Toner End Condition; Fusing Efficiency - Ricoh FT7770 Service Manual

10 August 1990

3.1.3 Toner End Condition

If VSP becomes greater than 0.65 V twice consecutively, the CPU determines
that it is time to replace the toner cartridge.
In the F21 the limit was 0.75 V. The CPU does not detect the ratio of VSP and
VSG; it detects VSP directly (please correct the F21 service manual page 2-
32).
This change is to prevent the ID level from decreasing and to prevent the car-
rier from being transfered onto the paper.
3.2 FUSING

3.2.1 Fusing Efficiency

To improve the efficiency of fusing, the pressure between the rollers has
been increased and the fusing temperature has also been increased, as fol-
lows.
Fusing rollers spring
Fusing lamp on
Fusing lamp off
F21
23.0 ± 0.5 kg
(26 mm)
F21
182°C
15-6
F22
29 ± 3 kg
(26 mm)
F22
185°C