Riso RP-255, Technical Manual

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PRINT DRUM SECTION
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Mechanism
1. Master on Drum (Pre-printing) Check Mechanism
This mechanism checks whether there is a master on the print drum when printing begins.
The print drum begins to rotate when the Start key is pressed, and when the print drum reaches the 75°
position, the master sensor [B] checks whether there is a master [C] on the print drum.
The information checked by the master sensor is stored until either the print drum is pulled out or the
power is switched off. Subsequent printing therefore starts immediately after the Start key is pressed.
If light is not reflected back to the master sensor [B] (implying that the master is absent) when the print
drum reaches the 75° position at the start of the printing, it is assumed that there is no master on the
print drum.
Print drum
75° position
Print drum 75°
position
B
C
A
B
A: Light absorber strip
B: Master sensor (reflective type)
C: Master
0801
0802