JPH1139084A - Molding for pen tip of input pen and coordinate input device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce occurrence of the directivity of an input pen used for inputting coordinates of a coordinate input device by injection-molding a composition containing at least a liquid crystal resin on a mold member for molding the outer form of a pen tip so as to mold the molding of the pen tip. SOLUTION: The molding of the pen tip 12 of the input pen for a coordinate input device where vibration is inputted to a vibration transmission board 5, transmitted vibration is detected and an instructed coordinate is detected is provided. The molding is molded by injection-molding a composition containing a liquid crystal resin and graphite on the mold member for molding the outer form of the pen tip 12. The liquid crystal resin is a liquid crystal polymer. For molding the pen tip 12 by molding liquid polymer, graphite is mixed as filler for improving fluidity and mechanical intensity and the pen tip 12 is molded. The liquid crystal polymer, into which graphite is mixed, is superior in fluidity compared to polyamide imide and it can obtain a result whose average value of directivity is satisfactory.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molded article and coordinates of a pen tip of an input pen for a coordinate input device for inputting vibration to a vibration transmission plate, detecting vibration propagating the vibration, and detecting a designated coordinate. It relates to an input device.

[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 described in this description is made of polyamideimide which is a resin, and (1) has excellent 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. That is, the characteristics were satisfied.

[0004]

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 contacted with the vibration transmitting plate and the input pen is rotated about the axis of the input pen, a phenomenon occurs in which 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 occurs.
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. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has a pen tip molded article and a coordinate input device capable of reducing the occurrence of directivity of an input pen used for inputting coordinates of a coordinate input device. The purpose is to provide.

[0008]

To achieve the above-mentioned object, a molded product of a pen tip of an input pen according to the present invention has the following arrangement. That is, a molded product of a pen tip of an input pen for a coordinate input device for inputting vibration to a vibration transmission plate, detecting vibration propagating the vibration, and detecting a designated coordinate, wherein the molded product is the pen A composition containing at least a liquid crystalline resin is injected into a mold member for molding the above outer shape, and molded.

[0009] Preferably, the liquid crystalline resin is a liquid crystalline polymer. Also, preferably, the composition further includes graphite. In order to achieve the above object, a pen tip molded product of the input pen according to the present invention has the following configuration. That is, a molded product of a pen tip of an input pen for a coordinate input device for inputting vibration to a vibration transmission plate, detecting vibration propagating the vibration, and detecting a designated coordinate, wherein the molded product is the pen In the mold member for molding the outer shape,
It is characterized by being molded by injecting a composition containing a liquid crystal resin and graphite.

A coordinate input device according to the present invention for achieving the above object has the following configuration. That is, an input pen having a pen tip molded from a composition containing at least a liquid crystalline resin, which is a coordinate input device that detects a vibration that propagates through a vibration transmission plate and detects a designated coordinate. And generating means for generating vibration.

A coordinate input device according to the present invention for achieving the above object has the following configuration. That is, a coordinate input device that detects a vibration that propagates through a vibration transmission plate and detects a designated coordinate, wherein an input pen having a pen tip molded from a composition containing a liquid crystal resin and graphite, and an input pen inside the input pen And generating means for generating vibration.

[0012]

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 main structure of the vibration pen used in the coordinate input device of the present invention will be described with reference to FIG. <Pen Configuration (FIG. 1)> FIG. 1 is a diagram showing a main structure of a vibration pen according to an embodiment of the present invention.

In FIG. 1, a vibrator 4 built in a vibrating pen 3 is driven by a vibrator driving circuit 2 described later. The electric drive signal is converted into mechanical ultrasonic vibration by the vibrator 4. Then, the vibration is transmitted to the pen tip 12 via the vibration transmission member 5, and the pen tip 12 comes into contact with a vibration transmission plate 8 (see FIG. 2), which will be described later, so that vibration is incident on the vibration transmission plate 8.

The vibrator 4 has a disk shape. In this embodiment, a thickness vibration mode in which the polarization direction and the vibration direction are parallel to each other is used, and the vibrator 4 is attached to the large end face of the vibration transmission member 5 by bonding. In the present embodiment, the vibration transmission member 5 is
It is made of aluminum (this is for the purpose of transmitting vibration efficiently and may be other metal such as stainless steel), and is positioned by the conductive holder 13 so that its axis is aligned. And fixed by bolts 135. It is needless to say that the outer periphery of the holder 13 may be coated with, for example, a rubber insulator to improve the grip feeling.

One electrode of the vibrator 4 is connected to the vibrator drive circuit 2 via the vibration transmitting member 5, the holder 13, and the electrode spring B137. The other electrode is connected to the vibrator drive circuit 2 via an electrode spring A136. Note that the vibrator drive circuit 2 may be stored in the housing of the vibrating pen 3 or an arithmetic control circuit 1 described later.
(See FIG. 2).

The pen tip 12 is positioned so that its axis coincides with the small end face of the vibration transmitting member 5. And
The pen point 12 is fixed to the holder 13 by screwing so that a pressing force is generated at a contact portion between the pen point 12 and the small end face of the vibration transmitting member 5. In this manner, by interposing the vibration transmitting member 5 between the vibrator 4 that is the vibration source and the pen tip 12, the pen tip 12 can be easily replaced. In addition, the user is able to replace the worn pen tip 12 by himself / herself when the pen tip 12 is worn.

The specifications required for the pen tip 12 of the vibrating pen 3 are as follows. First, the vibration generated by the vibrator 4 can be efficiently incident on the vibration transmission plate 8. Second, the vibration transmission plate 8 must not be damaged when entering. Under the first condition, a metal material such as aluminum or stainless steel is generally treated as an optimum material with a small energy loss as the material, but there is a problem that the vibration transmission plate 8 is damaged when inputting coordinates. Occurs. On the other hand, under the second condition, it can be said that resin is a more preferable material than metal.

In consideration of these conditions, in the present embodiment, the specifications of the vibration transmitting member 5 and the pen tip 12 for causing the vibration of the vibrator 4 to be incident on the vibration transmitting plate 8 are as follows.
First, aluminum is used as the material of the vibration transmitting member 5. Therefore, the loss of vibration energy is small,
Even if the axial length becomes relatively large, the vibration from the vibrator 4 can be sufficiently transmitted. Further, since aluminum is conductive, it also has a member for conducting with the electrodes of the vibrator 4.

The resin nib 12 provided at the tip of the vibration transmitting member 5 is intended to damage the vibration transmitting plate 8 or to improve the wear resistance of the pen nib 12 itself. As a pen tip, a pen tip using a polyamideimide is known, and although its vibration propagation characteristics are greatly reduced as compared with metals, it exhibits outstanding vibration transmission characteristics among resins. And, by interposing the vibration transmitting member 5,
The distance over which the vibration must be transmitted (the distance from the position where the pen tip 12 contacts the vibration transmitting member 5 to the part where the pen tip 12 contacts the transmission diaphragm 8) is short, and the shape as a writing instrument is maintained. Can be. This improves the reduction in vibration transmission efficiency.

Next, a coordinate input device for realizing coordinate input using the vibrating pen 3 and a coordinate calculation method thereof will be described in order. First, regarding the configuration of the coordinate input device,
This will be described with reference to FIG. <Description of Coordinate Input Device (FIG. 2)> FIG. 2 is a diagram showing a configuration of a coordinate input device according to an embodiment of the present invention.

In FIG. 2, reference numeral 1 denotes an arithmetic control circuit for controlling the entire apparatus and calculating a coordinate position. A vibrator driving circuit 2 vibrates the vibrator 4 built in the vibrating pen 3. The vibration generated by the vibrator 4 is input to the vibration transmission plate 8 via the vibration transmission 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 coordinate input by the vibration pen 3 is performed in a coordinate input effective area on the vibration transmission plate 8 (a region indicated by a solid line A in the drawing: hereinafter, effective). (Called an area). Further, the vibration input material reflected by the end face of the vibration transmission plate 8 to prevent the vibration input from the vibration pen 3 from returning to the center portion (attenuating the reflected wave) is provided on the vibration transmission plate 8. It is provided on the outer periphery.

Vibration sensors 6a to 6d for converting mechanical vibration of a piezoelectric element or the like into an electric signal are fixed to the periphery of the vibration transmission plate 8. 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
Will be described later in detail.

Reference numeral 11 denotes a display, such as a liquid crystal display, capable of displaying in units of dots, and is disposed behind the vibration transmission plate 8. Then, by driving the display drive circuit 10, dots are displayed at the positions traced by the vibration 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). ing.

The vibrator 4 incorporated in the vibrating pen 3 is driven by the vibrator driving 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.

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. In addition, 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 can be performed. As described above, the vibration transmission plate 8
The elastic wave transmitted to the vibration transmitting plate 8 is a plate wave, and has an advantage that the surface of the vibration transmitting plate 8 is less susceptible to a scratch, an obstacle or the like as compared with a surface wave or the like.

Next, details of the arithmetic control circuit will be described with reference to FIG. <Description of Arithmetic Control Circuit> In the configuration described above, the arithmetic control circuit 1 outputs a signal for driving the vibrator 4 in the vibrating pen 3 to the vibrator drive circuit 2 at a predetermined cycle (for example, every 5 ms). The internal timer (constituted by a counter) starts counting time. And the vibration pen 3
The generated vibration arrives with a delay according to the distance to the vibration sensors 6a to 6d.

The vibration waveform detection circuit 9 includes the vibration sensors 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 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 pen 3 to control the display on the display 11 or to output the coordinate to an external device by serial or parallel communication. (Not shown).

FIG. 3 shows an arithmetic control circuit 1 according to an embodiment of the present invention.
FIG. 3 is a block diagram showing a detailed configuration. In FIG.
Reference numeral 31 denotes a microcomputer that controls the arithmetic control circuit 1 and the entire coordinate input device, and includes an internal counter, a ROM storing operation procedures, a RAM used for calculations, a non-volatile memory storing constants, and the like. I have.
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 signal for causing the vibrator driving circuit 2 to start driving the vibrator 4 in the vibrating pen 3. To start the timing. As a result, the start of timing and the detection of vibration by the sensor are synchronized, and the delay time until vibration is detected by the vibration sensors 6a to 6d can be measured.

The vibration arrival timing signals output from the vibration wave detection circuit 9 from the vibration sensors 6a to 6d 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. When the determination circuit 36 determines that the vibration arrival timing signals have been received by the respective vibration sensors 6a to 6d 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 pen 3 on the vibration transmission plate 8 is calculated. By outputting the calculated coordinate position to the display drive circuit 10 via the I / O port 37,
For example, information such as dots can be displayed at corresponding positions on the display 11. Alternatively, by outputting the coordinate position to the interface circuit via the I / O port 37, the coordinate position 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 Transmission Time Detection (FIGS. 4 and 5)> FIG. 4 is a diagram for explaining a detection waveform input to the signal waveform detection circuit according to the embodiment of the present invention and a vibration transmission time measurement process based thereon. It is.

Here, the case of the vibration sensor 6a will be described, but the other vibration sensors 6b, 6c, 6d
Is exactly the same, and the details are omitted. It has already been described that the measurement of the vibration transmission time to the vibration sensor 6a starts 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 drive signal 41 travels for a time corresponding to the distance to the vibration sensor 6a, and is detected by the vibration sensor 6a. A signal 42 in the figure 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.
The speed of propagation (group speed Vg) of 1 and the speed of propagation of phase 422 (phase speed Vp) are different. Therefore, the envelope 42 of the detected waveform with respect to the transmission 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 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, a process for detecting the group delay time Tg and the phase delay time Tp will be described with reference to FIG. The output signal 42 of the vibration sensor 6a is amplified to a predetermined level by the preamplifier circuit 51. Thereafter, an extra 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 transmitted by the waveform 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 velocity is related to the group velocity Vg. Delay time t
g is obtained. Therefore, it is amplified by the preamplifier circuit 51,
The signal that has passed through the band-pass filter 511 is input to an envelope detection circuit 52 including an absolute value circuit, a low-pass filter, and the like.
Only those are retrieved. Further, a gate signal 46 of a portion exceeding a preset threshold level 441 for the envelope 45 is generated by a gate signal generating 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 for 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, a method of calculating the distance between the vibration pen 3 and the vibration sensors 6a to 6d will be described.
This will be described with reference to FIG.

<Description of Calculation of Distance Between Vibrating Pen and Sensor (FIG. 6)> Based on the group delay time tg and the phase delay time tp obtained as described above, the vibrating pen 3 and each of the vibration sensors 6a to 6d. A method for calculating the distances to the respective points 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, the distance L between the vibration 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 the equation (1), the distance L cannot be obtained with high accuracy. L = Vg · tg (1) Then, in order to determine higher-definition coordinates, an arithmetic process is performed based on the expression (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). Therefore, by determining the integer n, the pen-sensor distance L can be accurately determined. Therefore, the above (1)
The above-mentioned integer n can be obtained by the equation (3) from the equation and the equation (2).

N = int [(Vg · tg−Vp · tp) / λp + ／] (3) In the expression (3), since the plate wave is used as the detection wave, This is because the linearity of the delay 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, the error amount to be generated is within ± 1/2 wavelength. if there is,
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 pen 3 and the vibration sensor 6a can be accurately measured by substituting n obtained as described above into the expression (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 vibrating 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 time latched by the phase circuit delay time etp and the group circuit delay time etg (see 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 pen 3). 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, the distance from the position of the origin O in FIG. 7 to the vibration sensor 6a is Ra (= sqrｑX /
2) ² + (Y / 2) ² }, see FIG. 7). Then, an input is made with the vibration pen 3 at the origin O, and the actually measured vibration transmission time from the origin O to the vibration sensor 6a is represented by tg0 *, tg0.
Let p0 *. Further, assuming that transmission times required for the plate wave to actually propagate on the vibration transmission plate 8 from the origin O to the vibration sensor 6a are tg0 and tp0, tg0 * = tg0 + etg (6) tp0 * = tp0 + etp (7) ) There is a relationship.

On the other hand, an actual measurement value tg at an arbitrary input point P
Similarly, * and tp * are as follows: tg * = tg + etg (8) tp * = tp + etp (9) When the differences between the expressions (6) and (8), and the expressions (7) and (9) are calculated, 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, the distance difference between the distance Ra and the distance da can be obtained by using the equations (1), (2), and (3). That is, tg = tg * −tg0 * (12) tp = tp * −tp0 * (13) As a result, the distance is calculated using the expressions (1), (2), and (3), and the value is vibrated. Distance Ra from sensor 6a to 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 tgo * and tpo * measured at the origin O are stored in advance in a storage medium such as a non-volatile memory, the distance between the vibration pen 3 and the vibration sensor 6a can be increased. Can be determined. The other vibration sensors 6b to 6d can be obtained in the same procedure.

Next, the principle of calculating the coordinate position on the vibration transmission plate 8 by the vibration pen 3 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 calculation according to the embodiment of the present invention. As shown in FIG. 7, when four vibration sensors 6a to 6d are provided at four corners on the vibration transmission plate 8, each of the vibration sensors 6a is moved from the position P of the vibration pen 3 based on the procedure described above.
The linear distances da to dd to the positions 6 to 6d can be obtained. Further, the arithmetic control circuit 1 calculates the linear distance da to
Based on dd, the coordinates (x, y) of the position P of the vibrating pen 3 can be obtained from the three-square theorem as follows.

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

In the above calculation, the calculation is performed using the distances to the three vibration sensors. However, in the present embodiment, since four vibration sensors 6a to 6d are installed, of these vibration sensors, The distance to the three vibration sensors can be used to calculate the coordinates of the vibration 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 having the largest pen-sensor distance L (the distance L increases, the detection signal level decreases and the probability of being affected by noise increases) without using the remaining three. The coordinates of the vibration pen 3 may be calculated using the distance to the vibration sensor.

In this embodiment, four vibration sensors 6a
６6d are arranged, and the coordinates of the vibration pen 3 are calculated using the distances to the three vibration sensors. However, geometrically, if the distances to two or more vibration sensors are used, It is needless to say that the coordinates can be calculated and the number of vibration sensors can be set according to the product specifications.

<Detailed description of a mold for forming the pen tip of a vibrating pen capable of reducing the directivity of the vibrating pen> As described above, the coordinate input device of the present embodiment uses a plate wave as a detection wave. Then, the group delay time T related to the group velocity Vg
g, the basic principle is to first derive the distance between the vibration source and each vibration sensor by measuring the phase delay time Tp related to the phase velocity Vp. Equations (1) to (3) were used as the distance calculation equations, and equation (5) was shown as a necessary condition when using them.

In view of the above points, the vibration generated from the vibration pen 3 was measured using the measuring device shown in FIG. This measuring device is for quantifying the behavior of the vibration generated from the vibration pen 3 when the vibration spreads like a ripple 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 transmitting plate 8 and the vibrating pen 3 is configured to scan the vibrating pen 3 at equal distances around the position of the sensor. ing.
When the vibrating pen 3 goes around the sensor 360 times,
The vibration pen 3 is driven at regular intervals. Then, the signal detected by the sensor is transferred to the arithmetic and control circuit 1 shown in the above embodiment.
And the like, and detects the group delay time tg and the phase delay time tp at each measurement point (measure the delay time for each angle of 1 degree). From the group delay time tg and the phase delay time tp obtained at the measurement point, when the integerization error ΔN shown in Expression (5) is obtained, every time the vibrating pen 3 makes one rotation, 360 integerization errors ΔN are obtained. Can be The difference between the maximum value and the minimum value of the integer error ΔN is determined by the vibration pen 3 as 1
It was defined as a numerical value indicating the directivity of the vibrating pen 3 when it circulated, and the measurement by the measuring device was repeated a plurality of times. At that time,
It is shown in Table 1.

Table 1 shows the materials used for the pen tip, and the average and minimum values of the directivity of the pen tip formed from the material. The machining in Table 1 indicates that a round bar of polyamideimide was extruded.

[0052]

[Table 1] As shown in Table 1, the average value of directivity is very large (= 0.43) in the molded product of polyamideimide, and is close to the allowable value of directivity of 0.5. The above-mentioned integer error ΔN (allowable value 0.5) is generated by this directivity,
The directivity is desired to be as small as possible because it also occurs due to non-linearity or noise with respect to the distance of the group delay time tg. Therefore, if a molded product of polyamideimide is used, the tolerance of the integer error ΔN can easily be exceeded.

Examination of the results in Table 1 shows that, when the pen tip is formed by machining polyamide imide, the pen tip is formed by machining a round bar of polyamide imide formed by extrusion. You. And the round bar formed by extrusion in this way is considered to have mechanical characteristics of axial symmetry. That is,
It is considered that a relatively good directivity was obtained because a pen tip in which the axis of the round bar coincides with the axis of the pen tip obtained by machining can be formed. However, as compared with molding, there is a disadvantage that many processing steps are required and the cost is high.

When the nib is molded by molding the polyamideimide, since the polyamideimide is a material having very high viscosity and poor fluidity, it is necessary to mold the polyamideimide symmetrically with respect to the axis of the nib. Very difficult.
Improvements (particularly, gate position and gate type) that are symmetrical with respect to the axis of the pen tip have been proposed, but at present good results have not been obtained. For this reason, in order to obtain a pen tip having no directivity, it is necessary to inspect and sort the pen tip with the above-mentioned measuring instrument after molding.

As described above, when a pen tip is formed using polyamideimide, there is a disadvantage that the cost is high or a pen tip which can reduce the directivity cannot be formed. In view of the above, the present invention solves the above-mentioned drawbacks by using a liquid crystalline polymer. When a liquid crystal polymer is used to mold a pen tip by molding, the pen tip is molded by mixing graphite as a filler for the purpose of improving the above-mentioned fluidity and mechanical strength. The liquid crystalline polymer mixed with graphite has excellent fluidity as compared with polyamideimide. Therefore, as can be seen from Table 1, the average value of the directivity is also a good result (this is equivalent to a machined product of polyamide imide and has sufficient specifications). The reason why graphite is used as the filler is to prevent damage to the vibration transmission plate 8. Although it is possible to use a glass filler (a commonly used technique) as the filler, it has been confirmed that the glass is damaged particularly when the vibration transmission plate 8 is glass. The use of graphite as a filler has a special effect that damage to the vibration transmission plate 8 can be prevented.

The pen tip made of a liquid crystalline polymer mixed with graphite has a moderate durability and a vibration transmission plate 8 having a moderate durability compared to a pen tip made of polyamideimide.
"Writing taste" felt by the user when writing with the pen tip touching the pen can be improved. Thus, a vibration input pen with good operability can be configured. Also,
Regarding the vibration transmission efficiency, a sufficient S / N ratio can be obtained by the processing in the signal waveform detection circuit 9 described above, and the vibration transmission efficiency has a sufficient performance for the operation of inputting coordinates.

Further, since graphite is mixed in the pen tip, a vibration input pen using this pen tip can leave a locus of drawing on paper, for example. Therefore, a coordinate input device as described below can also be configured. In FIG. 2, the vibration transmission plate 8 is a member capable of transmitting vibration (for example, a metal (opaque) such as aluminum or, of course, a transparent glass). When inputting coordinate data (trajectory information), the user places a recording medium such as paper on the vibration transmitting plate 8 and inputs coordinates on the paper using the above-described vibration input pen using the pen tip. . In this case, the trajectory drawn by the user is recorded on the paper, and the vibration generated by the vibration input pen passes through the paper and is input to the vibration transmission plate 8. The input vibration is processed according to the signal processing procedure of the above-described embodiment, and the coordinate position is calculated.

With such a configuration, the trajectory recorded on the paper can be directly digitized as trajectory data, and a circuit such as the display drive circuit 10 that realizes a display function is not required. Therefore, a very inexpensive input device with good operability can be realized. As described above, according to the present embodiment, by using a vibration input pen using a pen tip made of a liquid crystalline polymer mixed with graphite as a vibration input pen used for inputting coordinates of the coordinate input device, 1 ) Vibration can be transmitted to the vibration transmission plate 8 satisfactorily. 2) Effects such as excellent wear resistance can be realized. 3) The directivity of the pen tip is reduced to improve coordinate calculation accuracy. Accuracy can be maintained.

Such excellent effects as described above can be realized.
Further, the pen tip can be molded at low cost because it enables mold molding for mass production at the time of mass production and does not require inspection such as sorting. In particular, the pen tip will eventually lose its operability due to its wear.
The pen tip needs to be replaced. Therefore, it is needless to say that the production of the pen tip at low cost contributes to the reduction of the running cost, that is, the reduction of the burden on the user.

[0060]

As described above, according to the present invention,
It is possible to provide a molded product of a pen point of the input pen and a coordinate input device that can reduce the occurrence of directivity of the input pen used for inputting coordinates of the coordinate input device.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main structure of a vibration 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 1 according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining a detection waveform input to a signal waveform detection circuit according to an 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 calculating a coordinate position 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.

[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 10 Display drive circuit 11 Display 12 Pen tip 13 Holder 135 Bolt 136 Electrode spring A 137 Electrode spring B

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hajime Sato 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Atsushi Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside the corporation

Claims (10)

[Claims] 1. A molded product of a pen tip of an input pen for a coordinate input device for inputting vibration to a vibration transmission plate, detecting vibration propagating the vibration, and detecting designated coordinates, wherein the molded product is A molded product of a pen tip of an input pen, wherein the composition is formed by injecting a composition containing at least a liquid crystalline resin into a mold member for molding the outer shape of the pen tip. 2. The molded product of the pen tip of the input pen according to claim 1, wherein the liquid crystalline resin is a liquid crystalline polymer. 3. The pen point of the input pen according to claim 1, wherein the composition further comprises graphite. 4. A molded product of a pen tip of an input pen for a coordinate input device for inputting vibration to a vibration transmission plate, detecting vibration propagating the vibration, and detecting designated coordinates, wherein the molded product is A molded product of a pen tip of an input pen, wherein a composition containing a liquid crystalline resin and graphite is injected into a mold member for molding the outer shape of the pen tip. 5. The molded product of the pen tip of the input pen according to claim 4, wherein the liquid crystalline resin is a liquid crystalline polymer. 6. A coordinate input device for detecting a pointing coordinate by detecting vibration propagating through a vibration transmitting plate, comprising: an input pen having a pen tip molded from a composition containing at least a liquid crystalline resin; A coordinate input device comprising: a pen for generating vibration; 7. The pen point molded product of the input pen according to claim 6, wherein the liquid crystalline resin is a liquid crystalline polymer. 8. The pen point of the input pen according to claim 6, wherein the composition further comprises graphite. 9. A coordinate input device for detecting a pointing coordinate by detecting vibration propagating through a vibration transmitting plate, comprising: an input pen having a pen tip molded from a composition containing a liquid crystal resin and graphite; A coordinate input device comprising: an input pen; and a generating unit that generates vibration. 10. The molded product of the nib of the input pen according to claim 9, wherein the liquid crystalline resin is a liquid crystalline polymer.