Electrophotography – Diagnostics – Fixing
Reexamination Certificate
2000-01-31
2001-06-12
Beatty, Robert (Department: 2852)
Electrophotography
Diagnostics
Fixing
C399S069000, C219S216000, C219S470000
Reexamination Certificate
active
06246842
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention.
The present invention relates to an electrophotographic machine, and, more particularly, to a fuser assembly in an electrophotographic machine.
2. Description of the Related Art.
A fuser assembly is used in an electrophotographic machine to fuse previously applied toner onto a surface of a print medium, such as paper. The fuser assembly includes a fuser roll which presses the toner into the print medium. The fuser roll is heated internally by a heating element, such as a fuser lamp, disposed therein.
The increase in function and speed of electrophotographic printers has driven a continuing increase in the amount of current drawn from the wall outlet to power the printing operation. The wattage of the system power supply continues to increase as more functions and higher speeds are demanded. The higher speeds, expressed in pages per minute, have led to the use of higher wattage fuser lamps and the use of multiple lamps to facilitate the toner fusing operation at these higher print speeds.
A problem is that the combination of the current drawn by the power supply and the fuser lamps can now exceed the amount of current available from a standard 15 ampere, 120 volt wall outlet. The high current draw can result in nuisance tripping of the circuit breaker. It is known to avoid such nuisance tripping by specifying the use of a dedicated, high current outlet. A problem is that such dedicated high current outlets require installation by a qualified electrician, which is both costly and time consuming.
What is needed in the art is a way of preventing the fuser assembly of an electrophotographic machine from causing nuisance tripping of the circuit breaker without having to install a dedicated high current outlet.
SUMMARY OF THE INVENTION
The present invention provides a method and apparatus for preventing the combined load of a printing system power supply and multiple high wattage fuser lamps from exceeding the alternating current (AC) line current available from a standard 15 ampere, 120 volt wall outlet.
The invention comprises, in one form thereof, a method of operating a fuser assembly in an electrophotographic machine. A first heating device heats a first fuser roll. A second heating device heats a second fuser roll. It is determined whether a first temperature of the first fuser roll is below a first target temperature. It is also determined whether a second temperature of the second fuser roll is below a second target temperature. If both the first temperature is below the first target temperature and the second temperature is below the second target temperature, the first heating device is operated during a first time period and operation of the second heating device is inhibited throughout the first time period.
An advantage of the present invention is that both a primary fuser lamp and a back-up fuser lamp may be operated without exceeding the amount of current available from a standard 15 ampere, 120 volt wall outlet.
Another advantage is that installation of a dedicated high current outlet is not required.
REFERENCES:
patent: 5051780 (1991-09-01), Stelter et al.
patent: 5325164 (1994-06-01), Tai et al.
patent: 5329343 (1994-07-01), Saito
patent: 5517293 (1996-05-01), Tonai et al.
patent: 5543904 (1996-08-01), Kato et al.
patent: 5978618 (1999-11-01), Yamamoto et al.
patent: 6173131 (2001-01-01), Kitamura et al.
patent: 59-033480 (1984-02-01), None
patent: 59-111669 (1984-06-01), None
patent: 62-157073 (1987-07-01), None
patent: 09-311584 (1997-12-01), None
Beatty Robert
Lexmark International Inc.
Taylor & Aust
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