Toshiba e-STUDIO163, Service Manual

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e-STUDIO163/203 © 2005 - 2008 TOSHIBA TEC CORPORATION All rights reserved
FUSER / EXIT UNIT
13 - 6
13.5.2 Temperature detection section
To maintain the surface temperature of the fuser roller at a certain level, 3 thermistors (center, side and
edge) detect the surface temperature of the fuser roller to turn ON/OFF and control 2 heater lamps
(center and side).
1) Relation between the thermistor output voltage and surface temperature of the fuser roller
2) Control of the surface temperature of the fuser roller
Fig. 13-3
Remark:
During warming-up, 2 heater lamps (center and side) are turned ON to raise the surface temper-
ature of the fuser roller. During ready and printing status, each heater lamp is turned ON/OFF
alternately to maintain the surface temperature of the fuser roller at a certain level (setting tem-
perature of each status).
3) Temperature control for the both ends of the fuser roller
During continuous printing, the temperature of the end of the fuser roller (area where the paper does
not pass on) generally tends to be higher than that of other areas (areas where the paper passes
on). For this reason, the edge thermistor detects the temperature of the end of the fuser roller. When
this thermistor detects the abnormal temperature (Approx. 235ºC), the heater lamp is turned OFF
regardless of the temperature of the area where the paper passes on.
Output voltages of thermistors [V] Surface temperatures of fuser roller [ºC]
Approx. 0.5 40
Approx. 1.9 100
Approx. 3.7 170
°C
170
0
Ready (170°C) Warming-up
Temperature
of fuser roller
During printing (170°C)
OFF Heater lamp ON ON OFF ON OFF ON OFF OFF ON ON