LED Array Control Module Pin Reduction via Multiplexing
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Solution Overview
Problem
Existing LED driver circuits for LCD displays using the field sequential color (FSC) driving method require a large number of pins for interfacing with the LED backlight unit, which is inefficient and not optimized for individual LED control, especially in smaller displays.
Innovation Solution
A compact integrated circuit module with a limited number of pins is developed, featuring transistor switches and LED drivers that allow for precise control of drive currents to individual LEDs, enabling optimized drive characteristics for Red, Green, and Blue LEDs, with feedback mechanisms for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional LED driver circuit with separate circuit module is used, then individual LED control capability is provided, but the number of pins required for interfacing increases
Solution Approach 1:
The patent combines the LED driver circuit and control logic into an integrated circuit package that directly interfaces with the LED array, eliminating the need for a separate circuit module. This integration reduces the total number of pins required while maintaining individual LED control capability through shared control lines and multiplexed signaling.
Solution Approach 2:
The integrated circuit implements multi-functional control where a limited set of pins can address and control multiple individual LEDs through time-multiplexed or space-multiplexed schemes. The circuit can selectively activate different LEDs using the same control lines at different time intervals or through different signal patterns, providing universal control capability with reduced pin count.
2Device complexity
If the circuit module is integrated into a compact package, then the number of pins is reduced, but the drive precision to individual LEDs may be compromised
Solution Approach 1:
The integrated circuit incorporates feedback mechanisms where the drive current to each LED is monitored and adjusted based on detected parameters. The circuit can sense the actual current flowing through each LED and make real-time adjustments to maintain precise drive levels, compensating for variations in LED characteristics and ensuring accurate control despite the compact integration.
Solution Approach 2:
The circuit dynamically adjusts drive parameters such as current magnitude, pulse width, or frequency based on detected LED characteristics and operating conditions. By changing these parameters in real-time, the integrated circuit maintains precise control over individual LEDs while operating within the constraints of a compact pin configuration.
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 allows for efficient and optimized control of LEDs in LCD displays, reducing the number of pins required and improving drive precision, thereby enhancing the display's brightness and power consumption while maintaining a reduced thickness, suitable for both large and small displays.
Implementation Method 1
The control module includes a plurality of transistor switches having a control terminal, a first terminal and a second terminal
Implementation Method 2
The array includes a first row of Red LEDs, a second row of Green LEDs and a third row of Blue LEDs
Implementation Method 3
LEDs that provides improved power consumption, brightness and weight
Data Source
AI summary
A control module for driving an LED array, with the array including N number of LED current drivers connected to N number of electrical terminals of the module, and Y number of transistor switches connected between Y number of electrical terminals of the module and a common voltage point. N and Y are each at least three. An N number of column conductors and a Y number of row conductors are to be connected to the respective N and Y number of electrical terminals. At least one of the N×Y number of LEDs is connected between each pair of the column and row conductors. The control module further includes a controller for controlling the states of the N number of LED current drivers and the Y number of transistor switches so that, during a given LED drive period, all of the LED current drivers are activated and only one of the transistor switches is turned ON to provided a selected row conductor in which case only those LEDs connected to a selected row conductor are activated.