1
Philip M Anderson III, Gerald R Bretts, James E Kearney: Surveillance system having magnetomechanical marker. Allied Corporation, Ernest D Buff, Gerhard H Fuchs, Paul Yee, April 9, 1985: US04510489 (261 worldwide citation)

A magnetic article surveillance system marker is adapted, when armed, to resonate at a frequency provided by an incident magnetic field applied within an interrogation zone. The marker is an elongated ductile strip of magnetostrictive ferromagnetic material disposed adjacent to a ferromagnetic eleme ...


2
J o slashed rn S o slashed rensen: Method and a device for sensing the distance between a first object and a second object. August 24, 1999: US05942975 (185 worldwide citation)

A method and device for sensing the distance between a first object and a second object so as to activate or facilitate predetermined actions when the distance has attained a certain value. A person (1) (first object) holds a handle (2) of a power tool, the handle being connected to a function gener ...


3
Rickey D Hughes, James T Reese: Proximity responsive capacitance sensitive method, system, and associated electrical circuitry for use in controlling mechanical and electro-mechanical equipment. Saf T Margin, William J Bethurum, January 14, 1992: US05081406 (172 worldwide citation)

A method and system and associated circuitry for controlling and stopping the motion of dangerous moving parts such as power saw blades substantially instantaneously in response to body or human capacitance produced by an operator coming with a predetermined critical distance from the moving part. T ...


4
Guetersloh John W: Proximity detector. Tyco Laboratories, LeBlanc & Shur, August 13, 1974: US3829850 (147 worldwide citation)

A capacitive proximity detector protects against injury, damage or unauthorized entry into a protected area. It comprises an unbalanced capacitive bridge including an antenna or sensor which produces an output proportional to the capacitance of the antenna to ground. A change in capacitance is detec ...


5
Norman F Fyler: Electronic personnel safety sensor. The Stanley Works, March 30, 1976: US03947734 (139 worldwide citation)

An electronic personnel safety sensor is provided capable of causing a machine or operation to be shut off to prevent injury to personnel or damage to equipment protected, by detecting, indicating, and acting upon a predetermined increase or decrease in effective capacitance caused by the introducti ...


6
John M Vranish, Robert L McConnell: Driven shielding capacitive proximity sensor. The United States of America represented by the Administrator of the National Aeronautics & Space Administration, Paul S Clohan Jr, R Dennis Marchant, Guy M Miller, November 24, 1992: US05166679 (127 worldwide citation)

A capacitive proximity sensing element, backed by a reflector driven at the same voltage as and in phase with the sensor, is used to reflect the field lines away from a grounded robot arm towards an intruding object, thus dramatically increasing the sensor's range and sensitivity.


7
Philip M Anderson III, James E Kearney, Gerald R Bretts: Coded surveillance system having magnetomechanical marker. Allied Corporation, Ernest D Buff, Gerhard H Fuchs, Paul Yee, April 9, 1985: US04510490 (117 worldwide citation)

A magnetic article surveillance system marker is adapted, when armed, to resonate at preselected frequencies provided by an incident magnetic field applied within an interrogation zone. The marker is a plurality of elongated ductile strips of magnetostrictive ferromagnetic material each of the strip ...


8
Wesley K Waldron: Single-electrode capacitance touchpad sensor systems. General Electric Company, Geoffrey H Krauss, Marvin Snyder, James C Davis, December 2, 1980: US04237421 (110 worldwide citation)

Each of an array of capacitive touchpad sensors has a single touchpad electrode fabricated upon a substrate and accessible to user personnel, with series coupling and shunt capacitance being provided respectively between a driving generator and the touchpad electrode, and the touchpad electrode and ...


9
Ronald D Ingraham: Capacity responsive control circuit. Nartron Corporation, Price Heneveld Cooper DeWitt & Litton, May 16, 1989: US04831279 (98 worldwide citation)

A capacitive detecting circuit for detecting transient capacitive changes such as that of a person moving into proximity of a sensing element. A sensing element is coupled to a threshold level controlled amplifier supplied with relatively high frequency signals from an oscillator through a high inpu ...


10
Tomio Yasuda, Jun Sato, Masao Ohashi: Capacitive occupancy detector apparatus. Aisin Seiki Kabushiki Kaisha, Sughrue Mion Zinn Macpeak and Seas, January 3, 1989: US04796013 (94 worldwide citation)

A capacitive occupancy detector apparatus includes a personnel containment device having first and second electrodes which will define an electric field therebetween which will be intercepted by a person present in the containment device. A detecting device is provided for detecting the capacitance ...