US3702937A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motion detector
Assignee: MICROLENS Inc
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Filing: 1968-05-01
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Granted: 1972-11-14
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Expires: 1988-05-01
Abstract
Abstract A motion detector is disclosed wherein an image of the surveyed field is divided by a planar array of Fresnel biprisms into two portions focused on separate photocells. The photocells are incorporated in a balanced bridge circuit having a signal device connected between the null points of the bridge. Differential lighting from a moving object unbalances the bridge activating the signal device.
Inventors
- 👤 Iben Browning
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:58
CPC Classifications
G; G08; G08B; G08B13/00; G08B13/18; G08B13/189; G08B13/1895; G01; G01V; G01V8/00; G01V8/10
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
96 words
An image motion detector comprising: lens means adapted to form an image of a surveyed field in a plane spaced from said lens means; a planar array of biprisms positioned substantially in the image plane of said lens means and adapted to divide the wave front of an image formed by said lens means into two portions; first and second photoelectric cells spaced from said planar array of biprisms; and second lens means positioned adjacent the planar array of biprisms and adapted to focus the divided image portions on the first and second photoelectric cells respectively.
Claim 2
Dependent Claim
96 words
An image motion detector comprising: lens means adapted to form an image of a surveyed field in a plane spaced from said lens means; a planar array of biprisms positioned substantially in the image plane of said lens means and adapted to divide the wave front of an image formed by said lens means into two portions; first and second photoelectric cells spaced from said planar array of biprisms; and second lens means positioned adjacent the planar array of biprisms and adapted to focus the divided image portions on the first and second photoelectric cells respectively.
Claim 3
Dependent Claim
28 words
An image motion detector as set forth in claim 1 wherein the first and second photoelectric cells are connected respectively in adjacent legs of a balanced bridge circuit.
Claim 4
Dependent Claim
82 words
An image motion detector comprising: image forming means adapted to form an image of a surveyed field in a plane spaced from said image forming means; a planar row of adjacent biprisms positioned in the image plane of said image forming means; second image forming means positioned adjacent the planar row of biprisms and adapted to focus light transmitted through said planar row of biprisms; and first and second photoelectric cells positioned to receive light focused by said second image forming means.
Claim 5
Dependent Claim
82 words
An image motion detector comprising: image forming means adapted to form an image of a surveyed field in a plane spaced from said image forming means; a planar row of adjacent biprisms positioned in the image plane of said image forming means; second image forming means positioned adjacent the planar row of biprisms and adapted to focus light transmitted through said planar row of biprisms; and first and second photoelectric cells positioned to receive light focused by said second image forming means.
Claim 6
Dependent Claim
27 words
An image motion detector as set forth in claim 3 wherein said first and second photoelectric cells are incorporated in adjacent legs of a balanced bridge circuit.
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) | 1975-11-14 | 1976-05-15 | 1976-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-14 | 1980-05-15 | 1980-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-14 | 1984-05-15 | 1984-11-14 | $7700.00 | Window Closed / Lapsed |