Canon CANOSCAN FB330 series Service Manual page 56

CHAPTER 2
C. CanoScan FB630U/FB636U Document Scanning Sequence
Sequence
Scanning unit drive motor (M1)
LED ON signal
Home position sensor
detection signal
Interface signal
(Data1-8)
Scanning unit position
Home position
Document
scan area
Sequence
After a power on sequence is
STBY
completed until the scanner
(Standby)
receives a scan command
from the host computer.
After the scanner received a
STUP
scan command until
(Setup)
document scan starts.
SCFW After the scanning unit starts
moving forward until it reaches
(Scanning unit
the starting position
forward)
of the scan area specified by
the host computer.
SCAN After the scanning unit starts
(Document scan) scanning until all area
specified by the host
computer are scanned.
SCRTN After the scanning unit starts
moving backward until it
(Scanning unit
returns to the home position.
return)
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COPYRIGHT © 1999 CANON INC. CANOSCAN FB330/FB630 SERIES REV.0 OCT. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
STBY STUP SCFW
Scan command is received
Figure 2-15
To maintain the scanner ready
for scan.
To make a gate array setting,
buffer RAM initialization, etc.
as a preparation for scan.
To move the scanning unit with
a uniform speed to the vertical
scanning position specified by
the host computer.
To perform various image
processing according to the
command from the host
computer and transmit the
image data during scan.
To return the scanning unit to
the home position to ready for
the next scan.
Table 2-2
SCAN
Purpose
Home position is determined by the
home position sensor.
SCRTN STBY
A4, 600 dpi, 100%, 24 bit color
Reverse
Remarks