LED Backlight Circuit Shunt Tap Edge Color Uniformity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
LCD displays with LED backlights face issues of color uniformity along the edges due to uneven distribution of red, green, and blue LEDs, leading to undesirable picture quality.
Innovation Solution
An electrical circuit design that divides LEDs into center and edge groups with a shunt tap at the electrical node to divert current away from edge LEDs, attenuating their light emission and achieving uniform color distribution across the display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If high brightness color LEDs are arranged in a pattern behind the LCD glass to achieve best color presentation, then color reproduction is improved, but color uniformity along the edges deteriorates
Solution Approach 1:
The patent applies local quality by creating different electrical circuit configurations for different regions of the LED array. Center LEDs are connected in series to provide high brightness for color presentation, while edge LEDs are connected through shunt taps that divert excess current, reducing their brightness. This local differentiation resolves the contradiction by allowing high brightness in the center region while maintaining color uniformity at the edges.
2Area of stationary object
If LEDs are arranged to cover the entire surface area of the LCD glass, then luminance coverage is improved, but edge color uniformity deteriorates due to excessive light emission from edge positioned LEDs
Solution Approach 1:
The patent changes the electrical parameter (current flow) for different LED positions. By introducing shunt taps at specific nodes in the series circuit, the current flowing through edge LEDs is reduced compared to center LEDs. This parameter change allows the entire surface area to be covered while maintaining color uniformity by adjusting the brightness parameter locally at the edges.
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 improves picture quality by reducing excessive color emission at the edges, ensuring consistent color presentation across the entire LCD surface.
Implementation Method 1
At the electrical node between the center and edge LEDs a shunt tap is adapted to divert a portion of the total current away from the edge LEDs
Implementation Method 2
The use of LEDs (Light Emitting Diodes) is also known for the purpose of illuminating such LCD displays
Implementation Method 3
LEDs are eco-oriented and have a response time of several nanoseconds, thereby being effective for a video signal stream
Data Source
AI summary
An improved electrical circuit design and method to drive a plurality of LEDs in an LCD backlight in order to produce a uniform color distribution across the entire viewable surface of the display. The embodiments disclosed have features that permit a predetermined reduction in the amount of current provided to the LEDs positioned along the edge of the display region. This results in color uniformity, and consequently, an improved picture quality.