Linear Semiconductor Emitter Array for Optoelectronic Sensor
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Solution Overview
Problem
Existing optoelectronic sensors face challenges in detection reliability and range due to issues like black-white shift, inaccurate measurement caused by unknown remission properties of objects, and limited power density, which affects the precision and robustness of object detection.
Innovation Solution
A line arrangement of identical semiconductor emitters is used in a background-suppressing light scanner, where all emitters are activated synchronously to increase total energy and power density, and can be adjusted dynamically by switching off individual emitters to optimize light spot shape and power for specific detection situations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the emission area of a single light source is increased to achieve higher overall receiver power, then the total power increases, but the power density on the receiver does not increase
Solution Approach 1:
The single light source is segmented into multiple individual light sources (e.g., multiple LEDs or laser diodes) arranged in a linear array. Each light source emits light that contributes to the overall power while maintaining high power density at the receiver, thus resolving the contradiction between total power and power density.
Solution Approach 2:
The invention transitions from a single-point light source to a linear array of multiple light sources, adding spatial dimensionality to the emission configuration. This dimensional change allows the system to achieve both high total power and high power density by distributing sources along a line rather than concentrating in a single point.
2Shape
If optical elements like scattering foils or cylindrical lenses are used to generate a line beam, then a line-shaped light spot is achieved, but only identical light output is redistributed without increasing power density
Solution Approach 1:
Instead of using passive optical elements to reshape a single beam, the invention segments the light source into multiple individual emitters arranged in a line. This active segmentation allows each emitter to contribute independently to the line-shaped spot while maintaining high power density, overcoming the limitation of passive beam shaping.
3Reliability
If multiple light sources with different physical properties are used to introduce measurement variations, then object detection robustness improves, but installation space and production costs increase
Solution Approach 1:
The invention applies local quality by having all light sources in the linear array emit at the same wavelength and with the same physical properties, but positioned at different locations along the line. This allows the system to achieve detection robustness through spatial distribution rather than physical property variation, reducing complexity while maintaining reliability.
4Device complexity
If a single light source is used, then the device structure is simple, but the detection range and robustness are limited due to black-white shift effects
Solution Approach 1:
The single light source is segmented into multiple individual sources arranged in a linear array. This segmentation allows the system to overcome black-white shift effects by distributing the light emission across multiple points, improving detection robustness while maintaining relatively simple device structure through the use of identical light sources.
Solution Approach 2:
Multiple individual light sources are merged into a coordinated linear array that functions as a unified emission system. The combined output of all sources achieves the desired detection range and robustness while maintaining structural simplicity through synchronized operation and identical source characteristics.
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 approach enhances detection range and robustness by reducing disruptive effects of black-white shift, improving object detection accuracy, and allowing for precise light spot adjustment, while minimizing thermal load and production costs.
Implementation Method 1
Semiconductor elements, i.e. laser diodes or LEDs, are often used as light transmitters in a light scanner
Implementation Method 2
Since the optically emitted power is directly proportional to the injected current via the quantum efficiency of the material
Implementation Method 3
the light beam is scanned into the monitored area and is only registered in a light receiver when there is an object in the monitored area from which the light beam is reflected
Implementation Method 4
Photoelectric sensors are very often used to determine the presence of objects in a surveillance area
Data Source
Figure 1~2b
Figure 3~4
Figure 5a~6
AI summary
An optoelectronic sensor (10), in particular a photoelectric sensor, is described, comprising a light transmitter (12) for emitting transmitted light (16) into a monitoring area (18) and a light receiver (26) for receiving the transmitted light (22) reflected or remitted by objects (20) in the monitoring area (18), wherein the light transmitter (12) has a line array of several laser single emitters (12a-d) or LED single emitters (12a-d). The single emitters (12a-d) are formed on the same semiconductor crystal (44), and a common driver circuit (32) is provided with which the single emitters (12a-d) can be activated synchronously.