Auto Density Sensing - Lexmark T652 Service Manual

4062-XXX

Auto density sensing

Sensor shield assembly
Sensor (toner density)
The image density sensor assembly uses a reflection type sensor that detects a pre-placed toner patch and
image on the photoconductor (drum) and outputs pulses when the central line of the patch image aligns with
the central line of the detector. The sensor outputs pulses at the timing the patch image passes the sensor.
Therefore, observing changes of intervals at which pulses are output leads to toner density detection.
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Diagnostic aids