JPH0410023A - Vibrating pen for input of coordinates - Google Patents

Abstract

PURPOSE:To transmit the vibration energy generated by a piezoelectric element to a horn part with high efficiency by using a K33 mode columnar piezoelectric element which applies the both end faces of the piezoelectric element as the electrodes and holding together the horn part and an electrode plate as well as this plate and the piezoelectric element respectively with the pressure contact adhesive force. CONSTITUTION:A K33 mode is applied to a vibrator 4 of a vibrating pen, and an electrode plate 34 is provided between one of both sides of the vibrator 4 and a horn 5. The grease is applied between the horn 5 and the plate 34 as well as between the plate 34 and the element 4. Then the plate 34 and the element 4 are fixed with pressure by means of a spring 36 which is used to take out the other electrode of the element 4. As a result, a perfectly axial symmetrical pen is obtained and at the same time a vibrating pen is produced with high efficiency without using any adhering means. Thus no process control is required for the adhesion and the productivity is improved for the vibrating pen.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Fields] 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 transmits the vibrations of the vibrating pen. This invention relates to a vibrating pen used in a coordinate input device that detects position coordinates on a board.

[Prior Art] Conventionally, a vibrating pen for a coordinate input device detects vibrations input from a vibrating pen using a plurality of sensors provided on a vibration transmitting plate to detect position coordinates of the vibrating pen on a vibration transmitting plate. A piezoelectric element, which is an electromechanical transducer, was used as a vibration generation source. A typical vibration mote of a piezoelectric element is a moat (K31) in which the polarization direction and the vibration direction are perpendicular to each other.
moat) and a moat (K3) parallel to the polarization direction and vibration direction.
3 motes). FIG. 7(a) is an example using a cylindrical piezoelectric element of K31 moat. A certain part of the electrode spring 8361 and the electrode spring G371 are electrically connected to the cylindrical piezoelectric element 41 with a certain pressing force. Figure 7(b) Hani 3
This is an example using a 1-moat cylindrical piezoelectric element. In this case, the vibration direction of the piezoelectric element is the radial direction, and in order to efficiently transmit vibration energy to the horn portion 52, it is necessary to bond the piezoelectric element. FIG. 7(C) is an example using a cylindrical piezoelectric element of K33 moat. In this case, the electrodes of the piezoelectric element are located on both end faces of the element, and power is supplied through the electrode bin 72 and the electrode plate 71. If the electrode plate 71 is a horn part 72 or a conductive member (for example, metal such as aluminum),
Either it is not necessary, or in this case there is a drawback that the metal horn damages the propagating body which is the input surface, so the patent application No. 62-2
This is necessary when the horn is made of resin as in No. 73963. Conventionally, this electrode plate 71 was used by being glued to this resin horn 72 in order to efficiently transmit vibrations.

[Problems to be Solved by the Invention] However, the above conventional example had the following drawbacks. In the case of the K31 moat and cylindrical piezoelectric element, the electrodes are removed from the side by pressure contact or soldering, which changes the physical vibration characteristics of the piezoelectric element, resulting in uniform vibration relative to the axis of the piezoelectric element. You will no longer be able to obtain the characteristics.

As a result, different phenomena appear depending on the speed or direction of the vibration emitted from the tip of the vibrating pen or the wave excited in the propagating body when it enters the propagating body, resulting in directivity. This method has the disadvantage that it is difficult to construct a highly accurate coordinate input device.

In addition, in the case of the K3131 moat type and the 33 moto cylindrical type, bonding was always used to increase vibration transmission efficiency and to supply power to the element.

In order to maintain the accuracy of the coordinate input device, it is necessary to make the resonance characteristics of the vibration input pen uniform, and this not only reduces productivity due to the need to control the thickness of the adhesive layer, but also prevents air bubbles from forming in the adhesive layer. Furthermore, when the adhesion becomes partially incomplete, the above-mentioned directivity appears, resulting in a reduction in yield.

[Means for Solving the Problems (and Effects)] According to the present invention, a 33-mode cylindrical piezoelectric element is used, with both end surfaces of the piezoelectric element serving as electrodes, and an electrode is provided between the horn portion and the piezoelectric element. Apply grease between the horn part and the electrode plate, and between the electrode plate and the piezoelectric element. By sandwiching the electrode plate with the pressure contact force of the electrode on the opposite side, power is supplied to the piezoelectric element, and the piezoelectric element In addition to efficiently transmitting the vibration energy generated by the vibration input pen to the horn, it is possible to construct an axially symmetrical vibration input pen without using adhesive means, thereby eliminating the problem of directivity of the vibration input pen. Moreover, it is possible to improve productivity.

[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 transmitting plate 8, and displays input coordinate information on a display 11 consisting of a CRT placed over the input tablet. ′ is used to display the input image.

In the figure, a vibration transmission plate indicated by the reference numeral 8 is made of an acrylic or glass plate, and transmits the vibration transmitted from the vibration ben 3 to three vibration sensors 6 provided at its corners. In this embodiment, the coordinates of the vibration ben 3 on the vibration transmission plate 8 are detected by measuring the transmission time of the ultrasonic vibration transmitted from the vibration ben 3 to the vibration sensor 6 via the vibration transmission plate 8.

The vibration transmitting plate 8 has its peripheral portion supported by an anti-reflection material 7 made of silicone rubber or the like in order to prevent the vibration transmitted from the vibration vent 3 from being reflected at the peripheral portion and returning toward the central portion. ing.

The vibration transmitting plate 8 is arranged 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 ben 3. That is, a dot is displayed at a position on the display 11' that corresponds to the detected coordinates of the vibrating pen 3, and an image composed of elements such as points and lines input by the vibrating pen 3 is displayed as if it were on paper. It appears after the vibrating Ben's trajectory as if it were written.

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

The pen 3 that transmits ultrasonic vibrations to the vibration transmission plate 8 has a vibrator 4 made of a piezoelectric element inside, and transmits the ultrasonic vibrations generated by the vibrator 4 to a horn portion 5 with a sharp tip.
The vibration is transmitted to the vibration transmission plate 8 via.

FIG. 2 shows the structure of the vibrating vent 3. A vibrator 4 built into the vibrator 3 is driven by the vibrator drive circuit 2 described above. 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.
After being amplified by a predetermined gain by a vibrator drive circuit 2 capable of low impedance driving, the signal is applied to the vibrator 4.

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

The vibrator 4 in Fig. 2 is a cylindrical one. As shown in Figure 2-(b), it is a K33 mote vibrator.

The vibrator 4 is positioned with a clearance fit with the positioning member 32 so that its axis is aligned with the horn portion 5. Further, the positioning member 32 and the horn portion 5 are connected to the pen tip protection member 3.
3 and 3 are fitted with a clearance on their outer diameters, and are positioned so that their respective axes are aligned. The ground side electrode of the vibrator 4 is connected to the electrode plate 341 positioning member 32. Conduction link 38.
It is connected to the circuit through an electrode spring G37. Further, the signal side electrode of the vibrator 4 is connected to the electrode pin 35. Electrode spring S3
It is connected to the circuit through 6. Furthermore, the pen housing 3
1 and the pen tip protection member 33 are integrated through a conductive link 38 via a threaded portion. At this time, the pen tip is supported by the pen housing 31 by the pen tip protection member 33.

In this embodiment, the electrode plate 34 is made of copper foil with a thickness of 0.02a+m, and the electrode plate 34 is sandwiched between the horn part 5 and the vibrator 4 through grease on both sides, and the electrode plate 34 is sandwiched between the horn part 5 and the vibrator 4 through grease. 536 through the electrode pin 35. In this embodiment, the electrode plate 4 is fixed via a positioning member 32 by pressure contact force using a screw to ensure continuity.

As shown in Fig. 2, the structure of the vibrator 3 is completely symmetrical about the axis, and the resonance characteristics of the vibrator 4 may change due to soldering or the like, or even if it is not soldered, it may be partially pressed. Directivity of the pen due to changes in resonance characteristics (mode) when the electrode is taken out does not appear. moreover,
The pen tip can be easily replaced by loosening the screw.

In this way, the characteristics of the vibration transmitted to the vibration transmission plate 8 are uniform, so that the waveform of the vibration detection signal for the coordinate detection processing described later can be controlled to a constant shape. This greatly improves coordinate detection accuracy.

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 vibration ben 3 on the vibration transmission plate 8.

The detected coordinate information of the vibrating vent 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 10 based on the input coordinate information.

FIG. 3 shows the structure of the arithmetic control circuit 1 shown in FIG.

This mainly shows the structure of the drive system of the vibrating ben 3 and the vibration detection system using the vibration sensor 6.

The microcomputer 11 includes an internal counter ROM and RAM. The drive signal generation circuit 12 outputs a drive pulse of a predetermined frequency to the vibrator drive circuit 2 shown in FIG. 1, 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 obtains timing information of a detection signal for measuring vibration transmission time for coordinate detection and signal level information for pen pressure detection from the output of the vibration sensor 6 as described later. Output. These timing and level information are input to input ports 15 and 17, respectively.

The timing signal input from the waveform detection circuit 9 is input to the input port 15, and the latch circuit 1 is input by the determination circuit 16.
4 and the result is transmitted to the microcomputer 11. That is, the vibration transmission time is expressed as the latch value of the output take of the counter 13, and coordinate calculations are performed based on this vibration transmission time value.

Output control processing for the display 11' is performed via the input/output port 18.

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. What is indicated by reference numeral 41 in FIG. 4 is a drive signal pulse applied to the vibrating vent 3. Ultrasonic vibrations transmitted from the vibration ben 3 driven by such a waveform to the vibration transmission plate 8 pass through the vibration transmission plate 8 and are 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 this example is a dispersive wave,
Therefore, the relationship between the envelope 421 and the phase 422 of the detected waveform changes depending on the vibration transmission distance.

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

If we focus only on the envelope 421, its velocity is Vg.If a point on a particular waveform, for example a peak, is detected as indicated by the reference numeral 43 in FIG.
and the distance d between the vibration sensor 6 is d=Vg-tg, where the vibration transmission time is tg...
(1) This equation relates to one of the vibration sensors 6, or the same equation applies to the other two vibration sensors 6 and the vibration sensor 3.
Can show the distance between

Furthermore, in order to determine coordinate values with higher precision, processing based on phase signal detection is performed.

A specific detection point of the phase waveform 422 in FIG.
The distance between the vibration sensor and the vibration bench is d=n-person p+Vp+tp-(2).

Here, p 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= [(Vg4g-Vp-tp)/input p+1/N
] =・(3). Here, N is a real number other than 0, and an appropriate value is used. For example, if N=2, ±
If it is within 1/2 wavelength, n can be determined.

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

In order to measure the two vibration transmission times tg and tp shown in FIG. 3, the waveform detection circuit 9 can be configured as shown in FIG. 5, 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 extracted envelope peak is detected by the envelope peak detection circuit 53. The peak detection signal is formed into an envelope delay time detection signal Tg of a predetermined waveform by a signal detection circuit 54 composed of a mono multivibrator, etc., and is inputted to the arithmetic control circuit 16. A phase delay time detection signal Tp is formed by the detection circuit 58 from the original signal delayed by the adjustment circuit 57, and then sent to 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 in accordance with this pulse timing.
A threshold value for detecting the p signal is formed. As a result, the comparator level supply circuit 56 forms a signal 44 having a level and timing as indicated by reference numeral 44 in FIG. 3, and inputs it to the detection circuit 57.

That is, the monostable multivibrator 55 and the comparator level supply circuit 56 are designed to operate only for a certain period of time after measuring the phase delay time or detecting the envelope peak.

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 of each of the envelope delay times Tgl to h1 and the phase delay times Tpl to h are input to the arithmetic control circuit l.

In the arithmetic control circuit of FIG. 3, the above Tgl~h, "rpt
-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. Since the counter 13 is started in synchronization with the driving of the vibrator as described above, the latch 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. 6, the processing described in connection with FIG. The straight-line distances d1 to d3 from P to the position of each vibration sensor 6 can be determined. Furthermore, the coordinates (x,
y) can be obtained from the 3-square theorem as shown in the following equation.

x=X/2 + (dl ◆ d2) (di −
d2)/2X... (4)y-Y/2 +(d
l + d3) (di - d: 1) /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 S1).

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

[Effects of the Invention] As explained above, according to the present invention, vibrations input from a vibrating pen are detected by a plurality of sensors provided on a vibration transmitting plate, and the coordinates of the vibrating pen on the vibration transmitting plate are determined. In the coordinate input device to be detected, a 33 mode is used for the vibrator of the vibrating pen, an electrode plate is provided between one surface of the vibrator which is the electrode and the horn, and the horn and the electrode plate are connected to each other. By applying fleece between each piezoelectric element, using a spring to take out the other electrode of the piezoelectric element, and crimping and fixing the electrode plate together with the piezoelectric element, a completely axially symmetrical pen is constructed. Since it is possible to construct a vibrating pen without using any other means, it is possible to eliminate the problem of directivity of the pen, and also to control the process of adhesion, such as inspection for air bubbles, incomplete adhesion, and thickness of the adhesive layer. This has the great effect of eliminating management and improving productivity.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the configuration of an information input/output 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. Figure 4 is a waveform diagram showing the detected waveform explaining distance measurement between the vibrating pen and the vibration sensor, and Figure 5 is a flock diagram showing the configuration of the waveform detection circuit in Figure 1. Figure 6 is an explanatory diagram showing the arrangement of vibration sensors, Figures 7 (a) to (C)
is an explanatory diagram of a conventional example. 1... Arithmetic control circuit 3... Vibration pen 4... Vibrator 5... Horn section 6... Vibration sensor 8... Vibration transmission plate 15.16... Input boat 51... Preamplifier 52...enherobe detection circuit 54.58...signal detection circuit 5 Figure Hama 1 False leg circuit professional 1. Diagram (Jakuta circuit) Diagram 1-l-

Claims (1)

[Scope of Claims] 1) A vibrating pen for a coordinate input device that detects the coordinates of the vibrating pen on the vibration transmitting plate by detecting the vibration input from the vibrating pen with a sensor provided on the vibration transmitting plate. A vibration generating element that generates vibrations, a horn member that transmits the vibrations generated from the vibration generating element to the vibration transmission plate, and an electrode member interposed between the horn member and the vibration generating element, the 2. The coordinate input vibrating pen according to claim 1, further comprising a pressure contact member having both surfaces coated with a viscous member such as grease and pressing the vibration generating element and the electrode member against the horn member. 2) The vibrating pen for coordinate input according to claim 1, wherein the pressure contact member is a spring member and also serves as the other electrode.