Process Control; Potential Control - Ricoh B230 Service Manual

6.2

PROCESS CONTROL

6.2.1 OVERVIEW
This machine has the following two forms of process control:

Potential control

Toner supply control
The following machine components are used for process control:
Four ID (image density) sensors (black, magenta, cyan and yellow).
TD sensor.
Normally, process control is not disabled. If process control is disabled, fixed supply mode
is used for toner supply, and the VREF stored in SP 3222 is used.
6.2.2 POTENTIAL CONTROL
Overview
The machine determines VD using the ID sensor output, and then determines VB and V
V : Drum potential without exposure – to adjust this, the machine adjusts the charge
D
roller voltage.
V : Development bias
B
V : Drum potential at the strongest exposure – to adjust this, the machine adjusts the
L
laser power
At the same time, the machine also determines VREF: Reference TD sensor output, used
for toner supply control
If potential control is disabled (SP3-041-001 is set to "0"), V
following SP mode settings.
SP2-005 for V , SP2-229 for V
D
If LD power control is disabled (SP3-041-002 is set to "0"), the LD power is fixed by the
following SP mode setting.
SP2-221 for V
L
Process Control Self Check
This machine uses the process control self check method to do the potential control. The
machine uses seven types of process control self check. These are categorized according
to their execution timing.
The counter (SP3-510) is reset if a self-check is done (except for a forced self-check).
ΔT = Temperature change between the temperature of the previous process control and
the current temperature
B230/B237
B
6-8
and V are fixed by the
D B
.
L
SM