JPS6097253A - Vibration applying apparatus for ultrasonic microscope - Google Patents

Abstract

PURPOSE:To prevent the generation of undesired vibration in the longitudinal direction, by providing an ultrasonic wave head and a counter balance, whose mass is approximately equal to that of said head on the same axis, and vibrating the head and the balance with the middle point of the axis as the center. CONSTITUTION:An ultrasonic wave head 1 is held at a tip part 2 of a supporting rod 2. A counter balance 9, whose mass is approximately the same as that of the head 1, is attached to the tip part of a supporting rod 2'. Required ACs having equal amplitude are supplied to voice coils 6 and 6', which are wound around ball pieces 5 and 5' of magnets 3 and 3'. The ultrasonic wave head and the counter balance 9 are vibrated in he reverse direction to each other on the same axis in a symmetrical mode. In this way, the center of gravity of a vibration applying apparatus is always kept at a central position P between the ultrasonic wave head 1 and the counter balance 9. Therefore, the undesired generation of vibration in the longitudinal direction due to the shift of the center of gravity can be prevented.

Description

TECHNICAL FIELD The present invention relates to an excitation device for linearly vibrating an ultrasonic head having a piezoelectric transducer in order to scan a sample in an ultrasonic microscope.

BACKGROUND ART As a conventional vibration excitation device, for example, as shown in FIG. 8
, connected to the voice coil 6 wound between the yoke 4 and the pole piece 5 so as to cross the magnetic flux of the magnetic circuit having the yoke 4 and the pole piece 5, and in the axial direction of the voice coil 6 by the leaf spring 7. There is one in which the ultrasonic head 1 is supported so as to be displaceable in a direction orthogonal to the direction in which the ultrasonic waves are projected from the ultrasonic head 1, and the ultrasonic head 1 is vibrated by supplying a required alternating current to the voice coil 6. .

However, in the conventional vibration excitation device shown in FIG. For example, the ultrasonic head 1 vibrates in the projection direction of the ultrasonic wave, and the focal position changes according to the longitudinal vibration, and this longitudinal vibration is also transmitted to the sample stage, etc., so a high-resolution ultrasonic image is created. There are disadvantages that cannot be obtained.

OBJECTS OF THE INVENTION An object of the present invention is to eliminate the above-mentioned drawbacks and to provide an excitation device for an ultrasonic microscope that is suitably constructed so that undesired vertical vibrations do not occur.

Summary of the Invention The vibration device of the present invention comprises an ultrasonic head having a piezoelectric transducer and a counterbalance having the same mass, which are coaxially arranged symmetrically about the center of the ultrasonic head and the counterbalance. The device is characterized in that it includes a drive mechanism that vibrates.

Embodiment FIG. 2 shows the configuration of an example of the vibration excitation device of the present invention. This vibration excitation device is constructed by arranging the devices shown in FIG. 1 laterally symmetrically, and the yoke 8 is an integral unit having a laterally symmetrical shape. Support rods 2, 2',
The magnet 8.13', the pole pieces 5, 5', the voice coil/l/8e 6' and the plate 7.7' are of the same dimensions and the same mass, and the support rod 2' is At the tip, there is an ultrasonic head 1 held at the tip of the support rod 2.
Attach a counterbalance 9 with the same temperature as that of the counterbalance 9. In this way, voice coils 6 and 6' are
The ultrasonic head 1 and the counterbalance 9 are vibrated symmetrically on the same axis in opposite directions by supplying the required alternating currents 2 equal to a.

In this way, the center of gravity of the vibrating device is always maintained at the center position P between the ultrasonic head 1 and the counterbalance 9, thereby effectively preventing the generation of undesired vertical vibrations due to movement of the center of gravity. The counterbalance 9 in FIG. 2 can also be configured with an ultrasonic head having a piezoelectric transducer. In this way, two ultrasound images can be obtained at the same time. Further, 1. The means for vibrating the ultrasonic head in a predetermined direction may be constructed using a piezoelectric bimorph plate, an eccentric cam, an electromagnet, etc., instead of using the voice coil described above.

Effects of the Invention As described above, in the present invention, an ultrasonic head having a piezoelectric transducer for projecting ultrasonic waves onto a sample, and a counterbalance for the amount of
Since they are vibrated symmetrically in a predetermined scanning direction around the center on the same axis, there is no movement of the center of gravity, thus effectively preventing the occurrence of undesired vertical vibration of the entire vibrating device. This allows high-resolution ultrasound images to be obtained at all times.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the structure of a conventional vibration excitation device, and FIG. 2 is a front view showing the structure of an example of the vibration device of the present invention. 190. Ultrasonic head 2, 2'...Support rod, 8.3
'...Magnet 5,5'...Pole piece 6.6'
...Voice coil 7.7'...Plate spring 8...Yoke 9...Counter balance.

Claims (1)

[Claims] 1. The ultrasonic head having a piezoelectric transducer and the counterbalance having the same mass are provided with a drive mechanism that vibrates symmetrically about the center of the ultrasonic head and the counterbalance on the same axis. A vibrating device for an ultrasonic microscope.