LED Luminance Control Circuit with Parallel Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED luminance control technologies are costly and ineffective for large-scale illumination applications, particularly in liquid crystal displays, as they cannot individually control the luminance of each LED without affecting others and are not suitable for high numbers of LEDs.
Innovation Solution
An LED luminance control circuit with a parallel-connected control circuit comprising an operation amplifier, N-type MosFET switch element, and resistors, allowing independent luminance control of each LED by adjusting a duty-radio-adjustable voltage signal, which is connected in series with the LEDs to provide energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If multiple LEDs are connected in series with a single driving circuit, then the system complexity is reduced, but individual luminance control of each LED becomes impossible
Solution Approach 1:
The patent divides the control function by connecting each LED (or group of LEDs) with its own independent control circuit in parallel, rather than using a single centralized control. This segmentation allows individual luminance adjustment of each LED while keeping the overall system relatively simple.
Solution Approach 2:
The patent introduces a control circuit as an intermediary component between the power source and each LED. This control circuit, containing a switch element and resistors, acts as a mediator that enables independent current control for each LED without requiring complex centralized control logic.
2Ease of operation
If a separate driving circuit is used for each LED to enable individual luminance control, then individual luminance control is achieved, but the cost and device complexity increase significantly
Solution Approach 1:
The patent merges multiple control functions into a single control circuit that can manage one or more LEDs. By allowing one control circuit to control one or several LEDs connected in parallel, the number of control circuits is reduced while still enabling individual luminance control of each LED group.
Solution Approach 2:
The control circuit is designed with universal functionality to control different numbers and configurations of LEDs (single LED, multiple LEDs in parallel, or combinations of series and parallel connections). This multi-functionality reduces the need for different control circuits for different LED configurations.
3Quantity of substance
If conventional luminance control methods are used for large-scale LED illumination, then the system can handle many LEDs, but the cost increases and effectiveness decreases
Solution Approach 1:
The patent applies segmentation by creating modular control units that can be replicated and scaled. Each control circuit is a standalone module that can control one or more LEDs, allowing the system to scale to large numbers of LEDs by simply adding more identical modular units rather than redesigning the entire control system.
Solution Approach 2:
The patent uses copying by replicating the same control circuit design for multiple LED groups. Instead of designing unique control circuits for each LED or complex hierarchical control structures, the same simple control circuit pattern is copied and instantiated multiple times, reducing design complexity and manufacturing cost while enabling large-scale LED control.
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 simple, low-cost, and wide-range luminance control of each LED, solving the issue of high cost and low effectiveness in prior art, and improving luminance uniformity and power efficiency in LED matrices.
Implementation Method 1
a N-type MosFET switch element, wherein output terminal of the operation amplifier is connected to the gate of the switch element; the drain and source of the control circuit are connected to the positive terminal and negative terminal of the one or several LEDs to be controlled, respectively
Implementation Method 2
an operation amplifier, wherein output terminal of the operation amplifier is connected to the gate of the switch element
Implementation Method 3
The luminance of the LED increases as the current passing therethrough increases
Implementation Method 4
the LED as display device plays a more important role, and the driving and control technologies of the LED also become more important
Data Source
AI summary
The present invention discloses a LED luminance control circuit comprising one or several LEDs and a driving circuit, the driving circuit being connected in series with said one or several LEDs to provide energy to the one or several LEDs, wherein a control circuit is connected in parallel on both terminals of said one or several LEDs and controls on/off of the LEDs connected in parallel thereto. Connections between the several LEDs may be in parallel, in series, or combination thereof. The present invention also discloses an LED backlight source of a liquid crystal display using the above LED luminance control circuit. The present invention can implement the luminance control of various power LEDs quickly on basis of simplicity and low cost without influence on the luminance of other LEDs, by individual luminance control for every one or several LEDs, so as to solve some display technical problems when using LEDs as a display device.