Apparatus for the examination of objects with ultra-sound, comprising an array of piezo-electric transducer elements
First Claim
1. An apparatus for the examination of objects with ultrasound, comprising:
- a linear array of piezo-electric transducer elements each having a width W and a thickness T, wherein the thickness T of each of the transducer elements is equal to one half of a wavelength corresponding to a first frequency F for which on a diagram of curves F·
T=f(W/T) of the distribution of the resonant frequencies there exists a first vibratory mode at the said first frequency F and a second vibratory mode at or near a second frequency equal to 2F;
transmission means which excite the elements at the first frequency F using excitation signals having a spectrum which excludes the second frequency 2F; and
means functionally connected to the elements for receiving and processing echo signals which are received by the elements at said frequency 2F.
1 Assignment
0 Petitions
Accused Products
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·T=f(W/T), or respectively, on the three-dimensional diagram of the curves F·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.
45 Citations
2 Claims
-
1. An apparatus for the examination of objects with ultrasound, comprising:
-
a linear array of piezo-electric transducer elements each having a width W and a thickness T, wherein the thickness T of each of the transducer elements is equal to one half of a wavelength corresponding to a first frequency F for which on a diagram of curves F·
T=f(W/T) of the distribution of the resonant frequencies there exists a first vibratory mode at the said first frequency F and a second vibratory mode at or near a second frequency equal to 2F;transmission means which excite the elements at the first frequency F using excitation signals having a spectrum which excludes the second frequency 2F; and means functionally connected to the elements for receiving and processing echo signals which are received by the elements at said frequency 2F.
-
-
2. An apparatus for the examination of objects with ultrasound, comprising:
-
a two-dimensional array of parallelepipedic piezo-electric transducer elements each having a length L, a width W, and a thickness T, wherein the thickness T of each of the transducer elements is equal to one half of a wavelength corresponding to a first frequency F for which on a three-dimensional diagram of the curves F·
T=f(W/T, L/T) of the distribution of the resonant frequencies there exists a first vibratory mode at the said first frequency F and a second vibratory mode at or near a second frequency equal to 2F;transmission means which excite the elements at the first frequency F using excitation signals having a spectrum which excludes the second frequency 2F; and means functionally connected to the elements for receiving and processing echo signals which are received by the elements at said frequency 2F.
-
Specification