Abstract: A method of controlling noise in an impact printer that modulates the input pulse to the power amplifier of the printer. The resulting current waveform is then applied to the print wire solenoids. The final shape of the force input to the platen reduces or spreads the spectral envelope containing problem harmonics and acoustic output noise.

Abstract: The present invention provides a dot history compensation system for varying the drive current to the points of a thermal print head in response to the printing history of the points. One or two previous print lines may be examined. In addition, the history of points adjacent to a selected point may be used to compute a head drive signal. The inventive system is implemented in an auxiliary control device within a thermal printer. In addition, an end point compensation system is provided to ensure that end points of a thermal print head receive equivalent amounts of energy to central points, even when a large number of points may be simultaneously fired. The inventive system is adapted for operation with both single color and multiple color thermal printers. The auxiliary control device also manages paper movement functions, thus freeing the main microprocessor for communications and other duties within the printer.

Abstract: Methods of enhancing the appearance of, and safeguarding, sales receipts. The methods provide sales receipts with watermarks, strike-throughs, and circles-about-an-item. These added functions can be accomplished in real time. Some of them can be printed in distinguishing colors.

Abstract: Command protocol for enhancing the appearance of two-color thermal printing. The methods provide sales receipts with watermarks, strike-throughs, and graphic surrounding an item. These added functions can be accomplished in real time. Some of them can be printed in distinguishing colors.

Abstract: Methods of enhancing the appearance of, and safeguarding, sales receipts. The methods provide sales receipts with watermarks, strike-throughs, and circles-about-an-item. These added functions can be accomplished in real time. Some of them can be printed in distinguishing colors.

Abstract: A method of controlling noise in an impact printer that modulates the input pulse to the power amplifier of the printer. The resulting current waveform is then applied to the print wire solenoids. The final shape of the force input to the platen reduces or spreads the spectral envelope containing problem harmonics and acoustic output noise.

Abstract: A method for improving the image quality of a thermal print image uses preprocessed image and color matrices, in which special combinations of black dots and black dot patterns are filtered out. These patterns are then replaced with printer-friendly patterns. This altering technique improves the image quality and reduces halo effects.

Abstract: A method for improving the image quality of a thermal print image uses preprocessed image and color matrices, in which special combinations of black dots and black dot patterns are filtered out. These patterns are then replaced with printer-friendly patterns. This altering technique improves the image quality and reduces halo effects.

Abstract: The present invention provides a dot history compensation system for varying the drive current to the points of a thermal print head in response to the printing history of the points. One or two previous print lines may be examined. In addition, the history of points adjacent to a selected point may be used to compute a head drive signal. The inventive system is implemented in an auxiliary control device within a thermal printer. In addition, an end point compensation system is provided to ensure that end points of a thermal print head receive equivalent amounts of energy to central points, even when a large number of points may be simultaneously fired. The inventive system is adapted for operation with both single color and multiple color thermal printers. The auxiliary control device also manages paper movement functions, thus freeing the main microprocessor for communications and other duties within the printer.

Abstract: The present invention provides a dot history compensation system for varying the drive current to the points of a thermal print head in response to the printing history of the points. One or two previous print lines may be examined. In addition, the history of points adjacent to a selected point may be used to compute a head drive signal. The inventive system is implemented in an auxiliary control device within a thermal printer. In addition, an end point compensation system is provided to ensure that end points of a thermal print head receive equivalent amounts of energy to central points, even when a large number of points may be simultaneously fired. The inventive system is adapted for operation with both single color and multiple color thermal printers. The auxiliary control device also manages paper movement functions, thus freeing the main microprocessor for communications and other duties within the printer.