Preventing overheating of the printhead
There are restrictions on the duty cycle because of the heat generated by
the thermal printhead when printing solid blocks (regardless of the length of
the block in relation to the print line).
The restrictions are ambient temperature, the percentage of time (measured
against one minute) of continuous solid printing, and the amount of
coverage.
Keep in mind that the ambient temperature may be affected by factors such
as direct exposure to sun or close proximity to heating elements.
When the duty cycle exceeds the limits shown in the table, the receipt
printhead will heat up and shut down. This may damage the printhead.
To avoid this problem, do one or a combination of the following:
n
Reduce the amount of coverage.
n
Reduce the time of continuous solid printing.
n
Reduce the ambient temperature.
Allowable duty cycle (measured over one minute of continuous printing)
Amount of solid
coverage
Ambient temperature
25°C
35° C
50° C
20%
100%
50%
20%
40%
50%
25%
10%
100%
20%
10%
4%
Duty cycle
Percentage of time that the specified “Amount of solid coverage” can be
printed during a one minute period of time.
Example: at 20% solid coverage, 35° C temperature, a 50% duty cycle is to
be used, resulting in 30 seconds of printing and 30 seconds without printing.
PREVENTING OVERHEATING OF THE PRINTHEAD
44
