Id Sensor Pattern Production Timing - Ricoh B121 Service Manual

If the humidity drops, the drum potential goes up (to a higher –ve voltage) even if
the charge roller voltage supply stays the same (efficiency of voltage transfer is
higher with lower humidity). As a result, less toner is transferred to ID sensor
pattern [B]. If the sensor output reaches a certain point, the drum charge voltage
will be reduced.
To determine whether to change the drum charge roller voltage, the machine
compares Vsdp with Vsg.
• Vsdp/Vsg > 0.95 = Make the drum charge voltage less –ve (smaller) by 50 V
• Vsdp/Vsg < 0.90 = Make the drum charge voltage more –ve (larger) by 50 V

6.8.3 ID SENSOR PATTERN PRODUCTION TIMING

The ID sensor pattern is not made every page or every job.
It is only made in the following conditions:
• During warm-up at power on
⇒
• When the machine returns from the energy saver mode, and the fusing
temperature is at or below a certain degree (default: 30 degrees C). You can
change the fusing temperature setting with SP2-994.
• When the machine returns from the energy saver mode, and 100 or more
print/copy jobs were made since last the pattern was made.
B121 Series/B259 Series 6-36
DRUM CHARGE
SM