Symmetric Excitation Light Source Module for Uniform Color Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing projector designs face challenges in reducing size due to the requirement for either a phosphor wheel and filter wheel combination or a dedicated red light source, which complicates volume reduction and color uniformity in illumination systems.
Innovation Solution
An illumination system with a plurality of excitation light sources, a wavelength conversion element, and a light combining element, where second and third excitation light sources are integrated symmetrically to share an optical path, ensuring uniform color distribution and reducing device volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a phosphor wheel and filter wheel are used to generate red light, then red light can be obtained, but the projector volume increases
Solution Approach 1:
The patent combines multiple excitation light sources (blue light sources) with different optical paths into a single integrated illumination system. By merging the optical paths and using a common illumination objective lens, the system reduces the number of separate components needed, thereby reducing projector volume while maintaining red light output capability through wavelength conversion.
Solution Approach 2:
The illumination system is designed to generate multiple wavelengths (blue light and red light) using the same excitation light sources and wavelength conversion elements. The blue light sources serve dual purposes: directly providing blue light and exciting phosphor materials to generate red light, eliminating the need for separate dedicated red light sources and reducing overall system volume.
2Illumination intensity
If a dedicated red light source is used, then red light can be provided, but the projector volume increases
Solution Approach 1:
Instead of using a dedicated red light source, the patent merges the red light generation function into the existing blue light illumination system by introducing wavelength conversion elements (phosphor materials) that convert blue light to red light. This integration eliminates the need for separate red light source components and their associated optical paths, thereby reducing projector volume.
Solution Approach 2:
The patent changes the wavelength parameter of the light by using phosphor conversion materials. Blue light sources excite phosphor materials that emit red light, effectively transforming the wavelength from blue to red within the same optical path. This parameter change approach replaces the need for separate red light sources while maintaining compact system volume.
3Volume of stationary object
If multiple excitation light sources are integrated symmetrically, then device volume is reduced, but color uniformity may be affected
Solution Approach 1:
The patent employs asymmetric arrangement of the excitation light sources relative to the optical axis, with light sources positioned at different radial distances and angles. This asymmetric configuration, combined with specific optical elements, ensures that light from multiple sources converges uniformly on the target plane, maintaining color uniformity while enabling compact integration of multiple light sources.
Solution Approach 2:
The patent assigns different spatial positions and orientations to individual excitation light sources based on their specific functions (direct blue light transmission vs. phosphor excitation for red light). Each light source and its associated optical path are optimized for its local function, with the overall arrangement ensuring uniform color distribution across the illumination area while maintaining compact device volume.
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 achieves a smaller projector size with uniform color distribution in projection images by integrating light sources and arranging them symmetrically, allowing for a shared optical path and consistent incident angles, thus enhancing color uniformity and reducing device volume.
Implementation Method 1
The wavelength conversion element is disposed on a transmission path of the first excitation light beams, and is configured to convert the first excitation light beams into a converted light beam
Implementation Method 2
The light combining element is disposed on a transmission path of the second excitation light beams and the third excitation light beams, and reflects the converted light beam to the transmission path of the second excitation light beams and the third excitation light beams
Data Source
AI summary
An illumination system and a projection device are provided. The illumination system includes first excitation light sources, an excitation light source module, a wavelength conversion element and a light combining element. The excitation light source module includes second excitation light sources adapted to emit second excitation light beams and third excitation light sources adapted to emit third excitation light beams. The excitation light source module has a first symmetric axis and a second symmetric axis perpendicular to each other, where the second excitation light sources and the third excitation light sources are respectively arranged symmetrically relative to the first symmetric axis, and the second excitation light sources and the third excitation light sources are respectively arranged symmetrically relative to the second symmetric axis. The projection device includes the illumination system, a light valve and a projection lens. The illumination system and the projection device of the invention have smaller size, and are adapted to provide illumination beam and projection image with uniform color distribution.