Video Control Unit (Gavd) - Ricoh B205 Service Manual

IMAGE PROCESSING

6.5.6 VIDEO CONTROL UNIT (GAVD)

Fine Character and Image (FCI)
The FCI circuit performs image smoothing.
Fig. A
Fig. B
Fig. C
Usually, binary picture processing generates jagged edges on characters, as
shown in the above illustration. These are reduced using edge smoothing. The FCI
changes the laser pulse duration and position for certain pixels.
Fig. A shows the four possible pulse durations, and Fig. B shows how the laser
pulse can be in one of three positions within the pixel. Fig. C shows an example of
how edge smoothing is used.
This function only affects the received image for fax mode and for printer mode,
even if copy mode is also using binary picture processing.
B205/B209/D007/D008
4/4
Sub Scan
Direction
6-34
Main Scan Direction
3/4 2/4 1/4 0
SM