JP2541774Y2 - Ultrasonic microscope equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic microscope.

[0002]

2. Description of the Related Art An ultrasonic microscope transmits and receives an ultrasonic wave from an acoustic probe to a sample via an ultrasonic propagation medium to obtain an image of the sample. Therefore, the type of the acoustic probe, the distance between the acoustic probe and the sample surface, water, etc. The information on the state of the ultrasonic propagation medium is important in operation of the ultrasonic microscope and in labor saving and automation of measurement.

That is, the suitable ultrasonic frequency, focal length, operation level of the signal processing means, and length of the probe differ depending on the acoustic probe, and these values must be changed each time the acoustic probe is changed.

Further, since the focal length of the ultrasonic microscope is short, a sufficiently large output signal cannot be obtained unless the distance between the acoustic probe and the sample surface is accurately grasped. The sample or the acoustic probe may be damaged.

Further, if bubbles are generated in the ultrasonic wave propagation medium or if the ultrasonic wave propagation medium is insufficient or insufficient, an accurate sample image cannot be reproduced, and sometimes a sample image cannot be obtained at all. is there.

In the conventional ultrasonic microscope, the above-mentioned various information is visually grasped by the operator.

[0007]

Problems to be solved by the invention, however, are often bothersome and difficult to determine visually. Therefore, attempts have been made to automatically determine the above various information individually.

For example, with respect to the determination of the type of the acoustic probe, a method has been proposed in which information indicating the type of the acoustic probe is added to a device such as an impedance matching device used with the acoustic probe and the discrimination is made based on this information. Have been. However, in this method, although the type of the acoustic probe can be determined, other information among the above-mentioned various information cannot be obtained, and the operability of the ultrasonic microscope is not significantly improved.

As for the prevention of contact between the sample and the acoustic probe, a receiving gate for warning is set at a timing at which a reflected wave should arrive when the sample approaches the acoustic probe, and the reflected wave is transmitted to the receiving gate. A method has been proposed to give a warning when it is caught through a network (Japanese Patent Publication No. 2-52).
No. 218). However, this method cannot be used when air bubbles are generated in the ultrasonic wave propagation medium and a reflected wave from the sample is cut off.

The present invention has been made in order to solve these disadvantages of the conventional ultrasonic microscope, and provides information on the type of the acoustic probe, the distance between the acoustic probe and the sample, and the state of the ultrasonic propagation medium. It is an object of the present invention to provide an ultrasonic microscope device which can be grasped in a dynamic manner.

[0011]

An ultrasonic microscope device according to a first aspect of the present invention transmits and receives an electric signal to and from an acoustic probe formed by an electroacoustic transducer and an acoustic lens. In an ultrasonic microscope apparatus including a signal processing unit and a position adjusting unit that adjusts a relative position between the acoustic probe and the sample surface, the signal processing unit is configured to perform the signal processing based on a level of a signal received from the acoustic probe. Determining means for determining whether or not the frequency of the signal transmitted to the acoustic probe is appropriate; high-frequency signal generating means capable of arbitrarily setting the frequency of the signal transmitted to the acoustic probe; and Calculation means for calculating the length of the lens, and a focal length and a use frequency of the acoustic probe corresponding to the calculated length of the acoustic lens are registered in advance. Characterized in that a registering means.

In the ultrasonic microscope apparatus according to a second aspect of the present invention, in the ultrasonic microscope apparatus according to the first aspect, the signal processing means is configured to control the acoustic probe and the acoustic probe based on a signal received from the acoustic probe. It is characterized by comprising a distance calculating means for calculating a distance from the sample surface.

Further, in the ultrasonic microscope apparatus according to a third aspect of the present invention, in the ultrasonic microscope apparatus according to the first or second aspect, the signal processing means is configured to execute the signal processing based on a signal received from the acoustic probe. It is characterized in that it is provided with a discriminating means for discriminating the presence or absence of an ultrasonic wave propagating medium between an acoustic probe and the sample surface and the presence or absence of bubbles in the ultrasonic wave propagating medium.

[0014]

In the ultrasonic microscope apparatus according to the first aspect of the present invention, an electric signal is transmitted and received by the signal processing means to and from the acoustic probe formed by the electroacoustic transducer and the acoustic lens, and the position is adjusted by the position adjusting means. When adjusting the relative position between the acoustic probe and the sample surface, the judging means judges the suitability of the frequency of the signal transmitted to the acoustic probe based on the level of the signal received from the acoustic probe. If not suitable, the frequency of the transmission signal to the acoustic probe is reset by the high-frequency signal generation means, and if suitable, the length of the acoustic lens is calculated by the calculation means based on the reception signal from the acoustic probe. The focal length and the operating frequency of the acoustic probe according to the calculated acoustic lens length are recognized by a registration unit registered in advance. Thus, if the initial setting is performed each time it is necessary, each piece of information can be automatically determined afterwards without the need for visual observation by the operator.

In the ultrasonic microscope apparatus according to a second aspect of the present invention, the distance calculating means calculates the distance between the acoustic probe and the sample surface based on the signal received from the acoustic probe. If the initial setting is performed each time, each information can be automatically determined without depending on the eyes of the operator.

Further, in the ultrasonic microscope apparatus according to a third aspect of the present invention, the presence / absence of an ultrasonic wave propagating medium between the acoustic probe and the sample surface is determined based on a signal received from the acoustic probe by the discriminating means. Since the presence / absence of air bubbles in the ultrasonic wave propagation medium is determined, each information can be automatically determined without performing the visual check of the operator by performing the initial setting whenever necessary.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a block diagram showing a detailed configuration of the high-frequency transceiver 5 of the embodiment shown in FIG.

First, the overall configuration of the present embodiment will be described with reference to FIG.

The acoustic probe 1 comprises an electroacoustic transducer 1a for bidirectionally converting an electric signal and an ultrasonic wave, and an acoustic lens 1b for transmitting an ultrasonic wave. The length of the probe is set to a predetermined length according to the frequency of the propagating ultrasonic wave and the focal length of the acoustic lens 1b.

An ultrasonic wave propagation medium 2 such as water is provided between the tip of the acoustic lens 1b and the surface of the sample 3.

The sample 3 is mounted on a sample scanner 4 as a position adjusting means for adjusting a relative position between the acoustic probe 1 and the sample 3.

An electric signal 7 is transmitted from the high-frequency transceiver 5 to the acoustic probe 1, and the electric signal 7 from the acoustic probe 1 is received by the high-frequency transceiver 5. The output monitor signal 8 of the high-frequency transceiver 5 is input to the computer 6, and the operation of the high-frequency transceiver 5 is controlled by a control signal 9 input from the computer 6. Further, the computer 6 outputs a control signal 10 of the sample scanner 4 to the sample scanner 4. The computer 6 performs operations such as operation control of the entire embodiment, analysis of waveform data of a reflected wave from the sample 3, configuration of a microscope image of the sample 3, and the like.
The high-frequency transceiver 5 and the computer 6 constitute signal processing means.

The computer 6 is connected to image display means (not shown). The image display means displays the ultrasonic microscope image of the sample 3 and the length of the acoustic probe, the used frequency, the focal length, and the ultrasonic wave as required. Information such as the state of the propagation medium and the distance between the acoustic probe and the sample surface is displayed.

Next, the configuration of the high-frequency transceiver 5 will be described with reference to FIG.

The high-frequency pulse generator 11 is, for example, 200
A continuous pulse signal of MHz is generated, and the pulse signal is input to the gate circuit 12.

The gate circuit 12 is controlled by, for example, a 10 KHz gate signal 9a generated inside the high-frequency transceiver 5, and intermittently passes a pulse signal input from the high-frequency pulse generator 11 at a constant cycle. That is, the output signal of the gate circuit 12 becomes a burst wave or a wave packet. The gate signal 9a is also input to the computer 6.

The output signal from the gate circuit 12 is transmitted to the electroacoustic transducer 1a as its drive signal 7a.

The reflected wave received from the electroacoustic transducer 1a is input to the detection circuit 14 as an electric signal 7b. The detection circuit 14 amplifies the received signal and performs envelope detection.

The reflected wave signal detected by the envelope detection by the detection circuit 14 is input to a sample and hold circuit 15.
The sample hold circuit 15 is based on a sampling signal 9b input from the computer 6. The input intermittent pulse train signal is sequentially sampled at different timings.

The signal sampled by the sample and hold circuit 15 is converted into a digital signal by an A / D converter 16 and input to the computer 6 as an output signal 8.

Next, the operation of this embodiment will be described with reference to the timing charts of FIGS.

The continuous pulse signal output from the high-frequency pulse generator 11 is converted into an intermittent burst pulse signal by passing through the gate circuit 12, and is supplied to the acoustic probe 1 as a transmission wave 21. 3 and 4 show only the envelope of the transmission wave 21.

In the acoustic probe 1, the drive signal 7a
This excites the electroacoustic transducer 1a to generate ultrasonic waves, which propagate through the acoustic lens 1b. This ultrasonic wave is first reflected at the tip of the acoustic lens 1b. This reflected wave
The light propagates through the acoustic lens 1b in the opposite direction, is converted into an electric signal 7b by the electroacoustic transducer 1a, and is input to the detection circuit 14. The detection circuit 14 amplifies the input electric signal 7 b, performs envelope detection, and inputs the signal to the sample and hold circuit 15 as a reflected signal 22 from the acoustic probe 1.

On the other hand, the ultrasonic wave emitted from the tip of the acoustic lens 1b into the ultrasonic wave propagating medium 2 is reflected on the surface of the sample 3 and re-enters the acoustic probe 1, and then, from the sample surface in the same manner as described above. Is input to the sample-and-hold circuit 15 as a reflected wave 24.

At this time, if the ultrasonic wave propagation medium 2 is in a normal state, as shown in the upper part of FIG. 3 and (1) of FIG.
The transmission wave 21, the reflected wave 22 from the acoustic probe 1, and the reflected wave 24 from the sample surface are input to the high-frequency transceiver 5 in the order of time.

The sampling signal 9b is input from the computer 6 to the sample and hold circuit 15 of the high-frequency transceiver 5, and the input signal is sampled at the timing of the sampling signal 9b. Sampling signal 9b
Is intermittently sampled and held at a frequency slightly different from the gate signal 9a input to the gate circuit 12.
Is input to Therefore, the above-described reflected waves 22, 24
The temporal positional relationship between the sampling signal 9b and the sampling signal 9b slightly changes as shown in FIGS. As described above, the reflected waves of the intermittent pulse train input to the sample-and-hold circuit 15 are sampled and held sequentially at different timings while gradually changing the mutual time position relationship, so that the reflected waves of the respective reflected waves are The value of each phase of the envelope waveform is sampled and held at all phases, and the envelope waveforms of a series of transmission / reception waves shown in the upper part of FIG. 3 and (1) to (4) of FIG. Is converted into a digital signal through the A / D converter 16 and input to the computer 6. here,
As shown in FIG. 4 (6), the transmission start time is ta, the time when the reflected wave 22 from the acoustic probe surface is input to the sample and hold circuit 15 is tb, and the reflected wave 2 from the sample surface is 2
4 is input to the sample hold circuit 15 at time td.
Assuming that the sound speed of the ultrasonic wave in the acoustic lens 1b is Vp and the sound speed of the ultrasonic wave in the ultrasonic wave propagation medium is Vw, the length Lp of the acoustic probe 1 is Lp = (tb−ta) × Vp / 2 will be required. In the acoustic probe 1 of the present embodiment, the type of the acoustic probe is classified by the length Lp of the acoustic probe, so that the type of the acoustic probe can be determined very easily.

If the matching layer (matching layer) provided at the tip of the acoustic probe 1 is well matched, a reflected wave 22 from the acoustic probe 1 is obtained as shown in FIG. There may not be. In this case, the reflected wave 22 from the acoustic probe 1 can be obtained by appropriately changing the oscillation frequency of the high-frequency pulse generator 11.

Next, in order to determine the distance Lf between the acoustic probe 1 and the surface of the sample 3, the computer 6 may calculate Lf = (td−tb) × Vw / 2.

Here, when bubbles are generated in the ultrasonic wave propagation medium 2, as shown in FIG. 4 (2), the reflected waves 23 from the bubbles are reflected by the reflected waves from the acoustic probe 1. 22
And the reflected wave 24 from the sample surface, and when the reflected wave 23 is present at a timing much earlier than the arrival timing of the reflected wave 24 from the sample surface, the ultrasonic wave propagation medium 2 It can be determined that bubbles are generated inside.

As shown in FIG. 4 (3), when the reflected wave 24 from the sample surface does not exist within an appropriate timing, the sample scanner 4 is controlled by the control signal 10 so that the sample 3 and the acoustic probe are controlled. Change the interval to 1 and try again. As a result of this retry, when the reflected wave 24 is not obtained, a large bubble is generated in the ultrasonic wave propagation medium 2 or an amount sufficient for the ultrasonic wave propagation medium 2 to propagate the ultrasonic wave to the sample 3. Depending on whether there is no gap or the distance between the sample 3 and the acoustic means probe 1 is too large.
It can be determined that the ultrasonic wave emitted from the acoustic probe 1 has not reached the surface of the sample 3.

The data such as the type of the acoustic probe 1, the state of the ultrasonic wave propagation medium 2, and the distance between the acoustic probe 1 and the sample 3 obtained by the above operation are displayed on the image display means as described above. The information may be displayed as a message to the operator, or may be processed inside the computer 6 as data for labor saving and automation of the measurement.

In the present embodiment, the detection circuit 14
The temporal digital data of a series of reflected waves was obtained by sequentially sampling the reflected wave signals detected in the above at different timings, but the temporal digital data of the series of reflected waves were directly obtained using a digital synchroscope or the like. It may be obtained.

Next, FIGS. 5 and 6 show flowcharts of one embodiment of the measurement or processing using the ultrasonic microscope and the acoustic probe of the present invention.

First, the acoustic probe is mounted on the ultrasonic microscope (step S ₁ ), the distance between the sample and the probe is set to be large (step S ₂ ), and an ultrasonic wave propagation medium (water or the like) is placed between the sample and the probe. (Medium) (step S ₃ ).

Next, power is supplied to the ultrasonic microscope, an ultrasonic wave is transmitted to the sample, a reflected signal from the sample is received, and sample-and-hold is performed at a series of sampling timings to obtain an envelope waveform of a transmission / reception wave. (step S _4).

The envelope waveform is analyzed to determine whether there is any surface reflection from the tip of the acoustic probe (step S ₅ ). If there is no surface reflection wave, it is considered that the matching layer is suitable. Therefore, the surface reflection wave is obtained by changing the frequency. For this purpose, it is determined whether there is room for changing the frequency (step S ₆ ).

If there is no room to change the frequency, a message indicating that the type of the acoustic probe cannot be determined is displayed (step S ₈ ).

If the frequency can be changed, the frequency of the transmission wave is changed (step S ₇ ), an envelope waveform is obtained again (step S ₄ ), and the presence or absence of a surface reflected wave of the acoustic probe is determined (step S ₇ ). ₅ ).

When the surface reflected wave is obtained in this way, the length of the acoustic probe is calculated from the process time of the surface reflected wave, and the frequency used is determined by referring to a separately prepared length-to-probe type correspondence table. And the focal length are obtained (step S ₉ ).

Next, move the frequency of the transmission wave of the high frequency transceiver for transmitting ultrasonic waves to an acoustic probe to the frequency use of the acoustic probe obtained in step S _9, the focal length of the acoustic probe timing of the sample hold of the received wave Set the timing to be calculated backward from. Subsequently, for the sample is placed at the focal point of the acoustic probe, first performs initial setting of the sample scanner located in a position that minimizes the distance between the acoustic probe and the sample (Step S _11).

Next, the sample position is moved by the sample scanner in order to find the focal position, and the sample hold value corresponding to this movement amount is recorded (step S ₁₂ ). In this way, the sample position is moved. The movement and sampling are repeated while the movement amount of the sample scanner is smaller than the focal length of the acoustic probe (steps S ₁₃ and S ₁₃₎ .
₁₄ ) If the amount of movement is greater than the focal length of the acoustic probe, return the sample scanner to the scanner position that gives the maximum value in the sample hold value as a function of the amount of movement of the sample scanner. and it is possible to match the focal length of the acoustic probe (step S _13, S _15). In this case when a large sample hold value of the received wave well is not obtained, a message of deficiency or acoustic probe and the sample interval excessive effect of the medium (step S _15).

When the focus position is adjusted by obtaining the maximum value of the sample hold value in this way, the measurement is further performed under a series of sampling timings to obtain the envelope waveform of the transmission / reception wave. When there is a reflected wave of a timing close to the surface reflection wave of the acoustic probe during this envelope waveform to display a message to the effect that small bubbles in the medium is generated (step S _16).

In this way, the processing shifts to the next processing.

As described above, the present invention can improve operability and save labor when used as a part of various measurement or processing steps.

[0056]

[Effect of the invention] According to the invention, the type of the acoustic probe,
Various information on the state of the ultrasonic wave propagation medium and the distance between the acoustic probe and the sample can be obtained comprehensively, improving operability,
Labor saving can be easily achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a block diagram showing a specific configuration of the high-frequency transceiver of the embodiment of FIG.

FIG. 3 is a timing chart showing timings of a transmission wave, a reception wave, and a sampling pulse in the embodiment of FIG.

FIG. 4 is a timing chart showing various cases of a transmission wave, a reception wave, and a sampling pulse in the embodiment of FIG.

FIG. 5 is a part of a flowchart showing an example of measurement or processing using the embodiment of FIG. 1;

FIG. 6 is a part of a flowchart showing an example of measurement or processing using the embodiment of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Acoustic probe 2 Ultrasonic propagation medium 3 Sample 4 Sample scanner 5 High frequency transceiver 6 Computer 11 High frequency pulse generator 12 Gate circuit 13 Electroacoustic transducer drive circuit 14 Detection circuit 15 Sample hold circuit 16 A / D converter

Claims (3)

(57) [Scope of request for utility model registration] 1. An electroacoustic transducerAnd the shape from the acoustic lens
Is formedAcoustic probe and the acoustic probeAgainst telegraph
Send and receive issuesSignal processing means, and the acoustic probe
samplesurfacePosition adjusting means for adjusting the relative position with respect to
Ultrasonic microscopeapparatusIn the signal processing means, the acoustic probeBased on the level of the received signal from
Judgment of the frequency of the transmission signal to the acoustic probe
Determining means; The frequency of the signal transmitted to the acoustic probe can be set arbitrarily
High-frequency signal generating means, Based on the signal received from the acoustic probe, the acoustic
Calculating means for calculating the length of the lens, The acoustic probe corresponding to the calculated acoustic lens length
Registered in advance with the focal length and operating frequency of the probe.
Step and Acoustic microscope characterized by comprising:apparatus. 2. The acoustic probe according to claim 1 , wherein
Based on the received signal from the acoustic probe and the sample
2. The ultrasonic microscope apparatus according to claim 1, further comprising a distance calculating means for calculating a distance from the surface . 3. The acoustic probe according to claim 2 , wherein
Based on the received signal from the acoustic probe and the sample
The presence or absence of an ultrasonic wave propagating medium with the surface and the ultrasonic sound
Equipped with a judging means for judging the presence or absence of bubbles in the wave propagation medium
The ultrasonic microscope apparatus according to claim 1 or 2, wherein: