JPH0222343B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic microscope device that allows the observation field to be varied when observing a sample using an ultrasonic beam.

Ultrasonic microscopes have recently been developed as a new method of exploring the microscopic world of objects using sound waves instead of light. Unlike optical microscopes that use the refractive index of light, this system forms images based on physical characteristics, and it is possible to see parts hidden beneath the surface of objects.

In principle, this ultrasonic microscope mechanically scans the sample surface using narrowly focused ultrasonic waves, collects the scattered ultrasonic waves, converts them into electrical signals, and transmits them two-dimensionally onto the surface of a cathode ray tube. display and obtain microscopic images.

A general ultrasound microscope has two configurations: one detects ultrasound waves that have passed through the sample while being scattered or attenuated, and the other detects ultrasound waves that have passed through the sample while being scattered or attenuated. They are divided into transmission type and reflection type, depending on whether the reflected ultrasonic waves are to be detected.

FIG. 1 is a block diagram showing the basic configuration of a transmission type ultrasound microscope.

1 is a high frequency oscillator, 2 is an ultrasonic focusing lens on the transmitting side, 3 is an ultrasonic focusing lens on the receiving side, 4 is a sound field medium such as water, 5 is a sample holder, 6 is a sample, 7 is a sample holder 5 a scanning device for moving in the X and Y directions;
8 is a scanning circuit that controls the scanning device 7, 9 is a receiving circuit that receives the output from the receiving side ultrasonic focusing lens 3, and 10 is a display device.

In the ultrasonic microscope device as described above, first,
The ultrasonic waves emitted from the transmitting side ultrasonic focusing lens 2 are collected by the receiving side ultrasonic focusing lens 3 disposed at a confocal position with the transmitting side ultrasonic focusing lens 2, converted into an electrical signal. Here, if the specimen holding table 5 is vibrated in the X direction and moved little by little in the Y direction while the inspection surface of the specimen is located at the focal point of the ultrasonic focusing lens, the ultrasound beam will be relative to the specimen. The surface will be scanned.
When the ultrasonic beam passes through the sample, the amplitude and phase change, so the electron beam of the cathode ray tube (hereinafter abbreviated as CRT) in the display device 10 is adjusted to correspond to each point on the sample surface through which the ultrasonic beam passes. Sweep and
By applying brightness modulation according to the output signal of the receiving side ultrasonic focusing lens 3, a two-dimensional microscopic image can be obtained on the CRT.

By the way, with an ultrasonic microscope as mentioned above, it is difficult to observe a minute spot on a sample on a predetermined sample holder because the sample surface is wide, and it is very difficult to find and determine the minute spot. It was necessary. Until now, it was normal to obtain an ultrasound microscope image of a desired location only by taking ultrasound microscope images several times while slightly shifting the irradiation position of the ultrasound beam two-dimensionally in the vicinity of the target location. It was hot.

The present invention aims to improve such conventional drawbacks, and provides an ultrasonic microscope device that allows the observation field of the sample to be varied and easily obtains the observation field of a desired part. With the goal.

Next, one embodiment of the present invention will be described in detail.

FIG. 2 is a block diagram showing an embodiment of the ultrasonic microscope apparatus of the present invention. 14 is a reference oscillator;
12 is an amplifier, 13 is a gain adjuster for the amplifier 12, 7 is an exciter serving as a scanning device, and 5 is the exciter 7.
2 is a transmitting-side ultrasonic focusing lens; 3 is a receiving-side ultrasonic focusing lens; 9
1 is a receiving circuit that receives the output from the ultrasonic focusing lens on the receiving side; 10 is a display device; 15 is a phase shifter;
1 is an amplifier.

In the ultrasonic microscope device as described above, the first
As shown in the figure, the ultrasonic waves focused by the receiving side ultrasonic focusing lens 3 are converted into electrical signals and supplied to the display device 10 through the receiving circuit 9.

At this time, the exciter 7 is vibrated using the sine wave generated by the reference oscillator 14.
The amplitude of the vibrator 7 is controlled by a gain adjuster 13 that changes the gain of the amplifier 12, which is disposed between the reference oscillator 14 and the vibrator 7. The observation field in the display device 10 is determined by the movement width of the sample holder 5, and the movement width of the sample holder 5 is determined by the movement width of the sample holder 5.
Determined by the amplitude of

In this case, the mechanical scanning for moving the sample holding table 5 and the electron beam scanning in the display device 10 must of course be synchronized, but a phase shifter 15 and an intensifier 11 are required to achieve this synchronization. is arranged between the reference oscillator 14 and the display device 10. If the amplitude of the electron beam scanning in the display device 10 is kept constant by the output of the reference oscillator 14, and the amplitude of the mechanical scanning by the vibrator 7 is varied, it is possible to arbitrarily obtain an observation field on the screen of the display device 10. Can be done.

From the above, first, the amplitude of the vibrator 7 is increased to obtain a wide image of the vicinity of the location to be observed. Next, a desired location is determined from the previously obtained image, the amplitude of the vibrator 7 is reduced, and the sample is scanned again with the ultrasonic beam to obtain an image of the desired location. This is very convenient compared to conventional devices, which require a lot of time to obtain an observation field of view of a desired location.

Note that the amplitude of mechanical scanning can be determined by a step method, but if a continuously variable one linked to an indicating device such as a meter is used, the observation field of view can be determined arbitrarily, and the desired point can be selected. can be easily found. Also, as shown in Figure 3,
If the amplitudes of the directional vibrator 7a and the Y-direction vibrator 7b can be controlled independently, it is convenient because the sample can be stretched out only in the X or Y direction and observed.

Although the description has been made using a transmission type ultrasound microscope, it goes without saying that images can be obtained using a similar method using a reflection type ultrasound microscope.

As described above, according to the ultrasonic microscope device according to the present invention, since the observation field of the sample can be varied,
You can easily obtain the observation field of your desired location.
This is very convenient compared to conventional devices, which require a lot of time to obtain an observation field of view of a desired location.

[Brief explanation of drawings]

Figure 1 is a block diagram of a transmission type ultrasound microscope, Figure 2 is a block diagram of a transmission type ultrasound microscope according to one embodiment of the present invention, and Figure 3 is a block diagram of the main parts of an ultrasound microscope showing another embodiment. It is a diagram. 1... High frequency oscillator, 2... Ultrasonic focusing lens on the transmitting side, 3... Ultrasonic focusing lens on the receiving side, 4...
Sound field medium, 5...sample holding stand, 6...sample, 7...
...Scanning device (exciter), 8...Scanning circuit, 9...
Receiving circuit, 10... Display device, 11, 12... Amplifier, 13... Gain adjuster, 14... Reference oscillator, 15... Phase shifter.

Claims (1)

[Claims] 1. Mechanically scan the sample surface with an ultrasonic beam in the X direction for high-speed assessment and in the Y direction for low-speed scanning perpendicular thereto, collect the ultrasonic waves from the sample, and convert them into electrical signals. In a mechanical scanning sonic microscope equipped with a two-dimensional display device on the surface of a cathode ray tube, there is a vibrator for high-speed scanning in the X direction, and a magnification by varying the amplitude of the vibrator. and a control magnification indicating device, and by changing the gain of the amplifier, the amplitude of the vibrator can be changed so that the observation field of the sample can be varied and observed at a desired magnification. An ultrasonic microscope device characterized in that it is configured as follows.