JPS63174071A - Electrophotographic recording system - Google Patents

Abstract

PURPOSE:To eliminate the need for a corona discharger and to improve the reliability of a system and to reduce the size by exposing and charging electrostatically one of two photosensitive layers which differ in photosensitive wavelength, and exposing the other to an image. CONSTITUTION:A conductive layer 13, a photosensitive layer 14, and a photosensitive layer 15 which differs in photosensitive wavelength from the layer 14 are laminated successively on the surface of a base 12 to form a recording body 11. Then a voltage applying means 16 applies a voltage between the layers 13 and 15 and the recording body 1 is rotated as shown by an arrow A. The recording body 11 is exposed uniformly by a 1st short-wavelength exposing means 17 to generate photocarriers 22 in the layer 15 and the recording body is moved as shown by an arrow B. Consequently, the layer 15 is charged electrostatically and uniformly to the opposite polarity from the carriers 22. Then image exposure is performed by the long-wavelength exposure of a 2nd exposing means 18 to generate photocarriers 24 in the layer 14. Those carriers 24 have the same polarity with the carriers 22 and move to the border between the layers 14 and 15 to form a latent image on the recording body 11. This latent image is developed by a developing device 5 to obtain an image. Thus, a high-voltage power source is not required, the influence of humidity and coarse particles is small, and the improvement of reliability and size reduction are attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention provides an electrophotographic recording system in which a first film is placed on the surface of a conductive drum or a drum formed of a conductive transparent substrate without using a corona discharger in the charging process. A photosensitive layer and a second photosensitive layer having different sensitivity wavelengths from the first photosensitive layer are successively laminated in an endless manner to form a recording body, and the surface of the recording body is uniformly layered by applying a voltage to the second photosensitive layer and exposing it to light. A latent image is formed by exposing the first photosensitive layer to light.

[Industrial application field]

The present invention relates to an electrophotographic recording system, and particularly to an image forming system that does not use a corona discharger.

Currently, electrophotographic recording systems are widely used in copying machines and optical printers, and recording is performed through processes such as charging, exposure, development, transfer, and cleaning.

[Conventional technology]

FIG. 4 shows a schematic diagram of a conventional electrophotographic recording system. In the figure, reference numeral 1 denotes a recording medium, on the surface of which a photoconductive layer 2 of selenium or the like is laminated, and is rotated in the direction of arrow A.
The surface of the recording medium 1 is uniformly charged by the corona discharger 3,
Next, an image light is irradiated by the image exposure means 4 consisting of a laser or the like, and an electrostatic latent image (
An inverted image is formed by lowering the potential of the portion to which toner is to be attached, and then fine black particle toner is attached by a developing device 5 to visualize the electrostatic latent image.

In this case, the toner is charged to the same polarity as the charge charged by the corona discharger 3, and is electrostatically deposited on the recording medium 1 by an electric field to be developed. Next, the toner image is transferred onto the recording paper 10 by charging the recording paper 10 with a polarity opposite to that of the toner using the corona discharger 6, and the transferred toner image on the recording paper 10 is thermally fixed by the fixing device 7.

Further, the toner remaining on the recording medium 1 is cleaned by neutralizing the electric charge on the recording medium 1 and the electric charge of the toner with a static eliminating corona discharger 8, and removing the residual toner that has lost its binding force with a fur brush 9. At the same time, the surface potential of the recording medium 1 is reduced to approximately zero, and a series of image formation and transfer steps are repeated.

[Problem that the invention seeks to solve]

The conventional electrophotographic recording method described above uses a corona discharger 3.6.8 for charging and eliminating static electricity, and since the corona discharger is configured to apply a high voltage of several KV to the corona wire, high voltage is required. Since it requires a source and is easily affected by humidity and dust, it has the disadvantage of low reliability.

Furthermore, the ozone generated by the corona discharger produces odor, and the large amount of ozone has an adverse effect on the human body. Furthermore, charging, exposure, and development.

Since six processes, including static elimination and cleaning, are required, the device has the drawback of becoming complex and large.

The present invention was devised in view of the above-mentioned conventional drawbacks, and an object of the present invention is to provide an electrophotographic recording method that does not use a corona discharger.

[Means for solving problems]

The electrophotographic recording system of the present invention is illustrated in the principle diagram shown in FIG.
As shown in the layout diagram of FIG. 2 corresponding to the figure, a conductive layer 13 is formed on the surface of the base 12, a first photosensitive layer 14 is formed on the surface of the conductive layer 13, and the first photosensitive layer 14 is formed on the surface of the first photosensitive layer 14. The recording body 11 is a photoreceptor in which a second photosensitive layer 15 having a sensitivity wavelength different from that of the first photosensitive layer is laminated in an endless manner, and a voltage is applied between the conductive layer 13 and the second photosensitive layer 15. A voltage applying means 16 is provided to apply the voltage, and the recording medium 11 is rotated,
The first wavelength of sensitivity of the second photosensitive layer 15 is located along the rotation path.
The structure is such that an exposure means 17, a second exposure means 18 having a wavelength to which the first photosensitive layer is sensitive, and a developing device 5 are provided in this order.

Further, a rubber roller transfer device (19) is provided for transfer after development in the developing device 5, and a photostatic eliminator (19) is provided for charge removal after transfer.
20).

Further, the base body 12 may be formed of a conductive material and serve as both the base body and the conductive layer, or the base body 12 and the conductive layer 13 may each be formed of a transparent material.

Note that the first and second photosensitive layers 14 and 15 can each be formed of either a single-layer type photoreceptor member or a functionally separated type photoreceptor member.

[Effect]

Due to the voltage application means 16 and the first exposure means 17, photocarriers are generated in the second photosensitive layer 15 on the surface of the recording medium 11, and as the recording medium 11 rotates, the second photosensitive layer is exposed. The surface of the photocarrier 15 can be uniformly charged with a charge having a polarity opposite to that of the photocarrier. Thereafter, the first photosensitive layer 14 is imagewise exposed by the second exposure means 18 using a sensitivity wavelength that only the first photosensitive layer 14 is sensitive to, thereby forming a latent image on the surface of the recording medium 11. .

A rubber roller transfer machine 19 is used to transfer the latent image after development.
By using the optical static eliminator 20 to eliminate static electricity from residual toner, a corona discharger can be made unnecessary.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

Note that, in order to make the explanation of the configuration and operation easier to understand, the same parts are given the same reference numerals throughout all the figures, and repeated explanation thereof will be omitted.

FIG. 2 shows a sectional layout diagram of essential parts of the electrophotographic recording system of the present invention, which corresponds to the principle diagram of FIG. 1. In the figure, reference numeral 11 denotes a recording body used in the present invention, and the recording body 11 has an endless (domed) conductive layer 13 on the surface of a base 12. First photosensitive layer 14. The first photosensitive layer 14 and the second photosensitive layer 15 have different sensitivity wavelengths, and each member is laminated in this order.

16 is a voltage application means for applying a voltage between the conductive layer 13 and the second photosensitive layer 15; 17 is a first exposure means for the second photosensitive layer 15; and 18 is a first exposure means for the first photosensitive layer 14. 2 exposure means, 19 a rubber roller transfer device, and 20 an optical static eliminator.

The principle of FIG. 1 will be explained below with reference to FIG. FIG. 1A is a diagram for explaining the exposure state of the second photosensitive layer 15, in which a thin aluminum film of a conductive member is formed on the surface of the base 12 as a conductive layer 13, for example. Alternatively, the base 12 itself may be formed of conductive aluminum and the conductive layer 1
3 may also be used.

A charge generation layer 14 made of, for example, a phthalocyanine material having long wavelength sensitivity is deposited on the surface of the conductive layer 13, and a charge transport layer made of, for example, an oxazole material is further deposited on the surface thereof to form a first photosensitive layer. . A second photosensitive layer 15 made of, for example, a selenium-based material and having short wavelength sensitivity different from the sensitivity wavelength of the first photosensitive layer 14 is deposited on the surface thereof. Each of the above vapor deposition means may be a coating means. The photoreceptor thus formed into an endless shape (drum shape) is used as the recording member 11.

An electrode (not shown) connected to the second photosensitive layer 15 side of the voltage application means 16 that applies a voltage between the conductive layer 13 and the second photosensitive layer 15 is located outside the printing area. , is included in the exposure width area of the exposure means 18, which will be explained below.

As shown in FIG. 2, the drum-shaped recording medium 11 rotates in the direction of arrow A in the figure. In the charging exposure section 22, the light is uniformly exposed by a short-wavelength first exposure means 17, such as a filtered white fluorescent light source.

During this exposure period, the first photosensitive layer 14 having short wavelength sensitivity
As the photocarriers 22 are generated, the electrical resistance of the first photosensitive layer 14 becomes low, and as shown in FIG.
2 moves as shown by arrow B.

Recording body 1 passed through charging exposure section 21 due to rotation of the drum
After the exposure of the second photosensitive layer 15 in the photosensitive layer 1 is completed, the electrical resistance becomes high again. As a result, the photo carriers 22 that have moved can no longer return to the second photosensitive layer 15, and the second photosensitive layer 15 lacks charge by the amount of the transferred charge, so that the photo carriers 22 have polarities opposite to those of the photo carriers 22. It is uniformly charged (see Figure 1(b)).

The uniformly charged recording medium 11 further rotates and reaches the second exposure means 18 . In the image exposure section 23 to which the second exposure means 18 irradiates, image exposure is performed by the exposure means 18 provided facing the recording medium 11, for example, an le-Ne laser.

First photosensitive layer 1 having long wavelength sensitivity due to long wavelength exposure
4, the electrical resistance of the photosensitive layer 14 shown in FIG.
The photo carrier 24 moves to the boundary of the photosensitive layer 14 .

This moved photocarrier 24 has the same polarity as the photocarrier 22 described above, and since the photocarrier 24 and the second photosensitive layer 15 are very close to each other, the image received by the second photosensitive layer 15 is The surface potential of most of the exposed portions decreases, thereby forming an electrical latent image on the recording medium 11 (see FIG. 1(d)).

This latent image is developed by applying an appropriate developing bias to a developing device 5, such as a magnetic brush developing device, to obtain an image.

Furthermore, in place of the corona discharger 6 and static eliminating corona discharger 8 in the conventional example shown in FIG.
9. By using the optical static eliminator 20, an electrophotographic recording method that does not use a corona discharger at all can be realized.

FIG. 3 shows a sectional layout diagram of main parts according to another embodiment of the present invention. The difference between this figure and FIG.
The recording medium 11' is constructed using a transparent substrate 12' from the back side of the recording medium 11' (inner diameter side of the drum) instead of the second exposure means 18 that exposes the first photosensitive layer 14 from the outside of the recording medium 11. The structure includes a second exposure means 18' that exposes the first photosensitive layer 14 by transmitting light through the transparent conductive layer 13' and the transparent conductive layer 13'.

The transparent substrate 12' can also be constructed of a film-like transparent substrate made of polyethylene terephthalate, for example. The transparent conductive layer 13'' is made of indium-tin oxide (CITO), for example, and a voltage applying means for applying a voltage between the transparent conductive layer 13'' and the second photosensitive layer 15 is provided. The second exposure means 18 in the example is LE
It has a configuration in which a D array is arranged.

The image forming process is similar to that in FIG.

In the case of this embodiment, by arranging the second exposure means 18' on the back side of the recording medium 11', it is possible to prevent the second R light means 18' from being contaminated by developer.

Furthermore, the first exposure means 17 can also be similarly arranged on the back side of the recording medium 11°, and it is also possible to prevent the first exposure means 17 from being contaminated by the developer.

〔Effect of the invention〕

As explained in detail above, according to the electrophotographic recording method of the present invention, there is no need to use a corona discharger, so a high voltage power supply is not required, and miniaturization is possible.
Also, due to the influence of humidity, dust, etc.

Claims (3)

[Claims] (1) A conductive layer (13) on the surface of the substrate (12), a first photosensitive layer (14) on the surface of the conductive layer (13), and the first photosensitive layer (14) on the surface of the first photosensitive layer (14). The recording body (11) is a photoreceptor in which a second photoreceptor layer (15) having a different sensitivity wavelength from the photoreceptor layer (14) is sequentially laminated in an endless manner, and the conductive layer (13) and the second photoreceptor layer A voltage applying means (16) for applying a voltage between the recording medium (11) and the recording medium (11) is provided, and the recording medium (11) is rotated so that the first wavelength of the sensitive wavelength of the second photosensitive layer (15) is provided along the rotation path. An exposure means (17) and a second exposure means (18) having a sensitivity wavelength of the first photosensitive layer (14) are sequentially provided, and the voltage application means (16) and the first exposure means (17) An electrophotographic recording method characterized in that the surface of a recording medium (11) is uniformly charged, and then imagewise exposed by the second exposure means (18) to form a latent image. (2) The electrophotographic record according to claim (1), characterized in that the base (12) is formed of a conductive member, and the base (12) and the conductive layer (13) also serve as a conductive layer. method. (3) The base (12) and the conductive layer (13) are formed of transparent members, and the second exposure means (18) is
2. An electrophotographic recording system according to claim (1), wherein the electrophotographic recording system is arranged opposite to each other.