LED Driving Circuit Periodic Control for Color Shift Reduction
Solution Overview
Problem
Active matrix light-emitting diode displays experience color shift due to current regulation, affecting picture quality and luminous efficacy.
Innovation Solution
An electronic device with a driving unit that receives a first data voltage and operates in multiple driving periods within a frame period, storing data voltage in capacitors to generate corresponding currents for LEDs, thereby reducing color shift and increasing luminous efficacy by adjusting current levels and time intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the LED is driven by regulating current to achieve different brightness levels, then the brightness control is improved, but color shift occurs affecting picture quality
Solution Approach 1:
The patent applies periodic action by dividing the frame period into multiple driving periods with different duty cycles. The LED is driven in a periodic manner with alternating high and low brightness periods, where the high brightness period uses a first duty cycle and the low brightness period uses a second duty cycle. This periodic driving approach allows the LED to operate at higher current levels more frequently, reducing color shift while maintaining average brightness control through duty cycle adjustment.
Solution Approach 2:
The patent implements dynamics by making the duty cycle adjustable and variable. The driving unit can dynamically change the duty cycle between different driving periods based on required brightness levels. This dynamic adjustment allows the system to optimize the balance between brightness control and color accuracy by adapting the high brightness period duration according to viewing conditions and content requirements.
2Manufacturing precision
If the current level is increased to reduce color shift, then color accuracy is improved, but power consumption increases
Solution Approach 1:
The patent uses periodic action to reduce power consumption while maintaining color accuracy. By implementing alternating high and low brightness periods with different duty cycles, the LED operates at high current levels only during specific high brightness periods rather than continuously. The average power consumption is controlled by adjusting the proportion of high brightness periods, allowing the system to achieve good color accuracy during critical display periods while reducing overall power consumption through periodic low brightness intervals.
Solution Approach 2:
The patent creates an inert environment in the temporal domain by introducing dark intervals (low brightness periods) between high brightness periods. These dark periods act as a temporal 'inert atmosphere' that allows the LED to rest and reduces cumulative power consumption, while still maintaining color accuracy during the active display periods when human vision is most sensitive to color information.
3Loss of energy
If multiple driving periods are used within a frame period, then luminous efficacy is improved, but device complexity increases
Solution Approach 1:
The patent applies periodic action to improve luminous efficacy by structuring the frame period into multiple driving periods with alternating duty cycles. This periodic structure allows the LED to operate at optimal current levels during high brightness periods, improving luminous efficacy when it matters most for visual perception. The regular periodic pattern simplifies the driving circuit design compared to arbitrary variable duty cycle approaches, as it requires only simple timing control logic to generate the alternating high and low brightness periods.
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
The solution effectively reduces color shift and enhances luminous efficacy by increasing the current levels and adjusting the time intervals of LED operation, improving the overall quality and reducing power loss in the electronic device.
Implementation Method 1
an active matrix light-emitting diode display can drive the light-emitting diode (LED) by regulating the current
Implementation Method 2
storing data voltage in capacitors to generate corresponding currents for LEDs
Data Source
AI summary
An electronic device includes an electronic unit including a light emitting diode (LED) and a driving unit coupled to the light emitting diode for receiving a data voltage. The electronic unit has a plurality of driving periods in a frame period, and the driving unit drives the LED according to the data voltage in the plurality of driving periods.