Optical Interference Range Sensor for Rough and Mirror Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical interference range sensors struggle to accurately measure distances to targets with both rough and mirror surfaces due to multiple reflections causing disturbance light.
Innovation Solution
An optical interference range sensor that generates interference beams by splitting a light beam into multiple spots, each with a different optical path length difference, allowing for peak detection and distance calculation in both mirror and rough surface modes, using a single objective lens and adjustable optical paths to enhance accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple light beams are radiated toward multiple spots on the measurement target, then measurement accuracy is improved, but multiple reflections from mirror surfaces create disturbance light that degrades measurement reliability
Solution Approach 1:
The patent divides the measurement function into multiple independent light beams (first, second, third light beams) radiating toward different spots on the measurement target. Each beam operates independently with its own optical path length difference, allowing the system to process multiple reflection components separately and identify the valid measurement signal among disturbance light from mirror surfaces.
Solution Approach 2:
The patent changes the optical path length difference parameter for each light beam (first light beam has first optical path length difference, second light beam has second optical path length difference, third light beam has third optical path length difference). This parameter differentiation enables the system to distinguish between multiple reflection components and select the valid measurement signal, resolving the contradiction between measurement precision and reliability.
2Measurement precision
If the optical path length difference is made different among light beams, then peak detection accuracy is improved, but device complexity increases due to multiple optical paths
Solution Approach 1:
The patent employs a single objective lens that serves multiple functions: it radiates multiple light beams toward different spots on the measurement target and also receives multiple reflected light beams. This multi-functional design achieves the required different optical path length differences without proportionally increasing device complexity, as one optical component performs multiple roles in the measurement system.
Solution Approach 2:
The patent combines multiple measurement functions into a unified optical system where a single objective lens handles both radiation and reception of multiple light beams. By merging these functions into one component rather than using separate components for each beam, the system achieves different optical path length differences while controlling overall device complexity.
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
Enables accurate distance measurement on targets with both rough and mirror surfaces by appropriately detecting peaks and calculating distances based on the shortest optical path length difference, reducing overlapping peaks and enhancing measurement precision.
Implementation Method 1
generate interference beams by interference between a measurement beam radiated toward the measurement target and reflected at the measurement target and a reference beam passing through an optical path that is at least partially different from an optical path of the measurement beam
Data Source
AI summary
A light source projects a light beam. An interferometer includes a splitting unit that splits the light beam. The interferometer generates interference beams with the respective split light beams. Each of the interference beam is generated by interference between a measurement beam radiated toward the measurement target and reflected at the measurement beam and a reference beam passing through an optical path. A light-receiving unit receives the interference beams. A processor calculates a distance to the measurement target by associating at least one detected peak with at least one of the spots in accordance with a mirror surface mode or a rough surface mode. The optical path length difference is made different among the split light beams. In the mirror surface mode, the processor uses a distance calculated based on a peak corresponding to a spot for which the optical path length difference is shortest.