Toshiba e-studio550 Service Manual page 214

14. 4. 5. Temperature detecting section
To keep the fuser roller at a certain temperature, the center thermistor and side thermistor (rear) detect
the temperature of the fuser roller and control ON/OFF of the IH coil. Outputs from the thermistors are
used to detect abnormalities of the fuser roller temperature.
(1) Relation between the thermistor output voltage and surface temperature of the fuser roller:
Approx. 4.0V when the temperature is 200°C
Approx. 3.8V when the temperature is 183°C, and approx. 3.7V when the temperature is 177°C.
(2) Temperature control for the surface of the fuser roller:
Temperature
200°C and above IH coil turned OFF
183~200°C IH coil turned ON
177~183°C Copying continued but the copy speed lowered (e-STUDIO810 only)
Below 177°C Copying interrupted and back to the ready
C
200
Temperature
183
of fuser roller
177
Copy speed
(3) Temperature control for both ends of the fuser roller
During the multiple copying, the temperature of both ends of the fuser roller (where a paper does not
pass on) generally becomes higher than that of the other areas (where a paper does pass on). The side
thermistor (front) detects the temperature of the ends, in this case, it controls the center IH coil and
side IH coil to unify the fuser roller temperature.
(4) Error detection during warming up (1)
If the output voltage of either the center thermistor or side thermistor (rear) does not go over
approx. 0.5V(40°C) even in a certain period of time after the heater has turned ON, the "Call for
service" [C41] is displayed.
e-STUDIO550/650/810 FUSER UNIT
Fusing control
Normal copy speed
Warming-up
Herter
ON ON
OFF OFF
e-STUDIO810 e-STUDIO810
(A4/LT)
Ready (200°C) During copying
ON ON OFF OFF ON ON ON ON ON
81 81
0 0 0 0 0 0 65 65
14 - 8
During
Ready
copying
ON ON ON ON ON ON ON ON ON
81 81 65 65 0 0
81 81 65 65
JUNE 2002 © TOSHIBA TEC
During
waiting
ON ON
0 0