Resonant piezoelectric sensor
June 26, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 2625035 2875354 3187207 3472063 Sonic echo-sounder for the measurement of levels of substances Piezoelectric resonator with acoustic reflectors Piezoelectric or pyroelectric polymer input element for use as a transducer in keyboards Method and apparatus for producing cross-sectional images using ultrasound Ultrasonic transducer with a plastic piezoelectric receiving layer and a non plastic transmitting layer Acoustic transducer InventorsApplicationNo. 06/879213 filed on 06/26/1986US Classes:310/323.21, Detector (e.g., sensor)310/321, Combined with resonant structure310/328, With mechanical energy coupling means310/334, Acoustic wave type generator or receiver310/338, Force or pressure measuring type310/366, More than two310/800, PIEZOELECTRIC POLYMERS (E.G., MYLAR, PVDF)73/702Vibration typeExaminersPrimary: Budd, Mark O.Attorney, Agent or FirmInternational ClassesG01L 5/22 (20060101)G06F 3/033 (20060101) G10K 11/02 (20060101) G10K 11/00 (20060101) B06B 1/06 (20060101) G01L 1/16 (20060101) Foreign Application Priority Data1985-07-03 NLAbstractA sensor for generating a signal in response of a variation at the tactile face. The sensor comprises superposed transmitting and receiving layers, which are provided with electrodes for the supply and pick-up of electrical signals to the transmitting layer and from the receiving layer respectively. With a high acoustic impedance of the boundary medium adjacent to the transmitting layer and a low acoustic impedance of the boundary medium adjacent to the receiving layer or vice versa, the sum of the thicknesses of the transmitting and receiving layers is an odd number of v/4f. With similar impedances, either low or high, of the said boundary media the aforesaid sum is an even number of v/4f. v is the propagation velocity of the acoustic vibration in the material of the transmitting and receiving layers and f the frequency of the signal supplied.Other References
Field of SearchAcoustic wave type generator or receiverWith lens or reflector Nondestructive testing type Underwater type On back of piezoelectric element Force or pressure measuring type PIEZOELECTRIC POLYMERS (E.G., MYLAR, PVDF) Acoustic wave type generator or receiver Combined with resonant structure Adding or subtracting mass With mechanical energy coupling means | |
