Acoustic imaging systems

US5796003A · kind A · utility

Inventors

• Jaswinder S. Sandhu · Buffalo Grove, US
• Witold J. Popek · Rantoul, US
• Honghui Wang · Beijing, CN

Key dates

• Filing date: Jan 30, 1996
• Grant date: Aug 18, 1998
• Expiry date: Jan 30, 2016

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N2291/048
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

An ultrasonic inspection system for inspecting a test object and producing substantially artifact-free images, which system includes (1) a sound source for emitting ultrasonic energy toward a test object, (2) a liquid crystal detector for detecting emitted ultrasonic energy and displaying an image, and (3) a coupling medium for sonically coupling the sound source, the test object and the detector. The ultrasonic energy is emitted at each of a plurality of frequencies within a predetermined range. It has been determined that the ultrasonic energy insonifing the object can be caused to scan the object and be angularly varied with respect thereto. Moreover, the rate of frequency scanning is substantially less that the detector image decay so as to produce a substantially flicker-free image. The angular variation is performed by rocking the sound source through a small angle, such as 2.degree. to 6.degree. relative to the liquid crystal detector. Desirably the pivot axis about which the sound source is rocked falls within the body of the sound source or locus of points through which the sound source is moved. This rocking action minimizes disturbance of the coupling medium.