JP3109887B2 - Coordinate input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a vibration input from a coordinate input device, particularly a vibration pen, using a vibration sensor provided on a vibration transmission plate, measures the vibration transmission time to the vibration pen, and obtains the result. The present invention relates to a coordinate input device for detecting input coordinates of a vibration pen on a vibration transmission plate based on the coordinate input device.

[0002]

2. Description of the Related Art Conventionally, coordinate input devices using ultrasonic waves have been known. In this type of device, the coordinates of the vibration pen on the vibration transmission plate are detected from the vibration transmission time of the vibration input from the vibration pen.

In this type of apparatus, it is necessary to instruct the vibrating pen from the side of the apparatus including the vibration transmitting plate to drive the vibrating pen. However, since such a wired pen does not have good operability, a wireless configuration has been proposed in which the pen is connected to the apparatus main body by wireless connection such as optical communication, and the driving timing of the pen is input to the pen. I have.

[0004]

In the above wireless configuration, since a communication device must be built in the vibrating pen, the structure of the vibrating pen becomes complicated and the size of the device becomes large. In addition, operations other than coordinate input operation on the vibration pen
To change modes or make menu selections
However, when trying to add a switch required for an application, there is a problem that the structure becomes more complicated and larger, and the operability is further deteriorated.

An object of the present invention is to solve the above problems, the seat
An operation other than the marker input operation, such as changing the mode
Ri is to provide a coordinate input device, even if the application <br/> switches provided such, that the simple and inexpensive to the operation information can be transmitted to the main body for performing menu selection.

[0006]

In order to solve the above problems, according to the present invention, a vibration input from a vibration pen is detected by a vibration sensor provided on a vibration transmission plate, and the vibration is transmitted to the vibration pen. In a coordinate input device that measures time and detects input coordinates on the vibration transmission plate of the vibration pen based on the result, operation information other than coordinate input operation is transmitted via vibration transmission from the vibration pen to the vibration transmission plate. In this case, the vibration pen is used to transmit the coordinates to the main unit that performs the coordinate detection process.

[0007]

According to the above construction, operation information other than coordinate input,
For example such as the operation information of the switch provided in the vibration pen,
No separate transmission means such as cables and wireless signals should be provided via the same vibration transmission used for coordinate input.
And can be transmitted to the main body.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments 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 causes an input tablet comprising a vibration transmission plate 8 to perform coordinate input by a vibrating pen 3, and a display 1 comprising a CRT arranged on the input tablet in accordance with the inputted coordinate information.
1 'displays an input image.

In the figure, a reference numeral 8 denotes a vibration transmission plate made of acrylic, glass plate or the like, which transmits vibration transmitted from the vibration pen 3 to vibration sensors 6 provided at three corners thereof. In the present embodiment, the coordinates of the vibration pen 3 on the vibration transmission plate 8 are 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. A pen holder 81 is provided on a part of the vibration transmission plate 8, which will be described later in detail.

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

The vibration transmission plate 8 is arranged on a display 11 'capable of displaying dots, such as a CRT (or a liquid crystal display), and performs dot display at a position traced by the vibration pen 3. . That is, a dot is displayed at a position on the display 11 ′ corresponding to the detected coordinates of the vibration pen 3, and an image composed of elements such as points and lines input by the vibration pen 3 is written as if on paper. Appears after the trajectory of the vibrating pen.

According to such a configuration, the display 1
For 1 ', an input method such as displaying a menu and selecting the menu item with a vibrating pen or displaying a prompt and bringing the vibrating pen 3 into contact with a predetermined position can be used.

The vibrating pen 3 for transmitting ultrasonic vibration to the vibration transmitting plate 8 includes a vibrator 4 having a piezoelectric element or the like therein.
And transmits the ultrasonic vibration generated by the vibrator 4 to the vibration transmission plate 8 via the horn portion 5 having a sharp tip.

FIG. 2 shows the structure of the vibration pen 3. The vibrating pen 3 contains all members necessary for generating vibration. The vibrator 4 of the vibrating pen 3 is driven by the vibrator drive circuit 2 at a predetermined frequency. Power required for the operation of the vibrating pen 3 is supplied from a power supply unit 25 including a battery or the like.

The vibration frequency of the vibrator 4 is selected to a value at which a plate wave can be generated on the vibration transmission plate 8 made of acrylic, glass, or the like. In driving the vibrator, a vibration mode in which the vibrator 4 mainly vibrates in the vertical direction of FIG. Further, by setting the vibration frequency of the vibrator 4 to the resonance frequency of the vibrator 4, efficient vibration conversion is possible. The driving frequency of the vibrator 4 is
2, which will be described later.

The elastic wave transmitted to the vibration transmitting plate 8 as described above is a plate wave, and has an advantage that the surface of the vibration transmitting plate 8 is less susceptible to scratches and obstacles than surface waves. Have.

On the other hand, the generation of vibration of the vibration pen and the operation of the vibration detection unit connected to the vibration transmission plate 8 must be synchronized. In this embodiment, the following configuration is used to make the vibration pen a wireless configuration.

An oscillation circuit 22 is provided inside the vibration pen 3 in addition to the members described above.

The vibrating pen 3 drives the vibrator 4 intermittently at a cycle Ta generated by the oscillator 22. On the other hand, on the main body side, a counter for measuring the vibration transmission time at the cycle Ta is started.

If the counter start and the pen drive start are set to the same cycle Ta and they are synchronized by any method, the vibration transmission time can be obtained.
Based on this, coordinate calculation becomes possible.

Next, a method of synchronizing the pen driving and the counter start will be described with reference to FIG.

To simultaneously generate a pen-side drive signal (hereinafter referred to as Pdr) and a count start signal (hereinafter referred to as CS) of a main body-side counter in synchronism, first generate a Pdr signal and a CS signal at the same cycle Ta. Keep it. At this time, the two signals have not been synchronized yet.

Next, a position on the vibration transmission plate 8 at a known distance d from the predetermined vibration sensor 6 (for example, a pen holder 81)
Is input by the vibrating pen 3 oscillating at the cycle Ta.

At this time, the vibration transmission time Td from the input position to the predetermined vibration sensor 6 is measured in advance and is known. Therefore, the CS signal may be generated based on the transmission time Td. Pen drive and counter start can be synchronized.

For example, since the Pdr signal is generated after the vibration transmission time Td and the time period Ta-Td from the period Ta, after detecting the vibration (Ta-Td) time, the Pdr signal is output.
Generate an S signal. The timing of the synchronization input is
The timing is designated using a switch 31 described later.

After the coordinate input operation for synchronization (hereinafter referred to as synchronization input), the timing remains unchanged.
Both the Pdr signal and the CS signal are generated. From the above,
It becomes possible to make the vibration pen cordless.

If a synchronous input operation is performed using a plurality of sensor outputs and an average value is obtained, the pen driving and the counter start can be more accurately synchronized.

Further, the pen holder 81 has a structure in which the vibration pen 3 is always in contact with the vibration transmitting plate 8 at the horn 5 when the vibration pen 3 is stored therein. By simply storing the pen, the pen drive and the counter start can be synchronized, and when the user picks up the vibrating pen 3, the coordinate input can be immediately performed. When using the pen holder 81,
The switch 31 is provided inside the pen holder 81 so as to be turned ON when the vibration pen 3 is stored in the pen holder 81.

Simultaneous generation of the Pdr signal and the CS signal in FIG. 7 means that they are almost simultaneous to the extent that there is no problem in counting the vibration transmission time and calculating the coordinates. Even if they are not simultaneous, even if they have a certain offset time, they can be operated as long as they are synchronized.

As described above, all members necessary for generating vibration in the vibration pen 3, means for generating a counter start signal having the same cycle as the cycle Ta of the pen drive signal on the body of the coordinate input device, By providing means for synchronizing the two signals and generating them simultaneously, a cable for connecting the vibration pen 3 and the coordinate input device can be omitted. Hereinafter, a configuration for detecting vibration and calculating coordinates will be described.

Referring again to FIG. 1, the vibration sensor 6 provided at the corner of the vibration transmission plate 8 is also constituted by a mechanical to electric conversion element such as a piezoelectric element. The output signals of each of the three vibration sensors 6 are input to a waveform detection circuit 9, and the arrival timing of the vibration at each sensor is detected by a waveform detection process described later. This detection timing signal is input to the arithmetic and control circuit 1.

The arithmetic and control circuit 1 can know the vibration transmission time to each sensor as the time from the CS signal after the above-mentioned synchronization to the vibration detection timing output by the waveform detection circuit 9, and further, from this vibration transmission time. The coordinate input position of the vibration pen 3 on the vibration transmission plate 8 is detected.

The detected coordinate information of the vibration pen 3 is processed in the arithmetic and control circuit 1 in accordance with the output system by the display 11 '. That is, the arithmetic and control circuit operates the display 11 ′ via the video signal processing device 10 based on the input coordinate information.
Control the output operation.

FIG. 3 shows the structure of the arithmetic and control circuit 1 of FIG. Here, a structure of a drive system of the vibration pen 3 and a vibration detection system by the vibration sensor 6 is mainly shown.

The microcomputer 11 has an internal counter, a ROM and a RAM. The drive signal generation circuit 12 performs the above-described signal simultaneous generation operation (when the signal simultaneous generation switch 31 is turned ON) Ta-Td
Microcomputer 11 with a circuit for counting the time
Then, a start signal indicating the start of vibration input is input to the counter 13 for measuring the propagation delay time.

After the above operation is completed (switch 31OF)
At the time of F), the microcomputer 11 generates a start signal in the cycle Ta of the start signal.

The count value of the counter 13 is latched by 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 a vibration transmission time from an output of the vibration sensor 6 as described later. These pieces of timing information are input to the input ports 15, respectively.

The timing signal input from the waveform detection circuit 9 is input to the input port 15 and stored in the 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 the latch value of the output data of the counter 13, and the coordinate calculation is performed based on the vibration transmission time value. At this time, the determination circuit 16 determines whether or not all pieces of waveform detection timing information from the plurality of vibration sensors 6 have been input, and notifies the microcomputer 11.

The output control process of the display 11 ′ is performed through the input / output port 17.

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

The measurement of the vibration transmission time is performed based on the counter start signal CS synchronized with the driving signal of the vibration pen 3 as described above.

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 vibration transmission plate 8 and is detected by the vibration sensor 6.

After traveling in 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 embodiment is a dispersive wave, so that the relationship between the envelope 421 and the phase 422 of the detected waveform changes according to the vibration transmission distance.

Here, the speed at which the envelope advances is referred to as group speed Vg, and the phase speed is referred to as Vp. From the difference between the group velocity and the phase velocity, the distance between the vibration pen 3 and the vibration sensor 6 can be detected.

First, focusing only on the envelope 421, its speed is Vg. When a point on a certain waveform, for example, a peak is detected as indicated by reference numeral 43 in FIG. D = Vg · tg (1) This equation relates to one of the vibration sensors 6, but the same equation is used to calculate the distance between the other two vibration sensors 6 and the vibration pen 3. Distance can be indicated.

Further, in order to determine a coordinate value with higher accuracy, processing based on detection of a phase signal is performed. If the time from a specific detection point of the phase waveform 422 in FIG. 4, 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) Becomes Here, 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 expressed as n = [(Vg · tg−Vp · tp) / λp + 1 / N] (3) Here, N is a real number other than 0, and an appropriate numerical value is used. For example, if N = 2 and n is within ± 1/2 wavelength, n 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 equation (2).

For measuring 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 amplifier circuit 51 described above.

The amplified signal is supplied to an envelope detection circuit 5
2 and only the envelope of the detection signal is extracted. The peak timing of the extracted envelope is detected by an envelope peak detection circuit 53.
As 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 monomultivibrator or the like, and is input to the arithmetic and control circuit 1.

A phase delay time detection signal Tp is formed by the detection circuit 58 from the timing of the Tg signal and the original signal delayed by the delay time adjustment circuit 57, and is input to the arithmetic and control circuit 1.

That is, the Tg signal is converted into a pulse having a predetermined width by the monostable multivibrator 55. Also,
The comparator level supply circuit 56 forms a threshold value for detecting the tp signal according to the pulse timing. As a result, the comparator level supply circuit 56
Signal 4 having a level and timing like reference numeral 44
4 is input to the detection circuit 58.

That is, the monostable multivibrator 55
The comparator level supply circuit 56 is provided so that the measurement of the phase delay time operates only for a predetermined time after the detection of the envelope peak.

This signal is input to a detection circuit 58 composed of a comparator or the like, and is compared with a delayed detection waveform as shown in FIG. 4, and as a result, a tp detection pulse 45 is formed.

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 be h, the envelope delay times Tg1 to h and the phase delay times Tp1 to Tp1
h detection signals of h are input to the arithmetic and control circuit 1.

In the arithmetic and control circuit shown in FIG.
h, Tp1 to h signals are input from the input port 15, and the count value of the counter 13 is taken into the latch circuit 14 with each timing as a trigger. Counter 1 as described above
Since 3 is started in synchronization with the driving of the vibration pen, the latch circuit 14 receives data indicating the delay time of each 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 linear distances d1 to d1 from the position P of the vibration pen 3 to the position of each vibration sensor 6 by the processing described with reference to FIG.
d3 can be obtained. Further, the arithmetic control circuit 1 can determine the coordinates (x, y) of the position P of the vibration pen 3 based on the linear distances d1 to d3 from the theorem of three squares as in the following equation.

X = X / 2 + (d1 + d2) (d1-d2) / 2X (4) y = Y / 2 + (d1 + d3) (d1-d3) / 2Y (5) where X and Y are S2 and S3 Are the distances along the X and Y axes between the vibration sensor 6 at the position (1) and the sensor at the origin (position S1).

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

According to the above embodiment, the cable for connecting the vibrating pen to the apparatus main body can be completely omitted, and it is not necessary to provide a device for performing only communication with the main body in the vibrating pen. The vibrating pen can be configured to be lightweight, and can provide the same operability as a general writing instrument.

In the above embodiment, the pen drive signal Pdr
The signal and the CS signal which is the counter start signal are synchronized
Although this is realized acoustically using the transducer 4 for inputting coordinates, this can also be realized electrically. For example, at a certain timing, the vibration pen 3 is directly electrically connected to the main body, and Pd is
The r signal and the CS signal can be synchronized, and both can be synchronized.

Here, too, as shown in FIG.
Can be used. In this case, when the vibrating pen 3 is stored in the pen holder 81, the pen drive signal generated by the vibrating pen 3 is temporarily connected to the main body side such that the pen holder 81 and the vibrating pen 3 are temporarily connected to each other by electrodes and the like. A portion 81a is provided.

With such a structure, while the vibrating pen 3 is housed in the pen holder 81, the CS signal generated in the same cycle as the Pdr signal is synchronized by a PLL circuit or the like. With such a configuration, the same effect as described above can be obtained.

In order to connect the pen and the main body, it is not necessary to use the pen holder 81, and the vibration pen 3 and the main body may be connected by any means.

Further, operations other than the coordinate input operation are performed with the cordless vibrating pen in the coordinate input device configured as described above.
Operation, for example, to change modes or make menu selections.
The Nau processing, application to the cordless vibration pen
It can be realized by attaching a switch for
Hereinafter, this configuration will be described.

For example, the pen drive signal generated in synchronization with the main body is transmitted to the original vibration transmission time T as indicated by reference numeral 94 in FIG.
After the signal (PD) for detecting D, a signal (SWD) that is emitted only when the pen switch (SW) is pressed is output. Then, the detection signal is after the TD like 96,
After a certain time, the switch-on detection signal TSW is detected at Tc. In this manner, the state of the switch mounted on the vibration pen 3 can be transmitted to the main body using the elastic wave for detecting the coordinate value.

The process of forming the signal of TD / TSW 96 from the detection signal 95 is the same as in the case of the detection of Tg and Tp described above.

The switch is mounted on the vibrating pen 3 as shown in FIGS . The pen switch 24 is a PD
It is connected to the signal generation circuit 23. The drive circuit 2 includes a PD signal generation circuit 2a that generates a signal based on a signal from the oscillation circuit 22, and a PZT drive circuit 2b that directly drives the PZT 4.

The PD signal trigger circuit 23 triggers the PD signal generation circuit 2a. Other configurations are the same as those described above.

The PD signal trigger circuit 23 is a pen switch 2
When 4 is in the ON state and a PD signal is generated from the PD signal generation circuit, a trigger signal (SWD signal) for generating a PD signal again after waiting for a certain time is sent to the PD signal generation circuit 23 to generate a PD signal again. .

FIG. 12 shows the configuration of FIG.
1 shows a configuration in which a circuit for determining the ON / OFF state of the device is added. 3 is the same as FIG. 3 except that the pen switch determination circuit 18 is connected to the microcomputer 11 as shown.

The pen switch judging circuit 18 is provided with the TD shown in FIG.
Upon receiving the signal, a detection window is set for detecting whether or not the signal of TSW exists for a predetermined period after a predetermined time.

When the TSW signal is detected, the pen switch 24 is determined to be ON, and otherwise, it is determined to be OFF, and the pen switch determination circuit 18 outputs a determination signal to the microcomputer 11.

As described above, a pen switch can be formed in a cordless pen using elastic waves in the same manner as the coordinate value detection.

The pen switch 24 can be used in various ways, such as selecting a menu displayed on the display 11 'or using a shift key to change the meaning of the menu.

In the above embodiment, when the pen switch 24 is in the ON state, the pen drive signal PD is identified by two occurrences at a certain interval, but as shown in FIG. A method in which the signal Tsw is generated in a cycle shorter than the coordinate value sampling cycle may be considered. When TSW is detected in such a short cycle, it is determined that the switch is in the ON state.

[0081]

As apparent from the above, according to the present invention, the vibration input from the vibration pen is detected by the vibration sensor provided on the vibration transmission plate, and the vibration transmission time to the vibration pen is measured. In a coordinate input device that detects input coordinates of the vibration pen on a vibration transmission plate based on the result ,
Since the operation information other than the coordinate input operation is transmitted to the main unit that performs the coordinate detection processing from the vibration pen through the vibration transmission from the vibration pen to the vibration transmission plate, the operation other than the coordinate input operation is performed. Information, such as the operation information of a switch provided on the vibrating pen, is the same as that used for coordinate input.
An excellent effect that the pen can be transmitted from the vibrating pen to the main unit with a simple and inexpensive configuration without providing separate transmission means such as cables and wireless signals through the transmission of vibration.
There is fruit .

[0082]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an information input / output device employing the present invention.

FIG. 2 is an explanatory view showing the structure of the vibration pen of FIG. 1;

FIG. 3 is a block diagram showing a structure of the arithmetic and control circuit of FIG. 1;

FIG. 4 is a waveform diagram showing a detection waveform for explaining a distance measurement between a vibration pen and a vibration sensor.

FIG. 5 is a block diagram showing a configuration of a waveform detection circuit of FIG. 1;

FIG. 6 is an explanatory diagram showing an arrangement of a vibration sensor.

FIG. 7 is an explanatory diagram showing synchronization between a pen drive signal and a counter start signal.

FIG. 8 is an explanatory diagram of a temporary connection synchronization method.

FIG. 9 is an explanatory diagram of a signal of a pen switch.

FIG. 10 is a block diagram of a vibration pen built-in circuit.

FIG. 11 is a block diagram of a vibration pen with a switch.

FIG. 12 is a block diagram of an arithmetic control circuit with a pen switch determination circuit.

FIG. 13 is an explanatory diagram of a signal of a pen switch.

FIG. 14 is an explanatory diagram of a vibration pen with a switch.

[Explanation of symbols]

 Reference Signs List 1 arithmetic control circuit 3 vibrating pen 4 vibrator 6 vibration sensor 8 vibration transmission plate 15, 16 input port 51 preamplifier 52 envelope detection circuit 54, 58 signal detection circuit 59 A / D conversion circuit 91 peak hold circuit 92 addition circuit 93 Comparator 510 Latch circuit

──────────────────────────────────────────────────続 き Continuing on the front page (72) Atsushi Tanaka, Inventor 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yuichiro Yoshimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon (72) Inventor Shinnosuke Taniishi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-2-125326 (JP, A) JP-A-63-126025 ( JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G06F 3/03

Claims (2)

(57) [Claims] 1. A vibration sensor provided on a vibration transmission plate detects vibration input from a vibration pen, measures a vibration transmission time up to the vibration pen, and, based on the result, displays the vibration on the vibration transmission plate of the vibration pen. In the coordinate input device for detecting the input coordinates of the above, the operation information other than the coordinate input operation is transmitted from the vibrating pen to the main body unit that performs the coordinate detection process via the vibration transmission from the vibrating pen to the vibration transmitting plate. Coordinate input device to be characterized. 2. The information other than the input coordinates is transmitted to a vibration pen.
It is characterized by the operation information of the provided switch
The coordinate input device according to claim 1.