Ricoh SH-P1 Series Training page 68

Drum Charge and Cleaning
The dual charge rollers [A] give the drum surface a
negative charge of approximately –900 V.
The cleaning blade [B] removes any toner remaining on the
drum's surface after image development and transfer.
Slide 68
The charge rollers are charged to -1550 V and they transfer -900 V to the drum.
Cleaning blade is composed of polyurethane.
Q: Why two charge rollers?
A: Even with the cleaning blade the charge rollers will slowly get dirty. Design
testing showed that two rollers are necessary to ensure sufficient charging for
the life of the AIO under all environmental conditions.
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SH-P1 Training