JPH1124825A - Forming mold and method for input pen point - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a forming mold which forms an input pen point and can reduce the occurrence of directivity of an input pen by preparing a gate which is formed to a mold member at a position symmetrical to the center axis of the pen point and injects the resin. SOLUTION: A mold member is prepared to form an external shape of a pen point together with a gate which is formed to a mold member at a position symmetrical to the center axis of the pen point. That is, a pin gate 100 is prepared at the tip part of the pen point having an axis symmetrical shape to be coincident with an axis AA of the pen point and can inject the resin at the tip part. Thus, the resin that forms the pen point is supplied through the tip part of a 1st mold consisting of molds A1 and B1 and flows in the 1st mold to be symmetrical to the axis AA of the pen point. In other words, the pen point that is formed by the 1st mold has its mechanical characteristic symmetrical to the axis AA and is improved against the directivity of a vibrating input pen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for a pen tip of an input pen of a coordinate input device and a method for molding the pen tip.

[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-mentioned problems, and has a molding die for molding a pen tip of an input pen capable of reducing the occurrence of directivity of the input pen in an input pen of a coordinate input device. An object of the present invention is to provide a method for forming a pen tip.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, a molding die of an input pen according to the present invention has the following arrangement. That is, a molding die for molding a pen tip of an input pen used for inputting coordinates of a coordinate input device,
A mold member for molding the outer shape of the pen tip, and at least one gate for injecting a resin formed on the mold member and arranged at a position symmetrical with respect to a central axis of the pen tip. Prepare.

Preferably, the gate is arranged on an axis of the mold member corresponding to a central axis of the pen tip. Preferably, a plurality of the gates are arranged at positions symmetrical with respect to an axis of the mold member corresponding to a central axis of the pen tip. Also, preferably, the resin is a polyamideimide.

Preferably, the resin is a liquid crystalline polymer. In order to achieve the above object, a pen tip forming method of an input pen according to the present invention has the following configuration.
That is, a method for molding a pen tip of an input pen used for inputting coordinates of a coordinate input device, wherein the pen tip is formed on a mold member for molding an outer shape of the pen tip, and is symmetric with respect to a center axis of the pen tip. An injection step of injecting a resin into at least one gate disposed at a certain position; and a processing step of processing a molded body molded into the mold member into the pen tip.

Preferably, when the gate is arranged on the axis of the mold member corresponding to the central axis of the pen tip, the processing step includes the step of forming the molded body corresponding to the tip of the pen tip. Gate the tip. Preferably, when a plurality of the gates are arranged at positions symmetrical with respect to an axis of the mold member corresponding to a central axis of the pen tip, the processing step is performed on the mold member. Cut the gate of the molded body.

[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 sound 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.

The material of the pen point 12 of the vibration pen 3 to be measured is a polyamide imide (hereinafter referred to as PAI) and a liquid crystalline polymer (hereinafter referred to as LCP) which have been conventionally used.
) Was used. This is the vibrator 4
The above two types of resins were selected from the viewpoint that the vibrations generated in step (1) can be transmitted and that the condition that the vibration transmitting plate 8 as the input surface is not damaged at the time of coordinate input is satisfied. The processing conditions of the pen tip 12 are shown below.

1) The shape of the pen tip 12 is manufactured by machining from a round bar obtained by extrusion molding. 2) Mold molding with a mold having the same shape as the pen tip 12) Molding with a first mold described below 4) FIG. 10 shows the structure of a first mold composed of a mold A1 and a mold B1 in the second mold described below. As shown in FIG. 10, one pin gate 100 is provided at the tip of the pen tip having an axially symmetric shape so as to coincide with the axis AA of the pen tip 12, so that resin can be injected from the tip. ing. Therefore, the resin for molding the pen tip 12 is supplied from the tip of the first mold, and flows through the first mold so as to be symmetrical with respect to the axis AA of the pen tip 12. That is, the mechanical characteristics of the pen tip 12 formed by the first die are axially symmetric, and a good result can be obtained for the directivity of the vibrating pen 3. The pen tip 12 formed by the first die is subjected to gate processing (mechanical processing for rounding the tip of the pen tip).

In order to make the pen point 12 symmetrical with respect to the axis AA, the gate is connected to the pen point 12 and the vibration transmitting member 5.
It is needless to say that the gate 100 may be provided at the tip portion in consideration of the easiness of the post-process. On the other hand, type A2, type B2, type C
1. A second mold structure consisting of mold C2 is shown in FIG.
As shown in FIG. 11, two side gates 200 are provided so as to coincide with the axis AA of the pen tip 12. The position of the side gate 200 is provided at a position symmetrical (opposing position) with respect to the axis AA of the pen tip 12, and is different in this point from a conventional product formed by one gate which is not at an axially symmetric position. Further, with this configuration, the screw portion for fixing the pen tip 12 can be formed at the same time, and the post-processing for removing the gate portion can be performed only by cutting with the nipper. It can be manufactured at a lower cost. In the second type, two gates 200 are provided, but three gates (arranged every 120 degrees in the circumferential direction) or four gates (arranged every 90 degrees in the circumferential direction). It is also possible to provide gates at a plurality of locations. Thereby, the occurrence of directivity can be further reduced.

The directivity measurement using the above-described measuring device was performed on the pen point formed by the first and second molds described above together with the conventional pen point. Table 1 shows the results of these measurements. Table 1 shows an average value and a minimum value of the directivity at the time of performing measurement for each pen tip ten times. The machining in the table means that a round bar of polyamideimide was extruded.

[0055]

[Table 1] Since the above-mentioned integer error ΔN (allowable value 0.5) occurs not only with the directivity shown in Table 1 but also due to non-linearity or noise with respect to the distance of the group delay time tg, the directivity should be as small as possible. It is desirable to make it smaller. Then, as shown in Table 1, with a conventional pen tip, the PAI
Is the lowest value of the directivity (= 0.4
3) is large, and if it is used as it is, the allowable value of the integer error ΔN is easily exceeded, and the necessary condition for coordinate calculation cannot be satisfied. In the pen tip using LCP, the minimum value of the directivity is improved to some extent,
Further improvement is desired to improve reliability.

On the other hand, in the pen tip using the first type, the minimum value of the directivity is greatly improved. Thereby, an excellent effect that the improvement in reliability becomes remarkable can be obtained. This means that a sufficient margin is compensated for the allowable value 0.5 of the integer error ΔN, and conversely, an excellent effect that measures against noise and other factors can be simplified can be obtained. Obtainable.

Although the minimum value of the directivity of the pen tip using the second type is improved as compared with the conventional one, the first type is different from the first type in that the mechanical characteristics of the pen point are axisymmetric. It is considered to be inferior to the pen tip using. In fact, the minimum value of directivity has not been improved as much as the pen tip using the first type. However, the feature of the pen tip using the second mold is that the post-process (such as gate processing) can be simplified as compared with the pen tip using the first mold, which is advantageous in terms of cost. I have.

As described above, it can be said that the pen tip using the first type of the present invention or the pen point using the second type of the present invention can have much higher reliability than the conventional pen tip.
Whether the pen tip is molded using the first mold or the second mold is a design matter selected by the user in terms of performance and cost. As a material for determining the selection, for the allowable value 0.5 of the integer error ΔN, a factor (for example, a liquid crystal display as an output device, CRT, PD
The value differs depending on which method is used, such as P, and the factors to be used are determined, and then the mold used for molding the pen tip may be selected.

Although a specific mold for molding two nibs has been described above, a gate is provided so that the flow of resin is symmetrical with respect to the axis of the nib when molding the nib. It is needless to say that the adoption of such a type improves the directivity of the pen tip. For example, a method of molding a pen tip by pouring a resin from the circumferential direction symmetrically with respect to the axis of the pen tip using a film gate (a completely axially symmetric structure, and molding the pen tip using a first mold) It is needless to say that a method of increasing the number of gates and the like can be adopted in the method of molding the pen tip using the second mold. As described above, in consideration of the required performance (directivity) and cost, the user may employ a mold for molding the pen tip.

As described above, according to the present embodiment, since the directivity of the pen tip is not generated, the necessary condition (integralization error ΔN <0.5) for the measurement of the measuring device is provided with a margin. Can be guaranteed. That is, not only the erroneous detection of coordinates is eliminated, but also an excellent effect of maintaining the coordinate calculation accuracy of the coordinate input device with high accuracy can be obtained.

Further, since the specification having a margin can be obtained, management in manufacturing becomes easy, and an excellent effect that steps such as inspection can be greatly reduced can be obtained. Furthermore, since the directivity of the pen tip is improved, the deformation of the waveform of the vibration input by the vibration pen 3 is eliminated, and stable vibration can be input regardless of the direction of the pen tip. As a result, an excellent effect of being able to provide a coordinate input device capable of calculating coordinates with high accuracy regardless of the direction of the pen tip can be obtained.

[0062]

As described above, according to the present invention,
In the input pen of the coordinate input device, it is possible to provide a molding die for molding the pen tip of the input pen, which can reduce the occurrence of directivity of the input pen, and a molding method of the pen tip.

[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.

FIG. 10 is a diagram showing a structure of a first type according to the embodiment of the present invention;

FIG. 11 is a diagram illustrating a second type structure 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 100 Pin gate 200 Side gate

 ──────────────────────────────────────────────────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 (8)

[Claims] 1. A molding die for molding a pen tip of an input pen used for inputting coordinates of a coordinate input device, comprising: a molding member for molding an outer shape of the pen tip; and a molding member formed on the molding member. And a at least one gate for injecting a resin disposed at a position symmetrical with respect to a center axis of the pen tip. 2. The molding die according to claim 1, wherein the gate is disposed on an axis of the mold member corresponding to a central axis of the pen tip. 3. The molding die according to claim 1, wherein a plurality of the gates are arranged at positions symmetrical with respect to an axis of the die member corresponding to a central axis of the pen point. 4. The mold according to claim 1, wherein the resin is a polyamideimide. 5. The mold according to claim 1, wherein the resin is a liquid crystalline polymer. 6. A method for forming a pen tip of an input pen used for inputting coordinates of a coordinate input device, comprising: a forming member for forming an outer shape of the pen tip;
An injection step of injecting a resin into at least one gate disposed at a position symmetrical with respect to a center axis of the pen tip, and a processing step of processing a molded body molded into the mold member into the pen tip. A molding method, comprising: 7. When the gate is disposed on an axis of the mold member corresponding to a central axis of the pen tip, the processing step includes a step of setting a tip of the molded body corresponding to a tip of the pen tip to a gate. The forming method according to claim 6, wherein the forming is performed. 8. When the plurality of gates are arranged at positions symmetrical with respect to the axis of the mold member corresponding to the central axis of the pen tip, the processing step is performed on the mold member. The molding method according to claim 6, wherein a gate portion of the molded body is cut.