Optoelectronic Sensor Field Lens Equidistant Axes
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Solution Overview
Problem
Optical rotation angle sensors face low light yield due to divergent light sources and mechanical tolerances, leading to poor signal quality and restricted resolution and accuracy, as well as installation space constraints and increased production costs in reflective systems with separate light paths.
Innovation Solution
An optoelectronic sensor design featuring a field lens with a short focal length, positioned equidistant from the light transmitter and receiver optical axes, collimates transmitted light and focuses reflected light, allowing for higher light yield and mechanical freedom while minimizing direct crosstalk and space requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If divergent light sources (e.g., LEDs) are used, then the device complexity is reduced, but the light yield at the receiver becomes very low
Solution Approach 1:
A beam shaping component is introduced as an intermediary element between the LED light source and the modulator. This component collimates the divergent light from the LED and directs it toward the modulator, significantly improving the light yield at the receiver without requiring a more complex light source
Solution Approach 2:
The patent changes the spatial distribution parameters of the light beam by using optical components to transform the divergent light from the LED into a more directed beam. This parameter change (from divergent to collimated/directed) improves the light yield while keeping the simple LED source
2Object-affected harmful factors
If reflective systems with separate light paths are used, then direct crosstalk between transmitter and receiver is avoided, but the installation space increases
Solution Approach 1:
The patent merges the illumination and detection light paths by using a single modulator that both modulates the transmitted light and reflects the modulated light back to the receiver. This combining of functions reduces the lateral distance requirements between transmitter and receiver while still avoiding direct crosstalk through the modulator's modulation action
Solution Approach 2:
The modulator serves multiple functions: it modulates the transmitted light to encode measurement information and simultaneously reflects the modulated light back to the receiver. This multi-functionality allows the system to operate with reduced installation space while maintaining the ability to avoid direct crosstalk
3Illumination intensity
If beam shaping optical components are used to direct light, then the light yield at the receiver is improved, but the device complexity and production costs increase
Solution Approach 1:
The patent uses relatively simple and cost-effective optical components for beam shaping rather than complex precision optics. The beam shaping component is designed to be a practical, affordable element that provides sufficient light direction without requiring expensive manufacturing or precise alignment mechanisms
Solution Approach 2:
The beam shaping component is designed to provide adequate light direction with moderate optical parameters rather than requiring perfect collimation or focusing. This parameter optimization reduces the complexity and cost of the optical component while still achieving improved light yield
4Ease of operation
If mechanical tolerances are relaxed for greater freedom of movement, then the ease of operation is improved, but the signal quality deteriorates
Solution Approach 1:
The beam shaping component acts as an intermediary that creates a more robust optical path less sensitive to mechanical tolerances. By pre-collimating and directing the light beam, the system becomes more tolerant of variations in component positioning and movement, maintaining signal quality with greater mechanical freedom
Solution Approach 2:
The optical design incorporates built-in tolerance compensation through the beam shaping approach. The collimated beam and optimized light path are designed to accommodate expected mechanical variations, cushioning against the deteriorating effect of tolerances on signal quality
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 design achieves a higher light yield and greater mechanical freedom, improving signal quality and reducing production costs by ensuring a compact, robust, and sensitive sensor with adjustable beam paths and reduced sensitivity to defects or dirt.
Implementation Method 1
the transmitted light is collimated, in particular parallelized, by the field lens
Implementation Method 2
the reflected light is focused by the field lens
Data Source
Figure 1
AI summary
To ensure increased light yield for improved signal evaluation, an optoelectronic sensor (10) is provided, particularly for detecting a rotation angle, comprising a light source (1) that emits transmitting light (SL) in a transmitting light direction and has a first light axis (1a), a modulator (2) that modulates the transmitting light (SL) and reflects it as a return light (RL) and has a second light axis (2a), and a light receiver (3) that receives the return light (RL) and has a third light axis (3a), wherein the modulator (2) is rotatably arranged relative to the light source (1) and the light receiver (3), the light source (1) and the light receiver (3) are arranged opposite the modulator (2), and a field lens (4) with an optical axis (4a) is arranged between the modulator (2) and the two light sources (1) and light receiver (3), and wherein the field lens (4) is arranged such thatthat the optical axis (4a) is located at an equal distance (A) from the first and third light axes (1a, 3a).