JPS6019500B2 - Electrophotography and its equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic method and an apparatus therefor that can simultaneously form a first image and a second image.

As the electrophotographic method, the electrofax method, the Xerox method, the PIP method, the NP method (for example, Japanese Patent Publication No. 42-23910, etc.) are known.

The electrofax method and the Xerox method form an electrostatic image by the so-called Carlson process, in which a photoconductor layer of oxide film (electrofax), amorphous selenium (Xerox), etc. is used as a support. The photoconductor surface of the photosensitive plate formed above is uniformly charged by corona discharge, and then the original image is irradiated to attenuate the charge in the light-irradiated area, and an electrostatic image that follows the light and dark pattern of the original image is charged. After being developed and visualized with colored particles, an electrophotographic image is obtained by fixing it or once transferring it onto a support such as paper and then fixing it, and the PIP method is based on the physical properties of crab-like substances, etc. In other words, a latent image is formed using persistent internal polarization and photoconductivity, whereas the NP method uses the capacitance difference and photoconductivity between the photoconductor layer and the insulating layer used above it. An electrostatic image is formed, and an electrophotographic image is obtained through development, transfer, and fixing steps in the same manner. To date, copying devices using these electrophotographic methods have been developed, but there are devices that overlap multiple originals on a photosensitive plate and expose them to form a composite latent image, which is then developed into a developed image. Although the demand for this is increasing, there is no product that fully satisfies this demand, and it has only been used for very limited purposes.

In addition, such a composite image forming process itself uses an optically composite composite image or an electrically composite signal to obtain a composite image, and the different steps that make up the electrostatic image forming process are used. Overlay methods, in which a composite image is formed on a photosensitive plate by combining images, have been extremely limited. The present invention meets the above-mentioned needs, improves the previously proposed methods, and provides the first step in the electrostatic imaging process.
, an object of the present invention is to provide a simple method and apparatus for performing overlay using the second step. A feature of the present invention is that in an electrophotographic method using a photosensitive plate whose basic components are a conductive support, a photoconductive layer, and an insulating layer, a first image is formed almost simultaneously when the surface of the insulating layer is charged. By applying a forming irradiation and then performing AC static elimination, a second image forming irradiation is applied almost simultaneously, and furthermore, by exposing the entire surface of the insulating layer, an electrostatic image of a composite image of the first and second images is created. There is an electrophotographic method and an apparatus therefor.

Another feature resides in an electrophotographic method and an apparatus for forming a static latent image in which the first image and the second image are positioned and superimposed in synchronization.

First, an outline of an embodiment of the electrophotographic method according to the present invention will be briefly described. A photosensitive plate whose basic components are a conductive support, a photoconductive layer, and an insulating layer is used.

The surface of the insulating layer of the photosensitive plate is positively or negatively charged almost simultaneously with the first light beam irradiation. Next, the surface of the insulating layer is subjected to alternating current neutralization almost simultaneously with the irradiation of the second light image, and then the entire surface of the insulating layer is uniformly exposed to light that is a bright part of the first light image and a part of the second light image. A surface potential difference is generated between the dark area and the other areas to form a composite latent image of the first optical image and the second optical image. After the electrostatic image is developed and visualized with a developer mainly composed of charged colored particles, the visible image is transferred to a transfer material such as paper using an internal or external electric field, and then an infrared lamp The transferred image is fixed with heat rays using a fixing means such as a hot plate to obtain an electrophotographic image, and after the transfer is performed, the surface of the insulating layer is cleaned to remove remaining charged particles, and the photosensitive plate is is used repeatedly. Next, embodiments of the present invention will be described below with reference to the drawings.

Figure 1 is an explanatory diagram of the structure of a photosensitive plate that forms an electrostatic image.
1 is a conductive support, and 2 is a photoconductive layer coated on the conductive support 1, for example, by spraying or using a coater, furler, etc., to improve bonding with the cell layer if necessary. Therefore, a small amount of binder, mainly resin, may be added. Reference numeral 3 denotes an insulating layer that is uniformly formed in close contact with the photoconductive layer 2 .

In this way, the photosensitive plate A is basically formed of three layers: the conductive support 1, the photoconductive layer 2, and the insulating layer 3. A layer for trapping charges may be formed between the support and the photoconductive layer, and may also be added to the surface or near the surface of the photoconductive layer. Further, it is preferable that the photoconductive property has as high a resistance as possible in the tray. The conductive support 1 is made of a metal conductor such as tin, copper, or aluminum, or hygroscopic paper, but a support made of paper with aluminum foil attached is inexpensive and can be wrapped around a drum or the like. It is convenient when used.

The material of the photoconductive layer is CdS, CdSe, crystalline Se, Z
Usable materials include n0, ZnS, Se, Ti02, SeTe, and P, or mixtures thereof. Some such photoconductive layers have a charge injection property in which charges of a specific polarity are injected from the conductive support into the photoconductive layer when it is charged in the store. In embodiments, if the charge distribution due to the first light image irradiation, which is performed almost simultaneously with the primary charging, is positively influenced due to such properties, the charge at such a stage is used as the primary charging polarity. It shall be charged with a polarity that does not cause injection. In the case of a photoconductive material that does not substantially have a charge injection property, or even if it does have it, it does not substantially affect the charge distribution due to the above-mentioned photoimage irradiation, it can be charged to any polarity. The material constituting the insulating layer 3 has high abrasion resistance, high resistance, and can hold static charge.
Any material that satisfies the three requirements of being transparent can be used, and coatings such as fluororesin, polycarbonate resin, polyethylene resin, cellulose acetate resin, and polyester resin can be used. In particular, fluororesin has the property of being easy to clean. Therefore, it is a preferred material in the embodiment of the present invention because the photosensitive plate can be used repeatedly through a post-transfer cleaning process as described below. Figures 2 to 4
The figure illustrates the process of forming a composite latent image on the photosensitive plate configured as described above and the charging pattern of the photosensitive plate.

In FIG. 2, first, the surface of the insulating layer 3 of the photosensitive plate A is charged, for example, negatively (1) by the corona discharger 4, and a first light image is irradiated almost simultaneously.

At this time, since the photoconductive layer 2 has a high resistance in the dark area, a positive (10) charge 32 is transferred. In addition, in the bright area, the photoconductive layer 2 becomes conductive due to light stimulation, so positive (10) charges are injected from the conductive support 1 and are attracted to the surface charge (1) of the insulating layer, causing the photoconductive layer to become conductive. 2 and the insulating layer 3 (FIG. 2). Through this process, the surface potential of the insulating layer 3 increases to negative (1) with the charging time, and exhibits the characteristics shown in FIG. 5VP.
Next, at the same time as the second light image irradiation is applied to the surface of the insulating layer 3, AC corona discharge is applied by an AC corona discharger 8 (FIG. 3).
.

Since the corona discharger 4 and the AC corona discharger 8 perform discharge almost simultaneously with the irradiation of the light image, it is preferable that the upper part thereof is transparent or has an optically open structure without a shield plate.

The negative (one) charge 31 that was charged on the surface of the insulating layer 3 in the dark areas 1 and 0 during the first light image irradiation has no binding force, so all or most of it is discharged. .

In addition, the photoconductive layer 2 is made conductive by optical stimulation in the bright area during the first light image irradiation and also in the bright area W during the second light image irradiation, and the photoconductive layer 2 and the insulating layer Since the positive (10) charges 33 that remained at the interface of the insulating layer 3 are easily released to the conductive support 1, the negative (1) charges 31 that had been charged on the surface of the insulating layer 3 lose their binding force. All or most of it is discharged together with the positive (10) charge 33 that had stopped.

The amount of these discharges depends on the AC corona discharge time and intensity. On the other hand, in the portion m that was a bright area when the first light image was irradiated and a dark area when the second light image was irradiated, the resistance value of the photoconductive layer 3 is high and the conductivity of the positive (10) charges 33 that remains near the interface is high. Since there is no emission to the support 1, the negative (1) charge 31 on the surface of the insulating layer 3 is restrained by this positive (10) charge 33, and the negative (1) charge 31 on the surface of the insulating layer 3 becomes an AC corona. The degree of discharge is smaller than that of the dark part when the first light image is irradiated or the bright part 0, W when the second light image is irradiated.

In this way, the bright part m of the first light image and the bright part m of the second light image
In this case, there is a large amount of negative (1) charge remaining on the surface of the insulating layer 3, but at the same time, a positive (10) charge 33 remains on the photoconductive layer 2.
Since a large amount of remains stationary, the field due to the surface charge of the insulating layer 3 acts quite strongly in the direction of the positive (10) charges 33 stationary on the photoconductive layer 2, and the external field due to the surface charge is It becomes extremely small (Figure 3). Next, the entire surface of the insulating layer 3 is exposed from the surface side (or from this side if the conductive support is translucent) (fourth step).
figure).

In the dark areas of the first optical image or the bright areas 1, 2, and W of the second optical image, there is substantially no change in the exposure distribution state within the photoconductive layer 2, so that the insulating layer 3 The surface potential of is also approximately 0 potential, same as in FIG.

However, in the bright area of the first light image and the dark area of the second light image, the photoconductive layer 2 exhibited high resistance because there was no light irradiation during exposure of the second light image. Since it is exposed to light during exposure, its resistance value decreases rapidly and it becomes conductive. Therefore, the positive (10) charges 33 that had been trapped inside until then are released to the conductive support 1 and disappear, leaving only the amount of charge equivalent to the charge load 31 on the surface of the insulating layer 3. .
As a result, the external field increases rapidly on the charged load 31 on the surface of the insulating layer, and the surface potential increases. Changes in the surface potential of the insulating layer 3 due to these processes exhibit characteristics as shown in FIG.

In other words, the military area of only the part of the town that was a bright area when the first light image was irradiated and a dark area when the second light image was irradiated is VL. is large, and the other portions 1, 2, and W have a substantially zero potential such as Voo, VoL, and VLL. Therefore, when this photoreceptor A is developed with toner, a composite image of the first light image and the second light image is visualized.

FIG. 6 shows the case of development with a toner having the above-mentioned primary charging polarity and reverse gutter polarity, that is, positive polarity. Toner adheres to the surface. FIG. 7 shows reversal development, that is, development with a toner having a negative gutter property of the same polarity as the primary band electromagnetic property, in which development is performed in the opposite direction to that in the case of normal development, and parts 1, B, and W are used. Toner adheres to the surface.

In this case, it is well known that better development can be achieved if a developing electrode is used. Figures 9 to 12 show examples of such composite image formation, in which a is the original of the first optical image, b is the original of the second optical image, and c is the toner with positive polarity. d shows a composite image of a and b when developed, and d shows a when developed with toner with negative polarity.
, b.

As can be seen from these composite images, different composite images can be obtained according to the light and dark patterns of the first and second light images and their yin and yang, and can be selected depending on the purpose.
Next, the visible image formed on the surface of the insulating layer is transferred onto a transfer material 11 such as paper by applying a corona discharge 10, an external voltage such as a bias voltage, or an internal electric field, as shown in FIG. Finally, the transferred image is fixed using infrared rays, a hot plate, etc., or a pressure fixing means to obtain an electrophotographic image.

On the other hand, since the photosensitive plate is used repeatedly, after the transfer is performed, the surface of the insulating layer is cleaned by a known cleaning method to remove charged particles remaining on the surface.

At this time, the cleaning effect will be enhanced if the cleaning is performed after removing the electrostatic image formation charges on the insulating layer surface in the bright areas of the original image mainly by recharging. To do this, before cleaning, the surface of the insulating coating may be exposed to an alternating current corona discharge to remove the charge caused by the electrostatic image formation, and then cleaned with an elastic blade, fur brush, or the like. In this case, the cleaning effect can be enhanced by providing the cleaning means with an exposure field having a polarity opposite to that of the charged colored particles. The effectiveness of this cleaning also depends on the properties and tackiness of the material of the insulating coating, so all of the resins mentioned above are suitable as electrostatic image forming materials, but among them, fluororesin coatings are especially suitable. It is the most effective in that it resists stickiness, assists in the detachment of charged colored particles during cleaning, and has a remarkable cleaning effect.

The preferred electrostatic image for development is '1) Said VLo and V plate V.

Sufficient surface potential difference with LVLL '2' V above
No surface potential difference occurs between oDVLoVLL.

In order to satisfy this {1} Photoconductive substance 2 '2) First and second exposure amounts {3' Polarity and intensity of the initial charge {4} Intensity of AC corona discharge It is necessary to set the following appropriately.

Next, a quantitative explanation of one embodiment of the static exposure latent image forming method according to the present invention is as follows.

Add 100 grams of copper-activated cadmium sulfide to 10 grams of vinyl chloride, and then add a small amount of thinner and mix. The photosensitive material obtained is coated on a surface-polished aluminum cylinder to a thickness of about 50 grams. Next, an insulating layer having a thickness of 35 mm is laminated on the surface of this photoconductive film to obtain a photosensitive plate.
Next, 16. Almost at the same time as the corona discharge of RO V is applied, the first light image (bright part has a light intensity of about 12 lux for 0.3 seconds) is irradiated. Then AC7. Almost simultaneously with the alternating current corona discharge of arc V, a second light image having the same amount of light as the first light image is irradiated. Furthermore, the entire surface is covered with approximately 0.0. A high-contrast electrostatic image is formed on the surface of the insulating layer by uniformly exposing the main stage to light. When the surface potential during this electrostatic image formation process was measured using a surface electrometer, the portion corresponding to VP in Fig. 5 was -1400V, the portion corresponding to VLD and VLL,
V. . ,V. A surface potential difference of about 400 V with respect to the L-corresponding portion was obtained. Next, as an embodiment of the present invention, an example in which a laser beam recording device with an overlay function such as a fixed format is applied will be described with reference to the drawings.

FIG. 13 is a perspective view of this embodiment, and FIG. 14 is a cross-sectional view of the same embodiment. In FIGS. 13 and 14, an original 11' in a standard format or the like is placed on a document table 10 that can be moved in synchronization with laser exposure, as will be described later, and is illuminated by a document table exposure lamp 12. The original image is bent toward the original image lens 14 by the mirror 13, and is exposed onto the photosensitive drum 20 as a first exposure to be described later.

Further, the second exposure of the laser exposure is performed with a laser beam in synchronization with the original image of the first exposure, such as in a standard format.

This laser beam second exposure will be explained below. A laser beam oscillated by a laser oscillator 21 is guided to an input gate of a deflection/modulator 23 via a reflection mirror 22. The reflecting mirror 22 is inserted to bend the optical path in order to reduce the space of the apparatus, and can be removed if unnecessary. For the deflection/modulator 23, an acousto-optic deflection/modulation element using a known acoustic effect or an electro-optical element using an electro-optic effect is used. deflection·
In the modulator 23, the laser beam is subjected to intensity modulation and deflection according to the input signal to the deflection/modulator 23. In addition, if the laser oscillator is a semiconductor laser, or if a gas laser or the like is used, the modulator 23 is not necessary when using a laser with an internal modulation pole that allows current modulation or a type that incorporates a modulation element in the oscillation optical path. It is.

The light from these light sources reaches the beam expander 24 after passing through appropriate optical systems. The beam diameter of the laser beam from the modulator 23 is expanded by a beam expander while remaining a parallel beam.

Furthermore, the laser beam with enlarged beam diameter cuts the mirror surface by 1
The light is incident on the polyhedral rotating mirror 25, which has one or more polyhedral rotating mirrors.
The polyhedral rotating mirror 25 is a high-load bearing (for example, an air bearing).
A polyhedral rotating mirror 25 mounted on a shaft supported by a shaft and driven by a constant speed motor 26 (for example, a hysteresis synchronous motor or a DC servo motor) scans horizontally. This scanning may be performed using galvano mirrors. The laser beam horizontally scanned by the polyhedral rotating mirror 25 is imaged as a spot on the photosensitive drum 40 by the imaging lens 27 having f-ley characteristics.

In a general imaging lens, when the incident angle of the light ray is 8, the image forming position r on the image plane is rnif・nen8
......[1] There is a relationship of 0 (f: actual point distance of the imaging lens), and as in this embodiment, the laser beam 28 reflected by the polygonal rotating mirror 25 of constant rotation.
The angle of incidence on the imaging lens 27 changes linearly with time.

Therefore, the moving speed of the imaged spot position on the photosensitive drum 40, which is the mound surface, changes non-linearly and is not constant. That is, the moving speed increases at the point where the angle of incidence increases. Therefore, when a laser beam is turned on at regular time intervals to draw a spot array on the photosensitive drum 40, the intervals between the spots are wider at both ends than at the center. In order to avoid this phenomenon, the imaging lens 27 is configured such that r=f・〇
------[It is designed to have the following characteristics. Such an imaging lens 27 is called an f-0 lens. Furthermore, when collimated light is imaged into a spot by an imaging lens, the minimum spot diameter dmin is dmin
= f meeting ------ {3' However, f: Focal length of the imaging lens ^: Wavelength of the light used A: Incident aperture of the imaging lens ○ If f and ^ are constant, then A By increasing , a spot diameter dmin of 4 mm can be obtained.

The beam expander 24 mentioned above is used to provide this effect. Therefore, if the required dmin can be obtained by the beam diameter of the laser oscillator, the beam expander 24 is omitted. The beam detector 29 consists of four small entrance slits and a photoelectric conversion element (for example, a PIN diode) with a fast response time. The beam detector 29 detects the position of the swept laser beam 28,
Using this detection signal, the start timing of a horizontal scanning input signal to the modulator 23 for providing desired optical information on the photosensitive drum is determined. As a result, it is possible to reduce synchronization errors in the horizontal direction signals due to errors in the division accuracy of each reflective surface of the polyhedral rotating mirror 25 and uneven rotation.
Not only can a high-quality image be obtained, but the tolerance range of accuracy required for the polyhedral rotating mirror 25 and the drive motor 26 is increased, and the manufacturing cost is lower. In the manner described above, the laser beam 28 modulated by the external signal is exposed onto the photosensitive drum 40 as second exposure, which will be described later.

Next, the printing section shown in FIGS. 13 and 14 will be described.

A corona discharger 41 for initial charging is installed on the surface of the insulating layer of the photosensitive plate 40, which basically consists of a conductive support, a photoconductive layer, and an insulating layer.
Almost at the same time when the first exposure of an original image in a standard format or the like is performed through the insulating layer 41, the surface of the insulating layer is negatively charged by the corona discharger 41. When the partial force of the first exposure on the photosensitive plate 40 rotating in the direction of the arrow comes to the position of the AC corona discharger 42, a second exposure is performed which has been positionally synchronized with the first exposure in advance. A certain laser beam exposure is performed on the surface of the insulating layer, and at about the same time, an AC corona discharger 42 neutralizes the surface of the insulating layer. Next, the lamp 43 exposes the entire surface of the insulating layer. Through the above process, a surface potential is generated on the photosensitive plate in the bright area (white background) of the original image in the first exposure and in the area not hit by the laser beam in the second exposure, and in other areas to form a composite electrostatic image. do. In this case, a negative (1) charge remains on the surface of the insulating layer in a portion that is a bright portion of the first exposure and a dark portion of the second exposed portion, and the other surface of the insulating layer has approximately zero potential. Next, the composite electrostatic image is developed and visualized by a developer means 44 using a developer mainly composed of negatively (uni) polar charged colored particles for reversal development, and then transferred to a transfer material 45 such as paper. The visible image is transferred using an internal or external electric field 46, and then the transferred image is fixed by a fixing means 47, such as an infrared lamp, a hot plate, or a pressure fixing means, to obtain an electrophotographic print image 48. On the other hand, after the transfer is performed, the surface of the photosensitive plate 4 or the insulating layer is cleaned by a cleaning means 49 to remove remaining charged particles, and the photosensitive plate is used repeatedly. As described above, in this embodiment, when reverse development is performed, charged colored particles adhere to the dark part of the first exposure and the bright part of the second exposure where the first exposure is a bright part (see Figure 7). ), the original format for the first exposure can be a positive original, which is easy to create, and the signal control of the laser beam for the second exposure can be done using the control method of the laser beam recording device that has already been developed in recent years. It can be used.

Furthermore, although this embodiment has been described with reference to an apparatus in which an overlay function such as a fixed format is added to a laser beam recording device, the present invention can also be applied to an apparatus in which an overlay function such as a fixed format is added to an electrophotographic copying machine according to the present invention. For example, a device using a CRT in place of a printer, a device combining an electrophotographic copying machine and a microfilm enlargement printing machine, etc. are equally effective.

Next, an example of a method for positionally synchronizing the first optical image and the second optical image will be described.

Of course, there are cases where it is not necessary to synchronize the first optical image and the second optical image. For example, when the first light image or the second light image is used repeatedly for a pattern on a printed material, a squash pattern, etc.
The explanation in this case will be omitted. There are the following types of combinations of the first optical image and the second optical image to be synchronized.

(1) The first light image has the reflected light of the original, the second light image has the reflected light. The first light image has the reflected light of the original, the second light image has the reflected light of the original. The first light image has the reflected light of the original. Laser light, laser beam into the second light image '4' Laser light into the first light image, reflected light from the original into the second light image, light transmitted through the film-like original instead of reflected light from the original,
Microfilm magnified transmitted light, etc., laser light, beam light spot exposure may be used, and spot light from a CRT or the like may also be used.

An example of how to achieve synchronization in cases 1 to 4 above will be described in order below. First, the case of 0- is the case of the above-mentioned device embodiment.

When the document table 10 moving at a constant speed in FIGS. 13 and 14 moves to a predetermined position, it is detected by, for example, a microswitch (not shown), and a ready signal is generated as shown in the timing chart of FIG. .

After a certain period of time T, exposure of the top portion of the document is started. Thereafter, after an adjustment time, data is input and laser beam exposure is started. The time difference L between the start of exposure of the top part of the document and the start of laser beam fog Z light is T2=E2-
E, Vp However, E2-E,; Distance between the first light image exposure section and the second light image exposure section J; vp: Circumferential speed of the photosensitive drum.

The time chart at this time is shown in Figure m5.

Here, T is determined mechanically, that is, by the relationship between the mounting position of the ready signal generation switch on the document table and the top position of the document.
T2 is set by electrically known counting means. Next, an example of how to achieve synchronization in the case where the original reflected light is applied to the first optical image and the original reflected light is applied to the second optical image will be described.

This will be explained using the explanatory diagram shown in FIG. 1st and 2nd
The top position of the originals 11-, 11-2 and the first and second
The first and second documents can be synchronized by setting the positions of the exposure sections E, E2 on the photosensitive drum surface in the following relationship. 12-11-E2-E4 Vf Vp Start, L; Distance of movement of the document table until it rises during constant speed movement, or a greater distance 12-1,; Amount of deviation between the tops of the first and second documents vr ;Velocity vp of the document table 10;Peripheral velocity E2-E of the photosensitive drum 20;;Distance between the first light image exposure section and the second light image exposure section What is the specific means for synchronizing such movement? Well-known means may be used.

Next, an example of {3} will be shown.

A laser beam is used for the first optical image, and a laser beam is used for the second optical image, and they are synchronized by starting the second laser beam exposure L after the start of the first laser beam exposure, and T
The time 2 may be electrically set to a time that satisfies the following relationship. T2=E2-E, However, E2-E,; Distance vp between the first light image exposure part and the second light image exposure part; Circumferential speed of the photosensitive drum An example will be shown in which a laser beam and reflected light from the original are used as the second optical image.

An explanatory diagram is shown in FIG.

When the document table 101, which moves at a constant speed, reaches a predetermined position, it issues a ready signal as shown in FIG. Then, after an adjustment time, the data is input and laser beam exposure 28 is started. The time is adjusted so that the top of the original 11 is exposed when the laser beam exposure starting portion of the photosensitive drum rotates and comes to the original reflected light exposure position, that is, the second light image exposure position 0.
The time difference T2 between the start of data input for laser beam exposure and the start of top exposure of document 11 is T2=E2-E,Vp. Distance vp from the light exposure position, that is, the second light image exposure position; the circumferential speed of the photosensitive drum is 0, and the time T from the generation of the ready signal to the start of top exposure of the original 11 is T, = sign, where talr −f: Distance between the mounting position of the ready signal generation switch and the document top position (not shown) vf: Movement speed of the document table 10.

The ready signal can be generated by installing a microswitch or the like so that it can be turned on or off by moving the document table.

As can be seen from the time chart shown in Fig. 16, by adjusting the time from receiving the ready signal to starting data input/exposure by the laser beam and starting to expose the top of the original, that is, by adjusting the time T, ~L. Adjust the timing,
The top of the manuscript is synchronized.

The method for synchronizing the first optical image and the second optical image has been briefly described above.

As detailed above, the present invention provides the following features: [1] In an electrophotographic method using a photosensitive plate whose basic components are a conductive support, a photoconductive layer, and an insulating layer, almost simultaneously the surface of the insulating layer is charged. Applying the first bride-forming irradiation, then applying the second image-forming irradiation almost at the same time as AC static elimination, and further exposing the entire surface of the insulating layer to the static charge of the composite group of the first and second images. The present invention provides an electrophotographic method characterized by forming a silkworm latent image and an apparatus thereof.

In this method, the present invention also provides an overlay method and a device thereof, which is characterized in that a static latent image is formed by overlapping a first image and a second image in positional synchronization. Therefore, by combining the first image and the second image, various composite latent images can be formed using the first and second steps of latent image formation.

Therefore, the image forming apparatus can be adapted to a wide range of uses, and is extremely useful for synthetic recording of various data and information.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the structure of a photosensitive plate that can be applied to the present invention. FIGS. 2 to 4 show the photosensitive plate shown in FIG.
An explanatory diagram showing the process of irradiating the second image forming light and forming a composite submarine squad. Figure 5 shows the changes in the surface potential of the photosensitive plate during the process shown in Figures 2 to 4. 6 and 7 are diagrams showing the process of developing a latent image, Figure 8 is a diagram showing the process of transferring a developed image, and Figures 9 a, b, c, d~Figure 12 a, b, c, d are the first and second
13 is a perspective view of an embodiment of the electrophotographic apparatus according to the present invention, FIG. 14 is a cross-sectional view thereof, and FIGS. 1
FIG. 6 is a diagram showing a time chart of the synchronization method of the first and second image forming exposures in the embodiment according to the present invention, respectively;
FIGS. 17 and 18 are explanatory diagrams showing the synchronization method. 0 1... Conductive support, 2... Photoconductive layer, 3... Insulating layer, A, 20... Photosensitive plate, 4, 41... ...Charge applying means, 8, 42...
- AC disarming means, 43...Full exposure means. Depart! Figure group 2 figure moving figure 4 figure leopard and figure ※5 figure holly tree figure 8 figure chrysanthemum? My younger brother io my younger brother! L-shaped younger brother, illustrated younger brother, illustrated younger brother, l4 illustrated hair, l5 illustrated younger brother, l, box younger brother [illustrated younger brother]

Claims (1)

[Scope of Claims] 1. In an electrophotographic method using a photosensitive plate whose basic constituents are a conductive support, a photoconductive layer, and an edge layer, the first image forming method is applied almost simultaneously when the surface of the insulating layer is charged. By applying irradiation, then applying a second image-forming irradiation almost simultaneously with AC static elimination, and further exposing the entire surface of the photosensitive plate,
An electrophotographic method characterized by forming an electrostatic latent image of a composite image of first and second images. 2. The photophotography method according to claim 1 is characterized in that an electrostatic latent image is formed by positionally synchronizing and overlapping a first image and a second image. Electrophotography. 3. In the electrophotographic method according to claim 1 or 2, the first image is provided by irradiating an original image with a light image, and the second image is provided by spot irradiation with a beam of light. An electrophotographic method characterized by 4. An electrophotographic method according to claim 1 or 2, wherein the first and second images are each provided by irradiating an original image with a light image. 5. In the electrophotographic method according to claim 1 or 2, the first image is provided by spot irradiation with a beam of light, and the second image is provided by light image irradiation of an original image. An electrophotographic method characterized by 6. An electrophotographic method according to claim 1 or 2, characterized in that the first and second images are provided by spot irradiation with beam light. 7. A photosensitive plate having a conductive support, a photoconductive layer, and an insulating layer as basic constituents; a means for applying a first image-forming irradiation to the photosensitive plate substantially simultaneously with charging the surface of the insulating layer; A means for applying irradiation for forming a second image almost at the same time as AC charge removal on the surface to be charged is performed later, and a means for exposing the entire surface of the photosensitive plate after that, are provided, and the composite latent of the first and second images is provided. An electrophotographic device characterized by forming an image. 8. A photosensitive plate having a conductive support, a photoconductive layer, and an insulating layer as basic components; a means for applying a first image-forming irradiation to the photosensitive plate almost simultaneously with charging the surface of the insulating layer; means for applying irradiation for forming a second image almost simultaneously when AC charge removal is performed on the surface to be charged; An electrophotographic apparatus comprising means for positionally synchronizing the irradiation of the photosensitive plate and means for exposing the entire surface of the photosensitive plate to form a composite latent image of the first and second images.