JPH02125326A - Coordinate input device - Google Patents

Abstract

PURPOSE:To simplify the constitution of an oscillation pen and compact by starting time counting based on transmission of a signal, which prompts oscillation of the input pen, by a time counting means at the time of transmission of this signal and oscillating the penpoint of the input pen by the input pen itself. CONSTITUTION:An operation control circuit 11 outputs a signal indicating generation of a driving signal 17 to a driving signal generating circuit 10. Then, a modulating circuit 8 modulates a carrier wave 16 from a carrier wave generating circuit 9 based on the driving signal 17 and generates a modulated signal 18, and this signal is originated through an antenna. This signal is received by a reception circuit 31 of the input pen and converted to a demodulated signal by a demodulating circuit 32. Thereafter, the signal 19 is amplified by an amplifying circuit 33 and outputted as a driving signal (pen driving signal 20) of an oscillator 34. Thus, the device consists of a simple circuit in spite of a cordless system, and the device is made compact.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention detects vibrations emitted from a coordinate input device, particularly a vibrating pen, using a plurality of sensors provided on a vibration transmission plate of the device body, and The present invention relates to a coordinate input device that detects the coordinate position of the vibrating pen on the vibration transmission plate based on the transmission time required until the sensor detects the coordinate position.

[Prior Art] Conventionally, there is a method of inputting coordinates using ultrasonic vibration as a medium.

In a device employing this coordinate input method, the tablet (here, the vibration transmitting material) is made of glass, metal, etc., and a plurality of vibration sensors are arranged at predetermined positions on the corners of the tablet.

Then, by indicating a desired position on the tablet with an input pen having a vibrator, vibrations generated from the pen tip are propagated on the tablet. Each vibration sensor will detect this vibration, but the time it takes to detect it differs depending on the distance between the input pen and each vibration sensor. In other words, by measuring the vibration transmission time until it is detected by each vibration sensor, the distance from each vibration sensor to the point indicated by the input pen can be determined.
As a result, it becomes possible to determine the coordinate position of the point indicated by the input pen.

[Problems to be Solved by the Invention] By the way, in order to measure the time it takes for vibrations to reach each vibration sensor, it is necessary to use some means to determine the start time of the vibration generated from the input pen and the time measurement start time of each sensor in the main body of the device. It is necessary to synchronize.

Normally, in order to supply a vibration start instruction signal from the device main body to the input pen, the main body and the input pen are connected with a special cable, and the device main body outputs the vibration start instruction signal to the input pen via this cable. Synchronization was achieved by timing the arrival time of the vibrations.

However, when the main body of the device and the input pen are connected by a cable, the cable may get wrapped around the user's hand, etc., resulting in operational problems.

Therefore, it is conceivable to make the input pen cordless, but this would require not only a circuit to generate vibration drive within the input pen, but also a circuit to synchronize with the main body of the device. , it is difficult to miniaturize the input pen. In other words, it is expected that the input pen will be of a relatively large size, and its operability will deteriorate.

The present invention has been made in view of this problem, and it is an object of the present invention to provide a coordinate input device that allows a vibrating pen to be made compact with a simple configuration.

[Means for Solving the Problem] A coordinate input device of the present invention that solves this problem includes the arrangement shown below.

That is, the vibration emitted from the vibrating pen is detected by a plurality of sensors provided on the vibration transmitting plate of the device main body, and the vibration transmitting plate by the vibrating pen is determined by the transmission time required for each sensor to detect the vibration. In the coordinate input device for detecting the coordinate position above, at least the main body of the device includes a transmitting means for wirelessly transmitting a signal to prompt the vibrating pen to vibrate, and a transmitting means to transmit a signal to the sensor based on the signal transmitted by the transmitting means. a clock means for starting time measurement related to detection of the arrival of vibration; a receiving means for receiving a signal transmitted by the transmitting means in the vibrating pen; vibrating means for vibrating its own pen tip.

[Function] In the configuration of the present invention, the main body of the apparatus transmits a signal that prompts the input pen to vibrate by the transmitting means, and also causes the clocking means to start measuring time based on the signal transmission. The input pen receives the transmitted signal with the receiving means and vibrates its own pen tip with the vibrating means.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

<Explanation of the outline of the configuration (FIG. 1)> FIG. 1 shows a block configuration diagram of the coordinate input device in the embodiment.

In the figure, 1 is a cordless input pen that indicates the coordinate position, and the pen tip vibrates (includes a vibrator) by receiving a drive signal described later.
Reference numeral 2 denotes a vibration transmission plate made of transparent glass (plastic may also be used), which propagates vibrations generated by the input pen 1, and forms a so-called coordinate input area. Vibration sensors made of piezo elements or the like shown as 3a to 3C are fixed to the three corners of the vibration transmission plate 2, and the vibrations generated from the input pen 1 are detected by these vibration sensors 3a to 3c. Reference numeral 4 denotes an anti-reflection material made of silicone rubber or the like for preventing vibrations transmitted from the input pen 1 from being reflected at the periphery of the vibration transmission plate 2 and returning toward the center thereof. 5 is CRTJ? It is a display made of an hLCD panel or the like, and is located behind the vibration transmission plate 2. In other words, since the vibration transmission plate 2 is located in front of the display 5, the displayed content can be read through the vibration transmission plate 8. A display drive circuit 6 controls the display drive of the display 5, and displays a predetermined image such as a dot or line based on instructions from an arithmetic control circuit 11, which will be described later. For this reason, for example, it is possible to display images, characters, etc. input with the input pen 3 on the display 5 in their original size and in real time, or to display the keyboard layout surface on the display 5 and have them operated using the vibrating pen 3. , various uses are possible. 7 is a signal waveform detection circuit, and vibration sensors 3a to 3
A signal corresponding to the vibration detected at c is detected, and a corresponding pulse signal is output to the arithmetic control circuit 11. A modulation circuit 8 modulates the carrier wave output from the carrier wave generation circuit 9 based on the drive signal from the drive signal generation circuit 1o.

Note that the modulated signal is received by the input pen 1 via the antenna, and is used as a drive signal for the vibrator of the input pen, as described above.

The arithmetic control circuit 11 outputs a signal for starting the vibration of the input pen 1 to the drive generation circuit 10, and also calculates the indicated position of the input pen 1 based on the detection signal from the signal waveform detection circuit 7.

1 to 4) FIG. 2 shows a part of the signal waveform detection circuit 9 in the embodiment, and FIG. 3 shows the internal configuration of the input pen 1.

The configuration shown in FIG. 2 shows a part of the signal waveform detection circuit 9 for the vibration sensor 3a, and the other vibration sensors 3b and 3c have exactly the same configuration. be.

The operation of each component shown in FIGS. 1 to 3 will be described below with reference to the timing chart shown in FIG. 4.

First, the arithmetic control circuit 11 (more precisely, the microcomputer within the arithmetic control circuit) outputs a signal to the drive signal generation circuit 10 to cause the drive signal 17 to be generated. Then, the modulation circuit 8 modulates the carrier wave 16 from the carrier wave generation circuit 9 based on this drive signal 17 to generate a modulation signal 18. This modulated signal 18 is transmitted via an antenna.

This signal is received by a receiving circuit 31 of the input pen, and converted into a demodulated signal 19 by a demodulating circuit 32. Thereafter, the demodulated signal 19 is amplified by the amplifier circuit 33 and output as a drive signal (pen drive signal 20) for the vibrator 34.

In this way, although the input pen 1 in the embodiment is cordless in structure, it can be configured with a simple circuit, so it can be made extremely compact. Although the explanation is a bit complicated, the battery that serves as the driving source is built-in, but its size is well known and there is no real harm to it.

Now, the vibrator 34 provided at the pen tip of the input pen 1 (specifically, fixed on the horn part forming the pen tip) will vibrate according to the pen drive signal 20. When the pen tip is in contact with the top of the vibration transmission plate 8, it becomes a vibration wave (elastic wave) and propagates to the vibration sensor 3a (the same applies to the vibration sensors 3b and 3c). still,
As is clear from the above, the pen drive signal 20 is synchronized with the drive signal 17 of the drive signal generation circuit 10.

When the vibration sensor 3a detects this vibration wave, it generates a corresponding electric signal, that is, a vibration waveform signal 12.

In principle, by measuring the elapsed time until the vibration waveform 12 is detected, the time required for the vibration wave generated from the tip of the input pen 1 to reach the vibration sensor 3a can be detected. However, the problem is which point in the vibration waveform signal 12 should be the detection point.For example, if the waveform shown in the figure is at its maximum amplitude, the group velocity and phase velocity of the elastic wave may differ. Therefore, there will be a maximum shift of 1/2 wavelength, so you must be prepared for the error.

Therefore, in the embodiment, the envelope of the vibration waveform signal 12 (envelope: the broken line portion shown in the figure) is obtained, and the detection is performed based on its peak position. In order to detect the peak position, since the slope of the waveform at the peak position is 0'', it is sufficient to differentiate and detect the position where the waveform reaches the 0 level.

Specifically, the vibration waveform signal 12 is sent to an envelope detection circuit 61 (the configuration itself is well known, so the explanation will be omitted).
Generate with it. Then, in order to detect the peak position of the obtained envelope signal 13, a differentiation circuit 62 performs differentiation. The partial waveform signal 14 obtained by the differentiating circuit 62 is taken into the next signal detection circuit 63.

The signal detection circuit 63 is a zero-cross detection circuit composed of a comparator with a 0-level threshold, and the detected signal becomes a timing signal 15 and is sent to the arithmetic control circuit 11.

In this way, upon receiving similar timing signals from the vibration sensors 3b and 3c, the arithmetic control circuit 11 detects the time for the vibration waveform signal to reach the vibration sensors 3a to 3c, and calculates the position indicated by the input pen 1. I will do it.

Description of Arithmetic Control Circuit (FIG. 5)> Next, the internal configuration of the arithmetic control circuit 11 is shown in FIG. 5, and its operation processing will be described below.

In the figure, 41 is a microcomputer that controls the arithmetic control circuit 11 and the entire coordinate input device. A signal generating circuit 42 generates a signal instructing the drive signal generating circuit 10 described above to drive based on instructions from the microcomputer 41. Reference numeral 43 denotes a timer that measures a reference clock (not shown), and starts timing at the same time as it outputs a signal to that effect to the signal generation circuit 42. In other words, this synchronizes the start of time measurement and the timing of vibration generation.

The circuits that constitute the lot number components will be explained in order.

Each vibration sensor 3a obtained via the signal waveform detection circuit 7
Detection signals 3c (timing signal 15) are input to latch circuits 44a to 44c via a detection signal input port 45. The latch circuits 44a to 44c are the vibration sensor 3a
- 3c, and when each receives a detection signal from the corresponding vibration sensor via the input port 45, it latches the time value of the timer 43 at that time. When the determination circuit 46 determines that all detection signals have been received, it outputs a signal to that effect to the microcomputer 41. When the microcomputer 41 receives this signal from the determination circuit 46, the latch circuits 44a to 4
4c to each vibration sensor, the coordinate position of the input pen 1 on the vibration transmission plate 2 is calculated through predetermined calculations, and the calculated result is displayed on the display via the I10 port 47. By outputting the signal to the drive circuit 6, a cursor or the like is displayed on the display 5.

Regarding the calculation of the coordinate position, since the transmission speed of vibration, the coordinate position of the vibration sensors 3a to 3C, and the transmission time to the vibration sensor are known, the coordinates of the point indicated by the input pen can be easily calculated. I will omit the explanation here as it deviates from the purpose of this article.

Description of other embodiments (Fig. 6) In the embodiments described above, a vibration drive signal was transmitted to the input pen by AM modulation, but the transmission method is not limited to this. For example, FM modulation may be used.Also, as shown in FIG. This is because it is sufficient if an instruction to prompt the pen to vibrate can be sent.

As explained above, according to this embodiment, time measurement is started at the same time as a signal prompting the input pen to start vibrating, so at least the input pen detects the reception of the signal and adjusts the pen tip based on the detection. It would be a good idea to have a circuit that vibrates. Therefore, even though it is a cordless input pen, it can be constructed with a simple circuit configuration, making it possible to reduce its size.

[Effects of the Invention] As described above, according to the present invention, the cordless input pen can have a simple structure and be miniaturized, so that operability can be improved.

[Brief explanation of the drawing]

1 is a block configuration diagram of the coordinate input device in this embodiment, FIG. 2 is a partial circuit diagram of a signal waveform detection circuit in the embodiment, FIG. 3 is a diagram showing the configuration of the input pen in the embodiment, The figure is a timing chart for explaining the principle related to coordinate detection in the embodiment, Figure 5 is a diagram showing a specific example of the arithmetic control circuit in the embodiment, and Figure 6 is a diagram showing a transmission signal in another embodiment. It is a diagram. In the figure, 1... input pen, 2... vibration transmission plate, 3a~
3c... Vibration sensor, 4... Anti-reflection material, 5...
Display, 6... Display drive circuit, 7...
- Signal waveform detection circuit, 8... Modulation circuit, 9... Carrier wave generation circuit, 10... Drive signal generation circuit, 11...
Arithmetic control circuit, 31... Receiving circuit, 32... Demodulating circuit, 33... Amplifying circuit, 34... Vibrator, 41...
・Microcomputer, 42...Signal generation circuit, 4
3...Counter, 43...Timer, 44a to 44c
...Latch circuit, 45...Detection signal input port, 4
6... Judgment circuit, 47... I10 boat, 60...
・Preamplifier circuit, 6I...Envelope detection circuit, 6
2...Differential circuit, 63... Signal detection circuit.

Claims (1)

[Claims] The vibration emitted from the vibrating pen is detected by a plurality of sensors provided on the vibration transmission plate of the device main body, and the vibration emitted from the vibrating pen is A coordinate input device for detecting a coordinate position on a vibration transmission plate according to the present invention includes, at least in the main body of the device, a transmitting means for wirelessly transmitting a signal urging the vibrating pen to vibrate; , a timer for starting timekeeping for detecting the arrival of vibrations at the sensor; a receiving means for receiving a signal transmitted by the transmitting means; and a timer for receiving a signal transmitted by the transmitting means; A coordinate input device comprising: a vibration means for vibrating its own pen tip based on a signal from the coordinate input device.