JPS5999375A - Drive system of switched linear array vibrator - Google Patents

Abstract

PURPOSE:To obtain a sound line generated at a pitch half the pitch of a vibrator in such a state that the sound lines of directionality and display are coincided without generating the difference in the sensitivity of each transmission reception wave, by a method wherein the numbers of vibrators to be driven are always same and one or odd numbered central vibrators are energized or not. CONSTITUTION:Eight continued vibrators 1-8 are subjected to phase driving [energized in delayed time distribution so as to form a wave surface (a)] to obtain a sound line A and eight vibrators 1-4 and 6-9 are subsequently subjected to phase driving so as to form a wave surface (b'') to obtain a sound line B''. As mentioned above, linear scanning is performed while driving is successively shifted. By this drive system, sensitivity difference is not generated because the vibrators are always driven at every eights and the non-coincidence of the sound line during scanning and the sound line related to display is not generated. In this case, this drive system is simultaneously performed not only during transmission but also during reception.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a driving method for a switched linear array transducer used in an ultrasound imaging device.

Electronic linear B with switched linear play method
In a scanning ultrasonic imaging device, there are cases where it is desired to obtain information from a sound object of II+ pitch as much as possible with a limited number of transducers. With conventional devices, a fine sound ray pitch is achieved by interleaving sound rays by sending out 7 and 8 vibration elements, or by scanning minute angle sectors. In 7-element and 8-element driving, As shown in Figure 1, oscillators 1 to 7 are energized with a delay time distribution such that the wave front becomes a to obtain sound ray A, and then oscillators Vi 1 to 8 are energized with a delay time distribution such that the wave front becomes b. The sound ray Bt is obtained by energizing with a delay time distribution.Since each sound ray coincides with the central axis of the aperture (1.t in the element), the sound ray shifts by half the element pitch between 7 elements and 8 elements. , such a drive becomes 1
By shifting the elements one by one, a half-pitch sound ray density is achieved.

In small angle sector scanning, 1 to 8 as shown in 2nd r24
The oscillators are energized with a delay time distribution such that the wavefront is 6 to obtain the sound ah, and then the oscillators 1 to 8 are energized with a delay time distribution such that the wavefront is b to obtain the sound ray A. Obtain a sound ray B that is slightly deflected without being deflected. Fine-pitch sound rays are obtained by such deflection driving, so-called micro-angle sector scanning.

Another method is to change the delay time distribution between transmission and reception so that the sound rays are shifted by half a pitch.

However, the 7-element and 8-element drives have the drawback that there is a difference in sensitivity, and the other two systems have the drawback that the sound rays have a different directivity from the sound rays related to CR7 display.

The purpose of the present invention is to eliminate such drawbacks, and to do so without causing a difference in sensitivity and to be able to match the actual sound rays of ultrasound and CR.
The object of the present invention is to provide a vibrator drive system that can obtain sound rays shifted by half a pitch without causing any difference between the sound rays and the sound rays on the T display.

The present invention will be described in detail below using the drawings. FIG. 3 is a diagram for explaining one embodiment of the system of the present invention. So, first, 8 consecutive oscillators 1 to 8 are driven in 4 phases (energized with a delay time distribution such that the wave surface is a) to obtain sound ray A, and then 1 Eight vibrators 4 and 6 to 9 are phase-driven to form a wavefront b'' to obtain a sound ray B''.

Such driving is sequentially shifted to perform linear scanning.

According to such a driving method, since eight transducers are always driven, there is no difference in sensitivity, and there is no mismatch between the sound line during trench scanning and the sound line related to the display. Note that such a powered system is used not only when transmitting waves but also when receiving waves.

Also, the element that is not driven is not limited to the one in the center (
2m+1 (m"L 2r'*...).Furthermore, the number of elements driven at one time is 2k (k=1.2...).
s,...) is sufficient.

Furthermore, if there is some disturbance in the directivity, 2n
+l (n= 1.2.5....) element, 61<
The number of non-driven elements at the center is also 21 (t=1.
2.5. ...and t<n). Alternatively, interleaving may be performed in which one center is not energized and two centers are not energized.

As explained above, according to the present invention, the number of oscillators to be driven is always the same, and linear scanning is performed by energizing one or an odd number of oscillators in the center and not 7'C. Therefore, it is possible to obtain sweat glands generated at a pitch that is half the pitch of the vibrator, without causing a difference in sensitivity between each transmitted and received wave, and in a state where the directivity and the displayed sound ray match.

In the method of the present invention, the weighting signal processing 3;! l! 'x
Since it is possible to suitably generate a half-pitch sound ray density simply by switching the vibrator, the effect is great in practical use.

[Brief explanation of the drawing]

Figure 1 shows the conventional 7-element/8-element driving force formula;
This figure shows a conventional small angle sector scanning method, and FIG. 5 shows an embodiment of the driving method of the present invention. 1 to 8... vibrator.

Claims (1)

[Claims] In an electronic linear B-scan ultrasonic imaging device based on a linear array system, one or an odd number of transducers are effectively used in a given shape. Move only the element width! ? By b, the starting point of the sound ray is effectively set at the pin of the vibrator. A driving method for a switched linear array vibrator, characterized in that the transducer is moved in units of half of a cell.