Outline Of Electrical System - Canon CANOSCAN N1220U Service Manual

CHAPTER 2
B. Outline of Electrical System
Figure 2-2 shows the outline of electrical system. CPU is not equipped in the main PCB.
The device driver installed in the host computer includes a control program, which functions
as CPU.
Image signals read by the contact image sensor are converted into digital data by the A/D
converter in the gate array. The converted image data are image-processed by the gate array,
then output to the host computer via USB port.
Drive motor
M1
Contact
image
sensor
CS1
2 - 2
COPYRIGHT 2000 CANON INC.
Main PCB
J2
J3
Figure 2-2
CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)
USB Connector
PCB
J2
J1
Buffer
RAM
Gate array
Host computer
J1
Control
program
Start button
S1
Home position
sensor
Q4