Segmented transducers for acoustic applications

Abstract

Some disclosed devices may include a display stack, a cover layer proximate a first side of the display stack and a segmented transducer array proximate a second side of the display stack. The segmented transducer array may include a plurality of separate transducer segments. Each of the separate transducer segments may include a piezoelectric layer and a thin-film transistor (TFT) layer. The separate transducer segments may include transmitter transducer segments and receiver transducer segments. In some examples, a spacing between at least a first plurality of the transmitter transducer segments may correspond to a display stack and cover layer oscillation mode frequency in a range from

Description

[Technical Field]

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Patent Application No. 17 / 301,061, filed March 23, 2021, entitled "SEGMENTED TRANSDUCERS FOR ACOUSTIC APPLICATIONS", the entire contents of which are incorporated herein by reference.

[0003] This disclosure is generally related to transducers and related methods, including but not limited to acoustic transducers and methods of using acoustic transducers. [Previous Technology]

[0004] Many existing products include one or more acoustic transducers. Ultrasonic transducers can be used for biometric identification, which is an important function for controlling access to devices such as mobile phones. Although some existing acoustic transducers provide satisfactory performance, improved methods and devices are desired. [Summary of the Invention]

[0005] The systems, methods and apparatuses disclosed herein each have several innovative forms, none of which are a single correspondence to the ideal properties disclosed herein.

[0006] The innovative aspects of the technical subject matter described in this disclosure can be implemented in an apparatus. The apparatus may include a display stack and a cover layer adjacent to a first side of the display stack. The apparatus may include a segmented transducer array adjacent to a second side of the display stack. In some examples, the segmented transducer array may include a plurality of separate transducer segments. In some examples, each of these separate transducer segments may include a piezoelectric layer and a thin-film transistor (TFT) layer. In some implementations, the separate transducer segments may include transmitter transducer segments and receiver transducer segments. According to some examples, the spacing between at least the first plurality of transmitter transducer segments may correspond to the display stack and cover layer oscillation mode frequency. In some implementations, the display stack and cover layer oscillation mode frequency may be in the range of 20 Hz to 20 kHz. In some examples, the display stack and cover layer oscillation mode frequency is in the range of 15 kHz to 200 kHz, or in the range of 20 kHz to 400 kHz.

[0007] Some implementations may include a control system. In some examples, at least a portion of the control system is coupled (e.g., electrically or wirelessly coupled) to the segmented transducer array. The control system may include one or more general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or combinations thereof.

[0008] According to some examples, the control system can be configured to control at least a first plurality of transmitter transducer segments to reproduce audio signals by causing the display stack and overlay to oscillate at frequencies in the range of 20 Hz to 20 kHz.

[0009] In some examples, the control system may be configured to drive transmitter transducer segments and / or obtain receiver signals from receiver transducer segments. According to some examples, the control system may be configured to perform noise cancellation based on receiver signals received from two or more receiver transducer segments. In some such examples, the control system may be further configured to detect gestures at least in part based on signals received via one or more receiver transducer segments. In some such examples, the control system may be configured to control at least a first plurality of transmitter transducer segments to cause the display stack and overlay to oscillate at frequencies in the range of 20 kHz–400 kHz. According to some such examples, the control system may be configured to detect gestures at least in part based on ultrasonic signals received via one or more receiver transducer segments.

[0010] In some implementations, the spacing between at least the second plurality of transmitter transducer segments may correspond to a display stacking and overlay oscillation mode for frequencies in the range of 20 Hz to 20 kHz.

[0011] Depending on some implementations, the control system may be further configured to perform noise cancellation based on receiver signals received from two or more receiver transducer segments.

[0012] In some implementations, the distance between the centers of the first plurality of transmitter transducer segments may be equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, which corresponds to the frequency of the display stack and overlay oscillation mode. In such an example, the "mode wavelength" corresponds to the distance between the peaks of the display stack and overlay oscillation mode.

[0013] According to some examples, the thickness of each of the first plurality of transmitter transducer segments may be different from the thickness of each of the first plurality of receiver transducer segments. In some such examples, the thickness of the piezoelectric layer of each of the first plurality of receiver transducer segments may be greater than the thickness of the piezoelectric layer of each of the first plurality of transmitter transducer segments.

[0014] In some examples, a first subset of separate transducer segments may have a first segment width, and a second subset of separate transducer segments may have a second segment width.

[0015] According to some examples, the control system can be configured to drive the transmitter transducer segments in a high-order mode. In some such examples, adjacent transmitter transducer segments of the first plurality of transmitter transducer segments can be driven in opposite directions.

[0016] In some examples, the control system can be configured to drive the transmitter transducer segments in an intermediate-order mode. In some such examples, during the period when the first transmitter transducer segment of the first plurality of transmitter transducer segments can be driven in a first direction, the second transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is not driven, and the third transducer segment of the first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in a second direction opposite to the first direction.

[0017] According to some examples, the control system can be configured to drive the transmitter transducer segments in a low-order mode. In some such examples, during the time during which a first transmitter transducer segment of a first plurality of transmitter transducer segments is driven in a first direction, a second transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is driven in the first direction, and a third transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the first direction.

[0018] Other innovative embodiments of the technical subject matter described in this disclosure can be implemented in an apparatus. The apparatus may include a display stack and a cover layer adjacent to a first side of the display stack. The apparatus may include a segmented transducer array adjacent to a second side of the display stack. In some examples, the segmented transducer array may include a plurality of separate transducer segments. In some examples, each of these separate transducer segments may include a piezoelectric layer and a thin-film transistor (TFT) layer. In some implementations, the separate transducer segments may include transmitter transducer segments and receiver transducer segments. According to some examples, the spacing between at least the first plurality of transmitter transducer segments may correspond to the oscillation mode frequency of the display stack and the cover layer. In some implementations, the oscillation mode frequency of the display stack and the cover layer may be in the range of 20 kHz to 400 kHz.

[0019] According to some examples, the distance between the centers of the first plurality of transmitter transducer segments may be equal to one mode wavelength, half a mode wavelength, one-quarter a mode wavelength, or one-eighth a mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

[0020] Other innovative forms of the technical subject matter described in this disclosure can be implemented in a method for controlling a segmented transducer array. According to some examples, the method may involve controlling at least a first plurality of transmitter transducer segments of a segmented transducer array to reproduce an audio signal by causing the display stack and overlay to oscillate at frequencies in the range of 20 Hz to 20 kHz.

[0021] In some examples, the method may involve driving a transmitter transducer segment and / or obtaining a receiver signal from a receiver transducer segment. According to some examples, the method may involve performing noise cancellation based on receiver signals received from two or more receiver transducer segments. In some such examples, the method may involve detecting a gesture at least in part based on signals received via one or more receiver transducer segments. In some such examples, the method may involve controlling at least a first plurality of transmitter transducer segments to cause the display stack and overlay to oscillate at frequencies in the range of 20 kHz to 400 kHz. According to some such examples, the method may involve detecting a gesture at least in part based on ultrasonic signals received via one or more receiver transducer segments.

[0022] In some implementations, the spacing between at least the second plurality of transmitter transducer segments may correspond to a display stacking and overlay oscillation mode for frequencies in the range of 20 Hz to 20 kHz.

[0023] According to some implementations, the method may involve performing noise cancellation based on receiver signals received from two or more receiver transducer segments.

[0024] In some implementations, the distance between the centers of the first plurality of transmitter transducer segments may be equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the frequency of the display stack and overlay oscillation mode. In such an example, the "mode wavelength" corresponds to the distance between the peaks of the display stack and overlay oscillation mode.

[0025] According to some examples, the thickness of each of the first plurality of transmitter transducer segments may be different from the thickness of each of the first plurality of receiver transducer segments. In some such examples, the thickness of the piezoelectric layer of each of the first plurality of receiver transducer segments may be greater than the thickness of the piezoelectric layer of each of the first plurality of transmitter transducer segments.

[0026] In some examples, a first subset of separate transducer segments may have a first segment width, and a second subset of separate transducer segments may have a second segment width.

[0027] According to some examples, the method may involve driving transmitter transducer segments in higher-order modes. In some such examples, adjacent transmitter transducer segments of the first plurality of transmitter transducer segments may be driven in opposite directions.

[0028] In some examples, the method may involve driving the transmitter transducer segment in an intermediate-order mode. In some such examples, during the time when the first transmitter transducer segment of the first plurality of transmitter transducer segments is driven in a first direction, the second transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is not driven, and the third transducer segment of the first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in a second direction opposite to the first direction.

[0029] According to some examples, the method may involve driving transmitter transducer segments in a low-order mode. In some such examples, during the time during which a first transmitter transducer segment of a first plurality of transmitter transducer segments is driven in a first direction, a second transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is driven in the first direction, and a third transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the first direction.

[0030] Some or all of the operations, functions, and / or methods described herein may be performed by one or more devices according to instructions (e.g., software) stored on one or more non-transitory media. Such non-transitory media may include memory devices as described herein, including but not limited to random access memory (RAM) devices, read-only memory (ROM) devices, etc. Therefore, some innovative aspects of the technical subject matter of this disclosure may be implemented in one or more non-transitory media on which software is stored. For example, the software may include instructions to control one or more devices to perform one or more (in some cases, all) of the disclosed methods for controlling segmented transducer arrays.

Implementation Method

[0047] The following description is directed to certain implementations and is intended to illustrate the innovative nature of this disclosure. However, those skilled in the art will readily recognize that the teachings herein can be applied in a variety of different ways. The described implementations can be implemented in any device, appliance, or system that includes the segmented transducer array disclosed herein. Furthermore, the described implementations can be included in or associated with various electronic devices, such as, but not limited to: mobile phones, cellular phones supporting multimedia internet, mobile TV receivers, wireless devices, smartphones, smart cards, wearable devices, such as bracelets, armbands, wristbands, rings, headbands, patches, etc. Bluetooth® devices, Personal Data Assistants (PDAs), Wireless Email Receivers, Handheld or Portable Computers, Minicomputers, Notebooks, Smartphones, Tablets, Printers, Copiers, Scanners, Fax Devices, Global Positioning System (GPS) Receivers / Navigators, Cameras, Digital Media Players (such as MP3 Players), Camcorders, Game Consoles, Watches, Clocks, Calculators, Television Displays, Flat Panel Displays, E-reading Devices (such as E-readers), Mobile Health Devices, Computer Monitors, Automobiles, including but not limited to automotive displays (including odometer and speedometer displays), cockpit controls and / or displays, camera view displays (such as rearview camera displays in vehicles), Electronic Photographs, Electronic Billboards or Signs, Projectors, Building Structures, Microwave Ovens, Refrigerators, Audio Systems, Tape Recorders or Players, DVD Players, CD Players, Video Recorders, Radios, Portable Memory Chips, Washing Machines, Dryers, Washer / Dryer Units, Parking Meters, Packaging, etc. The teachings herein can also be applied to, but are not limited to, electronic switching devices, radio frequency filters, sensors, accelerometers, gyroscopes, motion sensing devices, magnetometers, inertial components of consumer electronics, parts of consumer electronics, steering wheels, door handles or other automotive parts, transformers, liquid crystal devices, electrophoresis apparatus, drive systems, manufacturing processes, and electronic testing equipment. Therefore, the present invention is not limited to the implementations described in the figures, but has broad applicability, as will be apparent to those skilled in the art.

[0048] The inventors have developed novel devices, some of which utilize materials previously deployed in ultrasonic sensor systems, such as piezoelectric layers (e.g., piezoelectric polymers). Some of these devices are configured for gesture detection, e.g., ultrasonic gesture detection. Alternatively or additionally, some of these devices are configured to generate sound in a frequency range audible to humans, approximately 20 Hz to 20,000 Hz. Some of these devices include an in-display audio reproduction transducer, which may be referred to herein as an in-display speaker or in-display amplifier. In developing these novel devices, the inventors discovered that simply increasing the size of the in-display acoustic transducer does not necessarily produce a device capable of providing sufficiently high sound pressure levels for a satisfactory in-display speaker.

[0049] The inventors have developed various segmented transducer array designs. In some examples, the segmented transducer array may include a plurality of separate transducer segments. Each of the separate transducer segments may include a piezoelectric layer and a thin-film transistor (TFT) layer. Some such devices are configured to selectively actuate the transducer array electrodes to increase the sound pressure level (SPL). In some implementations, the transducer segments may have different sizes to optimize transmission or reception, and / or to optimize transmission or reception at different frequencies.

[0050] Specific implementations of the technical subject matter described in this disclosure may achieve one or more of the following potential advantages. Some disclosed devices include segmented transducer arrays that can provide sufficiently high sound pressure levels for satisfactory in-display speakers. Some such devices can provide satisfactory gesture detection functionality. According to some examples, two or more transmitter transducer segments with different center frequencies can be configured to operate simultaneously to expand the transmission bandwidth. In some examples, two or more transmitter transducer segments can be configured for beamforming to improve the transmitted signal. According to some implementations, the control system can be configured to perform noise cancellation and / or beamforming based on receiver signals received from two or more receiver transducer segments.

[0051] Figure 1A shows a cross-section through a portion of an apparatus according to an example. According to this example, the apparatus 101 includes a non-segmented transducer stack 103 extending to a region including a majority of the overlying display stack 105. More detailed examples of the transducer stack and display stack will be described below. In some cases, the display stack 105 may include a cover plate. The sine wave 107a represents the combined oscillation of the non-segmented transducer stack 103 and the overlying display stack 105, generated by causing the non-segmented transducer stack 103 and the overlying display stack 105 to vibrate at a specific frequency. This sine wave may also be referred to herein as a vibration mode or oscillation mode.

[0052] Some of the inventors' initial efforts in developing in-display applications (including but not limited to in-display speaker applications) involved the assumption that a design similar to FIG. 1A, in which a non-segmented transducer stack extends to an area corresponding to most or all of the overlying display stack, could be optimized to provide suitable functionality. However, the inventors found that simply increasing the size of the acoustic transducer stack to correspond to the entire display did not produce a device capable of providing sufficiently high sound pressure levels for a satisfactory in-display speaker. Furthermore, even optimizing the thickness of each layer of the transducer stack configured as shown in FIG. 1A did not produce a device capable of generating sufficiently high sound pressure levels, for example, a satisfactory in-display speaker.

[0053] Figure 1B shows a cross-section of a portion of an alternative device according to an example. According to this example, appliance 101 includes a segmented transducer stack 109 extending to a large portion of an overlying display stack 105. In this example, the segmented transducer stack 109 includes individual transducer segments 111. According to this implementation, the spacing between the transducer segments 111 (which may be transmitter transducer segments in some implementations) corresponds to the desired display stack and overlying layer oscillation mode frequencies. In Figure 1B, a sine wave 107b represents the combined oscillation of the segmented transducer stack 109 and the overlying display stack 105. In this example, the spacing between the centers of the individual segments 111 corresponds to the "mode wavelength" of the sine wave 107b as described herein (shown as λ1 in Figure 1B). As used herein, the term "mode wavelength" refers to the distance between the peaks of the display stack and overlying layer oscillation modes. In this example, the desired display stack and overlying layer oscillation mode frequencies correspond to the quality, rigidity, and dimensions of the structure, for example, as described below.

[0054] Figure 1C shows a cross-section of a portion of the device of Figure 1B according to another example. According to this example, the device 101 includes the same segmented transducer stack 109 shown in Figure 1B. However, in this example, the device 101 is controlled to oscillate at different and lower frequencies. In Figure 1C, the sine wave 107c represents the oscillation of the combined segmented transducer stack 109 and the overlay display stack 105 at this different and lower frequency. According to this implementation, the spacing between at least the first plurality of transmitter transducer segments is one-quarter of the oscillation mode frequency of the display stack and overlay, corresponding to the rigidity, mass, and size of the entire stack. In Figure 1C, an example of the resting position of transducer segment 111 is labeled 111a, and an example of the displaced transducer segment 111 is labeled 111b. By comparing Figures 1B and 1C, it can be seen that the same set of transducer segments 111 can be used to transmit or receive sound waves of different frequencies.

[0055] Figure 2A is a graph showing the relationship between sound pressure level (SPL) and frequency according to an example. In this example, graph 200 corresponds to the SPL generated by individual transducer segments. Each SPL peak shown in Figure 2A corresponds to a different resonant frequency. Each resonant frequency has a specific vibration mode.

[0056] Figures 2B, 2C, 2D, and 2E show examples of vibration modes corresponding to the SPL peak shown in Figure 2A. According to these examples, individual transducer segments 211a are driven in the display stack 205 to generate vibration modes corresponding to the SPL peak in Figure 2A. Figure 2B shows vibration mode 225 corresponding to the SPL peak 205 of Figure 2A. The integers from -3 to 3 in Figures 2C, 2D, 2E, and 2F correspond to the spacing between the peaks and adjacent troughs of vibration mode 225 shown in Figure 2B. In this example, the spacing between the peaks and adjacent troughs is 1 x 10⁴ micrometers, indicating that the mode wavelength λa of vibration mode 225 is approximately 2 x 10⁴ micrometers.

[0057] Figure 2C shows vibration mode 230 corresponding to SPL peak 210 in Figure 2A. Figure 2D shows vibration mode 235 corresponding to SPL peak 215 in Figure 2A. Figure 2E shows vibration mode 240 corresponding to SPL peak 220 in Figure 2A. It can be observed that the mode wavelengths of vibration modes 230, 235, and 240 are increasingly longer than the mode wavelength λa of vibration mode 225.

[0058] The oscillation frequency of the structure (such as the stacked and overlay layers shown) corresponds to the frequency of the sound waves excited into the air. This oscillation frequency depends on the size of the structure and the material properties. Specifically, for a rectangular plate of uniform thickness with all edges clamped, this resonant frequency can be calculated as follows.

[0059] In Equation 1, (= 1, 2, ...) represents constants, depending on the vibration mode and the ratio of the width to the length of the plate, represents the width of the plate, represents the weight per unit area of ​​the plate (depending on the size and material density), represents the gravitational acceleration, and represents the bending stiffness of the plate. The bending stiffness of the plate can be expressed as follows. In Equation 2, represents the Young's modulus of the material, represents the thickness of the plate, and represents the Poisson's ratio of the material. The relevant material is described in Young, Warren C., Richard G. Budynas and Ali M. Sadegh, Roark's formulas for stress and strain, (McGraw-Hill Education, 2012), which is incorporated herein by reference.

[0060] According to some implementations, at least some of the transducer segments of the segmented transducer stack can be spaced according to one or more desired vibration modes. When the segmented transducer stack is used in transmission mode, at least some of the transducer segments of the segmented transducer stack can be driven according to the spacing of the transducer segments and one or more desired vibration modes.

[0061] Figures 3A, 3B, and 3C illustrate examples of driving a segmented transducer stack under various vibration modes. Figure 3A shows an example of driving a segmented transducer stack in "Configuration 3", which corresponds to vibration mode 225 shown in Figure 2B. However, vibration mode 225 shown in Figure 2B is caused by driving only individual transducer segments 211a. In Configuration 3, adjacent transducer segments of the segmented transducer stack 309 are driven in opposite directions. For example, when transducer segment 311a is driven in the direction of arrow 301a, transducer segments 311b and 311c are driven in the directions of arrows 301b and 301c. As shown in Figure 3A, driving the segmented transducer stack 309 according to Configuration 3 results in an SPL (Surface Performance Level) of approximately 14 kHz generated by the segmented transducer stack 309 and the attached display stack 305 that is approximately 10 dB higher than the SPL generated by the individual transducer examples in Figure 2B.

[0062] Figure 3B shows an example of driving the segmented transducer stack 309 in "Configuration 2", which corresponds to vibration mode 235 shown in Figure 2D. However, vibration mode 225 shown in Figure 2D is caused by driving only individual transducer segments 211a. In Configuration 2, each of the other transducer segments is driven in the opposite direction. For example, when transducer segment 311a is driven in the direction of arrow 301f, transducer segments 311d and 311e are driven in the directions of arrows 301d and 301e. In some examples of Configuration 2, transducer segments 311b and 311c may not be driven. As recorded in Figure 3B, driving the segmented transducer stack 309 according to Configuration 2 produces a vibration mode of approximately 3 kHz, which is much larger than the displacement produced by the individual transducer example in Figure 2D.

[0063] Figure 3C illustrates an example of driving the segmented transducer stack 309 in "Configuration 1", corresponding to the vibration mode 240 shown in Figure 2E. In Configuration 1, at least some adjacent transducer segments are driven in the same direction. For example, when transducer segment 311a is driven in the direction of arrow 301i, transducer segments 311b and 311c are driven in the directions of arrows 301h and 301j. In some such examples, when transducer segment 311a is driven in the direction of arrow 301i, transducer segments 311d and 311e are driven in the directions of arrows 301g and 301k, respectively. As shown in Figure 3C, according to configuration 1, the segmented transducer stack 309 is driven so that the segmented transducer stack 309 and the attached display stack 305 produce an SPL at approximately 0.5 kHz that is about 10 dB higher than the SPL produced by the individual transducer examples in Figure 2E at the same frequency.

[0064] Figure 4A shows the SPL versus frequency for five examples of transducers and transducer arrays. All the graphs shown in Figure 4A correspond to the SPL generated by these five different types of transducers and transducer arrays, each of which is attached to a display stack and overlay of the same type and size. Each graph shown in Figure 4A corresponds to the SPL generated by the oscillations of the display stack and overlay caused by the transducer or transducer array within the indicated frequency range. In this example, the frequency range is zero to 20 kHz, which includes the audible spectrum for most people.

[0065] Curve 405 corresponds to the SPL generated by the single transducer implementation, which is the single transducer implementation described above with reference to Figures 2B-2E in this example. Curve 405 corresponds to the graph shown in Figure 2A.

[0066] According to this example, curve 410 corresponds to a "full-coverage" non-segmented transducer that extends across the entire display stack area. One might expect that a larger "full-coverage" transducer would produce a much higher SPL at most or all frequencies than a single-transducer implementation. However, this is not the case. While the "full-coverage" transducer produces a higher SPL than a single transducer in certain frequency ranges (e.g., 1–2 kHz, 4–6 kHz, and 9–12 kHz), in other frequency ranges (e.g., 2.5–3 kHz, 7–8 kHz, and 14–18 kHz), a single-transducer implementation slightly outperforms the "full-coverage" transducer.

[0067] In this example, curve 415 corresponds to the SPL generated by the segmented transducer driven according to configuration 1, one example of which is described above with reference to Figure 3C. The SPL generated by the segmented transducer driven according to configuration 1 is higher than that of the "full coverage" transducer or the single transducer in certain frequency ranges (e.g., below about 700 Hz, 2-2.5 kHz, 11.5-14 kHz, and 17-20 kHz), but the "full coverage" transducer and the single transducer outperform the segmented transducer driven according to configuration 1 in other frequency ranges.

[0068] According to this example, curve 420 corresponds to the SPL generated by the segmented transducer driven by configuration 2, one example of which is described above with reference to Figure 3B. The segmented transducer driven by configuration 2 generates a higher SPL in certain frequency ranges (e.g., 2-2.5 kHz and 17.5-20 kHz) than the implementation of the "full coverage" transducer or the single transducer, but the "full coverage" transducer and the single transducer implementation outperform the segmented transducer driven by configuration 2 in other frequency ranges.

[0069] In this example, curve 425 corresponds to the SPL generated by the segmented transducer driven according to configuration 3, one example of which is described above with reference to Figure 3A. The SPL generated by the segmented transducer driven according to configuration 3 is higher than that of the "full coverage" transducer or single transducer in certain frequency ranges (e.g., 2-2.5 kHz, 5.5-6.5 kHz, and 10.5-20 kHz), but the "full coverage" transducer and single transducer outperform the segmented transducer driven according to configuration 3 in other frequency ranges.

[0070] Figure 4B shows the displacement versus frequency for the same five examples of transducers and transducer arrays described above with reference to Figure 4A. All the graphs shown in Figure 4B correspond to the displacements produced by these five different types of transducers and transducer arrays, each type being connected to a display stack and overlay of the same type and size. In this example, the frequency range is zero to 20 kHz, which is the same range shown in Figure 4A.

[0071] Curve 430 corresponds to the displacement produced by the single transducer implementation, which is the single transducer implementation described in this example with reference to Figures 2B-2E above. According to this example, curve 435 corresponds to a "full-coverage" non-segmented transducer. At most or all frequencies, the displacement produced by the "full-coverage" transducer is larger than that produced by the single transducer implementation. However, the difference between the displacement produced by the "full-coverage" transducer implementation and the single transducer implementation is not as large as one might expect, especially in certain frequency ranges (e.g., around 3 kHz, 7-8 kHz, and 14-15 kHz).

[0072] In this example, curve 440 corresponds to the displacement produced by the segmented transducer driven according to configuration 1. The segmented transducer driven according to configuration 1 produces a higher displacement than the "full coverage" transducer in certain frequency ranges (such as 2-2.5 kHz, around 6 kHz, 10-14.5 kHz, and 16-20 kHz), and a higher displacement than the single transducer implementation in most frequency ranges.

[0073] According to this example, curve 445 corresponds to the displacement produced by the segmented transducer driven according to configuration 2. The segmented transducer driven according to configuration 2 produces a higher displacement than the "full coverage" transducer in certain frequency ranges (e.g., 1.5-3 kHz, around 6 kHz, 12.5-14.0 kHz, and 16-20 kHz), and a higher displacement than the single transducer implementation in most frequency ranges.

[0074] In this example, curve 450 corresponds to the displacement produced by the segmented transducer driven according to configuration 3. The segmented transducer driven according to configuration 3 produces a higher displacement than the "full coverage" transducer in certain frequency ranges (such as 2-2.5 kHz, 4.5-6.5 kHz, and 9.5-20 kHz), and a higher displacement than the single transducer implementation in most frequency ranges.

[0075] In view of the information summarized in Figures 4A and 4B, and additional information corresponding to higher frequency ranges, the inventors have determined that improved in-display speaker performance and / or gesture detection performance can be provided via an apparatus comprising a display stack, a cover layer adjacent to a first side of the display stack, and a segmented transducer array adjacent to a second side of the display stack. In some implementations, the apparatus may include a control system configured to cause the segmented transducer array, the display stack, and the cover layer to vibrate in a plurality of vibration modes. In some implementations, each vibration mode may correspond to one or more desired frequency ranges.

[0076] Figure 5 is a block diagram illustrating example components of an appliance according to some disclosed implementations. In this example, appliance 501 includes a segmented transducer array 502, a display stack 510, and a cover 508. In some implementations, appliance 501 may include a control system 506. In some examples, appliance 501 may include an interface system 504. As with other disclosed implementations, the types, numbers, and arrangements of elements shown in Figure 5 are merely illustrative.

[0077] In some examples, as indicated by the dashed lines within the segmented transducer array 502, the segmented transducer array 502 may include a receiver transducer segment 503 and a transmitter transducer segment 505. However, various examples of segmented transducer arrays are disclosed herein, some of which may include separate transmitter and receiver transducer segments, while others may not. Although shown as separate elements in FIG. 5, in some implementations, at least some transducer segments of the segmented transducer array may be configured for both transmission and reception.

[0078] In some implementations, each transducer segment may include a piezoelectric layer and a thin-film transistor (TFT) layer. For example, the piezoelectric layer may include a layer of polyvinylidene fluoride (PVDF) polymer and / or polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) copolymer. In some implementations, the piezoelectric layer may include other piezoelectric materials, such as aluminum nitride (AlN) or lead zirconate titanate (PZT). In some examples, the segmented transducer array 502 may include an array of ultrasonic transducer segments.

[0079] The control system 506 may include one or more general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or combinations thereof. According to some examples, the control system 506 may include dedicated components for controlling the segmented transducer array 502. The control system 506 may also include one or more memory devices (and / or be configured to communicate with them), such as one or more random access memory (RAM) devices, read-only memory (ROM) devices, etc. Accordingly, the appliance 501 may have a memory system including one or more memory devices, although the memory system is not shown in FIG. 5. The control system 506 may be configured to receive and process data from at least a portion of the segmented transducer array 502, for example, data from the receiver transducer segment 503. If the appliance 501 includes a transmitter transducer segment 505, the control system 506 may be configured to control the transducer segment 505. In some implementations, the functionality of the control system 506 can be divided among one or more controllers or processors, for example, between a dedicated transducer controller and an application processor for the motion device.

[0080] Some implementations of the device 501 may include an interface system 504. In some examples, the interface system 504 may include a wireless interface system. In some implementations, the interface system 504 may include a user interface system, one or more network interfaces, one or more interfaces between the control system 506 and the memory system, and / or one or more interfaces between the control system 506 and one or more external device interfaces (e.g., ports or application processors).

[0081] Interface system 504 can be configured to provide communication (including wired or wireless communication, electrical communication, radio communication, etc.) between components of appliance 501. In some such examples, interface system 504 can be configured to provide communication between control system 506 and segmented transducer array 502. According to some such examples, interface system 504 can couple at least a portion of control system 506 to segmented transducer array 502, for example, via a conductive material, such as conductive metal wire or conductor. If appliance 501 includes separate receiver transducer segment 503 and transmitter transducer segment 505, interface system 504 can be configured to provide separate communication between control system 506 and receiver transducer segment 503 and transmitter transducer segment 505.

[0082] According to some examples, the interface system 504 can be configured to provide communication between the appliance 501 and other devices and / or people. In some such examples, the interface system 504 may include one or more user interfaces. In some examples, the interface system 504 may include one or more network interfaces and / or one or more external device interfaces (e.g., one or more Universal Serial Bus (USB) interfaces or Serial Peripheral Interfaces (SPI)). In some implementations, the appliance 501 may include a memory system. In some instances, the interface system 504 may include at least one interface between the control system 506 and the memory system.

[0083] According to some examples, the apparatus 501 may include a cover 508. The cover 508 may or may not be optically transparent, depending on the specific implementation. The cover 508 may be formed of any suitable material, such as glass, hard plastic, metal, etc. If at least a portion of the cover 508 covers the display, then this portion of the cover 508 is preferably formed of an optically transparent material, for example, a material transparent to electromagnetic waves in the human visible spectrum.

[0084] In some implementations, apparatus 501 includes a display stack 510. For example, apparatus 501 may include a display layer, which may be referred to herein as a "display stack". In some examples, the display stack may be or may include a light-emitting diode (LED) display, such as an organic light-emitting diode (OLED) display.

[0085] The device 501 can be deployed in various devices and / or systems. In some examples, a mobile device (e.g., a mobile phone or other portable display device) may include the device 501. In some such examples, a control system 506 may be configured to control the device 501 to provide in-display speaker functionality and / or gesture detection functionality. In some such examples, the control system may be configured to control the mobile device at least in part based on the gesture detection functionality provided by the device 501.

[0086] In some implementations, the Internet of Things (IoT) device may include appliance 501. For example, in some such implementations, a device for use in the home (e.g., a remote control (e.g., a remote control for a smart TV), stove, oven, refrigerator, cooktop, coffee maker, alarm system, door lock, mail / parcel lock, thermostat, etc.) may include appliance 501. In some such examples, control system 506 may be configured to control appliance 501 to provide in-display speaker functionality and / or gesture detection functionality. In some such examples, control system may be configured to control the IoT device at least in part based on the gesture detection functionality provided by appliance 501.

[0087] In alternative implementations, a vehicle or a portion thereof (including, but not limited to, partially or fully autonomous vehicles), a partially or fully autonomous delivery vehicle or a portion thereof, a drone, or another device typically used outside the home may include appliance 501. In some such examples, control system 506 may be configured to control appliance 501 to provide in-display speaker functionality and / or gesture detection functionality. In some such examples, control system may be configured to control vehicles, drones, etc., at least in part based on the gesture detection functionality provided by appliance 501.

[0088] In some examples, including but not limited to many IoT implementations, there may be a layer of metal, plastic, ceramic, or polymer between the outer surface of the appliance 501 or the outer surface of a device including the appliance 501. In such implementations, sound waves transmitted to and reflected from a finger or other target may need to pass through the metal, plastic, ceramic, or polymer layer. Ultrasound and other sound waves can successfully pass through, for example, a metal layer, while some other types of waves (e.g., light waves) cannot. Similarly, ultrasound and other sound waves can successfully pass through optically opaque plastic, ceramic, or polymer layers, while some other types of waves, such as light waves, cannot. This characteristic is another potential advantage of some disclosed implementations compared to devices relying on optical or capacitive sensors.

[0089] In some examples, cover plate 508 may be close to (e.g., adjacent to, within one or two layers, etc.) a first side of display stack 510. In some examples, cover plate 508 may be attached to the first side of display stack 510, for example, via an adhesive layer. The first side may be, for example, the side facing the exterior of appliance 501. In some such examples, segmented transducer array 502 may be close to a second side of display stack. The second side may be, for example, the side facing the interior of appliance 501. According to some such examples, segmented transducer array 502 may include a plurality of separate transducer segments. In some cases, separate transducer segments may include separate transmitter transducer segments 505 and receiver transducer segments 503. However, in other examples (e.g., some in-display speaker implementations), separate transducer segments may include only separate transmitter transducer segments 505. In still other examples, at least some transducer segments may be configured as both transmitter and receiver transducer segments.

[0090] In some implementations, each of the separate transducer segments may include a piezoelectric layer and a thin-film transistor (TFT) layer. According to some examples, the spacing between at least the first plurality of transmitter transducer segments 505 may correspond to the display stack and overlay oscillation mode frequency. In some examples, the display stack and overlay oscillation mode frequency is in the range of 20 Hz to 20 kHz. In some such examples, the control system 506 may be configured to control at least the first plurality of transmitter transducer segments 505 to reproduce audio signals by causing the display stack and overlay to oscillate at frequencies in the range of 20 Hz to 20 kHz.

[0091] According to some examples, the distance between the centers of the first plurality of transmitter transducer segments 505 may be equal to the mode wavelength corresponding to the frequency of the display stack and overlay oscillation mode. One such example is shown in Figure 1B and described above.

[0092] In some implementations, the distance between the centers of the first plurality of transmitter transducer segments 505 may be equal to half the mode wavelength corresponding to the frequency of the display stack and overlay oscillation mode. An example of this is shown in Figure 3A and described therein.

[0093] According to some implementations, the distance between the centers of the first plurality of transmitter transducer segments 505 may be equal to one-quarter of the mode wavelength corresponding to the display stack and overlay oscillation mode frequency. An example of this is shown in FIG. 3B and described above. In some implementations, the distance between the centers of the first plurality of transmitter transducer segments 505 may be equal to one-eighth of the mode wavelength corresponding to the display stack and overlay oscillation mode frequency. In other cases, the distance between the centers of the first plurality of transmitter transducer segments 505 may be equal to different portions of the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

[0094] In some implementations, the control system 506 may be configured to drive one or more of the first plurality of transmitter transducer segments 505 by applying voltage to the electrodes of each of the one or more transmitter transducer segments 505. In some such examples, each electrode may be adjacent to a corresponding piezoelectric layer of the transmitter transducer segment, for example, as shown in FIG6 and described below. According to some implementations, the control system 506 may be configured to drive the transmitter transducer segments 505 in a higher-order mode, wherein adjacent transmitter transducer segments of the first plurality of transmitter transducer segments are driven in opposite directions. In some implementations, the control system 506 may be configured to drive the transmitter transducer segment 505 in an intermediate-order mode, wherein during the time during which the first transmitter transducer segment of the first plurality of transmitter transducer segments is driven in a first direction, the second transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is not driven, and the third transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in a second direction opposite to the first direction.

[0095] According to some examples, the control system 506 can be configured to drive the transmitter transducer segment 505 in a low-order mode, wherein, during the time during which a first transmitter transducer segment of a first plurality of transmitter transducer segments 505 is driven in a first direction, a second transmitter transducer segment of a first plurality of transmitter transducer segments 505 adjacent to the first transmitter transducer segment is driven in the first direction. In some such examples, a third transducer segment of a first plurality of transmitter transducer segments 505 adjacent to the second transmitter transducer segment is driven in the first direction.

[0096] In some implementations, the control system 506 can be configured to perform noise cancellation based on receiver signals received from two or more receiver transducer segments 503. Some examples are described below.

[0097] According to some examples, the spacing between at least a second plurality of transmitter transducer segments 505 corresponds to a display stack and overlay oscillation mode with frequencies in the range of 15 kHz to 200 kHz. In some examples, the spacing between at least one plurality of transmitter transducer segments 505 may correspond to a display stack and overlay oscillation mode frequency in the range of 20 kHz to 400 kHz. According to some examples, a control system 506 may be configured to control at least one plurality of transmitter transducer segments 505 to cause the display stack and overlay to oscillate at frequencies in the range of 15 kHz to 400 kHz. In some implementations, the control system 506 may be configured to drive the transmitter transducer segments and receive receiver signals from the receiver transducer segment 503. In some such implementations, the control system 506 may be configured to detect the position and / or gestures of a target object based at least in part on ultrasonic signals received via one or more receiver transducer segments 503.

[0098] FIG6 shows a cross-section of a portion of the apparatus of FIG5 according to an example. According to this implementation, the apparatus 501 includes a segmented transducer array 502. Here, the segmented transducer array 502 includes a piezoelectric layer 608, an electrode layer 610 on one side of the piezoelectric layer 608, and TFT layers 604 on the second and opposite sides of the piezoelectric layer 608. In this implementation, the piezoelectric layer 608 includes one or more piezoelectric polymers.

[0099] According to this example, the electrode layer 610 is located between the passivation layer 612 and the piezoelectric layer 608. In some examples, the passivation layer 612 may include an adhesive, such as an epoxy resin film, a polymer layer (such as a polyethylene terephthalate (PET) layer), etc.

[0100] In this example, the thin-film transistor (TFT) layer 604 includes a TFT substrate and circuitry. The TFT layer 604 can be a metal-oxide-semiconductor field-effect transistor (MOSFET), fabricated by depositing a thin film of an active semiconductor layer, a dielectric layer, and metal contacts on the TFT substrate. In some examples, the TFT substrate can be a non-conductive material, such as glass.

[0101] In this example, the apparatus 501 includes a display stack 510, which in this example is an OLED display stack. Here, the display stack 510 is attached to the TFT layer 604 via an adhesive layer 602. According to this example, the apparatus 501 includes a cover plate 508 on the outer surface of the display stack 510. In this example, the cover plate 508 is a cover glass.

[0102] In this implementation, the segmented transducer array 502 includes at least one transmitter segment 611a and at least one receiver segment 611b. For example, the receiver segment 611b may be one of a plurality of receiver transducer segments 503, while the transmitter segment 611a may be one of a plurality of transmitter transducer segments 505. According to this implementation, the TFT layer 604 and electrode layer 610 of both the transmitter segment 611a and the receiver segment 611b are electrically coupled to at least a portion of the control system 506 via a portion of an interface system 504, which in this example includes conductive material and a flexible printed circuit (FPC). According to this example, the electrical connection between the control system 506 and the transmitter segment 611a is outside the plane of the cross section and is therefore not shown in FIG. 6.

[0103] In this example, the control system 506 is configured to control the transmitter segment 611a to transmit one or more electrical signals via the electrode layer 610 of the transmitter segment 611a to emit one or more acoustic waves 613. According to this example, the acoustic waves 613 are transmitted through the TFT layer 604, the display 110, and the cover glass 108. According to this example, the reflection 614 of the acoustic waves 613 is caused by the acoustic impedance contrast between the outer surface of the target object 618 (in this example, a finger) and the air outside the appliance 501. As used herein, the term "finger" can refer to any finger, including the thumb. In this example, the reflection 614 causes the piezoelectric layer 608 of the receiver segment 611b to transmit one or more electrical signals to the control system 506 via the electrode layer 610.

[0104] Depending on some implementations, one or more dimensions of the transducer segments can be fine-tuned or optimized, for example, for transmission or reception. In some examples, the transmitter segment thickness of each of the first plurality of transmitter transducer segments 505 may differ from the receiver segment thickness of each of the first plurality of receiver transducer segments 503. In some such examples, the receiver segment piezoelectric layer thickness of each of the first plurality of receiver transducer segments 503 may be greater than the transmitter segment piezoelectric layer thickness of each of the first plurality of transmitter transducer segments 505.

[0105] According to some implementations, a first subset of the separate transducer segments may have a first segment width, and a second subset of the separate transducer segments may have a second segment width. In some implementations, one or more dimensions of the transducer segments may be fine-tuned or optimized for transmission or reception at one or more frequencies or within one or more frequency ranges.

[0106] Figure 7 shows a cross-section of a portion of the appliance of Figure 5 according to another example. As with other disclosed implementations, the number, type, and arrangement of the elements depicted in Figure 7 are merely illustrative. Other implementations may have different numbers, types, and / or arrangements of elements.

[0107] In this example, the apparatus 501 includes a display stack 510, which in this example is an OLED display stack. According to this example, the apparatus 501 includes a cover plate 508 on the outer surface of the display stack 510. The cover plate 508 in this example is a cover glass.

[0108] According to this implementation, the device 501 includes a segmented transducer array 502, which includes transmitter transducer segments 711a and 711c, and receiver transducer segments 711b and 711d. For example, transducer segments 711a-711d may be instances of a plurality of identical or substantially identical (e.g., identical within ±5%, identical within ±10%, etc.) transducer segments included in the complete version of the device 501.

[0109] In this example, each segment 711a-711d includes a piezoelectric layer segment. Segments 711a-711d each include piezoelectric layer segments 608a-608d. According to this implementation, piezoelectric layer segments 608a-608d include PVDF, but in other implementations, the piezoelectric layer segments may include one or more other types of piezoelectric materials. The inventors have determined that the optimal PVDF thickness for transmission may not be optimal for reception. For example, a relatively thick PVDF is generally ideal for the receiver transducer segment. Therefore, receiver transducer segments 711b and 711d have relatively thicker piezoelectric layer segments than transmitter transducer segments 711a and 711c. In this example, the thinnest piezoelectric layer segment is piezoelectric layer segment 608c, and the thickest piezoelectric layer segment is piezoelectric layer segment 608d. In some examples, the thickness of the piezoelectric layer segments can range from approximately 10 micrometers to approximately 30 micrometers. However, in other implementations, the thickness of the piezoelectric layer can range from greater than or less than 10 micrometers to greater than or less than 30 micrometers.

[0110] In this example, each segment 711a-711d includes a TFT layer segment. Segments 711a and 711d include TFT layer segments 604a and 604c, while segments 711b and 711c each include a portion of TFT layer segment 604b. The inventors have determined that, in many cases, transducer segments having relatively thin TFT layers (e.g., in the range of 50 to 100 micrometers) provide relatively superior performance compared to transducer segments having relatively thick TFT layers (e.g., in the range of 200 to 250 micrometers).

[0111] According to this example, segment 711a has a width w1, segment 711b has a width w2, segment 711c has a width w3, and segment 711d has a width w4. The inventors have determined that transducer segments of different sizes (e.g., widths) can produce different frequency responses (e.g., different SPL peaks and troughs in an SPL vs. frequency graph). Transducer segments of different sizes (e.g., widths between 5 and 70 micrometers) can be advantageously integrated into a single device to provide satisfactory performance within the frequency range of interest.

[0112] According to this example, transducer segments 711a and 711d include spacer layer segments 702a and 702b, respectively. In this implementation, transducer segments 711b and 711c do not include spacer layer segments, while in some other implementations, transducer segments 711b and 711c may include spacer layer segments. The inventors have determined that the effect of the spacer layer thickness in the transducer segment also depends on the relative width of the transducer segment. In some cases, a narrow transducer segment (e.g., having a width of 20 micrometers or less) with a relatively thin spacer layer or no spacer layer (e.g., a spacer layer in the range of 0 to 100 micrometers) can provide relatively better performance (e.g., higher SPL). In some cases, a wider transducer segment (e.g., having a width of 60 micrometers or more) with a relatively thick spacer layer (e.g., a spacer layer in the range of 200 to 400 micrometers) can provide relatively better performance (e.g., higher SPL).

[0113] Figure 8 shows another example of the apparatus of Figure 5. As with other disclosed implementations, the number, type, and arrangement of the elements described in Figure 8 are shown as examples only. Other implementations may have different numbers, types, and / or arrangements of elements.

[0114] In this example, the device 501 includes three types of transducer segments. Here, transducer segment 811a is a transmitter transducer segment, while transducer segments 811b and 811c are receiver transducer segments. According to this example, transducer segments 811a-811c include a range of dimensions to provide satisfactory performance over a range of frequencies.

[0115] Figure 9 illustrates an example of noise / interference cancellation in a segmented transducer array. Depending on some implementations, the control system (e.g., control system 506 of appliance 501) can be configured to provide noise / interference cancellation functionality by utilizing the redundancy of signals from two or more adjacent (e.g., neighboring) receiver transducer segments. Although only two receiver transducer segments are shown in Figure 9 for simplicity, the noise / interference cancellation concept described with reference to Figure 9 can be extended to implementations using more than two receiver transducer segments for noise / interference cancellation and may become more effective.

[0116] In this example, and represent two sound sources as functions of time. According to this example, represents the signal received by transducer segment 1 from and , and and represent constants. In this example, represents the signal received by transducer segment 2 from and , and and represent constants. In this example, transducer segment 1 and transducer segment 2 are adjacent.

[0117] To solve for and from and, some implementations involve estimating and for different cases. The relationship between and can be expressed as follows. (Formula 3)

[0118] In one example case, and are independent signals. In one example, if is the desired signal, then is an interference signal. In this case, the relationship between , , and in the frequency domain can be expressed as: (Equation 4) (Equation 5)

[0119] In Formula 4, represents the first delay time, which is the difference between the times when transducer segment 1 and transducer segment 2 receive the sound. In Formula 5, represents the second delay time, which is the difference between the times when transducer segment 1 and transducer segment 2 receive the sound. Depending on some implementations, the control system can be configured to estimate and by cross-correlation between and .

[0120] In another example, and are not independent signals. Instead, in such an example, is the reflection of. In this case, the relationship between and can be expressed as follows. (Equation 6)

[0121] In Formula 6, represents the delay time between and . Therefore, the relationship between , and can be expressed as follows: (Formula 7) (Formula 8)

[0122] In Equations 7 and 8, and represent different complex constant factors. According to some examples, the control system can be configured to be estimated from the frequency domain at frequency, as shown below. (Equation 9)

[0123] Depending on some implementation methods, after estimation, the control system can be configured to estimate c, as shown below. (Equation 10)

[0124] The above method can be extended to implementations involving three or more receiver transducer segments. Other implementations may involve different noise cancellation methods, such as those described below: Li Cheng et al., "DOA Estimation for Highly Correlated and Coherent Multipath Signals with Ultralow SNRs" (International Journal of Antennas and Propagation, vol. 2019, Article ID 2837315 (2019)), or H. Almansouri et al., "Model-Based Iterative Reconstruction for One-Sided Ultrasonic Nondestructive Evaluation" (IEEE Transactions on Computational Imaging, vol. 5, no. 1, pp. 150-164 (March 2019)), both of which are incorporated herein by reference.

[0125] In some implementations, apparatus 501 can be configured for transmit-side or receive-side beamforming. For example, in some implementations, control system 506 can be configured to control a plurality of transmitter transducer segments for transmit-side beamforming. Alternatively, in some implementations, control system 506 can be configured to control a plurality of receiver transducer segments for receive-side beamforming. Beamforming can result in noise cancellation and thereby increase the signal-to-noise ratio of signals transmitted or received by the transducer segment array.

[0126] Figures 10A, 10B, 10C, and 10D provide examples of receiver-side beamforming according to some implementations. As with other disclosed implementations, the size, number, arrangement, and type of the elements shown in Figures 10A, 10B, 10C, and 10D are for illustrative purposes only.

[0127] Figure 10A illustrates transducer segment 1011a and adjacent transducer segments of the segmented transducer array portion 1009. In this example, transducer segment 1011a generates transmitted sound wave 1013. Here, the outer surface 1044 of the target object portion 1018 reflects the transmitted sound wave 1013, generating reflected sound wave 1014. Figure 10A shows that the reflected sound wave 1014 is received by transducer segment 1011a. In this example, the separation between the target object surface 1044 and transducer segment 1011a is a distance. A 5x5 portion of transducer segment 1011 in the transducer segment array 1009 is shown to illustrate the concept described herein, although a 5x5 array is not intended to be a limitation.

[0128] In some cases, the transmitted sound wave 1013 may pass through one or more layers (not shown) between the transducer segment array 1011 and the outer surface of the device 501 (e.g., TFT layer, display stack, and cover plate) and through an air layer before reaching the outer surface 1044 of the target object portion 1018. The reflected sound wave 1014 may reach the transducer segment array 1011, where the local amplitude of the reflected sound wave 1014 can be detected. The first acquisition time delay between generating the transmitted sound wave 1013 and sampling the reflected wave 1014 may correspond to the distance between the transducer segment 1011a and the target object surface 1044. For example, the acquisition time delay (e.g., RGD1) may be approximately equal to the flight time of the sound wave traveling twice the distance, given by the speed of sound in the layer between the transducer segment 1011a and the target object surface 1044.

[0129] Figure 10B illustrates the reflected sound wave 1014 of the transmitted sound wave 1013 from the outer surface 1044 of the target object portion 1018 to a first group of neighboring transducer segments 1011b near a selected transducer segment 1011a of the segmented transducer array portion 1009. The reflected sound wave 1014 can reach neighboring elements 1011a and 1011b. The difference in time of flight can be used to identify the precise x / y position of the finger's presence. For example, a second acquisition time delay can explain the average (e.g., mean) distance between the selected transducer segment 1011a and a group of neighboring transducer segments 1011b near the selected transducer segment 1011a (the neighboring transducer segments 1011b are shown as transducer segments adjacent to the two sides of the selected transducer segment 1011a). For example, the second acquisition time delay, or equivalent to the range gate delay (e.g., RGD2), can be approximately equal to the acoustic wave travel distance and the flight time of the hypotenuse of the triangle given by the side length, as described below with respect to Figure 10D. The first and second acquisition time delays can differ to account for the phase difference between the reflected first acoustic wave arriving at the selected transducer segment and the reflected second acoustic wave arriving at the first set of adjacent transducer segments.

[0130] Figure 10C illustrates the transmitted sound wave 1013 emitted from the outer surface 1044 of the target object portion 1018 to the reflected sound wave 1014 of a second group of adjacent transducer segments 1011c near the selected transducer segment 1011a of the bottom segmented transducer array portion 1009. The flight times to the central element 1011a and its adjacent elements 1011c are different. By identifying these differences, the control system can accurately locate the x / y position of the object. For example, a third acquisition time delay can explain the average (e.g., mean) distance between the selected transducer segment 1011a and the second group of adjacent transducer segments 1011c near the selected transducer segment 1011a (the adjacent transducer segments 1011c are shown as transducer segments that are in corner contact with the selected transducer segment 1011a). For example, the third acquisition time delay (e.g., RGD3) can be approximately equal to the acoustic wave travel distance and the flight time given by the side length and the hypotenuse of the triangle, as described below with respect to Figure 10D.

[0131] Figure 10D illustrates a selected transducer segment 1011a() of the segmented transducer array portion 1009 and multiple groups of neighboring transducer segments near the selected transducer segment 1011a. The selected transducer segment 1011a can be virtually any transducer segment in the transducer segment array 10010, as specified in the figure. To illustrate the point, a circle is shown whose radius corresponds to the distance from the center of the selected transducer segment to the center of the first group of neighboring transducer segments, representing the average (mean) distance between the selected transducer segment and the first group of neighboring transducer segments (e.g., the center-to-center distance between two adjacent transducer segments). A second circle is shown whose radius corresponds to the distance from the center of the selected transducer segment to the center of the second group of neighboring transducer segments, representing the average (mean) distance between the selected transducer segment and the second group of neighboring transducer segments. The additional circle displays the radius and corresponding distances from the center of the selected transducer segment to the centers of several other sets of neighboring transducer segments, where distances represent the average distances between the selected transducer segment and the other sets of neighboring transducer segments, respectively. This process can be used to identify and assign additional transducer segments to the sets of neighboring transducer segments, allowing for compensation of time-of-flight differences caused by x / y position.

[0132] It can be noted that, due to the position of the finger, the transducer segment output signal can be significantly corrected by acquiring more sets of transducer segment output signals and generating a corrected output signal using transducer segment data from neighboring transducer segment sets. In some implementations, correction can be performed by acquiring transducer segment output signals from only one set of neighboring transducer segments near each selected transducer segment (e.g., the nearest neighbor). In some implementations, correction can be performed by acquiring transducer segment output signals from two different sets of neighboring transducer segments near each selected transducer segment (e.g., the nearest neighbor and the second nearest neighbor). In some implementations, correction can be performed by acquiring transducer segment output signals from three, four, five, or more different sets of neighboring transducer segments near each selected transducer segment.

[0133] In some alternative implementations, the output signals of two, three, four, five, or more different neighboring transducer segments near the selected transducer segment can be cross-correlated with the output signal of the selected transducer segment. One or more amplitude peaks or troughs can correspond to the reflection of the target object portion 1018. The acquisition time corresponding to the amplitude peaks or troughs can serve as a reference for time-shifting the output signal from the neighboring transducer segment before adding the signal from the neighboring transducer segment to the output signal from the selected transducer segment. The resulting summed signal typically has a higher signal-to-noise ratio than the output signal of the selected transducer segment.

[0134] Figures 11 and 12 are flowcharts of example blocks comprising methods according to the two disclosed implementations. Methods 1100 and 1200 may be implemented, for example, by a control system, such as control system 506 of appliance 501. As with other methods disclosed herein, the methods outlined in Figures 11 and 12 may include more or fewer blocks than shown. Furthermore, the blocks of the methods disclosed herein are not necessarily performed in the indicated order. In some cases, one or more blocks may be performed simultaneously.

[0135] Referring first to FIG11, in this example, block 1105 relates to receiving audio data by a control system of appliance 501 as shown in FIG5. For example, the audio data may be received via an interface system (such as interface system 504). In this example, the appliance includes a display stack, a cover layer adjacent to a first side of the display stack, and a segmented transducer layer adjacent to a second side of the display stack. Here, the segmented transducer layer includes a plurality of transducer segments.

[0136] According to this example, block 1110 relates to reproducing audio via an in-display speaker comprising a plurality of transducer segments. Here, block 1110 relates to a control system controlling at least a first plurality of transducer segments to reproduce the audio signal by causing the display stack and overlay to oscillate at frequencies in the range of, for example, 20 Hz to 20 kHz.

[0137] Referring now to FIG. 12, method 1200 relates to a device for target object localization and / or motion detection using a device 501 similar to that of FIG. 5. In this example, the device includes a display stack, a cover layer adjacent to a first side of the display stack, and a segmented transducer layer adjacent to a second side of the display stack. According to this implementation, the segmented transducer layer includes a plurality of transducer segments. Here, block 1205 relates to a control system for controlling the device, one or more transducer segments, to cause the display stack and cover layer to oscillate at frequencies in, for example, a range of 15 kHz to 400 kHz. In this example, the oscillation causes one or more transmitted acoustic waves to propagate through the display stack and cover layer.

[0138] According to this example, at least some of the transmitted sound waves are reflected by the target object. In this implementation, block 1210 involves the control system receiving receiver signals from one or more transducer segments. In this example, the receiver signals correspond to the transmitted sound waves (or a portion thereof) reflected from the target object. In this example, block 1215 involves the control system detecting the position and / or movement of the target object, at least in part, based on the receiver signals. In some examples, method 1200 may involve providing gesture detection functionality. According to some implementations, method 1200 may involve controlling an appliance or another appliance based on one or more detected gestures.

[0139] As used herein, a phrase referring to a list of "at least one" items means any combination of these items, including a single member. As an example, "at least one: a, b, or c" means including: a, b, c, ab, ac, bc, and abc.

[0140] The various illustrative logics, logic blocks, modules, circuits, and algorithmic processes related to the implementation methods disclosed herein can be implemented as electronic hardware, computer software, or a combination of both. Functionally, the interchangeability of hardware and software has been generally described and illustrated in the various illustrative components, blocks, modules, circuits, and processes described above. Whether this functionality is implemented in hardware or software depends on the specific application and the design constraints of the overall system.

[0141] Hardware and data processors used to implement the various illustrative logics, logic blocks, modules, and circuits related to the states disclosed herein may be implemented or performed by general-purpose single-chip or multi-chip processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof, to perform the functions described herein. A general-purpose processor may be a microprocessor, or any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. In some implementations, specific processes and methods may be performed by circuitry specific to a particular function.

[0142] In one or more embodiments, the described functions can be implemented by hardware, digital electronic circuits, computer software, firmware, including the structures disclosed in this specification and their equivalents, or any combination thereof. The technical subject matter described in this specification can also be implemented as one or more computer programs, i.e., one or more computer program instruction modules encoded on a computer storage medium, executed or controlled by a data processing device.

[0143] If implemented in software, these functions can be stored or transmitted as one or more instructions or code on or through a computer-readable medium, such as a non-transitory medium. The processes of the methods or algorithms disclosed herein can be implemented in a processor-executable software module that may reside on a computer-readable medium. Computer-readable media includes computer storage media and communication media, including any media that enables a computer program to be transferred from one place to another. Storage media can be any available media that can be accessed by a computer. For example, and not limitingly, non-transitory media can include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other media that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer. In addition, any connection can be properly referred to as computer-readable media. Disks and optical discs as used herein include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVDs), floppy disks, and Blu-ray discs, wherein disks typically magnetically reproduce data, while optical discs optically reproduce data using lasers. The aforementioned combinations should also be included within the scope of computer-readable media. Furthermore, the operation of a method or algorithm may exist as a single, or any combination thereof, or as a set of code and instructions on machine-readable and computer-readable media, which may be incorporated into a computer program product.

[0144] Various modifications to the implementations described in this disclosure may be apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the spirit or scope of this disclosure. For example, in some implementations, the segmented transducer array may include a piezoelectric micromechanical ultrasonic transducer (PMUT) array, a capacitive micromechanical ultrasonic transducer (CMUT) array, and so on. In some such examples, PMUT elements in a single-layer PMUT array or CMUT elements in a single-layer CMUT array may be used as transmitter transducer segments and receiver transducer segments. Therefore, this disclosure is not intended to be limited to the implementations shown herein, but is intended to be given the broadest scope consistent with the scope, principles, and novel features of the claims disclosed herein. Where applicable, the word "exemplary" is used herein specifically to mean "as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as being more preferred or advantageous than other implementations.

[0145] Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented separately in multiple implementations or in any suitable sub-combination. Furthermore, although the aforementioned features may be described as functioning in certain combinations, or even initially claimed to be so, in some cases, one or more features from the claimed combination may be removed from that combination, and the claimed combination may be directed to a sub-combination or a variation of the sub-combination.

[0146] Similarly, although the operations in the diagrams are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or sequentially, or requiring all described operations to be performed to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the above implementations should not be construed as requiring such separation in all implementations. It should be understood that the described program components and systems can generally be integrated into a single software product or packaged into multiple software products. In addition, other implementations are also within the scope of the following claims. In some cases, the actions described in the claims can be performed in different orders and still achieve the desired result.

[0147] It is understood that, unless features in any particular described implementation are explicitly identified as incompatible with each other, or the surrounding context suggests that they are mutually exclusive and not easily combined in a complementary and / or supporting sense, the present disclosure as a whole considers and contemplates that specific features of those complementary implementations can be selectively combined to provide one or more comprehensive but slightly different technical solutions. Therefore, it will be further understood that the above description is given by way of example only, and modifications to the details are possible within the scope of this disclosure.

[0148] Examples of implementation methods are described in the following numbered clauses.

[0149] 1. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; and a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments comprising a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments comprising an emitter transducer segment and a receiver transducer segment, wherein the spacing between at least the first plurality of emitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer.

[0150] 2. The apparatus of Clause 1 further includes a control system configured to control at least a first plurality of transmitter transducer segments to reproduce an audio signal by causing the display stack and overlay to oscillate at frequencies in the range of 20 Hz to 20 kHz.

[0151] 3. The apparatus of Clause 1 or Clause 2, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, one-quarter of the mode wavelength, or one-eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency, wherein the mode wavelength is the distance between the peaks of the display stack and overlay oscillation mode.

[0152] 4. An apparatus of any of the terms 1-3, wherein the thickness of each of the first plurality of transmitter transducer segments is different from the thickness of each of the first plurality of receiver transducer segments.

[0153] 5. The apparatus of Clause 4, wherein the piezoelectric layer thickness of the receiver segment of each of the first plurality of receiver transducer segments is greater than the piezoelectric layer thickness of the transmitter segment of each of the first plurality of transmitter transducer segments.

[0154] 6. An appliance as described in any of Clauses 1-5, wherein a first subset of the separate transducer segments has a first segment width and a second subset of the separate transducer segments has a second segment width.

[0155] 7. The appliance of any of the terms 1-6 further includes a control system configured to drive the transmitter transducer segment and obtain receiver signals from the receiver transducer segment.

[0156] 8. An appliance of any of the terms 1-7 further includes a control system configured to drive the transmitter transducer segments in a high-order mode, wherein adjacent transmitter transducer segments of the first plurality of transmitter transducer segments are driven in opposite directions.

[0157] 9. An appliance of any of the terms 1-8 further includes a control system configured to drive the transmitter transducer segments in an intermediate mode, wherein during a period when a first transmitter transducer segment of a first plurality of transmitter transducer segments is driven in a first direction, a second transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is not driven, and a third transducer segment of a first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in a second direction opposite to the first direction.

[0158] 10. An apparatus of any of the terms 1-9 further includes a control system configured to drive transmitter transducer segments in a low-order mode, wherein during a period when a first transmitter transducer segment of a first plurality of transmitter transducer segments is driven in a first direction, a second transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is driven in the first direction, and a third transducer segment of a first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the first direction.

[0159] 11. The apparatus of any of the terms 1-10 further includes a control system configured to perform noise cancellation based on receiver signals received from two or more receiver transducer segments.

[0160] 12. An apparatus of any of the terms 1-11, wherein the spacing between at least the first plurality of transmitter transducer segments corresponds to a display stack and overlay oscillation mode frequency in the range of 20 Hz to 20 kHz.

[0161] 13. An apparatus of any of the terms 1-12, wherein the spacing between at least the second plurality of transmitter transducer segments corresponds to a display stack and overlay oscillation mode for frequencies in the range of 15 kHz to 200 kHz.

[0162] 14. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; and a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments comprising a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments comprising an emitter transducer segment and a receiver transducer segment, wherein the spacing between at least the first plurality of emitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer.

[0163] 15. The apparatus of Clause 14, wherein the spacing between at least the first plurality of transmitter transducer segments corresponds to the display stack and overlay oscillation mode frequency in the range of 20 kHz to 400 kHz.

[0164] 16. The apparatus of Clause 14 or Clause 15, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

[0165] 17. An apparatus of any of the terms 14-16, wherein the spacing between at least the second plurality of transmitter transducer segments corresponds to a display stack and overlay oscillation mode for frequencies in the range of 20 Hz to 20 kHz.

[0166] 18. The apparatus of any of the terms 14-17 further includes a control system configured to control at least a first plurality of transmitter transducer segments to cause the display stack and overlay to oscillate at frequencies in the range of 20 kHz to 400 kHz.

[0167] 19. An appliance of any of the terms 14-18, wherein the control system is further configured to detect gestures based at least in part on ultrasonic signals received via one or more receiver transducer segments.

[0168] 20. An appliance of any of the terms 14-19, wherein the control system is further configured to perform noise cancellation based on receiver signals received from two or more receiver transducer segments.

[0169] 21. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments comprising a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments comprising a transmitter transducer segment and a receiver transducer segment, wherein the spacing between at least a first plurality of transmitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer; and a control member for controlling at least a first plurality of transmitter transducer segments to reproduce an audio signal by oscillating the display stack and the cover layer in a frequency range of 20 Hz to 20 kHz.

[0170] 22. The apparatus of Clause 21, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

[0171] 23. The apparatus of Clause 21 or Clause 22, wherein the spacing between at least the first plurality of transmitter transducer segments corresponds to the display stack and overlay oscillation mode frequency in the range of 20 Hz to 20 kHz.

[0172] 24. An apparatus of any of the terms 21-23, wherein the thickness of each of the first plurality of transmitter transducer segments is different from the thickness of each of the first plurality of receiver transducer segments.

[0173] 25. The apparatus of Clause 24, wherein the piezoelectric layer thickness of the receiver segment of each of the first plurality of receiver transducer segments is greater than the piezoelectric layer thickness of the transmitter segment of each of the first plurality of transmitter transducer segments.

[0174] 26. An appliance of any of the terms 21-25, wherein a first subset of the separate transducer segments has a first segment width and a second subset of the separate transducer segments has a second segment width.

[0175] 27. An appliance of any of the terms 21-26 further includes a control element configured to drive a transmitter transducer segment and obtain a receiver signal from a receiver transducer segment.

[0176] 28. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments comprising a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments comprising an emitter transducer segment and a receiver transducer segment, wherein the spacing between at least a first plurality of emitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer; and a control member for controlling at least the first plurality of emitter transducer segments to cause the display stack and the cover layer to oscillate at a frequency in the range of 20 kHz to 400 kHz.

[0177] 29. An appliance as described in Clause 28, wherein the control element includes a component for detecting a gesture based at least in part on ultrasonic signals received via one or more receiver transducer segments.

[0178] 30. An appliance of any of the terms 28-29, wherein the control element includes a component for performing noise cancellation based on receiver signals received from two or more receiver transducer segments.

[0179] 31. An apparatus of any of the terms 28-30, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

[0180] 32. An apparatus of any of the terms 28-31, wherein the spacing between at least the first plurality of transmitter transducer segments corresponds to the display stack and overlay oscillation mode frequency in the range of 20 kHz to 400 kHz.

[0181] 33. An apparatus of any of the terms 28-32, wherein the spacing between at least the second plurality of transmitter transducer segments corresponds to a display stack and overlay oscillation mode for frequencies in the range of 20 Hz to 20 kHz.

[0182] 34. An apparatus of any of the terms 28-33, wherein the control element includes a component for driving the transmitter transducer segments in a higher-order mode, wherein adjacent transmitter transducer segments of the first plurality of transmitter transducer segments are driven in opposite directions.

[0183] 35. An apparatus of any of the terms 28-34, wherein the control member includes a member for driving a transmitter transducer segment in an intermediate mode, wherein during a period when a first transmitter transducer segment of a first plurality of transmitter transducer segments is driven in a first direction, a second transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is not driven, and a third transducer segment of a first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in a second direction opposite to the first direction.

[0184] 36. An apparatus of any of the terms 28-35, wherein the control member includes a member for driving a transmitter transducer segment in a low-order mode, wherein during a period when a first transmitter transducer segment of a first plurality of transmitter transducer segments is driven in a first direction, a second transmitter transducer segment of a first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is driven in the first direction, and a third transducer segment of a first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the first direction. [Simplified Explanation of the Diagram]

[0031] Details of one or more implementations of the technical subject matter described in this specification are set forth in the accompanying drawings and the embodiments below. Other features, features, and advantages will become apparent from the embodiments, drawings, and claims. Note that the relative dimensions of the following figures may not be drawn to scale. Similar symbols and names in the various figures denote similar elements.

[0032] Figure 1A shows a cross-section of a portion of the device according to the example.

[0033] Figure 1B shows a cross-section of a portion of the alternative device according to the example.

[0034] FIG1C shows a cross-section of a portion of the device according to another example of FIG1B.

[0035] Figure 2A is a graph showing the relationship between sound pressure level (SPL) and frequency according to an example.

[0036] Figures 2B, 2C, 2D and 2E show examples of vibration modes corresponding to the SPL peak shown in Figure 2A.

[0037] Figures 3A, 3B and 3C show examples of driving a segmented transducer stack like that in Figure 2B under various vibration modes.

[0038] Figure 4A shows the relationship between SPL and frequency for five examples of transducers and transducer arrays.

[0039] Figure 4B shows the displacement versus frequency relationship for the same five examples of transducers and transducer arrays described above with reference to Figure 4A.

[0040] Figure 5 is a block diagram showing an example component of an appliance according to some publicly disclosed implementations.

[0041] Figure 6 shows a cross-section of a portion of the appliance of Figure 5 according to an example.

[0042] Figure 7 shows a cross-section of a portion of the appliance of Figure 5 according to another example.

[0043] Figure 8 shows another example of the appliance in Figure 5.

[0044] Figure 9 shows an example of noise / interference cancellation in a segmented transducer array.

[0045] Figures 10A, 10B, 10C and 10D provide examples of receiver-side beamforming according to some implementation methods.

[0046] Figures 11 and 12 are flowcharts of example blocks including methods according to two disclosed implementations.

Claims

1. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; and a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments including a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments including an emitter transducer segment and a receiver transducer segment, wherein the spacing between at least the first plurality of emitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer.

2. The apparatus of claim 1 further includes a control system configured to control at least the first plurality of transmitter transducer segments to reproduce an audio signal by causing the display stack and the overlay to oscillate at frequencies in the range of 20 Hz to 20 kHz.

3. The apparatus of claim 1, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency, wherein the mode wavelength is the distance between the peaks of the display stack and overlay oscillation mode.

4. The apparatus of claim 1, wherein the thickness of each of the first plurality of transmitter transducer segments is different from the thickness of each of the first plurality of receiver transducer segments.

5. The apparatus of claim 4, wherein the piezoelectric layer thickness of each of the first plurality of receiver transducer segments is greater than the piezoelectric layer thickness of each of the first plurality of transmitter transducer segments.

6. The apparatus of claim 1, wherein a first subset of the separate transducer segments has a first segment width and a second subset of the separate transducer segments has a second segment width.

7. The apparatus of claim 1 further includes a control system configured to drive the transmitter transducer segments and obtain receiver signals from the receiver transducer segments.

8. The apparatus of claim 1 further includes a control system configured to drive the transmitter transducer segments in a high-order mode, wherein adjacent transmitter transducer segments of the first plurality of transmitter transducer segments are driven in opposite directions.

9. The apparatus of claim 1 further includes a control system configured to drive the transmitter transducer segments in an intermediate-order mode, wherein, During the period when the first transmitter transducer segment of the first plurality of transmitter transducer segments is driven in the first direction, the second transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is not driven, and the third transducer segment of the first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the second direction opposite to the first direction.

10. The apparatus of claim 1, further comprising a control system configured to drive the transmitter transducer segments in a low-order mode, wherein, During the period when the first transmitter transducer segment of the first plurality of transmitter transducer segments is driven in the first direction, the second transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is driven in the first direction, and the third transducer segment of the first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the first direction.

11. The appliance of claim 1 further includes a control system configured to perform noise cancellation based on receiver signals received from two or more receiver transducer segments.

12. The appliance as claimed in claim 1, wherein, At least the spacing between the first plurality of transmitter transducer segments corresponds to the display stack and overlay oscillation mode frequency in the range of 20 Hz to 20 kHz.

13. The apparatus of claim 1, wherein the spacing between at least the second plurality of transmitter transducer segments corresponds to a display stacking and overlay oscillation mode for frequencies in the range of 15 kHz to 200 kHz.

14. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; and a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments including a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments including an emitter transducer segment and a receiver transducer segment, wherein the spacing between at least the first plurality of emitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer.

15. The appliance as claimed in claim 14, wherein, At least the spacing between the first plurality of transmitter transducer segments corresponds to the display stack and overlay oscillation mode frequency in the range of 20 kHz to 400 kHz.

16. The apparatus of claim 14, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

17. The apparatus of claim 14, wherein the spacing between at least the second plurality of transmitter transducer segments corresponds to a display stack and overlay oscillation mode for frequencies in the range of 20 Hz to 20 kHz.

18. The apparatus of claim 14 further includes a control system configured to control at least the first plurality of transmitter transducer segments to cause the display stack and the overlay to oscillate at frequencies in the range of 20 kHz to 400 kHz.

19. The apparatus of claim 18, wherein the control system is further configured to detect gestures based at least in part on ultrasonic signals received via one or more receiver transducer segments.

20. The appliance of claim 18, wherein the control system is further configured to perform noise cancellation based on receiver signals received from two or more receiver transducer segments.

21. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments including a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments including a transmitter transducer segment and a receiver transducer segment, wherein the spacing between at least a first plurality of transmitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer; and a control member for controlling at least the first plurality of transmitter transducer segments to reproduce an audio signal by causing the display stack and the cover layer to oscillate at frequencies in the range of 20 Hz to 20 kHz.

22. The apparatus of claim 21, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

23. The appliance as claimed in claim 21, wherein, At least the spacing between the first plurality of transmitter transducer segments corresponds to the display stack and overlay oscillation mode frequency in the range of 20 Hz to 20 kHz.

24. The apparatus of claim 21, wherein the thickness of each of the first plurality of transmitter transducer segments is different from the thickness of each of the first plurality of receiver transducer segments.

25. The apparatus of claim 24, wherein the piezoelectric layer thickness of each of the first plurality of receiver transducer segments is greater than the piezoelectric layer thickness of each of the first plurality of transmitter transducer segments.

26. The apparatus of claim 21, wherein a first subset of the separate transducer segments has a first segment width and a second subset of the separate transducer segments has a second segment width.

27. The apparatus of claim 21 further includes a control element configured to drive the transmitter transducer segments and obtain receiver signals from the receiver transducer segments.

28. An apparatus comprising: a display stack; a cover layer adjacent to a first side of the display stack; a segmented transducer array adjacent to a second side of the display stack, the segmented transducer array comprising a plurality of separate transducer segments, each of the separate transducer segments including a piezoelectric layer and a thin-film transistor (TFT) layer, the separate transducer segments including an emitter transducer segment and a receiver transducer segment, wherein the spacing between at least a first plurality of emitter transducer segments corresponds to an oscillation mode frequency of the display stack and the cover layer; and a control member for controlling at least the first plurality of emitter transducer segments to cause the display stack and the cover layer to oscillate at a frequency in the range of 20 kHz to 400 kHz.

29. The apparatus of claim 28, wherein the control element includes a component for detecting gestures based at least in part on ultrasonic signals received via one or more receiver transducer segments.

30. The apparatus of claim 28, wherein the control element includes a component for performing noise cancellation based on receiver signals received from two or more receiver transducer segments.

31. The apparatus of claim 28, wherein the distance between the centers of the first plurality of transmitter transducer segments is equal to the mode wavelength, half of the mode wavelength, a quarter of the mode wavelength, or an eighth of the mode wavelength, the mode wavelength corresponding to the display stack and overlay oscillation mode frequency.

32. The appliance as claimed in claim 28, wherein, At least the spacing between the first plurality of transmitter transducer segments corresponds to the display stack and overlay oscillation mode frequency in the range of 20 kHz to 400 kHz.

33. The apparatus of claim 28, wherein the spacing between at least the second plurality of transmitter transducer segments corresponds to a display stacking and overlay oscillation mode for frequencies in the range of 20 Hz to 20 kHz.

34. The apparatus of claim 28, wherein the control member includes means for driving the transmitter transducer segments in a higher-order mode, wherein adjacent transmitter transducer segments of the first plurality of transmitter transducer segments are driven in opposite directions.

35. The apparatus of claim 28, wherein the control element includes a component for driving the transmitter transducer sections in an intermediate mode, wherein, During the period when the first transmitter transducer segment of the first plurality of transmitter transducer segments is driven in the first direction, the second transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is not driven, and the third transducer segment of the first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the second direction opposite to the first direction.

36. The apparatus of claim 28, wherein the control element includes means for driving the transmitter transducer sections in a low-order mode, wherein, During the period when the first transmitter transducer segment of the first plurality of transmitter transducer segments is driven in the first direction, the second transmitter transducer segment of the first plurality of transmitter transducer segments adjacent to the first transmitter transducer segment is driven in the first direction, and the third transducer segment of the first plurality of transmitter transducer segments adjacent to the second transmitter transducer segment is driven in the first direction.

Images