JPH08140978A - Ultrasonic diagnostic apparatus - Google Patents

Abstract

PURPOSE: To provide an ultrasonic diagnostic apparatus having a transmission part capable of altering the voltage of a transmission signal by low voltage.low current circuit constitution. CONSTITUTION: A transmission power supply part 104-1 is provided to the transmission parts 101-(1)-(n) of respective vibrators controlling the transmission of ultrasonic beam on the source side of an MOS transistor Q2 in a transmission output part operated by a transmission trigger signal. The transmission power supply part 104-(1) has a resistor R1 for a power supply connected to a reference transmission power supply (-HV) at one terminal thereof and the condenser C1 for the power supply connected to other terminal of the resistor R1 for the power supply. Further, a collector is connected to the connection point of the resistor R1 and the condenser C1, and an emitter is connected to the MOS transistor Q2 and a transmission power supply transistor Q3 receiving the supply of a transmission voltage control signal is provided to a base. By controlling the base voltage of the transmission power supply transistor Q3 by the transmission voltage control signal, transmission voltage can easily be made variable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic apparatus for diagnosing a subject by using information based on ultrasonic waves, and more particularly to a structure of the ultrasonic diagnostic apparatus capable of controlling a transmission voltage of an ultrasonic beam.

[0002]

2. Description of the Related Art As an ultrasonic diagnostic apparatus using a linear type probe, a convex type probe or the like as a probe,
A plurality of transducers provided in the probe are divided into a predetermined number of transducer groups, and scanning is selectively performed. Then, the transducers to be selected are sequentially shifted and selected for each transducer group,
The ultrasonic beam is being transmitted.

The configuration of the transmitting section of this ultrasonic diagnostic apparatus will be described with reference to FIG.

Here, the transmitting section (101-1) of the ultrasonic diagnostic apparatus
Up to 101-n) are circuits individually provided for one oscillator (1 to n). Below is the transmitter 10
The circuit configuration will be described by taking 1-1 as an example, but the configurations of the transmitting units for other vibrators are the same as in 101-1.

The transmission trigger input terminal 12 has a gate of a p-type MOS transistor Q1 via a capacitor C2,
The gate of the n-type MOS transistor Q2 is connected in parallel via the capacitor C3. Also, the capacitor C2
And a gate of the MOS transistor Q1 are connected to a resistor R2 whose one end is connected to a predetermined power supply −VG, and one end is connected to the power supply −VG between the capacitor C3 and the gate of the MOS transistor Q2. The connected resistor R3 is connected.

The source of the MOS transistor Q1 is grounded, and the drain is connected to the drain of the MOS transistor Q2. One end of the bidirectional diode D1 is connected to a connection point P1 between the drain of the MOS transistor Q1 and the drain of the MOS transistor Q2. Further, the other end of the bidirectional diode D1 is connected to a resistor R5 whose one end is grounded and a vibrator 10 via a cable.
And are connected. Here, this bidirectional diode D
1 is for improving the responsiveness of the circuit particularly to the fall of the transmission signal and the reception signal.

The source of the MOS transistor Q2 is connected to the reference transmission power source (-HV: eg -1) via the power source resistor R1.
00V). In addition, power supply resistors R1 and M
A power supply capacitor C1 whose one end is grounded is connected to a connection point with the source of the OS transistor Q2.

[0008] The transmission unit (101-1 to
101-n) individually controls the transmission operation of each transducer 10 in the probe. This will be explained below.

When the vibrator 10 is not selected, ultrasonic waves (reflection)
During the beam reception period, the transmission trigger signal is at L level, the MOS transistor Q1 is turned on, and the voltage across the vibrator 10 is controlled to be equal. The MOS transistor Q2 is off, and the power supply capacitor C1 is charged by the reference transmission power supply (-HV).

On the other hand, when the transmission trigger signal rises to select the oscillator 10 and a positive pulse is supplied to the transmission trigger input terminal 12, the MOS transistor Q1 turns off and the MOS transistor Q2 turns on accordingly. .
When the MOS transistor Q2 is turned on, a transmission signal having a voltage value equal to its source voltage is supplied to the vibrator 10 as a negative pulse. Then, the ultrasonic wave pulse is transmitted from the transducer 10 according to the transmission signal.

When an ultrasonic beam is formed, side lobes (unnecessary radiation beams), which are acoustic noise, are formed in a direction different from the main direction in addition to the main beam formed in the main direction. It is known.
If a strong reflection region of the subject exists in the direction of this side lobe, an unnecessary side lobe signal appears in the received signal which is a reflected beam, and the ultrasonic image is deteriorated.

Therefore, as a method for reducing this side lobe, it has been proposed to control the voltage -HV of the reference transmission power supply supplied to each transducer 10 to weight the transmission voltage. In this method, each transmitter controls the voltage -HV of the reference transmission power source, and the transmission voltage applied to the vibrator 10 is lowered as going from the center of the vibrator group to the vibrators 10 at both ends.

[0013]

However, the power supply capacitor C1 shown in FIG. 3 is required to have an extremely large capacity capable of sufficiently charging the vibrator 10 as a load.

Therefore, even if the voltage -HV of the reference transmission power supply is changed, it takes time to charge and discharge the power supply capacitor C1. Therefore, there is a problem that it takes a long time for the voltage level of the transmission signal to change, and it becomes impossible to control the transmission voltage of the ultrasonic beam in a short time.

On the other hand, in order to change the voltage level of the transmission signal in a short time, a large current had to be supplied from the transmission power supply to the power supply capacitor C1. And in order to do this, it is necessary to use high voltage and large current compatible elements in the circuit of the transmitter, and the elements become large,
An ultrasonic diagnostic apparatus that requires a large number of transmission circuits is inconvenient because it cannot be downsized.

The present invention has been made to solve the above problems, and provides an ultrasonic diagnostic apparatus having a low-voltage and low-current circuit configuration and having a transmission section capable of changing the voltage of a transmission signal in real time. With the goal.

[0017]

In order to achieve the above object, the ultrasonic diagnostic apparatus according to the present invention has the following features.

An ultrasonic diagnostic apparatus for transmitting an ultrasonic beam from a plurality of transducers to a subject and receiving a reflected beam to display a predetermined ultrasonic image, wherein the ultrasonic diagnostic device responds to a transmission trigger signal supplied to a gate. A transmission power supply means for controlling a voltage value of the transmission signal, and the transmission power supply means is for a power supply whose one end is connected to a reference transmission power supply. A resistor, a power supply capacitor connected to the other end of the power supply resistor, a collector connected to a connection point between the power supply resistor and the power supply capacitor, and an emitter connected to the source of the MOS transistor. A power supply transistor, and a transmission voltage control signal is supplied to a base of the transmission power supply transistor, and the MOS is provided in response to the transmission voltage control signal.
The voltage value of the transmission signal supplied to the source of the transistor is controlled.

The transmission trigger signal is supplied to the gate of the MOS transistor via a first capacitor,
One end of a first resistor is connected to a connection point between the gate of the MOS transistor and the first capacitor, and a base of the transmission power supply transistor is connected to a voltage control signal output section for outputting a transmission voltage control signal. Two resistors, the other end of the first resistor is connected to a connection point between the voltage control signal output section and the second resistor, and the second resistor is connected to the base of the transmission power transistor. Second to the point
One end of a capacitor is connected to the first resistor and the first resistor.
The time constant defined by the capacitor and the time constant defined by the second resistor and the second capacitor are set to be substantially equal to each other.

An ultrasonic diagnostic apparatus for transmitting an ultrasonic beam from a plurality of transducers to a subject and receiving a reflected beam to display a predetermined ultrasonic image, wherein the transducers respond to a transmission trigger signal. A transmission output means for controlling the transmission of the ultrasonic beam, and a transmission power supply means for controlling the voltage value of the transmission signal supplied to the transmission output means, wherein the transmission output means is configured to receive the transmission trigger signal. Two MOS transistors supplied to the gate, the drain of one MOS transistor being connected to the drain of the other MOS transistor, and having two MOS transistors that are alternately turned on and off according to the transmission trigger signal, At the connection point between the drains of the two MOS transistors,
The oscillator is electrically connected, the transmission power supply means, a power supply resistor having one end connected to the reference transmission power supply, a power supply capacitor connected to the other end of the power supply resistor, A collector is connected to a connection point between the power source resistor and the capacitor, and a transmission power supply transistor having an emitter connected to the source of the MOS transistor of the two MOS transistors which is turned on by the pulse of the transmission trigger signal. A transmission voltage control signal is supplied to the base of the transmission power supply transistor, and a voltage value of the transmission signal supplied to the source of the MOS transistor is controlled according to the transmission voltage control signal. And

The transmission trigger signal is supplied to the gate of the MOS transistor, which is turned on by the pulse of the transmission trigger signal, via a first capacitor, and the connection point between the gate of the MOS transistor and the first capacitor is connected. , One end of the first resistor is connected, and the base of the transmission power supply transistor is connected to a voltage control signal output section for outputting a transmission voltage control signal via a second resistor.
The other end of the resistor is connected to a connection point between the voltage control signal output section and the second resistor, and one end of a second capacitor is connected to a connection point between the second resistor and the base of the transmission power supply transistor. The time constant defined by the first resistor and the first capacitor and the time constant defined by the second resistor and the second capacitor are set to be substantially equal to each other.

The transducers constitute a transducer group for every predetermined number, the transducers to be selected are sequentially shifted, the transducers are selected and the ultrasonic beam is scanned, and the transducer groups are selected. Among them, a transmission signal having a high voltage value is supplied to a vibrator located in a central portion, and a transmission signal having a low voltage value is supplied to the vibrators at both ends of the vibrator group. To do.

The voltage value of the transmission signal supplied to the source of the MOS transistor is changed during reception of the reflected wave beam one scan before.

[0024]

In the ultrasonic diagnostic apparatus according to the present invention, the source side of the MOS transistor that outputs the transmission signal to the vibrator is
Transmission power supply means for controlling the voltage value of the transmission signal is provided. Then, the base voltage of the transmission power supply transistor of the transmission power supply means is controlled by the transmission voltage control signal, and the transmission voltage supplied to the source of the MOS transistor is made variable by setting a predetermined voltage value between the collector and the emitter of the transmission power supply transistor. did.

Therefore, it is possible to change the voltage of the transmission signal output from the MOS transistor with an extremely simple circuit configuration of low voltage and low current. In addition, M
Since the source voltage (transmission voltage) of the OS transistor is changed, the transmission signal applied to the vibrator will not be delayed with respect to the trigger of the transmission trigger signal. That is, according to the configuration of the present invention, there is an effect that the responsiveness of the vibrator to the transmission trigger signal is good.

Further, in the present invention, the time constant defined by the first resistor and the first capacitor is made substantially equal to the time constant defined by the second resistor and the second capacitor, and the gate of the MOS transistor is It was connected to the voltage control signal output section via the first resistor. As a result, a change in the gate voltage of the MOS transistor and a change in the source voltage of the MOS transistor occur almost at the same time, and the malfunction of the MOS transistor can be prevented.

Further, when driving the transducer of the ultrasonic diagnostic apparatus, the position of the transducer within the transducer group must be shifted for each scanning of one ultrasonic beam line. According to the present invention, the voltage value of the transmission signal supplied to the transducer can be controlled for each scanning of the ultrasonic beam line simply by controlling the gate voltage of the transmission power supply transistor.

Therefore, it becomes easy to change the voltage value of the transmission signal of each transducer according to the position of the transducer in the transducer group every scanning of the ultrasonic beam line. For example, in each scan, it is possible to supply a transmission signal having a low voltage value to the vibrators as the vibrators located at both ends of the vibrator group are approached. By performing such voltage control, it is possible to reliably reduce the generation of side lobes.

Further, the transmission output section is provided with two MOS transistors that are turned on and off alternately according to the transmission trigger signal, and the drain of one MOS transistor is connected to the drain of the other MOS transistor. This makes it possible to reliably control the output voltage to the vibrator during a period such as when the vibrator is not selected or when an ultrasonic beam (reflected beam) is received.

[0030]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 illustrates a circuit configuration of a transmitter of an ultrasonic diagnostic apparatus according to an embodiment of the present invention. The same parts as those in FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. The circuit configuration of the transmitter 101-1 of one transducer 10 will be described below as an example, but the configuration of the transmitters of the other transducers 10 is the same.

The transmission unit 101-1 includes a transmission output unit 102-1 for controlling the transmission of ultrasonic beams from each transducer 10 according to a transmission trigger signal, and a transmission output unit for controlling the transmission voltage supplied to the transmission output unit. It is composed of a power supply unit 104-1.

In the transmission output section 102-1, the transmission trigger signal is supplied to the transmission trigger input terminal 12. And
To the transmission trigger input terminal 12, the gate of the p-type MOS transistor Q1 and the gate of the n-type MOS transistor Q2 are connected in parallel via the capacitor C2 and the capacitor C3. Also, the capacitor C2 and the MOS
A resistor R2, one end of which is connected to a predetermined power supply −VG, is connected between the gate of the transistor Q1 and one end of the transmission power supply unit 104-1 between the capacitor C3 and the gate of the MOS transistor Q2. The connected resistor R3 is connected.

The source of the MOS transistor Q1 is grounded and the drain thereof is connected to the drain of the MOS transistor Q2. Then, as in FIG. 3, a bidirectional diode D1 is provided at a connection point P1 between the drain of the MOS transistor Q1 and the drain of the MOS transistor Q2.
The vibrator 10 is connected via a resistor R5 whose one end is grounded. A transmission power supply section 104-1 is provided on the source side of the MOS transistor Q2.

In this embodiment, two MOS transistors Q1 and Q2 are not necessarily required. However, by setting the polarity to be turned on and off alternately according to the transmission trigger signal, it is possible to reliably control the output voltage to the vibrator 10 when the vibrator 10 is not selected or during the reception period.

In the transmission power supply section 104-1, the reference transmission power supply (-
HV: -100 V, for example, one end of the power supply resistor R1 is connected, and one end of the power supply capacitor C1 is connected to the other end of the power supply resistor R1.

A PNP type transmission power transistor Q3, to which a transmission voltage control signal is supplied to the base, is provided. The collector of the transmission power supply transistor Q3 is connected to the connection point of the power supply resistor R1 and the power supply capacitor C1, and the emitter of the transmission power supply transistor Q3 is connected to the source of the MOS transistor Q2.

Further, the base of the transmission power supply transistor Q3 is connected to a voltage control output section described below via a resistor R4. Further, one end of a capacitor C4 is connected to a connection point between the resistor R4 and the base of the transmission power supply transistor Q3. The other end of the capacitor C4 is connected to the reference transmission power supply (-HV) for stabilizing the base voltage of the transmission power supply transistor Q3.

Next, a configuration example of the voltage control output section will be described. Digital voltage control data output from the control unit of the ultrasonic diagnostic apparatus main body is supplied to the latch unit 20. The output side of the latch unit 20 is
An analog (D / A) converter 22 is provided and this D
The output side of the A / A converter 22 is a PNP that is an amplifier.
The base of the type transistor Q6 is connected. The emitter of the transistor Q6 is connected to a predetermined reference power source (+ VE) via the resistor R7, and the collector of the transistor Q6 is connected to the reference transmission power source (-HV) via the resistor R6. Also, the collector of the transistor Q6 and the resistor R
The base of the NPN type transistor Q4 and the base of the PNP type transistor Q5 are connected to the connection portion with 6.

The emitter of the transistor Q4 and the emitter of the transistor Q5 are connected to each other, and the connection point P
2, the gate of the transmission power supply transistor Q3 is connected via the resistor R4, and the gate of the MOS transistor Q2 is connected via the resistor R3. The collector of the transistor Q4 is grounded, and the transistor Q4
The collector of 5 is connected to the reference transmission power supply (-HV).

The transmitting section 101-1 having such a configuration is
The transmission operation of the transducer 10 in the probe is individually controlled. The operation of the transmitting unit 101-1 will be described below with reference to FIGS. 1 and 2.

The period t1 shown in FIG. 2 (a) is a scanning period (transmission period) of one ultrasonic beam line.
The period t2 is a period for receiving the ultrasonic reflected beam from the subject and a period for setting transmission conditions (transmission voltage etc.) for the next scanning.

In the period t2, the transmission trigger signal of FIG. 2B is at L level, and the MOS transistor Q1 is on. Since the voltage across the transducer 10 is equal, the ultrasonic beam is not transmitted, and the transducer 10 receives the already transmitted ultrasonic beam (reflected beam) (n-1).
The second time). At this time, the MOS transistor Q2 is off, and the power source capacitor C1 is charged by the reference transmission power source (-HV) via the power source resistor R1.

Further, when digital control voltage data necessary for the next (nth) scanning period is output from the ultrasonic diagnostic apparatus main body to the latch section 20, the latch section 20 outputs the digital control voltage data.
It latches by the latch trigger of (d). Further, the D / A converter 22 analog-converts the latched data and supplies it to the base of the transistor Q6.

A predetermined transmission voltage control signal is output from the connection point P2, which is the output terminal of the voltage control output section, in accordance with the analog voltage control data supplied to the base of the transistor Q6.

This output transmission voltage control signal is supplied to the base of the transmission power supply transistor Q3 via the resistor R4 and the capacitor C4 to control the base voltage. The emitter voltage VE of the transmission power transistor Q3 is
It becomes almost the base voltage, and the voltage corresponding to this VE is MOS
The source of the transistor Q2 is supplied with a transmission voltage as shown in FIG.

The output from the connection point P2 is the resistance R3.
Also, it is supplied to the gate of the MOS transistor Q2 via the capacitor C3. Here, the resistor R that is the first resistor
3 and the capacitor C3, which is the first capacitor, and the time constant defined by the resistor R4, which is the second resistor, and the capacitor C4, which is the second capacitor, are set to be substantially equal. Therefore, when the transmission voltage control signal applied to the gate of the transmission power supply transistor Q3 changes, the gate voltage of the MOS transistor Q2 changes almost simultaneously with the change of the source voltage of the MOS transistor Q2. As a result, even if the voltage at the connection point P2 suddenly changes, the gate-source voltage VGS of the MOS transistor Q2 does not change unless the transmission trigger signal rises, and the malfunction of the MOS transistor Q2 can be reliably prevented.

Furthermore, a PNP type transmission power transistor Q
The base-emitter voltage VBE of 3 controls the voltage on the emitter side so that it is always higher than the base voltage. On the other hand, the MOS transistor Q2 is an n-type, and its gate is applied with a voltage substantially the same as that of the base of the transmission power supply transistor Q3 (when the transmission trigger signal is at the L level). Therefore, the gate voltage of the MOS transistor Q2 is
The voltage is controlled to be lower than the source voltage, and this also prevents the MOS transistor Q2 from malfunctioning.

Next, in the period t1, when the vibrator is selected, the transmission trigger signal supplied to the transmission trigger input terminal 12 rises to the H level (for example, +15).
V). In response to this, the MOS transistor Q1 turns off and the MOS transistor Q2 turns on. This time,
A transmission signal having a voltage value corresponding to the transmission voltage of FIG. 2E supplied to the source of the MOS transistor Q2 is output from the connection point P1 of the MOS transistor Q1 and the MOS transistor Q2 (see FIG. 2F). ). Then, when the transmission signal is applied to the transducer 10, the transducer 10 transmits an ultrasonic beam corresponding to the voltage value of the transmission signal to the subject.

In this embodiment, during the n-th reception period t2,
The voltage of the transmission signal in the next (n + 1) th scanning period is set. Then, during the next (n + 1) th ultrasonic beam transmission period t1, a transmission signal corresponding to the already set voltage is supplied to the transducer.

Therefore, it is possible to supply the transmission signals having different voltage values to the transducer for each scanning of the ultrasonic beam line. Then, the voltage control of the transmission signal can be executed without directly controlling the charge amount of the power source capacitor C1,
The capacitors C3 and C4 for voltage control are C3 << C
1, C4 << C1 can be set, and the voltage of the transmission signal can be controlled with an extremely simple and low-voltage / low-current circuit configuration.

Since the source voltage (transmission voltage) of the MOS transistor Q2 is changed, the transmission signal applied to the vibrator 10 is not delayed with respect to the trigger of the transmission trigger signal. That is, the configuration of this embodiment has an effect that the response of the vibrator to the transmission trigger signal is extremely good.

Further, as described above, in order to reduce the side lobe, it is effective to lower the transmission voltage applied to the vibrator 10 as going from the central portion of the vibrator group to the vibrators 10 at both ends. Is. However, each transducer 10
The position within the transducer group of is shifted for each scanning of the ultrasonic beam.
The voltage value of the transmission signal must be changed for each scan.

According to the present embodiment, by controlling the base voltage of the transmission power supply transistor Q3 during the reception period, it is possible to change the voltage value of the transmission signal during the transmission. Therefore, the generation of side lobes can be reliably reduced, and an ultrasonic image with extremely high accuracy can be obtained.

In this embodiment, the transmission trigger signal is a positive pulse and the reference transmission power source is a negative polarity to form a negative transmission signal. However, the present invention is not limited to this, and the polarity is reversed. Also good. When the transmission trigger signal has a negative polarity and the reference transmission power source has a positive polarity, p-type MO
A transmission power supply unit 104-1 is provided on the source side of the S transistor Q1. Further, the p-type MOS transistor Q1 has a source of N
By connecting the emitter of the PN type transmission power transistor Q3, the same effect as this embodiment can be obtained. Further, if the time constant defined by the resistor R1 and the capacitor C1 and the time constant defined by the resistor R4 and the capacitor C4 are made substantially equal, malfunction of the MOS transistor Q1 can be prevented.

[0056]

As described above, according to the ultrasonic diagnostic apparatus of the present invention, the MO that outputs the transmission signal to the vibrator.
Transmission source means for controlling the voltage value of the transmission signal is provided on the source side of the S transistor. Then, the base voltage of the transmission power supply transistor of this transmission power supply means is controlled by the transmission voltage control signal,
The transmission voltage supplied to the source of the MOS transistor was made variable by setting a predetermined voltage value between the emitters.

Therefore, it is possible to change the voltage of the transmission signal output from the MOS transistor with an extremely simple circuit configuration of low voltage and low current. Also, M
Since the source voltage (transmission voltage) of the OS transistor is changed, the transmission signal applied to the oscillator is not delayed with respect to the transmission trigger signal, and the oscillator has an extremely good response to the transmission trigger signal.

Further, in the present invention, the time constant defined by the first resistor and the first capacitor is made substantially equal to the time constant defined by the second resistor and the second capacitor, and the gate of the MOS transistor is It was connected to the voltage control signal output section via the first resistor. As a result, a change in the gate voltage of the MOS transistor and a change in the source voltage of the MOS transistor occur almost at the same time, and the malfunction of the MOS transistor can be prevented.

Further, according to the configuration of the present invention, the voltage value of the transmission signal of each transducer is changed every scanning of the ultrasonic beam line according to the position of the transducer in the transducer group. Will be easier. For example, in each scan, it is possible to supply a transmission signal having a low voltage value to the vibrators as the vibrators located at both ends of the vibrator group are approached. Then, if the oscillator is driven by performing such voltage control,
It is possible to reliably reduce the generation of side lobes.

Further, in the transmission output section, two MOS transistors that are turned on and off alternately according to the transmission trigger signal are provided, and the drain of one MOS transistor is connected to the drain of the other MOS transistor. This makes it possible to reliably control the output voltage to the vibrator during a period such as when the vibrator is not selected or when an ultrasonic beam (reflected beam) is received.

[Brief description of drawings]

FIG. 1 is a diagram showing a transmission unit of an ultrasonic diagnostic apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing drive waveforms of a transmission unit 101-1 of FIG.

FIG. 3 is a diagram showing a transmitter of a conventional ultrasonic diagnostic apparatus.

[Explanation of symbols]

 10 oscillator 12 transmission trigger input terminal 20 latch unit 22 D / A converter 101-1 transmission unit 102-1 transmission output unit 104-1 transmission power supply unit

Claims (6)

[Claims] 1. An ultrasonic diagnostic apparatus for transmitting an ultrasonic beam from a plurality of transducers to a subject, receiving a reflected beam to display a predetermined ultrasonic image, and a transmission trigger signal supplied to a gate. In accordance with the above, there is provided a MOS transistor for supplying a predetermined transmission signal to the vibrator, and a transmission power supply means for controlling a voltage value of the transmission signal. The transmission power supply means has one end connected to a reference transmission power supply. A power source resistor, a power source capacitor connected to the other end of the power source resistor, a collector is connected to a connection point between the power source resistor and the power source capacitor, and an emitter is connected to a source of the MOS transistor. A transmission voltage control signal is supplied to a base of the transmission power supply transistor, and the MOS transistor is provided according to the transmission voltage control signal. Ultrasonic diagnostic apparatus voltage value of the transmission signal supplied to the source is being controlled. 2. The ultrasonic diagnostic apparatus according to claim 1, wherein the transmission trigger signal is supplied to the gate of the MOS transistor via a first capacitor, and the gate of the MOS transistor and the first capacitor are connected to each other. One end of a first resistor is connected to the connection point, and the base of the transmission power supply transistor is connected to a voltage control signal output section for outputting a transmission voltage control signal via a second resistor, and the first resistor is connected. The other end of is connected to a connection point between the voltage control signal output section and the second resistor, and one end of a second capacitor is connected to a connection point between the second resistor and the base of the transmission power supply transistor. The time constant defined by the first resistor and the first capacitor and the time constant defined by the second resistor and the second capacitor are set to be substantially equal to each other. Ultrasound diagnostic device to collect. 3. An ultrasonic diagnostic apparatus for transmitting an ultrasonic beam from a plurality of transducers to a subject, receiving a reflected beam to display a predetermined ultrasonic image, wherein the vibration is generated according to a transmission trigger signal. A transmission output unit that controls the transmission of the ultrasonic beam from the child, and a transmission power supply unit that controls the voltage value of the transmission signal supplied to the transmission output unit, wherein the transmission output unit is the transmission trigger signal. Are two MOS transistors each of which is supplied to the gate, and the drain of one MOS transistor is connected to the drain of the other MOS transistor, and the two MOS transistors are turned on / off alternately according to the transmission trigger signal. The oscillator is electrically connected to a connection point between the drains of the two MOS transistors, and the transmission power supply unit includes: A power source resistor having one end connected to the quasi-transmission power source, a power source capacitor connected to the other end of the power source resistor, a collector connected to a connection point between the power source resistor and the capacitor, and Among the MOS transistors, there is a transmission power supply transistor whose emitter is connected to the source of the MOS transistor that is turned on by the pulse of the transmission trigger signal, and the transmission voltage control signal is supplied to the base of the transmission power supply transistor. The ultrasonic diagnostic apparatus is characterized in that the voltage value of the transmission signal supplied to the source of the MOS transistor is controlled according to the transmission voltage control signal. 4. The ultrasonic diagnostic apparatus according to claim 3, wherein the transmission trigger signal is supplied via a first capacitor to a gate of the MOS transistor which is turned on by a pulse of the transmission trigger signal. One end of a first resistor is connected to a connection point between the gate of the first capacitor and the first capacitor, and the base of the transmission power supply transistor is provided with a second resistor at a voltage control signal output section for outputting a transmission voltage control signal. And the other end of the first resistor is connected to a connection point between the voltage control signal output section and the second resistor, and a connection point between the second resistor and the base of the transmission power transistor is , One end of a second capacitor is connected, a time constant defined by the first resistor and the first capacitor, and a time constant defined by the second resistor and the second capacitor Is an ultrasonic diagnostic apparatus, which is set to be substantially equal. 5. The ultrasonic diagnostic apparatus according to claim 1, claim 2, claim 3, or claim 4, wherein a group of transducers is configured and selected for each transducer. The transducers are sequentially shifted, the ultrasonic beam is selected and selected for each transducer group, and a transmission signal having a high voltage value is supplied to the transducer located in the center of the transducer group. The ultrasonic diagnostic apparatus is characterized in that a transmission signal having a lower voltage value is supplied to the transducers at both ends of the transducer group. 6. The ultrasonic diagnostic apparatus according to claim 5, wherein the voltage value of the transmission signal supplied to the source of the MOS transistor is changed during reception of the reflected wave beam one scan before. Ultrasonic diagnostic equipment.