SERVICE PROGRAM TABLES April, 2007 5-90
3562
Display Vk Display Vk (Development Start Voltage)
Displays Vk, the development start voltage. This development start volt age is used
to indicate whether the developer has deteriorated. However, this is only a rough
measurement due to other factors:
• A low threshold setting for the target development gamma.
• Operational variations between machines
• Precision of the ID sensor measurements
Normal range for Vk: -150V to +150V
3563
Display Vr Display Vr (Residual Potential)
Vr is the potential that remains on the surface of the drum after full exposure t o the
laser. The existence of this residual voltage is used as an indicator to determine the
level of deterioration of the drum. Vr becomes larger as the drum deteriorates.
Normal range for Vr: -200V to 0V
001
K
002
M
003
C
004
Y
[-300 to +300/1 V]
3571
Display V0 Display Vd (Value for Control of Charge Potential)
Displays the value for V0, the measure of drum potential on dark areas of the drum
before laser exposure.
Normal range: -700 V to –500 V
001
K
002
M
003
C
004
Y
[-999~0/1 V]
3572
Display Vdhome Display Vl (Value for Control of Halftone Drum Potential)
Displays the value for Vdhome, the electrical potential of the drum after a f ixed dc
bias (dc –700V) is applied by the drum charge roller.
Normal range: -700V to –500V
001
Vl Ctrl:Half:K
002
Vl Ctrl:Half:M
003
Vl Ctrl:Half:C
004
Vl Ctrl:Half:Y
[-999~0/1 V]