JPS6083126A - Coordinate detector for input position - Google Patents

Abstract

PURPOSE:To detect the coordinates of input positions on an input board by radiating acoustic signals from a point on the input board and measuring the difference between transmission times of the acoustic signals received by flat plate- shaped piezoelectric elements set at two sides orthogonal to the input board. CONSTITUTION:When an input pen 12 is pressed to the coordinates on the surface of an input board 10, the elastic waves are radiated evenly within the board 10. These elastic waves are transmitted within the board 10 and detected by flat plate-shaped piezoelectric elements 11a and 11b for X and Y axes respectively to be converted into electric signals. These electric signals are amplified by amplifiers 15a and 15b, and the output waveforms of these amplifiers are supplied to comparators 16a and 16b. Then the stop signal of a counter 17 is delivered from comparators 16a and 16b respectively. While the cycle signals are supplied to the counters 17a and 17b from an electric-mechanic transducer oscillation circuit 14 as the counter start signals. The counters 17a and 17b measure the times when they receive the counter stop signals and deliver the measured times to a position orientation circuit 18. Then the counter 18 calculates the position of the pen 12 from the counter output value.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an information input device for inputting information such as handwritten characters and figures on a light-transmitting medium to a computer, a display device, etc. The present invention relates to a sound source input position coordinate detecting device that can be made with a simple configuration and at low cost by using the following.

[Background of the invention]

Currently, with the spread of office automation, etc., the ease of use of electronic computers is becoming increasingly important.

One of them is that the display section and input section are the same.
From a convenient point of view, you can use the display without using the keyboard.
Light-transmissive touch input devices are often considered for writing characters, pictures, etc. directly on a screen and inputting that information.

For example, a light-transmitting type four solder sheet f: is arranged in a matrix shape with the width of the same mm in the X-axis and Y-axis directions, and a partial metal switch is formed in which four solder sheets on the X-axis and the Y-axis overlap. The user turns on the switch by pressing the desired input location with a finger, etc.
Therefore, the input location of Xl11] and 2 in the Y-axis direction can be detected. However, in order to improve the input coordinate n degrees, it is necessary to make the width of the conductive point narrower, which results in a complicated structure and higher cost.

Furthermore, as a different approach, all position measurements of input coordinates are performed using the method shown in FIG.

That is, the X-axis piezoelectric element 3a and the Y-axis circumferential piezoelectric element 3b'f are attached to a light-transmitting type manifold m2 such as an acrylic resin mirror mounted parallel to the display screen l, and the piezoelectric element excitation circuit 4a #4 for the Y-axis is attached. b x ') Alternately input pulse signals i3a, 3b, respectively, on the X axis.

By exciting the Y-axis pressing elements 3a and 3b, elastic waves are radiated into the input panel 2. Further, when the input pen 5 is brought into contact with the input panel 2, the elastic wave t1 propagated inside the input panel 2
The signal is converted into an electrical signal by a mechanical-electrical conversion confectionery 6 built in the human wall 15 and inputted to the counting circuit 7. That is, as shown in the waveform diagram of FIG. 2, the time Tx from the time when the X-axis compression element 3a is excited until the elastic wave 1d is received at the input vent is 111 as shown in FIG. It is counted by the counting circuit 7 shown, and the position is determined by six methods.

However, in the same method, piezoelectric elements 3a for the X-axis and Y-axis
, 3b must be mutually excited. Also, in the counting circuit 7, the input wall 15 is also outputted.
Electrical No. 16'(<It must be counted separately as electrical signals for the X-axis and Y-axis, and it cannot be denied that the configuration becomes complicated.

Other methods include a method in which piezoelectric elements are finely divided and placed on two sides perpendicular to a light-transmissive input panel, and the input position coordinates are determined using the above-mentioned elastic wave method.Input position coordinate detection using laser light Many methods have been proposed, but all of them have complex configurations and many elements that make them expensive.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide an input position coordinate detection device that has a simple configuration, is inexpensive, and has high accuracy.

[Summary of the invention]

A feature of the present invention is that an acoustic signal is emitted from a single point on an input board made of a light-transmissive medium, and is received by flat piezoelectric elements installed on two sides orthogonal to the input board.

That is, the input position coordinates on the input panel are detected by measuring the propagation time difference from the acoustic signal emission to the reception at each piezoelectric element.

[Embodiments of the invention]

A manual position coordinate detection device which is an example of the present invention will be explained below with reference to FIG.

In the figure, reference numerals 9 and 10 indicate a light-transmissive input panel made of acrylic material, glass material, or the like. At the ends of the surface of the input panel 0, flat pressure oxygen elements 11a for the X-axis are arranged perpendicularly to each other.
A flat piezoelectric element 11b for the XY axes is attached. 12
The input wall 9 has an electro-mechanical transducer 13, for example, a piezoelectric element, and the ridge-mechanical transducer excitation circuit 14 has a ridge-mechanical transducer excitation circuit 14 in the input wall 12. The pulse waveform shown in FIG. 4 is periodic. has been entered.

When the input pen 12 is pressed against the coordinates of the manual board 10, elastic waves are uniformly radiated into the input 31110, the elastic waves propagate inside the input board 10, and each X
It is detected by the flat piezoelectric elements IIA, ILB around the axial and Y axes, converted into a negative signal, and then amplified by amplifiers 15a and 15b.

FIG. 4 shows the output waveforms of each amplifier. Next, the output waveform of the multiplier 11g is input to the co/parators 16a, 16b, and the waveform shown in FIG. 4 is output from the co/parators 16a, 16b.
, 17b. 2. The comparator is a zero-cross circuit or a comparator with a constant threshold voltage (D, whichever is fine - 0) On the other hand, the counters 17a and 17b are , the periodic signal shown in FIG. 4 is manually inputted as a start signal for the counter, and the signals 17a and 17b are output from the comparators 16a and 16b as shown in FIG. Time until stop signal is manually activated ΔT&J
llb is measured and the value is output to the position locating circuit 18. The position locating circuit 18 performs all calculations on the position of the human powered bench 12 based on the output values of the color/receivers 17a and 17b.

All you need to do is calculate the entire calculation using the following simple formula.

In other words, the distance from the position of input wall /12 to Xll1fI, Y-axis flat pressure la element 11a, , Tosurubi, Δl,, =v・ΔT, ・・・・・・・・・・・・(
1) Δh b = V ”llb ・・・・・・・・・・・・
...(2) The position of the human depth/12 can be determined from the above equation. Therefore, by attaching the input panel parallel to the display device 20 of the busy computer 19 and sequentially inputting information to the computer 19 using the input pen, the display device 2
It becomes possible to read out information displayed on the screen 0, write handwritten information on the display device, etc.

Figure 5 shows how to use this device to move towards the person's side 7 in the direction of the arrow shown in figure s6.
Measurement time error ΔTg when moving 12r, that is, Δ
Tz=lΔT, -ΔTb An example of the results of measuring the value of l is shown below. As can be seen from FIG. 6, there is no difference in distance between the $ movement position ΔLI+ΔLb of the human wall/12. Finally) Ideally, the measurement time error Tye should be zero.

However, an error occurs in the smile as shown in FIG. It can be seen that the maximum error is 0.05 μs.

This error is converted into a distance, and the positioning accuracy ΔLx is checked.

The input panel uses quartz glass. 2 on quartz glass
The propagation sound speed of an elastic wave is 3,160 m/s, so by substituting this into the following equation, it can be obtained in the following one straight line.

ΔLz=3160X0.032μS in 0.16 -...
- (3) The positioning accuracy of this device is 0.16m
Since it can be set at about m, the input position is l! Performance as a coordinate detection device? It turns out that we have enough. It should be noted that it is even more difficult to use a material other than quartz glass, which has a slow acoustic wave propagation speed.
? : It cannot be said that the accuracy improves.

As explained above, by using the present invention, with a simple configuration,
Moreover, since it is possible to detect the input position coordinates using the input position coordinates, by placing it on the surface of a display device such as a computer computer, you can directly check the display device with your eyes and add + to the display device.
It offers very great advantages, such as being able to threaten information on the 4F, read out display information, etc. with a high degree of resistance.

Next, an example of 5A2 of the present invention will be described.

In the present invention, the following circuit is added to the apparatus shown in FIG. 3 to improve its functionality.

That is, as shown in FIG.
The electro-mechanical conversion element excitation circuit 14 installed in
1 drive switch 30, the electro-mechanical conversion element excitation circuit 14, and the counters 17a, 17b.
Between the monostable multivibrator 10 (hereinafter M
-M) 31 and an analog switch 32 between the amplifiers 15g, 15b and the co/parators 16a, 16b.
a, 32b are added, and information other than the information from the input wall/12 is added, such as electric noise or elastic input to the manual panel IO due to operator error (e.g....
If this occurs (if the input panel is accidentally hit and squeezed), it will be treated as foreign noise,
Points to avoid detecting input information & (Ruru.

Embodiments of the present invention will be specifically described below using FIG. 8. In the figure, (a) shows the case where the operator inputs the position information @ (elastic wave) to the input panel 10 using the input wall 712, and (b) shows the case where the operator inputs the position information @ (elastic wave) to the input board 12 on the input wall 712.
Even though the information is not input manually, the electrical noise caused by a printer or the like is transmitted to the X-axis and Y-axis rectangular flat piezoelectric elements 11a.

11b shows the output waveforms of each circuit when received at 11b.

In the case of (a), the operator inputs the position information to the input panel IO after inputting the drive switch 30. Since the drive switch 30 is turned on, the electro-mechanical conversion element excitation circuit 14 outputs the waveform shown in FIG. 8 including the synchronization signal. Accordingly, as explained in the embodiment of FIG. 3, the waveforms shown in FIG. 8 are output from the amplifiers 15a and 15b. Next, in the M-M31, a synchronizing signal is inputted to the electro-mechanical conversion element excitation circuit 14, and the waveform is shaped, and as shown in FIG. Output.

Next, the output signal from MM31 is the analog switch 32a.
, 32b, respectively. As shown in FIG. 8, the analog switches 32a and 32b are switches that close their gates only when Hirh information is input at the TTL level. , 32b. Next, the signals output from the analog switches 32a and 32b are passed through the comparators 16a and 16b, and the eighth
Outputs the signal shown in the figure. Thereafter, the process is performed in the manner described in the embodiment of FIG. 3, and the position coordinates of the input wall are detected.

Note that the time constant of the MM31 can be changed arbitrarily, so by changing the time constant, the manual control panel l
It is also possible to arbitrarily change the monitoring range of the input coordinates at O2.

On the other hand, in case b), the operator does not input the drive switch 30 installed on the input vent 12, so the synchronization signal is not output from the electro-mechanical conversion element excitation circuit 14 as shown in FIG. Including 11 issues are not output.

However, the X-axis and Y-axis plate-shaped piezoelectric elements 11a, ll
Since the amplifier circuit 1 receives electrical noise at
The /ζ waveform shown in FIG. 8 is output from 5a and 15b. However, as shown in the figure, since no signal is output from MM31, analog switches 32a and 32b
gate will not close. Therefore, the analog switch 32a,
As shown in the figure, a signal is constantly output from 32b. Since it is determined that no evening report was input, the human position coordinates will not be detected.

As described above, if the non-implemented example is used, the device will not operate due to so-called foreign noise other than when the operator inputs information using the input sensor, so the input position coordinate detection device is highly reliable. It has the great advantage of being able to obtain

Next, a third embodiment of the present invention will be described.

As shown in Fig. 9, when an elastic wave is radiated from the human wall /40 to the input panel 41, the elastic wave is a longitudinal wave L? transverse wave s
The wave becomes a surface wave, propagates while manipulating multiple electric reflections in the direction of the boundary, and is received by the flat piezoelectric element 42 installed on the surface of the input panel 40. For example, input panel 41
If it is an acrylic material, the sound speed of the longitudinal wave is 2720 m/s, the 8z transverse wave is 1460 m/s, and the surface wave is 1310 m/s.
It propagates at a speed of s. Differences in the sound source incidence position on the input panel f Since the propagation path of the multiplexed wave described above differs depending on the angle of incidence of the elastic wave due to the input vent, etc., the effect of these differences in sound speed has a considerable effect on the precision of the input position coordinates. It may have an influence and appear as an error.

Therefore, in this embodiment, as shown in FIG.
1, a shoe 43 having a specific angle α is provided and a flat piezoelectric element 42 is installed so that only surface waves among the elastic waves are fully detected.

Like light, elastic waves are refracted when they pass through dissimilar materials. That is, Snell's law shown below holds between the sound velocity of the material and the debris angle shown in the gxo diagram.

sin β sin α 111 (4) vB ML Here, VR is the surface wave sound velocity of the input panel, VL is the longitudinal wave sound velocity of the input panel, and β is calculated at 90°.

If the input ff141 is made of quartz glass and the shoe 43 is made of acrylic material, α=59.4°.

When the above material is used, the flat pressure element 42 is installed on the shoe 43 having an angle of 59.4°, and the first O
If it is installed on a manual panel 41 as shown in the figure, it is possible to detect only surface waves.

If the method described above is used, longitudinal waves with different i speeds -? Since it is possible to detect only surface waves with a constant sound speed without detecting transverse waves, it is possible to obtain a highly accurate input position coordinate detection device without orientation errors of input position coordinates.

Next, a fourth embodiment of the present invention will be described.

The present invention relates to the installation position of a flat plate-like pressure element on an input panel. In other words, as shown in figure il1, the input panel 5
Flat pressure elements 51a, 5 for the X-axis and Y-axis are provided on the side surface of the end of the
Even if 1bi is installed, it is possible to provide the same effects as those explained in the embodiments of FIGS. 3 and 7.

Next, a fifth embodiment of the present invention will be described.

The present invention relates to an improvement plan for a manual panel. Hypothetically, as shown in FIG. 12, when an elastic wave r is incident on point @tb
-t-i. An example of a love waveform is shown in the MLa diagram. However, JM Zeng, input board 6, where elastic waves were incident on the two points shown in the same figure.
Due to the interference with the elastic wave 63 reflected from the side surface of 0, the waveform of the elastic wave received by the flat pressure element 61 becomes
(The waveform shown in the figure, ip, and point X) is likely to have a different phase than the incident elastic wave. If the position a is different, an error will naturally occur in the nape of the human position coordinates.

Therefore, in the present invention, the 14th. 15th. As shown in Fig. 16, by processing the manual input panel, or by attaching an absorbent material τ to the input panel, elastic waves are generated by multiple reflections of elastic waves from the sides of the input panel, or from the paper surface. This removes the effects of mutual interference.

First, FIG. 14 will be explained. This figure is a partial cross-sectional view of the input panel 70. As shown in the figure, the end of the input panel 70 is polished so that it becomes thinner toward the tip. By adopting this shape, the elastic waves 71 shown in the figure are attenuated without being reflected by the side surface of the input panel 70, so that no interference occurs.

Furthermore, if the end of the input panel 80 is processed into a sawtooth shape as shown in FIG. 15, the elastic waves will be attenuated without being reflected from the side surfaces.

Furthermore, FIG. 16 shows that the side and bottom surfaces of the input panel 90 are made of light-transmitting sound absorbing material 91. fc is a cross-sectional view when molded with silicone/rubber or the like. With the configuration shown in the figure, the two longitudinal waves 92 and transverse waves 93 propagating within the input panel 90 are absorbed as shown by the broken lines in the figure. In addition, the surface waves 94 near the side surfaces of the manual panel 90 are also absorbed in the same way, so that there is no interference between the elastic waves due to multiple reflections. Therefore, it is possible for only the first arriving surface wave 96 of the elastic wave incident through the input bend 95 to emerge at the flat piezoelectric element 97.

〔Effect of the invention〕

If the method described above is used, the influence of mutual interference between elastic waves is eliminated, so it is possible to obtain a highly accurate input position coordinate detection device with little positioning error.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional example of an input position coordinate detection device, FIG. 2 is a waveform diagram for explaining the operation of FIG. 1, FIG. 3 is an explanatory diagram of the first embodiment of the present invention, and FIG. is a waveform example for explaining the first embodiment of the present invention, FIG. 5 is a diagram showing an example of measuring the orientation error of input position coordinates in the first embodiment of the present invention, and FIG. 5 is an auxiliary diagram for explaining the present invention, FIG. 7 is a diagram for explaining the second embodiment of the present invention, FIG. 8 is a waveform diagram for explaining the second embodiment of the present invention, and FIG. 9 is a diagram for explaining the second embodiment of the present invention. Third invention
FIG. 1O is an explanatory diagram of the third embodiment of the present invention, FIG. 11 is an explanatory diagram of the fourth embodiment of the present invention, and FIGS. The auxiliary drawings for explaining the fifth embodiment of the invention, FIGS. 14, 15, and 16 are explanatory views of the fifth embodiment of the invention. DESCRIPTION OF SYMBOLS 10... Input board, lla... Flat pressure island element for X axis, 11b... Flat piezoelectric element for Y shoes, 12... Input ben, 13... Electro-mechanical conversion element, 14 ...(air-mechanical conversion element excitation circuit, 15a... amplifier, 15b
...Amplifier, 16a...Comparator, 16b...
・Core palletator, 17a... Calashita, 17b...
Counter, 18...Position locating circuit, 30...Drive switch, 31...Monostaple multipipulator IC, 32a...Analog switch, 32b...Analog switch, Fig. 1b $2 Fig. 1h3 Figure $9I21 $10 Box 2 1st I ffl 130th $14 Day 1 Along qθ Figure 15 Figure 16

Claims (1)

[Scope of Claims] 1. An input panel made of a light-transmissive medium, an input vent with a built-in flat piezoelectric element and an electro-mechanical conversion element installed on two orthogonal sides of the input panel, and the input pen. An electric circuit for outputting a signal for exciting the built-in electro-mechanical conversion element and a periodic signal synchronized therewith, and for emitting elastic waves into the input panel when the input ben is brought into contact with the input panel. - a mechanical transducer excitation circuit, each amplifier for amplifying the elastic lacrimal gold converted into an electrical signal by each of the flat piezoelectric elements, and a circuit for converting multiple output signals from each of the amplifiers into a digital signal; The synchronization signals output from each comparator and the atherosclerotic-mechanical conversion element excitation circuit are used as a start signal, the signal output from the comparator is used as a stop signal, and the propagation time of the elastic wave in the input board is measured. and a position locating circuit for locating all the input position coordinates of the input wall on the input panel according to the time measured by each of the counters. Input position coordinate detection device. 2. A monostaple multivibrator IC that outputs a TTL level rectangular wave number 1G having a certain time constant when multiple synchronization signals are input from the electro-mechanical conversion element excitation circuit, and the monostaple multivibrator. Each analog switch provided between each of the above amplifiers and the valley converter closes the switch only while the IC is outputting the rectangular wave signal, and passes the Lb signal output from each of the amplifiers to the valley converter. and a drive switch for operating the electro-mechanical conversion element excitation circuit attached to the human-powered pen, and only the elastic waves emitted from the input pen are used as long-range position information, including item 9. , has the configuration been configured so that no other external noise is taken in? An input position coordinate detection device according to claim 1. 3. The input position coordinate detection device according to claims 1 and 2, wherein the flat piezoelectric element is mounted on the surface of the input panel. 4. 3. The input position coordinate detection device according to claim 1, wherein the flat piezoelectric element is mounted on a side surface of the input panel. 5. Patent Mf4X characterized in that the flat piezoelectric element is mounted at a specific angle with respect to the surface of the input panel.
The input position coordinate detection device according to the first and second terms. 6. The input position coordinate detection device according to claims 1 and 2, wherein the end portion of the input panel becomes thinner toward the tip. 7. The input position coordinate detection device according to claims 1 and 2, wherein the end of the input panel is processed into a sawtooth shape. 8. The input position coordinate detection device according to claims 1 and 2, characterized in that the end and bottom portions of the input panel are covered with a light-transmissive sound absorbing material.