Optoelectronic Sensor Multi-LED Focal Adjustment
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Solution Overview
Problem
Existing optoelectronic sensors with light barriers or light scanners face challenges in reliably detecting small objects at varying distances due to limited sensitivity and high costs associated with laser usage, and mechanical adjustments are expensive and prone to errors.
Innovation Solution
The use of at least two light sources arranged at different distances from the transmission optics, allowing for focal adjustment without mechanical components, and an optical axis configuration that enables focus on the object by selecting the appropriate light source, combined with a position-sensitive detector for distance determination using the triangulation method.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If laser light is used as light source in light barriers and light scanners, then small light spot diameter can be maintained over large distance range, but the system becomes very expensive and has limited service life
Solution Approach 1:
The patent divides the light source function into multiple LEDs with different focal lengths instead of using a single laser source. Each LED is responsible for a specific distance range, segmenting the overall detection task into multiple specialized components that collectively achieve the precision of a laser while avoiding its high cost and limited lifespan.
Solution Approach 2:
The patent changes the focal length parameter of the light sources to match different object distances. By selecting LEDs with appropriate focal lengths (e.g., 8mm, 12mm, 16mm), the system adapts its optical parameters to maintain a small light spot diameter across various distances without requiring expensive laser technology.
2Ease of manufacture
If LED light sources are used with fixed focal length, then the system becomes cost-effective, but the device can only be used for a predetermined distance range
Solution Approach 1:
The patent makes the light source system multi-functional by incorporating multiple LEDs, each capable of operating at a specific distance range. This universal design allows a single sensor unit to handle various detection distances (from close to far range) without requiring mechanical adjustment or multiple separate devices, achieving both cost-effectiveness and adaptability.
3Adaptability or versatility
If mechanical adjusting device is used to change back focus distance, then different distances can be set, but the system becomes expensive and the focal length can be adjusted in the event of a shock
Solution Approach 1:
The patent replaces the mechanical adjustment system with an electronic selection system. Instead of using a mechanical device to physically change the back focus distance, the system electronically selects the appropriate LED based on the desired detection distance. This substitution eliminates mechanical complexity and improves reliability by removing moving parts that could be affected by shocks or wear.
4Device complexity
If receiving and transmitting lenses are attached geometrically separate, then the system structure is simple, but sensitivity in close range is reduced
Solution Approach 1:
The patent applies local quality by optimizing the optical path for close-range detection through specific positioning of the receiving lens relative to the transmitting lens. The receiving lens is positioned to capture light reflected from close objects, and the system uses LEDs with appropriate focal lengths to ensure the light spot remains small and intense at close distances, thereby maintaining high sensitivity without increasing overall system 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
This configuration achieves high spatial resolution and cost-effectiveness by eliminating the need for mechanical adjustments and reducing near-range sensitivity issues, while maintaining low operating costs and long service life.
Implementation Method 1
the rays emitted by the light sources are focused on different distances
Implementation Method 2
light beams emitted by the light sources impinge directly on the transmission optics
Implementation Method 3
distance determination using the triangulation method
Data Source
Figure 1A~1C
Figure 2A~2B
Figure 3
AI summary
The optoelectronic sensor has a transmission optics (11) and two light sources (S1,S2,S3) which are designed for emitting light rays from impinging directly on the transmission optics. The two light sources are arranged at different distances from a main plane (4) of the transmission optics. The main plane proceeds perpendicular to an optical axis (5) of the transmission optics.