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:
Jul. 12, 1994
Filed:
Nov. 22, 1991
George F Garlick, Kennewick, WA (US);
Todd F Garlick, Kennewick, WA (US);
Advanced Imaging Systems, Richland, WA (US);
Abstract
The description details a preferred embodiment of an improved large area ultrasonic transducer 70 capable of reducing the generation of adverse 'edge effect' waves. The transducer has a thin piezoelectric wafer 72 that has a high area-to-thickness ratio of preferably between 30 and 300. A front electrode coating 84 is deposited on the front surface 74, over the front edge 77, along the side surface 82 and over the back edge 78 and onto a border of the back surface 76 to minimize the application of a voltage potential along the side surface. A voltage modifying layer 92 is placed on the back surface 76 along the back edge 78 for further minimizing the generation of 'edge effect' waves. The layer 92 varies in thickness to progressively decrease the voltage applied to the back surface 76 from a large central area 79(a) to the back edge 78. The layer 92 is preferably composed of a non-piezoelectric dielectric material.