Coaxial Illumination Imaging Optical System for 3D Depth Precision
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Solution Overview
Problem
Existing 3D cameras face challenges in acquiring precise depth information due to separate illumination and imaging optical systems with non-coaxial axes, leading to parallax and reduced utilization efficiency of illumination light, especially at greater camera-object distances and varying object surface states.
Innovation Solution
Integration of the illumination and imaging optical systems with coaxial axes, where the illumination optical system is integrated with the objective lens to form a single optical system, ensuring that the illumination light travels along the same axis as the imaging optical system, thereby eliminating parallax and improving the collection of incident light for more precise depth information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate illumination and imaging optical systems are used, then device complexity is reduced and ease of manufacture is improved, but measurement precision deteriorates due to parallax between non-coaxial optical axes
Solution Approach 1:
The illumination optical system and imaging optical system are merged into a single integrated optical system with coaxial optical axes. The illumination objective lens and imaging objective lens are positioned coaxially, allowing illumination light and imaging light to share the same optical path, thereby eliminating parallax and improving depth measurement precision.
2Loss of energy
If separate illumination and imaging optical systems are used, then device complexity is reduced, but utilization efficiency of illumination light deteriorates due to misalignment between optical axes
Solution Approach 1:
By merging the illumination and imaging optical systems into a coaxial integrated system, the illumination light is properly aligned with the imaging path, maximizing the utilization efficiency of illumination light and reducing energy loss through misalignment.
3Measurement precision
If coaxial integration of illumination and imaging optical systems is implemented, then measurement precision is improved by eliminating parallax, but device complexity increases
Solution Approach 1:
The illumination objective lens is nested within the aperture of the imaging objective lens, with the illumination optical system positioned inside the central region of the imaging optical system. This nested configuration allows coaxial alignment while maintaining a compact structure that is feasible to manufacture.
Solution Approach 2:
The integrated optical system performs multiple functions through a unified coaxial structure, combining illumination and imaging capabilities in a single system that can be manufactured as an integrated unit, reducing the overall manufacturing complexity despite the advanced functionality.
4Measurement precision
If coaxial integration is implemented, then signal-to-noise ratio is improved by increasing incident light collection, but device complexity increases
Solution Approach 1:
The coaxial integration of illumination and imaging optical systems merges the light paths, allowing the imaging system to collect maximum incident light reflected from the object along the same optical axis used for illumination, thereby improving the signal-to-noise ratio through efficient light collection.
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 integration enhances the precision of depth information acquisition by ensuring that a greater portion of illumination light is utilized, improving the signal-to-noise ratio and reducing the imprecision associated with distance measurements, especially at greater camera-object distances.
Implementation Method 1
TOF techniques measure a travel time of illumination light reflecting off an object after having been irradiated thereon to a light receiving unit for receiving the illumination light
Implementation Method 2
TOF techniques measure a travel time of illumination light reflecting off an object after having been irradiated thereon
Data Source
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AI summary
An optical system including integrated illumination and imaging optical systems, and a 3-dimensional (3D) image acquisition apparatus including the optical system. In the optical system of the 3D image acquisition apparatus, the illumination optical system and the imaging optical system are integrated to have a coaxial optical path. Accordingly, there is no parallax between the illumination optical system and the imaging optical system, so that depth information about an object acquired using illumination light may reflect actual distances between the object and the 3D image acquisition apparatus. Consequently, the depth information about the object may be more precise. The zero parallax between the illumination optical system and the imaging optical system may improve utilization efficiency of the illumination light. As a result, a greater amount of light may be incident on the 3D image acquisition apparatus, which ensures to acquire further precise depth information about the object.