Gestetner B147 Service Manual page 321

3-920 [OPC Refresh]
3-920-1 Temperature
This SP determines the temperature threshold for determining whether refresh mode
is done just after the machine is switched on.
The charge roller generates NOx (nitrogen oxides), and these contaminate the OPC
drum surface and may cause a smeared image.
Just after the main switch is turned on, if the temperature measured by both the
thermistor located at the right side on the laser optics housing unit and the
temperature/humidity sensor is greater than the temperature specified in this SP
mode, refresh mode is done before initial process control.
During refresh mode, toner is developed on the OPC with 50V development potential
and cleaned to remove NOx. This cycle is repeated a few times.
3-920-2 Humidity
This SP determines the humidity threshold for determining whether refresh mode is
done just after the machine is switched on.
Just after the main switch is turned on, if the humidity measured by the
temperature/humidity sensor is greater than the humidity specified in this SP mode,
refresh mode is done before the initial process control self-check.
3-920-3 Prints
Specifies how often refresh mode is done.
When the total number of prints since the last refresh mode exceeds the number
specified in this SP mode, refresh mode is done before the job end process control
self-check.
3-920-4 Mode Set
Enables/disables refresh mode.
NOTE: Refresh mode is done during the toner end recovery self-check after a new
toner cartridge is installed.
3-920-5 Forced
Executes a forced refresh mode.
Use this mode when the image is smeared. It takes about 1 minute.
Also use after replacing the components of the transfer unit (see section 3).
3-920-6 Auto Toner Refresh
(Auto Toner Refresh)
Performs a toner refresh during the OPC refresh mode by changing the development
bias from 50V to 400V.
Enable this SP mode when dirty background and/or firefly spots appear intermittently
on prints with a low image area ratio.
While making prints with a low image area ratio, developer is agitated with less toner
supplied. This may cause the toner-carrier attraction force to increase or toner to
coagulate.
This sometimes causes firefly spots or dirty background when a large amount of toner
is supplied.
NOTE: When enabling this SP mode, the following SP modes should be changed.
SP3-906-001 Job End Process Control Self-check
200 (Default) -> 100
SP3-920-003 OPC Refresh Mode / Prints
200 (Default) -> 100
SM
*BCU
[ 10 to 30 / 25 / 1°C /step ]
*BCU [ 10 to 90 / 75 / 1%/step ]
*BCU [ 10 to 2550 / 200 / 10 prints/step ]
*BCU [ 0 to 2 / 2 / 1/step ] Alphanumeric
0: Disabled
1: Done at power on and toner end recovery
2: Done at power on, toner end recovery, and
after the specified number of prints.
*BCU [ 0 or 1 / 1 / - ]
0: Disabled
1: Enabled
5-33
COPY SERVICE MODE
B147/B149/B190