Lighting Device Code Modulation for Dimming Compatibility
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Solution Overview
Problem
Existing visible light communication systems for LED lighting struggle to work independently with different dimming levels and methods, requiring prior knowledge of the dimming mode and method used, which is cumbersome and often impossible, especially when a single lighting device needs to employ multiple dimming modes for increased efficiency.
Innovation Solution
A lighting device and receiver system that employs compatible amplitude modulation, allowing data extraction without prior knowledge of the dimming mode or level, by modulating the integrated light output power over a time period, enabling seamless data extraction using an integrate-and-dump process, and switching between amplitude modulation and pulse-width modulation based on the requested light output level.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed data modulation approach is used for a specific dimming mode, then data communication is simple and reliable, but the receiver cannot work independently with different dimming levels and methods
Solution Approach 1:
The patent applies universality by designing a receiver that can universally detect and decode data signals across multiple dimming modes (AM-D, PWM-D, PDM-D) without requiring prior knowledge of the specific mode. The receiver incorporates multiple detection paths that can identify and process data embedded in different modulation schemes, making it adaptable to various lighting device configurations while maintaining reliable data communication.
Solution Approach 2:
The patent applies dynamics by implementing an automatic dimming mode detection mechanism in the receiver. The receiver dynamically adjusts its detection strategy based on the actual dimming mode detected from the incoming light signal. This dynamic adaptation allows the receiver to switch between different decoding approaches (amplitude-based, pulse-width-based, or pulse-density-based) depending on the lighting device's operational mode, thereby achieving both reliability and versatility.
2Productivity
If a lighting device employs multiple dimming modes for increased efficiency, then lighting flexibility and energy efficiency improve, but the receiver requires prior knowledge of the dimming method which is cumbersome and often impossible
Solution Approach 1:
The patent applies self-service by enabling the receiver to automatically identify and adapt to the dimming mode used by the lighting device without external configuration or prior knowledge. The receiver autonomously analyzes the incoming light signal characteristics to determine whether AM-D, PWM-D, or PDM-D is being used and accordingly selects the appropriate decoding method. This self-service capability eliminates the need for complex manual setup while supporting multiple dimming modes for improved lighting efficiency.
3Ease of manufacture
If data modulation is customized for each dimming method, then implementation cost is low and lamp efficiency is maximized, but compatibility across different dimming modes is lost
Solution Approach 1:
The patent applies universality by designing a receiver that can universally detect and decode data signals across multiple dimming modes (AM-D, PWM-D, PDM-D) without requiring prior knowledge of the specific mode. The receiver incorporates multiple detection paths that can identify and process data embedded in different modulation schemes, making it adaptable to various lighting device configurations while maintaining reliable data communication.
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 data extraction from lighting devices using multiple dimming modes without prior knowledge of the dimming method, ensuring high power efficiency and accurate dimming, while maintaining compatibility with human perception of light levels.
Implementation Method 1
a light source (101), here being a light emitting diode, LED
Data Source
Figure 1~2b
Figure 3a~4b
Figure 5~6
AI summary
There is provided a method and corresponding lighting device (100), and a receiver, which employs code modulation which provides a compatibility of code modulation in a dimmable lighting system. The lighting device comprises means for dimming the output light (102), which employs multiple dimming modes, each representing dimming the light output from lighting device by means of a respective dimming method, and means for embedding a code in the light output (103). The means for embedding a code in the light output employs code modulation which is based on controlling the instantaneous dimmed light output from the lighting device such that the integrated value of the dimmed light output during a time period T is modulated to embed the code. The code may then subsequently be extracted from the modulated light by means of an integrate-and-dump process at a receiver, without knowledge of the dimming method and/or dimming level of the lighting device.