Induction Fusing Device PWM Control Warm-Up Time
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Solution Overview
Problem
Conventional fusing devices using halogen lamps as heat sources require lengthy warm-up times and suffer from reduced flicker characteristics due to high and uncontrolled current flow, leading to user inconvenience and suboptimal toner fixation.
Innovation Solution
A fusing device that employs induced current control through a pulse width modulation signal and proportional-integral controllers to maintain the fusing unit at a predetermined temperature, using an AC current generating unit and insulating transformer to manage the induced current efficiently, thereby improving flicker characteristics and reducing warm-up time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a halogen lamp is used as a heat source in a fusing device, then the fusing unit can be heated to the target temperature, but the warm-up time becomes excessively long (several seconds to several minutes)
Solution Approach 1:
The patent replaces the halogen lamp heating system with an induction heating system that uses electromagnetic fields to directly heat the fusing roller. The induction heating apparatus generates a magnetic field that induces eddy currents in the fusing roller, producing heat internally and rapidly achieving the target fusing temperature without the lengthy warm-up period associated with halogen lamps.
Solution Approach 2:
The patent employs periodic switching of the induction heating power through pulse width modulation (PWM) control. The power supply unit switches the induction heating power on and off at high frequency, allowing rapid temperature adjustment and quick achievement of target temperature, thereby reducing warm-up time while maintaining precise temperature control.
2Power
If high voltage is applied to the heating unit in a halogen lamp system, then the heating power is sufficient, but the current flow drastically increases reducing flicker characteristics
Solution Approach 1:
The patent incorporates a feedback control system that includes a temperature sensor to detect the fusing roller temperature and a controller that adjusts the induction heating power based on the temperature feedback. This closed-loop control maintains stable heating power while preventing current surges, thereby improving flicker characteristics and ensuring consistent heating performance.
Solution Approach 2:
The patent uses dynamic PWM control to adjust the induction heating power in real-time based on temperature feedback. The duty cycle of the PWM signal is dynamically modified to maintain optimal heating power, preventing current instability and improving flicker characteristics while ensuring sufficient heating capability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution allows for instantaneous control of induced current, reducing warm-up time and enhancing flicker characteristics, ensuring consistent and efficient toner fixation on print paper.
Implementation Method 1
a fusing unit which is resistance heated or induction heated by an induced current
Implementation Method 2
a fusing unit which is resistance heated or induction heated by an induced current
Implementation Method 3
The heating unit 250 is resistance heated by the input voltage, and the heat generated at the heating unit 250 heats the fusing roller 240
Data Source
AI summary
A device for fusing and fixing a transferred toner of a predetermined image onto a print paper is provided. In particular, a fusing device which can instantly control induced current provided to a fusing unit in an image printing apparatus which heats the fusing unit using the induced current is provided. The fusing device includes a fusing unit which is resistance heated or induction heated by an induced current, and fuses the toner onto the print paper using the generated heat. A sensing unit senses the temperature of the fusing unit. A reference current generating unit generates a predetermined reference current to heat the fusing unit to reach a predetermined temperature based on the temperature of the sensed fusing unit and the reference temperature. A pulse width modulation signal generating unit generates a pulse width modulation signal for generating the induced current so that the induced current corresponding to the reference current is supplied to the fusing unit.