Thermal transfer video printer having improved temperature correction function of coloring density

Claim 1

A thermal transfer printer for carrying out density reproduction of N (N being a positive integer) toner levels on a coloring medium, comprising: thermal head means having a heating element for carrying out printing on said coloring medium by heating; thermal head control means for applying in succession i energizing pulses having durations corresponding to respective tones to said heating element, for printing a desired i-th tone level (i being an integer of 1 to N) among said N tone levels, wherein said thermal head control means includes memory means storing a tone table formed of N data which are bases for determining durations of energizing pulses for respective said tones, wherein said tone table includes a variable first data which is a basis for determining a duration of a first energizing pulse required from when said heating element begins to be heated until just before said coloring medium colors, and fixed second to Nth data which are bases for determining respective durations of second to Nth energizing pulses following said first energizing pulse, wherein said thermal head control means further includes holding means for holding a variable value that is multiplied by said fixed second to Nth data, and means for determining the durations of i energizing pulses according to the data in said tone table and the value of said holding means, measuring means for measuring a temperature of said thermal head, and data modifying means responsive to the temperature measured by said measuring means for modifying the variable first data included in said tone table to a corresponding data calculated in advance, and the variable value held in said holding means to said corresponding value calculated in advance.