Ultrasonic array transceiving method and module thereof

Abstract

The present application provides an ultrasonic array transmitting and receiving method and module. The method comprises the following steps: a, providing an ultrasonic pixel array composed of N×M ultrasonic pixels; b, determining the number of ultrasonic pixel groups in the ultrasonic pixel array; c, generating a first sound wave; d, transmitting the first sound wave to obtain a plurality of second sound waves; e, receiving the plurality of second sound waves, wherein the ultrasonic pixels receiving the plurality of second sound waves are located at or adjacent to the middle position of the ultrasonic pixel groups; f, calculating the plurality of second sound waves to generate pixel signals; g, repeating steps c to f; and h, determining an image according to the plurality of pixel signals.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of acoustic wave sensing imaging, in particular, an ultrasonic array transceiving method and module thereof applying wave peaks and wave troughs related to a biometric feature. BACKGROUND

[0002] Conventionally, in order to provide protection of personal digital information, a mechanism for a user to perform identity verification is provided on an electronic device, such as identity verification through an account and a password, or identity recognition using a biometric feature. Among them, the method of identity verification using a biometric feature is currently widely used, which has the advantages of fast judgment and memory-free.

[0003] Taking fingerprint recognition commonly used in biometric features as an example, the user's own fingerprint is used as the source of identity recognition; however, with the development of thin electronic devices, how to provide electronic components with the requirements of miniaturization, high process yield, and high reliability will be a very important issue.

[0004] Therefore, the present application proposes an ultrasonic array transceiving method and module thereof to solve the shortcomings of the prior art. SUMMARY

[0005] The first object of the present application is an ultrasonic array transceiving method, which extracts images of wave peaks and wave troughs related to a biometric feature to replace, for example, conventional capacitive sensing, so as to achieve the purposes of improving anti-counterfeiting and use in harsh environments (such as the state of a wet finger).

[0006] The second object of the present application is an ultrasonic array transceiving method, which, through a packaged ultrasonic array transceiving module, can be used for biometric image recognition after thin packaging / coupling (such as a packaging thickness of 300 μm-500 μm), such as application in side fingerprint sensing of a portable mobile device or fingerprint sensing in other positions.

[0007] The third object of the present application is an ultrasonic array transceiving method, which can perform regional pixel recognition by grouping ultrasonic pixel groups to quickly perform high-resolution recognition.

[0008] The fourth object of the present application is an ultrasonic array transceiving method, which performs switching of transmission and reception in an ultrasonic pixel group to obtain partial or complete (or all) images related to a biometric feature in a transmission phase (TX-phase) and a reception phase (RX-phase).

[0009] The fifth object of the present application is to provide an ultrasonic array transceiving method according to the above, by using the ultrasonic pixel located in the middle of the ultrasonic pixel group as the pixel receiving the reflected sound wave, the aforementioned ultrasonic pixel can provide a better signal-to-noise ratio, and by obtaining the reflected sound wave with the largest amplitude among the multiple reflected sound waves to obtain a clear pixel pattern.

[0010] The sixth object of the present application is an ultrasonic array transceiving module capable of implementing the ultrasonic array transceiving method to obtain the image of the wave crest and trough related to the biological characteristics.

[0011] The seventh object of the present application is an ultrasonic array transceiving module according to the above, which can be applied to a Piezoelectric Micromachined Ultrasonic Transducers (PMUT) structure or a Capacitive micromachined ultrasonic transducers (CMUT) structure.

[0012] To achieve the above objects and other objects, the present application provides an ultrasonic array transceiving method for wave crests and troughs related to biological characteristics. The ultrasonic array transceiving method comprises the following steps: step a, providing an ultrasonic pixel array composed of N×M ultrasonic pixels, wherein N and M are integers; step b, determining the number of multiple ultrasonic pixel groups in the ultrasonic pixel array, wherein the ultrasonic pixel group is composed of n×m ultrasonic pixels, wherein n is not greater than N and m is not greater than M; step c, driving at least one of the multiple ultrasonic pixel groups, so that at least one of the multiple ultrasonic pixels in the driven ultrasonic pixel group generates a first sound wave, wherein the first sound wave is generated by at least one of the multiple ultrasonic pixels, and at least one of the multiple ultrasonic pixels generating the first sound wave is defined as a transmission phase (TX-phase); step d, the first sound wave is radiated in a certain direction to act on the wave crest and trough to reflect multiple second sound waves; step e, driving at least one of the multiple ultrasonic pixels with the generated first sound wave to receive the multiple second sound waves, wherein the ultrasonic pixel receiving the multiple second sound waves is located at or adjacent to the middle position of the ultrasonic pixel group, and the ultrasonic pixel receiving the multiple second sound waves is defined as a receiving phase (RX-phase); step f, calculating the multiple second sound waves to generate a pixel signal, wherein the pixel signal is related to the wave crest and trough; step g, repeating steps c to f to generate pixel signals corresponding to at least part of the multiple ultrasonic pixel groups; and step h, calculating the multiple pixel signals to determine the complete image or partial image corresponding to the biological characteristics.

[0013] To achieve the above object and other objects, the present application provides an ultrasonic array transceiver module which acts on wave crests and wave troughs associated with a biological feature. The ultrasonic array transceiver module includes an ultrasonic pixel array, a driving unit, and a control unit. The ultrasonic pixel array includes a plurality of ultrasonic pixel groups, and each ultrasonic pixel group is composed of n x m ultrasonic pixels. Here, n and m are integers. The driving unit is connected to the ultrasonic pixel array. The driving unit generates a first driving signal to drive at least one of the plurality of ultrasonic pixels of at least one of the plurality of ultrasonic pixel groups to generate a first sound wave, and the driving unit generates a second driving signal to drive at least one of the plurality of ultrasonic pixels of at least one of the plurality of ultrasonic pixel groups to receive a plurality of second sound waves to generate a pixel signal. Here, the first sound wave is transmitted in a direction approaching the wave crests and wave troughs, and the plurality of second sound waves are transmitted in a direction away from the wave crests and wave troughs. The control unit is connected to the driving unit. The control unit executes an application program to drive the driving unit so that the first driving signal and the second driving signal drive at least a portion of the plurality of ultrasonic pixel groups, and the control unit executes the application program to calculate the pixel signal to generate a full image or a partial image corresponding to the biological feature.

[0014] Compared with conventional techniques, the present application provides an ultrasonic array transceiving method and module which can obtain a full image or a partial image of a biological feature, such as a fingerprint image, by transmitting sound waves and receiving reflected sound waves. In the present application, the ultrasonic array transceiving array is further divided into a plurality of ultrasonic pixel groups, and ultrasonic pixels in each ultrasonic pixel group are used to transmit sound waves and receive sound waves. In one embodiment, ultrasonic pixels, such as those located at the middle positions of the ultrasonic pixel groups, are particularly selected to receive. The pixel signal is formed by receiving a plurality of reflected sound waves reflected after acting on the biological feature from the aforementioned ultrasonic pixels, and taking out the signal with the best (e.g., the largest amplitude) from the plurality of reflected sound waves. A full image or a partial image of the biological feature is obtained by repeatedly performing the plurality of ultrasonic pixel groups. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a flowchart of an ultrasonic array transceiving method according to an embodiment of the present application.

[0016] Figure 2 is a structural schematic diagram of an ultrasonic array transceiver module according to the present application. Figure 1

[0017] Figure 3 is a top view of an ultrasonic pixel array according to a first embodiment of the present application.

[0018] Figure 4a is a structural schematic diagram of an ultrasonic pixel using a capacitive ultrasonic microtransducer according to the present application. ​

[0019] Figure 4b is a structural diagram illustrating an ultrasonic pixel of the present application using a micro-mechanical ultrasonic transducer.

[0020] Figure 5 is a top view of an ultrasonic pixel array and an ultrasonic pixel group of an embodiment of the present application.

[0021] Figure 6a is a top view of an ultrasonic pixel array of another embodiment of the present application. Figure 5

[0022] Figure 6b is a top view of an ultrasonic pixel array of another embodiment of the present application. Figure 5

[0023] Figure 7a 7b and 7c are embodiment diagrams illustrating driving of an ultrasonic pixel of an embodiment of the present application.

[0024] Figure 8a 8b and 8c are embodiment diagrams illustrating driving of an ultrasonic pixel of another embodiment of the present application.

[0025] Figure 9 is a driving voltage diagram for driving an ultrasonic pixel to generate a first sound wave and receive a second sound wave of an embodiment of the present application.

[0026] Figure 10 is a block diagram of an ultrasonic array transceiver module of an embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to fully understand the purpose, features and effects of the present application, the following specific embodiments are described in detail, together with the accompanying drawings, as follows.

[0028] In the present application, "a" or "an" is used to describe units, elements and components described herein. This is only for convenience and to provide a general sense of the scope of the present application. Therefore, unless clearly indicated otherwise, such description should be understood to include one, at least one, and singular also includes plural.

[0029] In the present application, the words "comprise", "include", "have", "contain", or any other similar words are intended to encompass non-exclusive inclusion. For example, an element, structure, article or device containing plural elements is not limited to only the elements listed herein, but can include other elements not explicitly listed but generally inherent to the element, structure, article or device. In addition, unless clearly indicated otherwise, the word "or" means inclusive "or", not exclusive "or".​​​​

[0030] Please refer to Figure 1 , which is a flowchart of the ultrasonic array transceiving method of the embodiment of the present application. In Figure 1 , the ultrasonic array transceiving method acts on the wave peaks and wave troughs related to the biological characteristics, for example, the biological characteristics can be fingerprints, palm prints, etc. Here, the fingerprints are taken as an example for illustration.

[0031] Please refer to Figure 2 , which is a structural schematic diagram of the ultrasonic array transceiving module of the present application. Figure 1 In Figure 2 , the ultrasonic array transceiving module 5 is briefly described as a plurality of structural layers, which are stacked from bottom to top, respectively, substrate 52, driving and sensing circuit layer 54, ultrasonic pixel array layer 56, and coupling layer 58, etc. The fingerprints 2 are arranged on one side of the coupling layer, so that the wave peaks 22 and wave troughs 24 of the fingerprints 2 are attached to the coupling layer 58. In the foregoing, the coupling layer 58 can be a single layer or composed of multiple layers, which are collectively referred to as the coupling layer 58.

[0032] The ultrasonic array transceiving method starts from step S11, which provides an ultrasonic pixel array composed of N×M ultrasonic pixels. Wherein, N and M are integers, N refers to column and M refers to row, for example, N×M can be 160×30, etc. Here, 18×7 is taken as an example for illustration, and please refer to Figure 3 , which is a top view of the ultrasonic pixel array of the first embodiment of the present application. In an embodiment, N and M can determine the shape of the ultrasonic pixel array, for example, a long rectangular ultrasonic pixel array can be applied to the side edge of a thin electronic product.

[0033] In addition, the ultrasonic pixel can be a Piezoelectric Micromachined Ultrasonic Transducers (PMUT) structure or a Capacitive micromachined ultrasonic transducers (CMUT) structure. Please refer to Figure 4a and Figure 4b , which respectively illustrate the structure of a single ultrasonic pixel in the embodiment of the present application. Figure 4a , which illustrates the structure of the ultrasonic pixel of the present application using a Capacitive micromachined ultrasonic transducers structure, and Figure 4b , which illustrates the structure of the ultrasonic pixel of the present application using a Piezoelectric Micromachined Ultrasonic Transducers structure.

[0034] In Figure 4a , the structure of the capacitive ultrasonic micro transducer includes a metal electrode 62 from the lower layer, and in order, a gap 64, a dielectric layer 66, and another metal electrode 68. Among them, the dielectric layer can be silicon dioxide, aluminum oxide, silicon nitride and other materials, and its thickness can range from 0.1 μm to 1.5 μm; the electrode can be aluminum (Al), nickel (Ni), titanium (Ti), copper (Cu), silver (Ag) and other metal materials, and can also include other alloys or silicides, and its thickness can range from 0.1 μm to 1.5 μm; and the gap (or capacitance gap) can be different according to the process, so that the thickness of the gap can range from 30 μm to 100 μm, and the gap is filled with gas or in a vacuum state.

[0035] In Figure 4b , the mechanical ultrasonic micro transducer is illustrated by taking a piezoelectric type as an example. Among them, the structure of the mechanical ultrasonic micro transducer 7 includes a floor structure 72 from the lower layer, and in order, a gap 74, a bottom electrode 76, a piezoelectric material 78, and a top electrode 710. Among them, the floor structure can be silicon dioxide, aluminum oxide, silicon nitride and other materials, and its thickness can range from 0.1 μm to 1.5 μm; the electrode can be aluminum, nickel, titanium, copper, silver, molybdenum and other metal materials, and can also include other alloys or silicides, and its thickness can range from 0.1 μm to 1.5 μm; the piezoelectric material can include aluminum nitride, scandium-doped aluminum nitride (ScAlN), and lead zirconate titanate (PZT), and its thickness can range from 0.1 μm to 1.5 μm; and the gap can be as described above, which is not repeated here.

[0036] Step S12 is to determine the number of ultrasonic pixel groups in the ultrasonic pixel array. Among them, the ultrasonic pixel group is composed of n x m ultrasonic pixels, where n refers to column and m refers to row, which can be referred to in Figure 5This is a top view of the ultrasonic pixel array and ultrasonic pixel group according to an embodiment of the present invention. n is less than or equal to N and m is less than or equal to M. In this step, n×m ultrasonic pixels can be flexibly selected as the ultrasonic pixel group depending on the actual situation. In another embodiment, n and m are odd numbers, and n and m are respectively greater than or equal to 3. In yet another embodiment, n equals m, such that each ultrasonic pixel group has the same number of ultrasonic pixels in both rows and columns, for example, 3×3 or 5×5 ultrasonic pixels are selected as the ultrasonic pixel group. In this embodiment, 3×3 ultrasonic pixels are used as an example.

[0037] It is worth noting that, to achieve better performance, besides planning the entire row and column of the ultrasonic pixel array as ultrasonic pixel groups, the rows and columns at the outer edge of the ultrasonic pixel array can also be excluded from the plan. In other words, at least one of the rows and columns of the ultrasonic pixel array can be reduced, such that the ultrasonic pixel array is reduced from N×M ultrasonic pixels to (NX)×(MY) ultrasonic pixels. The ultrasonic pixel array consisting of (NX)×(MY) ultrasonic pixels can also be called an effective ultrasonic pixel array. Here, X and Y can be integers. X is less than or equal to N and Y is less than or equal to M. For example, see [reference needed]. Figure 6a and 6b This is to illustrate the present invention. Figure 5 Top views of ultrasonic pixel arrays from two other embodiments. Figure 6a In China, the following is adopted Figure 5 A 3×3 ultrasonic pixel group, where n and m are both 3. Here, X and Y are illustrated using a factor of 2, resulting in an effective ultrasonic pixel array that reduces the ultrasonic pixel array from 18×7 ultrasonic pixels to 16×5 ultrasonic pixels. The reduced portion is represented by dashed lines, which can also be called the ineffective region. As mentioned earlier, the effective ultrasonic pixel array composed of (NX)×(MY) ultrasonic pixels can determine the number of multiple ultrasonic pixel groups. Figure 6b In this example, a 5×5 ultrasonic pixel group is used, meaning that n and m can each be 5, and X and Y can each be 4. Here, we will use an 18×9 ultrasonic pixel array as an example. Based on the aforementioned selection of X and Y, the ultrasonic pixel array is reduced from 18×9 ultrasonic pixels to an effective ultrasonic pixel array consisting of 14×5 ultrasonic pixels. The reduced ineffective area is still represented by dashed lines.

[0038] Step S13, driving one of the plurality of ultrasonic pixel groups, so that at least one of the plurality of ultrasonic pixels in the driven ultrasonic pixel group generates a first sound wave. For example, the driving voltage range used to drive the ultrasonic pixel can be several volts to several hundred volts, and the frequency can be 10-30 MHz. Again, the first sound wave is generated by at least one of the plurality of ultrasonic pixels, and the at least one of the plurality of ultrasonic pixels generating the first sound wave is defined as a transmission phase (TX phase), which is illustrated as an ultrasonic pixel group. Among them, the first sound wave refers to the set of sound waves generated by one or more ultrasonic pixels driven synchronously or asynchronously (or oscillated), for example, in an embodiment, the sound wave can be a set of sound waves generated by a plurality of ultrasonic pixels, and the set of sound waves is a plane wave. In other words, the plurality of ultrasonic pixels can be driven synchronously or simultaneously, or can be driven asynchronously or non-simultaneously.

[0039] Step S14, the first sound wave is radiated in a direction to act on the wave crest and wave trough to reflect a plurality of second sound waves. Among them, the aforementioned direction refers to the direction towards the wave crest and wave trough, for example, the aforementioned direction can be perpendicular to the plane of the ultrasonic pixel array, close to perpendicular (or small angle, for example, the angle is less than or equal to 10 degrees) to the plane of the ultrasonic pixel array, or not perpendicular (or large angle, for example, greater than 10 degrees) to the plane of the ultrasonic pixel array. It is worth noting that in order to obtain better second sound waves, the first sound wave is transmitted in a direction perpendicular to the plane of the ultrasonic pixel array.

[0040] Step S15, driving at least one of the plurality of ultrasonic pixels that generates the first sound wave to receive a plurality of second sound waves. Here, the at least one ultrasonic pixel receiving the plurality of second sound waves is located at or adjacent to the middle position of the ultrasonic pixel group, and the plurality of ultrasonic pixels receiving the plurality of second sound waves is defined as a receiving phase (RX phase).

[0041] For reference Figure 7a , 7b and 7c is a schematic diagram of an embodiment of the application for driving ultrasonic pixels. In Figure 7a , 7b In 7c, the left side represents the control state of the ultrasonic pixel driving to transmit the first sound wave, and the right side represents the control state of the ultrasonic pixel driving to receive the second sound wave. Here, the ultrasonic pixel group is taken as an example of 3x3 ultrasonic pixels, which is also applicable to other n x m ultrasonic pixels. Here, the control state is taken as an example of three, in fact, there are still many changes in the state, which all belong to the invention scope of the application.

[0042] State 1

[0043] In Figure 7aIn the diagram on the left, all the ultrasonic pixels are driven to emit sound waves to generate the first sound wave, denoted by Tx. Figure 7a In the diagram on the right, only the ultrasonic pixel located in the middle of the ultrasonic pixel group is driven to receive the second sound wave, denoted by Rx. In this configuration, the ultrasonic pixel located in the middle of the ultrasonic pixel group is driven to emit the first sound wave during the transmission phase and to receive the second sound wave during the reception phase.

[0044] State Sample 2

[0045] exist Figure 7b In the diagram on the left, all ultrasonic pixels except the one located in the middle of the ultrasonic pixel group are driven to emit sound waves to generate the first sound wave. That is, the ultrasonic pixel located in the middle of the ultrasonic pixel group does not emit sound waves, while... Figure 7b In the diagram on the right, only the ultrasonic pixel located in the middle of the ultrasonic pixel group is driven to receive the second sound wave. In this configuration, the ultrasonic pixel located in the middle of the ultrasonic pixel group is only driven to receive the second sound wave during the receiving phase, and does not transmit the first sound wave during the transmitting phase.

[0046] State Sample 3

[0047] exist Figure 7c In the left-hand diagram, the ultrasonic pixels in the driving section emit sound waves to generate a first sound wave. However, in the state of sample two, the ultrasonic pixel located in the middle of the ultrasonic pixel group does not emit the first sound wave. Figure 7c In the diagram on the right, similarly only the ultrasonic pixel located in the middle of the ultrasonic pixel group is driven to receive the second sound wave.

[0048] You can refer to them together. Figure 8b , 8b Figure 8c is a schematic diagram illustrating another embodiment of the present invention, showing the driving state of the ultrasonic pixel. Here, the example is given with a group of 5×5 ultrasonic pixels, which also includes the descriptions of states one to three mentioned above, and will not be repeated here.

[0049] Please refer to the above. Figure 9 This is a schematic diagram of the driving voltage for driving ultrasonic pixels to generate a first sound wave and receive a second sound wave, according to an embodiment of the present invention.

[0050] exist Figure 9In the upper graph of FIG. 1, the vertical axis of the driving voltage schematic diagram represents the voltage value (or bias voltage) for driving the ultrasonic pixel, which can be driven by direct current (DC), pulse or alternating current (AC), and the horizontal axis represents the change of the voltage value for driving the ultrasonic pixel at a certain time. Figure 9 In the lower graph of FIG. 1, the vertical and horizontal axes of the driving voltage schematic diagram are also defined similarly. Figure 9 As described in the upper graph of FIG. 1, the difference is that Figure 9 In the upper graph of FIG. 1, the vertical axis represents the change of the voltage value for driving the ultrasonic pixel to transmit the first sound wave, and Figure 9 In the lower graph of FIG. 1, the vertical axis represents the change of the voltage value for driving the ultrasonic pixel to receive the second sound wave. In addition, in the upper and lower graphs of FIG. 1, Figure 9 In the upper and lower graphs of FIG. 1, three stages are shown, in addition to the transmission stage (TX-phase) and the reception stage (RX-phase) mentioned above, a time of flight is also included, which is defined as the waiting time from the transmission of the first sound wave to the reception of the strongest amplitude (current or voltage type). In an embodiment, in the transmission stage, the ultrasonic pixel is driven in such a way that after the ultrasonic pixel generates the first sound wave, the ultrasonic pixel stops transmitting the first sound wave immediately, and after the ultrasonic pixel stops transmitting the first sound wave, the ultrasonic pixel group is switched from the transmission stage to the reception stage to wait for the second sound wave.

[0051] In step S16, a plurality of second sound waves are calculated to generate a pixel signal. The pixel signal is related to the wave crest and the wave trough. In an embodiment, the pixel signal can be obtained by calculating the second sound wave with the maximum amplitude in the second sound wave.

[0052] Step S17, the steps S13 to S16 are repeated to generate pixel signals of at least a part of the plurality of ultrasonic pixel groups. In the foregoing steps, the pixel signals of a part of the fingerprint are obtained by an ultrasonic pixel group composed of n x m ultrasonic pixels, and in order to obtain the pixel signals of the remaining part of the fingerprint, the corresponding pixel signals are still needed to be obtained by the next ultrasonic pixel group. The foregoing driving modes include various modes, such as sequential driving or scanning driving. In the sequential driving mode, only one ultrasonic pixel group is driven at a time, and the driving voltage can be applied to the next ultrasonic pixel group by switching different lines, so that the driving can be performed by a single set of driving unit and control unit, thereby saving the layout area and cost of the circuit. In another embodiment, each ultrasonic pixel group can also be provided with an independent driving unit and control unit. Furthermore, the next ultrasonic pixel group referred to herein can be designed according to actual needs, for example, the next ultrasonic pixel group can be selected from the ultrasonic pixel groups located on the left, right, top, bottom, or even diagonal direction. Figure 3 For example, the ultrasonic pixel array 12 is taken as an example to illustrate that after the actuation of a single ultrasonic pixel group is completed, the ultrasonic pixel groups located on the left, right, top, bottom, or even diagonal direction can be selected. It is worth noting that one or more ultrasonic pixel groups can be selected to be driven at a time.

[0053] Step S18, the pixel signals are calculated to determine the whole image or part of the image corresponding to the biometric feature.

[0054] Please refer to Figure 10 is a block diagram of an ultrasonic array transceiver module according to an embodiment of the present application. In Figure 10 , the ultrasonic array transceiver module 10 acts on the peaks 22 and valleys 24 related to the biometric feature 2.

[0055] The ultrasonic array transceiver module 10 includes an ultrasonic pixel array 12, a driving unit 14, and a control unit 16.

[0056] The ultrasonic pixel array 12 includes a plurality of ultrasonic pixel groups 122, and each ultrasonic pixel group 122 is composed of n x m ultrasonic pixels 1222. Wherein, n and m are integers. In an embodiment, n and m can be odd numbers, for example, n and m can be greater than or equal to 3, that is, n and m can be 3, 5, 7, 9, etc. odd number. Also, in another embodiment, n is equal to m, so that the number of ultrasonic pixels in the row of the ultrasonic pixel group is equal to the number of ultrasonic pixels in the column, that is, it can present a symmetrical pattern.

[0057] The driving unit 14 is connected to the ultrasonic pixel array 12. The driving unit 14 generates a first driving signal FDS to drive the ultrasonic pixels 1222 in the ultrasonic pixel group 1222 to generate a first sound wave FW, and the driving unit 14 generates a second driving signal SDS to drive the ultrasonic pixels 1222 in the same ultrasonic pixel group 122 to receive a plurality of second sound waves SW to generate a pixel signal PS. The first sound wave FW is transmitted in a direction approaching the wave peak 22 and the wave valley 24, and the plurality of second sound waves SW are transmitted in a direction away from the wave peak 22 and the wave valley 24. As described above, if n and m are odd numbers, the driving unit 14 can select the ultrasonic pixels 1222 in the middle position of each ultrasonic pixel group 122 to receive the second sound waves SW. In addition, the first driving signal FDS is at least one of a sinusoidal wave, a tone-burst wave, and a square wave, and the driving frequency of the first driving signal FDS is at least tens of MHz. Preferably, the driving frequency can range between 10 MHz and 50 MHz.

[0058] In addition, the driving unit 14 generates a first driving signal FDS to synchronously drive the ultrasonic pixels 1222 in the ultrasonic pixel group 122 to generate a plurality of first sound waves FW, so that the first sound waves FW are superimposed into quasi-plane waves or plane waves. At this time, the number of ultrasonic pixels 1222 synchronously driven further determines whether the plurality of first sound waves FW after superposition are quasi-plane waves or plane waves, for example, the more the number of driving, the closer to the plane wave.

[0059] It is worth noting that the driving unit 14 can actually further include at least one of a signal amplification circuit, a filter circuit, a direct current source generation circuit, an alternating current source generation circuit, a peak detection circuit, a digital / analog conversion circuit, or an analog / digital conversion circuit, etc. to perform electrical signal processing on the second sound waves, for example, the signal amplification circuit can amplify the signal received by the ultrasonic pixel 1222, the filter circuit can filter out noise of the signal, the direct current source generation circuit can generate a direct current bias, the alternating current source generation circuit can generate an alternating current bias, the peak detection circuit can detect or distinguish the amplitude strength of the signal, the digital / analog conversion circuit can convert digital signals into analog signals, and the analog / digital conversion circuit can convert analog signals into digital signals. Since the driving unit can select one or more of the above circuits according to circuit design, the type of circuit is not limited here.

[0060] The control unit 16 is connected to the drive unit 14. The control unit 16 executes the application program APP to drive the drive unit 14 so that the first drive signal FDS and the second drive signal SDS drive at least a portion of the plurality of ultrasonic pixel groups 122, and the control unit 16 executes the application program APP to calculate the pixel signal PS to generate the full image or the partial image 26 corresponding to the biometric feature 2. In an embodiment, the control unit 16 sequentially drives each ultrasonic pixel group 122 with the first drive signal FDS and the second drive signal SDS according to the application program APP.

[0061] Further, the ultrasonic array transceiver module 10 can further include a coupling layer (not shown) to cover the ultrasonic pixel array 12. The coupling layer has a thickness to form a cavity between the biometric feature and the ultrasonic pixel array. The coupling layer can be a single layer of material or a multi-layer structure.

[0062] The present application has been described in relation to the preferred embodiment, although persons skilled in the art will recognize that changes and modifications can be made thereto without departing from the scope of the application. It is also to be understood that the preceding description is illustrative of the application and should not be used to limit the scope of the application. Various substitutions, alterations, and / or modifications can be made to the illustrative embodiments without departing from the spirit and scope of the application as defined by the following claims. Therefore, the scope of the application should be determined by the following claims.

[0063] SYMBOL DESCRIPTION

[0064] 2…biometric feature

[0065] 5…ultrasonic array transceiver module

[0066] 52…substrate

[0067] 54…drive and sense circuit layer

[0068] 56…ultrasonic pixel array layer

[0069] 58…coupling layer

[0070] 6…capacitive ultrasonic microtransducer

[0071] 62…metal electrode

[0072] 64…gap

[0073] 66…dielectric layer

[0074] 68…metal electrode

[0075] 7…mechanical ultrasonic microtransducer

[0076] 72…underlying substrate

[0077] 74…gap

[0078] 76...lower electrode

[0079] 78...piezoelectric material

[0080] 710...top electrode

[0081] 10...ultrasound array transceiver module

[0082] 12...ultrasound pixel array

[0083] 122...ultrasound pixel group

[0084] 1222...ultrasound pixel

[0085] 14...drive unit

[0086] 16...control unit

[0087] 22...wave peak

[0088] 24...wave trough

[0089] 26...image

[0090] FDS...first drive signal

[0091] SDS...second drive signal

[0092] FW...first sound wave

[0093] SW...second sound wave

[0094] PS...pixel signal

[0095] APP...application

[0096] S11-S18...steps

Claims

1. An ultrasonic array transceiver method, acting on peaks and troughs related to biometrics, the ultrasonic array transceiver method comprising the following steps: Step a: Provide an ultrasonic pixel array consisting of N×M ultrasonic pixels, wherein, N and M are integers; Step b: Determine the number of multiple ultrasonic pixel groups in the ultrasonic pixel array, wherein the ultrasonic pixel group consists of n×m ultrasonic pixels, where n is not greater than N and m is not greater than M; Step c: Drive at least one of the plurality of ultrasonic pixel groups, such that at least one of the plurality of ultrasonic pixels in the driven ultrasonic pixel group generates a first sound wave, wherein the first sound wave is generated by at least one of the plurality of ultrasonic pixels, and the generation of the first sound wave by at least one of the plurality of ultrasonic pixels is defined as the transmission phase. Step d: The first sound wave radiates in a certain direction to act on the wave crest and the wave trough and reflect multiple second sound waves; Step e: Drive at least one of the plurality of ultrasonic pixels generated by the first sound wave to receive the plurality of second sound waves, wherein the ultrasonic pixel receiving the plurality of second sound waves is located at or near the center of the group of ultrasonic pixels, and the receipt of the plurality of second sound waves by the ultrasonic pixel is defined as a receiving phase. Step f: Calculate the plurality of second sound waves to generate pixel signals, wherein the pixel signals are related to the peaks and troughs; Step g, repeating steps c to f, causes at least a portion of the plurality of ultrasonic pixel groups to generate their corresponding pixel signals; and Step h: Calculate multiple pixel signals to determine all or part of the image corresponding to the biometric feature.

2. The ultrasonic array transceiver method as described in claim 1, wherein, Step b further includes reducing at least one of the rows and columns of the ultrasonic pixel array, such that the ultrasonic pixel array is reduced from N×M ultrasonic pixels to an ultrasonic pixel array of (NX)×(MY) ultrasonic pixels, wherein X and Y are integers, and X is less than or equal to N or Y is less than or equal to M.

3. The ultrasonic array transceiver method as described in claim 2, wherein, The reduced rows and columns of the ultrasonic pixel array are located at the outer edge of the ultrasonic pixel array.

4. The ultrasonic array transceiver method as described in claim 2, wherein, Step b further includes determining the number of the plurality of ultrasonic pixel groups in the ultrasonic pixel array composed of (NX)×(MY) ultrasonic pixels.

5. The ultrasonic array transceiver method as described in claim 1 or 2, wherein, The n and m are odd numbers, and the n and m are each not less than 3.

6. The ultrasonic array transceiver method as described in claim 1 or 2, wherein n is equal to m, such that each ultrasonic pixel group has the same number of ultrasonic pixels in both rows and columns.

7. The ultrasonic array transceiver method as described in claim 6, wherein n is equal to m, and the ultrasonic pixel located at the middle position of the ultrasonic pixel group receives the plurality of second sound waves, wherein... The ultrasonic pixel located in the middle of the ultrasonic pixel group selectively serves as the emission source for radiating the first sound wave.

8. The ultrasonic array transceiver method as claimed in claim 1, step c further includes stopping the generation of the first sound wave by the ultrasonic pixels in the ultrasonic pixel group after at least one of the plurality of ultrasonic pixels generates the first sound wave.

9. The ultrasonic array transceiver method as described in claim 8, further comprising, before step e, switching the ultrasonic pixel group from the transmitting phase to the receiving phase after stopping the generation of the first sound wave, in order to wait for the plurality of second sound waves.

10. The ultrasonic array transceiver method as claimed in claim 1, step f further includes obtaining the second acoustic wave with the maximum amplitude among the plurality of second acoustic waves to calculate the pixel signal.

11. An ultrasonic array transceiver module, acting on peaks and troughs related to biometrics, the ultrasonic array transceiver module comprising: An ultrasonic pixel array has multiple ultrasonic pixel groups, and each ultrasonic pixel group consists of n×m ultrasonic pixels, where... n and m are integers; A driving unit, connected to the ultrasonic pixel array, generates a first driving signal to drive at least one of the ultrasonic pixels in the plurality of ultrasonic pixel groups to generate a first sound wave, and generates a second driving signal to drive at least one of the ultrasonic pixels in the plurality of ultrasonic pixel groups to receive a plurality of second sound waves to generate a pixel signal, wherein the first sound wave is sent in a direction close to the wave crest and the wave trough, and the plurality of second sound waves are sent in a direction away from the wave crest and the wave trough; as well as A control unit, connected to the driving unit, executes an application program to drive the driving unit such that the first driving signal and the second driving signal drive at least a portion of the plurality of ultrasonic pixel groups, and the control unit executes the application program to calculate the pixel signals to generate all or part of an image corresponding to the biometric feature.

12. The ultrasonic array transceiver module as described in claim 11, wherein, The driving unit further includes at least one of a signal amplification circuit, a filtering circuit, a DC source generation circuit, an AC source generation circuit, a peak detection circuit, a digital / analog conversion circuit, or an analog / digital conversion circuit to perform electrical signal processing on the plurality of second acoustic waves.

13. The ultrasonic array transceiver module as described in claim 11, wherein, The n and m are odd numbers, and the n and m are each not less than 3.

14. The ultrasonic array transceiver module as described in claim 13, wherein, The n is equal to the m, such that the number of ultrasonic pixels in a row in each ultrasonic pixel group is equal to the number of ultrasonic pixels in a column.

15. The ultrasonic array transceiver module as described in claim 14, wherein, The ultrasonic pixel at the middle position of each ultrasonic pixel group is selected to receive the plurality of second sound waves.

16. The ultrasonic array transceiver module as described in claim 11, wherein, The control unit sequentially drives each ultrasonic pixel group with the first drive signal and the second drive signal according to the application.

17. The ultrasonic array transceiver module as described in claim 11, wherein, The multiple ultrasonic pixels are micromechanical ultrasonic transducer structures or capacitive ultrasonic microtransducer structures.

18. The ultrasonic array transceiver module of claim 11, further comprising a coupling layer covering the ultrasonic pixel array and having a certain thickness to form a cavity between the biometric feature and the ultrasonic pixel array, wherein... The coupling layer is composed of a single material or a multi-layer material structure.

19. The ultrasonic array transceiver module as described in claim 11, wherein, The driving unit generates a first driving signal to synchronously drive the multiple ultrasonic pixels of the multiple ultrasonic pixel groups to generate multiple first sound waves, such that the multiple first sound waves are superimposed into a plane wave or a plane wave.

20. The ultrasonic array transceiver module as described in claim 11, wherein, The first driving signal is at least one of a sine wave, an audio pulse wave, and a square wave.

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