JPH08202490A - Ultrasonic detecting device - Google Patents

Abstract

PURPOSE: To provide a ultrasonic detecting device that can automatically correct the influence of variation with temperature, etc., on base line data to be the reference for detecting a body. CONSTITUTION: This device is provided with a sampling means which samples an ultrasonic wave propagated in a panel 1, a digital filter 26 which digitally filters the sampled data, and a storage means 21 which stores the digitally filtered data as base line data. Consequently, the influence of variation on the stored line data is reduced and the data are automatically updated into new data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic detecting device for detecting the presence or the position of an object by ultrasonic waves.

[0002]

2. Description of the Related Art An ultrasonic detecting device is generally composed of a panel which is arranged to cover a display screen such as a CRT and a control unit which controls a detecting operation, and absorbs ultrasonic waves propagated to the panel by a contact object. The position (touch position) or the presence or absence of the object is detected from the amount.

Available ultrasonic waves include surface acoustic waves (SAW: Surface Acoustic Wave) propagating on a solid surface.
ic Wave) and bulk acoustic wave (GA) propagating in a solid
W: Guided Acoustic Wave).

FIG. 19 shows a schematic plane structure of an ultrasonic panel. The panel 1 is formed of substantially rectangular glass having the same curvature as that of a liquid crystal panel or a CRT display, and four peripheral portions of the surface of the panel 1 are formed. A plurality of reflective elements 2 printed with low melting point glass powder on each part
The reflective array 3 is formed. Reflection array 3
The rectangular portion surrounded by is the detection surface 6, and the detection surface 6
A transmitter 4 for transmitting an ultrasonic wave is provided at one end of one of two parallel reflecting arrays 3 facing each other across the
A receiver 5 for receiving the ultrasonic waves transmitted from the transmitter 4 is attached to one end of the pair to form one detection pair. The position coordinates on the detection surface 6 are specified by the two detection pairs that are perpendicular to each other on the panel 1. The reflection arrays 3 of the two detection pairs respectively correspond to the XY coordinate axes of the normal XY coordinate plane, and if the reflection array 3 of the one detection pair is taken as the X axis, the reflection array of the other detection pair will be described. 3 is Y
Corresponds to the axis.

FIG. 20A shows a state in which a transmitter or a receiver for surface acoustic waves is attached. The transmitter 4 and the receiver 5 are composed of a pressure transmission element 7 and a prism 8 and are on the surface of the panel 1. Mounted in the above-mentioned position. Further, a volume acoustic wave (GAW) transmitter 4 and a receiver 5 propagating in a solid are directly attached to the end surface of the panel 1 as shown in FIG. In the following description, the surface acoustic wave shown in FIG. 20A will be described as an example of ultrasonic waves.

Next, the operation principle of detecting the coordinate position of the object on the panel surface will be briefly described. As shown in FIG. 21 (A), when a 5.5 MHz transmitted shock wave is applied from the control unit to the piezoelectric element 7, the piezoelectric element 7 vibrates and is converted into a longitudinal wave in the prism 8. Prism 8 and panel 1
At the interface of 1, the longitudinal wave is converted into a surface acoustic wave, propagates on the reflection array 3 on the panel 1, and reflects a very small amount of energy at right angles by each reflection element 2 of the reflection array 3. The reflected surface acoustic wave is reflected by the panel 1 as shown by the arrow in FIG.
On the whole of the detection surface 6 and toward the opposite reflecting array 3, is reflected by the reflecting array 3 at a right angle, and is received by the piezoelectric element 7 of the receiver 5. The signal received by the receiver 5 has a long duration as shown in FIG. In this case, when an object comes into contact with the detection surface 6 of the panel 1 (a touch occurs), elastic wave energy is absorbed at the contact portion, and a signal corresponding to the contact portion is lost as shown in FIG. 11C. , Appears as a depression H in the received signal. In this case, in FIG. 19, an elastic wave passing through the shortest distance a, an elastic wave passing through the touch position b, or an elastic wave passing through the longest distance c causes a time lag in reaching the receiver 5, so that the elastic wave received first is received. If the elapsed times T ₁ and T ₀ of the received elastic waves corresponding to the touch position b and the longest distance c from the wave are measured, the position of the object 9 (touch position)
The coordinate component of can be obtained.

The received wave shown in FIG. 21 is converted into a voltage by the receiving piezoelectric element, but the time variation of the voltage (amplitude) showing the received wave is not uniform as shown in FIG.
Actually, as shown in FIG. 22, it becomes non-uniform on the time axis. The shape of this amplitude is because the interface between the prism 8 and the panel 1, the reflective element 2, the panel surface, etc. are not necessarily uniform and the surface acoustic waves do not propagate uniformly. When the interface of is determined by manufacturing, it is regarded as a unique shape (constant). When the panel 1 is touched with a finger or the like, the surface acoustic wave of the portion corresponding to the touch position is absorbed as shown by the dotted line in FIG. The coordinate component of the touch position is calculated from the position of the dent due to this absorption on the time axis. That is, by transmitting the transmitted shock waves alternately to the two transmitters 4 of the detection pair on the panel 1, the plane coordinate position of the touch position is calculated from the position of the dent due to absorption on the X and Y coordinate axes, and the touch position is calculated. The coordinates are detected.

More specifically, first, when there is no contact object on the detection surface 6 (not touched), the voltage waveform of FIG. 22 is A / A at equal time intervals as shown by the circles in FIG.
Sampling is performed at high speed by the D converter, and the sampling data is stored in the RAM. This stored data is
It is sampling data of surface acoustic waves received when not touched, and serves as a baseline (reference) for subsequent detection of touch-on.

Next, the received wave is similarly sampled at the time of normal detection, and the difference obtained by subtracting the data corresponding to the current sampling time previously stored in the RAM as the baseline from the current sampling data is calculated. , Measured data at time t. This difference indicates a value indicating the presence of absorption of ultrasonic waves due to contact with an object.
After memorizing the baseline, if there is no object contact,
The measured sampling data does not change and the difference from the baseline is 0.

FIG. 24 shows a dent of a received voltage waveform which appears when a finger is touched with a dotted line when the baseline is used as a reference. Furthermore, FIG.
FIG. 25 is a diagram showing an enlarged dotted line portion showing a touch in FIG. 24 and showing a difference between a baseline and a digital value of a received voltage waveform. In FIG. 25, each sampling time on the time axis, ..., t _n-2 , t _n-1 , t _n , t _{n + 1} , t _{n + 2} , ...
・ It shows that it was sampled for. In the figure, the difference ΔA _n of the sampling data becomes maximum at time t = t _n .

Conventionally, in order to determine the presence or absence of a touch and the touch coordinates, each time a transmission shock wave is output from the transmission element 4, a maximum difference ΔA _n is obtained and compared with a reference level value Ath, and ΔA _n ≤Ath. ... No touch, ΔA _n> Ath ··· there is touch, and judgment, and time t _n corresponding to ΔA _n in the case where there is touch
The touch position is detected from the coordinate components of the X and Y coordinate axes by using the coordinate component obtained from the above as the touch position coordinate component on the panel 1.

By the way, when using an ultrasonic detection device as a touch sensor, a problem is a waterproof and drip-proof structure. Generally, in an ultrasonic detection device, when an object is brought into close contact with the glass surface constituting the detection surface 6 of the detection panel 1 for waterproofing, the sound wave is absorbed or escaped. Therefore, as shown in FIG. It is difficult to make the liquid crystal display B mounted on the liquid crystal display unit main body A by closely fixing the bezel 10 to the panel 1 so as to have a completely waterproof and drip-proof structure.
In particular, in a touch sensor using surface acoustic waves in which sound wave energy is concentrated near the glass surface, the degree of absorption of sound waves is large even with a slight contact structure, so waterproofing,
Drip-proof has a theoretical difficulty. On the other hand, in the volume acoustic wave method, since the degree of sound wave absorption is not so large as in the case of the surface acoustic wave, waterproofing and drip-proofing are possible to some extent.

FIG. 27 shows a reflection array 3 attached to the outer peripheral surface of the detection panel 1 by attaching the bezel 10 to the outer peripheral surface of the glass detection panel 1 by the double-sided tape 101 in the volume acoustic wave system. A bezel 10 including a transmitter 4 and a receiver 5 provided on the end surface of the detection panel 1.
This is a waterproof and drip-proof structure for the area covered by. Further, in FIG. 28, the O-ring 102 is interposed between the bezel 10 and the outer peripheral surface portion of the detection panel 1, and pressure is applied between the detection panel 1 and the bezel 10 to form a close contact structure, so that waterproof and drip-proof are achieved. It was realized.

[0014]

Problem A In an ultrasonic detection device, the characteristics of LiNbO ₃ single crystal or piezoelectric ceramics generally used as a transducer are largely changed by temperature. In addition, the temperature characteristic changes of the electronic circuit parts and the sensor plate are also added, and the baseline itself shown in FIG. 23 causes a large temperature drift. Due to this temperature drift, for example, when the ultrasonic detection device and the host computer are powered on for a while, the actual baseline may be largely deviated, and the presence / absence of a touch may be erroneously determined, resulting in a malfunction. In order to deal with this problem, the work of refreshing the baseline has been conventionally performed. Refresh is, for example, an A / D that becomes a baseline in a cycle of 30 seconds or 1 minute.
Replacing the conversion value with the latest A / D conversion value.
However, with this method, when refresh is performed while touching with a finger, the touched sampling data is stored as baseline data, so it is necessary to wait until the next refresh is performed without touching. There is an inconvenience that the touch of the part that has been touched cannot be determined. Further, when the ambient temperature changes drastically, the influence of the temperature change on the sampling data is significant between the current refresh and the next refresh, and the baseline data does not follow the temperature change, so that a malfunction is likely to occur.

Further, the circuit of the control unit of the ultrasonic detection device is easily affected by noise from the power supply circuit, the host computer or electromagnetic waves. This is because the A / D conversion used for sampling operates at high speed, and the internal impedance of the piezoelectric element 7 is high, and external noise is easily picked up. For example, as shown in FIG. 29, A / D
An error E due to noise is superimposed on the converted sampling data, and in a normal case, the difference between the P point and Q point where noise is superimposed is larger than the R point detected as the maximum value of the difference from the baseline, and the maximum. Detected as a value, so that the touch position is the correct sampling time tn corresponding to the R point.
Since it is obtained from the incorrect sampling time t _P or t _Q corresponding to the point P or the point Q without being calculated from, the detection of the touch position is erroneous due to noise. Further, as shown in FIG. 30, when the reference value for detecting a touch is not actually exceeded, noise such as point B is added and the reference value Ath is momentarily exceeded, or the touched finger pressure fluctuates. There is a possibility that an erroneous operation such as erroneous detection or repeated touch / non-touch may occur.

An object of the present invention is to provide an ultrasonic detection device capable of automatically correcting the influence of fluctuations due to the baseline temperature and the like. Another object of the present invention is to provide an ultrasonic detection device that prevents erroneous detection due to the influence of electrical noise or the like.

Problem B The conventional ultrasonic detecting device of the type that transmits ultrasonic waves of the same wavelength has the following drawbacks. That is, in this type of ultrasonic detecting device, in order to increase the resolution of the detected coordinates (X coordinate, Y coordinate), the A / D converting the ultrasonic signal received by the receiver 5 is performed. It is necessary to increase the sampling speed of the D converter. For example, when the velocity of the sound wave on the glass is about 3000 m / sec, the sampling rate is set to 0.3 mm for the coordinate resolution.

[Formula 1] 0.3 mm / 3 × 10 ⁶ (mm / sec) =
0.1 / 10 ⁶ (sec) = 0.1 μsec Therefore, the sampling frequency is 1 / (0.1 μse
c) = 10 MHz needs to be set. This is a considerably high speed as an A / D converter, so that the IC used for the A / D converter becomes expensive, which causes an increase in the cost of the entire circuit.

Further, although the AM detection (AM demodulation) of the ultrasonic wave is performed before the A / D conversion, the frequency of the sound wave used for detection is about 5 MHz, and the ripple is completely removed at this sound wave frequency. Since it is difficult to do so, ripple becomes a big problem when performing high-speed sampling above this frequency. Further, it is difficult to control the timing from the microprocessor in order to cope with a higher sampling rate, and it is necessary to specifically provide a high-speed timing generation and control circuit in hardware, which causes a problem of high cost. In addition, in order to realize a high-speed control circuit, the control circuit becomes a high-consumption current type, which easily overheats and easily causes drift due to the temperature of the baseline data, so it is necessary to use a low-current consumption circuit. Have difficulty.

To increase the touch coordinate resolution, it is necessary to increase the data sampling rate. Since the propagation speed of sound waves is constant, doubling the sampling speed doubles the resolution. However, if the sampling speed is increased, the number of sampled data points is increased in proportion thereto, and the data processing time becomes longer. Also, in order to increase the sampling speed, a faster and more expensive A / D converter is required, and the number of data points stored in the SRAM increases, so the SRAM memory size must also be increased. Cause rise.

Another object of the present invention is to provide a high resolution ultrasonic detecting device without performing high speed A / D conversion.

Problem C Conventionally, the following problems have been encountered in processing sampled data. Regarding this problem, the panel 1 having the detection surface 6 of 300 mm × 200 mm as shown in FIG.
Will be described as an example. The speed of sound waves propagating in glass is 300
Assuming 0 m / s, as shown in FIG.
The distance of the longest path of the sound wave output from is approximately,

[Expression 2] 300 × 2 + 200 = 800 (mm). The transit time of the sound wave passing through this path is

[Equation 3] 800 (mm) / 3000 (m / s) = 0.2
It becomes 7 (ms). That is, it takes 0.27 ms until a shock wave is emitted and data sampling is completed. Similarly, the time until the data sampling of the sound wave output from the Y-axis transmitter 4 is completed is

[Equation 4] (300 + 200 × 2) (mm) / 3000
(M / s) = 0.23 (ms). Therefore, the time required for data sampling for both X-axis and Y-axis is

## EQU5 ## 0.27 + 0.23 = 0.5 (ms). As described above, in the ultrasonic detection device, since the sampling speed is high, it is completed in a short time from the sound wave transmission to the end of sampling.

The data sampling rate is set to 5 MH, for example.
If z, 1 sampling time 1 / (5 × 10 ⁶ )
The distance of the sound wave traveling in (s) is

[Equation 6] 3 × 10 ⁶ (mm / s) · 1 / (5 × 10 ⁶ )
Since (s) = 0.6 (mm), the resolution of the detection coordinates is 0.6 (mm) /2=0.3 (mm) in consideration of the round trip of the sound wave. Regarding the number of samples, when the resolution is 0.3 mm (5 MHz sampling), the number of samples on the X axis is

## EQU00007 ## 300 (mm) / (0.3 (mm)) = 1000 points The number of samples on the Y-axis is

## EQU00008 ## 200 (mm) / (0.3 (mm)) = 667 points. Increasing the resolution will further increase the number of samples. The total sampling time for the X-axis and the Y-axis is short, but the number of data points for sampling is large, so the time for processing the data becomes long. This data processing time has been a cause of slowing down the overall speed of touch detection.

For example, when the data processing is performed by a commonly used 8-bit microprocessor, the processing time for the X coordinate and the Y coordinate is about 20 ms. This processing time requires about 3 ms due to the time required from the driving of the transmitter to the detection and other processing time (for example, conversion time to ASCII code for communication to the host computer). It takes about 23 ms as the total scanning time required for. Furthermore, if data correction processing is performed to prevent drift and noise due to the temperature of the baseline data, it will be approximately 10 to 20 m.
Since the processing time of s is added, the total scanning time is about 33-
43ms is reached.

At this scanning speed, a normal touch operation causes almost no problem in time, but in pen computing using a pen or name sign with a finger, for example, the touch operation is considerably fast, and data processing is performed. Will not be able to accurately follow touch operations. A tablet used for pen computing has a sampling rate of touch coordinates of about 5 ms. Therefore, when the ultrasonic touch panel is used for pen computing or the like, it is necessary to set the scanning speed to the sampling speed to about 5 ms.

An object of the present invention is to provide an ultrasonic detection device capable of high speed scanning.

Problem D The waterproof and drip-proof structure in the conventional volume elastic wave system is capable of waterproofing and drip-proof to some extent, but is not a completely sealed structure. For example, in the waterproof structure shown in FIG. 27, the double-sided tape 101 has a very strong sound wave absorbing power, and if the double-sided tape 101 is adhered with a width larger than that required for complete sealing, the double-sided tape 101 absorbs most of the sound wave, and thus cannot be used as a touch sensor. . Specifically, the double-sided tape 101 requires a width of about 7 mm for complete sealing, but the double-sided tape 101 has a detection panel 1
Since the adhesive parts to be provided on both sides of the detection panel 1,
A double-sided tape having a width of mm will be used for the traveling path of the bulk acoustic wave. At this width, even bulk acoustic waves are almost absorbed. Therefore, the width of the double-sided tape must be limited to a width that does not hinder the touch detection, which is an incomplete waterproof and drip-proof structure.

In the waterproof structure shown in FIG. 28, when an O-ring or a gasket is interposed between the detection panel 1 and the bezel 10, it is necessary to apply a certain pressure or more in order to obtain a completely sealed structure. By the way, when the pressure required for complete sealing is applied, there is a problem that the glass of the detection panel 1 or the bezel 10 is bent, and a large amount of sound waves themselves are absorbed, making it unusable as a touch sensor. Furthermore, FIG.
It is difficult to apply pressure in the direction of the arrow shown in 8 in the manufacturing process.

An object of the present invention is to provide an ultrasonic detecting device utilizing volume elastic waves, which realizes a completely sealed structure for waterproofing and drip-proofing.

[0029]

In order to solve the problem A, an ultrasonic detecting device of the present invention comprises a sampling means for sampling the ultrasonic wave propagating through the panel, and a digital filter for digitally filtering the sampled data. And a storage unit that stores the digitally filtered data as baseline data that serves as a reference for detecting an object. Further, according to the present invention, the sampling data in the vicinity of the touch position during the touch of the object on the panel is provided with a data selection unit that is excluded from the baseline data. Also,
The ultrasonic detection device of the present invention has a sampling means for sampling the ultrasonic wave propagating through the panel, a storage means for storing the sampled data as baseline data to be a reference for detecting an object, and at least:
Obtaining each difference data between the sampling data sampled in the vicinity of the touch position while the object is touching the panel and the baseline data stored in the storage means corresponding to each position of the sampling data, Smoothing processing means for mutually smoothing the respective difference data. Further, the ultrasonic wave detection device of the present invention detects an object by sampling means for sampling the ultrasonic wave propagating through the panel, a digital filter for digitally filtering the sampled data, and the digitally filtered data. A storage means for storing the reference baseline data, at least sampling data sampled in the vicinity of the touch position while the object is touching the panel, and the storage means corresponding to each position of the sampling data. Obtain each difference data from the stored baseline data,
Smoothing processing means for mutually smoothing the respective difference data.

In order to solve the problem B, the ultrasonic detecting device of the present invention uses a plurality of ultrasonic waves of different wavelengths to transmit X rays of the panel.
Direction and Y direction, oscillating means, transmission control means for controlling time-division transmission of different ultrasonic wavelengths transmitted from the transmission means, and receiving means for receiving the transmitted ultrasonic waves. And is arranged at a predetermined interval corresponding to each of the plurality of different wavelengths on the panel through which the transmitted ultrasonic waves propagate, and selects and reflects ultrasonic waves of a predetermined wavelength passing through the detection surface on the panel. Detecting the presence / absence of a touch of an object at a reflection position of a corresponding predetermined wavelength by comparing a reflection array pair propagating to the reception unit and an ultrasonic wave of a predetermined wavelength received from the reception unit with a reference level And means for doing so. Further, the ultrasonic detection device of the present invention obtains sampling data by sampling the ultrasonic waves propagating through the panel,
A means for storing the sampling data, a baseline data serving as a reference for detecting an object from the sampling data, a means for storing the baseline data, a difference between the sampling data and the baseline data, The presence or absence of a touch of the object on the panel is detected from the difference, and when the touch of the object is detected, interpolation data is calculated as data of a non-sampling period between sampling points of the sampling data by the interpolation method, and the sampling is performed. And a calculation unit that obtains the touch position of the object from the data and the interpolation data.

In order to solve the problem C, the ultrasonic detection apparatus of the present invention samples ultrasonic waves propagating through a panel to obtain sampling data, stores the sampling data, and an object from the sampling data. Baseline data serving as a reference for detection is obtained, and means for storing the baseline data is compared with baseline data selected from the sampling data to detect whether or not an object on the panel is touched. When a touch of the object is detected, the data processing of the sampling data is configured to limit to sampling data in the vicinity where the touch is detected. In addition, the ultrasonic detection device of the present invention is a means for sampling the ultrasonic waves propagating through the panel to obtain sampling data, storing the sampling data, and a baseline serving as a reference for detecting an object from the sampling data. Means for obtaining data and storing the baseline data, subtraction means for obtaining difference data between the sampling data and the baseline data, and comparing the difference data with a reference value to detect whether or not the object is touched Comparing means for, and when the touch of the object is detected by the output from the comparing means, the data processing of the sampling data, the control means for limiting to the sampling data in the vicinity where the touch is detected, The subtracting means and the comparing means are configured by hardware.

In order to solve the problem D, in the ultrasonic detection device of the present invention, the detection panel and the bezel are fixed by an adhesive that does not absorb sound waves. Further, according to the present invention, a spacer is fixed to the bezel by vibration welding, and the spacer is fixed to the detection panel with an adhesive having no sound wave absorbing power. Further, the present invention has a configuration in which a reinforcing member that reinforces the fixation between the detection panel and the bezel is attached between the back surface of the outer peripheral surface of the detection panel and the bezel. Further, in the present ultrasonic detection device, the detection panel and the bezel are fixed by vibration welding. Further, in the present invention, the vibration welding portion is provided on the outer peripheral surface of the detection panel outside the reflection array. Further, in the present invention, the distance between the vibration welded portion and the transmitter or the receiver is a certain value or more to avoid resonance between the volume elastic wave transmitted or received and the reflected wave of the volume elastic wave caused by the vibration welded portion. Separated by distance.

[0033]

In order to solve the problem A, the ultrasonic detection apparatus of the present invention sequentially calculates sampling data through a digital filter and stores the data, and as a result, the baseline data is not affected by drift. It is buffered and automatically updated with new data. In addition, the present invention includes smoothing processing means, and prevents erroneous detection due to noise by smoothing the difference data in the vicinity of the touch position while the object is touching the panel.

In order to solve the problem B, the present invention oscillates a plurality of ultrasonic waves having different wavelengths, and the ultrasonic wave is transmitted through different detection surface positions on the panel by different reflection array pairs for different wavelengths of the ultrasonic waves. Propagate to. Since different wavelengths of ultrasonic waves are made to correspond to different detection positions on the detection surface and the presence or absence of a touch at the corresponding detection positions is judged from the ultrasonic waves of the received wavelength, high resolution can be achieved regardless of the sampling speed. . Further, the present invention obtains the difference between the sampling data and the baseline data, calculates the interpolation data as the data of the non-sampling period between the sampling points of the sampling data by the interpolation method from the difference, and calculates the sampling data and the interpolation data. Since the touch position of the object is obtained from, high resolution can be achieved.

In order to solve the problem C, the present invention detects the presence / absence of a touch of an object from the selected sampling data, and when the touch of the object is detected, the data processing of the sampling data is performed in the vicinity where the touch is detected. Since the sampling data is limited to the sampling data of 1, the processing time of the sampling data is reduced, and thus the scanning time can be shortened.
Further, according to the present invention, since the subtraction means and the comparison means are configured by hardware, it is possible to quickly determine the presence or absence of a touch, so that the scanning time can be shortened.

In order to solve the problem D, the present invention adopts a structure in which the detection panel and the bezel are fixed by an adhesive that does not absorb sound waves, or the detection panel and the bezel are fixed by vibration welding. It is possible to realize an excellent waterproof and drip-proof structure while suppressing the volume acoustic wave absorption to the extent that it does not hinder touch detection.

[0037]

EXAMPLES Example A A schematic configuration of an example of an ultrasonic detecting apparatus of the present invention for solving the problem A will be described with reference to FIG. In FIG. 1, the shock wave of the ultrasonic wave output from the shock wave generator 11 is given to the X-axis switch 13 and the Y-axis switch 14 via the transmission amplifier 12. X-axis switch 13 and Y
The shock wave output from the shaft switch 14 is input corresponding to the X-axis transmitter 4a and the Y-axis transmitter 4b corresponding to the transmitter 4 provided in the panel 1 shown in FIG. The ultrasonic waves output from the X-axis transmitter 4a and the Y-axis transmitter 4b propagate in the X-axis direction and the Y-axis direction as surface acoustic waves on the panel surface, respectively, and the receiver provided in the panel 1 shown in FIG. 5 is received by the X-axis receiver 5a and the Y-axis receiver 5b. X-axis receiver 5
The surface acoustic waves received by the a and Y-axis receivers 5b are converted into ultrasonic electric signals and given to the corresponding X-axis switch 15 and Y-axis switch 16, respectively. It is input to the reception amplifier 17. The X-axis switches 13, 15 and the Y-axis switches 14, 16 are controlled by the microprocessor 26, and the X-axis switches 13, 15 or the Y-axis switch 1
It is controlled so that either one of 4, 16 turns on and the other turns off.

The ultrasonic signal amplified by the receiving amplifier 17 is sent to the demodulator 18, where the ultrasonic signal is AM.
(Amplitude modulation) Detected and converted to DC component. The output of the demodulator 18 is an A / D (analog / digital) converter 19
And is sampled at high speed over time. The sampling data from the A / D converter 19 is sent to the SRAM (Static Random Access Memory) 21 via the buffer 20 and stored therein.
The CPU 23 of the microprocessor 26 writes the sampling data stored in the SRAM 21 via the buffer 22 when the sampling operation of the A / D converter 19 is completed. The CPU 23 automatically corrects the sampling data stored in the SRAM 21 by performing digital filtering at regular intervals, stores the corrected data in the SRAM 21 as new baseline data, and thereafter uses this baseline data as a reference for the panel. The calculation for determining whether or not there is a touch on the object 1 and the calculation for determining the coordinates of the touch position are performed. The CPU 23 is the buffer 20,
22 to control the direction of data flow. In addition to the CPU 23, the microprocessor 26 includes a RAM 24 used for storing the calculation of the CPU 23 and a ROM 25 storing a calculation program. The touch-on / touch-off and touch position coordinate data determined by the CPU 23 are sent to the host computer 28 via the interface 27.

Next, the presence / absence of touch-on of the object and the position coordinate detecting operation according to the present invention will be briefly described. First, prior to the detection operation, shock waves are output in the X-axis direction and the Y-axis direction, respectively, and ultrasonic sampling data corresponding to the X-axis and the Y-axis are digitally filtered to serve as baseline data for the SRAM 21. Be stored in. The X-axis detection operation is performed in a state where the X-axis switches 13 and 15 are on (the Y-axis switches 14 and 16 are off). That is, the shock wave is intermittently output from the shock wave generator 11,
The sampling data of the ultrasonic electric signal based on the shock wave through the A / D converter 19 is SRAM2 as the measurement data.
1 is stored. Further, the RAM 24 is set with reference level values for the X-axis and the Y-axis, which are used as references for determining the presence or absence of touch-on. CPU23 is ROM2
The detection operation of the measurement data is performed according to the calculation program stored in 5.

The flow chart of FIG. 2 shows the detecting operation of the present invention, and in step S1, the sampling time for starting the reception of the measurement data representing the ultrasonic electrical signal (hereinafter,
The start value) and the sampling time of the reception end (hereinafter referred to as the end value) are read from the SRAM 21 and stored in the register of the CPU 23. In step S2, the reference level value related to the X axis stored in the RAM 24 is written in the CPU 23. Next, in step S3, the baseline data and the measurement sampling data stored in the SRAM 21 are read out to the CPU 23, and the difference data between the measurement sampling data and the baseline data is obtained at each sampling time. It is calculated and stored in the register of the CPU 23. Next, in step S4, as shown in FIG. 25, the maximum difference data among the difference data is obtained, and it is determined whether or not it exceeds the reference level Ath stored in the register. When it exceeds the reference level, the sampling time is set to X _M and stored in the register, and the process proceeds to the next step S5. The Y-axis switches 14 and 16 are turned on, and steps S1 to S4 are similarly executed for the Y-axis, and the maximum difference data for the Y-axis ultrasonic wave exceeds the reference level value for the Y-axis. If it is determined that the object is touched (touch-on) on the panel 1, the process proceeds to step S6. In step S6, X corresponding to the sampling time X _M
The position of the axis is specified as the touch-on X coordinate, and similarly the Y coordinate is specified. CPU23 in step S7
Sends data indicating touch-on to the host computer 28 together with its coordinate data.

If the maximum difference data does not exceed the reference level value in step S4, it is considered that there is no touch-on, and the operation of detecting the next measurement sampling data on the X axis is repeated without proceeding to step S5. Further, even if the maximum difference data regarding the Y axis does not exceed the reference level value in step S5, it is determined that touch-on has not been detected, and the detection operation is repeated without proceeding to step S6.

Prior to the above-described detection operation, the baseline data is updated in real time by sampling at regular intervals. Here, the principle of digital filtering applied to the present invention will be briefly described. Real-time filtered values of the newly measured sampled data are used to eliminate baseline data drift. Generally, in an analog circuit, the response f after t seconds when the step unit signal 1 is given to the first-order lag element is

F = 1−exp (−t / τ) (1) Response f _n when t = nΔt, t =
Assuming that the response f _{n + 1} at the time of (n + 1) Δt is Δt sufficiently small with respect to the time constant τ, approximately,

## EQU10 ## f _{n + 1} = f _n + (Δt / τ) (1-f _n ) (2) holds. Here, if τ = p · Δt is set,

F _{n + 1} = f _n + 1 / p · (1-f _n ) (3) Applying equation (3) to digital filtering,
The input signal is not always a step signal, so g _{n + 1}
Filtered value f _{n + 1 at} t = (n + 1) Δt
Is the filtered value f _{n at} t = nΔt and t
From the input value g _{n + 1 at} = (n + 1) Δt,

F _{n + 1} = f _n + 1 / p · (g _{n + 1} −f _n ) (4)

In the present invention, the CPU 23 stores the previously filtered baseline data f _{n at} t = nΔt stored in the SRAM 21 and the measured sampling data g at the current A / D converted t = (n + 1) Δt.
Baseline data f _{n + 1} which is digitally filtered this time from _{n + 1} is calculated by the equation (4). Here, p is p = τ from the sampling interval Δt and the time constant τ.
It is a constant obtained by / Δt. For example, if the sampling interval Δt = 30 msec and the time constant τ = 30 sec, then 1 / p = Δt / τ = 1/1000. Digital filtering operation is performed for each data corresponding to each sampling time (corresponding to coordinates) according to the equation (4) to update the baseline data, and the updated sampling data is replaced with the previous baseline data.
After updating the baseline data, the detection operation is performed based on this latest baseline data. This digital filtering mitigates the effects of fluctuations, so the baseline data that has been digitally filtered will not be affected if noise is added to the measured sampling data or if drift due to temperature occurs. . Further, even when the panel is touched, the touch time within the fixed delay time determined by the time constant τ does not affect the baseline data.

However, when the touch on the panel is continued for a long time, the influence of the touch appears on the digitally filtered baseline data from the measured sampling data, resulting in a large error. To solve this problem, digital filtering of the baseline data near the touch position, that is, updating only part of the baseline data, is not performed between the touch detection and the touch off detection. It may be configured (programmed).

Next, in addition to the above-mentioned correction of the baseline data, when noise occurs in the measurement sampling data and causes a malfunction, it is necessary to remove the noise from the measurement sampling data itself. An embodiment of the present invention that solves this problem will be described with reference to the flowchart of FIG. In step S11 shown in FIG. 3, the sampling time at which reception of measurement sampling data representing an ultrasonic electrical signal is started (hereinafter referred to as a start value) and the sampling time at which reception is ended (hereinafter referred to as an end value) are read from the SRAM 21. And stored in the register of the CPU 23. In step S12, the reference level value related to the X axis stored in the RAM 24 is written in the CPU 23. Next, moving to step 13, the baseline sampling data and the measurement sampling data stored in the SRAM 21 are read out to the CPU 23, and the difference data between the measurement sampling data and the baseline data corresponding to each sampling time is obtained. It is calculated and stored in the register of the CPU 23.

Next, in step S14, the CPU 23 obtains the n-th smoothed difference data ΔH _n by, for example, n-2, n-1, n, stored in the register.
n + 1, n + second difference data ΔA _n-2 , ΔA _n-1 , Δ
A _n , ΔA _{n + 1} , and ΔA _{n + 2} are read and the smoothing equation (5) is obtained.

ΔH _n = (1/8) (ΔA _n-2 + 2ΔA _n-1 + 2ΔA _n +2 ΔA _{n + 1} + ΔA _{n + 2} ) Calculate the smoothed difference data ΔH _n according to (5) and register it. Remember. Hereinafter, the detection operation is performed based on the smoothed difference data ΔH _n .

Next, in step S15, as shown in FIG. 25, the maximum difference data of the difference data is obtained and it is determined whether or not it exceeds the reference level Ath stored in the register. When the reference level is exceeded, the sampling time X _M is stored in the register, and the next step S1
Go to 6. The Y-axis switches 14 and 16 are turned on, and steps S11 to S15 are similarly executed for the Y-axis, and the maximum difference data for the Y-axis ultrasonic wave exceeds the Y-axis reference level value. If it is determined that the object is touched (touch-on) on the panel 1, the process proceeds to step S17. In step S17, the X-axis position corresponding to the sampling time X _M is the touch-on X
It is specified as a coordinate, and similarly, the Y coordinate is also specified. In step S18, the CPU 23 causes the host computer 2
The data indicating the touch-on is sent to 8 together with the coordinate data.

If the maximum difference data does not exceed the reference level value in step S15, it is considered that there is no touch-on, and the operation of detecting the next measurement sampling data on the X axis is repeated without proceeding to step S16. Further, even if the maximum difference data regarding the Y-axis does not exceed the reference level value in step S16, it is assumed that touch-on is not detected and step S17 is performed.
The detection operation is repeated without moving to.

The smoothing equation in step S14 is Δ
In addition to H _n ,

ΔH _n = (1/3) (ΔA _n-1 + ΔA _n + ΔA _{n + 1} ) (6)

[Number 15] _{ΔH n = (1/4) (ΔA} n-1 + 2ΔA n + ΔA n + 1) (7)

ΔH _n = (1/5) (ΔA _n-2 + ΔA _n-1 + ΔA _n + ΔA _{n + 1} + ΔA _{n + 2} ) (8) may be used. The smoothing equation may be weighted as in equations (5) and (7). Although the degree of weighting is free, as the weight for .DELTA.A _n is large, the value and the smoothed data .DELTA.A _n is close values. Further, the sampling data for smoothing may be smoothed not only at three points but also at a large number of points as shown in equations (6) and (7). In the smoothing formula, if the division value is set to 2 ^N (N is an integer), the division can be performed only by shifting bits in the arithmetic processing, so high-speed arithmetic is possible. is there. For example, (5)
If the formula is used, the number of divisions is 8 = 2 ³ , so division can be realized only by a bit shift of 3 bits.

As described above, smoothing processing is performed every time on all points of the measurement sampling data to smooth the measurement sampling data itself, and it is possible to prevent malfunction due to noise. However, smoothing all the measurement sampling data requires time for calculation and may slow down the operation speed. At this time, first, the presence or absence of a touch is determined using the unsmoothed difference data ΔA _n, and only when it is determined that there is a touch, the smoothing process is performed only on the difference data near the touch position. It is also possible to detect the touch position accurately at high speed.

The measurement sampling data can be digitally filtered using equation (4) to correct the baseline data at regular intervals, and the smoothing equation can be used to successively smooth the measurement sampling data. If the detection operation is performed using the calibrated baseline data and the smoothed measurement sampling data,
Malfunction due to drift and noise can be reliably prevented.

Example B An example of the present invention for solving the problem B will be described. FIG. 4A shows a panel 3 which constitutes the present invention.
1 is an example. A transmitter 32 for generating elastic waves in the X direction is provided at one corner of the panel 31, and a corner on a diagonal line from the one corner is provided for receiving the elastic wave in the X direction transmitted from the transmitter 32. A receiver 33 is provided. Similarly, a transmitter 34 for generating an elastic wave in the Y direction is provided at the one corner, and a corner diagonal to the one corner is provided for receiving the elastic wave in the Y direction transmitted from the transmitter 34. A receiver 35 is provided. A reflective array 36 including a plurality of reflective elements 2 is formed on four peripheral portions of the surface of the panel 31. At one peripheral portion in the X direction, the distance (pitch) between adjacent reflecting elements 2 and 2
Is different from the interval between the other adjacent reflecting elements 2, 2. The spacing between the reflecting elements 2 and 2 in the peripheral portion in the other X direction is equal to the spacing between the opposing reflecting elements 2 and 2 in the peripheral portion in the one X direction, and forms a pair of reflecting arrays in the X direction. are doing. This reflection array pair is provided at an angle at which the elastic wave transmitted from the transmission element 32 propagates at a right angle on the detection surface of the panel 31 by the reflection element of the corresponding reflection array pair and is received by the reception element 33.
Also in the peripheral portion of the panel 31 in the Y direction, there are provided reflective array pairs arranged in the same manner as in the peripheral portion of the X direction. X
Since the same operation is performed in the case of the direction and the case of the Y direction, only the case of the X direction will be described below.

For example, the ultrasonic wave output from the X-direction oscillator 32 propagates as shown in FIG. The ultrasonic wave is reflected by the reflecting element at the point A where the element spacing matches the wavelength of the propagating ultrasonic wave, and travels in the direction of the receiver 33 at the point B of the reflective array pair in FIG. 4A. Change. The distance between the reflecting elements 2 at the point B is equal to the distance between the reflecting elements 2 at the point A, and therefore equal to the wavelength of the propagating sound wave. Therefore, the sound wave reflected at the point A is reflected again at the point B, diverts its course again in the X-axis direction as shown in FIG. 4 (A), and is received by the receiver 33 in the X-direction in FIG. .
The sound wave reflected at the point A in FIG. 4A is not actually concentrated only at the point A but is distributed over the width of the sound wave propagation region S in FIG. 4A. The reason why such reflection is performed is that the reflection element is configured as a reflector of an elastic wave having frequency selectivity called a grating. That is, at a frequency at which the distance between the reflecting elements is an integral multiple of half the wavelength of the elastic wave, all the reflected elastic waves are added in the same phase, so a known phenomenon that strong reflection known as Bragg reflection occurs is used. ing.

In FIG. 4B, the coordinates of the left end of the detection surface in the X direction are X _L , the coordinates of the right end are X _R, and the intervals (pitch) of the reflecting elements at the respective coordinates are λ _XL and λ _XR . In the case, it is a figure which shows roughly the relationship of the distribution of the X coordinate on the X direction detection surface, and the space | interval of a reflective element. The pitch distribution of the reflective element does not necessarily have to be in a linear relationship with the element position X as shown in FIG. In FIG. 4B, the wavelength λ transmitted from the transmitter 32 with respect to the X coordinate is

Equation 17] represented by _{λ = (λ XR -λ XL)} / (X R -X L) · (X-X L) + λ XL = a · X + b (9). For example, in order to generate a sound wave of λ = 0.6 mm, f = 3000 (m / sec) /0.6 (mm) when the speed of sound in glass is about 3000 m / sec.
It is necessary to cause the oscillator 32 to generate vibration of 5 MHz. Here, from the transmitter 32 in the X direction, the wavelength λ = λ _XL ~
When a sound wave in the range of λ _XR is emitted and received by the receiver 33 and the intensity of the received sound wave with respect to the wavelength λ is measured, it becomes as shown in FIG. In the figure, the solid line is the received sound wave intensity distribution when the finger is not touched, and this is the baseline. When touched with a finger, a sound wave having a wavelength λ = λ _X equal to that of the reflecting element corresponding to the touched X coordinate position is absorbed by the finger and falls below the baseline as shown by the dotted line in the figure. To be exact, the wavelength at the point of the lowest fall from the baseline should be λ _X. By substituting λ = λ _X into the equation (9),

[Equation 18] X = (λ _X −b) / a (10) calculates the touched X coordinate position.

FIG. 6 is a circuit configuration diagram for solving the problem B. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In FIG. 6, the microprocessor 26 sequentially time-divisionally outputs different digital values that increase at a constant rate.
Output to the D / A converter 41. The D / A converter 41 sequentially converts the input digital value into a corresponding analog voltage value and applies the voltage value v to the voltage controlled oscillator (VCO) 42. The voltage control oscillator 42 sequentially outputs shock waves that are sine waves of different frequencies corresponding to the voltage value v. A so-called V / F converter (voltage-frequency converter) may be used instead of the voltage control oscillator 42.

The shock wave output from the voltage control oscillator 42 is applied to the X-axis switch 13 and the Y-axis switch 14 via the transmission amplifier 12, and the signal passed through the X-axis switch 13 is transmitted to the oscillator 32 and The signals passed through the Y-axis switch 14 are given to the transmitters 34, respectively. Further, the shock wave is also given to the waveform shaper 43, where the sine wave is shaped into a rectangular wave and output to the counter 44. The counter 44 counts the shaped rectangular pulse,
The count value is output to the microprocessor 26. The waveform shaper 43 may not be provided in particular. By using the counter 44, the input voltage v to the voltage controlled oscillator 42
And the output frequency f, the voltage v
When the voltage is applied to the voltage control oscillator 42, the frequency f can be obtained in real time.

When the oscillators 32 and 34 are driven at a frequency f, ultrasonic waves having a wavelength λ of λ = c / f (where c is the speed of sound in a sensor plate, eg glass) are generated. This ultrasonic wave is received by the receiver 33 or 35 as described above, and is given to the microprocessor 26 via the X-axis switch 15 or the Y-axis switch 16, the reception amplifier 17, the demodulator 18, and the A / D converter 19, respectively. , Is saved in the RAM 24 as sampling data. RAM24 is
When the number of data to be stored is large, the microprocessor 26
It may be provided outside of.

The microprocessor 26 controls the input voltage v to the voltage control oscillator 42 via the D / A converter 41 to change the frequency (and hence the wavelength λ) of the ultrasonic wave stepwise, as shown in FIG. Sampling data when not touching is first obtained, and RAM2 is used as baseline data.
Store in 4. At this time, the counter 44 is operated for a fixed time T
The frequency f = K / T is calculated from the count value K sequentially sent every time, and the wavelength is further calculated by the formula λ = c / f.
The coordinates are calculated according to 0) and are sequentially stored in the RAM 25.
As a result, the baseline data and the coordinates correspond.

Measurement sampling data is obtained in the same frequency (wavelength) range for which the baseline data is obtained, and calculation for determining whether or not there is a touch of an object on the panel 1 and calculation for determining the coordinates of the touch position are performed. The shock wave is output stepwise from the voltage control oscillator 42, and the sampling data of the ultrasonic electric signal based on the shock wave through the A / D converter 19 is R as measurement data corresponding to the frequency (wavelength).
It is stored in the AM 24. The RAM 24 is set with reference level values for the X-axis and the Y-axis, which are used as references for determining the presence or absence of touch-on. The CPU 23 performs a measurement data detection operation according to an arithmetic program stored in the ROM 25.

The flow chart of FIG. 7 shows the detection operation of the present invention, and in step S31, the sampling time at which the measurement data representing the ultrasonic electric signal starts to be received (hereinafter referred to as a start value) and the sampling time at the end of reception ( Hereinafter, referred to as an end value) is read from the RAM 24 and stored in the register of the CPU 23. Step S32
At, the reference level value related to the X axis stored in the RAM 24 is written in the CPU 23. Then step S3
3, the baseline sampling data and the measurement sampling data stored in the RAM 24 are stored in the CPU 2
3, the difference data between the measurement sampling data and the baseline data is calculated corresponding to each frequency (wavelength), and stored in the register of the CPU 23. Next, in step S34, as shown in FIG. 25, the maximum difference data among the difference data is obtained, and it is determined whether or not it exceeds the reference level Ath stored in the register. When it exceeds the reference level, the frequency (wavelength) is set to λ _X and stored in the register, and the routine goes to the subsequent Step S 35. The Y-axis switches 14 and 16 are turned on, and steps S31 to S34 are similarly performed for the Y-axis, and the maximum difference data for the Y-axis ultrasonic wave exceeds the Y-axis reference level value. If it is determined that
It is determined that there is an object touch on the panel 1 (touch-on), and the process proceeds to step S36. In step S36, the position of the X axis corresponding to the sampling frequency (wavelength) λ _X is specified as the touch-on X coordinate, and similarly the Y coordinate is also specified. In step S37, the CPU 23 sends touch-on data to the host computer 28 together with the coordinate data. If the maximum difference data does not exceed the reference level value in step S34, it is considered that the touch-on has not occurred, and the operation of detecting the next measurement sampling data on the X axis is repeated without moving to step S35. Even if the maximum difference data regarding the Y-axis does not exceed the reference level value in step S35, it is determined that touch-on has not been detected, and the detection operation is repeated without proceeding to step S36.

The received ultrasonic wave intensity distribution of FIG. 5 is obtained, for example, by sampling the A / D converter 19 discretely at equal intervals as shown in FIG. This sampling speed is D / A time-divisionally from the microprocessor 26.
Since it is related to the voltage v applied to the voltage control oscillator 42 via the converter 41, it can be freely adjusted without being directly affected by the speed of sound. Therefore, the A / D converter 19
Does not need to be particularly fast. The resolution of the measurement sampling data is determined in principle by the resolution of the voltage v applied to the voltage control oscillator 42, and hence the resolution of the D / A converter 41. Further, since the time for sampling one point can be set long if necessary, the demodulator 18
Since the time constant of the smoothing circuit can be made sufficiently long in the AM detection performed in (1), the ripple of the AM detection output (and therefore the A / D conversion input) can be sufficiently removed, and highly accurate signal measurement can be performed. .

In order to improve the touch detection resolution without increasing the sampling speed, it is possible to use the curve complement method. In this method, optimum touch position data between points actually sampled is obtained based on actual sampling values in the vicinity of the points. There are various interpolation methods, for example, there is a primary interpolation method using a polynomial, a secondary interpolation method, a tertiary interpolation method ,. Here, a case where the quadratic interpolation method is used will be described as an example. In FIG. 9, ΔA _n-1 , ΔA _n , Δ
A _{n + 1} and ΔA _{n + 2} are A / D conversion values (differences from the baseline) sampled at the time points of t = t _n-1 , t _n , t _{n + 1} , and t _{n + 2.} . Since sampling is performed at equal intervals, the interval is set to h, and D _n−1 , D _n , and
Defining D _{n + 1} , k, k ₁ ,

[Formula 19] D _n-1 = ΔA _n −ΔA _n-1 D _n = ΔA _{n + 1} −ΔA _n D _{n + 2} = ΔA _{n + 2} −ΔA _n-1 k = (t−t _n ) / h k ₁ = k (1-k) / 4 (11) Here, if t _n '= (t _n + t _{n + 1} ) / 2, then (1
From equation 1)

## EQU20 ## k = (t _n '-t _n ) / h = (t _{n + 1} -t _n ) / 2h k ₁ = k (1-k) / 4. On the other hand, the quadratic interpolation formula of the difference ΔA (t) from the baseline for interpolating the time point of t is

ΔA (t) = ΔA _n + kD _n −k ₁ (D _{n + 1} −D _n−1 ) (12) Therefore, the difference Δ at time t _n '
A _n 'is calculated by the equation (12).

The value of this difference ΔA _n 'is determined at the time points t _n and t _{n + 1.}
The value of the intermediate time point t _n 'of is obtained by the interpolation method.
Further, it is possible to obtain an arbitrary number between t _n and t _{n + 1} by the equations (11) and (12). Although the data processing by the quadratic interpolation method has been described, if a higher order interpolation method is performed, a more accurate value can be calculated, but the calculation takes time. Further, it is not efficient to perform the data processing by the complementing method for all the difference data because the processing time becomes enormous, so for the touch position (for example, the maximum difference value) obtained by detecting the touch in advance by the data before the complementing, It is sufficient to apply the complementary method to the difference data in the vicinity.

To obtain the touched position by the quadratic interpolation method, for example, as shown in FIG. 11, when the maximum difference directly known from the sampling data is ΔA _n , ΔA _n-1 ,
Substituting ΔA _n , ΔA _{n + 1} , and ΔA _{n + 2} into equations (11) and (12) to obtain ΔA _n ′, and further calculating ΔA _n-2 , ΔA _n-1 , and Δ
Substituting A _n and ΔA _{n + 1} into the equations (11) and (12), t _n-1
And a difference ΔA _n-1 ′ between t _n and t _n is calculated. Then Δ
The maximum value of A _n-1 ', ΔA _n , and ΔA _n ' is set as the touched position.

Practical Example C As described in Problem C, since the ultrasonic detection apparatus has a large number of data points, the data processing time becomes long and the scanning time becomes long. Therefore, if the data processing after sampling is made faster, the scanning speed becomes faster. For example, the width of the finger is 1
Since it is about 0 mm, when the panel 1 is touched with a finger, the sampled A / D conversion value decreases from the baseline value due to the absorption of sound waves only at the finger width part. Therefore, when the resolution is 0.3 mm, 10 / 0.3 = 33 points, so that it is sufficient to perform data processing on, for example, about 50 points before and after the touched position. For example, when the processing time is calculated under the same conditions as in the case of task C, it becomes about 0.5 ms, and when the X and Y coordinates are combined, it becomes 1.0 ms. The driving time of the A / D converter and the other processing time are added to this, resulting in about 4 ms. Further, even if noise smoothing or the like is performed, only about 2 to 3 ms is added, and the scanning time falls within about 6 to 7 ms. This scanning time is a speed that can sufficiently follow the operation time of the tablet. If a 16-bit microprocessor and a high-speed clock are used, the scanning time will be faster.

The flowchart of FIG. 10 which operates in the ultrasonic detection apparatus shown in FIG. 1 shows an embodiment of the present invention. In step S41, the sampling time for starting the reception of the measurement data representing the ultrasonic electrical signal (hereinafter , The start value) and the sampling time of the reception end (hereinafter,
(Called the end value) is read from the SRAM 21 and CP
It is stored in the register of U23. In step S42, the reference level value related to the X axis stored in the RAM 24 is written in the CPU 23. Next, in step S43, selected one of the sampling data stored in the SRAM 21, for example, measurement sampling data at intervals of one or two and baseline data corresponding to the measurement sampling data are read by the CPU 23. , The difference data between the two data is calculated and stored in the register of the CPU 23. Next, in step S44, it is determined for each sampling time from the start value to the end value whether or not the difference data exceeds the reference level Ath stored in the register, and the sampling time that first exceeds the reference level Ath is determined. the first time X _L, are respectively stored in the registers sampling time immediately before the following again the reference level from exceeding a reference level as a second time point X _R. If the difference data exceeds the reference level value, the process proceeds to step S45, the Y-axis switches 14 and 16 are turned on, and steps S41 to S are similarly performed for the Y-axis.
44 is executed, and if it is determined that the difference data for the Y-axis ultrasonic wave exceeds the reference level value of the Y-axis, it is determined that an object is touched (touch-on) on the panel 1 and the step is performed. Move to S46.

[0067] is the value X _L -C start value setting constant C for region setting stored is obtained by subtracting the C from the sampling time X _L read in RAM24 in step S46, the C sampling time X _R The added value X _R + C is set as the end value and stored in the register of the CPU 23. In step S47, all measurement sampling data between the start value and the end value are read without being selected,
Each difference data is calculated from the corresponding baseline data and stored in the register. Then, the maximum difference data is obtained from each difference data, and the sampling time is set to X _M and stored in the register, and the next step S4
Go to 8. Similarly for the Y-axis, steps S46 and S4
7 is executed. In step S49, the position of the X axis corresponding to the sampling time X _M is specified as the touch-on X coordinate, and similarly the Y coordinate is also specified. In step S50, the CPU 23 sends touch-on data to the host computer 28 together with the coordinate data. Since the sampling time and the coordinate have a one-to-one correspondence, if the setting constant C is set to about 10, detailed data processing may be performed on the difference data of about 50 points.

If the difference data does not exceed the reference level value in step S44, it is considered that there is no touch-on, and the operation of detecting the next measurement sampling data on the X axis is repeated without proceeding to step S45. Further, even if the difference data regarding the Y axis does not exceed the reference level value in step S45, the touch-on is not detected, and the detection operation is repeated without proceeding to step S46.

[0069] At the step S41 to S45, the time series of _{sampling, X 0, X 1, ...} , X 0 with respect to X _n,
X _1, ..., and instead of sequentially reading, for example, X ₀ in one interval, X _2, X _4, ..., a, or, X ₀ in two intervals,
, X ₃ , X ₆ , ... Are read at a predetermined interval, data is read, and the above determination operation is performed to obtain X _L and X _R. If the data reading interval is provided, the data processing time can be shortened and the scanning speed can be increased. X
_{After L} and X _R have been obtained, the data from the start value to the end value are subjected to the data processing of steps S46 to S50 without a gap.

[0070] a judgment of the touch whether fast hardware, micro knowing period X _L to X _R touch there earlier, the data of the neighborhood thereafter as previously described in that X _L to X _R Alternatively, the data may be fetched into the processor 26 and only that portion may be processed in detail. FIG. 11 shows an embodiment of a circuit for rapidly detecting whether or not an object touches the panel by hardware. FIG. 11 is a circuit diagram of FIG. 1 which includes an SRAM 51 for storing a baseline, a subtractor 52, a comparator 53,
A timing generation circuit 54 is added. The microprocessor 26 controls the SRAM 51, the comparator 53, the timing generation circuit 54, and the timing generation circuit 54.
Is an A / D converter 19, a buffer 20, a SPRAM 21,
The operation timing of 51 and the subtractor 52 is controlled. FIG.
The signal demodulated by AM in the demodulator 18 of
9 is converted into, for example, 8-bit data P, and SRA
It is stored in M21. At the same time, this data P
The data is input to one end of 2 and is also given to the buffer 22. On the other hand, the baseline sampling data is stored in the SRAM in advance.
51 and the microprocessor 26 is A /
The sampling data Q of the baseline corresponding to the same position as the D-converted measurement sampling data P is stored in the SRAM 5
Output from 1 and input to the other end of the subtractor 52. Then, the subtracter 52 calculates the difference ΔA = Q− between the two inputs P and Q.
P is output to one input terminal of the comparator 53. If the data P and Q are 8-bit data, ΔA is also 8-bit data, but a borrow signal may be output.
At the other input terminal of the comparator 53, the microprocessor 2
A reference value Ath for touch-on / off is input from 6.
This Ath is also a digital value. For example, if ΔA is 8 bits, Ath will also be 8 bits. The comparator 53 compares the magnitudes of these two inputs ΔA and Ath and outputs a determination signal of the magnitude. This signal is read by the microprocessor 26.

FIG. 12 shows a scanning flow using the circuit of FIG. 11, and in step S51, the X-axis detection operation is performed with the X-axis switches 13 and 15 turned on (Y-axis switches 14 and 16 turned off). Then, the circuit shown in FIG. 11 calculates the difference ΔA at the same time as sampling the measurement data, compares the difference ΔA with the reference value Ath, and informs the microprocessor 26 of the result. When the difference exceeds the reference value, the following detailed data processing is executed. In step S52, the setting constant C for setting the area stored in the RAM 24 is read. Step S
First, the sampling time X stored in the register of the CPU 23 at 53 exceeds the reference level Ath.
_L and the sampling time X _R just after the reference level is exceeded and immediately before it becomes less than the reference level, and from the set constant C, X _L
The value X _L -C minus the C from is the starting value, C to X _R
The value X _R + C to which is added is set as the end value and stored in the register of the CPU 23. Next, in step S54, the measurement sampling data and the baseline sampling data stored in the SRAM 21 and the SRAM 31 from the start value to the end value are read out by the CPU 23, and the measurement sampling data corresponding to each sampling time is obtained. The difference data from the baseline data is calculated and CP
It is stored in the register of U23. Next, the process proceeds to step S55, the maximum difference data among the difference data is obtained and set as X _M , and the process proceeds to the next step S56. Y-axis switch 14, 1
6 is switched on and the difference is similarly calculated for the Y axis and compared with the reference value. If the difference exceeds the reference value, steps S51 to S55 are then executed, and the maximum difference data is calculated for the Y-axis ultrasonic wave. In step S57, X corresponding to the sampling time X _M
The position of the axis is specified as the touch-on X coordinate, and similarly the Y coordinate is specified. CPU2 in step S58
3 sends data indicating touch-on to the host computer 28 together with its coordinate data.

If the difference data does not exceed the reference level value in step S51, it is considered that touch-on has not occurred, and the operation of detecting the next measurement sampling data on the X axis is repeated without proceeding to step S52. Further, even if the difference data regarding the Y-axis does not exceed the reference level value in step S56, it is determined that touch-on is not detected, and the detection operation is repeated without proceeding to step S57.

It is also possible to detect the touch by using the circuit of FIG. 11 and by a procedure different from the procedure of the flow of FIG. That is, all the A / D converted values by the A / D converter 19 are stored in the SRAM 21 in advance, and after the A / D conversion is completed, the measured sampling data is output from the SRAM 21 and the baseline data corresponding to the data is output from the SRAM 51. Each of them is output, and the judgment result of the magnitude with the reference value Ath of the touch presence judgment is fetched into the microprocessor 26 via the subtractor 52 and the comparator 53. In this case, the data output from the SRAMs 21 and 51 may be sequentially performed from time X ₀ , for example.

Example D FIGS. 13 to 18 show an example of the ultrasonic detecting device of the present invention which utilizes a volume elastic wave having a completely sealed structure for waterproofing and drip-proofing. It is known that shear mode acoustic waves do not propagate in a fluid among bulk acoustic waves. Therefore, even if a material having a low viscosity, such as liquid silicone rubber, which does not absorb sound waves is used as an adhesive having a closed structure, the sound waves are not relatively absorbed, so that the touch can be detected.

FIG. 13 shows a structure in which the bezel 10 and the glass detection panel 1 are bonded together with a liquid silicone rubber 61. The adhesive surface between the bezel 10 and the detection panel 1 is completely waterproof,
Take a wide width until a sealed structure that is drip-proof can be realized.
Since the liquid silicone rubber cures at room temperature, there is no risk of the liquid spilling after bonding. The reflective array 3 is the bezel 1
It is provided on the inner surface of 0 and near the outer periphery of the detection panel 1. Since the adhesive force of the silicone rubber 61 is not strong (for example, double-sided tape), in order to prevent peeling,
The supporter 62 is applied to the back surface of the detection panel 1 and fixed to the bezel 10 with screws. In order to fix the supporter 62 to the bezel 10, it is also possible to use, for example, double-sided tape instead of screwing. The supporter 62 may use a spring that is somewhat effective. Since the supporter 62 is for reinforcement, it is sufficient to stop the supporter 62 at an appropriate position on the detection panel 1.

FIG. 14 is substantially the same as the structure of FIG. 13 in which the bezel 10 is fixed to the detection panel 1 with the liquid silicone rubber 61, but the bezel 10 and the glass detection panel 1 are made to facilitate the assembly process. The spacer 63 is interposed between the two. First, a spacer 63 is attached to the detection panel 1.
Are bonded with, for example, silicone rubber 61, and then the bezel 1
0 and the spacer 63 are adhered to each other with a double-sided tape 64 in a completely sealed manner. Similar to FIG. 13, since the adhesive force of the silicone rubber 61 is weak, the supporter 62 is applied to the detection panel 1 and the bezel 10 is pressed.
Secure with screws to reinforce. In FIG. 14, the reflection array 3 is provided on the back surface near the outer periphery of the detection panel 1, but when it is provided on the front surface of the detection panel as shown in FIG. 13, a space in the lateral direction is required in addition to the spacer 63. This is to improve this because the number of detection surfaces decreases. The reflection array 3 is protected by a waterproof and drip-proof structure as in FIG. In the volume acoustic wave method, the surface of the detection panel 1 on the opposite side of the reflection array 3 can be used as a touch surface.

FIG. 15 is similar to the structure of FIG. 14 in which the spacer 63 is interposed between the bezel 10 and the detection panel 1 and is fixed by the liquid silicone rubber 61, but the structure is made stronger than the structure of FIG. Is. The two spacers 63 are slightly separated from each other and lightly fixed to the surface of the glass detection panel 1 with the double-faced tape 65 in advance, and then the space between the spacers 63 is filled with the liquid silicone rubber 61 to detect the spacer 63. Fixed to 1. Since the double-sided tape 65 used at this time is for temporary fixing, it does not matter if it has a small width, and there is no problem in detecting the touch. After that, the upper surface of the spacer 63 and the rear surface of the bezel 10 are removed as shown in FIG.
A double-sided tape 66 having a wide width as shown in FIG. FIG.
4, the reflection array 3 is provided on the back surface of the detection panel 1, and the bezel 10 is attached to the detection panel 1 by the supporter 62.
Fixed to.

FIG. 16 shows a structure in which the spacer 62 and the bezel 10 shown in FIG. 14 are fixed to the double-sided tape 64 by vibration welding, which is a completely waterproof structure. A material that can be vibration-welded, such as acrylic or plastic, is used as the material of the spacer 67, and as shown in the figure, the bezel 10 and the spacer 67 are welded by vibration welding. As shown in FIG. 16, if the burr pool 68 is prepared in advance when vibration welding is performed, vibration welding can be easily performed. The other structure is similar to that of FIG.

FIG. 17A shows a structure in which the bezel 10 and the detection panel 1 are directly welded by vibration welding when a material that can be vibrationally welded such as acrylic or plastic is used for the bezel 10 and the detection panel 1. The reflection array 3 is provided on the back surface of the outer peripheral portion of the detection panel 1. The reason why the tip of the bezel 10 is projected so as to cover the reflection array 3 is to prevent the reflection array 3 from entering the field of view. As shown in the figure, when the position of the vibration welded portion 69 on the surface of the detection panel 1 is set to the outer peripheral portion of the detection panel 1 rather than the position of the reflection array 3, the influence of reflection of sound waves by the welded portion 69 is eliminated. Normally, the positions of the vibration welded portions 69 at the four corners of the detection panel 1 are provided along the ridge line as shown by the dotted line in FIG. 17B, but it is preferable to bend the four corners as shown by the solid line. As shown in FIG. 18, the distance between the oscillator 4 or the receiver 5 and the vibration welded portion 69 is such that the shock wave (burst) of the sound wave emitted from the oscillator 4 or the receiver 5 is reflected by the vibration welded portion 69. This is to keep the distance L above a certain level in order to avoid resonating and disturbing the wave motion.

[0080]

According to the present invention, the baseline data is updated by performing digital filtering on the measured sampling data, so that even if noise is instantaneously added, the baseline data is hardly affected. Also,
Even if the panel is touched, the baseline data is not immediately affected within a certain time by digital filtering. In addition, if the digital filter processing is not performed on the baseline near the touched position from the time when the touch is detected until the touch-off is detected, even if a certain position is continuously touched for a long time. There is no error in the baseline. Therefore, it is possible to prevent malfunction.

Further, according to the present invention, since the measurement sampling data is smoothed, noise is eliminated from the smoothed measurement sampling data itself, so that malfunction can be prevented. In addition, if the baseline data is corrected by digital filtering and the measurement sampling data is smoothed, it is possible to eliminate the fluctuation of the baseline, the electric noise, etc., and to reliably prevent the malfunction.

Further, according to the present invention, by changing the wavelength (frequency) of the ultrasonic wave to be transmitted, it is possible to detect the touch position with high accuracy without requiring high-speed sampling. Since it is not necessary to increase the sampling speed in particular, it is not necessary to perform high-speed design on the circuit, and the circuit design is correspondingly easy and inexpensive. Further, since it is not necessary to use a high speed IC, the current consumption of the circuit can be suppressed to a low level. Further, according to this aspect of the invention, since the data between the actual measurement sampling points is calculated by the interpolation method, the coordinate data having a higher resolution than the actual measurement can be obtained without requiring high-speed sampling.

Further, according to the present invention, the position touched by high-speed data processing by using only the selected sampling data of the measurement sampling data or by constructing the subtraction means and the comparison means in hardware. Is detected and the touch coordinates are acquired by performing detailed data processing only in the vicinity of the touch position, so that high-speed scanning can be performed, and high-speed input equivalent to a tablet can be performed.

Further, according to this invention, since the bezel is fixed to the detection panel with an adhesive having no sound wave absorbing power, a waterproof and drip-proof closed structure can be provided without impairing the detection of touch. . Further, according to this aspect of the invention, the spacer is fixed to the bezel by vibration welding, and the spacer is fixed to the detection panel with an adhesive that does not absorb sound waves. Therefore, it is easy to manufacture a waterproof and drip-proof closed structure. Can be done. Further, according to this invention, since the reinforcing member for reinforcing the fixation between the detection panel and the bezel is attached between the back surface of the outer peripheral surface of the detection panel and the bezel, the waterproof and drip-proof closed structure is firmly configured. be able to. Further, according to this invention, since the detection panel and the bezel are fixed only by vibration welding, it is possible to provide a completely waterproof and drip-proof closed structure. Further, according to this invention, since the vibration welding portion is provided on the outer peripheral surface of the detection panel outside the reflection array, it is possible to avoid the influence of the reflection of the sound wave at the welding portion. Further, according to this invention, the distance between the vibration welding portion and the transmitter or the receiver avoids resonance between the transmitted or received volume elastic wave and the reflected wave of the volume elastic wave caused by the vibration welding portion. Since they are separated by a certain distance or more, it is possible to prevent the shock wave of the sound wave emitted from the transmitter or the receiver from resonating with the reflected wave by the vibration welding portion to disturb the wave.

[Brief description of drawings]

FIG. 1 is a schematic overall configuration diagram of an ultrasonic detection device of the present invention.

FIG. 2 is a flowchart showing a detection operation of the ultrasonic detection device of the present invention.

FIG. 3 is a flowchart showing another detection operation of the ultrasonic detection device of the present invention.

FIG. 4 is a diagram showing a panel surface on which an ultrasonic wave is propagated and a principle of a detection operation of the ultrasonic detection device of the present invention.

FIG. 5 is a diagram showing the intensity distribution of a received ultrasonic signal as a change in wavelength.

FIG. 6 is a schematic overall configuration diagram of an ultrasonic detection device of the present invention.

FIG. 7 is a flow chart showing an embodiment of a detection operation of the ultrasonic detection device of the present invention.

FIG. 8 is a diagram showing an example of sampling of a received ultrasonic signal.

FIG. 9 is a diagram illustrating an interpolation method of the present invention.

FIG. 10 is a flowchart illustrating an embodiment of the detection operation of the present invention.

FIG. 11 is a main part configuration diagram of an embodiment of an ultrasonic detection device of the present invention.

FIG. 12 is a flowchart illustrating an embodiment of data scanning of the present invention.

FIG. 13 is a main part configuration diagram of an embodiment showing a waterproof structure of the ultrasonic detection device of the present invention.

FIG. 14 is a main part configuration diagram of an embodiment showing a waterproof structure of the ultrasonic detection device of the present invention.

FIG. 15 is a main part configuration diagram of an embodiment showing a waterproof structure of the ultrasonic detection device of the present invention.

FIG. 16 is a main part configuration diagram of an embodiment showing a waterproof structure of the ultrasonic detection device of the present invention.

FIG. 17 is a cross-sectional view of a main part of an embodiment showing a waterproof structure of an ultrasonic detection device of the present invention and a plan view of a detection panel showing a vibration welding position.

FIG. 18 is a main part configuration diagram of one embodiment showing a waterproof structure of the ultrasonic detection device of the present invention.

FIG. 19 is a diagram showing a panel surface of an ultrasonic detection device in which ultrasonic waves are propagated.

FIG. 20 is a view showing a mounting structure of a transmitter that transmits ultrasonic waves.

FIG. 21 is a diagram showing a state of a reception signal of ultrasonic waves propagated through a panel and received.

FIG. 22 is a diagram showing the time course of the voltage of the received ultrasonic signal.

FIG. 23 is a diagram for explaining sampling of received ultrasonic signals.

FIG. 24 is a diagram showing a sampled ultrasonic signal as a reference baseline.

FIG. 25 is a diagram showing a difference between measurement sampling data with touch-on and a baseline.

FIG. 26 is an overall external view of a liquid crystal display device used in an ultrasonic detection device.

FIG. 27 is a main part configuration diagram showing a conventional example of a waterproof structure of an ultrasonic detection device.

FIG. 28 is a main part configuration diagram showing a conventional example of a waterproof structure of an ultrasonic detection device.

FIG. 29 is a diagram illustrating a reason why a detection malfunction occurs due to noise.

FIG. 30 is a diagram for explaining another reason why a detection malfunction due to noise occurs.

[Explanation of symbols]

1 Detection Panel 2 Reflection Element 3 Reflection Array 4 Transmitter 5 Receiver 6 Detection Surface 9 Object 10 Bezel 19 A / D Converter 21 SRAM (Static Random Access Memory) 23 CPU 24 RAM 25 ROM 26 Microprocessor 31 Panel 32 oscillator 33 receiver 34 oscillator 35 receiver 41 D / A converter 42 voltage control oscillator 43 waveform shaper 44 counter 51 SRAM 52 subtractor 53 comparator 54 timing generation circuit 61 liquid silicone rubber 62 supporter 63 spacer 69 Vibration weld

Claims (14)

[Claims] 1. A position of an object for absorbing an ultrasonic wave propagating on the panel, comprising a receiver for propagating the ultrasonic wave transmitted from a transmitter in the X direction and the Y direction of the panel and receiving the ultrasonic wave. Alternatively, in an ultrasonic detection device for detecting the presence or absence, sampling means for sampling ultrasonic waves propagating through the panel, a digital filter for digitally filtering the sampled data, and an object for detecting the digitally filtered data. An ultrasonic detection device, comprising: a storage unit that stores baseline data that serves as a reference. 2. The ultrasonic wave according to claim 1, further comprising a data selection unit that excludes sampling data in the vicinity of the touch position while the object is touching the panel from the baseline data. Detection device. 3. A position of an object that absorbs the ultrasonic wave propagating on the panel, the ultrasonic wave being transmitted from the transmitter, propagating in the X direction and the Y direction of the panel, and having a receiver for receiving the ultrasonic wave. Alternatively, in an ultrasonic detection device for detecting the presence or absence, sampling means for sampling the ultrasonic waves propagating through the panel, storage means for storing the sampled data as baseline data to be a reference for detecting an object, at least , Each difference data between the sampling data sampled in the vicinity of the touch position while the object is touching the panel and the baseline data stored in the storage means corresponding to each position of the sampling data, And a smoothing processing means for smoothing the respective difference data with each other. Output device. 4. A position of an object which absorbs the ultrasonic wave propagating on the panel, the ultrasonic wave being transmitted from a transmitter and propagating in the X direction and the Y direction of the panel and having a receiver for receiving the ultrasonic wave. Alternatively, in an ultrasonic detection device for detecting the presence or absence, sampling means for sampling ultrasonic waves propagating through the panel, a digital filter for digitally filtering the sampled data, and an object for detecting the digitally filtered data. Storage means for storing as baseline data that serves as a reference, sampling data sampled at least while the object is touching the panel and near the touch position, and the storage means corresponding to each position of the sampling data Difference data from the baseline data stored in Determined, ultrasonic detecting apparatus characterized by comprising: a smoothing means for mutually smooth the respective differential data. 5. A plurality of ultrasonic waves of different wavelengths are applied to the panel X.
Direction and Y direction, oscillating means, transmission control means for controlling time-division transmission of different ultrasonic wavelengths transmitted from the transmitting means, and receiving means for receiving the transmitted ultrasonic waves. And arranged at a predetermined interval corresponding to each of the plurality of different wavelengths on the panel through which the transmitted ultrasonic waves propagate, and selects and reflects ultrasonic waves of a predetermined wavelength passing through the detection surface on the panel. Detecting the presence or absence of a touch of an object at a reflection position of a corresponding predetermined wavelength by comparing a reflection array pair propagating to the reception means and an ultrasonic wave of a predetermined wavelength received from the reception means with a reference level Means for detecting the presence or absence or position of an object that absorbs the ultrasonic waves propagating on the panel. 6. The presence or absence of an object that absorbs the ultrasonic waves propagating on the panel, comprising a receiver that propagates the ultrasonic waves transmitted from the transmitter in the X and Y directions of the panel and receives the ultrasonic waves. Alternatively, in an ultrasonic detection device for detecting a position, a means for sampling the ultrasonic waves propagating through the panel to obtain sampling data, storing the sampling data, and a baseline serving as a reference for detecting an object from the sampling data A means for obtaining data and storing the baseline data, a difference between the sampling data and the baseline data is obtained, and the presence or absence of the touch of the object on the panel is detected from the difference, and the touch of the object is detected. In the case of An ultrasonic detecting device, comprising: an arithmetic unit that calculates interpolation data and obtains a touch position of an object from the sampling data and the interpolation data. 7. The presence or absence of an object that absorbs ultrasonic waves propagating on the panel, comprising a receiver for propagating ultrasonic waves transmitted from a transmitter in the X and Y directions of the panel and receiving the ultrasonic waves. Alternatively, in an ultrasonic detection device for detecting a position, a means for sampling the ultrasonic waves propagating through the panel to obtain sampling data, storing the sampling data, and a baseline serving as a reference for detecting an object from the sampling data Means for obtaining data and storing the baseline data; detection means for comparing the selected data of the sampling data with the baseline data to detect the presence or absence of a touch on the object on the panel; When a touch is detected, data processing of the sampling data is performed in the vicinity of the sample where the touch is detected. Ultrasonic detection device including means for limiting the bridging data. 8. The presence or absence of an object that absorbs the ultrasonic waves propagating on the panel, comprising a receiver for propagating the ultrasonic waves transmitted from the transmitter in the X and Y directions of the panel and receiving the ultrasonic waves. Alternatively, in an ultrasonic detection device for detecting a position, a means for sampling the ultrasonic waves propagating through the panel to obtain sampling data, storing the sampling data, and a baseline serving as a reference for detecting an object from the sampling data Means for obtaining data and storing the baseline data; subtraction means for obtaining difference data between the sampling data and the baseline data; and comparing the difference data with a reference value to detect whether or not the object is touched. And a sampler that detects the touch of the object by the output from the comparator. Data processing ring data comprises a control means for limiting the sampled data of the neighborhood where the touch is detected, wherein the subtraction means and the comparison means are ultrasonic detection apparatus characterized by being hardware configuration. 9. A transparent detection panel arranged to cover a display portion of a display device, a transmitter and a receiver attached to an end surface of the detection panel, and a reflection formed on an outer peripheral surface of the detection panel. An array and a bezel provided to cover the surface of the outer peripheral surface of the detection panel, the volume acoustic wave transmitted from the transmitter propagates through the detection panel via the reflection array and is received by the receiver, In the ultrasonic detection device for detecting the object that comes into contact with the surface of the detection panel by the volume elastic wave being absorbed by the object, the detection panel and the bezel are fixed by an adhesive that does not absorb sound waves. An ultrasonic detection device characterized in that 10. A transparent detection panel arranged to cover a display portion of a display device, a transmitter and a receiver attached to an end surface of the detection panel, and a reflection formed on an outer peripheral surface of the detection panel. An array and a bezel provided to cover the surface of the outer peripheral surface of the detection panel, the volume acoustic wave transmitted from the transmitter propagates through the detection panel via the reflection array and is received by the receiver, In the ultrasonic detection device that detects the object that comes into contact with the surface of the detection panel due to the volume elastic wave being absorbed by the object, a spacer is fixed to the bezel by vibration welding, and the spacer absorbs sound waves. An ultrasonic detection device, characterized in that the ultrasonic detection device is fixed to the detection panel with a non-sticking adhesive. 11. A super member according to claim 9, wherein a reinforcing member for reinforcing the fixation of the detection panel and the bezel is attached between the rear surface of the outer peripheral surface of the detection panel and the bezel. Acoustic wave detection device. 12. A transparent detection panel arranged to cover a display portion of a display device, a transmitter and a receiver attached to an end surface of the detection panel, and a reflection formed on an outer peripheral surface of the detection panel. An array and a bezel provided to cover the surface of the outer peripheral surface of the detection panel, the volume acoustic wave transmitted from the transmitter propagates through the detection panel via the reflection array and is received by the receiver, An ultrasonic detection device for detecting an object in contact with the surface of a detection panel by absorbing the volume elastic wave by an object, wherein the detection panel and the bezel are fixed by vibration welding. Ultrasonic detector. 13. The ultrasonic detection device according to claim 12, wherein the vibration welding portion is provided on the outer peripheral surface of the detection panel outside the reflection array. 14. The distance between the vibration welding portion and the transmitter or the receiver is constant so as to avoid resonance between the volume elastic wave transmitted or received and the reflected wave of the volume elastic wave caused by the vibration welding portion. The ultrasonic detection device according to claim 12 or 13, wherein the ultrasonic detection device is separated by the above distance.