Light Source Device With Diffraction Grating Light Guide
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing light source devices for projectors require separate light sources and optical systems to produce white light, leading to increased size and complexity, as they need to combine different colored lights, which complicates the design and increases the size of the device.
Innovation Solution
A light source device with a light guide section and a wavelength conversion section using phosphors, where the light guide section has a diffraction grating to direct light and the wavelength conversion section converts light into different wavelengths, allowing for the emission of white light without the need for additional phosphor sources, thereby reducing the device's size and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If separate light sources and optical systems are used to produce white light, then the light source device can achieve the necessary spectral composition, but the device size and complexity increase
Solution Approach 1:
The patent combines the light guide function and wavelength conversion function into a single integrated structure. The light guide section guides blue light from the LED, while the wavelength conversion section with phosphor converts part of this light to yellow, producing white light without requiring separate optical combining systems. This merging of functions directly resolves the contradiction by maintaining spectral quality while reducing device complexity and size.
Solution Approach 2:
The light guide section serves multiple functions: it guides the blue light from the LED, directs light to the wavelength conversion section, and also serves as a structural support. The wavelength conversion section simultaneously performs wavelength conversion and acts as part of the light output system. This multi-functionality eliminates the need for separate dedicated components, thereby reducing device size while maintaining the required spectral composition.
2Illumination intensity
If multiple light sources are used to generate different colored lights, then the desired white light output can be achieved, but the number of components and optical systems increases
Solution Approach 1:
Instead of using separate light sources for blue and yellow light, the patent uses a single blue LED whose light is partially converted to yellow by phosphor within the wavelength conversion section. This merging of light generation and conversion into a single system dramatically reduces the number of components while achieving the same white light output.
Solution Approach 2:
The patent changes the wavelength parameter of light through phosphor conversion. The blue LED emits light at a specific wavelength, and the phosphor in the wavelength conversion section converts part of this blue light to yellow light at a different wavelength. This parameter change approach allows a single light source to effectively produce multiple wavelengths, reducing component count while maintaining white light quality.
3Ease of operation
If a diffraction grating is added to the light guide section, then light directionality and control are improved, but the device complexity increases
Solution Approach 1:
The diffraction grating is applied locally only to specific surfaces of the light guide section where light direction control is most needed, rather than throughout the entire device. This localized application provides the necessary light directionality while minimizing the increase in overall device complexity. The grating is integrated into the light guide structure itself, further reducing additional components.
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 enables a compact light source device that efficiently produces white light by integrating light guide and wavelength conversion functions, reducing the need for separate phosphor sources and optical systems, thus improving light use efficiency and minimizing device size.
Implementation Method 1
the first side surface is provided with a diffraction grating, the partial light enters the light guide section from the first side surface via the diffraction grating
Implementation Method 2
a wavelength conversion section which includes a phosphor, which other partial light of the first light emitted from the light source enters, and which converts the other partial light into second light in a second wavelength band different from the first wavelength band
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A light source device (2) according to the present disclosure includes a light source (53) that emits first light in a first wavelength band, a light guide section (51) that guides partial light of the first light, a wavelength conversion section (58) including a phosphor, which other partial light of the first light, and which converts the other partial light into second light in a second wavelength band. A first side surface (51c1) of the light guide section (51) and a second side surface (58c1) of the wavelength conversion section (58) are opposed to each other, and the first side surface (51c1) is provided with a diffraction grating (51f). The partial light enters the light guide section (51) from the first side surface via the diffraction grating (51f), and the other partial light enters the wavelength conversion section (58) from the second side surface (58c3). The partial light and the second light are emitted in one of a normal direction of the first end surface (51a) of the light guide section (51) and a normal direction of the third end surface (58a) of the wavelength conversion section (58).