Ricoh Aficio Color 4006, Service Manual

Page: 79 / 487

SCANNER UNIT 24 February, 1999
2-30
The machine cannot recognize the size of the original on the exposure glass if it is
A5 lengthwise/HLT or smaller. Therefore, when all sensor outputs are off, the
machine either will detect A5 lengthwise/HLT or will display an error message
stating that it cannot detect the size of the original (this depends on SP 4-303).
While the main switch is on, these sensors are active and the original size data is
always sent to the main CPU. However, the main CPU checks the data only when
the platen cover is open.
The check starts when the platen cover position sensor ([D] on the previous page)
turns on; this is when the platen is about 15 cm above the exposure glass. At this
time, only the sensors beneath the original receive the reflected light and are on; all
other sensors are off.
The main CPU can recognize the original size from the signals from the sensors. If
a copy is made with the platen open, the main CPU determines the size of the
original from the sensor output at the time that the start key is pressed.
This original size detection method eliminates the necessity for pre-scanning,
which increases the productivity of the machine.
1 5 0
2 4 8 . 5
2 7 3 . 5
3 1 6
62.2
248.5
273.5
71
A P S 1
A P S 2
A P S 3
A P S 4
A P S 5
A259D800.WMF
Unit: mm