Toshiba e-STUDIO281c Service Manual page 95

3) Data reading (scanning)
Data reading is a process of illuminating the original with light and converting the reflected light into
electrical signals.
The light reflected from the original is directed to the Charge Coupled Device (CCD) and this optical
image information is converted to electrical signals (image signals), which are then transmitted to
the image processing section via the scanner control PC board.
The CCD for color processing has RGB filters provided over its surface, which allow the CCD to
read the light amount in the respective ranges of wavelength. The image data corresponding to the
respective RGB colors is then transmitted to the image processing section.
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Fig. 3-7
( Example )
CCD light Value of image
receiving signals to be
output
amount
Light 255
Dark
0
Fig. 3-8
3 - 5
CCD board
Scanning section
control PC board
Image processing
section
Difference between
"light " and "dark" is
divided into 256 steps.
e-STUDIO281c/351c/451c
COPY PROCESS
3