Ricoh G147 Service Manual page 346

After 10 prints
The ID sensor reads the sensor pattern and outputs this reading as Vsp and sends it to the
CPU where it is used to calculate Vref (Vsp/Vsg = Vref).
This number of prints can be adjusted with SP2210-01 (Pattern Interval – ID Sensor).
When the number of prints exceeds 10 during a print job, the ID sensor pattern is not
created and read until after the print job completes.
After every 100 prints
This number of prints can be adjusted with SP2973-01.
When the number of prints exceeds 100 during a print job, the ID sensor pattern is not
created and read until after the print job completes.
At this time, a halftone pattern is added to the standard ID sensor pattern. The reading
from this pattern, Vsm, is used with Vsg (Vsm/Vsg) to calculate the value to be used to
determine the amount of LD (laser diode) power adjustment required. This method
improves consistent greyscale reproduction, slows the deterioration of the OPC drum,
and reduces scatter.
After every 200 prints
The halftone pattern is added to the standard ID sensor pattern every 200 prints. This
interval can be changed with SP2210-02 (Large Job).
When 200 prints is reached, even if in the middle of a job, the ID sensor pattern will be
made. For example, if the job contains 1,100 sheets, the ID sensor patterns will be
made every 200 sheets, and at the end of the job.
When the front door of the machine is opened and closed
The halftone pattern is added to the standard ID sensor pattern at this time also.
The following SP codes are also used for grayscale control. Refer to the SP code table for
full details.
SP Code
Grayscale Copy Interval
2973-01
Check
2972-01 Grayscale Upper Limit
2972-02 Grayscale Lower Limit
G147
Name
Determines how often the halftone pattern is
added to the standard ID sensor pattern.
Default setting: 100
Sets the upper limit for LD adjustment based
on the Vsm/Vsg calculation.
Sets the lower limit for LD adjustment based
on the Vsm/Vsg calculation.
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What It Does
SM