Induction Fusing Unit PWM Current Ramp for Flicker Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fusing apparatuses using halogen lamps for toner image fusion suffer from long warm-up times and deteriorating flicker characteristics due to sudden increases in current when voltage is applied, leading to inefficient heat transfer and image printing delays.
Innovation Solution
A fusing apparatus that employs induced current with a pulse width modulation (PWM) signal generation unit to gradually increase the induced current to the fusing unit, allowing for controlled heat generation and improved flicker characteristics by using an AC generation unit, insulation unit, and a sensing unit to manage the heating process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If voltage is applied to the heating unit in conventional fusing apparatus, then the heating unit generates heat to fuse toner, but the amount of current drastically increases causing deteriorating flicker characteristics
Solution Approach 1:
The patent applies dynamics by making the current supply to the heating unit adjustable and controllable over time. The controller gradually increases the current from zero to the target current level, transforming the static current application into a dynamic, time-varying process that prevents current spikes and improves flicker characteristics while achieving the required fusing temperature.
2Temperature
If voltage is applied to the heating unit, then heat is generated for toner fusion, but warm-up time is extended to several seconds or minutes
Solution Approach 1:
The patent applies preliminary action by pre-heating the heating unit using a gradual current increase mechanism before actual toner fusion operations begin. The controller progressively ramps up the current to warm the heating unit in advance, reducing the warm-up time delay that would otherwise occur during actual printing operations.
3Loss of energy
If conventional heating methods are used, then toner fusion is achieved, but heat transfer efficiency is reduced due to long warm-up periods
Solution Approach 1:
The patent applies continuity of useful action by maintaining continuous, optimized heating control throughout the operation. The controller continuously adjusts the current to the heating unit, ensuring that heat generation is maintained at optimal levels without interruption or inefficient warm-up periods, thereby improving overall heat transfer efficiency and reducing energy loss.
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 enables faster and more efficient heating of the fusing unit, reducing warm-up time and improving flicker characteristics, allowing for quicker and more stable toner fusion onto paper while maintaining optimal temperature levels during consecutive image printing.
Implementation Method 1
The heating unit 250 is resistance-heated by the filtered voltage input thereto, and heat generated by the heating unit 250 heats the fusing roller 240.
Implementation Method 2
the fusing roller 11 is heated by radiant heat transferred from the heating body 12
Implementation Method 3
the fusing roller 11 is heated by radiant heat transferred from the heating body 12
Data Source
AI summary
A fusing apparatus in an image forming apparatus that heats a fusing unit by applying an induced current is provided. The flicker characteristics of the fusing apparatus are improved by gradually increasing the amount of induced current applied to the fusing unit for a predetermined amount of time so that the amount of induced current applied to the fusing unit is prevented from severely varying. The fusing apparatus comprises a fusing unit which is resistance-heated or induction-heated by applying an induced current and fuses toner onto paper using the heat. The fusing apparatus further comprises a pulse width modulation (PWM) signal generation unit which generates a PWM signal in response to the ON signal so that the amount of induced current input to the fusing unit gradually increases to a reference current.