| 摘要 |
<p>1. An echographic probe comprising a transducer formed from a case (1), containing a coupling liquid and having a window (2) for the passage of an ultrasonic beam, in which are immersed a piezoelectric element (3) in the form of a disk, an electric motor means and a mechanical transmission means (32 to 36) between the shaft (31) of the motor and the piezoelectric element, a deformable membrane (4) coupled to the mobile piezoelectric element (3) so as to form therewith a chamber containing a liquid with a refraction index for the acoustic waves different from that of the coupling liquid, thus forming a first lens, said chamber being connected, by means of a duct, to a fixed liquid reservoir (7), said fixed reservoir being associated with means (8) for varying the volume of the liquid which it contains, so that the first lens be deformable, characterized in that the coupling liquid has an index different from that of water with respect to the acoustic waves and in that said window (2) is formed by a relatively rigid hemispherical membrane so as to form a second non deformable lens, in that the movement of said piezoelectric element is an oscillation about an axis (XX') passing through the center of the half sphere which the membrane forms and offset with respect to the plane of said disk, so that said deformable membrane (4) is situated close to said hemispherical membrane and opposite thereto, and in that the duct comprises a mobile flexible portion (5-6) which allows the oscillating movement of the first lens.</p> |
