JPS5988751A - Image forming method - Google Patents

Abstract

PURPOSE:To obtain a fog-free image which deteriorates less on repetitive use by rubbing the magnetic toner, which is held on a magnetic roll, on the opposite side while exposing the image from a transparent substrate side. CONSTITUTION:A light of a lamp 10 is irradiated from the transparent conductive layer 2 side of a photosensitive body 1 through a slit 8 and an original 9 to the photosensitive body and at the same time the photosensitive body 1 and an original 9 are moved in an arrow direction so that the (semi)conductive toner 6 held on a developing roll 5 having internally a magnet in the state of being impressed with a voltage rubs the surface of the photosensitive body. The toner 6 sticks on the photosensitive body corresponding to the image part (non-exposed part) of the original 9. No exposing is made on the image part of the photosensitive body and therefore the photosensitive body has high surface resistance and the toner 6 having electric charge sticks on the photosensitive body. Since exposure is made on the non-image part, the surface resistance of the photosensitive body decreases and the toner does not stick on the photosensitive body as the quantity of the electric charge decreases.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a novel device capable of providing a simple and stable copying device that can be used once again in a copying device, a printer, etc.
This relates to a method for forming one surface image.

Conventionally, there are devices for copying images, documents, etc. (In printers, there is an electrophotographic method called the Carlson method, which uses a photoreceptor repeatedly, as an image recording method that can use plain paper. In this method, the photosensitive layer made of the original conductive material is charged, and the electrostatic latent (8) formed by one-dimensional exposure is converted into an actual value with toner, which is then transferred and fixed onto the surface (transfer). After transferring one image to the photoconductor, it is cleaned and used again (repeatedly).In this method, the final image is obtained.The recording paper is plain paper,
The image does not change over time (semi-permanent buttons maintain high quality images).

However, this method generally requires that the photoreceptor be uniformly distributed in advance. Therefore, a charging device such as a corona charging device is required, and the entire device becomes complicated. Furthermore, when a corona charging device is used as a charging device, the image quality becomes unreliable due to deterioration of the photoreceptor due to the generation of ozone and uneven charging caused by toner adhesion to the corona charging device. F.

In order to overcome these problems of the Carlson method, a method called the charging method has been proposed as a method that does not use a corona charger.

This method involves irradiating a photoreceptor with sustained light-guiding acidity with light to form electrical latent particles with different degrees of conductivity in one square area and one non-image area on one surface, and then applying conductive toner or semiconductor. 'Ill sex toner'Ichikawa's state of being applied 'J'Ho' 2nd time #
It! By bringing the toner into contact with the toner, a toner image is formed on the high resistance portion of the photoreceptor.

Since this method does not use a corona charger, the problems of the Carlson method mentioned above are solved, but since a continuous photoconductor is used as a photoreceptor, there is a difficulty in using it repeatedly. If you perform the next exposure after forming an image and before the sustained light intensity recovers, you will get a good 1J image.
Iiif cannot be obtained. Furthermore, this method requires the photoreceptor to be a continuous light guide, which limits the type of photoreceptor that can be used.

The object of the present invention is to provide an image forming method that eliminates the drawbacks of the electrophotographic method and does not use a corona charger.

5. Also, the present invention provides a method for forming an image in which a photoreceptor can be used repeatedly. purpose. Furthermore, the present invention improves the sensitivity (, it is possible to obtain fog-free copies7++1ii
The purpose is to provide a method for forming lJi'.

The object of item 11J is achieved by devising the method of forming one image of the present invention so that development is performed simultaneously with exposure from the back side of one photoreceptor.

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

FIG. 1 is a sectional view showing the basic structure of a photoreceptor used in the present invention. The photoreceptor 1 consists of a transparent conductive substrate 2 and an original conductive layer 3. Figure i42 is a sectional view showing another basic structure of the photoreceptor used in the present invention. The photoreceptor 1 has a transparent conductive substrate 2. It consists of a transparent insulating layer 4 and a light guiding layer 3. As the transparent conductive substrate 2, on a transparent substrate such as transparent glass or transparent steel film, 32302. 5
One in which transparent conductive fine particles such as n02 are dispersed in a resin can be used. In the photoreceptor used in the present invention, a photoconductor layer 3 is provided on a transparent conductive substrate 2. The photoconductor layer 3 may be a layer in which fine powder of an inorganic photoconductor such as lead oxide or cadmium sulfide is dispersed and coated in a binder, or a layer of amorphous Se.
Then, one layer of an inorganic photoconductive material such as Se alloy or amorphous St is vacuum-deposited.

Alternatively, eutectic or aggregate of thiapyrylium salt and polycarbonate is dispersed and coated in a polycarbonate/triphenylmethane derivative matrix. layers can be used. In some cases, as shown in FIG. 2, after the transparent insulating layer 4 is provided on the transparent conductive substrate 2, the original conductive layer 3 may be provided. In this case, as the transparent insulating layer, urethane resin, epoxy resin, polyester resin, polycarbonate resin, cellulose acetate resin, etc. can be used. By providing the transparent insulating layer 3, fogging is improved.

Next, the principle of the image forming method according to the present invention will be explained with reference to FIG.

The image roller 5 has a magnet inside and holds magnetic conductive toner 6 on its surface. As the toner, a toner exhibiting electrical conductivity or semiconductivity with a resistance value of 10100 (7) or less can be used. The magnetic conductive toner 6 is in contact with the light guiding layer 3 while being electrically connected to one terminal of a power source 7. The other terminal of the power source 7 is electrically connected to the transparent conductive layer of the photoreceptor 1. In the above state, the source of the paint 10 is irradiated onto the photoreceptor 1 from the transparent conductive layer 2 side of the photoreceptor 1 through the slit 8 and the original 9, and at the same time, the magnetic conductive toner 6 is applied to the surface of the photoreceptor. When the photoreceptor 1 and the original 9 are moved in the direction of the arrow in the figure in a rubbing manner, toner adheres to the photoreceptor corresponding to the image area (unexposed area) of the original 9. The surface resistance of the photoconductor is high because the image margin area of the photoconductor is not exposed to light (charged toner adheres to the photoconductor due to electrostatic force. Since this is not carried out, the surface resistance of the photoreceptor is lowered, and the toner does not adhere to the photoreceptor because the amount of charge is reduced.

When using a photoreceptor having a transparent insulating layer as shown in FIG. 2, it is possible to form an image in a similar manner. The voltage applied to the conductive toner is selected from −2000 to +2000 V depending on the characteristics of the toner used, the photoreceptor, and the like.

As described above, according to the method of the present invention, a photoreceptor is generated from the back side of the photoreceptor at the same time as exposure, so it is possible to use not only a photoreceptor with a non-persistent photoconductor but also a photoreceptor with a non-persistent photoconductor. I can do it,
Therefore, material selection for the photoreceptor becomes easy. Furthermore, by using a non-persistent photoconductor (or a photoconductor with extremely short duration), it is possible to obtain a photoconductor that exhibits less deterioration even after repeated use. Since a voltage is applied to the photoreceptor by the developing roller at the same time as exposure, it is possible to obtain an image with no fog.Especially when using a photoreceptor provided with a transparent insulating layer. In the exposed area, the charge transferred from the toner to the photoconductor escapes to the ground substrate due to the influence of the insulating layer, so the potential of the photoconductor increases, and the electric field becomes weak (the electric field becomes weak), which acts on the toner. It will stick to the photoreceptor (and it will be possible to obtain a good image without fogging).

The image forming method of the present invention will be explained below with reference to Examples and Comparative Examples.

Example 1 On a transparent conductive substrate on which In2O3'r was thinly vapor-deposited on a transparent polyester film, ZnO having the composition F: 9 was deposited.
0 parts by weight Rose Bengal: 0.05% by weight stearic/copper acid for ZnO, 0.05tt% for ZnO Silicone resin (KR-214: Shin-Etsu Silicon): 10 parts by weight in a solvent The mixture was then placed in a ball mill and dispersed.

Next, this dispersion was applied to give a dry film thickness of about 10 μm.
Photoconductive It'! The transparent conductive layer of this photoreceptor was grounded, and the conductive magnetic toner held on a developing roller with a magnet inside was set up as a photoreceptor.
Apply voltage (2) to perform image exposure from the back side of the photoreceptor, and at the same time, the magnetic conductive toner of the roller is brought into contact with the photoconductive layer of the photoreceptor and rubbed, transferred, and fixed. As a result, a good image was obtained.

Comparative Example 1 For comparison, the same photoconductor as in Example 1 was used, and after exposure from the photoconductive layer side of the photoconductor, an image was observed under the same conditions as in Example 1. was gotten. However, if the dew i:t is the same as in Example 1, then the obtained 1Iiii
The 7r elephant had more fog than Example 1. In order to obtain an image with no fog to the same degree as in Example 1, it was necessary to increase the exposure dose. A bath solution containing equimolar amounts of polyvinylcarbazole and trinitrofluorenone mixed and dissolved was coated to form a photoconductive layer having a dry film thickness of about 5 μm to form a photoreceptor.

The transparent conductive layer of this photoreceptor is grounded, and the conductive magnetic toner held on a developing roller equipped with a magnet inside is 100%
Voltage (2) was applied to expose one image from the back side of the photoconductor, and at the same time, the magnetic conductive toner on the above-mentioned roller was brought into contact with the photoconductive layer of the photoconductor and rubbed, transferred, and fixed. However, one good image was obtained.

Ratio 1 bite IHJ 2 For ratio 1 bite, the same photoconductor as in Example 2? After exposing the photoreceptor to light from the i-type layer side, a phenomenon was observed in the same manner as in Example 2, but no results were obtained.

Example 3 A thin layer of In2O3 was deposited on a transparent polyester film, and one finger of urethane (urethane 40 was deposited on a transparent conductive substrate).
26, manufactured by Kansai Paint) is coated with a dry film of approximately 1 μm and is completely transparent! A layer was formed on the layer, and then an equimolar amount of polyvinyl trifluorochloride was mixed and dissolved, and then a photoconductive layer with a dry film thickness of about 5 μm was formed as a photosensitive layer. .

The transparent conductive layer of this photoreceptor is grounded and held on a roller with a magnet inside.
A voltage of 0 V is applied to perform image exposure from the back side of the photoreceptor, and at the same time, the magnetic conductive toner on the first roller is brought into contact with the photoconductive layer of the photoreceptor and rubbed; After transferring and fixing, a good image was obtained.

[Brief explanation of the drawing]

1 and 2 are schematic cross-sectional views of examples of photoreceptors used in the present invention. FIG. 3 is an explanatory diagram of the principle of the image forming method of the present invention. Symbols in the figure: 1... Photoreceptor; 2... Transparent 4-electroconductive substrate; 3... Light guiding layer; 4... Transparent insulating layer: 5... Developing roller; 6...・Magnetic conductive toner; 7...Power source; 8...
・Slit; 9...Manuscript; 10...Rung. Figure IIIFigure 2Figure 3

Claims (1)

[Claims] From the transparent substrate side of a photoreceptor having a transparent substrate, conductive or semiconductive mother toner is held on a photoreceptor roll having an internal magnet with a voltage applied to it while performing image exposure. An image formation method characterized by forming a toner layer by rubbing the surface of a photoreceptor on the opposite side of the transparent substrate.