Fixing Device Warm-Up Control for Image Formers
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Solution Overview
Problem
Conventional fixing devices in image forming apparatuses face challenges in maintaining the temperature of the fixing roller and press roller at optimal levels during stand-by mode, leading to reduced fixation quality due to their larger thermal capacity compared to the heat roller, resulting in increased power consumption and longer warm-up times.
Innovation Solution
A fixing device with a controller that manages the heat sources of the fixing rotary body and press rotary body to maintain the surface temperature of the fixing belt at a preselected warm-up temperature by rotating the fixing belt continuously after reaching the temperature, even when not in use, and adjusts heat source operation based on temperature sensors to prevent temperature drops during sheet passes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the fixing roller and press roller are provided with surface layers formed of rubber, then the fixation quality is improved, but the thermal capacity increases leading to slower temperature response and longer warm-up time
Solution Approach 1:
The invention divides the heating system into three separate heaters (fixing roller heater, press roller heater, and heat roller heater) that can operate independently. This segmentation allows selective heating of components based on operational needs, enabling the rubber-coated rollers to be heated only when required rather than continuously, thus reducing overall warm-up time while maintaining fixation quality.
Solution Approach 2:
The controller performs preliminary heating of the fixing roller and press roller during standby mode before actual printing operations begin. By anticipating the need for heat and pre-heating the rubber-coated rollers during idle periods, the system ensures they reach optimal temperature without delaying the actual printing process, effectively reducing perceived warm-up time.
2Speed
If the heat roller is provided with a small thermal capacity, then the thermal response speed is improved, but the power consumption increases due to the need for continuous high heat generation
Solution Approach 1:
The heat roller heater operates in periodic cycles rather than continuously. The controller alternates between heating phases and idle phases, allowing the heat roller to reach target temperature quickly during heating phases, then maintain temperature during idle phases. This periodic operation reduces average power consumption while preserving rapid thermal response capability when needed.
Solution Approach 2:
The system recovers and retains heat in the heat roller during idle periods between printing operations. Instead of continuously generating high heat, the heater operates at high intensity briefly to charge the heat roller's thermal energy, then allows it to discharge and maintain temperature naturally. This heat recovery approach reduces power consumption while maintaining fast thermal response.
3Use of energy by moving object
If the amount of heat output from the heaters of fixing roller and press roller is made smaller, then the power consumption is reduced, but the temperature of these rollers is lowered after belt stoppage
Solution Approach 1:
The controller incorporates temperature sensors and feedback control mechanisms that continuously monitor the temperatures of the fixing roller, press roller, and heat roller. Based on real-time temperature data and operational state (printing vs. standby), the controller dynamically adjusts heater output to maintain optimal temperatures while minimizing power consumption. This feedback loop prevents temperature drops after belt stoppage by activating heaters proactively when temperature thresholds are approached.
Solution Approach 2:
The heating system transitions from static, fixed-power heating to dynamic, adaptive heating. The controller modifies heater power output based on real-time conditions including operational mode (printing/standby), current temperatures, and environmental factors. This dynamic adjustment allows the system to maintain roller temperatures during standby with minimal power consumption, then rapidly increase heating during printing operations as needed.
4Stability of the object's composition
If the fixing belt is caused to turn continuously after reaching warm-up temperature, then the temperature uniformity is improved, but the energy consumption increases
Solution Approach 1:
The fixing belt rotation is controlled in periodic cycles rather than continuously. During printing operations, the belt rotates to convey media and distribute heat uniformly. During standby periods, the belt rotates intermittently or remains stationary while the heaters maintain temperature. This periodic rotation maintains temperature uniformity through occasional circulation while dramatically reducing energy consumption compared to continuous operation.
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 reduces warm-up time, maintains the fixing belt temperature, and optimizes power consumption by ensuring consistent fixation quality and efficient heating of the rollers, thereby improving the overall performance of the image forming apparatus.
Implementation Method 1
causing at least one of the first and second heat sources to generate heat
Implementation Method 2
causes the fixing rotary body to rotate
Implementation Method 3
maintain the surface temperature of the fixing belt at a preselected warm-up temperature
Data Source
AI summary
A fixing device, including a fixing rotary body including a first heat source, a pressing rotary body including a second heat source, and a control device configured to cause, at a time of warm-up of the fixing device, the fixing rotary body to rotate while causing at least one of the first heat source and the second heat source to generate heat, and to allow, after a surface temperature of the fixing rotary body has risen to a preselected warm-up temperature, a sheet pass or a printing to be executed and cause, if a sheet pass is not executed, the fixing rotary body to rotate for a preselected period of time.