Microlens Array Illumination Device for 3D Sensing Aberration Control
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Solution Overview
Problem
Existing illumination devices for 3D sensing, particularly those using microlens arrays, suffer from optical aberrations that degrade the quality of both dot and flood light patterns, leading to inaccurate depth determination in 3D sensing applications.
Innovation Solution
An illumination device comprising a light source array and a microlens array, where the distance between the light source array and the microlens array is optimized to satisfy specific conditional expressions, such as z=z0+dz and z0=(m/2) * (P^2 / λ), to produce high-quality structured and flood light patterns by compensating for optical aberrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a microlens array is used as the light-shape generating element, then the device can produce light patterns, but optical aberration of the lens element degrades the quality of the light pattern
Solution Approach 1:
The patent changes the geometric parameters of the microlens array, specifically setting the lens pitch P to satisfy P < 0.06 mm and optimizing the distance z between the light source array and microlens array to satisfy (m-1) * 0.005 mm < z < (m-1) * 0.02 mm where m is the magnification. These parameter changes compensate for optical aberrations and improve light pattern quality without changing the fundamental microlens array structure
Solution Approach 2:
The patent introduces a new dimensional parameter - the distance z between the light source array and microlens array - as a controllable variable. By optimizing this distance along with the lens pitch P, the system compensates for optical aberrations in the lateral dimension, thereby improving overall light pattern quality
2Measurement precision
If both dot pattern and flood pattern are required for enhanced depth accuracy, then the 3D sensing performance is improved, but the device complexity increases
Solution Approach 1:
The patent makes the microlens array perform multiple functions by optimizing its parameters (lens pitch P < 0.06 mm and distance z). The same microlens array structure can produce both dot patterns and flood patterns depending on the operating conditions, eliminating the need for separate optical paths or additional components for each pattern type
Solution Approach 2:
By optimizing the lens pitch and distance parameters, the system enables the microlens array to flexibly switch between producing dot patterns and flood patterns. This parameter optimization allows one component to serve multiple functions, reducing overall device complexity while maintaining enhanced depth accuracy
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 optimized illumination device produces structured and flood light patterns with higher quality, enhancing depth accuracy in 3D sensing by minimizing optical aberrations and improving pattern clarity.
Implementation Method 1
The microlens array includes a plurality of microlenses arranged in an array. The illumination device satisfies the following conditional expressions so as to produce structured light: z=z0+dz and z0=(m/2) ∗ (P^2 / λ), where P is a lens pitch of the microlens array, λ is a wavelength of light, and m is an odd number
Implementation Method 2
The illumination device satisfies the following conditional expressions so as to produce structured light: z=z0+dz and z0=(m/2) ∗ (P^2 / λ), where P is a lens pitch of the microlens array, λ is a wavelength of light
Implementation Method 3
The illumination device satisfies the following conditional expressions so as to produce flood light: z=z0+dz and z0=(m/2) ∗ (P^2 / λ), where P is a lens pitch of the microlens array, λ is a wavelength of light, and m is an even number
Data Source
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AI summary
An illumination device including a light source array and a microlens array is provided. The light source array includes a plurality of light sources arranged in an array. The microlens array includes a plurality of microlenses arranged in an array. The illumination device satisfies the following conditional expressions so as to produce structured light: z=z0+dz and z0=(m/2)∗(P2/λ), where z is a distance between the light source array and the microlens array along a central axis of the microlens array, P is a lens pitch of the microlens array, λ is a wavelength of the light sources, m is an integer and m' is a non-integer number. The illumination device satisfies 1% ≦ dz/z0 ≦ 5% or -5%≦dz/z0 ≦-1 %.