Paper Feed Mechanism - Samsung SCX-4200 Series Service Manual

3.1.4.1 Paper Feed Mechanism

The printer has a universal cassette which automatically loads paper and a manual feed which supplies paper
single sheet at a time. The cassette has a friction pad which separates paper to ensure single sheet feeding, and it
has a sensor, which checks when the paper tray is empty.
- Feeding Method: Universal Cassette Type
- Feeding Standard: Center Loading
- Feeding Capacity: Cassette-250 sheets (75g/m2 , 20lb paper standard)
Manual 1 sheet (Paper, OHP, Envelop, etc.)
- Paper detecting sensor: Photo sensor
- Paper size sensor: None
3.1.4.2 Transfer Ass'y
This consists of the PTL (pre-transfer lamp) and the Transfer Roller. The PTL shines a light onto the OPC drum.
This lowers the charge on the drum's surface and improves transfer efficiency.
The transfer roller transfers toner from the OPC drum surface to the paper.
- Life expectancy: Over 50,000 sheets (at 15~30°C)
3.1.4.3 Drive Ass'y
A gear driven power unit. The motor supplies power to the paper feed unit, the fuser unit, and the toner cartridge.
3.1.4.4 Fixing Part(Fuser)
Heat Lamp type used on 220V Export models and all 110V models.
The Heat Lamp type fuser consists of the Heat Lamp, Heat Roller, Pressure Roller, Thermistor, and Thermostat. It
fixes toner to the paper using pressure and heat to complete the printing job.
1)Heat Lamp power cut-off (Thermostat)
The thermostat is a temperature sensing device, which cuts off the power to the heat lamp to prevent overheating
fire when the heat lamp or heat roller overheats.
2)Temperature Detecting Sensor (Thermistor)
The Thermistor detects the surface temperature of the heat roller, this information is sent to the main processor
which uses this information to regulate the temperature of the heat roller.
3) Heat Roller
The surface of the Heat Roller is heated by the Heat Lamp. As the paper passes between the Heat and Pressure
rollers the toner is melted and fixed permanently to the paper. The surface of the roller is coated with Teflon. This
ensures that toner does not adhere to the roller surface.
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