Ricoh D014 Service Manual page 951

3. Potential Control (Development Gamma Measurement)
The laser diodes write the 4-grade potential sensor patterns on each drum. To make the
different densities, the machine changes the PWM duty of the laser diodes.
Potential sensor reads the 4-grade patterns on the image transfer belt. The required
potentials are calculated.
ID sensor reads the patterns 4-grade patterns on the image transfer belt to calculate
the amount of toner coverage required.
The combined readings of the potential sensor and ID sensor are used to retrieve from
a lookup table the optimum values for:
1) Vd (charge potential)
2) Vb (development bias)
3) Vpl (drum potential after exposure)
The development gamma must be in the range 0.3 to 6.0 V. Development start voltage
(Vk) must be in the range –150 to 150 V. This development start voltage is used to
indicate whether the developer has deteriorated. However, this is only a rough
measurement that can be affected by ambient conditions and the condition of other
electrical components.
Possible Errors at ID Sensor Pattern Detection
SC Codes
SC410~SC413
SC414~SC417
SP3821
SM
CÓPIA NÃO CONTROLADA
For More Details:
See "Process Control Troubleshooting" in "4.
Troubleshooting" in the Venus-C1 (B132/B200) Service
Manual.
55, 56, 57, 58, 59, 60
6-47
CÓPIA NÃO CONTROLADA
Process Control
D014/D015/D078/D079