US4568187A
Expired / Lapsed
US
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Concave grating spectrometer
Assignee: Hitachi Ltd
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Filing: 1983-06-15
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Granted: 1986-02-04
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Expires: 2003-06-15
Abstract
Abstract In a concave grating spectrometer for creating a spectral image by dispersing a light to be measured according to the wavelength, an arrangement comprising a concave grating with varied spacing and/or curved grooves formed on a concave spherical surface, and an entrance slit located at such a position on a vertical focal line passing through the center of curvature of the spherical surface, that the sum of the square of the difference between horizontal and vertical focal lengths at each wavelength in the wavelength range takes a minimum value. The light to be measured projected through the entrance slit is dispersed by the concave grating according to the wavelength and an image is focused on the vertical focal line passing through the center of curvature of the spherical grating.
Inventors
- 👤 Toshiaki Kita
- 👤 Tatsuo Harada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:14
CPC Classifications
G; G01; G01J; G01J3/00; G01J3/12; G01J3/18
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
160 words
A concave grating spectrometer having a concave grating for dispersing a light to be measured in a wavelength range, according to the wavelength and for providing a spectral image, comprising: a concave grating having varied spacing and/or curved grooves formed on a concave spherical surface, which can produce a horizontal focal line crossing a vertical focal line; entrance slit means disposed at such a position on the vertical focal line passing through the center of curvature of the spherical surface so that the sum of the square of the difference between horizontal and vertical focal lengths at each wavelength in the wavelength range takes a minimum value, whereby the light to be measured incident through said entrance slit means on the grating is dispersed thereby according to the wavelength and an image is focused by said concave grating on the vertical focal line passing through the center of curvature; and a light detecting means located at the image focusing position.
Claim 2
Dependent Claim
160 words
A concave grating spectrometer having a concave grating for dispersing a light to be measured in a wavelength range, according to the wavelength and for providing a spectral image, comprising: a concave grating having varied spacing and/or curved grooves formed on a concave spherical surface, which can produce a horizontal focal line crossing a vertical focal line; entrance slit means disposed at such a position on the vertical focal line passing through the center of curvature of the spherical surface so that the sum of the square of the difference between horizontal and vertical focal lengths at each wavelength in the wavelength range takes a minimum value, whereby the light to be measured incident through said entrance slit means on the grating is dispersed thereby according to the wavelength and an image is focused by said concave grating on the vertical focal line passing through the center of curvature; and a light detecting means located at the image focusing position.
Claim 3
Dependent Claim
20 words
A concave grating spectrometer according to claim 1, wherein said entrance slit means comprises a plurality of aligned pin holes.
Claim 4
Dependent Claim
17 words
A concave grating spectrometer according to claim 1, wherein said light detecting means comprises a photodiode array.
Claim 5
Dependent Claim
23 words
A concave grating spectrometer according to claim 1, wherein concave grating has varied spacing and curved grooves formed on a concave spherical surface.
Claim 6
Dependent Claim
169 words
A concave grating spectrometer having a concave grating for dispersing a light to be measured in a wavelength range according to the wavelength and for providing a spectral image, comprising: a concave grating having varied spacing and/or curved grooves formed on a concave spherical surface, which can produce a horizontal focal line crossing a vertical focal line; entrance slit means disposed at such a position on the vertical focal line passing through the center of curvature of the spherical surface so that the sum of the square of the difference between horizontal and vertical focal lengths at each wavelength in the wavelength range takes a minimum value; means for forming an image on the vertical focal line passing through the center of curvature; whereby a light to be measured, incident through said entrance slit means, is dispersed by said concave grating according to the wavelength and an image is focused by said concave grating on the vertical focal line; and a light detector located at the image focusing position.
Claim 7
Dependent Claim
169 words
A concave grating spectrometer having a concave grating for dispersing a light to be measured in a wavelength range according to the wavelength and for providing a spectral image, comprising: a concave grating having varied spacing and/or curved grooves formed on a concave spherical surface, which can produce a horizontal focal line crossing a vertical focal line; entrance slit means disposed at such a position on the vertical focal line passing through the center of curvature of the spherical surface so that the sum of the square of the difference between horizontal and vertical focal lengths at each wavelength in the wavelength range takes a minimum value; means for forming an image on the vertical focal line passing through the center of curvature; whereby a light to be measured, incident through said entrance slit means, is dispersed by said concave grating according to the wavelength and an image is focused by said concave grating on the vertical focal line; and a light detector located at the image focusing position.
Claim 8
Dependent Claim
22 words
A concave grating spectrometer according to claim 5, wherein said entrance slit means comprises an alignment of a plurality of pin holes.
Claim 9
Dependent Claim
16 words
A concave grating spectrometer according to claim 5, wherein said light detector comprises a photodiode array.
Claim 10
Dependent Claim
24 words
A concave grating spectrometer according to claim 5, wherein said concave grating has varied spacing and curved grooves formed on a concave spherical surface.
References Cited (Backward Citations)
US4012843A
Cited
US4030828A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |