Variable Width Heater for Electrophotographic Fixing
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Solution Overview
Problem
Existing film heating fixing devices in electrophotographic printers face challenges in preventing temperature rises in non-sheet passage areas due to their low heat capacity, leading to increased power consumption and longer first print out times, necessitating a more effective heater design to manage heat distribution.
Innovation Solution
A heater design featuring an elongated substrate with specific conductor patterns and heat generating resistors, where the widths of the conductor patterns and heat generating resistors vary along the substrate to optimize heat generation and distribution, reducing temperature rises in non-sheet passage areas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If a low heat-capacity member is used in the film heating fixing device, then power consumption and wait time for heating are reduced, but temperature rise in non-sheet passage area easily occurs
Solution Approach 1:
The heat generating resistor is designed with non-uniform width along the longitudinal direction, creating different heat generation characteristics in different regions. The wider central portion generates more heat for effective fixing, while the narrower end portions generate less heat to prevent temperature rise in non-sheet passage areas.
Solution Approach 2:
The heat generating resistor is segmented into different width regions (central wider portion and end narrower portions) to create zones with different heat generation capabilities, allowing independent optimization of heat distribution across the heater surface.
2Productivity
If continuous printing is performed on small size recording media, then productivity increases, but temperature rise in non-sheet passage area occurs more easily
Solution Approach 1:
The heat generating resistor's non-uniform width creates localized heat control where the central region maintains high temperature for continuous printing on small media, while end regions are designed to prevent excessive temperature accumulation during high-speed operation.
3Loss of time
If the size and heat capacity of heater components are reduced, then first print out time and power consumption are reduced, but temperature control precision in non-sheet passage area becomes more difficult
Solution Approach 1:
The heat generating resistor is designed with spatially varying width to create different thermal characteristics in different regions, enabling precise temperature control in small-size components by optimizing heat generation locally rather than uniformly across the entire heater.
Solution Approach 2:
The solution transitions from controlling temperature through time-based heating to spatial-based heat distribution by varying the width of the heat generating resistor across its surface, adding a dimensional approach to temperature management.
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 proposed heater design effectively reduces temperature rises in non-sheet passage areas, enhancing fixability and reducing power consumption while maintaining efficient heat fixation of toner images on recording media.
Implementation Method 1
a heat generating resistor having a positive temperature coefficient (PTC)... An electrical current is applied to the heat generating resistors... the electrical resistance of the heater increases with increasing temperature... heat generation in the non-sheet passage area is reduced
Data Source
AI summary
A heater used for a fixing device includes a substrate, first and second conductor patterns formed at either end of the substrate in the short direction of the substrate, a third conductor pattern formed between the first and second conductor patterns and separated from the two conductor patterns, a first heating member disposed between the first and third conductor patterns and electrically connected to the two conductor patterns, and a second heating member disposed between the second and third conductor patterns and electrically connected to the conductor patterns. The heater has both end regions in which the widths of the third conductor pattern in the short direction is smaller than that of a middle portion of the third conductor pattern. The widths of the first and second heating members in the end regions are smaller than the widths of the first and second heating members in the other region, respectively.