LED Array Driving Apparatus with Variable Resistance Current Control
Solution Overview
Problem
Existing LCD devices require an external PWM signal to adjust the luminance of the LED array, limiting manufacturers' ability to develop electronic products and necessitating separate circuits for synchronization with the frame rate, which complicates manufacturing and increases power consumption.
Innovation Solution
An LED array driving apparatus that includes a current amount setter and a controller, allowing the adjustment of current levels based on input voltage and resistance, eliminating the need for a PWM signal by varying the resistance value in response to a selection signal from an external system to control the luminance of the LED array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If an external PWM signal is used to adjust LED array luminance, then luminance control is achieved, but device complexity increases due to the need for additional synchronization circuits
Solution Approach 1:
The patent extracts the luminance control function from the external PWM signal requirement and relocates it to an internal current amount setter circuit. This eliminates the need for external synchronization circuits while maintaining luminance adjustment capability through resistance value changes in the internal circuit.
Solution Approach 2:
The controller is designed to perform multiple functions: driving the LED array, controlling luminance through the current amount setter, and managing power consumption. This multi-functionality eliminates the need for separate external circuits, reducing overall device complexity.
2Illumination intensity
If an external PWM signal is required for luminance adjustment, then luminance control is possible, but ease of manufacture decreases due to manufacturing complexity
Solution Approach 1:
The patent merges the luminance control function into the LED array driving apparatus itself through the current amount setter. This consolidation eliminates the need for separate external PWM signal generation and synchronization circuits, simplifying the manufacturing process and reducing assembly complexity.
3Illumination intensity
If PWM signal processing is implemented, then luminance adjustment capability is achieved, but power consumption increases
Solution Approach 1:
The patent replaces the electronic PWM signal processing mechanism with a resistance-based current control mechanism. The current amount setter uses resistance value changes to directly control the current amount supplied to the LED array, eliminating the need for continuous PWM signal generation and processing, thereby reducing power consumption.
4Adaptability or versatility
If the current amount setter varies resistance value in response to selection signals, then luminance adjustment flexibility is improved, but device complexity increases
Solution Approach 1:
The current amount setter is designed to automatically vary its resistance value in response to selection signals from the external system without requiring complex internal control logic. This self-service approach provides luminance adjustment flexibility while keeping the control circuit simple and easy to manufacture.
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
Enables independent adjustment of LED array luminance without external PWM signals, reducing power consumption and simplifying manufacturing by eliminating the need for additional synchronization circuits, thereby improving the flexibility and efficiency of LCD device operation.
Implementation Method 1
An amount of light emitted from an LED is proportional to a level of a driving current passing through an active layer of the LED
Data Source
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AI summary
Disclosed are an apparatus for driving a light emitting diode (LED) array and an LCD device using the same. The apparatus for driving the LED array includes a current amount setter configured to have a resistance value which varies according to a selection signal inputted from an external system, and a controller configured to generate a driving voltage and a driving current by using an input voltage inputted from the external system and the resistance value set by the current amount setter, and supply the driving voltage and the driving current to the LED array.