US3741654A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Measuring apparatus
Assignee: Farrand Optical Co Inc
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Filing: 1972-03-01
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Granted: 1973-06-26
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Expires: 1992-03-01
Abstract
Abstract Disclosed is a non-contacting measuring system relying upon the difference in the focal points of two transmitted, differently modulated, coaxial light bundles. The difference in intensity of the light reflected back from a to-be-measured object located between the focal points of the two light bundles defines the precise location of the object relative to the two focal points.
Inventors
- 👤 I Brenholdt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:13
CPC Classifications
G; G01; G01C; G01C3/00; G01C3/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
75 words
A measuring apparatus comprising, means for modulating first and second light bundles with first and second different characteristics, means for focusing said light bundles at first and second different focal points, means for detecting resultant radiation from an object located between said focal points whereby the relative position of said object between said focal points is measured by the difference in energy in said resultant radiation derived from said first and said second light bundles.
Claim 2
Dependent Claim
75 words
A measuring apparatus comprising, means for modulating first and second light bundles with first and second different characteristics, means for focusing said light bundles at first and second different focal points, means for detecting resultant radiation from an object located between said focal points whereby the relative position of said object between said focal points is measured by the difference in energy in said resultant radiation derived from said first and said second light bundles.
Claim 3
Dependent Claim
18 words
The apparatus of claim 1 wherein said means for modulating modulates said light bundles at two different frequencies.
Claim 4
Dependent Claim
50 words
The apparatus of claim 2 wherein said means for modulating includes a source of radiation, a light chopping wheel having two different sets of alternating transparent and opaque areas of different frequencies, means for transmitting light from said source through said sets to modulate said light at two different frequencies.
Claim 5
Dependent Claim
27 words
The apparatus of claim 1 wherein said means for focusing coaxially focuses said first and second light bundles whereby said first and second focal points are coaxial.
Claim 6
Dependent Claim
19 words
The apparatus of claim 4 wherEin said means for detecting is coaxial with said first and second light bundles.
Claim 7
Dependent Claim
50 words
The apparatus of claim 5 wherein said detecting means includes an optical detector for forming an electrical signal and means for filtering said electrical signal at two different frequencies corresponding to the two different frequencies of modulation and including means for forming the difference between the two filtered electrical signals.
References Cited (Backward Citations)
US3523731A
Cited
US3523732A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |