Heating Roller End Covers for Compact Image Fixing
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Solution Overview
Problem
Conventional fixing units for image forming apparatuses are difficult to downsize due to the structural constraints of covering both the heating and pressurizing rollers, which hinders the compactification of the image forming apparatus, especially in space-constrained environments like bookshelves.
Innovation Solution
A compact fixing unit design where the unit case is open on the side opposing the pressurizing roller, allowing for reliable pressure contact and enhanced thermal insulation through end covers that cover the heating roller, facilitating easier maintenance and exchange of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the heating roller and pressurizing roller are totally covered with a case, then the structure is complete and protected, but the fixing unit cannot be downsized
Solution Approach 1:
The case is segmented into a rear case covering the heating roller and a front case covering the pressurizing roller, with a gap between them. This segmentation allows the fixing unit to be compact while maintaining reliable pressure contact through the front case's positioning structure that ensures proper alignment of the pressurizing roller with the heating roller.
2Volume of moving object
If the heating roller is exposed, then downsizing is achieved, but thermal insulation performance deteriorates
Solution Approach 1:
The rear case is designed with heat-insulating properties to locally provide thermal insulation for the heating roller. This localized heat insulation approach maintains energy efficiency while allowing the overall fixing unit to be downsized by eliminating unnecessary case portions.
3Ease of repair
If the case is opened for maintenance, then ease of maintenance is improved, but structural completeness worsens
Solution Approach 1:
The case is divided into a rear case and a front case that can be separated from each other. The front case can be detached to provide easy access to the pressurizing roller for maintenance, while the rear case remains intact to maintain structural integrity and heat insulation. This segmented design resolves the contradiction between maintenance accessibility and structural completeness.
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 achieves a compact form factor for the fixing unit while ensuring effective thermal insulation and reliable pressure contact between the rollers, enabling proper fixing processes and easy maintenance, thus contributing to the downsizing of the image forming apparatus.
Implementation Method 1
The heating roller contains therein a heat source such as a halogen lamp. While the recording medium such as recording paper passes between the heating roller and the pressurizing roller, developer such as toner that has been partly melted and admixed by heating will penetrate into the recording medium, and will be fixed.
Implementation Method 2
because the fixing unit is provided with the end covers for covering the ends in the longitudinal direction of the heating roller, the fixing unit attains such advantage that the heating roller can be thermally insulated with enhanced heat insulation performance
Data Source
AI summary
An image forming apparatus includes a fixing unit for fixing a toner image. The fixing unit includes a heating roller and a pressurizing roller opposed to the heating roller and urged toward the heating roller. A unit case rotatably supports both ends of the heating roller in a longitudinal direction of the heating roller. The unit case is open at one side of the heating roller opposed to the pressurizing roller and covers the other side of the heating roller opposite to the pressurizing roller. A pair of pressurizing roller supporting bodies are respectively provided at both ends in a longitudinal direction of the unit case and rotatably support both ends of the pressurizing roller. A pair of end covers cover both the ends of the heating roller in the longitudinal direction of the heating roller.