18 patents in this list

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Modern LED lighting systems must achieve precise spectral output while managing thermal loads and optical efficiency. Current multi-color LED arrays typically operate at 20-30% electrical-to-optical conversion efficiency, with phosphor-converted white LEDs showing significant Stokes losses and spectral gaps that limit color rendering capabilities to CRI values around 80.

The fundamental challenge lies in balancing spectral coverage and quantum efficiency while maintaining consistent output across temperature variations and operating conditions.

This page brings together solutions from recent research—including nanowire-based orange LEDs combined with blue laser diodes, sector-based LED modules with specialized phosphor compounds, and hybrid systems using purple-white LED combinations. These and other approaches focus on achieving high color rendering while preserving energy efficiency in practical lighting applications.

1. LED Lamp with Alternating White and UVA-Emitting Purple LEDs for Enhanced Color Rendering

Xiamen PVTECH Co., Ltd., 2023

LED lamp design to improve color rendering by using a combination of white LEDs and purple LEDs. The purple LEDs emit in the UVA spectrum. The white LEDs provide the main light output while the purple LEDs fill in the UVA range. The combined light enhances color rendering compared to just white LEDs. Alternating white and purple LEDs allows overlap of the UVA range. The purple LEDs can be 400-420nm wavelength.

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2. Lighting Device with Blue and Purple LEDs in Phosphor-Coated Housing for Enhanced Color Rendering

Xiamen PVTECH Co., Ltd., 2023

A lighting device with high-color rendering using a combination of blue and purple LEDs. The device includes a substrate with blue and purple LEDs, enclosed in a phosphor-coated transparent housing. The blue and purple LEDs stimulate the phosphor to emit white light with enhanced color rendering. The combination of blue and purple light allows the emitted white light to partially overlap the UVA spectrum, significantly improving color rendering compared to devices with only blue LEDs.

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3. Endoscope Distal Tip Illumination Apparatus with Multi-Spectral LED Array and Common Phosphor Layer

HOYA CORPORATION, 2023

A compact illumination apparatus for endoscope distal tips that provides synchronized multi-spectral illumination for improved tissue imaging contrast. The apparatus features multiple LEDs with different peak wavelengths arranged in a circular or segmented pattern on a PCB, covered by a common phosphor layer. This design enables the endoscope tip to deliver mixed-spectrum illumination without needing separate LEDs for each wavelength, ensuring compactness and enhanced imaging capabilities.

4. Lighting System with Multi-Color LEDs and External Sensor for Adjustable Spectrum Control

LumiGrow, Inc., 2020

A lighting system for facilitating plant growth that provides precise control over the color spectrum of emitted light. The system uses multiple LEDs of different colors to create a custom spectrum that can be adjusted to optimize plant growth. An external light sensor can be used to automatically adjust the intensity of the artificial light to maintain desired light levels in a greenhouse.

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5. Continuous Wave Multi-Color LED Light Source with Tunable Correlated Color Temperature

OSRAM Opto Semiconductors GmbH, 2020

Precisely controlling a multi-color LED light source to generate white light with tunable color temperature. The method involves operating the LEDs in continuous wave mode and not pulse width modulation. Each LED is run at least 5% of max current to prevent undercurrent. The LEDs emit blue, bluish-white, greenish-white, and red light. These are mixed to generate white light with adjustable correlated color temperature.

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6. LED Lighting System with Adjustable Spectrum and Intensity Control via External Sensors

LumiGrow, Inc., 2020

Lighting system using LEDs to provide a desired color of light. The system allows adjustment of the color spectrum to match the needs of plants or other applications. The system can also use external sensors to adjust light intensity and turn on/off lights as needed. The ability to adjust the color, intensity, and timing of the light can optimize growth conditions.

7. Hybrid Nanowire LED and Laser Diode System for Concurrent Illumination and Data Transmission

King Abdullah University of Science and Technology, 2020

A hybrid lighting and communication system that uses an orange nanowire LED combined with a blue laser diode for high-speed communication. This allows tunable white lighting with high color rendering and also optical wireless data transmission. The orange nanowire LED emits broad-spectrum white light with good color rendering. The blue laser provides high-speed communication capability. The combined LED/laser system enables both illumination and data transmission using visible light.

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8. Lighting System with Multi-Color LEDs and External Sensor for Adjustable Emission Spectrum

LUMIGROW, INC., 2020

Lighting system for facilitating the growth of plants that allows the color of the emitted light to be better controlled. The system uses LEDs of different colors, such as red, blue, green, yellow, orange, violet, and white, to provide a full spectrum of light that can be adjusted to optimize plant growth. It includes an external light sensor to provide light level data to adjust the intensity of the lighting system in a greenhouse.

9. White Light Device Architecture Combining Orange Nanowires LED and Narrow Linewidth Blue Laser Diode

King Abdullah University of Science and Technology, 2019

A white light device architecture based on an orange nanowires LED combined with a narrow linewidth blue laser diode for simultaneous illumination and optical wireless communication. The orange nanowires LED provides tunable white light with high color rendering. The blue laser diode enables high-speed data transmission. This hybrid LED/laser system offers improved efficiency, color quality, and data rates compared to conventional phosphor-based white LEDs. The orange nanowires LED has a broad linewidth that fills the spectrum for better color rendering.

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10. LED Module with Circular Sector Light-Emitting Zone and Phosphor-Enhanced Potting Compound

TRIDONIC JENNERSDORF GMBH, 2019

LED module for emitting mixed light, preferably white light, that can be used in lamps with small reflector sizes. The LED module has a circular light-emitting zone divided into flat sectors, like slices of a pie. Each sector can emit a different light spectrum. Phosphor can be added to the potting compound between the sectors to create white light. This allows producing a homogeneous mixed light from individual sector emissions. The circular sector design allows a small light-emitting zone suitable for small reflector lamps.

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11. Lighting System with LED Array and Adjustable Spectral Output for Plant Growth

Kevin T. Wells, 2019

A lighting system for plant growth that provides precise control over light color to optimize plant growth. The system uses LEDs of different colors to create tailored light spectra optimized for specific plants and growth stages. A controller adjusts the intensity of each LED color based on external light sensors to mimic natural lighting conditions.

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12. Illumination Method Using Light Emitting Devices with Spectrum-Matched Hue, Saturation, and Color Temperature

CITIZEN ELECTRONICS CO., LTD., 2019

An illumination method that creates natural, vivid, highly visible and comfortable color appearances by optimizing the light spectrum for objects. The method involves illuminating objects with light that, when measured at the object position, matches specific criteria for hue, saturation and color temperature compared to a reference light. This recreates natural color appearances indoors under typical lighting conditions. The illumination is achieved using light emitting devices such as LEDs with specific spectra. The method aims to provide favorable color appearances under moderate indoor lighting conditions while maintaining energy efficiency.

13. LED Lighting with Composite Spectrum Configured for Enhanced Lighting Preference Index

GE Lighting Solutions, LLC, 2019

LED lighting with optimized color spectrum for enhanced color preference compared to standard LED sources. It uses a metric called Lighting Preference Index (LPI) as a quantitative measure to design light sources with maximum color preference. The optimized composite light sources contain blue, green/yellow-green, and red emitters or downconverters in specific wavelength ranges to achieve LPI of at least 120. These optimized LED spectra provide significantly higher color preference than standard LEDs.

14. OLED Display Pixel Configuration with Quadruple Subpixel Arrangement for Enhanced Blue Spectrum

Universal Display Corporation, 2019

Pixel design for OLED displays that enhances blue color range while maintaining overall color accuracy and display lifetime. The pixel contains four OLED subpixels - red, green, light blue, and deep blue - to render full color. The deep blue subpixel can have lower lifetime and efficiency since it only contributes to blue spectrum. This allows using more efficient but less deep blue emitters compared to the industry standard. The other subpixels maintain color quality.

15. White Light Device Architecture with Orange Nanowires LED and Blue Laser Diode Integration

King Abdullah University of Science and Technology, 2018

A white light device architecture suitable for illumination and optical wireless communications. The architecture uses an orange nanowires LED combined with a blue laser diode. This achieves both high quality white light generation and high speed optical communications in a single device. The orange nanowires LED provides tunable color rendering with a high CRI, while the blue laser enables optical wireless data transmission.

16. Circuit Board with Specific Pattern Arrangement of Differently Colored LEDs and Variable Trace Widths

LG INNOTEK CO., LTD., 2018

A light emitting module with groups of differently colored LEDs arranged in a specific pattern on a circuit board to improve color rendition, color control, and heat distribution. Groups of red LEDs are positioned on the outer circumference, followed by groups of green LEDs, and then groups of blue LEDs in the center. The red LEDs are connected in series, followed by the green and blue LEDs. The number of each type of LED increases as the wavelength decreases. The circuit board has wider traces for the red LED connections.

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17. LED Array with Multi-Channel Control and Phosphor-Coated Chips for High CRI and Adjustable CCT

DiCon Fiberoptics, Inc., 2018

LED lighting with high color rendering index (CRI) and adjustable color temperature. The LED array contains multiple strings, each comprising several LED chips of potentially different wavelengths, with each string controlled electronically as a separate channel. Phosphors of multiple types and emissions spectra are dispensed or applied on top of all of the individual LED chips, such that it is possible to have a different phosphor type on each individual LED chip, or on different subsets of the LED chips. The multiple channels allow for each string of LEDs and hence their output color and power to be independently switched on/off and varied in intensity, respectively. This allows the LED illuminator to provide variable or adjustable color temperature (CCT), while maintaining extremely high CRI.

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18. LED Luminaire with Dispersed Colored LED Elements for Enhanced Color Mixing and Uniformity

SCHREDER, 2018

LED luminaire with improved color mixing and uniformity by dispersing the colored LED elements within the array to provide a uniform color output. This overcomes issues like visible color banding, non-homogeneous illumination and poor color mixing of regular patterns. The dispersed arrangement allows creating larger luminaires by replicating a base module of colored LEDs because replicating square base modules maintains the uniformity.

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Request the PDF report with complete details of all 18 patents for offline reading.

These developments highlight different methods for creating multicolored LED illumination. Some attempt to produce a larger color spectrum by combining white and purple LEDs to improve color rendering. Others generate adjustable white light with data transfer capabilities by combining LEDs and lasers.