Solid State Lighting Apparatus Direct AC Operation
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Solution Overview
Problem
Solid state lighting systems face challenges in providing good color rendering and high luminous efficacy while maintaining brightness and efficiency, particularly when operating directly from an AC power source without an AC-DC converter, leading to issues like flicker and thermal management.
Innovation Solution
The development of solid state lighting apparatuses that operate directly from an AC power source using a substrate with non-metallic layers and electrical components, featuring an array of solid state light emitters and a receiver adapted to receive AC power, which reduces physical interference and enhances light extraction, thermal management, and dimming capabilities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If LED chips are used to provide high luminous efficacy and long lifetime, then energy efficiency and durability are improved, but color rendering quality and dimmable color behavior deteriorate compared to incandescent lighting
Solution Approach 1:
The patent divides the LED lighting system into multiple independently controllable groups or strings of LED chips. Each group can be selectively activated or dimmed to achieve different color temperatures and rendering qualities. This segmentation allows the system to switch between efficiency-oriented configurations (using cooler temperature LEDs) and quality-oriented configurations (using warmer temperature LEDs with better color rendering), thereby resolving the contradiction between luminous efficacy and color rendering quality.
2Device complexity
If LED chips operate directly from AC power source without AC-DC converter, then cost and device complexity are reduced, but flicker and thermal management problems worsen
Solution Approach 1:
The patent implements periodic switching control of LED groups synchronized with the AC power cycle. By selectively turning on and off different LED strings in a periodic manner synchronized with the AC waveform, the system eliminates perceptible flicker while maintaining direct AC operation. This periodic action allows the LEDs to be driven directly from AC power without complex conversion circuits while still achieving stable, flicker-free illumination.
3Device complexity
If LED chips operate directly from AC power source without AC-DC converter, then cost is reduced, but thermal management difficulty increases due to heat generation
Solution Approach 1:
The patent extracts the electrical conversion function from the thermal management system by using LED chips with higher forward voltage ratings that can operate directly from AC power. This extraction eliminates the need for AC-DC converters that would generate additional heat, thereby simplifying the overall system and reducing the thermal management burden while maintaining direct AC operation capability.
4Adaptability or versatility
If multiple groups of LED chips are powered on during different AC waveform half-cycles, then direct AC operation is achieved, but perceptible flicker increases
Solution Approach 1:
The patent employs dynamic control strategies where the activation and dimming of LED groups are continuously adjusted based on the AC waveform characteristics and human visual perception thresholds. The system dynamically modifies the duty cycle and timing of LED group activation to minimize flicker perception while maintaining direct AC operation, thereby resolving the contradiction between adaptability and flicker 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
The solution achieves improved brightness, thermal management, and reduced cost, enabling LED systems to approximate incandescent lighting behavior with reduced flicker and increased efficiency, making them more viable for consumer and commercial applications.
Implementation Method 1
Solid state emitters generate light through the recombination of electronic carriers (electrons and holes) in a light emitting layer or region of an LED chip
Implementation Method 2
thermal management, including efficiently dissipating heat generated by LED chips without overheating individual chips
Data Source
AI summary
Solid state lighting apparatuses and related methods are described. In some aspects, a solid state lighting apparatus includes a substrate. The substrate includes a non-metallic body having a first surface and one or more electrical components supported on the first surface of the substrate. At least one electrical component is spaced from the non-metallic body by one or more non-metallic layers. The apparatus can also include an array of solid state light emitters supported by the first surface of the substrate and electrically coupled to the one or more electrical components thereof. The apparatus can further include a receiver supported by the first surface of the substrate, wherein the receiver is adapted to receive alternating current (AC) directly from an AC power source. Related systems and methods are also disclosed.