Sharp AR-160, AR-161 specifications Fusing section

AR-161

(2) Manual paper feed tray operation

Select the manual paper feed tray and press the START button, and the manual paper feed roller will be turned on to bring the paper feed roller in contact with paper and lift the shutter simultaneously.

The drive power of the main motor is transmitted through the manual paper feed roller clutch to the manual paper feed roller, rotating the manual paper feed roller and feeding paper.

(3) Resist roller

In order to make synchronization between the paper lead edge fed from the paper feed port and the image lead edge, the roller is kept stationary for a certain time after the paper reaches at the roller to warp the paper a little.

When the paper is warped to a certain level, the resist roller solenoid is turned on to release the resist roller clutch.

The drive power of the main motor is transmitted through the resist roller clutch to the resist roller, rotating the resist roller and feeding paper.

B. Heat roller

A pressure roller is used for the heat roller and a silicone rubber roller is used for the lower heat roller for better toner fusing performance and paper separation.

C. Separator pawl

Four separator pawls are used on the upper heat roller. The separator pawls are teflon coated to reduce friction with the roller and prevent a smear on the paper caused by the separator pawl.

D. Thermal control

1)The heater lamp, thermistor, main PWB, DC power supply PWB, and triac within the power supply unit are used to control the temperature in the fuser unit.To prevent against abnormally high temperature in the fuser unit, a thermostat is used for safety pur- poses.

6. Fusing section

A. Basic composition

Safety device

(thermal breaker, thermal fuse)

Triac (in the power supply unit)

Heated by the heater lamp. (950W )

The surface temperature of the upper heat roller

is sensed by the thermistor.

Level of the thermistor is controlled by the main PWB.

With the signal from the main PWB, the triac is controlled on and off.

(power supply PWB )

(Top view)

1	Before-fusing	Guides the paper transported from
	paper guide	the process section to the fusing unit.
2	Upper heat roller	Applies heat and pressure to the
		paper to fuse.
3	Thermistor	Detects the surface temperature of
		the upper heat roller.
4	Thermostat	Stops power supply to the heat roller
		in case of an abnormally high
		temperature of the heat roller.
5	Separation pawl	Separates the print paper from the
		upper heat roller.
6	POD1	Detects that the paper has been
		transported from the fusing section.
7	Heater lamp	Heats the heat roller.
8	Lower heat roller	Applies a pressure to the paper
		together with the upper heat roller.

2)The surface temperature of the upper heat roller is set to 180˚C ~ 195˚C. The surface temperature during the power save mode is set to 100˚C.

3)The self-check function comes active when one of the following malfunctions occurs, and an "H" is displayed on the copy quantity display.

Fusing temperature error value H4 (Low temperature error)

•During machine operation

The case where the fusing temperature (thermistor output value) does not reach 155˚C within 55 sec from lighting of the heater lamp. (If the toner motor rotates for 10 sec or more continuously when starting the machine, the case where the fusing temperature does not reach 155˚C within 60 sec.)

•During printing

When the fusing temperature (thermistor output value) falls below 145˚C.

H3 (High temperature error)

Fusing temperature (thermistor output value) of about 220 to 240˚C (varies depending on the resistance.)

E. Fusing resistor

(1) Fusing resistor

Since the upper heat roller is conductive when copy paper is highly moistured and the distance between the transfer unit and the fusing unit is short, the transfer current leaks through the copy paper, the upper heat roller and the discharging brush.

To prevent against this, a resistor of 150MOhm is provided between the frame and the discharge brush to minimize leak current and improve transfer efficiency.

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