Heating Roller Temperature Detection via Switchable Sensor Points
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Solution Overview
Problem
Image forming apparatuses, especially electrophotographic devices, face challenges in precisely controlling the temperature of heating rollers when switched from a horizontal to an upright position due to changes in air convection patterns affecting non-contact temperature sensors.
Innovation Solution
The apparatus includes a switchable detection point for temperature sensors, ensuring accurate temperature control by relocating the detection point based on the device's orientation, maintaining precise temperature adjustment regardless of the orientation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the image forming apparatus is used in the upright position to save space, then the installation space requirement is reduced, but the temperature detection accuracy of the heating roller deteriorates due to changed air convection patterns
Solution Approach 1:
The patent applies the dynamics principle by making the temperature sensor's detection point movable rather than fixed. The sensor can switch between a first detection point (optimized for horizontal position) and a second detection point (optimized for upright position) based on the apparatus orientation. This dynamic adjustment ensures accurate temperature detection regardless of whether the apparatus is placed horizontally or uprightly, resolving the contradiction between space-saving upright placement and temperature detection accuracy.
2Object-affected harmful factors
If a non-contact temperature sensor is used to avoid damaging the heating roller surface, then the roller surface is protected, but the temperature control precision deteriorates when the apparatus orientation changes
Solution Approach 1:
The patent maintains the non-contact sensor design to protect the roller surface while improving temperature control precision through dynamic positioning. By switching the detection point between two predetermined locations based on apparatus orientation, the sensor continuously achieves optimal detection conditions without contacting the roller surface, thus maintaining both surface protection and control precision.
Solution Approach 2:
The patent applies parameter changes by adjusting the spatial position parameter of the temperature sensor's detection point. Two different detection points are established, each optimized for specific orientation conditions. The system changes which detection point is active based on whether the apparatus is in horizontal or upright position, ensuring consistent temperature control precision across different orientations while maintaining non-contact operation.
3Manufacturing precision
If the detection point is fixed for horizontal position operation, then the temperature control is optimized for horizontal use, but the temperature detection accuracy deteriorates when switched to upright position
Solution Approach 1:
The patent transforms the fixed detection point system into a dynamic one that can adapt to different orientations. The temperature sensor is configured to switch between a first detection point (optimized for horizontal position) and a second detection point (optimized for upright position). This dynamic capability enables the system to maintain optimal temperature control precision whether the apparatus is used horizontally or uprightly, thereby improving orientation adaptability without sacrificing control optimization.
Solution Approach 2:
The temperature detection system is designed with multi-functionality to handle both horizontal and upright operating modes. By providing two predetermined detection points and switching between them based on orientation, the single detection system serves multiple functions - optimizing temperature detection for both horizontal and upright positions. This universal design resolves the contradiction between optimization for a specific orientation and adaptability to multiple orientations.
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 solution enables stable and precise temperature control of the heating rollers in both horizontal and upright positions, ensuring consistent print quality by adapting to changes in air convection patterns.
Implementation Method 1
a non-contact temperature sensor is generally configured to detect the temperature of the conductive heat due to the natural convection of the air existing between the heating roller and the temperature sensor
Implementation Method 2
a heater that heats the heating roller
Data Source
AI summary
An image forming apparatus orientatable in either a first position or a second position, the second position being different from the first position in inclination with respect to a horizontal plane, comprising: a fixing device including a heating roller and a pressurizing member, pressing the pressurizing member against a surface of the heating roller to form a fixing nip, and thermally fixing a toner image on a recording sheet passing through the fixing nip; at least one temperature detector detecting surface temperature of the heating roller without contact with the surface; a heater heating the heating roller; a controller controlling the heater according to the surface temperature, thereby controlling the surface temperature; and a switcher switching a detection point of the temperature detector between a first and a second detection point according to whether the image forming apparatus is in the first or the second position.