Potential Control; Overview; Process Control Self-Check - Ricoh G104 Service Manual

6.2.2 POTENTIAL CONTROL

Overview

Potential control controls development to keep the toner images on the drums at
the same density. It does this by compensating for variations in drum chargeability
and toner density.
The machine uses the ID sensor to measure the reflectivity of the transfer belt and
the density of a standard sensor pattern. This is done during the process control
self-check.
The machine measures these values from the ID sensor output and a reference
table in memory.
• V
: Drum potential without exposure – to adjust this, the machine adjusts the
D
charge roller voltage.
• V
: Development bias
B
• V
: Drum potential at the strongest exposure – to adjust this, the machine
L
adjusts the laser power.
(Also, V is corrected. This is used for toner supply control.)
REF
This controls the development potential to make sure that the maximum quantity of
toner applied to the drum is constant.
If SP3-501-001 process control is set to 1 (Fixed), the machine does not perform
the potential control, but uses these fixed parameters:
• Development bias adjusted with SP2-212-001 to –008
• Charge roller voltage adjusted with SP2-201-001 to –009
• Laser power selected with SP2105-001 to –012.
• However, these SPs are not normally adjusted in the field.

Process Control Self-check

This machine performs potential control with a procedure that is known as the
process control self-check. This procedure is done at these 9 times.
1. Initial
This starts automatically at the following times:
• Immediately after the power is turned on
• When the machine comes back from energy saver mode
• 6 hours after the power was turned on (can be changed with SP 3554 001)
• If absolute humidity changes more than ± 6 g/m
70%). The humidity threshold can be changed with SP 3554 002.
SM
CÓPIA NÃO CONTROLADA
6-9
CÓPIA NÃO CONTROLADA
PROCESS CONTROL
(e.g. 23°C/ 50% 27°C/
3
G104