
CHAPTER 2
2 - 2
COPYRIGHT
2000 CANON INC. CANOSCAN N650U/N656U/N1220U REV.0 JUNE 2000 PRINTED IN JAPAN (IMPRIME AU JAPON)
J1
J3
M1
Main PCB
Start button
S1
USB Connector
PCB
Gate array
Home position
sensor
Q4
Host computer
Control
program
J2
J1
J2
Contact
image
sensor
CS1
Buffer
RAM
Drive motor
Figure 2-2
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.