Canon CANOSCAN FB330 series Service Manual page 55

B. CanoScan FB330P/FB630P Document Scanning Sequence
Sequence
Scan command is received
Time required (s)
Scanning unit drive motor (M1)
LED ON signal
Interface signal
(Data 1-8)
Scanning unit position
Home position
Document
scan area
Sequence
After a power on sequence is
STBY
completed until the scanner
receives a scan command
(Standby)
from the host computer.
After the scanner received a
HPDET
scan command until the home
(Home position
position is detected.
detection)
After the home position is
STUP
detected until document scan
(Setup)
starts.
After the scanning unit starts
SCFW
moving forward until it
(Scanning unit
reaches 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
(Scanning unit
moving backward until it
return)
returns to the home position.
COPYRIGHT © 1999 CANON INC. CANOSCAN FB330/FB630 SERIES REV.0 OCT. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
STBY HPDET STUP
5 - 6
G LED only
Figure 2-14
To maintain the scanner ready
for scan.
To detect the border between
black and white to define the
home position.
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 2-1
SCFW SCAN
Purpose
If the detection of the border
between black and white is failed,
the scanning unit stops there and
proceeds to the next step.
The distance to the home position
is calculated by the distance from
the detected home position to the
position the scan is completed.
CHAPTER 2
SCRTN STBY
A4, 300 dpi, 100%, 24 bit color
:Reverse
Remarks
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