The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 27, 1996
Filed:
Aug. 31, 1994
Kyung T Park, Berwyn, PA (US);
Minoru Toda, Lawrenceville, NJ (US);
The Whitaker Corporation, Wilmington, DE (US);
Abstract
An ultrasonic proximity sensor particularly suited for outdoor environments having a transducer including a polymer piezoelectric film bonded to a protective metal layer. The transducer is mounted in the sensor housing so that the protective metal layer is exposed to the environment through a window of the sensor housing. The transducer can be implemented as an asymmetric bimorph structure, having an electrode bonded to a surface of the polymer piezoelectric film opposite the protective metal layer and between support members. Deformation of the polymer piezoelectric film between the protective metal layer and the electrode occurs upon application of a voltage thereto, generating an ultrasonic wave. The transducer can also be used as a receiver, generating an output voltage from the electrode upon impingement of an ultrasonic wave upon the protective metal layer. The transducer can also be implemented as a curved length mode transducer including an arcuate shaped support member for supporting the polymer piezoelectric film to be curved between the support members. The radius of the curved length mode transducer is selected so that the transducer can be resonant at the resonance frequency of the curved length mode, therefore vibrating at high frequency to generate an ultrasonic wave.