising a step of performing 1ifII exposure and a step of developing after image exposure. Broadly speaking, the object of the present invention is achieved by a method for forming an II image, which is characterized in that it includes a step of heating the image forming element sideways.

In the present invention, by applying a voltage to the persistent photoconductive layer provided with an electrode and performing imagewise exposure, the exposed and unexposed areas of the persistent photoconductive layer are differentiated by a change in resistance in the exposed area. A potential image is formed by creating a difference in divided voltages and using a difference in surface potential of the image forming element that occurs in response to this difference in divided voltages. This potential image is retained even after the li exposure, and can be made into an ll image after the image exposure. Further, the voltage application may be performed simultaneously with the image exposure or after the image exposure, and the IIIiI exposure and development can be performed on the same side of the image forming element, which simplifies the structure of the apparatus.

Hereinafter, details of the present invention based on the drawings will be described. I will clarify.

A typical configuration of the II image forming element according to the present invention is shown in FIG. ii* Forming element l includes a support 2, a first electrode [13], a second electrode [14], a persistent photoconductive layer 5, an isolated conductor 10 having a light-transmitting part 11 and a light-blocking part 12, a transparent insulating layer 13 consisting of a pair of first electrode 3 and second electrode 41 for each isolated conductor.
14 are provided. 1. The support 2 must be insulating and more resistive than the persistent photoconductive layer. Specifically, it is made of glass, resin, or the like. The ag1 electrode 3 and the second electrode 4 are patterned electrodes formed on the support 2, and have a comb-like shape as shown in FIG. 112. The it-th electrode 3 and the second electrode 4 are formed by various methods. A typical m method is a method using vapor deposition and etching using a 7-photoresist. This person ff1K
According to the method, after the materials forming the INK first electrode 3 and the second electrode 4 are deposited on the surface of the support, a masking pattern of the Kushiya electrode is formed using a photoresist, and then a predetermined etching solution is used to remove the electrodes. After selectively etching and removing the material layer, the photoresist masking pattern is removed to form the first electrode 3 and the second electrode 4. First electrode 3
And as a material for the second electric li4,! Town 01, Smog
Metal oxides such as Mut, U, Ha, Z*a, Group, A
m, Cr, Me, 1-Nb, Ta%U, TI, P
Various metals such as i are used and formed into layers by vapor deposition, sputtering, etc. As the photoresist, commonly available ones, such as KPR manufactured by Kodak, can be used. As another method for forming the first electrode 3 and the second electrode 4, a method of vapor depositing the electrode material through a mask having comb-layered openings can also be used.

The thickness of 1st electric fi3 and II2 electric 1 to 4 is tool~5
It is one degree. After the first electrode 3 and the second electrode 4 are formed, a sustaining conductive layer 5 is formed.

The sustained photoconductive layer is a layer that has sustained photoconductivity, preferably containing a layer 1 that also has heat release properties. The term "sustained photoconductivity" here refers to the change in conductivity due to light irradiation.
This refers to a phenomenon in which changes in conductivity persist for a certain period of time even after light irradiation is cut off. Electrical conductivity (PL) of the part exposed to light irradiation
It is preferable that the conductivity change is such that the ratio h/- of the conductivity (D) of the part and the part that is not exposed to light irradiation is 10 or more, and this change in conductivity is determined by: i
It is preferable to use a photoconductive material that has a sufficiently longer duration than that of a photoconductive material, and it is preferable to use a photoconductive material that maintains a change in conductivity for at least one second, preferably one minute or more, although this is not a rule.
Thermal release property refers to a phenomenon in which the excited state is released by heating or infrared irradiation, and the conductivity returns to the dark state. Regarding heat release properties, photoconductive materials that exhibit heat release properties at temperatures above about 60°C are jL%A, taking into account the temperature inside the device and the heating device.
Examples of photoconductive materials exhibiting such sustained photoconductivity and heat release properties include zinc oxide, titanium dioxide, polyvinyl carbazoles, and the like. These photoconductive materials may contain sensitizers such as dyes and acids for sensitization. Typical sensitizing dyes include triphenylmethane, cyanine,
Typical sensitizing acids include common sensitizing acids, carboxylic acids, carboxylic acid anhydrides, and phenols.

Dispersed photoconductive materials such as zinc oxide and titanium dioxide can be used in polyester resins such as 111 acrylic resins, silicone resins, alkylene resins, epoxy resins, uremene resins, butadiene-styrene 11Fli, imide resins, silicone-butadiene resins, etc. A coating liquid dispersed in a binder using a dispersing means such as a &-Lumill dispersion machine or an ultrasonic dispersion machine is applied to form a sustained photoconductive layer. The thickness of the sustained photoconductor 45 is typically about 500 λ to 100 tones. A lone conductor 10 is formed over the persistent photoconductive layer 5. isolated conductor 1
0 is a light-shielding conductive material, such as l-0@, S+a01, etc., which is formed into an island shape, and then the light-shielding conductive material is formed into the above-mentioned light-transmitting conductive material.
It is made by forming it so that it partially overlaps with the solder body. Light-shielding conductive materials include kA, At, Wb, Z*
, Nl, Lm, etc. can be used. The isolated conductor lO is formed in the same manner as the first electrode 3 or the second electrode 1i4. The isolated conductor 10 is a discontinuous island-shaped conductor, and becomes a pixel that is not formed. Examples of the shape of the isolated conductor are shown in FIGS. 3 and 4, but the shapes are not limited to these and other shapes may be used.

A method of forming a potential image using the above-mentioned shadow forming element will be explained with reference to FIG. The first electrode 3 and the second electrode 4 are electrically connected via the conductor (17). In this state, when ms exposure is performed through the original 8 from the isolated conductor side,
The potential of the isolated conductor differs between the portions that are irradiated with light and the portions that are not, and a potential image that corresponds to the original is formed. An equivalent circuit of FIG. 5 is shown in FIG. The voltage applied by the power supply 7 is V-
, and the resistance between the second electrode 4 and the isolated conductor lO is 11
．． The resistance between the first electrode 3 and the isolated conductor 1o is R8. Potential V of isolated conductor 10.

is the voltage between the isolated conductor 10 and the first voltage 1i3, and is expressed by the following equation (1).

When clear exposure is performed from the isolated conductor side with voltage Va applied, the light does not reach the continuous photoconductive layer 5 in the light-shielding portion 12 of the isolated conductor in the exposed area, so that the second electrode 4 and the isolated conductor The resistance between the first electrode and the isolated conductor 10 does not change, and the light-transmitting part 11 of the isolated conductor remains unchanged since the light reaches the photoconductive layer. According to the above equation, the potential of the isolated conductor also decreases. On the other hand, in the non-Russian party
1 and - do not change, so the potential of the isolated conductor also does not change. As a result, a potential image with a lower potential is formed in the photosensitive portion. The potential image thus formed is developed by a normal developing method in electrophotography and transferred to transfer paper. Since the image forming element of the present invention uses a persistent conductive layer, a potential iron is formed even after light irradiation.
Since it is not necessary to perform AM at the same time as exposure, there are fewer restrictions on placement. In addition, since exposure and development can be performed on the isolated conductor side even if there is an i shift, the configuration of the apparatus can be simplified. Furthermore, since development is possible as long as the continuous photoconductivity does not disappear, it is possible to obtain a plurality of copies with one exposure. IIK to form a new lii square is used repeatedly after leaving the li image forming element in a dark place or after heating it. The heating conditions depend on the characteristics of the long-lasting conductive layer used, but are preferably about 50 to 200°C. There are several possible configurations. According to the above equation, the contrast increases by decreasing the resistance l.

Next, the present invention will be explained with reference to Examples.

Example l A comb-shaped first electrode with a thickness of about 20,001 mm and a width of 100 JI and a pitch of 250 μm was deposited on a glass substrate through a metal mask.
An electrode was formed.

Next K Z + aO powder in % parts by weight, 10 parts by weight of acrylic resin as adhesive and a small amount of rose bengal (Q for ZaOK, 1 wtfi), a small amount of stearin forged steel (2 theories OK)
On the other hand, a paint in which 01wt91G) was dispersed together with silane was applied onto the electrode substrate and dried to form a continuous conductive layer. The film thickness of the continuous conductive film was about 1011I. Further, an isolated conductor of 10 g of In with a thickness of about 2000 Jl was formed thereon via a metal mask. Furthermore, some parts are 1m, O, isolated 4111hlrz4・1...
,,5KL''Cvxzt-*t,-'cmo.

The isolated conductor was formed to a thickness of about 1001 mm.

The size of each electrode of the Li image forming element manufactured by the above method was approximately the following value in 5112m and 481st. 1=50μ, b=xs.

Voice, C=100*, 4 x s z 22571, f=
gx25#%hx125s, Todoroki=100J1゜1i above
The g1 electrode 3 of the ivIl forming element was grounded, a voltage of soo v was applied to the second electrode, and after exposure from the isolated conductor side, development was performed using a two-component dry developer. It adhered and an image was obtained.

Transfer the developed toner image onto transfer paper in a dark place! After that, an IA image was taken again without exposure, and an lji image similar to the first image was obtained. After cleaning this Im image forming element, approximately 10
When the same test was performed again after heating at a temperature of 0℃, #
-〇11 staff had completely disappeared, and I was able to use them repeatedly.

Example 2 Using the same III image forming element as in Example 1, after exposing from the isolated conductor side, the first electrode 3 was grounded and the second electrode fi4
3 by applying a voltage of KsOOV and using a two-component dry iA imager.
When performing a J image, toner adhered to the isolated conductor in the non-image area, and an image was obtained. When the 17A toner image was transferred to a transfer paper in a dark place and then subjected to 11@ again without being exposed to light, an image similar to the filth image was obtained. When this image forming element was heated at a temperature of about 100° C. after cleaning and the same test was performed again, the previous image completely disappeared and it was possible to use it repeatedly.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the basic configuration of the image forming element according to the present invention, FIG. 112 is a schematic diagram showing the electrodes of the 11f11 forming element according to the present invention, and FIGS. This is an example of the shape of an isolated conductor of an element, and FIG. 5 is an explanatory diagram of a lii formation method using an Ili@ formation element of the present invention, and 61g1 is an equivalent circuit diagram of FIG. 5. Symbols in the figure: 1...thi image forming element; 2...support; 3...
1st electrode; 4... Second electrode; 5... Sustaining conductive layer; 7... Electrode; 8... Document; 9... Light source; 10.
...Isolated conductor; 112'14 113 Figure 1 4th interval 5th Figure 6

Claims (1)

[Claims] The invention is characterized by comprising a support 2, a first IE electrode 3 and a second electrode 4, a persistent photoconductive layer 5, and an isolated conductor having a light-shielding portion and a light-shielding portion in a continuous region. An image forming element. A first electrode of a painter-forming element consisting of a support 2, a first electrode 3 and a second electrode 4, a persistent photoconductive layer 5, and an isolated conductor having a light-shielding portion and a light-sensitive portion in a continuous region; #I2
A method for forming a LII image, comprising the steps of applying a voltage to an electrode, exposing the LII image from the isolated electrode side, and developing the LII image.