MEMS Optical Device Scanning Range Stabilization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical devices for distance measurement face challenges in accurately separating reflected light from ambient light due to individual variations in light emitting elements, leading to variations in scanning range and optical path, which affect measurement accuracy.
Innovation Solution
An optical device comprising an emitting unit, a scanning unit, an optical member that guides light based on wavelength, and a control unit to suppress variations in the scanning range by adjusting the optical path and emission timing, ensuring that only light of the same wavelength is received, thereby improving separation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a bandpass filter with a certain wavelength width is used to separate reflected light from ambient light, then the separation accuracy is improved, but the scanning range varies due to wavelength variations
Solution Approach 1:
The patent adjusts the center wavelength of the bandpass filter to match the actual emission wavelength of the light source, compensating for individual variations. This parameter adjustment allows the filter to maintain high separation accuracy while the control unit compensates for scanning range variations by adjusting emission timing.
Solution Approach 2:
The control unit monitors the actual emission wavelength and adjusts the emission timing based on this feedback. This closed-loop control compensates for wavelength variations, preventing scanning range shifts while maintaining the benefits of the bandpass filter for light separation.
2Measurement precision
If the center wavelength of the bandpass filter is adjusted to follow the emission wavelength, then the separation accuracy is maintained, but the device complexity increases
Solution Approach 1:
Instead of using a mechanically complex wavelength-tunable filter, the patent uses an electronically controlled bandpass filter with a fixed center wavelength that is adjusted during manufacturing to match the light source. This replaces potential mechanical adjustment mechanisms with a simpler electronic solution.
Solution Approach 2:
The center wavelength of the bandpass filter is set as a fixed parameter during manufacturing based on the light source characteristics, eliminating the need for dynamic adjustment mechanisms and reducing device complexity while maintaining separation accuracy.
3Stability of the object's composition
If the emission timing is adjusted to compensate for optical path changes, then the scanning range stability is improved, but the control complexity increases
Solution Approach 1:
The control unit uses feedback from wavelength monitoring to adjust emission timing, creating a closed-loop system that automatically compensates for optical path changes. This feedback mechanism maintains scanning range stability without requiring complex manual intervention.
Solution Approach 2:
The system automatically compensates for its own wavelength variations by monitoring and adjusting emission timing internally. This self-service capability eliminates the need for external calibration or complex manual control mechanisms.
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 effectively stabilizes the scanning range and enhances the accuracy of distance measurement by maintaining consistent optical paths for emitted and reflected light, even with changes in wavelength, thereby improving the separation of reflected light from ambient light.
Implementation Method 1
an optical member that guides the emitted light to the scanning unit by guiding the emitted light in a direction corresponding to a wavelength
Data Source
AI summary
Provided is an optical device capable of suppressing variations in the range for scanning light. This optical device comprises: a light source that emits a laser beam; a MEMS mirror that scans the laser beam toward a predetermined range; and a diffraction grating that guides the laser beam to the MEMS mirror by guiding the laser beam in a direction corresponding to the wavelength thereof. The optical device also comprises an MEMS control unit that performs control such that, by employing a change in the optical path of the laser beam caused through the diffraction grating by a change in the wavelength of the laser beam, variations in the scanning range of the laser beam by the MEMS mirror are suppressed.