B245/B276/B277/B268/B269 Service Manual 18-Jan-06
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Video Control Unit (VCU)
Fine Character and Image (FCI)
The FCI performs image smoothing. This functions only affects binary picture processed
images for certain original modes.
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.
FCI smoothing is only effective when Text 2 or Special 1 is selected. There is no SP
adjustment for this.
Printer Gamma Correction
Printer correction corrects the data output from the IPU to the laser diode to account for the
characteristics of the engine components (e.g. drum, laser diode, lenses).
The machine chooses the most suitable gamma curve for the original type selected by the
user. There is no SP adjustment for this.
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