Toner Density Control; Toner Supply Timing - Gestetner B070 Service Manual

6.12.8 TONER DENSITY CONTROL

Overview
There are two modes for controlling toner supply: sensor control mode and image
pixel count control mode. The mode can be selected with SP2208. The factory
setting is sensor control mode. Image pixel count mode should only be used if the
TD or ID sensor is defective and cannot be replaced immediately.
[B]
[A]

Toner Supply Timing

After the trailing edge of the image leaves the development area, the machine
calculates how long the toner supply clutch should be switched on (based on the
TD sensor reading). Then, the toner supply clutch switches on for the time
prescribed by the calculation. Until the toner supply clutch switches off, the
development motor, main motor, charge, and development bias all remain on.
Regardless of whether the machine is in the sensor control or pixel count toner
supply mode, toner is supplied based on the setting for the toner supply interval
entered with SP2974 (Toner Supply Interval); the default is every print.
• If the TD sensor malfunctions, then toner is supplied for each copy and the
setting for SP2974 is ignored.
• The SP2974 setting has no effect on the ID sensor pattern interval; the ID sensor
pattern interval is set with SP2210 (ID Sensor Pattern Interval)
SM
CÓPIA NÃO CONTROLADA
Toner Supply Clutch On Time
Pixel Count
TD Sensor
Output (V
VT Reference
Voltage (V
VT Reference
Voltage Update
V
ID Sensor Output
(V /V
SP
TD Sensor Initial
Setting (V
6-79
CÓPIA NÃO CONTROLADA
DEVELOPMENT
Calculation
GAIN
)
T
)
REF
(New V )
REF
Update
REF
)
SG
)
REF
B070D644.WMF
B070/B071