US3770355A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thick window transmission spectrophotometer and method
Assignee: Optical Coating Laboratory Inc
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Filing: 1972-05-31
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Granted: 1973-11-06
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Expires: 1992-05-31
Abstract
Abstract A spectrophotometer for ascertaining transmission of enery by a test piece and having a housing with a source of energy in the housing and means carried by the housing for forming an image limiting aperture. Optical means within the housing is provided for receiving energy from the source for forming a beam of energy and imaging the source in the aperture. Means is provided for chopping the beam. Filter means is provided for passing selected narrow spectral bands of energy in the beam. Optical means is provided for receiving energy passing through the aperture and includes collimating means and means for causing the beam to be tilted at an angle with respect to the test piece. Means including a detector is provided for receiving the beam after it has passed through the test piece. In the method, a beam of energy is provided which is collimated and is offset at an angle with respect to the test piece so that back reflected energy is substantially eliminated and will not influence the tests being made on the test piece. Tests are made with and without the test piece in the beam.
Inventors
- 👤 E Anthon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:28
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01M; G01M11/00; G01N21/17; G01N21/59; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24802; Y10T428/24843; Y10T428/28; Y10T428/2813; Y10T428/2817; Y10T428/2826
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
175 words
In a spectrophotometer for testing optical transmission properties of a relatively thick test piece, a housing, a source of energy disposed on the housing, means forming an image limiting aperture in the housing, optical means within the housing for receiving energy from the source and forming a beam of the energy and for forming an image of the source in the aperture, detector means and optical means for receiving energy passing through the aperture, and for supplying energy to the detector, said last named optical means including means for collimating the energy in the beam prior to the time that it passes through the test piece and also including means for causing the beam to be tilted with respect to the test piece by a sufficient angle so that substantially all energy which is reflected by the test piece is at an angle so that such reflected energy is out of the optical path and will not have any significant effect on the amount of energy from the beam which passes through the test piece.
Claim 2
Dependent Claim
175 words
In a spectrophotometer for testing optical transmission properties of a relatively thick test piece, a housing, a source of energy disposed on the housing, means forming an image limiting aperture in the housing, optical means within the housing for receiving energy from the source and forming a beam of the energy and for forming an image of the source in the aperture, detector means and optical means for receiving energy passing through the aperture, and for supplying energy to the detector, said last named optical means including means for collimating the energy in the beam prior to the time that it passes through the test piece and also including means for causing the beam to be tilted with respect to the test piece by a sufficient angle so that substantially all energy which is reflected by the test piece is at an angle so that such reflected energy is out of the optical path and will not have any significant effect on the amount of energy from the beam which passes through the test piece.
Claim 3
Dependent Claim
27 words
A spectrophotometer as in claim 1 together with filter means disposed in the beam for passing only selected relatively narrow spectral bands of energy in the beam.
Claim 4
Dependent Claim
44 words
A spectrophotometer as in claim 2 wherein said filter means comprises a plurality of separate filters, with each of the filters passing only a relatively narrow spectral band of energy the beam and means for selectively positioning each of said filters in said beam.
Claim 5
Dependent Claim
27 words
A spectrophotometer as in claim 1 together with means for chopping the beam at a predetermined frequency, and means for demodulating the output from the detector means.
Claim 6
Dependent Claim
31 words
A spectrophotometer as in claim 4 together with means operated in conjunction with said means for selecting one of said filters for inserting a selected value of resistance in said output.
Claim 7
Dependent Claim
21 words
A spectrophotometer as in claim 5 wherein said resistance means includes coarse and fine trimming potentiometers for each of said filters.
Claim 8
Dependent Claim
76 words
A spectrophotometer as in claim 4 together with a reference source of energy, means for chopping said reference source of energy at a frequency which is proportional to the frequency that said beam is chopped, and means for detecting energy from said reference source after it has been chopped, and wherein said means for demodulating the output includes means for phase sensitive demodulating said output using the detected energy from said reference source as a reference
Claim 9
Dependent Claim
49 words
A spectrophotometer as in claim 1 which is adapted to measure test pieces of various thicknesses, and means for adjusting the position of the detector means to make it possible to provide equivalent optical paths through air for the beam with and without the test piece in the beam.
Claim 10
Dependent Claim
46 words
A spectrophotometer as in claim 1 wherein said housing is provided with an opening to permit said beam to pass therethrough together with a carriage mounted on said housing adapted to carry said test piece for moving said test piece into and out of said beam.
Claim 11
Dependent Claim
21 words
A spectrophotometer as in claim 9 together with means mounted on said housing for moving said carriage between said two positions.
Claim 12
Dependent Claim
24 words
A spectrophotometer as in claim 1 together with beam blocking means mounted in said housing and having a blocking filter movable into said beam.
Claim 13
Dependent Claim
35 words
A spectrophotometer as in claim 11 wherein said blocking filter is inclined at an angle to the axis for said beam so that energy reflected by the blocking filter is directed out of the beam.
Claim 14
Dependent Claim
17 words
A spectrophotometer as in claim 12 wherein said blocking filter has approximately 2 - 7 micron range.
Claim 15
Dependent Claim
39 words
A spectrophotometer as in claim 1 in which a limiting aperture is carried by the housing which has a size which is less than the cross-sectional area of the beam so that the aperture is over-filled by the beam.
Claim 16
Dependent Claim
28 words
A spectrophotometer as in claim 14 wherein said beam is formed so that the energy of said beam is substantially uniform over The cross-sectional area of the beam.
Claim 17
Dependent Claim
24 words
A spectrophotometer as in claim 1 wherein said first named optical means includes an optical element having a concave surface for forming the beam.
Claim 18
Dependent Claim
58 words
A spectrophotometer as in claim 16 wherein said second named optical means for receiving energy after it has passed through the aperture includes an optical element providing a concave surface for forming a collimated beam and another optical element for receiving the collimated beam for collecting the energy from the beam and focusing the same on the detector.
Claim 19
Dependent Claim
27 words
A spectrophotometer as in claim 17 wherein said optical collecting means is smaller than the cross-sectional area of the collimated beam to thereby form said limiting aperture.
Claim 20
Dependent Claim
23 words
A spectrophotometer as in claim 1 wherein said means forming an image limiting aperture includes means for adjusting the size of the aperture.
Claim 21
Dependent Claim
97 words
In a method for measuring the transmission of thick test pieces, introducing a collimated beam of energy through said test piece tilted at an angle with respect to said test piece so that energy reflected by the test piece will be thrown out of the optical path of the beam passing through the test piece, measuring the energy in the beam with the test piece out of the beam to provide a reference measurement, and thereafter measuring the energy of the beam passing through the test piece to determine the transmission of energy through the test piece.
Claim 22
Dependent Claim
97 words
In a method for measuring the transmission of thick test pieces, introducing a collimated beam of energy through said test piece tilted at an angle with respect to said test piece so that energy reflected by the test piece will be thrown out of the optical path of the beam passing through the test piece, measuring the energy in the beam with the test piece out of the beam to provide a reference measurement, and thereafter measuring the energy of the beam passing through the test piece to determine the transmission of energy through the test piece.
Claim 23
Dependent Claim
19 words
A method as in claim 20 wherein said first and second measurements are made through optically equivalent air paths.
Claim 24
Dependent Claim
32 words
A method as in claim 20 wherein said first and second measurements are made utilizing one at a time of a plurality of relatively narrow spectral bands of energy from the beam.
Claim 25
Dependent Claim
30 words
A method as in claim 20 together with the step of forming the energy from the source into a beam and forming an image of the source in an aperture.
Claim 26
Dependent Claim
19 words
A method as in claim 20 together with the step of chopping the beam and detecting the measured information.
Claim 27
Dependent Claim
25 words
A method as in claim 20 wherein said beam is tilted with respect to the test piece at an angle ranging from 4* to 10*.
Claim 28
Dependent Claim
38 words
A method as in claim 24 together with the step of forming a chopped reference signal which is chopped at the same frequency as the beam, utilizing said chopped reference signal to phase sensitive demodulate the detected information.
Claim 29
Dependent Claim
21 words
A method as in claim 26 together with the step of compensating the detecting output in accordance with the spectral region.
References Cited (Backward Citations)
US3628872A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |