Ultrasonic transmitter, ultrasonic transmission / reception unit, and ultrasonic inspection device

Abstract

The purpose of this disclosure is to provide an ultrasonic transmitter capable of enhancing the accuracy of an inspection on a subject. An ultrasonic transmitter 1 according to one embodiment of this disclosure comprises: a burst wave generation unit 2 that generates a burst wave B; and an ultrasonic transmission unit 3 that receives the burst wave B and outputs an ultrasonic wave U. The burst wave B has a waveform including a pulse having a first amplitude b1 and a pulse having an amplitude smaller than the first amplitude b1.

Description

Ultrasonic transmitter, ultrasonic transmitting / receiving unit, and ultrasonic inspection device

[0001] The present disclosure relates to an ultrasonic transmitter, an ultrasonic transmitting / receiving unit, and an ultrasonic inspection device.

[0002] An ultrasonic inspection device is known that inspects defects in an object by transmitting ultrasonic pulses transmitted from an ultrasonic transmitter through the object and receiving the ultrasonic pulses that have transmitted through the object with an ultrasonic receiver (see Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2008-128965

[0004] Patent Document 1 describes an airborne ultrasonic flaw detection system including a transmitting ultrasonic probe and a receiving ultrasonic probe that are arranged opposite to an object to be inspected via air. Patent Document 1 describes that the transmitting ultrasonic probe converts a square wave burst signal into an ultrasonic pulse and then irradiates the ultrasonic pulse into the object to be inspected. Patent Document 1 also describes that the signal level of the transmitted wave signal can be increased by increasing the wave number N in the square wave burst signal or by selecting and setting the frequency f in the square wave burst signal to an optimal frequency depending on the material of the object to be inspected.

[0005] The present inventors have conducted extensive research to improve the inspection accuracy of an inspection device that uses ultrasound to inspect an object, determining whether the object is good or bad. As a result, they have found that with a conventional configuration such as that described in Patent Document 1, it is not possible to increase the S / N ratio (signal-to-noise ratio) of the ultrasound received by the ultrasound receiver, making it difficult to sufficiently improve the inspection accuracy.

[0006] An object of one aspect of the present disclosure is to provide an ultrasound transmitter that can improve the accuracy of testing a subject.

[0007] An ultrasonic transmitter according to one aspect of the present disclosure includes a burst wave generating unit that generates a burst wave, and an ultrasonic transmitting unit that receives the burst wave and outputs an ultrasonic wave, wherein the burst wave has a waveform that includes a pulse of a first amplitude and a pulse of an amplitude smaller than the first amplitude.

[0008] FIG. 1 is a block diagram showing a configuration of an ultrasonic transmitter according to an embodiment of the present disclosure. FIG. 2 is a diagram showing an example of burst waves generated by a burst wave generating unit in the ultrasonic transmitter of FIG. 1 and ultrasonic waves output from the ultrasonic transmitting unit. FIG. 3 is a block diagram showing a configuration of an ultrasonic transceiver unit according to an embodiment of the present disclosure. FIG. 4 is a schematic cross-sectional view showing the positional relationship between the ultrasonic transmitting unit and the ultrasonic receiving unit in the ultrasonic transceiver unit of FIG. 3. FIG. 5 is a diagram showing an example of burst waves generated by a burst wave generating unit, ultrasonic waves output from the ultrasonic transmitting unit, and a received waveform received by the ultrasonic receiving unit in the ultrasonic transceiver unit of FIG. 3. FIG. 6 is a diagram showing an example of burst waves generated by a burst wave generating unit, ultrasonic waves output from the ultrasonic transmitting unit, and a received waveform received by the ultrasonic receiving unit in a conventional ultrasonic transceiver unit. FIG. 7 is a diagram showing an example of an ultrasonic path in the ultrasonic transceiver unit of FIG. 3. FIG. 8 is a schematic plan view showing an ultrasonic inspection device according to an embodiment of the present disclosure. FIG. 9 is a schematic side view of the ultrasonic inspection device of FIG. 8. FIG. 10 is a diagram showing an example of burst waves generated by a burst wave generating unit in an ultrasonic transmitter according to another embodiment of the present disclosure.

[0009] [1] An ultrasonic transmitter according to one aspect of the present disclosure includes a burst wave generating unit that generates a burst wave, and an ultrasonic transmitting unit that receives the burst wave and outputs an ultrasonic wave, wherein the burst wave has a waveform that includes a pulse of a first amplitude and a pulse of an amplitude smaller than the first amplitude.

[0010] [2] In the above [1], the first amplitude may be the maximum amplitude in the waveform.

[0011] [3] In the above [1] or [2], the first amplitude may be present in the first half of the waveform.

[0012] [4] In any one of [1] to [3] above, the first amplitude may be present in the first or second period of the waveform.

[0013] [5] In any of [1] to [4], the amplitude of the kth period in the waveform (where n is the number of periods in the waveform, 1≦k≦n−1) is A ｋ In this case, A ｋ ≧A ｋ＋１ It would be good if that were the case.

[0014] [6] In any one of [1] to [5] above, the number of periods in the waveform may be 10 or less.

[0015] [7] An ultrasonic transmitting / receiving unit according to one aspect of the present disclosure includes an ultrasonic transmitter according to any one of [1] to [6] and an ultrasonic receiver facing the ultrasonic transmitter with a gap therebetween.

[0016] [8] In [7], when the straight-line distance of the ultrasonic wave when it travels in a straight line between the ultrasonic transmitter and the ultrasonic receiver is L [mm], the increase rate when the ultrasonic path becomes longer than the straight-line distance L is α, the wavelength of the ultrasonic wave output from the ultrasonic transmitter is λ [mm], and the position of the pulse of the first amplitude in the waveform is X [cycle], it is preferable that either of the following formulas (1) or (2) is satisfied.

[0017] [9] An ultrasonic examination device according to one aspect of the present disclosure includes the ultrasonic transmission / reception unit of [7] or [8] and a transport mechanism that transports a subject between the ultrasonic transmitter and the ultrasonic receiver.

[0018]

[10] In the above [9], it is preferable to have a plurality of the ultrasonic receivers arranged in an array.

[0019] In this disclosure, a "burst wave" refers to a waveform signal of a single frequency that lasts for a predetermined period of time. A "pulse" refers to a signal that includes positive and negative amplitudes and forms a burst wave. In the waveform of a burst wave, a "period" refers to one period of a pulse in the burst wave, and refers to the period formed by successive pulses having positive and negative amplitudes, for example. "The first amplitude is present in the first half of the waveform" means that, of all pulses contained in the burst wave, the pulse of the first amplitude is present in the first half in the propagation direction. Specifically, if the number of periods contained in the burst wave is n and the pulse of the first amplitude is present in the a-th period, this means that a≦n / 2 (where n and a are both positive integers).

[0020] In the present disclosure, the "increase rate α" when the ultrasonic path is longer than the straight-line distance L means a value expressed as α=(L'-L) / L, where L' is the path length when the ultrasonic path is longer than the straight-line distance L. [Effects of the present disclosure]

[0021] An ultrasound transmitter according to one aspect of the present disclosure can improve the accuracy of examining a subject.

[0022] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. It should be noted that with respect to the numerical values ​​described in this specification, only one of the upper and lower limit values ​​described may be adopted, or the upper and lower limit values ​​may be arbitrarily combined. In this specification, all combinable numerical ranges are described as preferred ranges. Furthermore, each figure is a schematic representation and may not correspond to actual dimensions, ratios, etc. In this disclosure, the terms "first" and "second" are used to distinguish the components to which they are attached, and do not limit the number, order, priority, etc.

[0023] <Ultrasonic Transmitter> As shown in FIG. 1 , an ultrasonic transmitter 1 according to one embodiment of the present disclosure includes a burst wave generating unit 2 that generates burst waves and an ultrasonic transmission unit 3 that receives the burst waves and outputs ultrasonic waves. As shown in FIG. 2 , a burst wave B has a waveform including a pulse of a first amplitude b1 (hereinafter also referred to as a "first pulse") and a pulse of an amplitude (second amplitude b2) smaller than the first amplitude b1 (hereinafter also referred to as a "second pulse"). Note that FIG. 2 illustrates the waveform when the time axis t is taken from left to right. In the waveform of the burst wave B, the number of first pulses (the number of pulse periods forming the burst wave B) may be one or two or more. Furthermore, the number of second pulses may be one or two or more. When the number of second pulses is two or more, the amplitudes of the multiple second pulses may be the same or different.

[0024] The ultrasonic transmitter 1 allows the ultrasonic receiver to detect a waveform with a large S / N ratio by including a first amplitude b1 greater than a second amplitude b2 in the waveform of the burst wave B. Therefore, the ultrasonic transmitter 1 can improve the accuracy of testing the subject. Furthermore, the ultrasonic transmitter 1 prevents a high voltage from being continuously applied to the ultrasonic transmission unit 3 by including a second amplitude b2 in the waveform of the burst wave B as well as the first amplitude b1. Therefore, the ultrasonic transmitter 1 can suppress damage caused by heat generation.

[0025] 1, the burst wave generating unit 2 has a signal generating unit 2a and an amplifying unit 2b. The burst wave generating unit 2 may be a computer including a processor such as a CPU (Central Processing Unit) and a program memory that stores programs executed by the processor. The burst wave generating unit 2 is realized, for example, by the processor executing a program stored in the program memory.

[0026] The signal generating unit 2a generates a burst signal as a signal for controlling the ultrasonic waves U output from the ultrasonic wave transmitting unit 3. The signal generating unit 2a generates the burst signal according to the timing and intensity of the ultrasonic waves U output by the ultrasonic wave transmitting unit 3. The signal generating unit 2a generates the burst signal so that the burst wave B generated by the amplifying unit 2b has a waveform including a first amplitude b1 and a second amplitude b2. The signal generating unit 2a generates the burst signal intermittently.

[0027] The burst signal generated by the signal generating unit 2a includes a plurality of square waves. The burst signal may include a positive square wave or a negative square wave. In particular, the burst signal may include both positive and negative square waves, or may alternate between positive and negative square waves. This configuration can reduce the voltage applied to the ultrasonic transmitter 3 compared to when the burst signal includes only positive or negative square waves. As a result, it is possible to improve the accuracy of testing the subject while suppressing damage caused by heat generation in the ultrasonic transmitter 1.

[0028] The amplifier 2b generates a burst wave B of a predetermined frequency in response to the burst signal generated by the signal generator 2a, and transmits the generated burst wave B to the ultrasonic transmitter 3. The amplifier 2b transmits to the ultrasonic transmitter 3 the burst wave B having a waveform including a first pulse and a second pulse.

[0029] It is preferable that the first amplitude b1 is the maximum amplitude in the waveform of the burst wave B. With this configuration, the effect of improving the accuracy of the examination of the subject based on the first pulse can be significantly obtained.

[0030] The number of first pulses and the number of second pulses in the waveform of the burst wave B are not particularly limited. However, it is preferable that the number of first pulses is smaller than the number of second pulses. With this configuration, it is possible to obtain the effect of improving the accuracy of the examination of the subject based on the first pulses, while sufficiently preventing the ultrasonic transmitter 1 from being damaged due to heat generation.

[0031] The upper limit of the number of first pulses in the waveform of the burst wave B may be 4, 3, or 2, from the viewpoint of sufficiently suppressing damage caused by heat generation in the ultrasonic transmitter 1. The lower limit of the number of first pulses in the waveform of the burst wave B is 1.

[0032] It is preferable that the first amplitude b1 exists in the first half of the waveform of the burst wave B. With this configuration, the waveform portion output from the ultrasonic transmitter 3 based on the first pulse is less susceptible to interference from other ultrasonic waves, etc. As a result, the accuracy of the examination of the subject can be more reliably improved.

[0033] When the first amplitude b1 exists in the first half of the waveform of the burst wave B, the first amplitude b1 may also exist in the first half or later of the waveform of the burst wave B. However, from the viewpoint of sufficiently suppressing damage caused by heat generation of the ultrasonic transmitter 1, it is preferable that the first amplitude b1 exists only in the first half of the waveform of the burst wave B.

[0034] The first amplitude b1 preferably exists in the first or second cycle of the waveform of the burst wave B, and more preferably exists in the first cycle of the waveform of the burst wave B. This configuration can more reliably prevent the waveform portion output from the ultrasonic transmitter 3 based on the first pulse from being interfered with by other ultrasonic waves, etc. Furthermore, this configuration can allow the ultrasonic receiver to detect a waveform with a large amplitude in a short time using only a front portion of the waveform output from the ultrasonic transmitter 3. As a result, the accuracy of the examination of the subject can be easily and reliably improved.

[0035] When the first amplitude b1 is present in the first cycle in the waveform of the burst wave B, the first amplitude b1 may also be present in the second and subsequent cycles of the burst wave B. In this case, it is preferable that the first amplitude b1 is present continuously from the first cycle in the waveform of the burst wave B. That is, the waveform of the burst wave B may have a first pulse group that is continuous from the first cycle. In this case, the waveform of the burst wave B may not have any first pulses other than the first pulse group. In other words, the burst wave B may have a waveform that includes a first pulse group that is continuous from the first cycle and one or more second pulses other than these.

[0036] The amplitude of the kth period (where n is the number of periods in the waveform) of the burst wave B is defined as A. ｋ In this case, A ｋ ≧A ｋ＋１ According to this configuration, the ultrasonic receiver can detect a waveform with a large amplitude in a short time by using the front part of the waveform output from the ultrasonic transmitter 3. As a result, the accuracy of the test on the subject can be improved more reliably. Note that in the ultrasonic transmitter 1, A ｋ ≧A ｋ＋１ It is preferable that the following is satisfied.

[0037] From the viewpoint of efficiently examining the subject, the upper limit of the number of periods in the waveform of the burst wave B is preferably 10. The upper limit of the number of periods may be 8 or 6. On the other hand, the lower limit of the number of periods in the waveform of the burst wave B is not particularly limited as long as it includes the first pulse and the second pulse, and may be 2 or 4.

[0038] (Ultrasound Transmitter) The ultrasound transmitter 3 is not particularly limited in its specific configuration as long as it can receive burst waves B and output ultrasound waves U, but may include, for example, a piezoelectric element (transmitting piezoelectric element). The ultrasound transmitter 3 is capable of transmitting ultrasound waves U based on the vibration of the transmitting piezoelectric element.

[0039] The ultrasonic transmission unit 3 transmits ultrasonic waves using a resonance frequency. The ultrasonic transmitter 1 includes a first pulse in the waveform of the burst wave B, allowing the amplitude of the ultrasonic waves U transmitted from the ultrasonic transmission unit 3 to increase rapidly. More specifically, if the waveform of the burst wave B includes only a second pulse of the same amplitude, the amplitude of the ultrasonic waves U transmitted from the ultrasonic transmission unit 3 gradually increases due to resonance. In this case, in order for the ultrasonic receiver to detect the waveform with a large amplitude, it is necessary to use the rear portion of the waveform that has increased due to resonance. However, this rear portion of the waveform is likely to be affected by interference from other ultrasonic waves, making it difficult to achieve a sufficiently large S / N ratio. In contrast, the ultrasonic transmitter 1 includes a first pulse in the waveform of the burst wave B, allowing the amplitude of the ultrasonic waves U transmitted from the ultrasonic transmission unit 3 to increase quickly. As a result, the ultrasonic transmitter 1 can improve the accuracy of testing the subject.

[0040] 3 and 4 includes an ultrasonic transmitter 1 and an ultrasonic receiver 11 that faces the ultrasonic transmitter 1 with a gap therebetween. The ultrasonic transmitter 1 may be the same as the ultrasonic transmitter 1 in Fig. 1. In this disclosure, the expression "the ultrasonic transmitter 1 and the ultrasonic receiver 11 facing each other with a gap therebetween" means that the ultrasonic transmitting unit 3 included in the ultrasonic transmitter 1 and the ultrasonic receiving unit 12 (described later) included in the ultrasonic receiver 11 face each other with a gap therebetween.

[0041] In the ultrasonic transmitting and receiving unit 10, the burst wave B includes a first amplitude b1 that is larger than the second amplitude b2, allowing the ultrasonic receiver 11 to detect a waveform with a large S / N ratio. Therefore, the ultrasonic transmitting and receiving unit 10 can improve the accuracy of testing the subject. Furthermore, in the ultrasonic transmitting and receiving unit 10, the burst wave B includes the second amplitude b2 as well as the first amplitude b1, preventing a high voltage from being continuously applied to the ultrasonic transmitting unit 3. Therefore, the ultrasonic transmitting and receiving unit 10 can suppress damage to the ultrasonic transmitter 1 due to heat generation.

[0042] (Ultrasonic receiver) As shown in FIG. 3, the ultrasonic receiver 11 has an ultrasonic receiving unit 12 that receives the ultrasonic waves U transmitted from the ultrasonic transmitting unit 3, and a receiving processing unit 13 that acquires the analog detection signal converted by the ultrasonic receiving unit 12 and converts it into a digital detection signal.

[0043] 4, the ultrasonic receiver 12 and the ultrasonic transmitter 3 face each other with a gap therebetween. An object P is placed in the space between the ultrasonic receiver 12 and the ultrasonic transmitter 3. The ultrasonic transmitter-receiver unit 10 is configured so that the ultrasonic waves U transmitted from the ultrasonic transmitter 3 are transmitted through the object P and then received by the ultrasonic receiver 12. The ultrasonic transmitter-receiver unit 10 is also configured so that it can determine whether the object P is good or bad using the ultrasonic waves U received by the ultrasonic receiver 12.

[0044] (Ultrasound Receiving Unit) The ultrasound receiving unit 12 receives the ultrasound U transmitted from the ultrasound transmitting unit 3 and converts it into an analog detection signal. The ultrasound receiving unit 12 is not particularly limited in its specific configuration as long as it can receive the ultrasound U transmitted from the ultrasound transmitting unit 3, but may include, for example, a piezoelectric element (receiving piezoelectric element). The ultrasound receiving unit 12 is able to receive the ultrasound U based on the vibration of the receiving piezoelectric element.

[0045] (Reception Processing Unit) The reception processing unit 13 receives the analog detection signal from the ultrasonic reception unit 12, amplifies the signal, equalizes the signal, and converts it into a digital detection signal by AD (analog-to-digital) conversion.

[0046] The waveform of the ultrasonic wave received by the ultrasonic receiving section 12 in the ultrasonic transmitting / receiving unit 10 will be described with reference to FIGS. 5 and 6. FIG.

[0047] FIG. 5 shows an example of a burst wave B generated by the burst wave generating unit 2 in the ultrasonic transmitting / receiving unit 10, an ultrasonic wave U transmitted by the ultrasonic transmitting unit 3, and a received waveform W received by the ultrasonic receiving unit 12. FIG. 5 shows waveforms when the time axis t is taken from left to right in the horizontal direction. In the ultrasonic transmitting / receiving unit 10, the waveform of the burst wave B includes a first pulse, thereby enabling the amplitude of the ultrasonic wave U transmitted from the ultrasonic transmitting unit 3 to be sharply increased. In FIG. 5, the first pulse is included in the first period of the burst wave B, and therefore the amplitude of the ultrasonic wave U transmitted from the ultrasonic transmitting unit 3 is large in the first period. As a result, the amplitude of the received waveform W received by the ultrasonic receiving unit 12 is also large in the first period, corresponding to the waveform of the ultrasonic wave U transmitted from the ultrasonic transmitting unit 3. With this configuration, the waveform with a large amplitude in the front portion of the received waveform W can be detected with high accuracy, thereby enabling the quality of the subject P to be inspected with high accuracy.

[0048] FIG. 6 shows an example of a burst wave B' generated by a burst wave generator in a conventional ultrasonic transmitting / receiving unit, an ultrasonic wave U' transmitted by an ultrasonic transmitting unit 3', and a received waveform W' received by an ultrasonic receiving unit 12'. FIG. 6 illustrates waveforms when the time axis t is plotted from left to right. In this ultrasonic transmitting / receiving unit, the waveform of the burst wave B' contains only the second pulse, so the amplitude of the ultrasonic wave U' transmitted from the ultrasonic transmitting unit 3' gradually increases due to resonance. As a result, the amplitude of the received waveform W' received by the ultrasonic receiving unit 12' corresponding to the waveform of the ultrasonic wave U' transmitted from the ultrasonic transmitting unit 3' also gradually increases toward the latter half. In this configuration, it is necessary to detect the waveform including the rear portion where the amplitude is sufficiently large. However, the rear waveform is likely to include unwanted ultrasonic waves that have bypassed the subject P and reached the ultrasonic receiving unit 12'. Furthermore, in a configuration in which multiple ultrasonic receiving units 12' are aligned, the rear waveform may be subject to interference from vibrations of adjacent ultrasonic receiving units 12'. Therefore, it is difficult for conventional ultrasonic transmitting and receiving units to inspect the quality of the subject P with high precision, as can be done by the ultrasonic transmitting and receiving unit 10.

[0049] As shown in FIG. 7 , when the straight-line distance of the ultrasonic wave U traveling between the ultrasonic transmitter 1 and the ultrasonic receiver 11 (more specifically, between the ultrasonic transmitter 3 and the ultrasonic receiver 12) is L [mm], the increase rate when the path R of the ultrasonic wave U becomes longer relative to the straight-line distance L is α, the wavelength of the ultrasonic wave U output from the ultrasonic transmitter 1 is λ [mm], and the position of the first pulse in the waveform of the burst wave B is X [cycle], it is preferable that either of the following formulas (1) or (2) is satisfied.

[0050]

[0051] By satisfying the above formula (1) or (2), it is possible to increase the amplitude of the ultrasonic waves U that have bypassed the subject P before they reach the ultrasonic receiving unit 12, with respect to the received waveform W received by the ultrasonic receiving unit 12. As a result, it is possible to inspect the quality of the subject P with higher accuracy.

[0052] The meanings of the above formulas (1) and (2) will be explained. The difference (ΔL) in the propagation distance of the ultrasound U when it travels a straight distance L and when it travels a path R is expressed as ΔL = L(1 + α) - L = Lα. Here, in order to increase the amplitude of the ultrasound U that has bypassed the subject P before it reaches the ultrasound receiving unit 12, it is necessary to make the position of the first pulse smaller than the value obtained by converting ΔL into the number of cycles. Therefore, if the position of the first pulse in the waveform of the burst wave B is X, then ΔL / λ = Lα / λ > X, and the above formula (1) is obtained. Furthermore, since X is a positive integer, X≧1, and the above formula (2) is obtained as the smallest possible value for X.

[0053] Next, the increase rate α will be considered with reference to FIG. 7 . Assume that an ultrasonic wave U is transmitted through an inspection object P having a defect D to inspect the quality of the inspection object P. In this case, for example, the straight-line distance L may be 10 mm, and the diameter d of the defect D may be 5 mm. Assuming that the inspection object P is located midway between the ultrasonic wave transmitter 3 and the ultrasonic wave receiver 12, the path length L′ of the path R that bypasses the defect D is 10.6 mm. Calculating α based on these values ​​yields α=0.06. Therefore, the increase rate α can be set to a value based on the type of inspection object P (more specifically, the expected size of the defect D in the inspection object P) and the straight-line distance L. The increase rate α can be set to, for example, 0.18, 0.15, or 0.10. The straight-line distance L can be set to, for example, 0.5 mm or more and 300 mm or less.

[0054] 8 and 9 includes the ultrasonic transmitting / receiving unit 10 and a transport mechanism 21 that transports the subject P so that the subject P passes between the ultrasonic transmitter 1 and the ultrasonic receiver 11. The ultrasonic testing device 20 also includes an inspection unit 22 that inspects the quality of the subject P based on the digital detection signal converted by the reception processing unit 13 of the ultrasonic receiver 11.

[0055] In the ultrasonic inspection device 20, the burst wave B includes a first amplitude b1 that is larger than the second amplitude b2, so that the ultrasonic receiver 11 can detect a waveform with a large S / N ratio. Therefore, the ultrasonic inspection device 20 can improve the inspection accuracy of the subject P. Furthermore, in the ultrasonic inspection device 20, the burst wave B includes the second amplitude b2 as well as the first amplitude b1, so that the ultrasonic inspection device 20 can prevent a high voltage from being continuously applied to the ultrasonic transmission unit 3. Therefore, the ultrasonic inspection device 20 can suppress damage to the ultrasonic transmitter 1 due to heat generation.

[0056] As shown in FIG. 9 , the ultrasonic inspection device 20 includes an ultrasonic transmitter 1. The ultrasonic inspection device 20 also includes an ultrasonic receiver 11 arranged opposite the ultrasonic transmitter 1. In the ultrasonic inspection device 20, a plurality of ultrasonic receivers 11 are arranged in an array relative to the ultrasonic transmitter 1. More specifically, the ultrasonic receiving units 12 included in the ultrasonic receiver 11 are arranged in an array opposite the ultrasonic transmission units 3. Note that "array" includes a configuration in which the ultrasonic receivers are arranged in a line or in a matrix. The ultrasonic transmitter 1 may include one or more ultrasonic transmission units 3. When the ultrasonic transmitter 1 includes a plurality of ultrasonic transmission units 3, the plurality of ultrasonic transmission units 3 may be arranged in an array. When a plurality of ultrasonic transmission units 3 are arranged in an array, each ultrasonic transmission unit 3 may be arranged opposite an ultrasonic reception unit 12.

[0057] Even when the ultrasonic inspection device 20 has a plurality of ultrasonic receivers 11 arranged in an array, there is little risk that the accuracy of the inspection of the subject P by the inspection unit 22 will be reduced due to vibrations of adjacent ultrasonic receiving units 12. Therefore, the ultrasonic inspection device 20 can easily and reliably inspect the subject P with high accuracy.

[0058] [Test Subject] The test subject P has a test part 101, which is a target part for ultrasonic testing. The test subject P is not particularly limited, but an example of the test subject 101 is a container having a sealed portion. The container is not particularly limited, but an example of the test subject 101 is a bag such as a pouch having a heat-sealed portion. The test subject P is transported by the transport mechanism 21 at a constant speed in a direction perpendicular to the thickness direction, and passes through the space between the ultrasonic transmitter 3 and the ultrasonic receiver 12. When the test subject P is a pouch, the ultrasonic testing device 20 may be used to inspect for defects such as poor sealing of the heat-sealed portion.

[0059] (Transport Mechanism) The transport mechanism 21 has a holder 21a that holds the subject P. The transport mechanism 21 transports the subject P so that the inspection portion 101 of the subject P passes between the ultrasound transmitter 3 and the ultrasound receiver 12. The transport mechanism 21 may transport the subject P along the longitudinal direction of the inspection portion 101.

[0060] (Inspection Unit) The inspection unit 22 may be a computer including a processor such as a CPU (Central Processing Unit) and a program memory that stores a program executed by the processor. The inspection unit 22 may determine whether the subject P is healthy or not using a portion of the received waveform W received by the ultrasound receiving unit 12. The inspection unit 22 may determine whether the subject P is healthy or not using a waveform portion corresponding to the first pulse.

[0061] [Other Embodiments] The above-described embodiments do not limit the configuration of the present invention. Therefore, the above-described embodiments may include omissions, substitutions, or additions of components based on the description in this specification and common general technical knowledge, and all of these should be construed as falling within the scope of the present invention.

[0062] In the above embodiment, a configuration has been described in which the first amplitude is present in the first period in the waveform of the burst wave B. However, in the present disclosure, the position of the first amplitude b1 can be set depending on the configuration of the ultrasound inspection device, the type of subject, etc. For example, as shown in FIG. 10 , the first amplitude b1 may be present only after the first period in the waveform of the burst wave B. Furthermore, depending on the configuration of the ultrasound inspection device and the type of subject, the first amplitude b1 may be present in the latter half of the waveform of the burst wave B.

[0063] In the present disclosure, the specific configurations of the ultrasonic transmitter, ultrasonic transmission / reception unit, and ultrasonic inspection device are not limited to those of the above-described embodiments. For example, the above-described embodiments describe a transmission-type ultrasonic transmission / reception unit and an ultrasonic inspection device that perform ultrasonic inspection with a test object placed between the ultrasonic transmission unit and the ultrasonic reception unit. However, the ultrasonic transmission / reception unit and the ultrasonic inspection device of the present disclosure may be a reflection-type ultrasonic inspection device in which ultrasonic waves transmitted from the ultrasonic transmission unit are reflected by the test object and the reflected ultrasonic waves are received by the ultrasonic reception unit. Furthermore, the ultrasonic inspection device of the present disclosure may include only one ultrasonic transmitter and one ultrasonic receiver.

[0064] REFERENCE SIGNS LIST 1 ultrasonic transmitter 2 burst wave generating section 2a signal generating section 2b amplifier section 3, 3' ultrasonic transmitting section 10 ultrasonic transmitting / receiving unit 11 ultrasonic receiver 12, 12' ultrasonic receiving section 13 receiving processing section 20 ultrasonic inspection device 21 transport mechanism 21a holding section 22 inspection section 101 inspected part B, B' burst wave b1 first amplitude b2 second amplitude D defect d diameter of defect L straight distance of ultrasonic wave P inspected object R ultrasonic path U, U' ultrasonic waves W, W' received waveform

Claims

1. An ultrasonic transmitter comprising: a burst wave generating unit that generates burst waves; and an ultrasonic transmission unit that receives the burst waves and outputs ultrasonic waves, wherein the burst waves have a waveform that includes pulses of a first amplitude and pulses of an amplitude smaller than the first amplitude.

2. The ultrasonic transmitter of claim 1, wherein said first amplitude is the maximum amplitude in said waveform.

3. The ultrasonic transmitter of claim 2, wherein the first amplitude is present in the first half of the waveform.

4. The ultrasonic transmitter according to claim 2, wherein the first amplitude is present in the first or second period of the waveform.

5. The amplitude of the kth period in the waveform (where n is the number of periods in the waveform, 1≦k≦n-1) is A ｋ In this case, A ｋ ≧A ｋ＋１ 2. The ultrasonic transmitter of claim 1, wherein:

6. The ultrasonic transmitter of claim 1, wherein the number of periods in said waveform is 10 or less.

7. An ultrasonic transmitting / receiving unit comprising: an ultrasonic transmitter according to any one of claims 1 to 6; and an ultrasonic receiver facing the ultrasonic transmitter with a gap therebetween.

8. The ultrasonic transmitting and receiving unit according to claim 7, which satisfies either formula (1) or (2) below, wherein the straight-line distance of ultrasonic waves traveling in a straight line between the ultrasonic transmitter and the ultrasonic receiver is L [mm], the rate of increase when the path of the ultrasonic waves becomes longer than the straight-line distance L is α, the wavelength of the ultrasonic waves output from the ultrasonic transmitter is λ [mm], and the position of the pulse of the first amplitude in the waveform is X [cycle].

9. An ultrasonic inspection device comprising: the ultrasonic transmission / reception unit according to claim 7; and a transport mechanism for transporting a test object so that the test object passes between the ultrasonic transmitter and the ultrasonic receiver.

10. The ultrasonic inspection device according to claim 9, comprising a plurality of said ultrasonic receivers arranged in an array.

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