JPH0758455B2 - Coordinate input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention detects a vibration input from a coordinate input device, particularly a vibration input member, by a plurality of vibration sensors provided on the vibration transmission plate, and detects the vibration. The present invention relates to a coordinate input device that calculates the coordinates of a vibration input point from the vibration transmission time.

[Prior Art] Conventionally, a coordinate input device using various input pens, tablets, and the like has been known as a device for inputting handwritten characters, figures, and the like into a processing device such as a computer. In this type of system, the input image information including characters and figures is output to a display device such as a CRT display or a recording device such as a printer.

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

In such a method using ultrasonic vibration, since the input tablet can be made of a transparent material such as an acrylic plate or a glass plate, the input tablet is placed on the liquid crystal display or the like, and it is as if writing an image on paper. It is possible to configure an information input / output device that can be used in the.

FIG. 11 shows the structure of a conventional ultrasonic vibration type coordinate input device.

As shown in the figure, the input tablet is composed of a vibration transmission plate 8 whose peripheral portion is supported by a vibration isolator 7 for preventing reflected waves. The vibration transmitting plate 8 has a plurality of corners (here, 3
A vibration sensor 6 including individual piezoelectric elements is provided.

On the other hand, the vibrating pen 3 for inputting vibration to the tablet has a vibrator 4 including a piezoelectric element and a horn portion 5 for inputting the vibration of the vibrator to the vibration transmission plate 8. The vibrating pen 3 is driven by the vibrator drive circuit 2 in synchronization with the coordinate detection process described later.

When a vibration is input to a desired position on the vibration transmission plate 8 by the vibration pen 3, this vibration is input to each sensor 6 while spending a transmission time corresponding to the distance on the vibration transmission plate 8. in this case,
The distance between the sensor and the input point can be obtained by the product of the vibration transmission speed peculiar to the vibration transmission plate 8 and the transmission time.

The output of the vibration sensor 6 is input to three processing circuits of the preamplification circuits 80 to 82, the vibration waveform detection circuits 83 to 85, and the latch circuits 86 to 88, and the vibration transmission time on the vibration transmission plate 8 is detected. To be done. The processing circuits of the three systems have exactly the same configuration. Here, the lowermost circuit will be described.

The output of the vibration sensor 6 is amplified by the preamplifier 80 with a predetermined gain and then input to the vibration waveform detection circuit 83.
The waveform detection circuit 83 mainly detects the envelope of the detection signal, and detects the input of vibration to the sensor when it exceeds a predetermined level.

The detection signal of the waveform detection circuit 83 is input to the latch circuit 86,
The latch circuit 86 fetches the output data of the clock counter 9 which has been started in synchronization with the vibration input by the vibration pen 3 at the timing of inputting the detection signal.

Therefore, the vibration transmission time data until the input vibration is input to each sensor is stored in the latch circuits 86 to 88 connected to the subsequent stage of each vibration sensor 6.

As described above, the distance between the input point and the vibration sensor is determined by the transmission speed and time of the vibration in the vibration transmission plate 8,
Since the transmission speed of vibration is a substantially constant constant if the material of the transmission plate 8 is the same, the data latched by the latch circuits 86 to 88 can be considered as distance information as it is.

The distance d between the vibration input point and each sensor is d = v · t (A) where v is the vibration transmission speed in the vibration transmission plate and t is the vibration transmission time.

The time or distance information latched by each of the latch circuits 86 to 88 is input to the arithmetic control circuit 1 configured by a microprocessor or the like and converted into coordinate information on the coordinate system set on the vibration transmission plate 8. . When the Cartesian coordinate system is used, the coordinate information can be calculated by processing the information corresponding to the linear distance between the latched sensor and the input point based on the Pythagorean theorem.

In addition, the time determined from the maximum transmission time (that is, the transmission time when the distance between the sensor and the pointing point is the maximum in the effective area for coordinate input) after the vibration of the pen, the circuit delay time, etc. If the vibration waveform is not detected even after passing, it means that the pen-up is in progress, so the measurement of the transmission time is stopped and the control from the driving of the vibration pen 3 is repeated.

The above operation is repeated to detect the designated point coordinates.

[Problems to be Solved by the Invention] In the above-described conventional configuration, it is determined whether or not coordinate input is performed, whether or not the vibrating pen is in contact with the vibration transmitting plate (this state is hereinafter referred to as pen down). To be detected.

In the conventional device, the pen-down is detected by the vibration input from the vibrating pen being transmitted to the vibration sensor via the vibration transmission plate and the vibration detection signal being output from the vibration sensor.

Therefore, in order to detect pen-down, it is necessary to drive the vibrating pen at regular intervals, and there is a problem that power is wasted. This allows the vibration pen 3
If a battery is built in as a power source, the battery life will be shortened.

When the vibrating pen has a power supply and a power switch built therein, the power switch of the vibrating pen may be cut off when the coordinate input is not performed, but this method makes the operation very complicated.

In view of this point, a structure was considered in which a mechanical pen-down sensor that operates in response to writing pressure was provided at the tip of the vibrating pen, but this method causes an operating stroke of the sensor, which makes the writing feel uncomfortable. There is a problem that there is.

[Means for Solving Problems] In order to solve the above problems, according to the present invention, the vibration input by the vibration input means is detected by a plurality of vibration sensors provided on the vibration transmission plate, In a coordinate input device for deriving the coordinates of a vibration input point from the vibration transmission time on the transmission plate, collision vibration detection means for detecting the vibration generated when the vibration input means collides with the vibration transmission plate is provided. A structure having a control means for controlling the coordinate detection processing according to the output of the collision vibration detection means is adopted.

[Operation] According to the above configuration, it is possible to detect the collision vibration when the vibration input unit comes into contact with the vibration transmission plate, and control the coordinate input process based on the collision vibration. For example, it is possible to detect whether or not the operator is in contact with the vibration transmitting plate for the coordinate calculation, and unnecessary operations can be omitted when the coordinate input is not performed.

[Examples] Hereinafter, the present invention will be described in detail based on examples shown in the drawings.

First Embodiment FIG. 1 (A) shows the configuration of a coordinate input device adopting the present invention. In the figure, the same or corresponding members as those of the conventional example are designated by the same reference numerals, and detailed description thereof will be omitted.

As shown in the figure, the device has an operation section similar to that of the conventional example. That is, there is a vibration pen 3 having a vibrator 4, and a vibration transmission plate 8 having three vibration sensors 6 whose periphery is supported by a vibration isolator 7.

The structure of FIG. 1A is different from the conventional example of FIG. 11 in that the respective outputs of the preamplifiers 80 to 82 are inputted to the vibration waveform detecting circuits 83 to 85 and the pen down detecting circuit 19. Is.

The pen-down detection circuit 19 is for detecting the pen-down state by detecting the vibration applied to the vibration transmission plate 8 when the vibration pen 3 is brought into contact with the vibration transmission plate 8.

The pen-down detection circuit 19 is composed of each component as shown in FIG. That is, these are set by the comparators 61 to 63 that input the outputs of the preamplifiers 80 to 82, the OR gate 64 that inputs the outputs of the comparators 61 to 63, and the outputs of the OR gate 64, and reset by the arithmetic control circuit 1. This is a flip-flop 65. The output of the flip-flop 65 is given to the arithmetic control circuit 1 as a pen down detection signal.

The output signal of each vibration sensor 6 is amplified to a predetermined level by the preamplifier 66, and the amplified signal level is output to the comparator 61.
~ 63 are compared with predetermined reference levels, respectively.

The outputs of the comparators 61 to 63 are input to the OR gate 64 and the logical sum thereof is calculated. Therefore, if the vibration detection signal of any one of the vibration sensors 6 is higher than a predetermined level, the OR gate 64 is used. Then, the flip-flop 65 is set, and the pen down is detected. The output signal of the flip-flop 65 is input to the arithmetic control circuit 1 as a pen down detection signal.

The structure of the vibrating pen 3 is shown in FIG.

The vibrator 4 built in the vibrating pen 3 is the vibrator driving circuit 2
Driven by. The drive signal for the vibrator 4 is supplied as a low-level pulse signal from the arithmetic control circuit 1, amplified by a predetermined gain by the vibrator drive circuit 2 capable of low impedance driving, and then applied to the vibrator 4.

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

The vibration frequency of the vibrator 4 is selected to a value capable of generating a plate wave on the vibration transmission plate 8 such as acrylic or glass. When driving the vibrator, the
A vibration mode is selected in which the vibrator 4 mainly vibrates in the vertical direction in FIG. Further, by setting the vibration frequency of the vibrator 4 as the resonance frequency of the vibrator 4, it is possible to perform efficient vibration conversion.

The elastic wave transmitted to the vibration transmitting plate 8 as described above is a plate wave, and has an advantage that it is less susceptible to scratches and obstacles on the surface of the vibration transmitting plate 8 as compared to surface waves.

FIG. 2 shows the structure of the control circuit 1. As shown, the control circuit 1 comprises a microprocessor 31, a drive signal generation circuit 32, and an input / output port 33. The input / output port 33 is used to output the input coordinate information to another information processing device.

The drive signal generation circuit (which is composed of an oscillator or the like) 32 is for generating a timing signal to be given to the vibrator drive circuit 2.

In FIG. 2, the preamplifier, the vibration waveform detection circuit, and the latch circuit are shown only in blocks for one system, respectively.
As shown, the microprocessor 31 includes latch circuits 86-
88, clears the clock counter 79, and controls the start of the clock counter 79. Further, the information on the waveform detection timing of the vibration waveform detection circuits 83 to 85 is fetched and used for the control described later.

In the above configuration, the coordinate input process is started on condition that the pen-down detection circuit 19 detects the pen-down of the vibrating pen 3.

The pen-down detection circuit 19 detects a vibration detection signal generated at the time of pen-down, and at that time, the comparators 61-63.
By setting the threshold value of, the operation is performed so as to detect only the vibration of a predetermined noise level or higher. Pen down detection circuit
19 is a microprocessor when detecting the vibration of the pen down
A signal indicating the pen-down detection is output to 31, and in response to this, the microprocessor 31 starts the clock counter 79.

The start signal of the clock counter 79 is the same as the start signal of the drive signal generation circuit 32, and when this signal is output from the microprocessor 31, the drive signal generation circuit 32 starts the output of the pulse train of the predetermined frequency, Clock counter 79
Starts counting the counter clock. As a result, vibration generation by the vibrator 4 of the vibrating pen 3 is started, and the vibrator 4
The signal generated by is input to a desired coordinate input position on the vibration transmission plate 8 via the horn 5.

On the other hand, the elastic wave signal input to the vibration sensor 6 through the vibration transmission plate 8 is converted into an electric signal again by the vibration sensor 6 and amplified by the preamplifiers 80 to 82, and then the vibration waveform detection circuit.
Entered in 83-85. The vibration waveform detection circuits 83-85 determine the detection timing by the waveform processing described later, and the latch circuits 86-88 take in the output of the clock counter 79 and transmit it to the microprocessor 31 by using this detection timing signal as a trigger signal.

The microprocessor 31 performs coordinate calculation by the method described later to determine input coordinates.

If the vibration waveform detection signal is not output even after a predetermined time determined by the maximum delay time, the circuit delay time, etc. after the microprocessor 31 outputs the start signal, the vibration pen 3 transmits the vibration. It is separated from the board 8 (pen-up), that is, the input is not performed, the timing processing is stopped, the transmission time measurement circuit 15 and the timing counter 18 are reset by a clear signal, and the pen-down detection circuit 19 detects the pen-down again. Wait for the signal to be input. The internal counter of the microprocessor 31 or the like is used to measure the pen-up determination.

As described above, if the coordinate calculation process including the vibrator driving of the vibrating pen 3 is performed based on the pen down detection, the vibrating pen 3 is not wastefully driven, and the power consumption can be reduced.

Next, the coordinate calculation will be described in detail.

FIG. 3 shows detection waveforms input to the waveform detection circuits 12 to 14,
The measurement process of the vibration transmission time based on it will be described. In FIG. 3, reference numeral 41 indicates a drive signal pulse applied to the vibrating pen 3. The ultrasonic vibration transmitted to the vibration transmission plate 8 from the vibration pen 3 driven by such a waveform passes through the inside of the vibration transmission plate 8 and is detected by the vibration sensor 6.

The time corresponding to the distance to the vibration sensor 6 in the vibration transmission plate 8
After traveling through tg, 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 this embodiment is a dispersive wave, and therefore the relationship between the envelope 421 and the phase 422 of the detected waveform changes according to the vibration transmission distance.

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

First, focusing only on the envelope 421, its speed is V
g, and when a point on a certain specific waveform, for example, a peak is detected as indicated by reference numeral 43 in FIG. 3, the distance d between the vibration pen 3 and the vibration sensor 6 is d = Vg with its vibration transmission time being tg. .Tg (1) This equation relates to one of the vibration sensors 6, but the same equation can indicate the distance between the other two vibration sensors 6 and the vibrating pen 3.

Further, in order to determine the coordinate value with higher accuracy, processing based on the detection of the phase signal is performed. Phase waveform 42 in Fig. 3
If the time from the application of the vibration to the zero cross point after the peak is passed at 2 specific detection points is tp, the distance between the vibration sensor and the vibration pen is d = n · λp + Vp · tp (2). Here, λp is the wavelength of the elastic wave, and n is an integer.

From the expressions (1) and (2), the integer n is expressed as n = [(Vg · tg−Vp · tp) / λp + 1 / N] (3). Here, N is a real number other than 0, and an appropriate value is used. For example, if N = 2 and n is within ± 1/2 wavelength, n can be determined.

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

For measuring the two vibration transmission times tg and tp shown in FIG. 3, the waveform detection circuit 9 can be constructed, for example, as shown in FIG.

In FIG. 4, the output signal of the vibration sensor 6 is amplified to a predetermined level by the aforementioned amplification circuits 80 to 82.

The amplified signal is input to the envelope detection circuit 51,
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. The peak detection signal is an envelope delay time detection signal of a predetermined waveform by the signal detection circuit 54 composed of a mono multivibrator or the like.
Tg is formed and input to the arithmetic and control circuit 1.

Also, the timing of this Tg signal and the delay time adjustment circuit 52
The phase delay time detection signal Tp is formed by the detection circuit 57 from the original signal delayed by and is input to the arithmetic control circuit 1.

The Tg signal is converted into a pulse having a predetermined width by the monostable multivibrator 55. In addition, the comparator level supply circuit
56 forms a threshold value for detecting the tp signal according to the pulse timing. As a result, the comparator level supply circuit 56 forms the signal 44 having the 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 for allowing the measurement of the phase delay time to operate only for a fixed time after the envelope peak is detected.

This signal is detected by the detection circuit 57 composed of a comparator, etc.
And is compared with the detection waveform delayed as shown in FIG. 3, and as a result, a tp detection pulse such as reference numeral 45 is formed.

The circuit shown above is for one of the vibration sensors 6, and the same circuit is provided for each of the other sensors.
If the number of sensors is generalized to be h, then h detection signals of envelope delay times Tg1 to h and phase delay times Tp1 to h are input to the arithmetic and control circuit 1.

In the arithmetic control circuit of FIG. 4, the signals Tg1 to h and Tp1 to h described above are input from the input port 15, and the respective count values of the counter 79 are fetched into the latch circuits 86 to 88 with each timing as a trigger. As described above, since the counter 79 is started in synchronization with the driving of the vibrating pen, the latch circuits 86 to 88 receive the data indicating the respective delay times of the envelope and the phase.

As shown in FIG. 5, when the three vibration sensors 6 are arranged at the corners of the vibration transmission plate 8 at the positions of S1 to S3, the processes described with reference to FIG. The straight line distances d1 to d3 to the position of the vibration sensor 6 can be obtained. Further, in the arithmetic control circuit 1, this linear distance d1 to d3
Based on, the coordinates (x, y) of the position P of the vibrating pen 3 can be obtained from the Pythagorean theorem as in the following equation.

x = X / 2 + (d1 + d2) (d1-d2) / 2X (4) y = Y / 2 + (d1 + d3) (d1-d3) / 2Y (5) where X and Y are the positions of S2 and S3. This is the distance along the X and Y axes between the vibration sensor 6 and the sensor at the origin (position S1).

Second Embodiment Although the example in which the pen down detection mechanism is provided on the vibration detection mechanism side of the vibration transmission plate 8 has been described above, the pen down detection mechanism may be provided on the vibration pen 3 side.

FIG. 6 and FIG. 7 show the configuration of the device when the pen down detection circuit is provided on the vibrating pen 3 side. FIG. 6 is a view corresponding to FIGS. 1 to 11, and the structure of the vibration detection system connected to the vibration transmission plate is constructed in exactly the same way as in FIG.

The difference in this embodiment is that the vibrator 4 of the vibrating pen 3 can be connected to either the vibrator drive circuit 2 or the pen-down detection circuit 20 via a switch 21. As shown in FIG. 109, the pen-down detection circuit 20 has the same structure as the pen-down detection circuit 19 described above.

That is, the pen-down detection circuit 20 includes a preamplifier 66, a comparator 67 and a flip-flop 68.
When the vibrator 4 and the pen-down detection circuit 20 are connected by the switch 21, the vibration sensor 3 functions as a vibration sensor that detects vibration when the tip of the vibration pen 3 contacts another member.

The output signal of the oscillator 4 is amplified to a predetermined level by the preamplifier 66, and the amplified signal level is compared with a predetermined reference level by the comparator 67.

When the vibration detection signal is larger than the predetermined level, the flip-flop 68 is set by the output of the comparator 67, whereby the pen down is detected. The output signal of the flip-flop 68 is input to the arithmetic control circuit 1 as a pen-down detection signal.

The flip-flop 68 is reset by the arithmetic control circuit 1. The switching of the switch 21 is also controlled by the arithmetic control circuit 1.

The control of the pen down detection state and the coordinate input process in this embodiment is the same as above, and the coordinate input is started by the pen down detection, and the process is stopped when the vibration sensor of the vibration transmission plate 8 cannot detect the vibration for a predetermined time or longer. .

That is, in the standby state, the arithmetic and control circuit 1 connects the vibrator 4 of the vibrating pen 3 and the pen-down detection circuit 20 with the switch 21 composed of an analog switch. The horn 5 at the tip of the vibrating pen 3 is the vibration transmitting plate. An electric signal is output from the vibrator 4 due to the vibration when it collides with 8, and the flip-flop 68 is set when the amplified signal is detected by the comparator 67 to be equal to or higher than a predetermined level. Detects pen down state.

When the pen down is detected, the arithmetic control circuit 1 switches
21 is switched to connect the vibrator 4 and the vibrator drive circuit 2, and the vibration detection system shown in the lower part of FIG. 8 is operated in the same manner as described above to perform the same coordinate calculation as described above.

When no vibration is input to the vibration transmission plate 8 for a predetermined time or more, the coordinate input process is stopped as described above, and the process returns to the standby state. At that time, the switch 21 is switched again, and the oscillator 4
And the pen down detection circuit 20 are connected.

With the above-described structure, the same effect as that of the above-described embodiment can be obtained.

In the above-described embodiment, the structure in which the drive signal or the power is supplied to the vibrator of the vibrating pen 3 from the control device of the apparatus main body has been described. An example of the structure when no connection is made is shown.

FIG. 8 shows the structure of the vibrating pen 3 used in this embodiment. The structure of the vibration transmitting plate side is assumed to be the same as that of the conventional example shown in FIG.

In the figure, reference numeral 111 is a vibration sensor for detecting a pen-down which is composed of a piezoelectric element or the like, and is located between the horn 5 and the vibrator 4, and mechanical vibration by the vibrator 4 is generated by this vibration sensor.
It is transmitted to the horn 5 via 111. The vibrator 4 is for generating vibration for detecting coordinates, and is driven by the vibrator drive circuit 123. The drive pulse at a predetermined timing is formed by the control circuit 113.

On the other hand, the vibration applied to the tip of the horn 5 from the outside is input to the vibration sensor 111 through the vibration sensor 111, and the vibration sensor 111
111, like the vibration sensor 6 of the vibration transmission plate 8, converts mechanical vibration into an electric signal. The output signal of the vibration sensor 111 is input to the pen down detection circuit 112, and the pen down detection circuit 1
Reference numeral 12 detects pen-down vibration and transmits a detection signal to the control circuit 113.

The signal obtained by the pen down detection circuit 112 is sent to the control circuit 113, and the control circuit 113 controls the vibrator drive circuit 123 based on the pen down signal of the pen down detection circuit 112,
The oscillator 4 is driven.

The control circuit 113 operates according to the procedure stored in the ROM as shown in the flowchart of FIG. Reference numeral 121 is a power supply for supplying power to the pen-down detection circuit 112, the control circuit 113, and the vibrator drive circuit 123, and is composed of a battery or the like. Reference numeral 121a is a power switch.

By providing the vibration sensor for pen down detection on the vibrating pen 3 side as described above, driving of the vibrator 4 can be stopped in the pen up state on the vibrating pen 3 side, and power consumption can be reduced. Such a structure is effective when a power source such as a battery is built in the vibrating pen 3. The driving of the vibrator of the pen and the synchronization of the coordinate calculation can be performed by transmitting and receiving a predetermined timing signal between the vibrating pen 3 and a circuit on the apparatus main body side. Transmission and reception of this timing signal can be performed by wire communication using a cable or the like, or wireless communication using an optical signal or the like.

FIGS. 9A to 9C show the operation in the above configuration.

FIG. 9A shows the output signal of the vibrator drive circuit 123
Figure (B) shows the output signal of the vibration sensor 111, and
FIG. 6C shows the vibration of the propagation material.

When the operator turns on the switch 121a and instructs the vibration pen 110 to input coordinates, when the tip of the horn 5 is brought into contact with the vibration transmission plate, vibration due to the collision between the horn 5 and the vibration transmission plate 8 causes vibration sensor 111. Then, a waveform 133 is generated as shown in FIG. 9 (B).

At this time, the vibration transmitting plate produces a vibration indicated by reference numeral 136 in FIG. 9 (C). When the pen-down detection circuit 112 detects the waveform 133, the detection signal is input to the control circuit 113.

As a result, the control circuit 113 determines that it is in the pen-down state and issues a drive command to the vibrator drive circuit 123. Transducer drive circuit 1
23 is output as indicated by reference numeral 131 in FIG. 9 (A) to vibrate the oscillator 4, and the generated vibration is transmitted to the vibration transmission plate via the vibration sensor 111, and the waveform 137 (see FIG. )) Generate vibration.

At this time, the vibration sensor 111 is affected by the vibration from the vibrator 4 and the elastic wave of the vibration transmission plate and outputs a vibration waveform such as reference numeral 134. In FIG. 9A, a waveform 132 is a signal applied from the vibrating pen 3 after the input with the vibrating pen 110 is completed and the pen is up. The detected waveform 135 based on this vibration is generated by the vibration generated by the vibrator 4 for detecting the coordinates, but is not affected by the vibration transmission plate, and thus the waveform
Faster decay than 134.

Therefore, if the sensor output is detected after an appropriate delay time t1 in accordance with the damping characteristics determined by the vibration transmission plate, the vibrator 4, the vibration sensor 111, the horn 5, etc., it is possible to specify whether the pen is up or down. . In the pen-down state, the envelope of the sensor output after t1 has an envelope level as shown by reference numeral 34 ', but in the pen-up state, it is
As shown in 35 ', the vibration sensor 111 in the pen-up state is
The detection signal envelope of is almost 0 as shown in FIG. 9 (B).

Therefore, the oscillator 4 is driven and the envelope of the sensor output is analyzed by the pen down detection circuit 112 after t1. If the output level is higher than a certain value, it means that the pen is in the pen down state and the coordinate is being input. Then, the drive is repeated at the cycle t2, the drive of the vibrator is stopped when the envelope of the sensor output becomes smaller than a certain value, and the detection of the waveform 133 by the next pen down is waited.

FIG. 10 shows the control circuit 113 of the vibrating pen 3 in this embodiment.
3 is a flowchart of the control means performed by the.

The illustrated control procedure is started when the switch 121a is turned on.

First, in step S42, the pen-down detection circuit 1
Wait for the collision vibration detection signal output from 12. That is, the process waits in step S42 until the pen is down, and when the collision vibration due to the pen down is detected, the process proceeds to step S43 to drive the vibrator 4.

In step S44, after the vibrator is driven, the process waits for t1 hours and then the process proceeds to step S45. In step S45, the envelope of the signal obtained from the vibration sensor 111 is verified, and if it is larger than the specific level, the process proceeds to step S46, and after t3 time, the vibrator is driven again in step S43. Also, step S45
If it is smaller than the specific level, the pen is up, and the process returns to step S42 to wait for the next pen down.

As described above, the oscillator is driven at the cycle t2 when the pen is down, but the driving is stopped when the pen is up. The power consumption of the pen-down detection circuit 112 is sufficiently low that it can be almost ignored as compared with the driving of the vibrator 4, and useless driving of the vibrator 4 can be avoided, resulting in significant power saving. It is possible to extend the life of the battery when the power source is composed of a battery. Therefore, the switch 121a is not always necessary, the troublesome operation of the operator is not necessary, and the switch 121a can be omitted altogether.

Further, since the vibration sensor 111 and the vibrator 4 reversibly convert electric vibration and mechanical vibration, the same element such as a piezoelectric element can also be used. In this case, if a large drive voltage is applied to the detection circuit during use as a vibrator, the detection circuit may be destroyed. Therefore, a protection circuit for the detection circuit, such as switching by an electronic switch circuit, may be provided. However, compared to the case where the sensor and the vibrator are composed of different elements, the mechanical connection portion is reduced, so that the vibration damping can be reduced and the stability of operation can be expected to be improved.

Further, it is clear that the coordinate instruction is not limited to the shape of the pen, and the same effect can be obtained even with a shape such as a mouse generally used for coordinate input.

In each of the above embodiments, the vibration input process is controlled according to the pen-up and pen-down states of the vibration pen.
The information indicating the pen-up and pen-down states obtained by the above configuration can be variously used for other processes in coordinate input processing and control of members.

[Effects of the Invention] As is apparent from the above, according to the present invention, the vibration input by the vibration input means is detected by the plurality of vibration sensors provided on the vibration transmission plate, and the vibration is transmitted on the vibration transmission plate. In a coordinate input device for deriving the coordinates of a vibration input point from time, collision vibration detection means for detecting vibration generated when the vibration input means collides with the vibration transmission plate is provided, and an output of the collision vibration detection means is provided. Since the configuration having the control means for controlling the coordinate detection processing in accordance therewith is adopted, it is possible to detect the collision vibration when the vibration input means comes into contact with the vibration transmission plate and control the coordinate input processing based on this. . For example, it is possible to detect whether the operator is contacting the vibration transmitting plate with the coordinate input member for coordinate calculation,
In the state where the coordinate input is not performed, unnecessary operations can be omitted, and power consumption can be reduced, which is an excellent effect.

[Brief description of drawings]

FIG. 1 (A) is an explanatory diagram showing the structure of a coordinate input device adopting the present invention, and FIG. 1 (B) is a block diagram showing the structure of the pen-down detection circuit of FIG. 1 (A). FIG. 2C is an explanatory diagram showing the structure of the vibrating pen of FIG. 1A, FIG. 2 is a block diagram showing the structure of the arithmetic control circuit of FIG. 1, and FIG. 3 is for coordinate calculation. Waveform diagram showing the signal waveform, No. 4
FIG. 5 is a block diagram showing the configuration of a waveform detection circuit, FIG. 5 is an explanatory diagram showing the arrangement of vibration sensors, FIG. 6 is an explanatory diagram showing the configuration of a different device, and FIG. 7 is a different pen-down detection circuit. FIG. 8 is a block diagram showing the configuration, FIG. 8 is a block diagram showing a different configuration of the vibrating pen, and FIGS. 9A to 9C are waveform diagrams showing signal waveforms in the configuration of FIG. Is a flow chart showing the control procedure in the configuration of FIG. 8, and FIG. 11 is an explanatory diagram showing the structure of a conventional coordinate input device. 1 ... Arithmetic control circuit, 2 ... Oscillator drive circuit 3 ... Vibration pen, 4 ... Oscillator 5 ... Horn, 6 ... Vibration sensor 7 ... Vibration isolator, 8 ... Vibration transmission plate 19, 20, 112 ...... Pen-down detection circuit 21, 121a ...... Switch 31 ...... Microprocessor 80-82 ...... Preamplifier 83-85 …… Vibration waveform detection circuit 86-88 …… Latch circuit

Claims (3)

[Claims] 1. A coordinate input device for detecting a vibration input by a vibration input means by a plurality of vibration sensors provided on a vibration transmission plate and deriving coordinates of a vibration input point from a vibration transmission time on the vibration transmission plate. A collision vibration detection means for detecting a vibration generated when the vibration input means collides with the vibration transmission plate, and a control means for controlling the coordinate detection processing according to the output of the collision vibration detection means. A coordinate input device characterized by. 2. A circuit on the side of the vibration transmitting plate is provided with a detecting device for detecting the vibration generated when the vibration inputting device collides with the vibration transmitting plate. The coordinate input device according to the item. 3. A circuit for detecting the vibration generated when the vibration input means collides with the vibration transmitting plate, is provided in a circuit on the side of the vibration input means. The coordinate input device according to the item.