Thermal printing with normal and reverse image

Claim 1

A thermal printing system for printing in either normal image forming mode or reversed mirror image forming mode, comprising: a system for coding a total printing area as a matrix of dot areas substantially closely arranged in two dimensional directions along an abscissa and an ordinate, said dot areas each being so small that any figure to be printed by normal use of said thermal printing system is expressed by a particular combination of a plurality of said dot areas in said matrix; a plurality of thermal dot generating means which, when actuated, provide heat at selected ones of said dot areas in said matrix; a means for receiving input information for printing; a means for decoding said input information for printing into a series of digital printing signals, each of which determines actuation or non-actuation of said thermal dot generating means, according to an order of scanning which scans the dot areas of said matrix, said order being sequential with respect to at least one of said two dimensional directions so that every dot area which belongs to a certain position of said abscissa alternatively ordinate is scanned after every dot area which belongs to a position adjacently preceding to said certain position of said abscissa alternatively ordinate has been scanned but before every dot area which belongs to a position adjacently succeeding to said certain position of said abscissa alternatively ordinate is scanned; a means for actuating said thermal dot generating means according to said series of digital printing signals according to an order of scanning which scans the dot areas of said matrix, said order being sequential with respect to at least one of said two dimensional directions so that every dot area which belongs to a certain position of said abscissa alternatively ordinate is scanned after every dot area which belongs to a position adjacently preceding to said certain position of said abscissa alternatively ordinate has been scanned but before every dot area which belongs to a position adjacently succeeding to said certain position of said abscissa alternatively ordinate is scanned; and a means for controlling at least one of said order of scanning performed by said means for actuating said thermal dot generating means and said order of scanning performed by said means for decoding said input information for printing so as to selectively reverse the relative order of scanning performed by said means for actuating said thermal dot generating means to said order of scanning performed by said means for decoding said input information for printing at least with respect to the sequence with respect to said one of said dimensional directions.