Spectrometer Package Curved Surface Grating Groove Positioning
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Solution Overview
Problem
Conventional spectrometers experience positional deviations in grating grooves due to distortions caused by temperature changes or external forces, leading to compromised spectral characteristics.
Innovation Solution
A spectrometer design featuring a package with a first area of grating grooves on a curved surface and a surrounding second area on the same continuous curved surface, along with orthogonal grooves on the package's outer face, which disperses distortions and prevents positional deviations, and a light transmitting substrate for precise alignment of the photodetector.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the grating groove is fixed on a planar area surrounded by a curved surface, then the spectroscopic unit can be manufactured, but distortion concentrates at the boundary causing positional deviation in the grating groove
Solution Approach 1:
The patent applies curvature throughout the package inner wall face, forming both the first area with grating grooves and the surrounding second area on the same continuous curved surface. This eliminates the boundary between planar and curved regions, preventing distortion concentration and maintaining grating groove positional accuracy while enabling manufacturing.
2Reliability
If the package structure is made thick to resist distortion, then positional deviation is inhibited, but the device size increases
Solution Approach 1:
The curved surface design allows the package to achieve sufficient thickness and structural rigidity to resist distortion while maintaining a compact overall size. The curvature distributes mechanical stress more effectively than a planar design, providing reliability without excessive volume.
3Manufacturing precision
If grooves are added to the package outer face to prevent sink marks, then manufacturing quality improves, but the structure becomes more complex
Solution Approach 1:
The package outer face is segmented with grooves that extend in a direction orthogonal to the grating groove arrangement direction. These grooves divide the surface into sections, preventing sink mark formation during resin-molding while maintaining a relatively simple overall structure that does not interfere with the spectroscopic unit.
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 effectively inhibits positional deviations in the grating grooves, maintaining spectral characteristics and ensuring precise light detection even under thermal or external stress.
Implementation Method 1
a spectroscopic unit for spectrally resolving the incident light into a spectrum
Implementation Method 2
a photodetector for detecting the spectrally resolved light
Data Source
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AI summary
A spectrometer 1, in which a spectroscopic unit 3 spectrally resolves and reflects light L1 having entered the inside of a package 2 while a photodetector 4 detects reflected light L2, comprises a package 2 accommodating the photodetector 4 therein. The package 2 has a semispherical recess 10, while the recess 10 has a bottom face formed with an area 12 having a plurality of grating grooves 14 arranged in a row along a predetermined direction and an area 13 surrounding the area 12. The areas 12 and 13 are continuous with each other and formed on the same curved surface. This can inhibit the grating grooves 14 from shifting their positions even when distortions are generated in the package 2.