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4967159 Self-balancing reflectometer
VIII
New Patents phase difference between the reference signal and the replica thereof is continuously monitored. If the angular phase difference departs significantly from a specified value, an alarm is set as a warning that the fiber optic communications link has been compromised.
4965857 METHOD FOR SYNCHRONIZED POLARIZATION SWITCHING OF AN OPTICAL TRANSMISSION SIGNAL OF AN OPTICAL TRANSMISSION SYSTEM HAVING SUPERHETERODYNE RECEPTION AND AN APPARATUS FOR THE IMPLEMENTATION OF SAID METHOD Franz Auracher, Alfred Ebberg, Bernd Noll, Eckhard Meissner, Hermann-Johan Rodler, Baierbrunn, Federal Republic Of Germany assigned to Siemens Aktiegesellschaft A method for generating an FSK-modulated optical signal with an optical two-filter FSK superheterodyne receiver. The optical signal has two different polarization conditions that are orthogonal to one another. Due to orthogonal conditions, polarization-independent reception is possible. Synchronized polarization shifting occurs to generate a polarized modulated optical signal having alternating orthogonal polarization conditions. A delay stage for delaying the switching signal by one-half a clock period ensures accurate synchronization. The frequency shift of the FSK-modulated signal can be freely selected while maintaining excellent bandwidth characteristics and optimum sensitivity.
4965858 POLARIZATION DIVERSITY OPTICAL RECEIVER FOR COHERENT OPTICAL COMMUNICATION
optical local oscillating circuit (7) for oscillating local oscillating light; a mixing circuit (8) for mixing signal light and the local oscillating light to obtain two polarized components; a detecting circuit (9) for detecting the polarized component to output intermediate frequency signals (eS and eP); and a frequency control circuit (11) for controlling, in accordance with the intermediate frequency signals (eS and eP), the oscillating frequency of the optical local oscillating circuit (7). To ensure that the intermediate frequency does not disappear, the frequency control circuit (i i) outputs a combined signal of a sum and a difference of the intermediate frequency signals (eS and eP).
4967158 PORTABLE DETECTOR DEVICE FOR DETECTING PARTIAL ELECTRICAL DISCHARGE IN LIVE VOLTAGE DISTRIBUTION CABLES AND]OR EQUIPMENT Antoni Gonzalez, Greenfield Park, Canada assigned to Hydro-Quebec A portable detector device for detecting partial electrical discharge in live voltage distribution cables and/or equipment. The device comprises a probe secured to an insulated portable handle for manual displacement of the probe. A detector device is connected to the probe for detecting a signal in the range of 5 to 10 MHz emitted by the partial discharge. The detector has an input attenuator circuit which is connected to the probe to lower the level of the detected signal to a desired level. A transformation circuit is further provided to change the detected signal to a predetermined frequency signal substantially free of noise and representative of the magnitude of the detected partial discharge signal. An amplifier circuit amplifies the pre~letermined frequency signal and an output circuit generates signals indicative of the presence and magnitude of the partial discharge.
4967159
Takao Naito, Terumi Chikama, Shigeki Watanabe, Tetsuya Kiyonaga, Yoshihito Onoda, Hideo Kuwahara, Hiroshi Onaka, Hideyuki Miyata~ Kawasaki, Japan assigned to Fujitsu Limited
Michael Manes assigned to Abbott Laboratories
A polarized wave diversity optical receiver for coherent optical communication including: an
A preferred embodiment of a self-balancing reflectometer is disclosed in conjunction with a
SELF-BALANCING REFLECTOMETER
New Patents
system including an RF source, an RF load, and an RF transmission channel that carries RF signals transmitted by the source to the load. The self-balancing reflectometer includes a load current sampler that generates a first sample signal related to load current by a first fixed value of gain and a load voltage sampler that generates a second sample signal related to load voltage by a voltage-responsivesecond variable value of gain. The first sample signal is subtracted from the second sample signal and the resulting difference signal is applied to the RF port of a double balanced mixer. The RF voltage signal appearing at the load is applied to the LO port of the mixer, which generates an IF signal that varies with both rapid load impedance modulation corresponding to load data and long term basal variations in load impedance unrelated to load data. A high gain amplifier generates output data signals corresponding to the load data and an integrator generates a gain adjustment voltage which varies with the long term variations. The gain adjustment voltage is applied to the load voltage sampler to vary the second variable value of gain in a manner to drive the difference signal to zero, thus automatically balancing the reflectometer. At the balance point, the value of the gain adjustment voltage is related to the value of load impedance by a known formula. The reflectometer is selectably responsive to either the rear or imaginary component of load impedance.
IX
with image fields. The drive circuit is capable of rapidly processing short duration synchronization signals with very low power consumption. In one embodiment, two liquid crystal cell assemblies are mounted in an eyeglass frame and used as a wireless selection device for a fieldsequential stereoscopic image. Preferably, the invention includes a synchronization signal receiver having a narrow angular reception range so that the receiver is sensitive to only one synchronization signal at a time, so that the invention may be employed to view several monitors without interference between different synchronization signals from the different monitors. Preferably, the inventive shutter assemblies are capable of operating in a nonoccluding state, and each inventive shutter assembly may conveniently be switched between a state suitable for stereoscopic viewing and a non-occluding state suitable for viewing a nonstereoscopic image.
4967273 TELEVISION PROGRAM TRANSMISSION VERIFICATION METHOD AND APPARATUS Burton Greenberg assigned to VidCode Inc
4967268 LIQUID CRYSTAL SHUTTER SYSTEM FOR STEREOSCOPIC AND OTHER APPLICATIONS Lenn Lipton, Marvi Ackerman assigned to StereoGraphics A liquid crystal shutter system for selecting fields of a field-sequential image, by transmitting the field-sequential image, with a synchronization signal, to one or more remote liquid crystal cell shutter assemblies. Each shutter assembly transmits selected fields of the field-sequential image in response to a drive signal, and includes a drive circuit for receiving the synchronization signal and generating each drive signal in response to the synchronization signal so that each drive signal has transitions synchronized
A method and apparatus for verifying the proper airing of television program having a digital identification code recorded on a preselected scan line which is not normally visible to the television viewer. A plurality of television channels are automatically simultaneously monitored by a primary monitoring system at a site 30 within the reception area and broadcast cflcoded programs are identified and timed and appraised as to their audio and video signal quality. The information generated is stored locally for later comparision with centrally stored 62 information specifying the program that should have been aired. Each of the channels is sequentially monitored for a preselected fixed time interval, which depends on the number of channels being monitored, under the control of a programmable sequential controller 54. A secondary monitoring system is provided for use as a backup or for monitoring cable channels. Means 74 responsive to a code recorded in the program signal are provided for locally recording the final portion of the program.
New Patents phase difference between the reference signal and the replica thereof is continuously monitored. If the angular phase difference departs significantly from a specified value, an alarm is set as a warning that the fiber optic communications link has been compromised.
4965857 METHOD FOR SYNCHRONIZED POLARIZATION SWITCHING OF AN OPTICAL TRANSMISSION SIGNAL OF AN OPTICAL TRANSMISSION SYSTEM HAVING SUPERHETERODYNE RECEPTION AND AN APPARATUS FOR THE IMPLEMENTATION OF SAID METHOD Franz Auracher, Alfred Ebberg, Bernd Noll, Eckhard Meissner, Hermann-Johan Rodler, Baierbrunn, Federal Republic Of Germany assigned to Siemens Aktiegesellschaft A method for generating an FSK-modulated optical signal with an optical two-filter FSK superheterodyne receiver. The optical signal has two different polarization conditions that are orthogonal to one another. Due to orthogonal conditions, polarization-independent reception is possible. Synchronized polarization shifting occurs to generate a polarized modulated optical signal having alternating orthogonal polarization conditions. A delay stage for delaying the switching signal by one-half a clock period ensures accurate synchronization. The frequency shift of the FSK-modulated signal can be freely selected while maintaining excellent bandwidth characteristics and optimum sensitivity.
4965858 POLARIZATION DIVERSITY OPTICAL RECEIVER FOR COHERENT OPTICAL COMMUNICATION
optical local oscillating circuit (7) for oscillating local oscillating light; a mixing circuit (8) for mixing signal light and the local oscillating light to obtain two polarized components; a detecting circuit (9) for detecting the polarized component to output intermediate frequency signals (eS and eP); and a frequency control circuit (11) for controlling, in accordance with the intermediate frequency signals (eS and eP), the oscillating frequency of the optical local oscillating circuit (7). To ensure that the intermediate frequency does not disappear, the frequency control circuit (i i) outputs a combined signal of a sum and a difference of the intermediate frequency signals (eS and eP).
4967158 PORTABLE DETECTOR DEVICE FOR DETECTING PARTIAL ELECTRICAL DISCHARGE IN LIVE VOLTAGE DISTRIBUTION CABLES AND]OR EQUIPMENT Antoni Gonzalez, Greenfield Park, Canada assigned to Hydro-Quebec A portable detector device for detecting partial electrical discharge in live voltage distribution cables and/or equipment. The device comprises a probe secured to an insulated portable handle for manual displacement of the probe. A detector device is connected to the probe for detecting a signal in the range of 5 to 10 MHz emitted by the partial discharge. The detector has an input attenuator circuit which is connected to the probe to lower the level of the detected signal to a desired level. A transformation circuit is further provided to change the detected signal to a predetermined frequency signal substantially free of noise and representative of the magnitude of the detected partial discharge signal. An amplifier circuit amplifies the pre~letermined frequency signal and an output circuit generates signals indicative of the presence and magnitude of the partial discharge.
4967159
Takao Naito, Terumi Chikama, Shigeki Watanabe, Tetsuya Kiyonaga, Yoshihito Onoda, Hideo Kuwahara, Hiroshi Onaka, Hideyuki Miyata~ Kawasaki, Japan assigned to Fujitsu Limited
Michael Manes assigned to Abbott Laboratories
A polarized wave diversity optical receiver for coherent optical communication including: an
A preferred embodiment of a self-balancing reflectometer is disclosed in conjunction with a
SELF-BALANCING REFLECTOMETER
New Patents
system including an RF source, an RF load, and an RF transmission channel that carries RF signals transmitted by the source to the load. The self-balancing reflectometer includes a load current sampler that generates a first sample signal related to load current by a first fixed value of gain and a load voltage sampler that generates a second sample signal related to load voltage by a voltage-responsivesecond variable value of gain. The first sample signal is subtracted from the second sample signal and the resulting difference signal is applied to the RF port of a double balanced mixer. The RF voltage signal appearing at the load is applied to the LO port of the mixer, which generates an IF signal that varies with both rapid load impedance modulation corresponding to load data and long term basal variations in load impedance unrelated to load data. A high gain amplifier generates output data signals corresponding to the load data and an integrator generates a gain adjustment voltage which varies with the long term variations. The gain adjustment voltage is applied to the load voltage sampler to vary the second variable value of gain in a manner to drive the difference signal to zero, thus automatically balancing the reflectometer. At the balance point, the value of the gain adjustment voltage is related to the value of load impedance by a known formula. The reflectometer is selectably responsive to either the rear or imaginary component of load impedance.
IX
with image fields. The drive circuit is capable of rapidly processing short duration synchronization signals with very low power consumption. In one embodiment, two liquid crystal cell assemblies are mounted in an eyeglass frame and used as a wireless selection device for a fieldsequential stereoscopic image. Preferably, the invention includes a synchronization signal receiver having a narrow angular reception range so that the receiver is sensitive to only one synchronization signal at a time, so that the invention may be employed to view several monitors without interference between different synchronization signals from the different monitors. Preferably, the inventive shutter assemblies are capable of operating in a nonoccluding state, and each inventive shutter assembly may conveniently be switched between a state suitable for stereoscopic viewing and a non-occluding state suitable for viewing a nonstereoscopic image.
4967273 TELEVISION PROGRAM TRANSMISSION VERIFICATION METHOD AND APPARATUS Burton Greenberg assigned to VidCode Inc
4967268 LIQUID CRYSTAL SHUTTER SYSTEM FOR STEREOSCOPIC AND OTHER APPLICATIONS Lenn Lipton, Marvi Ackerman assigned to StereoGraphics A liquid crystal shutter system for selecting fields of a field-sequential image, by transmitting the field-sequential image, with a synchronization signal, to one or more remote liquid crystal cell shutter assemblies. Each shutter assembly transmits selected fields of the field-sequential image in response to a drive signal, and includes a drive circuit for receiving the synchronization signal and generating each drive signal in response to the synchronization signal so that each drive signal has transitions synchronized
A method and apparatus for verifying the proper airing of television program having a digital identification code recorded on a preselected scan line which is not normally visible to the television viewer. A plurality of television channels are automatically simultaneously monitored by a primary monitoring system at a site 30 within the reception area and broadcast cflcoded programs are identified and timed and appraised as to their audio and video signal quality. The information generated is stored locally for later comparision with centrally stored 62 information specifying the program that should have been aired. Each of the channels is sequentially monitored for a preselected fixed time interval, which depends on the number of channels being monitored, under the control of a programmable sequential controller 54. A secondary monitoring system is provided for use as a backup or for monitoring cable channels. Means 74 responsive to a code recorded in the program signal are provided for locally recording the final portion of the program.