Abstract: The invention relates to persistent screens where the image to be stored is stored in a layer (3) which contains as an active substance an illuminable luminophor (5) and which is tinted to increase the picture sharpness. The luminophor (5) is a rather small quantity of organic and/or inorganic UV luminophor material. In this connection, it has been found to be desirable to at least reduce the light loss caused by the tinting. To this end, the invention avoids dispersions of the scanning beam (14) in the persistence layer (3) during scanning by admixing to the luminophor (5) an UV luminophor (6) as well as an optical brightener (7). It has also been found appropriate to apply the persistence layer (3) on a substrate (2), such as a polyester foil, which is tinted with a substance that absorbs the light of the scanning beam (14) used for illuminating the layer (5). Such a screen utilizing the inventive principles is particularly useful in medical technology applications.

Abstract: A process is described for improving the quality of images which have been formed by screen printing a liquid photo curable photopolymer. Images formed by screen printing, especially heavy coatings such as solder masks on printed wiring boards, inherently have indistinct boundaries, and may have feathered edges and photopolymer smears. These indistinct boundaries are removed and the resolution improved by a process which utilizes the oxygen inhibition effect characteristic of selected photopolymers. Thus, a screen printed image can be 0.001 inches thick at the center of a line, tapering off to 0.0001 inch thick smears, and these smears may be eliminated by irradiating the entire image with a moderate amount light energy, which cures the thick image portion and leaves a liquid boundary layer on the order of 0.0001 inch thick due to the oxygen effect. When washed with a mild solvent the liquid layer is removed, including the smears, leaving the thick image portion undisturbed.

Abstract: The photoscreen for making a halftone reproduction from a photograph is used in a process where the photograph is placed in a reproducing position relative to a reproducing apparatus and the screen is interposed between the photograph and the reproducing means of the reproducing apparatus so that upon operation of the reproducing apparatus, a halftone reproduction is created. The photoscreen comprises a sheet of transparent material having on the bottom surface thereof an array of light modulating, varying density, light gray, vignetting dots mixed with an array of light modulating white dots preferably printed on the top surface thereof.

Abstract: Process for preparation of dot-etched, photopolymerizable lithographic film which comprises (a) exposing imagewise a photopolymerizable element consisting essentially of a support and two caustic or water soluble layers, the upper layer being clear, unpigmented photopolymer and the lower layer being a polymeric binder having dispersed therein a chemically soluble pigment, e.g., colloidal silver or other metal; and optionally an overcoat layer; developing the exposed element with caustic solution and then water; and treating the developed image with a solubilizing agent, e.g., K.sub.2 Fe(CN).sub.6, FeCl.sub.3,Na.sub.2 S.sub.2 O.sub.3, KCNS, KOH, NH.sub.3, etc. A dot-etched lithographic film is prepared.

Abstract: A fluorescent screen of a black matrix type color picture tube is manufactured by forming a graphite film on an inner surface of a face plate, applying a photoresist film on the graphite film, exposing to light portions of the photoresist film where phosphor picture elements are to be formed subsequently, removing the exposed portions of the photoresist film to expose portions of the graphite film, removing the exposed portions of the graphite film to form a black matrix film having voids corresponding to the exposed portions of the graphite film, and thereafter depositing triads of phosphors of picture elements on the inner surface of the face plate through the voids. In a modification, a reflective film is interposed between the graphite film and the photoresist film and portions of the reflective film in register with portions of the photoresist film exposed to light are removed by etching.

Abstract: Process for preparation of dot-etched photopolymerizable lithographic film which comprises (a) exposing imagewise a photopolymerizable element consisting essentially of a support and two layers of caustic soluble photopolymer, the upper layer being clear and the lower layer having dispersed therein a chemically soluble pigment, e.g., iron oxide; and optionally an overcoat layer; (b) developing the exposed element with caustic solution; and (c) treating the developed element with a chemical solubilizing agent for the pigment thereby reducing the size of the pigmented area by diffusion etching. A dot-etched lithographic film is prepared.

Abstract: Process for preparation of dot-etched photopolymerizable lithographic film which comprises (a) exposing imagewise a photopolymerizable element consisting essentially of a support and a layer of caustic soluble photopolymerizable composition having dispersed therein a chemically soluble pigment, e.g., iron oxide, and optionally an overcoat layer; (b) developing the exposed element with caustic solution; and (c) treating the developed element with a chemical solubilizing agent for the pigment. A lithographic film is prepared.

Abstract: Process for preparation of dot-etched photopolymerizable lithographic film which comprises (a) exposing imagewise a photopolymerizable element consisting essentially of a support bearing (i) layer of acid soluble photopolymerizable composition having dispersed therein a chemically soluble pigment; or (ii), in order, (a) layer of acid soluble photopolymer having dispersed therein chemically soluble pigment, (b) layer of clear, unpigmented acid soluble photopolymer composition; or (iii), in order, (a) nonphotosensitive layer of an aqueous soluble polymeric binder having dispersed therein chemically soluble pigment, (b) layer of clear unpigmented acid soluble photopolymer composition, and optionally on each of said elements an overcoat layer; (b) developing the exposed element with acid solution; and (c) treating the developed element with a chemical solubilizing agent for the pigment. Lithographic films are prepared.

Abstract: Radiation is directed toward a support through an ordered array of lateral walls to form interlaid radiation-exposed and shadowed microareas on the support. A first composition is then located on the support in either the shadowed or unshadowed microareas. At least one additional composition is then positioned on the support in laterally displaced microareas forming an interlaid pattern with the first microareas.

Abstract: In engraving of printing forms particularly of gravure cylinders, it has previously been possible to produce run-free color raster configurations for only two colors. The present invention discloses rastering methods for run-free color production of four color impressions and polychromatic impressions.

Abstract: A printing plate is made in accordance with a particular method and is used in a printing process wherein it is effective to produce a substantially continuous tone printing effect. A negative screen having an overall pattern defined by rows of closely spaced substantially square-shaped areas is exposed two times on an image carrier. An image screen pattern is developed on the image carrier wherein each of the two exposures of the overall pattern on the negative screen is effected at an angle of 30.degree. with respect to each other. A unique printing screen pattern is obtained which is then used for printing a reproduced image.

Abstract: A thin translucent film is applied onto a plate of glass by pouring an asphalt solution on such plate. The asphalt coating is dried under influence of light whereby the asphalt will become insoluble and a fine grain is developed. This grain is thereafter printed optically onto a photosensitive material.

Abstract: An imaged element containing a polymeric relief or stencil image, in which the polymer contains crosslinkable moieties, is subjected to an image enlargement process by contacting the image with a solution containing a swelling agent for the image, and a crosslinking agent. The process is particularly useful in enlarging the half-tone image dot area of photopolymer litho masks wherein the half-tone image areas consist of hardened upper skins which rest on softer undervolumes having a lesser degree of polymerization or hardening.

Abstract: Process for modifying a tacky surface of a multilayer negative-working surprint proof having a photosensitive tacky layer as the outer layer which comprises exposing the tacky layer through a screen tint, e.g., having a tint value of 25 to 75 percent, and applying an admixture of particulate material and carrier particles and removing excess particulate material and the carrier particles from the tacky surface. The ratio of average particle diameter of the carrier particles to average particle diameter of the particulate material is greater than 2 and the weight ratio of particulate material to carrier particles is less than 1. A durable matte finish is obtained that is nonblocking, is capable of being written on, and is noncracking over extended storage periods.

Abstract: Rare earth oxyhalide phosphors activated with terbium and/or thulium ion are described exhibiting improved brightness which are particularly useful in x-ray image converter devices by reason of producing less light scattering and absorption as a result of superior crystalline characteristics. A multilayer x-ray screen construction utilizing said phosphor material is also described utilizing said phosphor material which exhibits improved image sharpness and a reduced crossover problem. An improved process for producing said phosphor material is further disclosed wherein the selected oxyhalide is recrystallized in a molten alkali metal halide flux to produce the superior crystalline characteristics.

Abstract: A computer-generated halftone contact screen is disclosed which consists of a rectangular array of small abutting square areas each of uniform transmittance (density), in which the transmittance (density) of the squares is described by a random variable whose distribution is controlled to give the screen a desired reproduction curve. The facsimile produced using the screen, its equivalent produced by computer-assisted means, and its representation in computer memory are disclosed.

Abstract: A printing plate is made in accordance with a particular method and is used in a printing process wherein it is effective to produce a substantially continuous tone printing effect. A negative screen having an overall pattern defined by rows of closely spaced substantially square-shaped areas is exposed a plurality of times on an image carrier. An image screen pattern is developed on the image carrier wherein each of the plurality of exposures of the overall pattern on the negative screen is effected at a different angle with respect to each other. A unique printing screen pattern is obtained which is then used for printing a reproduced image.

Abstract: An improved halftone dot screen for use in reproduction of continuous-tone graphic images is disclosed. The screen comprises a two-dimensional matrix of cells (dots) each cell having a common pattern of transmittance to radiation utilized in the reproduction process. The common pattern of transmittance for each cell is characterized by a finite number of different discrete transmittance level patterns. In a preferred embodiment, these patterns include portions arranged along the respective sides of a parallelogram. In one preferred embodiment, the discrete transmittance level patterns comprise an array of concentric parallelograms. Each parallelogram has a plurality of dot portions arranged along the sides of the parallelogram. The sides of the parallelogram patterns are preferably disposed at a substantial angle to the horizontal to reduce moire and rosette pattern effects and to simplify the reproduction process.

Abstract: A method of making a halftone contact screen having a plurality of discrete different optical transmittance levels by making multiple relative translations of light-sensitive material under and in close contact with a ruling mask while exposures to light through the ruling mask are made between the translations. The mask comprises a thin flat plate having an array of parallel periodic equal width opaque straight bars separated by an array of parallel equal width transparent bars. In a first process, translations are normally made perpendicular to the parallel of the bars. Two-dimensional or dot halftone contact screens are made by repeating the process wherein the light-sensitive material is rotated relative to the ruling mask, in its own plane, at an angle greater than zero to the direction of the ruling bars during the first process. Using the single process creates a line halftone contact screen; adding the second process creates a dot halftone contact screen.

Abstract: A spot of light is formed upon a photosensitive material which is moved in a scanning direction, and the spot is vibrated to and fro along a vibration direction at a considerable angle to the scanning direction, and the amplitude of vibration, and the center of the vibration path, are controlled so that the spot exposes areas on the photosensitive material which form half-tone dots.

Abstract: This disclosure depicts a new low cost color photographic film assembly which is of the additive type but is of very high speed due to its extremely efficient utilization of available exposure light. The assembly includes a photosensitive layer actinic to light in the entire visible bandwidth of the exposure light for recording intensity variations in light incident thereon. It includes a spectral separation phase structure comprising a pattern of periodically repetitive, wavelength-sensitive phase elements effective to deflect incident light of predetermined different colors in different directions. The phase structure is supported adjacent to the photosensitive layer and spaced therefrom by a prescribed distance which is such that each element of an image formed on the assembly is analyzed into a number of color separation elements segregated on the photosensitive layer. The image is recorded in the layer as a dissected composite of interleaved color separation elements.

Abstract: Negative and positive films for use in multi-color printing are prepared by a process which utilizes crystals and interstices therebetween in color-separation negatives for multi-color printing without the use of half-tone screens. Exposure through masks of controlled density ranges relative to the color-separation negatives and positives prepared from the color original result in final negatives and positives as well as duplication negatives and positives which can be utilized in the multi-color printing process.