LED Driver Chain Configuration for Local Dimming Signal Integrity
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Solution Overview
Problem
Existing LED driving technologies face challenges in efficiently controlling local dimming zones in display devices, particularly in achieving high contrast ratios and rapid response to content changes due to issues with signal distortion and parasitic components in the signal path.
Innovation Solution
The proposed solution involves an LED driver with a controller that identifies unique identifiers from input signals to generate control signals for LED driving currents, and a repeater that amplifies signals to reduce noise and latency, allowing for efficient local dimming control. The LED driver is connected in a chain configuration to minimize signal path length and eliminate parasitic component effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LED drivers are connected in a chain configuration to minimize signal path length, then signal distortion and parasitic component effects are reduced, but device complexity increases
Solution Approach 1:
The system divides the LED backlight control into multiple independent LED driver modules connected in a chain. Each module handles a specific local dimming zone, segmenting the overall control function. This segmentation allows each driver to process signals with shorter path lengths, reducing signal distortion and parasitic effects while maintaining manageable device complexity through modular architecture.
Solution Approach 2:
The patent introduces a hierarchical control structure where LED drivers are arranged in a chain configuration along one dimension (signal transmission path), while simultaneously organizing them into rows and columns (spatial dimension). This multi-dimensional arrangement optimizes signal path length in the transmission dimension while using the spatial dimensions for systematic addressing and control, resolving the contradiction between signal quality and device complexity.
2Reliability
If repeater is used to amplify signals, then noise and latency are reduced, but device complexity increases
Solution Approach 1:
The repeater functions as an intermediary component between the controller and LED drivers, amplifying and regenerating signals to compensate for transmission losses. This intermediary element improves signal integrity and reduces latency without requiring complex processing at each LED driver, thereby managing device complexity through functional specialization.
Solution Approach 2:
The repeater automatically detects signal degradation and performs amplification without external intervention, providing self-service signal conditioning. This automated function reduces noise and latency while maintaining simple control architecture, as the repeater operates autonomously based on signal characteristics.
3Illumination intensity
If local dimming zones are increased to achieve fine contrast ratio, then display performance is improved, but control overhead and latency increase
Solution Approach 1:
The backlight is divided into multiple local dimming zones, each controlled by a dedicated LED driver module in the chain. This segmentation enables independent control of each zone, allowing fine contrast ratios through precise local brightness adjustment while reducing control latency compared to centralized control of all zones.
Solution Approach 2:
The chain-configured LED drivers are pre-addressed and configured during system initialization, with each driver storing its assigned zone information and control parameters. This preliminary configuration reduces control overhead during operation, as the controller can directly send commands to specific drivers without complex address resolution, thereby reducing latency while maintaining fine contrast capability.
Data Source
AI summary
A light-emitting diode (LED) driver configured to generate an LED driving current based on an input signal may include a terminal exposed to outside, a controller configured to identify a first identifier and data from the input signal, identify a second identifier based on a signal applied to the terminal, and when the first identifier and the second identifier are identical to each other, generate a control signal based on the data. The LED driver further may further include a current source configured to generate the LED driving current based on the control signal.