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:
Dec. 27, 1994
Filed:
Dec. 20, 1991
Fujitsu Limited, Kawasaki, JP;
Abstract
An acoustic imaging system includes pairs of variable gain amplifiers for deriving essentially pairs of signals from respective signals generated in respective ultrasonic vibrators and the pairs of signals are superimposed on each other in a time difference corresponding to a phase angle of .pi./2 in frequency of ultrasonic waves. Amplification factors of the variable gain amplifiers are controlled so that the desired phase shift of the superimposed signals is obtained to attain dynamic focusing. Another acoustic imaging system includes a switch circuit having a two stage matrix switches construction that performs matrix switch functions in a smaller number of switch elements. Still another acoustic imaging system includes constituents for the aforementioned phase control for fine adjustment of delay time, the aforementioned switch circuit for rough adjustment of delay time, and variable gain amplifiers that perform smooth switching of the delay time.