Ricoh is01 Betriebsanweisung

Selects the following gamma correction settings:
Normal - emphasizes contrast slightly to improve a scanned image.
Sharp - emphasizes contrast to sharpen an image.
Smooth - weakens contrast to soften an image.
Linear - outputs an image as scanned.
User defined - loads user gamma correction curve into the
scanner.

Select one of the above settings, depending on your original and
output device. When you want to perform fine correction of an
image, select the “User defined” setting to load your own gamma
correction curve to the scanner.