Segmented Heating Assembly for Fixing Film Warm-Up
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing fixing devices for image forming apparatuses face issues with long warm-up times due to high heat capacity heating rollers and unstable operation of fixing films with ceramic heaters, leading to faulty toner images and increased driving torque.
Innovation Solution
A fixing device with an endless belt-shaped fixing member, a nip formation member, a pressing member, a heating assembly, and thermally deformable supports that contact and support the fixing member after warm-up, ensuring uniform heat transmission and preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If a heating roller with large heat capacity is used, then stable heat transmission is achieved, but warm-up time increases
Solution Approach 1:
The heating assembly is segmented into multiple independent heating units distributed along the fixing member, allowing localized heating of specific regions rather than heating the entire roller, thus reducing overall heat capacity while maintaining stable heat transmission at the nip region
Solution Approach 2:
Heat generation is concentrated locally at the nip region where it is most needed, rather than distributing heat throughout the entire heating roller. This local heating approach reduces the heat capacity that needs to be warmed up while ensuring stable heat transmission at the critical fixing location
2Loss of time
If a fixing film with ceramic heater is used, then warm-up time is reduced, but friction increases causing unstable movement and increased driving torque
Solution Approach 1:
A support member is introduced as an intermediary between the fixing member and the heating assembly. This support member carries the heating assembly and provides a stable mounting structure that reduces friction and ensures smooth movement of the fixing film without direct contact between the ceramic heater and the fixing member
Solution Approach 2:
The direct mechanical contact between the ceramic heater and the fixing member is replaced by a support member structure that allows the heating assembly to be carried separately, reducing mechanical friction and improving movement stability
3Loss of time
If ceramic heater heats only at nip region, then warm-up time is reduced, but temperature uniformity decreases causing faulty toner images
Solution Approach 1:
The heating assembly is divided into multiple segmented heating units distributed along the fixing member, with each unit heating a specific region. This segmentation allows heat to be applied at multiple locations simultaneously, improving temperature uniformity across the fixing surface while maintaining quick warm-up response
Solution Approach 2:
The heating assembly is positioned to pre-heat regions of the fixing member before they reach the nip region. This preliminary heating action ensures that the entire path of the fixing member maintains adequate temperature, preventing cold spots that would cause faulty toner images while keeping warm-up time short
4Device complexity
If heating assembly is fixed inside loop, then structure is simple, but thermal deformation causes gap variation and overheating
Solution Approach 1:
The support member structure is designed to be dynamically adjustable, allowing the heating assembly to move and adapt its position in response to thermal expansion and contraction of the fixing member. This dynamic adjustment maintains consistent contact and gap uniformity, preventing overheating while keeping the overall structure relatively simple
Solution Approach 2:
The positional parameters of the heating assembly are made variable through the support member design, allowing automatic adjustment of the gap between the heating assembly and the fixing member in response to temperature changes. This parameter change compensates for thermal deformation and maintains reliable heat transmission
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 reduces warm-up time, maintains stable operation, and prevents overheating, ensuring consistent image quality and reduced driving torque.
Implementation Method 1
The heating assembly heats a part of the fixing member
Implementation Method 2
The heating assembly is thermally deformable to contact and move the fixing member
Data Source
AI summary
A fixing device includes a fixing member formed into a loop and rotatable in a predetermined direction of rotation. A heating assembly faces a first region on an inner circumferential surface of the fixing member to heat the fixing member. The heating assembly is thermally deformed to contact and move the fixing member. A first fixing member support and a second fixing member support face a second region on the inner circumferential surface of the fixing member other than the first region. The first fixing member support and the second fixing member support contact and support the rotating fixing member moved by the thermally deformed heating assembly.