JPS63318622A - Coordinate input device - Google Patents

Abstract

PURPOSE:To obtain a higher coordinate detecting resolution by detecting a variation detecting time by a unit time smaller than a unit measuring time of a time counting counter from the storage contents of a storage means. CONSTITUTION:By starting a driving signal generating circuit, a time counting counter 18 starts to count a counter clock. On the other hand, an elastic wave which is inputted to a vibration sensor 6 through a vibration transfer plate 8 is converted to an electric signal again by the vibration sensor 6 and amplified by amplifiers 9-11, and thereafter, inputted to vibration waveform detecting circuits 12-14. The circuits 12-14 determine a detection timing by a waveform processing, and by using this detection timing signal as a trigger signal, transfer time measuring circuits 15-17 take in the output of the time counting counter 18, and transfer it to a microprocessor in a control circuit 1. Also, outputs of the detecting circuits 12-14 are inputted to this microprocessor, as well, and in accordance with a signal of the waveform detection timing, the next detection processing timing is determined. By executing repeatedly said processing, an input coordinate by a vibration pen 3 can be detected in a real time.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a coordinate human power device; 4. ) relates to a coordinate input device that detects vibration input from a vibrating pen to a vibration transmission plate using a vibration sensor provided on the vibration transmission plate, and detects the coordinates of the vibration input point from the vibration transmission time on the vibration transmission plate. be.

[Prior Art] Coordinate input devices using various hand-powered pens, tablets, etc. have been known as devices for manually inputting handwritten characters, figures, etc. to a processing device such as a computer. In this type of system, image information consisting of human-generated characters, graphics, etc. is output to a display device such as a CRT display or a recording device such as a printer.

In this type of device, ultrasonic vibrations transmitted from a vibration input pen to a tablet are input to a vibration transmission plate, detected from the input point by a vibration sensor installed at a predetermined part of the vibration transmission plate, and transmitted to each sensor. A configuration is known in which the coordinates of an input point are identified by transmission time.

In this type of method that uses ultrasonic vibration, the input tablet can be constructed from a transparent material such as an acrylic plate or glass plate, so the human-powered tablet can be stacked on top of a liquid crystal display, etc., and the input tablet can be placed on top of a liquid crystal display, etc., as if an image were written on a piece of paper. It is possible to construct an information input/output device with a good operating feel that can be used as if it were a computer.

[Problems to be Solved by the Invention] FIG. 12 shows the structure of a conventional ultrasonic vibration type coordinate human power device.

As shown in the figure, the input tablet is constituted by a vibration transmission plate 8 whose peripheral portion is supported by a vibration isolating material 7 for preventing reflected waves. At the corner of the vibration transmission plate 8, there are a plurality of (here, 3
A vibration sensor 6 consisting of several piezoelectric elements or the like is provided.

On the other hand, a vibrating pen 3 that inputs vibrations to a tablet has a vibrator 4 made of a piezoelectric element or the like, and a horn section 5 for inputting the vibrations of the vibrator to a vibration transmission plate 8. The vibrating pen 3 is driven by the vibrator drive circuit 2 in synchronization with coordinate detection processing, which will be described later.

When the vibrating pen 3 is used to manually apply vibration to a position ψ on the vibration transmitting plate 8, this vibration is input to each sensor 6 after a transmission time corresponding to the distance on the vibration transmitting plate 8. in this case,
The distance between the sensor and the point of human effort can be determined by the product of the vibration transmission speed specific to the vibration transmission plate 8 and the transmission time.

The output of the vibration sensor 6 is input to three processing circuits including preamplifiers 9 to 11, vibration waveform detection circuits 12 to 14, and latch circuits 15' to 17', and the vibration transmission time is detected. The three systems of processing circuits have a complete circuit configuration. Here, the lowest circuit will be explained.

The output of the vibration sensor 6 is amplified by a predetermined gain in a preamplifier 9 and then input to a vibration waveform detection circuit 12 . The waveform detection circuit 12 detects the envelope of the detection signal, and when the envelope exceeds a predetermined level, it detects input of vibration to the sensor.

The detection signal of the waveform detection circuit 12 is manually input to the latch circuit 15', and the latch circuit 15' outputs the output of the timing counter 18, which has been started in advance in synchronization with the vibration input from the vibrating pen 3, at the human input timing of the detection signal -). Ingest data.

Therefore, the latch circuits 15' to 17' connected to the rear stage of each vibration sensor 6 store vibration transmission time data until the input vibration is input to each sensor.

Like a serious crime, the distance between the input point and the vibration sensor is.

It is determined by the vibration transmission speed in the vibration transmission plate 8 and the time, but since the vibration transmission speed is a fixed constant, the data latched in each latch circuit 15' to 17' can be considered as distance information as it is. You can also do it.

The distance ad between the vibration input point and each sensor is d=v@t...(A)
Here, V is the vibration transmission speed in the vibration transmission plate, and t is the vibration transmission time.

The time or distance information latched in each of the latch circuits 15' to 17' is manually inputted to a control device configured by a microprocessor, etc., and sent to the coordinate information of the coordinate system 5 set on the vibration transmission plate 87. converted. When using an orthogonal coordinate system, coordinate information can be calculated by processing information corresponding to the straight-line distance between the latched sensor and the input point based on the 3-middle theorem or the like.

Coordinate detection is performed as described above, and the detected coordinate information is input to another information processing device such as a computer system and used for various processing such as display, recording output, and editing of one image.

In the configuration as shown in L, the resolution of coordinate detection is obtained from equation (A) by the vibration transmission speed V and the counter time measurement 7:p11
1 (hereinafter referred to as unit measurement time), that is, it can be seen that it is defined by the period of the counter clock. That is, the resolution Δd is expressed as Δd=vaΔt·(B), where Δ1 is one period of the counter clock.

Here, for example, if a crown glass with a thickness of 1 mm is used as the vibration transmission plate and the vibration frequency of the vibrating pen is 500 KHz, the vibration transmission speed V is approximately 2000 m/s, so from equation (B), 0. It can be seen that in order to obtain a resolution of 1 mm, the frequency of the counter clock should be set to 20 MHz.

In the conventional structure described above, in order to further improve the resolution, it is sufficient to increase the frequency of the counter clock, but in order to do so, the counter, the latch circuit that latches the counted value of the counter, and the clock generation circuit must be further improved. It needed to be fast.

However, high-speed devices are expensive, and high-speed operation also increases energy consumption. Therefore, conventionally, there has been a problem that it is difficult to provide a coordinate input device that is inexpensive, has low power consumption, and has high resolution.

[Means for Solving the Problems] In order to solve the above IF1+JfJ, the present invention detects the vibration input from the vibrating pen to the vibration transmission plate by a vibration sensor provided on the vibration transmission plate, and transmits the vibration. A coordinate input device that detects the coordinates of a vibration input point from the vibration transmission time on a board includes a time counter that is activated in synchronization with the human vibration of the vibrating pen, and an output of the time counter that is detected by the vibration sensor. means for storing in accordance with the timing, and a stage for inputting the vibration detection timing signal of the vibration sensor or the output of the time counter to the storage means after delaying the vibration detection timing signal of the vibration sensor or the output of the time counter by a time shorter than the unit measurement time of the time counter, 1ti from the information stored in the storage means
We adopted a configuration that detects the vibration transmission time in units of time smaller than the unit measurement time of the time counter.

[Function] According to the configuration described above, the storage means for storing and retaining the vibration transmission time is operated based on the vibration detection timing signal or time information delayed by a time shorter than the unit measurement time of the time counter, The vibration detection time can be detected in units of time smaller than the unit measurement time of the time counter from the stored contents of the means, and higher coordinate detection resolution can be obtained.

[Example] Hereinafter, the present invention will be described in detail based on an example shown in the drawings.

FIG. 1(A) shows the configuration of a coordinate input device employing the present invention. In FIG. 1, members that are the same or corresponding to those of the conventional example are given the same reference numerals, and detailed explanation thereof will be omitted.

As shown in the figure, the device has an operating section that is almost the same as that of the conventional example. That is, it is a vibration transmission plate 8 having a vibrating pen 3 having a vibrator 4 and three vibration sensors 6 supported around one periphery by a vibration isolating material 7.

Here, FIG. 1(B) shows the structure of the vibrating pen 3 and its drive system.

A vibrator 4 built into the vibrating pen 3 is connected to a vibrator drive circuit 2.
Driven by. The drive signal for the vibrator 4 is shown in Figure 1 (A).
Vibrator drive circuit 2 which is supplied as a low level pulse No. 74.1 from the control circuit 1 of the
After being amplified by a predetermined gain, the signal is applied to the vibrator 4.

The electrical drive signal is converted into mechanical ultrasonic vibration by the vibrator 4 and transmitted to the diaphragm 8 via the horn section 5.

The vibration frequency of the vibrator 4 is selected to be able to generate plate waves on the vibration transmission plate 8 made of acrylic, glass, etc. Also, when driving the vibrator, the first
A vibration mode in which the vibrator 4 mainly vibrates in the vertical direction in FIG. 3(B) is selected. Further, by setting the vibration frequency of the vibrator 4 to the resonance frequency of the vibrator 4, efficient vibration conversion can be achieved.

The elastic waves transmitted to the vibration transmission plate 8 as described in -I- are plate waves, which have the advantage of being less affected by scratches on the surface of the vibration transmission plate 8, obstacles, etc. compared to surface waves. have

FIG. 2 shows the structure of the control circuit 1. As shown in FIG. 2, the control circuit 1 is composed of a microcomputer 31 and an input/output board 33. The input/output port is used to output input coordinate information to another information processing device.

The control circuit 1 also includes a drive signal generation circuit (consisting of an oscillation circuit, etc.) that generates a timing signal to be applied to the vibrator drive circuit 2.

In Figure 2, the preamplifier, vibration waveform detection circuit, and transmission time measurement circuit are each! As shown in the diagram, a microprocessor 31 controls the transmission time measurement circuits 15 to 17, clearing of the time counter 18, and starting of the time counter 18. In addition, information on the waveform detection timing of the vibration waveform detection circuits 12 to 14 is taken in,
Used for control described later.

Here, the transmission time measuring circuits 15 to 17 are not conventional wide latch circuits, but have a configuration as described later.

The start signal of the time counter 18 is generated by the drive signal generation circuit 3.
This signal is the same as the start signal in step 2, and when this signal is output from the microprocessor 31.

The drive signal generation circuit 32 starts outputting the pulse train of the predetermined frequency, and the time counter 18 starts counting counter clocks.

On the other hand, the elastic wave signal input to the vibration sensor 6 via the vibration transmission plate 8 is converted into an electric signal again by the vibration sensor 6 and amplified by the amplifiers 9 to 1-1, and then to the vibration waveform detection circuits 12 to 14. is input.

The vibration waveform detection circuits 12 to 14 determine the detection timing by waveform processing to be described later. Using this detection timing signal as a signal, the transmission time measurement circuits 15 to 17 take in the output of the time counter 18 and transmit it to the microprocessor 31. do.

On the other hand, the outputs of the vibration waveform detection circuits 12 to 14 are also input to the microprocessor 31, and the next detection processing timing is determined according to this waveform detection timing signal.

By repeating the following processes, the coordinates input by the vibrating pen 3 can be detected in real time. Also,
If the vibration waveform detection circuits 12 to 14 do not output a waveform detection signal even after a predetermined time determined by the maximum delay time, circuit delay time, etc. after the microprocessor 31 outputs the start signal, the vibration It is assumed that the pen 3 is away from the vibration transmission plate 8 (pen up), that is, no input is being performed, and the time measurement process is stopped, and the transmission time measurement circuits 15 to 17. The time counter 18 is reset by the clear signal. Timing for this pen-up detection is performed using an internal counter of the microprocessor 31 or the like.

FIG. 3 explains the detected waveforms manually input to the waveform detection circuits 12 to 14 and the vibration transmission time measurement process based on the detected waveforms. In FIG. 3, reference numeral 41 indicates a drive signal pulse applied to the vibrating pen 3. The ultra-a wave vibration transmitted from the vibrating pen 3 driven by such a waveform to the vibration transmission plate 8 passes through the vibration transmission plate 8 and is detected by the vibration sensor 6.

After traveling within the vibration transmission plate 8 for a time tg corresponding to the distance to the vibration sensor 6, the vibration reaches the vibration sensor 6. Reference numeral 42 in FIG. 3 indicates a signal waveform detected by the vibration sensor 6. The plate wave used in the tree x example is a dispersive wave, so the envelope 42 of the detected waveform
The relationship between 1 and phase 422 changes depending on the vibration transmission distance.

Here, the speed at which the envelope advances is assumed to be group velocity Vg, and the phase velocity is assumed to be Vp. The distance between the vibrating pen 3 and the vibration sensor 6 can be detected from the difference in group velocity and phase velocity.

First, focusing only on the envelope 421, its velocity is Vg, and when a point on a certain waveform, for example a peak, is detected as indicated by the reference numeral 43 in FIG. d is the vibration transmission time t
As g, d=Vg-t g...(1)
Although this equation relates to one of the vibration sensors 6, the distances between the other two vibration sensors 6 and the vibration pen 3 can be indicated by the same equation.

Furthermore, in order to determine coordinate values with higher precision, processing is performed based on the detection of a single phase signal.
22 specific detection points, for example, if the time from vibration application to the zero cross point after passing the peak is tp, then the distance between the vibration sensor and the vibration pen is d=n*in p+Vp 11t p - (2)
where p is the wavelength of the elastic wave and n is an integer.

From the above equations (1) and (2), the integer n in L is n - [(Vgll tg - Vpll tp)/input p
+ 1/N ] = (3). Here, N is a real number other than 0, and an appropriate value is used. For example, if N=2, n can be determined if it is within ±l/2 wavelength.

By substituting n obtained as follows into equation (2), the distance between the vibrating pen 3 and the vibration sensor 6 can be accurately measured.

In order to measure the two vibration propagation times tg and tp shown in FIG. 3, the waveform detection circuit 9 can be configured as shown in FIG. 4, for example.

In FIG. 4, the output signal of the vibration sensor 6 is amplified to a predetermined level by the aforementioned amplifier circuits 9-11.

The amplified signal is input to an envelope detection circuit 51, and only the envelope of the detection signal is taken out. The timing of the peak of the extracted envelope is detected by the envelope peak detection circuit 53. From the peak detection signal, an envelope delay time detection signal Tg having a predetermined waveform is formed by a signal detection circuit 54 composed of a mono-multivibrator or the like, and is input to an arithmetic control circuit l.

Further, a phase delay time detection signal Tp is formed by the detection circuit 57 from this Tg times signal timing and the original signal delayed by the delay time adjustment circuit 5"2, and is inputted to the arithmetic control circuit 1.

That is, it is converted into a pulse of a predetermined width by the Tg multiplied signal monostable multivibrator 55. Further, the comparator level supply circuit 56 outputs t according to this pulse timing.
A threshold fIi for detecting the p signal is formed. As a result, the comparator level supply circuit 56 forms a signal 44 having a level and timing as indicated by reference numeral 44 in FIG. 3, and inputs it to the detection circuit 57.

That is, the monostable multivibrator 55 and the comparator level supply circuit 56 are used to ensure that the phase delay time measurement is activated only for a certain period of time after the envelope peak is detected.

This signal is sent to a detection circuit 5 consisting of a comparator etc.
7 and is compared with the delayed detection waveform as shown in FIG. 3, resulting in a tp detection pulse 45.

The circuit shown above is for one vibration sensor 6, and the same circuit is provided for each of the other sensors.

If the number of sensors is generalized to h, then h detection signals each having an envelope delay time Tgl-h and a phase delay time "rpl-h" are input to the arithmetic control circuit l.

When three vibration sensors 6 are arranged at the corners of the vibration transmission plate 8 at positions from St to S3 as shown in FIG. Straight line distances #d1 to d3 to the position of the vibration sensor 6 can be determined.

Furthermore, in the vtrX control circuit J31, this straight line distance fadl~d
Based on 3, the coordinates (x, y) of the vibrating pen 3 digit 71P are 3
It can be obtained from the theorem on the ′+ side as shown in the following equation.

x = IX/2 + (dl+d2)(di-d2
) / 2X ・= (4)y
-Y/2◆(dl◆d3)(dl-d3) / 2Y
...(5) Here, x and Y are the X and Y of the vibration sensor 6 at the positions S2 and S3 and the sensor at the origin (position 'as l)
is the distance along the axis.

Here, FIG. 6 shows the configuration of the transmission time measuring circuits 15 to 17.

Here, a configuration is shown in which the d delay time of either the envelope or the phase is measured.

In FIG. 6, reference numeral 18 is the aforementioned time counter;
This is a 14-bit binary counter that counts with respect to a 0 MHz counter clock (period: 100 ns). This clock speed is 0.1 mm as described in the conventional example section.
It is half of 20MHz to achieve a resolution of .

Reference numeral 20 is a latch circuit that latches the output of the 13th E-order bit of the counter, and 21 to 24 are latch circuits that latch the output of the lower 1 bit.

These latch circuits 21 to 24 increase the daily output of the time counter using the detection signal from the vibration waveform detection circuit as a trigger, but the latch circuits 22 to 24 (B, C,
The trigger for D) is delayed for a certain period of time by the connectors 25-27.

These AI elements each provide a delay of 25 ns, and with the circuit configuration shown in Figure 1, the latch circuit 23 has a delay of 25 ns for the latch circuit 22 (B).
There is a delay of 50 ns for (C) and a delay of 75 ns for the latch circuit. Although the delay time d is not limited to this, it needs to be at least shorter than one cycle of the counter clock.

FIGS. 7(A) to 7(F) show specific timings during the timekeeping operation.

FIG. 7(A) shows the counter clock, and FIG. 7(B) shows the output of the counter. After outputting the start signal (i.e.
(after starting time counter 18) 100.08
If the vibration waveform detection signal is output after JLs has elapsed, the latch circuit 21 performs latching at the timing shown in FIG. 3(C).

Also, the latch circuits 22 to 24 are (D), (E),
Latching is performed at the timing shown in (F). From the contents of the four lower 1 bits obtained in this way, a 16-bit measurement result can be obtained by performing conversion as shown in the table of FIG.

FIG. 8 shows a pattern of 1-bit latching results generated in the latch circuits 21 to 24 (A-D) triggered with a time lag of 25 nS. As is clear from FIG. 7, the eight extensions of 25 ns each act to divide one clock period of 100 ns into four, so depending on where the clock edge trigger occurs after the trigger of the latch circuit 21, the illustrated A bit pattern like this is generated. Therefore Olo, 0. ON1.1, 1.1~1.0
．． The measurement results for a bit pattern of 0.0 can be decoded as shown in the right column of FIG.

In the example shown in FIG. 6, the latched contents of the latch circuits 21 to 24 are "0", rlJ, rlJ, and rlJ, respectively, so the measurement results are 1111101'ooO, 11(:
Binary number. In decimal notation, it is 1000.75).

Generally, m low-order 1-bit latch circuits are provided, and the trigger for each latch circuit is Δt 2Δt (nn-1)・ΔtO1□,
・・・mm
m (where Δt is the period of the counter clock), the resolution Δd can be set to 1 by measuring with a delay of Δt as shown in the table of FIG. Since the delay is performed, the resolution of coordinate detection is given by equation (2). If vp is 2000 m/s, then 0.0
A 5 mm coordinate detection and resolution section can be obtained. In other words,
In the conventional method, the resolution was 0.1 mm with a 20 MHz clock, but with half the clock rate, the resolution was 0.1 mm.
Double the resolution can be achieved.

The process of converting a 4-bit input into a 3-bit output as shown in the table of FIG. 8 can be easily realized using the software of the microcomputer 31, but the decoding circuit may also be configured using hardware. Of course.

As described below, according to this embodiment, the resolution of coordinate detection can be improved without increasing the oscillation frequency of the counter clock and the operating speed of the time counter and latch circuit. Therefore, a 41i device can be constructed without requiring expensive parts such as a high-speed counter or an oscillator, and a high-resolution coordinate input device can be provided easily and inexpensively. 2
Since a 'N delay element of about 5 nS can be easily constructed, the construction is simpler and cheaper than using a high-speed latch circuit.

FIG. 9 shows different configurations of the transmission time measuring circuits 15 to 17 according to the present invention. The difference from FIG. 6 is that the delay elements 25 to 27 are not connected to the trigger outputs (vibration waveform detection signals) of the latch circuits 22 to 24, but to the output lines of the lower 1 bit of the time counter 8 to the respective latch circuits. This is the point where it is inserted.

As described above, the latch circuits 20 to 24 use the vibration waveform detection signal as a trigger to latch the output of the time counter 8, but the counter outputs to the latch circuits 22 to 24 are delayed for a certain period of time by the delay elements 25 to z7. That is, the latch circuits 22, 23 .
24 are delayed by 25.59 and 75 ns, respectively.

10(A) to 10(F) show the timing of the time counting operation, and FIG. 10(A) is the same counter clock as in FIG. 7. Here, if the vibration waveform detection signal is output as shown in FIG. 10(B) after 100.03 pLS has passed since the microprocessor 31 outputs the start signal, the latch circuits 21 to 24 are as shown in FIG. 10(C). The latch is performed at the timing shown in ~(F).

The timing of the output signal of the lower 1 bit of the time counter 18 is determined by the delay elements 25 to 27 as shown in FIGS.
Since iM is extended as shown in F).

The launch circuits 21 to 24 include rQ4. rQ'', r'lJ,
rlJ is latched.

A 16-bit measurement result can be obtained by performing conversion as shown in the table of FIG. 11 from the contents of the four lower 1 bits obtained in this way using the same principle as described above. In the example in Figure 10, 1111101000
．． 01 (: Binary number, 10if!Rtehal OOO, 2
5) Even if the count output of the time counter 18 manually input to the latch circuit is delayed as shown in 2.
Similar to the embodiment described in iii, the simple and inexpensive configuration can improve the resolution speed of coordinate detection.

[Effects of the Invention] As is clear from the above, according to the present invention, the vibration input from the vibrating pen to the vibration transmission plate is detected by the vibration sensor provided on the vibration transmission plate, and the vibration is transmitted on the vibration transmission plate. In a coordinate input device that detects the coordinates of a vibration input point from time, a time counter is activated in synchronization with the vibration input of the vibrating pen, and an output of the time counter is stored in accordance with the vibration detection timing of the vibration sensor. means, and an L stage for delaying the vibration detection timing signal of the vibration sensor or the output of the time counter by a time shorter than the unit measurement time of the time counter and inputting it to the storage means, and from the information stored in the storage means. Since the configuration is adopted to detect the vibration transmission time in units of time smaller than the unit measurement time of the time counter, the storage means for storing and retaining the vibration transmission time is used only for a time shorter than the intermediate measurement time 111 of the time counter. It operates based on the delayed vibration detection timing signal or clock information, and detects the vibration detection time in a unit time smaller than the unit measurement time of the time counter from the memory contents of the storage means, thereby obtaining higher coordinate detection resolution. . Therefore, there is no need to use high-speed and expensive elements for time counters, clock generators, latch elements, etc., and there is an excellent effect that the 4R device can be constructed easily and inexpensively, and power consumption can be reduced.

[Brief explanation of drawings]

154(A) is a block diagram showing the structure of a coordinate input device adopting the present invention, FIG. 1(B) is an explanatory diagram showing the structure of the vibrating pen of FIG. 1(A), and FIG. 1st v! J(A
), Fig. 3 is a waveform diagram showing signal processing for distance detection, Fig. 4 is a block diagram showing the structure of the vibration waveform detection circuit, Fig. 5 is an explanatory diagram showing the sensor arrangement of the device in FIG. 1(A), FIG. 6 is a block diagram showing the configuration of the transmission time measuring circuit in FIG. 1(A), and FIGS. 7(A) to (F) ) is a timing chart showing the timing operation in the circuit of Fig. 6, Fig. 8 is a table showing the processing of measurement results in the circuit of Fig. 6, and Fig. 9 shows a different configuration of the transmission time measuring circuit. Block diagram, 1st
Figures 0 (A) to (F) are timing charts showing the timing operation in the circuit of Figure 9, Figure 11 is a table showing the processing of measurement results in the circuit of Figure 9, and Figure 12 is the conventional 1 is a block diagram showing the structure of a coordinate input device of FIG. ■... Control circuit 3... Vibration pen 4... Vibrator 6... Vibration sensor 7... Vibration isolating material
8... Vibration transmission plates 9-11... Preamplifiers 12-14... Vibration waveform detection circuits 15-17... Transmission time measurement circuit 18... Time counter 21-24... Latch Circuits 25 to 27...Delay elements

Claims (1)

[Claims] In a coordinate input device that detects vibration input from a vibration pen to a vibration transmission plate by a vibration sensor provided on the vibration transmission plate and detects coordinates of a vibration input point from a vibration transmission time on the vibration transmission plate, the vibration pen a timing counter that is activated in synchronization with the vibration input of the timing counter; means for storing the output of the timing counter in accordance with the vibration detection timing of the vibration sensor; and means for storing the vibration detection timing signal of the vibration sensor or the output of the timing counter; A means is provided for inputting the delayed time to the storage means by a time shorter than the unit measurement time of the time counter, and detects the vibration transmission time in a unit time smaller than the unit measurement time of the time counter from the information stored in the storage means. A coordinate input device characterized by: