Touch panel, driving method thereof, and touch device

Abstract

The application relates to a touch panel and a driving method thereof and a touch device. The touch panel comprises a housing which is arranged to form an accommodating space, the accommodating space is sequentially connected by a touch surface part, a first side wall, a back surface part and a second side wall; a first piezoelectric transducer is adjacent to the first side wall; a waveguide medium plate is arranged between the first piezoelectric transducer and the second side wall, and the waveguide medium plate extends along a first direction; a first acoustic coupler is arranged between the first piezoelectric transducer and the waveguide medium plate; an acoustic coupling layer is arranged between the first piezoelectric transducer, the first acoustic coupler, the waveguide medium plate and the touch surface part; wherein the first piezoelectric transducer is configured to emit a first ultrasonic wave; the first piezoelectric transducer, the first acoustic coupler and the waveguide medium plate are cooperatively configured to convert the first ultrasonic wave into a first target guided wave mode which propagates along the first direction in the waveguide medium plate. The application can be applied to a long strip-shaped touch interface.

Description

Technical Field

[0001] This application relates to the field of touch technology, and in particular to a touch panel and its driving method and touch device. Background Technology

[0002] Touch is one of the most important forms of human perception and the most natural way for humans to interact with machines. Touch devices have since been widely used in personal computers, smartphones, public information systems, smart home appliances, industrial control, and many other fields. Currently, the main types of touch devices include resistive touch devices, photoelectric touch devices, acoustic wave touch devices, planar capacitive touch devices, and projected capacitive touch devices.

[0003] Acoustic touch devices represent a novel form of human-computer interaction. Current acoustic touch technology involves a sound wave generator emitting a high-frequency sound wave that reaches the surface of a cover plate. When a finger touches the cover plate, the sound wave at the touch point is reflected. This reflection alters the propagation state of the sound wave within the cover plate, causing a change in the sound wave signal received by the sound wave receiver. The receiver processes this signal, analyzes it, and calculates the finger's coordinates relative to the cover plate. Based on these coordinates, it executes corresponding operations to achieve interaction between the user and the device. With the increasing prevalence of wearable devices and portable electronic products (such as smart glasses, smartphones, tablets, and other devices with narrow bezels), the demand for interactive operations on device bezels or narrow surfaces is growing.

[0004] However, existing ultrasonic touch panels have many problems, such as being difficult to apply to long and narrow touch interfaces. Summary of the Invention

[0005] Therefore, it is necessary to address the numerous problems of existing ultrasonic touch panels, such as their difficulty in being applied to elongated touch interfaces, and to provide a touch panel, its driving method, and a touch device.

[0006] According to a first aspect of this application, a touch panel is provided, comprising:

[0007] The housing surrounds and forms a receiving space, which is formed by sequentially connecting a touch surface portion, a first side wall, a back portion, and a second side wall; the touch surface portion and the back portion are arranged opposite to each other, and the first side wall and the second side wall are arranged opposite to each other in a first direction, which is parallel to the extending direction of the touch surface portion;

[0008] A first piezoelectric transducer is disposed within the accommodating space and adjacent to the first sidewall;

[0009] A waveguide dielectric plate is disposed between the first piezoelectric transducer and the second sidewall, and the waveguide dielectric plate extends along the first direction;

[0010] A first acoustic coupler is disposed between the first piezoelectric transducer and the waveguide dielectric plate;

[0011] An acoustic coupling layer is disposed between the first piezoelectric transducer, the first acoustic coupler, the waveguide dielectric plate, and the touch surface portion;

[0012] A driving circuit structure is disposed between the waveguide dielectric substrate and the back surface.

[0013] An isolation structure is located between the first piezoelectric transducer, the first acoustic coupler, the waveguide dielectric plate, and the driving circuit structure;

[0014] The first piezoelectric transducer is configured to emit a first ultrasonic wave; the first piezoelectric transducer, the first acoustic coupler, and the waveguide dielectric plate are configured together to perform mode conversion on the first ultrasonic wave and excite a first target guided wave mode that propagates along the first direction within the waveguide dielectric plate.

[0015] In some embodiments, the first acoustic coupler is triangular in cross-section parallel to the first direction;

[0016] The waveguide dielectric plate has an inclined surface on its end face in the first direction, and the inclined surface is parallel to and attached to the surface of the first acoustic coupler.

[0017] In some implementations, the touch panel further includes:

[0018] A second piezoelectric transducer is disposed between the waveguide dielectric plate and the second sidewall;

[0019] A second acoustic coupler is disposed between the second piezoelectric transducer and the waveguide dielectric plate;

[0020] The first piezoelectric transducer and the second piezoelectric transducer are arranged opposite to each other in the first direction;

[0021] The second piezoelectric transducer is configured to emit a second ultrasonic wave; the second piezoelectric transducer, the second acoustic coupler, and the waveguide dielectric plate are configured together to perform mode conversion on the second ultrasonic wave and excite a second target guided wave mode that propagates along the first direction within the waveguide dielectric plate.

[0022] In some embodiments, both the first acoustic coupler and the second acoustic coupler are triangular in shape in a cross section parallel to the first direction;

[0023] The waveguide dielectric plate has beveled end faces at both ends in the first direction, and is respectively parallel to and attached to the surfaces of the first acoustic coupler and the second acoustic coupler.

[0024] In some embodiments, in a cross-section parallel to the first direction, both the first acoustic coupler and the second acoustic coupler are right-angled triangles;

[0025] The hypotenuse of the right triangle is connected to the corresponding end face of the waveguide dielectric substrate;

[0026] The right-angled triangle corresponding to the first acoustic coupler has one leg connected to the first piezoelectric transducer;

[0027] The right-angled triangle corresponding to the second acoustic coupler has one leg connected to the second piezoelectric transducer.

[0028] In some embodiments, the angle between the normal to the hypotenuse of the right triangle and the acute angle of the first direction is a first angle θ, and the volume longitudinal wave phase velocity of the materials of the first acoustic coupler and the second acoustic coupler is V. wedge The axial phase velocity of the guided wave mode of the waveguide dielectric substrate is V. waveguide The first included angle θ satisfies the following formula:

[0029] .

[0030] In some embodiments, the waveguide dielectric substrate has a thickness of 1 mm to 2.5 mm perpendicular to the first direction;

[0031] The driving circuit structure includes a driver configured to provide driving signals to the first piezoelectric transducer and the second piezoelectric transducer, and the driving frequency of the driver is 12MHz-15MHz.

[0032] In some embodiments, the first target guided wave mode and the second target guided wave mode are at least one of an antisymmetric fundamental Lamb wave A0 mode and a quasi-longitudinal guided wave mode that propagates inside the waveguide dielectric plate and satisfies the symmetric boundary conditions of the waveguide dielectric plate.

[0033] In some embodiments, the material of the insulating structure includes rubber, foam, polyurethane; and / or,

[0034] The isolation structure includes air gaps.

[0035] According to a second aspect of this application, based on the same concept, a driving method for a touch panel is provided, applied to the touch panel described in any one of the above-mentioned applications, the driving method for the touch panel comprising:

[0036] Obtain the peak time of the emission pulse from the first piezoelectric transducer and set the peak time as time zero t0;

[0037] When an external object is detected touching the touch point of the touch surface, a backscattered feature echo or multiple backscattered feature echoes that are separated from each other on the time axis is extracted from the received signal of the first piezoelectric transducer, and the envelope peak time tn of the backscattered feature echo is obtained.

[0038] The absolute coordinate position dn of the corresponding touch point along the first direction is calculated according to the following formula:

[0039] ;

[0040] Among them, V g The group velocity of the first target waveguide mode at the set thickness and operating frequency of the waveguide dielectric plate is tn; the envelope peak time of the corresponding backscattered characteristic echo is tn; the absolute coordinate position dn takes the position of the first piezoelectric transducer as the coordinate origin; the backscattered characteristic echo is the first backscattered echo formed after the first target waveguide mode is backscattered by the touch point.

[0041] In some implementations, it also includes:

[0042] The scattered echo received by the first piezoelectric transducer at the touch point in the touch surface portion under non-touch conditions is obtained, and the reference amplitude f0 is obtained.

[0043] The first piezoelectric transducer receives the scattered echo of the touch point in the touch surface under touch conditions, and obtains the first amplitude f1.

[0044] The amplitude variation (NAD) of the scattered echo at the touch point under touch conditions is obtained according to the following formula:

[0045] ;

[0046] The external touch pressure at the touch point is calculated based on the amplitude change of the scattered echo.

[0047] In some embodiments, the driving circuit structure includes an analog front end and a variable gain amplifier, and the driving method of the touch panel further includes:

[0048] Dynamic gain compensation is performed through the analog front end and the variable gain amplifier, and the dynamic gain compensation includes compensation for static geometric loss and dynamic propagation loss respectively;

[0049] The static geometric loss includes the material loss of the first acoustic coupler, the fixed geometric path loss of the first acoustic coupler, and the penetration loss at the interface between the first acoustic coupler and the waveguide dielectric plate. The static geometric loss is compensated by a preset initial reference gain.

[0050] The dynamic propagation loss is the propagation loss of the first target waveguide mode within the waveguide dielectric substrate, and the dynamic propagation loss is mitigated by an effective attenuation coefficient a. c Characterized by the fact that the amplitude attenuation of the scattered echo satisfies The exponential decay law; based on the relationship between the distance and time of guided wave propagation, 2d = V g ×tn, where the variable gain amplifier applies a time-varying gain curve that varies with time to counteract the propagation attenuation of the waveguide dielectric plate, and d is the distance from the touch point to the first piezoelectric transducer.

[0051] In some embodiments, the touch panel further includes: a second piezoelectric transducer disposed between the waveguide dielectric plate and the second sidewall; and a second acoustic coupler disposed between the second piezoelectric transducer and the waveguide dielectric plate; wherein the first piezoelectric transducer and the second piezoelectric transducer are disposed opposite to each other in a first direction; the second piezoelectric transducer is configured to emit a second ultrasonic wave; the second piezoelectric transducer, the second acoustic coupler, and the waveguide dielectric plate are configured to perform mode conversion on the second ultrasonic wave to excite a second target guided wave mode propagating along the first direction within the waveguide dielectric plate;

[0052] The driving method for the touch panel further includes:

[0053] In the first detection cycle, the first piezoelectric transducer emits a first ultrasonic wave, which is converted into the first target guided wave mode by mode conversion; the first piezoelectric transducer receives the first backscattered echo corresponding to the first target guided wave mode, and the second piezoelectric transducer simultaneously receives the transmitted wave signal corresponding to the first target guided wave mode.

[0054] During the second detection cycle, the second piezoelectric transducer emits a second ultrasonic wave, which is converted into the second target guided wave mode by mode conversion; the second piezoelectric transducer receives the second backscattered echo corresponding to the second target guided wave mode, and the first piezoelectric transducer simultaneously receives the transmitted wave signal corresponding to the second target guided wave mode.

[0055] The first detection cycle and the second detection cycle are performed alternately.

[0056] According to a third aspect of this application, based on the same concept, a touch device is provided, comprising the touch panel described in any one of the above claims.

[0057] In some embodiments, the touch device is eyeglasses, which include a first frame, a second frame, a first temple and a second temple, wherein the first frame is connected to the second frame, the first temple is connected to the first frame, and the second temple is connected to the second frame;

[0058] The touch panel is disposed on the first temple and / or the second temple.

[0059] In some embodiments, the touch device further includes a display panel disposed on the side of the touch device and located on one side of the end of the display panel.

[0060] In this embodiment, in a first direction, a first piezoelectric transducer, a first acoustic coupler, and a waveguide dielectric plate are sequentially disposed within a receiving cavity surrounded by a housing. The first piezoelectric transducer is configured to emit a first ultrasonic wave; the first piezoelectric transducer, the first acoustic coupler, and the waveguide dielectric plate are configured collaboratively to perform mode conversion on the first ultrasonic wave, thereby exciting a first target guided wave mode propagating in the first direction within the waveguide dielectric plate. That is, the first piezoelectric transducer is configured to emit a first ultrasonic wave, and the sequential arrangement of the first piezoelectric transducer, the first acoustic coupler, and the waveguide dielectric plate in the first direction allows the first ultrasonic wave emitted by the repeated expansion and contraction vibration of the first piezoelectric transducer to be converted / excited into a first target guided wave mode propagating in the first direction after passing through the contact interface between the first acoustic coupler and the waveguide dielectric plate; the first target guided wave mode can be at least one of an antisymmetric fundamental Lamb wave mode and a quasi-longitudinal guided wave mode that propagates within the waveguide dielectric plate and satisfies the symmetric boundary conditions of the waveguide dielectric plate. Firstly, the first ultrasonic wave performs mode conversion within the waveguide dielectric plate, exciting a first target guided wave mode that propagates along a first direction. This first target guided wave mode can travel a considerable distance along the waveguide dielectric plate in the first direction, allowing for the formation of a touch surface portion with a relatively long length in the first direction. This is particularly suitable for elongated touch interfaces (especially slender touch interfaces). The slender waveguide dielectric plate avoids problems such as multi-mode aliasing, signal interpretation difficulties, and insufficient multi-point resolution, thereby improving touch accuracy. Secondly, the first piezoelectric transducer, the first acoustic coupler, and the waveguide dielectric plate are sequentially disposed within the receiving cavity surrounded by the housing. Unlike conventional technologies, they do not require oblique contact with the external wedge slope, thus avoiding the problem of easy failure under dynamic mechanical stress caused by oblique contact. The embodiments of this application possess at least one of the aforementioned beneficial effects. Attached Figure Description

[0061] To more clearly illustrate the technical solutions in the embodiments or exemplary embodiments of this application, the drawings used in the description of the embodiments or exemplary embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0062] Figure 1 This is a schematic diagram of a first cross-sectional structure of a touch panel provided in an embodiment of this application.

[0063] Figure 2 This is a schematic diagram of a second cross-sectional structure of a touch panel provided in an embodiment of this application.

[0064] Figure 3 This is a first schematic diagram illustrating the modal conversion process of a first ultrasonic wave in a touch panel, as provided in an embodiment of this application.

[0065] Figure 4 This is a second schematic diagram illustrating the modal conversion process of a first ultrasonic wave in a touch panel, as provided in an embodiment of this application.

[0066] Figure 5 This is a schematic diagram of the working range of a first target waveguide mode or a second target waveguide mode in a touch panel, provided as an embodiment of this application.

[0067] Figure 6 This is a schematic diagram illustrating the flow steps of a touch panel driving method provided in an embodiment of this application.

[0068] Figure 7 This is a schematic diagram illustrating the control process of a touch panel driving method provided in an embodiment of this application.

[0069] Figure 8 This is a schematic diagram of a single-point touch process in a driving method for a touch panel provided in an embodiment of this application.

[0070] Figure 9 This is a schematic diagram of the amplitude of the scattered echo from a single touch in a driving method for a touch panel provided in an embodiment of this application.

[0071] Figure 10 This is a schematic diagram of the multi-touch process in a driving method for a touch panel provided in an embodiment of this application.

[0072] Figure 11 This is a schematic diagram of the amplitude of the scattered echo from multi-touch in a driving method for a touch panel provided in an embodiment of this application.

[0073] Figure 12This is a schematic diagram of the amplitude of the scattered echo after dynamic gain compensation is performed during multi-touch in a driving method for a touch panel provided in an embodiment of this application.

[0074] Figure 13 This is a first overall schematic diagram of a touch device provided in an embodiment of this application.

[0075] Figure 14 This is a first partially enlarged schematic diagram of a touch device provided in an embodiment of this application.

[0076] Figure 15 This is a second overall schematic diagram of a touch device provided in an embodiment of this application.

[0077] Figure 16 This is a second partially enlarged schematic diagram of a touch device provided in an embodiment of this application.

[0078] Reference numerals: Touch device 1000; Touch panel 100; Housing 10; First piezoelectric transducer 21; Waveguide dielectric substrate 40; First acoustic coupler 31; Acoustic coupling layer 70; Drive circuit structure 50; Isolation structure 60; Accommodation space 10q; Touch surface portion 11; First sidewall 12; Back surface portion 13; Second sidewall 14; Second piezoelectric transducer 22; Second acoustic coupler 32; First isolation portion 61; Air gap 62; First sub-backscattered echo 1011; Second sub-backscattered echo 1012; Reference amplitude f0; First amplitude f1; First compensated amplitude f12;

[0079] First direction X; First target waveguide mode 101; First included angle θ; Hypotenuse 311; Inclined surface 411; Right-angled side 312; First thickness h; Time zero point t0; Envelope peak time tn; First touch point C1; Second touch point C2; First time t1; Second time t2; Absolute coordinate position dn; First frame 10J1; Second frame 10J2; First temple 10J3; Second temple 10J4; Display panel 10X1. Detailed Implementation

[0080] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0081] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0082] Furthermore, where the terms "first" and "second" appear, these terms are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0083] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0084] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0085] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0086] Existing ultrasonic touch panels suffer from numerous problems, such as difficulty in applying them to elongated touch interfaces. For example, when applied to elongated touch interfaces (especially slender ones), the slender waveguide structure suffers from multimodal aliasing, difficulty in signal interpretation, and insufficient multi-point resolution. Furthermore, active transducers typically require oblique bonding to an external wedge-shaped surface, and this traditional oblique bonding method makes them prone to failure under dynamic mechanical stress.

[0087] In view of the above problems, this application provides a touch panel and its driving method and touch device.

[0088] Please see Figures 1 to 16 . Figure 1 This is a schematic diagram of a first cross-sectional structure of a touch panel provided in an embodiment of this application. Figure 2 This is a schematic diagram of a second cross-sectional structure of a touch panel provided in an embodiment of this application. Figure 3 This is a first schematic diagram illustrating the modal conversion process of a first ultrasonic wave in a touch panel, as provided in an embodiment of this application. Figure 4 This is a second schematic diagram illustrating the modal conversion process of a first ultrasonic wave in a touch panel, as provided in an embodiment of this application. Figure 5 This is a schematic diagram of the working range of a first target waveguide mode or a second target waveguide mode in a touch panel, provided as an embodiment of this application.

[0089] Figure 6 This is a schematic diagram illustrating the flow steps of a touch panel driving method provided in an embodiment of this application. Figure 7 This is a schematic diagram illustrating the control process of a touch panel driving method provided in an embodiment of this application.

[0090] Figure 8 This is a schematic diagram of a single-point touch process in a driving method for a touch panel provided in an embodiment of this application. Figure 9 This is a schematic diagram of the amplitude of the scattered echo from a single touch in a driving method for a touch panel provided in an embodiment of this application.

[0091] Figure 10This is a schematic diagram of the multi-touch process in a driving method for a touch panel provided in an embodiment of this application. Figure 11 This is a schematic diagram of the amplitude of the scattered echo from multi-touch in a driving method for a touch panel provided in an embodiment of this application.

[0092] Figure 12 This is a schematic diagram of the amplitude of the scattered echo after dynamic gain compensation is performed during multi-touch in a driving method for a touch panel provided in an embodiment of this application.

[0093] Figure 13 This is a first overall schematic diagram of a touch device provided in an embodiment of this application. Figure 14 This is a first partially enlarged schematic diagram of a touch device provided in an embodiment of this application.

[0094] Figure 15 This is a second overall schematic diagram of a touch device provided in an embodiment of this application. Figure 16 This is a second partially enlarged schematic diagram of a touch device provided in an embodiment of this application.

[0095] Firstly, such as Figures 1 to 5 As shown, this application provides a touch panel 100, which includes a housing 10, a first piezoelectric transducer 21, a waveguide dielectric plate 40, a first acoustic coupler 31, an acoustic coupling layer 70, a driving circuit structure 50, and an isolation structure 60. The housing 10 encloses a receiving space 10q, which is formed by sequentially connecting a touch surface portion 11, a first sidewall 12, a back surface portion 13, and a second sidewall 14. The touch surface portion 11 and the back surface portion 13 are arranged opposite to each other, and the first sidewall 12 and the second sidewall 14 are arranged opposite to each other in a first direction X, which is parallel to the extension direction of the touch surface portion 11. The first piezoelectric transducer 21 is disposed within the receiving space 10q and adjacent to the first sidewall 12. The waveguide dielectric plate 40 is disposed between the first piezoelectric transducer 21 and the second sidewall 14, and extends along the first direction X. A first acoustic coupler 31 is disposed between the first piezoelectric transducer 21 and the waveguide dielectric plate 40. An acoustic coupling layer 70 is disposed between the first piezoelectric transducer 21, the first acoustic coupler 31, the waveguide dielectric plate 40, and the touch surface portion 11. A driving circuit structure 50 is disposed between the waveguide dielectric plate 40 and the back surface portion 13. An isolation structure 60 is located between the first piezoelectric transducer 21, the first acoustic coupler 31, the waveguide dielectric plate 40, and the driving circuit structure 50. The first piezoelectric transducer 21 is configured to emit a first ultrasonic wave; the first piezoelectric transducer 21, the first acoustic coupler 31, and the waveguide dielectric plate 40 are configured collaboratively to perform mode conversion on the first ultrasonic wave, exciting a first target guided wave mode 101 propagating along a first direction X within the waveguide dielectric plate 40.

[0096] For example, the housing 10 includes a touch surface portion 11, a first sidewall 12, a back surface portion 13, and a second sidewall 14. In a cross-section parallel to the first direction X, the touch surface portion 11, the first sidewall 12, the back surface portion 13, and the second sidewall 14 are sequentially connected, forming a receiving space 10q. The receiving space 10q is used to accommodate a first piezoelectric transducer 21, a waveguide dielectric plate 40, a first acoustic coupler 31, a driving circuit structure 50, an isolation structure 60, etc. In some subsequent embodiments, the receiving space 10q may also be used to accommodate a second piezoelectric transducer 22 and a second acoustic coupler 32, etc.

[0097] For example, the touch surface portion 11 is a part or interface for finger touch or external object pressing, and the touch surface portion 11 has a touch interface.

[0098] For example, the touch surface portion 11 can be integrally formed with the first sidewall 12, the back portion 13 and the second sidewall 14, and the touch surface portion 11 can also be made of different structures and / or materials with the first sidewall 12, the back portion 13 and the second sidewall 14.

[0099] For example, the material of the touch surface portion 11 includes at least one of glass, polycarbonate, polymethyl methacrylate, and polyethylene terephthalate, but is not limited thereto. For instance, the material of the touch surface portion 11 may be formed of glass, tempered glass, polycarbonate (PC), polymethyl methacrylate (PMMA), polyethylene terephthalate (PET), or composites thereof, and the outer surface of the touch surface portion 11 may be provided with a hardening layer, an anti-fouling layer, an anti-glare layer, or an anti-reflective layer as needed to improve scratch resistance, ease of cleaning, and tactile feel.

[0100] For example, the first piezoelectric transducer 21 and the second piezoelectric transducer 22 (described in subsequent embodiments) are devices that use the piezoelectric effect to convert electrical energy and mechanical energy (ultrasound) to each other. The materials of the first piezoelectric transducer 21 and the second piezoelectric transducer 22 may include any one of lead zirconate titanate (PZT) piezoelectric ceramics, barium titanate (BaTiO3) piezoelectric ceramics, and polyvinylidene fluoride (PVDF) piezoelectric polymers, but are not limited thereto.

[0101] For example, the first piezoelectric transducer 21 and the first acoustic coupler 31 can provide a volume longitudinal wave with sufficient amplitude in the desired frequency band.

[0102] For example, the waveguide dielectric plate 40 is used to transmit the first target guided wave mode 101, and the waveguide dielectric plate 40 constitutes the main path for the propagation of the dominant guided elastic wave. The material of the waveguide dielectric plate 40 includes at least one of metal, glass, and polymer. For example, the material of the waveguide dielectric plate 40 may be aluminum alloy, stainless steel, titanium alloy, glass fiber reinforced plastic, polycarbonate, polyamide, PEEK, or other materials sufficient to conduct Lamb waves or quasi-longitudinal guided wave modes in an elongated structure.

[0103] For example, the waveguide dielectric plate 40 is elongated, and the ratio of the length of the waveguide dielectric plate 40 in the first direction X to the width perpendicular to the first direction X can be greater than or equal to 5. The ratio of the length of the waveguide dielectric plate 40 in the first direction X to the width perpendicular to the first direction X can be any value among 5, 8, 10, and 12.

[0104] For example, the ratio of the longitudinal wave velocity of the first acoustic coupler 31 to the phase velocity of the target guided wave mode (first target guided wave mode 101) of the waveguide body (waveguide dielectric plate 40) is suitable to form the equivalent critical angle (first included angle θ) described later. The material of the first acoustic coupler 31 includes any one of polymer, metal, or polymer-metal composite material.

[0105] For example, an acoustic coupling layer 70 is disposed between the touch surface portion 11 and the waveguide medium plate 40 to transfer the mechanical contact load (touch behavior) of the outer panel to the waveguide medium plate 40 and to provide mechanical fixation and acoustic impedance transition between the two.

[0106] For example, the material of the acoustic coupling layer 70 includes at least one of silicone, epoxy resin, polyurethane adhesive, pressure-sensitive adhesive, and optical adhesive, but is not limited to these. For instance, the material of the acoustic coupling layer 70 can be silicone, epoxy resin, polyurethane adhesive, pressure-sensitive adhesive, optical adhesive, or other viscoelastic materials. The thickness of the acoustic coupling layer 70 can be designed to range from tens of micrometers to hundreds of micrometers depending on the required touch sensitivity, damping control, and manufacturing tolerances, so that the local pressing, sliding, or contact load borne by the touch surface portion 11 can be effectively coupled to the waveguide dielectric plate 40 without excessive dissipation of guided wave energy.

[0107] For example, the isolation structure 60 is a damping layer, an isolation layer, or an air gap to isolate the drive circuit structure 50 from the first piezoelectric transducer 21, the waveguide dielectric plate 40, and the first acoustic coupler 31, etc.

[0108] For example, the material of the isolation structure 60 includes rubber, foam, polyurethane; and / or, the isolation structure 60 includes an air gap. For instance, the material of the isolation structure 60 may be rubber, foam, polyurethane, or other viscoelastic materials, or the isolation structure 60 may be a reserved air gap used to adjust the damping of the overall structure and reduce the influence of the external structure on the propagation of guided waves.

[0109] For example, the drive circuit structure 50 may include a driver, an analog front-end, a control chip, a processor, etc., and the drive circuit structure 50 may be electrically connected to the first piezoelectric transducer 21 (and / or the second piezoelectric transducer 22) via wires or a flexible circuit board. The drive circuit structure 50 may drive the first piezoelectric transducer 21 (and / or the second piezoelectric transducer 22) and process the scattered echo signal received by the first piezoelectric transducer 21 (and / or the second piezoelectric transducer 22).

[0110] For example, such as Figure 1 As shown, in the first direction X, the first piezoelectric transducer 21, the first acoustic coupler 31 and the waveguide dielectric plate 40 are arranged in sequence.

[0111] For example, the first piezoelectric transducer 21 is configured to emit a first ultrasonic wave; the first piezoelectric transducer 21, the first acoustic coupler 31, and the waveguide dielectric plate 40 are configured together to perform mode conversion on the first ultrasonic wave, thereby exciting a first target guided wave mode 101 propagating along the first direction X within the waveguide dielectric plate 40. That is, the first piezoelectric transducer 21 is configured to emit the first ultrasonic wave, and the first piezoelectric transducer 21, the first acoustic coupler 31, and the waveguide dielectric plate 40 are sequentially arranged in the first direction X, so that the first ultrasonic wave emitted by the repeated expansion and contraction vibration of the first piezoelectric transducer 21, after passing through the contact interface between the first acoustic coupler 31 and the waveguide dielectric plate 40, is converted / excited to generate the first target guided wave mode 101 propagating along the first direction X. The first target guided wave mode 101 can be at least one of the following: an antisymmetric fundamental Lamb wave A0 mode, or a quasi-longitudinal guided wave mode that propagates within the waveguide dielectric plate 40 and satisfies the symmetric boundary conditions of the waveguide dielectric plate 40.

[0112] In this embodiment, in the first direction X, a first piezoelectric transducer 21, a first acoustic coupler 31, and a waveguide dielectric plate 40 are sequentially disposed within the accommodating space 10q surrounded by the housing 10. The first piezoelectric transducer 21 is configured to emit a first ultrasonic wave; the first piezoelectric transducer 21, the first acoustic coupler 31, and the waveguide dielectric plate 40 are configured in concert to perform mode conversion on the first ultrasonic wave, thereby exciting a first target guided wave mode 101 propagating along the first direction X within the waveguide dielectric plate 40. That is, the first piezoelectric transducer 21 is configured to emit a first ultrasonic wave. The first piezoelectric transducer 21, the first acoustic coupler 31 and the waveguide dielectric plate 40 are arranged sequentially in the first direction, so that the first ultrasonic wave emitted by the repeated expansion and contraction vibration of the first piezoelectric transducer 21 passes through the contact interface between the first acoustic coupler 31 and the waveguide dielectric plate 40 and is transformed / excited to generate a first target guided wave mode 101 that propagates along the first direction X. The first target guided wave mode 101 can be at least one of the antisymmetric fundamental Lamb wave A0 mode and a quasi-longitudinal guided wave mode that propagates inside the waveguide dielectric plate 40 and satisfies the symmetric boundary conditions of the waveguide dielectric plate 40. Firstly, the first ultrasonic wave undergoes mode conversion within the waveguide dielectric plate 40, exciting a first target guided wave mode 101 that propagates along the first direction X. This first target guided wave mode 101 can travel a considerable distance along the first direction X within the waveguide dielectric plate 40, allowing for the formation of a larger length of the touch surface portion 11 along the first direction X. This is particularly suitable for elongated touch interfaces (especially slender ones), as the slender waveguide dielectric plate 40 avoids problems such as multi-mode aliasing, signal interpretation difficulties, and insufficient multi-point resolution, thereby improving touch accuracy. Secondly, the first piezoelectric transducer 21, the first acoustic coupler 31, and the waveguide dielectric plate 40 are sequentially disposed within the receiving cavity 10q surrounded by the housing 10. Unlike conventional technologies, they do not require oblique contact with the external wedge slope, thus avoiding the problem of easy failure under dynamic mechanical stress caused by oblique contact. The embodiments of this application possess at least one of the aforementioned beneficial effects.

[0113] In some implementations, such as Figure 1 As shown, in a cross section parallel to the first direction X, the first acoustic coupler 31 is triangular; the end face of the waveguide dielectric plate 40 in the first direction X has a bevel 411, and the bevel 411 is parallel and attached to the surface of the first acoustic coupler 31.

[0114] In some implementations, such as Figure 2As shown, the touch panel 100 also includes a second piezoelectric transducer 22 and a second acoustic coupler 32. The second piezoelectric transducer 22 is disposed between the waveguide dielectric plate 40 and the second sidewall 14; the second acoustic coupler 32 is disposed between the second piezoelectric transducer 22 and the waveguide dielectric plate 40. The first piezoelectric transducer 21 and the second piezoelectric transducer 22 are disposed opposite each other in the first direction X; the second piezoelectric transducer 22 is configured to emit a second ultrasonic wave; the second piezoelectric transducer 22, the second acoustic coupler 32, and the waveguide dielectric plate 40 are configured collaboratively to perform mode conversion on the second ultrasonic wave, exciting a second target guided wave mode propagating along the first direction X within the waveguide dielectric plate 40.

[0115] For example, the second piezoelectric transducer 22 and the second acoustic coupler 32 can provide a volume longitudinal wave with sufficient amplitude in the desired frequency band.

[0116] For example, the ratio of the longitudinal wave velocity of the second acoustic coupler 32 to the phase velocity of the target guided wave mode of the waveguide dielectric plate 40 is suitable for forming the equivalent critical angle (first included angle θ) described later. The material of the second acoustic coupler 32 includes any one of polymer, metal, or polymer-metal composite material.

[0117] For example, such as Figure 2 As shown, in the first direction X, the first piezoelectric transducer 21, the first acoustic coupler 31 and the waveguide dielectric plate 40, the second acoustic coupler 32 and the second piezoelectric transducer 22 are arranged in sequence.

[0118] For example, the second piezoelectric transducer 22 is configured to emit a second ultrasonic wave; the second piezoelectric transducer 22, the second acoustic coupler 32, and the waveguide dielectric plate 40 are configured in concert to perform mode conversion on the second ultrasonic wave, thereby exciting a second target guided wave mode propagating along the first direction X within the waveguide dielectric plate 40. That is, the second piezoelectric transducer 22 is configured to emit a second ultrasonic wave, and the second piezoelectric transducer 22, the second acoustic coupler 32, and the waveguide dielectric plate 40 are sequentially arranged in the first direction X, such that the second ultrasonic wave emitted by the repeated expansion and contraction vibration of the second piezoelectric transducer 22, after passing through the contact interface between the second acoustic coupler 32 and the waveguide dielectric plate 40, is converted / excited to generate a second target guided wave mode propagating along the first direction X. The second target guided wave mode can be at least one of the following: an antisymmetric fundamental Lamb wave A0 mode, or a quasi-longitudinal guided wave mode propagating within the waveguide dielectric plate 40 and satisfying the symmetric boundary conditions of the waveguide dielectric plate 40.

[0119] For example, the propagation direction of the first target waveguide mode 101 is opposite to that of the second target waveguide mode.

[0120] For example, with Figure 1 In contrast, when the length of the waveguide dielectric substrate 40 in the first direction X is too large, it is simultaneously set Figure 2 The first piezoelectric transducer 21 and the second piezoelectric transducer 22, as exemplified, can improve touch accuracy when the attenuation of the first target waveguide mode 101 transmitted within the waveguide dielectric plate 40 is too large.

[0121] In some implementations, such as Figures 1 to 4 As shown, in a cross section parallel to the first direction X, both the first acoustic coupler 31 and the second acoustic coupler 32 are triangular; the end faces of the waveguide dielectric plate 40 at both ends in the first direction X are inclined and are respectively parallel to and attached to the surfaces of the first acoustic coupler 31 and the second acoustic coupler 32.

[0122] For example, such as Figure 3 and Figure 4 As shown, in a cross-section parallel to the first direction X, both the first acoustic coupler 31 and the second acoustic coupler 32 are triangular, with the triangle including the hypotenuse 311. The end faces of the waveguide dielectric plate 40 at both ends in the first direction X each have a slope 411.

[0123] For example, combined Figure 1 , Figure 3 and Figure 4 As shown, in some embodiments, the waveguide dielectric plate 40 is in the shape of an elongated plate. The end of the waveguide dielectric plate 40 connected to the first acoustic coupler 31 is provided with a bevel 411 at a specific angle (an interface inclined relative to the first direction X). The first acoustic coupler 31 is triangular, and the surface where the hypotenuse 311 of the triangle is located is in face-to-face contact with the bevel 411 of the waveguide dielectric plate 40. A thin film adhesive layer can be used to form an acoustically tight bond, so as to facilitate the effective transmission of ultrasonic waves from the first acoustic coupler 31 to the waveguide dielectric plate 40.

[0124] For example, combined Figure 2 , Figure 3 and Figure 4 As shown, in some other embodiments, the waveguide dielectric plate 40 is in the shape of an elongated plate, and the end of the waveguide dielectric plate 40 connected to the second acoustic coupler 32 is provided with a bevel 411 at a specific angle (an interface inclined relative to the first direction X). The second acoustic coupler 32 is triangular, and the surface where the hypotenuse 311 of the triangle is located is in face-to-face contact with the bevel 411 of the waveguide dielectric plate 40. An acoustically tight bond can be formed by a thin film adhesive layer to facilitate the effective transmission of ultrasonic waves from the second acoustic coupler 32 to the waveguide dielectric plate 40.

[0125] In some implementations, such as Figures 1 to 4As shown, in a cross section parallel to the first direction X, both the first acoustic coupler 31 and the second acoustic coupler 32 are right-angled triangles; the hypotenuse 311 of the right-angled triangle is connected to the corresponding end face of the waveguide dielectric plate 40; the right leg 312 of the right-angled triangle corresponding to the first acoustic coupler 31 is connected to the first piezoelectric transducer 21; and the right leg 312 of the right-angled triangle corresponding to the second acoustic coupler 32 is connected to the second piezoelectric transducer 22.

[0126] For example, such as Figure 3 and Figure 4 As shown, in a cross-section parallel to the first direction X, both the first acoustic coupler 31 and the second acoustic coupler 32 are right-angled triangles, each including a hypotenuse 311 and a first right-angled side 312. The extension direction of the first right-angled side 312, or the extension direction of the surface on which the first right-angled side 312 is located, is perpendicular to the first direction X.

[0127] For example, combined Figure 1 , Figure 3 and Figure 4 As shown, in some embodiments, the first piezoelectric transducer 21 is bonded to the surface where the first right-angled side 312 is located, such that the main expansion and contraction vibration direction of the first piezoelectric transducer 21 is parallel to the first direction X. The entire first piezoelectric transducer 21 and the first acoustic coupler 31 can be housed and fixed in the receiving cavity 10q inside the first sidewall 12, avoiding shear fatigue and reliability degradation caused by traditional oblique bonding.

[0128] For example, combined Figure 2 , Figure 3 and Figure 4 As shown, in some other embodiments, the second piezoelectric transducer 22 is simultaneously bonded to the surface where the first right-angled side 312 is located, such that the main expansion and contraction vibration direction of the second piezoelectric transducer 22 is parallel to the first direction X. The entire second piezoelectric transducer 22 and the second acoustic coupler 32, etc., can be housed and fixed within the receiving cavity 10q inside the second sidewall 14, avoiding shear fatigue and reliability degradation caused by conventional oblique bonding.

[0129] In some implementations, such as Figures 1 to 4 As shown, the angle between the normal to the hypotenuse 311 of the right triangle and the acute angle with the first direction X is the first angle θ. The volume longitudinal wave phase velocity of the materials of the first acoustic coupler 31 and the second acoustic coupler 32 is V. wedge The axial phase velocity of the guided wave mode of the waveguide dielectric substrate 40 is V. waveguide The first included angle θ satisfies the following formula:

[0130] .

[0131] For example, in order for the first piezoelectric transducer 21 to excite longitudinal waves on the side of the first acoustic coupler 31 of the triangle, and / or for the second piezoelectric transducer 22 to excite longitudinal waves on the side of the second acoustic coupler 32 of the triangle, so that they can be effectively converted into guided elastic wave modes (first target guided wave mode 101 and / or second target guided wave mode) propagating along the length direction of the waveguide dielectric plate 40 at the interface between the corresponding acoustic coupler (first acoustic coupler 31 and / or second acoustic coupler 32) and the inclined surface 411 of the waveguide dielectric plate 40, the inclined surface 411 of the waveguide dielectric plate 40 is configured to satisfy a phase velocity matching condition of an equivalent critical angle (first included angle θ).

[0132] For example, this phase velocity matching condition corresponds to the phase continuity principle in the interface tangential direction, which causes the bulk wave energy in the triangular acoustic coupler (first acoustic coupler 31 and / or second acoustic coupler 32) to be preferentially converted into the target guided elastic wave mode (first target guided wave mode 101 and / or second target guided wave mode) in the waveguide dielectric plate 40, rather than being radiated in large quantities as non-target bulk waves or other stray modes.

[0133] It should be noted that, to account for manufacturing tolerances and operating temperature variations, the equivalent critical angle (first included angle θ) can be set within an error range. For example, the value of the first included angle θ can be: the design target value + / - Δθ. + / - Δθ ​​represents the maximum error considering manufacturing tolerances and operating temperature variations. This allows for better maintenance of the high coupling efficiency of the target mode and suppression of non-target mode energy.

[0134] In some implementations, such as Figure 4 and Figure 5 As shown, the thickness (first thickness h) of the waveguide dielectric plate 40 in the direction perpendicular to the first direction X is 1mm-2.5mm; the driving circuit structure 50 includes a driver, which is configured to provide a driving signal to the first piezoelectric transducer 21 and the second piezoelectric transducer 22, and the driving frequency of the driver is 12MHz-15MHz.

[0135] For example, the waveguide dielectric substrate 40 has a thickness of 1mm-2.5mm perpendicular to the first direction X; the driving circuit structure 50 includes a driver configured to provide a driving signal to the first piezoelectric transducer 21 and / or the second piezoelectric transducer 22, and the driving frequency of the driver is 12MHz-15MHz. Under the constraint of the product of this specific frequency and the thickness of the waveguide dielectric substrate 40 (f⋅h), and in conjunction with the coupling efficiency design of the equivalent critical angle (first included angle θ) mentioned above, the energy and sensing response of the system can be dominated by a specific dominant directional elastic wave mode, while other non-target modes are suppressed to a degree that does not affect signal interpretation. Figure 5 The vertical axis represents phase velocity / group velocity. Figure 5The horizontal axis represents the product of the driver's driving frequency f and the thickness h of the waveguide dielectric plate 40. Figure 5 The dashed box in the middle indicates the design working range (f·h restricted area). The working range of the first target waveguide mode 101 / the second target waveguide mode is a single dominant mode. Figure 5 The dashed circle in the middle indicates the intervals of non-target volume wave / non-target mode energy / other stray modes / multi-mode mixed region.

[0136] For example, the thickness (first thickness h) of the waveguide dielectric substrate 40 perpendicular to the first direction X is 1mm-2.5mm, and the first thickness h can be any value among 1mm, 1.5mm, 2mm, and 2.5mm. The driving frequency of the driver is 12MHz-15MHz, and the driving frequency of the driver can be any value among 12MHz, 13MHz, 14MHz, and 15MHz.

[0137] For example, compared to the prior art, where the operating frequency of the active transducer is relatively low (e.g., 2MHz to 5MHz), leading to a sensing dead zone near the endpoint of the active transducer due to residual vibration and excessively wide pulses, the embodiments of this application set the driving frequency of the first piezoelectric transducer and / or the second piezoelectric transducer 22 to be higher (driving frequency up to 12MHz-15MHz), making it less likely that a sensing dead zone due to residual vibration and excessively wide pulses will exist near the endpoint of the first piezoelectric transducer and / or the second piezoelectric transducer 22.

[0138] In some implementations, such as Figure 5 As shown, the first target guided wave mode 101 and the second target guided wave mode are at least one of the antisymmetric fundamental Lamb wave A0 mode and a quasi-longitudinal guided wave mode that propagates inside the waveguide dielectric plate 40 and satisfies the symmetric boundary conditions of the waveguide dielectric plate 40.

[0139] For example, the quasi-longitudinal guided wave mode is the S0 fundamental symmetric Lamb wave.

[0140] For example, the antisymmetric fundamental Lamb wave A0 mode is highly sensitive to surface contact (very sensitive to surface defects and loads), and is responsible for sensing touch events, making it very suitable for surface touch detection of thin plate structures (the waveguide dielectric plate 40 can be a thin plate structure); the quasi-longitudinal guided wave mode is not sensitive to external surface liquids and stains, and serves as a reference channel to suppress false triggering, while also assisting in pressure calculation and signal distortion correction.

[0141] For example, the first target waveguide mode 101 and the second target waveguide mode are at least one of the antisymmetric fundamental Lamb wave A0 mode and a quasi-longitudinal waveguide mode that propagates inside the waveguide dielectric plate 40 and satisfies the symmetric boundary conditions of the waveguide dielectric plate 40. When applied to a long strip-shaped touch interface (touch surface portion 11), the problems of multi-mode aliasing, difficulty in signal interpretation and insufficient multi-point resolution are avoided or improved.

[0142] It should be noted that the first acoustic coupler 31 and the second acoustic coupler 32 are used to selectively excite the Lamb wave mode propagating within the waveguide dielectric plate 40, and suppress edge waves and surface waves.

[0143] In some implementations, such as Figure 1 and Figure 2 As shown, the materials of the isolation structure 60 include rubber, foam, polyurethane; and / or, the isolation structure 60 includes air gaps.

[0144] For example, such as Figure 1 and Figure 2 As shown, on a plane parallel to the first direction X, the isolation structure 60 may include a first isolation part 61 and an air gap 62 surrounded by the first isolation part 61. The material of the first isolation part 61 may be at least one of rubber, foam, and polyurethane.

[0145] Secondly, based on the same inventive concept, please refer to Figure 6 This application also provides a driving method for a touch panel, which can be applied to the touch panel 100 described above. The driving method for the touch panel includes steps S100, S200, and S300.

[0146] Step S100: Obtain the peak time of the emission pulse of the first piezoelectric transducer and set the peak time as the time zero point t0.

[0147] For example, such as Figure 9 As shown, or as Figure 11 As shown, the peak time of the emission pulse of the first piezoelectric transducer 21 is obtained, and the peak time is set as the time zero point t0.

[0148] Step S200: When an external object is detected touching the touch point of the touch surface, extract one backscattered feature echo or multiple backscattered feature echoes that are separated from each other on the time axis from the received signal of the first piezoelectric transducer, and obtain the envelope peak time tn of the backscattered feature echo.

[0149] For example, such as Figure 8 and Figure 9 As shown, or as Figure 10 and Figure 11As shown, when an external object touches the touch point of the touch surface 11, a backscattered feature echo or multiple backscattered feature echoes that are separated from each other on the time axis is extracted from the received signal of the first piezoelectric transducer 21, and the envelope peak time tn of the backscattered feature echo is obtained.

[0150] For example, Figure 8 and Figure 9 This illustrates a touch point, namely the first touch point C1. Figure 10 and Figure 11 Two touch points are shown: the first touch point C1 and the second touch point C2.

[0151] For example, in Figure 1 In the example, combined Figure 8 and Figure 9 As shown, or in combination Figure 10 and Figure 11 As shown, the acquired backscattered characteristic echo is the first backscattered echo corresponding to the first target waveguide mode 101. The first backscattered echo returned from the first touch point C1 is the first sub-backscattered echo 1011; the first backscattered echo returned from the second touch point C2 is the second sub-backscattered echo 1012. Part of the energy of the first target waveguide mode 101 continues to be transmitted as a transmitted wave signal along the first direction X.

[0152] For example, the envelope peak time of the first sub-backscattered echo 1011 at the first touch point C1 is the first time t1; the envelope peak time of the second sub-backscattered echo 1012 at the second touch point C2 is the second time t2.

[0153] Step S300: Calculate the absolute coordinate position dn of the corresponding touch point along the first direction X according to the following formula:

[0154] ;

[0155] Among them, V g The group velocity of the first target waveguide mode at the set thickness and operating frequency of the waveguide dielectric plate is tn; the envelope peak time of the corresponding backscattered characteristic echo is tn; the absolute coordinate position dn takes the position of the first piezoelectric transducer as the coordinate origin; the backscattered characteristic echo is the first backscattered echo formed after the first target waveguide mode is backscattered by the touch point.

[0156] For example, the absolute coordinate position dn of each touch point along the first direction X is calculated according to the following formula:

[0157] ;

[0158] Among them, Vg tn is the group velocity corresponding to the first target waveguide mode 101 at the set thickness and operating frequency of the waveguide medium plate 40; tn is the envelope peak time of the corresponding backscattered characteristic echo; the absolute coordinate position dn takes the position of the first piezoelectric transducer 21 as the coordinate origin; the backscattered characteristic echo is the first backscattered echo formed after the first target waveguide mode 101 is backscattered by the touch point.

[0159] For example, the absolute coordinate position dn takes the position of the first piezoelectric transducer 21 as the origin of the coordinate system. In this case, the absolute coordinate position dn can represent the distance between the touch point and the first piezoelectric transducer 21 in the first direction X.

[0160] For example, such as Figure 10 As shown, the absolute coordinates of the first touch point C1 are the first position (also the first distance d1), and the first backscattered echo corresponding to the first touch point C1 is the first sub-backscattered echo 1011. The absolute coordinates of the second touch point C2 are the second position (also the second distance d2), and the first backscattered echo corresponding to the second touch point C2 is the second sub-backscattered echo 1012.

[0161] For example, the absolute coordinate position dn of the touch point can be obtained according to steps S100, S200 and S300.

[0162] It should be noted that, Figure 9 , Figure 11 and Figure 12 The diagram illustrates the excitation voltage and receiving voltage-time waveforms of the corresponding piezoelectric transducer. Figure 9 , Figure 11 and Figure 12 In the figure, the vertical axis represents the voltage of the electrical signal converted from the scattered echo received by the piezoelectric transducer under the no-touch condition, and the voltage of the electrical signal converted from the scattered echo received by the piezoelectric transducer under the touch condition represents the first amplitude f1. Figure 9 , Figure 11 and Figure 12 In the figure, the horizontal axis represents the peak time of the corresponding piezoelectric transducer's emitted pulse (time zero t0), and the envelope peak time tn of the acquired backscattered characteristic echo (first time t1 and second time t2).

[0163] In some embodiments, the driving method for the touch panel further includes steps S101, S201, S301, and S401.

[0164] Step S101, as follows Figure 9 As shown, or as Figure 11As shown, the scattered echo received by the first piezoelectric transducer 21 at the touch point in the touch surface portion 11 under non-touch conditions is obtained, and the reference amplitude f0 is obtained.

[0165] Step S201, as follows Figure 8 and Figure 9 As shown, or as Figure 10 and Figure 11 As shown, the scattered echo received by the first piezoelectric transducer 21 at the touch point in the touch surface portion 11 under touch conditions is obtained, and the first amplitude f1 is obtained.

[0166] For example, Figure 9 and Figure 11 The first amplitude f1 is illustrated using a single touch point as an example.

[0167] Step S301: Obtain the amplitude change (NAD) of the scattered echo from the touch point under touch conditions according to the following formula:

[0168] ;

[0169] Step S401: Calculate the external touch pressure at the touch point based on the amplitude change of the scattered echo.

[0170] For example, when an external object presses against the touch surface 11, the increased touch force alters the local mechanical load of the contact area, thereby increasing the degree of scattering, reflection, or absorption of guided wave energy, resulting in a measurable change in the amplitude of the measured scattered echo. To estimate / calculate the amount of pressure applied, the amplitude change NAD can be calculated using the normalization formula described above.

[0171] In some implementations, the driving circuit structure 50 includes an analog front end and a variable gain amplifier, and the driving method of the touch panel further includes step S102.

[0172] Step S102 involves performing dynamic gain compensation through an analog front-end and a variable gain amplifier. The dynamic gain compensation includes compensating for static geometric loss and dynamic propagation loss respectively.

[0173] The static geometric loss includes the material loss of the first acoustic coupler 31, the fixed geometric path loss of the first acoustic coupler 31, and the penetration loss of the interface between the first acoustic coupler 31 and the waveguide dielectric plate 40. The static geometric loss is compensated by a preset initial reference gain.

[0174] Dynamic propagation loss is the propagation loss of the first target guided wave mode 101 within the waveguide dielectric plate 40. Dynamic propagation loss is mitigated by the effective attenuation coefficient α. c Characterized by the fact that the amplitude attenuation of the scattered echo satisfies The exponential decay law; based on the relationship between the distance and time of guided wave propagation, 2d = Vg ×tn, the variable gain amplifier applies a time-varying gain curve that varies with time to counteract the propagation attenuation of the waveguide dielectric plate 40, where d is the distance from the touch point to the first piezoelectric transducer 21.

[0175] For example, such as Figure 10 As shown, the distance from the first touch point C1 to the first piezoelectric transducer 21 is the first distance d1, and the distance from the second touch point C2 to the first piezoelectric transducer 21 is the second distance d2.

[0176] For example, in some implementations, before the execution position and pressure channel calculation, i.e. before executing steps S100-S300, and / or before executing steps S101-S301, step S102 can be executed first, i.e., dynamic gain compensation (DGC) is performed first through the analog front end (AFE) and variable gain amplifier (VGA) to distinguish the propagation loss into two parts: static geometric loss and dynamic propagation attenuation.

[0177] For example, in some implementations, the dynamic gain compensation in step S102 can be performed first, followed by the echo extraction in steps S100-S300, and then the touch pressure calculation in steps S101-S301 can be performed.

[0178] For example, in some implementations, the received signal of the corresponding piezoelectric transducer first undergoes dynamic gain compensation through an analog front-end, a variable gain amplifier, etc., and the compensated signal is then subjected to echo extraction, peak moment extraction, and amplitude extraction to complete the position calculation and pressure calculation.

[0179] For example, static geometric loss includes: material loss within the first acoustic coupler 31 and the second acoustic coupler 32, loss along the fixed path length of the coupler geometry, and penetration loss between the surface of the coupler's inclined edge 311 and the inclined surface 411 of the waveguide dielectric plate 40. For the same touch panel 100, static geometric loss can be considered as a fixed constant loss that does not change with the touch position and can be compensated once by an initial base gain G0.

[0180] For example, the dynamic propagation loss is the propagation loss along the length direction in the waveguide dielectric substrate 40, and the dynamic propagation loss can be controlled by the effective attenuation coefficient α. c Characterized by the amplitude decay of the reflected / scattered echo, it can be expressed as: The exponential decay law describes the exponential decrease in amplitude or intensity with increasing distance; the decay coefficient describes the exponential decrease in amplitude or intensity with increasing distance. Based on this, a variable gain amplifier (VGA) can be used according to the relationship between time axis and distance: 2d = V g×t, a time-varying gain curve G(t) is applied to counteract the effect of the natural attenuation of the waveguide body on the amplitude. Through the above compensation for static geometric loss and dynamic propagation loss, the amplitude of the compensated reflected signal can be significantly reduced by the interference of distance variables, making it more specific to touch pressure and local contact states. For example... Figure 12 As shown, the amplitude of the second sub-backscattered echo 1012 corresponding to the second touch point C2 before compensation is increased from the first amplitude f1 before compensation to the amplitude f12 after compensation.

[0181] For example, step S102 avoids the amplitude of the reflected wave / scattered echo being affected by both distance attenuation and pressure from the external object (touch pressure), thus improving the accuracy of pressure calculation.

[0182] In some implementations, combined Figure 2 and Figure 7 As shown, the touch panel 100 also includes a second piezoelectric transducer 22 and a second acoustic coupler 32. The second piezoelectric transducer 22 is disposed between the waveguide dielectric plate 40 and the second sidewall 14; the second acoustic coupler 32 is disposed between the second piezoelectric transducer 22 and the waveguide dielectric plate 40. The first piezoelectric transducer 21 and the second piezoelectric transducer 22 are disposed opposite each other in the first direction X; the second piezoelectric transducer 22 is configured to emit a second ultrasonic wave; the second piezoelectric transducer 22, the second acoustic coupler 32, and the waveguide dielectric plate 40 are configured collaboratively to perform mode conversion on the second ultrasonic wave, exciting a second target guided wave mode propagating along the first direction X within the waveguide dielectric plate 40. The driving method of the touch panel further includes steps S1000 and S2000.

[0183] In step S1000, during the first detection cycle, the first piezoelectric transducer 21 emits a first ultrasonic wave, which is converted into a first target guided wave mode 101. The first piezoelectric transducer 21 receives the first backscattered echo corresponding to the first target guided wave mode 101, and the second piezoelectric transducer 22 simultaneously receives the transmitted wave signal and / or the first backscattered echo corresponding to the first target guided wave mode 101.

[0184] In step S2000, during the second detection cycle, the second piezoelectric transducer 22 emits a second ultrasonic wave, which is converted into a second target guided wave mode by mode conversion; the second piezoelectric transducer 22 receives the second backscattered echo corresponding to the second target guided wave mode, and the first piezoelectric transducer 21 simultaneously receives the transmitted wave signal and / or the second backscattered echo corresponding to the second target guided wave mode; wherein, the first detection cycle and the second detection cycle are performed alternately.

[0185] For example, combined Figure 2 and Figure 7As shown, the drive circuit structure 50 includes components such as an analog front-end (AFE), a variable gain amplifier (VGA), and a processor. The processor, analog front-end, and other components can work together to control the first piezoelectric transducer 21 and the second piezoelectric transducer 22 in a time-division multiplexing (TDM) manner.

[0186] For example, combined Figure 2 and Figure 7 As shown, in the first detection cycle, the first piezoelectric transducer 21 first switches to output mode and emits a first ultrasonic wave. Then, the first piezoelectric transducer 21 switches to receiving mode and receives the first backscattered echo corresponding to the first target guided wave mode 101, while the second piezoelectric transducer 22 simultaneously receives the transmitted wave signal and / or the first backscattered echo corresponding to the first target guided wave mode 101.

[0187] For example, combined Figure 2 and Figure 7 As shown, during the second detection cycle, the second piezoelectric transducer 22 first switches to output mode and emits a second ultrasonic wave. Then, the second piezoelectric transducer 22 switches to receiving mode and receives the second backscattered echo corresponding to the second target guided wave mode, while the first piezoelectric transducer 21 simultaneously receives the transmitted wave signal and / or the second backscattered echo corresponding to the second target guided wave mode.

[0188] It should be noted that, as Figure 2 As shown, when the touch panel 100 includes a first piezoelectric transducer 21, a first acoustic coupler 31, a waveguide dielectric plate 40, a second acoustic coupler 32, and a second piezoelectric transducer 22, the first piezoelectric transducer 21, the first acoustic coupler 31, and the waveguide dielectric plate 40 can execute any of the above-mentioned touch panel driving methods; the second piezoelectric transducer 22, the second acoustic coupler 32, and the waveguide dielectric plate 40 can also execute any of the above-mentioned touch panel driving methods, which will not be elaborated here.

[0189] It should be noted that, as Figure 2 As shown, in some embodiments, the touch panel 100 can perform dual-phase velocity V g Calibration, under no-load (touch) conditions, involves measuring the distance (e.g., 2d1, 2d2) traveled by the ultrasonic wave from emission to reception of the backscattered wave during the first and second detection cycles, with a time interval of tn. Since this satisfies the relationship 2d = Vg × tn, the phase velocity V of the target elastic wave mode on the waveguide dielectric plate 40 can be obtained. gThis data can be recorded in the system and updated after a fixed period of time to compensate for phase velocity shifts (static geometric losses) caused by material / structural aging, so as to make subsequent touch position / touch force calculations more accurate.

[0190] It should be noted that, as Figure 2 As shown, in some embodiments, the effective attenuation coefficient a c The calibration, under no-load (touch) conditions, is performed by measuring the first and second detection cycles to obtain the original amplitude fa emitted by the first piezoelectric transducer 21 and the attenuated amplitude fb received by the second piezoelectric transducer 22, because they satisfy the relationship... This data can be recorded in the system and updated after a fixed period of time to compensate for the attenuation coefficient shift (static geometric loss) caused by material / structural aging, so as to make subsequent touch position / touch force calculations more accurate.

[0191] It should be noted that in some embodiments, when the touch surface portion 11 exhibits a slight or minor degree of curvature, this curvature causes a gradual difference in the local group velocity of the guided wave mode along the length direction. Therefore, the equivalent average group velocity Vg' under this curvature state can be measured using the end-reflected wave from the dual-ended piezoelectric transducers (first piezoelectric transducer 21 and second piezoelectric transducer 22) in the touch state. This equivalent average group velocity Vg' is then used in the touch calculation, thereby ensuring that the calculation of touch position and touch force still meets accuracy requirements under fixed or slowly changing curvature conditions.

[0192] Thirdly, based on the same inventive concept, please refer to Figures 13 to 16 This application also provides a touch device 1000, which includes a touch panel 100 of any of the above data.

[0193] In some implementations, such as Figure 13 and 14 As shown, the touch device 1000 is a pair of glasses, which includes a first frame 10J1, a second frame 10J2, a first temple 10J3, and a second temple 10J4. The first frame 10J1 is connected to the second frame 10J2, the first temple 10J3 is connected to the first frame 10J1, and the second temple 10J4 is connected to the second frame 10J2. The touch panel 100 is disposed on the first temple 10J3 and / or the second temple 10J4.

[0194] For example, the glasses can be smart glasses such as AR glasses or VR glasses, and the first temple 10J3 and / or the second temple 10J4 have touch functions, and the first temple 10J3 and / or the second temple 10J4 are provided with a touch panel 100 of any of the above.

[0195] For example, the first piezoelectric transducer 21 and the first acoustic coupler 31 are fully housed within the rigid fixing area of ​​the first temple 10J3 and / or the second temple 10J4, and the waveguide dielectric plate 40 can be housed within the temple rod of the first temple 10J3 and / or the second temple 10J4, so that the waveguide dielectric plate 40 with bending flexibility is located within the temple rod, thereby reducing the dynamic opening and closing stress of the first temple 10J3 and / or the second temple 10J4 and improving the packaging reliability.

[0196] In some implementations, such as Figure 15 and 16 As shown, the touch device 1000 also includes a display panel 10X1, which is disposed on the side of the touch device 1000 and located on one side of the end of the display panel 10X1.

[0197] For example, the touch device 1000 also includes a display panel 10X1. The touch device 1000 can be a smartphone or a tablet computer. The side end of the touch device 1000 has a touch function, and the side end of the touch device 1000 is provided with a touch panel 100 of any of the above.

[0198] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0199] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A touch panel, characterized in that, include: The housing surrounds and forms a receiving space, which is formed by sequentially connecting a touch surface portion, a first side wall, a back portion, and a second side wall; the touch surface portion and the back portion are arranged opposite to each other, and the first side wall and the second side wall are arranged opposite to each other in a first direction, which is parallel to the extending direction of the touch surface portion; A first piezoelectric transducer is disposed within the accommodating space and adjacent to the first sidewall; A waveguide dielectric plate is disposed between the first piezoelectric transducer and the second sidewall, and the waveguide dielectric plate extends along the first direction; A first acoustic coupler is disposed between the first piezoelectric transducer and the waveguide dielectric plate; An acoustic coupling layer is disposed between the first piezoelectric transducer, the first acoustic coupler, the waveguide dielectric plate, and the touch surface portion; A driving circuit structure is disposed between the waveguide dielectric substrate and the back surface. An isolation structure is located between the first piezoelectric transducer, the first acoustic coupler, the waveguide dielectric plate, and the driving circuit structure; The first piezoelectric transducer is configured to emit a first ultrasonic wave; the first piezoelectric transducer, the first acoustic coupler, and the waveguide dielectric plate are configured together to perform mode conversion on the first ultrasonic wave and excite a first target guided wave mode that propagates along the first direction within the waveguide dielectric plate.

2. The touch panel according to claim 1, characterized in that, In a cross-section parallel to the first direction, the first acoustic coupler is triangular; The waveguide dielectric plate has an inclined surface on its end face in the first direction, and the inclined surface is parallel to and attached to the surface of the first acoustic coupler.

3. The touch panel according to claim 1, characterized in that, Also includes: A second piezoelectric transducer is disposed between the waveguide dielectric plate and the second sidewall; A second acoustic coupler is disposed between the second piezoelectric transducer and the waveguide dielectric plate; The first piezoelectric transducer and the second piezoelectric transducer are arranged opposite to each other in the first direction; The second piezoelectric transducer is configured to emit a second ultrasonic wave; the second piezoelectric transducer, the second acoustic coupler, and the waveguide dielectric plate are configured together to perform mode conversion on the second ultrasonic wave and excite a second target guided wave mode that propagates along the first direction within the waveguide dielectric plate.

4. The touch panel according to claim 3, characterized in that, In a cross-section parallel to the first direction, both the first acoustic coupler and the second acoustic coupler are triangular in shape; The waveguide dielectric plate has beveled end faces at both ends in the first direction, and is respectively parallel to and attached to the surfaces of the first acoustic coupler and the second acoustic coupler.

5. The touch panel according to claim 4, characterized in that, In a cross-section parallel to the first direction, both the first acoustic coupler and the second acoustic coupler are right-angled triangles; The hypotenuse of the right triangle is connected to the corresponding end face of the waveguide dielectric substrate; The right-angled triangle corresponding to the first acoustic coupler has one leg connected to the first piezoelectric transducer; The right-angled triangle corresponding to the second acoustic coupler has one leg connected to the second piezoelectric transducer.

6. The touch panel according to claim 5, characterized in that, The angle between the normal to the hypotenuse of the right triangle and the acute angle of the first direction is the first angle θ. The volume longitudinal wave phase velocity of the materials of the first acoustic coupler and the second acoustic coupler is V. wedge The axial phase velocity of the guided wave mode of the waveguide dielectric substrate is V. waveguide The first included angle θ satisfies the following formula: 。 7. The touch panel according to claim 3, characterized in that, The thickness of the waveguide dielectric substrate perpendicular to the first direction is 1mm-2.5mm; The driving circuit structure includes a driver configured to provide driving signals to the first piezoelectric transducer and the second piezoelectric transducer, and the driving frequency of the driver is 12MHz-15MHz.

8. The touch panel according to claim 3, characterized in that, The first target guided wave mode and the second target guided wave mode are at least one of the following: the antisymmetric fundamental Lamb wave A0 mode and the quasi-longitudinal guided wave mode that propagates inside the waveguide dielectric plate and satisfies the symmetric boundary conditions of the waveguide dielectric plate.

9. The touch panel according to claim 1, characterized in that, The materials of the isolation structure include rubber, foam, polyurethane; and / or, The isolation structure includes air gaps.

10. A driving method for a touch panel, characterized in that, A method for driving a touch panel, applicable to any one of claims 1 to 9, comprises: Obtain the peak time of the emission pulse from the first piezoelectric transducer and set the peak time as time zero t0; When an external object is detected touching the touch point of the touch surface, a backscattered feature echo or multiple backscattered feature echoes that are separated from each other on the time axis is extracted from the received signal of the first piezoelectric transducer, and the envelope peak time tn of the backscattered feature echo is obtained. The absolute coordinate position dn of the corresponding touch point along the first direction is calculated according to the following formula: ； Among them, V g The group velocity of the first target waveguide mode at the set thickness and operating frequency of the waveguide dielectric plate is tn; the envelope peak time of the corresponding backscattered characteristic echo is tn; the absolute coordinate position dn takes the position of the first piezoelectric transducer as the coordinate origin; the backscattered characteristic echo is the first backscattered echo formed after the first target waveguide mode is backscattered by the touch point.

11. The driving method for a touch panel according to claim 10, characterized in that, Also includes: The scattered echo received by the first piezoelectric transducer at the touch point in the touch surface portion under non-touch conditions is obtained, and the reference amplitude f0 is obtained. The first piezoelectric transducer receives the scattered echo of the touch point in the touch surface under touch conditions, and obtains the first amplitude f1. The amplitude variation (NAD) of the scattered echo at the touch point under touch conditions is obtained according to the following formula: ； The external touch pressure at the touch point is calculated based on the amplitude change of the scattered echo.

12. The driving method for a touch panel according to claim 10, characterized in that, The driving circuit structure includes an analog front end and a variable gain amplifier, and the driving method of the touch panel further includes: Dynamic gain compensation is performed through the analog front end and the variable gain amplifier, and the dynamic gain compensation includes compensation for static geometric loss and dynamic propagation loss respectively; The static geometric loss includes the material loss of the first acoustic coupler, the fixed geometric path loss of the first acoustic coupler, and the penetration loss at the interface between the first acoustic coupler and the waveguide dielectric plate. The static geometric loss is compensated by a preset initial reference gain. The dynamic propagation loss is the propagation loss of the first target waveguide mode within the waveguide dielectric substrate, and the dynamic propagation loss is mitigated by an effective attenuation coefficient a. c Characterized by the fact that the amplitude attenuation of the scattered echo satisfies The exponential decay law; based on the relationship between the distance and time of guided wave propagation, 2d = V g ×tn, where the variable gain amplifier applies a time-varying gain curve that varies with time to counteract the propagation attenuation of the waveguide dielectric plate, and d is the distance from the touch point to the first piezoelectric transducer.

13. The driving method for a touch panel according to claim 10, characterized in that, The touch panel further includes: a second piezoelectric transducer disposed between the waveguide dielectric plate and the second sidewall; and a second acoustic coupler disposed between the second piezoelectric transducer and the waveguide dielectric plate; wherein the first piezoelectric transducer and the second piezoelectric transducer are disposed opposite to each other in a first direction; the second piezoelectric transducer is configured to emit a second ultrasonic wave; the second piezoelectric transducer, the second acoustic coupler, and the waveguide dielectric plate are configured to perform mode conversion on the second ultrasonic wave, thereby exciting a second target guided wave mode propagating along the first direction within the waveguide dielectric plate; The driving method for the touch panel further includes: In the first detection cycle, the first piezoelectric transducer emits a first ultrasonic wave, which is converted into the first target guided wave mode by mode conversion; the first piezoelectric transducer receives the first backscattered echo corresponding to the first target guided wave mode, and the second piezoelectric transducer simultaneously receives the transmitted wave signal corresponding to the first target guided wave mode. During the second detection cycle, the second piezoelectric transducer emits a second ultrasonic wave, which is converted into the second target guided wave mode by mode conversion; the second piezoelectric transducer receives the second backscattered echo corresponding to the second target guided wave mode, and the first piezoelectric transducer simultaneously receives the transmitted wave signal corresponding to the second target guided wave mode. The first detection cycle and the second detection cycle are performed alternately.

14. A touch device, characterized in that, Including the touch panel as described in any one of claims 1 to 9.

15. The touch device according to claim 14, characterized in that, The touch device is a pair of glasses, which includes a first frame, a second frame, a first temple and a second temple. The first frame is connected to the second frame, the first temple is connected to the first frame, and the second temple is connected to the second frame. The touch panel is disposed on the first temple and / or the second temple.

16. The touch device according to claim 14, characterized in that, The touch device also includes a display panel, which is disposed on the side of the touch device and located on one side of the end of the display panel.

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