Wide-Angle Depth Imaging Lens Thermal Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image-based depth sensors face errors in depth sensing due to factors like thermal expansion affecting the optical system, particularly in wide-angle applications where conventional lens constructions fail to maintain image quality and field of view.
Innovation Solution
A wide-angle, high-speed infrared imaging lens assembly with a specific configuration of lens stages and substages, including a first negative stage and a second positive stage with multiple positive and negative lens elements, achieving a low relative aperture and wide field of view, and ensuring telecentricity to maintain image focus despite thermal expansion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a conventional lens construction is used, then the device complexity is lower, but the field of view is insufficient and image quality deteriorates under thermal expansion
Solution Approach 1:
The lens construction is divided into multiple discrete lens elements arranged in specific groups, allowing each element to be optimized for particular optical functions while collectively achieving wide field of view and thermal stability. This segmentation enables complex optical performance without requiring a monolithic complex structure.
Solution Approach 2:
The patent employs composite lens design combining different optical materials with varying thermal expansion properties. By strategically selecting and combining materials, the system achieves thermal compensation where expansion in one element compensates for contraction in another, maintaining image quality across temperature variations.
2Illumination intensity
If the lens assembly is designed for wide field of view, then the relative aperture decreases, but manufacturing precision requirements increase due to thermal sensitivity
Solution Approach 1:
The patent systematically varies critical parameters including curvature radii, thicknesses, and spacing between lens elements to optimize the balance between relative aperture and thermal stability. By adjusting these parameters, the design achieves wide aperture while compensating for thermal effects that would otherwise require excessive manufacturing precision.
Solution Approach 2:
The design converts the harmful effect of thermal expansion into a beneficial compensation mechanism. By arranging lens elements with different thermal characteristics, the natural thermal expansion and contraction of materials is harnessed to maintain optical alignment and focus, reducing the stringency of manufacturing precision requirements.
3Measurement precision
If telecentricity is maintained to compensate for thermal expansion, then depth sensing precision improves, but the lens construction complexity increases
Solution Approach 1:
The lens construction is designed to simultaneously achieve multiple functions: wide field of view, telecentricity for depth precision, and thermal compensation. By integrating these functions into a unified multi-element design, the patent avoids the need for separate complex subsystems for each function, thereby managing overall complexity while delivering superior depth sensing performance.
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 lens assembly provides a wider field of view and lower relative aperture, effectively reducing errors in depth sensing by maintaining image stability and focus even under thermal expansion, enhancing performance in light-starving conditions.
Implementation Method 1
A wide-angle, high-speed infrared imaging lens assembly with a specific configuration of lens stages and substages
Data Source
AI summary
Embodiments are disclosed herein related to the construction of optical elements for depth sensor systems. One disclosed embodiment provides a wide-angle lens construction comprising a first, negative stage, and a second, positive stage positioned behind the first, negative stage along an optical axis of the lens construction. The second, positive stage further comprises a first positive lens substage, a second positive lens substage, a third positive lens substage, the second positive lens substage positioned between the first positive lens substage and the third positive lens substage.