TWI896915B - Ultrasonic detection device - Google Patents

Abstract

An ultrasonic detection device includes a matching element, a backing layer, piezoelectric layers between the matching element and the backing layer, and a controller electrically connected to the piezoelectric layers directly or indirectly. The piezoelectric layers include a first piezoelectric element in a first position and a second piezoelectric element in a second position along a first direction. The matching element, the backing layer and the piezoelectric layers are disposed along a second direction. The piezoelectric layers are arranged along a third direction. The first direction, the second direction and the third direction are perpendicular to each other. The controller is used to drive at least one of the first piezoelectric element to make the first piezoelectric element generate a first ultrasonic signal and the second piezoelectric element to make the second piezoelectric element generate a second ultrasonic signal. The first ultrasonic signal has a first signal waveform. The second ultrasonic signal has a second signal waveform. The first signal waveform is different from the second signal waveform.

Description

Ultrasonic detection device

The present invention relates to an ultrasonic detection device, and more particularly to an ultrasonic detection device capable of performing short-axis spatial encoding.

Ultrasonic detectors (or transducers) emit ultrasonic signals at a target object and then use the echo signals to evaluate the target object. They are currently widely used in various fields, including medicine, industry, and the Internet of Things. Ultrasonic detectors can be divided into various types, such as single-element and two-dimensional array, depending on the configuration of their array elements (or sound wave generating units). Traditional single-element ultrasonic detectors require a motor, which leads to long scanning times and difficult motor maintenance. Two-dimensional array ultrasonic detection devices consist of multiple array elements arranged in a two-dimensional array. However, because each array element needs to be individually wired to electrically connect to the circuit board, it has disadvantages such as complex assembly and large size.

Therefore, there is an urgent need to propose a new ultrasonic detection device to improve the above problems.

This disclosure relates to an ultrasonic detection device whose piezoelectric layer can output multiple ultrasonic signals with different signal waveforms along the short-axis direction to achieve short-axis spatial encoding, thereby improving the aforementioned problems.

According to one aspect of the present invention, an ultrasonic detection device is provided. The ultrasonic detection device includes a matching element, a backing layer, a plurality of piezoelectric layers arranged between the matching element and the backing layer, and a controller directly or indirectly electrically connected to the plurality of piezoelectric layers. The plurality of piezoelectric layers include a first piezoelectric element arranged at a first position along a first direction and a second piezoelectric element arranged at a second position. The matching element, the plurality of piezoelectric layers and the backing layer are arranged along a second direction. The plurality of piezoelectric layers are arranged along a third direction. The first direction, the second direction and the third direction are perpendicular to each other. The controller is used to at least drive the first piezoelectric element so that the first piezoelectric element outputs one of a first ultrasonic signal having a first signal waveform and drive the second piezoelectric element so that the second piezoelectric element outputs one of a second ultrasonic signal having a second signal waveform. The first signal waveform is different from the second signal waveform.

In order to better understand the above and other aspects of the present invention, the following embodiments are specifically described in detail with reference to the accompanying drawings:

10, 20, 30, 40: Ultrasonic detection device

101, 102, 402: Matching components

103, 203, 303, 403: Piezoelectric structure

104,204,404:Background layer

105: Controller

113,213,313: Piezoelectric layer

181,182,183,281,282,283,381,382,383:Signal waveform

206: Reflective layer

401: Lens

1131, 1132, 1133, 2131, 2132, 2133, 3131, 3132, 3133: Piezoelectric components

D1, D2, D3: Direction

H1, H2, H3, H4, H5, H6: Thickness

P1, P2, P3: Location

S: Interface

T1, T3: Groove combination

T11~T17, T31~T37: Grooves

FIG1A is a schematic diagram illustrating a cross-section of an ultrasonic detection device according to one embodiment of the present invention in the third direction. FIG1B is a schematic diagram illustrating a cross-section of the ultrasonic detection device according to FIG1A in the first direction. FIG1C is a schematic diagram illustrating a signal waveform according to one embodiment of the present invention. FIG2A is a schematic diagram illustrating a cross-section of an ultrasonic detection device according to a second embodiment of the present invention in the third direction. FIG2B is a schematic diagram illustrating a cross-section of the ultrasonic detection device according to FIG2A in the first direction. FIG2C is a schematic diagram illustrating a signal waveform of an embodiment of the present invention; FIG3A is a schematic diagram illustrating a cross-sectional view of an ultrasonic detection device in a third direction according to a third embodiment of the present invention; FIG3B is a schematic diagram illustrating a cross-sectional view of the ultrasonic detection device in FIG3A in a first direction; FIG3C is a schematic diagram illustrating a signal waveform of an embodiment of the present invention; and FIG4 is an exploded view of an ultrasonic detection device in an embodiment of the present invention.

In order to better understand the above and other aspects of the present invention, the following embodiments are specifically described below with reference to the accompanying drawings.

Please refer to Figures 1A and 1B. Figure 1A is a schematic cross-sectional view of an ultrasonic detection device 10 according to one embodiment of the present invention, taken along a third direction D3. Figure 1B is a schematic cross-sectional view of the ultrasonic detection device 10 shown in Figure 1A, taken along a first direction D1. The ultrasonic detection device 10 includes a matching element 101, a matching element 102, a piezoelectric structure 103, a backing layer 104, and a controller 105. The matching element 101, the matching element 102, the piezoelectric structure 103, and the backing layer 104 can be arranged along a second direction D2. The matching element 102 is located between the matching element 101 and the piezoelectric structure 103. The piezoelectric structure 103 is located between the matching element 102 and the backing layer 104. In this embodiment, the ultrasonic detection device 10 is shown as including two matching elements (i.e., matching element 101 and matching element 102), but the present invention is not limited thereto. The ultrasonic detection device may include more or fewer matching elements.

The piezoelectric structure 103 may include a plurality of piezoelectric layers 113 arranged along a third direction D3. The plurality of piezoelectric layers 113 are disposed between the matching element 101 and the back layer 104. As shown in FIG1B , each piezoelectric layer 113 may extend along a first direction D1. The first direction D1, the second direction D2, and the third direction D3 may be perpendicular to each other. In one embodiment, the ultrasonic detection device 10 may include a long axis direction and a short axis direction, the long axis direction may be, for example, the same as the third direction D3, and the short axis direction may be the same as the first direction D1. The piezoelectric layer 113 may include a plurality of piezoelectric elements, for example, at least two piezoelectric elements. The plurality of piezoelectric elements may be disposed along the first direction D1 and respectively disposed at different positions on the first direction D1. For example, as shown in FIG. 1B , the piezoelectric layer 113 may include a piezoelectric element 1131, a piezoelectric element 1132, and a piezoelectric element 1133 arranged along a first direction D1. The piezoelectric element 1131 may be arranged at position P1 in the piezoelectric layer 113. The piezoelectric element 1132 may be arranged at position P2 in the piezoelectric layer 113. The piezoelectric element 1133 may be arranged at position P3 in the piezoelectric layer 113. Position P1, position P2, and position P3 are different from each other. In this embodiment, position P2 may be between position P1 and position P3. The piezoelectric element 1132 may be located between the piezoelectric element 1131 and the piezoelectric element 1133. In this embodiment, the ultrasonic detection device 10 is shown as including three piezoelectric elements, but the present invention is not limited thereto; the ultrasonic detection device may include more or fewer piezoelectric elements. In one embodiment, gaps (filled with glue or maintaining air gaps) may be provided between the plurality of piezoelectric layers 113 arranged along the third direction D3. In one embodiment, the piezoelectric element 1131 may be adjacent to the piezoelectric element 1132, and the piezoelectric element 1132 may be adjacent to the piezoelectric element 1131 and the piezoelectric element 1133. In one embodiment, the piezoelectric elements 1131, 1132, and 1133 may not include gaps filled with glue or air gaps between each other.

The piezoelectric element 1131, the piezoelectric element 1132, and the piezoelectric element 1133 may have different thicknesses in the second direction D2. The thickness may represent the distance between the upper surface (e.g., the surface facing the back layer 104) and the lower surface (e.g., the surface facing the matching element 102) of the piezoelectric element in the second direction D2. For example, as shown in FIG. 1B , the piezoelectric element 1131 has a thickness H1 in the second direction D2, the piezoelectric element 1132 has a thickness H2 in the second direction D2, and the piezoelectric element 1133 has a thickness H3 in the second direction D2. The thickness H1 of the piezoelectric element 1131, the thickness H2 of the piezoelectric element 1132, and the thickness H3 of the piezoelectric element 1133 may be different from each other. In this embodiment, the thickness H2 of the piezoelectric element 1132 is greater than the thickness H1 of the piezoelectric element 1131 and the thickness H3 of the piezoelectric element 1133. The thickness H1 of the piezoelectric element 1131 may be greater than the thickness H3 of the piezoelectric element 1133, but the present invention is not limited to this. The thicknesses of the piezoelectric elements 1131, 1132, and 1133 may vary in steps or gradients.

Piezoelectric devices may include piezoelectric materials, such as one or more of lead-zirconate-titanate (PZT), PZT ceramics, single-crystalline lead magnesium niobate-lead titanate (PMN-PT), polyvinylidene fluoride (PVDF), poly(vinylidenefluoride-co-trifluoroethylene) (PVDF-TrFE), and other PVDF copolymers. Piezoelectric devices can generate voltage (piezoelectric effect) or deformation (inverse piezoelectric effect) by applying an external force (pressure). Additionally, the piezoelectric element may also include a micromachined ultrasonic transducer (MUT). Piezoelectric element 1131, piezoelectric element 1132, and piezoelectric element 1133 can utilize the vibration of thin plates of varying thickness, length, or width, different driving voltage signals, or other methods as described in the present invention to cause piezoelectric element 1131, piezoelectric element 1132, and piezoelectric element 1133 to output different signal waveforms.

The controller 105 is directly or indirectly electrically connected to the plurality of piezoelectric layers 113 and can be used to drive one or more piezoelectric elements to output ultrasonic signals. The controller 105 applies voltage to the piezoelectric elements, causing them to vibrate at a high frequency to output ultrasonic signals to the target object. The piezoelectric elements can also receive ultrasonic signals reflected and/or scattered from the target object to produce an ultrasonic image of the target. Controller 105 can be used to perform at least one of the following actions (a) through (c): (a) driving piezoelectric element 1131 so that piezoelectric element 1131 outputs an ultrasonic signal having a signal waveform; (b) driving piezoelectric element 1132 so that piezoelectric element 1132 outputs an ultrasonic signal having a signal waveform; (c) driving piezoelectric element 1133 so that piezoelectric element 1133 outputs an ultrasonic signal having a signal waveform. Controller 105 can be used to perform one or more of actions (a) through (c), that is, to drive one or more of piezoelectric element 1131, piezoelectric element 1132, and piezoelectric element 1133. In one embodiment, the controller 105 can drive multiple piezoelectric elements simultaneously or with time intervals. Because the thickness H1 of the piezoelectric element 1131, the thickness H2 of the piezoelectric element 1132, and the thickness H3 of the piezoelectric element 1133 are different, the ultrasonic signal waveforms output by the piezoelectric element 1131, the ultrasonic signal waveforms output by the piezoelectric element 1132, and the ultrasonic signal waveforms output by the piezoelectric element 1133 are different. The different ultrasonic signal waveforms can be caused by different frequencies, different periods, different waveform sizes, or different waveform compositions. In other words, the piezoelectric layer 113 of the present invention can output multiple ultrasonic signals with different waveforms along the short-axis direction, and these multiple ultrasonic signals with different waveforms originate from different locations within the piezoelectric layer 113, thereby achieving a short-axis spatial encoding effect. In one embodiment, as shown in FIG1C , the ultrasonic signal output by piezoelectric element 1131 may have a waveform 181, the ultrasonic signal output by piezoelectric element 1132 may have a waveform 182, and the ultrasonic signal output by piezoelectric element 1133 may have a waveform 183.

Please refer to Figures 2A and 2B. Figure 2A is a schematic cross-sectional view of an ultrasonic detection device 20 according to another embodiment of the present invention, taken along the third direction D3. Figure 2B is a schematic cross-sectional view of the ultrasonic detection device 20 of Figure 2A, taken along the first direction D1. The differences between the ultrasonic detection device 20 of Figures 2A-2B and the ultrasonic detection device 10 of Figures 1A-1B are described below. The ultrasonic detection device 20 further includes a reflective layer 206 disposed on the backing layer 204. The backing layer 204 may be positioned between the reflective layer 206 and the piezoelectric structure 203 in the second direction D2. The piezoelectric structure 203 may include a plurality of piezoelectric layers 213 arranged along the third direction D3. As shown in FIG. 2B , each piezoelectric layer 213 may extend along a first direction D1. The piezoelectric layer 213 may include a plurality of piezoelectric elements, such as at least two piezoelectric elements, arranged along the first direction D1 and at different positions in the first direction D1. For example, the piezoelectric layer 213 may include a piezoelectric element 2131, a piezoelectric element 2132, and a piezoelectric element 2133 arranged along the first direction D1. The piezoelectric element 2131 may be arranged at position P1 in the piezoelectric layer 213. The piezoelectric element 2132 may be arranged at position P2 in the piezoelectric layer 213. The piezoelectric element 2133 may be arranged at position P3 in the piezoelectric layer 213. Position P1, position P2, and position P3 are different from each other. Position P2 may be between positions P1 and P3. Piezoelectric element 2132 may be located between piezoelectric element 2131 and piezoelectric element 2133. In one embodiment, piezoelectric element 2131 may be adjacent to piezoelectric element 2132, and piezoelectric element 2132 may be adjacent to piezoelectric element 2131 and piezoelectric element 2133. In one embodiment, no gaps filled with adhesive or air may exist between piezoelectric element 2131, piezoelectric element 2132, and piezoelectric element 2133. The piezoelectric element 2131, piezoelectric element 2132, and piezoelectric element 2133 of the piezoelectric layer 213 may have the same thickness in the second direction D2.

The back layer 204 may have varying thicknesses. The portion of the back layer 204 corresponding to position P1 has a thickness H4 in the second direction D2. The portion of the back layer 204 corresponding to position P2 has a thickness H5 in the second direction D2. The portion of the back layer 204 corresponding to position P3 has a thickness H6 in the second direction D2. Thicknesses H4, H5, and H6 may differ from each other. The thickness of the back layer 204 may vary in a stepwise or gradient manner. The reflective layer 206 and the back layer 204 are made of different materials. The reflective layer 206 has a first acoustic reflection coefficient, and the back layer 204 has a second acoustic reflection coefficient. The first acoustic reflection coefficient of the reflective layer 206 may be greater than the second acoustic reflection coefficient of the back layer 204. The reflective layer 206 and the backing layer 204 are made of different materials, creating an interface S between the reflective layer 206 and the backing layer 204. There is a first distance between the piezoelectric element 2131 and the interface S (which may be approximately equal to thickness H4), a second distance between the piezoelectric element 2132 and the interface S (which may be approximately equal to thickness H5), and a third distance between the piezoelectric element 2133 and the interface S (which may be approximately equal to thickness H6). The first, second, and third distances may be different.

The controller 105 can be used to perform at least one of the following actions (a) to (c): (a) driving the piezoelectric element 2131 so that the piezoelectric element 2131 outputs an ultrasonic signal having a signal waveform; (b) driving the piezoelectric element 2132 so that the piezoelectric element 2132 outputs an ultrasonic signal having a signal waveform; (c) driving the piezoelectric element 2133 so that the piezoelectric element 2133 outputs an ultrasonic signal having a signal waveform. In this embodiment, controller 105 drives piezoelectric element 2131 to emit a front ultrasonic signal toward the target object (e.g., in the negative second direction D2, or toward matching elements 101 and 102). It also emits a rear ultrasonic signal toward reflective layer 206 and back layer 204 (or in the positive second direction D2). The rear ultrasonic signal is reflected and/or refracted at interface S, redirected toward the target object. The redirected rear ultrasonic signal interferes with the front ultrasonic signal to form an ultrasonic signal having a signal waveform. The ultrasonic signals output by piezoelectric element 2132 and piezoelectric element 2133 are generated in a manner similar to that of the ultrasonic signal generated by piezoelectric element 2131. In one embodiment, interference between the redirected rear ultrasonic signal and the front ultrasonic signal occurs before the front ultrasonic signal reaches the target object. Because the first distance between the piezoelectric element 2131 and the interface S, the second distance between the piezoelectric element 2132 and the interface S, and the third distance between the piezoelectric element 2133 and the interface S are different, the ultrasonic signal waveforms output by the piezoelectric element 2131, the ultrasonic signal waveforms output by the piezoelectric element 2132, and the ultrasonic signal waveforms output by the piezoelectric element 2133 are different. In other words, the piezoelectric layer 213 of the present invention can output multiple ultrasonic signals with different signal waveforms along the short-axis direction, and the multiple ultrasonic signals with different signal waveforms come from different positions of the piezoelectric layer 213, thereby achieving the effect of short-axis spatial encoding.

The controller 105 can be used to perform one or more of actions (a) to (c), namely, driving one or more of the piezoelectric element 2131, the piezoelectric element 2132, and the piezoelectric element 2133. In one embodiment, the controller 105 can drive multiple piezoelectric elements simultaneously or with time intervals. In one embodiment, as shown in FIG. 2C , the ultrasonic signal output by the piezoelectric element 2131 can have a waveform of signal 281, the ultrasonic signal output by the piezoelectric element 2132 can have a waveform of signal 282, and the ultrasonic signal output by the piezoelectric element 2133 can have a waveform of signal 283.

Please refer to Figures 3A and 3B. Figure 3A is a schematic cross-sectional view of an ultrasonic detection device 30 according to another embodiment of the present invention, taken along a third direction D3. Figure 3B is a schematic cross-sectional view of the ultrasonic detection device 30 of Figure 3A taken along a first direction D1. The differences between the ultrasonic detection device 30 of Figures 3A-3B and the ultrasonic detection device 10 of Figures 1A-1B are described below.

The piezoelectric structure 303 may include a plurality of piezoelectric layers 313 arranged along a third direction D3. Each piezoelectric layer 313 may extend along a first direction D1. The piezoelectric layer 313 may include a plurality of piezoelectric elements, such as at least two piezoelectric elements, arranged along the first direction D1 and at different positions in the first direction D1. For example, as shown in FIG. 3B , the piezoelectric layer 313 may include a piezoelectric element 3131, a piezoelectric element 3132, and a piezoelectric element 3133 arranged along the first direction D1. The piezoelectric element 3131 may be arranged at position P1 in the piezoelectric layer 313. The piezoelectric element 3132 may be arranged at position P2 in the piezoelectric layer 313. The piezoelectric element 3133 may be disposed at position P3 in the piezoelectric layer 313. Positions P1, P2, and P3 are different from each other. Position P2 may be between position P1 and position P3. The piezoelectric element 3132 may be located between the piezoelectric element 3131 and the piezoelectric element 3133. The piezoelectric element 3131, the piezoelectric element 3132, and the piezoelectric element 3133 of the piezoelectric layer 313 may have the same thickness in the second direction D2.

The multiple piezoelectric elements of the piezoelectric layer 313 may or may not include trenches. The trench combination includes one or more trenches extending along the second direction D2. For example, as shown in Figure 3B , piezoelectric element 3131 includes trench combination T1 extending along the second direction D2, piezoelectric element 3133 includes trench combination T3 extending along the second direction D2, and piezoelectric element 3132 may not include trenches. In one embodiment, gaps (filled with glue or maintaining air gaps) may be provided between the multiple piezoelectric layers 313 arranged along the third direction D3.

The trench assembly T1 of the piezoelectric element 3131 may include one or more trenches T11-T17 extending downward from the upper surface of the piezoelectric element 3131 along the second direction D2. The trenches T11-T17 may be spaced apart from one another along the first direction D1. In this embodiment, the trenches T11-T17 may be spaced apart from one another and arranged sequentially along the positive first direction D1. The trenches T11-T17 may have a depth in the second direction D2. The depths of the trenches T11-T17 may be the same or different, or the depths of some of the trenches T11-T17 may be the same (and the depths of other trenches may be the same or different). For example, as shown in FIG3B , the depths of trenches T12, T13, T14, and T15 in trench assembly T1 are the same, the depths of trenches T11 and T16 are the same, the depths of trenches T12, T13, T14, and T15 are different from the depths of trenches T11 and T16, and the depth of trench T17 is different from the depths of trenches T11-T16. The depth of trench T11 may be greater than the depth of trench T12. The depths of trenches T11-T17 may be greater than zero and less than or equal to the thickness of the piezoelectric element 3131 in the second direction D2. In one embodiment, when the trench depth is greater than zero and less than the thickness of the piezoelectric element 3131 in the second direction D2, the piezoelectric element 3131 is not completely severed, and the piezoelectric elements on both sides of the trench can share electrodes or wiring. In one embodiment, when the trench depth is equal to the thickness of the piezoelectric element 3131 in the second direction D2, additional electrodes or wiring can be placed on both sides of the trench to ensure electrical connection. In one embodiment, trenches T11-T17 can be filled with glue or maintain air gaps.

Adjacent trenches T11-T17 may have a spacing in the first direction D1. The spacings may be the same (i.e., trenches T11-T17 are equally spaced) or different, or some of the spacings may be the same (and others may be the same or different). For example, as shown in FIG3B , the spacing between trenches T13 and T14 may be greater than the spacing between trenches T11 and T12, and the spacing between trenches T11 and T12 may be greater than the spacing between trenches T15 and T16.

The trench assembly T3 of the piezoelectric element 3133 may include one or more trenches T31-T37 extending downward from the upper surface of the piezoelectric element 3133 along the second direction D2, spaced apart from each other. The trenches T31-T37 may be spaced apart from each other along the first direction D1. In this embodiment, trenches T37 and T31-T36 may be spaced apart from each other in sequence along the positive first direction D1. The trenches T31-T37 may have a depth in the second direction D2. The depths of the trenches T31-T37 may be the same or different, or the depths of some of the trenches T31-T37 may be the same (while the depths of other trenches may be the same or different). For example, as shown in FIG3B , the depths of trenches T31, T32, T34, and T35 in trench assembly T3 are the same, while the depths of trenches T33 and T36 are the same. The depths of trenches T31, T32, T34, and T35 are different from the depths of trenches T33 and T36. The depth of trench T37 is different from the depths of trenches T31-T36. The depth of trench T32 may be less than the depth of trench T33. The depths of trenches T31, T32, T34, and T35 may be less than the depths of trenches T11-T17 in trench assembly T1. The depths of trenches T31-T37 may be greater than zero and less than or equal to the thickness of the piezoelectric element 3133 in the second direction D2. In one embodiment, when the trench depth is greater than zero and less than the thickness of the piezoelectric element 3133 in the second direction D2, the piezoelectric element 3133 is not completely severed, and the piezoelectric elements on both sides of the trench can share electrodes or wiring. In one embodiment, when the trench depth is equal to the thickness of the piezoelectric element 3133 in the second direction D2, additional electrodes or wiring can be placed on both sides of the trench to ensure electrical connection. In one embodiment, the trenches T31-T37 can be filled with glue or maintain air gaps.

Adjacent trenches T31-T37 may be spaced apart in the first direction D1. The spacings may be the same (i.e., trenches T31-T37 are equally spaced) or different, or some of the spacings may be the same (and others may be the same or different). For example, as shown in FIG3B , trenches T31-T37 may be spaced approximately the same. The spacing between trenches T13 and T14 in trench combination T1 may be greater than the spacing between trenches T32 and T33 in trench combination T3.

In this embodiment, the piezoelectric element 3131, the piezoelectric element 3132, and the piezoelectric element 3133 have different groove combinations, so that the ultrasonic signals output by the piezoelectric element 3131, the piezoelectric element 3132, and the piezoelectric element 3133 when driven by the controller 105 have different waveforms. The different groove combinations may mean that the grooves included in the groove combinations are different in form and/or distribution. For example, different trench combinations may mean that the number of trenches included in each of the plurality of trench combinations is different (for example, the number of trenches included in the piezoelectric element 3131 and the number of trenches included in the piezoelectric element 3132 in FIG. 3B is different); or different trench combinations may mean that the depth of the trenches included in each of the plurality of trench combinations is different (for example, the depth of the trench T12 in the piezoelectric element 3131 in FIG. 3B in the second direction D2 is different from that of the piezoelectric element 3132 in FIG. 3B). The depth of the trench T31 in the piezoelectric element 3133 in the second direction D2, while the piezoelectric element 3132 does not include a trench); or the different trench combinations may mean that the trench depths in the multiple trench combinations are arranged in a different order. For example, one trench combination may include trenches arranged in descending order of depth along the positive first direction D1, while another trench combination may include trenches arranged in descending order of depth along the positive first direction D1. The piezoelectric element 3131 in FIG. 3B includes a trench T11 and a trench T12 arranged along the positive first direction D1, wherein the depth of the trench T11 in the second direction D2 is greater than the depth of the trench T12 in the second direction D2, and the piezoelectric element 3133 includes a trench T32 and a trench T33 arranged along the positive first direction D1, wherein the depth of the trench T32 in the second direction D2 is less than The depth of trench T33 in the second direction D2); or different trench combinations can mean that the trench spacings within each of the multiple trench combinations are different (for example, the spacing between trenches T13 and T14 in piezoelectric element 3131 in FIG. 3B is different from the spacing between trenches T31 and T32 in piezoelectric element 3133). All of these can change the waveform of the ultrasonic signal output by the piezoelectric element. FIG. 3B illustrates one example of different trench combinations, but the present invention is not limited thereto. The form and/or distribution of the trenches in a trench combination can vary greatly. In other words, the piezoelectric layer 313 of the present invention can output multiple ultrasonic signals with different signal waveforms along the short-axis direction, and the multiple ultrasonic signals with different signal waveforms come from different positions of the piezoelectric layer 313, thereby achieving the effect of short-axis spatial encoding.

The controller 105 can be used to drive one or more of the piezoelectric element 3131, the piezoelectric element 3132, and the piezoelectric element 3133. In one embodiment, the controller 105 can drive multiple piezoelectric elements simultaneously or at intervals. In one embodiment, as shown in FIG3C , the ultrasonic signal output by the piezoelectric element 3131 can have a waveform 381, the ultrasonic signal output by the piezoelectric element 3132 can have a waveform 382, and the ultrasonic signal output by the piezoelectric element 3133 can have a waveform 383.

In one embodiment, the ultrasonic detection devices 10, 20, and 30 can also be implemented as curved ultrasonic detection devices, which can have a larger viewing angle than flat ultrasonic detection devices. For example, FIG4 shows an ultrasonic detection device 40. The ultrasonic detection device 40 includes a lens 401, a matching element 402, a piezoelectric structure 403, a backing layer 404, and a controller (not shown) arranged along the second direction D2. The piezoelectric structure 403 can have a curved surface. The curved surface can include a spherical surface, an aspherical surface, a hemispherical surface, a curved surface with different curvatures of the major and minor axes, and the like. The configuration of the piezoelectric layer and the piezoelectric element in the piezoelectric structure 403 can apply the configuration of the piezoelectric structures 103, 203, and 303 in the ultrasonic detection devices 10, 20, and 30. The backing layer 404 can employ the configuration of the backing layers 104 and 204 in the ultrasonic detection devices 10, 20, and 30. In one embodiment, the ultrasonic detection device 40 may also include a reflective layer (not shown), as shown in FIG. 2B .

The ultrasonic detection device provided by the present invention comprises multiple piezoelectric layers arranged in one dimension (e.g., the long axis). A single piezoelectric layer can output multiple ultrasonic signals with different waveforms along another dimension (e.g., the short axis) to achieve short-axis spatial encoding, thereby obtaining two-dimensional spatial information. Compared to traditional single-array and two-dimensional array ultrasonic detection devices, the present invention ensures two-dimensional spatial information while reducing the number of short-axis wiring and eliminating the need for a motor. It offers the advantages of simple assembly, compact size, light weight, high compatibility, fast scanning speed, and easy maintenance.

In summary, although the present invention has been disclosed above through the use of embodiments, these are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application.

10: Ultrasonic detection device 101, 102: Matching element 104: Back layer 113: Piezoelectric layer 1131, 1132, 1133: Piezoelectric elements D1, D2, D3: Directions H1, H2, H3: Thickness P1, P2, P3: Position

Claims (9)

An ultrasonic detection device includes: a matching element; a backing layer; a plurality of piezoelectric layers disposed between the matching element and the backing layer, the piezoelectric layers including a first piezoelectric element disposed at a first position along a first direction and a second piezoelectric element disposed at a second position, the matching element, the piezoelectric layers and the backing layer being disposed along a second direction, the piezoelectric layers being arranged along a third direction, the first direction, the second direction and the third direction being perpendicular to each other; a controller directly or indirectly electrically connected to the piezoelectric layers, the controller being configured to at least drive the first piezoelectric element so that the first piezoelectric element outputs a second signal waveform having a first signal waveform. an ultrasonic signal and driving the second piezoelectric element so that the second piezoelectric element outputs one of a second ultrasonic signal having a second signal waveform, the first signal waveform being different from the second signal waveform; and a reflective layer, the backing layer being disposed between the reflective layer and the piezoelectric layers, the reflective layer having a first acoustic reflection coefficient, the backing layer having a second acoustic reflection coefficient, the first acoustic reflection coefficient being greater than the second acoustic reflection coefficient, wherein the backing layer has a first thickness in the second direction at a portion corresponding to the first position, and has a second thickness in the second direction at a portion corresponding to the second position, the first thickness being different from the second thickness. The ultrasonic detection device as described in claim 1, wherein the ultrasonic detection device includes a long axis direction and a short axis direction, and the first direction is the same as the short axis direction. The ultrasonic detection device as described in claim 1, wherein the piezoelectric layers further include a third piezoelectric element disposed at a third position, the controller drives the third piezoelectric element so that the third piezoelectric element outputs a third ultrasonic signal having a third signal waveform, and the first signal waveform, the second signal waveform and the third signal waveform are different from each other. The ultrasonic detection device as described in claim 3, wherein the back layer has a third thickness in the second direction at a portion corresponding to the third position, and the third thickness is different from the first thickness. The ultrasonic detection device as described in claim 1, wherein there is an interface between the reflective layer and the back layer, there is a first distance between the first piezoelectric element and the interface, there is a second distance between the second piezoelectric element and the interface, and the first distance is different from the second distance. An ultrasonic detection device as described in claim 5, wherein the piezoelectric layers further include a third piezoelectric element, which is arranged at a third position, and the controller drives the third piezoelectric element so that the third piezoelectric element outputs a third ultrasonic signal having a third signal waveform, the first signal waveform, the second signal waveform and the third signal waveform are different from each other, and there is a third distance between the third piezoelectric element and the interface, and the first distance, the second distance and the third distance are different from each other. The ultrasonic detection device as described in claim 6, wherein the second piezoelectric element is adjacent to the first piezoelectric element and the third piezoelectric element. The ultrasonic detection device as described in claim 1, wherein the first piezoelectric element is adjacent to the second piezoelectric element. The ultrasonic detection device as described in claim 1, wherein the back layer has a thickness that changes in a stepwise manner or a gradually changing manner in the second direction.