JPH10307671A - Coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the input process by such a coordinate input device that the monitor and operator are at a distance. SOLUTION: Vibration from a vibration pen 3 which is inputted to a vibration transmission plate 8 is detected by vibration sensors 6a to 6d provided to the vibration transmission plate and the coordinates of the input point is detected from a detected vibration transmission time. If the vibration is not detected owing to an insufficient touch of the vibration pen 3 on the vibration transmission plate 8 or if it becomes clear that the detected coordinates is wrong, a sound generating means 10 indicates that no touch is detected or that the calculated coordinate value is wrong. In case of no detection or misdetection, the operator can know that normal input is not done from an indication of sound, etc., and performs rewriting on the spot without confirmation on the monitor, so that efficient operation can be done.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device, particularly to a coordinate input device separate from a monitor in a system including a personal computer or the like.

[0002]

2. Description of the Related Art A computer system comprises a personal computer, a monitor, a keyboard, various storage media, a pen input tablet as a coordinate input device, and the like. The tablet is used, for example, when inputting figures, pictures, and the like into a personal computer. The input figures, pictures, etc. are displayed on the monitor. The monitor and the tablet are physically separate bodies, and a figure, a picture, and the like are input through the tablet while looking at the monitor as needed.

[0003] In the above system, there is a system in which a tablet becomes large in size of a blackboard (diagonal is 1 to several meters). In such a system, the pen also functions as a marker, and the position coordinates of the pen are detected while characters, graphics, pictures, and the like are drawn on the input surface of the tablet with the marker, and are input to the personal computer. Also in this system, input figures, pictures, and the like are displayed on a monitor. This allows the operator to confirm the input result.

[0004] The above-mentioned tablet is used in accordance with a coordinate input method.
It has various configurations. For example, in the case of a so-called resistive film method (pressure-sensitive method), the input plate of the tablet has a configuration in which two or more glass plates or resin films having resistors are stacked. The pen serving as the coordinate input means is not limited to a dedicated pen, but may be a pole pen or the like.

In the case of the so-called capacitive coupling method or electromagnetic induction method, one or more sheets of glass, resin, metal, etc. having a linear or loop coil electrode pattern in the X and Y directions are used. It is a plate consisting of The electrode pattern may be formed on a printed circuit board, and a predetermined gap may be provided on the front surface of the printed circuit board to provide an input plate with which a pen actually contacts.

In the case of a so-called ultrasonic system in which the position coordinates of the pen are derived by detecting vibrations propagating in the input plate, the input plate is simply a plate made of glass, resin, metal, or the like. . An ultrasonic coordinate input device detects the delay time of a wave propagating on a tablet, which is an input surface, and calculates position coordinates. Therefore, it is possible to provide an inexpensive device in terms of cost.

[0007] In any of the above methods, in a system using a blackboard-sized tablet, the pen also serves as a marker, and the input plate has a front surface such that it can be filled in with a marker like a so-called whiteboard. Is being processed.

[0008]

However, in the above-mentioned conventional coordinate input device, if the pen position is erroneously detected at the time of input or is not detected at all (hereinafter referred to as "undetected"), the operator monitors after input. You can know it only after confirming it. The cause of the erroneous detection or non-detection differs depending on the coordinate input method, but is caused by electric noise, touch, proximity of a conductor or a magnetic body, and the like. In this case, there is a disadvantage that the operability is deteriorated because the erroneously detected portion or the undetected portion must be confirmed and then erased and written again or the undetected portion must be overwritten.

As described above, in a system using a blackboard-sized tablet that cannot frequently see the monitor at the time of input, the tablet is large and the monitor is located away from the operator. Frequent rewriting or overwriting greatly reduces efficiency and deteriorates operability.

[0010] Accordingly, the present invention has been made in view of such a problem, and an object of the present invention is to provide a coordinate input device with improved operability.

[0011]

According to the present invention, there is provided a coordinate input device for detecting the position coordinates of a coordinate input device input to a coordinate input plate. Detecting means for detecting whether or not the contact is normal, determining means for determining whether the detected coordinate value is correct, and determining that the contact is not normal or determining that the coordinate value is incorrect. And an instructing means for giving an instruction when the vehicle is turned on.

According to the present invention, the vibration input from the vibration pen to the vibration transmission plate is detected by a vibration sensor provided on the vibration transmission plate, and the coordinates of the input point are calculated from the detected vibration transmission time. In the input device, a detection unit that detects whether the contact of the vibration pen with the vibration transmission plate is normal, a unit that calculates the transmission time from the calculated coordinate value to the vibration sensor, and a transmission time that is calculated back. A determination unit that determines whether the calculated coordinate value is correct or not by comparing the detected transmission times, and when it is detected that the contact is not normal,
Alternatively, a configuration having an instruction means for giving an instruction when the coordinate value is determined to be incorrect is also adopted.

[0013] The abnormal contact is caused, for example, by a weak and insufficient contact pressure despite an operator touching an input means such as a pen with a coordinate input plate (vibration transmission plate) for input. Or a state in which position detection is not performed in the first place due to noise or the like, resulting in a so-called undetected state.

In any of the configurations, if there is an abnormal contact or an erroneous detection, the operator can be informed by sound instructions or the like that the input has not been performed properly, and the operator can check the monitor immediately without checking the monitor. Rewriting can be performed, and efficient operation can be performed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings.

In this embodiment, a coordinate input device using a tablet utilizing ultrasonic waves will be described as an example.

<Overall Configuration> FIG. 1 is a block diagram showing a schematic configuration of a coordinate input device. In the figure, reference numeral 1 denotes an arithmetic control circuit for controlling the entire apparatus and calculating a coordinate position. Reference numeral 2 denotes a vibrator driving circuit that vibrates the vibrator 4 in the vibrating pen 3 and transmits the vibration to the vibration transmitting plate via the pen tip 5. Reference numeral 8 denotes a vibration transmission plate made of an acrylic, aluminum plate, glass plate, or the like. Coordinate input by the vibration pen 3 is performed by touching the vibration transmission plate 8. That is, by specifying the area within the area indicated by the symbol A (hereinafter referred to as an effective area) indicated by a solid line in the drawing with the vibrating pen 3,
Is configured to be able to calculate the position coordinates.

Outside the center of each side of the effective area, a vibration sensor 6 such as a piezoelectric element for converting mechanical vibration into an electric signal is provided.
a to 6d are fixed. Further, in order to prevent (reduce) the propagated wave from being reflected at the end face of the vibration transmission plate 8 and returning the reflected wave to the center, a vibration isolator 7 is provided on the outer periphery of the vibration transmission plate 8. Have been.

Reference numeral 9 denotes a signal waveform detection circuit that outputs a signal obtained by detecting a vibration by each of the vibration sensors 6a to 6d to the arithmetic and control circuit 1.

The vibrator 4 built in the vibrating pen 3 is driven by the vibrator driving circuit 2. The driving signal of the vibrator 4 is supplied as a low-level pulse signal from the arithmetic and control circuit 1, amplified by the vibrator driving circuit 2 with a predetermined gain, and applied to the vibrator 4. The electric drive signal is converted into mechanical vibration by the vibrator 4 and transmitted to the vibration transmitting plate 8 via the pen tip 5.

Here, 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 glass. Further, when the vibrator 4 is driven, a mode in which the vibrator 4 vibrates in the vertical direction in FIG. Further, by setting the vibration frequency of the vibrator 4 to the resonance frequency including the pen tip 5, efficient vibration conversion is possible. The elastic wave transmitted to the vibration transmission plate 8 as described above is a plate wave,
It has the advantage that it is less susceptible to scratches, obstacles, etc. on the surface of the vibration transmission plate than surface waves.

When the vibration transmitting plate 8 is made of glass, an end surface of the glass may be applied to a pin or the like when the vibration transmitting plate 8 is positioned and fixed to a housing (not shown). In such a case, if the glass end face is damaged, the glass is easily broken. The larger the size of the glass, ie the larger the input surface of the tablet, the greater the risk of such breakage. In order to avoid this danger, a U-shaped metal or resin member may be provided on the end surface of the glass, and the glass, that is, the vibration transmission plate 8 may be positioned through this member.

The arithmetic and control circuit 1 operates at predetermined intervals (for example, 5
msec), the vibration pen 3
In addition to outputting a signal for driving the vibrator 4 therein, the internal timer (constituted by a counter) starts counting time. The vibration generated by the vibration pen 3 propagates on the vibration transmission plate 8 and arrives with a delay according to the distance to the vibration sensors 6a to 6d. In addition, a detection result of a detection unit that detects whether a pen 3 described later is in contact with the vibration transmission plate 8, that is, whether a normal input has been performed during input by the operator, and a position of the detected pen 3 described later Based on the determination result of the determination unit that determines whether the coordinates are correct or not, the sound generation unit 10 which is an instruction unit for notifying the operator of a non-detection or erroneous detection is controlled.

The signal waveform detection circuit 9 includes the vibration sensors 6a to 6a.
The signal from 6d is detected, a signal indicating the timing of arrival of vibration at each vibration sensor is generated by waveform detection processing described later, and a signal for each sensor is output to the arithmetic and control circuit 1.
The arithmetic and control circuit 1 detects the vibration transmission time to each of the vibration sensors 6a to 6d, outputs the position information of the vibration pen 3 to the personal computer 11, and displays the locus of the pen 3 on the monitor 12.

<Description of Arithmetic Control Circuit> FIG. 3 is a block diagram showing a schematic configuration of the arithmetic control circuit 1, and each component and its operation will be outlined below.

In the figure, reference numeral 31 denotes a microcomputer for controlling the arithmetic control circuit 1 and the entire coordinate input device, and includes an internal counter, a ROM storing processing procedures, a RAM used for calculations and the like, and a nonvolatile memory storing constants and the like. It is composed of a memory and the like. Reference numeral 33 denotes a timer (constituting, for example, a counter) for measuring a reference clock (not shown), which inputs a start signal for starting driving of the vibrator 4 in the vibrating pen 3 to the vibrator driving circuit 2. Then, the timing is started. As a result, the start of timing and the detection of vibration by the sensor are synchronized, and the sensor (6a
6d) makes it possible to measure the delay time until vibration is detected.

Other circuits constituting each component will be described in order.

The vibration arrival timing signals from the vibration sensors 6a to 6d output from the signal waveform detection circuit 9 are supplied to the latch circuits 34a to 34 via the detection signal input port 35.
is input to d. Each of the latch circuits 34a to 34d corresponds to each of the vibration sensors 6a to 6d, and when receiving a timing signal from the corresponding sensor, latches the time value of the timer 33 at that time. When the detection circuit 36 determines that all the detection signals have been received,
A signal to that effect is output to the microcomputer 31.
When the microcomputer 31 receives the signal from the detection circuit 36, the microcomputer 31 calculates the vibration transmission time from the latch circuits 34a to 34d to the respective vibration sensors.
4d, a predetermined calculation is performed, and the vibration transmission plate 8
The coordinate position of the upper vibration pen 3 is calculated. And I / O
By outputting the calculated coordinate position information to the personal computer 11 via the port 37, dots and the like can be displayed at the corresponding positions on the monitor 12.

<Description of Vibration Transmission Time Detection (FIGS. 4 and 5)
Next, the principle of measuring the vibration transmission time from the vibration pen 3 to the vibration sensors 6a to 6d will be described.

FIG. 4 is a diagram for explaining a detection waveform input to the signal waveform detection circuit 9 and a process of measuring a vibration transmission time based on the detection waveform. Hereinafter, the case of the vibration sensor 6a will be described, but other vibration sensors 6b, 6c,
The same is true for 6d.

It has already been described that the measurement of the vibration transmission time to the vibration sensor 6a is started simultaneously with the output of the start signal to the vibrator drive circuit 2. At this time, the drive signal 41 is applied from the transducer drive circuit 2 to the transducer 4. The ultrasonic vibration transmitted from the vibration pen 3 to the vibration transmission plate 8 by the signal 41 advances over a time tg corresponding to the distance to the vibration sensor 6a, and is detected by the vibration sensor 6a. A signal indicated by reference numeral 42 indicates a signal waveform detected by the vibration sensor 6a. Since the vibration used here is a plate wave, the relationship between the envelope 43 and the phase 42 of the detected waveform with respect to the transmission distance in the vibration transmission plate 8 changes according to the transmission distance during the vibration transmission. I do. Here, the traveling speed of the envelope 43, that is, the group velocity is Vg,
The speed at which the phase 42 advances, that is, the phase speed is Vp. If the group velocity Vg and the phase velocity Vp are known,
The distance between the vibration pen 3 and the vibration sensor 6a can be calculated from the vibration transmission time.

First, focusing only on the envelope 43, the speed is Vg, and a point on a specific waveform, for example, the first zero-cross point of the signal 44 which is a twice-differentiated waveform of the envelope 43 is defined as an inflection point of the envelope 43. Is detected as the distance d between the vibration pen 3 and the vibration sensor 6a.
Is given by d = Vg · tg (1), where tg (the circuit delay is subtracted from 45 signals tg ′). This equation relates to the vibration sensor 6a, but the other three vibration sensors 6b to 6d
And the distance between the vibrating pen 3 can be similarly expressed.

Further, in order to determine a coordinate position with higher definition, a process based on the detection of the phase signal is performed. The time from a specific detection point of the phase waveform signal 42, for example, the application of vibration to the zero cross point after a certain signal level 431 is represented by t.
p′47 (obtained by generating a window signal 46 having a predetermined width from the time exceeding the level 431 and comparing it with the phase signal 42)
Then, the distance between the vibration sensor and the vibration pen is as follows: d = n · λp + Vp · tp (2) (in the equation, tp is a value obtained by subtracting the delay time of a circuit or the like from tp ′). 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 = int [(Vg · tg−Vp · tp) / λp + 1 / N] (3)

Here, N ≒ uses an appropriate real value other than “0”. For example, if N = 2.0, even if a detected value of tg or tp having an error within ± 1/2 wavelength is obtained, the value of the equation (2) n can be correctly determined. The distance between the vibration pen 3 and the vibration sensor 6a can be accurately measured by substituting N obtained as described above into the expression (2).

For measuring the two vibration transmission times tg 'and tp', the signal waveform detection circuit 9 for generating the signals 45 and 47 is configured as shown in FIG.

In FIG. 5, after the output signal of the vibration sensor 6a is amplified by the preamplifier circuit 51, the extra frequency components of the detection signal are removed by the band-pass filter 511. The signal is input to an envelope detection circuit 52 constituted by a pass filter or the like, and only the envelope 43 of the detection signal is extracted. The timing of the envelope inflection point (44 zero crossing point) is detected by the envelope inflection point detection circuit 53. In the peak detection circuit, a signal tg ′ (signal 45 in FIG. 4) which is an envelope delay time detection signal having a predetermined waveform is formed by a tg signal detection circuit 54 composed of a monomultivibrator or the like, and is input to the arithmetic and control circuit 1.

On the other hand, reference numeral 55 denotes a signal detection circuit, which is an envelope signal 43 detected by the envelope detection circuit 52.
A pulse signal of a portion exceeding a threshold signal 431 of a predetermined level is formed. Reference numeral 56 denotes a monostable multivibrator, which opens a gate signal 46 having a predetermined time width triggered by the first rising of the pulse signal. 57 is a tp comparator, which is a phase signal 42 while the gate signal 46 is open.
Is detected, a phase delay time signal tp'47 is supplied to the arithmetic and control circuit 1. The circuit described above is for the vibration sensor 6a, and the same circuit is provided for other vibration sensors.

<Explanation of Circuit Delay Time Correction> What is actually measured by the signal waveform detection circuit 9 is t including the offset of the delay time in the vibrating pen 3 and in the circuit.
Although g ′ and tp ′ are to be substituted into the expressions (2) and (3), it is necessary to subtract the offset and correct them to tg and tp.

The vibration transmission time latched by the latch circuit includes a circuit delay time et and a phase offset time toff. The errors caused by these always include the same amount when the vibration is transmitted from the vibration pen 3 to the vibration transmission plate 8 and the vibration sensors 6a to 6d.

Therefore, for example, from the position of the origin O in FIG.
For example, the distance to the vibration sensor 6a is R1 (= X / 2), an input is made at the origin O with the vibration pen 3, and the actually measured vibration transmission time from the origin O to the sensor 6a is tg.
Assuming that the true transmission times from the origin O to the sensor are tgz and tpz, the circuit delay time et and the phase offset toff are as follows: tgz '= tgz + et (4) tpz' = tpz + et + toff ... (5)

On the other hand, an actual measurement value tg 'at an arbitrary input point P
Similarly, tp 'is as follows: tg' = tg + et (6) tp '= tp + et + toff (7) When the difference between (4) (6) and (5) (7) is obtained, tg′−tgz ′ = (tg + et) − (tgz + et) = tg−tgz (8) tp′−tpz ′ = (tp '+ Et + toff)-(tpz + et + toff) = tp-tpz (9) The circuit delay time et and the phase offset toff included in each transmission time are removed, and the sensor 6a between the position of the origin O and the input point P is started. The difference of the true transmission delay time according to the distance can be obtained.
The distance difference can be obtained by using the equation (3).

Since the distance from the vibration sensor 6a to the origin O is previously stored in a nonvolatile memory or the like and is known, the distance between the vibration pen 3 and the vibration sensor 6a can be determined. The same applies to the other sensors 6b to 6d.

The actual measured values tgz 'and tpz' at the origin O are stored in the non-volatile memory at the time of assembling at the factory or at the time of shipment, and before the calculation of the equations (2) and (3), (8) and (9) The equation is executed, which allows for a highly accurate measurement.

<Description of Coordinate Position Calculation (FIG. 6)> Next, the principle of detecting the coordinate position on the vibration transmitting plate 8 by the actual vibration pen 3 will be described. Now, if four vibration sensors 6a to 6d are provided near the middle point of the four sides on the vibration transmission plate 8 at the positions of S1 to S4, based on the principle described above, each of the four vibration sensors 6a to 6d The linear distances da to dd to the positions of the vibration sensors 6a to 6d can be obtained. Further, based on the linear distances da to dd, the arithmetic control circuit 1 can obtain the following equation from the theorem of the square of the coordinates (x, y) of the position P of the vibration pen 3 as follows.

X = (da + db) · (da−db) / 2X (10) y = (dd + dc) · (dd−dc) / 2Y (11) where X and Y are the vibration sensors 6a and 6b, respectively. And the distance between the vibration sensors 6c and 6d.

In the above equations (2) and (3), to calculate the distance, the values of Vg, Vp and λp (= Vp / f) corresponding to the group velocity, the phase velocity, and the wavelength are set in advance. It is necessary to keep. Normally, f calculated from a plurality of tp of the detected vibration and Vp corresponding to the phase velocity based on the thickness of the vibration transmission plate 8, Vg corresponding to the group velocity based on the thickness of the vibration transmission plate 8, and f and Vp Λp is set more. Then, the set Vg, Vp, and λp (= V
p / f) is stored in a nonvolatile memory or the like.

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

<Explanation of Judgment Method> Next, the means for judging the correctness of a detection point according to the present invention will be described. For details, see, for example, Japanese Patent Application No. 63-15989 (JP-A-1-191922).
The description is omitted here. Da, d as described above
The coordinate values are obtained from b, dc, and dd based on equations (10) and (11). The distance between the pen 3 and the sensors 6a to 6d can be calculated back from the coordinate values. That is, the distances La, Lb, corresponding to da, db, dc, dd,
Lc and Ld are calculated by the following equations. When only La is shown, it is as follows.

[0050]

(Equation 1)

If the detection points are normal, dn and Ln (n =
a to d) should be da ≒ La (13). Here, the relation between the two sides of the equation (13) is not equal but substantially equal to each other because of the quantum error in measuring the vibration transmission time, the mounting accuracy of the sensor,
This is because it is inevitable that a slight error occurs due to factors such as an arithmetic error in the calculation of the coordinate value.

However, in the case of an erroneously detected detection point caused by noise or the like, the expression (13) cannot be satisfied. That is, whether or not Δf = da−La 、 0, in other words, the measured vibration transmission distance is compared with the vibration transmission distance calculated back from the coordinate values, and there is a significant difference between the two. It is possible to determine whether the detection point is correct or not. If it is determined that the detection is erroneous, no output is made to the personal computer, and the erroneous detection point can be removed. The above processing is performed by the microcomputer 3
1 is performed.

Although the above is an example of comparing the measured distance with the distance calculated backward from the coordinate values, the vibration transmission time can also be calculated backward from the coordinate values. Therefore, it goes without saying that the erroneous detection point may be determined by comparing the measured vibration transmission time with the vibration transmission time calculated backward from the coordinate value.

<Description of Detection Method> Next, an undetected detection means according to the present invention will be described.

When the latch circuits 34a to 34d can receive only signals from some of the sensors, the detection circuit 36 attempts to input by the operator, but the influence of noise or the like or the influence of the vibration pen It is determined that the contact pressure on the vibration transmitting plate is insufficient and the state cannot be detected, and a signal to that effect is output to the microcomputer 31.

If the above erroneous detection or non-detection is made, the microcomputer 31 controls the sound generation means 10.
Is driven, and a predetermined sound is generated to inform the operator that normal input has not been performed. The sound generating means 10 includes, for example, a piezoelectric buzzer and a drive circuit thereof. Then, the operator can know that the input has not been performed normally,
When the erroneous detection or the non-detection is performed without recognizing the monitor 12, rewriting can be performed on the spot and efficient operation can be performed.

<Other Embodiments> The present invention is applicable not only to the coordinate input device of the ultrasonic type, but also to a coordinate input device of any type such as a resistive type, an electrostatic coupling type, an electromagnetic induction type and an optical type. Is also applicable. It goes without saying that the size of the input surface is not limited. Also,
The shape of the coordinate input means is not limited to a pen,
Any shape such as a mouse shape may be used.

In the coordinate input device of various types, the means for determining whether the detected point is correct or not has, for example, the following configuration. The coordinate input device samples the position coordinates of the input point at predetermined time intervals. For example, sampling is performed 100 times per second. Usually, on the assumption that the distance S between two adjacent sampling points of the input straight line or curve does not exceed a certain distance Smax,
When the distance S exceeds Smax, it is determined that erroneous detection has been performed, and an input point sampled later in time may be determined as an erroneously detected point.

Next, the undetected detecting means has, for example, the following configuration.

When the pen comes into contact with the input plate, the pen tip of the pen is provided to slide in the axial direction of the pen, and a switch built in the pen is operated by the slide. Thereby, when the switch is ON, that is, when the operator intends to input and the pen is in contact with the input plate, if the predetermined detection cannot be performed due to noise or the like, it is detected as not detected, and a sound is generated to that effect. Means can inform the operator.

The means for determining erroneous detection and the means for undetected detection are not limited to the above, and it goes without saying that the present invention can be applied by any method.

The indicator means (instruction means) is not limited to sound. An LED is provided at the rear end of the pen, and the LED is turned on when erroneous detection or non-detection is performed. You may tell them. Alternatively, the entire pen may be vibrated. That is, any method can be used as long as the method can be recognized by the operator.

Various variations can be considered for the timing of the indicator. That is, when erroneous detection or non-detection is found, the indication may be made immediately. Alternatively, an indication may be made when the number of erroneously detected or undetected points exceeds a predetermined number. In this case, even if there are several erroneous detections or the like in continuous input, when there is no large difference in the input result, the work is not interrupted and excellent operability can be realized. When erroneous or undetected points continue, the quality of the indicator may be gradually changed. For example, any method such as gradually increasing the sound or shortening the interval at which the LED is intermittently blinked may be used.

The present invention can also be applied to a system in which a personal computer screen is displayed by a projector on an input plate which also serves as a screen instead of a monitor. In such a system, the present invention is effective when the operator blocks the projection light of the projector at the time of input. That is, in the case described above, the screen of the input portion is not visible to the operator, so that it is difficult to know whether the input has been normally performed. Therefore, by notifying the operator of erroneous detection or non-detection, an efficient input operation can be performed.

[0065]

As described above, according to the present invention,
If there is an undetected or erroneous detection, the operator can be informed by a sound or the like that the input has not been performed normally,
Rewriting can be performed on the spot without checking the monitor, and efficient operation can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of a coordinate input device.

FIG. 2 is a cross-sectional view illustrating a configuration of a vibration pen.

FIG. 3 is a block diagram illustrating an internal configuration of an arithmetic control circuit in detail.

FIG. 4 is a time chart of signal processing.

FIG. 5 is a block diagram illustrating a configuration of a signal waveform detection circuit.

FIG. 6 is an explanatory diagram illustrating coordinate calculation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operation control circuit 2 Vibrator drive circuit 3 Vibration pen 6a-6d Vibration sensor 8 Vibration transmission board 9 Signal waveform detection circuit 10 Sound generation means 11 Personal computer 12 Monitor

(72) Inventor Yuichiro Yoshimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Katsuyuki Kobayashi 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A coordinate input device for detecting a position coordinate of a coordinate input device input to a coordinate input plate, a detecting device detecting whether contact of the coordinate input device with the coordinate input plate is normal, Determination means for determining whether the coordinate values are correct or incorrect, and instruction means for giving an instruction when it is detected that the contact is not normal or when it is determined that the coordinate values are incorrect. Coordinate input device. 2. A coordinate input device for detecting vibration from a vibration pen input to a vibration transmission plate by a vibration sensor provided on the vibration transmission plate, and calculating coordinates of an input point from the detected vibration transmission time. Detecting means for detecting whether the contact of the vibration pen with the vibration transmission plate is normal, means for calculating the transmission time from the calculated coordinate value to the vibration sensor, and the calculated transmission time, Determining means for comparing the transmission time to determine whether the calculated coordinate value is correct; and instructing means for giving an instruction when it is detected that the contact is not normal or when it is determined that the coordinate value is incorrect. A coordinate input device comprising: