JP2007065799A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a touch panel device whose detecting sensitivity for detecting the contact of an object is high. <P>SOLUTION: The touch panel device 1 shown by figure 1 is provided with a substrate 2; a transmission part 3X and a transmission part 3Y for generating an acoustic surface wave; a reception part 4X and a reception part 4Y for receiving the acoustic surface wave and a reflector 5X and a reflector 5Y for reflecting the acoustic surface wave. The reflector 5X for reflecting an acoustic surface wave generated from the transmission part 3X to the second side faced to the first side is installed along the first side among four sides of the substrate 2 and the reception part 4X for receiving the acoustic surface wave reflected by the reflector 5X is installed along the second side. Also, the reflector 5Y for reflecting the surface acoustic wave generated by the transmission part 3Y to the fourth side faced to the third side is installed along the third side adjacent to the first side of the substrate 2. The reception part 4Y for receiving the surface acoustic wave reflected by the reflector 5Y is installed along the fourth side. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a touch panel device.

For example, it is mounted on a display device such as a liquid crystal display of an electronic device, and by touching the surface of the touch panel with a fingertip or other object according to the display content, the contact position is specified and various operations and input of the electronic device are performed. A touch panel device is known.
Various methods have been proposed for driving the touch panel device, and as one of them, a surface acoustic wave type touch panel device has been proposed (for example, see Patent Document 1).

A surface acoustic wave type touch panel device is a surface acoustic wave (SAW: Surface Acoustic Wave) excited on a substrate, and the surface acoustic wave generated by contacting (touching) the substrate with a fingertip or an object. It has a function of detecting a touch position by detecting a change in intensity.
The touch panel device detects an X-direction transmission unit that generates a first surface acoustic wave for detecting the X-direction touch position on the substrate, and a Y-direction touch position substantially orthogonal to the X direction. A Y-direction transmitter for generating a second surface acoustic wave, an X-direction receiver for receiving the first surface acoustic wave, and a Y-direction receiver for receiving the second surface acoustic wave, respectively. Is provided.

The upper surface of the substrate becomes the touch surface, and the first surface acoustic wave and the second surface acoustic wave are attenuated, that is, the intensity is changed by the contact of the fingertip or the like. By receiving this intensity change by the X direction receiving unit and the Y direction receiving unit and converting it into position information, the contact position of the fingertip or the like can be specified.
Such a touch panel device includes a reflector that reflects the first surface acoustic wave and the second surface acoustic wave, respectively. This reflector is configured to change the propagation direction of the surface acoustic wave to a substantially right angle twice. That is, the propagation directions of the first surface acoustic wave and the second surface acoustic wave are finally changed by 180 °.
However, mainly in the second reflection, part of the surface acoustic wave is transmitted through the reflector and the surface acoustic wave leaks out of the substrate, and the X direction receiving unit and the Y direction receiving unit receive the elasticity. There is a problem that surface waves are attenuated. As a result, the detection sensitivity of the change in the intensity of the surface acoustic wave due to contact with an object or the like is lowered, and it may be difficult to specify the touch position.

JP-A 61-239322

  An object of the present invention is to provide a touch panel device having high detection sensitivity for detecting contact of an object.

Such an object is achieved by the present invention described below.
The touch panel device of the present invention is a touch panel device that has a touch surface and detects the touch position of an object that contacts the touch surface,
A substrate that is rectangular or square and propagates the first and second surface acoustic waves;
A first transmitter that is provided at one end of a first side of the four sides of the substrate and that generates the first surface acoustic wave toward the other end of the first side;
A first reflection provided along the first side and configured to reflect the first surface acoustic wave generated from the first transmission unit toward a second side opposite to the first side. And
A first receiver provided along the second side for receiving the first surface acoustic wave;
A second transmitter that is provided at one end of a third side adjacent to the first side and generates the second surface acoustic wave toward the other end of the third side;
A second reflection provided along the third side and configured to reflect the second surface acoustic wave generated from the second transmission unit toward a fourth side opposite to the third side. And
A second receiving unit provided along the fourth side for receiving the second surface acoustic wave;
A power supply unit that applies a high-frequency voltage to operate the first transmission unit and the second transmission unit;
A detecting unit for detecting a temporal change in intensity of the first surface acoustic wave received by the first receiving unit and a temporal change in intensity of the second surface acoustic wave received by the second receiving unit; ,
And a control unit having a function of specifying the touch position based on a detection result of the detection unit.
Thereby, a touch panel device with high detection sensitivity for detecting contact of an object is obtained.

In the touch panel device according to the aspect of the invention, it is preferable that each of the first transmission unit and the second transmission unit includes a surface acoustic wave element.
Since surface acoustic wave elements can easily and reliably set conditions such as frequency characteristics of surface acoustic waves to be generated, the conditions of surface acoustic waves generated from each surface acoustic wave element can be adjusted with high accuracy. it can. As a result, a touch panel device with excellent touch position detection accuracy can be obtained. In addition, since the surface acoustic wave element can be made very thin, the touch panel device can be made thinner and lighter.
In the touch panel device according to the aspect of the invention, it is preferable that each of the first reception unit and the second reception unit is configured by a surface acoustic wave element.
Since the surface acoustic wave element itself can be made very thin, the touch panel device can be made thinner and lighter.

In the touch panel device of the present invention, it is preferable that at least one of the first receiving unit and the second receiving unit is configured by connecting a plurality of surface acoustic wave elements in parallel.
Thereby, for example, a decrease in the reception sensitivity of the first receiving unit or the second receiving unit due to variations in the electrode width, the inter-electrode distance, the electrode electrical resistance, etc. in the pair of electrode fingers is reduced for each constituent unit. It is possible to disperse, and it is possible to suppress a decrease in reception sensitivity of the entire receiving unit. In other words, when a predetermined reception sensitivity is obtained, it is possible to expand an allowable range of variations such as electrode width, distance between electrodes, and electric resistance of the electrodes. As a result, the first receiver or the second receiver can be manufactured more easily and reliably.

In the touch panel device according to the aspect of the invention, it is preferable that the surface acoustic wave element includes a piezoelectric layer and a pair of electrodes that are arranged to face each other via the piezoelectric layer and apply a voltage to the piezoelectric layer.
The surface acoustic wave device having such a configuration can efficiently generate surface acoustic waves even when the distance between electrode fingers of the electrodes is relatively wide.
In the touch panel device according to the aspect of the invention, the surface acoustic wave element includes a piezoelectric layer and a pair of comb-like electrodes that are provided on one surface of the piezoelectric layer and apply a voltage to the piezoelectric layer. It is preferable.
The surface acoustic wave device having such a configuration can efficiently generate a surface acoustic wave having a relatively high strength.

In the touch panel device according to the aspect of the invention, at least one of the surface acoustic wave element included in the first transmission unit and the surface acoustic wave element included in the second transmission unit may generate elasticity in one direction to generate the surface acoustic wave. It is preferable that the intensity of the surface wave is larger than the intensity of the surface acoustic wave generated in the direction opposite to the one direction.
Thereby, a stronger surface acoustic wave can be generated without changing the voltage applied to the piezoelectric layer. As a result, it is possible to improve the detection sensitivity of the touch panel device while maintaining power consumption.

In the touch panel device according to the aspect of the invention, at least one of the surface acoustic wave element included in the first transmission unit and the surface acoustic wave element included in the second transmission unit is a reflective array on the side opposite to the side that generates the surface acoustic wave. It is preferable to provide.
Thereby, a stronger surface acoustic wave can be generated.
In the touch panel device according to the aspect of the invention, at least one of the surface acoustic wave element included in the first reception unit and the surface acoustic wave element included in the second reception unit is a reflective array on the side opposite to the side receiving the surface acoustic wave. It is preferable to provide.
Thereby, the receiving sensitivity of a 1st receiving part or a 2nd receiving part can be improved.

In the touch panel device of the present invention, the piezoelectric layer is preferably a thin film.
Thereby, it is suitably applied when a piezoelectric material that is difficult to obtain a large single crystal is used as the constituent material of the piezoelectric layer. For this reason, it is possible to adjust the oscillation frequency of the first transmission unit or the second transmission unit over a wider range by using piezoelectric materials having a wide variety of piezoelectric characteristics (for example, propagation speed of surface acoustic waves). it can.

In the touch panel device of the present invention, it is preferable that the piezoelectric layer is composed mainly of at least one of zinc oxide, aluminum nitride, and lead zirconate titanate.
Such a material can form a uniform crystal thin film relatively easily. In addition, since these materials have a relatively high propagation speed of surface acoustic waves, a touch panel device with a high response speed can be obtained.

In the touch panel device of the present invention, it is preferable that the first receiving unit and the second receiving unit share a bias electrode.
Thereby, compared with the case where a bias electrode is not shared, the wiring pattern of a receiving wiring can be simplified, and the degree of freedom in designing a touch panel device can be increased. As a result, the frame portion of the touch panel device can be reduced, and the effective touch area can be enlarged.
In the touch panel device according to the aspect of the invention, it is preferable that a time for detecting the first surface acoustic wave and a time for detecting the second surface acoustic wave are time-divided by the detection unit.
Accordingly, it is possible to reliably obtain the position information of the touch position while preventing the electric signal from the first receiving unit and the electric signal from the second receiving unit from being mixed.

In the touch panel device of the present invention, the substrate has a rectangular or square shape, and propagates the first surface acoustic wave and the second surface acoustic wave,
The position specifying means includes a first transmitter that generates the first surface acoustic wave in the substrate;
A second transmitter for generating the second surface acoustic wave having a frequency different from that of the first surface acoustic wave in a direction substantially orthogonal to the first surface acoustic wave;
A first receiver for receiving the first surface acoustic wave;
A second receiver for receiving the second surface acoustic wave;
A second high-frequency voltage having a first frequency capable of generating the first surface acoustic wave is applied to the first transmitter, and a second frequency different from the first frequency capable of generating the second surface acoustic wave. A power supply unit that applies a high-frequency voltage of the frequency to the second transmission unit;
A detecting unit for detecting a temporal change in intensity of the first surface acoustic wave received by the first receiving unit and a temporal change in intensity of the second surface acoustic wave received by the second receiving unit; ,
It is preferable to have a control unit having a function of specifying the touch position based on the detection result of the detection unit.
Accordingly, an X / Y switch can be omitted, and a touch panel device that is small and lightweight and has a simple circuit configuration can be obtained.

In the touch panel device of the present invention, it is preferable that the first transmission unit and the second transmission unit share a bias electrode.
Thereby, the wiring pattern of the power supply wiring can be simplified and the degree of freedom in designing the touch panel device can be increased. As a result, the frame portion of the touch panel device can be reduced, and the effective touch area can be enlarged.

In the touch panel device of the present invention, the surface acoustic wave element preferably generates surface acoustic waves having different frequencies according to the crystal orientation of the thick piezoelectric layer.
Thus, even a surface acoustic wave element made of the same kind of piezoelectric material and having the same width, spacing, thickness, etc., of electrode fingers can have different oscillation frequencies by changing the crystal orientation. Can be obtained.

In the touch panel device of the present invention, the surface acoustic wave element generates an SH wave and a Rayleigh wave according to the crystal orientation of the thick film piezoelectric layer,
It is preferable that either one of the first transmission unit and the second transmission unit generates the SH wave, and the other generates the Rayleigh wave.
Since these oscillation modes are relatively stable modes, they are suitable as surface acoustic waves used in a touch panel device.

In the touch panel device of the present invention, it is preferable that the thick-film piezoelectric layer is composed mainly of quartz.
Since quartz has many useful crystal orientations, an element that generates surface acoustic waves in various oscillation modes (oscillation frequencies) can be easily obtained. In addition, there is an advantage that the thermal conductivity is high and the thermal stability at high temperature is excellent. Furthermore, since raw materials are inexpensive, there is also an aspect that large crystals are easily available.

In the touch panel device of the present invention, the power supply unit modulates the frequency of the high-frequency voltage applied to the first transmission unit and the second transmission unit to the first frequency and the second frequency. Accordingly, it is preferable to control the first transmission unit and the second transmission unit so that they can operate exclusively.
Thereby, the switch required conventionally when switching the operating power supplied to the first transmitter and the second transmitter can be omitted, and the manufacturing cost of the touch panel device can be reduced. it can.

Hereinafter, the touch panel device of the present invention will be described in detail with reference to the accompanying drawings.
<First Embodiment>
First, a first embodiment of the touch panel device of the present invention will be described.
FIG. 1 is a schematic view (plan view) showing a first embodiment of the touch panel device of the present invention, FIG. 2 is an enlarged view around the X-direction transmission unit of the touch panel device shown in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line A′-A ′ in the vicinity of the X-direction transmitter, FIG. 4 is a diagram illustrating another configuration example of the X-direction transmitter, and FIG. 5 is an A ″ -around the X-direction transmitter illustrated in FIG. FIG. 6 and FIG. 7 are diagrams showing another configuration example of the X-direction transmission unit, FIG. 8 is a diagram showing another configuration example of the X-direction reception unit, and FIG. 9 is FIG. AA line sectional view of the touch panel device shown, FIG. 10 is a diagram showing an example of the waveform of each surface acoustic wave transmitted from the transmitting unit and received by the receiving unit. In the following, for convenience of explanation, the front side of the page in FIGS. 1, 2, 4 and 6 to 8 is “up”, the back side of the page is “down”, the right side is “right”, and the left side is “left”. ”, The lower side is called“ front ”, the upper side is called“ back ”, the upper side in FIGS. 3, 5 and 9 is“ up ”, the lower side is“ lower ”, the right side is“ right ”, and the left side is“ left ” "The front side of the paper is called" front "and the back side of the paper is called" back ".
A touch panel device 1 shown in FIG. 1 includes a substrate 2, a transmission unit 3 provided on the substrate 2, a reception unit 4, a reflector 5, and a transmission unit 3, a reception unit 4, and a reflector with respect to the substrate 2. 5 and a sheet material 8 provided via 5 and an external device 10 provided outside the substrate 2.

The substrate 2 is rectangular or square.
The substrate 2 and a sheet material 8 described later are substantially transparent (colorless transparent, colored transparent, translucent). Thereby, the display content of the display apparatus etc. which were provided on the opposite side to the sheet | seat material 8 of the board | substrate 2 can be confirmed via the touch panel apparatus 1, for example.
Examples of the display device include a cathode ray tube, a plasma display, a liquid crystal display, and an organic EL display. The display contents include images such as letters, numbers, and figures (including both moving images and still images).

As a constituent material of the substrate 2, resin materials such as polyethylene terephthalate, polyethylene naphthalate, polypropylene, cycloolefin polymer, polyamide, polyether sulfone, polymethyl methacrylate, polycarbonate, polyarylate, quartz glass, soda glass, etc. Glass materials and the like.
Although the average thickness of such a board | substrate 2 is not specifically limited, It is preferable that it is about 0.1-30 mm, and it is more preferable that it is about 0.1-10 mm.

  Note that a transparent substrate included in the display device described above may be used as the substrate 2. In this case, since the substrate 2 is shared by the touch panel device 1 and the display device, the total number of parts including the display device in the touch panel device 1 can be reduced to reduce the weight. Further, since the number of substrates through which light including display content is transmitted decreases, the light transmittance in the touch panel device 1 can be increased.

A substrate 2 shown in FIG. 1 has a rectangular shape in plan view, and serves as a medium through which surface acoustic waves propagate.
A transmitter 3 and a receiver 4 are provided in the vicinity of the corner of the substrate 2.
Among these, the transmission unit 3 generates an X-direction transmission unit (first surface wave) that generates a surface acoustic wave (first surface acoustic wave) for detecting the X-direction touch position of the substrate 2 in the Y direction substantially orthogonal to the X direction. 1 transmission unit) 3X and a Y-direction transmission unit (second transmission unit) 3Y that generates a surface acoustic wave (second surface acoustic wave) for detecting the Y-direction touch position of the substrate 2 in the X direction. It consists of and.

In the present embodiment, the X-direction transmission unit 3X and the Y-direction transmission unit 3Y are provided near both ends of the left side (first side) of the four sides of the substrate 2, respectively.
The X-direction transmitter 3X shown in FIGS. 2 and 3 includes a surface acoustic wave element, and has an IDT (a pair of comb-shaped electrodes) 33 and a piezoelectric layer 32 that are sequentially stacked on the substrate 2. is doing. That is, the X-direction transmission unit 3 </ b> X has the IDT 33 provided on the lower surface (one surface) of the piezoelectric layer 32. The X-direction transmitter 3X having such a configuration can efficiently generate a surface acoustic wave having a relatively high strength.
Such an X-direction transmission unit 3X applies a high-frequency voltage to the piezoelectric layer 32 by an IDT (Interdigital Transducer) 33, thereby causing displacement on the surface of the piezoelectric layer 32 due to the reverse piezoelectric effect. The first surface acoustic wave is generated from the front side end of the left side of the left side toward the back side end.

The IDT 33 shown in FIG. 2 and FIG. 3 includes two pairs of electrode fingers 332 and 333 arranged side by side at substantially equal intervals. By setting the widths and thicknesses of the electrode fingers 332 and 333, the distance d _X between the adjacent electrode fingers 332 and the electrode fingers 333, the composition of the piezoelectric layer 32 described later, the crystal orientation, and the like, transmission in the X direction is performed. The frequency characteristics and the like of the first surface acoustic wave generated from the portion 3X can be adjusted to a desired one.

  Further, the number of electrode fingers 332 and 333 of the IDT 33 is not particularly limited. However, when a pair of electrode fingers 332 and one electrode finger 333 is formed, about 5 to 50 pairs are preferable, and 20 to 40 are preferable. The degree of pairing is more preferable. In the IDT 33, generally, the amount of energy dissipation changes in accordance with the number of electrode fingers 332 and 333. Specifically, the greater the number of electrode fingers 332 and 333, the smaller the energy dissipation amount. Conversely, the smaller the number of electrode fingers 332 and 333, the greater the energy dissipation amount. For this reason, by making the number of the pair of electrode fingers 332 and 333 within the above range, the energy dissipation amount can be surely reduced, and a surface acoustic wave with sufficient amplitude can be generated, and the detection sensitivity of the touch panel device 1 can be lowered. Can be prevented. In addition, the area occupied by the IDT 33 can be optimized, and a sufficient touch effective area can be secured.

In the present embodiment, the electrode finger 332 and the electrode finger 333 are provided at substantially equal intervals, but there may be a portion where the interval changes.
Examples of the constituent material of IDT33 include Al, Cu, W, Mo, Ti, Au, Y, Pb, Sc, Cr, and alloys containing these, and one or more of these are combined. (For example, as a laminate).

The piezoelectric layer 32 has piezoelectric characteristics, and has a function of causing displacement near the surface due to the inverse piezoelectric effect when a high-frequency voltage is applied via the IDT 33. Conversely, when displacement occurs in the piezoelectric layer 32, a potential difference is generated in the IDT 33 due to the piezoelectric effect.
When the frequency of the high-frequency voltage applied to the piezoelectric layer 32 satisfies the resonance conditions of the X-direction transmission unit 3X determined by various conditions of the IDT 33 and the piezoelectric layer 32, the X-direction transmission unit 3X causes the first elasticity. A standing wave of a surface wave can be generated particularly efficiently.
Examples of such a piezoelectric layer 32 include those in the form of a thin film or a bulk. Hereinafter, the piezoelectric layer 32 will be sequentially described for each form.

I. When the piezoelectric layer 32 is formed of a thin film This configuration is suitably applied when a piezoelectric material that is difficult to obtain a large single crystal is used as the constituent material of the piezoelectric layer 32. For this reason, the oscillation frequency of the X-direction transmitting unit 3X can be adjusted in a wider range by using piezoelectric materials having various piezoelectric characteristics (for example, propagation speed of surface acoustic waves).

Specific examples of the piezoelectric material include zinc oxide, aluminum nitride, lithium tantalate, lithium niobate, potassium niobate, lead zirconate titanate (PZT), barium titanate, and various other materials. One of these or a combination of two or more thereof can be used, and in particular, a material mainly containing at least one of zinc oxide, aluminum nitride, and lead zirconate titanate is preferable. Such a material can form a uniform crystal thin film relatively easily. Moreover, since these materials have a relatively high propagation speed of surface acoustic waves, the touch panel device 1 having a high response speed can be obtained.
The average thickness of the piezoelectric layer 32 is not particularly limited, but is preferably about 1 to 20 μm, and more preferably about 2 to 10 μm. Thereby, a surface acoustic wave having an amplitude necessary and sufficient for detecting the touch position of the touch panel device 1 can be obtained.

II. When Piezoelectric Layer 32 is Configured in Bulk This configuration is preferably applied when a piezoelectric material that can easily obtain a large single crystal is used as the constituent material of the piezoelectric layer 32.
The bulk (single crystal) piezoelectric material can obtain piezoelectric layers 32 having different crystal orientations by setting the cutting angle. Since the piezoelectric characteristics of the piezoelectric layer 32 differ depending on the crystal orientation, even if the piezoelectric material is of the same type, one having different piezoelectric characteristics can be obtained by selecting the crystal orientation. This makes it easier to set the crystal orientation to make the oscillation frequency easier even for surface acoustic wave elements made of the same kind of piezoelectric material and having the same width, spacing, thickness, etc. of electrode fingers. Can be adjusted.

The bulk piezoelectric layer 32 is preferably capable of oscillating surface acoustic waves in a plurality of oscillation modes. Thereby, a surface acoustic wave in an oscillation mode suitable for the operation of the touch panel device can be easily selected.
Examples of surface acoustic wave oscillation modes include Rayleigh waves, SH waves, Lamb waves, creeping waves, and the like. Among these, it is preferable that the piezoelectric layer 32 used in the X direction transmission unit 3X can generate Rayleigh waves and SH waves according to the crystal orientation. Since these oscillation modes are relatively stable modes, they are suitable as surface acoustic waves used in the touch panel device 1.

  Examples of such piezoelectric materials include quartz, sapphire, lithium borate, aluminum phosphate, tellurium oxide, potassium niobate, and various other materials, and one or more of these are combined. In particular, it is preferable to use quartz. Since quartz has many useful crystal orientations, an element that generates surface acoustic waves in various oscillation modes (oscillation frequencies) can be easily obtained. In addition, there is an advantage that the thermal conductivity is high and the thermal stability at high temperature is excellent. Furthermore, since raw materials are inexpensive, there is also an aspect that large crystals are easily available.

In this case, the average thickness of the piezoelectric layer 32 is not particularly limited, but is preferably about 10 to 500 μm, more preferably about 20 to 400 μm. Thereby, the amplitude of the surface acoustic wave necessary and sufficient for detecting the touch position of the touch panel device 1 can be obtained.
The Y-direction transmission unit 3Y has the same configuration as the X-direction transmission unit 3X as described above. That is, the Y-direction transmission unit 3Y includes an IDT 33 and a piezoelectric layer 32 that are sequentially stacked on the substrate 2.

Such a Y-direction transmitter 3Y applies a high-frequency voltage to the piezoelectric layer 32 via the IDT 33, thereby causing displacement on the surface of the piezoelectric layer 32 due to the reverse piezoelectric effect, and the back side of the substrate 2 ( A second surface acoustic wave is generated from the left end of the third side adjacent to the first side toward the right end.
In the Y-direction transmitter 3Y, as in the X-direction transmitter 3X, the frequency of the high-frequency voltage applied to the piezoelectric layer 32 is determined by various conditions of the piezoelectric layer 32 and the IDT 33. If the resonance condition is satisfied, the standing wave of the second surface acoustic wave can be generated particularly efficiently from the Y-direction transmitter 3Y.

Further, the X direction transmission unit 3X and the Y direction transmission unit 3Y are each connected to an X / Y switch 12 described later via a power supply wiring 6.
The power supply wiring 6 is made of various conductive materials, but is preferably made of the same material as the IDT 33 and formed integrally with the IDT 33. Thereby, in the manufacturing process of the touch panel device 1 to be described later, the power supply wiring 6 and the IDT 33 can be formed at the same time, and the manufacturing process can be simplified.

  The X-direction transmission unit 3X and the Y-direction transmission unit 3Y include a flat plate-like lower electrode 31, a piezoelectric layer 32 ′, and an IDT (upper electrode having a comb shape or a comb shape) 33 on the substrate 2, respectively. A configuration like the X-direction transmitting unit 3X ′ shown in FIGS. In other words, the X-direction transmitting unit 3X ′ includes a piezoelectric layer 32 ′, a lower electrode 31 and an IDT 33 ′ (a pair of electrodes) that are disposed to face each other with the piezoelectric layer 32 interposed therebetween. The X-direction transmitter 3X ′ having such a configuration can efficiently generate surface acoustic waves even if the distance between the electrode fingers of the IDT 33 ′ is relatively wide.

Such an X-direction transmitter 3X ′ applies a high-frequency voltage between the lower electrode 31 and the IDT 33 ′, thereby causing a displacement due to the inverse piezoelectric effect on the surface of the piezoelectric layer 32 ′, and the first elasticity. It generates surface waves.
As shown in FIGS. 4 and 5, the IDT 33 ′ includes a plurality of electrode fingers 331 provided at approximately equal intervals. By setting the width and thickness of the electrode fingers 331, the distance d _X between adjacent electrode fingers 331, the composition of the piezoelectric layer 32 ′, the crystal orientation, and the like, the first generated from the X-direction transmitter 3X ′ The characteristics such as the oscillation frequency of the surface acoustic wave can be adjusted to a desired one.
The lower electrode 31 can be made of the same material as the IDT 33 ′.

By the way, it is preferable that at least one of the X-direction transmission unit 3X and the Y-direction transmission unit 3Y includes the reflection array 35 on the side opposite to the side that generates the surface acoustic wave.
In the IDT 33 of FIG. 6, the surface acoustic wave is generated toward the back side, and thus the reflective array 35 is provided on the front side of the IDT 33. The IDT 33 normally generates surface acoustic waves on both the back side and the near side in FIG. Then, by providing the reflective array 35 on the front side of the IDT 33 as shown in FIG. 6, the surface acoustic wave propagating from the IDT 33 toward the reflective array 35 is reflected by the reflective array 35 and propagates to the back side. Thereby, a stronger surface acoustic wave can be generated from the X-direction transmitter 3X.

  At this time, it is preferable to set the position of the reflective array 35 so that the surface acoustic wave generated from the IDT 33 toward the back side and the reflected wave reflected by the reflective array 35 are in phase with each other. As a result, the surface acoustic wave and the reflected wave are combined, and a surface acoustic wave having higher strength can be generated. As a result, the detection sensitivity of the touch panel device 1 can be improved.

The reflection array 35 is configured by arranging a plurality of electrode fingers 334 at a predetermined interval. These electrode fingers 334 are provided at intervals satisfying a condition that causes Bragg reflection in the surface acoustic wave, for example.
In addition, at least one of the X-direction transmission unit 3X and the Y-direction transmission unit 3Y has a surface acoustic wave intensity that is generated in a direction opposite to the one direction. It is preferable to be configured to be greater than the strength.

  The IDT 33 ″ shown in FIG. 7 is configured such that the number of electrode fingers 333 is larger than the number of electrode fingers 332. In the IDT 33 ″ having such a configuration, the IDT 33 ″ is arranged in a predetermined direction, here in the back of FIG. The intensity of the surface acoustic wave generated toward the front is stronger than the intensity of the surface acoustic wave generated toward the near side. Thereby, a stronger surface acoustic wave can be generated without changing the voltage applied to the piezoelectric layer 32. As a result, it is possible to improve the detection sensitivity of the touch panel device 1 while maintaining power consumption.

The receiving unit 4 includes an X-direction receiving unit (first receiving unit) 4X that receives the first surface acoustic wave generated from the X-direction transmitting unit 3X, and a second surface acoustic wave generated from the Y-direction transmitting unit 3Y. And a Y-direction receiving unit (second receiving unit) 4Y.
As shown in FIG. 1, the X-direction receiving unit 4 </ b> X is provided along the right side of the substrate 2 (second side facing the first side).
The X-direction receiving unit 4X includes a surface acoustic wave element, and includes an IDT 43 and a piezoelectric layer (not shown) that are sequentially stacked on the substrate 2.

  The IDT 43 shown in FIG. 1 includes two pairs of comb-like electrode fingers 432 and 433 that are provided at approximately equal intervals. The pair of electrode fingers 432 and 433 are disposed along substantially the entire length of the right side of the substrate 2. By setting the widths and thicknesses of the electrode fingers 432 and 433, the distance between the adjacent electrode fingers 432 and the electrode fingers 433, the composition of the piezoelectric layer, the crystal orientation, etc., the X-direction receiving unit 4X mainly Characteristics such as receivable frequency can be adjusted to a desired one.

  Further, the number of electrode fingers 432 and 433 is not particularly limited. However, when one electrode finger 332 and one electrode finger 333 are paired, about 5 to 50 pairs are preferable, and about 20 to 40 pairs are more preferable. By making the number of the pair of electrode fingers 432 and 433 within the above range, the amount of energy dissipation can be surely reduced, and a surface acoustic wave with sufficient amplitude can be generated to prevent a decrease in detection sensitivity of the touch panel device 1. be able to. In addition, the area occupied by the IDT 43 can be optimized, and a sufficient touch effective area can be secured.

In the present embodiment, the electrode fingers 432 and the electrode fingers 433 are provided at substantially equal intervals, but the touch panel device of the present invention is not limited to such a configuration. That is, it may be provided such that the interval changes partially. Further, the numbers of the electrode fingers 432 and the electrode fingers 433 may be different from each other, and the numbers are not particularly limited.
Such an IDT 43 is made of the same material as the IDT 33 described above.
The piezoelectric layer is also made of the same material as that of the piezoelectric layer 32 described above.

As shown in FIG. 1, the Y-direction receiving unit 4 </ b> Y is provided along the front side of the substrate 2 (the fourth side facing the third side).
The Y direction receiving unit 4Y also has the same configuration as the X direction receiving unit 4X. That is, the Y-direction receiving unit 4Y includes an IDT 43 and a piezoelectric layer that are sequentially stacked on the substrate 2, and the IDT 43 includes two pairs of comb-like electrode fingers 432 and 433. By setting the width and thickness of the pair of electrode fingers 432 and 433, the distance between the adjacent electrode fingers 432 and the electrode fingers 433, the composition of the piezoelectric layer, the crystal orientation, etc., the Y-direction receiving unit 4Y It is possible to adjust characteristics such as receivable frequency to a desired one.
As shown in FIG. 8, at least one of the X-direction receiving unit 4X and the Y-direction receiving unit 4Y preferably includes a reflection array 45 on the side opposite to the surface receiving the surface acoustic wave.

  For example, the X-direction receiving unit 4X in FIG. 8 includes a reflective array 45 on the right side of the IDT 43 in order to receive a surface acoustic wave propagating from the left side of the IDT 43. Thereby, when the surface acoustic wave propagating from the left side of the IDT 43 unintentionally passes through the IDT 43, the surface acoustic wave can be reflected by the reflection array 45 and returned to the IDT 43. The reception sensitivity can be improved.

Similarly to the X direction receiver 4X, the Y direction receiver 4Y can also improve the reception sensitivity of the IDT 43 by including the reflective array 45.
The reflection array 45 is configured by arranging a plurality of electrode fingers 434 at a predetermined interval. For example, the electrode fingers 434 are provided at intervals satisfying a condition that causes Bragg reflection in the surface acoustic wave.

  Moreover, it is preferable that the reflective array 45 is configured to have partially different reflectivities in the longitudinal direction. Normally, the surface acoustic wave that reaches the back side of the reflective array 45 is more attenuated because the propagation path length is longer than the surface acoustic wave that reaches the near side. Therefore, in such a case, the reflection array 45 is configured such that the portion of the reflection array 45 located on the back side has a higher reflectance, thereby averaging the variation in the intensity of the surface acoustic wave due to the difference in the path length to obtain the IDT 43. A substantially uniform reception sensitivity can be obtained over the entire length of the.

The X direction receiving unit 4X and the Y direction receiving unit 4Y are each connected to an X / Y switch 15 to be described later via a receiving wiring 7.
The receiving wiring 7 is made of the same material as that of the power feeding wiring 6 described above, but is preferably formed integrally with the IDT 43 in particular. Thereby, in the manufacturing method of the touch panel device 1 described later, the receiving wiring 7 and the IDT 43 can be formed at the same time, and the manufacturing process can be simplified.

  In the present embodiment, a case has been described in which all of the X-direction transmission unit 3X, the Y-direction transmission unit 3Y, the X-direction reception unit 4X, and the Y-direction reception unit 4Y are configured by surface acoustic wave elements. The X direction transmission unit 3X and the Y direction transmission unit 3Y may be configured by surface acoustic wave elements, and the remaining ones may be configured by other means for generating surface acoustic waves. Further, the X-direction receiving unit 4X and the Y-direction receiving unit 4Y may be constituted by surface acoustic wave elements, and the remaining ones may be constituted by other surface acoustic wave elements. Since surface acoustic wave elements can easily and reliably set conditions such as frequency characteristics of surface acoustic waves to be generated, the conditions of surface acoustic waves generated from each surface acoustic wave element can be adjusted with high accuracy. it can. As a result, a touch panel device with excellent touch position detection accuracy can be obtained.

In addition, since the surface acoustic wave element can be made very thin, the touch panel device can be made thinner and lighter.
A reflector 5 is provided on the substrate 2. The reflector 5 includes a first reflector 5X provided along the left side of the substrate 2 and a second reflector 5Y provided along the back side.

The first reflector 5X has a function of reflecting the first surface acoustic wave generated from the X-direction transmitting unit 3X at a substantially right angle toward the right side.
Similarly, the second reflector 5Y has a function of reflecting the second surface acoustic wave generated from the Y-direction transmitter 3Y substantially at right angles toward the front side.
In the first reflector 5X and the second reflector 5Y, a large number of reflective elements having reflective surfaces inclined by approximately 45 ° with respect to the side of the substrate 2 are provided at predetermined intervals (intervals that satisfy the Bragg reflection condition). ), And a reflection element group configured by the arrangement.

The reflective element group has a reflective surface, and is configured to reflect a part of the surface acoustic wave that has reached the reflective surface and transmit the remaining part. As a result, the surface acoustic wave is branched by each reflecting element and propagates so as to scan the X direction and the Y direction of the substrate 2 uniformly.
In this case, since the path length of the surface acoustic wave reflected for each reflection element is different, the surface acoustic wave reflected by each reflection element has a time difference corresponding to this path length difference, and each receiving unit 4X, 4Y. Will be reached. With this time difference, position information for specifying the touch position can be obtained in the detection unit and the control unit described later. In addition, the area | region where the surface acoustic wave of the board | substrate 2 propagates becomes an area | region which can detect a touch position, ie, a touch effective area | region.

  In this way, after the surface acoustic wave is generated, it is configured to be received through only one reflection at a right angle, so that the elastic surface associated with the reflection is compared with the case where the conventional two reflections are performed. Wave attenuation can be reduced. As a result, the surface acoustic wave is received in a relatively high intensity state, so that it is possible to more easily detect the intensity change of the surface acoustic wave due to the contact of an object or the like with the touch surface. it can. As a result, the detection sensitivity of the touch panel device 1 can be improved.

The constituent material of the reflector 5 is not particularly limited, and is made of, for example, the same material as the power supply wiring 6 and the reception wiring 7 described above.
A sheet material 8 is provided above the transmitter 3, the receiver 4, and the reflector 5 on the substrate 2.
The sheet material 8 is normally provided in a state where a predetermined interval is maintained by a spacer (not shown) or the like so as not to contact the substrate 2.

  In the present embodiment, when the touch panel device 1 is operated (touched), the upper surface of the sheet material 8 functions as a touch surface. That is, when the sheet material 8 bends downward and the sheet material 8 comes into contact with the substrate 2, the surface acoustic wave that passes through the portion corresponding to the touch position of the substrate 2 can be attenuated. As a result, the touch position can be specified by a detection unit described later.

The sheet material 8 is preferably composed of an elastic member. Specific examples of the elastic member include a resin material and a glass material similar to the constituent material of the substrate 2, or a material combining these materials.
The sheet material 8 may be provided as necessary and can be omitted. In this case, the upper surface of the substrate 2 can be operated as a touch surface.

As shown in FIG. 9, a plurality of protrusions 9 are provided on the lower surface of the sheet material 8.
The protrusion 9 is displaced downward when the upper surface of the sheet material 8 is pressed by a fingertip or the like (operating the touch panel device 1) and the sheet material 8 is bent downward. Thereby, the protrusion 9 can contact the upper surface of the substrate 2 preferentially. The protrusions 9 that are in contact with the upper surface of the substrate 2 can surely attenuate the surface acoustic waves that propagate through the substrate 2.
Further, in this case, by setting the area where the protrusion 9 contacts the substrate 2 to be small, the protrusion 9 preferentially contacts the substrate 2 even when the contact surface of the object contacting the upper surface of the sheet material 8 is relatively large. In order to make contact, the touch position can be specified more accurately.

  The external device 10 includes a high-frequency power source (power supply unit) 11 that supplies operating power to the transmission unit 3 via the power supply wiring 6, and an X / Y switch provided between the high-frequency power source 11 and the transmission unit 3. 12, a detection unit 13 that receives an electrical signal generated by the reception unit 4 via the reception wiring 7, and an amplification unit 14 that is provided between the reception unit 4 and the detection unit 13 and amplifies the electrical signal. Control which calculates the position information which the fingertip or the object etc. contact based on the result of the electric signal which X / Y switch 15 provided between amplification part 14 and receiving part 4 and detection part 13 received Part 16.

The high-frequency power source 11 can generate a high-frequency voltage having a frequency corresponding to the frequency characteristic of each surface acoustic wave element in the X-direction transmitter 3X and the Y-direction transmitter 3Y.
The X / Y switch 12 has a function of switching the operating power supplied from the high-frequency power supply 11 between the X-direction transmitter 3X and the Y-direction transmitter 3Y. As a result, the X-direction transmission unit 3X and the Y-direction transmission unit 3Y are controlled to generate the first surface acoustic wave and the second surface acoustic wave exclusively from each other.

The X / Y switch 15 includes an electric signal generated when the X-direction receiving unit 4X receives the first surface acoustic wave, and an electric signal generated when the Y-direction receiving unit 4Y receives the second surface acoustic wave. And has a function of transmitting to the amplifying unit 14.
The amplifying unit 14 amplifies the electrical signal generated when the receiving unit 4 receives the surface acoustic wave, and the detecting unit 13 relatively increases the rate of change in the strength of the electrical signal due to the contact of the fingertip or the object. , To make it easier to catch intensity changes.

The detection unit 13 has a function of detecting a change over time in the intensity of the electrical signal amplified by the amplification unit 14.
The control unit 16 is configured to control each operation of the high-frequency power source 11, the X / Y switchers 12 and 15, and the detection unit 13. Thereby, each operation | movement of supply of the operating power of the high frequency power supply 11, switching of the X / Y switchers 12 and 15, and reception of the electric signal of the detection part 13 can be controlled to a desired timing.
As an example of this timing, there is a timing at which the detection unit 13 sets the time for detecting the first surface acoustic wave and the time for detecting the second surface acoustic wave to be divided in time.

  Specifically, first, the X / Y switch 12 is set, and a high-frequency voltage that satisfies the condition for the X-direction transmission unit 3X to generate the first surface acoustic wave from the high-frequency power source 11 is applied to the X-direction transmission unit 3X. Apply to. As a result, a first surface acoustic wave is generated from the X-direction transmitter 3X, and the first surface acoustic wave is received by the X-direction receiver 4X. The electric signal obtained by this reception is detected by the detection unit 13 via the reception wiring 7 by setting the X / Y switch 15.

  Next, the X / Y switch 12 is switched, and a high frequency voltage that satisfies the condition for the Y direction transmission unit 3Y to generate the second surface acoustic wave from the high frequency power supply 11 is applied to the Y direction transmission unit 3Y. Thereby, the 2nd surface acoustic wave is generated from Y direction transmitting part 3Y, and this 2nd surface acoustic wave is received by Y direction receiving part 4Y. The electrical signal obtained by this reception is detected by the detection unit 13 via the reception wiring 7 by switching the X / Y switch 15.

Next, the X / Y switch 12 is switched again, and a high frequency voltage that satisfies the condition for the X direction transmission unit 3X to generate the second surface acoustic wave from the high frequency power supply 11 is applied to the X direction transmission unit 3X. . By repeatedly performing such an operation, it is possible to reliably obtain the position information of the touch position while preventing a mixture of the electric signal from the X direction receiving unit 4X and the electric signal from the Y direction receiving unit 4Y. Then, this position information is transmitted to various electronic devices.
In addition to this, the control unit 16 further includes a calculation unit (not shown) for converting into position information of the touch position based on the change over time of the strength of the electrical signal received by the detection unit 13.

Next, an example of a usage method (action) of the touch panel device 1 as described above will be described.
[1] First, the X / Y switch 12 is set so that the high-frequency power supply 11 and the X-direction transmission unit 3X are energized. Then, a high-frequency voltage that satisfies the condition for causing the X-direction transmission unit 3 </ b> X to generate the first surface acoustic wave is applied to the IDT 33 via the power supply wiring 6. Thereby, the piezoelectric layer 32, the strain in the vicinity of the surface due to the reverse piezoelectric effect occurs, mainly to generate a first surface acoustic wave having a wavelength corresponding to the interval d _X.
Here, as an example of the first surface acoustic wave, a case will be described in which a burst wave (surface acoustic wave) 51 having a waveform as shown in FIG. 10A is generated from the X-direction transmitter 3X.

[2] The burst wave 51 generated in the X-direction transmission unit 3X travels toward the back side in FIG. 1, and a part thereof is reflected by the reflection element group of the first reflector 5X and the remaining part is transmitted. As a result, the burst wave 51 is branched, propagated as the surface acoustic wave 52 in the X direction (right direction) of the substrate 2, and reaches the X direction receiving unit 4X. At this time, when a fingertip or an object touches (touches) the upper surface of the sheet material 8, for example, a received wave 55 including attenuation 54 as shown in FIG. 10A is obtained.
The received wave 55 including the attenuation 54 that has reached the X-direction receiving unit 4 </ b> X causes distortion corresponding to the intensity (amplitude) of the received wave 55 near the surface of the piezoelectric layer 32. This distortion causes a potential difference between the electrode finger 332 and the electrode finger 333 due to the piezoelectric effect of the piezoelectric layer 32. That is, the received wave 55 is converted into an electric signal corresponding to the intensity in the X-direction receiving unit 4X.

[3] Next, the X / Y switch 15 is set so that the X-direction receiver 4X and the detector 13 are energized. As a result, the electrical signal obtained by the X direction receiving unit 4X is transmitted to the detecting unit 13 via the receiving wiring 7, the X / Y switch 15 and the amplifying unit 14. The detection unit 13 detects a temporal change in the intensity of the first surface acoustic wave received by the X direction reception unit 4X. And based on the detection result of this detection part 13, a touch position is specified by the calculating part with which control part 16 is provided. Specifically, for example, the time T _X from the reception start time of the reception wave 55 shown in FIG. 10A to the reception time of the attenuation 54 is converted into a distance in the X direction, and the X coordinate of the touch position is calculated.

[4] Next, the X / Y switch 12 is switched, and a high-frequency voltage that satisfies the condition for the Y-direction transmitter 3Y to generate the second surface acoustic wave is applied to the IDT 33 via the power supply wiring 6. . As a result, a burst wave 61 having a waveform as shown in FIG. 10B is generated from the Y-direction transmitter 3Y.
[5] Hereinafter, similarly to the X direction, the received wave 65 including the attenuation 64 as shown in FIG. 10B is obtained. Then, the detection unit 13 detects the time-dependent change in the intensity of the second surface acoustic wave Y direction receiver 4Y has received, it is possible to calculate the Y coordinate of the touch position from the time T _Y.
As described above, the position information of the touch position is obtained, and various electronic devices can be operated using the position information.

Second Embodiment
Next, a second embodiment of the touch panel device of the present invention will be described.
FIG. 11 is a schematic view (plan view) showing a second embodiment of the touch panel device of the present invention. In the following, for convenience of explanation, the front side in FIG. 11 is referred to as “up”.
Hereinafter, the second embodiment of the touch panel device of the present invention will be described with reference to this figure, but the description will focus on differences from the first embodiment, and the description of the same matters will be omitted.

The touch panel device 1 of the present embodiment is the same as that of the first embodiment except that the configuration of the receiving unit 4 is different.
The X-direction receiving unit 4X ′ shown in FIG. 11 includes a surface acoustic wave element having an IDT 43 ′ and a piezoelectric layer (not shown) stacked in order on the substrate 2, and three such structural units are arranged in parallel. Connected to and configured.

The IDT 43 ′ includes two pairs of electrode fingers 432 and 433 provided at equal intervals.
As described above, the X-direction receiving unit 4X ′ is configured by connecting a plurality of surface acoustic wave elements in parallel, so that the electrode width, the distance between the electrodes, and the electric resistance of the electrodes in the pair of electrode fingers 432 and 433 are obtained. The decrease in the reception sensitivity of the X-direction receiving unit 4X ′ due to such variations can be distributed to each structural unit, and the decrease in the reception sensitivity of the entire X-direction receiving unit 4X ′ can be suppressed.

In other words, when a predetermined reception sensitivity is obtained, an allowable range of variations such as the electrode width, the distance between the electrodes, and the electric resistance of the electrodes in the IDT 43 ′ can be expanded. As a result, the X-direction receiving unit 4X ′ can be manufactured more easily and reliably.
The IDT 43 ′ shown in FIG. 11 is configured by connecting three surface acoustic wave elements. The number of surface acoustic wave elements to be connected depends on the touch position detection accuracy (resolution) required by the touch panel device 1. ) And the like, and is not particularly limited.

Further, the number of electrode fingers 432 and 433 included in the comb electrode of the structural unit is not particularly limited, but is preferably about 5 to 50 pairs, and more preferably about 20 to 40 pairs. Thereby, sufficient detection sensitivity of the touch panel device 1 can be ensured while preventing the area occupied by the IDT 43 ′ from becoming unnecessarily large.
On the other hand, the Y-direction receiving unit 4Y ′ shown in FIG. 11 is configured in the same manner as the X-direction receiving unit 4X ′ except that the number of structural units is four.
In the touch panel device 1 of the second embodiment as described above, the same operations and effects as those of the first embodiment can be obtained.

<Third Embodiment>
Next, a third embodiment of the touch panel device of the present invention will be described.
FIG. 12 is a schematic view (plan view) showing a third embodiment of the touch panel device of the present invention. In the following, for convenience of explanation, the front side in FIG. 12 is referred to as “up”.
Hereinafter, the third embodiment of the touch panel device of the present invention will be described with reference to this figure, but the description will focus on differences from the first and second embodiments, and the description of the same matters will be omitted. To do.
The touch panel device 1 of the present embodiment is the same as that of the first embodiment except that the configuration of the receiving unit 4 is different.

  The receiving unit 4 illustrated in FIG. 12 includes an X-direction receiving unit 4X and a Y-direction receiving unit 4Y. A part of these IDTs 43 are electrically connected and share a bias electrode. Thereby, compared with the case where a bias electrode is not shared, the wiring pattern of the receiving wiring 7 can be simplified, and the degree of freedom in designing the touch panel device 1 can be increased. As a result, the frame portion of the touch panel device 1 can be reduced, and the effective touch area can be increased.

In addition, the number of terminals used for output of electrical signals from the receiving unit 4, that is, the number of parts can be reduced, and the circuit configuration from the receiving unit 4 to the amplifying unit 14 can be simplified.
In the touch panel device 1 of the third embodiment as described above, the same operations and effects as those of the first and second embodiments can be obtained.

<Fourth embodiment>
Next, a fourth embodiment of the touch panel device of the present invention will be described.
FIG. 13 is a schematic view (cross-sectional view) showing a fourth embodiment of the touch panel device of the present invention. In the following, for convenience of explanation, the upper side in FIG. 13 is referred to as “upper” and the lower side is referred to as “lower”.
Hereinafter, the fourth embodiment of the touch panel device of the present invention will be described with reference to this figure, but the description will focus on the differences from the first to third embodiments, and the same matters will not be described. To do.

The touch panel device 1 of the present embodiment is the same as that of the first embodiment except that the configuration of the sheet material is different.
Sheet material 8 'shown in FIG. 13 is comprised by the laminated body which consists of two layers. This laminated body has a glass layer 8a on the upper side and a resin layer 8b on the lower side.
Moreover, the transmission part 3 and the receiving part 4 are provided so that the resin layer 8b may be contacted. And between the sheet | seat material 8 'and the board | substrate 2, it is provided in the state which hold | maintained the predetermined space | interval by the spacer (not shown) etc. so that the transmission part 3 and the receiving part 4 may not contact the board | substrate 2. FIG.

Further, a plurality of protrusions 9 are provided on the upper surface of the substrate 2 as shown in FIG.
In the touch panel device 1 having such a configuration, the surface acoustic wave generated from the transmission unit 3 propagates through the sheet material 8 ′. That is, the sheet material 8 ′ functions as a substrate that propagates surface acoustic waves (first surface acoustic wave and second surface acoustic wave).
Further, when the upper surface of the glass layer 8a is pressed with a fingertip or the like (the touch panel device 1 is operated), the sheet material 8 'is bent downward, and the lower surface of the resin layer 8b is in contact with the protrusion 9. Thereby, the surface acoustic wave propagating through the glass layer 8a can be surely attenuated, and the touch position can be specified more accurately.
In the touch panel device 1 of the fourth embodiment as described above, the same operations and effects as those of the first to third embodiments can be obtained.

<Fifth Embodiment>
Next, a fifth embodiment of the touch panel device of the present invention will be described.
FIG. 14 is a schematic view (plan view) showing a fifth embodiment of the touch panel device of the present invention. In the following, for convenience of explanation, the front side in FIG. 14 is referred to as “up”.
Hereinafter, a touch panel device according to a fifth embodiment of the present invention will be described with reference to this drawing. However, the description will focus on differences from the first to fourth embodiments, and description of similar matters will be omitted. To do.
The touch panel device 1 of the present embodiment is the same as that of the third embodiment except that the configurations of the transmission unit 3, the transmission unit 4, the power supply wiring 6, the reception wiring 7, and the external device 10 are different.
The transmission unit 3 illustrated in FIG. 14 includes an X-direction transmission unit 3X and a Y-direction transmission unit 3Y.

  The frequency of the first surface acoustic wave generated by the X-direction transmitter 3X is different from the frequency of the second surface acoustic wave generated by the Y-direction transmitter 3Y. In this case, the frequency characteristic that can be mainly received by the X-direction receiving unit 4X is matched with the frequency of the first surface acoustic wave, and the frequency characteristic that can be mainly received by the Y-direction receiving unit 4Y is made to be the second surface acoustic wave. Therefore, the first surface acoustic wave generated from the X-direction transmitter 3X is reliably received only by the X-direction receiver 4X, and the second surface wave generated from the Y-direction transmitter 3Y is obtained. The surface acoustic wave is reliably received only by the Y direction receiver 4Y. As a result, it is possible to reliably prevent the reception of the surface acoustic wave from the direction that should not be received, that is, noise, and to increase the detection sensitivity of the touch panel device 1.

Therefore, the electrical signal generated from the reception unit 4 can be selectively detected by the detection unit 13 without switching between the X direction component and the Y direction component. Thereby, the X / Y switch 15 can be omitted, and the number of parts and the manufacturing cost of the touch panel device 1 can be reduced.
Further, the frequency of the high-frequency voltage that satisfies the condition that the X-direction transmitter 3X resonates and generates the first surface acoustic wave is set as the first frequency, and the Y-direction transmitter 3Y resonates to generate the second surface acoustic wave. Assuming that the frequency of the high-frequency voltage that satisfies the condition for generating the second frequency is the second frequency, the X-direction transmission unit 3X and the Y-direction transmission unit 3Y have a high frequency of either the first frequency or the second frequency. It is preferable to apply a voltage. Thereby, these can be selectively operated, without switching a high frequency voltage between X direction transmission part 3X and Y direction transmission part 3Y.

In other words, by setting the frequency of the high-frequency voltage to either the first frequency or the second frequency, the X-direction transmitter 3X and the Y-direction transmitter 3Y generate surface acoustic waves exclusively from each other. Can be controlled. Thereby, the X / Y switch 12 can be omitted, and the number of parts and the manufacturing cost of the touch panel device 1 can be reduced.
Furthermore, in this case, as shown in FIG. 14, the X-direction transmitter 3X and the Y-direction transmitter 3Y can be electrically connected and the bias electrode can be shared. Thereby, compared with the case where a bias electrode is not shared, the wiring pattern of the power supply wiring 6 can be simplified, and the degree of freedom in designing the touch panel device 1 can be increased. As a result, the frame portion of the touch panel device 1 can be reduced, and the effective touch area can be increased.

In addition, the number of terminals used to apply operating power to the transmitter 3, that is, the number of components can be reduced, and the circuit configuration from the high frequency power supply 11 to the transmitter 3 can be simplified.
In the touch panel device 1 of the fifth embodiment as described above, the same operations and effects as those of the first to fourth embodiments can be obtained.

The touch panel device of the present invention has been described based on the illustrated embodiment. However, the present invention is not limited to this, and the configuration of each part constituting the touch panel device is an arbitrary configuration having the same function. Can be substituted. Moreover, other arbitrary components may be added.
In addition, the touch panel device of the present invention may be a combination of any two or more configurations (features) of the above embodiments.

It is the schematic (plan view) which shows 1st Embodiment of the touchscreen apparatus of this invention. FIG. 2 is an enlarged view of the vicinity of an X direction transmission unit of the touch panel device shown in FIG. 1. FIG. 3 is a cross-sectional view taken along line A′-A ′ in the vicinity of the X-direction transmission unit illustrated in FIG. 2. It is a figure which shows the other structural example of a X direction transmission part. FIG. 5 is a cross-sectional view taken along line A ″ -A ″ in the vicinity of the X-direction transmission unit illustrated in FIG. 4. It is a figure which shows the other structural example of a X direction transmission part. It is a figure which shows the other structural example of a X direction transmission part. It is a figure which shows the other structural example of a X direction receiving part. It is the sectional view on the AA line of the touch panel apparatus shown in FIG. It is a figure which shows an example of the waveform of each surface acoustic wave transmitted by the transmission part and received by the receiving part. It is the schematic (plan view) which shows 2nd Embodiment of the touchscreen apparatus of this invention. It is the schematic (plan view) which shows 3rd Embodiment of the touchscreen apparatus of this invention. It is the schematic (sectional drawing) which shows 4th Embodiment of the touchscreen apparatus of this invention. It is the schematic (plan view) which shows 5th Embodiment of the touchscreen apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Touch panel apparatus 2 ... Board | substrate 3 ... Transmission part 3X, 3X '... X direction transmission part 3Y ... Y direction transmission part 4 ... Reception part 4X, 4X' ... X direction reception part 4Y, 4Y ' …… Y direction receiver 5 …… Reflector 5X …… First reflector 5Y …… Second reflector 6 …… Power supply wiring 7 …… Reception wiring 8 …… Sheet material 8a …… Glass layer 8b …… Resin layer 9 …… Projection 10 …… External device 11 …… High frequency power supply 12, 15 …… X / Y switch 13 …… Detection unit 14 …… Amplification unit 16 …… Control unit 31 …… Lower electrode 32, 32 ′ …… piezoelectric layer 33, 33 ′, 33 ″, 43, 43 ′ …… IDT 331-334, 432-434 …… electrode finger 35, 45 …… reflecting array 51, 61 …… burst wave 52 …… Surface acoustic wave 54, 64 …… Attenuation 55, 65 …… Receiving wave

Claims (13)

A touch panel device that has a touch surface and detects a touch position of an object that contacts the touch surface,
A substrate that is rectangular or square and propagates the first and second surface acoustic waves;
A first transmitter that is provided at one end of a first side of the four sides of the substrate and that generates the first surface acoustic wave toward the other end of the first side;
A first reflection provided along the first side and configured to reflect the first surface acoustic wave generated from the first transmission unit toward a second side opposite to the first side. And
A first receiver provided along the second side for receiving the first surface acoustic wave;
A second transmitter that is provided at one end of a third side adjacent to the first side and generates the second surface acoustic wave toward the other end of the third side;
A second reflection provided along the third side and configured to reflect the second surface acoustic wave generated from the second transmission unit toward a fourth side opposite to the third side. And
A second receiving unit provided along the fourth side for receiving the second surface acoustic wave;
A power supply unit that applies a high-frequency voltage to operate the first transmission unit and the second transmission unit;
A detecting unit for detecting a temporal change in intensity of the first surface acoustic wave received by the first receiving unit and a temporal change in intensity of the second surface acoustic wave received by the second receiving unit; ,
A touch panel device comprising: a control unit having a function of specifying the touch position based on a detection result of the detection unit.   The touch panel device according to claim 1, wherein each of the first transmission unit and the second transmission unit includes a surface acoustic wave element.   The touch panel device according to claim 1, wherein each of the first receiving unit and the second receiving unit includes a surface acoustic wave element.   The touch panel device according to claim 3, wherein at least one of the first receiving unit and the second receiving unit is configured by connecting a plurality of surface acoustic wave elements in parallel.   5. The touch panel according to claim 2, wherein the surface acoustic wave element includes a piezoelectric layer and a pair of electrodes that are arranged to face each other via the piezoelectric layer and apply a voltage to the piezoelectric layer. apparatus.   6. The surface acoustic wave element includes a piezoelectric layer and a pair of comb-like electrodes provided on one surface of the piezoelectric layer and applying a voltage to the piezoelectric layer. A touch panel device according to any one of the above.   At least one of the surface acoustic wave element included in the first transmission unit and the surface acoustic wave element included in the second transmission unit has an intensity of the surface acoustic wave generated in one direction in which the surface acoustic wave should be generated. The touch panel device according to claim 6, wherein the touch panel device is configured to be larger than the intensity of the surface acoustic wave generated in a direction opposite to the one direction.   The at least one of the surface acoustic wave element included in the first transmission unit and the surface acoustic wave element included in the second transmission unit includes a reflective array on the side opposite to the side that generates the surface acoustic wave. The touch panel device according to any one of 7 to 7.   The at least one of the surface acoustic wave element provided in the first receiving unit and the surface acoustic wave element provided in the second receiving unit includes a reflective array on the side opposite to the side receiving the surface acoustic wave. The touch panel device according to any one of 8 to 8.   The touch panel device according to claim 5, wherein the piezoelectric layer is a thin film.   The touch panel device according to any one of claims 5 to 10, wherein the piezoelectric layer is composed mainly of at least one of zinc oxide, aluminum nitride, and lead zirconate titanate.   The touch panel device according to claim 1, wherein the first receiving unit and the second receiving unit share a bias electrode. The touch panel device according to any one of claims 1 to 12, wherein a time for detecting the first surface acoustic wave and a time for detecting the second surface acoustic wave are time-divided by the detection unit.

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