International Business Machines Corporation

Phillip Keith Hoskins

Steven G Ludwig

Stephen Dale Hanna

Joan LaVerne Mitchell

Jean Margaret Aschenbrenner

David E Finlay

Charles Harwood Morris, Iii

Harmon W Johnson

Operations for decompression of compressed data is performed in parallel and in a pipelined manner to generate addresses into a memory on-the-fly rather than using a large look-up table. The logic circuits for doing so are thus reduced to the point of being able to be formed by suitable programming of a field programmable gate array (FPGA) while achieving substantial increase in processing speed beyond speed increases attributable to increase of clock rates.

Digital data decompression implemented in a field programmable array device

Disclosed is a method, system, and logic for processing pixel data. A first and second logic units each receive line work data and control data for pixels on a sheet from at least one object. The control data for one pixel indicates whether to use the line work data for the pixel or contone data for the pixel. Multiple objects may provide line work data and control data for a same pixel. The first and second logic units output control data indicating to use contone data or line work data for the pixel. A third logic unit receives the line work and control data outputted from the first and second logic units. The third logic unit then outputs control data indicating to use the contone data or line work data for the pixel.

Method, system, and logic for selecting line work and control data for a pixel from multiple objects of line work data provided for the pixel

A system, apparatus, method and program for controlling and tracking printable object headers associated with print objects being processed for printing in a printing system. The print object headers are provided in a plurality of queues, which are serially arranged in a stacked queue configuration. Print object headers are received at a first one of the queues, and as additional print object headers enter the stacked object queue via the first queue, they are controllably shifted through the remaining queues as they become available.

System and method for managing print objects using stacked objects queue

Disclosed is a method, system, and program for error checking raster objects including pixel information for a print job. A plurality of raster objects form the print job. A raster object is received including sequence information indicating an ordering of the raster object with respect to other raster objects in the print job. A determination is made from the sequence information as to whether the raster object is received in a correct order with respect to other raster objects in the print job. This ensures that the pixel information for the raster object is intended for a current pixel line being processed. An indication of error status is made if the sequence information indicates that the raster object was not received in the correct order with respect to the other raster objects in the print job.

Method, system, and program for error checking raster objects

A method and apparatus for error checking in a digital scanning device. An error detection pattern is written into each of a plurality of parallel data streams. Each of the data streams is then transmitted through a separate parallel data channel. The error detection patterns in the data streams are then concurrently compared to one another to check for an error condition of the data stream. If the error detection patterns are not received substantially concurrently, an error condition is considered to have occurred. The error detection pattern may comprise end of scan, end of sheet or First-In First-Out (FIFO) buffer data. While all error conditions are false, printing and data transmission continue. Printing and data transmission are terminated if any error condition is true, and an error notification message is generated.

Error detection in digital scanning device having parallel data streams

Electronic lead determining circuitry operates to advantage with nonconstant relative movement between a paper record medium and an ink drop projector carrier of ink drop printing apparatus. Electronic lead determining circuitry is arranged for calculating the proper lead times for displacing the normal print enabling signals by factors dependent on the actual carrier positions and the lead for projecting ink drops at the desired positions. Ink drop printing apparatus of the type having a carrier bearing an ink drop projector across a record medium at a velocity relative to the record medium which may be varying substantially--either by design or unintentionally--, and bearing print position location detecting elements, and bearing ink drop projection controlling elements is perfected by controlling electronic circuitry for calculating lead time at a given print position for enabling printing at a predetermined designated print position precisely at the predetermined desired location on the paper. Preferably, a velocity-time profile for the apparatus is chosen for low g-force loading of the moving components, and printing is effective over most of the profile in contradistinction to conventional printing over linear portions only of conventional profiles. Phase locked oscillator loop circuitry is used for tracking the carrier position and adjusting phase, while several alternate lead calculating circuits are arranged in cooperation therewith. Print position and carrier travel direction data are updated in real time as the apparatus operates under data processing control.

Circuitry for perfecting ink drop printing at nonlinear carrier velocity

A high resolution letter quality 24 by 40 dot matrix ink jet printer includes a movable print head having print elements disposed to print along a slanted line, a character generating module providing character dot patterns to be printed and a modular skewing circuit arranged to receive the dot pattern information and provide the information to the print head in a rearranged order that corresponds to the order in which dot patterns are printed by the print elements. Because the skewing circuit divides each character dot pattern into eight dot pattern modules and operates on the dot pattern modules one at a time in sequence, the finer resolution of a slant head printer can be obtained without need for a huge triangular shift register operating on all of the dot rows of a dot column in parallel to skew the dot pattern information into conformity with the corresponding relative print element locations.

Growing community of inventors

Berthoud, CO, United States of America

Phillip Keith Hoskins