US4498773A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pencil beam interferometer
Assignee: Boeing North American Inc
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Filing: 1983-05-04
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Granted: 1985-02-12
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Expires: 2003-05-04
Abstract
Abstract An interferometer which provides for the precise figure measure of optical surfaces through the interference of two pencil beams, reflected off the optical surface, comprises a laser for generating a laser beam which is split into two parallel beams by a beam splitter and a mirror, the two pencil beams are reflected off a second beam splitter, through an alignment invariant optical device and onto the optical surface to be measured. The two pencil beams are reflected and back-trace through the alignment invariant optical device, propagate through the second beam splitter and enter an optical lens which is capable of focusing two beams in its back focal plane where the interference of the two pencil beams takes place. This information is then relayed through optical spatial filter and optional micro objective into the readout section.
Inventors
- 👤 Karlheinz Von Bieren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:23
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/30; G01B11/306; G01B9/00; G01B9/02; G01B9/02055; G01B9/02056; G01B9/02061
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
181 words
A pencil beam interferometer for measuring optical surfaces, comprises: a light beam; a first beam splitter optically oriented to receive and to split said incoming light beam into a first and a second pencil beam; means for deflecting said second pencil beam, wherein said deflected second pencil beam is displaced from but parallel to said first pencil beam; means for redirecting and transmitting said parallel pencil beams while concurrently maintaining them in parallel; an alignment invariant optical device disposed to receive the output of said means for redirecting and transmitting said parallel pencil beams, and wherein said alignment invariant optical device directs said pencil beams to the optical surface to be measured; an optical lens capable of focusing said two pencil beams in its back focal plane, and wherein said optical lens is disposed to receive the reflected pencil beams from said optical surface after they pass back through said alignment invariant optical device and said means for redirecting and transmitting said parallel pencil beams; and a readout section optically positioned to detect the interference pattern generated by said focused beams.
Claim 2
Dependent Claim
181 words
A pencil beam interferometer for measuring optical surfaces, comprises: a light beam; a first beam splitter optically oriented to receive and to split said incoming light beam into a first and a second pencil beam; means for deflecting said second pencil beam, wherein said deflected second pencil beam is displaced from but parallel to said first pencil beam; means for redirecting and transmitting said parallel pencil beams while concurrently maintaining them in parallel; an alignment invariant optical device disposed to receive the output of said means for redirecting and transmitting said parallel pencil beams, and wherein said alignment invariant optical device directs said pencil beams to the optical surface to be measured; an optical lens capable of focusing said two pencil beams in its back focal plane, and wherein said optical lens is disposed to receive the reflected pencil beams from said optical surface after they pass back through said alignment invariant optical device and said means for redirecting and transmitting said parallel pencil beams; and a readout section optically positioned to detect the interference pattern generated by said focused beams.
Claim 3
Dependent Claim
21 words
The interferometer of claim 1 wherein said means for redirecting and transmitting said parallel pencil beams is a second beam splitter.
Claim 4
Dependent Claim
13 words
The interferometer of claim 1 wherein said alignment invarient device is a prism.
Claim 5
Dependent Claim
12 words
The interferometer of claim 3 wherein said prism is a penta prism.
Claim 6
Dependent Claim
12 words
The interferometer of claim 3 wherein said prism is a deflection prism.
Claim 7
Dependent Claim
12 words
The interferometer of claim 3 wherein said prism is a rhomb prism.
Claim 8
Dependent Claim
31 words
The interferometer of claim 1 further comprising a spatial filter and micro objective optically aligned between said optical lens and said readout to enhance the interference pattern inputted to said readout.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |