Patent US2397540A successfully refreshed from Google Patents.
Patent US4099050A successfully refreshed from Google Patents.
US4099050A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Codable optical transponder
Assignee: United States Department of the Air Force
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Filing: 1970-07-10
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Granted: 1978-07-04
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Expires: 1990-07-10
Abstract
Abstract A transponder illuminated by broadband optical radiation which is reflected back towards the illuminator by means of corner reflectors. In front of the corner reflectors are placed a plurality of narrow band filters which define the communication channels. The return signal will consist of the activation of a number of discrete channels corresponding to the number of filters used. The system is not restricted to the visible spectrum permitting infrared and ultraviolet radiation to be used to provide a covert communication system.
Inventors
- 👤 Gerhard O. Sauermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:51
CPC Classifications
H; H04; H04B; H04B10/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
180 words
In an optical line-of-sight communication system having an interrogator section and a receiver section both located in substantially the same general area for generating and receiving radiation signals, respectively; a remotely positioned codable optical transponder comprising, a corner reflector located in line-of-sight with said interrogator section for receiving and reflecting radiation therefrom, at least one narrow band optical filter positioned immediately in front of said corner reflector and operatively attached thereto to absorb all radiation from said interrogator except that of specific wavelengths, and a coded opaque mask positioned immediately in front of said filter in operative association therewith to prevent a predetermined portion of the radiation from the interrogator from from reaching said corner reflector, said corner reflector, optical filter and opaque mask being constructed as a portable unit capable of being handcarried by a person, the configuration of said mask being designed to allow radiation to reach only specified areas of said corner reflector thereby forming a signal containing intelligence corresponding to the mask configuration which is subsequently reflected back to the receiver section of the communication system.
Claim 2
Dependent Claim
180 words
In an optical line-of-sight communication system having an interrogator section and a receiver section both located in substantially the same general area for generating and receiving radiation signals, respectively; a remotely positioned codable optical transponder comprising, a corner reflector located in line-of-sight with said interrogator section for receiving and reflecting radiation therefrom, at least one narrow band optical filter positioned immediately in front of said corner reflector and operatively attached thereto to absorb all radiation from said interrogator except that of specific wavelengths, and a coded opaque mask positioned immediately in front of said filter in operative association therewith to prevent a predetermined portion of the radiation from the interrogator from from reaching said corner reflector, said corner reflector, optical filter and opaque mask being constructed as a portable unit capable of being handcarried by a person, the configuration of said mask being designed to allow radiation to reach only specified areas of said corner reflector thereby forming a signal containing intelligence corresponding to the mask configuration which is subsequently reflected back to the receiver section of the communication system.
Claim 3
Dependent Claim
33 words
The communication system defined in claim 1 wherein said codable optical transponder is positioned on the ground and the interrogator and receiver are positioned in an aircraft within line-of-sight view of said transponder.
Claim 4
Dependent Claim
19 words
The communication system defined in claim 2 wherein the radiation reflected by said transponder is in the visible range.
Claim 5
Dependent Claim
19 words
The communication system defined in claim 2 wherein the radiation reflected by said transponder is in the infrared range.
Claim 6
Dependent Claim
19 words
The commmunication system defined in claim 2 wherein the radiation reflected by the transponder is in the ultraviolet range.
Claim 7
Dependent Claim
24 words
The communication system defined in claim 2 wherein a plurality of filters of various absorption characteristics define the responding signal channels to the receiver.
Claim 8
Dependent Claim
21 words
The communication system defined in claim 2 wherein the source of the radiation reflected by said transponder is in discrete bands.
Claim 9
Dependent Claim
19 words
The communication system defined in claim 2 including a readout device to receive color coded messages from the interrogator.
Claim 10
Dependent Claim
22 words
The communication system defined in claim 2 including a self-contained power unit for readout to increase the range of the communication system.
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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) | 1981-07-03 | 1982-01-02 | 1982-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-03 | 1986-01-02 | 1986-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-03 | 1990-01-02 | 1990-07-04 | $7700.00 | Window Closed / Lapsed |