Variable Heating Span Reflector for Fixing Belt
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Solution Overview
Problem
Existing fixing devices in image forming apparatuses face issues with uneven heating of recording media of varying sizes, leading to fixing failures due to an invariable heating span that does not match the width of the media, resulting in insufficient heating or overheating of the media edges.
Innovation Solution
A fixing device with a reflector that includes a movable portion to direct light from a heater onto a variable heating span of a fixing rotary body, adjusting based on the width of the recording medium, ensuring even heating across the media.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single planar plate reflector is used to reflect light from the heater onto the thermal conductor, then the device structure remains simple, but the heating span becomes invariable and cannot match recording media of various sizes, resulting in uneven heating
Solution Approach 1:
The reflector is designed with a movable portion that can change its position or angle, transforming it from a static single planar plate into a dynamic structure. This allows the reflector to adjust the heating span dynamically to match different recording medium sizes, resolving the contradiction between adaptability and structural simplicity by introducing controlled movement rather than complete structural complexity
Solution Approach 2:
The reflector is divided into a fixed portion and a movable portion, allowing independent functionality for each segment. The fixed portion maintains structural stability while the movable portion provides adjustment capability, enabling the system to achieve variable heating span without requiring the entire reflector structure to be complex
2Reliability
If the heating span is made invariable to simplify the reflector structure, then the device complexity is reduced, but recording media of various sizes cannot be heated evenly, leading to fixing failures
Solution Approach 1:
The movable portion of the reflector enables dynamic adjustment of the heating span to match different recording medium widths, ensuring reliable fixing across various media sizes. This dynamic capability is achieved through a mechanically simple arrangement that does not significantly increase overall device complexity
Solution Approach 2:
The reflector structure applies different properties to different portions: the fixed portion provides structural stability while the movable portion provides adjustment functionality. This local differentiation allows the system to achieve reliable heating for various media sizes without making the entire reflector structure complex
3Object-affected harmful factors
If the heating span exceeds the recording medium width, then the structure is simplified, but the edges of the recording medium are overheated causing thermal damage to the fixing belt
Solution Approach 1:
The movable portion of the reflector can be positioned to limit the heating span to precisely match the recording medium width, preventing overheating of edges and thermal damage to the fixing belt. This dynamic control allows the system to adapt to different media sizes without requiring complex additional protective mechanisms
Solution Approach 2:
The heating span parameter is made adjustable through the movable reflector portion, allowing optimization of the heating area to match the recording medium dimensions. This parameter control prevents excessive heating and thermal damage while maintaining a relatively simple device structure through mechanical adjustment rather than complex control systems
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 ensures consistent and efficient heating of recording media of different sizes, preventing fixing failures and thermal damage to the fixing belt, while maintaining a simple device structure.
Implementation Method 1
A reflector, disposed opposite an inner circumferential surface of the fixing rotary body via the heater, reflects light emitted from the heater onto the fixing rotary body
Implementation Method 2
the fixing belt heated by the heater 110R through the heating roller 111R
Data Source
AI summary
A fixing device includes a fixing rotary body rotatable in a given direction of rotation and a pressing rotary body pressed against the fixing rotary body to form a fixing nip therebetween through which a recording medium bearing a toner image is conveyed. A heater is disposed inside the fixing rotary body to heat the fixing rotary body. A reflector, disposed opposite an inner circumferential surface of the fixing rotary body via the heater, reflects light emitted from the heater onto the fixing rotary body. The reflector includes a movable portion movable relative to the heater to direct the light emitted from the heater onto a variable heating span of the fixing rotary body spanning in an axial direction thereof. The variable heating span varies depending on a width of the recording medium in the axial direction of the fixing rotary body.