: Feb. 6 2004
1
AR-M550/M620/M700 DETAILS OF EACH SECTION 6 - 103
C. Details of operations
(1) Fusing unit drive
To drive the fusing unit, the drive power is transmitted from the drive
motor (FUM) through the connection gear to the upper heat roller gear.
The drive motor DC brushless motor is driven according to the control
signal sent from the PCU.
(2) Heater lamp drive
The surface temperature of the heat roller detected by the thermistor is
sent to the PCU.
When the temperature is lower than the specified level, the heater
lamp lighting signal is sent from the PCU to the heater lamp drive cir-
cuit in the sub power PWB.
The power triac in the heater lamp drive circuit is turned on, and the AC
power is supplied to the heater lamp, lighting the lamp and heating the
heat roller.
To prepare for an abnormally high temperature of the heat roller, the
thermostat is provided for safety.
When the thermostat is opened, power supply (AC line) to the heater
lamp is cut off.
(3) Fusing operation
Toner on paper is heated and pressed to be fused by the heat roller.
Two heater lamps are provided for the fusing heat roller (heating) and
one heater lamp is provided for the auxiliary heat roller for the fusing
roller (pressing) to heat paper from above and below.
This is because toner on paper must be heated from above and below
to be fused on paper.
1) Paper is separated upward. (Since the fusing roller (heating) is of
higher hardness, the fusing roller (pressing) is deformed to sepa-
rate paper upward.)
2) The nip quantity is increased to increase heat capacity for paper.
3) By pressing paper with the flexible roller, toner is fused without
deformation. (The flatness, however, is not so high.)
(4) Fusing temperature control
The temperature sensor is provided at the center of the fusing roller
(heating) and the auxiliary heat roller.
The roller temperature is detected by the installed temperature sensor,
and the heater lamp is controlled so that the temperature is maintained
at the specified level.
In addition, the fusing temperature is switched according to the kind of
paper.
(5) Cleaning operation
The fusing roller removes toner and dusts from the heat roller and the
pressure roller surfaces by the following two methods.
1. Sub-heat roller (Heating): Clean the sub heat roller with the clean-
ing sheet.
7 Fusing cleaning scraper Cleans the surface of the fusing roller (pressing). (AR-M550N/U,
AR-M620N/U)
8 Cleaning sheet Clean the sub heat roller surface.
9 Oil roller Apply oil to the fusing roller. (AR-M700N/U)
10 Cleaning plate Clean the fusing (pressure) roller surface. (AR-M700N/U)
No. Name Function/Operation
Active
condition
Note
1
1
1
FUMPCU
1
Fusing roller (Heating)
HL2
HL1
---------
Fusing roller (Pressing)
HL3
Auxiliary heat roller
Paper exit
The fusing rollers (pressing) are of silicon rubber because of the follow-
ing reasons and purpose.
Mode Paper
Fusing roller Auxiliary heat roller
Inch
(U.S.A.,
Canada)
AB_B
(Europe,
U.K.)
AB_A
(Australia)
Inch
(U.S.A.,
Canada)
AB_B
(Europe,
U.K.)
AB_A
(Australia)
Ready
condition
print
mode
Normal paper
200°C 205°C 200°C 205°C
Heavy paper
200°C 205°C 200°C 205°C
Tab paper
200°C 205°C 200°C 205°C
Postcard
200°C 205°C 200°C 205°C
Pre-heat –
170°C 170°C 170°C 170°C
2.Fusing roller (Pressing): Mechanical cleaning by the cleaning
scraper (the cleaning plate for the AR-M700N/U)
No. Name
1 Cleaning sheet
2 Fusing roller (Pressing)
3
Cleaning scraper (AR-M550N/U, AR-M620N/U)
4 Discharge brush
5 Fusing roller (Heating)
6 Sub-heat roller
7 Cleaning plate (AR-M700N/U)
8 Oil roller (AR-M700N/U)
1
1
1
[AR-M550N/U, AR-M620N/U] [AR-M700N/U]
5
2
4
8
1
6 7
5
2
4
3
1
6
1
1
1
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