Discharging Electrode Heating for Corona Charging Stability
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Solution Overview
Problem
Existing fixing devices face issues with electrostatic offset and non-uniform discharge due to impurities adhering to the discharging electrode, leading to destabilization of the discharge state and potential image forming failures.
Innovation Solution
A fixing device with a controller that supplies heat to the discharging electrode to a temperature higher than the heating temperature during a cleaning mode, using a corona charging device with a discharging electrode and auxiliary electrode to form an electric field opposite to the fixing operation, and rotating the heating belt to remove impurities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the discharging electrode is used continuously to charge the first rotating body, then electrostatic offset is prevented, but impurities adhere to the discharging electrode causing non-uniform discharge and destabilization of discharge state
Solution Approach 1:
The patent applies preliminary action by heating the discharging electrode to a temperature higher than the heating temperature during a cleaning mode operation performed during non-fixing periods. This preliminary cleaning action removes impurities before they can cause non-uniform discharge and destabilization, ensuring the electrode is ready for reliable operation in subsequent fixing operations.
Solution Approach 2:
The patent implements periodic action by alternating between fixing operations and cleaning mode operations. During non-fixing periods, the discharging electrode is heated to a higher temperature to remove impurities, then returned to normal operating temperature for charging operations. This periodic cleaning cycle prevents cumulative impurity buildup that would otherwise cause discharge instability.
2Reliability
If the heating temperature is increased to remove impurities from the discharging electrode, then discharge uniformity is improved, but energy consumption increases
Solution Approach 1:
The patent uses periodic action to balance energy consumption and discharge uniformity. Instead of continuously heating the discharging electrode to high temperatures, the system performs cleaning mode operations only during non-fixing periods, then returns to normal operating temperature for fixing operations. This periodic high-temperature treatment achieves impurity removal while minimizing overall energy consumption.
Solution Approach 2:
The patent applies preliminary action by performing impurity removal during non-fixing periods before the next fixing operation begins. The discharging electrode is heated to a higher temperature in advance during cleaning mode to remove impurities, ensuring uniform discharge is maintained during subsequent fixing operations without requiring continuous high energy input.
3Reliability
If a cleaning operation is added to remove impurities from the discharging electrode, then discharge state stability is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by making the heating mechanism serve dual functions: heating the discharging electrode to normal operating temperature for fixing operations and heating to higher temperatures for cleaning mode operations. The same heating structure and control system handle both fixing and cleaning functions, avoiding the need for separate cleaning mechanisms and reducing overall device complexity.
Solution Approach 2:
The patent merges the cleaning function with the existing heating mechanism. The heating mechanism that normally maintains the discharging electrode at operating temperature is also used to perform cleaning by temporarily raising the temperature higher than the heating temperature during non-fixing periods. This consolidation eliminates the need for a separate cleaning system and simplifies device structure.
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
Stabilizes the discharge state, prevents electrostatic offset, and maintains long-term uniformity of discharge, reducing the risk of image forming failures and achieving miniaturization and lower manufacturing costs.
Implementation Method 1
The first rotating body is formed in a cylindrical shape and heats media on which toner images are formed at a heating temperature while rotating
Implementation Method 2
The charging part is positioned opposite to the first rotating body, charges the first rotating body, includes a discharging electrode and an auxiliary electrode to form an electric field in cooperation with the discharging electrode
Implementation Method 3
causes the discharging electrode to discharge in a state where the electric field is formed, and charges the first rotating body with a same polarity as polarity of toner
Implementation Method 4
The second heat supplying part supplies the discharging electrode with heat that enables a temperature of the discharging electrode to be higher than the heating temperature
Data Source
AI summary
A first rotating body heats media on which a toner image is formed at a heating temperature. A second rotating body sandwiches the media in cooperation with the first rotating body and presses the media. A first heat supplying part supplies the first rotating body with heat. A charging part charges the first rotating body, includes a discharging electrode and an auxiliary electrode to form an electric field in cooperation with the discharging electrode, causes the discharging electrode to discharge, and charges the first rotating body with a same polarity as polarity of toner. A second heat supplying part supplies the discharging electrode with heat. A controller controls the second heat supplying part in a period in a non-fixing operation and executes heat supplying mode.