Optical Apparatus Wavelength Selection for Surface Shape Measurement
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Solution Overview
Problem
Conventional optical methods for measuring object shapes in a contactless manner often require dispersing light, which can be inefficient and may not accurately capture surface information without direct illumination.
Innovation Solution
An optical apparatus comprising a lighting unit, an imaging unit with wavelength selection regions, and a processor that estimates ray directions based on color phase information, allowing for surface inspection without dispersing light at the lighting side, by using a lighting unit that emits rays with different wavelengths and a sensor to acquire color phase information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If light is dispersed at the lighting side to illuminate the object, then the illumination can be directed, but the device complexity and loss of light increase
Solution Approach 1:
The patent introduces a wavelength selecting unit as an intermediary component between the object and the sensor. This unit selectively transmits specific wavelength components of the reflected light to the sensor, enabling precise measurement without requiring light dispersion at the lighting side. The wavelength selecting unit acts as a mediator that filters and directs only the necessary spectral information to the detection system.
2Illumination intensity
If light is dispersed at the lighting side, then directional illumination is achieved, but the device complexity increases
Solution Approach 1:
The wavelength selecting unit serves as an intermediary that simplifies the overall system architecture. Instead of using complex light dispersion mechanisms at the lighting side, the patent places a wavelength-selective filter at the detection side, which achieves the same measurement capability with simpler illumination optics.
3Loss of information
If conventional light dispersion method is used, then surface information can be acquired, but measurement precision is insufficient
Solution Approach 1:
The patent changes the measurement parameter from general light intensity to wavelength-specific color phase information. By measuring the color phase (spectral characteristics) of reflected light at different wavelengths, the system achieves higher measurement precision for surface inclination and shape, as different surface angles reflect different wavelength components with characteristic phase relationships.
Solution Approach 2:
The wavelength selecting unit acts as an intermediary that enables precise spectral measurement. It separates the reflected light into different wavelength components and directs them to the sensor, allowing the system to capture detailed surface information through wavelength-resolved detection rather than broad-spectrum imaging.
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
Enables accurate measurement of object surface inclinations and shapes by identifying ray directions and inclining angles, improving inspection accuracy and expanding the range of applicable inspection, while maintaining high signal-to-noise ratios.
Implementation Method 1
a first wavelength selection region and a second wavelength selection region. The first wavelength selection region converts a first ray passing through the first wavelength selection region among the illumination rays into a first selected ray whose dominant wavelength is a first wavelength. The second wavelength selection region converts a second ray passing through the second wavelength selection region among the illumination rays into a second selected ray whose dominant wavelength is a second wavelength different from the first wavelength
Implementation Method 2
The sensor is able to acquire color phase information indicating color phases of the first selected ray and the second selected ray
Implementation Method 3
The processor is configured to estimate a ray direction of the first ray and a ray direction of the second ray based on the color phase information and a relative position of the wavelength selecting unit in the imaging unit
Implementation Method 4
The lighting unit emits illumination rays
Data Source
AI summary
According to an embodiment, an optical apparatus includes a lighting unit, an imaging unit, and a processor. The lighting unit emits illumination rays. The imaging unit includes: a wavelength selecting unit including first and second wavelength selection regions; and a sensor. The first wavelength selection region converts a first ray passing through the first wavelength selection region into a first selected ray. The second wavelength selection region converts a second ray passing through the second wavelength selection region into a second selected ray. The sensor can acquire color phase information indicating color phases of the first selected ray and the second selected ray. The processor estimates a ray direction of the first ray and a ray direction of the second ray based on the color phase information and a relative position of the wavelength selecting unit in the imaging unit.