US3822940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Velocimeter
Assignee: Singer Co
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Filing: 1972-10-20
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Granted: 1974-07-09
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Expires: 1992-10-20
Abstract
Abstract The present invention relates to velocity measuring devices wherein the center frequency of a pattern of backscattered energy, proportional to the relative velocity between two objects, is detected. In particular it improves the accuracy of prior art systems by desensitizing the device to variations in distance between the device and the reflecting surface. This is achieved by interposing in the receiving section of the device a limiting aperture which restricts the backscattered energy contributing to the detected pattern to that energy which remains identical as the reflected surface passes through the field of illumination of the device.
Inventors
- 👤 L Goldfischer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 13:16
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/36; G01P3/366
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
200 words
In combination with an apparatus for determining the relative velocity between two objects, wherein means are provided for directing a beam of monocromatic wave energy toward one of said objects whereby a portion of said energy is back scattered from the surface of said one object and, wherein lens means for optically resolving the back scattered pattern and for focusing the pattern on means for receiving said back scattered energy including optical grating means and at least one restricted receiving aperature is provided, wherein is provided means for determining the frequency of said pattern and thereby the relative velocity between the two objects, the improvement which comprises the interposition of a telecentric aperature between the optical resolving means and the optical grating means in the path of said back scattered energy, said telecentric aperature to have a maximum diameter governed by the equation: D1 < OR = D3 - D2/2 where D1 is a diameter of the opening in the telecentric aperature D2 is the diameter of the receiving aperature and D3 is the diameter of the lens means, whereby said telecentric aperature will be the limiting aperature in the combination of itself with the lens means and receiving means.
Claim 2
Dependent Claim
200 words
In combination with an apparatus for determining the relative velocity between two objects, wherein means are provided for directing a beam of monocromatic wave energy toward one of said objects whereby a portion of said energy is back scattered from the surface of said one object and, wherein lens means for optically resolving the back scattered pattern and for focusing the pattern on means for receiving said back scattered energy including optical grating means and at least one restricted receiving aperature is provided, wherein is provided means for determining the frequency of said pattern and thereby the relative velocity between the two objects, the improvement which comprises the interposition of a telecentric aperature between the optical resolving means and the optical grating means in the path of said back scattered energy, said telecentric aperature to have a maximum diameter governed by the equation: D1 < OR = D3 - D2/2 where D1 is a diameter of the opening in the telecentric aperature D2 is the diameter of the receiving aperature and D3 is the diameter of the lens means, whereby said telecentric aperature will be the limiting aperature in the combination of itself with the lens means and receiving means.
Claim 3
Dependent Claim
20 words
The apparatus of claim 1 where the telecentric aperture is located substantially at the focal plane of said resolving means.
Claim 4
Dependent Claim
20 words
The apparatus of claim 2 where the telecentric aperture is symmetrically disposed about the optical axis of said resolving means.
Claim 5
Dependent Claim
14 words
The apparatus of claim 1 wherein the opening of said telecentric aperture is circular.
Claim 6
Dependent Claim
50 words
The apparatus of claim 4 wherein said means for directing a beam of monochromatic wave energy toward one of said objects includes means for producing a collimated beam having a substantially elliptically shaped cross section, the major axis of which coincides with the relative velocity vector between said two objects.
Claim 7
Dependent Claim
15 words
The apparatus of claim 5 wherein said lens means is a simple double-convex converging lens.
References Cited (Backward Citations)
US3525569A
Cited
US3723004A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-07-08 | 1978-01-07 | 1978-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-08 | 1982-01-07 | 1982-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-08 | 1986-01-07 | 1986-07-09 | $7700.00 | Window Closed / Lapsed |