JPH1131045A - Coordinate input device - Google Patents

Abstract

(57) [Summary] [Problem] To realize low cost and miniaturization,
Provide an easy-to-use coordinate input device. SOLUTION: An electrode 102XB, 102YB on one side surface of a pair of piezoelectric elements 102X, 102Y is connected to a conductive member 10.
6 and a pair of piezoelectric elements 102X, 102Y and electrodes 102XA, 1
02YA is electrically connected to the amplifier or driver 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device for detecting vibrations propagating through a propagation body and detecting designated coordinates.

[0002]

2. Description of the Related Art As a conventional coordinate input device, the following one is known. That is, an ultrasonic vibration is generated from the pen-type position pointing tool and is brought into contact with the plate-shaped propagation body. Next, each sensor detects the arrival time of the ultrasonic vibration generated from the position indicator that arrives at each sensor composed of the piezoelectric elements arranged at the four corners of the plate-shaped propagation body, and the position indicator indicates. Calculate the distance from the position to each sensor. Then, the coordinates indicated by the position indicator are detected in the manner of triangulation.

[0003] An example of the configuration of a coordinate input device using a position pointing device that generates such ultrasonic vibration will be described with reference to FIG. FIG. 9 is a plan view showing the configuration of a conventional coordinate input device. FIG. 9 shows a plan view of the coordinate input device, and particularly shows a state where the upper lid of the coordinate input device is removed so that the sensor units 10A to 10D provided at the four corners of the coordinate input device can be confirmed. ing.

In FIG. 9, reference numeral 1 denotes a chassis of the entire apparatus;
Reference numeral 2 denotes a transmitting body made of glass, 3 denotes an inputtable range, 4 denotes a control circuit, 5 denotes a pen which is a position indicator, and 6 denotes an electric wire connecting the pen 5 and the control circuit 4. When coordinates are actually input from the pen 5, an ultrasonic wave 21 spreads from a contact point 20 of the pen 5 with respect to the glass 2 by a vibrating piezoelectric element (not shown) provided in the pen 5. Then, the four sensor units 10A to 10D measure the arrival times of the ultrasonic waves generated from the pen 5. Coordinates can be calculated with a minimum of two sensors, but in this example, four sensors are used to ensure sufficient sensitivity and accuracy over the entire input surface.

Next, a detailed configuration of the sensor units 10A to 10D will be described with reference to FIGS. 10 and 11. Since the sensor units 10A to 10D all have the same function, here, the sensor unit 10A will be described. I will explain only. FIG. 10 is an enlarged plan view of a conventional sensor unit, and FIG. 11 is a side view of the conventional sensor unit.

Reference numeral 102 denotes a piezoelectric element whose shape is determined so that ultrasonic waves generated by the pen 5 can be detected efficiently. The piezoelectric element 102 is polarized in the axial direction as shown by an arrow (see FIG. 11), and the detection electrodes 102A, 102
B is formed by metal plating. One electrode 10
2A is directly connected to the amplifier 105 by a leaf spring 103. The other electrode 102B is a thin electrode pattern 1 made of a conductive material provided on the carrier 2 by printing or the like.
01 is adhered by a conductive adhesive. The leaf spring 104 is brought into contact with the electrode pattern 101 to be connected to the amplifier 105.

The electrode pattern 101 is used to efficiently transmit ultrasonic energy from the propagation body 2 to the piezoelectric element 102, so that one electrode surface of the piezoelectric element 102 is brought into close contact with the propagation body as much as possible, and electrical connection is made. It is provided in a way that is compatible with what it does. For example, as a means for forming conductive inclusions as thin as possible, a method in which a resin mixed with carbon powder or metal powder is printed and then baked is used to form an electrode pattern 1 which is a thin conductive film having good adhesion.
01 is provided.

The connection between the electrode pattern 101 and the electrode 102A and the amplifier 105 is performed by the leaf springs 104 and 103 because of the constraint condition for the piezoelectric element 102 to stably and efficiently detect vibration, that is, the restriction of the piezoelectric element 102. This is because the fixing method, the mass, the stress state, and the like can be made constant. As a method of connecting the electrode pattern 101 and the electrode 102A to the amplifier 105 while satisfying the constraint conditions, there is a method of soldering with an electric wire. In this case, however, it is difficult to control processes such as controlling the amount of solder. Not practical.

The electrode pattern 101 and the electrode 102
Since the connection between A and the amplifier 105 needs to be performed after the piezoelectric element 102 is bonded to the electrode pattern 101, equipment for handling the size of the propagation body 2 is required. Therefore, the electrode pattern 101 and the electrode 102A can be easily assembled.
And the amplifier 105 can be connected, and in this regard, connection by the leaf springs 104 and 103 can be realized. In addition, the carrier 2 is glass and the chassis 1
Is generally a resin (or a metal), and each has a different coefficient of thermal expansion. Therefore, the relative position slightly changes due to the change in temperature and humidity. The connection by the leaf springs 104 and 103 is also effective in absorbing this.

By the way, among well-known elastic waves transmitted through a plate-like propagator, a plate wave propagates through the entire plate. Therefore, in a coordinate input device in which a user's hand, a document, or the like may come into contact with the surface of the propagation body, a coordinate detection method using a plate wave with small vibration attenuation is suitable. In addition, the plate wave is hardly affected by a case where a flaw or dirt adheres to the propagator, and is more convenient than the surface wave.

There are various modes in the plate wave that vary depending on the product of the frequency and the thickness. As a fundamental mode in a region of a relatively small product, vibrations of two modes having greatly different velocities ( S0 wave and A0 wave). The coordinate input device cannot detect coordinates unless it is known which mode is to be detected. For example, in a propagation body made of glass having a plate thickness of 1.5 mm and a frequency of 500 kHz, the S0 wave is about 5000 m / sec,
The wave is about 2500 m / sec. Here, the output from the sensor unit when vibration is detected is several times larger in the A0 wave than in the S0 wave. Therefore, by using an output from the sensor unit having a predetermined level or higher, it is possible to detect coordinates using only the A0 wave.

[0012]

However, the configuration of the above-mentioned conventional coordinate input device has the following problems. First, since the electrode patterns 101 must be formed directly at the four corners of the propagation body 2, the forming device must be capable of handling the size of the propagation body 2. Therefore, in order to handle the large-sized propagation body 2, a very large and expensive one is required. Similarly, an apparatus for firing the electrode pattern 101 needs to be able to handle the size of the propagation body 2.

When a coordinate input device having a slightly different size is manufactured, the electrode pattern 101 is formed to the size of the propagation body 2 even though the sensor units 10A to 10D themselves can use common components. In addition, it is necessary to change the setup of other equipment or jigs and tools. Therefore, in order to manufacture coordinate input devices of different sizes, the manufacturing cost is inevitably increased, and there is a problem in increasing the types of product sizes.

Further, a leaf spring 1 is connected to the amplifier 105.
Although the contact pressures of 03 and 104 are used, too large contact pressure cannot be applied in order not to impair the vibration characteristics of the piezoelectric element and not to damage the piezoelectric element which is a brittle ceramic. For example, there is a possibility that a contact failure may occur. Therefore, even if expensive gold plating is used, the reliability is not sufficient.

Second, the coordinate detection using only the A0 wave is performed by utilizing the fact that the A0 wave is several times larger than the S0 wave in the coordinates detected by the sensor unit. In addition, environmental conditions such as temperature and humidity, operating conditions such as a minimum required writing pressure, a maximum allowable writing pressure, and a pen tilt allowable range are limited to predetermined ranges. Therefore, outside the predetermined range, not only the coordinates cannot be input, but also the S0 wave may be detected in some cases, and the coordinates having a large error may be detected.

Third, in order to prevent the waveform from being distorted by the reflected wave from the side surface around the propagation body 2 and deteriorating the detection accuracy, the outer shape of the propagation body 2 needs to be larger than the input range. . Further, in order to reduce the influence of the reflected wave, a vibration absorbing member must be attached around the entire body 2, which inevitably leads to an increase in the size of the coordinate input device and a restriction in design.

The present invention has been made in view of the above problems, and realizes low cost and small size.
It is an object of the present invention to provide a convenient coordinate input device.

[0018]

The structure of the coordinate input device according to the present invention for achieving the above object has the following structure. That is, a coordinate input device that detects a vibration generated from a pointing device that points to a propagation body and detects a coordinate pointed by the pointing device, wherein electrodes on one side of a pair of piezoelectric elements are electrically conductive members. An integrated vibration detecting means and a connecting means for electrically connecting the electrodes on the other side of the pair of piezoelectric elements to an amplifier or a driver are provided.

Preferably, the propagation body propagates at least two types of plate waves including at least a first plate wave and a second plate wave. Preferably, a center-to-center distance between the pair of piezoelectric elements is substantially a natural number times a half wavelength of the first plate wave or the second plate wave. By doing so, a phase difference occurs between the vibrations detected by the pair of piezoelectric elements. For example, when the wavelength is set to a half wavelength of the first plate wave (for example, equivalent to one wavelength of the second plate wave), , The same phase for the second plate wave,
Vibration of opposite phase is applied to each piezoelectric element with respect to the first plate wave. Therefore, by changing the polarization direction of the piezoelectric element, the first
This is because one of the plate wave and the second plate wave can be added together, and the other can be canceled out, so that the gain can be greatly different from the other. Thereby, the allowable range in which only one of the first and second plate waves can be detected can be greatly expanded.

Preferably, the pair of piezoelectric elements are arranged in the center direction of the input range of the propagation body. Also, preferably, the pair of piezoelectric elements are arranged at positions substantially equidistant from the center of the input range of the propagation body. By arranging in this way, the gain for the reflected wave can be reduced.

Preferably, the polarization directions of the pair of piezoelectric elements are the same. Also, preferably,
The polarization directions of the pair of piezoelectric elements are different from each other. Preferably, the apparatus further comprises a reinforcing member for reinforcing between the pair of piezoelectric elements.

Preferably, the reinforcing member is an insulator. Preferably, the vibration detecting means is bonded to the propagation body via the conductive member. Preferably, a central portion of the conductive member corresponding to a space between the pair of piezoelectric elements has a space with respect to a bonding surface to the propagation body.

[0023] Preferably, the pair of piezoelectric elements is formed by dividing one piezoelectric element by a slit.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. (Embodiment 1) FIG. 1 is a plan view showing a configuration of a coordinate input device according to Embodiment 1 of the present invention. FIG. 1 shows a plan view of the coordinate input device. In particular, a state where the upper lid of the coordinate input device is removed so that the sensor units 10A 'to 10D' provided at the four corners of the coordinate input device can be confirmed. Is shown. In FIG. 1, the same components as those of the coordinate input device shown in FIG. 9 are denoted by the same reference numerals, and the details are omitted.

Next, the sensor units 10A 'to 10D'
2 and FIG. 3, the sensor units 10A ′ to 10D ′ all have the same function.
Will be described only. FIG. 2 is an enlarged plan view of the sensor unit according to the first embodiment of the present invention, and FIG. 3 is a side view of the sensor unit according to the first embodiment of the present invention.

Reference numerals 102X and 102Y denote a pair of piezoelectric elements, the shapes of which are determined so that ultrasonic waves having a wavelength to be used can be detected efficiently. Piezoelectric elements 102X, 10
2Y, it is polarized in the axial direction as indicated by an arrow (see FIG. 3). In each of the pair of piezoelectric elements 102X and 102Y, a metal plate member 106 is fixed to one of the electrode surfaces 102XB and 102YB. The pair of piezoelectric elements 102 </ b> X and 102 </ b> Y are integrated by a resin-made reinforcing member 107, and the plate-like member 106 side is adhesively fixed to a predetermined position on the propagation body 2.

The other electrode surfaces 102XA and 102YA of the pair of piezoelectric elements 102X and 102Y are connected to the amplifier 105 by metal terminals 103X and 103Y, respectively. The metal terminals 103 </ b> X and 103 </ b> Y are fixed by a resin holder 104 so as to maintain a constant interval. Thereby, the pair of piezoelectric elements 102X, 10X
The work of integrating 2Y with the plate member 106 and the reinforcing member 107 can be performed by a simple process such as spot welding or soldering. Therefore, these piezoelectric elements 102X, 1
02Y, the plate-like member 106, and the reinforcing member 107 can be a common unit that can be used as a small unit for various sizes of transmitters.

Of course, the metal terminals 103X and 103Y held by the holder 104 may be mounted on the amplifier 105 side in advance.
In such a case, a connection work facility is required to be incorporated into the device. However, even in such a case, according to the present invention, it goes without saying that the effect of improving the performance using the pair of piezoelectric elements 102X and 102Y is the same.

As a method of fixing the pair of piezoelectric elements 102X and 102Y and the plate-like member 106, a method other than bonding such as welding, pressure welding, or brazing is also possible. Further, the reinforcing member 107 is not always necessary, and the plate-like member 106 is not necessary.
Can be omitted if it has sufficient strength. vice versa,
After being integrated by the reinforcing member 107, the plate member 106 may be formed by processing such as plating or sputtering. As the reinforcing member 107, an insulating material such as low-melting glass may be used instead of the resin. Although the shape becomes complicated, the reinforcing member 107 and the holder 104 may be integrated to reduce the number of parts. In the first embodiment, the upper part of the reinforcing member 107 is
By protruding from 2XA and 102YA, the connecting leaf springs 103 and 104 are guided to prevent short circuit. For this reason, only an insulator can be used for the reinforcing member 107, but a metal can be used if the shape is such that the electrodes are not short-circuited.

To further supplement the method of integration, the pair of piezoelectric elements 102X and 102Y can be thermally and
It goes without saying that various methods are possible as long as they do not cause chemical damage. Also, if a pair of long and thin rod-shaped piezoelectric elements are integrated and then separated by a slicer as in a method commonly used when integrating a magnetic head or the like, a large number of parts can be obtained at once. Therefore, the production efficiency can be increased. Therefore, it can be produced much more easily and inexpensively than the conventional method of forming an electrode pattern.

Next, a pair of piezoelectric elements 102X, 102Y
The waveform from the coordinate pointing device detected by will be described. In the first embodiment, for example, it is assumed that coordinate detection is performed using 1.5 mm thick glass as a propagator 2 and a 500 kHz pen 5 using an A0 wave having a phase speed of about 2500 m / sec. In this case, the phase velocity of the S0 wave is about 50.
00 m / sec, and the wavelength is approximately doubled.

Under such conditions, the pair of piezoelectric elements 102X and 102Y are arranged such that the center-to-center distance is about half the wavelength of the A0 wave as shown in FIG. In this arrangement, when a pair of piezoelectric elements 102X and 102Y are connected in series such that the polarization directions are opposite, the piezoelectric elements physically have an A0 wave in opposite phase and an S0 wave with about 90 degree phase difference. Is transmitted. Also, electrically the A0 wave is about doubled,
The SO wave is suppressed to about 70%. As a result, the ratio (sensitivity difference) between the two output voltages is improved by about 2.8 times as compared with the related art. Actually, when the input point is in a direction other than the center, the phase difference of vibration changes. Therefore, it is better to slightly increase the center-to-center distance.
About 2 times.

As described above, according to the first embodiment, the output ratio of the detection voltage can be improved. Therefore, for example, when the amplitude of the S0 wave at the maximum allowable writing pressure of the coordinate pointing device 5 does not change, the amplitude of the A0 wave can be set to about 1.5 to 2 times as compared with the related art. The lower limit of the minimum allowable writing pressure of the pen 5 can be reduced by 50 to 70%. Of course, it is also possible to use the expanded allowable range as a margin for output variations due to environmental or manufacturing variations. As described above, enormous effects such as expansion of the allowable range of use conditions, improvement of reliability, and cost reduction can be obtained. (Embodiment 2) FIG. 4 is a side view showing a configuration of a sensor unit according to Embodiment 2 of the present invention.

In FIG. 4, a pair of piezoelectric elements 102X,
Embodiment 1 is different from Embodiment 1 except that the shape of 102Y is configured so that the SO wave can be detected efficiently and the polarization direction is different.
The configuration is the same as that described above. Thus, the pair of piezoelectric elements 10
If the polarization directions of 2X and 102Y are different from each other, the A0 wave is suppressed and the S0 wave is added with a phase difference of 90 degrees. Therefore, in the second embodiment, it is possible to perform the distance measurement by detecting the S0 wave. In this case, electrically A0
Since the wave is suppressed to about 1/5 compared to the conventional,
It is possible to improve the ratio of output voltage to zero wave (sensitivity difference). That is, the allowable range of the use condition can be expanded. (Embodiment 3) FIG. 5 is a side view showing the structure of a sensor unit according to Embodiment 3 of the present invention.

In FIG. 5, a pair of piezoelectric elements 102X,
The configuration is the same as that of the second embodiment except that the center-to-center distance of 102Y is half the wavelength of the S0 wave, the polarization direction is different, and the height of the reinforcing member 107 is low. In this case, it is clear that the S0 wave is electrically enhanced approximately twice and the A0 wave is suppressed. That is, the allowable range of the use condition can be expanded. In addition, by making the reinforcing member 107 low as shown in FIG. 5, it is not necessary to short-circuit between the electrodes, so that the reinforcing member 107 can be made of metal. (Embodiment 4) FIG. 6 is a side view showing a configuration of a sensor unit according to Embodiment 4 of the present invention.

In FIG. 6, a pair of piezoelectric elements 102X,
The shape of 102Y is configured to efficiently detect the A0 wave, the polarization direction is different, and the plate-like member 106 fixed to the reinforcing member 107 and the metal terminals 103X and 103Y fixed to the holder 104 are sandwiched. The configuration is the same as that of the third embodiment except that the piezoelectric elements 102X and 102Y are integrated. In this case, A0
Since the wave is emphasized about twice and the S0 wave is considerably suppressed, a greater improvement is possible compared to the first embodiment.
However, there is also a disadvantage that the configuration of the sensor unit becomes large. Also, since the change of the phase difference when deviating from the center direction becomes large, the actual improvement ratio is 2 to
It is about three times.

As described above, the pair of piezoelectric elements 102X, 10X
When the center-to-center distance of 2Y is relatively large, the reinforcing member 1
A configuration that facilitates the integration work using the holder 07 and the holder 104 is effective. In addition, the central portion of the plate-like member 106 is separated from the propagation body 2 as shown in FIG.
In particular, it is effective as a means for avoiding the problem of vibration attenuation when it becomes a problem, and is also effective for reinforcing the plate-like member 106. (Embodiment 5) FIG. 7 is a side view showing a configuration of a sensor unit according to Embodiment 5 of the present invention.

In FIG. 7, instead of using two pairs of piezoelectric elements 102X and 102Y as described above, a pair of piezoelectric elements 102X and 102Y are provided by providing slits.
Is composed. Needless to say, this configuration is applicable to each of the embodiments described above. In this case, an extra material for the piezoelectric element is required.
Since step 06 is unnecessary, the number of steps can be reduced.
Further, since the center-to-center distance between the pair of piezoelectric elements 102X and 102Y is determined by processing, there is an advantage that high accuracy can be easily achieved. The depression provided on the electrode 102B side is the same as that of the fourth embodiment.
As in the configuration described above, when vibration attenuation is a problem, it is effective as a means for avoiding the problem, but may be omitted. (Embodiment 6) FIG. 8 is a plan view showing the configuration of a coordinate input device according to Embodiment 6 of the present invention.

In FIG. 8, the pair of piezoelectric elements 102X and 102Y are not arranged vertically in the center of the input surface as shown in FIG. 1, but are arranged substantially horizontally. This is intended not to improve the output ratio of the direct wave (A0 wave and S0 wave) from the pen 5 but to suppress the reflected wave from the surrounding end face. In this case, since the direct wave (arrow 201 in FIG. 8) arrives at almost the same phase, the improvement of the output voltage ratio as described in the second and fourth embodiments cannot be obtained. However, the reflected wave from the end of the propagation body 2 (FIG. 8)
With respect to the middle arrow 202), at least one of the S0 wave and the A0 wave can be suppressed, and as a result, the output voltage ratio can be improved as compared with the related art. Accordingly, the gain of the reflected wave can be reduced without using a method that causes an increase in the size of the device, such as attaching a vibration absorbing member to the outer peripheral portion of the propagation body 2 in order to reduce the gain of the reflected wave. As a result, it is possible to reduce the size of the coordinate input device and eliminate design constraints.

The thickness and the material of the propagation body 2 used in the description of the present invention are not limited to those used in the above-described embodiments, and various kinds can be used. The same applies to the frequency generated by the pen 5, but the coordinate input device is configured to detect one of the different wavelength components and detect the coordinates, such as a plate wave having two modes. In particular, the present invention is particularly effective.

As described above, according to the present invention, the electrodes on one side of the pair of piezoelectric elements are integrated by a plate-shaped member made of a conductive material and then adhered to the propagation body. It becomes unnecessary to print the electrode pattern. Therefore, the equipment required for manufacturing is simplified, and common parts can be used by bonding to different sizes of propagation bodies, so that various types of products can be produced at low cost.

Further, since the pair of piezoelectric elements are connected in series, the voltages detected by the amplifiers are added to obtain a larger output than using one piezoelectric element, so that the operation can be stabilized. In addition, by setting the center-to-center distance between the pair of piezoelectric elements to be substantially a natural number times a half wavelength of the A0 wave or the S0 wave, the allowable range in which only one of the A0 wave and the S0 wave can be detected is greatly expanded. Can be. As a result, a very easy-to-use coordinate input device can be realized such that input can be performed with a lighter writing pressure, and input can be performed without malfunction even when the pen is tilted. It is also possible to allocate the expanded allowable range to a manufacturing margin, and in that case, cost reduction can be realized.

Further, by arranging a pair of piezoelectric elements in a row with respect to the center direction of the input range, the influence of the reflected wave can be reduced and the outer diameter of the propagation body can be reduced. As a result, the size of the coordinate input device can be reduced, and design constraints can be reduced.

[0044]

As described above, according to the present invention,
It is possible to provide a low-cost and compact coordinate input device that is easy to use.

[Brief description of the drawings]

FIG. 1 is a plan view illustrating a configuration of a coordinate input device according to a first embodiment of the present invention.

FIG. 2 is an enlarged view illustrating a configuration of a sensor unit according to the first embodiment of the present invention.

FIG. 3 is a side view illustrating a configuration of the sensor unit according to the first embodiment of the present invention.

FIG. 4 is a side view illustrating a configuration of a sensor unit according to Embodiment 2 of the present invention.

FIG. 5 is a side view illustrating a configuration of a sensor unit according to Embodiment 3 of the present invention.

FIG. 6 is a side view illustrating a configuration of a sensor unit according to a fourth embodiment of the present invention.

FIG. 7 is a side view illustrating a configuration of a sensor unit according to Embodiment 5 of the present invention.

FIG. 8 is a plan view illustrating a configuration of the coordinate input device according to the first embodiment of the present invention.

FIG. 9 is a plan view showing a configuration of a conventional coordinate input device.

FIG. 10 is an enlarged plan view showing a configuration of a conventional sensor unit.

FIG. 11 is a side view showing a configuration of a conventional sensor unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chassis 2 Propagation body 3 Input possible range 4 Control circuit 5 Pen 6 Electric wire 10A-10D Sensor unit 102X, 102Y Piezoelectric element 103X, 103Y Metal terminal 104 Holder 105 Amplifier 106 Plate member 107 Reinforcement member

Claims (12)

[Claims] 1. A coordinate input device for detecting vibrations propagating through a propagation body and detecting designated coordinates, comprising: vibration detection means in which electrodes on one side of a pair of piezoelectric elements are integrated with a conductive member; Connection means for electrically connecting electrodes on the other side of the pair of piezoelectric elements to an amplifier or a driver. 2. The method according to claim 1, wherein the propagating body includes at least a first plate wave,
The coordinate input device according to claim 1, wherein two or more types of plate waves including the second plate wave are propagated. 3. The device according to claim 2, wherein the center-to-center distance between the pair of piezoelectric elements is substantially a natural number times a half wavelength of the first plate wave or the second plate wave. Coordinate input device. 4. The coordinate input device according to claim 1, wherein the pair of piezoelectric elements are arranged in a center direction of an input range of the propagation body. 5. The coordinate input device according to claim 1, wherein the pair of piezoelectric elements are arranged at positions substantially equidistant from the center of the input range of the propagation body. 6. The coordinate input device according to claim 1, wherein the polarization directions of the pair of piezoelectric elements are the same. 7. The coordinate input device according to claim 1, wherein the polarization directions of the pair of piezoelectric elements are different from each other. 8. The coordinate input device according to claim 1, further comprising a reinforcing member for reinforcing between the pair of piezoelectric elements. 9. The coordinate input device according to claim 8, wherein the reinforcing member is an insulator. 10. The coordinate input device according to claim 1, wherein said vibration detecting means is adhered to said propagation body via said conductive member. 11. The coordinate according to claim 1, wherein a central portion of the conductive member corresponding to a space between the pair of piezoelectric elements has a space with respect to an adhesive surface to the propagation body. Input device. 12. The coordinate input device according to claim 1, wherein the pair of piezoelectric elements is configured by dividing one piezoelectric element by a slit.