Ricoh D0C8, Service Manual

Page: 807 / 1647

Toner Supply Section
SM 7-55 D0CA/D0C9/D0C8/D0CB
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Toner End is detected if one of the following conditions is met:
(1) Toner End detection by Toner End sensor (S11-S13).
(2) Toner End detection by Vt output.
Toner End detection by Toner End sensor (S11-S13):
Toner Near End detection by the Toner End sensor (S11-S13) is done with colors other than
black.
1.
Check that the toner residual amount (SP3-101-001 to 004) is "1".
2.
In Step 1, if the Toner End Counter (SP3-121-001 to 004) exceeds the threshold to detect
Toner End by the Toner Sensor (SP3-130-001 to 004), Toner Near End is detected.
Toner End Detection by Vt Output of Other than That of Black
1.
Calculate the difference (delta Vt) between the TD sensor current voltage (Vt)
(SP3-210-002 to 004) and its target figure (Vtref) (SP3-230-002 to 004).
2.
If delta Vt is higher than the delta Vt threshold value (SP3-131-001), the value is added to
sigma-delta Vt (SP3-132-002 to 004).
If the condition is not met even once, the added values (SP3-132-002 to 004) are cleared.
3.
If sigma-delta Vt (SP3-132-002 to 004) exceeds the total delta Vt threshold (SP3-131-002),
Toner End is detected.
Toner End Detection by Vt Output of Black
1.
In the case of high toner density, check that the toner density (SP3-200-001) is not below
the toner density threshold (SP-3-131-041).
In the case of low toner density, check that the toner density (SP3-200-001) is not above
the toner density threshold (SP-3-131-041).
2.
In the Step 1 status, calculate the difference (delta Vt) between the TD sensor current
voltage (Vt) (SP3-210-001) and its target figure (Vtref) (SP3-230-001).
3.
If delta Vt is not below the delta Vt threshold for high/low toner density (SP3-131-021 / 031),
that value is added as sigma-delta Vt (SP3-132-001).
If delta Vt goes below the delta Vt threshold for high/low toner density (SP3-131-021 / 031),
the added values (SP3-132-001) are cleared.
4.
If sigma-delta Vt (SP3-132-001) exceeds the sigma-delta Vt threshold for high/low toner
density (SP3-131-022 / 032), Estimated Toner End is notified.