Optoelectronic Sensor Deflection Element Crosstalk Suppression
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Solution Overview
Problem
Laser scanners face issues with incomplete shielding effects and signal loss due to shadowing effects from transmission tubes, which lead to reduced detection accuracy and range, especially in close-range applications.
Innovation Solution
A deflection element is arranged around the beam path to redirect reflected transmitted light that would otherwise be lost due to shadowing, allowing it to reach the light receiver, thereby increasing the signal level and detection range without compromising the shielding effect against crosstalk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a transmitting tube is used to shield transmitted light and prevent crosstalk, then crosstalk suppression is improved, but signal level and detection range deteriorate due to shadowing effects
Solution Approach 1:
The transmitting tube is divided into multiple sections: a first section that shields the transmitted light beam and a second section with an opening that allows reflected light to pass through. This segmentation enables the tube to simultaneously prevent crosstalk while allowing useful reflected light to reach the detector, resolving the contradiction between crosstalk suppression and signal level maintenance.
Solution Approach 2:
Different sections of the transmitting tube have different optical properties: the first section is opaque to block transmitted light and prevent crosstalk, while the second section has a locally transparent opening to allow reflected light through. This local quality differentiation enables the structure to perform both crosstalk suppression and signal transmission functions simultaneously.
2Object-affected harmful factors
If a transmitting tube is attached to the rotating mirror to shield light, then crosstalk is reduced, but detection range and sensitivity worsen due to shadowing the mirror and receiving optics
Solution Approach 1:
The transmitting tube is segmented into a first section for shielding and a second section with an opening for light passage. This allows the tube to prevent crosstalk while maintaining detection accuracy by allowing reflected light to reach the detector through the opening in the second section.
Solution Approach 2:
The opening in the second section of the transmitting tube acts as an intermediary element that selectively allows reflected light to pass through while blocking transmitted light. This mediator enables both crosstalk prevention and accurate detection to coexist.
3Object-affected harmful factors
If the transmitting tube completely shields the beam path, then crosstalk is eliminated, but useful reflected light is blocked causing signal loss
Solution Approach 1:
The transmitting tube is divided into sections with different functions: the first section provides complete shielding to eliminate crosstalk, while the second section contains an opening that allows useful reflected light to pass through to the detector, preventing signal loss.
Solution Approach 2:
Instead of making the entire transmitting tube opaque to block all light, the invention inverts the approach by making most of it opaque (first section) but strategically transparent (second section with opening) where needed. This inverted thinking allows simultaneous crosstalk elimination and signal preservation.
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
The solution enhances the signal level and detection accuracy by utilizing previously lost light, increasing the effective detection range and sensitivity while maintaining full shielding against crosstalk, and can be produced inexpensively using injection molding or glass.
Implementation Method 1
A deflection element is arranged around the beam path to redirect reflected transmitted light that would otherwise be lost due to shadowing
Implementation Method 2
A light emitter generates transmitted light and sends it into the monitoring area... The corresponding received signal of a light receiver is evaluated
Data Source
Figure 1
Figure 2~3
AI summary
An optoelectronic sensor (10) for detecting objects in a monitoring area (20) is specified, wherein the sensor (10) has a light transmitter (12) for emitting transmitted light (16), a movable deflection unit (18) for periodically deflecting the transmitted light (16), a light receiver (28) for generating a received signal from transmitted light (24) emitted by objects in the monitoring area (20), and a control and evaluation unit (36) for acquiring information about objects in the monitoring area (20) based on the received signal, wherein a shielding device (22) is arranged around the beam path of the transmitted light (16) to suppress crosstalk of the transmitted light (16) to the light receiver (28).In this arrangement, a deflecting element (30, 44) is arranged in the beam path of the remitted transmitted light (24) in order to deflect a portion of the remitted transmitted light (24a-b) to the light receiver (28) which would otherwise hit the shielding device (22) without the deflecting element (30, 44).