Modulated retroreflector system
First Claim
1. A reflector system, comprisinga reflector for reflecting incident electromagnetic energy,a shutter for controlling at least one of electromagnetic energy incident on and electromagnetic energy reflected by said reflector, said shutter comprising a field effect scattering type liquid crystal shutter including plural volumes of liquid crystal material in a containment mediuma controller for controlling said shutter to control such incident or reflected electromagnetic energy, andcoding means for causing said controller to modulate such energy according to a prescribed code.
1 Assignment
0 Petitions
Accused Products
Abstract
A reflector system including a reflector for reflecting incident electromagnetic energy, a shutter for controlling at least one of electromagnetic energy incident on and electromagnetic energy reflected by the retroreflector, a controller for controlling the shutter to control such incident or reflected electromagnetic energy, and a coding or modulating device for causing the controller to modulate such energy according to a prescribed code. The reflector system may be used in a closed communications system and/or in a system for seeking, locating and/or identifying an object.
-
Citations
34 Claims
-
1. A reflector system, comprising
a reflector for reflecting incident electromagnetic energy, a shutter for controlling at least one of electromagnetic energy incident on and electromagnetic energy reflected by said reflector, said shutter comprising a field effect scattering type liquid crystal shutter including plural volumes of liquid crystal material in a containment medium a controller for controlling said shutter to control such incident or reflected electromagnetic energy, and coding means for causing said controller to modulate such energy according to a prescribed code.
-
8. A reflector system, comprising
a reflector for reflecting incident electromagnetic energy, a shutter for controlling at least one of electromagnetic energy incident on and electromagnetic energy reflected by said reflector, a controller for controlling said shutter to control such incident or reflected electromagnetic energy, coding means for causing said controller to modulate such energy according to a prescribed code, and said shutter comprising a surface mode liquid crystal cell.
-
9. A closed communications system, comprising a source of electromagnetic energy,
retroreflector means for receiving and reflecting such electromagnetic energy, modulator means at a location separated from said source for modulating such electromagnetic energy, said modulator means including a liquid crystal shutter comprising plural volumes of liquid crystal material in a containment medium, detector means at a location separated from said retroreflector means for detecting such electromagnetic energy, and demodulator means for demodulating the response of said detector means to such electromagnetic energy.
-
17. A system for seeking and locating a distant object, comprising:
-
directing means for directing incident electromagnetic energy toward an area to seek such object, detector means for receiving electromagnetic energy reflected from such object, retroreflector means positioned with respect to said object for reflecting incident electromagnetic energy from said directing to said detector means, modulator means for modulating at least one of the electromagnetic energy incident on and reflected by said retroreflector means, said modulator means including a liquid crystal shutter comprising plural volumes of liquid crystal material in a containment medium, and demodulator means coupled with respect to said detector means for determining whether electromagnetic energy detected by said detector means is modulated according to the modulation caused by said modulator means. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
-
-
25. A closed communications system, comprising:
-
a source of electromagnetic energy, retroreflector means for receiving and reflecting such electromagnetic energy, modulator means at a location separated from said source for modulating such electromagnetic energy, said modulator means comprising means for effecting spacial modulation, detector means at a location separated from said retroreflector means for detecting such electromagnetic energy, and demodulator means for demodulating the response of said detector means to such electromagnetic energy. - View Dependent Claims (26, 27, 28, 29)
-
-
30. A closed communications system, comprising:
-
a source of electromagnetic energy, retroreflector means for receiving and reflecting such electromagnetic energy, modulator means at a location separated from said source for modulating such electromagnetic energy, detector means at a location separated from said retroreflector means for detecting such electromagnetic energy, demodulator means for demodulating the response of said detector means to such electromagnetic energy, means for interrogating said modulator means with a first signal having prescribed characteristics, and sensing means for sensing the occurrence of such first signal to energize said modulator means to effect prescribed modulating function. - View Dependent Claims (31)
-
-
32. A system for seeking and locating a distant object, comprising:
-
directing means for directing incident electromagnetic energy toward an area to seek such object, said directing means comprising a lens system for directing ambient light toward such area, detector means for receiving electromagnetic energy reflected from such object, retroreflector means positioned with respect to said object for reflecting incident electromagnetic energy from said directing to said detector means, modulator means for modulating at least one of the electromagnetic energy incident on and reflected by said retroreflector means, and demodulator means coupled with respect to said detector means for determining whether electromagnetic energy detected by said detector means is modulated according to demodulation caused by said modulator means.
-
-
33. A system for seeking and locating a distant object, comprising:
-
directing means for directing incident electromagnetic energy toward an area to seek such object, detector means for receiving electromagnetic energy reflected from such object, retroreflector means positioned with respect to said object for reflecting incident electromagnetic energy from said directing to said detector means, modulator means for modulating at least one of the electromagnetic energy incident on and reflected by said retroreflector means, demodulator means coupled with respect to said detector means for determining whether electromagnetic energy detected by said detector means is modulated according to the modulation caused by said modulator means, and scan control means for scanning said directing means to direct incident electromagnetic energy toward a plurality of areas to detect such object. - View Dependent Claims (34)
-
Specification