International Business Machines Corporation

Keith S Pennington

Ali Afzali-Ardakani

Krishna Gandhi Sachdev

Mitchell S Cohen

William B Pennebaker

Mukesh K Desai

Frederick Hochberg, Deceased

Eva Erika Simonyi

Walter Crooks

Frederick Hochberg

Jan-Pieter Hoekstra

Bradford J Factor

Joan LaVerne Mitchell

Ari Aviram

Ephraim Feig

Frederick Cole Mintzer

Ali Afzali-ardakani

Eugene S Schlig

Karen L Anderson

James M White

Savvas G Chamberlain

Gene D Rohrer

John C Shen

Eric Gung-Hwa Lean

Samuel C-c Tseng

Lawrence Kuhn

Han C Wang

Peter S Hauge

William Boone Pennebaker, Jr

Stephen Anthony Shear

Hugo Karl Seitz

Jean-Piet Hoekstra

Ronald T Cannavaro

Jahn P Hoekstra

John G Cahill

William D Weber

Yi-Hsin Chen

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. By subjecting the 'smeared' image data upon de-compression to an inverse global block transformation, such as an inverse global block Hadamard transformation, then, even if a portion of the 'smeared' data for an image is obliterated during transmission or playback, the entire image can still be advantageously reconstituted, though at a somewhat degraded quality, from the remaining 'smeared' data.

Technique for use in a transform coder for imparting robustness to

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.

Electroerosion printing plates

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.

Electroerosion recording medium of improved corrosion resistance

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.

Direct negative from resistive ribbon

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.

Electroerosion print media having protective coatings modified with

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. Each pixel in the reduced image may by set equal to a center pixel in each block.

Method for enlarging an image stored in run representation form

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. Consequently, when the resistive ribbon is in contact with the heat-conductive layer while at a temperature level above the predetermined melting temperature of the first layer and is then drawn away from the heat-conductive layer, the selected areas will be removed from the heat-conductive layer forming the pattern to be printed therein.

Direct negative and offset master production using thermal liftoff

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.

Direct offset master by resistive thermal printing

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.

Scratch resistant recording materials for electroerosion printing

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.

Resistive ribbon for high resolution printing

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.

Metal transfer to form printing master plate or printed circuit board

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.

Resistive printing ribbon having improved properties

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. Converting to various patterns to suit the output device such as a specific printer, is possible by permitting the conversion of the bits for an IMAGE block from one pattern table to another.

System for reproducing mixed images

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.

Hydrophilic protective coatings for electroerosion printing

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.

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Somers, NY, United States of America

Keith S Pennington