Fixing Device Heater Temperature Sensor Placement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional image forming apparatuses face challenges in accurately detecting fixing temperatures, especially when dealing with sheets of varying sizes, due to the temperature sensor's limited ability to accurately measure temperatures at the ends of the heater, which are affected by the central low-temperature areas.
Innovation Solution
The implementation of a fixing device with a heater, an endless belt, a holder, and two heat conductive members arranged in the longitudinal direction, where the temperature sensor is in contact with one of the heat conductive members, positioned closer to the end areas than the central position of the resistance heating element, allowing for more accurate temperature detection at the ends of the heater.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a single heat conductive member is used to support the heater across the maximum sheet width, then the heater can be supported over the full width, but the temperature sensor cannot accurately detect the temperature at the end part of the heater when minimum width sheets are processed
Solution Approach 1:
The heat conductive member is divided into multiple segments (first heat conductive member, second heat conductive member, third heat conductive member) arranged in the longitudinal direction of the heater. This segmentation allows the temperature sensor to be positioned on a specific segment (the first heat conductive member) that is closer to the end part of the heater, enabling accurate temperature detection at the heater end while maintaining full width coverage through the combined segments.
Solution Approach 2:
The first heat conductive member acts as an intermediary between the heater and the temperature sensor. By positioning this intermediate heat conductive member closer to the heater end, it mediates the temperature transmission to the sensor, allowing the sensor to accurately detect the temperature at the heater end part without being directly attached to the heater itself.
2Measurement precision
If the temperature sensor is positioned at the end part of the heater to detect end temperature, then accurate end temperature detection is possible, but the sensor is affected by low-temperature areas in the central part of the heater
Solution Approach 1:
Different segments of the heat conductive member are positioned at different locations relative to the heater. The first heat conductive member is specifically positioned closer to the end part of the heater where higher temperatures occur, giving it the local quality of being the optimal detection point. This local positioning ensures the temperature sensor detects the actual end temperature without being influenced by the cooler central areas.
Solution Approach 2:
The solution transitions from a single-point temperature detection approach to a multi-segmented heat conductive member arrangement in the longitudinal direction. By distributing heat conductive members along the longitudinal dimension, the system can selectively position the temperature sensor on the segment closest to the heater end, achieving accurate end temperature detection while isolating it from central area temperature influences.
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
This configuration enables high-accuracy detection of fixing temperatures regardless of sheet sizes, improving the precision of temperature measurement at the ends of the heater, which tend to have higher temperatures than the central area.
Implementation Method 1
a heater having a resistance heating element
Implementation Method 2
the first heat conductive member and the second heat conductive member being configured to conduct heat in the longitudinal direction of the heater
Data Source
AI summary
A fixing device includes a heater including a substrate and a resistance heating element, an endless belt, a holder, a first heat conductive member and a second heat conductive member arranged in a longitudinal direction of the heater such that a first end of the first heat conductive member and a second of the second heat conductive member in the longitudinal direction of the heater are adjacent to each other, a temperature sensor configured to detect a temperature at an end part of the heater. The temperature sensor is in contact with the first heat conductive member. A position located between first end of the first heat conductive member and the second end of the second heat conductive member is closer to the temperature sensor than a central position of the resistance heating element in the longitudinal direction of the heater.