WO2015041640A2

WO2015041640A2 - Flexible surface acoustic wave touchscreen

Info

Publication number: WO2015041640A2
Application number: PCT/US2013/060300
Authority: WO
Inventors: Christopher J. ROTHFUSS; Sung-Wei Chen
Original assignee: Empire Technology Development Llc
Priority date: 2013-09-18
Filing date: 2013-09-18
Publication date: 2015-03-26
Also published as: WO2015041640A3

Abstract

Disclosed herein are electronic devices that can detect contact with a flexible touch panel substrate using surface acoustic waves. The electronic devices include one or more layers of bending sensors that can sense an amount bending in the flexible touch panel substrate. The electronic device can optionally include a controller configured to determine if and where an object has contacted the flexible touch panel substrate based on surface acoustic wave attenuation.

Description

FLEXIBLE SURFACE ACOUSTIC WAVE TOUCHSCREEN

BACKGROUND

[0001] Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.

[0002] A surface acoustic wave (SAW) touch panel includes transmitting transducers that transmit surface acoustic waves propagating the panel surface and receiving transducers that receive the surface acoustic waves. The surface acoustic waves are absorbed when a user touches the SAW touch panel surface. The partially attenuated surface waves received by the receiving transducers can be correlated with the location that user contacts the touch panel.

SUMMARY

[0003] In some embodiments, an electronic device is disclosed. The device may include a controller; a flexible transparent touch panel substrate; two or more transmitting transducers operatively coupled to the controller, wherein the transmitting transducers are each configured to generate a surface acoustic wave within the flexible touch panel substrate; two or more receiving transducers operatively coupled to the controller, wherein the receiving transducers are each configured to sense the surface acoustic wave generated by at least one of the transmitting transducers; and one or more bending sensors operatively coupled to the controller and configured to sense an amount of bending in the flexible touch panel substrate. The one or more bending sensors may include piezoelectric bending sensors. The piezoelectric bending sensors may include lead zirconium titanate, polyvinylidene fluoride, ammonium dihydrogen phosphate, barium sodium niobate, barium titanate, ethylene diamine tartrate, lead barium niobate, lead potassium niobate, lithium sulfate, lithium tantalite, quartz, potassium dihydrogen phosphate, Rochelle salt, sodium chlorate, triglcine sulfide, tourmaline, zinc sulfide, or any combination thereof. The piezoelectric bending sensors comprise polvinylidene fluoride or a copolymer thereof. [0004] Some embodiments of the electronic device further include a first insulating layer and a first array of bending sensors disposed between the first insulating layer and the flexible transparent touch panel substrate, where each bending sensor in the first array of bending sensors is operatively coupled to the controller. In some embodiments, a second insulating layer and a second array of bending sensors disposed between the second insulating layer and the first insulating layer may be included, where each bending sensor in the second array of bending sensors is operatively coupled to the controller. Each of the bending sensors in the first array of bending sensors may be configured to sense bending in the touch panel substrate about a first direction, and each of the bending sensors of the second array of bending sensors may be configured to sense bending in the touch panel substrate about a first direction, where the first direction is different than the second direction. In some embodiments, the first direction is approximately perpendicular to the second direction.

[0005] Some embodiments of the electronic device further include a display panel coupled to the touch panel substrate and configured to transmit an image through the touch panel substrate. The display panel may be a liquid crystal display panel, an organic light- emitting diode display panel or an electrophoretic ink display panel. The display panel may be disposed between the one or more bending sensors and the touch panel substrate. Alternatively, the bending sensors may be disposed between the display panel and the touch panel substrate.

[0006] In some embodiments of the electronic device, the bending sensors are transparent.

[0007] Some embodiments of the electronic device further include two or more acoustic reflectors configured to redirect surface acoustic waves generated by at least one of the transmitting transducers.

[0008] In some embodiments of the electronic device, two or more bending sensors are included, where at least one of the two or more bending sensors is configured to sense bending in the touch panel substrate about a first direction, at least one of the two or more bending sensors is configured to sense bending in the touch panel substrate about a second direction, and wherein the first direction is different than the second direction. The first direction may be approximately perpendicular to the second direction. [0009] In some embodiments, the electronic device is configured to: generate surface acoustic waves in the touch panel substrate from the transmitting transducers; receive the surface acoustic waves at the receiving transducers; send electrical signals representing the received surface acoustic waves from the receiving transmitters to the controller; send electrical signals representing an amount of bending in the touch panel substrate from the bending sensors to the controller; and determine via the controller whether an attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of an object with the touch panel substrate. In some embodiments, determining via the controller whether the attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of the object with the touch panel substrate includes: computing a maximum expected amount of attenuation in the surface acoustic waves received at the receiving transmitters based on the amount of bending in the touch panel received from the bending sensors; and determining that the attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of the object with the touch panel substrate when the attenuation exceeds the maximum expected amount of attenuation. The electronic device may also be configured to compute a location of the object contacting the touch panel substrate based on when the attenuation was received at the receiving transmitters.

[0010] A method of using an electronic device is also disclosed. The method includes: generating surface acoustic waves in a flexible transparent touch panel substrate using one or more transmitting transducers; receiving the surface acoustic waves at one or more receiving transmitters; sending electrical signals representing the received surface acoustic waves from the receiving transmitters to a controller; sending electrical signals representing an amount of bending in the flexible transparent touch panel substrate from one or more bending sensors to the controller; and computing whether an attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of an object with the touch panel substrate. In some embodiments, computing whether the attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of the object with the touch panel substrate includes: computing a maximum expected amount of attenuation in the surface acoustic waves received at the receiving transmitters based on the amount of bending in the touch panel substrate received from the bending sensors; and determining that the attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of the object with the touch panel substrate when the attenuation exceeds the maximum expected amount of attenuation.

[0011] In some embodiments, the method of using an electronic device also includes computing a location of the object contacting the touch panel substrate based on when the attenuation was received at the receiving transmitters.

[0012] A method of making an electronic device is disclosed. The method includes: forming one or more bending sensors on an insulating substrate; and coupling the insulating substrate to a flexible transparent touch panel substrate so that the bending sensors can sense bending in the flexible transparent touch panel substrate. In some embodiments, the method of making also includes forming two or more transmitting transducers on the flexible transparent touch panel substrate, where the transmitting transducers are each configured to generate a surface acoustic wave within the flexible touch panel substrate. In some embodiments, the method of making also includes forming two or more receiving transducers on the flexible transparent touch panel substrate, where the receiving transducers are each configured to sense to the surface acoustic wave generated by at least one of the transmitting transducers. In some embodiments, the method of making also includes operatively coupling a controller to the bending sensors, the transmitting transducers, and the receiving transducers.

[0013] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings.

[0015] FIGURES 1A-F are cross-sectional views of examples of an electronic device that is within the scope of the present application.

[0016] FIGURE 2 is a flow diagram illustrating one example of a method using an electronic device in accordance with at least some examples of the present disclosure.

DETAILED DESCRIPTION

[0017] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be used, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

[0018] The present disclosure is related to an electronic device. The electronic device can include: a controller; a flexible transparent touch panel substrate; two or more transmitting transducers operatively coupled to the controller; two or more receiving transducers operatively coupled to the controller; and one or more bending sensors operatively coupled to the controller and configured to sense an amount of bending in the flexible touch panel substrate. In some embodiments, the transmitting transducers are each configured to generate a surface acoustic wave within the flexible touch panel substrate. In some embodiments, the receiving transducers are each configured to sense the surface acoustic wave generated by at least one of the transmitting transducers.

[0019] The present disclosure is also related to a method of using an electronic device. The method, in some embodiments, include: generating surface acoustic waves in a flexible transparent touch panel substrate using one or more transmitting transducers; receiving the surface acoustic waves at one or more receiving transmitters; sending electrical signals representing the received surface acoustic waves from the receiving transmitters to a controller; sending electrical signals representing an amount of bending in the flexible transparent touch panel substrate from one or more bending sensors to the controller; and computing whether an attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of an object with the touch panel substrate. The method, in some embodiments, include forming one or more bending sensors on an insulating substrate; and coupling the insulating substrate to a flexible transparent touch panel substrate so that the bending sensors can sense bending in the flexible transparent touch panel substrate.

[0020] Some embodiments disclosed herein relate to an electronic device. FIGURES 1A-F are cross-sectional and top views of one example of an electronic device that is within the scope of the present application. FIGURE 1A is a cross-sectional, side view of electronic device 100 which includes flexible touch panel substrate 105, first bending sensor layer 110, and second bending sensor layer 115. First bending sensor layer 110 is disposed between flexible touch panel substrate 105 and second bending sensor layer 115. First bending sensor layer 110 and second bending sensor layer 115 can be operably coupled to (for example, laminated to) flexible touch panel substrate 105 so that bending sensors in first bending sensor layer 110 and second bending sensor layer 115 can sense bending in flexible touch panel substrate 105. The flexible touch panel 105 may be made of made of any transparent and bendable material. In some preferred embodiments, flexible touch panel 105 may include an alkali-aluminosilicate toughened glass sheet (for example, GORILLA GLASS® from Corning, Inc.), a flexible borosilicate glass sheet (for example, WILLOW GLASS® from Corning, Inc.), or layers of one or both of these materials. The electronic device 100 can be configured so that is flexible. The electronic device may be sufficiently flexible so that it can bend to form curves having a radius of, for example, less than or equal to about 1 m, less than or equal to about 50 cm, less than or equal to about 20 cm, less than or equal to about 10 cm, or less than or equal to about 5 cm. [0021] FIGURE IB is a top view of flexible touch panel substrate 105 in electronic device 100. Flexible touch panel substrate 105 includes transmitting transducers 120 which are configured to generate surface acoustic waves within flexible touch panel substrate 105. Transmitting transducers 120 can be operatively coupled to controller 125 to control, for example, the timing and duration of generating the surface acoustic waves. Acoustic reflectors 130 are configured to redirect surface acoustic waves transmitting by transmitting transducers 120 so that the surface acoustic waves can be received by receiving transducers 135. Receiving transducers 135 can be operatively coupled to controller 125 so that controller 125 can receive a signal representing the surface acoustic waves received by receiving transducers 135. The received signal can then be used to determine the location of any touching by a user to the touchscreen panel. For example, a user touching the touch panel can result in attenuation in the surface acoustic wave. The timing of the attenuation detected by the receiving transducer can be correlated with a location where the user touched the touch panel. Accordingly, flexible touch panel substrate 105 can generally function as a surface acoustic wave (SAW) touch panel. For further discussion regarding the typical function for a SAW touch panel, see, for example, U.S. Patent No. 7,952,568.

[0022] FIGURE 1C is a cross-sectional, top view of an embodiment of first bending sensor layer 110 in electronic device 100. An array of bending sensors 140 is disposed on insulating layer 145. Conductors 150 can operatively couple bending sensors 140 to controller 125 so that controller 125 can receive signals representing an amount bending in electronic device 100. As shown, bending sensors 140 are elongated and each extend in generally the same direction (for example, aligned along the x-axis as shown in FIGURE 1C). Bending sensors 140 can each be configured to sense an amount of bending about the z- axis at different locations as shown in FIGURE 1C.

[0023] FIGURE ID is a cross-sectional, top view of an embodiment of second bending sensor layer 115 in electronic device 100. An array of bending sensors 155 is disposed on insulating layer 160. Conductors 165 can operatively couple bending sensors 155 to controller 125 so that controller 125 can receive signals representing an amount bending in electronic device 100. As shown, bending sensors 155 are elongated and each extend in generally the same direction (for example, aligned along the z-axis as shown in FIGURE ID). Bending sensors 155 may each be configured to sense an amount of bending about the z-axis at different locations as shown in FIGURE ID.

[0024] FIGURE IE shows a cross-sectional, top view of another embodiment of a first bending sensor layer 110 in electronic device 100. An array of bending sensors 165 is disposed on insulating layer 170. Conductors 160 can operatively connect one or more bending sensors 165 to controller 125 so that controller 125 can receive signals representing an amount bending in electronic device 100. As shown, bending sensors 165 are elongated and each extend in generally the same direction (for example, aligned along the x-axis as shown in FIGURE IE). Bending sensors 165 can each be configured to sense an amount of bending about the z-axis at different locations as shown in FIGURE IE.

[0025] FIGURE IF is a cross-sectional, top view of another embodiment of second bending sensor layer 115 in electronic device 100. An array of bending sensors 185 is disposed on insulating layer 190. Conductors 180 can operatively connect one or more bending sensors 185 to controller 125 so that controller 125 can receive signals representing an amount bending in electronic device 100. As shown, bending sensors 185 are elongated and each extend in generally the same direction (for example, aligned along the z-axis as shown in FIGURE IF). Bending sensors 185 may each be configured to sense an amount of bending about the z-axis at different locations as shown in FIGURE IF.

[0026] Bending in the electronic device can attenuate surface acoustic waves that are received by the receiving transducers (for example, receiving transducers 135 as depicted in FIGURE IB). This may lead to erroneously detecting contact with the touch panel because the electronic device may rely on observed attenuation to detect the contact. Applicants appreciate that surface attenuation due to bending can be predicted by characterizing the shape and curvature of the SAW touchscreen using mathematical modeling. In one such model, a geodesically complete manifold is mathematically defined by the bending sensor layer(s), in which the paths of the acoustic waves are predicted to be geodesies of the manifold. Such methods of mathematical modeling are well known and are described in detail in for example, Gregory, R.D., "The Propagation of Rayleigh Waves Over Curved Surfaces at High Frequency," Mathematical Proceedings of the Cambridge Philosophical Society, Vol. 70, pp. 103-121, 1971. From the mathematical model, the paths of the surface acoustic waves, dispersion of the waves due to propagation over a curved surface, and the unperturbed (base) wave velocity of the surface acoustic waves can be calculated. The controller 125 can, in some embodiments, be programmed to compute these parameters.

[0027] The electronic devices disclosed in the present application (for example, electronic device 100 as depicted in FIGURES 1A-F) may advantageously compensate for bending in the electronic device when determining whether contact has been made with the touch panel substrate (for example, a touches the substrate). For example, the bending sensors may provide an amount of bending that can be used to predict an amount of attenuation due to bending. If the attenuation is greater than that predicted due to bending, this attenuation may be correlated with a location of contact with the touch panel substrate.

[0028] The bending sensors in the electronic device (for example, bending sensors 140, bending sensors 155, bending sensors 165, and bending sensors 185) are not particularly limited. Various bending sensors that are commercially available can be used in the electronic device. In some embodiments, the bending sensors are piezoelectric sensors. The piezoelectric sensors can include, for example, lead zirconium titanate, polyvinylidene fluoride (PVDF), ammonium dihydrogen phosphate, barium sodium niobate, barium titanate, ethylene diamine tartrate, lead barium niobate, lead potassium niobate, lithium sulfate, lithium tantalite, quartz, potassium dihydrogen phosphate, Rochelle salt, sodium chlorate, triglcine sulfide, tourmaline, and zinc sulfide. In some embodiments, the piezoelectric bending sensor includes PVDF or a copolymer thereof. In some embodiments, the piezoelectric bending sensor includes polytetrafluoroethylene (PFTE) or a copolymer thereof. In some embodiments, the piezoelectric bending sensor includes PVDF-zirconium oxide, PVDF/graphene oxide-silica, or a mixture thereof.

[0029] The number of bending sensors in the electronic device can vary. For instance, the number of bending sensors in the electronic device can vary depending on, for example, the flexibility of the electronic device and desired sensitivity of the touch panel substrate. For example, a relatively inflexible electronic device can only include two bending sensors, a first sensor to sense bending about a first axis and a second sensor to sense bending about a second axis. The first axis and second axis can be different (for example, generally perpendicular). The number of bending sensors in the electronic device can be, for example, at least 1, at least 2, at least 4, at least 8, at least about 16, at least about 32, at least about 100, at least about 500, or at least about 1000. The number of bending sensors in the electronic device can be, for example, less than or equal to about 10000, less than or equal to about 1000, less than or equal to about 500, less than or equal to about 100, or less than or equal to about 50. In some embodiments, the number of bending sensors in the electronic device can be about 1 to about 10000, or about 1 to about 100.

[0030] The configuration for the bending sensors is also not particularly limited. For example, all of the bending sensors may each be disposed on a single insulating layer rather than including two or more insulating layer having the bending sensors. As an example, electronic device 100 as depicted in FIGURES 1A-F can be modified to remove second bending sensor layer 115. The bending sensor can each be aligned on a layer, or they may be rotated relative to each other. For example, a single layer may include bending sensors in array, however, the bending sensors may be rotated (for example, rotated 90°) relative to adjacent bending sensors.

[0031] The one or more bending sensor layers in the electronic device (for example, first bending sensor layer 110 and second bending sensor layer 115 as depicted in FIGURES 1A-F) can be transparent. Thus, the bending sensors, conductors, and insulating layer may include transparent materials. For example, the conductors may be formed from indium tin oxide.

[0032] The electronic device can optionally include a display panel operatively coupled to the touch panel substrate and configured to transmit an image (for example, video) through the touch panel substrate. In some embodiments, the display panel is disposed between one or more of the bending sensor layers and the touch panel substrate. For example, the display panel could be disposed between first bending sensor layer 110 and touch panel substrate 105 in electronic device 100. In some embodiments, the bending sensor layer is disposed between the display panel and the touch panel substrate. The display can be, for example, a liquid crystal display panel, an organic light-emitting diode display panel or an electrophoretic ink display panel (for example, E INK). [0033] The number transmitting transducers and receiving transducers is not particularly limited. In some embodiments, the number transmitting transducers is the same or about the same as the number of receiving transducers. The number of transmitting transducers in the electronic device can be, for example, at least two, at least 4, at least about 8, at least about 20, at least about 100, or at least about 500. The number of receiving transducers in the electronic device can be, for example, at least two, at least 4, at least about 8, at least about 20, at least about 100, or at least about 500. In some embodiments, the touch panel substrate does not include acoustic reflectors. The transmitting transducers can therefore transmit acoustic waves in generally a straight line across the touch panel substrate. Thus, a series of transmitting transducing may be disposed along two edges of the touch panel substrate, and a series of receiving transducers may disposed along the other two edges of the touch panel substrate.

[0034] The controller (for example, controller 125 as depicted in FIGURE IB) can be configured to determine whether an attenuation in the surface acoustic waves received at the receiving transducers was generated by contact of an object with the touch panel substrate. The controller may be configured to synchronize generating surface acoustic waves in the touch panel substrate via the transmitting transducers and then receive a signal from the receiving transducers representing the received surface acoustic waves. The controller can also be configured to receive signals from the bending sensors representing an amount of bending in the electronic device. The controller can be configured to then compute a maximum expected amount of attenuation in the surface acoustic wave for a given time point based on the amount bending. Furthermore, the controller can be configured to determine that an object contacted the touch panel substrate if the surface acoustic waves received by the receiving transmitters exhibited attenuation greater than the maximum expected amount of attenuation. The timing of the attenuation that associated with contact by an object can then be correlated with the location of the contact on the touch panel substrate.

[0035] The controller can be, for example, a microprocessor (μΡ), a microcontroller (μ¾, a digital signal processor (DSP), or any combination thereof. The controller can also optionally include system memory operatively coupled to the controller. The system memory can be, for example, volatile memory (such as RAM), non-volatile memory (such as ROM, flash memory, etc.), or any combination thereof.

[0036] Various methods for computing the maximum expected amount of attenuation can be used. As described above, surface attenuation due to bending can be predicted using mathematical modeling, for example, geodesic manifold modeling, described in Gregory, R.D., "The Propagation of Rayleigh Waves Over Curved Surfaces at High Frequency," Mathematical Proceedings of the Cambridge Philosophical Society, Vol. 70, pp. 103-121, 1971. Thus, these equations themselves, or some linear regression thereof (for example, a polynomial fit) may be used. In some embodiments, the controller may be configured to use a look-up table that provides the maximum expected amount of attenuation based on the amount bending. In some embodiments, the controller may be configured to use an empirical equation (for example, a linear regression, such as a polynomial fit) based on previous test results. In some embodiments, the electronic device may determine the maximum expected amount of attenuation based on the amount bending using calibration techniques. The electronic device may prompt a user to contact specific region on the touch panel while bending the touch panel a pre-determined amount. The controller may use the observed attenuation profiles to provide a maximum expected amount of attenuation in a look-up table.

[0037] The controller can optionally use the amount of bending received from the bending sensor for other purposes than compensating for attenuation in the surface acoustic waves. In some embodiments, the amount bending may be treated as input by the user. For example, when a pre-determined amount of bending is sensed, the controller can recognize the bending as input from the user in order to complete a certain action (for example, turn off, close an application, or other actions).

[0038] Some embodiments disclosed herein include a method of using an electronic device. The method can, for example, be used with any of the electronic devices disclosed in the present application (for example, electronic device 100 as depicted in FIGURES 1A-F). FIGURE 2 is a flow diagram illustrating one example of a method using an electronic device in accordance with at least some examples of the present disclosure. As illustrated in FIGURE 2, method 200 can include one or more functions, operations, or actions as illustrated by one or more of operations 210-230.

[0039] Processing for method 200 can begin at operation 210, "Generating surface acoustic waves in a flexible transparent touch panel substrate using one or more transmitting transducers." Operation 210 can be followed by operation 220, "Receiving the surface acoustic waves at one or more receiving transmitters." Operation 220 can be followed by operation 230, "Sending electrical signals representing the received surface acoustic waves from the receiving transmitters to a controller." Operation 230 can be followed by operation 240, "Sending electrical signals representing an amount of bending in the flexible transparent touch panel substrate from one or more bending sensors to the controller." Operation 240 can be followed by operation 250, "Computing whether an attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of an object with the touch panel substrate."

[0040] In FIGURE 2, operations 210-250, are illustrated as being performed sequentially with operation 210 first and operation 230 last. It will be appreciated however that these operations may be reordered, combined, and/or divided into additional or different operations as appropriate to suit particular embodiments. In some embodiments, additional operations may be added. In some embodiments, one or more of the operations can be performed at about the same time.

[0041] At operation 210, "Generating surface acoustic waves in a flexible transparent touch panel substrate using one or more transmitting transducers," surface acoustic waves a generating for detecting contact with the touch panel substrate. For example, transmitting transducers 120 can transmit surface acoustic waves in touch panel substrate 105. The transmitting transducer may be controlled by an appropriate controller.

[0042] At operation 220, "Receiving the surface acoustic waves at one or more receiving transmitters," the surface acoustic waves are received for analysis to determine if an object has contact the touch panel substrate. For example, receiving transducers 135 can receive surface acoustic waves in touch panel substrate 105 that have been transmitted by transmitting transducers 120 and reflected by acoustic reflectors 130. [0043] At operation 230, "Sending electrical signals representing the received surface acoustic waves from the receiving transmitters to a controller," the controller receives a signal representing the surface acoustic wave for detecting whether an object had contacted the touch panel substrate. For example, receiving transducers 135 in electronic device 100 may receive surface acoustic waves in touch panel substrate 105 and provide a signal to controller 125.

[0044] At operation 240, "Sending electrical signals representing an amount of bending in the flexible transparent touch panel substrate from one or more bending sensors to the controller," an amount of bending is determined so that attenuation from bending can be accounted when determining if an object has contact the touch panel substrate. For example, bending sensors 140 and bending sensors 155 in electronic device 100 may provide an electrical signal to the controller that represent an amount bending at certain regions in the touch panel substrate.

[0045] At operation 250, "Computing whether an attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of an object with the touch panel substrate," the amount of bending and received surface acoustic waves are analyzed to determine whether an object has contacted the touch panel substrate. For example, controller 125 may analyze the signals receive from transmitting transducers 135, bending sensors 140, and bending sensors 155 in electronic device 100. The controller can apply an of the techniques disclosed in the present application for determining whether an object has contacted the touch panel substrate. For example, the controller can use a look-up table to determine a maximum expected amount of attenuation due to bending. The controller may determine that contact has occurred when the amount of attenuation exceeds the maximum expected amount of attenuation. In some embodiments, controller can also determine the location of the contact based on when the attenuation was received at the receiving transmitters.

[0046] Some embodiments disclosed herein include a method of making an electronic device. The method can, for example, be used to prepare any of the electronic devices disclosed in the present application (for example, electronic device 100 as depicted in FIGURES 1A-F). The method can include: forming one or more bending sensors on an insulating substrate; and coupling the insulating substrate to a flexible transparent touch panel substrate so that the bending sensors can sense bending in the flexible transparent touch panel substrate. The bending sensors can be formed using conventional semiconductor fabrication techniques, including one or more of spin coating and photolithography.

[0047] The method can also include, in some embodiments, forming two or more transmitting transducers on the flexible transparent touch panel substrate, where the transmitting transducers are each configured to generate a surface acoustic wave within the flexible touch panel substrate. For example, the transmitting transducers can be formed on the touch panel substrate in the same configuration as transmitting transducers 120 in electronic device 100.

[0048] The method can also include, in some embodiments, forming two or more receiving transducers on the flexible transparent touch panel substrate, wherein the receiving transducers are each configured to sense to the surface acoustic wave generated by at least one of the transmitting transducers. For example, the receiving transducers can be formed on the touch panel substrate in the same configuration as receiving transducers 130 in electronic device 100.

[0049] The method can also include, in some embodiments, operatively coupling a controller to the bending sensors, the transmitting transducers, and the receiving transducers. For example, the controller can be coupled via conductors (for example, wires) to receive an electrical signal from these components.

EXAMPLES

[0050] Additional embodiments are disclosed in further detail in the following examples, which are not in any way intended to limit the scope of the claims.

Example 1 - Bending Sensor

[0051] An array of 100 flex sensors is evenly distributed parallel to the x-axis across a 100 cm x 100 cm, insulative 0.1 mm thick layer of transparent polyethylene terephthalate (PET) to form a first layer. Each flex sensor includes a serial linear array of 5 mm long by 2 mm wide PVDF flex sensor strips, with a 2 mm separation pitch between array members. Each strip is independently provided with a transparent ITO wire for coupling to a controller of a device to which the sensor strips will be incorporated. Strip midpoints are staggered from one sensor to the next. As such, the y-axis strain is fully characterized throughout the 100 cm PET layer through a decon volution of the cumulative piezoelectric responses of the strips.

[0052] A second layer, identical to the first layer, is rotated 90 degrees and placed atop the first layer such that the PET layer provides isolation insulation between the two layers, while the flex sensor array of the second layer is oriented perpendicular to the flex sensor array of the first layer.

[0053] A third 0.1 mm thick PET layer is then placed atop the second layer to provide further insulation for the flex sensor array of the second layer. Together, the three insulating layers of PET, along with the 2 arrays of flex sensors form a transparent bending sensor capable of providing local bending information.

Example 2 - SAW Touchscreen Apparatus

[0054] A 1 mm thick layer of flexible borosilicate glass (for example, Willow Glass) is sealed to the transparent bending sensor from Example 1 , and fitted with X and Y piezoelectric transducers, sensors, controller and reflectors in a standard conformation typical of a surface acoustic wave (SAW) sensor to form the SAW touchscreen apparatus.

[0055] All local bending information is provided by the sensor array to a software engine for real time analysis that produces a complete surface geometry of the sheet based on known mathematical theories, such as those described in Gregory, R.D., "The Propagation of Rayleigh Waves Over Curved Surfaces at High Frequency," Proceedings of the Cambridge Philosophical Society, Vol. 70, pp. 103-121, 2007, the content of which is expressly incorporated by reference in its entirety.

[0056] Based on the surface geometry, surface geodesies are established within the software engine in real time. One example of the methods that can be used to establish surface geodesies is described in Baek et al. ("Finding geodesies on surfaces", the content of which is expressly incorporated by reference in its entirety). These surface geodesies represent the paths that the surface acoustic waves will take as they travel through the material.

[0057] Signals received by the SAW touch screen apparatus are then processed based on the geodesic models resident within the software engine. The amount of bending received from the bending sensor may be treated as an input by the user to complete a certain action in the apparatus. For example, when a pre-determined amount of bending is sensed, the controller can recognize the bending as input from the user to close an application.

[0058] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to volume of wastewater can be received in the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.

[0059] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (for example, bodies of the appended claims) are generally intended as "open" terms (for example, the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "includes but is not limited to," etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (for example, "a" and/or "an" should be interpreted to mean "at least one" or "one or more"); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (for example, the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (for example, " a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (for example, " a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B."

[0060] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0061] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible sub-ranges and combinations of sub-ranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non- limiting example, each range discussed herein can be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like include the number recited and refer to ranges which can be subsequently broken down into sub-ranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 articles refers to groups having 1, 2, or 3 articles. Similarly, a group having 1-5 articles refers to groups having 1, 2, 3, 4, or 5 articles, and so forth.

[0062] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.

[0063] One skilled in the art will appreciate that, for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments.

[0064] One skilled in the art will appreciate that, for this and other processes and methods disclosed herein, the functions performed in the processes and methods may be implemented in differing order. Furthermore, the outlined steps and operations are only provided as examples, and some of the steps and operations may be optional, combined into fewer steps and operations, or expanded into additional steps and operations without detracting from the essence of the disclosed embodiments.

Claims

WHAT IS CLAIMED IS:

1. An electronic device comprising:

a controller;

a flexible transparent touch panel substrate;

two or more transmitting transducers operatively coupled to the controller, wherein the transmitting transducers are each configured to generate a surface acoustic wave within the flexible touch panel substrate;

two or more receiving transducers operatively coupled to the controller, wherein the receiving transducers are each configured to sense the surface acoustic wave generated by at least one of the transmitting transducers; and

one or more bending sensors operatively coupled to the controller and configured to sense an amount of bending in the flexible touch panel substrate.

2. The electronic device of Claim 1 , wherein the one or more bending sensors comprise piezoelectric bending sensors.

3. The electronic device of Claim 2, wherein the piezoelectric bending sensors comprise lead zirconium titanate, polyvinylidene fluoride, ammonium dihydrogen phosphate, barium sodium niobate, barium titanate, ethylene diamine tartrate, lead barium niobate, lead potassium niobate, lithium sulfate, lithium tantalite, quartz, potassium dihydrogen phosphate, Rochelle salt, sodium chlorate, triglcine sulfide, tourmaline, zinc sulfide, or any combination thereof.

4. The electronic device of Claim 2, wherein the piezoelectric bending sensors comprise polvinylidene fluoride or a copolymer thereof.

5. The electronic device of Claim 1 , further comprising a first insulating layer and a first array of bending sensors disposed between the first insulating layer and the flexible transparent touch panel substrate, wherein each bending sensor in the first array of bending sensors is operatively coupled to the controller.

6. The electronic device of Claim 5, further comprising a second insulating layer and a second array of bending sensors disposed between the second insulating layer and the first insulating layer, wherein each bending sensor in the second array of bending sensors is operatively coupled to the controller.

7. The electronic device of Claim 6, wherein each of the bending sensors in the first array of bending sensors is configured to sense bending in the touch panel substrate about a first direction, each of the bending sensors of the second array of bending sensors is configured to sense bending in the touch panel substrate about a first direction, and wherein the first direction is different than the second direction.

8. The electronic device of Claim 7, wherein the first direction is approximately perpendicular to the second direction.

9. The electronic device of Claim 1, further comprising a display panel coupled to the touch panel substrate and configured to transmit an image through the touch panel substrate.

10. The electronic device of Claim 9, wherein the display panel is a liquid crystal display panel, an organic light-emitting diode display panel or an electrophoretic ink display panel.

11. The electronic device of Claim 9, wherein the display panel is disposed between the one or more bending sensors and the touch panel substrate.

12. The electronic device of Claim 9, wherein the bending sensors are disposed between the display panel and the touch panel substrate.

13. The electronic device of Claim 12, wherein the bending sensors are transparent.

14. The electronic device of Claim 1, further comprising two or more acoustic reflectors configured to redirect surface acoustic waves generated by at least one of the transmitting transducers.

15. The electronic device of Claim 1, wherein the electronic device comprises two or more bending sensors, at least one of the two or more bending sensors is configured to sense bending in the touch panel substrate about a first direction, at least one of the two or more bending sensors is configured to sense bending in the touch panel substrate about a second direction, and wherein the first direction is different than the second direction.

16. The electronic device of Claim 15, wherein the first direction is approximately perpendicular to the second direction.

17. The electronic device of Claim 1, wherein the electronic device is configured to:

generate surface acoustic waves in the touch panel substrate from the transmitting transducers;

receive the surface acoustic waves at the receiving transducers; send electrical signals representing the received surface acoustic waves from the receiving transmitters to the controller;

send electrical signals representing an amount of bending in the touch panel substrate from the bending sensors to the controller; and

determine via the controller whether an attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of an object with the touch panel substrate.

18. The electronic device of Claim 17, wherein determining via the controller whether the attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of the object with the touch panel substrate comprises:

computing a maximum expected amount of attenuation in the surface acoustic waves received at the receiving transmitters based on the amount of bending in the touch panel received from the bending sensors; and

determining that the attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of the object with the touch panel substrate when the attenuation exceeds the maximum expected amount of attenuation.

19. The electronic device of Claim 17 or 18, wherein the electronic device is further configured to compute a location of the object contacting the touch panel substrate based on when the attenuation was received at the receiving transmitters.

20. A method of using an electronic device, comprising:

generating surface acoustic waves in a flexible transparent touch panel substrate using one or more transmitting transducers;

receiving the surface acoustic waves at one or more receiving transmitters; sending electrical signals representing the received surface acoustic waves from the receiving transmitters to a controller; sending electrical signals representing an amount of bending in the flexible transparent touch panel substrate from one or more bending sensors to the controller; and

computing whether an attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of an object with the touch panel substrate.

21. The method of Claim 20, wherein computing whether the attenuation in the surface acoustic waves received at the receiving transmitters was generated by contact of the object with the touch panel substrate comprises:

computing a maximum expected amount of attenuation in the surface acoustic waves received at the receiving transmitters based on the amount of bending in the touch panel substrate received from the bending sensors; and

22. The method of Claim 20 or 21, further comprising computing a location of the object contacting the touch panel substrate based on when the attenuation was received at the receiving transmitters.

23. A method of making an electronic device, the method comprising:

forming one or more bending sensors on an insulating substrate; and coupling the insulating substrate to a flexible transparent touch panel substrate so that the bending sensors can sense bending in the flexible transparent touch panel substrate.

24. The method of Claim 23, further comprising forming two or more transmitting transducers on the flexible transparent touch panel substrate, wherein the transmitting transducers are each configured to generate a surface acoustic wave within the flexible touch panel substrate.

25. The method of Claim 24, further comprising forming two or more receiving transducers on the flexible transparent touch panel substrate, wherein the receiving transducers are each configured to sense to the surface acoustic wave generated by at least one of the transmitting transducers.

26. The method of Claim 25, further comprising operatively coupling a controller to the bending sensors, the transmitting transducers, and the receiving transducers.