SU792205A2 - Heat method of image recording - Google Patents

Description

The invention relates to methods for obtaining images using light, heat and electron fluxes, as well as photosensitive compositions. Photographic methods of image recording are known, concluding that the image is reproduced on photosensitive layers from the north. edge-on and then chemically-photographic processing 1. A disadvantage of the known methods is the necessity of using the edge along with the chemical-photographic processing and the impossibility of re-using the exposed layers. The known thermal method of recording images, which means that an image of an object is fixed directly to an optically non-transparent medium with high resolution and the possibility of fast and repeated rewriting, while using a heterogeneous medium with the possibility of aggregate transformations as a medium, placing it in a force field , and when fixing the image, the solvent of the heterogeneous medium is cooled below the temperature of the aggregate transformation 2. The disadvantage of this method is low sensitivity due to the fact that particles of a heterogeneous medium perform two functions at once: convert radiation into heat (particles are opaque) and change the transparency of the medium (the force field creates directional movement of particles). The purpose of the invention is to increase the sensitivity by increasing the conversion factor of radiation into heat. For this, according to the proposed method, a substance is added to the heterogeneous medium, the absorption coefficient of which is greater than the absorption coefficient of its particles. The substance is applied to particles of a heterogeneous medium. The substance is photochemically actipno. A photoconductor is used as a substance, it is placed in contact with a heterogeneous medium, and voltage is applied to it. The photoconductor can be connected to the medium from the illuminated side, i.e. placed between the light source and the recording medium, or attached to the medium from the unlighted side. In the latter case, the increase in sensitivity is achieved by increasing the contrast of the image recorded on the exposed medium. This is because the intensity of light transmitted to the photoconductor does not correspond to the heat generated in it depending on the transparency of the exposed medium. Because of this, those areas of the medium that were illuminated during exposure are more heated and brightly illuminated. After the medium is heated to the temperature of the aggregate conversion of the transparent solvent, the opaque particles are displaced in the force field, leading to a change in the transparency of the medium, and when the image is fixed, the solvent is cooled below the temperature of the aggregate transformation. Technical characteristics can be estimated by the following formulas. The exposure time t is proportional to M, where M is Hc1 is the magnetization of a unit volume of a particle. It is usually convenient to use a small external magnetic field H, not exceeding several tens of Oersteds. In such a field, a particle of a magnetically soft material, a needle-shaped needle, can be magnetized almost to the saturation of M MD. A particle of the same material, having a sphere shape, is magnetized to the value of M.N. (1) The gain K in the exposure time and, consequently, in sensitivity when using needle-shaped particles of carrier magnetic dipole charge compared to spherical, is the heat energy released by c in the volume of the photoconductor when light is incident on it, calculated per unit area, expressed as Fpres –rg voltage applied to the photoconductor; illuminated photoconductor area; time, depending on the intensity of illumination, the specific resistance of the photoconductor; photoconductor layer thickness. The density of the absorbed -media light energy is b- - n- and where P is the luminous power absorbed by the recording medium in the absence of the photoconductor. The gain K in sensitivity from the use of a photoconductor is k, fp v --- rtg. The energy density released by the mixture of substances during a photochemical reaction can be calculated using the van't Hoff-Einstein law a (l) t where incident light power, j — photochemically active substance absorption coefficient; E is the layer thickness of the photochemically active substance; 14.1.05 erg sec is Planck's constant, f is the radiation frequency, y is the quantum yield of the partial t photochemical reaction, the heat of formation of a chemical compound during the i-th exothermic photochemical reaction, N is the Avogadro number 6.025-10 / / mol. The gain in sensitivity from the use of the photochemical reaction K is YFH. ". Here it is assumed (with a margin) that the heat for recording in the absence of chemically active substances completely absorbs light. Work on the method is carried out in the following manner. Example 1. The needle-like particles of a medium substance with a high magnetization, for example, iron oxides are coated with a non-magnetic shell. nitrous substances, such as carbon black, which have a higher absorption coefficient than magnetic particles. Such particles are magnetized to saturate Md 5-10 Gs in a weak magnetic field H 50 O. This gives a gain in sensitivity compared to spherical magnetic particles according to formula 2, equal to K 2-10.

Consequently, the sensitivity is increased by more than 1000 times in comparison with the prototype.

Example 2. A Cu-Cd plate with a thickness to which a constant voltage E 60 is applied is used as a photoconductor. The resistivity of such a plate is 10 Ω-cm and drops to 10 OhSM when illuminated with a laser power P W. Therefore, with a minimum cross section of the light beam S, a gain in sensitivity is obtained according to formula 5 equal to

K 1,8-10

Therefore, the sensitivity is increased in comparison with the prototype by more than 100 times.

Example 3. In a microcapsule with a diameter with transparent walls, photochemically active substances and the recording medium are placed under a pressure of p 100 atm. Photographic and active substances are selected as such / which enter into an exothermic reaction, for example, chlorine and hydrogen, chlorine and methane, chlorine and carbon monoxide, and others. The gain in sensitivity from the use of chlorine, C1d and hydrogen HI vapors for which TG is 10. dH is 4.5–10 cal / mol, d 4 cm, according to the formula 7 K, 10.

Sensitivity increases 100,000 times.

Thus, this method provides a significant increase in sensitivity from 100 to 100,000 times.

In order to record the color images in the method, a color filter that performs spatial analysis and color synthesis is added to the medium on which the image is obtained.

This filter can be made in the same way as in the additive raster method of color photography, i.e. may be a single-layer spatially inhomogeneous light filter producing a mixture of colors according to the principle of pointelism.

On Wednesday design an image of a color object through a light filter. Heating of the medium occurs when light is absorbed, specifically those of its spectral components that are filtered through. After the medium is heated to the temperature of the aggregate conversion, a change in its optical density occurs, which is fixed when the medium cools, causing the reverse aggregate transformation. The optical density of the image captured on the medium is determined by the intensity and spectral composition of the light reflected (or emitted) by the color object. When observing the exposed medium through a light filter attached to it.

You will see an image that is good, conveys the look and colors of the object.

Example. 4. As a light filter, a layer of small (less than 10 µm diameter) plexiglass grains is used, each of which is colored in one of the primary colors (red, green, blue) and located close to each other on a transparent substrate. The grains serve as single-band light filters both when shooting and

0 when observing the finished image. Due to the smallness of the grains, each individually is not distinguishable by the eye, and if the grains are randomly mixed with each other, the light filter, when viewed through the lumen, looks colorless due to the mixing of primary colors in the eye. The small gaps between the grains can be filled with an opaque adhesive. When you record an image, the light from the object falls on

0 medium for recording through a light filter. Let for definiteness the object is red. Then the light from the object can pass only through the red grains and will be detained (absorbed) by the green and blue grains. Therefore, the optical density of the medium, when its aggregate state changes, will change only where at the location of the object projection on the filter

0 there are red grains. The change in optical density will be recorded at the reverse aggregate change of the medium. When observing the environment from the side of the filter, an image of the object colored in red will be visible. In this way, an image is obtained that correctly conveys the appearance and color of the object and does not require any further processing.

Copy the image obtained by

0 in the same way that the original image was made. The recorded image can be erased by heating the medium above its aggregate conversion temperature.

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Example 5. As a light filter, thin walls of microcapsules (about 10 µm in diameter) made of polyvinyl chloride, painted in one of the primary colors, or coloring substances placed inside transparent microcapsules are used. Microcapsules are randomly mixed and arranged in a single layer on a transparent substrate close to each other. Inside the micro 5 capsules, place the medium for recording, therefore each of the microcapsules is opaque. When recording an image, the light from the object enters the medium for recording through the walls of colored microcapsules or through dyes.

Let for definiteness the object is red. Then the light from the object will be able to pryuyti to the environment, pledged only P red microcapsules, and will be detained (absorbed) by the walls of green and blue microcapsules or dyes contained therein. Therefore, the change in optical density will occur even in red microcapsules located under the projection of the image on the medium. When observing a film with recording medium, an image of the object colored red will be visible.

Thus, a picture is obtained that correctly represents the appearance and color of the object and does not require any further processing. A copy of the image is obtained in the same way that the original image was made. The recorded image can be erased by heating the medium above the temperature of the aggregate transformation. Thus, an image is obtained that correctly captures the appearance and color of the object and allows copying that does not require additional processing and allows erasing and rewriting of images.

Claims (4)

1. Thermal way to record images on author. St. No. 717706, in order to increase sensitivity by increasing the conversion factor of radiation into heat, in it a substance is added to the heterogeneous medium, the absorption coefficient of which is greater than the absorption coefficient of its particles. 2. A method according to claim 1, characterized in that the substance is applied to particles of a heterogeneous medium, 3. A method according to claim 1, characterized in that the substance is photochemically active. 4. The method according to claim 1, I distinguish 5 Sch and with the fact that a photoconductor is used as a substance, it is placed in contact with a heterogeneous medium and voltage is applied to it. Sources of information taken into account in the examination 1. Neblit K. B. and photography, its materials and processes., M., 1958, 25 seconds 161. 2. USSR author's certificate according to the application 2462902 / 18-10, cl. G 03 G 5/00, 1977 (prototype).