阅读说明：本技术 超声波影像系统 (Ultrasonic imaging system ) 是由 富田隆 北见薰 菅谷夏树 伊藤正一 于 2019-07-02 设计创作，主要内容包括：提供即使在探测器的移动速度是高速时也能够抑制波动的超声波影像系统。超声波影像系统具备超声波影像装置和水槽(10),在水槽(10)的端部,配设有使在超声波影像装置的超声波探测器(20)扫描时产生的作为超声波的传播介质的液状物质的波的端部处的反射波衰减的反射波衰减单元(30)。反射波衰减单元(30)具有多个突起(32),在超声波影像装置的超声波探测器(20)在X轴方向上扫描时,在X轴方向的水槽(10)的两端部配设有反射波衰减单元(30)。(Provided is an ultrasonic imaging system capable of suppressing fluctuation even when the moving speed of a probe is high. An ultrasonic imaging system is provided with an ultrasonic imaging device and a water tank (10), and a reflected wave attenuation means (30) for attenuating a reflected wave generated at an end of a wave of a liquid substance as a propagation medium of an ultrasonic wave generated when an ultrasonic probe (20) of the ultrasonic imaging device scans is disposed at the end of the water tank (10). The reflected wave attenuation unit (30) has a plurality of protrusions (32), and the reflected wave attenuation unit (30) is disposed at both ends of the water tank (10) in the X-axis direction when the ultrasonic probe (20) of the ultrasonic imaging apparatus scans in the X-axis direction.)

1. An ultrasonic imaging system is characterized in that,

comprises an ultrasonic imaging device and a water tank,

a reflected wave attenuation means is disposed at an end portion of the water tank in the X-axis direction, the reflected wave attenuation means being capable of changing a position of a gap with inner wall surfaces on both sides in the X-axis direction, and attenuating a reflected wave of a liquid substance as a propagation medium of an ultrasonic wave generated when a probe of the ultrasonic imaging apparatus scans the end portion,

the reflected wave attenuation unit includes a rectangular and plate-shaped base and a plurality of projections arranged on one surface of the base, the projections being arranged toward the probe,

a gap position changing means having an insertion groove in which the reflected wave attenuation means is arranged so as to change the gap position with respect to the inner wall surfaces on both sides in the X-axis direction is arranged at an end of the water tank.

2. An ultrasonic imaging system is characterized in that,

comprises an ultrasonic imaging device and a water tank,

a reflected wave attenuation means is disposed at an end portion of the water tank in the X-axis direction, the reflected wave attenuation means being capable of changing a position of a gap with inner wall surfaces on both sides in the X-axis direction, and attenuating a reflected wave of a liquid substance as a propagation medium of an ultrasonic wave generated when a probe of the ultrasonic imaging apparatus scans the end portion,

the reflected wave attenuation means includes a rectangular plate-shaped base body having a plurality of openings serving as flow paths and a plurality of projections arranged on one surface of the base body,

the protrusion is disposed toward the end of the water tank,

a gap position changing means having an insertion groove in which the reflected wave attenuation means is arranged so as to change the gap position with respect to the inner wall surfaces on both sides in the X-axis direction is arranged at an end of the water tank.

3. The ultrasonic imaging system according to claim 1 or 2,

in the reflected wave attenuation unit, when the probe scans at the scanning position in the Y-axis direction after scanning by an amount of 1 row line in the X-axis direction, at least one of the projections is located further outside than a start point position in the Y-axis direction of a subject as an image acquisition target, and at least one of the projections is located further outside than an end point position in the Y-axis direction of the subject.

4. The ultrasonic imaging system of claim 3,

in the reflected wave attenuation unit, at least one of the projections is located at a height position above a surface of the liquid substance in the water tank in a vertical direction.

5. The ultrasonic imaging system of claim 3,

in the reflected wave attenuation unit,

when the measurement mode of the ultrasonic imaging apparatus is a reflection method, at least one of the projections is located at a height position lower than a lower surface of the mounting table of the subject in a vertical direction,

when the measurement mode of the ultrasonic imaging apparatus is a transmission method, at least one of the protrusions is located at a height position lower than a lower end of the lower probe unit in a vertical direction.

6. The ultrasound imaging system of claim 4,

in the reflected wave attenuation unit,

when the measurement mode of the ultrasonic imaging apparatus is a reflection method, at least one of the projections is located at a height position lower than a lower surface of the mounting table of the subject in a vertical direction,

when the measurement mode of the ultrasonic imaging apparatus is a transmission method, at least one of the protrusions is located at a height position lower than a lower end of the lower probe unit in a vertical direction.

7. The ultrasonic imaging system according to claim 1 or 2,

the ultrasonic imaging system has a scanner that scans the probe in the X-axis direction by 1 line and then in the Y-axis direction at a scanning position,

one end side of the reflected wave attenuation means is located further outside than at least a start point position in the Y axis direction of a subject to be an image acquisition target, and the other end side is located further outside than at least an end point position in the Y axis direction of the subject.

8. The ultrasonic imaging system according to claim 1 or 2,

in the reflected wave attenuation unit, an upper end edge is located at a height position at least above a surface of the liquid substance in the water tank in a vertical direction.

9. The ultrasound imaging system of claim 7,

in the reflected wave attenuation unit, an upper end edge is located at a height position at least above a surface of the liquid substance in the water tank in a vertical direction.

10. The ultrasonic imaging system according to claim 1 or 2,

in the reflected wave attenuation unit,

when the measurement mode of the ultrasonic imaging apparatus is a reflection method, the lower end side is located at a height position lower than at least the lower surface of the mounting table of the subject in the vertical direction,

when the measurement mode of the ultrasonic imaging apparatus is a transmission method, the lower end side is located at a height position lower than at least the lower end of the probe in the vertical direction.

11. The ultrasound imaging system of claim 7,

in the reflected wave attenuation unit,

when the measurement mode of the ultrasonic imaging apparatus is a reflection method, the lower end side is located at a height position lower than at least the lower surface of the mounting table of the subject in the vertical direction,

when the measurement mode of the ultrasonic imaging apparatus is a transmission method, the lower end side is located at a height position lower than at least the lower end of the probe in the vertical direction.

12. The ultrasound imaging system of claim 8,

in the reflected wave attenuation unit,

when the measurement mode of the ultrasonic imaging apparatus is a reflection method, the lower end side is located at a height position lower than at least the lower surface of the mounting table of the subject in the vertical direction,

when the measurement mode of the ultrasonic imaging apparatus is a transmission method, the lower end side is located at a height position lower than at least the lower end of the probe in the vertical direction.

13. The ultrasonic imaging system of claim 9,

in the reflected wave attenuation unit,

when the measurement mode of the ultrasonic imaging apparatus is a reflection method, the lower end side is located at a height position lower than at least the lower surface of the mounting table of the subject in the vertical direction,

when the measurement mode of the ultrasonic imaging apparatus is a transmission method, the lower end side is located at a height position lower than at least the lower end of the probe in the vertical direction.

14. The ultrasonic imaging system according to claim 1 or 2,

the insertion groove has a width into which the reflected wave attenuation unit is inserted,

the space position changing unit has a plurality of the insertion grooves.

15. An ultrasonic imaging system is characterized in that,

comprises an ultrasonic imaging device and a water tank,

a reflected wave attenuation means is disposed at an end portion of the water tank in the X-axis direction, the reflected wave attenuation means being capable of changing a position of a gap with inner wall surfaces on both sides in the X-axis direction, and attenuating a reflected wave of a liquid substance as a propagation medium of an ultrasonic wave generated when a probe of the ultrasonic imaging apparatus scans the end portion,

the reflected wave attenuation means is formed by joining a 1 st base and a 2 nd base each having a square shape and a plate shape,

the 1 st substrate has a plurality of 1 st openings which are flow paths,

the 2 nd substrate has a plurality of 2 nd openings which become flow paths,

the opening ratio of the 2 nd opening is smaller than that of the 1 st opening,

the 2 nd base body side is arranged toward the end part side of the water tank,

a gap position changing means having an insertion groove in which the reflected wave attenuation means is arranged so as to change the gap position with respect to the inner wall surfaces on both sides in the X-axis direction is arranged at an end of the water tank.

Technical Field

The present invention relates to an ultrasonic imaging system.

Background

An ultrasonic imaging system uses an ultrasonic imaging device, and places a test object such as a semiconductor having a multilayer structure on a sample placement table, dips the test object into a liquid material, which is a propagation medium of ultrasonic waves, stored in a liquid storage tank such as a water tank, irradiates the test object with ultrasonic waves from a probe provided in the ultrasonic imaging device, and receives reflected waves or transmitted waves of the ultrasonic waves to image an object interface. The probe scans the subject from a start point (one end point) to an end point (the other end point) of the subject in the X-axis direction at a predetermined speed while irradiating the subject with ultrasonic waves. After the detector reaches the end point, the detector is moved by a predetermined amount in the Y-axis direction, and is scanned in the opposite direction from the start point to the end point at a predetermined speed in the X-axis direction. When the probe is scanned, bubbles are generated and fluctuation is generated.

Patent document 1 discloses "an ultrasonic inspection apparatus including: an ultrasonic probe that radiates an ultrasonic wave to a subject via water and receives a reflected wave thereof; and a scanner for performing ultrasonic scanning by moving the ultrasonic probe in a predetermined axial direction, the ultrasonic scanner comprising: a water level detector detecting a water level; an arithmetic unit for calculating the submergence amount of the probe based on the detection value of the water level detector and the position of the ultrasonic probe; a storage unit for storing a relationship between a moving speed of the scanner and a flooding amount; and a water level adjustment means for adjusting the water level so that the flooding amount obtained by the calculation means matches the flooding amount obtained from the storage unit when the moving speed is determined.

Disclosure of Invention

In patent document 1, although the moving speed of the probe is effective at a low speed, a further countermeasure against the hunting is required as the moving speed becomes higher.

When the probe scans in the X-axis direction, the moving speed thereof reaches 2000 mm/sec (based on the applicant's product), although it is also based on the size of the subject. Since the probe moves in the liquid material accumulated in the water tank, it is needless to say that a wave (traveling wave) is generated on the surface of the liquid material in the direction in which the probe unit advances due to the movement. The traveling wave collides with the wall of the water tank in the X-axis direction to generate a reflected wave. The reflected wave is combined with the traveling wave. By repeating this process, a standing wave having a larger amplitude is formed. As a result, when the X-axis position of the detector portion coincides with a position (or a position near thereto) at which the displacement of the standing wave becomes minimum, there is a concern that the detector portion is exposed to the outside from the liquid substance. When the ultrasonic wave irradiation portion of the probe portion is exposed from the liquid substance, there is a problem that an image of the target interface cannot be acquired.

The present invention has been made in view of the above problems, and an object thereof is to provide an ultrasonic imaging system capable of suppressing fluctuation even when the probe moving speed is high.

In order to achieve the above object, an ultrasonic imaging system according to the present invention includes an ultrasonic imaging apparatus and a water tank, wherein a reflected wave attenuation means is disposed at an end portion of the water tank in an X-axis direction so as to be able to change a position of a gap between the ultrasonic imaging apparatus and an inner wall surface on both sides in the X-axis direction, and attenuates a reflected wave of a liquid substance as a propagation medium of an ultrasonic wave generated when a probe of the ultrasonic imaging apparatus scans the end portion, the reflected wave attenuation means includes a rectangular plate-shaped base and a plurality of projections disposed on one surface of the base, the projections are disposed toward the probe side, and a gap position changing means having an insertion groove in which the reflected wave attenuation means is disposed so as to change a position of a gap between the ultrasonic imaging apparatus and an inner wall surface on both sides in the X-axis direction is disposed at the end. Other aspects of the present invention will be described in the embodiments described below.

According to the present invention, the fluctuation can be suppressed even when the moving speed of the probe is high.

Drawings

Fig. 1 is an external view showing a configuration of an ultrasonic imaging system having a reflected wave attenuation unit.

Fig. 2 is an explanatory view showing a configuration of the air gap position changing means, (a) is a view showing a method of arranging the reflected wave attenuation means, and (b) is a side view of the air gap position changing means.

Fig. 3 is a plan view showing the arrangement position of the reflected wave attenuation unit in the water tank.

Fig. 4 is a block diagram showing the configuration of a control system and a signal processing system of the ultrasonic imaging system.

Fig. 5 is a schematic structural view showing a reflected wave attenuation unit according to example 1, where (a) is a side view when the reflected wave attenuation unit is disposed in a water tank, and (b) is a perspective view of the reflected wave attenuation unit.

Fig. 6 is a schematic structural view showing a reflected wave attenuation unit according to example 2, wherein (a) is a side view when the reflected wave attenuation unit is disposed in a water tank, and (b) is an exploded perspective view of the reflected wave attenuation unit.

Fig. 7 is a schematic structural view showing a reflected wave attenuation unit according to example 3, wherein (a) is a side view when the reflected wave attenuation unit is disposed in a water tank, and (b) is a perspective view of the reflected wave attenuation unit.

Fig. 8 is a schematic structural view showing a reflected wave attenuation unit according to example 4, wherein (a) is a side view when the reflected wave attenuation unit is disposed in a water tank, and (b) is a perspective view of the reflected wave attenuation unit.

Fig. 9 is a schematic structural view showing a reflected wave attenuation unit according to example 5, wherein (a) is a side view when the reflected wave attenuation unit is disposed in a water tank, and (b) is a perspective view of the reflected wave attenuation unit.

Fig. 10 is a schematic structural view showing a reflected wave attenuation unit according to example 6, wherein (a) is a side view when the reflected wave attenuation unit is disposed in a water tank, and (b) is a perspective view of the reflected wave attenuation unit.

Fig. 11 is a schematic structural view showing a reflected wave attenuation unit according to example 7, wherein (a) is a side view when the reflected wave attenuation unit is disposed in a water tank, and (b) is a perspective view of the reflected wave attenuation unit.

Fig. 12 is a schematic structural view showing a tank side wall top return unit according to example 8, wherein (a) is a side view when the unit is disposed in a tank, and (b) is a perspective view of the tank side wall top return unit.

Fig. 13 is a diagram showing a configuration of an ultrasonic imaging apparatus of the transmission method.

Fig. 14 is an explanatory diagram illustrating a case where the reflected wave attenuation unit according to example 1 is applied to an ultrasonic imaging apparatus of the transmission method.

(symbol description)

1: a coordinate system; 10: a water tank; 11: water; 11A: a liquid substance; 12: a sample stage; 15: a subject; 17: an inspection object holder; 20: an ultrasonic detector; 30. 30A, 30B, 30C, 30D, 30E, 30F, 30G: a reflected wave attenuation unit; 31: a substrate; 32: a protrusion (protuberance); 37: a sink sidewall top return unit; 40: a gap position changing unit; 41: inserting the groove; 50: an image display device; 70: a scanner device; 71: an X-axis scanner; 72: a Y-axis scanner; 81: 1 st ultrasonic probe (upper probe); 82: a 2 nd ultrasonic probe (lower probe); 90: an ultrasonic imaging device; 100: an ultrasonic imaging system.

Detailed Description

Embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings as appropriate.

Fig. 1 is an external view showing the configuration of an ultrasonic imaging system 100 having a reflected wave attenuation unit 30. In fig. 1, reference numeral 1 denotes an X, Y, Z orthogonal 3-axis coordinate system. The ultrasonic imaging system 100 includes an ultrasonic imaging device 90 and a water tank 10.

The ultrasonic imaging apparatus 90 includes: an ultrasonic probe 20 for transmitting and receiving ultrasonic waves; an image display device 50 for displaying an ultrasonic image by controlling the ultrasonic imaging device 90 as a whole; a transmission/reception device 60 (see fig. 4) that inputs and outputs an electric signal to and from the ultrasound probe 20; an X-axis scanner 71 and a Y-axis scanner 72 for mechanically scanning the ultrasonic probe 20; and a mechanical control device 77 (see fig. 4) for controlling the X-axis scanner 71 and the Y-axis scanner 72. The ultrasonic probe 20 is supported by the X-axis scanner 71 and the Y-axis scanner 72, immersed in the water 11 filled in the water tank 10, and disposed so as to face the subject 15. In addition, the Z-axis scanner of the ultrasound probe 20 is omitted.

Water 11 is poured into the water tank 10, and the subject 15 is placed in the water 11 in a submerged state. The water 11 in the water tank 10 is a liquid substance as a propagation medium necessary for efficiently propagating the ultrasonic waves radiated from the opening surface at the lower end of the ultrasonic probe 20 (ultrasonic probe) inside the subject 15. The object 15 is a semiconductor package including, for example, a wafer, a multilayer structure (or a stacked structure), or the like.

The ultrasound probe 20 is supported and set by a holder 73. The holder 73 is mounted to the X-axis scanner 71. The ultrasonic probe 20 is immersed in water 11 filled in the water tank 10, and is disposed to face the upper portion of the subject 120 at a predetermined distance in the Z direction.

The arm-shaped X-axis scanner 71 has a function of moving the holder 18 in the X-axis direction, and the Y-axis scanner 72 has a function of moving the X-axis scanner 71 in the Y-axis direction. The scanner device 70 is constituted by an X-axis scanner 71 and a Y-axis scanner 72. The scanner device 70 can freely move the ultrasonic probe 20 in the XY direction. According to this movement operation, the ultrasonic probe 20 can scan a predetermined measurement range on the surface of the subject 15, transmit ultrasonic waves, receive reflected echoes at a plurality of predetermined measurement points within the measurement range, and image defects included in the internal structure of the measurement range for inspection. The ultrasound probe 20 is connected to a transmission/reception device 60 (see fig. 4) via a cable 23.

The ultrasonic imaging system 100 according to the present embodiment is characterized in that the reflected wave attenuation means 30 for attenuating the reflected wave of the water 11 (liquid substance) reflected at the end of the water tank 10, which is generated when the ultrasonic probe 20 of the ultrasonic imaging apparatus 90 scans, is disposed at both ends of the water tank 10 in the X-axis direction. The reflected wave attenuation means 30 is disposed at two different ends of the water tank 10 in the X-axis direction by the gap position changing means 40. The gap position changing means 40 will be described later with reference to fig. 2. Details of the reflected wave attenuation unit 30 will be described later with reference to fig. 5 to 14.

The present inventors investigated a large subject 15 of about 600mm square as the subject 15, as in the recent panel-level package (PLP). It is found that when the ultrasonic probe 20 performs a reciprocal scan in the X-axis direction at a high speed of, for example, 2000 mm/sec on such a large subject 15, there is a problem of water fluctuation. The reflected wave attenuation unit 30 of the present embodiment is completed to solve the problem of suppressing the influence of the composite wave of the wave even in such a large subject. In addition, PLP is not a silicon substrate, but a glass panel used in liquid crystal production is used to achieve cost reduction.

Fig. 2 is an explanatory view showing the structure of the air gap position changing means 40, where (a) is a view showing a method of arranging the reflected wave attenuation means, and (b) is a side view of the air gap position changing means. The reflected wave attenuation unit 30 shown in fig. 2(a) is formed of a square-shaped and lattice-shaped base 31 having a large number of projections 32. At the end of the water tank 10 in the X direction, a gap position changing means 40 is disposed, and the gap position changing means 40 has an insertion groove 41 in which the reflected wave attenuation means 30 is disposed so as to change the gap position with respect to the inner wall surfaces on both sides in the X axis direction. In the case of fig. 2(a), the insertion groove 41 has, for example, 5 portions. By changing the insertion position into the insertion groove 41, the position between the reflected wave attenuation unit 30 and the wall surface of the water tank can be changed. The lower end of the gap position changing means 40 has a lower end 45 that can be positioned in the Z-axis direction. The reflected wave attenuation means 30A is locked at the lower end 45 as shown in fig. 2 (a). As shown in fig. 2(b), the gap position changing means 40 has a reverse U-shaped locking portion 42 that can be locked to an end of the water tank.

In the example shown in fig. 2, the reflected wave attenuation unit 30 is inserted into the insertion groove 41 of the gap position changing unit 40 by 1, but the present invention is not limited thereto. For example, the reflected wave attenuation units 30 may be inserted into the 3 rd and 5 th insertion grooves 41, respectively, counted from the left side. This can more effectively suppress fluctuations that occur when the moving speed of the ultrasound probe 20 is high.

To summarize the point of fig. 2, a gap position changing means 40 is disposed at an end of the water tank 10 of the present embodiment, and the gap position changing means 40 has an insertion groove 41 in which the reflected wave attenuation means 30 is disposed so as to change the gap position of the inner wall surfaces on both sides in the X axis direction. The insertion groove 41 has a width for inserting the base 31 of the reflected wave attenuation unit 30, and the gap position changing unit 40 has a plurality of insertion grooves 41. By changing the insertion position of the reflected wave attenuation unit 30 into the insertion groove 41, the positions of the reflected wave attenuation unit 30 and the wall surface of the water tank can be changed.

Fig. 3 is a plan view showing the arrangement position of the reflected wave attenuation unit 40 in the water tank 10. The water tank 10 is composed of 4 side surface parts and a bottom surface part. A subject 15 is disposed on the sample stage 12 in the water tank 10. The clearance position changing means 40 is engaged with the left side surface portion 10L and the right side surface portion 10R of the water tank 10 in the X-axis direction. As shown in fig. 3, in the left air gap position changing means 40, the reflected wave attenuating means 30 is inserted into the 3 rd insertion groove 41 from the left side surface portion 10L of the water tank 10. Similarly, in the right gap position changing unit 40, the reflected wave attenuation unit 30 is inserted into the 3 rd insertion groove 41 from the right side surface portion 10R of the water tank 10.

When the ultrasonic probe 20 (see fig. 1) scans the X-axis direction by 1 row line and then scans the scanning position in the Y-axis direction, in the reflected wave attenuation unit 30, it is preferable that at least one of the projections 32 (projections) is located outside a start point position 16s in the Y-axis direction of the subject 15 to be an image acquisition target, and at least one of the projections 32 (projections) is located outside an end point position 16e in the Y-axis direction of the subject 15. This can suppress the fluctuation further outside the start position 16s in the Y axis direction and further outside the end position 16e in the Y axis direction of the subject 15.

In the reflected wave attenuation unit 30, one end side is preferably located outside at least the Y-axis direction start point position 16s of the subject 15 to be imaged, and the other end side is preferably located outside at least the Y-axis direction end point position 16e of the subject 15. This can suppress the fluctuation further outside the start position 16s in the Y axis direction and further outside the end position 16e in the Y axis direction of the subject 15.

Fig. 4 is a block diagram showing the configuration of a control system and a signal processing system of the ultrasonic imaging system. The ultrasound probe 20 includes: an encoder 21 that detects a scanning position of the ultrasonic probe 20; and a piezoelectric element 22 that mutually converts the electric signal and the ultrasonic signal. The piezoelectric element 22 is a single focus type ultrasonic sensor.

The image display device 50 includes: a scan control unit 51 for controlling the scanning position of the ultrasonic probe 20; a frequency control unit 52 for controlling the frequency of the ultrasonic wave; a timing control unit 53 for controlling the timing of transmission and reception of the ultrasonic waves; and an image generating unit 54 for generating an ultrasonic image.

The transmission/reception device 60 includes: a burst wave transmitter 61 that generates an electrical signal of a burst wave; a pulse wave transmitter 62 that generates an electric signal of a pulse wave; a switch 63; an amplifier 64 that amplifies the reception signal received by the ultrasonic probe 20; an a/D converter 65 that converts the received signal from an analog signal to a digital signal; and a signal processing unit 66 for performing signal processing on the received signal.

The scan control unit 51 is connected to the mechanical control device 77 so as to be capable of input and output. The scan control unit 51 controls the scanning position of the ultrasound probe 20 by the mechanical control device 77, the X-axis scanner 71, and the Y-axis scanner 72, and receives current scanning position information of the ultrasound probe 20 from the mechanical control device 77.

The output side of the mechanical control device 77 is connected to the X-axis scanner 71 and the Y-axis scanner 72. The output side of the encoder 21 of the ultrasonic probe 20 is connected to the mechanical control device 77. The mechanical control device 77 detects the scanning position of the ultrasonic probe 20 from the output signal of the encoder 21, and controls the ultrasonic probe 20 to be the instructed scanning position by the X-axis scanner 71 and the Y-axis scanner 72. The machine control unit 77 receives a control instruction of the ultrasound probe 20 from the scan control unit 51, and responds to the scanning position information of the ultrasound probe 20.

The timing control unit 53 outputs a transmission/reception timing signal (information) of the ultrasonic wave to the transmission/reception device 60 and frequency information of the ultrasonic wave to the frequency control unit 52 based on the scanning position information of the ultrasonic probe 20 acquired from the scanning control unit 51.

The frequency control section 52 instructs the burst wave transmitter 61 to output a burst wave of a predetermined frequency by a predetermined number of pulses, based on the frequency information of the ultrasonic wave output by the timing control section 53.

The burst wave transmitter 61 outputs a burst wave of a predetermined frequency to the piezoelectric element 22 by a predetermined number of pulses based on the signal output from the frequency control unit 52. The pulse wave transmitter 62 outputs a pulse wave to the piezoelectric element 22 based on the timing signal output from the timing control unit 53. The switch 63 switches which of the pulse train wave and the pulse wave is output to the piezoelectric element 22 according to an output signal of the timing control unit 53.

The piezoelectric element 22 is a member having electrodes on both surfaces of a piezoelectric film, and is made of zinc oxide (ZnO), ceramic, fluorine-based copolymer, or the like. The piezoelectric element 22 transmits ultrasonic waves from the piezoelectric film when a voltage is applied between the two electrodes. Further, the piezoelectric element 22 converts an echo (reception wave) received by the piezoelectric film into a reception signal which is a voltage generated between the two electrodes. The amplifier 64 is a means for amplifying the received signal and outputting the amplified signal as an output signal Vout. The a/D converter 65 is a means for converting the amplified received signal from an analog signal to a digital signal.

The signal processing unit 66 performs signal processing on the received signal. The signal processing unit 66 extracts only a predetermined period of the received signal based on the gate pulse Vgate output from the timing control unit 53. The signal processing unit 66 outputs amplitude information of the received signal for a predetermined period or time information of the received signal for a predetermined period to the image generating unit 54. The image generating unit 54 generates an ultrasonic image at a predetermined frequency based on the output signal of the signal processing unit 66.

(operation of ultrasonic imaging apparatus)

Referring to fig. 4, a series of operations of the ultrasonic imaging apparatus 90 will be described.

The scanning control unit 51 scans the ultrasonic probe 20 in the + X direction to obtain pixels corresponding to 1 row line. If the scanning control unit 51 detects that the ultrasonic probe 20 is located at the end in the X direction, the ultrasonic probe 20 is moved by a predetermined pitch in the + Y direction, and then scanned in the-X direction to obtain an image corresponding to 1 row line. This process is repeated, and the scan control unit 51 performs scanning of a predetermined range.

The timing control unit 53 of the image display device 50 receives the scanning position information of the ultrasound probe 20 in the X direction and the Y direction from the scanning control unit 51, instructs the frequency control unit 52 of the frequency according to the scanning position information in the Y direction, instructs the transmission/reception device 60 of the ultrasound according to the scanning position information in the X direction, and outputs the gate pulse Vgate for performing signal processing on the received signal.

The transceiver 60 switches between the pulse signal output from the burst wave transmitter 61 and the pulse signal output from the pulse wave transmitter 62 by the switch 63, and outputs the signals to the ultrasound probe 20. Further, the transmitting/receiving device 60 amplifies the reception signal of the echo (reception wave) received by the ultrasonic probe 20 with the amplifier 64, and then converts the signal into a digital signal by the a/D converter 65. The signal processing unit 66 performs signal processing on the received signal (digital signal) based on the gate pulse Vgate input from the timing control unit 53, and outputs the signal to the image display device 50.

The video display device 50 displays the internal structure of the subject 15 as an image by using the information of the scanning position acquired by the scanning control unit 51 as the pixel position and the information of the reception signal-processed by the transmission/reception device 60 as the luminance information of the pixel. The ultrasonic image showing the inside of the subject 120 may be an image based on amplitude information of the received signal or an image based on information of a time when the received signal has reached a predetermined amplitude or more.

Hereinafter, the various reflected wave attenuation units 30 will be described.

(example 1)

Fig. 5 is a schematic diagram showing the structure of the reflected wave attenuation unit 30A according to example 1, where (a) is a side view when disposed in the water tank 10, and (b) is a perspective view as viewed from the side of the reflected wave attenuation unit 30A that is in contact with (faces) the wall of the water tank 10. That is, fig. 5 (b) is a perspective view of the side surface portion 10R side (right side) of fig. 5 (a). As shown in fig. 5 (a), the reflected wave attenuation unit 30A is disposed at a position spaced apart from the side surface portions 10L, 10R of the water tank 10 by a predetermined distance. As shown in fig. 5 (b), the reflected wave attenuation unit 30A is formed of a square-shaped lattice-shaped base 31 having a large number of projections 32. The projection 32 is made of a flexible material such as a resin material, and is preferably made of a resin such as PP (polypropylene), EPDM (ethylene-propylene rubber), ABS (acrylonitrile, butadiene, styrene), or the like. The protrusion 32 may be made of a metal material such as a thin wire.

When the sample mounting table 12 is provided in the liquid substance 11A stored in the water tank 10 and the ultrasonic probe 20 is moved at a high speed above the object 15, a traveling wave is generated on the surface of the liquid substance in the water tank 10, and the traveling wave hits the inner wall of the water tank (for example, the inner walls of the side surface portions 10L and 10R) to generate a reflected wave. By repeating the reciprocating operation of the ultrasonic probe 20 in the X-axis direction, the forward wave and the reflected wave are synthesized, and a larger synthesized wave is generated. Accordingly, when the displacement of the surface of the liquid substance 11A becomes large and the distal end of the ultrasonic probe 20 is exposed from the liquid substance 11A, the image of the subject 15 cannot be acquired by the ultrasonic waves. Further, if the composite wave exceeds the height of the side surface of the water tank 10, the liquid substance 11A overflows from the water tank 10, and it is difficult to stand the subject 15. Further, the bubble is entangled in the liquid material 11A, which hinders the acquisition of an image by ultrasonic waves.

Therefore, in the present embodiment, by providing the reflected wave attenuation means 30A on the side wall of the water tank 10, reflected waves of the wave of the liquid substance 11A as a propagation medium of the ultrasonic wave can be suppressed at the side surface portions 10L, 10R (end portions). The reflected wave attenuation unit 30A has a structure in which a plurality of thin protrusions 32, the tips of which are slightly bent, are provided in a base having a through-hole (for example, a lattice-shaped base 31). By disposing the projection 32 toward the side wall of the water tank 10, the traveling wave passes through the base provided with the through-hole and is diffused in the projection 32, and the reflected wave can be suppressed.

In the reflected wave attenuation unit 30A, at least one of the projections 32 (projections) is preferably located at a height position above the surface of the liquid substance 11A in the water tank 10 in the vertical direction (Z-axis direction). In the reflected wave attenuation unit 30A, the upper edge 30Au is preferably at a height position at least above the surface of the liquid substance 11A in the water tank 10 in the vertical direction. This can suppress the fluctuation above the surface of the liquid substance 11A.

In the reflected wave attenuation unit 30A, at least one of the protrusions 32 (projections) is preferably located at a height position lower than the lower surface 12d of the mounting table of the subject in the vertical direction (Z-axis direction). In the reflected wave attenuation unit 30A, the lower end edge 30Ad is preferably at a height position lower than at least the lower surface 12d of the sample stage 12 of the object 15 in the vertical direction. This can suppress the fluctuation in the liquid substance 11A in the vicinity of the lower surface 12d of the placement table of the subject.