Id Sensor And Ptl - Ricoh FT5034 Service Manual

4.8 ID SENSOR AND PTL

4.8.1 Mechanical Parts
1. Overview
Drum
ID Sensor
ID Sensor
Pre-Transfer Lamp
PTL
This machine checks toner density using an ID
Original
sensor. After the sensor pattern is developed,
its reflectivity is checked by the image density
sensor.
The sensor pattern image is made every 10th
copy. In the check cycle, the sensor pattern is
ID sensor pattern
exposed prior to exposure of the original. So,
this sensor pattern image does not appear on
the paper. Normally this sensor pattern is
erased by an erase lamp.
After the latent image is developed but before
the image is transferred to the copy paper, the
drum surface is illuminated by the pre-transfer
lamp. This illumination reduces the positive
Drum
potential on the drum surface. This is to
prevent the toner particles once attracted to
Photo Transistor
the paper surface from being reattracted to the
positively charged drum during the paper
ID Sensor
separation process. It also makes image
transfer and paper separation easier.
LED
Developed Sensor Pattern
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