AR-C260 (serv.man10). All Sections - Sharp Copying Equipment Service Manual (repair manual). Page 2

AR-C260/C260M  DESCRIPTIONS OF EACH SECTION  7 - 2

RW: Abbreviation of Related Wiring, which means the said load is specified in the related figure of the mechanical and the electrical sections.

To drive the fusing unit, drive power is transmitted from the drive motor
(FUSM) through the connection gear to the upper heat roller gear. 

The drive motor (stepping motor) is driven by the motor drive IC in the
driver PWB according to the control signal sent from the PCU.

The surface temperature detected by the thermistor is sent to the PCU.
When the temperature is lower than the specified level, the PCU sends
the heater lamp lighting signal to the heater lamp drive circuit in the DC
power PWB.

The triac in the heater lamp drive circuit is turned on to apply AC power
to the heater lamp, which turns on to heat the heat rollers.

The thermostats are provided as a safety measure to prevent against
an abnormally high temperature of the heat rollers.

When the thermostat is opened, the power supply (AC neutral) to the
heater lamp is cut off.

Color toner of YMCK on paper is heated and pressed by the heat roll-
ers to be fused on paper. 

At that time, color toner of YMCK is mixed to reproduce nearly actual
colors of document images.

The upper and the lower heat rollers are provided to heat from above
and below. This is because it is necessary to heat four layers of toner
from above and below and right and left to fuse it on paper.

The upper and lower heat rollers are of silicon rubber. This is because
of the following reasons:

1) To provide a greater nip quantity and a higher heating capacity for

paper.

2) The soft, flexible rollers press multi-layer toner without deformation

to fuse on paper.

3) An even pressure is applied to an uneven surface of multi-layer

toner.

6

1

6

2

4

1

5

3

4

1

2

2

6

3

6

6

1

2

4

5

4

5

1

1

3

120V 950W
120V 350W

No.

Name

Code, Signal name

Function

1

Heat roller

—

Heats and presses toner to fuse it on paper. Silicon rubber rollers are used 
as the upper and the lower heat rollers. Teflon tube is wound around the 
upper heat roller.

2

Upper/lower separation pawls

—

Mechanically separate paper from the heat roller, which was not separated 
naturally.

3

Heater lamp

Upper: HL1, Lower: HL2

Heats the heat rollers.

4

Thermistor

Upper: THSU, Lower: THSD

Detects the surface temperature of the heat roller. (Keeps the roller surface 
temperature at a constant level.)

5

Thermostat

Upper: HLTS1, Lower: HLTS2

Cuts conduction of the heater lamp when an abnormally high temperature is 
detected.

6

Paper exit sensor

POD1

Detects paper discharged from the fusing section.

RW

Control signal

FUSM_A, A’, B, B’

Drives the fusing section.

RW

Control signal

FUCHin

Fusing unit installation detecting signal

RW

Control signal

DSWL

Left cabinet open/close detection signal

RW

Control signal

HLPR

Heater lamp power relay (in the DC power PWB) drive signal

FUSM

PCU

Driver
PWB