Id Sensor; Warm-Up Control (Vsg Correction) - Ricoh Neptune-P1 Service Manual

ID Sensor

The ID sensor [A] regularly reads two areas of the drum:
• Bare surface of the drum. The ID sensor measures the reflectivity of the bare drum, converts this reading
to a voltage, and stores this value (Vsg) in NVRAM.
• ID sensor pattern. The LPH writes an ID sensor pattern on the drum. The ID sensor reads the density
of this pattern, converts it to a voltage, and stores this value (Vsp) in NVRAM.
The machine makes an ID sensor pattern to read Vsp after each copy.
But, the machine reads Vsg only one time. This is done during machine warm-up (see the next section).

Warm-up Control (Vsg Correction)

In order to prevent the occurrence of dirty background on the first copy after the machine warms up, the
value of Vsg is checked after the upper unit is closed and after the machine is turned on (or returns from
low power mode).
After Closing the Upper Unit
The machine measures Vsg after the upper unit is closed, and recalibrates the ID sensor if necessary.
• If the machine detects Vsg < 2.5 V twice, the machine issues SC401 (ID Sensor Vsg Error.
• If the machine detects Vsg > 2.5 V, it will perform adjustments or issue SC401 as shown below, based
on the value of the Vsg reading. (See the "ID Sensor Recalibration Table" below.)
After Power On
If the fusing temperature is below 50°C (122°F) after the machine is powered on (or returns from the low
power mode), the machine measures Vsg. The machine compares this Vsg reading with the PWM value
that was stored when the ID sensor was initialized, in order to determine if the current Vsg value is correct.
• If the machine detects Vsg < 2.5 V twice, the machine issues SC401 (ID Sensor Vsg Error).
Development
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