Toshiba e-studio281c, Service Manual, Page: 276 / 414

e-STUDIO281c/351c/451c © 2005 - 2008 TOSHIBA TEC CORPORATION All rights reserved
DEVELOPER UNIT
12 - 6
12.4.3 Black auto-toner sensor circuit
1) Functions of auto-toner circuit
- Detection of the toner density in the developer material
- Density lowered
→
Toner supplied
- Detection of the toner being empty in the toner cartridge
Fig. 12-5
2) Functions of the black auto-toner sensor
- Initializing function: When unpacking and replacing the developer material
The automatic adjustment is made so that the output of the auto-toner sensor (input value of the
engine CPU) will be 2.45V to 2.55V for the toner density of new developer material.
- Toner density stabilizing function: During the printing operation
Through the following phases, the toner density is kept constant.
Toner is consumed.
→
Toner density decreases.
→
Output change of the auto-toner sensor is detected depending on the humidity.
→
Drives toner motor.
→
Supplies toner to the developer unit from the toner cartridge.
- Toner-empty detection/clear function:
Detects toner being empty in the toner cartridge.
Drives toner motor.
→
Output of the auto-toner sensor is not changed.
→
Toner density is not changed.
→
Detects toner being empty.
Toner-empty clear
Drives toner motor.
→
Supplies toner from the toner cartridge.
→
Output of the auto-toner sensor changes.
→
Toner density recovers to its normal value.
→
“Toner-empty” is cleared.
Engine
CPU
Gate array
#1
D/A
converter
-
+
+5.1V
-
+
DA2DAT
ATSVR
ATSVR
ATSDET
ATS
Black
auto-toner sensor
LGC board
ATSDET
ATS
DA2LTH
DA2SCK
+5.1V