Operational Descriptions; Spf Open/Close Detection (Book Document Detection) - Sharp AL2020 Service Manual

C. Operational descriptions
Document set
SPID ON
Document feed unit lamp ON
PSW ON
MRMT rotation
(Copier side)
MM rotation
Main motor rotation
Paper feed
CPFS ON
PPD ON
RRC ON Synchronization
Paper transport
(Transfer)
(Fusing)
POD ON
(Paper exit)
In the zooming mode, the magnification ratio in the sub
scanning direction (paper transport direction) is adjusted
by changing the document transport speed.
PSW
MRMT
SPF M
CL
SPPD
SCANST
MAIN M
CPFS1
RRS
PPD1
PPD2
POD
SPF JAM generation condition
1) When SPPD is ON (document remaining) in initializing
2) When SPPD is not turned ON within about 1.5 sec (at 100%
copy) after starting the document feed operation.
3) When SPPD is not turned OFF within about 4.7 sec (at 100%
copy) after turning on SPPD.
4) When the OC cover is opened during document transport
(during SPF motor rotation) (The SPF motor is stopped during
document transport, but the OC cover open error occurs
instead of the SPF JAM.)
Document set sensor
Copy start
The scanner is shifted
to the exposure position.
(SPF side)
SPFM rotation SPF motor rotation
Document transport sensor
SPPD ON
Document transport
(Exposure)
(Document exit)
260ms
AL-2040 OPERATIONAL DESCRIPTIONS 7 - 8
182ms
D. SPF open/close detection (book document
detection)
SPF open/close detection (book document) detection is performed
by detecting the interval between the reference lines on the white
Mylar attached to the paper exit guide (document scanning sec-
tion) by the scanner (CCD) and detecting the varied quantity.
B
A
(White Mylar)
Reference line
(CCD)
B
A
(Floating)
Reference line
A - B = Varied quantity of pixels
(pixel)