JP4989461B2 - Elastic wave touch screen - Google Patents

Description

  The present invention relates to a touch sensor. More particularly, the present invention relates to an elastic wave touch sensor and an elastic wave touch screen having a narrow border having functionality and a touch detection area with increased sensitivity.

  The elastic wave touch sensor includes a touch detection area that can detect the presence and position of a touch due to a touch effect applied to an elastic wave that propagates (or propagates) across the touch sensor substrate. Such an elastic wave touch sensor uses a Rayleigh wave (including a pseudo Rayleigh wave), a Lamb wave, a shear wave, or a combination of various elastic waves.

  FIG. 1 shows an operation mode of a conventional acoustic wave touch sensor and acoustic wave touch screen 1. The touch screen 1 has a touch detection area 2 that determines the position of the touched two-dimensional coordinate. For example, the touch detection area 2 includes an area bounded by a dotted line 16 (a dotted line representing the inner boundary of the bezel 10). The first transmission transducer 3a is disposed outside the touch detection area 2, and is coupled to the surface of the touch screen 1 so as to transmit elastic waves. The first transmission transducer 3a transmits an elastic wave signal in the form of an elastic wave 11a so as to propagate in parallel at the upper end of the touch screen 1 (generally, it propagates on the surface of the touch screen 1). . The first linear array 13a of the partially reflected elastic wave elements 4 is disposed in the propagation path of the elastic wave 11a. Each of the elastic wave elements 4 transmits an elastic wave signal by partially reflecting (at an angle of about 90 °), whereby a plurality of elastic waves (for example, propagating vertically in the touch detection area 2) (for example, 5a, 5b and 5c) will result. The distance between the reflecting elements 4 changes as the distance from the first transmitter 3a increases so that the attenuation of the elastic wave signal is compensated. Even when the reflective elements 4 are uniformly spaced, the signal can be made uniform by changing the reflection intensity of the reflective elements 4. The elastic waves 5a, 5b and 5c are reflected again by the second linear array 13b of the partial elastic reflection elements 4, and are approximately 90 ° (in the direction indicated by the arrow 11b) toward the first receiving transducer 6a. Change direction. Then, after the elastic waves 5a, 5b and 5c are detected by the first receiving transducer 6a, they are converted into electric signals and processed. A configuration similar to this configuration is provided along the left and right edges of the touch screen 1. The second transmission transducer 3b generates an elastic wave 12a along the right edge. Due to the third linear array 13c of the elastic wave reflecting elements 4, the elastic wave 12a is converted into a plurality of elastic waves (for example, 7a, 7b, and 7c) that travel across the touch detection area 2 in the horizontal direction (parallel to the X axis). Is done. The elastic waves 7a, 7b and 7c are redirected in the direction of the receiving transducer 6b (the direction of the arrow 12b) by the fourth linear array 13d of the elastic wave reflecting elements 4. The receiving transducer 6b detects the elastic waves 7a, 7b and 7c and converts them into electric signals.

  In the touch detection area 2, when the position indicated by reference numeral 8 is touched by an object such as a finger or a stylus, some of the energy of the elastic waves 5b and 7a is absorbed by the touched object. As a result, attenuation occurs, and fluctuation (or perturbation) of the elastic wave signal is detected in the receiving transducers 6a and 6b. If the time delay of the data is analyzed using a microprocessor (not shown), the coordinates of the touched position 8 can be determined. The device of FIG. 1 can function as a touch screen using two types of transducers, a transmitting transducer and a receiving transducer.

  A housing 9 represented by a dotted line in FIG. 1 is related to the touch screen 1. The housing can be formed from a suitable material such as, for example, a molded polymer or sheet material. The housing 9 includes a bezel 10 (in FIG. 1, the inner contour of the bezel is indicated by a dotted line 16 and the outer contour of the bezel is indicated by a dotted line 17). The inner dotted line 16 represents the overlap between the housing 9 and the outer periphery of the touch screen 1. The housing 9 allows the transmission transducer, the reception transducer and other elements to be hidden from view, while exposing the touch sensing area 2. In such a configuration, hidden elements will be protected from contamination and / or damage. In addition, an aesthetic appearance is provided and a touch detection area for the user is defined.

  The touch screen comprises a separate face plate provided on the display panel. The faceplate is typically formed from glass, but any other suitable substrate may be used. The display panel may be a cathode ray tube (CRT), liquid crystal display (LCD), plasma display, electroluminescent display (or electroluminescent display) or organic light emitting diode display (OLED display), or other It may be a type of display.

  As shown in FIG. 1, the touch detection area 2 is surrounded by a border area 15. In the border region 15, the reflection element 4, the transmission transducer 3a, and the reception transducer 3b are arranged. When the width of the border area 15 decreases, the touch detection area 2 increases. For touch sensor applications using a transparent touch sensor such as a touch screen, the width of the border is particularly important. If the border area 15 of the touch sensor is narrower, the touch sensor can be incorporated into a display monitor having a narrow border portion around the display image. Such a feature is desirable in view of the fact that devices such as monitors have a fancy design and a mechanically compact design has become a general trend. In addition, a touch sensor with a narrower border region 15 can be sealed more easily, is lighter, and has more detection areas. Among competing touch screen technologies (such as elastic wave touch screen technology, capacitive touch screen technology, resistive touch screen technology, and infrared touch screen technology), the elastic wave touch screen has a wider border portion. .

  It is known to provide a transducer for substantially transmitting and receiving elastic waves to a touch detection surface located above the substrate of the elastic wave touch sensor. For acoustic waves, instead of incorporating a reflective array, a transducer-detector path can be used to direct the acoustic wave across the touch sensing area of the touch sensor, but many transducers Must be used. The transducer used is a wedge transducer provided on the touch surface, thereby occupying valuable border space. As disclosed in US Pat. No. 6,756,973, a touch screen without a reflective array can also be designed using a comb-type transducer (the disclosure of US Pat. No. 6,756,973 is incorporated herein by reference). Incorporated in the description). The comb-shaped transducer disclosed in US Pat. No. 6,756,973 is placed on the top surface of the touch screen, thereby occupying valuable border space. So far, in touch sensors that use several transducers and reflective arrays to direct elastic waves through the touch sensor, the array is located on the same board surface border as the touch sensing area, This occupies border space.

  It is also known to provide a transducer for transmitting and receiving elastic waves on the side wall of the substrate of the elastic wave touch sensor. Even in such a case, the reflective array must be placed on the touch surface, thereby occupying valuable border space.

  Reducing the border area of a touch screen using a waveguide to collect elastic waves in the border area, as described in US Pat. No. 6,636,201, the contents of which are incorporated herein by reference. Is possible. However, another solution is desired that eliminates the need to provide a waveguide on the touch surface of the touch sensor substrate.

  In addition to reducing the border area of the touch sensor, it is desirable to make the touch sensor as flat as possible. This is particularly advantageous in that the touch sensor can be integrated with the LCD panel to produce a touch screen. If the touch sensor is very flat and parallel to the LCD panel, the touch sensor and the LCD panel can be easily combined, thereby creating a compact system that can be easily sealed. If the touch sensor has a bulky bezel and border area, the sealing between the LCD panel and the touch sensor becomes complicated.

  For the above reasons, a new elastic wave touch sensor design with a very narrow border area is desired. There is also a need for a new acoustic wave touch sensor design that is flat and can be easily integrated and sealed with planar devices (eg, LCD monitors).

  In one embodiment, the touch sensor includes a substrate capable of propagating elastic waves. The substrate includes a first surface having a touch detection area, and a first side wall intersecting the first surface at a first edge. A transmitter is provided on the first side wall of the substrate. The transmitter generates an elastic wave that propagates directly from the first sidewall. Such elastic waves pass through at least a part of the touch detection area.

  In another aspect, the touch sensor system comprises a substrate capable of propagating elastic waves. The substrate includes a first surface having a touch detection area. The first side wall and the second side wall intersect the first surface. A transmitter is provided on the first side wall of the substrate. The transmitter generates an elastic wave that propagates directly from the first side wall, and the elastic wave propagates across at least a part of the touch detection area. A detector is provided on the second side wall of the substrate, whereby the elastic wave after crossing at least a part of the touch detection area is detected.

  As another aspect, a method for detecting a touch performed on a touch detection region of a substrate capable of propagating an elastic wave is provided. A substrate used in this method includes a first surface having a touch detection area, and first and second sidewalls intersecting the first surface. In such a method, an elastic wave is generated in the vicinity of the first side wall of the substrate. After the elastic wave propagates through the substrate so as to pass through a part of the first side wall of the substrate, the elastic wave is directed so as to cross at least a part of the touch detection area. Thereafter, an elastic wave is detected in the vicinity of the second side wall of the substrate.

  In another aspect, the touch sensor includes a substrate capable of propagating elastic waves. The substrate includes a first surface having a touch detection area. A transducer is formed on the substrate. The transducer comprises a piezoelectric element that is formed on a substrate and then subjected to thermosetting. The transducer is configured to perform at least one of generation of elastic waves and detection of elastic waves.

  In another aspect, the touch sensor includes a substrate capable of propagating elastic waves. The substrate includes a first surface having a touch detection area. The transducer is configured to generate and / or receive elastic waves. The transducer includes a strip comprising a piezoelectric material. The strip is attached to the substrate.

  In another aspect, a method is provided for forming a transducer on a touch sensor substrate. The substrate used in this method includes a first surface having a touch detection area. In such a method, a conductive layer is provided (or formed) on the substrate. The piezoelectric layer is provided on the substrate so that at least part of the first conductive layer is covered (at least part of the first conductive layer is covered by the piezoelectric layer). The piezoelectric layer is subjected to heat curing after being supplied to the substrate.

  The foregoing description and the following detailed description of certain aspects of the present invention will become better understood with reference to the drawings. It will be understood that the present invention is not limited to the arrangements and instrumentality shown in the drawings.

BEST MODE FOR CARRYING OUT THE INVENTION

  The conventional reflective array as shown in FIG. 1 has a width of about 5 mm to 15 mm corresponding to about 9 to 26 elastic wave wavelengths (a conventional frequency of about 5 MHz has a wavelength of about 0.57 mm). Assumed to be equivalent). Narrower reflective arrays are typically used for smaller screens.

  FIG. 2 illustrates a touch sensor substrate 20 having a touch surface 24, edges 22 and sidewalls 32 in accordance with aspects of the present invention. The opposing edge 26 of the substrate is formed at a location where a surface corresponding to the second surface 28 of the substrate 20 and a surface corresponding to each side wall 32 intersect. An appropriate material such as glass, ceramic and metal (for example, aluminum or steel) may be used for forming the substrate 20. In some applications, a glass with low acoustic wave loss would be desirable. For example, borosilicate glass has less loss and can increase the amplitude of the received signal, allowing for a larger touch sensor area.

  The angle 42 and the angle 44 formed at the place where the side wall 32 abuts on the touch surface 24 is 90 °, or 20 ° to 90 °, and the side wall 32 is perpendicular or substantially perpendicular to the touch surface 24. It is perpendicular to. The side wall 32 is formed to be substantially defect-free or defect-free, such as chipping, streaks, dents, and non-uniform areas. The deviation (or the portion causing the deviation) has a dimension shorter than the elastic wave wavelength (for example, the wavelength of the Rayleigh wave), and preferably has a dimension of less than 20% of the wavelength of the Rayleigh wave.

  The clean sidewall 32 can be formed by a method suitable for the material used to form the substrate 20. For example, glass can be cut and machined to obtain clean sidewalls 32. In some cases, if practicable, the glass may be scribed and thereby a clean sidewall 32 can be formed on the opposite side of the scribed surface. Alternatively, the clean side wall 32 may be formed by controlling the cracks (or fractures) further with thermal stress using, for example, a local laser heating method and a cooling method by gas injection. Good. Further, the edge 22 may be formed to be substantially free of defects, similar to the clean sidewall 32.

  FIG. 3 shows a touch sensor 50 having mechanisms 52-58 on the side wall 32 for generating or detecting elastic waves in accordance with an aspect of the present invention. Sidewall 32 is represented as side walls 34-40 for clarity. The touch sensor 50 includes the substrate 20 having the touch detection surface 24. The mechanisms 52 to 58 respectively arranged with respect to the side walls 34 to 40 generate and / or detect elastic waves. Therefore, it is not necessary to form a mechanism such as a reflective array on the touch surface 24 of the substrate 20. In some cases, each mechanism 52-58 has a tab 60-66 that extends beyond the substrate 20 to provide electrical connection.

  For example, two of mechanisms 52 and 56 can generate elastic waves, while two of mechanisms 54 and 58 can detect elastic waves. The mechanism 52 and the mechanism 56 form an elastic wave (for example, a bulk shear wave) that travels in a direction substantially parallel to one diagonal line of the rectangular substrate 20 (a direction as indicated by an arrow 71).

  FIG. 4 illustrates a mechanism 52 for generating or receiving elastic waves formed on the side wall 32 in accordance with an aspect of the present invention. A first conductive layer or first electrode 84 is formed on the sidewall 32. The first electrode 84 may be formed so as to cover the surface of the side wall 32 entirely or substantially entirely. On the first electrode 84, a layer of piezoelectric material 83 (eg, a piezoelectric polymer film or a fired piezoelectric ceramic material) is applied. For example, a part 85 of the first electrode 84 may extend beyond the piezoelectric layer 83 so that electrical connection is possible at the tab 60 or the like. A second electrode 80 having a base portion 81 and a periodically continuous structure extending from the base portion 81 (for example, fingers 82) is arranged along the side wall 32 on the piezoelectric layer 83. The second electrode 80 can be formed from a material such as copper. Fingers 82 function as an array of transmitters or receivers (phased arrays) that generate or receive acoustic waves in a desired direction coherently (or coherently, coherently). Alternatively, the mechanism 52 shown in FIG. 4 may be formed as a piezo strip (or elongated piezo strip) that is formed separately from the substrate 20. Such piezo strips can be piezo strips 12-14 similar to the piezo strips of FIG. 9 described below.

  Mechanism 52 may be used to generate or receive shear waves, Lamb waves, or Rayleigh waves. The first electrode 84 may be grounded and an oscillating voltage (not shown) may be applied to the second electrode. The embodiment using shear waves will be described in more detail below. When shear waves are used, the length 82 of the finger 82 extends in the height direction of the side wall 32 (so as to occupy substantially the entire side wall height) or in the direction of the depth 60 of the substrate 20, and the base portion 81 becomes small. If formed, the mechanism 52 can be optimized. On the other hand, when Rayleigh waves are used, since there are many Rayleigh waves near the touch surface 24 of the substrate 20, the length 70 of the finger 82 is less than twice the wavelength λ of the elastic wave or less than the wavelength λ of the elastic wave. Thus, the mechanism 52 can be optimized. The fingers 82 are spaced apart from each other such that they are separated by a distance 72 measured between their centers or ends (between ends as shown), but generate or receive such distances 72. It can be made larger than the wavelength λ of the elastic wave. The ratio of λ / distance 72 is equal to the sine value of the emission angle (or generation angle) or the reception angle with respect to the normal direction of the substrate side wall 32.

  FIG. 5 illustrates the cross-sections 74 and 76 of the layers formed on the substrate 20 of FIG. 4 in accordance with aspects of the present invention. The cross section 74 shows a portion including the finger 82 of the second electrode 80. The cross section 76 shows a portion between the fingers 82, and the second electrode 80 forms a base portion 81.

  FIG. 6 illustrates touch areas 102-108 formed on the touch surface 24 of the substrate 20 in accordance with aspects of the present invention. As in FIG. 3, the side walls 34 to 40 are shown for easy understanding. In each of the touch areas 102 to 108, the elastic wave path “U” or “V” in the diagonal direction is used instead of the Cartesian coordinates “X” and “Y” which are conventionally used. Arrows 122 to 128 indicate the directions of the respective elastic wave paths from one side of the substrate 20 to the other adjacent side. For example, a signal generated due to a mechanism provided on the sidewall 38 proceeds to U1 (touch area 102) in the arrow 122 and is received by the mechanism on the sidewall 36. Further, a signal generated due to the mechanism provided on the side wall 38 proceeds to V1 (touch area 106) in the direction of the arrow 126 and is received by the mechanism of the side wall 40. Two-dimensional coordinates can be reconstructed from the signals U1, U2, V1 and V2 traveling in the four diagonal directions.

  FIG. 7 illustrates the geometry (or geometrical outline or shape dimension) of the touch sensor 100 formed in accordance with an aspect of the present invention. Transmission mechanisms 52 and 56 are disposed on the side walls 34 and 38 of the substrate 20, and reception mechanisms 54 and 58 are disposed on the side walls 36 and 40 of the substrate 20. For example, when the substrate 20 has a rectangular shape having a height 116 and a width 118 (height 116: width 118 = 3: 4), the distance 136 between the electrode fingers 82 formed on the transmission mechanisms 52 and 56 is 5λ / 4 and the interval 138 between the electrode fingers 82 formed on the receiving mechanisms 54 and 58 is 5λ / 3. When the distance between the electrode fingers 82 of the transmission mechanisms 52 and 56 is larger than one wavelength, coherent coupling is achieved in a desired direction.

  FIG. 8 shows a transmission mechanism 52 or reception mechanism 52 having comb electrodes (or electrodes formed to interdigitate in a comb shape) according to an embodiment of the present invention. Piezoelectric material 83 may be provided (or applied) on a ground electrode (not shown). Each of the first electrode 88 and the second electrode 90 has a structure that is periodically continuous. For example, the first electrode 88 and the second electrode 90 are formed as comb electrodes having electrode fingers 92 and 94 formed on the piezoelectric material 83, respectively. Yes. The fingers 92 are spaced from each other at regular intervals, and the fingers 94 are also spaced from each other at regular intervals, but such spacing is determined as described above in FIG. For example, the fingers 92 are spaced apart from each other so as to have a distance 72 (FIG. 4), and the distance between one finger 92 and an adjacent finger 94 is half that distance 72. Yes.

  Prior to placing the transmission and reception mechanisms 52-58 on the sidewall 32, they may be combined with each other. For example, a polymer-film sensor strip may be used. A particular subset of such polymers (materials with long chains of carbon skeleton) that have the property of expanding and contracting when subjected to an electric field has piezoelectric properties. A piezoelectric polymer is a continuous thin film having insulating properties. Such a strip comprises a piezoelectric polymer layer. Examples of the piezoelectric polymer include polyvinylidene fluoride (PVDF) or a copolymer of vinylidene fluoride (a copolymer of vinylidene fluoride and trifluoroethylene: p (VDF-TrFE)). The piezoelectric material 83 exists between the ground electrode and the comb-tooth electrodes 88 and 90, and can be formed of copper trace or metallized aluminum. Piezoelectric material 83 or polymer typically has a thin dimension (eg, 30 microns) that is smaller than the width dimension of fingers 92,94. The stop can be provided on the side wall 32 in any suitable manner. Preferably, the strip is formed by using a layer (eg, a thin hard adhesive layer) that effectively couples shear strain between the polymeric piezoelectric element and the substrate 20 (eg, glass). With a flexible cable, an electrical connection can be made from a controller (not shown) to the strip. In some cases, the same polymer film substrate that also functions as the transducer or the piezoelectric material of the mechanisms 52-58 may be provided continuously for electrical connection.

  A ground electrode (not shown) is grounded and the fingers 92, 94 are excited with different polarities. The mechanism 52 can transmit and / or receive elastic waves, and the fingers 92 and 94 transmit the elastic waves with a 180 ° phase shift. When the first electrode 88 and the second electrode 90 are excited with different polarities, the polymeric piezo or piezoelectric material 83 has a tendency to expand and contract in a plane as indicated by arrow 98. For example, when a negative voltage is applied to the finger 94, the piezoelectric material 83 contracts. Although the fingers 92 and 94 expand and contract somewhat, more importantly, corresponding stress is applied to the sidewalls 32 of the substrate 20.

  FIG. 9 illustrates a piezoelectric mode piezo strip 250 comprised of a polymer film that generates and receives "U" or "V" coordinates comprised of diagonal acoustic wave paths, in accordance with an aspect of the present invention. In the piezo strip 250, the first electrode 252 is provided on the first side 258 of the polymer piezo film 254. The second electrode 256 is provided on the second side 260 of the polymer piezo film 254. The piezo strip 250 can be flexible and therefore can be easily assembled and interconnected compared to hard and / or brittle materials. The first portion 262 of the piezo strip 250 can be adhesively attached to the second surface 28 of the substrate 20 so as to be adjacent to the edge 22. Alternatively, the first portion 262 of the piezo strip 250 may simply be attached to the second surface 28 without the use of an adhesive. The second portion 264 of the piezo strip 250 may extend from the substrate 20 so that electrical connections (not shown) can be easily attached to the first electrode 252 and the second electrode 256. .

  The piezo strip 250 is formed separately from the substrate 20 so as to provide flexibility for manufacturing and assembly. Therefore, the matter of “strain (or warpage) and / or other destruction that can occur in the substrate 20 due to the high temperature when the material comprising the piezo strip 250 is subjected to curing is considered. It is not necessary. As a result, further material can be used as the substrate 20 or can be used in a free space where there is a possibility of product design or usage environment.

  FIG. 10 illustrates a side view of the substrate 20 with a piezo strip 250 attached to the second surface 28 in accordance with an aspect of the present invention. The lattice 266 is formed on the touch surface 24 adjacent to the edge 22 so as to face the piezo strip 250. In some cases, a solid material 268 may be formed or attached onto the piezo strip 250 to provide an inertial mass to the piezo strip 250, thereby improving coupling efficiency.

  FIG. 11 illustrates a grid 266 formed on the touch surface 24 in accordance with an aspect of the present invention. The piezo strip 250 (not shown) has an active surface (corresponding to the first portion 262 of the piezo strip 250), which is covered by a grating transducer 266. Has been. When the first electrode 252 and the second electrode 256 are excited, an elastic wave is generated in the direction of the arrow 244.

  FIG. 12 illustrates a piezo strip 270 made of an alternative polymer film that generates and receives elastic waves in accordance with an embodiment of the present invention. In the piezo strip 270, a first electrode 272 is provided on the first side 278 of the polymer piezo film 274. The second electrode 276 is provided on the second side 280 of the polymer piezo film 274. The second electrode 276 has fingers 282. The first portion 284 of the piezo strip 270 is attached to the touch surface 24 of the substrate 20 so as to be adjacent to the edge 22. The second portion 286 of the piezo 270 can extend beyond the substrate 20, and thus electrical connections (not shown) can be easily attached to the first electrode 272 and the second electrode 276.

  FIG. 13 illustrates a piezo strip 290 made of another alternative polymer film that generates and receives elastic waves in accordance with an embodiment of the present invention. In the piezo strip 290, a ground electrode 292 is provided on the first side 300 of the polymer piezo film 294. The first electrode 296 and the second electrode 298 have interdigital fingers 308 and 310 and are provided on the second side 302 of the polymer piezo film 294. The first portion 304 of the piezo strip 290 is attached to the touch surface 24 of the substrate 20. The second portion 306 of the piezo 290 can extend beyond the substrate 20 and thus easily attach electrical connections (not shown) to the ground electrode 292, the first electrode 296 and the second electrode 298. be able to.

  FIG. 14 illustrates a piezo transducer 320 made of a polymer film that generates and receives elastic waves in accordance with an embodiment of the present invention. In the piezo transducer 320, a ground electrode 322 is provided on the first side 330 of the polymer piezo film 324. The first electrode 326 and the second electrode 328 have comb-like fingers 372 and 374 and are provided on the second side 332 of the polymer piezo film 324. The first portion 334 of the piezo transducer 320 is attached to the touch surface 34 of the substrate 20 so as to be adjacent to two or more corners of the substrate 20. The second portion 336 of the piezo transducer 320 can extend beyond the substrate 20, so that electrical connections can be easily attached to the ground electrode 322, the first electrode 326, and the second electrode 328. . A touch screen may be formed by combining the piezo transducer 320 with a reflective array (linear array 13a-13d in FIG. 1 as described above) formed on the touch surface 24 adjacent to the edge 22. .

  FIG. 15 illustrates a piezo strip 350 comprised of another alternative polymer film that generates and receives elastic waves from the sidewalls in accordance with an embodiment of the present invention. In the piezo strip 350, a ground electrode 352 is provided on the first side 360 of the polymer piezo film 354. The first electrode 356 and the second electrode 358 have comb-like fingers 360 and 370 and are provided on the second side 362 of the polymer piezo film 354. The first portion 364 of the piezo strip 350 is attached to the side wall 32 of the substrate 20. The second portion 366 of the piezo 350 can extend beyond the substrate 20, so that electrical connections can be easily attached to the ground electrode 352, the first electrode 356 and the second electrode 358. Piezo strip 350 coupled to side wall 32 is an option that may be applied to mechanism 52 of FIG.

  FIG. 16 illustrates the geometry of touch sensor 340 formed in accordance with an aspect of the present invention. The touch sensor 340 includes the substrate 20 having the touch surface 24. The piezo strips 342 to 348 are attached to the outer peripheral portion 338 of the touch surface 24 using, for example, an adhesive. For example, the piezo strips 342-348 can be either the piezo strip shown in FIG. 12 or the piezo strip shown in FIG. The strips 342 to 348 generate an elastic wave in a direction as indicated by the direction of the arrow 376 or receive an elastic wave in that direction. It should be noted that the piezo strips 342-348 are shown for clarity and not depending on the size of the touch sensor 340.

  17 shows a side view of a mechanism 52 for generating or detecting the elastic wave of FIG. 3 formed in accordance with an embodiment of the present invention. The mechanism 52 includes a first electrode 84, a piezoelectric layer 83, and an outer electrode 86 (for example, a comb-shaped first electrode 88 and second electrode 90 as shown in FIG. 8 or a second electrode as shown in FIG. 4). It is comprised so that it may have. The first electrode 84 of the mechanism 52 is coupled to the sidewall 32 by using an adhesive layer 85 made of, for example, epoxy. In some cases, the mechanism 52 extends beyond one or both of the plane forming the touch surface 24 or the opposing side 28 of the substrate 20 so that electrical connections can be attached to the electrodes 84, 86. You can do it.

FIG. 18 illustrates the mutual spacing or distance of the electrode fingers 82 (FIG. 4) in the U1 direction (FIG. 6) of aspects of the present invention. Transmission and reception of dimensionless horizontally polarized shear waves (known as ZOHPS waves or “GAW”) are made at a desired angle, resulting in a “U” elastic wave as shown in FIG. The mutual spacing of the electrode fingers 82 described in FIG. 4 can be adjusted so that a path and a “V” acoustic wave path are obtained. The substrate 20 has a height 116 and a width 118. A solid line 110 and a dotted line 111 respectively represent the maximum and the minimum of the elastic wave generated from the horizontal side surface 113 (the most negative amplitude having the same magnitude as the maximum case). Spacing of the projected maxima in the horizontal side 113 in the horizontal axis direction is represented as S _w. The elastic wave generated from the horizontal side surface 113 travels toward the vertical side surface 114 as indicated by an arrow 112. Spacing maxima (and minimum points) projected on the vertical sides 114 are expressed as S _H. The amount of S _w and _{S H} is represented by the following formula:
S _w = λ (H ² + W ² ) ^1/2 / W
S _H = λ (H ² + W ² ) ^1/2 / H
The wavelength λ is determined from the phase velocity V and the operating frequency f of the elastic wave mode used in the touch sensor for touch detection (relational expression λ = V / f). When using S _w and S _H to set the interval of electrode fingers 82 as described above, coherent combining is brought into elastic waves parallel to the diagonal of the rectangular touch surface 20, the two-dimensional coordinates in the touch area U1, U2, V1 and V2 acoustic wave paths are provided that allow measurement.

  FIG. 19 shows a coupling mechanism in the U1 region where a piezoelectric film (eg, PVDF film or fired piezoelectric ceramic layer) that expands and contracts due to an electric field, such as the piezoelectric material 83, and an elastic wave are coupled according to an embodiment of the present invention. Show. The black arrow 120 represents the movement of the shear elastic wave. The hollow arrow 124 represents the force along the horizontal side surface 114 caused by the transmission mechanism 52 (for example, the comb-tooth electrodes 88 and 90 and the piezoelectric material 83) as shown in FIG. A similar receiving mechanism 52 is provided along the vertical side surface 113. The inflating region 140 is represented by a “+” symbol, and the constricting region 142 is represented by a “−” symbol.

  When the piezoelectric material 83 is a fired piezoelectric coating or polymer layer (such as a PVDF layer), the piezoelectric material 83 is polarized (or polled) by inducing a dipole moment using an electric field so as to exhibit a piezoelectric behavior. This will be described with reference to FIG. If a commercially available electrode structure is used, the piezoelectric material 83 can be polarized most easily in a direction perpendicular to the side wall 32. In the piezoelectric material 83 polarized in the direction of the arrow 144, when a voltage is applied to the first electrode 84 and the outer electrode 86, expansion or contraction occurs in the direction 144 parallel to the applied electric field (this specification). Will be expanded or contracted in a direction 146 perpendicular to the electric field and parallel to the sidewall 32 (referred to herein as a “31” bond). Depending on the properties of the piezoelectric material 83, the contraction or expansion in the direction of 146 due to the “31” bond can be parallel or perpendicular to the touch surface 24 of the substrate 20 (or both). ). All three types of such piezoelectric material couplings, “33” coupling and two “31” couplings, are utilized to provide a coupling in which the desired elastic wave is generated and received.

  In FIG. 19, the coupling between horizontally polarized shear waves such as dimensionless horizontally polarized shear waves (ZOHPS) is shown. The black arrow 120 represents the movement of the shear wave, and the hollow arrow 124 represents the force resulting from the “31” coupling of the piezo material 83 (note that the arrow 146 exists within the surface of the touch surface 24. To do). Although not shown, an elastic wave is generated by exciting the shear wave motion component perpendicular to the side wall 32 (the component in the direction shown by the black arrow 120) using the “33” coupling in the piezoelectric material 83. be able to. Since Rayleigh waves propagating diagonally are associated with material motion in the sidewall 32 along all three axes, the “33” coupling and the two types of “31” couplings are used to excite Rayleigh and Lamb waves. Can be made.

  For example, a touch sensor 50 or 100 design that utilizes coupling to generate or receive the desired acoustic wave modes most efficiently and minimizes coupling to unwanted parasitic elastic modes is desirable. Further, the design of the transducer (eg, mechanism 52 or other mechanism described above) depends in part on the desired mode depth profile. For example, shear waves can travel through all or most of the depth of the substrate 20, while Rayleigh waves can only couple near the touch surface 24 of the substrate 20.

  FIG. 20 illustrates the elastic wave density of a dimensionless horizontally polarized shear wave (also called ZOHPS or “GAW” in the market) in the substrate 20 in accordance with an aspect of the present invention. ZOHPS or GAW has a uniform elastic wave energy density over the entire substrate 20, as indicated by arrows 152-156. In order to excite and detect such elastic waves, an active mechanism 52 that can transmit or receive (which may comprise a layer of piezoelectric material 83) is coupled uniformly along the side wall 32 in the depth 158 direction. It is preferable.

  FIG. 21 illustrates a higher dimensional plate wave transmission state in accordance with an aspect of the present invention. The mechanism 52 includes a first piezoelectric element 164 and a second piezoelectric element 166 that are opposite to each other and have opposite polarities. The first piezoelectric element 164 and the second piezoelectric element 166 are formed on the side wall 32 so as to be adjacent to the upper part (touch surface 24) and the bottom part (second surface 28) of the substrate 20. Accordingly, a higher-dimensional horizontally polarized shear wave (or another higher-dimensional plate wave) is transmitted in the vicinity of the touch surface 24 as indicated by arrows 168 and 170 and in the vicinity of the second surface 28. Are transmitted as indicated by arrows 172 and 174.

  FIG. 22 illustrates a state in which a Rayleigh wave is transmitted according to an aspect of the present invention. The elastic wave density of the Rayleigh wave is high near the touch surface 24 as indicated by arrows 192 and 194. In order to perform “31” coupling when the direction 146 is perpendicular to the touch surface 24, the mechanism 52 is moved to a region away from the touch surface 24 of the substrate 20 by a distance of about one wavelength λ176 of the Rayleigh wave. It is desirable to limit the active area of the piezoelectric material 83. Although the depth 158 of the mechanism 52 is shown to correspond to one wavelength λ176 of the Rayleigh wave, the active area of the piezoelectric material 83 is limited to an area within about one wavelength λ176 of the Rayleigh wave from the touch surface 24. It will be appreciated that the length of the mechanism 52 in the depth 158 direction may be greater.

  FIG. 23 illustrates a piezoelectric material 83 of mechanism 52 that couples with Rayleigh waves primarily through a “33” bond, in accordance with an aspect of the present invention. The phase of the vertical motion of the Rayleigh wave as shown by arrows 196 and 198 is reversed in the depth 158 direction. Therefore, the layers of active piezoelectric material 83 of mechanism 52 are excited with different polarities at different depths. In general, by combining simulation and experiment, the layer structure of the active piezoelectric material 83 of the mechanism 52 can be determined according to the desired elastic wave mode and the piezoelectric properties of the polarized piezoelectric layer.

  FIG. 24 illustrates a transducer structure having a periodic modulation layer 134 in accordance with an aspect of the present invention. A substrate 20 as shown in FIG. 2 can be used. As described above, the substrate 20 may be formed of any material such as glass, ceramic, and metal (aluminum or steel). In some applications, it is desirable to use glass with low elastic wave losses. As described above, the side wall 32 of the substrate is in a clean state.

  A first conductive layer 130 may be provided on each of the side walls 32 of the substrate 20 (or the first conductive layer 130 may be provided by coating), and in this case, the first conductive layer 130 is a first layer for a piezoelectric transducer. It can function as one electrode. As the material of the conductive layer, a suitable material such as silver frit, copper trace, or screen printable conductive ink can be used. For example, the first conductive layer 130 may be obtained by applying ink for screen printing to the side wall 32 and baking it at a high temperature (for example, 450 ° C.).

  Thereafter, the piezoelectric material layer 131 is applied to the side wall 32, and the piezoelectric material layer 131 is applied on the first conductive layer 130. Materials that can be used for the piezoelectric layer 131 include, but are not limited to, polymeric piezoelectric materials and fired piezoelectric ceramic materials. In some cases, a region 132 may be left near the corner to allow electrical connection to the first conductive layer 130.

  Next, a second conductive layer 133 is provided. The second conductive layer 133 can function as a second electrode for the piezoelectric transducer. Typically, the first conductive layer 130 can function as a ground electrode and the second conductive layer 133 can function as an excitation electrode or a received signal electrode so as to minimize the effect on electromagnetic interference. Unlike the electrode 80 shown in FIG. 4, the second conductive layer 133 is continuously formed so as to cover the piezoelectric layer 131, and therefore does not have a comb-like finger electrode structure. Instead, a periodic modulation layer 134 is provided on the second conductive layer 133.

  The periodic modulation layer 134 has a periodic structure and extends substantially from the top (or touch surface 24) to the bottom (or second surface 28) of the substrate 20, along the sidewall 32. And comprises material provided periodically as “strips”. Therefore, on the side wall 32, the first conductive layer 130, the piezoelectric layer 131, the second conductive layer 133, and the periodic modulation layer 134 are arranged so as to be stacked, whereby the transducer 141 (the touch sensor 50 of the touch sensor 50) is stacked. A transducer for generating or detecting elastic waves traversing the touch area 40 is constructed.

  The periodic modulation layer 134 of the transducer 141 functions to spatially modulate the elastic wave transmitted or detected by the transducer 141. When the periodic modulation layer 134 is present, the transmission characteristics of the piezoelectric layer 131 are modulated. When an oscillating voltage is applied between the first electrode 130 and the second electrode 133, the piezoelectric layer 131 is mechanically excited. Due to the “33” coupling of the piezoelectric properties, the piezoelectric layer 131 expands and contracts in a direction perpendicular to the side wall 32, thus creating a force against the vertical surface of the side wall 32. The two directions of the piezoelectric “33” bond cause expansion and contraction in a direction parallel to the plane of the side wall 32, so that a shear force in two directions is applied to the vertical plane of the side wall 32. . One or more of such piezoelectric couplings are useful for generating and receiving desired acoustic wave modes. For example, in order to form the elastic wave paths U1, U2, V1, and V2 by coherently coupling to the elastic wave, as described with reference to FIG. 18, the interval between the maximum point and the minimum point of the elastic wave is adjusted, The piezoelectric transducer must be adjusted. When the periodic modulation layer 134 is not used, an elastic wave is generated in a direction perpendicular to the side wall 32 in a coherent manner. However, in the case where coherent coupling is performed with respect to an elastic wave propagating in a diagonal direction using the periodic modulation layer 134, a horizontally polarized shear wave (for example, ZOHPS) is used by using “33” coupling of piezoelectric characteristics. Excitation and detection can be performed. The touch sensors 50, 100 using horizontally polarized shear waves are desirable for certain applications because the shear waves have little sensitivity to water contamination.

The periodic modulation layer 134 may adjust the amplitude or phase of coupling between the piezoelectric transducer on the sidewall 32 and the piezoelectric transducer on the substrate 20. The periodic modulation layer 134 may include a resonance unit, a phase shift unit, or an absorption unit. There are three possible cases:
(1) The case where the thickness of the piezoelectric layer 131 is considerably smaller than λ / 2 and the periodic modulation layer 134 is intended to modulate the amplitude by resonance (λ is a substrate) The pressure wave in the piezoelectric layer 131, not the pressure wave in 20);
(2) A case that is preferable when the thickness of the piezoelectric layer 131 is somewhat smaller than λ / 2 and the periodic modulation layer 134 is intended to modulate the phase by shifting the resonance frequency; And (3) a case that is preferred when the thickness of the piezoelectric layer 131 is approximately equal to λ / 2 and the periodic modulation layer 134 is intended to modulate the amplitude by an attenuation effect.

  25 and 26 show an example of a first case in which the piezoelectric mechanism 206 has a piezoelectric layer having a thickness substantially less than ½ wavelength, in accordance with an aspect of the present invention. The piezoelectric layer 131 is much harder than the polymer-piezo strip described above once formed on the substrate 20 (after firing). The periodic modulation layer 134 is not applied to the piezoelectric mechanism 206 shown in FIG. 25, and the piezoelectric mechanism 206 has a resonance frequency (or resonance frequency) that is considerably higher than the operating frequency of the touch sensor 50. become. The expansion and contraction of the piezoelectric layer 131 is not efficiently coupled to the substrate 20 so that an elastic wave is generated or detected. The portion of the piezoelectric mechanism 206 with the periodic modulation layer 134 is shown in FIG. The periodic modulation layer 134 is selected to be efficient so that the piezoelectric mechanism 206 including the periodic modulation layer 134 resonates (or resonates) at the operating frequency (eg, 5 MHz) of the touch sensor 50 (FIG. 3). Can be further improved. The piezoelectric mechanism 206 may be formed and adjusted using a material with low elastic wave attenuation (for example, glass frit). Alternatively, when the thickness 200 is set to ½ wavelength, the piezoelectric mechanism 206 may be detuned (or detuned) using the periodic modulation layer 134.

  FIG. 27 shows an example of a second case in which the piezoelectric mechanism 208 includes a piezoelectric layer 131 having a thickness 200 slightly thinner than ½ wavelength, and performs modulation by shifting the phase, according to an aspect of the present invention. Is shown. The piezoelectric mechanism 208 shown in FIG. 27 does not have the modulation layer 134 and is designed to have a resonance frequency slightly higher than the operating frequency of the touch sensor 50. The piezoelectric mechanism 208 shown in FIG. 28 has a modulation layer 134 and is designed to have a resonance frequency slightly lower than the operating frequency of the touch sensor 50.

FIG. 29 shows the dependence of the phase and amplitude coupled via resonance at ω ₀ in accordance with aspects of the present invention. A solid line 150 represents the normalized resonance amplitude A (left axis of the graph). A dotted line 151 represents a phase (°) (right axis of the graph). From FIG. 29, even if the phase is shifted from ω ₀ by, for example, ± 45 ° or ± 60 ° with respect to the resonating phase, a considerably large amplitude (amplitude of about 2/3 of the maximum amplitude) exists. Therefore, phase modulation can be performed in the range of 90 ° to 120 ° while leaving a large amount of resonance amplitude. The phase shift modulation layer 134 may be formed using a material with less elastic wave attenuation.

  In the third case (not shown), the modulation layer 134 functions as an absorber. The transducer 141 without the modulation layer 134 is designed to resonate at the operating frequency so as to be strongly coupled to the substrate. In the place where the absorption modulation layer 134 is provided, the acoustic wave resonance is greatly attenuated. Examples of the material of the absorption modulation layer include an epoxy containing metal (for example, tungsten) or other ultrasonic absorption material.

  FIG. 30 illustrates a piezoelectric mechanism 210 designed to generate a Rayleigh wave according to an aspect of the present invention. When the mechanism 52 (such as mechanism 52 of FIGS. 13 and 14) is limited in depth to match the Rayleigh wave depth profile, the Rayleigh wave edge transducer (the mechanism of FIGS. 4 and 8). 52 etc.) will be more efficient and produce less elastic wave parasitic signals. Therefore, in FIG. 30, the depth 212 of the active region of the piezoelectric layer 131 is limited to match the depth profile of the Rayleigh wave. This can be achieved by limiting to the depth 222 of the piezoelectric layer 131, the second electrode 133, the modulation layer 134, the conductive layer 130, or various combinations thereof. In some cases, it may be desirable to provide a layer (not shown) on the bottom (or second surface 28) of the substrate 20 that can attenuate all acoustic wave modes except Rayleigh waves. An example of a layer that provides such attenuation is a rigid optical coupling member comprising an epoxy layer between the substrate 20 and a device (eg, a display).

  For example, the periodic modulation layer 134 can be deposited and provided on the conductive layer 133, but the periodic modulation may be achieved by other techniques. For example, the piezoelectric layer 131 itself can be modulated by making the selected region inactive by annealing so as to be periodic. For example, the piezoelectric layer 131 itself may be modulated by locally heating the piezoelectric material above the phase transition point (eg, the Curie point of the ceramic material).

  FIG. 31 shows an example of obtaining modulation by periodically changing the substrate 20 according to an aspect of the present invention. For example, the substrate 20 can be periodically marked 135 using a local energy source such as a laser beam to form a periodic structure. When the substrate 20 is made of glass, it can be finely processed in the internal region of the substrate 20 using Nd: YAG (355 nm) having a triple frequency. The elastic wave properties of finely processed glass can vary (eg, increase attenuation or scattering), and such glass can be used to periodically modulate coherent coupling to the elastic wave. In other words, the optical diffraction grating can be formed so that the plurality of marking processing portions 135 are regularly spaced inside the substrate 20. In general, when other means for adjusting the elastic wave amplitude of the transducer 141 provided on the side wall 32 is used, the periodic modulation layer 134 may not be used. For example, the piezoelectric layer 131 may be a pressure mode piezo.

  Referring to FIG. 24, the transducer 141 may be formed by firing layers (first conductive layer 130, piezoelectric layer 131, and second conductive layer 133) provided continuously. That is, layers 130, 131, and 133 are subjected to thermosetting after being provided in the form of an uncured material. The modulation layer 134 may also be “baked”. Silver-containing ceramics having a relatively low sintering temperature are well known as materials used to form conductive traces on glass substrates and can be used in screen-printable form. For example, silver frit can be used to form the conductive layers 130 and 133. For the modulation layer 134 as shown in FIGS. 16B and 17B, a hard material with less elastic wave loss may be used. In that case, for the convenience of manufacturing, the same material as that used for the conductive layers 130 and 133 is used. Good. Alternatively, if the modulation layer 134 is to function as an attenuation layer, the modulation layer 134 may be formed from a thermosetting tungsten polymer.

In the embodiment of the structure shown in FIG. 24 having a fired layer, as an example of application of the piezoelectric material used for the layer 131, PZT particles dispersed in an Al ₂ O ₃ sol-gel solution and PZT sol-gel solution A sol-gel piezoelectric material such as dispersed LiTaO ₃ particles can be used. By baking such a sol-gel solution, a film having a thickness of 50 to 100 μm can be obtained. Other piezoelectric materials may be used, for example, Sr-added potassium sodium niobate or lead-free piezoelectric ceramics such as bismuth-containing piezoelectric ceramics. Such piezoelectric materials can be applied by a suitable method such as screen printing or spray coating. The above-described materials used for the modulation layer 134 can be cured by heating after being applied in an uncured state. The materials of layers 130, 131, 133, and 134 may each be applied continuously and subjected to curing, or may be cured simultaneously in the same heating cycle after all have been applied, or a combination thereof (Embodiment in which coating is continuously applied to a certain layer and cured, and then the remaining layers are simultaneously cured in the same heating cycle).

  When a material to be fired is used as the piezoelectric material of the piezoelectric layer 131, it is necessary to perform a polarization process in order to function it as a piezoelectric body. The polarization process can be performed by applying a large voltage between the conductive layer 130 and the conductive layer 133, thereby generating a large electric field in the material of the piezoelectric layer 131. Such polarization treatment must be performed after processing steps that can be performed at temperatures above the ferroelectric Curie point of the piezoelectric material.

When a material to be fired is used as the piezoelectric material of the electric layer 131, the substrate material must be selected so that it can withstand the firing temperature of the piezoelectric material and the subsequent annealing temperature (or annealing temperature). For example, Corning 1737 can be used. Corning 1737 has an annealing point of 721 ° C. and a softening point of 957 ° C., both of which are the sol-gel compositions (PZT particles and PZT sol-gel solution dispersed in the Al ₂ O ₃ sol-gel solution). It is higher than the firing temperature (450 ° C.) and annealing temperature (650 ° C.) of LiTaO ₃ particles dispersed therein.

  The piezoelectric transducer 141 may be formed separately from the substrate 20, and the piezoelectric transducer 141 may be applied as an assembly. For example, such an assembly may be a strip (a strip as described above) bonded to the substrate 20 using an adhesive or other suitable bonding means. The adhesive layer or the bonding layer is preferably thin so as to minimize the influence on the elastic wave action of the touch sensor 50, and preferably does not cause elastic wave attenuation to a satisfactory extent. The layered assembly including the first conductive layer 130, the piezoelectric layer 131, the second conductive layer 133, and the optional modulation layer 134 is, for example, a strip including a glass microsheet 134 having a thickness of 100 to 120 μm. It can be formed on the material. In that case, when the layered assembly is further divided (for example, dicing), a plurality of transducers 141 that can be coupled to the plurality of substrates 20 can be obtained.

  FIG. 32 illustrates a lattice transducer 400 formed on the substrate 20 in accordance with an aspect of the present invention. A first trace 406 is formed on the second surface 28. The first trace 406 comprises a conductive material such as a silver frit. The first trace 406 can be applied using screen printing, pad printing, or other deposition methods. The first side 410 of the pressure mode piezoelectric element 408 is provided on a portion of the first trace 406 and is interconnected with a portion of the first trace 406. The second trace 414 is formed on the second surface 28. The second trace 414 is provided on the side surface 418 and the second side portion 412 of the piezoelectric element 408, and is connected to them. As described further below, electrical connections that excite the piezoelectric element 408 are interconnected with each of the first trace 406 and the second trace 414.

  A lattice element 402 is formed on the touch surface 24. The grating elements 402 are formed with an interval 404 corresponding to the wavelength of the Rayleigh wave. The grid element 402 may even be formed by providing or removing material, such as by screen printing or etching as described above. A reflective array 416 is formed on the touch surface 24. The reflective array 416 can also be formed by providing or removing material.

  FIG. 33 illustrates a comb transducer 420 formed on the substrate 20 in accordance with an embodiment of the present invention. As in the case of FIG. 32, the lattice element 432 is formed on the touch surface 24. The first trace 422 is formed on the touch surface 24 so as to be positioned on the lattice element 432. The first side 424 of the thickness mode piezoelectric element 426 is applied over a portion of the first trace 422 and interconnected therewith. A second trace 430 is formed on the touch surface 24. The second trace 430 is applied to the side surface 434 and the second side portion 428 of the piezoelectric element 426 and is interconnected therewith.

  FIG. 34 illustrates an interdigital transducer 440 formed on the substrate 20 in accordance with an embodiment of the present invention. A first trace 442 and a second trace 444 are formed on the touch surface 24 of the substrate 20. The first trace 442 and the second trace 444 have comb-like fingers (not shown) such as the first electrode 88 and the second electrode 90 of FIG. Piezoelectric element 448 is applied over and interconnected with first trace 442 and second trace 444.

  FIG. 35 shows a touch sensor 450 with transducers 452-458 formed on the outer periphery 486 of the touch surface 24 in accordance with an aspect of the present invention. The reflective element 460 is provided at an angle of 45 ° with respect to the edges 462 to 468, and forms a reflective array within the outer peripheral portion 486.

  The transducers 452-458 constitute any one of the transducers 400, 420, or 440 shown in FIGS. First and second traces 470-484 are printed on the touch surface 24 adjacent to the edges 466, 468 and are interconnected with the appropriate transducers 452-458 shown. Such interconnection is determined by the type of transducer used. The first trace and the second trace 470 to 484 are connected to the cable 488 by soldering or the like.

  FIG. 36 illustrates an alternative transducer 490 formed on the substrate 20 in accordance with an aspect of the present invention. The first trace 492 and the second trace 494 are applied to the touch surface 24. FIG. 36 shows only one trace. In the first trace 492 and the second trace 494, the comb electrodes as described in FIG. 34 are formed. The first side 550 of the piezoelectric element 498 is applied on the first trace 492 and the second trace 494. The ground electrode 548 is applied to the touch surface 24, the second side portion 552 and the side surface 554 of the piezoelectric element 498.

  FIG. 37 illustrates a touch sensor 500 with transducers 502-508 formed on the outer periphery 544 of the touch surface 24 in accordance with an aspect of the present invention. The reflective array 510 is provided so as to form 45 ° with respect to the edges 512 to 518.

  The transducers 502-508 can form the transducer 490 of FIG. Ground traces, first traces, and second traces 520-542 are printed on the touch surface 24 and are interconnected with appropriate transducers 502-508. The ground trace, the first trace, and the second traces 520 to 542 can be connected to the cable 546 by soldering or the like.

  This will be described with reference to FIGS. 35 and 37. FIG. A controller (not shown) functions to send an electrical signal to the transducer via the first electrode and the second electrode, if necessary, and to send an electrical signal to the grounding part via the ground electrode. To work. Only one transducer is activated at a time. In the embodiment shown, four transducers are used. Two of them can function as transmitting transducers and the other two can function as receiving transducers. Build other forms with two or three transducers to transmit or receive or other forms with two or three transducers to both transmit and receive to receive signals from touch sensors It will be appreciated that other forms may be constructed, or alternatively, cover various portions or areas of the touch surface 24.

  FIG. 38 illustrates an alternative touch sensor 214 formed in accordance with aspects of the present invention. The side wall 32 and the edge 22 are in a clean state as described above. On the side wall 32 of the substrate 20, a transducer 160, a waveguide 161 and a reflective array 162 are arranged. The reflective array 162 can be formed adjacent to the edge 22 or can be formed across the edge 22. The transducer 160, the waveguide 161, and the reflection array 162 provided on each side wall 32 can be referred to as a mechanism 171. In some cases, additional waveguides and associated arrays may be formed on the touch surface 24 of the substrate 20. As shown in FIG. 38, the border area 216 is further reduced by arranging the waveguide 161 and the reflective array 162 required for the touch sensor mechanism 171 for generating, directing, and detecting the elastic wave on the side wall 32. be able to. The reflective array 162 and the waveguide 161 may be formed as a groove provided in the substrate 20, or may be formed as a protrusion made of a material provided on the side wall 32 of the substrate 20. The transducer 160 generates an elastic wave that is coupled to the waveguide 161. Elastic energy is focused at the core of the waveguide 161. The acoustic wave energy can be coupled to the substrate 20 as a surface acoustic wave by the array 162. A mechanism 171 comprising a transducer 160, a waveguide 161 and an array 162 may function to generate an elastic wave and direct it across the touch area 24 of the touch sensor 214, or touch sensor It may function to detect elastic waves after traversing 214 touch areas 24.

  As the elastic wave travels along the waveguide 161, the energy is lost. In many touch sensor 214 applications, it is desirable that the elastic wave energy received by the detector (such as mechanism 171) is not strongly dependent on the length of the path taken. Therefore, various elastic wave signal equalization schemes such as various reflection arrays designed to equalize the signal amplitude according to the path length may be incorporated. Designs that equalize the signal amplitude include changing the height or width of the reflective elements that make up the reflective array, or changing the dimensions of the reflective elements.

  FIG. 39 illustrates a waveguide 161 arranged to perform signal equalization in accordance with an aspect of the present invention. The transducer 160, the waveguide 161 and the reflective array 162 are represented as being disposed on the side wall 32 of the touch sensor substrate 20. The waveguide 161 is curved in the direction of the length 218 of the side wall 32. The waveguide 161 is disposed so as to be farthest from the array 162 at the first end 220 in the vicinity of the transducer 160 where the elastic wave energy is highest in the inside thereof. On the other hand, at the second end 222 away from the transducer 160 (the waveguide 161 has the least elastic wave energy inside it), it is arranged closer to the array 162 and / or with the array 162. Arranged to intersect and / or located on top of the array 162. Since the waveguide 161 is curved in this way, signal equalization can be performed.

  FIG. 40 illustrates a waveguide 161 formed to perform signal equalization in accordance with an aspect of the present invention. The core portion of the waveguide 161 is formed narrower as it moves away from the transducer 160 (or in the direction from the first end portion 220 toward the second end portion 222), effectively reducing the influence of the core. As the width of the core portion is reduced, the elastic wave is not restricted by the waveguide 161 and spreads, and the elastic wave overlapping the reflective array 161 increases. In this case, the mutual spacing of the elements 163 of the reflective array 162 may be changed in order to make the effect of wave velocity in the core of the tapered waveguide more pronounced. 39. The signal equalization provided by the waveguide 161 formed and / or arranged as shown in FIGS. 39 and 40 can be equally preferably applied even when the waveguide 161 is arranged on the touch surface 24. It will be understood.

  FIG. 41 illustrates another embodiment of a touch sensor 224 formed in accordance with an embodiment of the present invention. A substrate 20 having clean sidewalls 32 is provided (see FIG. 2). A strip 180 (a strip capable of propagating an elastic wave in its axial direction) is provided. The strip 180 is a waveguide having the same function as the waveguide 161 shown in FIGS. The elastic wave propagating in the strip 180 can be a stretching wave, a flexural plate wave (or bent plate), or other type of elastic wave. The strip 180 is disposed on the side wall 32 of the glass substrate 20. The strip 180 is coupled to the side wall 32 via a coupling layer 186 comprising a coupling element 187. A pressure mode piezoelectric element 183 is provided at one end 181 of the strip 180, and an energy dump region 184 is provided as necessary at the opposite end 182 of the strip 180. It has been. An energy dump region 184 may be provided at one end of the strip 180, thereby reducing reflection. The energy dump region 184 may comprise a suitable material (eg, a tungsten-containing epoxy) that can be adjusted to match the acoustic wave impedance of the substrate 20. The elastic wave generated in the strip 180 is sensitive to a touch performed on the substrate surface 24 and is coupled to the elastic wave in the substrate 20.

  The strip 180 can comprise a material (eg, metal or glass) through which elastic waves can propagate. The thermal expansion coefficient (CTE) of the strip material is close to the thermal expansion coefficient of the substrate. In some applications, it may be advantageous that the height of the strip 180 (height measured in the height direction of the sidewall 32) is approximately equal to the glass substrate thickness. The thickness of the strip 180 (thickness measured in the direction perpendicular to the strip height) is preferably thin so as not to extend far away from the substrate 20, thereby reducing the size of the outer edge of the touch sensor 224. Can be kept to a minimum. Strip materials can include glass rods and metal strips having a CTE close to that of the glass (eg, nickel alloys such as Invar® or related materials). Suitable examples of the cross-sectional shape of the strip material are a rectangular cross section of 3 mm × 1 mm and a square cross section of 1/2 mm × 1/2 mm.

  Electrical excitation of the piezoelectric element 183 can produce, for example, a wave that propagates longitudinally along the strip 180. Due to boundary conditions due to the cross-section of the strip 180, the wave in the strip 180 is not a pure pressure wave, but a stretching wave, a diagonally directed wave, or a lower dimensional symmetrical Lamb wave. Since a wave having a longitudinal component propagates, the material of the strip 180 has a component that moves parallel to the wave propagation direction (ie, a component that moves in the length direction of the strip 180).

  The coupling layer 186 provides mechanical coupling, and the spacing between the periodically spaced coupling elements 187 determines the scattering angle at which the waves generated in the strip 180 scatter into the elastic waves formed on the substrate 20. It is done. The coupling element 187 is formed to have a periodic structure similar to the reflective array. For example, if the touch sensor 224 is rectangular and is desired to be scattered at 90 ° with respect to the sidewall 32, the spacing of the coupling elements 187 should be equal to the wavelength of the elastic wave of the strip 180. The 90 ° scattering is represented by arrow 188 in FIG. Illustrating as an example of a coupling mechanism, since the coupling element 187 moves the shear force, the longitudinal movement of the wave in the strip 180 causes the transverse direction of the shear wave in the substrate 20 as shown by the arrow 189 in FIG. Will be coupled to the movement. Due to the compressive stiffness of the coupling element 187, the transverse motion of the wave in the strip can be coupled with the longitudinal component of the touch-sensing wave motion (eg, Rayleigh wave motion) on the substrate 20 (such a coupling aspect is not shown). . The strip 180 can also function to receive elastic waves from the substrate 20.

  FIG. 42 illustrates a touch sensor 226 that incorporates a strip 180 in accordance with an aspect of the present invention. Strip 180 is represented as strips 228 and 230 for clarity. A first strip 228 having a piezoelectric element 232 is disposed along the first sidewall 234 of the substrate 20. A second strip 230 having a piezoelectric element 236 is disposed along the second side wall 238 of the substrate 20. As indicated by arrow 190, after being generated at piezoelectric element 232, shear waves directed by strip 228 toward substrate 20 can be reflected at sidewall 240 and then redirected at strip 228, It is detected by the piezoelectric element 232. As indicated by arrow 191, a shear wave generated by piezoelectric element 236 and then directed toward substrate 20 by strip 230 can be reflected by sidewall 242 and then redirected by strip 230 to cause piezoelectric It will be detected by element 236. Electronic equipment (not shown) connected to the piezoelectric elements 232 and 236 can be used to time division multiplex the signal and adjust between the transmission mode and the reception mode.

  Alternatively, the touch sensor may be provided with strips on all side walls 32 (not shown). For example, for the rectangular substrate 20, four strips 180 are used. In that case, two of the two strips 180 may function in the transmission mode, and another two strips 180 may function in the reception mode.

  In the case where the strip 180 provided on the side wall 32 of the substrate 20 is designed to excite Rayleigh waves at the substrate 20, so as to efficiently couple to the Rayleigh waves shown in FIGS. 22 and 23. The coupling element 187 needs to be coupled to the side wall 32 in a region separated from the touch surface 20 by about one wavelength of Rayleigh wave. The depth dimension of the strip 180 may or may not match the depth dimension of the coupling element 187.

  The bond strength between the strip 180 and the substrate 20 is affected by any one or more of the stiffness, thickness or bonding area of the bonding element. Preferably, the amplitude of the elastic wave coupled to the substrate 20 is independent of the point on the side wall 32 where the coupling takes place. By using parameters that affect the coupling between the strip 180 and the substrate 20, the amplitude of the acoustic wave signal can be equalized as a function of the distance along the substrate 20 (or as a function of the distance along the substrate 20). it can.

  FIG. 41 shows a case of the bonding layer 186 in which the places where the bonding material exists (bonding elements 187) and the places where the bonding material does not exist are alternately provided. In such a bonding layer 186, the bonding strength between the strip 180 and the substrate 20 is spatially adjusted. The coupling can be spatially adjusted as desired by other means. For example, a bonding layer with no air gap is conceivable so that the mechanical properties of the bonding material are adjusted. It will be appreciated that after the strip 181 and the coupling element 187 are formed separately from the substrate 20, they may be attached as an assembly.

  FIG. 43 illustrates a touch sensor 560 with a transducer 562 formed on the sidewall 32 of the substrate 20 in accordance with an aspect of the present invention. When excited, the transducer 562 generates an edge wave that travels along the edge 22. The edge wave is reflected across the touch surface 24 by the reflection array 564. Such a touch sensor is disclosed in US Provisional Patent Application No. 60/562461 (Attorney Docket No. ELG064-US1), the contents of such provisional application being incorporated herein by reference. The transducer 562 may include a piezoelectric material printed on the sidewall 32 by screen printing or other methods described above. Alternatively, the transducer 562 may include a piezoelectric material that is individually formed and then bonded to the sidewall 32.

  In any aspect of the touch sensor described herein, the touch sensor can be connected to the controller by electrical interconnection means. For example, suitable interconnection means such as a cable harness can be used. Alternatively, the touch sensor may be incorporated directly into the touch sensor system. For example, a touch screen may be formed by integrating a touch sensor and a display. In some cases, screen printing may be performed on a surface of a substrate (for example, an instrument panel) used in a vacuum fluorescent display. For example, the substrate may form the outer layer of a display device such as a vacuum fluorescent display.

The configuration of the apparatus described above is merely illustrative of an application example of the principle of the present invention, and that other modes and modifications are possible without departing from the concept and scope of the present invention. It will be understood. The present invention as described above includes the following aspects:
1st aspect: The board | substrate which can propagate an elastic wave, Comprising: The board | substrate including the 1st side which has a touch detection area | region, and the 1st side wall which cross | intersects this 1st surface at the 1st edge, And
A transmitter provided on a first side wall of a substrate, wherein the transmitter generates an elastic wave that propagates directly from the first side wall so as to pass through at least a part of the touch detection region.
Comprising a touch sensor.
Second aspect: The touch sensor according to the first aspect, wherein the first surface and the first side wall intersect each other at an angle of about 90 ° at the first edge.
Third aspect: The touch sensor according to the first aspect, wherein the transmitter changes the direction of the elastic wave in a direction perpendicular to the first side wall.
Fourth aspect: The touch sensor according to the first aspect, wherein the transmitter further includes a first electrode having a structure formed so as to be periodically continuous along the first side wall.
Fifth aspect: In the first aspect, the transmitter further includes a first electrode and a second electrode, and the first electrode and the second electrode are alternately arranged along the first side wall. Touch sensor, including a continuous finger.
Sixth aspect: In the first aspect, the side wall has a first end and a second end, and the transmitter is disposed at the first end.
A touch sensor, wherein the side wall further comprises a waveguide oriented along the side and a reflective array disposed along the side wall adjacent to the first surface.
Seventh aspect: In the first aspect, the transmitter includes an electrode having fingers oriented in the height direction of the side wall, and the fingers are angled of elastic waves directed across the touch sensing area. Touch sensors that are spaced apart from each other to adjust.
Eighth aspect: The touch sensor according to the first aspect, in which the transmitter generates any one of a shear wave, a Lamb wave, and a Rayleigh wave as an elastic wave propagating through at least a part of the touch detection region.
Ninth aspect: The touch sensor according to the first aspect, wherein the elastic wave propagating across the touch detection region propagates in a direction that forms an acute angle with the first side wall.
Tenth aspect: In the first aspect, the detector further includes a detector provided on the second side wall of the substrate, and the detector detects an elastic wave after crossing at least a part of the touch detection area. ,Touch sensor.
Eleventh aspect: In the first aspect, the transmitter further includes a first transducer and a second transducer having a periodic structure;
A first transducer and a second transducer are provided on opposite first and second side walls of the substrate, respectively, and the first and second transducers are opposed to the opposite first and second side walls. A touch sensor that generates a first elastic wave and a second elastic wave that propagate in a direction that forms an acute angle.
Twelfth aspect: In the first aspect, the transmitter further includes a modulation layer that modulates the elastic wave, thereby damping the elastic wave, tuning and detuning of the elastic wave with respect to the resonance frequency, or A touch sensor in which any one of the phase shifts of elastic waves is performed.
Thirteenth aspect: A substrate capable of propagating an elastic wave, the substrate including a first surface having a touch detection region, and first and second sidewalls intersecting the first surface;
A transmitter provided on a first side wall of the substrate for generating an elastic wave that propagates directly from the first side wall across at least a portion of the touch sensing region; and
A detector provided on the second side wall of the substrate for detecting an elastic wave after traversing at least a part of the touch detection area
A touch sensor system comprising:
Fourteenth aspect: In the thirteenth aspect, the transmitter further includes a first electrode and a second electrode, and each of the first electrode and the second electrode has a periodic structure along the first side wall. Touch sensor system.
Fifteenth aspect: In the thirteenth aspect, the transmitter further includes a first comb-shaped transducer and a second comb-shaped transducer respectively provided on the first and third side walls facing each other. The first comb-shaped transducer and the second comb-shaped transducer generate the first elastic wave and the second elastic wave that propagate in a direction that forms an acute angle with respect to the opposing first and third side walls. Let the touch sensor system.
Sixteenth aspect: In the thirteenth aspect, the side wall has a first end and a second end, the transmitter is disposed at the first end, and the side wall is oriented along the same. And further comprising a reflective array disposed along the side wall adjacent to the waveguide and the first surface,
A touch sensor system in which the waveguide is either a strip coupled to the sidewall or a groove formed by removing material from the sidewall.
Seventeenth aspect: A method for detecting a touch in a touch detection region of a substrate capable of propagating elastic waves, the substrate including a first surface having a touch detection region, wherein the substrate is a first Having a first side wall and a second side wall intersecting the surface;
Generating an elastic wave in the vicinity of the first side wall of the substrate;
Passing through a portion of the first side wall of the substrate and then to the substrate and then directing the elastic wave across at least a portion of the touch sensing area; and
A step of detecting an elastic wave in the vicinity of the second side wall of the substrate
Comprising a method.
Eighteenth aspect: The method according to the seventeenth aspect, wherein the detection step further includes detecting a perturbation in the elastic wave that indicates the touched position.
Nineteenth aspect: In the seventeenth aspect, the elastic wave is directed in a linear direction extending from a wave source disposed along the first side wall so that the elastic wave passes through at least a part of the touch detection region. A method wherein the detecting step further includes traveling only a single path without reflection of the elastic wave.
Twentieth aspect: The method according to the seventeenth aspect, wherein the step of redirecting the elastic wave includes changing the direction of the elastic wave along the first side wall and reflecting the elastic wave.
Twenty-first aspect: a substrate that is capable of propagating elastic waves and includes a first surface having a touch detection region, and
Transducer formed on the substrate
A touch sensor comprising:
The transducer includes a piezoelectric element that is subjected to thermosetting after being provided on the substrate, and the transducer is configured to perform at least one of generation of elastic waves or detection of elastic waves; Touch sensor.
Twenty-second aspect: The touch sensor according to the twenty-first aspect, wherein the piezoelectric element is formed on the substrate by using either screen printing or pad printing.
Twenty-third aspect: In the twenty-first aspect, the substrate further includes a second surface parallel to the first surface, and the transducer further includes a lattice element formed on the first surface, A touch sensor, wherein a piezoelectric element is formed on the second surface so as to face the lattice element.
Twenty-fourth aspect: The touch sensor according to the twenty-first aspect, wherein the transducer further includes a lattice element formed on the first surface, and a piezoelectric element is formed on the lattice element.
Twenty-fifth aspect: In the twenty-first aspect, the transducer comprises:
A first conductive layer formed on the substrate;
A second conductive layer formed on the first conductive layer and comprising a piezoelectric element;
Third conductive layer formed on the second conductive layer
And further comprising
A touch sensor in which a first conductive layer and a third conductive layer are connected to each other using a first electrical connection portion and a second electrical connection portion.
Twenty-sixth aspect: in the twenty-first aspect, the transducer is
A first layer formed on the substrate;
A second layer formed on the first layer; and
Third conductive layer formed on the second layer
And further comprising
The first layer and the ground connection portion are connected to each other, the second layer includes a piezoelectric element, and the third conductive layer includes a first electrode and a second electrode, The touch sensor in which the second electrode, the first electrical connection portion, and the second electrical connection portion are connected to each other.
Twenty-seventh aspect: The touch sensor according to the twenty-first aspect, wherein the substrate forms an outer layer of the display device.
Twenty-eighth aspect: In the twenty-first aspect, the transducer comprises:
A first conductive layer formed on the substrate;
A second conductive layer formed on the first conductive layer and comprising a piezoelectric element;
A third conductive layer formed on the second conductive layer; and
A fourth modulation layer comprising a periodically applied material formed on the third conductive layer
And further comprising
A touch sensor, wherein the first conductive layer and the third conductive layer are interconnected with the electrical connection portion.
Twenty-ninth aspect: a substrate that is capable of propagating elastic waves and includes a first surface having a touch detection region, and
A transducer configured to generate and / or receive elastic waves
A touch sensor comprising:
A touch sensor, wherein the transducer includes a strip comprising a piezoelectric material, and the strip is attached to the substrate.
30th aspect: The touch sensor according to the 29th aspect, wherein the piezoelectric material comprises a polymer piezo material.
Thirty-first aspect: In the twenty-ninth aspect, the strip further includes at least two layers made of a conductive material, and the piezoelectric material is formed between the two layers made of the conductive material. Touch sensor.
Thirty-second aspect: In the twenty-ninth aspect, the first surface further includes a touch area having an outer peripheral portion, and the substrate further includes a second surface parallel to the first surface, The touch sensor, further comprising a lattice-shaped transducer formed in the outer peripheral portion of the first surface, wherein the strip is attached to the second surface so as to face the lattice-shaped transducer.
Thirty-third aspect: A method of forming a transducer on a touch sensor substrate including a first surface having a touch detection area,
Providing a first conductive layer on the substrate;
Providing a piezoelectric layer on the substrate such that at least a portion of the first conductive layer is covered; and
Process for thermosetting the piezoelectric layer
Comprising a method.
Thirty-fourth aspect: The method according to the thirty-third aspect, further comprising the step of providing a second conductive layer on the substrate so that at least a part of the piezoelectric layer is covered with the second conductive layer.
Thirty-fifth aspect: in the thirty-third aspect, the step of providing a second conductive layer on the substrate; and
Applying a first voltage and a second voltage to the first conductive layer and the second conductive layer, respectively, to polarize the piezoelectric layer
A method further comprising:
Thirty-sixth aspect: The method according to the thirty-third aspect, wherein the step of providing a piezoelectric layer further includes screen printing of a piezoelectric material.
Thirty-seventh aspect: In the thirty-third aspect, the method further includes forming a lattice element on the substrate by removing material from the substrate, wherein the step of providing the first conductive layer and the step of providing the piezoelectric layer include: A method further comprising providing a conductive layer and a piezoelectric layer on the lattice element.
Thirty-eighth aspect: in the thirty-third aspect,
Forming conductive traces on the substrate; and
Interconnecting conductive traces and conductive layers such that an electrical signal will be sent to the conductive layers
A method further comprising:
Thirty-ninth aspect: The method according to the thirty-third aspect, wherein the piezoelectric material comprises a sol-gel material.
40th aspect: The method according to the 33rd aspect, wherein the substrate further comprises a side wall intersecting the first surface at the edge so as to be substantially perpendicular to the first surface.

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of US Provisional Application No. 60 / 562,461 No. (entitled "acoustic touch sensor", filed on Apr. 14, 2004) and U.S. Provisional Patent Application No. 60 / 562,455 (Title of Invention: “Acoustic Wave Touch Sensor”, filing date: April 14, 2004), the disclosure of which is incorporated herein by reference.

FIG. 1 shows an operation state of a conventional acoustic wave touch sensor and an acoustic wave touch screen. FIG. 2 illustrates a touch sensor substrate having a touch surface, edges and sidewalls in accordance with aspects of the present invention. FIG. 3 shows a touch sensor having an elastic wave generating mechanism or an elastic wave detecting mechanism on a side wall according to an embodiment of the present invention. FIG. 4 shows an elastic wave generating mechanism or an elastic wave receiving mechanism formed on the side wall according to an embodiment of the present invention. FIG. 5 illustrates a cross-section of a layer formed on the substrate of FIG. 4 in accordance with an embodiment of the present invention. FIG. 6 illustrates a touch area formed on a touch surface of a substrate in accordance with an aspect of the present invention. FIG. 7 illustrates the geometry of a touch sensor formed in accordance with an aspect of the present invention, with a transmission mechanism disposed on two sidewalls of the substrate and a receiving mechanism disposed on the other two sidewalls of the substrate. FIG. 8 illustrates a transmission or reception mechanism having comb electrodes in accordance with an embodiment of the present invention. FIG. 9 shows a piezoelectric mode piezo strip made of a polymer film that generates and receives "U" or "V" coordinates consisting of diagonal acoustic wave paths, in accordance with an embodiment of the present invention. FIG. 10 illustrates a side view of a substrate having a piezo strip attached to a second surface in accordance with an embodiment of the present invention. FIG. 11 illustrates a grid formed on the touch surface in accordance with an aspect of the present invention. FIG. 12 shows a piezo strip made of another polymer film that generates and receives elastic waves in accordance with an embodiment of the present invention. FIG. 13 shows a piezo strip made of another polymer film that generates and receives elastic waves in accordance with an embodiment of the present invention. FIG. 14 illustrates a piezo transducer made of a polymer film that generates and receives elastic waves in accordance with an embodiment of the present invention. FIG. 15 shows a piezo strip made of another polymer film that generates and receives elastic waves from the sidewalls in accordance with an embodiment of the present invention. FIG. 16 illustrates the geometry of a touch sensor formed in accordance with an embodiment of the present invention. 17 shows a side view of the elastic wave generating mechanism or elastic wave detecting mechanism of FIG. 3 formed in accordance with an aspect of the present invention. FIG. 18 shows the mutual spacing or distance of the electrode fingers (FIG. 4) in the U1 direction (FIG. 6) of the embodiment of the present invention. FIG. 19 illustrates a U1 region coupling mechanism where an acoustic wave is coupled to a piezoelectric film (eg, PVDF film or fired piezoelectric ceramic layer) that expands and contracts due to an electric field such as a piezoelectric material, in accordance with an embodiment of the present invention. ing. FIG. 20 illustrates the elastic wave density of a dimensionless horizontally polarized shear wave (also called ZOHPS or “GAW” in the market) in a substrate in accordance with an aspect of the present invention. FIG. 21 illustrates a higher dimensional plate wave transmission state in accordance with an aspect of the present invention. FIG. 22 illustrates a state in which a Rayleigh wave is transmitted according to an aspect of the present invention. FIG. 23 illustrates a piezoelectric material with a mechanism for coupling with Rayleigh waves, primarily through a “33” bond, in accordance with an aspect of the present invention. FIG. 24 illustrates a transducer structure having a periodic modulation layer in accordance with an aspect of the present invention. FIG. 25 shows an example of a first case in which the piezoelectric mechanism has a piezoelectric layer having a thickness substantially less than ½ wavelength in accordance with an aspect of the present invention. FIG. 26 shows an example of a first case in which the piezoelectric mechanism has a piezoelectric layer having a thickness of less than ½ wavelength, in accordance with an aspect of the present invention. FIG. 27 shows an example of a second case in which the piezoelectric mechanism has a piezoelectric layer having a thickness slightly less than ½ wavelength according to an aspect of the present invention and performs modulation using phase shift. Show. FIG. 28 shows an example of a second case in which the piezoelectric mechanism comprises a piezoelectric layer having a thickness slightly less than ½ wavelength and modulates by shifting the phase according to an embodiment of the present invention. Yes. FIG. 29 shows the dependence of the phase and amplitude coupled via resonance at ω ₀ in accordance with an embodiment of the present invention. FIG. 30 illustrates a piezoelectric mechanism designed to generate Rayleigh waves according to an aspect of the present invention. FIG. 31 illustrates an example in which modulation is obtained by periodically changing a substrate in accordance with an aspect of the present invention. FIG. 32 illustrates a lattice transducer formed on a substrate in accordance with an embodiment of the present invention. FIG. 33 illustrates a comb transducer formed on a substrate in accordance with an embodiment of the present invention. FIG. 34 illustrates a comb-shaped transducer formed on a substrate in accordance with an embodiment of the present invention. FIG. 35 illustrates a touch sensor with a transducer formed on the outer periphery of the touch surface in accordance with an aspect of the present invention. FIG. 36 illustrates an alternative comb transducer formed on a substrate in accordance with an embodiment of the present invention. FIG. 37 illustrates a touch sensor with a transducer formed on the outer periphery of the touch surface in accordance with an aspect of the present invention. FIG. 38 illustrates an alternative touch sensor formed in accordance with aspects of the present invention. FIG. 39 shows a waveguide arranged to perform signal equalization in accordance with an aspect of the present invention. FIG. 40 illustrates a waveguide configured to perform signal equalization in accordance with an aspect of the present invention. FIG. 41 illustrates another embodiment of a touch sensor formed in accordance with an embodiment of the present invention. FIG. 42 illustrates a touch sensor incorporating a strip in accordance with an embodiment of the present invention. FIG. 43 illustrates a touch sensor with a transducer on the side wall of the substrate in accordance with an embodiment of the present invention.

Claims (8)

A touch sensor capable of propagating an acoustic wave, comprising a substrate including a first surface having a touch detection region, and a transducer formed on the substrate,
The transducer includes a piezoelectric ceramic element that is heat-cured after being provided on the substrate, and the transducer is configured to perform at least one of generation of elastic waves or detection of elastic waves. ,Touch sensor. The touch sensor according to claim 1, wherein the piezoelectric ceramic element is formed on the substrate by using either screen printing or pad printing. The substrate further includes a second surface parallel to the first surface, the transducer further includes a lattice element formed on the first surface, and the piezoelectric ceramic element is arranged to face the lattice element. The touch sensor according to claim 1, wherein the touch sensor is formed on two surfaces. The touch sensor according to claim 1, wherein the transducer further includes a lattice element formed on the first surface, and a piezoelectric ceramic element is formed on the lattice element. The transducer
A first conductive layer formed on the substrate;
A second conductive layer comprising a piezoelectric ceramic element formed on the first conductive layer;
And further comprising a third conductive layer formed on the second conductive layer,
The touch sensor according to claim 1, wherein the first conductive layer and the third conductive layer are connected to each other using the first electrical connection portion and the second electrical connection portion. A first layer in which a transducer is formed on a substrate;
A second conductive layer formed on the first layer; and a third conductive layer formed on the second layer;
The first layer and the ground connection portion are connected to each other, the second layer includes a piezoelectric ceramic element, and the third conductive layer includes a first electrode and a second electrode. The touch sensor according to claim 1, wherein the second electrode, the first electrical connection portion, and the second electrical connection portion are connected to each other.   The touch sensor according to claim 1, wherein the substrate forms an outer layer of the display device. The transducer
A first conductive layer formed on the substrate;
A second conductive layer comprising a piezoelectric ceramic element formed on the first conductive layer;
A third conductive layer formed on the second conductive layer; and a fourth modulation layer formed on the third conductive layer and comprising a periodically applied material.
The first conductive layer and the third conductive layer are interconnected with electrical connections, also
The touch sensor according to claim 1, wherein the periodically applied material of the fourth modulation layer comprises a resonance material, a phase shift material, or an absorption material .

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