Fixing Device Heater Control for Flicker Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image-forming apparatuses with multiple heaters face challenges in controlling power turn-on/off patterns to minimize flicker values, especially when there are significant power differences between patterns, which can affect temperature control and compliance with standards like noise terminal voltage and harmonic distortion.
Innovation Solution
A fixing device with a control unit that adjusts the switching time of heaters based on turn-on/off patterns with half-wave intervals, setting control intervals longer than 900 ms but shorter than 1500 ms to manage flicker values and power differences, and inserting additional patterns as needed to maintain compliance with flicker regulations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the control interval is shortened to improve response to temperature control, then the response speed is improved, but the flicker value increases and may not conform to standards
Solution Approach 1:
The patent applies periodic action by using turn-on/off patterns synchronized with half-wave intervals of AC power supply. The control interval is set to an integer multiple of half-wave intervals (e.g., 10 half-waves = 100ms at 50Hz), creating a periodic control rhythm that prevents flicker while maintaining responsive temperature control through rhythmic heater activation.
Solution Approach 2:
The patent changes the parameter of control interval duration, specifically setting it within the range of 900-1500ms and as an integer multiple of half-wave intervals. This parameter optimization resolves the contradiction by finding the sweet spot where the interval is long enough to prevent flicker but short enough to maintain responsive temperature control.
2Object-affected harmful factors
If the power difference between turn-on/off patterns is reduced to minimize flicker, then the flicker value is reduced, but the temperature control efficiency decreases
Solution Approach 1:
The patent applies dynamics by making the turn-on/off patterns adjustable and adaptable. The control system can dynamically select from multiple pattern configurations (different duty ratios, different control intervals) depending on operating conditions. This allows the system to optimize between flicker reduction and temperature control efficiency based on real-time requirements.
Solution Approach 2:
The patent segments the power supply into multiple half-wave intervals within the control interval, allowing independent control of heater activation in each segment. This segmentation enables fine-grained control where the heater can be turned on during specific half-waves and off during others, reducing power difference between patterns while maintaining control efficiency through strategic placement of on/off segments.
3Use of energy by moving object
If heat capacity of the fixing device is reduced to decrease power consumption, then the power consumption is reduced, but the temperature ripple increases
Solution Approach 1:
The patent uses periodic turn-on/off patterns synchronized with AC power supply half-waves to control heater activation. This periodic control allows the fixing device to operate with lower average power consumption while maintaining stable temperature by rhythmically activating the heater only when needed, preventing both overheating and excessive temperature ripple.
Solution Approach 2:
The patent employs feedback control where the control unit monitors temperature and adjusts the turn-on/off patterns accordingly. This feedback mechanism ensures that even with reduced heat capacity and lower power consumption, the temperature ripple is minimized by dynamically adjusting heater activation based on actual temperature conditions.
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
This solution effectively reduces flicker values and maintains temperature control precision, ensuring the fixing device conforms to various standards while optimizing energy usage.
Implementation Method 1
The fixing device has a fixing heater(s) for performing a heat transfer on the sheet
Implementation Method 2
a switching unit that switches from a turn-on state of the heaters in which the heaters are connected to the alternating current power supply to a turn-off state of the heaters in which the heaters are disconnected from the alternating current power supply
Data Source
AI summary
When changing the turn-on/off patterns, a controller of a fixing device sets a control interval of the turn-on/off pattern so as to be longer than a first period of time that does not exert any influence to a flicker value and to be shorter than a second period of time that does not exert any influence to a response to temperature control. The controller of the fixing device selects a third turn-on/off pattern in which power difference between power of a first turn-on/off pattern before the change in the turn-on/off pattern and power of a second turn-on/off pattern after the change in the turn-on/off pattern is smaller than a set reference power difference.