Minolta Di450 Service Manual page 54

Relation between laser emission timing and SOS signal
The light path of the laser beam changes as the Polygon Mirror turns. The SOS signal syn-
chronizes the rotation of the Polygon Mirror with the laser emission timing.
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Laser Diode (LD)
SOS Signal
Sequence
A. LD force-ON
The laser diode is forced ON to output an SOS signal.
B. SOS signal output
A laser beam strikes the SOS Sensor Board and sensor A
determines the SOS signal output timing.
After the timing has been determined, the laser beam is
turned OFF.
SOS Sensor Board
A
B C
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C. Start of image data output
The laser emission start timing is controlled according to
the size of the image to be output.
D. End of image data output
The laser radiation area is controlled according to the size
of the image to be output.
After the image area has been covered, the laser beam is
turned OFF.
Laser beam area according to the image data
ON
OFF
H
L
A
B
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Sensor A output only is used.
SOS signal output timing
C D
A
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