Canon Color imageRUNNER C4580 Service Manual - page 145
Chapter 5
5-15
5.5.3 Printer Output Image Processing
The main controller processes the image data arriving from the reader unit for output to the printer unit.
F-5-11
- Image data
serial/parallel conversion
- Video count
Main controller PCB
(main + sub (R-A)/
(sub PDRM-PE-A)
Reader unit
RGB
24
Image area
signal
CMYK
- F value adjustment
- Color balance correction
- Framing
- Blanking
- Background removal
- Bk generation
Output direct mapping
RGB->CMY conversion
Output gamma correction
Optimum screen selection
Smoothing
RGB
24
CMYK
32
Image area
signal
Here, the Bk signal is generated
if an ACS session identifies the
original as being black-and-white.
(Otherwise, it is let through.)
For the text area,
UCR processing is executed.
A correction LUT is prepared
as part of PASCAL control.
In color mode, the Bk signal
is generated here.
Y,M,C,Bk
To DC controller PCB