JPH06332609A - Coordinate input device - Google Patents

Abstract

PURPOSE:To provide the coordinate input device which can save consumption of energy. CONSTITUTION:A vibration pen 3 is provided with a steel ball 21 held in a cylindrical body 24 and a spring 23 for pressing down it. The steel ball 21 is pressed against a load cell 22, and the load cell 22 measures force applied thereto. When the pen 3 is inclined by an angle theta, the force applied to the load cell 22 becomes a force obtained by adding the force by the spring 23 and component force in the axial direction of gravity exerted on the steel ball 21. The force by the spring 23 and weight of the steel ball 21 are known in advance, therefore, by force measured by the load cell 22, an inclination thetaof the pen 3 is known. When amplitude of vibration by a vibrator 4 is varied by controlling a vibrator driving circuit contained in the pen 3 in accordance with this inclination, it is unnecessary to vibrate it by excessive amplitude for supposing the case when the angle theta is very small, and consumed energy can be saved.

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, by a plurality of vibration sensors provided on a vibration transmission plate, and detects an input coordinate from a vibration transmission time to each vibration sensor. The present invention relates to a coordinate input device for detecting.

[0002]

2. Description of the Related Art Conventionally, it has been proposed that a coordinate input device of this type should be constructed as follows.

A schematic structure is shown in FIGS.

In FIG. 10, the coordinate input device includes a vibration input pen 103, a vibration transmission plate 108, and a vibration detection sensor 10.
6a to 6c, a vibration isolator 107, an arithmetic control circuit 101, a vibrator drive circuit 102, and a signal waveform detection circuit 109.

That is, the arithmetic control circuit 101 to the drive circuit 102 that controls the entire apparatus and calculates the coordinate position.
Is supplied with a pulse signal for driving the vibrator 104 built in the input pen 103, and the pulse signal is supplied to the drive circuit 1.
It is amplified by 02 with a predetermined gain and applied to the vibrator 104. The electric drive signal is converted into mechanical vibration by the vibrator 104 and input to the transmission plate 108 via the pen tip of the input pen 103. The input vibration propagates through the transmission plate 108 and reaches the detection sensors 106a to 106c. The detection sensors 106a to 106c are sensors that convert mechanical vibrations of a piezoelectric element or the like into electric vibrations, and detect the propagating vibrations and output an electric signal. The output electric vibration is detected by the detection circuit 109 in a predetermined waveform detection process, and the detection sensors 106a to
It becomes a signal indicating the timing at which vibration reaches each of c, and is output to the arithmetic and control circuit 101. Arithmetic control circuit 101
The time from the supply of the pulse signal to the signal of the vibration arrival timing is measured by an internal timer composed of a counter and used as a signal propagation time. The distance between the input pen 103 and each of the detection sensors 106a to 106c is calculated from the product of the vibration propagation time and the speed at which the vibration propagates, and based on the calculated distance, the Pythagorean theorem of the input pen 103 is calculated. The position coordinates are obtained.

Here, the vibration frequency of the vibrator 104 is selected to a value capable of generating a plate wave on the vibration transmission plate 108 such as glass. When driving the vibrator, the vibration transmission plate 1
The mode that vibrates in the vertical direction of FIG. 11 with respect to 08 is selected. Also, input the vibration frequency of the vibrator 104 to the input pen 1.
By setting the resonance frequency to include the pen tip 105 of No. 03, efficient vibration conversion is possible. As described above, the elastic wave transmitted to the vibration transmission plate 108 is a plate wave, and has an advantage that it is less susceptible to damages and obstacles on the surface of the vibration transmission plate as compared to surface waves.

[0007]

In the above-mentioned conventional example, in the waveform detection processing in the detection circuit 109, in order to eliminate erroneous detection due to noise, if the level of the detected waveform does not exceed the threshold value of the predetermined level, vibration reaches. The timing is not detected. By the way, in the input of vibration from the vibration input pen 103 to the vibration transmission plate 108, if the input pen 103 is tilted from the direction perpendicular to the vibration transmission plate 108, the level of the detected waveform is lowered. This is because the vector of the input vibration is tilted by the inclination angle and the component in the direction perpendicular to the vibration transmission plate 108 is reduced, and the contact point between the input pen 103 and the vibration transmission plate 108 is the axis of the input pen 103. It is thought that this is because of a genuine shift. Further, naturally, the input pen 103 and the detection sensor 106a
The level of the detected waveform also changes depending on the distance between c and c and the contact pressure between the input pen 103 and the vibration transmission plate 108, that is, the writing pressure.

Therefore, the input pen 103 and the detection sensor 1
The distance between 06a-c is the maximum, the writing pressure is the minimum, and the detected waveform level in the case of the maximum value of the inclination of the input pen 103 used is equal to or higher than the threshold value. Drive voltage is set.

However, the drive voltage set by the above is the input voltage of the input pen 103 and the detection sensors 106a-c.
Except when the distance is maximum, the writing pressure is minimum, and the inclination of the input pen 103 is maximum, an excessive detection waveform level is generated and occupied. This is not preferable from the viewpoint of energy saving. Further, when the coordinate input device is incorporated in a battery-powered portable personal computer or the like, there is a drawback that the usable time becomes short.

Further, in the above-mentioned conventional example, when the user is operating the coordinate input device, a signal is always applied to the vibrator 104 at a constant cycle and detection is performed irrespective of the presence / absence of input by the input pen 103. The sensors 106a-c and the detection circuit 109 sense the presence or absence of vibration. However, in the operation state, the input pen 10 is actually used.
The input by 3 is not always performed, and the actual input time is about a fraction of the total operation time in consideration of the thinking time. This is not preferable from the viewpoint of energy saving as described above, and it shortens the usable time in the case of battery drive.

The present invention has been made in view of the above conventional example, and an object thereof is to provide a coordinate input device in which energy consumption is suppressed to a low level.

[0012]

In order to achieve the above object, the coordinate input device of the present invention has the following structure.

Vibration generating means for generating vibration, a vibration transmitting plate for transmitting the vibration generated by the vibration generating means, detecting means for detecting an angle formed by the vibration generating means and the vibration transmitting plate, Based on the angle detected by the detection means, a control means for controlling the driving means of the vibration generating means and a vibration transmitted through the vibration detecting plate are detected, and a delay from the generation of the vibration until the detection is detected. And means for calculating coordinates based on time.

[0014]

With the above structure, the angle formed by the vibration generating means and the vibration transmitting plate is detected, and the amplitude of the vibration is controlled according to the angle, whereby the vibration having the proper amplitude is transmitted to the vibration transmitting plate. .

[0015]

First Embodiment <Device Configuration> FIGS. 1 to 3 show the configuration of a coordinate input device according to a first embodiment of the present invention.

FIG. 1 shows a first embodiment of the vibration input pen of the coordinate input device of the present invention. In the figure, inside the input pen 3, the angle formed by the input pen 3 with respect to the vibration transmission plate 8 provided in the horizontal direction, that is, the angle θ formed by the surface of the vibration transmission plate 8 and the axis of the input pen 3 is detected. The angle detection means 20 is provided. The angle detecting means 20 is a steel ball 2.
1 and a cylindrical body 24 accommodating the steel ball 21, a strain gauge type load cell 22, a steel ball 21 and a load cell 2 with a predetermined force.
2 and a spring 23 that presses it. A predetermined gap is provided between the inner surface of the tubular body 24 and the steel ball 21, and the coefficient of friction between the inner surface of the tubular body 24 and the steel ball 21 is set to be as small as possible. In the above configuration,
The force F detected by the load cell 22 is the vibration transmission plate 8
When the angle θ formed between the input pen 3 and the input pen 3 is neglected, the frictional force between the inner surface of the cylindrical body 24 and the steel ball 21 is disregarded.

F = w sin θ + F ₀ (1) where, w: weight of steel ball F ₀ : pressing force of spring The force F is detected regardless of the tilting direction of the input pen 3. Calculate the angle θ by the above formula, or F
It is possible to detect the angle θ by facilitating a table of θ corresponding to Needless to say, the output of the load cell 22 is sent to the arithmetic control circuit 1 described later via the code 3a to detect the angle θ.

When the angle θ is detected, the voltage applied from the drive circuit 2 to the vibrator 4 is controlled according to the angle θ. For example, the voltage V ₀ when the angle formed by the vibration transmission plate 8 and the input pen 3 is 90 °, and the voltage V ₀ × 1 / sin θ when the angle θ is set. Alternatively,
It is also possible to experimentally obtain a table of voltage values that can obtain a detected waveform level equivalent to the case of 90 ° at the angle θ in advance, and control the drive voltage by the table.

If the angle θ is an angle that cannot be considered during normal input, for example, if the angle θ is detected to be 30 ° or less, it is determined that no input has been made, and the input pen 3 or the coordinate input device main body is detected. Power is saved by turning off the power.

Next, the drive circuit 2 of this embodiment will be described.

FIG. 2 shows a specific structure of the vibrator drive circuit 2 described above. In this embodiment, the drive voltage of the vibrator of the vibrating pen 3 can be switched in a plurality of steps by a switch. In the figure, the reference numeral 26 is a buffer amplifier for low impedance driving, which is composed of PNP and NPN transistors and diodes, and controls the vibrator of the vibrating pen 3 in accordance with the input drive signal pulse. It is driven by a drive waveform having an amplitude of Vcc.

In this embodiment, the power supply voltage + Vcc, -Vcc.
Are divided by resistors 22, 23 and 24, 25, respectively, and a switch 21 can select either ± Vcc or a divided value by each resistor as a drive voltage.

That is, in this embodiment, the drive energy of the vibrating pen 3 can be switched in two steps by the switch 21.

It is conceivable that the switch 21 and the resistors 21 to 25 are composed of variable resistors or the like. In this case, the input vibration intensity of the vibration pen 3 to the vibration transmission plate 8 can be continuously changed.

The configuration other than the above is the same as that of the conventional example as shown in FIG. 3, but the arithmetic control circuit 1, the vibration propagation time detection and correction, and the position coordinate calculation will be described in detail.

<Description of Arithmetic and Control Circuit> In the above-mentioned configuration, the arithmetic and control circuit 1 is a signal for driving the vibrator driving circuit 2 and the vibrator 4 in the vibration input pen 3 every predetermined period (for example, every 5 ms). Is output, and the internal timer (consisting of a counter) starts timing. Then, the vibration generated by the vibrating pen 3 propagates on the vibration transmission plate 8 and arrives with a delay depending on the distance to the vibration detection sensors 6a to 6c.

The signal waveform detection circuit 9 includes the respective vibration detection sensors 6
The signals from a to c are detected, and a signal indicating the vibration arrival timing to each vibration detection sensor is generated by the waveform detection processing described later. The arithmetic control circuit 1 inputs this signal for each detection sensor, The vibration arrival time to each of the vibration detection sensors 6a to 6c is detected, and the coordinate position of the vibration input pen 3 is calculated. In addition, the arithmetic control circuit 1 uses the calculated position information of the vibration input pen 3 to display the drive circuit 1.
0 is driven to control the display on the display 11, or the coordinates are output to an external device by serial or parallel communication.

FIG. 4 is a block diagram showing a schematic structure of the arithmetic and control circuit 1 of the embodiment, and each constituent element and its operation outline will be described below.

In the figure, reference numeral 31 is a microcomputer for controlling the arithmetic control circuit 1 and the coordinate input apparatus as a whole, and an internal counter, a ROM storing operation procedures, a RAM used for calculation and the like, and a nonvolatile memory storing constants and the like. It is composed of a sex memory. Reference numeral 33 denotes a timer (not shown) for counting a reference clock (for example, configured by a counter or the like).
When a start signal for starting the driving of the vibrator 4 therein is input, the time counting is started. As a result, the start of timing and the vibration detection by the sensor are synchronized, and the delay time until the vibration is detected by the detection sensors 6a to 6c can be measured.

The other circuits constituting the respective components will be described in order.

The vibration arrival timing signals from the vibration detection sensors 6a to 6c output from the signal waveform detection circuit 9 are:
Latch circuits 34 a to 3 via the detection signal input port 35
4c is input. Each of the latch circuits 34a to 34d corresponds to each of the signal detection sensors 6a to 3c, and when receiving a timing signal from the corresponding sensor, it latches the measured value of the timer 33 at that time. When the determination circuit 36 determines that all the detection signals have been received in this way, it outputs a signal to that effect to the microcomputer 31. When the microcomputer 31 receives the signal from the determination circuit 35, the vibration arrival time from the latch circuits 34a to 34c to the respective vibration sensors is read from the latch circuit, a predetermined calculation is performed, and the vibration on the vibration transmission plate 8 is vibrated. The coordinate position of the input pen 3 is calculated. Then, by outputting the calculated coordinate position information to the display drive circuit 10 (not shown) via the I / O port 37, dots or the like can be displayed at corresponding positions on the display 11, for example. Alternatively, the coordinate value can be output to an external device by outputting the coordinate position information to the interface circuit via the I / O port 37.

<Description of Vibration Propagation Time Detection (FIGS. 5 and 6)
> Hereinafter, the principle of measuring the vibration arrival time to the vibration detection sensors 6a to 6c will be described.

FIG. 5 is a diagram for explaining a detection waveform input to the vibration waveform detection circuit 9 and a vibration transmission time measuring process based on the detection waveform. The case of the vibration detection sensor 6a will be described below, but other vibration detection sensors 6a will be described.
The same applies to b and 6c. Vibration sensor 6
It has already been described that the measurement of the vibration transmission time to a is started simultaneously with the output of the start signal to the vibrator drive circuit 12. At this time, the drive signal 41 is applied from the vibrator drive circuit 12 to the vibrator 4. The vibration transmitted from the vibration input pen 3 to the vibration transmission plate 8 by the signal 41 progresses for a time tg corresponding to the distance to the vibration detection sensor 6a, and then is detected by the vibration detection detection sensor 6a.

The signal indicated by 42 in the figure is the vibration detection sensor 6
The signal waveform which a detected is shown. Since the vibration used in this embodiment is a plate wave, the envelope 421 and the phase 4 of the detected waveform with respect to the propagation distance in the vibration transmission plate 8
The relationship of 22 changes according to the transmission distance during vibration transmission. Here, the traveling speed of the envelope 421, that is, the group speed is Vg, and the phase speed of the phase 422 is Vp. The distance between the vibration input pen 1 and the vibration detection sensor 6a can be detected from the group velocity Vg and the phase velocity Vp.

First, focusing only on the envelope 421, its speed is Vg, and when a point on a certain specific waveform, for example, an inflection point or a peak like a signal shown in FIG. 43 is detected, the vibration input pen 3 and The distance between the vibration detection sensors 6a is given by d = Vg · tg (1) with the vibration transmission time being tg. Although this formula relates to one of the vibration detection sensors 6a, the distance between the other two vibration detection sensors 6b and 6c and the vibration input pen 3 can be similarly expressed by the same formula.

Further, in order to determine the coordinates with higher accuracy, processing based on the detection of the phase signal is performed. The time from the specific detection point of the phase waveform signal 422, for example, the application of vibration to the zero cross point after a certain predetermined signal level 46 is tp.
45 (obtained by generating a window signal 44 having a predetermined width with respect to the signal 47 and comparing it with the phase signal 422), the distance between the vibration detection detection sensor 6a and the vibration input pen 3 is d = n · λp + Vp · tp (2) 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 is a real number other than "0", and an appropriate value is used. For example, if N = 2, then n can be determined if there is a variation such as tg within ± 1/2 wavelength. The distance between the vibration input pen 3 and the vibration detection sensor 6a can be accurately measured by substituting the determined n into the equation (2). Signals 43 and 45 for measuring the above two vibration transmission times tg and tp
Is generated by the signal waveform detection circuit 9, which is configured as shown in FIG.

FIG. 6 is a block diagram showing the configuration of the vibration waveform detection circuit 9 of the embodiment. In FIG. 6, the output signal of the vibration detection sensor 6a is amplified to a predetermined level by the preamplifier circuit 51. The bandpass filter 511 removes extra frequency components of the detection signal from the amplified signal, and the amplified signal is input to an envelope detection circuit 52 including, for example, an absolute value circuit and a low-pass filter. Only is taken out. The timing of the envelope peak is detected by the envelope peak detection circuit 53. In the peak detection circuit, a signal tg (signal 43 in FIG. 5) which is an envelope delay time detection signal having a predetermined waveform is formed by the tg signal detection circuit 54 composed of a mono-multivibrator or the like, and the arithmetic control circuit 1
Entered in.

On the other hand, 55 is a signal detection circuit, which detects the envelope signal 42 detected by the envelope detection circuit 52.
The pulse signal 47 of the portion exceeding the threshold signal 46 of the predetermined level in 1 is formed. 56 is a monostable multivibrator, which opens the gate signal 44 of a predetermined time width triggered by the first rising edge of the pulse signal 47. Reference numeral 57 denotes a tp comparator, which detects the first rising zero-cross point of the phase signal 422 while the gate signal 44 is open, and supplies the phase delay time signal tp45 to the arithmetic control circuit 1. The circuit described above is for the vibration detection sensor 6a, and the same circuit is provided for other vibration detection sensors.

<Explanation of delay time correction> Strictly speaking, the vibration transmission time latched by the latch circuit is the time during which the sound wave travels through the pen tip of the input pen 3 and the detection sensor 6a.
It includes the time for which the circuit processes the signal output at 6c. Therefore, these delay times other than the time when the wave propagates on the vibration transmission plate 8 are defined as the intrinsic delay time et. The difference between the group delay time and the phase delay time at the reference point is defined as the phase offset time toff. The error caused by these is always included in the same amount when the vibration is transmitted from the vibration input pen 3 to the vibration transmission plate 8 and the vibration detection sensors 6a to 6c. Therefore, for example, when the position of the origin O in FIG. 7 is used as the reference point and the distance to the vibration detection sensor 6a is R1 (= X / 2), the vibration input pen 3 is used to make an input at the origin O for actual measurement. The measured vibration transmission time from the detected origin O to the detection sensor 6a is tgz ', tp
z ', the true transmission time from the origin O to the sensor and tg
Assuming z and tpz, these have a relationship of ttz '= tgz + et (4) tpz' = tpz + et + toff (5) with respect to the intrinsic delay time et and the phase offset toff.

On the other hand, the measured value t at an arbitrary input point P
Similarly, g ′ and tp ′ are tg ′ = tg + et (6) tp ′ = tp + et + toff (7). When the difference between (4), (6), (5) and (7) is calculated, 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 position of the origin O is eliminated. From this, the difference in the true transmission delay time depending on the distance from the position of the detection sensor 6a between the input points P as the starting point can be obtained, and the distance difference can be obtained by using the equations (2) and (3). it can. Since the distance from the vibration detection sensor 6a to the origin O is stored in a non-volatile memory or the like in advance and is known, the distance between the vibration input pen 3 and the vibration detection sensor 6a can be determined. The other sensors 6b and 6c can be similarly obtained. The measured value tgz ′ at the origin O
And tpz 'are stored in advance in a non-volatile memory,
The equations (8) and (9) are executed before the calculation of the equations (2) and (3), and highly accurate measurement can be performed.

<Description of Coordinate Position Calculation (FIG. 7)> Next, the principle of actually detecting the coordinate position on the vibration transmission plate 8 by the vibration input pen 3 will be described.

Now, in the vicinity of the corners of the four sides on the vibration transmission plate 8, 3
When the two vibration detection sensors 6a to 6c are provided at the positions S1 to S3, the linear distance da from the position P of the vibration input pen 3 to the position of each of the vibration detection sensors 6a to 6c is based on the principle described above. ~ Dc can be obtained. Further, in the arithmetic control circuit 1, based on the straight line distances da to dc,
The coordinates (x, y) of the position P of the vibration input pen 3 can be obtained from the Pythagorean theorem as follows.

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

In the coordinate input device having the above-described structure and operation, the drive applied voltage of the vibrator 4 is controlled in accordance with the angle formed by the vibration transmission plate 8 and the input pen 3 as described above, so that it is unnecessary. Low energy consumption and low power consumption. Further, it is possible to realize a coordinate input device having a long usable time even when incorporated in a battery-driven device.

[0047]

[Second Embodiment] In the first embodiment, the vibration transmission plate 8 is used.
Was installed horizontally, but when the coordinate input device is installed in a portable personal computer, etc., the state of use is not limited to the horizontal direction, and the personal computer body should be placed on the lap or held in your hand. In some cases, the vibration transmission plate 8 has various angles with respect to the horizontal direction.

In this embodiment, means for detecting the angle formed by the vibration transmitting plate 8 and the input pen 3 in the above case will be described.

FIG. 8 shows a personal computer 12 incorporating the input pen 3 and the coordinate input device of this embodiment. Inclination angle detecting means 60a and 60b with respect to the vertically downward direction are provided in the input pen 3 and the personal computer housing 12a, respectively.
Since the tilt angle detecting means 60a and 60b have the same configuration, only one of them will be described. Tilt angle detection means 60
The schematic configuration of a is shown in FIGS. In the figure,
A so-called printed contact potentiometer 61 is provided, and the movable terminal C is provided so as to be rotatable around an axis 62 in a direction perpendicular to the axis 3b of the input pen 3. A weight 63 fixed to the movable terminal C and rotatable about the shaft 62 is provided. The potentiometer 61
The weight 63 and a weight 63 are housed in a predetermined casing 65, and the casing 65 is held by pivot shafts 64a and 64b located on the shaft core 3b of the input pen 3. When the input pen 3 is tilted, the center of gravity of the housing 65 is biased so that the rotation axis of the movable terminal C is always perpendicular to a plane defined by the axis 3b of the input pen 3 and a vertical line. It is configured.

In the above structure, when the input pen 3 is tilted, the casing 65 rotates about the pivot shafts 64a and 64b so that the fixed terminal B side of the potentiometer 61 is always downward, and the weight 63 rotates about the shaft 62 at about the same time. When the input terminal 3 is rotated, the movable terminal C is rotated by the same angle as the input pen 3 is tilted. By detecting the voltage between the terminals A and C with respect to the voltage between the terminals A and B of the potentiometer 61, the tilt angle α of the input pen 3 with respect to the vertically downward direction can be detected.

Similarly, the tilt angle detection means 60b in the personal computer housing 12a can detect the tilt angle β of the personal computer housing 12a, that is, the vibration transmission plate 8 with respect to the vertically downward direction.

When the inclination angles of the input pen 3 and the vibration transmission plate 8 with respect to the vertically downward direction can be detected as described above, the input pen 3 is detected.
The angle ζ formed by the vibration transmission plate 8 and the vibration transmission plate 8 can be obtained by the following equation.

[Zeta] = 90 [deg.]-[Alpha] + [beta] Depending on the angle [zeta], power may be saved by controlling the drive voltage of the vibrator 4 or turning off the power source of the coordinate input device body as in the above-described embodiment.

Also in this embodiment, the power consumption is small,
Further, a coordinate input device suitable for battery drive can be realized. In particular, it is suitable for a coordinate input device incorporated in a portable personal computer or the like.

Needless to say, the potentiometer 61 in this embodiment may be a non-contact type potentiometer comprising a permanent magnet and a magnetoresistive element.

Further, the means for detecting the inclination angle of the input pen 3 or the vibration transmitting plate 8 is not limited to the first and second embodiments, and any means can be used as long as the angle can be detected. It goes without saying that it is good.

The present invention may be applied to a system composed of a plurality of devices or an apparatus composed of one device. Further, it goes without saying that the present invention can be applied to the case where it is achieved by supplying a program to a system or an apparatus.

[0058]

As described above, the coordinate input device of the present invention has the effect of suppressing energy consumption to a low level.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an input pen of a coordinate input device that is a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a drive circuit according to a first embodiment.

FIG. 3 is an overall schematic configuration diagram of a first embodiment.

FIG. 4 is a block diagram showing a schematic configuration of an arithmetic control circuit of the first embodiment.

FIG. 5 is an explanatory diagram of a vibration transmission time measurement process according to the first embodiment.

FIG. 6 is a block diagram of a signal waveform detection circuit of the first embodiment.

FIG. 7 is an explanatory diagram of coordinate position calculation according to the first embodiment.

FIG. 8 is a schematic sectional view of an input pen and a personal computer according to a second embodiment.

FIG. 9 is a schematic cross-sectional view of a tilt angle detecting means according to a second embodiment.

FIG. 10 is a schematic configuration diagram of a conventional example.

FIG. 11 is a schematic sectional view of a conventional input pen.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Arithmetic control circuit 2 Oscillator drive circuit 3 Input pen 4 Oscillator 5 Pen tip 6a-6c Detection sensor 8 Vibration transmission plate 9 Signal waveform detection circuit 20, 60a, 60b Inclination angle detection means 21 Steel ball 22 Load cell 61 Potentiometer 63 Weight 64a, b pivot shaft

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Katsuyuki Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Yuichiro Yoshimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Masaki Tokioka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A vibration generating means for generating vibration, a vibration transmitting plate for transmitting the vibration generated by the vibration generating means, and a detecting means for detecting an angle formed by the vibration generating means and the vibration transmitting plate. Controlling the drive means of the vibration generating means based on the angle detected by the detecting means, and detecting the vibration transmitted through the vibration detecting plate, until the vibration is detected And a means for calculating coordinates based on the delay time of the coordinate input device. 2. The detecting means detects the angle by measuring a component force along a direction of the vibration generating means among forces exerted by gravity on a weight having a predetermined mass. Coordinate input device. 3. The coordinate input device according to claim 1, wherein the detecting means detects the angle by measuring a resistance value of a variable resistor whose resistance value changes according to an inclination. 4. The detecting means measures the inclination of the vibration generating means and the inclination of the vibration transmitting plate, and combines the inclinations to detect the angle.
The coordinate input device described.