Abstract: 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.

Abstract: A method for controlling binary thermal printers increases the effective output resolution of the thermal printer above the native resolution of a print head having a plurality of individual resistive heating elements arranged in a print line. An increase in the effective resolution of a binary output image is achieved by using an over-drive energy to control a relative position of a binary edge of a pixel image at a resolution that is less than the native resolution of the thermal printer. In a preferred embodiment, an under-drive energy may also be used with an adjacent over-drive energy to further control the relative position of the binary image of the pixel image. The over-drive energy is higher than a native pixel drive energy, but lower than a maximum drive energy. The native pixel drive energy produces a binary pixel image having a native area corresponding to the native resolution of the thermal printer.

Abstract: 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.

Abstract: A two-dimensional coordinate measuring pad for use, for example, to recognize handwriting. A high resistivity sheet is bounded by a lower resistivity border connected to a switched voltage source to cause a current to flow first in one direction and then in a perpendicular direction through the resistive sheet. Potential measurements at an array of precisely predetermined points are employed to generate a set of correction values which are stored in a programmable read-only memory. Thereafter, to indicate the position of an arbitrarily selected contact point on the sheet, the stored correction values for the nearest points are fetched form the memory and combined with the measured values to produce adjusted output values which more accurately indicate the positional coordinates of the contact point.

Abstract: This invention is concerned with a character recognition device which includes a writing pad having a pair of sheets with one of the sheets comprising an area of high resistivity and the other one of the sheets comprising a layer of conductive material, the sheets being normally electrically insulated from one another but adapted to be brought into contact with one another by application of writing pressure by a writing implement upon the writing pad, the sheets being adapted to be connected to an electrical switching circuit whereby current is caused to flow through the pad along two alternate paths, wherein the high resistivity and the conductive sheet are separated by a layer of reticulated material and the conductive material is sufficiently elastomeric to provide good continuous electrical contact between the sheets when writing pressure is applied.