Head Temperature Monitoring - Printronix L5000 Series Maintenance Manual

Head Temperature Monitoring

The printer uses a thermistor (HTS) to monitor the LED head temperature to avoid
excessive printhead temperature during printing, When the LED head temperature
rises to 45 C, the printer considers it an error, stops printing operations, cools the
LED head with a heat pipe and a head cooling fan, waits until the LED temperature
falls below 45 C, and goes into the on-line idling state to become ready to resume
printing. The LED head output light intensity will also lower when the LED head
temperature rises. Therefore, the head thermistor also checks whether a temperature
of 35 C is exceeded. If the LED head temperature rises above 35 C, the LED
illumination time is increased by 5% (the normal illumination time is equivalent to
25% of the raster cycle).
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Principles of Operation