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. 22, 1987
Filed:
Oct. 22, 1986
Patrick R Pesque, Perigny, FR;
Jean-Marie C Nicolas, Paris, FR;
U.S. Philips Corporation, New York, NY (US);
Abstract
An apparatus for the examination of objects with ultrasound, comprising a linear or two-dimensional array (10) of piezo-electric transducer elements (10 (1), . . . , 10 (n)) with a length L and a width W, a stage for the repeated transmission of ultrasonic signals and a stage for the reception and processing of the ultrasonic echoes received. The thickness T of the elements is equal to half the wavelength corresponding to a first frequency F for which there exists, on the two-dimensional diagram of the curves F.multidot.T=f(W/T), or respectively, on the three-dimensional diagram of the curves F.multidot.T=f(W/T, L/T) of the distribution of the resonance frequencies, a first vibratory mode at the said first frequency F and a second vibratory mode at a second frequency equal to or near 2F. The transmission stage incorporates a generator (20) of excitation signals at the first frequency F, the spectrum of these excitation signals excluding at least the second frequency.