SU389486A1 - METHOD OF FORMING ELECTROSTATIC IMAGE - Google Patents

Description

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The invention relates to the field of electrography, and imbo to the method of forming the image on a dielectric.

A known method of forming an electrostatic image on a dielectric carrier using a photo semiconductor, which means that the dielectric carrier and the photo semiconductor are brought into contact, create an electric field between them and expose the photo semiconductor, after which they are separated.

However, in such a method it is necessary to have either a transparent recording medium or a transparent conductive base of the photoconductor, which complicates their manufacturing technology.

In order to use opaque maternals for the manufacture of the recording medium and the conductive base of the photosemiconductor, the exposure of the photosemiconductor is carried out before it is brought into contact with the dielectric carrier.

The proposed method is illustrated in the drawing, which gave the scheme for forming an electrostatic image.

The photosensitive element is a photo-semiconductor layer / with a long photoexcitation decay time, for example, a selenium layer deposited on conductive base 2. The image is projected onto this layer (see position a), and in the illuminated areas of the photoconductive layer a photoexcitation state occurs the intensity of which is proportional to the amount of light.

The layers with a slow decrease in the state of photo excitation are made of well-known semiconductor materials: selenium, selenium cadmium, sulfur dioxide, sulfur oxide, tri-sulfur antimony, and others.

After exposure, the photosensitive layer is brought into contact with a layer of dielectric 3, for example a polystyrene layer, on a conductive base 4, their conductive bases are connected to a constant voltage source 5 (see position b).

At a voltage of several hundred volts (usually at least 300-400 volts), charge transfer occurs between the surfaces of the photosemiconductor and the dielectric.

The electrical contrast of the image is also determined by the period from the end of the exposure to bringing the layers into contact, the contact time and the magnitude of the applied voltage.

The polarity of the generated image is determined by the polarity of the applied voltage.

After the transfer of the image is completed, the layers of the photosemiconductor and the dielectric are separated (see position c), and this separation can be carried out both with the applied voltage and after it is turned off. Subsequently, the electrostatic image on the dielectric is read or visualized either by an electrophotographic promoter, or, if the dielectric has thermoplastic properties, by the method of matting deformation.

When applying this method in electrophotographic apparatuses, the continuous process of restoring the photosensitive element from photo excitation to its original state (unexcited) is accelerated by illumination from the source of infrared radiation of the corresponding wavelength.

Subject invention

The method of forming an electrostatic image on a dielectric carrier using a photoconductor, concluded that the dielectric carrier and the photoconductor are brought into contact, create an electric field between them and expose the photoconductor, after which they are separated, characterized in that, in order to be able to use opaque materials for the manufacture of the recording medium and the conductive base of the photoconductor, the photosemiconductor is exposed to exposure to contact with dieslectric :: im nosntel.

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