DRUM UNIT
B234/B235/B236/D101/D102/D103 6-80 SM
Step 1: Charge Unit Corona Wire Cleaning
The machine executes charge corona wire cleaning at the beginning of every auto
process control cycle if SP2804 001 (Charge Corona Cleaner Setting) is set to "1".
Step 2: Process Control Begins (OPC Drum Start Timing)
Process control starts after the machine is turned on with the fusing temperature
below 100°C (regardless of the number of lamps that are on).
Step 3: ID Sensor Vsg Adjustment
Vsg (reflectivity of the bare surface of the drum) is automatically set:
Vsg = 4.0±2V
After this is done, you can display and confirm the Vsg setting with SP3103 002.
You can also display and confirm the PWM (Pulse Width Modulation) setting with
SP3001 001.
NOTE: If process control executes in response to a change in the drum rotation
speed (low to high speed, high to low speed mode), the Vsg adjustment is not done.
Therefore, SP3103 002, SP3001 001 will not reflect any changes.
Step 4: Vb (Development Bias Voltage), Vg (Charge Grid Voltage), LD (Laser
Diode) Power Adjustments (Based on Drum Potential Sensor Readings)
1. Determining ΔVL: ΔVL = (Target VL) –200
The difference between the value of VL read by the drum potential sensor and the
previous target VL value of –200V is obtained. ΔVL is then used to update VLref. If
the following result of the calculation is less than ΔVL, the lower value between
ΔVL1 and VL2 is used to update VLref.
• Vb = Vb setting of SP2201 001 + ΔVL > 800
ΔVL1= 800 – (Value of SP2201 001)
• VDref = Vd setting of SP2001 006) + ΔVL > 950
ΔVL2 = 950 – (Vd setting of SP2001 006)
The purpose of the calculations is to set Vb and VDref at the high limit of their
ranges to prevent over compensation during adjustment.
At the beginning of the process control cycle, the following components remain
turned on: drum motor, fusing motor, QL, charge unit, charge grid (using the
previous voltage, or the voltage set with SP2001 003 if the machine has just
been powered on), and development motor.
The development motor switches off, the laser creates the VL pattern on the
surface of the drum, and the drum potential sensor reads the VL pattern.
VL Pattern
Size Width: 30 mm Length: 40 mm
Exposure Level 15
Laser PM Same value as previous process control execution
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