Covert selective acquisition device for identifying friend or foe
First Claim
1. An infrared identification and communication assembly, including at least two devices, each of which comprises:
- a housing having a light receiving opening therein;
a spectral filter, mounted within said light receiving opening, which permits a frequency bandwidth of incident light to enter into and exit from said housing, said bandwidth including first and second frequencies, wherein one of said first and second frequencies comprises a transmitted frequency and the other of the first and second frequencies comprises a received frequency;
a dichroic beam splitter, mounted in optical receiving alignment with said spectral filter, for reflecting and passing therethrough selected portions of said frequency bandwidth, wherein said selected portions which are reflected include one of said first and second frequencies, and said selected portions which pass therethrough include the other of the first and second frequencies;
a photodiode, mounted in optical receiving alignment with said dichroic beam splitter, for receiving said received frequency, and converting same into a first electrical signal;
a solar noise rejection circuit, through which circuit the first electrical signal is directed, which includes a pair of amplifiers coupled via a feedback loop whereby constant level solar noise components of the first electrical signal are subtracted therefrom;
means by which a user may produce a second electrical signal; and
a light emitting diode, aligned in light transmitting alignment with said dichroic beam splitter, for converting said second electrical signal into a light signal comprising the transmitted frequency, and emitting said light signal through said spectral filter and out of said housing in a narrow beam.
1 Assignment
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Accused Products
Abstract
A compact infrared identification and communication assembly, including a transponder device and at least one interrogator device, is provided. Each device includes a housing having an opening therein through which light may be received or emitted. The opening has a spectral filter mounted therein which permits only a specific frequency band of incident light to pass into and out from the housing. A dichroic beam splitter is mounted in the housing, aligned with the spectral filter, for reflecting and transmitting separate selected portions of the specific frequency band. A photodiode is aligned with the beam splitter, thereby receiving light from one of the separate portions, for example the transmitted portion. The photodiode converts its received light into an electrical signal which is subsequently converted into a form which a user may easily understand, for example an LED display. The devices further include a light emitting diode, which is also aligned with said dichroic beam splitter, for converting a second electrical signal, produced by a user into an emitted light signal. The emitted light signal is of the other separate portion, for example the reflected range.
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Citations
23 Claims
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1. An infrared identification and communication assembly, including at least two devices, each of which comprises:
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a housing having a light receiving opening therein; a spectral filter, mounted within said light receiving opening, which permits a frequency bandwidth of incident light to enter into and exit from said housing, said bandwidth including first and second frequencies, wherein one of said first and second frequencies comprises a transmitted frequency and the other of the first and second frequencies comprises a received frequency; a dichroic beam splitter, mounted in optical receiving alignment with said spectral filter, for reflecting and passing therethrough selected portions of said frequency bandwidth, wherein said selected portions which are reflected include one of said first and second frequencies, and said selected portions which pass therethrough include the other of the first and second frequencies; a photodiode, mounted in optical receiving alignment with said dichroic beam splitter, for receiving said received frequency, and converting same into a first electrical signal; a solar noise rejection circuit, through which circuit the first electrical signal is directed, which includes a pair of amplifiers coupled via a feedback loop whereby constant level solar noise components of the first electrical signal are subtracted therefrom; means by which a user may produce a second electrical signal; and a light emitting diode, aligned in light transmitting alignment with said dichroic beam splitter, for converting said second electrical signal into a light signal comprising the transmitted frequency, and emitting said light signal through said spectral filter and out of said housing in a narrow beam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
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13. An interrogator device comprising:
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a housing having a light receiving opening therein; a spectral filter, mounted within said light receiving opening, which permits a specific frequency bandwidth of incident light to enter into and exit from said housing, said bandwidth including a first frequency for transmission and a second frequency for reception; a dichroic beam splitter, mounted in optical receiving alignment with said spectral filter, for reflecting and transmitting selected portions of said specific frequency bandwidth; a photodiode, mounted in optical receiving alignment with said dichroic beam splitter, for receiving one of said selected portions which includes said second frequency, and converting same into a first electrical signal; a solar noise rejection circuit, through which circuit the first electrical signal is directed, which includes a pair of amplifiers coupled via a feedback loop whereby constant level solar noise components of the first electrical signal are subtracted therefrom; means by which a user may produce a second electrical signal; and a light emitting diode, aligned in light transmitting alignment with said dichroic beam splitter, for converting said second electrical signal into an emitted light signal which comprises the first frequency range within said specific frequency bandwidth, and emitting said light signal through said spectral filter and out of said housing in a narrow beam. - View Dependent Claims (14, 15)
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16. A transponder device comprising:
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a housing having a light receiving opening therein; a spectral filter, mounted within said light receiving opening, which permits a specific frequency bandwidth of incident light to enter into and exit from said housing, said bandwidth including a first frequency for transmission and a second frequency for reception; a dichroic beam splitter, mounted in optical receiving alignment with said spectral filter, for reflecting and transmitting selected portions of said specific frequency bandwidth; a photodiode, mounted in optical receiving alignment with said dichroic beam splitter, for receiving one of said selected portions which includes said second frequency, and converting same into a first electrical signal; means by which a user may produce a second electrical signal; a light emitting diode, aligned in light transmitting alignment with said dichroic beam splitter, for converting said second electrical signal into an emitted light signal which comprises the first frequency range within said specific frequency bandwidth, and emitting said light signal through said spectral filter and out of said housing in a narrow beam; said housing further comprising an upper and a lower portion, said upper portion including said spectral filter and a reflecting mirror, said filter being oriented along a first axis, said lower portion of said housing including said dichroic beam splitter, said photodiode, and said light emitting diode, said dichroic beam splitter being oriented along a second axis, wherein said upper portion and said first axis are rotated relative to the lower portion, by a stepper motor through a 360 degree scanning field, and wherein said reflecting mirror maintains the optical alignments of the dichroic beam splitter and the spectral filter. - View Dependent Claims (17, 18, 19)
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20. A covert communication device, comprising at least one interrogator device and at least one transponder device, wherein each of said interrogator devices comprises:
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a housing having a light receiving opening therein; a spectral filter, mounted within said light receiving opening, which permits a specific frequency bandwidth of incident light to enter into and exit from said housing, said bandwidth including a first frequency for transmission and a second frequency for reception; a dichroic beam splitter, mounted in optical receiving alignment with said spectral filter, for reflecting and transmitting selected portions of said specific frequency bandwidth; a photodiode, mounted in optical receiving alignment with said dichroic beam splitter, for receiving one of said selected portions which includes said second frequency, and converting same into a first electrical signal; means by which a user may produce a second electrical signal; and a light emitting diode, aligned in light transmitting alignment with said dichroic beam splitter, for converting said second electrical signal into an emitted light signal which comprises the first frequency range within said specific frequency bandwidth, and emitting said light signal through said spectral filter and out of said housing in a narrow beam, and wherein each of said at least one transponder devices comprises; a housing having a light receiving opening therein; a spectral filter, mounted within said light receiving opening, which permits a specific frequency bandwidth of incident light to pass into and out of said housing, said bandwidth including a first frequency for transmission and a second frequency for reception; a dichroic beam splitter, mounted in optical receiving alignment with said spectral filter, for reflecting and transmitting selected portions of said specific frequency bandwidth; a photodiode, mounted in optical receiving alignment with said dichroic beam splitter, for receiving one of said selected portions which includes said second frequency, and converting same into a first electrical signal; means by which a user may produce a second electrical signal; and a light emitting diode, aligned in light transmitting alignment with said dichroic beam splitter, for converting said second electrical signal into an emitted light signal which comprises the first frequency range within said specific frequency bandwidth, and emitting said light signal through said spectral filter and out of said housing in a narrow beam, wherein said housing further comprises an upper and a lower portion, said upper portion including said spectral filter and a reflecting mirror, said filter being oriented along a first axis, said lower portion of said housing including said dichroic beam splitter, said photodiode, and said light emitting diode, said dichroic beam splitter being oriented along a second axis, wherein said upper portion and said first axis are rotated relative to the lower portion, by a stepper motor through a 360 degree scanning field, and wherein said reflecting mirror maintains the optical alignments of the dichroic beam splitter and the spectral filter. - View Dependent Claims (21, 22)
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23. An infrared identification and communication assembly, including at least two devices, each of which comprises:
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a housing having a light receiving opening therein; a spectral filter, mounted within said light receiving opening, which permits a frequency bandwidth of incident light to enter into and exit from said housing, said bandwidth including first and second frequencies, wherein one of said first and second frequencies comprises a transmitted frequency and the other of the first and second frequencies comprises a received frequency; a dichroic beam splitter, mounted in optical receiving alignment with said spectral filter, for reflecting and passing therethrough selected portions of said frequency bandwidth, wherein said selected portions which are reflected include one of said first and second frequencies, and said selected portions which pass therethrough include the other of the first and second frequencies; a photodiode, mounted in optical receiving alignment with said dichroic beam splitter, for receiving said received frequency, and converting same into a first electrical signal; means by which a user may produce a second electrical signal; a light emitting diode, aligned in light transmitting alignment with said dichroic beam splitter, for converting said second electrical signal into a light signal comprising the transmitted frequency, and emitting said light signal through said spectral filter and out of said housing in a narrow beam; wherein one of the devices comprises a transponder device and said housing of said transponder device further comprises an upper and a lower portion, said upper portion including said spectral filter and a reflecting mirror, said filter being oriented along a first axis, said lower portion of said housing including said dichroic beam splitter, said photodiode, and said light emitting diode, said dichroic beam splitter being oriented along a second axis, wherein said upper portion and said first axis are rotated relative to the lower portion, by a stepper motor through a 360 degree scanning field, and wherein said reflecting mirror maintains the optical alignments of the dichroic beam splitter and the spectral filter.
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Specification