JPH11249796A - Input pen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an input pen which can improve its operability, can reduce the occurrence of its directivity and also can easily be replaced by using a vibration generation element and a vibration transmission member and attaching a pen point member of a specific layer structure to the tip of the vibration transmission member. SOLUTION: A vibrator 4 contained in a vibration input pen is driven by a vibrator drive circuit 2. Electric drive signals are converted into mechanical ultrasonic vibrations by the vibrator 4 and transmitted to a pen point tip 12 via a vibration transmission member 5. When the tip 12 touches a vibration transmission plate, the vibrations are passed onto the vibration transmission plate. The tip part of the member 5 is formed into a columnar part of radius R2, and the tip of the columnar part has a shape including a hemispherical part of radius R2. The tip 12 contains a 1st layer having rubber elasticity and a 2nd layer of resin that is formed outside the 1st layer. It is desirable to use styrene thermoplastic elastomer to the 1st layer, to use polypropylene to the 2nd layer and to unify both layers via the double color molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an input pen used for input of a coordinate input device for determining an input position based on vibration propagating through a vibration transmitting plate.

[0002]

2. Description of the Related Art Conventionally, as a coordinate input device, there has been known a coordinate input device which detects an elastic wave vibration input from an input pen by a plurality of sensors provided on a vibration transmission plate and detects coordinates indicated by the input pen. ing. As a pen tip of an input pen of such a coordinate input device, for example, Japanese Patent Application No.
No. 73963. The pen tip in this description is constituted by a polyamideimide which is a resin,
(1) It is excellent in wear resistance due to friction or the like when inputting coordinates.

(2) Vibration can be transmitted efficiently without attenuating the vibration generated in the input pen.

The above characteristics were satisfied.

[0005]

However, since the nib of the input pen of the above-mentioned conventional coordinate input device uses polyamideimide which is a resin as its material, it can be molded and is excellent in mass production. However, the following problems have occurred in the tip of the formed input pen.

When the input pen incorporating the formed pen tip is vertically abutted on the vibration transmission plate and the input pen is rotated about the axis of the input pen, the waveform of the signal detected by the sensor changes. Was found. That is, when the vibration input from the input pen propagates in a ripple shape around the input point on the vibration transmission plate, a phenomenon occurs in which the waveform of the signal detected differs depending on the direction of the input pen. This phenomenon is called directivity and causes the following adverse effects.

In the conventional coordinate input device, since the basic principle is to derive the distance using the transmission time of the sound wave and the sound speed of the wave, not only the sound speed is constant in the propagation body but also the sensor detects the sound speed. It is desired that the detection signal waveform always has the same shape. That is, as shown in FIG. 8, even if vibration is input at the same point, if the detected signal waveform is different, the detected propagation time will be different. In other words, in the drawing, the propagation delay time 1 and the propagation delay time 2 input vibration at the same point, and therefore, the same value should be originally detected. Will be different. As a result, the coordinate input device performs an erroneous detection such as detecting vibration input from a different point. This means that the accuracy of the coordinate input device is reduced, and in order to realize a highly reliable coordinate input device,
A configuration that can always detect the same detection signal waveform is required.

As described above, the directivity of the input pen is generated as follows.
This is to reduce the coordinate calculation accuracy of this type of coordinate input device, and some measures are required to realize a highly accurate and highly reliable coordinate input device.

Further, in this type of input pen, it is an essential specification to transmit vibration, and a resin of a relatively hard material has been selected for that purpose. However, this “hard” property causes the following adverse effects from the user's point of view. Since the coordinate input surface has a function of transmitting the vibration incident by the input pen to the vibration detecting element, glass or a metal such as aluminum has been selected. Therefore, when the user inputs coordinates using the above-described input pen, a touch such as “click” is generated, which causes a decrease in the operational feeling at the time of inputting coordinates. Such an adverse effect has occurred.

As another problem, the input pen of this type of coordinate input device is always worn by the operator's writing (the durability is improved by using a resin having excellent wear resistance). However, it is desired that the pen tip be replaceable, since it will eventually wear out permanently.
No. 02 is known. The problem with this configuration is the loss of sound waves transmitted from the vibration transmitting member to the pen tip. In other words, in the above-described conventional example, the energy of the sound wave passing through is not constant unless the tightening torque of the screw (this is related to the pressure contact force between the vibration transmitting member and the pen tip) is controlled. In other words, if the tightening torque of the screw is not sufficiently obtained, it becomes impossible to transmit vibration to the pen tip, and it becomes impossible to input coordinates. Specifications that control the tightening torque of the screw by the user themselves reduce customer satisfaction. Therefore, even if the user replaces the pen tip by himself, the pressure contact force between the vibration transmitting member and the pen tip is improved. A fixed nib has been proposed. However, in the case of this pen tip, even when the pen tip is exchanged by the user himself, a configuration that always obtains a stable vibration is required, which causes an increase in cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. In an input pen of a coordinate input device, operability can be improved, the occurrence of directivity can be reduced, and replacement can be performed easily. It is an object to provide an input pen that can be used.

[0012]

An input pen according to the present invention for achieving the above object has the following arrangement. That is, an input pen used for input of a coordinate input device that determines an input position based on vibration propagating through the vibration transmission plate,
A vibration generating element that generates vibration, a vibration transmitting member that transmits vibration generated by the vibration generating element, and a first layer that is attached to a distal end of the vibration transmitting member and that is formed of a material having at least viscoelasticity. And a nib member having a layer structure formed on the outside by a second layer formed of a resin material.

Preferably, the first layer is formed from a styrene-based thermoplastic elastomer, and the second layer is formed from polypropylene.

Preferably, the first layer is made of a rubber material such as acrylonitrobutadiene rubber, chloroprene rubber, butyl rubber, or an elastomer such as olefin, urethane, polyester, polyamide, or vinyl chloride. Or a combination thereof.

[0015] Preferably, the second layer is formed of any one of polyacetal, polyimide, polycarbonate, polyamideimide, and ABS, or a combination thereof.

[0016] Preferably, the vibration transmitting member includes:
It has a hemispherical tip, and the first layer of the nib member is:
It has a hemispherical hole bottom, and the radius of the hole bottom is smaller than the radius of the tip.

Preferably, the thickness of the first layer is:
0.5 to 2 mm.

[0018] Preferably, the vibration transmitting member includes:
It has a flat-shaped tip, and the first layer of the nib member includes:
It has a planar bottom, and the radius of the bottom is smaller than the radius of the tip.

[0019] Preferably, the vibration transmitting member comprises:
The pen tip member has a spherical tip, and the first layer of the pen tip member has a spherical hole bottom, and the radius of the hole bottom is smaller than the radius of the tip.

Preferably, the second layer is formed outside the tip of the first layer so as to have a hemispherical shape.

Preferably, the first layer is formed into a hemispherical shape inside the bottom of the hole of the second layer.

Preferably, the pen point member has a 2
Manufactured by color molding.

Preferably, the first layer and the second layer are bonded by an adhesive.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

First, the overall configuration of a coordinate input device using a vibration input pen according to the present invention will be described with reference to FIG.

<Description of Coordinate Input Device (FIG. 2)> FIG. 2 is a diagram showing the configuration of the coordinate input device according to the embodiment of the present invention.

In FIG. 2, reference numeral 1 denotes an arithmetic and control circuit for controlling the entire apparatus and calculating a coordinate position. A vibrator driving circuit 2 vibrates the vibrator 4 incorporated in the vibration input pen 3. The vibration generated by the vibrator 4 is input to the vibration transmitting plate 8 via the vibration transmitting member 5 and the pen tip 12.

The vibration transmission plate 8 is made of a transparent member such as an acrylic or glass plate, and the coordinate input by the vibration input pen 3 is applied to a coordinate input effective area on the vibration transmission plate 8 (the area indicated by a solid line A in FIG. Hereafter, this is performed by touching an effective area. Further, the vibration input member 3 for reflecting the vibration input by the vibration input pen 3 on the end face of the vibration transmission plate 8 and preventing the vibration from returning to the center (attenuating the reflected wave) is provided on the vibration transmission plate 8. Is provided on the outer periphery.

At the periphery of the vibration transmission plate 8, vibration sensors 6a to 6d for converting mechanical vibration of a piezoelectric element or the like into electric signals are fixed. The signals from the vibration sensors 6a to 6d are
After being amplified by an amplifier circuit (not shown), it is sent to a signal waveform detection circuit 9. Then, the signal waveform detection circuit 9 performs signal processing, outputs the processing result to the arithmetic and control circuit 1, and calculates coordinates. The signal waveform detection circuit 9 and the arithmetic control circuit 1
The details of will be described later.

Reference numeral 11 denotes a display such as a liquid crystal display capable of displaying in units of dots, which is arranged behind the vibration transmission plate 8. Then, by driving the display drive circuit 10, dots are displayed at positions traced by the vibration input pen 3, and the dots can be seen through the vibration transmission plate 8 (for example, when made of a transparent member such as glass). It has become.

The vibrator 4 built in the vibration input pen 3 is
It is driven by the vibrator drive circuit 2. The electric drive signal of the vibrator 4 is supplied as a low-level pulse signal from the arithmetic and control circuit 1, amplified by the vibrator drive circuit 2 with a predetermined gain, and applied to the vibrator 4. The electric drive signal is converted into mechanical ultrasonic vibration by the vibrator 4 and transmitted to the vibration transmission plate 8 via the pen tip 12. Further, it goes without saying that the vibrator driving circuit 2 may be built in the vibration input pen 3 or may be mounted on the main body control board.

Here, 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. Further, by setting the vibration frequency of the vibrator 4 at this time to the resonance frequency including the vibration transmitting member 5 and the pen tip 12, efficient vibration conversion becomes possible. Furthermore, the vibration input pen 3 of the present invention is not limited to the above-described plate wave, and for example, when a surface wave propagating through the vibration transmission plate 8 is used as a detection wave, the vibration input pen 3 generates vibration. Frequency
A sufficiently high value for the thickness of the vibration transmission plate 8 (the vibration transmission plate 8
In such a state that the wavelength λ of the wave propagating through the plate becomes sufficiently small with respect to the thickness of the plate). Even in such a case, the structure of the vibration input pen 3 of the present invention can be an effective means.

Next, details of the arithmetic control circuit 1 will be described with reference to FIG.

<Explanation of Operation Control Circuit (FIG. 3)> In the above-described configuration, the operation control circuit 1 operates at predetermined intervals (for example,
At every 5 ms), a signal for driving the vibrator 4 in the vibration input pen 3 is output to the vibrator drive circuit 2 and the internal timer (constituted by a counter) starts counting time. Then, the vibration generated by the vibration input pen 3 arrives with a delay according to the distance to the vibration sensors 6a to 6d.

The vibration waveform detection circuit 9 is provided with each vibration sensor 6a
６6d are detected, and a signal indicating the timing of arrival of vibration at each of the vibration sensors 6aａ6d is generated by a waveform detection process described later. The arithmetic and control circuit 1 inputs this signal to each of the vibration sensors 6a to 6d,
The vibration arrival time from a to 6d is detected. The coordinate position of the vibration input pen 3 is calculated based on the detected vibration arrival time. The arithmetic control circuit 1 drives the display drive circuit 10 based on the calculated coordinate position of the vibration input pen 3 to control the display on the display 11,
Alternatively, coordinates are output to an external device by serial or parallel communication (not shown).

FIG. 3 is a block diagram showing a detailed configuration of the arithmetic and control circuit according to the embodiment of the present invention.

In FIG. 3, 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 for storing operation procedures, a RAM for use in calculations and the like, and a nonvolatile for storing constants and the like. It is composed of a non-volatile memory and the like. Reference numeral 33 denotes a timer (for example, constituted by a counter or the like) for measuring a reference clock (not shown), which is a start for causing the vibrator driving circuit 2 to start driving the vibrator 4 in the vibration input pen 3. When a signal is input, the timing starts.

The vibration arrival timing signals from the vibration sensors 6a to 6d output from the vibration wave detection circuit 9 are supplied to the latch circuits 34a to 34d via the detection signal input port 35.
Is input to Each of the latch circuits 34a to 34d corresponds to each of the vibration sensors 6a to 6d, and when receiving a vibration arrival timing signal from the corresponding vibration sensor, latches the time value of the timer 33 at that time (in this way, the vibration The vibration input by the input pen 3 is a vibration sensor 6
a to 6d can be measured until it is detected). When the determination circuit 36 determines that the vibration sensors 6a to 6d have received the vibration timing signal 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 36, the latch circuits 34a-34
d to each of the vibration sensors 6a to 6d,
The data is read from the corresponding latch circuits 34a to 34d. Next, a predetermined calculation is performed based on the read vibration arrival time, and the coordinate position of the vibration input pen 3 on the vibration transmission plate 8 is calculated. Then, by outputting the calculated coordinate position information to the display drive circuit 10 via the I / O port 37, for example, a dot or the like can be displayed at a corresponding position on the display 11. Alternatively, by outputting the coordinate position information to the interface circuit via the I / O port 37, the coordinate values can be output to the external device.

Next, the process of detecting the vibration transmission time and the detailed configuration of the signal waveform detection circuit 9 will be described with reference to FIGS.

<Description of Vibration Propagation Time Detection (FIGS. 4 and 5)
FIG. 4 is a diagram for explaining a detection waveform input to the vibration waveform detection circuit according to the embodiment of the present invention and a process of measuring a vibration transmission time based on the detection waveform.

Although the case of the vibration sensor 6a is described here, the other vibration sensors 6b, 6c, 6d
Is exactly the same, and the details are omitted.

As described above, 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 input pen 3 to the vibration transmission plate 8 by the drive signal 41 progresses over a time corresponding to the distance to the vibration sensor 6a, and then the vibration sensor 6a
Is detected by The illustrated signal 42 indicates a signal waveform detected by the vibration sensor 6a.

Since the vibration used in this embodiment is a plate wave as described above, the envelope 42 of the detected waveform is used.
1 is different from the speed at which the phase 422 propagates (the group speed Vg). Therefore, the envelope 42 of the detected waveform with respect to the propagation distance in the vibration transmission plate 8
The relationship between 1 and the phase 422 changes during vibration transmission according to the transmission distance. In the present embodiment, the distance between the vibration input pen 3 and the vibration sensor 6a is detected from the group delay time tg based on the group velocity Vg and the phase delay time tp based on the phase velocity Vp.

FIG. 5 is a block diagram showing a detailed configuration of the signal waveform detection circuit according to the embodiment of the present invention.

Hereinafter, the group delay time t will be described with reference to FIG.
g, a process for detecting the phase delay time tp will be described.

The output signal 42 of the vibration sensor 6a is amplified to a predetermined level by the preamplifier circuit 51. Thereafter, the excess frequency component of the detection signal is removed by the band-pass filter 511, and the signal 44 is obtained. Focusing on the envelope of the signal 44, the sound speed at which the waveform propagates is the group velocity Vg. When a point on a specific waveform, for example, a peak of the envelope or an inflection point of the envelope is detected, the sound velocity is related to the group velocity Vg. The delay time tg is obtained. Therefore, the signal is amplified by the preamplifier circuit 51 and
The signal passing through 11 is input to an envelope detection circuit 52 composed of an absolute value circuit, a low-pass filter, and the like, and only the envelope 45 of the detection signal is extracted. Further, a gate signal 46 of a portion exceeding a predetermined threshold level 441 for the envelope 45 is used.
Is generated by a gate signal generation circuit 56 composed of a multivibrator or the like.

In order to detect the group delay time tg relating to the group velocity Vg, the peak or inflection point of the envelope may be detected as described above. Inflection point (signal 4 described later)
3 falling zero crossing point). Therefore, the signal 45 output from the envelope detection circuit 52 is input to the envelope inflection point detection circuit 53 to obtain a twice differentiated waveform signal 43 of the envelope. The twice differentiated waveform signal 43 is compared with the gate signal 46, and is detected as an envelope delay time detection signal having a predetermined waveform by a tg signal detection circuit 54 composed of a multivibrator or the like.
A g signal 49 is generated and input to the arithmetic and control circuit 1.

On the other hand, the phase delay time tp relating to the phase speed Vp will be described. Reference numeral 57 denotes a tp signal detection circuit composed of a zero cross comparator, a multivibrator, and the like for detecting the phase delay time tp. The tp signal detection circuit 57 detects the first rising zero-crossing point of the phase signal 44 while the gate signal 46 is open,
The signal 47 of the phase delay time tp is supplied to the arithmetic and control circuit 1.

The above description has been made with respect to the vibration sensor 6a. However, the same circuit may be provided in the other vibration sensors 6b to 6d, and the sensors may be selected in a time-division manner using analog switches or the like. Needless to say, the circuits may be shared.

Next, the vibration input pen 3 and the vibration sensors 6a to 6a
A method of calculating the distance between 6d will be described with reference to FIG.

<Explanation of calculation of distance between vibration input pen and sensor (FIG. 6)> Group delay time tg obtained as described above
A method of calculating the distance between the vibration input pen 3 and each of the vibration sensors 6a to 6d based on the phase delay time tp and the vibration input pen 3 will be described.

FIG. 6 shows the group delay time t according to the embodiment of the present invention.
g is a diagram illustrating a relationship between a phase delay time tp and a pen-sensor distance L. FIG.

In this embodiment, since a plate wave is used as a detection wave, the group delay time tg cannot be said to have good linearity. Therefore, when the distance L between the vibration input pen 3 and the vibration sensor 6a is obtained as the product of the group delay time tg and the group velocity Vp, as shown in Expression (1), the distance L cannot be obtained with high accuracy.

L = Vg · tg (1) Therefore, in order to determine coordinates with higher accuracy, arithmetic processing is performed by equation (2) based on the phase delay time tp having excellent linearity.

L = Vp · tp + n · λp (2) where λp is the wavelength of the elastic wave, and n is an integer. The first term on the right side of the equation (2) indicates the distance L0 shown in FIG. 6, and the difference between the obtained distance L and the distance L0 is an integral multiple of the wavelength (the width of the staircase on the time axis) as is apparent from the figure. T * is one cycle of the signal waveform 44, and therefore, T * = 1 / frequency, and the width of the staircase is expressed by the distance is the wavelength λp). Accordingly, the distance L between the vibration input pen 3 and the vibration sensor 6a can be accurately obtained by obtaining the integer n. Therefore, the above-mentioned integer n can be obtained by the equation (3) from the above-described equations (1) and (2).

N = int [(Vg · tg−Vp · tp) / λp + ／] (3) In the equation (3), the integer is executed because the plate wave is used as the detection wave, and thus the group delay This is because the linearity of the time tg with respect to the distance cannot be said to be good. A necessary and sufficient condition for obtaining an accurate integer N is represented by Expression (5) derived from Expression (4).
N * = (Vg · tg−Vp · tp) / λp (4) ΔN = n * −n ≦ 0.5 (5) That is, if the generated error amount is within ± 1/2 wavelength ,
Even if the linearity of the group delay time tg is not good, the integer n can be accurately determined. The distance L between the vibration input pen 3 and the vibration sensor 6a can be accurately measured by substituting n obtained as described above into the equation (2).

This equation relates to one of the vibration sensors 6a, but the same equation is used for the other three vibration sensors 6b to 6b.
The distance between 6d and the vibration input pen 3 can be obtained in the same manner.

Next, a method for correcting the circuit delay time will be described with reference to FIGS. <Description of circuit delay time correction> Latch circuits 34a to 34d
The vibration transmission times tg and tp latched by the phase circuit delay time etp and the group circuit delay time etg (FIG. 6)
These times include, in addition to the circuit delay time, the time during which vibration propagates through the pen tip 12 of the vibration input pen 3). The error caused by these is
From the vibration input pen 3 to the vibration transmission plate 8, the vibration sensors 6a to 6
The same amount is always included in the transmission of vibration to d.

Therefore, for example, the distance from the position of the origin O in FIG. 7 to the vibration sensor 6a is Ra (= sqrｑ (X
/ 2) 2+ (Y / 2) 2} (see FIG. 7). Then, an input is made with the vibration input pen 3 at the origin O, and the vibration transmission time actually measured from the origin O to the vibration sensor 6a is tg0.
*, Tp0 *. In addition, the vibration sensor 6a starts from the origin O.
Assuming that tg0 and tp0 are transmission times required for the plate wave to actually propagate on the vibration transmission plate 8, there is a relationship of tg0 * = tg0 + etg (6) tp0 * = tp0 + etp (7)

On the other hand, an actual measurement value tg at an arbitrary input point P
Similarly, * and tp * are as follows: tp * = tp + etg (8) tp * = tp + etp (9) When the differences between the expressions (6) and (8), and the expressions (7) and (9) are obtained, tg * −tg0 * = (tg + etg) − (tg0 + etg) = tg−tg0 (10) tp * − tp0 * = (tp + etp) − (tp0 + etp) = tp−tp0 (11) As a result, the phase circuit delay time etp and the group circuit delay time etg included in each transmission time are removed, and an accurate time difference between the time when the wave propagates through the distance Ra and the time when the wave propagates through the distance da can be obtained. . Therefore,
Using the equations (1), (2), and (3), the distance difference between the distance Ra and the distance da can be obtained. In other words, tg = tg * -tg0 * (12) tp = tp * -tp0 * (13) The distance is calculated using equations (1), (2), and (3), and the vibration sensor 6a From the point O to the origin O
Add. Thereby, the vibration input pen 3 and the vibration sensor 6
The distance to a can be determined accurately. Therefore, if the distance Ra from the vibration sensor 6a to the origin O and the times tg0 * and tp0 * measured at the origin O are stored in advance in a storage medium such as a nonvolatile memory, the vibration input pen 3 and the vibration sensor 6a The distance between them can be determined. The other vibration sensors 6b to 6d can be obtained in the same procedure.

Next, the vibration transmission plate 8 by the vibration input pen 3
The principle of the above coordinate position calculation will be described with reference to FIG.

<Description of Coordinate Position Calculation (FIG. 7)> FIG. 7 is a diagram for explaining the principle of coordinate position detection according to the embodiment of the present invention.

As shown in FIG. 7, when the four vibration sensors 6a to 6d are provided at the four corners on the vibration transmission plate 8, each of the vibration sensors 6a to 6d is moved from the position P of the vibration input pen 3 based on the procedure described above. Linear distance da to the position of the vibration sensors 6a to 6d
dd can be determined. Further, the arithmetic control circuit 1 can obtain the coordinates (x, y) of the position P of the vibration input pen 3 from the three-square theorem based on the linear distances da to dd as in the following equation.

X = (da + db) · (da−db) / 2X (14) y = (da + dc) · (da−dc) / 2Y (15) where X and Y are between the vibration sensors 6a and 6b, respectively. The distance is the distance between the vibration sensors 6c and 6d, and the position coordinates of the vibration input pen 3 can be detected in real time as described above.

In the above calculation, the calculation is performed using the distances to the three vibration sensors. In the present embodiment, since four vibration sensors 6a to 6d are provided, of these vibration sensors, The distance to the three vibration sensors can be used to calculate the coordinates of the vibration input pen 3, and the distance to the remaining vibration sensors can be used to verify the certainty of the coordinates. Also, without using the distance of the vibration sensor in which the distance L between the vibration input pen 3 and the vibration sensor is the largest (the detection signal level is reduced because the distance L is increased and the probability of being affected by noise is increased), The coordinates of the vibration input pen 3 may be calculated using the distances to the remaining three vibration sensors.

In the present embodiment, four vibration sensors are arranged, and the coordinates of the vibration input pen 3 are calculated using the distances to the three vibration sensors. The coordinates of the vibration input pen 3 can be calculated by using the distance to the vibration sensor described above, and it goes without saying that the number of vibration sensors is set according to the product specifications. Next, details of the vibration input pen 3 will be described with reference to FIG.

<Pen Configuration (FIG. 1)><Vibration Input Pen Configuration (FIG. 1)> FIG. 1 is a diagram showing the main structure of a vibration input pen according to an embodiment of the present invention.

In FIG. 1A, a vibrator 4 built in the vibration input pen 3 is driven by the vibrator driving circuit 2 described above. The electric drive signal is converted into mechanical ultrasonic vibration by the vibrator 4 and transmitted to the pen tip 12 via the vibration transmitting member 5. And pen tip 1
When the vibration transmission plate 8 comes into contact with the vibration transmission plate 8,
Vibration is incident on. In the case of the present embodiment, the vibrator 4
A disk-shaped thickness vibration mode in which the polarization direction and the vibration direction are parallel to each other is used, and is attached to the large end surface of the vibration transmission member 5 by an adhesive means. In the case of the present embodiment, the vibration transmission member 5 is made of aluminum (for the purpose of efficiently transmitting vibration, and may be another metal such as stainless steel). The bolts 13 are positioned so that their axes match.
5 fixed. Needless to say, the outer periphery of the holder 13 may be coated with, for example, a rubber insulator to improve the grip feeling, and one of the electrodes of the vibrator 4 is composed of the vibration transmitting member 5, the holder 13, and the electrode. Spring B13
7 is connected to the vibrator drive circuit 2. Also,
The other electrode is connected to the vibrator drive circuit 2 through an electrode spring A136.

The distal end of the vibration transmitting member 5 has a cylindrical portion having a radius R2 and a distal end having a hemispherical portion having a radius R2. Further, as shown in FIG. 1B, the pen tip tip 12 has a first layer made of a member having rubber elasticity, and a second layer made of resin is formed outside the first layer. In the case of the present embodiment, a styrene-based thermoplastic elastomer is used for the first layer, and polypropylene is used for the second layer, and they are integrally manufactured by two-color molding. The pen tip 12 has a hemispherical hole bottom with a tip R1 and has a closed cap-like shape. The radius R2 of the tip of the vibration transmitting member 5 and the radius of the hole bottom of the pen tip 12 are determined. The relationship of the radius R1 is configured to satisfy the following.

R1 <R2 (16) Accordingly, when the vibration transmitting member 5 is press-fitted into the pen tip tip 12, the rubber elastic first layer of the pen tip tip 12 is easily deformed, and the two layers are integrally formed by the elastic force. It is composed of FIGS. 1B and 1C show an enlarged view of the tip and a view showing the mounted state, respectively. At this time, by press-fitting the vibration transmitting member 5, the hole bottom diameter R of the nib tip 12 is adjusted.
1 is elastically deformed as shown in FIGS.
At the same time, the two contact surfaces are in close contact with each other. Therefore, the vibration transmitted through the vibration transmitting member 5 can be transmitted to the pen tip 12 stably. In the present embodiment, the styrene-based thermoplastic elastomer is used for the first layer of the nib tip 12, but a material having a large elastic deformation, for example, NBR (acrylonitrile butadiene rubber), CR
(Chloroprene rubber), IIR (butyl rubber) and other rubber materials, or elastomers such as olefin, urethane, polyester, polyamide and vinyl chloride. These rubbers and other elastomers have lower Young's modulus than other materials,
It is a substance having so-called rubber (like) elasticity (rybber-likeelasticity).

In general, these substances are very disadvantageous because they have a large absorption from the viewpoint of transmitting sound waves, and are usually used as anti-vibration materials. Therefore, it is necessary to pay sufficient attention to the thickness of the first layer of the nib tip 12 employed in the present invention. In the present embodiment, a thickness of about 0.5 to 2 mm is used. .
On the other hand, since these substances have a small Young's modulus and can be easily deformed, they can be easily brought into close contact with each other by press-fitting the nib tip 12 into the vibration transmitting member 5. Enhancing the adhesion is very advantageous in that vibration is transmitted between the two members, and can be said to be a preferable material from this viewpoint. In the vibration input pen 3 according to the present invention, which has been performed in consideration of the thickness of the first layer of the nib tip 12 and the adhesion between them, the vibration incident on the vibration transmission plate 8 is the same as that of the conventional example shown in FIG. As compared with a vibration input pen, it is possible to obtain about 3 to 5 times under the same conditions, and it is possible to transmit and input a stable vibration.

It has been described that the elastomer is the most suitable member in view of the easiness of attachment / detachment and the possibility of unstable removal of vibration transmission even after repeated attachment / detachment. Contact with the plate 8 causes the following adverse effects. Since a member having rubber elasticity has a small Young's modulus, a large deformation is caused by a small stress. Therefore,
If such a member is a pen tip member, the pen tip is deformed in accordance with the pen pressure of the operator, and the area in contact with the vibration transmission plate 8 changes greatly. This not only makes fine coordinate input difficult, but also reduces the resolution of coordinate calculation. In general, this type of member has a large coefficient of friction on the surface, and when inputting coordinates continuously, gives the operator a feeling that the pen tip is caught, and gives a grip force for a long time input. You will feel reduced or accumulated fatigue. Therefore, in order to solve these issues,
The pen tip tip 12 has a two-layer structure, eliminates deformation of the pen tip, and has a small frictional resistance and excellent wear resistance.
It is provided outside the first layer having rubber elasticity.

In the present embodiment, the second layer of the pen tip 12 is made of polypropylene. However, the second layer may be made of a resin which has relatively excellent wear resistance and does not damage the vibration transmitting plate 8. For example, polyacetal, polyimide, polycarbonate, polyamideimide, and ABS can be adopted.

At this time, since the second layer is made of a harder material than the elastomer used for the first layer, deformation of the tip of the pen tip 12 during writing is eliminated, and fine coordinate input is possible. And On the other hand, since the second layer of the nib tip 12 is made of a relatively hard material, an impact may be felt at the time of inputting coordinates (particularly, when inputting coordinates at a high writing speed, the "click-and-click" ), Which makes the operator feel uncomfortable). However, the first layer having the rubber elasticity of the nib tip 12 serves as an absorbing material. Make up.

In the present embodiment, the pen tip 12 having a two-layer structure is manufactured by two-color molding, but both are manufactured by bonding (in this case, if the adhesive is made one layer, the three-layer structure is used). It goes without saying that the pen tip may be used).

Also, when the resin of the second layer is worn by the pen tip wear by writing and the elastomer of the first layer is exposed,
Needless to say, the pen tip can be freely replaced by the user himself, but it is also possible to improve the durability of the pen tip 12 by coating with a resin.

As described above, in the present embodiment, when it is necessary to replace the nib tip 12 due to wear or breakage of the nib tip 12 in actual use, the nib tip 12 may be replaced. The pen tip 12 can be easily attached to the vibration transmitting member 5 by utilizing the rubber elasticity of the first layer. That is, it is possible to provide the vibration input pen 3 that is easy for the user to maintain. In addition to this advantage, in the above-described replacement work, since the adhesion between the pen tip 12 and the vibration transmitting member 5 is naturally created, the vibration transmitted through the vibration transmitting member 5 can be efficiently and stably maintained. It can be transmitted to the nib tip 12. In other words, even if the user replaces the pen tip 12, there is no change in the vibration characteristics of the vibration input pen 3, and stable vibration can be made incident on the vibration transmission plate 8, so that highly accurate coordinate input can be permanently guaranteed. Now you can get some great benefits. In addition, by providing the pen tip 12 with a two-layer structure, it is possible to provide the vibration input pen 3 with good operability.

Further, by implementing such a configuration,
The excellent effects described below have also been obtained.

As described above, the coordinate input device of the present invention measures the group delay time tg relating to the group velocity Vg and the phase delay time tp relating to the phase velocity Vp by using the plate wave as the detection wave. The basic principle is to first derive the distance to each vibration sensor. The formulas (1) to (3) are used as the formulas for calculating the distance, and the formula (5) is shown as a necessary condition for using the formulas.

In view of the above, the vibration generated from the vibration input pen 3 was measured using the measuring device shown in FIG.
This measuring device is for quantifying the behavior when the vibration generated from the vibration input pen 3 spreads in a ripple shape around the vibration input point.

The measuring method using this measuring device will be described in detail. A sensor is arranged at the center of the vibration transmission plate 8 and the vibration input pen 3 is scanned at equal distances around the sensor position in a circumferential shape. . When the vibration input pen 3 makes a round around the sensor, the vibration input pen 3 is driven 360 times at equal intervals.
Then, the signal detected by the sensor is processed using the processing circuit such as the arithmetic and control circuit 1 shown in the above embodiment, and the group delay time tg and the phase delay time tp at each measurement point are detected ( The delay time is measured for each angle of 1 degree). From the delay time tg and the phase delay time tp obtained at each measurement point,
When the integer error ΔN shown in the equation (5) is obtained, 360 integer errors △ N are obtained every time the vibration input pen 3 makes one rotation. Then, the difference between the maximum value and the minimum value of the integer error △ N is determined by the vibration input pen 3 when the vibration input pen 3 makes one rotation.
The measurement was repeatedly performed by mounting samples of a plurality of types of nib tips on the vibration input pen 3.

The material of the pen tip 12 of the vibration input pen 3 to be measured is a conventionally used polyamideimide (hereinafter, referred to as PAI), a liquid crystal polymer (hereinafter, referred to as LCP), and There are three types of NBR adopted in the embodiment. PAI nib and LCP
FIG. 14 shows a conventional pen tip 12a and a pen structure employing a pen tip manufactured by Nissan.

PAI and LCP are selected from the viewpoint that the vibration generated by the vibrator 4 can be transmitted and that the vibration transmission plate 8 as the input surface is not damaged when inputting coordinates. When the directivity of each sample was measured using the above-mentioned measuring instrument (the pen tip was repeatedly attached and detached for each sample, and then repeatedly measured), the directivity was significantly smaller than the conventional pen structure (conventionally, 1/4 to 1/7 of the example).

The above-mentioned integer error ΔN (allowable value 0.5)
Occurs in this directionality that the present invention is the subject,
Since it also occurs due to non-linearity or noise with respect to the distance of the group delay time tg, reducing the directivity as much as possible will improve the reliability of the device. As a result, an excellent effect of ensuring a sufficient margin with respect to the allowable value 0.5 of the integer error ΔN (erroneous detection when the allowable value exceeds 0.5) can be obtained. Needless to say, the fact that a specification having a margin can be obtained makes it easy to manage the manufacturing process, and it is possible to obtain an excellent effect of greatly eliminating steps such as inspection.

Further, the fact that the directivity is improved means that the waveform is not deformed due to the direction of the vibration input pen 3 as described above. It is clear from the above description that an excellent effect of calculating coordinates with high accuracy can be obtained.

As another embodiment of the present invention, for example, the configurations shown in FIGS. 10 and 11 are also possible. First, in FIG. 10, when the tip of the vibration transmitting member 5 has a planar shape, the dimensions of the pen tip 12 and the vibration transmitting member 5 satisfy the following expression.

Φd1 <φd2 (17) When both are press-fitted, the pen tip 12 is mounted by utilizing the rubber elasticity of the first layer. Then, the pen tip 12 is deformed so as to expand with respect to its axis, and the deformation acts on the tip portion of the vibration transmitting member 5 so as to bring both the pen tip 12 and the vibration transmitting member 5 into close contact with each other. become. Therefore, stable transmission of vibrations becomes possible, and the same effect as in the above embodiment can be obtained.

In FIG. 11, the dimensional relationship between the vibration transmitting member 5 and the pen tip 12 satisfies the following expression.

Rl <R2 (18) In this configuration, the nib tip 12 can be fixed by the spherical shape of the tip of the vibration transmitting member 5, so that the relationship between φd1 and φd2 may satisfy the expression (17), or Both may be substantially equal, or the magnitude relationship may be reversed. Even with such a configuration, stable vibration can be input from the vibration transmitting member 5 to the vibration transmitting plate 8 via the pen tip 12 at the tip where the pen tip 12 contacts the vibration transmitting plate 8. The same effect as described in the embodiment can be obtained.

As shown in FIG. 12, it is needless to say that only the portion where the pen tip 12 actually contacts the vibration transmitting plate 8 (the tip end of the pen tip 12) may have a layered structure when the coordinates are input. , FIG. 13 is also possible. In FIG. 13, the first layer having rubber elasticity is present only at the tip end where the vibration transmitting member 5 and the nib tip 12 are in contact, and the other part of the nib tip 12 is constituted by the second layer. Satisfies the expression. When the pen tip 12 is mounted, the second layer is elastically deformed by press-fitting into the vibration transmitting member 5 and is fixed detachably. At this time, the above-mentioned first layer is easily deformed by its rubber elasticity, and the contact surface between the pen tip 12 and the vibration transmitting member 5 is brought into close contact with that portion. Therefore, the same effect as described in the above embodiment can be obtained.

As described above, 2 according to the present embodiment.
The vibration input pen 3 having the pen tip 12 having a layered structure
Since no directivity is generated, the above-described necessary condition for measurement of the measuring instrument (an integer error ΔN <0.5) can be guaranteed with a margin. That is, not only is the erroneous detection of coordinates eliminated, but also the coordinate calculation accuracy of the coordinate input device can be increased.

Further, the pen tip 12 can be easily replaced even when the pen tip 12 is actually used, and even if the operation is performed by the user, the vibration characteristics of the vibration input pen 3 can be stably maintained. An excellent effect can be obtained in which the input coordinates can be kept permanently.

Further, the durability of the pen point tip 12 is improved, the operability during writing is improved, and the vibration input pen 3 which is easy to use can be constructed. .

The present invention can be applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), but can be applied to a single device (for example, a copier, a facsimile machine). Etc.).

[0096]

As described above, according to the present invention,
In the input pen of the coordinate input device, it is possible to provide an input pen that can improve operability, reduce occurrence of directivity, and can be easily replaced.

[0097]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a main structure of a vibration input pen according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating a configuration of a coordinate input device according to an embodiment of the present invention.

FIG. 3 is a block diagram illustrating a detailed configuration of an arithmetic control circuit according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining a detection waveform input to a vibration waveform detection circuit according to the embodiment of the present invention and a process of measuring a vibration transmission time based on the detection waveform.

FIG. 5 is a block diagram illustrating a detailed configuration of a signal waveform detection circuit according to the embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a group delay time tg, a phase delay time tp, and a pen-sensor distance L according to the embodiment of the present invention.

FIG. 7 is a diagram for explaining the principle of coordinate position detection according to the embodiment of the present invention.

FIG. 8 is a supplementary diagram for explaining a problem.

FIG. 9 is a diagram showing a schematic configuration of a measuring instrument for measuring directivity according to the embodiment of the present invention.

FIG. 10 is a view showing a shape of a pen tip according to another embodiment of the present invention.

FIG. 11 is a view showing the shape of a pen tip according to another embodiment of the present invention.

FIG. 12 is a view showing a shape of a pen tip according to another embodiment of the present invention.

FIG. 13 is a view showing a shape of a pen tip according to another embodiment of the present invention.

FIG. 14 is a diagram showing a structure of a vibration input pen in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operation control circuit 2 Vibrator drive circuit 3 Vibration input pen 4 Vibrator 5 Vibration transmission member 6a-6d Vibration sensor 7 Vibration-proof material 8 Vibration transmission plate 9 Signal waveform detection circuit 12 Pen tip

Continued on the front page (72) Inventor Atsushi Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Hajime Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (12)

[Claims] 1. An input pen used for input of a coordinate input device for determining an input position based on vibration propagating through a vibration transmission plate, wherein the vibration generating element generates vibration, and the vibration generated by the vibration generating element is provided. A vibration transmission member, which is mounted on the distal end of the vibration transmission member, and is formed of a first layer formed of a material having at least viscoelasticity, and a second layer formed on the outside of the first layer formed of a resin material. An input pen comprising: a pen point member having a layer structure. 2. The input pen according to claim 1, wherein the first layer is formed of a styrene-based thermoplastic elastomer, and the second layer is formed of polypropylene. 3. The first layer is made of a rubber material such as acrylonitrobutadiene rubber, chloroprene rubber, butyl rubber, or an elastomer such as olefin, urethane, polyester, polyamide, or vinyl chloride. The input pen according to claim 1, wherein the input pen is formed from a combination. 4. The input pen according to claim 1, wherein the second layer is formed of any one of polyacetal, polyimide, polycarbonate, polyamideimide, and ABS or a combination thereof. 5. The vibration transmitting member has a hemispherical tip, the first layer of the pen point member has a hemispherical hole bottom, and the radius of the hole bottom is the radius of the tip. An input pen characterized by being smaller than a radius. 6. The input pen according to claim 1, wherein the thickness of the first layer is 0.5 to 2 mm. 7. The vibration transmitting member has a planar tip portion, the first layer of the pen tip member has a planar hole bottom, and the radius of the hole bottom is equal to the radius of the tip portion. The input pen according to claim 1, wherein the input pen is smaller than the radius. 8. The vibration transmitting member has a spherical tip, the first layer of the pen point member has a spherical hole bottom, and the radius of the hole bottom is the radius of the tip. The input pen according to claim 1, wherein the input pen is smaller than the radius. 9. The input pen according to claim 1, wherein the second layer is formed so as to have a hemispherical shape outside a tip portion of the first layer. 10. The input pen according to claim 1, wherein the first layer is formed into a hemispherical shape inside the hole bottom of the second layer. 11. The input pen according to claim 1, wherein the pen tip member is manufactured by two-color molding. 12. The input pen according to claim 1, wherein the first layer and the second layer are adhered by an adhesive.