вход по аккаунту



код для вставкиСкачать
Patent Translate
Powered by EPO and Google
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
Specification 1. Title of the invention
Acoustic transducer
3. Detailed Description of the Invention The present invention relates to an acoustic transducer
comprising a plurality of acoustic transducers-in particular, as a transducer of an ultrasound
imaging apparatus for obtaining high resolution, high speed scanning slices. It relates to an
optimal acoustic transducer. Heretofore, there has been carried out a method for obtaining a
tomogram at high speed by arranging a plurality of acoustic transducer elements and electrically
switching the drive of the vibrator at high speed. However, when simply switching driving is
performed, there is a problem that the resolution in the row direction in which the elements are
arranged is degraded due to the spread of the EndPage: 1-fold sound wave accompanying each
element. This degradation of resolution is generally referred to as degradation of lateral
resolution, or in the case of fan-like scanning, as degradation of azimuthal resolution. In order to
solve the degradation of the resolution in the lateral direction or the azimuthal resolution, for
example, as shown in FIG. 1, delay circuits 2-1 to 2-n for individual elements 1-1 to 1-n
constituting an element row are provided. According to the method, driving is performed by
giving a delay time, the phase of the signal of each element 1 is controlled, and a sound wave is
transmitted / received so that a specific position p <converges over the entire row. On the other
hand, as shown in FIG. 2, a plurality of elements 3-1 to 3-n are annularly arranged to
simultaneously drive one element without giving a distribution of delay time to each element.
There is a method of solving the degradation of lateral resolution by simultaneously receiving
waves. In the method of FIG. 2, since each element is driven at the same time, the waves from any
point pz all elements on the straight line 4 which passes through the center of the ring and is
perpendicular to the ring surface converge in the same phase . The advantage of this method is
that, as described above, the lateral resolution can be increased by focusing the sound wave
without delay driving. However, as can be seen also in FIG. 2, it is limited to a straight line 4
perpendicular to the annular surface passing through the center of the convergence point P. You
have to move the ring by mechanical means. Therefore, it is difficult to obtain a tomogram at
high speed like real time because of the time required to move the torus. The object of the
present invention is to eliminate the non-real time drawbacks of such co-drive toroidal elements
and to provide an acoustic transducer 7. Then, the purpose is to divide a plurality of acoustic
transducer elements into a plurality of sets so that each set comprises at least 7 elements or a
polygon, and sequentially operate each set This can be achieved by
Hereinafter, embodiments of the present invention will be described using the drawings. FIG. 3
shows a first embodiment of the present invention. In the figure, 5-1 to 5-n, 6-1 to 6-n,? 1M-7-n,
8-1 to 8-n are acoustic transducer elements disposed on the same plane and forming rows 9, 10,
11, 12 respectively. And, the extension direction of each row 9 to 12 corresponds to the
extension direction of the scanning line on the scanning surface. Also, the length in the extension
direction of this element is d. And these elements are divided into groups of six to form a regular
hexagon. The regular hexagonal relationship formed for each set is such that regular hexagons
move along the extension direction of the rows 9 to 12 at intervals of d on the element
arrangement surface. The first set of elements constituting the first hexagon are simultaneously
activated by the drive electric circuit (not shown), and the second set of elements constituting the
second hexagon separated by d at the same time simultaneously Activated state ... ... by
simultaneously activating the n-th set of elements constituting the n-th hexagon after the n-th
time, the center line (perpendicular to the element arrangement surface) 4 of each hexagon -1 to
4-n move in the direction of the rows 9 to 12 at an interval d. Therefore, the acoustic beam is
sequentially focused at the distance d on the scan line 13 on the scan plane parallel to the
element arrangement plane. EndPage: 2 A second embodiment of the present invention is shown
in FIG. The second embodiment is substantially the same as the first embodiment except that the
number of element rows 14 to 18 is large. A third embodiment of the present invention is shown
in FIG. The third embodiment is an embodiment in which the convergence point interval on the
scanning line is shorter than the element length. In this embodiment, eight element rows are
provided. The elements of the element rows 19 to 22 form a large hexagon, and the element
rows 23 to 26 form a small hexagon. The relationship between these large hexagons and small
hexagons is such that their centers 271 to 27-n and 28-1 to 28-n lie on a straight line.
Furthermore, the elements of the element row forming the large hexagon and the elements of the
small hole square forming element row are arranged so as to cause a gap. And, the drive of these
elements, the element which forms the 1st large hexagon, the element which forms the 1st small
hexagon, the elm which forms the 2nd large hexagon, the 2nd small hexagon The elements to be
formed are sequentially performed.
Therefore, the acoustic beam spots focused on the scanning line are formed at intervals of
successive lines. If it is desired to scan at narrower intervals, the number of element rows may be
increased, that is, the number of types of hexagons may be increased, and the amount of pitch
deviation between the rows may be reduced. A fourth embodiment is shown in FIG. This
embodiment is the same as the third embodiment except that the number of columns is
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram showing a conventional transducer
in which elements are arranged in one-dimensional direction, FIG. 2 is a diagram showing a
conventional circular element transducer, and FIGS. 3 to 6 The figure shows an acoustic
transducer according to first to fourth embodiments of the present invention. In FIG. 3, 5, 6. '7
and 8 are acoustic transducer elements, 9.10 and 11.12 are element arrays, and 13 is a scanning
line. Applicant Canon Inc. Representative Marujima Maru-EndPage: 3
Без категории
Размер файла
11 Кб
Пожаловаться на содержимое документа