Canon GP215 - Analog Image Processing

B. Analog Image Processing
1. Outline
The analog processor PCB converts CCD drive signals and CCD output signals (analog signals) to dig-
ital signals. (It also executes AE measurement.)
2. CCD/CCD Driver
The GP215/GP200’s CCD is a linear image sensor consisting of a single line of 7500 photocells. The
signals subjected to photoelectric conversion in the photocell unit are forwarded to the CCD drive circuit.
(The even-number pixels and the odd-number pixels are sent separately.) The CCD drive circuit synthe-
sizes the signals coming separately in even-number units and odd-number units for output to the A-D con-
version circuit.
Figure 3-302
CCD
CCD drive circuit
A-D
conversion
signal
ABC circuit
Reference
voltage circuit
Odd-number
pixel signal
Even-number
pixel signal
Image signal
(analog)
Image signal
(digital)
ABC circuit OFF signal
Analog signal setting signal
ABC setting signal
Analog processor PCB
Clock
pulses
G
3–31
COPYRIGHT © 1996 CANON INC. CANON GP215/200 REV.0 JULY 1996 PRINTED IN JAPAN (IMPRIME AU JAPON)
3. OPERATIONS AND TIMING