Abstract: A technique for use in, illustratively, a transform coder for imparting robustness against burst (or similar) errors to data patterns, such as illustratively two-dimensional image data, that exhibit local redundancy. Robustness is provided, in the case of images, by passing localized (blocked) image data, i.e. either pixel values or transformed, illustratively discrete cosine transform (DCT), image coefficient values therefor, through a global block transform, such as a global block Hadamard transform, prior to compression coding in order to produce "holographic-like" compressed data for subsequent transmission and/or storage. Specifically, globally transforming an image in this fashion effectively spreads (diffuses) the image data in each block of pixels in that image or in the transform coefficients therefor in a regularly ordered pre-defined global manner throughout the entire image to create what is, in effect, intentionally "smeared" image data.

Abstract: Improved electroerosion recording media can be prepared by utilizing, on top of a polyester, paper, or metal substrate, a polyvinylbutyral polymer cross-linked with a mixed phenol-tert-butylphenol formaldehyde cross-linking agent as a base layer, and an erodible metallic layer sufficiently thin to be erodible in response to current pulses delivered by a stylus of an electroerosion printer. In a preferred embodiment, the polymeric layer further contains silica. The recording medium may also be top coated with a lubricating agent. The formulation provides excellent adhesion of the conductive layer, and allows the thickness of the aluminum to be increased up to 75%, resulting in an optical density (with aluminum as the metallic layer) of up to 3.5.

Abstract: Electroerosion recording material with improved corrosion resistance provided by an overlayer of a protective lubricant composition of conductive particles of high lubricity dispersed in a partially crosslinked, water insoluble, hydrophilic polymeric binder.

Abstract: An improved apparatus and process are described in which a direct negative is formed using commercially available multi-stylus recording heads. A negative precursor comprised of a transparent support and an opaque thermoplastic ink layer carried thereon, is brought into contact with an ink receiving medium comprised of a resistive layer and a thin conductive ink receiving layer thereon. Electrical currents are provided by the recording styli of the multi-stylus recording head to the resistive layer to provide sufficient heat to soften regions of the opaque ink brought into contact with the conductive layer, by which regions of said opaque ink are transferred to the ink receiving conductive layer. In this manner, a pattern of opaque ink regions is removed from the surface of said transparent support, whereby a direct negative is formed having light opaque and light transparent regions.

Abstract: The present invention provides an improved electroerosin recording medium which comprises, in a preferred embodiment, a non-conductive support, a hard, abrasion resistant layer, preferably comprising an organic polymer matrix containing an inorganic particulate material, a thin conductive film, typically of a metal such as aluminum, and an abrasion resistant overlayer that most preferably comprises a solid conductive lubricant dispersed in an organotitanium regaent modified polymer system. The overlayer is highly adherent to the conductive surface, has a low organic binder content and provides effective protection against abrasion of the conductive layer and fouling of a print head during electroerosion printing.

Abstract: The method according to the present invention enlarges a binary digital image by a method comprising the steps of: storing the rows of the image as a plurality of run end representations, in which a row is represented as a sequence of values giving the white and black run ends; enlarging each row of the image along the horizontal axis by altering the value of each run end representation to achieve enlargement on the horizontal axis by a factor F1; enlarging the image along the vertical axis by interpolating rows between the lines of the partially enlarged image so as to produce enlargement along the vertical axis by a factor F2; storing the enlarged size image generated by the above steps in run end form. An image enlarged by the method of the present invention may be reduced by the simple technique of dividing the image into blocks of pixels and assigning one pixel in a reduced image for each block of pixels in the larger image.

Abstract: An improved printing member for use in a system wherein a current source, in combination with a resistive ribbon, produces heating in selected areas of the ribbon for effecting the formation of a printing pattern on the printing member, which member is composed of a first layer, having a predetermined melting temperature, and a heat-conducting layer which adheres to the first layer below its predetermined melting temperature and which adheres to said resistive ribbon at temperatures above said predetermined melting temperature, such that, when the second layer is heated to a temperature level above the predetermined melting temperature in selected areas forming a pattern to be printed, the selected areas will adhere to the resistive ribbon and release from the first layer.

Abstract: This invention describes a direct master for offset printing. The master comprises a thin metal layer, a thermoplastic layer disposed on the metal layer, and a conductive oxide layer evaporated on the metal layer. When this master is subjected to electrical pulses from the styli of a printer, some of the thermoplastic layer diffuses through the oxide layer changing selected regions of the oxide layer to oleophilic regions.

Abstract: Electroerosion recording materials of superior scratch resistance are provided by incorporating a hard, crosslinked polymer film or layer between the support and the removable, thin conductive layer to reduce plastic deformation of the support under stylus writing pressure. The intermediate polymer layer may be unfilled or filled with solid particles, such as silica particles. The materials may be used in various printing processes including making directly readable images, direct negatives, and offset masters.

Abstract: An improved thermal transfer resistive ribbon usable in high resolution printing comprising a dual resistive layer formed of a first layer of low resistivity and a second layer of high resistivity, method of production thereof, use thereof and apparatus including the same.

Abstract: An improved apparatus and process are described in which metal images are transferred to a softenable receiving layer using commercially available multi-stylus recording heads. The transfer medium is comprised of a resistive layer and a thin metal layer thereon. Electrical currents are provided by the recording styli of the multi-stylus recording head. Localized electrical currents in the resistive layer provide sufficient heat in the metal layer to soften regions of a metable receiving layer when it is brought into contact with said heated metal layer. Metal imaging for use in printed circuit board manufacture and in formation of printing masters can be transferred by this technique.

Abstract: An improved resistive ribbon for resistive thermal transfer printing is described in which the resistive layer of the ribbon has enhanced thermal and mechanical properties. The ribbon is a multi-layer ribbon including a resistive layer, an electrical current return layer, and an ink layer. The resistive layer has an additive therein which phase separates and concentrates in a thin surface region near the interface of the resistive layer and the current return layer. This thin region has superior thermal and mechanical properties, and protects the remainder of the resistive layer during the printing operation, without adversely affecting the mechanical, electrical, and thermal properties of the overall resistive layer. These additives are those which will form a polymer having a sufficiently high dissociation temperature to withstand the adverse effects of heat build-up at the interface. Suitable additives include graphite fluorides, fluorocarbon resins such as Teflon.RTM., and CeF.sub.4.

Abstract: An electronic processing system for reproducing mixed images, i.e., original images having areas of continuous tone and areas of text, in such a manner that both areas are of balanced, good quality in the reproduction. The image to be reproduced is (1) divided into non-overlapping 4.times.4 blocks of pixels or picture elements, and, (2) each block is classified as either of TEXT or IMAGE, based on the values of the 16 pixels within it. The classification is improved by (3) eliminating short runs of blocks with the same classification. The pixel values are then adjusted by appropriately (4) thresholding those in the TEXT blocks and, (5) averaging those in the IMAGE blocks. The IMAGE block values are quantized to one of 17 levels using an improved error diffusing process and then mapped onto a 4.times.4 pattern preparatory to (6) merging the binary images for the TEXT and IMAGE areas.

Abstract: Electroerosion recording materials for "direct negative" and "offset master" are provided with a surface protective coating of solid conductive lubricant dispersed in a hydrophilic, crosslinked polymeric matrix. The protective films are especially useful where direct offset masters are produced without removal of non-eroded lubricant film.The recording medium of this invention provides use as a defect-free "direct negative" and/or "direct offset master", without requiring the removal of the overlayer prior to use on the printing press. The protective coatings are applied from aqueous dispersions of polymer-particulate compositions and thus avoiding the use of organic solvents.

Abstract: For high speed electroerosion recording, this invention provides a polyorganosiloxane overlayer which includes high lubricity solid particles as a filler. The overlayer provides a combination lubricant and protective layer for the thin metal layer which is removed by electroerosion to prevent damage for the areas not removed by electroerosion. The polyorganosiloxane overlayer is preferably crosslinked, and is relatively hard, durable, and especially resistant to thermal degradation by the electroerosion arcing. This is important to avoid debris buildup at the recording electrodes resulting from the high temperature arcing for removal of the overlayer in the areas where recording takes place.

Abstract: The present invention relates to a dot matrix printer which makes use of multiple dot patterns distributed on the cylinder, belt, hand or drum of a line printer to provide an improved printing throughput for an all addressable line printer. In a dot-helix matrix printer, different arrangements of the dots are used which can be varied in position and spacing to increase printing speed. On a belt, band or drum line printer, multiple dot patterns are given a predetermined distribution. More specifically, arrangements of dots are used which provide enhanced performance due to the fact that they are determined by an analysis of the statistical occurrence of a particular dot pattern in a character set. The higher statistical probability dot patterns are used more often on the belt, band or drum.

Abstract: The Laplacian operator is obtained by using CCD architecture to provide positive and negative weights to respective inputs and then combining the weighted signals.

Abstract: Electroerosion recording materials are provided with a surface lubricant film of particulate lubricating nonconductive graphite fluoride and optional conductive materials in a polymeric binder. The lubricating agents reduce stylus scratching of the conductive layer during electroerosion printing, improve contrast, provide a beneficial coating on the writing electrode or stylus and improve the handling and writing characteristics of the recording material. The lubricating agents/polymer films are especially useful (1) where the substrate of the recording material is light transmissive and, after the electroerosion process, the resulting product is suitable for direct-negative applications and (2) where direct offset masters are produced by removal of noneroded lubricant film.

Abstract: Electroerosion recording materials of superior scratch resistance are provided without the need for a lubricant overcoat by incorporating a hard, lubricating hydrophobic polymer layer between the support and the removable, thin conductive layer to reduce plastic deformation of the support under stylus writing pressure. The intermediate polymer layer provides a highly adhering surface for the overlying aluminum film and contains graphite fluoride and/or fluorocarbon resins such as Teflon.RTM. and hard particles such as silica. The materials may be used in various printing processes including making directly readable images, direct negatives and wear resistant offset printing masters.

Abstract: Improved electroerosion recording media are described in which ablatable polymers are used in the electroerosion recording medium. This medium includes at least a substrate or support layer, a base layer which protects the substrate, a thin film of conductive material on the base layer and which can be eroded, and a protective overcoat layer. Ablatable polymers are used as binders in either the base layer or the top protective layer, or both, in order to provide advantages during electroerosion. These ablatable polymers undergo thermally induced depolymerization in such a way that the result is the formation of volatile monomeric or low molecular weight species as the predominant products, with little or no adherent residue.