JP2007065800A - Touch panel device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and lightweight touch panel device whose circuit is simply configured. <P>SOLUTION: This touch panel device 1 shown by figure 1 is provided with a substrate 2 configuring a rectangle or a square; a transmission part 3 for generating an acoustic surface wave; a reception part 4 for receiving the acoustic surface wave and a reflector 5 for reflecting the acoustic surface wave, and for changing the propagation direction. The transmitter 3 is provided with an X direction transmitting part 3X for generating the first acoustic surface wave for detecting the touch position of the X direction of the substrate 2 and an Y direction transmitting part 3Y for generating the second surface acoustic wave for detecting the touch position of the Y direction which is almost perpendicular to the X direction. The X direction transmitter 3Y and a Y direction transmitting part 3Y are electrically connected, and a bias electrode is shared. Also, the frequency of the first acoustic surface wave is made different from the frequency of the second surface acoustic wave. <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 a fingertip or other object is brought into contact with the touch surface in accordance with display contents, thereby specifying a contact position and performing various operations and inputs of the electronic device 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 is configured to switch the supply of operating power from the high-frequency power source to an X-direction transmission unit and a Y-direction transmission unit using a switch.

In addition, the electric signal generated by receiving the surface acoustic wave by the X direction receiving unit and the Y direction receiving unit is configured to be divided into an X direction component electric signal and a Y direction component electric signal by the switch. ing.
However, in such a configuration, at least two switches are required, and the configuration of a circuit used for power supply and electric signal transmission is complicated, and it is difficult to reduce the size and weight of the touch panel device. There is.

JP-A 61-239322

  An object of the present invention is to provide a touch panel device that is small and lightweight and has a simple circuit configuration.

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 for generating 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; ,
And a control unit having a function of specifying the touch position based on a 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, it is preferable that the first receiving unit and the second receiving unit share a bias electrode.
As a result, the wiring pattern of the receiving 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 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 electrical signal from the first receiving unit and the electrical signal from the second receiving unit from being mixed.
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 the surface acoustic wave element can relatively easily change conditions such as frequency characteristics of the surface acoustic wave to be generated, surface acoustic waves having different frequencies can be easily generated. 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 the surface acoustic wave element includes a thick piezoelectric layer and a pair of electrodes for applying a voltage to the piezoelectric layer.
A surface acoustic wave element having such a configuration can efficiently generate surface acoustic waves.
In the touch panel device according to the aspect of the invention, it is preferable that the surface acoustic wave element 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. For this reason, the manufacturing process of the surface acoustic wave element can be simplified, and the manufacturing cost of these, and thus the manufacturing cost of the touch panel device can be reduced.

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 transmitter and the second transmitter generates the SH wave, and the other generates the Rayleigh wave.
Thereby, even when each electrode pattern is set to be equal in the first transmitter and the second transmitter, surface acoustic waves having different frequencies and different modes can be generated. In such a configuration, the IDT of the first transmission unit and the IDT of the second transmission unit can be formed under the same manufacturing conditions, so that variation in the characteristics of each IDT after formation is suppressed and the manufacturing cost is reduced. Reduction can be achieved.

In the touch panel device of the present invention, it is preferable that the thick film piezoelectric layer is made of quartz as a main material.
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.

In the touch panel device of the present invention, furthermore, a power supply wiring connecting the first transmission unit and the second transmission unit, and the power supply unit,
A receiving wiring connecting the first receiving unit and the second receiving unit and the detecting unit;
Of the four sides of the substrate, the first transmitter is provided along two opposing sides parallel to the direction in which the first surface acoustic wave is generated. A first reflector that changes direction;
A second reflector provided along two opposing sides other than the two sides and changing a propagation direction of the second surface acoustic wave;
It is preferable that at least one of the first reflector and the second reflector is formed integrally with the power supply wiring or the reception wiring.
As a result, the first reflector and the second reflector can be formed closer to the edge side of the substrate, so that the touch effective area can be enlarged. In other words, the width of the frame portion of the touch panel device can be reduced, and the degree of design freedom can be increased.

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.
1 is a schematic diagram (plan view) showing a first embodiment of a touch panel device of the present invention, FIG. 2 is a partially enlarged view of an X-direction transmission unit of the touch panel device shown in FIG. 1, and FIG. FIG. 4 is a diagram illustrating an example of the waveform of each surface acoustic wave transmitted from the transmission unit and received by the reception unit. In the following, for convenience of explanation, the front side of the page in FIGS. 1 and 2 is “up”, the back side of the page is “down”, the right side is “right”, the left side is “left”, and the lower side is “front”. The upper side is called “back”, the upper side in FIG. 3 is called “upper”, and the lower side is called “lower”.

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 edge portion of the substrate 2, respectively.
The X-direction transmitter 3X shown in FIGS. 2 and 3 is composed of a surface acoustic wave element, and is paired with a flat plate-like lower electrode 31, a piezoelectric layer 32, and a lower electrode 31 that are sequentially stacked on the substrate 2. An IDT (an upper electrode having a comb shape or a comb shape) 33 is provided. The surface acoustic wave element 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 transmission unit 3X applies a high-frequency voltage between the lower electrode 31 and an IDT (Interdigital Transducer) 33, thereby causing displacement on the surface of the piezoelectric layer 32 due to the inverse piezoelectric effect, and the first The surface acoustic wave is generated.
Examples of the constituent material of the lower electrode 31 include Al, Cu, W, Mo, Ti, Au, Y, Pb, Sc, Cr, and alloys containing these, and one or more of these may be used. Can be used in combination (for example, as a laminate).
As shown in FIG. 3, the IDT 33 includes a plurality of electrode fingers 331 provided at substantially equal intervals. By setting the width and thickness of the electrode fingers 331, the distance d _X between the adjacent electrode fingers 331, the composition of the piezoelectric layer 32 to be described later, the crystal orientation, etc., the first generated from the X-direction transmitter 3X The frequency characteristics of the surface acoustic wave can be adjusted to a desired one.

  Further, the number of electrode fingers 331 of the IDT 33 is not particularly limited, but is preferably about 10 to 100, and more preferably about 40 to 80. In the IDT 33, generally, the amount of energy dissipation changes in accordance with the number of electrode fingers 331. Specifically, the greater the number of electrode fingers 331, the smaller the energy dissipation amount. Conversely, the smaller the number of electrode fingers 331, the greater the energy dissipation amount. For this reason, by making the number of electrode fingers 331 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. Can do. 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 fingers 331 are provided at substantially equal intervals, but there may be a portion where the interval changes.
The IDT 33 is made of the same material as that of the lower electrode 31 described above.
The piezoelectric layer 32 has a piezoelectric characteristic, and has a function of causing displacement near the surface by the inverse piezoelectric effect when a high frequency voltage is applied between the lower electrode 31 and the IDT 33. . Conversely, when a displacement occurs in the piezoelectric layer 32, a potential difference is generated between the lower electrode 31 and the IDT 33 due to the piezoelectric effect.

When the frequency (first frequency) of the high-frequency voltage applied to the piezoelectric layer 32 satisfies the resonance condition of the X-direction transmitter 3X determined by the various conditions of the lower electrode 31, the piezoelectric layer 32, and the IDT 33, X The standing wave of the first surface acoustic wave can be generated particularly efficiently from the direction transmitter 3X.
Examples of the piezoelectric layer 32 include a thin film or a bulk (thick film). 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. 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. For this reason, simplification of the manufacturing process of the X direction transmission part 3X can be aimed at, and these manufacturing costs and by extension, the manufacturing cost of the touch panel apparatus 1 can be reduced.
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. It is preferable that either one of the X direction transmission unit 3X and the Y direction transmission unit 3Y is configured to generate an SH wave and the other generate a Rayleigh wave. Thereby, even when the electrode patterns of both IDTs 33 are set to be equal, surface acoustic waves having different frequencies and different modes can be generated. In such a configuration, since the IDT 33 of the X-direction transmission unit 3X and the IDT 33 of the Y-direction transmission unit 3Y can be formed under the same manufacturing conditions, variation in the characteristics of each IDT 33 after formation is suppressed and the manufacturing cost is reduced. Reduction can be achieved.

Moreover, 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 transmitting unit 3Y includes the lower electrode 31, the piezoelectric layer 32, and the IDT 33 that are sequentially stacked on the substrate 2.
In the Y-direction transmission unit 3Y, as in the X-direction transmission unit 3X, the frequency of the high-frequency voltage applied to the piezoelectric layer 32 (second frequency) is the lower electrode 31, the piezoelectric layer 32, and the IDT 33. When the resonance condition of the Y-direction transmitter 3Y determined by various conditions is satisfied, the standing wave of the second surface acoustic wave can be generated particularly efficiently from the Y-direction transmitter 3Y.

  In the present invention, the frequency of the high-frequency voltage applied to the X-direction transmitter 3X (first frequency) is different from the frequency of the high-frequency voltage applied to the Y-direction transmitter 3Y (second frequency) (the frequency is Configured to modulate). Then, the operating power at any one of the first frequency that satisfies the resonance condition of the X-direction transmitter 3X and the second frequency that satisfies the resonance condition of the Y-direction transmitter 3Y ( By supplying (applying) a high-frequency voltage to the X-direction transmitter 3X and the Y-direction transmitter 3Y, the X-direction transmitter 3X and the Y-direction transmitter 3Y can be selectively operated without switching operating power. Can be made.

  In other words, by setting the frequency of the operating power to either the first frequency or the second frequency, the X direction transmission unit 3X and the Y direction transmission unit 3Y generate surface acoustic waves exclusively from each other. Can be controlled. Thereby, it is possible to omit the X / Y switch conventionally required when switching the operating power supplied to the X direction transmission unit 3X and the Y direction transmission unit 3Y, and to reduce the manufacturing cost of the touch panel device 1. Can be achieved.

  The X-direction transmission unit 3X and the Y-direction transmission unit 3Y may be electrically independent from each other, but are preferably electrically connected to each other via a power supply wiring 6 as shown in FIG. The bias electrode is preferably shared. Thereby, simplification of the wiring pattern of the wiring 6 for electric power feeding and the freedom degree of design of the touch panel apparatus 1 can be raised. As a result, the frame portion of the touch panel device 1 can be reduced, and the effective touch area can be increased.

  The power supply wiring 6 is made of various conductive materials. In particular, the power supply wiring 6 is made of the same material as the lower electrode 31 or IDT 33 and is formed integrally with the lower electrode 31 or IDT 33. Is preferred. Thereby, in the manufacturing process of the touch panel device 1 described later, the power supply wiring 6 and the lower electrode 31 or the IDT 33 can be formed at the same time, and the manufacturing process can be simplified.

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.
In the present embodiment, the X-direction receiving unit 4X and the Y-direction receiving unit 4Y are provided near both ends of the front side edge of the substrate 2, respectively.

The X direction receiving unit 4X and the Y direction receiving unit 4Y have the same configuration as the X direction transmitting unit 3X and the Y direction transmitting unit 3Y, respectively. That is, the X-direction receiving unit 4X and the Y-direction receiving unit 4Y each have a flat plate-like lower electrode 31, a piezoelectric layer 32, and an IDT 33 that are sequentially stacked on the substrate 2.
The X-direction receiving unit 4X generates an electrical signal between the lower electrode 31 and the IDT 33 in accordance with the piezoelectric effect generated by the displacement of the piezoelectric layer 32 by the first surface acoustic wave that has propagated through the substrate 2. It is.

Similarly to the X-direction receiving unit 4X, the Y-direction receiving unit 4Y generates an electrical signal according to the piezoelectric effect generated by the displacement of the piezoelectric layer 32 by the second surface acoustic wave.
The X direction receiver 4X has a frequency characteristic capable of mainly receiving the first surface acoustic wave generated from the X direction transmitter 3X, and the Y direction receiver 4Y is generated from the Y direction transmitter 3Y. It is preferable to have a frequency characteristic capable of mainly receiving the second surface acoustic wave. Thereby, for example, even when the second surface acoustic wave unintentionally arrives at the X direction receiving unit 4X, the frequency of the second surface acoustic wave is different from the frequency characteristics of the X direction receiving unit 4X. It is possible to prevent the second surface acoustic wave from being received as noise.

For this reason, even when the X / Y switch is omitted, either the X-direction receiving unit 4X or the Y-direction receiving unit 4Y is selectively used according to the frequency of the surface acoustic wave propagating through the substrate 2. And a surface acoustic wave can be received reliably. Thereby, the number of parts can be reduced, and the manufacturing cost of the touch panel device 1 can be reduced.
The frequency characteristics of the X-direction receiving unit 4X and the frequency characteristics of the Y-direction receiving unit 4Y are respectively the width and thickness of the electrode fingers 331 included in the IDT 33, the interval between adjacent electrode fingers 331, and the composition of the piezoelectric layer 32. By setting the crystal orientation or the like, it is possible to adjust the characteristics such as the frequency that can be mainly received by the X-direction receiving unit 4X and the Y-direction receiving unit 4Y to a desired one.

  Further, the X-direction receiving unit 4X and the Y-direction receiving unit 4Y may be electrically independent from each other, but are preferably electrically connected to each other via a receiving wiring 7 as shown in FIG. The bias electrode is preferably shared. Thereby, similarly to the transmission unit 3, the wiring pattern of the reception wiring 7 can be simplified and the degree of freedom in designing the touch panel device 1 can be increased. Thereby, the frame part of the touch panel device 1 can be reduced, and the touch effective area can be enlarged.

The receiving wiring 7 is made of the same material as that of the power feeding wiring 6 described above. In particular, the receiving wiring 7 is made of the same material as the lower electrode 31 or IDT 33 and is formed integrally with the lower electrode 31 or IDT 33. It is preferable. Thereby, in the manufacturing method of the touch panel device 1 described later, the receiving wiring 7 and the lower electrode 31 or the IDT 33 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 constituted by surface acoustic wave elements, and the remaining ones may be constituted by other means for generating surface acoustic waves. Since the surface acoustic wave element can relatively easily change conditions such as frequency characteristics of the surface acoustic wave to be generated, surface acoustic waves having different frequencies can be easily generated.

In addition, since the surface acoustic wave element can be made very thin, the touch panel device can be made thinner and lighter.
Further, as other means for generating the surface acoustic wave, for example, various vibrators and the like capable of giving a vibration that generates a transverse wave and / or a longitudinal wave to the substrate 2 can be cited.
A reflector 5 is fixed to each edge of the substrate 2.

The reflector 5 has a function of changing the propagation direction of the surface acoustic wave generated from the X direction transmission unit 3X and the Y direction transmission unit 3Y.
The reflector 5 shown in FIG. 1 includes two edges (two sides on the left and right sides of the substrate 2) substantially parallel to the direction in which the X-direction transmitting unit 3X generates the first surface acoustic wave (Y direction). A pair of first reflectors 5X ₁ , 5X ₂ provided in the vicinity of the part and a pair of second reflections provided in the vicinity of the edges of the two sides other than the two sides (upper and lower sides of the substrate 2) and a vessel _5Y 1, _{5Y 2.}

Each of these reflectors 5 is configured by arranging a large number of reflecting elements having reflecting surfaces inclined by approximately 45 ° with respect to each edge of the substrate 2 at predetermined intervals (intervals that satisfy the conditions of Bragg reflection). The reflection element group is constituted.
Each of the reflectors 5 has a function of changing the propagation directions of the first surface acoustic wave and the second surface acoustic wave by approximately 90 °. Specifically, the pair of first reflectors 5X ₁ and 5X ₂ is configured to change the propagation direction of the first surface acoustic wave by approximately 90 °, and finally change by approximately 180 °. The pair of second reflectors 5Y ₁ and 5Y ₂ is configured to change the propagation direction of the second surface acoustic wave by approximately 90 °, and finally change by approximately 180 °.

In addition, of the pair of first reflectors 5X ₁ and 5X ₂ and the pair of second reflectors 5Y ₁ and 5Y ₂ , the first reflector 5X ₁ and the second reflector 5Y responsible for the first reflection. ₁ is configured to reflect a part of the surface acoustic wave that has reached the reflecting surface of each reflecting element and to transmit the remaining part. Thereby, the surface acoustic wave is branched by each reflection element, and propagates so as to scan the X direction and the Y direction of the substrate 2 uniformly.

On the other hand, the first reflector 5X ₂ and the second reflector 5Y ₂ responsible for the second reflection reflect the surface acoustic wave that has reached the reflecting surface of each reflecting element, and are opposite to the reflecting surface. The surface acoustic wave that has reached the surface is transmitted. As a result, the surface acoustic waves are aggregated by the respective reflecting elements, and the propagation direction thereof is changed so as to go to the X direction receiving unit 4X and the Y direction receiving unit 4Y.

Further, in such a reflector 5, the path length of the surface acoustic wave reflected for each reflecting element is different, so that the surface acoustic wave reflected by each reflecting element has a time difference corresponding to the path length difference. Thus, each of the receiving units 4X and 4Y is reached. Due to this time difference, position information for specifying the touch position can be obtained in the detection 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.
The constituent material of the reflector 5 is not particularly limited, but is made of the same material as the power supply wiring 6 and the reception wiring 7 described above.

Further, in the present embodiment, as shown in FIG. 1, the first reflector 5X ₁ and power supply wire 6, and a second reflector 5Y ₁ and the receiving lines 7 are each integrally formed Yes. Thus, the reflector 5Y ₁ of the first reflector 5X ₁ and a second, it is possible to form by approaching the edge of the substrate 2, it is possible to enlarge the touch effective area. In other words, the width of the frame portion of the touch panel device 1 can be reduced and the degree of design freedom can be increased.

Further, in the manufacturing process of the touch panel device 1 to be described later, the power supply wiring 6 and the reception wiring 7, the first reflector 5X ₁ and the second reflector 5Y ₁ can be formed at the same time, and the manufacturing process is simplified. Can be achieved.
In addition, these reflectors and wiring may be separated, or may be formed integrally with only one of them.

A sheet material 8 is provided above the substrate 2, the transmitter 3, the receiver 4, and the reflector 5.
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. Thereby, the sheet material 8 bends downward and the sheet material 8 comes into contact with the substrate 2, whereby 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 and a control 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.
A plurality of protrusions (not shown) may be provided on the lower surface of the sheet material 8.

  The external device 10 receives 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 electric signal generated by the reception unit 4 via the reception wiring 7. Based on the result of the electrical signal received by the detection unit 12 and the amplification unit 13 provided between the unit 12, the reception unit 4 and the detection unit 12 for amplifying the electrical signal, a fingertip or an object is in contact And a control unit 14 that calculates position information.

The high-frequency power source 11 can apply at least two types of high-frequency voltages having different frequencies to the transmission unit 3. Thereby, as described above, 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.
The amplifying unit 13 amplifies the electrical signal generated when the receiving unit 4 receives the surface acoustic wave, and relatively increases the rate of change in the strength of the electrical signal due to the fingertip or the object touching in the detecting unit 12. , To make it easier to catch intensity changes.

The detection unit 12 has a function of detecting a change with time in the intensity of the electric signal amplified by the amplification unit 13.
The control unit 14 is configured to control each operation of the high frequency power supply 11 and the detection unit 12. Thereby, each operation | movement of supply of the operating power of the high frequency power supply 11 and the electrical signal reception of the detection part 12 can be controlled to a desired timing.
As an example, this timing is set by the detection unit 12 so that the time for detecting the first surface acoustic wave and the time for detecting the second surface acoustic wave are time-divided.

  Specifically, first, a high-frequency voltage that satisfies a condition for the X-direction transmission unit 3X to generate the first surface acoustic wave from the high-frequency power supply 11 is applied to the X-direction transmission unit 3X. 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 electrical signal obtained by this reception is detected by the detection unit 12 via the reception wiring 7.

Next, a high-frequency voltage that satisfies the condition for the Y-direction transmitter 3Y to generate the second surface acoustic wave from the high-frequency power source 11 is applied to the Y-direction transmitter 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 12 via the reception wiring 7.
Next, a high-frequency voltage that satisfies the condition for causing 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 again. 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 electrical signal from the X-direction receiving unit 4X and the electrical signal from the Y-direction receiving unit 4Y.
In addition to this, the control unit 14 further includes a calculation unit (not shown) that converts it into position information of the touch position based on a temporal change in the intensity of the electrical signal received by the detection unit 12. This position information is transmitted to various electronic devices.

Next, an example of a usage method (action) of the touch panel device 1 as described above will be described.
[1] First, a high-frequency voltage having a first frequency that satisfies the condition for the X-direction transmitting unit 3X to generate a first surface acoustic wave from the high-frequency power source 11 is connected to the lower electrode 31 and the IDT 33 via the power supply wiring 6. Apply between. 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. 4A 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 reflecting element group of the _first reflector 5X1 and the remaining part is transmitted. . As a result, the burst wave 51 is branched and propagated as the surface acoustic wave 52 in the X direction (right direction) of the substrate 2. Subsequently, the _second reflection is performed by the first reflector 5X2. Thereby, the reflected surface acoustic wave 53 travels toward the near side in FIG. 1 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. 4A 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 lower electrode 31 and the IDT 33 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 electrical signal obtained by the X direction receiver 4 </ b> X is transmitted to the detector 12 via the reception wiring 7 and the amplifier 13. The detection unit 12 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 12, a touch position is specified by the calculating part with which control part 14 is provided. Specifically, for example, the time T _X from the reception start time of the reception wave 55 shown in FIG. 4A 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, a high-frequency voltage of a second frequency that satisfies the condition for the Y-direction transmitter 3Y to generate the second surface acoustic wave is applied between the lower electrode 31 and the IDT 33 via the power supply wiring 6. Apply. As a result, a burst wave 61 having a waveform as shown in FIG. 4B 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. 4B is obtained. Then, the detection unit 12 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. 5 is a partially enlarged view of the X-direction transmission unit of the touch panel device according to the second embodiment, and FIG. 6 is a cross-sectional view taken along line A′-A ′ of the X-direction transmission unit shown in FIG. In the following, for convenience of explanation, the front side of the sheet in FIG. 5 is referred to as “upper”, the rear side of the sheet is referred to as “lower”, the upper side in FIG. 6 is referred to as “upper”, and the lower side is referred to as “lower”.

Hereinafter, the second embodiment of the touch panel device of the present invention will be described with reference to these drawings, 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 configurations of the transmission unit and the reception unit are different.
In the present embodiment, the transmission unit 3 ′ includes the X-direction transmission unit 3X ′ that generates a first surface acoustic wave in the Y direction for detecting the X-direction touch position of the substrate 2, and the Y-direction touch position. And a Y-direction transmitter that generates a second surface acoustic wave for detection in the X direction.

The X-direction transmitter 3X ′ shown in FIGS. 5 and 6 is composed of a surface acoustic wave element, and has an IDT (comb-like electrode) 33 ′ and a piezoelectric layer 32 ′ that are sequentially stacked on the substrate 2. ing. The surface acoustic wave device having such a configuration can efficiently generate a surface acoustic wave having a relatively high strength.
As shown in FIGS. 5 and 6, the IDT 33 ′ includes two pairs of comb-like electrode fingers 332 and 333 that are arranged at almost 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 333, the composition of the piezoelectric layer 32 ′ described later, the crystal orientation, and the like, the X direction The characteristics such as the oscillation frequency of the surface acoustic wave generated from the transmitter 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, but when a pair of electrode fingers 332 and one electrode finger 333 is formed, it is preferably about 5 to 50 pairs. About 40 pairs are more preferable. By making the number of the pair of electrode fingers 332 and 333 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. Further, the area occupied by the IDT 33 'can be optimized, and a touch effective area having a sufficient area can be secured.

The piezoelectric layer 32 ′ is made of the same material as that of the piezoelectric layer 32 of the first embodiment.
When the touch panel device 1 of this embodiment having such a configuration is used, X determined by various conditions of the electrode fingers 332 and 333 and the piezoelectric layer 32 ′ between the electrode fingers 332 and 333. A high frequency voltage having a first frequency that satisfies the resonance condition of the direction transmitter 3X ′ is applied. Thus, the X-direction transmission unit 3X ', the first surface acoustic wave primarily wavelength corresponding to the interval d _X occurs.

In the present embodiment, the electrode fingers 332 and the electrode fingers 333 are provided at substantially equal intervals, but there may be a portion where the interval changes.
The X direction transmission unit 3X ′ has been described above as a representative, but the Y direction transmission unit, the X direction reception unit, and the Y direction reception unit have the same configuration as the X direction transmission unit 3X ′.
In the touch panel device 1 of the present embodiment, the same operations and effects as those of the first embodiment 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. It is the elements on larger scale of the X direction transmission part of the touchscreen apparatus shown in FIG. It is the sectional view on the AA line of the X direction transmission part 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 elements on larger scale of the X direction transmission part of the touchscreen apparatus of 2nd Embodiment. FIG. 6 is a cross-sectional view taken along line A′-A ′ of the X direction transmission unit illustrated in FIG. 5.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Touch panel device 2 ... Board | substrate 3 ... Transmitting part 3X, 3X '... X direction transmitting part 3Y ... Y direction transmitting part 4 ... Receiving part 4X ... X direction receiving part 4Y ... Y direction receiving part 5 ...... reflector 5X _1, 5X ₂ ...... first reflector 5Y _1, 5Y ₂ ...... second reflector 6 ...... power supply wire 7 ...... receiving wiring 8 ...... sheet 10 ...... external Device 11 …… High frequency power supply 12 ...... Detection unit 13 ...... Amplification unit 14 ...... Control unit 31 ...... Lower electrode 32, 32 ′ …… piezoelectric layer 33, 33 ′ …… IDT 331, 332, 333 …… electrode Fingers 51, 61 ... Burst wave 52, 53 ... Surface acoustic wave 54, 64 ... Attenuation 55, 65 ... Received wave

Claims (11)

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 for generating 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; ,
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 the first transmission unit and the second transmission unit share a bias electrode.   The touch panel device according to claim 1, wherein the first receiving unit and the second receiving unit share a bias electrode.   4. The touch panel device according to claim 1, 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. 5.   5. 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 5, wherein the surface acoustic wave element includes a thick film piezoelectric layer and a pair of electrodes for applying a voltage to the piezoelectric layer.   The touch panel device according to claim 6, wherein the surface acoustic wave element generates surface acoustic waves having different frequencies according to a crystal orientation of the thick piezoelectric layer. The surface acoustic wave element generates an SH wave and a Rayleigh wave according to the crystal orientation of the thick piezoelectric layer.
8. The touch panel device according to claim 6, wherein one of the first transmission unit and the second transmission unit generates the SH wave, and the other generates the Rayleigh wave.   The touch panel device according to any one of claims 6 to 8, wherein the thick piezoelectric layer is made of quartz as a main material.   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, thereby the first transmission unit and the second transmission unit. The touch panel device according to claim 1, wherein the transmission unit and the second transmission unit are controlled so as to be able to operate exclusively. Furthermore, a power supply wiring connecting the first transmission unit and the second transmission unit, and the power supply unit,
A receiving wiring connecting the first receiving unit and the second receiving unit and the detecting unit;
Of the four sides of the substrate, the first transmitter is provided along two opposing sides parallel to the direction in which the first surface acoustic wave is generated. A first reflector that changes direction;
A second reflector provided along two opposing sides other than the two sides and changing a propagation direction of the second surface acoustic wave;
The touch panel device according to claim 1, wherein at least one of the first reflector and the second reflector is formed integrally with the power supply wiring or the reception wiring.

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