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(11) | EP 1 266 762 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Method and apparatus for controlling a heating element of a thermal head |
| (57) A control apparatus for controlling a heating element of a thermal head (10) has
a print data processing unit (40) and a drive control circuit (50). The print data
processing unit (40) has a first processing function for converting first color data
to first and second print data, a second processing function for converting second
color data to second print data, a first line buffer (43) for storing the first print
data, and a second line buffer (44) for storing the first and the second print data.
The print data processing unit (40) selectively outputs print data from the first
line buffer (43) or print data from the second line buffer (44) to the drive control
circuit. The drive control circuit (50) has a print buffer (52) and history buffer
(53), and energizes the heating elements of the thermal head (10) based on energizing
commands determined by a comparison of the content of the print buffer (52) with that
of the history buffer (53). |