US4544271A
Expired / Lapsed
US
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Densitometer
Assignee: Shimadzu Corp
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Filing: 1982-11-26
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Granted: 1985-10-01
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Expires: 2002-11-26
Abstract
Abstract A densitometer wherein a sample to be measured is illuminated and the light transmitted through or reflected by the sample is passed through a slit and dispersed by a dispersing element so that a spectral image of the sample as defined by the slit is formed on the image plane of the dispersing element. A plurality of image sensors each comprising a linear array of photodiodes are disposed on the image plane in such a manner that each of the image sensors substantially conform to one of the images of the slit formed by different wavelengths. The outputs from the photodiodes are processed by a computer to provide desired information about the sample.
Inventors
- 👤 Hiroshi Yamamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:10
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/59; G01N21/5907; G01N21/5911; G01N30/00; G01N30/90; G01N30/95
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
138 words
A densitometer comprising: means for supporting a sample to be measured; an entrance slit adjacent said sample supporting means; means for illuminating said sample and projecting an image of said sample onto said slit; means for spectrally dispersing an image section, passing through and defined by said slit, into corresponding spectral lines on an image plane; and at least one photodiode linear array disposed on said image plane so as to substantially conform to a particular one of said spectral lines at a particular frequency, such that each diode of said linear array receives and senses an amount of light of a corresponding segment of said particular spectral line and outputs a signal level accordingly to a computer for processing said signal levels; whereby a density measurement of said image section; at at least one frequency, is provided.
Claim 2
Dependent Claim
138 words
A densitometer comprising: means for supporting a sample to be measured; an entrance slit adjacent said sample supporting means; means for illuminating said sample and projecting an image of said sample onto said slit; means for spectrally dispersing an image section, passing through and defined by said slit, into corresponding spectral lines on an image plane; and at least one photodiode linear array disposed on said image plane so as to substantially conform to a particular one of said spectral lines at a particular frequency, such that each diode of said linear array receives and senses an amount of light of a corresponding segment of said particular spectral line and outputs a signal level accordingly to a computer for processing said signal levels; whereby a density measurement of said image section; at at least one frequency, is provided.
Claim 3
Dependent Claim
13 words
The densitometer of claim 1, wherein said dispersing element is a diffraction grating.
Claim 4
Dependent Claim
17 words
The densitometer of claim 1, further including means for displaying the processed data provided by said computer.
Claim 5
Dependent Claim
42 words
A densitometer as in claim 1, and further comprising: at least one other of said photodiode linear arrays disposed on said image plane and substantially conforming to another of said spectral lines, such that dual-wavelength measurement of said image section is provided.
Claim 6
Dependent Claim
83 words
A densitometer as in claim 1, and further comprising: a plurality of said photodiode linear arrays arranged side by side and disposed on said image plane to form a light receiving surface so that each of said spectral lines is substantially conformed to by a corresponding one of said photodiode linear arrays; and means for providing incremental relative movement between said slit and said sample image such that a successive plurality of said image sections correspond to adjacent portions of said sample image.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |