Fixing Device Contact Portions for Uniform Temperature

The patent applies local quality by creating contact portions with different contact areas at different locations on the cylindrical film surface. The first contact portion has a larger contact area to compensate for regions that lose more heat, while the second contact portion has a smaller contact area for regions that retain heat better. This non-uniform distribution of contact areas creates localized thermal compensation, achieving uniform temperature distribution across the film surface without requiring complex multi-zone heating systems.

The patent applies parameter changes by modifying the contact area parameter of the contact portions rather than changing the overall system architecture. By adjusting the contact area parameter locally (larger area at first contact portion, smaller area at second contact portion), the system achieves thermal uniformity through a simple structural modification. This approach avoids the complexity of multiple independent heating zones or complex control systems while effectively addressing the temperature distribution issue.

The patent applies local quality by strategically positioning the thermometer at a specific location that is not directly adjacent to the contact portions. This positioning allows the thermometer to measure the temperature of the cylindrical film surface in a region that represents the overall thermal state without being directly influenced by the localized thermal effects of the contact portions. The different contact areas at various locations compensate for thermal losses in a way that maintains uniform temperature across the film, including at the measurement location, thus achieving both measurement accuracy and control precision.