JPH0210379B2 - - Google Patents

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to an ultrasound microscope.

[Summary of the invention]

In recent years, it has become possible to generate and detect sound waves with ultrasonic frequencies up to 1 GHz, making it possible to realize sound wavelengths of approximately 1 μm underwater, and as a result, it has become possible to obtain high-resolution sound wave imaging devices. In other words, a concave lens is used to create a focused acoustic beam, achieving a high resolution of 1 μm.

By inserting a sample into the beam and detecting the reflected ultrasonic waves from the sample, we can elucidate the elastic properties of minute regions of the sample, or while mechanically scanning the sample in two dimensions, we can measure the intensity of this signal. By displaying this as a brightness signal on a cathode ray tube, it is possible to magnify the fine structure of the sample. This example is, for example,
No. 116058.

FIG. 1 is a diagram showing the main components of the ultrasound microscope. The focusing, transmission and reception of ultrasonic waves is carried out by a spherical lens 1, whose structure consists of optically polished one side of a material made of cylindrical fused silica, etc., and a layer of ZnO etc. sandwiched between the upper and lower electrodes 3. A piezoelectric thin film 2 is formed. A pulse 5 generated from a pulse oscillator 4 is applied to the piezoelectric thin film 2 having a sandwich structure as described above, thereby generating an ultrasonic wave 6. Also, the other end has a diameter of 0.1mmφ to 1.0mmφ
A concave hemispherical hole is formed, and a medium (for example, water) 8 is filled between the hemispherical hole and the sample for propagating the ultrasonic waves 6 to the sample 7.

Ultrasonic waves 6 generated by the piezoelectric thin film 2 propagate in the cylinder as plane waves. When this plane wave reaches the hemispherical hole, quartz (velocity of sound 5600 m/s) and water (velocity of sound
1500 m/s), a refraction effect occurs, and a focused ultrasonic wave 6 can be irradiated onto the surface of the sample 7. Conversely, the ultrasound reflected from the sample 7 is collected and phased by a spherical lens, becomes a plane wave, reaches the piezoelectric thin film 2, and is converted into an RF signal 9 here. This RF signal 9 is received by a receiver 10,
Here, the signal is detected by a diode and converted into a video signal 11, which is used as an input signal for a CRT display 12.

In the apparatus configured in this way, when the sample 7 is two-dimensionally scanned within the x-y plane by the sample stage drive power supply 13, the intensity of reflection from the sample surface as the sample scans changes two-dimensionally. displayed on screen 12.

Generally speaking, a portion of ultrasound waves is reflected from the surface of an object, but a large portion of the ultrasound waves are reflected within the object, regardless of whether the object is optically transparent or not. It returns as an echo that reflects differences in density, viscosity, and defects. Ultrasonic microscopes can utilize this property to detect aspects inside a sample.

When attempting to observe a sample by moving the ultrasound microscope configured as described above over a long period of time, the intensity of the ultrasound generated from the piezoelectric material remains the same as when the device was first manufactured, but the signal acquired It was found that the intensity gradually decreased.

When we investigated the cause of this problem, we found that impurities contained in the medium and substances emitted from the sample (often used when observing biological samples) adhere to the concave surface of the spherical lens. It was found that there is attenuation of ultrasound waves at the boundary.

[Purpose of the invention]

The present invention has been made in view of the above points, and
The purpose is to provide an ultrasonic microscope that can remove substances adhering to the concave surface of a spherical lens, and that can always observe a sample with high signal strength.

[Summary of the invention]

The present invention has a structure in which a cleaning soft material made of a soft fiber bundle is movably arranged opposite to the concave surface of an ultrasonic deep probe, and cleaning liquid and compressed air are supplied to the cleaning soft substance. It has the following characteristics.

[Embodiments of the invention]

FIG. 2 is a diagram showing an embodiment of the present invention. In the figure, a soft fiber bundle 14 is fixed to a support stand 15 at the bottom of a sample stand on which a sample 7 is mounted. Furthermore, a cleaning liquid such as water is constantly supplied to the support base 15 through a pipe 16. Further, the structure is such that compressed air can be discharged from a pipe 17 that is also attached to the support base. Although not shown in the figure, the support stand 15 has an up-and-down mechanism and a rotating machine.

FIG. 3 shows the state in which the concave surface of the spherical lens is being cleaned according to this embodiment, in which the sample stage on which the sample 7 is mounted is moved to the side and the support base 15 is
When the support base 15 rises as shown by R ₁ and the fiber bundle 14 attached to its tip comes into contact with the concave surface, the support base 15 rotates as shown by the arrow R ₂ . After rotating for a predetermined period of time, the support stand 15 lowers, and at the same time compressed air (its strength is 1 kg/cm ² ) is supplied from the pipe 17.
is discharged, and this compressed air blows out through the fiber bundle 14, instantly blowing away the water droplets adhering to the concave surface portion and the adhering portion.

〔Effect of the invention〕

As described above, according to the present invention, the difficulty in collecting sound waves accurately due to the influence of dirt attached to the concave surface of the spherical lens during sample observation can be easily solved. can.

[Brief explanation of drawings]

FIG. 1 shows the configuration of an ultrasonic microscope, FIG. 2 shows the configuration of an embodiment of the present invention, and FIG. 3 shows the configuration of an ultrasonic microscope.
It is a figure explaining the operation|movement.

Claims (1)

[Claims] 1. A sound wave propagator has a concave hemispherical hole at one end, has a sound wave lens having a predetermined focus, and a sample stage for holding a sample near the focus of the sound wave lens, and a liquid medium is ejected from the sound wave lens. In an ultrasonic microscope that irradiates the sample with ultrasonic waves through the sample and images the sample using the disturbance sound waves emitted from the sample, the ultrasonic microscope includes a cleaning soft substance made of a soft fiber bundle, holding the cleaning soft substance, and a support table having a moving means for moving toward the hemispherical hole of the sonic lens to bring the cleaning soft material into contact with the hemispherical hole and rotating it; and means for supplying cleaning liquid and compressed air to the cleaning soft material. An ultrasonic microscope characterized by being equipped with.