SU399819A1 - ELECTROPHOTOGRAPHIC LIGHT-SENSITIVE - Google Patents

Description

one

The invention relates to electrophotography, in particular, amplification and conversion of light.

Electrophotographic photosensitive materials are known that contain layers of a photoconductor and a nematic liquid crystal that visualizes the distribution of charges when the image is exposed.

The image obtained on this material is viewed either under continuous illumination with light to which the photoconductor layer is not sensitive, or under illumination with relatively short pulses of light during which the liquid crystal does not have time to change its state.

However, in the first case, the photoconductor must not be sensitive to the visible spectral region and ultraviolet radiation must be used for exposure. In the second case, the photoconductor may be sensitive to visible light, but viewing should be carried out in a darkened room.

In the proposed material, the image is viewed under continuous illumination with light, and the exposure is viewed with light in a wide spectral range. This is achieved by using a photoconductor, in which only carriers of the same sign, holes, are mobile. Depending2

depending on how light — strongly absorbed by a given layer, or weakly absorbed — expo- nated the photoconductor layer, charge carriers are generated at one surface

spread over the whole volume. Such a photoconductor is, for example.

The drawing shows an electrophotographic photosensitive material. Achaterial consists of a glass plate.

L covered with an electrically conductive film 2, for example a 5p2O film. Next comes a layer of liquid nematic crystal 3j layer of photoconductor 4, for example AsoSca, light filter 5, for example, filters SZS7, SZS8, which transmits only light strongly absorbed by the photoconductor, dielectric strips 6 and current source 7.

The positive pole of current source 7 is connected to nlenka 2. White light beams 8 exposing the image cause a current to form in the photoconductor layer 4, which excites light scattering in the liquid nematic crystal 3 layer. The illumination for visualization of the image is produced by the light beams 9 through the light filter 5. Media Charges are generated at the upper surface of the photoconductor layer 4 and do not participate in the creation of current through this layer. 3 Subject of the Invention An electrophotographic photosensitive material comprising a photoconductor layer and a layer visualizing the distribution of electric current, such as a layer of a liquid nematic crystal, characterized in that a photoconductor is used in the photoconductor layer to provide an opportunity to view the image under constant light in a wide spectral range in which carriers of one sign are mobile, and the material contains a spot filter that absorbs light in the spectral region of the weak absorption of the photoconductive layer and providing the photosensitivity layer on the side opposite to the imaging layer.

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