Wavelength Conversion and Splitting for Single-Source Projection
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Solution Overview
Problem
Conventional three-chip projection systems face high costs and low efficiency due to the need for multiple light sources and the requirement for narrow spectral ranges, which results in power loss and reduced brightness after filtering.
Innovation Solution
A projection system utilizing a light emitting device with a wavelength conversion layer that converts ultra-violet or near ultra-violet excitation light into wide-spectrum light, which is then split into primary colors, allowing for the generation of multiple colors using a single light source and reducing power loss through wavelength splitting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If three light sources are used to generate red, green, and blue lights respectively, then color saturation is improved, but cost increases significantly
Solution Approach 1:
The patent segments the wide-spectrum light into different color components (red, green, blue) using a light splitting device with dichroic mirrors, allowing a single light source to provide all three primary colors that were previously required from three separate sources
Solution Approach 2:
The single light source performs multiple functions by generating wide-spectrum light that contains all three primary color components, which are then separated and used for different color channels, replacing the need for three specialized light sources
2Illumination intensity
If color filters are used to obtain narrow spectral ranges for high color saturation, then color coordinates are improved, but brightness and efficiency decrease due to power loss
Solution Approach 1:
The patent extracts specific color components (red, green, blue) from the wide-spectrum light using a light splitting device with dichroic mirrors, obtaining narrow spectral ranges without the need for absorptive color filters that cause power loss
Solution Approach 2:
The light splitting device acts as an intermediary between the wide-spectrum light source and the display device, separating the spectrum into narrow bands for each color channel while preserving energy that would otherwise be lost in filtering
3Device complexity
If a single light source is used to generate multiple colors, then cost decreases, but color saturation and spectral purity worsen
Solution Approach 1:
The wide-spectrum light from a single source is segmented into distinct color components using a light splitting device, achieving the spectral purity of multiple sources while maintaining the cost advantage of a single source
Solution Approach 2:
Different portions of the spectrum are directed to different color channels with appropriate spectral characteristics, ensuring that each color channel receives light with the optimal spectral properties for high color saturation
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
This approach decreases the number of light sources and costs, while increasing efficiency by preventing power loss from discarded spectral ranges and maintaining brightness and color accuracy.
Implementation Method 1
a wavelength conversion device comprising a wavelength conversion layer which converts at least a part of the excitation light to a converted light
Implementation Method 2
a light splitting device for splitting the wide-spectrum light into at least two monochromatic lights propagating along different paths
Data Source
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AI summary
A light emitting device includes: an excitation light emitting source (71) for generating excitation light; a wavelength conversion device (72) comprising a wavelength conversion layer (722), the wavelength conversion layer (722) converting at least a part of the excitation light into converted light, and the converted light being light with a wide spectrum, or the converted light being mixed with excitation light not converted by the wavelength conversion layer (722) to form light with a wide spectrum; a driving device (73) for enabling the excitation light to move relative to the wavelength conversion layer; and a light splitting device (62) for splitting the light with the wide spectrum into at least two kinds of monochromatic light propagating along different paths. Further provided is a projection system comprising the light emitting device.