SU1442965A1 - Electrophotographic apparatus - Google Patents

Abstract

The invention relates to electrophotographic duplicating machines, computer input devices, devices for obtaining corrective prints in a photo set. The purpose of the invention is to increase the quality of copies and increase their quantity obtained from a single exposure of the original. The device has an additional charge, electrically connected to a constant-voltage power supply unit, and an additional light source. An additional charge is installed on the surface of the photoreceptor between the sites of development and image transfer. An additional light source is placed above the additional charge, wherein the power supply unit of the additional charge is configured to stepwise change the value of the constant voltage with each image transfer. 6 Il. x (L S

Description

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The invention relates to electrophotographic duplicating machines, computer output devices, devices for obtaining corrective prints in a photo set.

The purpose of the invention is to increase the quality of the copies and increase their quantity obtained from a single exposure of the original.

Fig. 1 is a schematic diagram of an electrophotographic apparatus; FIG. 2 shows a charging pattern using a sliding discharge; in fig. 3 is a view A of FIG. 2; in fig. 4 - additional charge diagram; Figures 5 and 6 show embodiments of the photoreceptor used in the apparatus;

The ACP contains a rotating cylinder 1 (FIG. 1), on the surface of which a photoreceptor is placed, consisting of layers of photoconductor 2 and dielectric 3. To sense the photoreceptor, there is a charge 4 connected to a DC power supply (not shown), equipped with an illuminator 5, the luminous flux of which affects the photoreceptor in its area

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The image is exposed to the photoreceptor surface from the original in duplicating machines, as well as in photo-type machines and output devices of a computer with a real and digital tape carrier, using node 6, which, together with a rotating mirror 7, is one or another optical system, In the area of exposure of the image, near the cylinder 1, there is a charge 8, consisting of a housing 9, a grid 10 connected to the housing of the apparatus, and a corona wire 11 connected to a constant power supply unit current (not shown)

The curtain 8 (FIGS. 2 and 3) can also be made in the form of metal rods 13 connected to the direct current source 12 and covered with an insulating layer 14. A thin wire 15 connected to the apparatus is wound in spiral form over the layer 14. Under the action of a voltage on the surface of the layer 14, a sliding discharge occurs, which generates in the air gap between the rods 13 and illind

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Adjacent to the charge 8 (Fig, 1), in the direction of rotation of cylinder 1, according to arrow B, illuminator 16 is located in housing 15, the luminous flux of which affects the photoreceptor.

To produce an image on a photoreceptor, there is a node 17. This node can use any of the known methods of dry image display, for example, a magnetic brush, cascade or aerosol display,

An additional charge 18 is connected to the development unit 17 and is connected to a power supply unit (not shown) and equipped with an illuminator 19, the luminous flux of which affects the photoreceptor with the developed image in its charging zone. The additional charge 18 (FIG. 4) also contains a corona wire 21 located in the housing 20 connected to the DC power supply unit 22, and a grid 23 connected to the DC power supply unit 24, the output voltage of which varies with each turn of the cylinder

The transfer of the threshold image shown on the photoreceptor to the paper tape 27 supplied from the roll 25 and removed from the apparatus by the rollers 26 is carried out in an electric field created by a rubber coated shaft 28 consisting of upper semiconducting and lower conducting layers of rubber connected 40 by a conductive layer to a DC power supply unit (not shown).

Between the shaft 28 and the rollers 26, thermal emitters 29 are placed to hold the powder image on the paper tape 27. The rotating fur roller 30 can be removed from the cylinder 1 using an electromagnet (not shown) and the lever 31 to clean the photoreceptor from the toner residues. and the illuminator 32, equipped with a charge 33 similar in construction to the charge of the bottom 8, serves to illuminate and neutralize the photoreceptor

In case of using the device in a copying-copying mode when exposing an image from an original and a long exposure (more than 20 ms), the photoreceptor structure

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it can be made rigid (Fig. 1) or flexible, with adhesive tape fixed to the cylinder along its edges (not shown). The photoreceptor tape (Fig. 5) is a photovoltage 34 packed between two, for example, mylar films 35, one of which has an inner (under photoconductor) conductive metal layer 36. Contact between the conductive layer 36 and the apparatus body is achieved, for example by applying a liquid electrolyte on the edge of the photoreceptor under the adhesive tape that holds the photoreceptor on the cylinder.

When using the device in the mode of a computer output device or a device for obtaining corrective prints in photoconversion and a short exposure (micro- and nanosecond range), the photoreceptor structure (Fig 6), containing photoconductor 34 and polyester films 35 with a metal layer 36, is complemented by for example, dispersed in a high-resistance binder layer 37 of the phosphor, which stores light energy during a short exposure and gives it to the photoconductor 34 for a long time, more than 20 ms. The phosphor can be introduced directly into the foreign Mylar film 35, desirably phosphorescent decay time is equal to or somewhat longer rotating cylinder 1 (FIG On the arrow B by an angle proportional to the length of the charging zone beneath the charge pho toretseptora days - com 8.

 The device works as follows.

When the cylinder 1 (Fig. 1) rotates in an arrow in continuous or start-stop mode, a charge is deposited on the surface of the photoreceptor dielectric 3, for example, of positive polarity in the zone of action of charge 4. Due to the generation of carriers in photoconductor 2 under the action of light from the illuminator 5, the shielded volume charge of the photoconductor 2 is located after the end of the charge at its interface with the dielectric 3. The same process also takes place in the photoreceptor shown in FIG. 5. When using the photoreceptor shown in FIG. 6, photoconductor illumination during charge deposition on dielect0

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ric as a result of excitation under the action of light by the layer 37 of the phosphor.

Post-charging of the photoreceptor on its surface (interface between photoconductor 2 and dielectric 3) exposes, for example, a positive image using an optical system (node 6 and a mirror 7). As a result of exposure of the image and acting on the photoelectric receptor for days-8 on test the (bright) parts of the image, the charge disappears, and on the printed (dark) areas of the image along the external circuit through ion contact (the gap between the grid 0 and the dielectric), the charge is redistributed between the substrate and the surface Lecturer 3 such that after the general illumination of the photoreceptor by the illuminator 16, it creates a charge and a potential relief, t, e, latent image. This is how the latent image is formed using the options of photoreceptors (Figs. 1 and 5) and long (more than 20 ms a) exposure, for example, in copying and duplicating mode.

With short exposures in the mode of computer output devices, a photoreceptor is used, shown in Fig. 6, in which the phosphor layer 37 stores light energy and gives it to the photoconductor 34 for a long time (more than 20 ms). In the same way, the light energy is transmitted to the photoconductor from illuminator 16. In order to avoid the structure of the grid during short exposures upon exposure of the image to the photoreceptor, radiator-8 in this case is constructed as shown in FIG. , 2, An ionic contact in it along an external circuit is formed between the surface of the photoreceptor and the wire 15. The latent image obtained on the photoreceptor appears in node L 7. and then enters the zone of action of additional charge 18. As a result of using additional charge 18 (FIG. 4), a metered amount of negative charge is deposited on the photoreceptor with an image at each revolution of cylinder I and image recording off. stepwise voltage increase on the grid from block 24 pita0

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5 14 neither. At the same time, due to exposure of the photoreceptor to light from the illuminator 19, the negative potential in the whitespaces of the image increases, and the positive potential of the printed areas of the latent image is slightly reduced due to the penetration of the part of negative ions to the photoreceptor surface. the layer and through it influence the photoreceptor of light radiation. As a result, as shown by experiments, the potential for image generation between the gap and the printed areas of the image is reduced rather slowly, which makes it possible to obtain a circulation of prints equal to 10-40 copies from the once formed latent image. The advanced photoreceptor charging with the image provides a stable transfer of toner from printed areas to paper regardless of the uncontrollable interaction of toner and photoreceptor charges.

During the replication of prints to transfer the image from the photoreceptor to the paper tape 27, a shaft 28 is used, which presses the tape 27 to the cylinder 1 and creates an electric field in the powder image. With this design of the transfer unit, no additional charge is deposited on the photoreceptor, thus eliminating noise on the whitespace of the displayed image.

The powder image obtained on the paper tape is fixed in the heat radiating unit 29 and is removed by the rollers 26 from the apparatus

Cleaning the photoreceptor's perceptibility from residual toner is carried out by rotating the fur roller 30 when it contacts the cylinder 1 after drilling through the process of replicating prints. After cleaning, the photoreceptor is neutralized by the simultaneous exposure of light from the illuminator 32 of the electric field from the charger 33 connected to the alternating current source,

The proposed apparatus may be used to copy and reproduce documentation from originals; Compared with the known devices, it allows

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Claims (1)

It reduces the number of manual feed cycles for originals and, therefore, makes it easier for the operator to save work. It is better to save the originals by reducing their wear and, in a number of cases, to increase the copying speed. When using the apparatus as a computer output device in text processing systems, a reduction in the range of equipment used and the amount of manual labor is achieved by eliminating the duplicating apparatus. In operative polygraphy, in those cases when the required print run of prints is no less than 50 copies, the device will make it possible to refuse to use offset machines and platemaking, which will also reduce the labor intensity of manual labor and the cost of production. When using it, the quality of copies is ensured and their number increases from one exposure. Invention Formula The electrophotographic apparatus mainly for making multiple copies from a single exposure, containing a multilayer photoreceptor on a cylindrical substrate, a photoreceptor charge electrically connected to a constant voltage power supply unit, an image exposure unit with a charger electrically connected to an alternating voltage power supply, the photoreceptor development, image transfer, cleaning and illumination units located around the photoreceptor, as well as the paper wiring and fixing , Wherein Pi iys in that, in order to increase the quality of copies and to increase their number w obtained from a single exposure of the original, the apparatus has an additional charge arrester,. electrically connected to a constant voltage power supply unit, and an additional light source, an additional charge placed on the photoreceptor surface between the imaging and imaging units, and an additional light source placed above the additional charge, the additional charge power supply unit being made with the possibility of a stepwise change in the magnitude of the constant voltage at each image transfer. 17 15 16 9 11 8 S 5 J2 9.y.y. / 9th year 15 RNGUNOUGL f 1 13 but 9g / / CU / / / / / / / f dZ5. five 35 37 J J5 35 X /   / / / / y ///// / U / // / U J5 J 36 35 ig.b