Abstract: A thermal printer apparatus has a plurality of print stations for recording image information onto a receiver moving past the print stations. An adjustable-speed receiver drive mechanism is adapted to advance the receiver along the path. A plurality of sensors adapted to detect the temperature of the receiver and other surfaces along the path. A controller adjusts the speed of the drive mechanism as a function of the detected temperatures so as to effect a shim of the average raster line pitch of the printer to compensate for changes in the temperature of the receiver. An empirical model of receiver speed as a function of measured receiver temperature is used in software to predict receiver speed during printing.

Abstract: A thermal print pulse controller and data shifter accomplishes control of a thermal print pulse by altering the pulse width of the print pulse according to the printing history. Data is obtained from the printhead and recirculated for logical operation with previous records back to the printhead during predetermined phases of the print pulse. As a result of the logical comparison a decision is made to continue or discontinue printing of a dot and thus prevent overheating the printing element.