Configurable Shunt Solid State Lighting for Color Rendering
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Solution Overview
Problem
Solid state lighting panels with phosphor-based white LED sources often have a low color rendering index, resulting in unnatural color representation due to limited spectral energy, particularly in the red portion of the visible spectrum, which is undesirable for large-scale backlight and illumination applications.
Innovation Solution
A solid state lighting apparatus featuring a circuit with a configurable shunt that allows for the bypassing of light emitting devices, enabling the adjustment of the color point by varying the number of active LEDs in series-connected strings, including white and red LEDs, to achieve a warm white light with a high color rendering index.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phosphor-based white LED sources are used, then energy efficiency is improved, but color rendering index deteriorates
Solution Approach 1:
The patent combines multiple LED types (white LEDs with phosphor conversion and red LEDs) in a single lighting apparatus to merge their spectral outputs. This merging of different light sources creates a composite spectrum that maintains the energy efficiency of LED technology while achieving superior color rendering by supplementing the red spectral region that is deficient in phosphor-based white LEDs alone.
2Manufacturing precision
If red light emitting devices are added to improve CRI, then color rendering index is improved, but device complexity increases
Solution Approach 1:
The patent segments the lighting apparatus into distinct functional modules: white LED strings with phosphor conversion and red LED strings. Each module can be independently configured and controlled. The configurable shunts allow selective activation or deactivation of specific LED devices within these modules, enabling flexible adjustment of color rendering properties without requiring complete redesign of the entire system.
Solution Approach 2:
The patent introduces dynamic configurability through configurable shunts that can selectively bypass individual LED devices. This dynamic adjustment capability allows the system to adapt its color rendering index and spectral output based on application requirements, transforming a static LED array into a dynamically adjustable lighting system that can optimize between energy efficiency and color rendering.
3Power
If multiple LED devices are connected in series, then voltage utilization is improved, but current control complexity increases
Solution Approach 1:
The patent introduces configurable shunts as intermediary elements that can selectively bypass individual LED devices in series strings. These shunts act as mediators between the power supply and the LED devices, allowing simple two-terminal connection while enabling complex current distribution patterns. The shunts facilitate independent current control of different LED subsets without requiring complex multi-terminal connections or sophisticated driver circuits.
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 effectively enhances the color rendering index by combining light from white and red LEDs, producing warm white light that more accurately represents natural colors, improving the lighting's ability to illuminate a broad range of colors naturally.
Implementation Method 1
a configurable shunt configured to bypass at least some current around at least one light emitting device
Implementation Method 2
a solid state light emitting device generates light through the recombination of electronic carriers, i.e. electrons and holes, in a light emitting layer or region
Implementation Method 3
a blue-emitting LED coated with a wavelength conversion phosphor that converts some of the blue light emitted by the LED into yellow light
Data Source
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AI summary
A solid state lighting apparatus according to some embodiments includes a circuit including a plurality of light emitting devices, and a configurable shunt configured to bypass at least some current around at least one light emitting device of the plurality of light emitting devices. The configurable shunt may include, for example, a tunable resistor, a fuse, a switch, a thermistor, and/or a variable resistor.