CHAPTER 2
2 - 3
COPYRIGHT
©
2000 CANON INC. CANOSCAN FB1210U REV.0 APR. 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)
2. Functions of the Main PCB
1) Analog IC
Converts the image signals (analog signals) read by the CCD into digital data.
- CDS (Correlated Double Sampling)
- AGC (Auto Gain Control)
- 14-bit A/D converter (Analog-to-Digital Converter)
2) ASIC
Performs various processing:
- DRAM control
- CCD timing clock creation
- Line buffer control
- CCD output line difference adjustment
- Image processing (Binary processing, Image inversion)
- Shading correction
- Motor driver control
3) DRAM
Stores the shading correction data when performing shading correction, and the image data
when scanning.
4) Motor Driver
A monolithic microstep motor driver supplies power to the drive motor.
5) USB Controller
Transmits data between the host computer and ASIC.
6) CPU
Interprets commands from the host computer to generate parameter for the ASIC to perform
various processing.