PROCESS CONTROL12 February 1992
1.2 ID SENSOR CONTROL
Sensor
Original Lead Edge
Pattern
Original
ONOFFONOFF
Leading Edge EraseDevelopment
ABCDEID SensorBias
Pattern
RAM Clear
1234567891011121314202122
Toner Density DetectionToner Density DetectionToner Density
Detection
1st2nd3rd
Low Toner Density
Toner Supply Timing
Detection
Toner Add
Toner Supply Clutch ONDetection
(10 times)
1.2.1 Overview
An ID (Image Density) sensor is used to control toner supply.
The sensor is located on the drum unit, under the cleaning unit. Placing the
sensor under the cleaning unit, instead of the development unit, reduces the
risk of scattered toner getting on the sensor.
The CPU checks toner density through the ID sensor by directly sensing the
image density on the drum. This is done every 10 copy cycles (every 5 copy
cycles for the color development unit). Turning the main switch off and on has
no effect because the count is stored in RAM. If the drum initialization is
performed (SP mode #66) or the RAM is cleared (SP mode #99), the CPU
starts counting for the toner density check from the beginning of the first copy
cycle.
The ID sensor pattern (black) is stuck on the operator side of the bottom of
the left scale bracket. During the check cycle, the ID sensor pattern is
exposed prior to exposure of the original.
2-2 |
ACEC
RICOH
