Heater with Variable Resistance Conductor Paths for Uniform Fixing
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Solution Overview
Problem
Existing heaters for fixing devices in image forming apparatuses face challenges in achieving uniform temperature distribution along the longitudinal direction of the fixing rotator, which affects the uniform heating of recording media, leading to inefficiencies in toner image fixation.
Innovation Solution
The proposed heater design includes a base with heat generators and conductor paths, where branch conductor paths have a lower electrical resistance per unit length than the main conductor paths, ensuring uniform heat distribution by reducing resistance differences among heat generators, thus uniformly heating the fixing belt and the recording medium.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If conventional conductor paths with uniform resistance are used, then the heater structure is simple, but the temperature distribution along the fixing rotator becomes non-uniform
Solution Approach 1:
The conductor path is designed with varying resistance characteristics along its length, creating local quality differences. Specifically, the conductor path has a first section with higher resistance and a second section with lower resistance, allowing different parts of the heater to generate different amounts of heat to compensate for heat loss patterns and achieve uniform temperature distribution.
Solution Approach 2:
The resistance parameter of the conductor path is deliberately changed along its length. The conductor path transitions from a first resistance value in the first section to a second resistance value in the second section, enabling controlled variation in heat generation across different zones of the fixing rotator to maintain uniform temperature.
2Power
If higher resistance conductor paths are used to increase heat generation, then heat output increases, but power consumption increases and energy efficiency decreases
Solution Approach 1:
The conductor path applies local quality by having different resistance sections only where needed. The first section with higher resistance is positioned where additional heat generation is required, while the second section with lower resistance is positioned where less heat is needed, optimizing power distribution and reducing overall energy consumption.
Solution Approach 2:
Instead of uniformly increasing resistance across the entire conductor path (which would cause excessive power consumption), the invention applies partial action by increasing resistance only in the first section where it is most needed, while maintaining lower resistance in the second section, thus achieving the required heat output with improved energy efficiency.
3Manufacturing precision
If uniform heat generation is achieved across the fixing rotator, then temperature distribution improves, but this requires complex conductor path design with varying resistance
Solution Approach 1:
The conductor path is designed with local quality variations through distinct first and second sections with different resistance characteristics. This allows precise control over heat generation in different zones, achieving uniform temperature distribution while keeping the overall structure relatively simple through systematic segmentation rather than complex continuous variation.
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 configuration ensures consistent heat generation across the fixing belt, enhancing the uniformity of toner image fixation on the recording medium, reducing wasteful power consumption and preventing overheating, while accommodating different sheet sizes.
Implementation Method 1
The conductor paths include a main conductor path connected to one of the electrodes and a branch conductor path branched from the main conductor path. At least a part of the branch conductor path has a lower electrical resistance per unit length than a resistance per unit length of the main conductor path.
Data Source
AI summary
A heater includes a base, a plurality of heat generators arranged on the base in parallel to a longitudinal direction of the base, a plurality of electrodes on the base, and conductor paths disposed on the base. The conductor paths are electrically connected to the heat generators and the electrodes. The conductor paths include a main conductor path connected to one of the electrodes and a branch conductor path branched from the main conductor path. At least a part of the branch conductor path has a lower electrical resistance per unit length than an electrical resistance per unit length of the main conductor path.