Patent ID: 8164609

Claim:
A direct thermal printer comprising: a thermal print head comprising a plurality of heating elements; a control circuit connected to the thermal print head that applies, during a first portion of a printing time, a first pulse pattern to the heating elements, and that applies, during a second portion of the printing time, a second pulse pattern to the heating elements; wherein the first pulse pattern comprises a first plurality of pulses having a first average power, wherein each of the first plurality of pulses has a common energy, wherein the first portion of the printing time comprises a first plurality of subintervals, and wherein the first plurality of pulses is provided in a plurality of consecutive subintervals; wherein the second pulse pattern comprises a second plurality of pulses having a second average power that differs from the first average power, wherein each of the second plurality of pulses has the common energy, wherein the second portion of the printing time comprises a second plurality of subintervals, and wherein the second plurality of pulses is provided in a plurality of nonconsecutive subintervals and have a period of N, where N>1.