Fixing Unit Heater Duty Control for Faster TCR Warm-Up
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Solution Overview
Problem
The use of TCR materials in on-demand heating devices leads to longer startup times due to the decrease in power consumption as temperature rises, which affects the efficiency of the heating process.
Innovation Solution
A controller varies the duty ratio of electric power applied to the first heater element during startup to achieve the target operating temperature using a TCR material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If TCR material is used in the heater, then power consumption is reduced and temperature rise of non-sheet-passing portion is reduced, but the time required for starting heating becomes longer
Solution Approach 1:
The patent applies dynamics by making the power supply mode changeable between constant power supply mode and variable power supply mode. The controller dynamically switches between these modes based on operational requirements, allowing the system to optimize between power consumption and startup time. In variable power supply mode, the power consumption is adjusted over time to achieve faster heating when needed.
Solution Approach 2:
The patent changes the power supply parameter from constant to variable to resolve the contradiction. By implementing variable power supply mode where power consumption varies over time during startup, the system can overcome the slow heating characteristic of TCR materials while still maintaining lower overall power consumption compared to traditional heaters.
2Loss of time
If constant power supply mode is used, then startup time is reduced, but power consumption increases
Solution Approach 1:
The system uses dynamics by implementing variable power supply mode that changes power consumption over time during startup. This allows the heater to initially consume higher power for rapid heating, then gradually reduce power consumption as the target temperature is approached, resolving the trade-off between startup speed and energy efficiency.
Solution Approach 2:
The patent applies periodic action through the variable power supply mode where power is supplied in a time-varying manner during startup. The power consumption follows a periodic pattern that provides higher initial power for rapid heating followed by reduced power as temperature increases, achieving both fast startup and controlled power consumption.
3Stability of the object's composition
If TCR material is used, then temperature distribution uniformity is improved, but heating speed decreases
Solution Approach 1:
The patent resolves this contradiction by implementing variable power supply mode that dynamically adjusts power consumption during startup. This allows the system to initially provide higher power for faster heating speed, then gradually reduce power to maintain the temperature uniformity advantage of TCR materials as the target temperature is approached.
Solution Approach 2:
The patent changes the power supply parameter from constant to variable to simultaneously achieve fast heating and uniform temperature distribution. By varying power consumption over time during startup, the system overcomes the slow heating characteristic of TCR materials while preserving their inherent advantage of uniform temperature distribution.
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 approach reduces the time required for the heating device to start up while maintaining power consumption control.
Implementation Method 1
a first heater element that is formed of a material (a "TCR" material) that increases in electrical resistance with increases in temperature
Implementation Method 2
A controller of the fixing unit is configured to vary a duty ratio of electric power applied to the first heater element during a start-up operation in which the temperature of the first heater element is raised to a target operating temperature
Data Source
AI summary
A fixing unit or device that can be used in an image forming apparatus includes a first heater element that is formed of a material that increases in electrical resistance with increases in temperature. A controller of the fixing unit is configured to vary a duty ratio of electric power applied to the first heater element during a start-up operation in which the temperature of the first heater element is raised to a target operating temperature. By varying the duty ratio during the start-up operation, changes in the resistance of the first heater element with the heating can be compensated. For example, the duty ratio can be increased during the course of the start-up to achieve the target operating temperature faster.