Toner Supply Control - Gestetner B147 Service Manual

6.2.5 TONER SUPPLY CONTROL

Overview
Toner supply control uses the following to determine the amount of toner to be
supplied. This is done before every development for each color.
• Density of the toner in the developer (as detected by the TD sensor) - V
• Pixel count
The image density is kept constant by adjusting the density of toner in the
development unit, while accommodating to changes in the development conditions
through the potential control mechanism. Environmental changes and the number
of prints made are also used in the calculation.
The amount of toner supplied is determined by the "on" time of the toner supply
clutch. The total "on" time for each toner supply clutch is stored in the memory chip
for the relevant toner cartridge. The amount of toner supplied also depends on the
process line speed for the current job. The machine supplies the calculated amount
of toner for each color.
Toner Supply Control Modes
This machine has three toner supply control modes. They are selected with SP2-
208-1 to -4.
1. Fuzzy control mode
This is the default toner supply control mode. The TD sensor, ID sensor, and
pixel count are used in this mode.
2. Proportional control mode
This mode is used when the ID sensor at the center becomes faulty. Only the
TD sensor is used to control toner supply. The machine uses the V
stored in SP2-224-5 to -8.
3. Fixed supply mode
This mode is used when the TD sensor becomes faulty. The amount of toner
supply can be adjusted with SP2-208-5 to -8 if the image density is incorrect
(the default setting is 5%).
SM 6-15
PROCESS CONTROL
, V
REF T
that is
REF
B147/B149/B190