Thermal line printer

摘要

A thermal line printer includes a semiconductor chip for control of A x N heaters arrayed in N groups past which thermally sensitive paper is stepped B times in printing a line of characters in an A x B dot matrix. A sequential access memory stores N multibit words, one word for each character to be printed on a given line with a commutator cyclically to read words from the memory A x B times for each line to be printed. A ROM has an A x B dot matrix code therein for each available character. A time sequencer and decoder connected to the ROM is synchronized with the commutator to produce a different one bit output from the ROM each time each given word is read from memory. A set of N enable circuits leads from the ROM to N groups of heaters. A set of A enable circuits leads from the sequencer to A groups of heaters where one heater in each A group is from one of the N groups. A decoder interfaces the sequencer to the A groups of heaters and to the motor sequentially to enable the heaters in one A group for each memory cycle and in order through the A columns and B rows of the matrix.