VCSEL Optical Range-Finding Sensor for Compact Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional optical range-finding sensors using semiconductor light-emitting diodes face challenges in achieving high accuracy and compact size due to the omnidirectional emission of light, leading to reduced irradiation light intensity and increased size, as well as difficulties in incorporating the light-emitting and light-receiving elements within a single package.
Innovation Solution
The use of a vertical cavity surface emitting laser as the light-emitting element, which provides high directivity for irradiation and reception of light, allowing for a compact design with reduced power consumption and cost, and enabling high accuracy by sealing the light-emitting, light-receiving, and control processing elements in a single resin package.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a semiconductor light-emitting diode is used as the light-emitting element, then the structure is simple and cost is reduced, but the light emission is omnidirectional causing reduced irradiation light intensity and increased size requirements
Solution Approach 1:
The patent changes the fundamental parameter of light emission directionality by replacing the omnidirectional LED with a VCSEL that emits light in a specific direction (typically perpendicular to the substrate). This parameter change resolves the contradiction by providing both sufficient irradiation intensity in the target direction and structural simplicity through the vertical cavity design.
Solution Approach 2:
Instead of trying to collect omnidirectional light from an LED using large lenses, the patent inverts the approach by using a VCSEL that naturally emits light in the desired direction. This inversion eliminates the need for complex light collection optics and resolves the contradiction between emission intensity and structural complexity.
2Illumination intensity
If the focal distance and diameter of the light-emitting side lens are increased to collect sufficient irradiation light, then the irradiation light intensity is improved, but the overall sensor size increases
Solution Approach 1:
The patent changes the emission pattern parameter from omnidirectional to directional, which eliminates the need for large focal distance and diameter lenses. The VCSEL's inherent directionality allows for compact lens design while maintaining sufficient irradiation intensity, thus resolving the size-intensity contradiction.
Solution Approach 2:
The patent extracts the light collection function from the lens system by using a light source (VCSEL) that already provides directional emission. This extraction eliminates the need for large lenses, resolving the contradiction between irradiation intensity and sensor size.
3Ease of manufacture
If a semiconductor light-emitting diode is used, then cost is reduced, but it is impossible to incorporate the diode with the position detecting light-receiving element and control processing integrated circuit in the same light-transmitting resin sealed package
Solution Approach 1:
The patent merges the light-emitting element (VCSEL), position detecting light-receiving element, and control processing integrated circuit into a single light-transmitting resin sealed package. This merging is enabled by the VCSEL's directional emission特性, which allows close proximity placement without optical interference, thus resolving the integration complexity issue while maintaining cost-effectiveness.
Solution Approach 2:
The patent transitions from planar arrangement to three-dimensional integration within the sealed package. The VCSEL's vertical emission structure allows stacking and close placement of components in the vertical dimension, enabling integration that would be impossible with omnidirectional LED emission in a planar configuration.
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 ensures sufficient light for range finding with reduced size and power consumption, improving detection accuracy and enabling the creation of a compact, reliable, and cost-effective optical range-finding sensor.
Implementation Method 1
the light-emitting element is a vertical cavity surface emitting laser
Implementation Method 2
a light-emitting side lens that collects the irradiation light and irradiates the light to a range-finding object
Implementation Method 3
reflected light Lr that is the irradiation light Ls reflected by the range-finding object MO
Implementation Method 4
a light-receiving side lens that collects reflected light Lr
Implementation Method 5
a position detecting light-receiving element that receives the collected reflected light and detects the position of the range-finding object
Data Source
AI summary
An optical range-finding sensor includes a light-emitting element that emits irradiation light, a light-emitting side lens that collects the irradiation light and irradiates the light to a range-finding object, a light-receiving side lens that collects reflected light of the irradiation light reflected by the range-finding object, a position detecting light-receiving element that receives the collected reflected light and detects a position of the range-finding object, and a control processing integrated circuit that controls light emission of the light-emitting element and processes a detection current of the position detecting light-receiving element. The light-emitting element is configured of a vertical cavity surface emitting laser.