Fixing Heater AC Voltage Control for Rapid FCOT
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image forming apparatuses face challenges in accurately controlling the power supply to the fixing unit, leading to deviations in the timing of triac activation, which results in errors in electric power delivery and limits rapid temperature control, thereby affecting the First Copy Output Time (FCOT).
Innovation Solution
An image forming apparatus that includes a zero-cross detection unit, voltage detection unit, current detection unit, and a processor to determine and correct the conduction ratio of the switching element, ensuring accurate power supply to the fixing heater by adjusting the timing of triac activation based on detected voltage, current, and resistance values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If phase control is used to supply power to the fixing unit, then power can be controlled to manage rated power and current limits, but the timing accuracy of triac activation deviates from ideal timing due to insufficient zero-cross detection accuracy, causing errors in electric power supply
Solution Approach 1:
The system measures the actual zero-cross timing of the AC voltage and uses this measurement feedback to correct the triac activation timing. By detecting the actual zero-cross point and adjusting the timing accordingly, the system compensates for detection errors and achieves accurate power supply control within rated limits.
Solution Approach 2:
The system performs preliminary detection of the AC voltage zero-cross timing before activating the triac. This preliminary action allows the system to determine the correct activation timing in advance, ensuring that the triac turns on at the ideal moment for accurate power control.
2Productivity
If maximum power is supplied to the fixing unit to achieve rapid temperature control, then the First Copy Output Time (FCOT) is shortened, but the limited available power restricts the ability to consistently deliver rated power
Solution Approach 1:
The system uses periodic AC voltage cycles and controls power delivery through phase-angle control within each cycle. By optimizing the conduction angle and timing within each AC period, the system maximizes power transfer efficiency to the fixing unit, enabling rapid heating while operating within available power constraints.
Solution Approach 2:
The system dynamically adjusts the triac conduction ratio and activation timing based on detected voltage and current conditions. By changing these parameters in real-time, the system optimizes power delivery to achieve maximum heating rate within the available power limits, thereby shortening FCOT.
3Manufacturing precision
If the triac activation timing deviates from ideal timing, then the conduction ratio differs from the predetermined value, but correcting the timing requires accurate detection and control mechanisms
Solution Approach 1:
The system uses a multi-functional control mechanism that performs multiple tasks: detecting zero-cross timing, measuring voltage and current, calculating the correct conduction ratio, and controlling triac activation. This universal approach consolidates multiple functions into a single control system, achieving high conduction ratio accuracy without proportionally increasing overall system complexity.
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 precise control of the fixing unit's temperature, ensuring optimal power delivery and reducing the difference between actual and predetermined conduction ratios, thereby shortening the FCOT by efficiently supplying the maximum allowable power to the fixing heater.
Implementation Method 1
a fixing heater, the fixing heater being configured to generate heat with electric power supplied from a commercial power source
Data Source
AI summary
An image forming apparatus includes an image forming unit configured to form an image; a transferring unit configured to transfer the image formed by the image forming unit on a recording material; a fixing unit having a fixing heater, the fixing heater being configured to generate heat with electric power supplied from a commercial power source, and the fixing unit being configured to fix the image on the recording material by heating the recording material on which the image is transferred with the heat generated by the fixing heater; a memory configured to store resistance information representing a resistance value of the fixing heater; a zero-cross detection unit configured to detect a zero-cross timing of an AC voltage supplied from the commercial power source, and a voltage detection unit configured to detect a voltage value of AC voltage.