Ricoh A-P4, Service Manual

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• After 100 prints
• After 200 prints
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 Name What It Does
2973-01 Grayscale Copy Interval Check
Determines how often the halftone pattern is added
to the standard ID sensor pattern. Default setting:
100
2972-01 Grayscale Upper Limit
Sets the upper limit for LD adjustment based on the
Vsm/Vsg calculation.
2972-02 Grayscale Lower Limit
Sets the lower limit for LD adjustment based on the
Vsm/Vsg calculation.
3103-04
Vsm/Vsg (Immediate Grayscale
Post-Pattern Output) Displays value used to determine the LD power ad-
justment (Normally, Vsm/Vsg = 65% ~ 85%)
6. Details
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