Movable Grating Spectral Measurement Device
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Solution Overview
Problem
Existing miniaturized spectrometers face challenges in stably separating light at a low cost due to the difficulties in spectral separation with small devices, particularly due to vibrations and high costs associated with using compound semiconductor photodiode arrays.
Innovation Solution
A spectral measurement device employing a light reflection grating with movable gratings and a movable grating drive unit, which alters the grating pattern to separate light effectively, coupled with a light detecting element and a computation unit to calculate light intensities at different wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a one-dimensional array sensor with compound semiconductor photodiodes is used for spectral separation, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent divides the spectral measurement function into two separate components: (1) a simple one-dimensional array sensor that only detects light intensity without requiring complex photodiode materials, and (2) a diffraction grating that performs the spectral separation function. This segmentation allows the sensor to be simpler while the grating handles the complex spectral dispersion task, resolving the contradiction between measurement precision and device complexity.
Solution Approach 2:
The patent replaces the need for complex compound semiconductor photodiode arrays with a mechanical/optical system using a diffraction grating. Instead of relying on complex semiconductor materials arranged in arrays, the system uses the physical diffraction phenomenon to separate wavelengths, with a simple photodiode array detecting the spatially separated light. This substitution achieves spectral measurement precision without the complexity of compound semiconductor arrays.
2Measurement precision
If a diffraction grating is rotated to separate light wavelengths, then spectral measurement capability is improved, but reliability deteriorates due to vibrations
Solution Approach 1:
The patent transitions from a static grating system to a dynamic one where the diffraction grating can be rotated or translated to change the dispersed light pattern across the photodiode array. This dynamic capability allows spectral measurement without requiring the grating to rotate during measurement, as the dispersed pattern can be captured in a fixed position, eliminating vibration-induced reliability issues while maintaining spectral separation capability.
3Ease of operation
If the spectrometer is miniaturized for portable use, then ease of operation is improved, but manufacturing precision requirements increase
Solution Approach 1:
The patent segments the spectrometer into modular components: a standard one-dimensional photodiode array (available in compact forms), a diffraction grating, and minimal additional optics. This segmentation allows each component to be manufactured using standard processes without requiring extreme precision, enabling miniaturization while avoiding prohibitively high manufacturing precision requirements.
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 reliable and cost-effective spectral measurements without the need for rotating the grating, improving the reliability and miniaturization of the device while reducing manufacturing costs.
Implementation Method 1
a light reflection grating including a plurality of movable gratings arranged side by side along a lateral direction... configured to displace the plurality of movable gratings to alter a grating pattern of the light reflection grating
Implementation Method 2
a light detecting element configured to detect light that is incident on the light reflection grating and reflected by the light reflection grating
Data Source
AI summary
A spectral measurement device includes a light reflection grating having a plurality of movable gratings and a movable grating drive unit that displaces the movable gratings to alter a grating pattern of the light reflection grating, a light detecting element that detects light incident on the light reflection grating, a storage unit storing a relationship between a light quantity to be detected by the light detecting element and corresponding light intensities at differing wavelengths for different grating patterns, and a computation unit that calculates light intensities at the differing wavelengths of the light incident on the light reflection grating based on the light quantity of the incident light detected by the light detecting element for each of the different grating patterns by altering the grating pattern based on the relationship between the light quantity and the corresponding light intensities for the different grating patterns stored in the storage unit.