KR102376692B1 - Piezoelectric ultrasonic transducer, biometric apparatus including the same, and display apparatus including the apparatus - Google Patents

Abstract

The piezoelectric ultrasonic transducer of the embodiment has a planar shape disposed around the receiving unit spaced apart from the receiving unit and the receiving unit for receiving the ultrasound, and includes a plurality of transmitting units for transmitting the ultrasound, and the receiving unit has a configuration or material having a higher ultrasonic receiving power than the transmitting unit Including at least one of, the transmitter includes at least one of a configuration or material having a higher ultrasonic transmission power than the receiver, and the receiver includes: a first piezoelectric member; and a plurality of first electrodes disposed in a matrix on at least one of an upper portion or a lower portion of the first piezoelectric member, wherein the transmitter includes: a second piezoelectric member; and a second electrode disposed on at least one of an upper portion, a lower portion, or an intermediate portion of the second piezoelectric member.

Description

Piezoelectric ultrasonic transducer, biometric apparatus including the same, and display apparatus including the apparatus

The embodiment relates to a piezoelectric ultrasonic transducer, an apparatus for measuring biometric information including the apparatus, and a display apparatus including the apparatus.

A fingerprint sensor is a sensor that detects a person's fingerprint, and is widely used not only for devices such as door locks that have been widely applied in the past, but also for determining whether to turn on/off the power of electronic devices or release the sleep mode. is becoming

The fingerprint recognition sensor may be classified into an ultrasonic type, an infrared type, and a capacitive type according to an operation principle thereof. For example, in the ultrasonic method, when ultrasonic waves (signals) of a certain frequency emitted from a plurality of piezoelectric sensors are reflected from valleys and ridges of the fingerprint, acoustic impedance at each valley and ridge A fingerprint is detected by measuring the difference in the reflected ultrasonic waves due to the difference using the plurality of piezoelectric sensors that are the ultrasonic sources. In particular, the advantage of the ultrasonic method is that it has a function of detecting the blood flow inside the finger by detecting the Doppler effect by generating the ultrasonic pulse in the form of a pulse beyond the simple fingerprint recognition function. Thus, it can have the advantage of determining whether or not a forged fingerprint is present.

Such a fingerprint sensor may recognize a fingerprint using ultrasonic waves reflected from the fingerprint after generating ultrasonic waves by arranging electrodes on both sides of a piezoelectric material. However, conventional fingerprint sensors transmit and receive ultrasonic waves by the same piezoelectric member. In general, the piezoelectric member has only excellent ultrasonic reception performance or only excellent ultrasonic ultrasonic transmission performance. Therefore, the existing fingerprint sensor has excellent performance of only one of transmission and reception and deteriorated performance of the other.

In addition, the existing fingerprint sensor has a complicated circuit structure because it requires a switch structure for controlling whether to transmit ultrasonic waves or not.

Korean Patent Laid-Open Publication No. 10-2013-0060874 (Publication Date: 2013.06.10, Title of Invention: Fingerprint recognition sensor and manufacturing method thereof.)

The embodiment provides a piezoelectric ultrasonic transducer having both excellent ultrasonic reception and transmission power, a biometric information measuring apparatus including the apparatus, and a display apparatus including the apparatus.

A piezoelectric ultrasonic transducer according to an embodiment includes a receiver configured to receive an ultrasonic wave; and a plurality of transmitters that are spaced apart from the receiver and have a planar shape disposed around the receiver and transmit ultrasonic waves, wherein the receiver includes at least one of a configuration or material having higher ultrasonic reception power than the transmitter, the The transmitter includes at least one of a configuration or material having a higher ultrasonic transmission power than the receiver, and the receiver includes: a first piezoelectric member; and a plurality of first electrodes arranged in a matrix form on at least one of an upper portion or a lower portion of the first piezoelectric member, wherein the transmitter includes: a second piezoelectric member; and a second electrode disposed on at least one of an upper portion, a lower portion, and a middle portion of the second piezoelectric member.

For example, the first piezoelectric member includes a first piezoelectric material, the second piezoelectric member includes a second piezoelectric material, and a voltage output constant of the first piezoelectric material is a voltage output of the second piezoelectric material greater than a constant, and a piezoelectric constant of the second piezoelectric material may be greater than a piezoelectric constant of the first piezoelectric material.

For example, the plurality of first electrodes of the receiver may include a plurality of first lower electrodes spaced apart from each other in a first horizontal direction; and a plurality of first upper electrodes spaced apart from each other in a second horizontal direction intersecting the first horizontal direction, wherein the first piezoelectric member of the receiver is spaced apart from each other to form a matrix with the first lower electrode and the It may include a plurality of piezoelectric pillars disposed between the first upper electrode.

For example, the receiving unit may include a filling member disposed between the piezoelectric pillars; an upper electrode protecting unit disposed to surround the plurality of first upper electrodes; and a lower electrode protecting unit disposed to surround the plurality of first lower electrodes.

For example, the receiver may further include a substrate disposed under the first piezoelectric member, and the plurality of first electrodes of the receiver may be spaced apart in a first horizontal direction between a lower portion of the first piezoelectric member and the substrate. a plurality of first lower electrodes disposed to be; and a plurality of first upper electrodes spaced apart from each other in a second horizontal direction intersecting the first horizontal direction on the first piezoelectric member.

For example, the second electrode of each of the plurality of transmitters may include a second upper electrode disposed on the second piezoelectric member; and a second lower electrode disposed under the second piezoelectric member.

For example, the second piezoelectric member of each of the plurality of transmitters includes a plurality of 2-1 piezoelectric segments arranged to be spaced apart from each other in a horizontal direction, and the second electrode of each of the plurality of transmitters includes the plurality of piezoelectric segments. a second upper electrode segment disposed on each of the 2-1 piezoelectric segments; and a second lower electrode segment disposed under each of the plurality of 2-1 piezoelectric segments.

For example, the plurality of 2-1 piezoelectric segments may be disposed to be spaced apart from each other with air or polymer interposed therebetween.

For example, the piezoelectric ultrasonic transducer is drawn from the plurality of first electrodes and receives an electrical signal corresponding to the received ultrasonic wave, and applies a pulse signal necessary for the second piezoelectric member to generate ultrasonic waves to the second electrode It may further include a driving control unit to

For example, the driving controller may control the transmitter and the receiver to transmit and receive the ultrasonic waves with a time difference.

For example, the first piezoelectric member may include a ceramic-based material, and the second piezoelectric member may include a polymer-based material.

For example, the piezoelectric ultrasonic transducer may be disposed at a position corresponding to the screen area at the lower end of the display panel.

According to another exemplary embodiment, an apparatus for measuring biometric information includes a piezoelectric ultrasonic transducer; and a biometric information analyzer configured to receive an electrical signal corresponding to the ultrasonic wave reflected from the living object from the piezoelectric ultrasonic converter and analyze biometric information of the living object, wherein the piezoelectric ultrasonic converter receives the ultrasonic wave reflected from the biometric object a receiving unit for receiving; a plurality of transmitters spaced apart from the receiver and having a planar shape disposed around the receiver and transmitting ultrasound to the living body object; and a driving control unit that controls the plurality of transmitters to generate and transmit the ultrasonic waves, and receives an electrical signal corresponding to the ultrasonic waves received from the receiver and outputs them to the biometric information analyzer, wherein the receiver has an ultrasonic reception power higher than that of the transmitter. At least one of a higher configuration or material, wherein the transmitter includes at least one of a configuration or material having a higher ultrasonic transmission power than the receiver, wherein the receiver includes: a first piezoelectric member; and a plurality of first electrodes disposed in a matrix form on at least one of an upper portion or a lower portion of the first piezoelectric member and transmitting the electrical signal corresponding to the received ultrasonic wave to the driving controller, wherein the transmitter includes a second piezoelectric member; and a second electrode disposed on at least one of an upper portion, a lower portion, and a middle portion of the second piezoelectric member.

A display apparatus according to another embodiment includes: a display panel including an active area; and a piezoelectric ultrasonic transducer disposed at a lower portion of the display panel in an area corresponding to the active area, wherein the piezoelectric ultrasonic transducer comprises: a receiver configured to receive an ultrasonic wave; and a plurality of transmitters that are spaced apart from the receiver and have a planar shape disposed around the receiver and transmit ultrasonic waves, wherein the receiver includes at least one of a configuration or material having higher ultrasonic reception power than the transmitter, the The transmitter includes at least one of a configuration or material having a higher ultrasonic transmission power than the receiver, and the receiver includes: a first piezoelectric member; and a plurality of first electrodes disposed in a matrix form on at least one of an upper portion or a lower portion of the first piezoelectric member, wherein the transmitter includes: a second piezoelectric member; and a second electrode disposed on at least one of an upper portion, a lower portion, and a middle portion of the second piezoelectric member.

The piezoelectric ultrasonic transducer according to the embodiment, the biometric information measuring device including the device, and the display device including the device have both excellent transmission power and excellent reception power, and relatively use at least one of the transmitter and the receiver without location restrictions. It can be freely arranged, and information about an object can be precisely acquired because of its excellent circuit structure, and the convenience of use can be improved by arranging the fingerprint sensor in the display screen area of the display device.

1A to 1C are plan views illustrating a piezoelectric ultrasonic transducer according to an embodiment.
2 (a) and (b) exemplarily show a plan view of ultrasonic waves transmitted from a plurality of transmitters shown in FIGS. 1B and 1C .
3A to 3D are sectional views, a top view, a bottom view, and transmittance, respectively, according to an embodiment of the receiver shown in FIGS. 1A to 1C , respectively.
4A and 4B are external perspective views of the first piezoelectric member and the filling member.
5A to 5C are cross-sectional views, top views, and bottom views, respectively, of the receiver shown in FIGS. 1A to 1C according to another embodiment.
6 is a view showing an example of a TFT structure.
7A to 7D are a cross-sectional view, a top view, a bottom view, and transmittance, respectively, according to another embodiment of the receiver shown in FIGS. 1A to 1C , respectively.
8A and 8B are a cross-sectional view and a top view, respectively, according to another embodiment of the receiving unit shown in FIGS. 1A to 1C , respectively.
9A and 9B are a cross-sectional view and a top view, respectively, according to another embodiment of the receiver shown in FIGS. 1A to 1C , respectively.
10 is a cross-sectional view of each of the transmitters shown in FIGS. 1A to 1C according to an embodiment.
11 is a cross-sectional view of each of the transmitters shown in FIGS. 1A to 1C according to another embodiment.
12 is a cross-sectional view of each of the transmitters shown in FIGS. 1A to 1C according to another embodiment.
13A to 13E are cross-sectional views illustrating a method of manufacturing the receiver illustrated in FIG. 3A .
14A to 14E are process plan views illustrating a method of manufacturing the receiver illustrated in FIG. 3A .
15 is a diagram illustrating an external appearance of an apparatus for measuring biometric information according to an embodiment;
16 is a cross-sectional view of a display device according to an exemplary embodiment.
17 is a cross-sectional view of a display device according to another exemplary embodiment.
18 is a cross-sectional view of a display device according to another exemplary embodiment.
19 is a cross-sectional view of a display device according to another embodiment.
20 is a cross-sectional view of a display device according to another exemplary embodiment.
21 is a cross-sectional view of a display device according to another exemplary embodiment.
22 is a flowchart for explaining a method of driving a display device.
23 (a) to (c) are diagrams to help the description of FIG. 22 .

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings to help the understanding of the present invention by giving examples and to explain the present invention in detail. However, embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided in order to more completely explain the present invention to those of ordinary skill in the art.

In the description of this embodiment, in the case of being described as being formed on "on or under" of each element, above (above) or below (below) ( on or under includes both elements in which two elements are in direct contact with each other or in which one or more other elements are disposed between the two elements indirectly.

In addition, when expressed as "up (up)" or "down (on or under)", the meaning of not only an upward direction but also a downward direction may be included based on one element.

Also, as used hereinafter, relational terms such as “first” and “second,” “top/top/top” and “bottom/bottom/bottom” refer to any physical or logical relationship between such entities or elements or It may be used to distinguish one entity or element from another without requiring or implying an order.

Hereinafter, a piezoelectric ultrasonic transducer 100A to 100C according to an embodiment, a biometric information measuring device 200 including the device, and a display device 300A to 300F including the device 100A to 100C or 200 are attached. It will be described as follows with reference to the drawings. For convenience, using a Cartesian coordinate system (x-axis, y-axis, z-axis), the piezoelectric ultrasonic transducer 100A to 100C, the biometric information measuring device 200 including the device, and the device 100A to 100C or 200) Although the display apparatuses 300A to 300F including the description are described, it goes without saying that this can also be described using other coordinate systems. According to the Cartesian coordinate system, the x-axis, the y-axis, and the z-axis are orthogonal to each other, but the embodiment is not limited thereto. According to another embodiment, the x-axis, y-axis, and z-axis may intersect each other.

1A to 1C are plan views of piezoelectric ultrasonic transducers 100A, 100B, and 100C according to an embodiment.

The piezoelectric ultrasonic transducer 100A, 100B, and 100C according to the embodiment includes a receiver 110 and a plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)].

The receiver 110 serves to receive an ultrasonic wave reflected from an object (not shown). To this end, the receiver 110 may include a first piezoelectric member and a plurality of first electrodes. The plurality of first electrodes may be disposed in an n x n matrix (or mesh shape) on at least one of an upper portion or a lower portion of the first piezoelectric member. Here, n may be a positive integer of 1 or more. For example, a matrix may have one or more rows and multiple columns, may have one or more columns and multiple rows, or may have multiple rows and multiple columns.

As will be described later, an image of an object reflecting the ultrasound may be generated by using an electrical signal corresponding to the ultrasound received by the receiver 110 . In this case, the value of n may vary according to the resolution of the generated image. For example, the resolution may be 350 dpi (dot per inch) to 1500 dpi. If the resolution is 500 dpi, n may be 160, but the embodiment is not limited to a specific value of n.

The plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] serve to transmit ultrasonic waves. To this end, each of the plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] may include a second piezoelectric member and a second electrode. can The second electrode may be disposed on at least one of an upper portion, a lower portion, or an intermediate portion of the second piezoelectric member.

The plurality of transmitters [(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] are disposed around the receiver 110 while being spaced apart from the receiver 110 . It may have a planar shape. For example, the plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] and the receiver 110 may be disposed on the same plane. can

As illustrated in FIG. 1A , the first and second transmitters 120-11 and 120-12 may be disposed on the left and right sides of the receiver 110 while being spaced apart from the receiver 110, respectively.

Alternatively, as illustrated in FIG. 1B , the first to fourth transmitters 120-21 to 120-24 may be disposed on the left, right, lower and upper sides of the receiver 110 while being spaced apart from the receiver 110, respectively. there is.

Alternatively, as illustrated in FIG. 1C , the first to sixth transmitters 120-31 to 120-36 may be radially disposed with respect to the receiver 110 while being spaced apart from the receiver 110 .

The embodiments shown in FIGS. 1A to 1C are provided to aid understanding, and the present invention is not limited thereto, and a plurality of transmitters may be disposed around the receiver 110 in various shapes. That is, if the plurality of transmitters can be disposed around the receiver 110 while being spaced apart from the receiver 110 , the plurality of transmitters is not limited to the planar arrangement illustrated in FIGS. 1A to 1C .

In addition, the object on which the ultrasonic wave is reflected is overlapped with the receiver 110 in a vertical direction (eg, the z-axis direction), while the transmitter [(120-11, 120-12), (120-21 to (120-21 to) 120-24) or (120-31 to 120-36)] do not overlap the object in the vertical direction. Therefore, the transmitter [(120-11, 120-12, (120-21 to 120-24), or (120-31 to 120-36)] is the receiver 110 so that the transmitted ultrasound can be focused on the object. can be placed around

In addition, the plurality of transmitters [(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] are arranged symmetrically with each other with the receiver 110 interposed therebetween. can be In this way, when the plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] are symmetrically arranged, the plurality of transmitters [( 120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)], the amount of the ultrasonic wave reaching the target increases, is reflected from the target, and the receiver 110 The intensity of the received ultrasound may increase.

Also, as the number of the plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] increases, the plurality of transmitters [(120-11) , 120-12), (120-21 to 120-24), or (120-31 to 120-36)], the amount of the ultrasonic wave reaching the target increases, is reflected from the target and received by the receiver 110 The intensity of the ultrasound may be increased.

2 (a) and (b) are plan views of ultrasonic waves transmitted from a plurality of transmitters [(120-21 to 120-24 or (120-31 to 120-36)] shown in FIGS. 1B and 1C) shown exemplarily.

For example, when the number of transmitters 120-31 to 120-36 is 6 as shown in FIGS. 1C and 2B, the transmitter 120 as shown in FIGS. 1B and 2A -21 to 120-24) than when the number is 4, since the ultrasonic wave (US) transmitted from the transmitter reaches the object more, the intensity of the ultrasonic wave reflected from the object and received by the receiver 110 can also increase. there is.

In addition, when the number of transmitters 120-21 to 120-24 is four as shown in FIG. 1B, as shown in FIG. 1A, when the number of transmitters 120-11 and 120-12 is two, , since more ultrasonic waves transmitted from the transmitter reach the object, the intensity of ultrasonic waves reflected from the object and received by the receiver 110 may increase.

In addition, each of the receiving unit 110 and the plurality of transmitting units [(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] is a polygonal, circular or oval, etc. It may have various planar shapes.

For example, as shown in FIGS. 1A to 1C , the receiver 110 may have a rectangular planar shape. Also, for example, as shown in FIGS. 1A and 1B, each of the plurality of transmitters [(120-11, 120-12) and (120-21 to 120-24)] may have a rectangular planar shape, As shown in FIG. 1C , each of the plurality of transmitters 120-31 to 120-36 may have a circular planar shape.

In addition, the interval at which the plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] are spaced apart from the receiver 110 may be the same. there is.

Referring to FIG. 1A , each of the plurality of transmitters 120-11 and 120-12 is spaced apart from the receiver 110 by a first distance D1 in a first horizontal direction (eg, y-axis direction). Referring to FIG. 1B , each of the plurality of transmitters 120-21 and 120-22 is spaced apart from the receiver 110 by a second distance D2 in the first horizontal direction, and the plurality of transmitters 120-23 and 120-24 ) are each spaced apart from the receiver 110 by a third distance D3 in a second horizontal direction (eg, x-axis direction) intersecting the first horizontal direction. For example, each of the first to third distances D1 to D3 may be 50 μm to 200 μm, preferably 500 μm to 1 mm, and more preferably 4 mm to 8 mm, but the embodiment is limited thereto. doesn't happen At this time, the horizontal length Y11 of the receiver 110 shown in FIGS. 1A to 1C is 3 mm to 8 mm, and the vertical length X11 is 8 mm to 13 mm, and each transmitter [(120-11, 120-) 12) or (120-21 to 120-24)], the horizontal length Y12 may be 1.5 mm to 4 mm, and the vertical length X12 may be 4 mm to 6 mm, but the embodiment is not limited thereto.

Also, referring to FIG. 1C , the center C1 of the receiver 110 and the center C2 of each of the plurality of transmitters 120-31 to 120-36 may be spaced apart by a fourth distance D1. For example, the fourth distance D4 may be 1.5 mm to 10 mm, but the embodiment is not limited thereto. In this case, the diameter of each of the transmitters 120-31 to 120-36 may be 1 mm to 5 mm, but the embodiment is not limited thereto. Although, in the case of FIG. 1C , the number of the plurality of transmitters 120-31 to 120-36 is exemplified as six, when the diameter of each of the plurality of transmitters 120-31 to 120-36 is adjusted, the plurality of transmitters The number of may be 4, 5, 7 or 8, but the embodiment is not limited thereto.

In the case of the piezoelectric ultrasonic transducer 100A to 100C according to the embodiment, the receiver 110 and the plurality of transmitters [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] have a planar shape spaced apart from each other, so the receiver 110 and the transmitter [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120) -36)], at least one of the configuration or material may be implemented differently.

Based on this, in the case of the embodiment, the receiving unit 110 includes at least one of a configuration or material that increases the ultrasonic receiving power more than the ultrasonic transmitting power, and the transmitting units [(120-11, 120-12), (120-21 to 120-) 24) or (120-31 to 120-36)] may be implemented to include at least one of a configuration or material that increases the ultrasonic transmission power more than the ultrasonic reception power. In this way, when at least one of the configuration or material of the receiver 110 is implemented to increase the ultrasonic reception power, the intensity of the ultrasonic wave received by the receiver 110 may be increased. In addition, at least one of the configuration or material of each of the plurality of transmitters ([(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] increases the ultrasonic transmission power If it is implemented to be high, ultrasonic waves will be generated faithfully to the pulse signal applied to the transmitter ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)]. Here, the pulse signal is an electrical signal having amplitude and frequency, and may be a voltage signal or a current signal, for example, the pulse signal may have an alternating current characteristic for imparting vibration to the piezoelectric material.

According to an embodiment, the receiving unit 110 has a higher ultrasonic receiving power than the transmitting unit ([(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)]). and the transmitter [(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] has a higher ultrasonic transmission power than the receiver 110 , the receiving unit 110 and the plurality of transmitting units ([(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] may have different materials.

The first piezoelectric member included in the receiver 110 includes a first piezoelectric material, and the transmitter ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-) 36)] Assume that the second piezoelectric member included in each includes a second piezoelectric material.

In this case, so that the receiving unit 110 has a relatively higher ultrasonic receiving power than the transmitting unit ([(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] In order to do this, the voltage output constant of the first piezoelectric material may be greater than the voltage output constant of the second piezoelectric material The voltage output constant means a voltage generation rate due to external vibration.

For example, the voltage output constant g33 of the first piezoelectric material may be 40 x 10 ^-3 Vm/N to 200 x 10 ^-3 Vm/N, but the embodiment is not limited thereto. For reference, g ₃₃ indicates that the vibration direction of the first piezoelectric member is in the z-axis direction (meaning the first number '3' among the subscripts of g ₃₃ ) and the alignment direction is in the z-axis direction (the second among the subscripts of g ₃₃ ) meaning of the number '3').

In addition, in order for the transmitter [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] to have a relatively higher ultrasonic transmission power than the receiver 110 , For this purpose, the piezoelectric constant of the second piezoelectric material may be greater than the piezoelectric constant of the first piezoelectric material. The piezoelectric constant refers to a ratio of strain caused by an external electric field.

For example, the piezoelectric constant d ₃₃ of the second piezoelectric material may be 300 pC/N to 3000 pC/N, but embodiments are not limited thereto. For reference, d ₃₃ indicates that the vibration direction of the second piezoelectric member is in the z-axis direction (meaning the first number '3' among the subscripts of d ₃₃ ) and the alignment direction is the z-axis direction (the second among the subscripts of d ₃₃ ) meaning of the number '3').

The material of each of the first and second piezoelectric members may include single crystal ceramics, polycrystalline ceramics, a polymer material, a thin film material, or a composite material in which a polycrystalline material and a polymer material are combined.

For example, the first piezoelectric member may be a piezoelectric ceramic (eg PZT), a piezoelectric single crystal (eg PMN-PT or PMN-PZT), a piezoelectric polymer (eg PVDF, PVDF-TrFE, PVDF- TrFE-CTFE), a piezoelectric composite (eg, PVDF series+PZT), or a piezoelectric thick film material (eg, PZT, AlN), but the embodiment is not limited thereto.

Also, for example, the second piezoelectric member may include at least one of a piezoelectric ceramic (eg, PZT) or a piezoelectric single crystal (eg, PMN-PT or PMN-PZT), but the embodiment is limited thereto. doesn't happen

Transmitting and receiving performance is improved by using a material with a relatively high piezoelectric constant such as piezoelectric polymer and piezoelectric composite for the first piezoelectric member, and using a material with a relatively high voltage output constant such as piezoelectric ceramic and piezoelectric single crystal for the second piezoelectric member can do it

In addition, each of the first and second electrodes is a material having conductivity, and may be a material that can be patterned. For example, each of the first and second electrodes may be chromium (Cr), nickel (Ni), copper (Cu), aluminum (Al), silver (Ag), or molybdenum (Mo). At least one of gold (Au), titanium (Ti), or an alloy thereof may be included, but the embodiment is not limited thereto.

According to another embodiment, the receiver 110 has a higher ultrasonic receiving power than the transmitter ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)]) In order for the transmitter [(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] to have a higher ultrasonic transmission power than the receiver 110 , , the receiver 110 and the plurality of transmitters ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] may have different configurations. As such, when the configuration of the receiving unit 110 and the transmitting unit ([(120-11, 120-12), (120-21 to 120-24) or (120-31 to 120-36)] is different, the first and The material of the second piezoelectric member may be the same as or different from each other.

Hereinafter, embodiments 110A to 110E of the above-described receiver 110 will be described with reference to the accompanying drawings.

3A to 3D show a cross-sectional view, a top view, a bottom view, and transmittance, respectively, according to an embodiment 110A of the receiver 110 shown in FIGS. 1A to 1C , respectively. In particular, FIG. 3A may correspond to a cross-sectional view of the receiver 110 shown in FIG. 1A taken along line I-I'. For ease of understanding, FIGS. 3B to 3D are examples illustrating a case in which the size of the matrix by the plurality of first electrodes is 4×4 (rows×columns). In addition, for ease of understanding, illustration of the protective layers UP and LP in FIGS. 3B to 3D is omitted.

The receiver 110A according to an embodiment may include a first piezoelectric member 112A and a plurality of first electrodes UEA1 and LEA1.

The plurality of first electrodes may include a plurality of first upper electrodes UEA1 and a plurality of first lower electrodes LEA1 . As illustrated in FIG. 3B , the plurality of first upper electrodes UEA1 are spaced apart from each other in a second horizontal direction (eg, the x-axis direction) intersecting the first horizontal direction (eg, the y-axis direction). and can be placed. As illustrated in FIG. 3C , the plurality of first lower electrodes LEA1 may be disposed to be spaced apart from each other in a first horizontal direction (eg, a y-axis direction).

In addition, the first piezoelectric member includes a plurality of piezoelectric pillars (or piezoelectric fibers) 112A spaced apart from each other and disposed between the first lower electrode LEA1 and the first upper electrode UEA1 in a matrix form. can do. The plurality of piezoelectric pillars may be arranged in a 2-2 composite or 1-3 composite structure.

For example, when viewed in a plan view, referring to FIG. 3D , a point at which the first upper electrode UEA1 and the second lower electrode LEA1 intersect (ie, a receiving segment) RS (Receiving Segment) (or a node region) ) is a position at which the piezoelectric column 112A is disposed. That is, each of the plurality of first upper electrodes UAE1 is disposed on the upper surface of the plurality of piezoelectric pillars 112A spaced apart from each other in the first horizontal direction (eg, the y-axis direction), and the plurality of first Each of the lower electrodes LEA1 is disposed under a lower surface of the plurality of piezoelectric pillars 112A spaced apart from each other in the second horizontal direction (eg, the x-axis direction). The ultrasonic wave reflected from the object may be received by the receiving segment RS.

An upper surface of each piezoelectric pillar 112A may be in contact with the first upper electrode UEA1 , and a lower surface of each piezoelectric pillar 112A may be in contact with the first lower electrode LEA1 . The thickness of each piezoelectric column 112A, that is, the height of each piezoelectric column 112A, which is the distance from the upper surface to the lower surface of the piezoelectric column 112A, may be about 50 μm to 200 μm, but the embodiment is not limited thereto. .

In addition, the width of each piezoelectric pillar 112A may be 5 μm to 50 μm, and an interval between the plurality of piezoelectric pillars 112A may be 5 μm to 50 μm.

In addition, by implementing the height of each piezoelectric pole 112A larger than the width of each piezoelectric pole 112A, the vibration force in the height direction of each piezoelectric pole 112A can be maximized.

When the size of the matrix is 4 x 4 (n=4), 16 (n squares) of receiving segments RS may exist, and in this case, the number of piezoelectric poles 112A is the number of receiving segments RS may be equal to the number. Alternatively, although not shown in the drawings, when the matrix size is 4×4, the number of piezoelectric pillars may be four connected in one direction of a row or column and spaced apart in the other direction.

If the interval between the plurality of receiving segments RS is large, the resolution may be lowered. Accordingly, the intensity of the ultrasonic waves received from the plurality of receiving segments RS is weak, so that the object cannot be accurately recognized, thereby reducing the reliability of the device. can be lowered

The number of the first electrodes UEA1 and LEA1, the line width, the interval, the number of the receiving segments RS, etc. may be determined in consideration of a manufacturing process error or resolution.

If the line width of the first electrodes UEA1 and LEA1 is less than about 0.1 μm, the manufacturing process may not be performed. For example, the line width of the first electrodes UEA1 and LEA1 may be from about 0.1 μm to about 10 μm, preferably from about 1 μm to about 5 μm, and more preferably from about 1.5 μm to about 3 μm. is not limited thereto.

If the thickness of the first electrodes UEA1 and LEA1 is less than about 100 nm, the electrode resistance may increase and thus electrical characteristics may be deteriorated, and if it exceeds about 1000 nm, the overall piezoelectric ultrasonic transducer 100A to 100C The thickness may be increased, and process efficiency may be reduced. For example, the thickness of the first electrodes UEA1 and LEA1 may be from about 100 nm to about 1000 nm, preferably from about 150 nm to about 500 nm, more preferably from about 180 nm to about 200 nm, but in practice Examples are not limited thereto.

Also, the receiving unit 110A according to an embodiment may include a filling member (or a resin layer) 114 , an upper electrode passivation unit UP, and a lower electrode protecting unit LP.

4A and 4B are external perspective views of the first piezoelectric member 112A and the filling member 114 .

Referring to FIG. 4A , it can be seen that a plurality of piezoelectric pillars 112A are spaced apart from each other and disposed in a matrix form, and the filling member 114 is filled and disposed between the piezoelectric pillars 112A. That is, the piezoelectric pillar 112A may be dispersedly disposed inside the filling member 114 , and the filling member 114 may be disposed to surround the piezoelectric pillar 112A.

The filling member 114 serves to support the piezoelectric column 112A. The filling member 114 may include at least one of a polymer and a resin, but the embodiment is not limited thereto.

Also, the upper electrode protector UP is disposed to surround the plurality of first upper electrodes UEA1 and serves to protect the plurality of first upper electrodes UEA1 . Also, the lower electrode protector LP is disposed to surround the plurality of first lower electrodes LEA1 and serves to protect the plurality of first lower electrodes LEA1 .

In addition, the piezoelectric ultrasonic transducer 100A to 100C according to the embodiment may further include a driving control unit 130 as shown in FIG. 3D . For example, the driving controller 130 may be implemented in the form of an integrated circuit (IC).

The driving controller 130 may be connected to the plurality of first lower electrodes LEA1 through the lower external wirings LL1 , LL2 , LL3 , and LL4 . In this case, the number of the lower external wirings LL1 to LL4 may be the same as the number of the plurality of first lower electrodes LEA1 , but the embodiment is not limited thereto. Also, the driving controller 130 may be connected to the plurality of first upper electrodes UEA1 through the upper external wirings UL1 , UL2 , UL3 , and UL4 . In this case, the number of the upper external wirings UL1 to UL4 may be the same as the number of the plurality of first upper electrodes UEA1 , but the embodiment is not limited thereto.

The plurality of first electrodes UEA1 and LEA1 outputs an electrical signal corresponding to the ultrasonic wave received from the reception segment RS to the driving controller 130 through the wires UL1 to UL4 and LL1 to LL4 . The driving controller 130 receives electrical signals drawn from the plurality of first electrodes UEA1 and LEA1 . Here, information about the object reflecting the transmitted ultrasound, for example, an image of the object may be generated using an electrical signal.

5A to 5C are cross-sectional views, top views, and bottom views, respectively, according to another embodiment 110B of the receiver 110 shown in FIGS. 1A to 1C , respectively. In particular, FIG. 5A may correspond to a cross-sectional view of the receiver 110 shown in FIG. 1A taken along line I-I'. For better understanding, FIGS. 5B and 5C are examples illustrating a case in which the size of the matrix formed by the plurality of first electrodes LEB1 is 4×4 (rows×columns).

The receiver 110B according to another embodiment may include a thin film transistor (TFT) structure 116 , a first piezoelectric member 112B, and a plurality of first electrodes UEB1 and LEB1 .

The first piezoelectric member 112B is disposed over the TFT structure 116 .

6 is a view showing an example of the TFT structure 116 .

Referring to FIG. 6 , the TFT structure 116 may include a data line (DL), a scan line (SL), and a switching TFT (STFT). Since the TFT structure 116 is widely known, a detailed description thereof is omitted here. 6 is only an example of the TFT structure 116, and the TFT structure 116 may have various shapes.

Again, referring to FIG. 5A , the plurality of first electrodes may include a plurality of first lower electrodes LEB1 and one first upper electrode UEB1 .

Referring to FIG. 5B , the first upper electrode UEB1 is disposed on the first piezoelectric member 112B and has no pattern, while referring to FIG. 5C , the plurality of first lower electrodes LEB1 is a first piezoelectric member 112B. It may be disposed in a matrix form between the lower portion of the member 112B and the TFT structure 116 . The plurality of first lower electrodes LEB1 serves to receive the ultrasonic wave received from the upper portion of the TFT structure 116 .

Although not shown, the plurality of first lower electrodes LEB1 and first upper electrodes UEB1 may be electrically connected to the driving controller 130 through an external wire as illustrated in FIG. 3D .

7A to 7D are a cross-sectional view, a top view, a bottom view, and transmittance, respectively, according to another embodiment 110C of the receiver 110 shown in FIGS. 1A to 1C , respectively. In particular, FIG. 7A may correspond to a cross-sectional view of the receiver 110 shown in FIG. 1A taken along line I-I'. For better understanding, FIGS. 7B to 7D are examples illustrating a case in which the size of the matrix formed by the plurality of first electrodes is 4×4 (rows×columns).

The receiver 110C according to another embodiment may include a first piezoelectric member 112C, a plurality of first electrodes UEC1 and LEC1 , and a substrate 118A.

First, the first piezoelectric member 112C may be disposed on the substrate 118A.

The plurality of first electrodes may include a plurality of first upper electrodes UEC1 and a plurality of first lower electrodes LEC1 . As illustrated in FIG. 7B , the plurality of first upper electrodes UEC1 is disposed on the first piezoelectric member 112C in a second horizontal direction (eg, y-axis direction) crossing the first horizontal direction (eg, y-axis direction). For example, in the x-axis direction) may be spaced apart from each other. As illustrated in FIG. 7C , the plurality of first lower electrodes LEC1 may be disposed to be spaced apart from each other in a first horizontal direction (eg, a y-axis direction).

When viewed in a plan view, referring to FIG. 7D , the number of points (ie, receiving segments) RS at which the first upper electrode UEC1 and the second lower electrode LEC1 intersect is 4 x 4 when the matrix size is 4 x 4 , may be 16.

In addition, the piezoelectric ultrasonic transducer 100A to 100C according to the embodiment may further include a driving control unit 130 as shown in FIG. 7D . The driving control unit 130 may be connected to the plurality of first lower electrodes LEC1 through the lower external wirings LL1 , LL2 , LL3 , and LL4 in the same manner as the driving control unit 130 illustrated in FIG. 3D . In this case, the number of the lower external wirings LL1 to LL4 may be the same as the number of the plurality of first lower electrodes LEC1 , but the embodiment is not limited thereto. Also, the driving controller 130 may be connected to the plurality of first upper electrodes UEC1 through upper external wirings UL1 , UL2 , UL3 , and UL4 . In this case, the number of the upper external wirings UL1 to UL4 may be the same as the number of the plurality of first upper electrodes UEC1 , but the embodiment is not limited thereto. The plurality of first electrodes UEC1 and LEC1 outputs an electrical signal corresponding to the ultrasonic wave received from the receiving segment RS to the driving controller 130 through the wires LL1 to LL4 and UL1 to UL4. The driving controller 130 receives electrical signals drawn from the plurality of first electrodes UEC1 and LEC1 . Here, information on the object reflecting the transmitted ultrasound, for example, an image of the object may be obtained using an electrical signal.

8A and 8B are cross-sectional views and top views, respectively, of another embodiment 110D of the receiver 110 shown in FIGS. 1A to 1C , respectively. In particular, FIG. 8A may correspond to a cross-sectional view of the receiver 110 shown in FIG. 1A taken along line I-I'. For better understanding, FIG. 8B is an example illustrating a case in which the size of a matrix by a micromachined ultrasonic transducer (MUT) is 4×4 (rows×columns).

The receiver 110D according to another embodiment may include a first piezoelectric member 112D, a plurality of MUT structures, and a substrate 118B.

The MUT structure may be disposed in a matrix form between the first piezoelectric member 112D and the substrate 118B. The plurality of MUT structures may include a first plurality of electrodes. Since the MUT structure is a general matter, a detailed description is omitted here.

In addition, the MUT structure shown in FIGS. 8A and 8B may be a capacitive-micromachined ultrasonic transducer (cMUT) structure or a piezoelectric-micromachined ultrasonic transducer (pMUT) structure, and the embodiment is not limited to a specific MUT structure.

Although not shown, the first electrode included in the plurality of MUT structures may be electrically connected to the driving control unit 130 through an external wiring as illustrated in FIG. 3D .

9A and 9B are cross-sectional views and top views, respectively, of another embodiment 110E of the receiver 110 shown in FIGS. 1A to 1C , respectively. In particular, FIG. 9A may correspond to a cross-sectional view of the receiver 110 shown in FIG. 1A taken along line I-I'. For better understanding, FIG. 9B is an example illustrating a case in which the size of a matrix formed by a FET (Field Effect Transistor) structure is 4×4 (rows×columns).

The receiver 110E according to another embodiment may include a plurality of FET structures and a substrate 118C.

Each of the substrates 118A, 118B, and 118C shown in FIGS. 7A, 8A, and 9A may be a silicon substrate, a silicon-on-insulation (SOI) substrate, a glass substrate, or a polymer substrate. 118B, 118C).

A plurality of FET structures may be disposed on the substrate 118C in a matrix form. In addition, each of the plurality of FET structures may include a source electrode S, a drain electrode D, a first piezoelectric member 112E, and a dielectric layer 117 . Here, a region between the source electrode S and the drain electrode D and under the dielectric layer 117 may correspond to the substrate 118C.

In each FET structure, the first piezoelectric member 112E may correspond to a gate electrode, and at least one of the source electrode S and the drain electrode D may correspond to the first electrode. As such, when the gate electrode is replaced with the first piezoelectric member in the general FET structure, the ultrasonic receiving power of the receiver 110E may increase. The dielectric layer 117 may play a role corresponding to the gate oxide layer in a general FET structure.

Components of each of the above-described FET structures are general, and detailed descriptions thereof are omitted herein. In addition, the FET structure shown in FIGS. 9A and 9B is only an example, and the embodiment is not limited to a specific FET structure.

Although not shown, the first electrode included in the plurality of FET structures may be electrically connected to the driving control unit 130 through an external wiring as illustrated in FIG. 3D .

Hereinafter, embodiments of the plurality of transmitters ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] described above will be described with reference to the accompanying drawings. It is explained as follows.

10 is an embodiment ( 120A) is shown.

As shown in FIG. 10 , the transmitter 120A according to an embodiment may include a second piezoelectric member 122A and second electrodes UED1 and LED1 .

The second electrode may include a second upper electrode UED1 and a second lower electrode LED1 . The second upper electrode UED1 may be disposed on the second piezoelectric member 122A, and the second lower electrode LED1 may be disposed under the second piezoelectric member 122A.

The driving controller 130 may be connected to the second upper electrode UED1 through the upper external wiring UL5 and may be connected to the second lower electrode LED1 through the lower external wiring LL5 .

The driving controller 130 serves to apply a pulse signal necessary for the second piezoelectric member 122A to generate ultrasonic waves to the second electrodes UED1 and LED1 .

A region between the receiver 110 and the object, for example, a region 115 in which ultrasonic waves reflected from the object in FIG. 3A are transmitted to the receiver 110A, and the transmitter ([(120-11, 120-12), (120) -21 to 120-24) or (120-31 to 120-36)] and the object, for example, in the area 150 in which the ultrasonic wave transmitted in FIG. 10 is transmitted to the object, air or cover glass may be present. Alternatively, at least one of a coupling medium and an impedance matching member may be disposed in the regions 115 and 150 .

The coupling medium serves to improve coupling between each of the transmitter and receiver and an object, and may be implemented with an adhesive, a gel, an acoustic coupling material, or the like. The impedance matching member is an impedance mismatch between the object and the receiver 110 or the object and the transmitter ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] It serves to improve the impedance mismatch between the liver, and the embodiment is not limited to a specific material and structure of the impedance matching member.

11 is another embodiment ( 120B) is shown.

11 , the transmitter 120B according to another exemplary embodiment may include a second piezoelectric member and a second electrode.

The second piezoelectric member may include a plurality of second-first piezoelectric segments 122B1 to 122B4 disposed to be spaced apart from each other in a horizontal direction (eg, a y-axis direction). For example, the plurality of 2-1 piezoelectric segments 122B1 to 122B4 may be disposed to be spaced apart from each other with air or a polymer interposed therebetween, but the embodiment is not limited thereto. Also, in the case of FIG. 11 , the second piezoelectric member is exemplified as including four 2-1 piezoelectric segments, but the embodiment is not limited thereto. According to another embodiment, the number of the second-first piezoelectric segments included in the second piezoelectric member may be 2, 3, or 5 or more.

The second electrode may include a plurality of second upper electrode segments UEE1 and a plurality of second lower electrode segments LEE1 . The second upper electrode segment UEE1 is disposed on each of the plurality of 2-1 piezoelectric segments 122B1 to 122B4, and the second lower electrode segment LEE1 includes the plurality of 2-1 piezoelectric segments 122B1 to 122B4. ) can be arranged under each. The number of each of the second lower electrode segment LEE1 and the second upper electrode segment UEE1 may be the same as the number of the second-first piezoelectric segments 122B1 to 122B4 .

The second upper electrode segment UEE1 is connected to the driving control unit 130 through upper external wirings UL6 to UL9 (here, UL7 and UL8 are not shown), and the second lower electrode segment LEE1 is connected to the lower external line. It may be electrically connected to the driving control unit 130 through the wirings LL6 to LL9. The driving controller 130 serves to apply a pulse signal necessary for the 2-1 th piezoelectric member segments 122B1 to 122B4 to generate ultrasonic waves to the second electrodes UEE1 and LEE1 .

In addition, the driving control unit 130 controls the plurality of second upper and lower electrode segments UEE1 and UEE1 at different time points so that the ultrasonic waves are generated and transmitted at different times from the plurality of 2-1 piezoelectric segments 122B1 to 122B4. A pulse signal can be applied to LEE1). That is, the driving control unit 130 uses a beam forming technology to transmit ultrasound. As described above, when ultrasonic waves are transmitted with a time difference based on the beamforming technology, the ultrasonic waves may be transmitted in the form of parallel waves or the ultrasonic waves may be simultaneously focused and reached on an object. For example, in FIGS. 1A to 1C , the receiving unit 110 overlaps the object in the vertical direction (eg, the z-axis direction), while the transmitting unit ([(120-11, 120-12), (120-21) to 120-24) or (120-31 to 120-36)] do not overlap the object in the vertical direction. In this case, when using the beamforming technique, a plurality of transmitters ([(120-11, 120-12) , (120-21 to 120-24) or (120-31 to 120-36)] may be simultaneously focused on and reach the object.

In this way, when the transmitter 120B is implemented as shown in FIG. 11 , the direction in which the transmitted ultrasonic waves travel can be adjusted.

12 is another embodiment of each of the transmitters ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36)] shown in FIGS. 1A to 1C) The sectional view by (120C) is shown.

12 , the transmitter 120C according to another embodiment may include a second piezoelectric member and a second electrode.

The second piezoelectric member may include a plurality of second-second piezoelectric segments 122C1 to 122C3 disposed to be spaced apart from each other in a vertical direction (eg, a z-axis direction). In this case, the second electrode may be disposed above and below the plurality of 2-2 piezoelectric segments 122C1 to 122C3.

12 , the second piezoelectric member is exemplified as including three 2-2 piezoelectric segments, but the embodiment is not limited thereto. According to another embodiment, the number of 2-2 piezoelectric segments included in the second piezoelectric member may be 2 or 4 or more.

The second electrode may include a second upper electrode segment UEF1 , a second lower electrode segment LEF1 , and two second middle electrode segments MEF1 and MEF2 . The second upper electrode segment UEF1 is disposed above the second-second piezoelectric segment 122C1 , and the second lower electrode segment LEF1 is disposed below the second-second piezoelectric segment 122C3 . The second middle electrode segment MEF1 may be disposed between the second-second piezoelectric segments 122C1 and 122C2, and the second intermediate electrode segment MEF2 may be disposed between the second-second piezoelectric segments 122C2 and 122C3. there is.

The second upper electrode segment UEF1 is connected to the driving control unit 130 through the upper external wiring UL10 , and the second lower electrode segment LEF1 is electrically connected to the driving control unit 130 through the lower external wiring LL10 . can be connected to Also, the second intermediate electrode segments MEF1 and MEF2 may be respectively connected to the driving controller 130 through the intermediate external wirings ML1 and ML2 .

The driving controller 130 serves to apply a pulse signal necessary for the 2-2nd piezoelectric member segments 122C1 to 122C3 to generate ultrasonic waves to the second electrodes UEF1 , LEF1 , MEF1 , and MEF2 .

In general, the driving pulse signal required to generate the ultrasonic wave in the second piezoelectric member is very high, for example, 10 volts to 20 volts. However, as the thickness of the second piezoelectric member increases, the level of the driving pulse signal may decrease. Accordingly, when a second piezoelectric member is realized by stacking a plurality of second-second piezoelectric member segments as shown in FIG. 12 , the driving pulse signal required to generate ultrasonic waves in the second piezoelectric members 122C1 to 122C3 is You can lower the level.

Hereinafter, a method of manufacturing a piezoelectric ultrasonic transducer according to an embodiment will be described with reference to the accompanying drawings. At this time, although only the manufacturing method of the receiving unit 110A of the piezoelectric ultrasonic transducer according to the embodiment shown in FIG. 3A will be described, other receiving units 110B to 110E may also be manufactured by modifying the manufacturing method of the receiving unit 110A. of course there is

13A to 13E are process cross-sectional views for explaining a method of manufacturing the receiving unit 110A shown in FIG. 3A , and FIGS. 14A to 14E are process plan views for explaining a manufacturing method of the receiving unit 110A shown in FIG. 3A . indicates

Of course, the manufacturing method of the receiver 110A is not limited to the manufacturing method shown in FIGS. 13A to 13E and 14A to 14E and may be manufactured by various other manufacturing methods.

First, referring to FIGS. 13A and 14A , an upper portion of the first piezoelectric material for a piezoelectric member (eg, PZT) layer 112 is patterned to form a plurality of piezoelectric pillars 112A. In this case, the piezoelectric material layer for the first piezoelectric member having the plurality of patterned piezoelectric pillars 112A may be first prepared and then diced to a desired size, or the first piezoelectric material layer for the first piezoelectric member may be diced. After performing the patterning, a plurality of piezoelectric pillars 112A may be formed.

Thereafter, referring to FIGS. 13B and 14B , the filling member 114 is filled on the piezoelectric material layer for the first piezoelectric member so as to surround the plurality of piezoelectric pillars 112A.

Thereafter, referring to FIGS. 13C and 14C , the results shown in FIGS. 13B and 14B are grinded to expose the upper and lower surfaces of the piezoelectric column 112A.

Thereafter, referring to FIGS. 13D and 14D , a first upper electrode UEA1 and a first lower electrode LEA1 are respectively formed above and below the resultant shown in FIGS. 13C and 14C .

Thereafter, referring to FIGS. 13E and 14E , the receiver 110A is completed by polishing the result shown in FIGS. 13D and 14D .

In the above, only the manufacturing method of the receiving unit 110A has been described, except for the processes shown in FIGS. 13A, 13B, 14A and 14B, the manufacturing method of the transmitting unit 120 is also the manufacturing method of the receiving unit 110A and may be similar.

In the case of the piezoelectric ultrasonic transducer 100A to 100C according to the above-described embodiment, the ultrasonic wave may be transmitted and then the ultrasonic wave may be received. That is, there is a difference between a time point at which an ultrasonic wave is transmitted and a time point at which the ultrasonic wave is received. In this way, so that the ultrasonic waves are transmitted and received with a time difference, the driving control unit 130 controls the transmission unit ([(120-11, 120-12), (120-21 to 120-24), or (120-31 to 120-36). )] and the receiver 110 can be controlled.

Meanwhile, the piezoelectric ultrasonic transducers 100A to 100C according to the above-described embodiment may be used in various devices or systems using ultrasonic waves. For example, the piezoelectric ultrasonic transducers 100A to 100C according to the embodiment are a mobile phone, a multimedia Internet mobile phone, a mobile TV receiver, a wireless device, a smart phone, a Bluetooth device, a personal digital assistant (PDA), and a wireless e-mail receiver. , portable computers, netbooks, notebooks, smartbooks, tablets, handwriting digitizers, fingerprint scanners, printers, copiers, scanners, facsimile devices, GPS receivers, GPS navigators, cameras, digital media players (eg MP3), camcorders, game consoles, wrist watches, wall clocks, calculators, television monitors, flat panel displays, electronic readers (eg e-readers), portable health (monitoring) devices, computer monitors, Automotive display devices (including odometers and speedometers), cockpit controls or display devices, camera view displays (eg, automotive black boxes), electronic cameras, electronic billboards, projectors, microwave ovens ), refrigerators, stereo systems, cassette recorders or players, DVD players, CD players, VCRs, radios, portable memory chips, washing machines, dryers, parking meters, packaging (EMS, MEMS, etc.), aesthetic structural devices (e.g. For example, it may be included in an electronic device such as an image display device used in a jewelry store or a clothing store), but the embodiment is not limited thereto.

Specifically, the piezoelectric ultrasonic transducer 100A to 100C according to the above-described embodiment may be applied to an electrical sensor array for biometric sensing, image, touch, and gesture recognition, or an interactive display.

More specifically, the piezoelectric ultrasonic transducer 100A to 100C according to the embodiment may be applied to a biosensing device such as an ultrasonic fingerprint sensor, a gesture inspection device, a microphone, a speaker, an ultrasonic imaging device, an ultrasonic chemical sensor, an ultrasonic touch pad, etc. . For example, as the biosensing device, there are not only an ultrasonic fingerprint sensor, but also an ultrasonic epidermal or dermal sensor, an ultrasonic skin condition sensor that recognizes a degree of skin tightness or a degree of damage to the skin, and the like.

When the fingerprint is recognized in the ultrasonic method by the piezoelectric ultrasonic transducers 100A to 100C, the fingerprint may be recognized more accurately due to less electrostatic interference than when recognizing the fingerprint in the capacitive method and high transmittance.

Hereinafter, the biometric information measuring apparatus 200 including the piezoelectric ultrasonic transducer 100A to 100C according to an embodiment will be described with reference to the accompanying drawings.

15 is a diagram illustrating an external appearance of an apparatus 200 for measuring biometric information according to an embodiment.

Referring to FIG. 15 , the biometric information measuring apparatus 200 according to an embodiment may include a piezoelectric ultrasonic transducer, an impedance matching member 202 , and a biometric information analyzing unit 210 .

The impedance matching member 202 serves to improve impedance mismatch between the biological object OB and the transmitter 120A and between the biological object OB and the receiver 110A. The piezoelectric ultrasonic transducer may include a receiver 110A, a transmitter 120A, and a driving controller 130 . Here, the receiving unit 110A corresponds to the receiving unit 110A shown in FIG. 3A , and the transmitting unit 120A and the driving control unit 130 correspond to the transmitting unit 120A and the driving control unit 130 shown in FIG. 10 , respectively. , the same reference numerals are used, and overlapping descriptions are omitted. The transmitter 120A included in the piezoelectric ultrasonic transducer shown in FIG. 15 may be replaced with other transmitters 120B and 120C, and the receiver 110A may be replaced with other receivers 110B to 110E.

The ultrasound generated by the transmitter 120A is transmitted to the living object OB. The biological object OB may be, for example, a fingerprint having a mountain (R: Ridge) and a valley (V: Valley).

The driving controller 130 controls the plurality of transmitters 120A to generate and transmit ultrasonic waves, and receives electrical signals corresponding to the ultrasonic waves received from the receiver 110A and outputs them to the biometric information analyzer 210 . A detailed look at this is as follows.

The driving controller 130 may apply a pulse signal having a resonance frequency of an ultrasonic band to the second electrodes UED1 and LED1 to generate ultrasonic waves in the second piezoelectric member 122A. Ultrasound transmitted from the transmitter 120A enters the living object OB at a portion of the upper surface 202T of the impedance matching member 202 in contact with the acid R of the biological object OB, whereas the impedance matching member A portion of the upper surface 202T of the 202 in contact with air may be reflected toward the inside of the piezoelectric ultrasonic transducer. As such, when the finger OB or the like does not contact or approach the ultrasonic wave, most of the ultrasonic wave is generated by the impedance matching member 202 due to the difference in acoustic impedance between the impedance matching member 202 from which the ultrasonic wave is to be emitted and the air. It cannot pass through the interface of air and On the other hand, in the case of a point where the finger OB touches or approaches, a part of the transmitted ultrasound penetrates the interface between the skin of the finger OB and the impedance matching member 202 and proceeds to the inside of the finger OB. In this case, the intensity of the reflected ultrasonic wave received by the receiver 110A is lowered, so that the fingerprint pattern can be detected therefrom.

The ultrasonic wave reflected from the living object OB is received by the receiver 110A. Although not shown, the driving control unit 130 is connected to the first electrodes UEA1 and LEA1 through the upper external wiring and the lower external wiring as shown in FIG. 3D to correspond to the ultrasonic wave received from the receiving unit 110A. receives an electrical signal and outputs it to the biometric information analysis unit 210 .

Although it is difficult to confirm with the naked eye, the fingerprint of the finger OB has a pattern in which numerous valleys V and ridges R are repeated, and is transmitted from the impedance matching member 202 corresponding to the valleys V of the fingerprint. Ultrasonic waves are emitted to the outside very little and most of them are reflected toward the inside of the piezoelectric ultrasonic transducer and are received by the receiving segment RS, and the ultrasonic waves emitted from the impedance matching member 202 corresponding to the crest R of the fingerprint are significant. As it passes through the interface of the finger OB and travels, the intensity of the ultrasonic wave reflected and received by the receiving segment RS is relatively greatly reduced.

The biometric information analysis unit 210 may analyze the biometric information of the biological object OB by using the electrical signal received through the driving control unit 130 . For example, when the biometric object OB is a fingerprint, the biometric information analyzer 210 uses an electrical signal to generate ultrasound generated from a difference in acoustic impedance according to the valley V and the crest R of the fingerprint OB. The fingerprint pattern of the finger may be detected by measuring the intensity or reflection coefficient of the received reflected signal. To this end, the receiving unit 110A shown in FIG. 15 may include a piezoelectric pillar 112A having a number proportional to the fingerprint image pixel.

Hereinafter, a piezoelectric ultrasonic transducer according to an embodiment and a conventional piezoelectric ultrasonic transducer are compared and described.

The piezoelectric ultrasonic transducer according to the comparative example transmits and receives ultrasonic waves by the same piezoelectric member. In general, the piezoelectric member may have excellent ultrasonic wave reception performance but low ultrasonic wave transmission ability, or may have excellent ultrasonic wave transmission performance but low ultrasonic wave reception capability. That is, a general piezoelectric member has only one performance of transmission and reception, and both transmission and reception performance cannot be excellent. Considering this, the performance of either the ultrasonic transmission or the ultrasonic reception of the conventional piezoelectric ultrasonic transducer is inevitably deteriorated.

On the other hand, in the piezoelectric ultrasonic transducer according to the embodiment, the transmitter for transmitting the ultrasonic wave and the receiver for receiving the ultrasonic wave are spaced apart from each other, and at least one of the configuration or material of the receiver 110 is implemented to increase the ultrasonic receiving power, and the transmitter ( 120), at least one of the configuration or material is implemented to increase the ultrasonic transmission power. Therefore, the piezoelectric ultrasonic transducer according to the embodiment has an excellent effect in both the ultrasonic transmitting power and the receiving power.

When the transmitting power of the ultrasonic wave from the transmitter 120 is increased and the intensity of the ultrasonic wave received from the receiver 110 is increased, information on the object can be accurately recognized. In consideration of this, unlike the conventional piezoelectric ultrasonic converter, the piezoelectric ultrasonic converter according to the embodiment has excellent ultrasonic transmission power of the transmitter and excellent ultrasonic receiving power of the receiver. has For example, in the biometric information measuring apparatus 200 shown in FIG. 15 , when the object OB that reflects the transmitted ultrasound is a fingerprint of a finger, it passes through the epidermis and is reflected from the dermis and the received ultrasound is received. age may increase. For this reason, the performance of the biometric information measuring apparatus 200 according to the embodiment of recognizing not only a fingerprint but also the epidermis and the dermis may be improved.

In addition, since the existing piezoelectric ultrasonic transducer transmits and receives ultrasonic waves by the same piezoelectric member, a switch structure for controlling whether to transmit ultrasonic waves or not, is required. Therefore, the circuit of the conventional piezoelectric ultrasonic transducer becomes complicated.

On the other hand, in the piezoelectric ultrasonic transducer according to the embodiment, the transmitter and the receiver are separated, and the driving controller 130 only controls the power supply to the separated transmitter and receiver, so a separate switch structure is not required. . Therefore, the piezoelectric ultrasonic transducer according to the embodiment does not have a more complicated circuit structure than the conventional piezoelectric ultrasonic transducer.

In addition, unlike the conventional piezoelectric ultrasonic transducer in which the transmitter and the receiver are vertically stacked, in the piezoelectric ultrasonic converter according to the embodiment, the transmitter and the receiver are horizontally spaced apart from each other, so that the thickness may be thinner than before. As described above, the piezoelectric ultrasonic transducer according to the embodiment capable of being thinned may be usefully used in a field requiring a thin thickness.

In addition, even if the transmitter does not overlap the object in the vertical direction, the ultrasonic wave can be focused and reached the object by using the beam forming technique, so that the intensity of the received ultrasonic wave increases, thereby improving the resolution of the image of the object. .

If the piezoelectric ultrasonic transducers 100A to 100C according to the above-described embodiment are applied to a display device, the piezoelectric ultrasonic transducers 100A to 100C may be disposed at the lower end of the screen area of the display of the display apparatus.

The piezoelectric ultrasonic transducer 100A to 100C according to the above-described embodiment may be applied as a fingerprint sensor in a display device. Since the display device includes a display panel and a cover substrate, the thickness may be about 1 mm. When a capacitive fingerprint sensor is used in such a display device, the accuracy of recognizing a fingerprint may be reduced due to interference by transmittance and an internal circuit of the display. On the other hand, when the piezoelectric ultrasonic transducer 100A to 100C according to the embodiment is adopted as the ultrasonic fingerprint sensor in the display device, the accuracy of recognizing a fingerprint may be increased, and the piezoelectric ultrasonic transducer 100A to 100C is displayed on the display. Even if it is placed at the bottom, fingerprint recognition may be possible.

Hereinafter, the display apparatuses 300A to 300F according to an embodiment including the above-described piezoelectric ultrasonic transducers 100A to 100C will be described with reference to the accompanying drawings.

16 is a cross-sectional view of a display device 300A according to an exemplary embodiment.

The display apparatus 300A according to an embodiment may include a cover member 310A, an adhesive layer 320A, a display panel 330A, and a piezoelectric ultrasonic transducer 340A. In some cases, the cover member 310A and the adhesive layer 320A may be omitted.

The cover member 310A may be rigid or flexible. Preferably, the cover member 310A may be flexible such that it can be bent or folded.

For example, the cover member 310A may include plastic or glass. In detail, the cover member 310A includes a reinforced or flexible plastic such as polyimide (PI), polyethylene terephthalate (PET), propylene glycol (PPG), polycarbonate (PC), or sapphire. may include

In addition, the cover member 310A may include a photoisotropic film. For example, the cover member 310 may include Cyclic Olefin Copolymer (COC), Cyclic Olefin Polymer (COP), optical isotropic polycarbonate (PC), or optical isotropic polymethyl methacrylate (PMMA).

The display panel 330A may be disposed under the cover member 310A. The display panel 330A and the cover substrate 310A may be adhered to each other through an adhesive layer 320A such as an optically clear adhesive.

The display panel 330A may include a first substrate 332 and a second substrate 334 .

When the display panel 330A is a liquid crystal display panel, the display panel 330A includes a first substrate 332 including a thin film transistor (TFT) and a pixel electrode, and a second substrate 334 including color filter layers. ) may be formed in a bonded structure with a liquid crystal layer interposed therebetween.

In addition, in the display panel 330A, a thin film transistor, a color filter, and a black matrix are formed on a first substrate 332 , and a second substrate 334 is bonded to the first substrate 332 with a liquid crystal layer interposed therebetween. It may be a liquid crystal display panel having a (color filter on transistor) structure. That is, a thin film transistor may be formed on the first substrate 332 , a protective film may be formed on the thin film transistor, and a color filter layer may be formed on the protective film.

In addition, a pixel electrode in contact with the thin film transistor is formed on the first substrate 332 . In this case, in order to improve the aperture ratio and simplify the mask process, the black matrix may be omitted, and the common electrode may also serve as the black matrix.

Also, when the display panel 330A is a liquid crystal display panel, the display device 300A may further include a backlight unit (not shown) that provides light from the rear surface of the display panel 330A.

For example, the display panel 330A may include an active area. Here, the active area may be an area from which a screen is actually output. In this case, the piezoelectric ultrasonic transducer 340A may be disposed at the lower end of the display panel 330A in an area corresponding to the active area. Specifically, the piezoelectric ultrasonic transducer may be disposed on the fingerprint area of the active area, and in particular, the receiver may be disposed to correspond to the fingerprint area.

In particular, in the case of using the piezoelectric ultrasonic transducer according to the embodiment as a biometric recognition device in a mobile display device, the fingerprint sensor button used in the past can be removed, so that the active area of the mobile display device can be widened. .

17 is a cross-sectional view of a display device 300B according to another exemplary embodiment.

The display device 300B illustrated in FIG. 17 may include a cover glass 310B, a plastic OLED (POLED) 330B, and a piezoelectric ultrasonic transducer 340B.

The cover glass 310B is a case in which the cover member 310A shown in FIG. 16 is made of glass, and performs the same role as the cover member 310A.

The POLED 330B is another example of the display panel 330A shown in FIG. 16 .

18 is a cross-sectional view of a display device 300C according to another exemplary embodiment.

The display device 300C illustrated in FIG. 18 may include a display panel 330C, an adhesive layer 320B, and a piezoelectric ultrasonic transducer 340C.

The display panel 330C, the adhesive layer 320B, and the piezoelectric ultrasonic transducer 340C correspond to each of the display panel 330A, the adhesive layer 320A, and the piezoelectric ultrasonic transducer 340A shown in FIG. 16, and perform the same role Since it can be performed, a redundant description will be omitted here.

19 is a cross-sectional view of a display device 300D according to another exemplary embodiment.

The display device 300D illustrated in FIG. 19 may include a display TFT 330D, an adhesive layer 320C, and a piezoelectric ultrasonic transducer 340D.

The display TFT 330D is a case in which the display panel 330A shown in FIG. 16 is implemented with a thin film transistor. The adhesive layer 320C and the piezoelectric ultrasonic transducer 340D correspond to each of the adhesive layer 320A and the piezoelectric ultrasonic transducer 340A shown in FIG. 16 , and since they can perform the same role, overlapping descriptions are omitted here.

20 is a cross-sectional view of a display device 300E according to another exemplary embodiment.

The display device 300E shown in FIG. 20 includes a display lower substrate (TFT) 330E, an adhesive layer 320D, a piezoelectric ultrasonic transducer 340E, a form tape 350 and a back plate. (360).

The display lower substrate (TFT) 330E plays the same role as the display TFT 330D shown in FIG. 19 . The foam tape 350 may be disposed between the display lower substrate 330E and the back plate 360 . The adhesive layer 320D and the piezoelectric ultrasonic converter 340E correspond to each of the adhesive layer 320A and the piezoelectric ultrasonic converter 340A shown in FIG. 16, and since they can perform the same role, overlapping descriptions are omitted here.

21 is a cross-sectional view of a display device 300F according to another exemplary embodiment.

The display device 300F shown in FIG. 21 includes a cover substrate 310C, a display panel 330F, a foam tape 350, a back plate 360, an adhesive layer 320E, and a piezoelectric ultrasonic transducer 340F. can

The cover substrate 310C corresponds to the cover member 310C shown in FIG. 16 and may perform the same role.

When the display panel 330F is an organic light emitting display (OLED) panel, the display panel 330F includes a self-luminous element that does not require a separate light source. The display panel 330F may include a polarizer 335 , an encapsulation 336 , a color filter array 337 , and an OLED TFT 338 .

The polarizing plate 335 is disposed between the cover substrate 310C and the encapsulant 336 . The encapsulant 336 may be disposed between the polarizer 335 and the filter array 337 , and serves as an encapsulation substrate for encapsulation.

The pixel array 337 may be implemented with a red pixel (R), a green pixel (G), and a blue pixel (B).

The OLED TFT 338 may be disposed between the pixel array 337 and the foam tape 350 . The OLED TFT 338 may include a thin film transistor (TFT) and an organic light emitting diode (OLED) in contact with the thin film transistor (TFT). The organic light emitting diode (OLED) may include an anode, a cathode, and an organic light emitting layer formed between the anode and the cathode.

The foam tape 350, the back plate 360, the adhesive layer 320E, and the piezoelectric ultrasonic transducer 340F are the foam tape 350, the back plate 360, the adhesive layer 320D and the piezoelectric ultrasonic transducer shown in FIG. It corresponds to each of the devices 340E and may perform the same role, so a redundant description will be omitted here.

The piezoelectric ultrasonic transducers 340A to 340F illustrated in FIGS. 16 to 21 correspond to the piezoelectric ultrasonic transducers illustrated in FIGS. 1A to 12 and may be fingerprint sensors. Also, as illustrated in FIG. 17 , the piezoelectric ultrasonic transducer 340B may be disposed in the effective area AA.

The piezoelectric ultrasonic transducers 340A to 340F of the display device according to FIGS. 16 to 21 may be used for user authentication. For example, the user may touch the fingerprint area in which the piezoelectric ultrasonic transducers 340A to 340F are disposed, and after authentication, the lock screen of the display device may be released.

22 is a flowchart for describing a method 400 of driving a display device.

23 (a) to (c) are diagrams to help the description of FIG. 22 .

Referring to FIG. 22 , it is determined whether a screen has been touched on the display device (step 410). If it is not recognized that the screen has been touched, the standby state in which the screen is turned off is maintained as shown in FIG. 23 (a). The touch in operation 410 may be a touch on a part other than the screen of the display device. The criterion for determining whether the screen has been touched may be a touch more than a predetermined number of times spaced at a predetermined time interval, a touch applying a predetermined pressure or more, or a touch maintaining a predetermined time or more, and is not particularly limited.

However, when the display device recognizes that the screen has been touched, the screen is turned on to display the fingerprint area and the fingerprint sensor is activated (step 420). Here, the turn-on of the screen means a state in which the screen is displayed to the user as illustrated in FIG. 23( b ). In operation 420, the locked state of the display device is maintained.

After operation 420, it is determined whether the screen of the display device has been additionally touched (operation 430). If it is determined that the screen of the display device is not further touched, the screen is turned off again. In addition, the criterion for determining whether the screen has been touched may be a separate touch input after the touch in step 410, or may be a touch input that maintains the touch in step 410, and a state in which recognition is possible with an activated fingerprint sensor. It is sufficient as long as it is an input capable of determining whether it is cognition, and the present invention is not limited thereto.

However, if it is determined that the screen of the display device has been touched, it is determined whether the fingerprint area of the display device has been touched (step 440). Here, the fingerprint area means an area in which the fingerprint sensor can detect a fingerprint, is located on the screen of the display device, and only when the user's fingerprint touches the fingerprint area, the fingerprint sensor can sense the fingerprint.

If it is determined that the fingerprint area of the display device has not been touched, a message to touch the fingerprint area is sent to the user, and then the process proceeds to step 420 (step 450). An example of a fingerprint area is shown in FIG. 23(b).

However, if it is determined that the fingerprint area has been touched, it is determined whether the touched fingerprint is a fingerprint permitted to use the display device (step 460). To this end, the fingerprint allowed to use the display device is stored in advance, and in operation 460, it is determined whether the touched fingerprint is the same as the previously stored fingerprint.

If it is determined that the touched fingerprint is not a fingerprint permitted to use the display device, a message requesting fingerprint re-recognition is sent to the user, and then the process proceeds to step 420 (step 470).

However, if it is determined that the touched fingerprint is a fingerprint permitted to use the display device, the display device is unlocked to allow the user to use the display device (step 480). 23 (c) shows an example in which the lock is released.

In the above, the embodiment has been mainly described, but this is merely an example and does not limit the present invention, and those of ordinary skill in the art to which the present invention pertains are not exemplified above in the range that does not depart from the essential characteristics of the present embodiment. It can be seen that various modifications and applications are possible. For example, each component specifically shown in the embodiment can be implemented by modification. And differences related to such modifications and applications should be construed as being included in the scope of the present invention defined in the appended claims.

100A, 100B, 100C, 340A to 340F: Piezoelectric ultrasonic transducer
110, 110A to 110E: receivers 112A to 112D: first piezoelectric member
114: filling member 116: FET structure
118A to 118C: substrate
120-11, 120-12, 120-21 to 120-24, 120-31 to 120-36, 120A to 120C: transmitter
122A, 122B1 to 122B4, 122C1 to 122C3: second piezoelectric member
130: drive control unit 200: biometric information measuring device
202: impedance matching member 210: biometric information analysis unit
300A to 300F: display device 310A: cover member
310B: cover glass 320A to 320E: adhesive layer
330A: display panel

Claims (14)

a receiver for receiving ultrasonic waves; and
It is spaced apart from the receiver and has a planar shape disposed around the receiver, and includes a plurality of transmitters for transmitting ultrasonic waves,
The receiving unit includes at least one of a configuration or a material that increases the ultrasonic receiving power more than the ultrasonic transmitting power,
The transmitter includes at least one of a configuration or material that increases the ultrasonic transmission power more than the ultrasonic reception power,
the receiving unit
a first piezoelectric member; and
a plurality of first electrodes disposed in a matrix form on at least one of an upper portion or a lower portion of the first piezoelectric member;
the transmitter
a second piezoelectric member; and
and a second electrode disposed on at least one of an upper portion, a lower portion, and an intermediate portion of the second piezoelectric member. The method of claim 1 , wherein the first piezoelectric member comprises a first piezoelectric material, the second piezoelectric member comprises a second piezoelectric material, and
a voltage output constant of the first piezoelectric material is greater than a voltage output constant of the second piezoelectric material;
A piezoelectric constant of the second piezoelectric material is greater than a piezoelectric constant of the first piezoelectric material. According to claim 1, wherein the plurality of first electrodes of the receiving unit
a plurality of first lower electrodes spaced apart from each other in a first horizontal direction; and
It includes a plurality of first upper electrodes spaced apart from each other in a second horizontal direction intersecting the first horizontal direction,
The first piezoelectric member of the receiving unit is
A piezoelectric ultrasonic transducer comprising a plurality of piezoelectric pillars spaced apart from each other and disposed between the first lower electrode and the first upper electrode in a matrix form. The method of claim 3, wherein the receiving unit
a filling member disposed between the piezoelectric pillars;
an upper electrode protecting unit disposed to surround the plurality of first upper electrodes; and
The piezoelectric ultrasonic transducer further comprising a lower electrode protector disposed to surround the plurality of first lower electrodes. According to claim 1, wherein the receiving unit further comprises a substrate disposed under the first piezoelectric member,
The plurality of first electrodes of the receiving unit are
a plurality of first lower electrodes spaced apart from each other in a first horizontal direction between a lower portion of the first piezoelectric member and the substrate; and
and a plurality of first upper electrodes disposed on an upper portion of the first piezoelectric member to be spaced apart from each other in a second horizontal direction intersecting the first horizontal direction. The method of claim 1, wherein the second electrode of each of the plurality of transmitters is
a second upper electrode disposed on the second piezoelectric member; and
and a second lower electrode disposed under the second piezoelectric member. According to claim 1, wherein the second piezoelectric member of each of the plurality of transmitters
It includes a plurality of 2-1 piezoelectric segments spaced apart from each other in the horizontal direction,
The second electrode of each of the plurality of transmitters is
a second upper electrode segment disposed on each of the plurality of 2-1 piezoelectric segments; and
and a second lower electrode segment disposed under each of the plurality of 2-1 piezoelectric segments. The piezoelectric ultrasonic transducer according to claim 7, wherein the plurality of 2-1 piezoelectric segments are spaced apart from each other with air or polymer interposed therebetween. The method of claim 1, further comprising: a driving control unit that is drawn out from the plurality of first electrodes and receives an electrical signal corresponding to the received ultrasound, and applies a pulse signal necessary for the second piezoelectric member to generate the ultrasound to the second electrode; Further comprising a piezoelectric ultrasonic transducer. The piezoelectric ultrasonic transducer of claim 9 , wherein the driving controller controls the transmitter and the receiver to transmit and receive the ultrasonic waves with a time difference. The piezoelectric ultrasonic transducer of claim 1, wherein the first piezoelectric member includes a ceramic-based material, and the second piezoelectric member includes a polymer-based material. The piezoelectric ultrasonic transducer according to claim 1, wherein the piezoelectric ultrasonic transducer is disposed at a position corresponding to the screen area under the display panel. piezoelectric ultrasonic transducer; and
and a biometric information analyzer configured to receive an electrical signal corresponding to the ultrasonic wave reflected from the living object from the piezoelectric ultrasonic converter and analyze the biometric information of the living object;
The piezoelectric ultrasonic transducer is
a receiver for receiving the ultrasonic wave reflected from the living object;
a plurality of transmitters spaced apart from the receiver and having a planar shape disposed around the receiver and transmitting ultrasound to the living body object; and
a driving control unit for controlling the plurality of transmitters to generate and transmit the ultrasonic waves, and for receiving an electrical signal corresponding to the ultrasonic waves received from the receiver and outputting them to the biometric information analyzer;
The receiving unit includes at least one of a configuration or a material that increases the ultrasonic receiving power more than the ultrasonic transmitting power,
The transmitter includes at least one of a configuration or material that increases the ultrasonic transmission power more than the ultrasonic reception power,
the receiving unit
a first piezoelectric member; and
a plurality of first electrodes disposed in a matrix form on at least one of an upper portion or a lower portion of the first piezoelectric member and transmitting the electrical signal corresponding to the received ultrasonic wave to the driving control unit;
the transmitter
a second piezoelectric member; and
and a second electrode disposed on at least one of an upper portion, a lower portion, and a middle portion of the second piezoelectric member. a display panel comprising an active area; and
a piezoelectric ultrasonic transducer disposed in an area corresponding to the active area under the display panel;
The piezoelectric ultrasonic transducer is
a receiver for receiving ultrasonic waves; and
It is spaced apart from the receiver and has a planar shape disposed around the receiver, and includes a plurality of transmitters for transmitting ultrasonic waves,
The receiving unit includes at least one of a configuration or a material that increases the ultrasonic receiving power more than the ultrasonic transmitting power,
The transmitter includes at least one of a configuration or material that increases the ultrasonic transmission power more than the ultrasonic reception power,
the receiving unit
a first piezoelectric member; and
a plurality of first electrodes disposed in a matrix form on at least one of an upper portion or a lower portion of the first piezoelectric member;
the transmitter
a second piezoelectric member; and
and a second electrode disposed on at least one of an upper portion, a lower portion, and a middle portion of the second piezoelectric member.

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