Image Processing; Outline - Canon CANOSCAN D1230 series Service Manual

III. IMAGE PROCESSING
A. Outline
Image processing system consists of the CCD, analog IC, and ASIC. Analog signals read by
the CCD is converted into digital data, then output to the host computer.
2. A/D
1. CCD
Conversion
B. Image Processing
1. CCD
The CCD is a single chip photoelectric conversion device which consists of several thousand
photosensitive devices of each several microns square, for reading RGB image signals, with a
built-in scanning circuit.
D1230U employs 3-line CCD, and D2400U employs 6-line CCD.
1) 6-line CCD
6-line CCD has two rows of staggered photosensitive devices for RGB each. The 6-line CCD
therefore can scan at 1200dpi x 2 = 2400dpi.
©
COPYRIGHT 2001 CANON INC. CANOSCAN D1230U/D2400U REV.0 MAR. 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
4. Filter
3. Calibration
Processing
Figure 2-12
Figure 2-13
Blue Image data
Processing
6. Image
Inversion
Green Image data
Processing
5. Binary 6. Image
Processing Inversion
Red Image data
Processing
6. Image
Inversion
CHAPTER 2
To Host
Computer
2 - 13