RGB Backlight Dimming Blocks With Matched LED Block Voltages
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Solution Overview
Problem
In LED-based backlight units, the block voltages for Red/Green/Blue LEDs differ when driven using a common voltage, leading to inefficiencies in current distribution and reduced driving efficiency.
Innovation Solution
The number of LEDs is varied by color, with specific ratios of Red, Green, and Blue LEDs connected in series, and separate current supply lines are used to distribute current efficiently, allowing similar block voltages for each color.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a common voltage is used to drive Red/Green/Blue LEDs, then the circuit design is simplified, but the block voltages for each color LED become different, leading to inefficient current distribution
Solution Approach 1:
The patent divides the common voltage supply into separate current supply lines for each LED color (Red, Green, Blue). This segmentation allows independent current control for each color group while maintaining a relatively simple overall circuit structure, resolving the contradiction between circuit simplicity and driving efficiency.
Solution Approach 2:
The patent applies different current distribution strategies to different LED colors based on their specific characteristics. By providing dedicated current supply lines for each color, the system optimizes current distribution locally for each LED type, improving overall driving efficiency without significantly increasing circuit complexity.
2Illumination intensity
If the number of LEDs is increased to improve light output, then the total current requirement increases, but this leads to higher current per LED cell and reduced driving efficiency
Solution Approach 1:
The patent segments the LEDs into different color groups (Red, Green, Blue) with dedicated current supply lines. This allows the total current to be distributed more efficiently across different color groups rather than forcing all LEDs to share a common voltage, enabling higher light output while maintaining optimal current levels for each LED type.
Solution Approach 2:
The patent changes the electrical parameters (current supply) for different LED colors to match their specific requirements. By adjusting the current distribution according to each color's characteristics, the system can support a higher total number of LEDs with improved driving efficiency.
3Productivity
If separate current supply lines are used for each LED color, then current distribution is optimized, but the device complexity increases
Solution Approach 1:
The patent implements segmentation by creating separate current supply lines for Red, Green, and Blue LEDs. This segmentation achieves optimized current distribution for each color while maintaining a modular and organized circuit structure that does not excessively increase overall 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 configuration enhances driving efficiency by ensuring similar block voltages for each color LED, improving current distribution and overall performance.
Implementation Method 1
The light emitting device includes, for example, a light emitting diode (LED) or an organic light emitting diode (OLED)
Data Source
AI summary
There is provided a display apparatus including a liquid crystal panel and a backlight unit configured to provide light to the liquid crystal panel, and the backlight unit may include a substrate; and a plurality of dimming blocks arranged in a plurality of rows and a plurality of columns on the substrate, each including a red light emitting diode (LED), a green LED, and a blue LED, and each of the red LED, the green LED, and the blue LED included in each of the plurality of dimming blocks may be divided into different numbers of LED cells, and the divided LED cells may be connected in series.