JPH01201714A - Coordinates input device - Google Patents

Abstract

PURPOSE:To operate the title device variously in accordance with the posture of an oscillating pen by detecting the posture of the oscillating pen at the time of input from the longitudinal wave of an oscillation transmitted to an oscillation transmitting plate. CONSTITUTION:An information input/output device inputs coordinates to an input tablet consisting of an oscillation transmitting plate 8 by an oscillating pen 3 and displays in accordance with input coordinates information by an annunciator 11' arranged over the input tablet. Oscillation sensors 102 are provided at the two corner parts of the oscillation transmitting plate 8, their outputs are inputted to an oscillating pen angle detecting circuit 101 and information about oscillation transmitting time to the oscillation sensor 102 is given to an arithmetic and control circuit 1. Thus, the posture of the oscillating pen 3 at the time of the input is detected from the longitudinal wave component of the oscillation and the a coordinate value is corrected in accordance with the posture of the pen. Further, information inputted by this posture is ignored or various processings such as switching an input mode are executed.

Description

[Detailed Description of the Invention] [Fields of Use of Rakudo] The present invention detects vibrations input from a coordinate input device, particularly a vibrating pen, using a plurality of sensors provided on a vibration transmitting plate, and detects vibrations input from a vibration transmitting plate of the vibrating pen. The present invention relates to a coordinate input device that detects coordinates on the top.

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

Conventionally, coordinate detection has been performed using various detection methods, but in particular, ultrasonic vibrations are input using a vibrating pen to an input tablet made of a vibration transmission plate, and the input is based on the vibration transmission time on the vibration transmission plate. There is a method to detect the coordinates of a point.

A plurality of vibration sensors are installed at predetermined positions on the vibration transmission plate, and the straight-line distance from the input point to the sensor is calculated based on the transmission time until vibration is input to these vibration sensors, and then from the calculated straight-line distance. Coordinate values in a predetermined coordinate system are calculated.

This type of detection method using ultrasonic vibration has a relatively simple device structure, and because the input tablet can be made of transparent material such as glass, the input tablet can be stacked on a document or display device. There are advantages.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional example, there is a problem in that the inclination angle at the time of input of the vibrating pen that applies vibration to the vibration transmitting plate affects the coordinate accuracy manually.

A vibrator made of a piezoelectric element is installed inside the vibrating pen, and the vibrations of this vibrator are input to the vibration transmission plate through the horn part of the pen tip.Normally, a vibrating pen is used as a writing instrument that does not allow sweat. Similarly, since the tablet is operated at a certain degree of inclination, the vibration of the vibrator is input in a certain vector direction with respect to the thickness direction of the vibration transmission plate.

As a result, the phase of the vibration is reversed in the process of propagating through the vibration transmission plate from the input point of the vibrating pen to the vibration sensor, causing an error in the vibration detection timing of the vibration sensor and reducing coordinate detection accuracy. was there.

In the conventional device d, there was no means for recognizing the posture of the vibrating pen during input, and therefore it was impossible to determine the validity of the detected coordinates based on the posture of the vibrating pen 3◆ The present invention is as follows. This was developed in view of the above problems, and the objective is to detect the posture of a vibrating pen during input and make it useful for controlling the device.

[Means for Solving the Problems] In order to solve the above problems, in the present invention, vibrations input from a vibrating pen are detected by a plurality of sensors provided on a vibration transmission plate, and the vibrations of the vibrating pen are transmitted. A coordinate input device that detects coordinates on a plate includes means for detecting a longitudinal wave component of vibration transmitted through the vibration transmission plate, and a means for detecting a longitudinal wave component of vibration transmitted through the vibration transmission plate, and a method for inputting a vibrating pen according to a phase state of an output signal of the detection means. We adopted a configuration that includes a control means to detect the posture of the robot.

[Function] According to the configuration described below, since the posture of the vibrating pen at the time of input can be detected from the longitudinal wave component of the vibration transmitted to the vibration transmission plate, various operations can be performed depending on the posture of the vibrating pen. becomes possible.

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

FIG. 1 shows the structure of an information input/output device employing the present invention. The information input/output device shown in FIG. 1 inputs coordinates using a vibrating pen 3 to an input tablet consisting of a vibration transmission plate 8, and a display 11' consisting of a CRT placed over the input tablet according to the input coordinate information. The input image is displayed on the screen.

In the figure, the reference numeral 8 denotes a vibration transmission plate made of acrylic, glass plate, etc., which transmits vibrations transmitted from the vibrating pen 3 to vibration sensors 6 provided at three corners thereof. By measuring the transmission time of the ultrasonic vibration transmitted from the vibrating pen 3 to the vibration sensor 6 via the vibration transmitting plate 8, the coordinates of the vibrating pen 3 on the vibration transmitting plate 8 are detected.

The vibration transmitting plate 8 is provided with an anti-reflection material 7 made of silicone rubber or the like around its periphery in order to prevent vibrations transmitted from the vibrating pen 3 from being reflected at the periphery and returning toward the center. Supported.

The vibration transmission plate 8 is disposed on a display device 11' capable of displaying dots, such as a CRT (or liquid crystal display), and displays dots at the position traced by the vibrating pen 3. In other words, a dot is displayed at a position 11 degrees above the display corresponding to the detected coordinates of the vibrating pen 3, and the image composed of elements such as points and lines input by the vibrating pen 3 is as if written on paper. Appears after the trajectory of the vibrating pen as if it were done.

Further, according to such a configuration, a menu is displayed on the display 11', and the menu item is selected using the vibrating pen, or a prompt is displayed and the vibrating pen 3 is brought into contact with a predetermined position. You can also use

The vibrating pen 3 transmits ultrasonic vibration to the vibration transmitting plate 8,
It has a vibrator 4 made of a piezoelectric element or the like inside, and transmits ultrasonic vibrations generated by the vibrator 4 to a vibration transmission plate 8 via a horn portion 5 having a sharp tip.

FIG. 2 shows the structure of the vibrating pen 3. A vibrator 4 built into the vibrating pen 3 is driven by a vibrator drive circuit 2. The drive signal for the vibrator 4 is supplied as a low-level pulse signal from the arithmetic and control circuit l shown in FIG. is applied to

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 a value that can generate plate waves on the vibration transmission plate 8 made of acrylic, glass, or the like. Further, when driving the vibrator, a vibration mode is selected in which the vibrator 4 mainly vibrates in the vertical direction in FIG. 2 with respect to the vibration transmission plate 8. Also, the vibration frequency of the vibrator 4 is set to
Efficient vibration conversion is possible by setting the resonance frequency to .

The elastic waves transmitted to the vibration transmission plate 8 as described in section 2 are plate waves, which have the advantage that they are less affected by scratches on the surface of the vibration transmission plate 8, obstacles, etc. compared to surface waves. .

Again, in FIG. 1, the vibration sensor 6 provided at the corner of the vibration transmission plate 8 is also constituted by a mechanical to electrical conversion element such as a piezoelectric element. The output signals of each of the three vibration sensors 6 are input to the waveform detection circuit 6, and are converted into detection signals that can be processed by the subsequent arithmetic control circuit 1. Arithmetic control circuit
performs vibration transmission time measurement processing and detects the coordinate position of the vibrating pen 3 on the vibration transmission plate 8.

The detected coordinate information of the vibrating pen 3 is processed in the arithmetic control circuit 1 according to the output method by the display 11'.

That is, the arithmetic control circuit controls the output operation of the display 11'' via the video signal processing device 1O based on the input coordinate information.

Further, in this embodiment, vibration sensors 102 and 102 are provided at two corner positions of the vibration transmission plate 8 in the thickness direction. Like the vibration sensor 6, the vibration sensor 102 is composed of a piezoelectric element or the like.

The output of the vibration sensor 102 is transmitted to the vibration pen angle detection circuit 101.
, and information on the vibration transmission time to the vibration sensor 102 is given to the arithmetic control circuit l. The structure of the vibrating pen angle detection circuit 101 will be described later.

The vibration sensor 102 mainly detects the longitudinal wave component of the vibration input to the vibration transmission plate 8. On the other hand, the vibration sensor 6 for detecting the coordinates described above mainly detects transverse wave components. The arithmetic control circuit 1 detects the tilt angle of the vibrating pen 3 at the time of input based on the phase state of the longitudinal wave component detected by the vibration sensor 102, and performs various controls based on the tilt angle of the pen obtained by the vibration sensor 6 side. This control will be described later.

:jS3 shows the structure of the arithmetic and control circuit l shown in FIG. Here, the structure of the drive system of the vibrating pen 3 and the vibration detection system using the vibration sensor 6 are mainly shown. Vibration sensor 1
The coordinate value correction using the output from the 02 side will be described later.

The microcomputer 11 includes an internal counter, ROM, and RAM. The drive signal generation circuit 12
It outputs a drive pulse of a predetermined frequency to the vibrator drive circuit 2 shown in the figure, and is activated by the microcomputer 11 in synchronization with the coordinate calculation circuit.

The count value of the counter 13 is latched into the latch circuit 14 by the microcomputer 11.

On the other hand, the waveform detection circuit 9 outputs timing information of a detection signal for measuring vibration transmission time for coordinate detection from the output of the vibration sensor 6 as described later. These timing information are input to input ports 15, respectively.

A timing signal inputted from the waveform detection circuit 9 is inputted to an input capacitor 15, stored in a storage area corresponding to each vibration sensor 6 in the latch circuit 14, and the result is transmitted to the microcomputer 11.

That is, the vibration transmission time is expressed as a latch value of the output data of the counter 13, and coordinate calculation is performed using this vibration transmission time value. At this time, the determination circuit 16 determines whether all waveform detection timing information from the plurality of vibration sensors 6 has been input, and determines whether the microcomputer 1
Notify 1.

Output control processing for the display device 11' is performed via the human output boat 17.

FIG. 4 explains the detected waveform input to the waveform detection circuit 9 of FIG. 1 and the total processing a14 of the vibration transmission time based on the detected waveform. :h'S4 In the diagram, what is indicated by the reference numeral 41 is a drive signal pulse applied to the vibrating pen 3. The ultrasonic vibrations transmitted from the vibrating pen 3 driven by such a waveform to the vibration transmitting plate 8 are transmitted to the vibration transmitting plate 8.
It passes through the inside 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. 4 indicates a signal waveform detected by the vibration sensor 6. The plate wave used in the non-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. Since the group velocity and phase velocity are high, the distance between the vibrating pen 3 and the vibration sensor 6 can be detected.

First, focusing only on the envelope 421, its speed 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. 4, the distance between the vibration pen 3 and the vibration sensor 6 d is the vibration transmission time t
As g, d=Vg conflict 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, the phase waveform 4 shown in FIG.
22 specific detection points, for example, if the time from vibration application to the zero cross point after passing the peak is tp, the distance between the vibration sensor and the vibration pen is d=n fist p+Vp number tp...(2), where where λP is the wavelength of the elastic wave, and n is an integer.

From the above equations (1) and (2), the above integer n is n = [(Vglltg - Vplltp) / input P + l
/N ] − (3). Here, N is a real number other than O, and an appropriate value is used. For example, if N=2, n can be determined if it is within ±1/2 wavelength.

By substituting n determined as above 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 at 512, for example.

In FIG. 5, the output signal of the vibration sensor 6 is amplified to a predetermined level by the amplification circuit 51 described above.

The amplified signal is input to the envelope detection circuit 52, and only the envelope of the detection signal is extracted. 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 58 from this Tg times signal timing and the original signal delayed by the delay time adjustment circuit 57, and the arithmetic control circuit 1
is input.

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 value for detecting a p-fold signal is formed. As a result, the comparator level supply circuit 56 is connected to the reference numeral 44 in FIG.
A signal 44 having a timing similar to the above is generated and inputted to the detection circuit 58.

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.
8 and is compared with the delayed detection waveform as shown in FIG.

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 of envelope delay time Tgl-h and phase delay time "rpt-h" are input to the arithmetic control circuit l.

In the arithmetic control circuit of FIG. 3, the above Tgl~h, Tpl-
The h signal is input from the input port 15, and the count value of the counter 13 is taken into the latch circuit 14 using each timing as a trigger.As mentioned above, the counter 13 is started in synchronization with the driving of the vibrating pen, so the latch circuit The circuit 14 receives data indicating the respective delay times of the envelope and the phase.

When three vibration sensors 6 are arranged at the corners of the vibration transmission plate 8 at positions S1 to S3 as shown in FIG. Straight hole tllIdl to the position of vibration sensor 6
~d3 can be obtained.

Furthermore, the coordinates (x, y) of the position Up of the vibrating pen 3 can be determined by the arithmetic and control circuit 1 based on the straight hole #dl-d3 using the following equation from the theorem of three squares.

x=X/2 (di + d2) (di
-d2) /2X-(4)! =Y/2◆(d
i◆d3)(di-d3)/2Y...(5)
Here, X and Y are the distances along the X and Y axes between the vibration sensor 6 at the positions S2 and S3 and the sensor at the origin (position 31).

As described above, the position coordinates of the vibrating pen 3 can be detected in real time.

Next, a configuration for detecting the inclination angle of the vibrating pen 3 at the time of input will be described.

FIG. 7 shows a detected waveform of the vibration sensor 102.

As described above, this detected waveform is the longitudinal wave component of the vibration input by the vibrating pen 3.

Figure 7 shows the detected waveform 1O-3 when inputting from the same input point with the vibrating pen 3 standing vertically, and the detected waveform 1O-3 when the vibrating pen 3 is input by about 4
The tilt of about 5° indicates the detected waveform 104 of life input.
As is clear from the figure, when the inclination angle is changed in this way, the phase of the detected waveform is not completely reversed depending on the angle of the vibrating pen 3, but it is considerably shifted.

Therefore, if thresholds 105 and 106 are provided as shown in FIG. 8 and the phase relationship between the detected waveforms 103 and 104 is compared, a detected amount corresponding to the tilt angle of the pen can be created. In other words, when the pen is held vertically, the signal 10 obtained at the threshold value 105 is
7 is obtained earlier in time than the signal 108 obtained at the threshold value 10B. When the pen is tilted by about 45 degrees, on the contrary, the signal 110 obtained at the threshold value 106 is obtained earlier than the signal 109 obtained at the threshold value 105. By detecting the time difference, the tilt of the pen can be detected.

Therefore, the vibrating pen angle detection circuit 101 shown in FIG. 1 is configured as shown in FIG. In Figure 9, one vibration sensor 1
Mainly shows the configuration of the vibrating pen angle detection circuit on the 02 side.

As shown, the output of the vibration sensor 6 is input via a preamplifier 111 to two comparators 112 and 113. These comparators 112.113 are connected to the above threshold 105.1
06 and the input signal. Flip-flops 114 and 115 are set by the outputs of comparators 112 and 113, respectively. The outputs of flip-flops 114 and 115 are input to the clear and clock input terminals of flip-flop 116, respectively. Therefore, flip-flop 1
16 is the output of flip-flops 114 and 115,
Reset and set respectively.

Circuits similar to those described above are also provided on the side of the other vibration sensor 102, and the outputs of these circuits are input to the arithmetic control circuit l via the OR gate 117.

FIG. 10 shows the operation of each element in FIG. 9 when an input is made with the vibrating pen in a vertical position or a position close to the vertical position.

In this case, the signal 103 obtained from the vibration sensor 102 by the preamplifier Ill is passed through the comparators 112 and 113 to generate the signal 10.
Get 7,108. At the rising edge of each first pulse a signal 1 is applied to the output of the free 2 flop 114, 115.
We get 20.121.

In this case, since the output of the flip-flop 70 knob 115 is raised later, the flip-flop 116 is set and its output becomes high level.

On the other hand, if input is performed with the vibrating pen 3 tilted to some extent, the detection timings of the comparators 112 and 113 are reversed as shown in FIG. 11 due to phase inversion. As a result, the flip-flops 114 and 115 are connected to the reference numeral 123 in FIG.
, 124. In this case, since the 4-flip flop 114 is set later, the flip-flop 116 is reset as indicated by reference numeral 125.

As described above, depending on the tilted state of the vibrating pen 3, the 10th
The waveforms of signals 122 (for vertical or near-vertical cases) to 125 (for inclined cases) in FIGS. Therefore, when the vertical state of the vibrating pen 3 is detected via any of the vibration sensors 102, a high level signal is sent to the arithmetic control circuit l via the OR gate 117,
02 also outputs a low level signal when the vertical state of the vibrating pen 3 is not detected.

Since the propagation delay time detected by the vibration sensor 6 is naturally affected to some extent by the pen angle, propagation 1! is determined based on the pen angle detection signal detected as described above. By determining whether the elapsed time is true or false, the accuracy during coordinate calculation can be improved.

For example, the vibrating pen 3 may ignore coordinate values input in a position other than vertical, or the vibrating pen 3 may ignore coordinate values input in a position other than vertical, or may replace the coordinate values (x
i, y1) and (x2, y2) average value (xl+x2
/2, yl+y2/2) may be used.

Alternatively, if the vibrating pen 3 is not vertical, a buzzer or the like may be generated to alert the operator.

In addition, the phase inversion of the longitudinal wave due to the inclination angle of the vibrating pen 3 is as follows.
It also varies depending on the direction of inclination. Taking advantage of this, the coordinate sensor and the sensor for detecting the pen tilt angle may be sequentially switched so that the coordinate calculation is performed using the sensor that detects the pen tilt angle and has no phase reversal.

In addition, the input mode can be switched based on the detected tilt angle of the vibrating pen 3. For example, if the vibrating pen 3 is vertical, it will be in character input mode, and if it is tilted at about 45 degrees, it will be in page turning mode in editing mode. , menu selection, etc. may also be performed.

Furthermore, in the above, the two vibration sensors 102 are for right-handed and
Although it is used as a left-handed tilt sensor, only one sensor may be used to detect the tilt of the vibrating pen.

In the embodiment described above, the pen angle was determined using hardware such as a flip-flop, but the signals from the comparators 112 and 113 may be directly processed by software calculations using a microprocessor or the like. .

In addition, in a device that uses longitudinal elastic waves, the signal from the sensor for coordinate position calculation can be used as it is to determine the pen angle.9 For example, four vibration sensors can be used as longitudinal wave sensors for coordinate calculation. Since the device installed in the thickness of the transmission plate 8 can calculate the coordinate position using at least two sensors, two of the four sensors are used to calculate the coordinate position, and the other two are used as sensors for the pen inclination angle. , it is also possible to use it for correction of coordinate calculations. With such a configuration, various controls based on the inclination angle of the vibrating pen 3 can be performed using substantially the same hardware configuration as the conventional one.

Although the above example uses two vibration sensors for detecting the angle of the vibration pen, the number of sensors may be one or more than two.

[Effects of the Invention] As is clear from the above, according to the present invention, vibrations input from a vibrating pen are detected by a plurality of sensors provided on the vibration transmitting plate, and the coordinates of the vibrating pen on the vibration transmitting plate are determined. A coordinate input device for detecting a vibration transmitting plate includes means for detecting a longitudinal wave component of vibrations transmitted through the vibration transmission plate, and detecting a posture of a vibrating pen at the time of input according to a phase state of an output signal of the detection means. Since the configuration is equipped with a control means, the posture of the vibrating pen at the time of input can be detected from the longitudinal wave component of the vibration transmitted to the vibration transmission plate, so the coordinate values can be adjusted according to the posture of the vibrating pen. It has an excellent advantage of being able to perform various processes such as correcting the vibration, ignoring input information depending on the posture of the vibrating pen, and switching input modes depending on the posture of the vibrating pen.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the configuration of a coordinate input device adopting the present invention, Fig. 2 is an explanatory diagram showing the structure of the vibrating pen shown in Fig. 1, and Fig. 3 is an explanatory diagram showing the structure of the vibrating pen shown in Fig. 1. A block diagram showing the structure, FIG. 4 is a waveform diagram showing detected waveforms to explain distance measurement between the vibrating pen and the vibration sensor, and FIG. 5 is a block diagram showing the configuration of the waveform detection circuit in FIG. 1. , Fig. 6 is an explanatory diagram showing the arrangement of the vibration sensor, Fig. 7 is a waveform diagram showing the output signal of the vibration sensor for detecting the angle of the vibrating pen, and Fig. 8 is an explanatory diagram showing the arrangement of the vibration sensor.
9 is a block diagram of the pen angle detection circuit shown in FIG. 1, and FIGS. 10 and 11 are timing charts showing the operation of the pen angle detection circuit. . 1... Arithmetic control circuit 3... Vibrating pen 4... Vibrator 6.102... Vibration sensor 8... Vibration transmission plate 101... Vibrating pen angle detection circuit 111... Preamplifier 112.113...Comparators 114-116...Flip-flops 117...O
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Claims (1)

[Claims] 1) In a coordinate input device that detects vibrations input from a vibrating pen using a plurality of sensors provided on a vibration transmitting plate to detect the coordinates of the vibrating pen on the vibration transmitting plate, A coordinate input device comprising: means for detecting a longitudinal wave component of vibration; and a control means for detecting a posture of a vibrating pen at the time of input according to a phase state of an output signal of the detecting means.