JPH0823798B2 - Vibration input pen - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coordinate input device for detecting a coordinate position based on a propagation delay time of an elastic wave.

[Conventional technology]

Conventionally, for example, the following is known as a coordinate input device called a digitizer for inputting coordinate positions.

One surface is used as a resistor and resistance films for x-coordinate and for y-coordinate are overlapped, and voltage or current is applied to each resistance film, and a point (coordinate input point) pressed by a pen or fingertip is applied. A type that uses a resistance film that measures the ratio of voltage or current, and detects and inputs the coordinate position of that point.

By generating a local magnetic field pulse from the pen tip, bringing this pen tip close to one of the electrode lines wired in a matrix on the panel, electromagnetically coupling, and measuring the current generated in the electrode line. A type that uses electromagnetic induction to detect and input the coordinate position of the pen tip.

As a type that uses ultrasonic waves, it measures the position coordinates by detecting the propagation delay time of surface waves due to the propagation medium of ultrasonic waves, or transmits the ultrasonic waves into the air and measures the propagation time of the ultrasonic waves. There are things to do.

[Problems to be Solved by the Invention] However, these conventional devices have the following drawbacks.

That is, in the resistance film utilizing type described in the above item, the uniformity of the resistor directly influences the accuracy of the figure input, so that the resistor having particularly excellent uniformity is required, which is very expensive. Further, since two resistance films for the x-coordinate and the y-coordinate are required, there is a drawback that the transparency is lowered.

Next, the electromagnetic induction type of the above item is not transparent because the electric wires are arranged in a matrix.

Furthermore, when the surface wave or the sound wave is used like the ultrasonic wave type in the above-mentioned section, if a flaw or an object, such as an obstacle such as a hand, exists between the sound wave transmitting unit and the sound receiving unit, Measurement points may be erroneously detected due to obstacles,
There is a drawback that problems such as inability to measure occur. On the other hand, in the case of the conventional coordinate input device using the plate wave of the elastic wave, since the group velocity and the phase velocity of the elastic wave are different, the peak of the envelope or the detection with the predetermined threshold (threshold) is ± There was a drawback that an error of 1/2 wavelength would occur.

In addition, from the viewpoint of transmitting vibration, if the vibration of the vibrating pen does not have pen pressure of the pen, sufficient vibration cannot be transmitted to the vibration propagating body and coordinates cannot be detected. Also has. Further, even if the coordinates are not input, the vibrator is constantly driven, which has a disadvantage of wasting power.

[Means and Actions for Solving the Problems] In order to solve the above problems, the present invention provides a vibration generating element and a horn member to which the vibration generating element is mounted and which transmits the vibration generated from the vibration generating element. And a switch means indicating whether or not the vibration input pen body is in an input state,
A switch operating member that is mounted on the horn member so that an external force is not applied to the vibration generating element, and that moves integrally with the horn member in the pen axis direction as the horn member moves to operate the switch means. There is a feature in the configuration of the vibration input pen.

〔Example〕

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of the vibrating pen used in this embodiment. Reference numeral 3 is a holder which is a vibrating pen body, and 4 is a vibrator which is a vibration generating source. In this embodiment, a piezoelectric element is used. Reference numeral 5 denotes a horn portion for inputting the vibration generated by the vibrator 4 to the vibration transmission plate 8. Reference numeral 30 denotes when the vibrating pen comes into contact with the vibration transmission plate and sufficient writing pressure is applied.
In this embodiment, 33 is a vibrator drive switch that is turned on, 33 is a switch pedestal that positions the vibrator drive switch and fixes it to the vibration pen body, and 32 is a moving body that directly turns the vibrator drive switch 30 on and off. It is screwed to the horn part 5. 31 is a coil spring for returning the vibrator drive switch 30 to the OFF state when the vibrating pen is not in the input state, and its spring constant is the vibration level that transmits the vibration level necessary for coordinate detection over the entire effective input surface of the digitizer. The transducer drive switch 30 is set to the ON state for the first time when the writing pressure that can be input to the board is obtained. With this configuration, the switch 30 that drives the vibrator is turned on.
The member for turning off / off is composed of the moving body 32, the horn unit 5 and the vibrator 4, and the moving body moves only when the vibrating pen 3 is in the input state. Moreover,
Since the vibrator 4 is not affected by the inclination of the vibrating pen 3 and the magnitude of the writing pressure at all, it can always generate stable vibration in the ON state. Moreover, when not in the input state, the drive circuit 2 for driving the vibrator 4, the arithmetic circuit, the detection circuit, and the like are turned off, so that power consumption can be improved.

FIG. 2 shows the structure of an information input / output device adopting the present invention. The device shown in FIG. 2 not only detects coordinates but also displays input information. That is, the illustrated information input device causes the input tablet made of the vibration transmission plate 8 to input coordinates by the vibration pen 3, and the display 11 'composed of the CRT arranged on the input tablet according to the inputted coordinate information. The input image is displayed.

The reference numeral 8 in the drawing denotes a vibration transmission plate made of acrylic, glass plate or the like, which transmits vibration transmitted from the vibration pen 3 to three vibration sensors 6 provided at the corners. In this embodiment, the coordinate of the vibration pen 3 on the vibration transmission plate 8 is detected by measuring the transmission time of the ultrasonic vibration transmitted from the vibration pen 3 to the vibration sensor 6 via the vibration transmission plate 8.

The vibration transmitting plate 8 has its peripheral portion supported by an antireflection material 7 made of silicon rubber or the like in order to prevent the vibration transmitted from the vibrating pen 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 11 'such as a CRT (or a liquid crystal display) capable of displaying dots, and the dots are displayed at the position traced by the vibration pen 3. That is, a dot display is performed at a position on the display 11 'corresponding 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 written as if it were written on paper. Appears after the locus of the vibrating pen 3 as if.

Further, according to such a configuration, the menu 11 is displayed on the display 11 ', and the menu item is selected by the vibrating pen 3, or a prompt is displayed to input the vibrating pen 3 to a predetermined position. A method can also be used.

Vibration pen 3 for transmitting ultrasonic vibrations to the vibration transmission plate 8
Has an oscillator 4 formed of a piezoelectric element or the like inside, and transmits the ultrasonic vibration generated by the oscillator 4 to the vibration transmission plate 8 via the horn portion 5.

When the vibration pen 3 comes into contact with the vibration transmission plate 8 and tries to input coordinates, the vibrator drive switch is first turned on, and the signal goes into the arithmetic control circuit 1, the vibrator drive circuit 2, the signal waveform. The detection circuit 9 is turned on. At this time, the oscillator 4 is driven by the oscillator drive circuit 2 at a predetermined frequency.

The electric drive signal generated by the drive circuit 2 is converted into mechanical ultrasonic vibration by the vibrator 4 and transmitted to the diaphragm 8 via the horn unit 5 configured as described above.

The vibration frequency of the vibrator 4 is selected to a value capable of generating a plate wave on the vibration transmission plate 8 such as acrylic or glass. Further, by setting the vibration frequency of the vibrator 4 as the resonance frequency of the vibrator 4, it is possible to perform efficient vibration conversion.

From the vibrating pen 3 configured as described above to the vibration transmission plate 8
The elastic wave transmitted to the plate is a plate wave, and has an advantage that it is less likely to be affected by scratches or obstacles on the surface of the vibration transmitting plate 8 as compared with surface waves.

Again, in FIG. 2, 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 the three vibration sensors 6 are input to the waveform detection circuit 9, and the calculation control circuit 1 in the subsequent stage receives the output signals.
Is converted into a processable detection signal. The arithmetic control circuit 1 performs the measurement process of the vibration transmission time, and detects the coordinate position of the vibration pen 3 on the vibration transmission plate 8.

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

Microcomputer 11 has an internal counter, ROM and R
Built-in AM. In order to measure the vibration transmission time in synchronization with the start of vibration, the microcomputer 11 gives a start signal to the drive signal generation circuit 12 to start driving the vibrator drive circuit 2 by the ON signal of the vibrator drive switch 30. The counter 13 of is started.

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

On the other hand, the waveform detection circuit 9 outputs timing information of the detection signal for measuring the vibration transmission time for coordinate detection from the output of the vibration sensor 6 as described later.

The timing signal input from the waveform detection circuit 9 is input to the input port 15 and compared with the count value in the latch circuit 14 by the determination circuit 16 and the result is obtained by the microcomputer.
Passed to 11. That is, the vibration transmission time is expressed as a latch value of the output data of the counter 13, and the coordinate calculation is performed based on this vibration transmission time value.

The output control process of the display 11 'is performed via the input / output port 18.

FIG. 4 illustrates a detection waveform input to the waveform detection circuit 9 of FIG. 1 and a vibration transmission time measuring process based on the detection waveform.

In FIG. 4, reference numeral 41 denotes a drive signal pulse applied to the vibration pen 3. The ultrasonic vibration transmitted to the vibration transmission plate 8 from the vibration pen 3 driven by such a waveform passes through the inside of the vibration transmission plate 8 and is detected by the vibration sensor 6.

The time corresponding to the distance from the vibration transmission plate 8 to the vibration sensor 6
After traveling through tg, the vibration reaches the vibration sensor 6. Reference numeral 42 in FIG. 4 indicates a signal waveform detected by the vibration sensor 6. The relationship between the envelope 421 and the phase 422 of the detected waveform with respect to the propagation distance of the plate wave used in this embodiment in the vibration transmission plate 8 changes according to the transmission distance during vibration transmission.

Here, the velocity of the envelope is Vg and the phase velocity is Vp. The distance between the vibration pen 3 and the vibration sensor 6 can be detected from the difference in group velocity and phase velocity.

First, focusing only on the envelope 421, its speed is Vg, and when a point on a certain specific waveform, for example, a peak is detected as indicated by reference numeral 43 in FIG. 4, the distance between the vibrating pen 3 and the vibration sensor 6 is detected. d is the vibration transmission time tg, and d = Vg · tg (1) This formula relates to one of the vibration sensors 6, but the same formula is used to calculate the distance between the other two vibration sensors 6 and the vibration pen 3. Can be shown.

Further, in order to determine the coordinate value with higher accuracy, processing based on the detection of the phase signal is performed. Phase waveform of Fig. 4
If the time from the specific detection point of 422, for example, the application of vibration to the zero crossing point after passing the peak is tp, the distance between the vibration sensor and the vibration pen is d = n · λp + Vp · tp (2). Here, λp is the wavelength of the elastic wave, and n is an integer.

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

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

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.

In FIG. 5, the output signal of the vibration sensor 6 is amplified to a predetermined level by the preamplifier circuit 51. 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. The peak detection signal is formed into an envelope delay time detection signal Tg having a predetermined waveform by a signal detection circuit 54 composed of a mono multivibrator or the like, and input to the arithmetic control circuit 1.

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

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

In the arithmetic control circuit of FIG. 3, the signals Tg1 to h and Tp1 to h described above are input from the input port 15, and the count value of the counter 13 is taken into the latch circuit 14 by using each timing as a trigger. As described above, since the counter 13 is started in synchronization with the driving of the transducer pen, the latch circuit 14 receives the data indicating the delay time of each of the envelope and the phase.

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

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

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

In the above-mentioned embodiment, the input tablet by the vibration transmitting plate 8 is used by being superimposed on the display 11 'by the CRT. However, the input tablet and the display do not have to be arranged in such a manner and they are separately provided. It doesn't matter. The display may be of another display type such as a liquid crystal display.

[Other Examples]

In the case of the above-described embodiment, the oscillator drive switch is used to turn on / off the oscillator drive circuit and the signal waveform detection circuit. However, depending on the application, for example, a point or an input device for inputting points as coordinate input (when the pen is not used for continuous movement but used only for a situation where the pen stops at a certain point) , Turn on / off the power supply Vcc of the entire device including the arithmetic and control circuit.
You can do F. Further, if the circuit configuration is such that the power supply rises sufficiently quickly, the above condition can be removed.

〔The invention's effect〕

As explained above, by attaching a vibrator and a member that inputs the vibration of the vibrator to the vibration transmission plate in the moving body, it is possible to turn ON / OFF the drive of the vibrator by writing pressure,
Moreover, the vibration characteristics of the vibrator are not affected by the writing pressure, and it is now possible to maintain a stable state. Further, when the coordinate is not input, the circuit necessary for detecting the coordinate is not driven, so that the power consumption is also improved.

[Brief description of drawings]

 FIG. 1 is a configuration diagram of a vibration input pen, FIG. 2 is an explanatory diagram of the apparatus, FIG. 3 is a block diagram of an arithmetic control circuit, FIG. 4 is a waveform diagram showing distance measurement, and FIG. 5 is a waveform detection circuit. Block diagram of Fig. 6, Fig. 6 is an explanatory diagram of the vibration sensor arrangement, 1 ... Arithmetic control circuit, 3 ... Vibration pen 4 ... Vibrator, 5 ... Horn section 6 ... Vibration sensor, 8 ... Vibration transmission plate 30 …… Transducer drive switch 31 …… Coil spring, 32 …… Mobile body

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Noriyuki Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yuichiro Yoshimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Kiyoshi Kiyoshi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Jun Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 56) References JP-A-60-134329 (JP, A) JP-A-60-83126 (JP, A) JP-A-60-3736 (JP, A)

Claims (1)

[Claims] 1. A vibration generating element, a horn member to which the vibration generating element is mounted, which transmits the vibration generated from the vibration generating element, and a switch means for indicating whether or not a vibration input pen body is in an input state. And a switch actuating member that is mounted on the horn member so that an external force is not applied to the vibration generating element, and that moves integrally with the movement of the horn member in the pen axis direction to actuate the switch means. Vibration input pen with.