Cylindrical Film Heating Apparatus Overheating Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image heating apparatuses with electromagnetic induction heating type rotatable heat generating members face overheating issues due to cracks, leading to temperature non-uniformity and image defects, which existing solutions fail to adequately address.
Innovation Solution
A cylindrical film with ring-shaped heat generating elements, a ring-shaped insulating portion, and a high thermal conductivity heat conductive layer (3 W/mK or more) that overlaps with the heat generating elements, allowing for efficient heat distribution and preventing overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the heat generating layer is electrically divided to suppress overheating at crack locations, then overheating is reduced, but temperature non-uniformity occurs across the rotatable member
Solution Approach 1:
The heat generating layer is divided into multiple independent heat generating elements along the longitudinal direction, with insulating portions separating adjacent elements. This segmentation prevents current continuity along cracks, suppressing overheating at defect locations while maintaining overall heating functionality through distributed elements
Solution Approach 2:
A heat conductive layer with thermal conductivity of 3 W/mK or more is introduced as an intermediary between the heat generating elements and the base layer. This layer acts as a thermal mediator that redistributes heat laterally, compensating for temperature non-uniformities caused by the segmented structure and ensuring uniform temperature distribution across the rotatable member surface
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 suppresses overheating and temperature non-uniformity, reducing the occurrence of image defects by ensuring uniform heat distribution across the film, even when cracks occur, thereby maintaining image quality.
Implementation Method 1
a plurality of heat generating elements configured to generate heat by a flow of a current
Implementation Method 2
an exciting coil unit configured to generate an induced current flowing through the film in a circumferential direction
Implementation Method 3
a heat conductive layer different from a layer of the heat generating elements with respect to a thickness direction of the film, wherein the heat conductive layer is 3 W/mK or more in thermal conductivity
Data Source
AI summary
A cylindrical film for use with an image heating apparatus includes a plurality of heat generating elements configured to generate heat by a flow of a current, in which each of the heat generating elements has a ring shape and is arranged along a longitudinal direction of the film; a ring-shaped insulating portion configured to electrically insulate the heat generating elements adjacent to each other; and a heat conductive layer different from a layer of the heat generating elements with respect to a thickness direction of the film, The heat conductive layer is 3 W/mK or more in thermal conductivity and overlaps with the heat generating elements with respect to the longitudinal direction.