JPS63120325A - Coordinate input device - Google Patents

Abstract

PURPOSE:To avoid fluctuation of vibration input conditions caused by an operator and to ensure accurate and stable detection of coordinates, by pressing a vibration generating means for vibration input member to a vibration transmitting plate at a fixed angle and with pressure contact force of a fixed level. CONSTITUTION:An operator moves a vibration input device 3 on an input tablet consisting of a vibration transmitting plate 8 to attain the coordinate input at a desired input point and displays the input coordinate information on a display device 11 put on the input tablet. The vibrations received from the device 3 are transmitted to three vibration sensors 6 set at the corner parts of the plate 8. A reflection preventing material 7 provided at the peripheral part of the plate 8 functions to prevent the vibrations returning to the center part. The device 3 is driven by a vibrator driving circuit 2 connected to an arithmetic/control circuit 1 and the vibrations detected by each sensor 6 are detected again by a signal waveform detecting circuit 9. This detection signal is supplied to the circuit 1. Then the device 3 is pressed to the plate 8 at a fixed angle and with pressure contact force of a fixed level. Thus it is possible to detect coordinates with high accuracy and high stability.

Description

Detailed Description of the Invention "Industrial Application Field" The present invention detects vibration transmitted to a vibration transmission plate using a vibration sensor provided on the vibration transmission plate, and detects the vibration transmitted to the vibration transmission plate from the transmission time of the vibration. The present invention relates to a coordinate input device that detects the coordinates of a vibration input point.

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

The following various methods are known for detecting the coordinates of a tablet in this type of device.

l) A method of detecting changes in the resistance value of a sheet material placed opposite the resistive film.

2) Electromagnetic or static electricity such as conductive sheets placed opposite each other? t
Method for detecting t-lead.

3) A method that detects ultrasonic vibrations transmitted from the input vent to the tablet.

In the above methods 1) and 2), it is difficult to form a transparent tablet because a resistive film or a conductive film is used. On the other hand, in method 3), the tablet can be constructed from a transparent material such as an acrylic plate or a glass plate, so the input tablet can be placed on top of a liquid crystal display (2) and used as if it were writing an image on paper. It is possible to construct a coordinate input device that is easy to operate.

[Problems to be Solved by the Invention] By the way, input tablets that use ultrasonic vibrations that have been considered conventionally use input pens that incorporate a vibrator with a shape similar to a writing instrument such as a pen or pencil.

The input pen is held and operated by the operator in the same way as a normal writing instrument. - A vibrator made of a piezoelectric element or the like is provided in the coos of the force input vent, and its vibration is transmitted to the vibration transmission plate via a vibration transmission member having a predetermined shape such as a horn shape at the tip. The vibration direction of the vibrator is =- with respect to the pen case.

Since the pen is set in a fixed direction, the vibration transmission efficiency changes depending on the angle at which the operator touches the pen to the vibration transmission plate or the pressure of the pen.Therefore, some operators may not be able to perform correct coordinate detection. In some cases, input may become impossible.

In addition, if the vibrating pen contacts the vibration transmission plate diagonally, the vibration given to the vibration transmission plate will be a combination of various vibration components such as transverse waves and longitudinal waves, so vibration detection is performed based on waveform detection. In some cases, there is a problem that the detection accuracy decreases or varies.

[F stage for solving the problem] In order to solve the problem 1-5 below, in the present invention,
In a coordinate input device that detects vibration transmitted from a vibration input member to a vibration transmission plate using a vibration sensor provided on the vibration transmission plate, and detects the coordinates of a vibration input point from the transmission time of the vibration, the vibration is transmitted to the vibration input member. The present invention employs a configuration that includes a vibration generating means for generating , and a means for pressing the first stage of vibration generation against the vibration transmission plate at a predetermined angle and with a predetermined pressing force.

[Sakukawa] According to the second configuration, the vibration generating means of the vibration input member is pressed against the vibration transmission plate at a constant angle and with a constant pressure contact force, so that the vibration input conditions can be adjusted by the operator's operation. Avoid variable problems.

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

The first IN shows the structure of a coordinate input device employing the present invention. The device shown in FIG. 1 allows the operator to move the vibration input device 3 using an input tablet consisting of a vibration transmission plate 8.
Coordinates are input at the desired input point, and C is placed on the input tablet according to the input coordinate information.
Input information is displayed on a display 11' consisting of an RT.

In the figure, the reference numeral 8 is a vibration transmission plate made of acrylic or glass plate, and three vibration sensors 6 installed at the corners of the plate transmit the vibrations transmitted from the vibration input device 3.
In this embodiment, the coordinates of the vibration input device 3 on the vibration transmission plate 8F are determined by measuring the transmission time of the ultrasonic vibration transmitted from the vibration input device 3 to the vibration sensor 6 via the vibration transmission plate 8. Detect.

The vibration transmission plate 8 is supported at its peripheral portion by an anti-reflection material 7 made of silicone rubber or the like in order to prevent vibrations transmitted from the vibration input device 3 from being reflected at the peripheral portion and returning toward the center. has been done.

The vibration transmission plate 8 is placed on a display device 11' capable of displaying dots, such as a CRT (or liquid crystal display, etc.), and the vibration input device i! A dot is displayed at the position traced by t3. That is, a dot is displayed at a position on the display 11' that corresponds to the detected coordinates of the vibration input device 3, and the image composed of elements such as points and lines input by the vibration input device 3 appears as if it were a piece of paper. It appears after the +ill trace of the vibration input device, as if writing was done.

Further, according to such a configuration, a menu is displayed on the display ll', and the menu item is selected by the vibration input device, a prompt is displayed, and the vibration input device 3 is brought into contact with a predetermined position. Input methods can also be used.

Vibration input device 3 that transmits ultrasonic vibration to vibration transmission plate 8
has a vibrator 4 made up of a piezoelectric element, etc., and transmits super-RF wave vibration generated by the vibrator 4 to a vibration transmission plate 8 via a horn portion 5 with a sharp tip.

In this example, a pen-shaped input member is not used, and FIG.
Vibration input for coordinate detection is performed using a vibration input device as shown in A).

The vibration input device 3 has a structure in which a vibration generating section is built in a lower case 22 having a substantially hemispherical L case 21 and pole-shaped legs 23 (only 12 of them are shown).

The internal cylindrical vibrator 4 is fixed to a horn portion 5 having a flange portion by a method such as adhesion. A vibration generating section consisting of a vibrator 4 and a horn section 5 is housed together with a spring 20 in a housing section 24 provided vertically within the first case 21 and lower case 22 of the vibration input device 3.

The spring 20 applies pressure to the flange portion of the horn portion 5, and urges the entire vibrating portion downward.

The tip of the horn portion 5 protrudes from the through hole in the center of the lower case,
It is pressed against the vibration transmission plate 8. At the position where the horn portion 5 comes into contact with the bottom of the storage portion 24 due to the bias of the spring 20, the tips of the two horn portions protrude beyond the pole-shaped legs 23 provided on the lower case 22.

With such a floating support structure, when the operator moves the vibration transmission plate 8-) while holding the vibration input device 3, the vibration generation part is always held perpendicular to the vibration transmission plate 8, and The spring 20 always presses against the vibration transmission plate 8 with a constant urging force.

A vibrator 4 built into the vibration input device 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 1 shown in FIG. 4
is applied to

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

When performing such vibration transmission, it is preferable to use plate waves instead of surface waves to vibrate in order to avoid the effects of scratches and obstacles on the vibration transmission plate 8. Therefore, the vibration frequency of the vibrator 4 is Of course, the value is selected so that a plate wave can be generated in the vibration transmission plate 8 made of acrylic, glass, etc. according to its inherent acoustic impedance. A vibration mode in which the vibrator 4 mainly vibrates in the vertical direction in the figure is selected. In addition, in order to focus on the efficiency of vibration transmission,
Let the vibration frequency of the vibrator 4 be the resonance frequency of the vibrator 4.

As is clear from the above, it can be seen that the plate wave can be transmitted to the vibration transmission plate 8 most efficiently when the horn part 5 is brought into contact with the vibration transmission plate 8 directly to the east. With the structure shown in (A), the horn portion 5 is always kept straight to the vibration transmission plate 8, so the vibration that can be applied to the vibration transmission plate 8 is a pure plate wave of a single waveform component. Become.

Moreover, since the horn portion 5 is always pressed against the vibration transmission plate 8 with a constant force by the spring 20 regardless of the operating force of the operator, the input vibration intensity is always kept stable. Generally, in such a vibration transmission method, if the contact pressure is insufficient, the vibration detection accuracy or the seat P3 detection resolution decreases. Therefore, while the conventional pen-type input device causes variations in detected viscosity due to differences in pen pressure, the above configuration can greatly improve the stability of coordinate input accuracy.

In addition, in the above configuration, the lower case 220 feet 2 are attached to the vibration transmission plate 8.
3 are in contact with each other, but since the plate wave is selected as the vibration mode of the vibration transmission plate 8 as described above, there is almost no problem with vibration transmission.

In the structure of the vibration input device 3 described above, the seventh and lower cases 21 and 22 can be made of the desired materials, such as metal or plastic. Moreover, its shape is not limited to that shown in the drawings, and may be various shapes.

For example, as shown in FIGS. 2(B) and 2(C), the vibration generating section may be provided at a position of a protrusion z6 offset from the main body of the cylindrical case 25. is the same here.

In the structure of the second Ifl (A), the vibration generating part is provided in the center of the case, so it is not suitable for inputting coordinates around the periphery of the tablet. The horn M5 can be easily brought into contact with the parts.

In either of FIGS. 2(A) and 2(B), the legs 23 may be integral with the case, but pole-shaped legs may be rotatably provided to improve the mobility of the vibrating bag d3.

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 pressure element. The output signals of each of the three vibration sensors 6 are input to the waveform detection circuit 9, and the subsequent arithmetic control circuit 1
The detected signal that can be processed is converted. The arithmetic control circuit 1 performs a vibration transmission time measurement process and detects the coordinate position of the vibration human-powered device 3 on the vibration transmission plate B.

The coordinate information of the detected vibration input device 3 is sent to the arithmetic control circuit 1.
Processing is performed in accordance with the output expression from 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 human coordinate information.

FIG. 3 shows the structure of the arithmetic control circuit l shown in FIG.

Here, the structure of the drive system of the vibration input device 3 and the vibration detection system using the vibration sensor 6 is mainly shown.

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 rotation with the circuit for calculating the oscillator W.

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. The timing information of the vibration detection signal is input manually to the input boat 15.

The input timing signal is compared with the count value in the determination circuit iM relatch 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.

Output control processing for the display device 11' is performed via the input/output port 17.

FIG. 4 explains the detected waveform input to the waveform detection circuit 9 of FIG. 1 and the vibration transmission time measurement process based on the detected waveform. In FIG. 4, the reference numeral 41 indicates a drive signal pulse applied to the vibration input device 3. In FIG. The ultrasonic vibration transmitted from the vibration input device 3 to the vibration transmission plate 8 driven by a waveform such as ζ 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 i g 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 this embodiment is a dispersive wave, and therefore, the detection waveform no envelope 421 and the phase 42 with respect to the propagation distance within the vibration transmission plate 8.
2 changes depending on the transmission distance during vibration transmission.

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 vibration input device 3 and the vibration sensor 6 can be detected from the difference in group velocity and phase velocity.

When the mass reaches only the envelope 421 [1], its velocity is Vg, and when a point on a certain waveform, for example a peak, is detected as indicated by reference numeral 43 in FIG. The distance #d between them is d=Vg-tg, where the vibration transmission time is tg.
(1) Although this equation relates to one of the vibration sensors 6, the distance between the other two vibration sensors 6 and the vibration input device 3 can be expressed by the same equation.

Furthermore, in order to determine a more accurate coordinate image, it is necessary to perform processing based on phase signal detection at a specific detection point of the phase waveform 422 in FIG. Letting the time tp be the distance between the vibration sensor and the vibration input device, d=n*in p+Vp fist t p (2). Here, 8p is the wavelength of the lrl wave, and n is an integer.

From the above equations (1) and (2), the integer n in 1- is n=
C(Vg it g-Vp*t p)/λP + 1
/Nl...(3) is shown. Here, N is a real number other than O, and an appropriate value is used. For example N=2
Then, n can be determined if it is within ±l/2 wavelength. n obtained as described above can be determined.

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

The two vibration transmission times tg and tp shown in FIG. 4 are measured by the waveform detection circuit 9 shown in FIG. The waveform detection circuit 9 is constructed as shown in FIG. The waveform detection circuit shown in FIG. 5 also processes level information of the output waveform of the vibration sensor 6, as will be described later, in order to detect pen pressure.

In FIG. 5, the output signal ji of the vibration sensor 6 is j11y widened to a predetermined level by the front neck width amplification circuit.

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 a comparator detection circuit 58 from this Tg multiplied signal and the original signal delayed by the delay time adjustment circuit 57, and the arithmetic control circuit 1
is input.

The circuit shown below is for one vibration sensor 6,
The same circuit is provided for each of the other sensors. If the number of sensors is generalized to h, then h detection signals of envelope delay times Tgl to h and phase delay times TPI to h are input to the arithmetic and control circuit 1, respectively.

In the arithmetic control circuit of FIG. 3, the above Tgl~h, Tp1~
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 described in JIRJ, the counter 3 is started in synchronization with the driving of the vibration input device 3. Therefore, the latch circuit 14 receives data indicating the delay time l111 of the envelope and the phase.

As shown in FIG. 6, when three vibration sensors 6 are arranged at the corners of the vibration transmission plate 8 at positions S1 to S3, the vibration input device 3 is Straight line distance to the position of the vibration sensor 6 * d r~
d3 can be obtained. Furthermore, the arithmetic control circuit 1 determines the position P of the vibration input device 3 based on the linear distances d1 to d3.
The coordinates (x, y) of can be determined from the 3-square theorem as follows.

Here, X and Y are the distances along x, y+h between the vibration sensor 6 at the positions S2 and s3 and the sensor at the origin (position Sl).

As described above, the coordinates of the vibrating human-powered device 3 can be detected in real time.

Embodiment L shows a configuration in which the input tablet formed by the vibration transmission plate 8 is stacked on the CRT display 11', but the input tablet and the display do not need to be arranged in such a way that they are stacked, and may be provided separately. In addition, the display may be of a 4fx display method such as a liquid crystal display.

[Effects of the Invention] As is clear from the following, according to the present invention, the vibration transmitted from the vibration input member to the vibration transmission plate is detected by the vibration sensor provided on the vibration transmission plate, and the transmission time of the vibration is determined. In a coordinate input device that detects the coordinates of a vibration input point from a vibration input member, the vibration generation means generates vibration in the vibration input member, and the vibration generation means is brought into pressure contact with the vibration transmission plate at a predetermined angle and with a predetermined pressure contact force. To provide an excellent coordinate input device which can maintain constant vibration transmission characteristics from a vibration input member to a vibration transmission plate and can accurately and stably detect coordinates by adopting a configuration provided with a means. I can do it.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the structure of a coordinate input device employing the present invention, FIG. 2 (A) is an explanatory diagram showing the structure of the vibration input device of FIG. 1, and FIG. 2 (B) is Partially broken side view showing different structures of the vibratory motion input neck, Part 2
Figure (C) is a top view of the mounting in Figure 2 (B), Figure 3 is a top view of the
Calculation in the figure: A block diagram showing the structure of the control circuit. Figure 4 shows the distance between the vibration input device and the vibration sensor! FIG. 5 is a block diagram showing the configuration of the waveform detection circuit of FIG. 1, and FIG. 6 is an explanatory diagram showing the arrangement of vibration sensors. l... Arithmetic control circuit 3... Vibration input device 4...
- Vibrator 6... Vibration sensor 8... Vibration transmission plate 51... Preamplifier 15... Input boat 20... Spring 21... 1, case
22...Lower case 23...Legs 52...Envelope' detection circuit 54.58...Signal detection circuit 59...A/D conversion circuit (detection port fill 0 performance control port day) -77 En Figure 3 Figure 4 Figure 5 Tadahikata exit is D, 590 Figure 5 Figure 6

Claims (1)

[Claims] In a coordinate input device that detects vibration transmitted from a vibration input member to a vibration transmission plate using a vibration sensor provided on the vibration transmission plate, and detects the coordinates of a vibration input point from the transmission time of the vibration, the vibration is transmitted to the vibration input member. 1. A coordinate input device comprising: a vibration generating means for generating a vibration; and a means for pressing the vibration generating means against the vibration transmission plate at a predetermined angle and with a predetermined pressing force.