Fixing Device Heat Equalizer Structure for Uniform Belt Temperature
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Solution Overview
Problem
Existing fixing devices face challenges in maintaining uniform temperature distribution across the width of the fixing belt, leading to uneven fixing of toner images due to heat transfer inefficiencies between the heat conductive member, heater, and heater holder.
Innovation Solution
A fixing device design incorporating a heat equalizing member with a specific storage recess and void part configuration, along with a holding member, to minimize heat transfer to the holding member and maintain uniform temperature distribution across the fixing belt.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heat conductive member is provided in contact with the heater to promote heat transfer from the non-sheet passing area to the sheet passing area, then the temperature distribution of the fixing belt can be made uniform, but the thermal efficiency of the heater may be lowered due to heat transfer to the heater holder
Solution Approach 1:
The storage recess is divided into two distinct parts: a heat equalizing member storage part with larger cross-sectional area and a void part with narrower cross-sectional area. This segmentation allows the heat conductive member to be positioned such that it contacts the heater for heat equalization while its rear surface contacts only the step surface between the two parts, minimizing heat loss to the heater holder.
Solution Approach 2:
The void part with narrower cross-sectional area is strategically positioned at the rear of the storage recess to create a localized region that limits heat transfer to the heater holder. This local structural modification allows the front portion to maintain good thermal contact for heat equalization while the rear portion minimizes parasitic heat loss.
2Temperature
If the heat conductive member is held between the heater and heater holder, then heat transfer from non-sheet passing area to sheet passing area is promoted, but heat is transferred from the heat conductive member to the heater holder causing thermal efficiency loss
Solution Approach 1:
The design extracts the heat conductive member from direct contact with the heater holder by creating a void part with narrower cross-sectional area. The rear surface of the heat conductive member contacts only the step surface between the storage parts, effectively removing the unwanted heat transfer path to the heater holder while preserving the beneficial heat equalization function.
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 design ensures uniform heat distribution and reduced heat loss, enhancing the thermal efficiency of the heater and improving toner image fixing consistency.
Implementation Method 1
The heater has a belt contact surface coming into contact with an inner circumferential surface of the fixing belt
Implementation Method 2
The heat conductive member is held between the heater and a heater holder so as to be in contact with a heat generating region of the heater. By providing such a heat conductive member, a transfer of heat from the non-sheet passing area to the sheet passing area is promoted
Data Source
AI summary
A fixing device includes a fixing belt, a heater, a heat equalizing member, a holding member, and a pressure roller. The heater has a belt contact surface coming into contact with an inner circumferential surface of the fixing belt. The heat equalizing member has a front contact surface coming into contact with a surface opposite to the belt contact surface of the heater and a rear contact surface. The holding member has a storage recess in which the heater and the heat equalizing member are stored. The presser member is pressed against the heater via the fixing belt to form a pressurized region. The storage recess has a heat equalizing member storage part, and a void part having a cross-sectional area narrower than that of the heat equalizing member storage part. The rear contact surface of the heat equalizing member comes into contact with a step surface formed between the heat equalizing member storage part and the void part.