Ultrasonic probe and ultrasonic diagnostic apparatus

Abstract

Provided is an ultrasonic probe and an ultrasonic diagnostic apparatus that can suppress a leakage current even when a high-voltage transmission circuit and a low-voltage transmission circuit each having a buffer section are used simultaneously. The ultrasonic probe includes a high-voltage transmission circuit that transmits a relatively high voltage, a low-voltage transmission circuit that transmits a relatively low voltage, and a transducer that is selectively transmitted with a voltage from the high-voltage transmission circuit and the low-voltage transmission circuit. The ultrasonic probe is characterized in that the high-voltage transmission circuit includes a current source section that changes an output current and an introduced current based on a set signal, a buffer section that drives the transducer in correspondence with the output current and the introduced current of the current source section, and an impedance control section that is connected to an input terminal and an output terminal of the buffer section.

Description

TECHNICAL FIELD

[0001] The present application relates to an ultrasonic probe for medical use and an ultrasonic diagnostic apparatus, and particularly relates to a transmission circuit that drives each vibrator of an ultrasonic probe. BACKGROUND

[0002] An ultrasonic diagnostic apparatus is an apparatus that images a tomographic image of an object and a Doppler image that images a blood flow distribution by receiving an echo signal of an ultrasonic wave transmitted to the object. As for each vibrator of an ultrasonic probe that transmits an ultrasonic wave, a relatively high voltage of 100 V or more is applied at the time of imaging of the tomographic image, and in contrast, a relatively low voltage of several V is continuously applied at the time of imaging of the Doppler image. Further, in order to improve the spatial resolution of the tomographic image and the Doppler image, it is necessary to make the size of each vibrator smaller, and it is necessary to downsize an amplification circuit that individually drives each vibrator by applying a voltage thereto.

[0003] In Patent Literature 1, an amplification circuit and an ultrasonic probe are disclosed that, in order to downsize the amplification circuit, are provided with: a current source section that varies an output current and an introduced current based on a set signal; and a buffer section that drives a vibrator in correspondence with the output current and the introduced current of the current source section.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: JP Patent No. 6309093

[0007] However, in a case where the amplification circuit of Patent Literature 1 is used as a high-voltage transmission circuit for imaging of a tomographic image and a low-voltage transmission circuit for imaging of a Doppler image is provided separately from the high-voltage transmission circuit, a leakage current sometimes occurs in the buffer section. That is, since the output impedance of the high-voltage transmission circuit provided with the buffer section is relatively low, a leakage current sometimes occurs with respect to a signal transmitted from the low-voltage transmission circuit. SUMMARY

[0008] Therefore, an object of the present application is to provide an ultrasonic probe and an ultrasonic diagnostic apparatus that can suppress a leakage current even in a case where a high-voltage transmission circuit provided with a buffer section and a low-voltage transmission circuit are used simultaneously.

[0009] To achieve the above objectives, the present invention comprises: a high-voltage transmitting circuit for transmitting a relatively high voltage; a low-voltage transmitting circuit for transmitting a relatively low voltage; and an oscillator from which voltage is selectively transmitted from the high-voltage transmitting circuit and the low-voltage transmitting circuit. The ultrasonic probe is characterized in that the high-voltage transmitting circuit comprises: a current source section for changing the output current and the input current based on a set signal; a buffer section for driving the oscillator corresponding to the output current and the input current of the current source section; and an impedance control section connected to the input and output terminals of the buffer section.

[0010] Furthermore, the present invention is characterized by an ultrasonic diagnostic device having the ultrasonic probe described above.

[0011] Invention Effects

[0012] According to the present invention, an ultrasonic probe and an ultrasonic diagnostic device can be provided that can suppress leakage current even when a high-voltage transmission circuit and a low-voltage transmission circuit with a buffer section are used simultaneously. Attached Figure Description

[0013] Figure 1 This is an overall structural diagram of the ultrasonic diagnostic device of the present invention.

[0014] Figure 2 This is a structural diagram of the ultrasonic probe of the present invention.

[0015] Figure 3 This is a structural diagram of the transmitting circuit of the ultrasonic probe of the present invention.

[0016] Figure 4 This is a diagram showing a specific example of a high-voltage transmitting circuit in a transmitting circuit.

[0017] Figure 5 This is a diagram illustrating an example of the configuration within the oscillator control assembly.

[0018] Figure 6 These are diagrams illustrating other examples of configurations within the oscillator control components.

[0019] Explanation of reference numerals in the attached figures

[0020] 1: Transmitting circuit; 2: Oscillator; 3: Wiring; 9: Transmitting signal generation circuit; 10: High-voltage transmitting circuit; 11: High-voltage control unit; 12: Level shifter; 13: High-voltage driver unit; 14: Buffer unit; 15: Impedance control unit; 16: Low-voltage transmitting circuit; 17: Low-voltage control unit; 18: Low-voltage driver unit; 20, 26: N-type MOS transistors; 21, 27, 28: N-type high-voltage MOS transistors; 22, 24: P-type MOS transistors; 23, 25, 29: P-type high-voltage MOS transistors; 30, 3 1: Switch; 32: Resistor; 40: High-voltage switch; 42, 43: Low-voltage switch; 91: Variable delay circuit; 100: Ultrasonic diagnostic device; 101: Main body; 102: Display unit; 103: Control unit; 104: Ultrasonic probe; 105: Cable; 106: Control IC; 107: Vibrator assembly; 110: Vibrator control assembly; 111: Receiving circuit; 115: Row peripheral circuit; 116: Column peripheral circuit; 117: Row control signal; 118: Column control signal; 120: Memory; 121: Setting information Detailed Implementation

[0021] The embodiments of the ultrasonic diagnostic apparatus and ultrasonic probe of the present invention will be described below with reference to the accompanying drawings. Furthermore, in all the drawings used to describe the embodiments, the same reference numerals are used to label the same components in principle, and repeated descriptions are omitted.

[0022] Furthermore, for convenience, the description may be divided into multiple paragraphs or implementation methods when necessary. However, unless explicitly stated otherwise, these are not unrelated to each other, but rather are variations, details, supplementary explanations, etc., in which one is a part or all of the other. In addition, in the following implementation methods, when referring to the number of elements (including quantity, value, amount, range, etc.), the references are not limited to that specific number, except as explicitly stated otherwise or where the number is clearly defined in principle. The references may be greater than or less than that specific number.

[0023] Furthermore, in the following embodiments, it is self-evident that the constituent elements (including element steps, etc.) are not necessarily essential, except where specifically stated or where they are explicitly considered necessary in principle. Similarly, in the following embodiments, when referring to the shape, positional relationship, etc., of constituent elements, etc., it is assumed that they include those that are substantially similar or analogous to the shape, etc., except where specifically stated or where they are explicitly considered not to be so in principle. The same applies to the values ​​and ranges mentioned above.

[0024] use Figure 1Here is an example of the ultrasound diagnostic apparatus 100 of the present invention. The ultrasound diagnostic apparatus 100 is a device that captures tomographic images and Doppler images of blood flow distribution of a subject by receiving echo signals of ultrasound waves transmitted to the subject. It is configured such that an ultrasound probe 104 and a main body 101 are electrically connected by a cable 105.

[0025] An ultrasonic probe 104 is a device that transmits ultrasonic waves to and receives echo signals from an object being inspected. It includes a transducer assembly 107 and a control IC (Integrated Circuit) 106. The control IC 106 is, for example, composed of a semiconductor chip. The detailed structure of the ultrasonic probe 104 is described using... Figure 2 To be discussed later.

[0026] The main body 101 is a device that supplies power to the ultrasonic probe 104 for transmitting ultrasonic waves and generates and displays tomographic and Doppler images based on the echo signals received by the ultrasonic probe 104. It includes a control unit 103 and a display unit 102. The control unit 103 includes a CPU (Central Processing Unit), a DSP (Digital Signal Processor), a storage device, a communication interface, and a user interface, and controls the power supplied to the ultrasonic probe or the generation of tomographic images based on the echo signals. The display unit 102 is, for example, a liquid crystal display (LCD), which displays the tomographic images generated by the control unit 103. The imaging conditions for the tomographic images are set by the operator via a user interface such as a keyboard, mouse, or a touch panel displayed on the display unit 102.

[0027] use Figure 2 Let's illustrate an example of an ultrasonic probe 104. As described above, the ultrasonic probe 104 has a transducer assembly 107 and a control IC 106. The transducer assembly 107 has a plurality of transducers 2 that transmit ultrasonic waves to the object being tested and receive echo signals from the object being tested. The plurality of transducers 2 are arranged, for example, m in the row direction (X direction) and n in the column direction (Y direction), in a two-dimensional configuration of n rows and m columns.

[0028] The control IC 106 has multiple oscillator control components 110, row peripheral circuits 115, column peripheral circuits 116, and a memory 120. The oscillator control components 110 are electrically connected to each oscillator 2 via wiring 3 and have a transmitting circuit 1, a transmitting signal generation circuit 9, a receiving circuit 111, and a variable delay circuit 91.

[0029] Transmitting circuit 1 is a circuit that drives transducer 2 to transmit ultrasonic waves by applying a voltage to transducer 2. The voltage applied to transducer 2 is controlled according to the image being captured. For example, a relatively high voltage of around 100V is applied when capturing a tomographic image, while a relatively low voltage of several V is applied continuously when capturing a Doppler image. The detailed structure of transmitting circuit 1 is described using... Figure 3 To be discussed later.

[0030] The signal generation circuit 9 is a circuit that controls the timing of the transmission circuit 1 driving the oscillator 2. For example, the signal generation circuit 9 controls the timing so that the ultrasonic waves transmitted from the multiple oscillators 2 scan overlapping points within the body being detected.

[0031] The receiving circuit 111 amplifies the echo signal received by the oscillator 2. The variable delay circuit 91 sets a delay time for the echo signal corresponding to the distance from the point where the ultrasound transmitted to the object being tested coincides with the distance from each oscillator 2. The echo signal with the set delay time is sent to the control unit 103 for use in the generation of tomographic images, etc.

[0032] The row peripheral circuit 115 controls each oscillator control component 110 on a row-by-row basis using n sets of row control signals 117. Furthermore, the column peripheral circuit 116 controls each oscillator control component 110 on a column-by-column basis using m sets of column control signals 118. The row control signals 117 and column control signals 118 include setting signals such as signals for selecting a specific oscillator 2 and signals for determining the delay time of each oscillator 2, which are stored as setting information 121 in the memory 120.

[0033] use Figure 3 Let me illustrate an example of the transmitting circuit 1. The transmitting circuit 1 has a high-voltage transmitting circuit 10 and a low-voltage transmitting circuit 16, which can selectively operate either the high-voltage transmitting circuit 10 or the low-voltage transmitting circuit 16 in response to the captured image.

[0034] The high-voltage transmitting circuit 10 operates during the capture of the tomographic image and applies a relatively high voltage to the oscillator 2. It includes a high-voltage control unit 11, a level shifter 12, a high-voltage driver unit 13, a buffer unit 14, and an impedance control unit 15. The high-voltage control unit 11 controls the transmission of the high-voltage signal sent from the transmitting signal generation circuit 9, generating a signal that is sent to the level shifter 12. The level shifter 12 transforms the voltage level of the signal sent from the high-voltage control unit 11. The high-voltage driver unit 13 outputs the signal, whose voltage level has been transformed by the level shifter 12, to the oscillator 2 via the buffer unit 14.

[0035] The low-voltage transmission circuit 16 operates during Doppler image capture and applies a relatively low voltage to the oscillator 2. It includes a low-voltage control unit 17 and a low-voltage driver unit 18. The low-voltage control unit 17 generates a signal to be sent to the low-voltage driver unit 18 based on the low-voltage transmission signal sent from the transmission signal generation circuit 9. The low-voltage driver unit 18 outputs the signal sent from the low-voltage control unit 17 to the oscillator 2.

[0036] As described above, the oscillator 2 is connected to the high-voltage transmitting circuit 10 and the low-voltage transmitting circuit 16. Because the output impedance of the high-voltage transmitting circuit 10, which has a buffer section 14, is relatively low, leakage current may sometimes occur in the buffer section 14 relative to the signal transmitted from the low-voltage transmitting circuit 16. Therefore, in Figure 3 The high-voltage transmitting circuit 10 is equipped with an impedance control unit 15 connected to the input and output terminals of the buffer unit 14. By providing the impedance control unit 15 in the high-voltage transmitting circuit 10, leakage current is suppressed in the buffer unit 14, where the input and output are at the same potential. In addition, the high-voltage control unit 11, the level shifter 12, and the high-voltage driver unit 13 function as variable current sources that change the output current and the input current based on a setting signal.

[0037] use Figure 4 Here is a specific example of a high-voltage transmitting circuit 10 having a high-voltage control unit 11, a level shifter 12, a high-voltage driver unit 13, a buffer unit 14, and an impedance control unit 15.

[0038] The high-voltage control unit 11 includes switches 30 and 31. Switch 30 receives a reference signal A at one end and is connected to the gate terminal of the N-type MOS transistor 20 of the level shifter 12 at the other end. Switch 31 receives a reference signal B at one end and is connected to the gate terminal of the P-type MOS transistor 24 of the level shifter 12 at the other end. The reference signal A and reference signal B are, for example, 1V and VDD-1V. The on / off state of switches 30 and 31 is controlled by control signals A and B, which are high-voltage transmission signals, respectively, transmitted from the transmission signal generation circuit 9.

[0039] The level shifter 12 has an N-type MOS transistor 20, an N-type high-voltage MOS transistor 21, a P-type MOS transistor 22, a P-type MOS transistor 24, a P-type high-voltage MOS transistor 25, and an N-type MOS transistor 26.

[0040] The N-type MOS transistor 20 connects its gate terminal to the switch 30, its source terminal to ground, and its drain terminal to the source terminal of the N-type high-voltage MOS transistor 21. The N-type high-voltage MOS transistor 21 receives a bias voltage VbiasA at its gate terminal, connecting its source terminal to the drain terminal of the N-type MOS transistor 20, and its drain terminal to both the drain terminal and gate terminal of the P-type MOS transistor 22. The P-type MOS transistor 22 connects its drain terminal and gate terminal to the drain terminal of the N-type high-voltage MOS transistor 21, and its source terminal to HVDD, which serves as the positive-side wiring for high voltage.

[0041] P-type MOS transistor 24 connects its gate terminal to switch 31, its source terminal to VDD (a low-voltage positive side wiring), and its drain terminal to the source terminal of P-type high-voltage MOS transistor 25. P-type high-voltage MOS transistor 25 receives a bias voltage VbiasB at its gate terminal, connecting its source terminal to the drain terminal of P-type MOS transistor 24, and its drain terminal to both the drain terminal and gate terminal of N-type MOS transistor 26. N-type MOS transistor 26 connects its drain terminal and gate terminal to the drain terminal of P-type high-voltage MOS transistor 25, and its source terminal to HVSS (a high-voltage negative side wiring).

[0042] If switch 30 is turned on by control signal A, a reference signal A is applied to the gate terminal of N-type MOS transistor 20, and a current corresponding to reference signal A flows through the drain terminal of N-type MOS transistor 20. When current flows through the drain terminal of N-type MOS transistor 20, a signal that changes the voltage level of control signal A is transmitted to P-type MOS transistor 22 via N-type high-voltage MOS transistor 21. That is, N-type MOS transistor 20, N-type high-voltage MOS transistor 21, and P-type MOS transistor 22 function as level shifters 12 that change the voltage level of control signal A, which controls the on / off state of switch 30. Similarly, P-type MOS transistor 24, P-type high-voltage MOS transistor 25, and N-type MOS transistor 26 also function as level shifters 12 that change the voltage level of control signal B, which controls the on / off state of switch 31.

[0043] The high-voltage driver section 13 includes a P-type high-voltage MOS transistor 23 and an N-type high-voltage MOS transistor 27. The P-type high-voltage MOS transistor 23 has its gate terminal connected to HVDD by a signal that modifies the voltage level of control signal A, and its drain terminal connected to the gate terminal of the N-type high-voltage MOS transistor 28 in the buffer section 14. The N-type high-voltage MOS transistor 27 has its gate terminal connected to HVSS by a signal that modifies the voltage level of control signal B, and its drain terminal connected to the gate terminal of the P-type high-voltage MOS transistor 29 in the buffer section 14.

[0044] If a signal that modifies the voltage level of the control signal A is applied to the gate terminal of the P-type high-voltage MOS transistor 23, a current corresponding to the voltage applied to the gate terminal flows through the drain terminal. That is, the P-type high-voltage MOS transistor 23 functions as a high-voltage driver section 13 that outputs a signal that modifies the voltage level. Similarly, the N-type high-voltage MOS transistor 27 also functions as a high-voltage driver section 13 that outputs a signal that modifies the voltage level.

[0045] The buffer section 14 includes an N-type high-voltage MOS transistor 28 and a P-type high-voltage MOS transistor 29. The gate terminal of the N-type high-voltage MOS transistor 28 is connected to the drain terminal of the P-type high-voltage MOS transistor 23, the drain terminal is connected to HVDD, and the source terminal is connected to the oscillator 2. The gate terminal of the P-type high-voltage MOS transistor 29 is connected to the drain terminal of the N-type high-voltage MOS transistor 27, the drain terminal is connected to HVSS, and the source terminal is connected to the oscillator 2. That is, the source terminals of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29 become the output terminals of the buffer section 14. Furthermore, connecting the gate terminals of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29 constitutes the input terminal of the buffer section 14.

[0046] The current flowing through the drain terminals of the P-type high-voltage MOS transistor 23 and the N-type high-voltage MOS transistor 27 in the high-voltage driver section 13 causes the voltage at the gate terminals of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29 to rise. As the gate terminal voltage rises, a voltage of the same level as the rising voltage is output from the source terminals of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29, and the oscillator 2 is driven by the voltage output from the source terminals. In other words, the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29 function as a buffer section 14 that drives the oscillator 2 based on the current output or input from the current source section, which includes the high-voltage control section 11, the level shifter 12, and the high-voltage driver section 13.

[0047] The impedance control section 15 is, for example, composed of a resistor 32 connected in parallel with the buffer section 14. Figure 4 In the transmitting circuit 1 shown, when the oscillator 2 is driven by the low-voltage transmitting circuit 16, a voltage is also applied to the output terminal of the high-voltage transmitting circuit 10 from the low-voltage transmitting circuit 16 along with the oscillator 2. However, during the operation of the low-voltage transmitting circuit 16, since the high-voltage transmitting circuit 10 is stopped and the high-voltage driver section 13 is in an off state, the transient voltage change at the input terminal of the buffer section 14 can be made to be at the same potential as the output terminal through the resistor 32. As a result, the gate-source voltages of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29 become the same potential. Consequently, leakage current generated in the buffer section 14 can be suppressed. In addition, the resistance value of the resistor 32 is preferably sufficiently low compared to the output impedance of the high-voltage driver section 13, and is at the same level as the drain-source resistance of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29.

[0048] The appropriate range of the resistance value Rzctl of resistor 32 can be determined by two constraints. The first constraint is that resistor 32 does not impede the driving of oscillator 2 by buffer section 14 of high-voltage transmitting circuit 10, that is, the ratio of input signal Vin to output signal Vout of buffer section 14, i.e., the amplification rate An, is close to 1. The amplification rate An of buffer section 14 is characterized by the following formula.

[0049]

Mathematical Formula 1

[0050]

[0051] Here, gm is the transconductance of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29, and ro is the output resistance of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29. Furthermore, the transconductance of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29 are set to the same value. In addition, the output resistance of the N-type high-voltage MOS transistor 28 and the P-type high-voltage MOS transistor 29 are also set to the same value.

[0052] According to general semiconductor processes, since gm·ro > 1, in order to make the amplification An close to 1, Rzctl only needs to be at least as high as ro. That is, Rzctl ≥ ro becomes the first constraint condition.

[0053] The second constraint is to eliminate the potential difference between the output and input of the buffer section 14 when a signal is applied from the output of the high-voltage transmitting circuit 10. When the output impedance of the high-voltage driver section 13 is Zout, the relationship between the input signal Vin and the output signal Vout of the buffer section 14 is characterized by the following formula.

[0054]

Mathematical Formula 2

[0055]

[0056] To set Vin / Vout = 1 in the above equation, Zout >> Rzctl is required, which becomes the second constraint. Therefore, according to the two constraints, the suitable range of the resistance value Rzctl of resistor 32 is ro ≤ Rzctl << Zout. When the resistance value Rzctl is within the suitable range, the operation of the high-voltage transmitting circuit 10 will not be hindered, and leakage current in the buffer section 14 can be suppressed.

[0057] use Figure 5 This illustrates an example of the configuration within the oscillator control assembly 110. Figure 5 In this circuit, a high-voltage switch 40 is positioned between the low-voltage transmitting circuit 16 and the receiving circuit 111 and the oscillator 2. The high-voltage switch 40 is controlled to be switched on / off according to the operation of the high-voltage transmitting circuit 10 and the low-voltage transmitting circuit 16. That is, the high-voltage switch 40 is switched off when the high-voltage transmitting circuit 10 is in operation, and switched on when the low-voltage transmitting circuit 16 is in operation. This switching control prevents damage to the low-voltage transmitting circuit 16 and the receiving circuit 111 caused by the relatively high voltage output from the high-voltage transmitting circuit 10.

[0058] Furthermore, the high-voltage transmitting circuit 10 and the low-voltage transmitting circuit 16 are selectively operated by the high-voltage transmitting signal and the low-voltage transmitting signal transmitted from the transmitting signal generation circuit 9. Moreover, during the operation of the low-voltage transmitting circuit 16, the receiving circuit 111 is disconnected. Furthermore, during the reception of the echo signal, the high-voltage switch 40 is turned on, and the low-voltage transmitting circuit 16 is turned off.

[0059] use Figure 6 Here are some other examples illustrating the configuration within the oscillator control assembly 110. Figure 6 In China, Figure 5 The configuration includes additional low-voltage switches 42 and 43, and a clamping diode 44. Low-voltage switch 42 is positioned between high-voltage switch 40 and the low-voltage transmitting circuit 16 and receiving circuit 111. Low-voltage switch 42 is turned on during echo signal reception and turned off during operation of the low-voltage transmitting circuit 16. Clamping diode 44 is connected between low-voltage switch 42 and receiving circuit 111. Low-voltage switch 43 has one end connected between high-voltage switch 40 and low-voltage switch 42, and the other end connected to the output terminal.

[0060] The receiving circuit 111 can be separated from the low-voltage transmitting circuit 16 by the low-voltage switch 42. Furthermore, excessive input to the receiving circuit 111 can be suppressed by the clamping diode 44. In addition, the echo signal can be output without passing through the receiving circuit 111 by the low-voltage switch 43.

[0061] The implementation methods described above can be varied. For example, the "lower voltage" and "higher voltage" mentioned above do not necessarily have to be several volts and 100 volts, as long as the "lower voltage" is less than the "higher voltage".

Claims

1. An ultrasonic probe, comprising: High-voltage transmitting circuit, transmitting relatively high voltage; Low-voltage transmitting circuit, transmitting a relatively low voltage; and The oscillator is selectively supplied with voltage from the high-voltage transmitting circuit and the low-voltage transmitting circuit. The ultrasonic probe is characterized in that... The high-voltage transmitting circuit has: The current source section changes the output current and the input current based on a set signal; The buffer section drives the oscillator according to the current output from the current source section and the current introduced; and The impedance control unit is connected to the input and output terminals of the buffer unit.

2. The ultrasonic probe according to claim 1, characterized in that, The impedance control unit is a resistor.

3. The ultrasonic probe according to claim 2, characterized in that, The buffer section includes N-type MOS transistors and P-type MOS transistors. When the output resistance of the N-type MOS transistor and the P-type MOS transistor is ro and the output impedance of the current source is Zout, the resistance value Rzctl of the resistor is in the range of ro≤Rzctl<<Zout.

4. The ultrasonic probe according to claim 1, characterized in that, The ultrasonic probe also features: The receiving circuit amplifies the echo signal received by the oscillator. A high-voltage switch is provided between the oscillator, the low-voltage transmitting circuit, and the receiving circuit. When voltage is transmitted from the high-voltage transmitting circuit, the high-voltage switch becomes open.

5. The ultrasonic probe according to claim 4, characterized in that, When a voltage is transmitted from the low-voltage transmitting circuit, the high-voltage switch is turned on, and the receiving circuit is turned off.

6. The ultrasonic probe according to claim 4, characterized in that, A low-voltage switch is provided between the high-voltage switch and the low-voltage transmitting circuit and the receiving circuit. When a voltage is transmitted from the low-voltage transmitting circuit, the low-voltage switch becomes open.

7. An ultrasonic diagnostic device, characterized in that, It has the ultrasonic probe as described in claim 1.

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