LED PWM Dimming with Lower Peak Current and Reduced Flicker
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Solution Overview
Problem
PWM dimming in LED backlighting causes flicker effects and reduces luminous efficiency due to fixed peak current, which does not fully utilize the light-emitting characteristics of LEDs.
Innovation Solution
An LED dimming method that decomposes original PWM count data to generate a target PWM drive signal with reduced peak current and increased duty ratio, maintaining LED brightness by adjusting the PWM signal parameters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If PWM dimming is used to achieve good display effects and energy saving, then electrical performance and dimming range are improved, but flicker effect is generated which is harmful to human eyes
Solution Approach 1:
The patent changes the PWM parameters by reducing the peak current data from z-bit to x-bit (where x < z) and adjusting the PWM cycle data, thereby modifying the duty ratio and peak current characteristics to reduce flicker while maintaining dimming range
Solution Approach 2:
The patent dynamically adjusts the PWM signal parameters based on the original PWM count data, creating a target PWM drive signal with optimized peak current and duty ratio that adapts to different lighting conditions to minimize flicker effect
2Ease of manufacture
If fixed peak current is used in PWM dimming, then implementation is simple, but luminous efficiency is reduced because LED light-emitting characteristics are not fully utilized
Solution Approach 1:
The patent changes the peak current parameter from a fixed value to a variable value derived from the original PWM count data, optimizing the peak current to match LED light-emitting characteristics and improve luminous efficiency while maintaining simple implementation through automated parameter transformation
3Illumination intensity
If original PWM drive signal is used, then LED brightness is maintained, but flicker depth is high and luminous efficiency is low
Solution Approach 1:
The patent transforms the original PWM drive signal parameters (peak current data, PWM cycle data) into optimized target parameters that maintain the same brightness level while reducing flicker depth through improved duty ratio and peak current characteristics
Data Source
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AI summary
The present disclosure provides an LED dimming method and display device. The method includes: acquiring original PWM count data including z-bit data from an original PWM drive signal; obtaining target peak current data, target PWM count data, and target PWM cycle data based on the original PWM count data, wherein the target peak current data are smaller than original peak current data of the original PWM drive signal and include x-bit data, the target PWM count data include y-bit data, the target PWM cycle data include y-bit data, (x, y, z are positive integers greater than 1, with x and y both smaller than z); and generating a target PWM drive signal based on the target peak current data, target PWM count data, and target PWM cycle data, wherein a duty ratio of the target PWM drive signal is greater than that of the original PWM drive signal.