SU1392539A1 - Method of producing electrographic halftone images - Google Patents

Abstract

This invention relates to methods for producing electrophotographic tone images. It allows you to improve the quality of images by eliminating the edge effect. The method includes charging a layer, exposing an image, charging a latent electrostatic image and its appearance with a liquid developer. Charging is carried out by liquid ions in accordance with the formula K m / g 6, / L (V) - m / g. e, / L- () dU, a is the displacement potential and the distance from the counter electrode to the electrophotographic carrier when charging and displaying a single electrode, where DU is a change in potentiality during liquid charging; The covering ability of a vita.ch; m and g, respectively, average weights: 1 mass of mass and charge of the particle of the developer; LI, respectively, the dielectric constant and the thickness of the electrophotographic () g) of the carrier, is the dielectric constant of vacuum; the dielectric constant (relative) of the projectile; h is the distance from the () (}) otog; () ich (.chk (Jth carrier to the counter-electrode; 4 with electrophotographic microfilming according to the ()) zitiv- | 10zigin;: Vc "-fV2 with electrophotographic microfilming according to the positive negative scheme; Positive potential bias; Y and Y., respectively, non-potentials on the space bar and the exposed clock; D is the required range of optical fluorescence on the recharged and photo-layer; B is the coefficient of the process opimation with the interval of 5.4 values (1.1 mm. 2 ill. &Amp; a with

Description

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The invention relates to the field of electrography and can be used to obtain electrophotographic diapho: uiTHBOB, microfiche, etc.

The purpose of the invention is to increase the quality of images by eliminating the edge-14) effect.

FIG. 1 shows an efficient view of the liquid charging zone; in fig. 2 - s.hematicheskom nid zone of liquid expression. The essence of the invention is as follows. To obtain an electrophotographic tone image, the electrophotographic carrier is first charged, and then an optical image is exposed to the carrier. The latent electrostatic image that was formed is recharged by the ion. Potencia. 1i, the displacement of the counter electrically charged and the counter electrode of the subsequent development and their distance to the electrophotographic carrier during charging and manifestation is set the same, and the charge value is set by the formula

the change in the potential of the electrophotographic layer as a result of charging; covering power production l;

Respectively, the average mass and charge of the particles of the developer; 35

wear electrophotographic floor thickness; 1; respectively, the dielectric constant of the vacuum, electrophotographic layer to wear. 1 and liquid developer, the sum of the mixing potential and the potential of carrier charge, the required range of optical density of images; coefficient of minimization

process with an interval of 5.4 to 6.1 mm;

carrier distance from the counter electrode.

The potential and value of the charging zone equal to the sign of the mixing potential in the zone of the same character of raspreectrostatic fields (with dielectric permittivity and recharging fluid and 55 electrophotographic non-electrode in the charging zones) are determined by the essence

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forming an electrophotographic image. It consists in the fact that the latent electrostatic image is shown in two stages; Initially, the latent image appears to be liquid ions and compensates for the marginal phenomena of the latent image. After the edge phenomena are compensated, the liquid ions (colorless spectators) compensate the manifestation by charged particles of the liquid developer. At the same time, during recharging with liquid, positive and negative ions are deposited on the surface of the photosensitive carrier layer with the latent image, and when developing, positive particles and negative ions of the developer are deposited. The charging of a hidden electrostatic image in a liquid medium using a charging zone that is geometrically and electrically identical to the zone of development ensures that the conditions of the process of charging and manifestation are identical, which excludes cases of deformation of the edge effect. The proposed formula, which expresses the level of recharge of the LL through the potential V - the algebraic sum of the displacement potential and the potential at the exposed (or spacing) sections before charging - and the required dynamic range of the optical density of the developed image, allows you to control sound reproduction, which ensures quality copies.

Example. Microfiche billet (organic electrophotographic film) is loaded into a special cassette, placed in the processing zone of the charging device, where it is electrostatically charged with positive air ions to a surface potential of V, 300 V. The image of the optical stage (edge of the knife) is exposed to the charged photo layer to a potential of V 100 V, which provides a depth of potential relief V t -Vj 200 V. After exposure, a microfiche billet with a hidden electrostatic image is placed in the area of p-discharge. Here, the photosensitive layer of the microfiche billet is placed at a distance h of 0.6 m from the grounded counter electrode. A negative displacement potential of VCM - 350 V is applied to the conductive carrier layer. Photoflo is charged using refrigerant-113 with impurities (e.g., curvature, acetone) when moving the preform relative to the counter electrode at a speed of mm / s. After charging in the dark by an electrodynamic electrometer, the electrostatic potential of the latent image is measured far from the edge of the formed stage. Dode billet

microfiche placed in the area of manifestation. The distance of the electrophotographic carrier from the grounded counter-electrode of the development site is chosen to be 0.6 mm. Negative bias potential V0 is applied to the conductive layer, - 350 V. During the development, the microfiche moves the workpiece relative to the counter electrode at a speed of mm / s. The development is carried out using black positive toner particles dispersed in refrigerant-113. The developed optical image

The exposure is subjected to microphotometry and the magnitude of the edge effect is determined. On the basis of these data, the coefficient B is determined. The coefficient B for different manufacturers and different technological modes is approximated by a value of 5.7. This makes it possible to select the tone reproduction mode during the technical design of the electrophotographic apparatus on the basis of this formula.

Claims (1)

Invention Formula A method for producing electrophotographic tonal images, including charging an electrophotographic carrier, exposing it, charging; the electrode of a latent electrostatic image and its development with a counter electrode by a liquid developer, characterized in that, in order to improve the image quality by eliminating the edge effect, the latent image is recharged by liquid ions, while the potentials of the counter electrodes are shifted. Where when they are charged and developed, they are set the same, and the charge charge is set according to the formula , .,, one Where DU is the charging level, and: increasing the potential of the electrophotographic layer as a result of charging; covering power; w and gf, respectively, are the average mass and charge values of the developer particles; L is the thickness of the electrophotographic layer of the carrier; ,, is the dielectric constant of vacuum, of the electrophotographic carrier layer and of the liquid developer, respectively; V is the sum of the bias potential and the potential of carrier charge; D - the required range of optical density of images; B - coefficient; ation process with an interval of values from 5,4 - 6,1 mm; ft is the distance of the electrophotographic carrier from the counter electrode. § Rossstoliye FIG. 2