Patent ID: 6476838
Filing Date: 2002-11-05
Classification: B41J

Abstract:
A control circuit for driving a thermal print head of a thermal printing apparatus, the print head oriented to transfer thermal energy to a thermally sensitive media, the print head transferring thermal energy to the media when operating in a printing mode upon reaching a desired printing temperature, the control circuit comprising:a switch operably linked to a power source and to the print head to provide a control pulse sequence, the control pulse sequence including a first pulse and a second pulse, the first pulse having a first electrical potential and being applied to the print head for a first duration to heat the print head to the desired temperature for initiating the print mode, and the second pulse having a second electrical potential lower than the electrical potential of the first pulse and being of a second duration to maintain the printing temperature of the printing head; and a timer for operating said switch at the end of the first pulse to provide the second pulse whereby the control pulse sequence provides an improved rate of heat input to the print head by decreasing the time required for the print head to attain the desired printing temperature and maintaining said temperature for the duration of said second pulse.