Triangulation Optical Sensor with Astigmatic Lens and Multi-Source Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional triangulation optical sensors with single light sources face reduced sensitivity and accuracy in distance determination due to varying working distances, especially for specific wavelengths, leading to incomplete light bundle reception and reduced sensitivity.
Innovation Solution
The optical sensor employs an astigmatic lens arrangement with different focal lengths for rays in distinct planes, forming a light bundle with a smaller divergence angle, allowing for a more compact design and increased sensing range, and includes multiple light sources with varying wavelengths, such as RGB LEDs, to enhance detection accuracy and range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional single light source triangulation optical sensors are used, then the device structure is simple, but the sensing range is limited and detection accuracy is reduced due to varying working distances and incomplete light bundle reception
Solution Approach 1:
The light transmitter is segmented into multiple light sources (at least two) with different wavelengths, where each light source contributes to illuminating different portions of the monitoring area. This segmentation allows the sensor to maintain accurate distance determination across varying working distances by ensuring complete light bundle reception from multiple angular perspectives, thereby resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
Multiple light sources with different wavelengths are merged into a single light transmitter unit that operates collectively to illuminate the monitoring area. This merging approach enhances the sensing range and maintains detection accuracy across varying distances while keeping the overall device structure integrated and manageable, effectively balancing measurement precision with device complexity.
2Adaptability or versatility
If multiple light sources with different wavelengths are used, then the sensing range and detection accuracy are enhanced, but the device complexity increases
Solution Approach 1:
The light transmitter is designed with multiple light sources that serve universal functions: each wavelength contributes to illuminating different portions of the monitoring area, and collectively they provide comprehensive coverage. This multi-functionality approach enhances adaptability and sensing range while maintaining a unified device structure, effectively resolving the contradiction between versatility and device complexity.
3Length of stationary object
If the light bundle divergence angle is reduced for compact design, then the sensing range increases, but the light receiver aperture requirements become more stringent
Solution Approach 1:
The solution addresses the divergence angle issue by introducing a temporal dimension through sequential activation of multiple light sources with different wavelengths. Instead of reducing the divergence angle spatially (which would require precise alignment), the system uses multiple light sources to cover different angular portions of the monitoring area, thereby extending sensing range without imposing stringent alignment requirements on the light receiver.
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 configuration increases the sensing range by 40% and ensures complete light bundle reception, improving detection accuracy and reducing light loss, while maintaining a compact design.
Implementation Method 1
a transmission optics to transmit a transmitted light beam into a monitored zone
Implementation Method 2
the transmission optics is configured to form the light emitted by the at least two light sources to form a transmitted light bundle of rays
Implementation Method 3
the light transmitter, the light receiver and the reception optics are arranged with respect to one another such that the position of the light spot on the light receiver in a direction of triangulation results in dependence on a distance of a location in the monitored zone wherefrom the transmitted light is remitted
Implementation Method 4
The light receiver comprises at least one array of photosensitive reception elements
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to an optical sensor for the detection of objects in a monitored zone in accordance with the principle of triangulation. The optical sensor comprises a light transmitter for transmitting transmitted light into the monitored zone, wherein the light transmitter comprises at least two light sources laterally spaced from each other, and a transmission optics; a light receiver that has a plurality of reception elements for receiving transmitted light from the monitored zone that is remitted by an object to be detected; and a reception optics arranged upstream of a light receiver for generating a light spot on the light receiver from the remitted light, wherein the light transmitter, the light receiver and the reception optics are arranged with respect to one another such that the position of the light spot on the light receiver in a direction of triangulation results in dependence on a distance of a location in the monitored zone wherefrom the transmitted light is remitted, and wherein the transmission optics is configured to form the light emitted by the at least two light sources to form a transmitted light bundle of rays, wherein the light bundle has a first focal point for rays propagating within a first plane and a second focal point for rays propagating within a second plane which is perpendicular to the first plane, wherein the distance of the first focal point from the transmission optics is shorter than the distance of the second focal point from the transmission optics.