Ricoh D0C8, Service Manual

Page: 821 / 1647

Process Control and MUSIC
SM 7-69 D0CA/D0C9/D0C8/D0CB
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LD Control is set with SP3-600-001 (Process Control/ Select ProCon: LD Control).
•
If SP 3-600-001 is set to LD Power Control by Process Control (Default): The LD strength is
adjusted based on a table which is determined by Development Bias Control and Vtref
Correction.
•
If SP 3-600-001 is set to use a fixed LD power, the LD power that is used depends on the
settings of SP2-221-001/002/003/004.
SP3-400-001, -002, -003, -004
0: Fixed supply method
2: PID method
4: DANC method (Default)
•
Fixed Supply method
Toner supply time is calculated based on the supply rate of SP3-440-001 through -004
(DrvTime: Setting).
•
PID method
PID (Proportion Integral Differential)
The amount of toner supply is calculated based on the pixel information and TD sensor
information.
•
DANC method
DANC (Divided Active Noise Control): Conventional PID active noise control. It
controls the timing to supply the developer to minimize uneven developer density in the
development unit.
Toner Near-End
First, the amount of remaining toner is detected with the pixel count and the driving time of the
toner supply motor(M1-M4). Then, when the amount of remaining toner is less than the
threshold for toner near-end (K = 23 g, CMY = 10 g), the machine determines a toner near-end.
For CMY, when the amount of remaining toner is less than 50 g, or when the toner end sensor
(S11-S13), which is a piezoelectric sensor, detects toner near-end twice, the machine also
determines a toner near-end.
Toner End
A toner end is detected when the toner end sensor (S11-S13) detects the end threshold six
times in the toner near-end condition.
The machine also detects a toner end when the difference of the Vt and Vtref, and their total
difference are as in the following matrix:
Condition Vt/Vtref: Diff Vt/Vtref: Diff: Total
K Before Near-End 0.7 V or more Over 10 V
After Near-End 0.3 V or more Over 3 V
CMY - 0.5 V or more Over 10 V
When you open and close the front door, or turn the main power OFF and ON, the machine