LIDAR Optical Device Convergent Beam Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Distance measurement devices using the LIDAR principle face a trade-off between wide horizontal field of view and object resolution, where enlarging the field of view typically results in poor object resolution due to beam divergence, requiring complex and costly high-resolution receiver elements.
Innovation Solution
The device employs a primary optic with positive refractive power to direct light as convergent beams to a secondary deflection means, minimizing beam divergence and maintaining good object resolution, even with a large horizontal field of view, by using a convex lens and an oscillating MEMS mirror with a secondary lens featuring a curved refractive surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a refractive secondary lens with cylindrical entry surface and flat exit surface is used to enlarge the horizontal field of view, then the field of view is widened, but the beam divergence increases and object resolution deteriorates
Solution Approach 1:
The patent applies curvature to both the entry and exit surfaces of the secondary lens, replacing the conventional cylindrical entry surface with a spherical or aspherical surface. This curved geometry allows the lens to control beam divergence more effectively while maintaining a wide field of view, thereby resolving the contradiction between field of view and object resolution
Solution Approach 2:
The patent changes the optical parameters of the secondary lens by introducing a specific refractive index range (1.5-1.7) and adjusting the curvature radii of the entry and exit surfaces. These parameter optimizations enable the lens to achieve both wide field of view and controlled beam divergence, improving object resolution without sacrificing adaptability
2Measurement precision
If high-resolution receiver elements are used to compensate for poor object resolution, then object resolution is improved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the beam divergence control function from the receiver side and places it in the transmitter side through the optimized secondary lens. By controlling the beam characteristics before the light reaches the receiver, the system achieves good object resolution without requiring complex high-resolution receiver elements, thus reducing overall device complexity
Solution Approach 2:
The optimized secondary lens acts as an intermediary element that mediates between the light source and the receiver. It controls beam divergence and shapes the light path to ensure that the receiver receives well-defined beams, thereby achieving good object resolution with simpler receiver elements
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 design achieves a small beam expansion in the distant field, allowing for high object resolution without the need for high-resolution receiver elements, effectively combining a large horizontal field of view with improved object detection capabilities.
Implementation Method 1
a primary optic (13) with positive refractive power to direct the light (12) as convergent beams to the second means of deflection (16)
Implementation Method 2
An oscillating mirror (4) deflects the light (3) into an angle range
Implementation Method 3
a refractive secondary lens (5) that features a cylindrical entry surface (6) and a flat exit surface (7)
Data Source
AI summary
An optical device is provided for a distance measurement device according to the LIDAR principle. At least one light source is provided, along with a first means of deflection that during operation of the device deflects light emitted by the at least one light source into a first angle range. A second means of deflection is also provided that during operation of the device deflects the light emitted from the first means of deflection into a second angle range which is larger than the first angle range. Finally, an optical means is provided that influences the light in such a way that it hits the second means of deflection as convergent light.