Ricoh K-C3, Service Manual

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B245/B276/B277/B268/B269 Service Manual 18-Jan-06
234
ƒ Vsp: The ID sensor output when checking the ID sensor pattern
In this way, the reflectivity of both the drum surface and the pattern on the drum are checked,
compensating for any variations in the reflectivity of the pattern on the drum or the reflectivity
of the drum surface.
The ID sensor pattern is made on the drum by the charge roller and laser diode.
Vsp/Vsg is not detected every page or job; it is detected at the following times to decide Vref.
ƒ During warm-up at power on
If the machine starts warming up when the fusing temperature is 30C or less (default) after
entering night mode or low power mode (SP 2994 specifies the temperature setting).
Toner Supply Reference Voltage (Vref) Determination
The toner supply reference voltage (Vref) is used for toner supply determination (see below).
Vref is determined using the following data:
ƒ ID sensor output (Vsp/Vsg)
ƒ (Vts or the current Vref) - Vt
Toner Supply Determination
The reference voltage (Vts or Vref) is the threshold voltage for determining whether or not to
supply toner. If Vt becomes greater than the reference voltage, the machine supplies
additional toner.
This can be checked using SP 2220.
Toner Supply Motor On Time Determinations
For fixed control mode, the toner supply motor on time is specified by the setting of SP 2925,
and does not vary. The default setting is 200 ms for each copy. The toner supply motor on
time for each value of SP 2925 is as follows.
Value of SP2-925 Motor On Time (t = 200 ms)
0 T
1 2t
2 4t
3 8t
4 12t
5 16t
6 Continuously
7 Not supplied