Coulter Systems Corporation

The Mead Corporation

Lysle D Cahill

John C Butler

Manfred R Kuehnle

John A Lawson

E Raymond Thomas

Ronald J Duke

Kenneth D Fraser

John L Tibbits

John F Keane

Theodore A Kessis

Gary L Frank

Stanley C Harting

George H Kramer

Lawrence J Bassuk

Brian N Wilcox

Vincent James Paul, Jr

William W Marshall

Arthur R Brunswick

Luke L Talley

Ernest Warren Drumm

Arnold Leroy Fife

An electrostatic image of binary data representing elements if formed on a particular electrophotographic member disclosed and claimed in U.S. Pat. No. 4,025,339. The electrostatic image is toned and the toned image is transferred to a storage medium. The storage medium is in the form of an extended length of dual-layer transparent synthetic resin material. One of the layers has a softening range of temperature less than the substrate. At the transfer, the one layer is heated and the toned image is pressed into the one layer. The storage medium carrying the toned image then is wound up on a storage or take-up spool while fresh medium is fed from a supply spool. The two spools are carried by a housing and the housing, spools and medium form an optical mass memory cassette. Reading of the data occurs by deflecting rays of light across the medium and the light that is transmitted through and blocked by the medium is sensed in bar sensors, one for each ray. The rays are deflected across the medium in a pattern similar to the pattern used for imaging the electrophotographic member. The electrical signals from the sensors are used to produce binary data representing the data stored on the medium.

Method and device for reading digital data in an optical mass memory

A digital laser platemaker for imaging an electrophotographic member by electrostatic techniques using information which is derived from a source of binary data. The binary data may be achieved by scanning a pattern or may be synthesized electrically to represent that which it is desired to reproduce on the electrophotographic member. The binary data is applied to a pixel generator which is constructed and arranged to produce an output in the form of signals for driving an acousto-optical deflector that in turn deflects a laser beam to form a composite of rays. The composite of rays represent the columns of a pattern to be applied to each pixel which is generated, the rows of the pixel being represented by the output of a shaft encoder that is synchronized with the rotation of a cylinder carrying the electrophotographic member. The pixel generator produces hexagonal pixels and the pattern in each pixel represents density information derived from the binary data originally received by the pixel generator. The patterns in the pixels are arranged to prevent undesirable moire effects. The electrophotographic member receives the composite rays from a carriage which moves in synchronism with the rotation of the cylinder and the rate at which the composite rays are applied. The resulting latent image is toned and fused on the cylinder. Thereafter it may be used as the printing plate after certain processing.

Electrophotographic imaging apparatus by variably placing pixel elements

An electrostatic image of binary data representing elements is formed on a particular electrophotographic member disclosed and claimed in U.S. Pat. No. 4,025,339. The electrostatic image is toned and the toned image is transferred to a storage medium. The storage medium is in the form of an extended length of dual-layer transparent synthetic resin material. One of the layers has a softening range of temperature less than the substrate. At the transfer, the one layer is heated and the toned image is pressed into the one layer. The storage medium carrying the toned image then is wound up on a storage or take-up spool while fresh medium is fed from a supply spool. The two spools are carried by a housing and the housing, spools and medium form an optical mass memory cassette. Reading of the data occurs by deflecting rays of light across the medium and the light that is transmitted through and blocked by the medium is sensed in bar sensors, one for each ray. The rays are deflected across the medium in a pattern similar to the pattern used for imaging the electrophotographic member. The electrical signals from the sensors are used to produce binary data representing the data stored on the medium. The data stored in the optical memory cassette is unaffected by magnetic and electric fields and light energy, a tremendous quantity of data can be stored on a relatively small length of storage medium, and the storage medium is inexpensive so that it may be discarded when the data is obsolete.

Optical mass memory system using electrophotography

Graphics and text data are combined selectively to discharge incremental areas of a charged electrophotographic member to form thereon a latent text and/or graphics image represented by the graphics and text data, the imaged member thereafter being toned and output from the system so that the toned image may be fused on the member and the member may be used as a printing plate in an offset lithographic printing press. The apparatus includes an optical system that may form a maximum of 22 individual rays which are deflected twice through a field flattening lens and then onto the charged member. The optical system further includes an optical scale or grating which provides electrical signals indicating the precise location of the individual rays along scan lines on the member. The apparatus further includes an electronic system which generates electrical signals from the graphics and text data to form the 22 individual rays. The text data is used to modulate signals produced by the graphics data, the result of the modulation being beam control signals used to form the 22 individual rays. The apparatus further includes a toning system that provides a vertical meniscus of toning fluid, the meniscus being essentially stationary with the electrophotographic member as the electrophotographic member is rotated past the toning station.

Digital plate maker system and method

A digital plate maker system to receive graphics and text data and selectively discharge incremental areas of a charged electrophotographic member to form thereon the latent images represented by the graphics and text data, the imaged member thereafter being toned and output from the system. Thereafter, the toned image may be fused on the member and the member being used in an offset lithographic printing press. The digital platemaker system includes an optical system which may form a maximum of 22 individual rays which are direct deflected twice through a field flattening lens and then onto the charged member. The optical system further includes an optical scale or grating which provides electrical signals indicating the precise location of the individual rays along scan lines on the member. The digital plate maker system further includes an electronic system which generates electrical signals to form the 22 individual rays. The text data is used to modulate signals produced by the graphics data, the result of the modulation being the beam control signals used to form the 22 individual rays. The digital plate maker system further includes a toning system which provides a vertical meniscus which is essentially stationary with the electrophotographic member as the electrophotographic member is rotated past the toning station.

Optical system for imaging an electrophotographic member

Half-tone xerography involving high speed charging of a limited region of an electrophotographic member and subsequent high speed discharging as by writing with a fine laser beam upon the limited region of the electrophotographic member, the beam being modulated with recordable intelligence from stored digital data. The member is mounted for rotary and axial movement relative to both charging unit and an axial movement beam directing unit. The member support for the member holds the member in a cylindrical or partially cylindrical form with the photoconductive coating inside. The member as a unit and a charging device and writing device as a unit are mounted for relative axial and rotating movement at high speed to enable charging and imaging of the limited regions in a continuous progressive manner.

High speed imaging of electrophotographic film by fine beam scanning

A digital laser platemaker for imaging an electrophotographic member by electrostatic techniques using information which is derived from a source of binary data. The binary data may be achieved by scanning a pattern or may be synthesized electrically to represent that which it is desired to reproduce on the electrophotographic member. The binary data is applied to a pixel generator which is constructed and arranged to produce an output in the form of signals for driving an acusto-optic deflector that in turn deflects a laser beam to form a composite of rays. The composite of rays represent the columns of a pattern to be applied to each pixel which is generated, the rows of the pixel being represented by the output of a shaft encoder that is synchronized with the rotation of a cylinder carrying the electrophotographic member. The pixel generator produces hexagonal pixels and the pattern in each pixel represents density information derived from the binary data originally received by the pixel generator. The patterns in the pixels are arranged to prevent undesirable moire effects. The electrophotographic member receives the composite rays from a carriage which moves in synchronism with the rotation of the cylinder and the rate at which the composite rays are applied. The resulting latent image is toned and fused on the cylinder. Thereafter it may be used as the printing plate after certain processing.

Imaging by varying the placement of elements in the pixels

An original image is reproduced on an electrophotographic member with a series of binary data bits having a statistically valid count corresponding to the relative density of the original image. A sensor senses the density value of individual information forming structure or structures in incremental areas of the original image and converts the density values into a series of binary data bits, one bit per incremental area. An imager receives the binary data bits and forms one binary element on the charged electrophotographic member surface in response to each bit. The elements formed on the member surface correspond in sense to the binary data bits from the sensor and the elements are formed in incremental areas of the member corresponding to the incremental areas of the original image from which their respective binary data bits were produced. An aperture of the sensor which determines the size and configuration of the incremental area scanned is adjustable to aproximately the size and configuration of the information structure and a threshold level value of the sensed density values is adjustable to the mean of the sensed densities of the original image so that a sensed density value above the threshold value produces a binary bit of one sense and a sensed density value below the threshold value produces a binary bit of the other sense to produce the statistically valid count of the series of binary data bits.

Binary scan system

Half-tone xerography involving high speed charging of a limited region of an electrophotographic member and subsequent high speed discharging as by writing with a fine laser beam upon the limited region of the electrophotographic member, the beam being modulated with recordable intelligence from stored digital data. The member is mounted for rotary and axial movement relative to both charging unit and an axial movement beam directing unit. The member as a unit and a charging device and writing device as a unit are mounted for relative axial and rotating movement to enable charging and imaging of the limited regions in a continuous progressive manner.

A latent electrostatic image is formed on an electrophotographic member having a crystalline, stable coating of wholly inorganic photoconductive material which is of the order of 0.2 to 2 microns thick. This is effected by moving a corona needle energized by a corona power source and a laser beam modulated from digital information together over the photoconductive coating in a progressive manner at high speed. The latent electrostatic image so formed is then developed.

A flat bed scanner system for optically sensing a transparent original image and producing three channels of binary digital data representing the densities of the original image. Each channel produces data in response to one sensing color and sensing of the original image occurs by directing a focused image of a beam of white light onto and across the original image in a pattern of parallel scan lines there being a plurality of sensing positions along each scan line, and producing the digital output data in response to the modulated beam of light transmitted by the original image. There is an optical system which provides for the directing of the beam of white light across the original image and which directs the modulated beam onto sensors. The optical system includes color correction and field flattening of the beam of white light and provides a cylinder condenser lens for the modulated beam of white light. An electronic system receives signals from the sensors and converts them into the desired digital data through analog to digital and logarithmic conversion circuits, base line correction circuits and references compensation circuits. The electronic system also provides a sample clock signal synchronizing the locations of the sensing beam with the locations of the sample positions by way of an optical grating system. An electromechanical system is provided to maintain the optical system in focus from scan line to scan line on both the original image and the optical grating system.

Flat bed scanner system and method

A dot matrix recording system records a wide range of gray levels without compromising recording resolution. Resolution is maintained by using a relatively small dot matrix, preferably a 2 by 2 matrix, for representation of the graphic information at a point within an image being reproduced. When adjacent points within the image have the same optical density, then the matrix representation thereof is altered from point to point so as to produce a matrix of effectively increased size. The larger matrix or matrix group may comprise 4 of the 2 by 2 matrices positioned in a square arrangement. Thus when two horizontally adjacent points within an image have the same optical density and are situated immediately above two other points having the same optical density, then the four-point area is represented by a matrix group comprising a total of 16 matrix cells arranged in a 4 by 4 pattern. Such an arrangement permits recording a gray scale comprising 17 gray levels from white to black, while preserving the resolution afforded by the smaller 2 by 2 matrix. A further gray scale extension is obtained by a 'special case' technique wherein the 2 by 2 matrices are combined into a rectangular matrix group which is 2 matrices high by 4 or 6 matrices wide for a total of 32 or 48 matrix cells.

Apparatus for dot matrix recording

A scanning and printing system scans and digitizes graphical information for recording on magnetic tape and also prints graphical information previously stored in digital form on a magnetic tape. Scanning and printing is accomplished by directing a laser beam through a pinhole in an aperture plate and thence through a set of optics, which collimate the beam and scan it across the surface of a graphic medium. For operation as a printer the laser beam is addressed by an acousto-optic modulator, which is positioned between the laser and the aperture plate. The acousto-optic modulator causes a shifting of the laser beam in accordance with digitized data trains representing positive and negative areas in an image to be reproduced. The laser beam is normally blanked out by the aperture plate and is periodically shifted by the acoustic-optic modulator for direction through the pinhole.

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Dayton, OH, United States of America

Lysle D Cahill