Fixing Device Movable Heat Shield Thermal Deformation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fixing devices in image forming apparatuses face challenges in quickly heating the endless belt or film to shorten print time and prevent overheating of axial ends, leading to thermal deformation and inefficiencies in heat distribution.
Innovation Solution
A fixing device with a movable heat shield that adjusts its position to shield the fixing belt from the heater, and a stationary heat shield to prevent overheating of axial ends, allowing for variable heat conduction based on the size of the recording medium, ensuring efficient heating and preventing thermal deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the heater continuously heats the fixing belt to shorten print time, then heating speed improves, but thermal deformation occurs at axial ends
Solution Approach 1:
The heat shield is made movable rather than fixed, allowing it to dynamically adjust its position between the heater and fixing belt. The heat shield can move closer to the heater during high-heat需求的 periods and retreat when thermal accumulation is sufficient, enabling adaptive heat management that prevents thermal deformation while maintaining fast heating capability
Solution Approach 2:
A heat shield is introduced as an intermediary component between the heater and the fixing belt. This heat shield acts as a buffer that can be positioned to control heat transmission, preventing direct excessive heating of the fixing belt axial ends while still allowing efficient heat transfer when needed, thus resolving the contradiction between heating speed and thermal stability
2Manufacturing precision
If the heater heats the entire fixing belt uniformly, then heat distribution improves, but axial ends overheat due to lack of heat dissipation
Solution Approach 1:
The heat shield is positioned specifically at the axial ends of the fixing belt where overheating occurs, rather than uniformly across the entire belt. This localized heat shielding allows the central regions to receive full heating for uniform heat distribution while protecting the axial ends from excessive heat accumulation, addressing the local thermal imbalance problem
3Stability of the object's composition
If a fixed heat shield is used to prevent axial end overheating, then thermal stability improves, but heating efficiency decreases
Solution Approach 1:
The heat shield transitions from a fixed position to a movable one, capable of adjusting its position based on thermal conditions. During heating phases, the heat shield can retreat to allow efficient heat transfer, and during thermal accumulation phases, it advances to prevent overheating, thus maintaining both heating efficiency and thermal stability
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 solution effectively shortens print time by optimizing heat distribution and preventing thermal deformation, ensuring consistent image quality and reducing maintenance needs.
Implementation Method 1
a heater (303R) located inside the metal thermal conductor (302R) heats the metal thermal conductor (302R)
Implementation Method 2
the metal thermal conductor (302R) heats the endless belt (301R)
Implementation Method 3
a heat shield (310) interposed between the heater (303R) and the fixing belt (301R) to shield the fixing belt (301R) from the heater (303R)
Data Source
AI summary
A fixing device includes a fixing rotary body and a heater disposed opposite and heating the fixing rotary body. A nip formation assembly presses against an opposed body via the fixing rotary body to form a fixing nip between the fixing rotary body and the opposed body, through which a recording medium is conveyed. A movable heat shield movable in a circumferential direction of the fixing rotary body is interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater in a variable axial span of the fixing rotary body. A stationary heat shield, interposed between the heater and the fixing rotary body to shield the fixing rotary body from the heater, is disposed outboard from a lateral edge of a heat generator of the heater in an axial direction of the fixing rotary body.