Ricoh FT 4015, Service Manual

Page: 43 / 229

6.5 TONER SUPPLY CONTROL
6.5.1 Modes Available
NOTE: The following pages explain how the various settings control the
toner supply mechanism. They should not be adjusted in the field,
unless instructed to do so as a countermeasure for a specific
problem that may occur in the future.
SP30
Setting
Toner Supply
Mode
Target Toner
Sensor Voltage
Toner Supply
Amount
Toner Near/End
Detection
0
Detect Supply
Mode Depends on the
initial TD sensor
setting (1.9
±
0.1
V).
Depends on the
TD sensor output.
Yes
1
Depends on SP53
(input manually). Depends on the
TD sensor output.
Yes
2
Depends on the
initial TD sensor
setting (1.9
±
0.1
V).
Fixed
No
3
Depends on SP53
(input manually). Fixed
No
4
Fixed Supply Mode None Fixed
No
Default setting: 0
Depending on the SP30 setting, Detect Supply mode or Fixed Supply mode
is selected. If 0, 1, 2, or 3 is selected with SP30, Detect Supply mode is used.
If 4 is selected, Fixed Supply mode is used.
Note that when 2, 3, or 4 is selected, the machine will not perform the toner
near-end/end detection. Normally, SP30 should always be kept at the default
setting. The following pages describe the toner supply mode settings in detail.
6.5.2 Detect Supply Mode
In Detect Supply mode, the CPU monitors the TD sensor voltage, which
depends on the toner to carrier ratio in the developer. As the toner in the
developer is consumed, the TD sensor output voltage increases.
The TD sensor voltage is compared with the standard voltage (known as the
Target Toner Sensor Voltage), and toner is supplied when the TD sensor
output is higher than this target voltage.
The machine has two ways of calculating the target toner sensor voltage
(either the initial TD sensor setting is used, or a value can be input using
SP53); the method used depends on SP30. The toner supply amount can
also be changed using SP31 or 32.
Det
ailed
Descript
ions
20 December 1996 TONER SUPPLY
2-29