JPH10320106A - Coordinate input device and oscillation transmission plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coordinate input device allowing another object to be fixed on its coordinate input surface by a means such as adhesives while holding measuring accuracy. SOLUTION: The coordinate input device has an oscillation transmission plate 8 for propagating inputted oscillation up to the fitted position of a detection sensor and an elastic member 25 arranged like a laminated layer in a state acoustically discontinous to the plate 8. The plate 8 is provided with a piezoelectric sensor 6 for detecting propagated oscillation. An upper case to be a part of a casing for the input device is stuck and fixed to the member 25 through an adhesive layer 24. The oscillation of an oscillation pen is inputted to the plate 8 through the member 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input device, and more particularly to a coordinate input device for measuring a transmission time of a vibration given to a coordinate input surface and detecting input coordinates, and a vibration transmission plate used for the coordinate input device. Things.

[0002]

2. Description of the Related Art Conventionally, as a coordinate input device utilizing vibration transmission, elastic wave vibration input from a vibration pen is detected by a plurality of sensors provided on the vibration transmission plate, and is input from the vibration pen to the vibration transmission plate. There is a coordinate input device that measures the transmission time of elastic wave vibration and detects the coordinates of a vibration input point by a vibration pen based on the transmission time.

As this type of apparatus, for example, a method of calculating a distance between two points using an ultrasonic wave is known, and a specific application example thereof is described in Japanese Patent Publication No. 5-60615. Such coordinate input devices are known. This device generates vibration and inputs vibration from a coordinate input pen as a coordinate input pointing device to a vibration transmission plate serving as a coordinate input surface, and a plurality of sensors attached to the vibration transmission plate (for example, sensors in FIG. 7). In 6a to 6d), the vibration is detected, and the time required for the vibration to reach each sensor is measured to calculate the coordinate position where the vibration is input.

By using such a coordinate input device, it is possible to input handwritten characters and figures by outputting position coordinates designated by a coordinate input pen to an information processing device such as a personal computer.

[0005]

However, in the coordinate input device as in the above-mentioned prior art, the time required for the sound wave to reach is measured using the physical phenomenon that the sound speed of the sound wave propagating through a certain medium is constant. Since the basic principle is to derive the distance between the vibration source and the vibration detection element, for example, if the sound speed changes as the vibration propagates, the detection accuracy (distance measurement accuracy, Or, the accuracy of coordinate calculation) is greatly reduced.

A specific example of the case where such a phenomenon occurs will be described with reference to a Lamb Wave as used in Japanese Patent Publication No. Hei 5-60615. It is known that it depends on the material or the thickness t of the plate and also the frequency of vibration. That is, when the thickness of the plate through which the vibration propagates changes (for example, when the cross section of the plate has a trapezoidal shape), the wave propagation speed changes according to the amount of change. Since this reduces the measurement accuracy of the device, it is common for this type of device to be configured to have a constant plate thickness.

However, even if the thickness of the plate is constant,
It has been confirmed that such a phenomenon occurs even when an adhesive such as cellophane tape is adhered to the vibration transmission plate, which leads to a significant decrease in accuracy. In other words, in this type of coordinate input device, it is preferable to adopt a configuration in which another object is fixed to the propagating body for transmitting vibration by means such as bonding, since this leads to a decrease in detection accuracy, and is thus preferable. Not that. However, when this kind of coordinate input device is actually made into a product form, it is often required to make a form as shown in FIG. That is,
To form an effective area where coordinates can be entered,
Alternatively, the case 10 may be used as a blinding means for the vibration detecting means, or as a positioning means for positioning a document (paper), or as a protecting means for protecting the apparatus.
A configuration to add 1 is required as a product specification.

[0008] At this time, the problem is that in this case 10
1 and the gap between the vibration transmission plate 100. If there is a gap, the original enters the space when the original is abutted, and the original cannot be positioned, or the original may be broken when the original is extracted. This is a very difficult product for the user. Also, if you spill coffee or other liquid during work (or if it gets wet in the rain), you will not be able to wipe off the liquid in that space, which will not only lead to equipment failure, but also cause water droplets. The existence of such a problem causes a problem that the above-mentioned sound speed changes (or a significant absorption occurs at that portion, and the sound wave is not transmitted), and the reliability of the device is greatly reduced.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and a coordinate input device and a vibration transmission device capable of fixing another object to a coordinate input surface by means such as an adhesive while maintaining measurement accuracy. The purpose is to provide a board.

[0010]

A coordinate input apparatus according to the present invention for achieving the above object has the following arrangement. That is, a coordinate input device for detecting a vibration transmitted through a vibration transmission plate and detecting a designated coordinate, wherein the vibration transmission plate is configured to have a first elasticity for transmitting the input vibration to a mounting position of a detection sensor. A member, a second elastic member arranged in a stacked state in an acoustically discontinuous state with the first elastic member, and a second elastic member mounted on the first elastic member and propagating through the first elastic member. Detecting means for detecting the vibration which occurs, and fixing means for fixing the portion of the second elastic member and the portion of the housing of the coordinate input device.

According to the vibration transmission plate of the present invention for achieving the above object, the first elastic member for transmitting the input vibration to the mounting position of the detection sensor, and the first elastic member are acoustically connected. A second elastic member arranged in a stacked state in a discontinuous state.

[0012]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

<Overall Configuration of Coordinate Input Device (FIG. 2)> FIG.
FIG. 1 is a block diagram showing an overall configuration of a coordinate input device according to the present embodiment. Hereinafter, the overall configuration of the coordinate input device according to the present embodiment will be described with reference to FIG. In the figure, 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 can be input to the vibration transmission plate 8 via the pen tip 5.

The vibration transmission plate 8 is made of a transparent member such as an acrylic or glass plate, and the coordinate input by the vibration pen 3 is applied to a coordinate input effective area (hereinafter referred to as an effective area,
This is performed by touching the area indicated by the symbol A indicated by a solid line in the figure. In addition, the vibration input material which reflects the vibration input by the vibration pen 3 on the end face of the vibration transmission plate 8 and prevents the vibration from returning to the center (attenuates the reflected wave) is provided on the outer periphery of the vibration transmission plate 8. It is provided in.

As shown in the figure, vibration sensors 6a to 6d for converting mechanical vibrations into electric signals, such as piezoelectric elements, are fixed around the vibration transmission plate 8. Vibration sensors 6a-6
After the signal from d is amplified by an amplifier circuit (not shown), it is sent to a signal waveform detection circuit 9 where the signal is processed, and the result is output to the arithmetic and control circuit 1 to calculate coordinates. The details of the signal waveform detection circuit 9 and the arithmetic control circuit 1 will be separately described later.

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

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

Here, the vibration frequency of the vibrator 4 is selected to a value capable of generating a plate wave on the vibration transmission plate 8 such as glass. At this time, by setting the frequency of the vibrator 4 to the resonance frequency including the pen tip 5, efficient vibration conversion can be performed.

The elastic wave transmitted to the vibration transmission plate 8 as described above is a plate wave, and has an advantage that the surface of the vibration transmission plate is less susceptible to scratches, obstacles, and the like than surface waves.

<Description of Arithmetic Control Circuit> In the above-described configuration, the arithmetic control circuit 1 operates every predetermined period (for example, every 5 ms).
In addition, a signal for driving the vibrator driving circuit 2 and the vibrator 4 in the vibrating pen 3 is output, and time measurement is started by a timer (configured with a counter) described later. And
The vibration generated by the vibration pen 3 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 to 6a.
6d, and a signal indicating the timing of arrival of vibration at each vibration sensor is generated by a waveform detection process described later. The arithmetic and control circuit 1 inputs this signal for each sensor and outputs the signal to each vibration sensor. Detecting the vibration arrival time from 6a to 6d and calculating the coordinate position of the vibration pen. The arithmetic control circuit 1 drives the display drive circuit 10 based on the calculated position information of the vibration pen 3 to control the display on the display 11 or to control the display
The coordinates are output to an external device by parallel communication (not shown).

FIG. 3 is a block diagram showing a schematic configuration of the arithmetic control circuit 1 of the present embodiment. The components of the arithmetic control circuit 1 and the outline of the operation will be described below.

In the figure, reference numeral 31 denotes a microcomputer which 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 and the like, and a nonvolatile memory storing constants and the like. It is composed of a memory and the like. Reference numeral 33 denotes a timer (constituting, for example, a counter) for measuring a reference clock (not shown), which inputs a start signal for starting driving of the vibrator 4 in the vibrating pen 3 to the vibrator driving circuit 2. Then, the timing is started. As a result, the start of timing and the detection of vibration by the sensor are synchronized, and the sensor (6a
6d), the delay time until the vibration is detected can be measured.

The other constituent circuits will be described in order. The vibration arrival timing signals from the vibration sensors 6a to 6d output from the vibration waveform detection circuit 9 are supplied to the latch circuits 34a to 34d via the detection signal input port 35.
Is input to Each of the latch circuits 34a to 34d corresponds to each of the vibration sensors 6a to 6d, and when receiving a timing signal from the corresponding sensor, latches the time value of the timer 33 at that time. When the determination circuit 36 determines that all the detection signals have been received,
A signal to that effect is output to the microcomputer 31.

When the microcomputer 31 receives the signal from the determination circuit 36, the latch circuits 34a-34
From the latch circuit, the vibration transmission time from d to each vibration sensor is read, and a predetermined calculation is performed.
The coordinate position of the upper vibration pen 3 is calculated. And I / O
By outputting the calculated coordinate position information to the display drive circuit 10 via the port 37, for example, dots or the like can be displayed at corresponding positions on the display 11. Alternatively, by outputting the coordinate position information to the interface circuit via the I / 0 port 37, the coordinate value can be output to the external device.

<Description of Vibration Propagation Time Detection (FIGS. 4 and 5)
FIG. 4 shows a detection waveform input to the vibration waveform detection circuit 9;
It is a figure for explaining measurement processing of vibration transmission time based on it. The case of the vibration sensor 6a will be described below, but the same applies to the other vibration sensors 6b, 6c, and 6d.

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 drive signal 41 causes the vibration pen 3 to move from the vibration transmission plate 8
Is transmitted by the vibration sensor 6a for a time corresponding to the distance to the vibration sensor 6a, and is detected by the vibration sensor 6a. A signal indicated by reference numeral 42 indicates a signal waveform detected by the vibration sensor 6a.

Since the vibration used in this embodiment is a plate wave as described above, the envelope 42 of the detected waveform is used.
1 is different from the speed at which the phase 422 propagates (the group speed Vg). Therefore, the envelope 42 of the detected waveform with respect to the propagation distance in the vibration transmission plate 8
The relationship between 1 and the phase 422 changes during vibration transmission according to the transmission distance. In the present embodiment, the distance between the vibration 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 of the vibration detection circuit 9. Hereinafter, the means for detecting the group delay time Tg and the phase delay time Tp will be described with reference to FIG.

After the output signal 42 of the vibration sensor 6a is amplified to a predetermined level by the preamplifier circuit 51, an extra frequency component of the detection signal is removed by the band-pass filter 511 to obtain a signal 44. Paying attention to the envelope of this signal 44, the sound velocity at which the waveform propagates is the group velocity Vg
When a point on a specific waveform, for example, a peak of the envelope or an inflection point of the envelope is detected, the group velocity V
The delay time tg related to g is obtained. Therefore, the signal amplified by the preamplifier circuit 51 and passed through the band-pass filter 511 is input to, for example, an envelope detection circuit 52 composed of an absolute value circuit, a low-pass filter, and the like. Is taken out.
Further, a gate signal 46 of a portion exceeding a preset threshold level 441 for this envelope 45 is
A gate signal generation circuit 56 composed of a multivibrator or the like is formed.

In order to detect the group delay time tg related 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). Then, 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 43 of the envelope. The differential waveform signal 43 is formed into a tg signal 49 composed of a multivibrator or the like based on the result of comparison with the gate signal 46, and is input to the arithmetic and control circuit 1.

On the other hand, the phase delay time t relating to the phase velocity Vp
To explain p, 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, and the first rising edge of the phase signal 44 while the gate signal 46 is open. The zero cross point is detected, and the signal 47 of the phase delay time tp is detected.
Is supplied to the arithmetic and control circuit 1.

Although the above description has been made with respect to one sensor, the same circuit may be provided in other vibration sensors, and the sensor may be selected in a time-division manner using an analog switch or the like, and It goes without saying that sharing may be performed.

<Description of Calculation of Distance Between Vibrating Pen and Sensor (FIG. 6)> A method of calculating the distance between the vibrating pen and each sensor from the group delay time tg and the phase delay time tp obtained in this way. Will be described. FIG. 6 shows the group delay time tg and the phase delay time tp obtained by the present embodiment.
FIG. 3 is a diagram schematically illustrating a relationship between the distance L and a pen-sensor distance L. In this embodiment, since the plate wave is used as the 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 given by the group delay time tg and the group velocity V as shown in equation (1).
When the distance L is obtained as a product of p, the distance L cannot be obtained with high accuracy.

L = Vg · tg (1)

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

L = Vp · tp + n · λp (2)

Here, λp is the wavelength of the elastic wave, and n is an integer. In other words, the first term on the right side of the equation (2) indicates the distance L0 in FIG. 6, and the difference between the distance L to be obtained and the distance L0 is an integral multiple of the wavelength (on the time axis) as is clear from the figure. The step width T * is one cycle of the signal waveform 44, and therefore T * = 1.
The width of the staircase is represented by the wavelength λp) in terms of / frequency and distance. Therefore, by obtaining the integer n, the pen-sensor distance L can be accurately obtained. Thus, from the above equations (1) and (2), the above integer n is
It can be obtained by equation (3).

N = [(Vg · tg−Vp · tp) / λp + 1 / N] (3)

Here, N is a real number other than "0", and an appropriate value is used. For example, if N = 2, even if the linearity of the group delay time tg is not good, the generation error is ± 1/2.
If it is within the wavelength, n can be accurately determined.
The distance between the vibration pen 3 and the vibration sensor 6a can be accurately measured by substituting n obtained as described above into the equation (2).

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

<Explanation of Circuit Delay Time Correction> The vibration transmission time latched by the latch circuits 34a to 34d includes a phase circuit delay time etp and a group circuit delay time et.
g (see FIG. 6, and these times include, in addition to the circuit delay time, the time during which vibration propagates through the pen tip 5 of the vibrating pen 3). The errors caused by the above always include the same amount when the vibration is transmitted from the vibration pen 3 to the vibration transmission plate 8 and the vibration sensors 6a to 6d.

Therefore, for example, from the position of the origin O in FIG.
For example, the distance to the vibration sensor 6a is Ra (= sqr
{(X / 2) ^ 2 + (Y / 2) ^ 2}, see FIG. 7), input is performed with the vibration pen 3 at the origin O, and the actually measured vibration transmission time from the origin O to the sensor 6a is measured. To tg0
*, Tp0 *, and assuming that the propagation time required for the wave to actually propagate from the origin O to the sensor on the propagation body is tg0, tp0, tg0 * = tg0 + etg (4) tp0 * = tp0 + etp (5) Have 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 (6) tp * = tp + etp (7) When the differences between the expressions (4) and (6), and the expressions (5) and (7) are calculated, tg * -tg0 * = (tg + etg)-(tg0 + etg) = tg-tg0. 8) tp * -tp0 * = (tp + etp)-(tp0 + etp) = tp-tp0 (9), and the phase circuit delay time etp included in each transmission time
And the group circuit delay time etg is removed, and the difference in the true transmission delay time according to the distance from the position of the origin O to the input point P with the position of the sensor 6a as a point can be obtained. The distance difference can be obtained by using the equations (2) and (3). That is, tg = tg * −tg0 * (10) tp = tp * −tp0 * (11) The distance is calculated using the expressions (1), (2) and (3), and the vibration sensor is used as the value. Distance Ra from 6a to origin O
Is added, the distance between the vibration input pen 3 and the vibration sensor 6a can be accurately obtained. Therefore, if the distance from the vibration sensor 6a to the origin O is stored in a nonvolatile memory or the like in advance, the distance between the vibration pen 3 and the vibration sensor 6a can be determined. The same applies to the other sensors 6b to 6d.

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

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

X = (da + db) · (da−db) / 2X (12) y = (da + dc) · (da−dc) / 2Y (13)

Here, X and Y are the vibration sensors 6 respectively.
The distance between the vibration pens 3a and 6b and the distance between the vibration sensors 6c and 6d can be detected in real time as described above.

In the above calculation, the calculation is performed using the distance information to three sensors. In the present embodiment, four sensors are installed, and the output is performed using the distance information of the remaining one sensor. Used to verify the certainty of coordinates. Of course, the remaining three sensors do not use, for example, distance information of the sensor having the largest pen-sensor distance L (the detection signal level is reduced because the distance L is increased, and the probability of being affected by noise is increased). The coordinates may be calculated. Further, in the present embodiment, four sensors are arranged and coordinates are calculated by three sensors. However, geometrically, coordinates can be calculated by two or more sensors, and the sensors are calculated according to product specifications. Needless to say, the number is set.

<Structure of Coordinate Input Unit> As described above, the coordinate input device according to the present embodiment detects the arrival delay times Tg and Tp of the sound wave, and the physical phenomenon that the sound speed (Vg and Vp) is constant. Is used to calculate the coordinates with high accuracy. However, when this device is actually commercialized,
A housing (protective case) for protecting this device is required. As a specific embodiment, a configuration when this apparatus is used as an editor for a copying machine will be described with reference to FIG.

FIG. 1 is a partial sectional view showing a state in which the above-described coordinate input device is incorporated in an exterior. An elastic member 25 is arranged on the vibration transmission plate 8 so as to overlap. In the case of the present embodiment, the vibration transmission plate 8 and the elastic member 25
Is fixed by the adhesive layer 27. This configuration has the following effects in addition to the purpose of assembling or improving mass productivity. As described above, the water droplets or the adhesive layer on the vibration transmission plate 8 change the speed of sound, and reduce the coordinate calculation accuracy of the apparatus. Therefore, if water droplets, oil, etc. enter between the vibration transmitting plate 8 and the elastic member 25, the reliability is reduced. Therefore, by sealing both of them at the ends with the second adhesive layer, this problem is eliminated. I have. Furthermore, since both spaces are sealed, if dry air is enclosed, an excellent effect of preventing dew condensation due to temperature change during use can be obtained (however, the amount of air is extremely low due to the configuration). It has been confirmed by experiments that the amount is small and that there is no problem in sealing at room temperature.) As described above, the vibration transmission plate 8 is made of glass, aluminum (other metals may be used).
Any material can be used as long as it can transmit sound waves. The elastic member 25 may be a resin film such as a pet or a material such as a metal. In short, any material that can transmit the vibration generated by the vibration pen 3 to the vibration transmission plate 8 through the elastic member 25, or a material having a sufficiently small thickness for that purpose may be used.

Since both the elastic member 25 and the vibration transmitting plate 8 are merely arranged one on top of the other, an air layer exists microscopically between them, and acoustically discontinuous characteristics. That is, if, for example, a water drop or the like exists between the two, an action of matching the acoustic impedance of the two occurs, and in such a case, the sound speed of the sound wave propagating through the vibration transmission plate 8 is reduced at that portion. It causes a great change. The air layer here means that the vibration transmitting plate 8 and the elastic member 25 may be arranged in contact with each other, and in other words, it indicates that it is sufficient that the liquid is not mixed.

Reference numeral 23 denotes a frame for fixing the coordinate input device. In the case of this embodiment, the frame 23 is joined to the vibration isolator 7 by, for example, a double-sided tape. The frame 23 has a sensor 6 (the above-described sensors 6a to 6a) installed on the vibration transmission plate 8.
An electrode 21 for extracting an electric signal from 6d) is attached. Further, an upper case 26 is fixed to the frame, and the upper case opening is configured to form an effective area in which coordinates can be input. With such a configuration, members such as the sensor 6 can be blindfolded and the user can recognize an area where coordinates can be input.

As shown, the upper case 26 and the elastic member 25 are fixed by the adhesive layer 24 near the coordinate input effective area. The adhesive layer 24 may be a double-sided tape or the like, but it is assumed that the upper case 26 bends when the opening is large (equivalent to a large coordinate input effective area). That is, when the upper case 26 is molded (resin upper case), the upper case bends due to thermal stress or the like. Therefore, in order to absorb this distortion, it is preferable that the adhesive layer has the following configuration.

That is, a foam such as malt plain or an elastic member such as silicon rubber is used as the adhesive layer 24, an adhesive layer is provided on the opposing surface, and the upper case 26 and the elastic member 25 are joined. With this configuration, it is possible to absorb the distortion of the upper case 26 due to the deformation of the adhesive layer 24.

Next, the vibration transmission plate 8, the elastic member 25,
The operation and effect of the configuration employing the adhesive layer 24 will be described.
For simplicity, first consider the case where the elastic member 25 is not provided in the configuration of FIG.

In general, devices containing this type of electronic circuit are reluctant to moisture. For example, if a liquid such as coffee is spilled on the coordinate input surface, it is necessary to wipe the liquid immediately. However, when the upper case is provided as described above, what happens to the liquid that has entered between the upper case 26 and the vibration transmission plate 8 is handled. I can't do it. That is, when the elastic member 25 is not provided, the liquid that cannot be wiped exists directly on the vibration transmission plate 8. If the existing position is closer to the effective area than the vibration sensor 6, the liquid cannot be wiped. In addition to a change in the sound velocity of the sound wave, the accuracy of the coordinate calculation is reduced, and the coordinate calculation cannot be performed due to the absorption of the sound wave by the liquid. In order to recover this, there is no other means than leaving it to dry naturally.

Therefore, it is conceivable to provide a waterproof effect by providing the adhesive layer 24. However, if the adhesive layer 24 is directly attached to the vibration transmission plate 8, the sound speed of the sound wave propagating at that portion changes, and the coordinate input device is also used. Will decrease the accuracy.

According to the present embodiment, the configuration in which the elastic member 25 is overlapped on the vibration transmitting plate 8 is adopted, and the elastic member 25 and the upper case 26 are connected by the adhesive layer 24, so that the vibration transmitting plate 8 is propagated. It is possible to protect the apparatus from liquids and the like while configuring so as to prevent the influence on the sound wave.

Further, by providing the elastic member 25,
Since other members (the adhesive layer 24 and the upper case 26 of the present embodiment) can be fixed on the coordinate input surface, a coordinate input device using ultrasonic waves can be used also as an editor for a copying machine. Now you can.

As a general use of the editor for a copying machine, a document is overlaid on a coordinate input surface, and coordinates are input by operations such as tracing the document. The area designated by the operation is stored, and is used for the purpose of copying only the portion or changing the color of the portion, for example, copying red when copying the original. In general, this apparatus has a specification in which a document is abutted against the end surface of the above-described upper case in order to make the coordinate system of the coordinate input device coincide with the coordinates of the document. At this time, if the adhesive layer 24 is not provided, the document may enter under the upper case, making the device difficult to use. In addition, the document may be broken when removing the entered document. In order to solve such a problem, the adhesive layer 24 is indispensable, and the elastic member 25 is indispensable in the sense that the coordinate calculation accuracy of the coordinate input device is guaranteed.

As described above, according to the coordinate input device of the present embodiment, the speed of sound of the sound wave propagating through the vibration transmitting plate 8 is kept constant, so that the coordinate calculation accuracy and reliability of the device are improved. For this reason, it is possible to protect the device by providing a waterproof structure and to calculate coordinates with high accuracy. Therefore, an excellent effect that the reliability of the device can be maintained permanently can be obtained. Further, since a member for positioning the document can be provided on the coordinate input surface, an excellent effect that can be applied to a coordinate input device using an ultrasonic wave, which can be applied to this type of device, can be obtained.

Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), an apparatus (for example, a copier, a facsimile) comprising one device Device).

[0064]

As described above, according to the present invention, it is possible to fix another object on the coordinate input surface of the coordinate input device by means of an adhesive or the like while maintaining the measurement accuracy. Becomes

[0065]

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a state where the coordinate input device described above is incorporated in an exterior.

FIG. 2 is a block diagram illustrating an overall configuration of the coordinate input device according to the embodiment;

FIG. 3 is a block diagram illustrating a schematic configuration of an arithmetic control circuit 1 according to the embodiment.

FIG. 4 shows a detection waveform input to a vibration waveform detection circuit 9;
It is a figure for explaining measurement processing of vibration transmission time based on it.

FIG. 5 is a block diagram of a vibration detection circuit 9;

FIG. 6 is a diagram schematically illustrating a relationship between a group delay time tg, a phase delay time tp, and a pen-sensor distance L obtained by the present embodiment.

FIG. 7 is a diagram illustrating calculation of coordinates of a vibration input position on a vibration transmission plate.

FIG. 8 is a diagram showing the appearance of a general coordinate input device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Operation control circuit 2 Vibrator drive circuit 3 Vibration input pen 4 Vibrator 5 Pen tip 6a-6d Vibration sensor 7 Vibration-proof material 8 Vibration transmission board 9 Signal waveform detection circuit 25 Elastic member 24 Adhesive layer 26 Case

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

Claims (8)

[Claims] 1. A coordinate input device that detects vibrations propagating through a vibration transmission plate and detects a designated coordinate, wherein the vibration input plate is configured to propagate the input vibration to a mounting position of a detection sensor. A first elastic member, a second elastic member arranged in a stacked manner with the first elastic member and an air layer interposed therebetween, and mounted on the first elastic member to propagate through the first elastic member. A coordinate input device comprising: a detection unit that detects vibration; and a fixing unit that fixes a portion of the second elastic member and a portion of a housing of the coordinate input device. 2. The apparatus according to claim 1, further comprising a vibration pen for generating vibration, wherein the vibration generated by the vibration pen at the position designated by the vibration pen is transmitted to the first elastic member via the second elastic member. The coordinate input device according to claim 1, wherein the coordinate input device is transmitted. 3. The coordinate input device according to claim 1, wherein the fixing unit arranges an adhesive layer near a periphery of a coordinate input effective area set on the vibration transmission plate. 4. The pressure-sensitive adhesive layer includes an elastic body having at least one pair of opposing surfaces, and a structure in which an adhesive layer is provided on each of the pair of opposing surfaces of the elastic body. The coordinate input device according to claim 1, wherein 5. The coordinate input device according to claim 1, wherein the second elastic member is a resin sheet. 6. The coordinate according to claim 1, wherein the first elastic member and the second elastic member are fixed at a peripheral end, and have a structure for sealing an air layer therebetween. Input device. 7. A first elastic member that propagates input vibration to a position where a detection sensor is mounted, and a second elastic member that is arranged in a stacked manner via the first elastic member and an air layer. A vibration transmission plate, comprising: 8. The method according to claim 1, wherein the first elastic member and the second elastic member are fixed outside a range in which the input vibration is to be propagated, and seal an air layer therebetween. Item 8. The vibration transmission plate according to Item 7.