Lasermaster Corporation

Other

John M Gilbert

Leonard R Steidel

Danny James Vatland

Lawrence J Lukis

Lawrence J Luckis

David H Bennefeld

Jonathan D Elliot

A driver circuit provides a plurality of drive energies having a plurality of thermal distributions associated therewith. These thermal distributions interact with print media to form binary images having active and inactive areas. A driver control circuit is responsive to source image information to apply selected drive energies to selected heating elements. These drive energies produce interacting thermal distributions for selectively positioning boundaries between active and inactive areas.

Method and apparatus for controlling a thermal print head

A thermal printer includes a thermal print head having a plurality of heating elements for printing dots. A source of drive pulses operates respective heating elements. Each drive pulse is modulated to provide first and second periods of the drive pulse to selectively energize the respective heating element, the first and second periods defining a selected energy level. A memory stores the modulated drive pulses and supplies respective modulated drive pulses to the respective heating elements. A measuring circuit measures a heating factor of each heating element and provides a correction factor for each heating element based on the respective measured heating factor. The correction factors are combined to the respective drive pulses to alter the first and second periods, thereby reducing variations in dots due to differences in the heating factors of the heating elements.

Heating control for thermal printers

A non-gray scale anti-aliasing method for smoothing one or more edges of an image to be printed by a binary imaging printer. The image is generated by rasterizing an ideal outline of the image using a processor means for processing a plurality of raster lines to form a pixel representation of the image to be communicated to the binary imaging printer. An ideal fill area representing the area inside the ideal outline for the pixel currently being processed is determined for each pixel in the raster line and then compared to at least a first and second comparison value. Based upon the comparison, a determination is made as to whether the pixel currently being processed will be turned on or turned off. In one embodiment, the comparison is made by the use of a lookup table having a set of predetermined comparison values that contain estimated fill values used by an accumulator to determine whether to selectively modify the pixel. In a different embodiment, the lookup table is replaced by using a fill function for translating the ideal fill value into the estimated fill value. In another embodiment, a control signal having a predetermined duty cycle is generated for all pixels within a boundary transition range defined by the first and second comparison values.

Duty cycle technique for a non-gray scale anti-aliasing method for laser

A line rasterization technique for a non-gray scale anti-aliasing method smoothes the edges of a single pixel width line image to be printed by a binary imaging printer. The line image is generated by rasterizing an ideal line image as a plurality of raster lines to form a pixel representation of the line image to be communicated to the binary imaging printer. For each vertical transition point created by the ideal line image crossing two adjacent raster lines, the present invention smooths the line image by selectively modifying the on and off states of one or more pixels in an adjacent raster line on either side of the vertical transition point. The pixel representation of the line image is then communicated to the printer such that the printer may print the smoothed line image.

Line rasterization technique for a non-gray scale anti-aliasing method

A non-gray scale anti-aliasing method for smoothing the horizontal components of the edges of an image to be printed by a laser printer having unequal pixel resolutions in the horizontal and vertical dimensions is accomplished by selectively modifying the on and off states of pixels on either side of each vertical transition point along the horizontal components of raster lines representing the edges of the pixel representation of the image. A processor is provided with an ideal outline of the image and rasterizes the ideal outline of the image to determine which pixels to turn on and which pixels to turn off in a frame buffer that stores a pixel representation of the iamge to be printed by the laser printer. The modified pixel representation in the frame buffer is then communicated to the laser printer such that the laser printer may print the smoothed image.

Non-gary scale anti-aliasing method for laser printers

A tuning machine is provided with an adjustable bearing surface for eliminating mesh backlash and end play which gradually develope between the worm and worm gear over years of service. The worm is held against the worm gear by a pair of saddle bearings formed on a sliding retainer. When the bearing wear develops an unacceptable backlash or end play develops, the retainer is loosened and repositioned closer to the worm. In the new position the worm is returned to its original intimate engagement with the worm gear. Simultaneously, the worm, is axially centered due to opposed bevel surfaces on the worm and saddle bearings. The new worm to worm gear mesh is free of backlash and endplay.

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Minneapolis, MN, United States of America

John M Gilbert