Multi-Lens Optical Element for Projector Illumination Uniformity
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Solution Overview
Problem
Existing image display devices, such as projectors, face issues with wavelength conversion efficiency and illuminance unevenness due to the growth in size of the optical system and increased temperature of phosphor elements, particularly when using multi-lens arrays to homogenize excitation light distribution.
Innovation Solution
An optical element with a first multi-lens surface and a second multi-lens surface, where the light is divided into multiple areas and cells to create separate partial irradiation areas, allowing for efficient heat dissipation and reduced temperature rise, thereby maintaining wavelength conversion efficiency and reducing illuminance unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a multi-lens array is used to homogenize the illuminance distribution of excitation light on the phosphor, then the illuminance uniformity is improved, but the wavelength conversion efficiency decreases due to temperature rise of the phosphor
Solution Approach 1:
The patent divides the illumination target into multiple separate irradiation areas by using a lens array that creates multiple partial light beams. Each partial light beam illuminates a distinct area on the wavelength conversion element, preventing concentration of heat in a single location and thereby reducing overall temperature rise while maintaining illuminance uniformity across the entire illuminated area.
2Device complexity
If the lens array and wavelength conversion element are configured with corresponding areas, then the optical system size increases, but the illuminance unevenness also increases
Solution Approach 1:
The patent merges the functions of multiple lenses into a single integrated lens array structure. This consolidation allows the system to achieve the desired light distribution and homogenization effects without requiring separate optical components for each function, thereby controlling the overall optical system size while maintaining uniform illuminance across the wavelength conversion element.
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 optical element effectively suppresses the rise in temperature of wavelength conversion elements, enhances wavelength conversion efficiency, and reduces illuminance unevenness, leading to improved performance and reliability in image display devices.
Implementation Method 1
a first multi-lens surface having m areas (R) arranged in an array... light enters the first multi-lens surface, the light is emitted from the second multi-lens surface
Implementation Method 2
a second multi-lens surface having m second cells (242) arranged in an array... a focal plane of the m second cells is located at an emission side of the n first cells
Implementation Method 3
a wavelength conversion element configured to convert a wavelength of the excitation light emitted from the optical element and emit converted light
Data Source
AI summary
An optical element includes a first multi-lens surface and a second multi-lens surface. The first multi-lens surface has m areas arranged in an array, the m areas including a plurality of first cells. The second multi-lens surface has m second cells arranged in an array, the m second cells corresponding to the m areas. Light enters the first multi-lens surface. The light is emitted from the second multi-lens surface. The m areas of the first multi-lens surface each have n first cells. A focal plane of the m second cells is located at an emission side of the n first cells. The number m is a natural number no smaller than 2, and the number n is a natural number no smaller than 2.