Ricoh K-C3 Service Manual page 222

B245/B276/B277/B268/B269 Service Manual
When you specify "2," instead of "1," in SP 4941 1, the feature erases darker white lines
(namely, less whiter lines). Note that this SP does not affect the width of white lines to be
erased.
Black Line Erase
The black line erase feature is the function that erases black lines made by the dust or dirt on
the exposure glass. The feature is validated (default) when you specify a value other than "0"
in SP 4942 1.
When you specify a larger value in this SP, the feature erases weaker black lines (namely,
less blacker lines). This SP also affects the width of black lines to be erased. If you specify "1"
or "2," the feature erases the black lines of 1- through 4-pixel width (approximately, up to 0.17
mm); if you specify "3," the feature erases the black lines of 1- through 6-pixel width
(approximately, up to 0.25 mm). Note that some black lines on the original may be erased
when you specify a larger value in the SP.
Auto Image Density (ADS)
In the SBU
ADS prevents the background of an original from appearing on copies. As the scanner scans
down the page, the IPU on the BICU detects the peak white level for each scan line. The IPU
determines the reference value for the A/D conversion for a particular scan line using the
peak white level for that scan line. Then, the IPU sends the reference value data to the
reference controller on the SBU.
When an original with a gray background is scanned, the density of the gray area is the peak
white level density. Therefore, the original background will not appear on copies. Because
peak level data is taken for each scan line, ADS corrects for any changes in background
density down the page.
As with previous digital copiers, the user can select manual image density when selecting
ADS, and the machine will use both settings when processing the original.
By Original Type
ADS mode is only enabled when the user has selected:
Text mode 1 or 2 (Normal or Sharp), Photo mode 2 (Text/Priority), or Special mode 1 or 2
(Unneeded background or Colored Text).
This can be done using Adjust Original Mode (3) in User Tools (Copier Features).
Scanner Gamma Correction
The CCD output is not proportional to the quantity of light received. Scanner correction
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