JPH06242876A - Coordinate inputting method and device - Google Patents

Abstract

PURPOSE:To automatically judge whether or not a coordinate input operation has been executed by detecting the position of a vibrating input pen from a distance calculated according to the detection signals of plural sensors, back- calculating the distance of the plural sensors from the detected position, and comparing it with the previous calculated distance. CONSTITUTION:When a start signal 38 is outputted from a microcomputer 31, the driving of a vibrating pen 3 and clocking is started by a vibrator driving circuit 2. When the detection signal of vibration made incident from each sensor 6a-6d on a vibration transmitting plate 8 is outputted before a prescribed time is clocked by a timer 33, the position indicated by the vibrating pen 3 and the distance to each sensor are back-calculated, and a coordinate value is calculated. Next, the distance to each sensor is back-calculated on the basis of the coordinate value. The back-calculated distance is compared with the previously calculated distance, and when the values are equal, the value is outputted to an outside circuit as the established value. On the other hand, when the compared values are different, the vibrating pen 3 is left behind on the vibration transmitting plate 8, and a power source cutting operation or the like is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate input method and device, and more particularly to a method for detecting elastic wave vibration input from a vibrating pen by a plurality of sensors provided on the vibrating plate so that the vibrating pen can be used to transfer the vibration. The present invention relates to a coordinate input method and apparatus for detecting the coordinates of a vibration input point by a vibrating pen based on the input transmission time of elastic wave vibration.

[0002]

2. Description of the Related Art Conventionally, various types of devices such as an electromagnetic type, an electrostatic coupling type or a pressure sensitive type have been proposed as coordinate input devices. In addition, such a coordinate input device is composed of a transparent plate, a transparent electrode, etc., and a display device (for example, a liquid crystal display) is provided under the coordinate input device to form an integrated structure.
There is known a device capable of inputting coordinate information by displaying a point designated by a coordinate input device on a display device as if a character or a figure were drawn on a paper with a pencil.

[0003]

However, the conventional coordinate input device described above has the following drawbacks.

Generally, an input pen is used as a pointing member for pointing coordinates in a coordinate input device, but it is necessary to provide some means for specifying the state of the input pen. That is, when the operator inputs a character by handwriting with the input pen, the input pen is used to determine whether the operator is actually inputting or whether the coordinate pointing operation is being performed because he is thinking for input. It is necessary to inform the coordinate input device. For this reason, for example, when the input pen is housed in a predetermined position (for example, a holder that fixes the input pen), the switch or the like operates to store the input pen in the predetermined position, and the input pen is actually used for coordinate input. It is possible to detect that the coordinate input device does not work. However, forcing the operator to perform such a special operation is not preferable in terms of operation because it interrupts the operator's thinking.

The present invention has been made in view of the above-mentioned conventional example, and whether or not the actual coordinate input operation is performed by making it possible to judge whether the detected position information of the vibration input pen is valid or not. It is an object of the present invention to provide a coordinate input method and device capable of automatically determining.

Other advantages and objects of the present invention will be apparent from the description given below with reference to the accompanying drawings.

[0007]

In order to achieve the above object, the coordinate input device of the present invention has the following configuration. That is, a coordinate input device that detects and outputs a coordinate position on the vibration transmission plate designated by the vibration input pen, based on elastic wave vibration from the vibration input pen input to the vibration transmission plate, Based on at least three or more sensors provided on the vibration transmission plate and detecting a vibration wave that is incident from the vibration input pen and propagated through the vibration transmission plate, based on signals detected by the plurality of sensors. Calculation means for calculating each distance to each of the plurality of sensors and the vibration input pen, position detection means for detecting the position of the vibration input pen based on each distance calculated by the calculation means, and the position detection By calculating a distance from the position of the vibration input pen detected by the means to each of the plurality of sensors, and comparing the distance with each of the distances calculated by the calculating means. A determination unit that determines whether or not the position of the vibration input pen detected by the position detection unit is valid, and outputs information indicating the state of the input pen based on the determination result by the determination unit. Have means.

In order to achieve the above object, the coordinate input method of the present invention comprises the following steps. That is, based on the elastic wave vibration from the vibration input pen input to the vibration transmission plate, a coordinate input method for detecting and outputting the coordinate position on the vibration transmission plate designated by the vibration input pen, At least 3 which is provided on the vibration transmission plate and detects a vibration wave which is incident from the vibration input pen and propagated through the vibration transmission plate.
A calculation step of calculating each distance to each of the plurality of sensors and the vibration input pen based on a signal detected by each of the plurality of sensors, and the vibration input based on each calculated distance. A step of detecting the position of the pen, calculating the distance from the detected position of the vibration input pen to each of the plurality of sensors, by comparing with each of the distances calculated by the calculating step,
Determining whether the position of the vibration input pen is valid.

[0009]

In the above structure, each distance between each of the plurality of sensors and the vibration input pen is calculated based on the signal detected by each of the plurality of sensors. The position of the vibration input pen is detected based on each of the calculated distances, and the distances from the detected position of the vibration input pen to each of the plurality of sensors are calculated and compared with the previously calculated distances. As a result, it is determined whether or not the position of the vibration input pen detected by the position detecting means is valid.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. In this embodiment, the vibration is propagated from the input pen to the vibration transmission plate, the plural sensors provided on the vibration transmission plate detect the propagation of the vibration, and the coordinates indicated by the input pen are detected by the detection signals from these sensors. A case of a coordinate input device for obtaining a position will be described.

FIG. 1 is a sectional view for explaining the main structure of an input pen (vibration pen) 3 according to an embodiment of the present invention.

In FIG. 1, the vibrator 4 built in the vibrating pen 3 is driven by a vibrator driving circuit 2 described later to vibrate. That is, the electric drive signal output from the vibrator drive circuit 2 is converted into mechanical ultrasonic vibration by the vibrator 4. The vibration of the vibrator 4 is transmitted to the pen tip 12 via the vibration transmission member 5, and the vibration is transmitted to the vibration transmission plate by the point contact between the pen tip 12 and the vibration transmission plate 8 (see FIG. 2) described later. To be The vibrator 4 has a cylindrical shape, and in this embodiment, the K ₃₃ 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 larger end surface of the vibration transmission member 5.

One electrode of the vibrator 4 is connected to the vibrator driving circuit 2 via the vibration transmitting member 5, the conduction ring 138 and the electrode spring 137. Further, the other electrode of the vibrator 4 is connected to the vibrator drive circuit 2 through the electrode pin 135 and the electrode spring 136. Also the pen housing 1
31 and the pen tip protection member (a part of the pen housing) 133 are fastened to each other at a conduction ring 138 via a screw portion.
The conduction ring 138 is made of a metal material, and is brought into contact with the vibration transmission member 5 to be electrically connected to the vibrator 4 via the vibration transmission member 5, and the vibration generated in the vibrator 4 causes the vibration transmission member 5 to pass through. It is also configured to be transmitted to the conduction ring 138 through.

On the other hand, the vibration input pen 3 is connected to the vibration transmission plate 8
When left on top (when placed horizontally on the vibration transmission plate 8), the vibration generated by the vibrator 4 passes through the conduction ring 138, the pen tip protection member 133, and the housing 131. It is transmitted to the vibration transmission plate 8. The vibration transmitted to the vibration transmission plate 8 in this way is not transmitted through the pen tip 12 (point) as in the case of normal coordinate input, but
In order to be transmitted in a linear shape in the longitudinal direction of the vibration pen 3,
A signal waveform detected by a plurality of sensors provided on a vibration transmission plate 8 described later is distorted and is different from a signal waveform input at a point via the pen tip 12. In addition, the pen tip 12
In this embodiment, the protective member 133 and the casing 131 are made of resin (ABS) and are set to have a thickness sufficient to transmit the vibration transmitted to the conduction ring 138 to the vibration transmission plate 8. The protection member 133 and the housing 131 are
Of course, other materials may be used as long as the vibration is sufficiently transmitted to the vibration transmission plate 8.

As a matter required for the vibrating pen 3 of the coordinate input device utilizing this vibration, first, the vibration generated by the vibrator 4 can be efficiently transmitted to the vibration transmission plate 8.
Secondly, the vibration transmission plate 8 must not be damaged when pointing the coordinate position.

For the first condition, a metal material such as aluminum or stainless steel is generally considered to be the most suitable material because of its low energy loss, but there is a risk of damaging the vibration transmission plate 8 at the time of inputting coordinates. . On the other hand, with respect to the second problem, it can be said that resin is a more preferable material than metal. In consideration of these points, in the present embodiment, in order to transmit the vibration of the vibrator 4 to the vibration transmission plate 8 described later, aluminum is used as the material of the vibration transmission member 5, and the vibration of the vibrator 4 is transmitted first. Inform member 5. Since the vibration transmitting member 5 is made of metal, the vibration energy loss is small, and it is possible to sufficiently transmit the vibration even when the axial length thereof is relatively large. Further, since the vibration transmitting member 5 is electrically conductive, it also serves as a member for electrically connecting with the electrode of the vibrator 4. A thread is formed on the smaller end surface of the vibration transmitting member 5, and the resin nib 12 is fixed to the tip by using the thread. In this embodiment, the pen nib 12 is made of polyamide-imide, which has relatively small energy loss of vibration (although the loss is considerably larger than that of metal) among resins, and also has excellent wear resistance and vibration transmission. Board 8
It has the advantage of not hurt. Needless to say, a material satisfying these two conditions, for example, a material such as polyphenyl sulfide (pps) may be used.

As described above, by interposing the member for transmitting the vibration between the vibrator 4 as the vibration source and the pen tip 12, the pen tip can be easily replaced, and the transmission member 5 is made of metal. By doing so, the axial length of the transmission member 5 can be increased, and the vibration input pen 3 having a shape that is easy for the operator to handle can be configured.

FIG. 2 shows the structure of a coordinate input device using the vibrating pen 3 of this embodiment.

In the figure, reference numeral 1 denotes an arithmetic control circuit for controlling the entire coordinate input device and calculating the coordinate position designated by the vibrating pen 3. 2 is a vibrator drive circuit,
The vibrator 4 of the vibrating pen 3 is driven to vibrate the pen tip 12. Reference numeral 8 is a vibration transmitting plate made of a transparent member such as acrylic or glass plate, and touching the vibration transmitting plate 8 with the vibrating pen 3 gives coordinate instructions. That is, the vibration generated by the vibrating pen 3 is incident on the vibration transmitting plate 8 by designating with the vibrating pen 3 the area (hereinafter referred to as the effective area) indicated by the solid line A in FIG. This incident vibration propagates through the vibration transmission plate 8 and is detected by the sensors 6a to 6d. By measuring the coordinate position based on the signals detected by these sensors 6a to 6d, the coordinate position on the vibration transmission plate 8 designated by the vibration pen 3 can be obtained.

In order to prevent (reduce) the vibration wave propagating through the vibration transmission plate 8 from being reflected at the end surface of the vibration transmission plate 8 and being propagated to the central portion of the vibration transmission plate 8, the vibration transmission is performed. A vibration isolator 7 is provided on the outer periphery of the plate 8. And Figure 2
As shown in FIG. 5, a vibration sensor 6a, which is formed near the inside of the vibration isolator 7 and which converts mechanical vibrations such as a piezoelectric element into an electric signal,
~ 6d is fixed. Reference numeral 9 denotes a signal waveform detection circuit, which detects a signal representing the vibration detected by each of the vibration sensors 6a to 6d and outputs it to the arithmetic control circuit 1. Reference numeral 11 is a display such as a liquid crystal display capable of displaying in dot units, and is arranged below the vibration transmission plate 8 (inside). This display 11 is a display drive circuit 1
It is possible to display a dot at a position corresponding to the position of the vibration transmission plate 8 which is driven by 0 and is designated by the vibration pen 3 and to see the display through the transparent vibration transmission plate 8.

As described above, the vibrator 4 built in the vibrating pen 3 is driven by the vibrator driving circuit 2. The drive signal for the oscillator 4 is supplied from the arithmetic control circuit 1 to the oscillator drive circuit 2 as a low-level pulse signal, amplified by the oscillator drive circuit 2 with a predetermined gain, and then applied to the oscillator 4. ing. In this way, the electric drive signal is converted into mechanical vibration by the vibrator 4, and is transmitted to the vibration transmission plate 8 via the pen tip 12.

Here, the frequency of the drive signal for driving the vibrator 4 (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. Further, by setting the vibration frequency of the vibrator 4 to the resonance frequency including the pen tip 12, it is possible to efficiently convert the electric signal into the mechanical signal. Here, the elastic wave due to the vibration transmitted from the vibrating pen 3 to the vibration transmitting plate 8 is a plate wave, which is less susceptible to scratches or obstacles on the surface of the vibration transmitting plate 8 than surface waves. Have.

<Description of Arithmetic and Control Circuit 1> In the above-mentioned configuration, the arithmetic and control circuit 1 has a predetermined cycle (for example, 5 ms).
Every time), a signal for driving the vibrator 4 in the vibrating pen 3 is output to the vibrator driving circuit 2, and the internal timer (for example, configured of a counter) starts timing.
As a result, the vibration incident on the vibration transmission plate 8 from the vibration input pen 3 propagates through the vibration transmission plate 8 and arrives with a delay depending on the distance from the input pen 3 to the vibration sensors 6a to 6d.

The signal waveform detection circuit 9 includes vibration sensors 6a to 6a.
A signal from each of the d is detected, and a signal indicating the vibration arrival timing from the vibration pen 3 to each vibration sensor is generated by the waveform detection processing described later. The arithmetic control circuit 1 outputs the timing signal corresponding to each sensor to the signal waveform detection circuit 9
The vibration arrival time to each of the vibration sensors 6a to 6d from the position designated by the vibration pen 3 is detected, and the coordinate position designated by the vibration pen 3 is calculated based on the detected value. Further, the arithmetic control circuit 1 drives the display drive circuit 10 to display the indicated point on the display 11 based on the calculated position information designated by the vibrating pen 3, or the serial or serial The detected coordinate data is output to an external device (not shown) by parallel communication.

FIG. 3 is a block diagram showing a schematic configuration of the arithmetic control circuit 1 of the embodiment.

In FIG. 3, reference numeral 31 is a microcomputer for controlling the arithmetic control circuit 1 and the coordinate input apparatus as a whole, a ROM 31a storing various data such as control programs and constants indicating control procedures, and execution of control processing. A RAM 31b used as a work area is provided therein. Reference numeral 33 is a timer (not shown) that counts a reference clock (for example, is configured by a counter), and when a start signal 38 for starting the driving of the vibrator 4 of the vibration pen 3 is input to the vibrator driving circuit 2, Start the timekeeping. As a result, the start of time measurement by the timer 33 and the vibration detection in each of the sensors 6a to 6d are synchronized, and the delay time until the vibration is detected by each of these sensors 6a to 6d can be measured.

The circuits which are the other constituent elements will be described in order.

A vibration arrival timing signal from each of the signal sensors 6a to 6d is output from the signal waveform detection circuit 9, and the latch circuit 34a via the detection signal input port 35.
Is input to ~ 34d. Each of the latch circuits 34a to 34d is provided corresponding to each of the vibration sensors 6a to 6d, and when a timing signal from the corresponding sensor is input, the clocked value of the timer 33 at that time is latched. When the determination circuit 36 determines that the detection signals from all the sensors have been input in this way, it outputs a signal to that effect to the microcomputer 31. When the microcomputer 31 inputs the signal from the determination circuit 36, it reads the vibration arrival time from the latch circuits 34a to 34d to each vibration sensor, performs a predetermined calculation, and uses the vibration pen 3 on the vibration transmission plate 8. Calculate the designated coordinate position. Then, the calculated coordinate position information is output to the display drive circuit 10 via the I / O port 37. Thus, for example, a dot or the like can be displayed at the position of the display 11 corresponding to the coordinate position designated by the vibrating pen 3. Alternatively, by outputting the calculated coordinate position information to the interface circuit via the I / O port 37, the coordinate value instructed to the external device can be notified. <Description of Vibration Propagation Time Detection (FIGS. 4 and 5)> The principle of measuring the vibration transmission time until the vibration from the vibrating pen 3 reaches each of the vibration sensors 6a to 6d will be described below.

FIG. 4 is a diagram for explaining a detection waveform input to the signal waveform detection circuit 9 and a vibration transmission time measuring process based on the detection waveform. In the following, the case of the vibration sensor 6a will be described, but the same applies to the other vibration sensors 6b, 6c, 6d.

The time until the vibration is transmitted to the vibration sensor 6a is measured by the start signal 38 to the vibrator drive circuit 2.
It has already been explained that is started at the same time as is output. When the oscillator 4 is driven, the drive signal 41 is applied from the oscillator drive circuit 2 to the oscillator 4. The drive signal 41 causes the vibrator 4 of the vibrating pen 3 to vibrate, and the pen tip 1
The ultrasonic vibration transmitted to the vibration transmission plate 8 through 2 arrives at the time tg corresponding to the distance to the vibration sensor 6a and is detected by the vibration sensor 6a.

In FIG. 4, a signal 42 indicates a signal waveform detected by the vibration sensor 6a. As described above, since the vibration used in this embodiment is a plate wave, the relationship between the envelope 421 of the detected waveform and the phase 422 during the transmission of the vibration with respect to the propagation distance in the vibration transmission plate 8 is the transmission distance. Change according to. Here, the traveling speed of the envelope 421, that is, the group speed is V _g , and the phase speed of the phase 422 is V _p . This group velocity V _g and phase velocity V _p
Therefore, the distance between the vibration pen 3 and the vibration sensor 6a can be detected. First, focusing only on the envelope 421, its speed is V _g , and when a point on a certain specific waveform, for example, an inflection point or a peak such as a signal indicated by 43 in FIG. 4 is detected, the vibration pen 3 and the vibration are detected. Distance d between sensors 6a
Is given by d = V _g · t _g (1) with its vibration transmission time being t _g . Although this formula relates to the vibration sensor 6a, the other three vibration sensors 6b to 6d are expressed by the same formula.
And the distance of the vibrating pen 3 can be similarly expressed.

Further, in order to determine the coordinates with higher accuracy, processing based on the detection of the phase signal is performed. The time from the specific detection point of the phase waveform signal 422, for example, the vibration application to the zero cross point after a certain predetermined signal level (indicated by 46) is t _p (the window signal 44 having a predetermined width is generated with respect to the signal 47, (Obtained by comparing with the phase signal 422),
The distance d between the vibration sensor 6a and the vibration pen 3 is d = n · λ _p + V _p · t _p (2). Here, λ _p is the wavelength of the elastic wave, and n is an integer.

From the above equations (1) and (2), the above integer n is represented by n = int [(V _p · t _g −V _p · t _p ) / λ _p + 1 / N] (3) To be done.

Here, N is a real number other than "0", and an appropriate value is used. For example, if N = 2, then n can be determined if there is a variation in t _g or the like within ± 1/2 wavelength. Then, by substituting n obtained as described above into the equation (2), the distance between the vibrating pen 3 and the vibration sensor 6a can be accurately measured.

The above two vibration transmission times t _g and t _p
The signal waveform detection circuit 9 generates the signals 43 and 45 for measuring
Is configured as shown in FIG.

FIG. 5 is a block diagram showing the configuration of the signal waveform detection circuit 9 of this embodiment.

In FIG. 5, the detection signal from the vibration sensor (6a) is amplified to a predetermined level by the preamplifier circuit 51. An extra frequency component is removed from the amplified detection signal by a bandpass filter 511, and the amplified detection signal is input to an envelope detection circuit 52 including, for example, an absolute value circuit and a low-pass filter. ) Is taken out. The peak timing of the envelope signal (421) is detected by the envelope detection circuit 53. An envelope delay time detection signal t _g (signal 43 in FIG. 4) having a predetermined waveform is formed by the t _g signal detection circuit 54 composed of a mono-multivibrator or the like according to the timing of the peak detected by the peak detection circuit 53. And this t _g
The signal is input to the arithmetic control circuit 1.

On the other hand, the signal detection circuit 55 detects the envelope signal (421) detected by the envelope detection circuit 52.
The pulse signal (47) of the portion exceeding the threshold signal 46 of the predetermined level is formed. 56 is a monostable multivibrator, which is triggered by the first rising edge of the pulse signal (47) and outputs the gate signal (44) for a predetermined time. t _p comparator 57, the gate signal (44) detects the first rising edge of the zero cross point of the phase signal (422) between the high level, the phase delay time signal t _p (45)
Are created and supplied to the arithmetic and control circuit 1. The circuit described above is for the vibration sensor 6a, and it goes without saying that the same circuit is provided corresponding to the other vibration sensors 6b to 6d.

<Explanation of delay time correction> Strictly speaking, the vibration transmission time corresponding to each vibration sensor latched by the latch circuits 34a to 34d is the time required for a sound wave to propagate through the vibration transmission plate 8. And the time required for the signal waveform processing circuit 9 to process the detection signal output from each sensor. Therefore, the delay time of the signal other than the time when the vibration wave propagates on the vibration transmission plate 8 is defined as the intrinsic delay time et. The difference between the group delay time and the phase delay time at the reference point is defined as the phase offset time t _off . The time error caused by these delay times must 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 origin O (0, 0) in FIG. 6 is set as the reference point described above, the distance from the reference point O to the vibration sensor 6a is set as R ₁ (= X / 2), and the origin O is designated by the vibrating pen 3. Then, the measured vibration transmission time from the origin O to the sensor 6a measured at this time is t _g
z ', t _p z'. Further, if the true transmission time from the origin O to the sensor 6a is t _g z, t _p z, these are t _g z '= t _g z + et (4) t _{p with} respect to the intrinsic delay time et and the phase offset t _off. z ′ = t _p z + et + t _off (5).

On the other hand, point P (x, y) which is an arbitrary input point
Similarly, the measured values t _g 'and t _p ' in the same manner are t _g '= t _g + et (6) t _p ' = t _p + et + t _off (7). These (4), (6), (5), (7) determining the difference _{therebetween, t g '-t g z'} = (t g + et) - (t g z + et) = t g -t g z _{... (8) t p '-t} p z' = (t p + et + t off) - (t p z + et + t off) = t p -t p z ... (9) , and the inherent delay time et and included in each transmission time The phase offset t _off is removed. As a result, the distance from the vibration sensor 6a to the origin O and the input point P (x,
The true difference in transmission delay time depending on the distance up to y) can be obtained, and the difference between these two distances can be obtained by using the above equations (2) and (3). Now, since the distance from the vibration sensor 6a to the origin O is stored in advance in a non-volatile memory or the like and is known, the distance between the vibration pen 3 and the vibration sensor 6a can be determined from this relationship.
In this way, the other sensors 6b to 6d can be similarly obtained. The measured values t _g z'and t _p z'at the origin O are stored in advance in a non-volatile memory.
Since the calculations shown in Expressions (8) and (9) are executed before the calculations of Expressions (2) and (3), highly accurate measurement can be performed.

<Description of Coordinate Position Calculation (FIG. 6)> Next, the principle of actually detecting the coordinate position designated on the vibration transmission plate 8 by the vibration pen 3 will be described. Now, the vibration sensors 6a to 6d are provided near the midpoints of the four sides of the vibration transmission plate 8 at the positions indicated by reference signs S1 to S4. The linear distances da to dd from the position P designated by the vibrating pen 3 to the respective positions of the vibration sensors 6a to 6d can be obtained based on the principle described above. Further, the arithmetic control circuit 1 uses the vibrating pen 3 based on these linear distances da to dd.
The coordinates (x, y) of the position P can be obtained from the Pythagorean theorem by the following equation.

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

As described above, when the vibration generated in the vibrating pen 3 is input to the vibration transmitting plate 8 through the pen tip 12 by point contact, the distance to each sensor is calculated,
Based on the result, the position coordinates of the vibrating pen 3 can be detected in real time.

<Description of State Discriminating Means (FIG. 7)> Now, let us consider a case where the vibrating pen 3 is left on the vibration transmitting plate 8. The vibration generated by the vibrating pen 3 is input to the vibration transmission plate 8 via the conduction ring and the pen tip protection member 133. In the present embodiment, the pen tip protection member 133 is made of resin (ABS), and has a sufficient thickness to input the vibration generated by the vibrating pen 3 to the vibration transmission plate 8 via the pen tip protection member 133. Although it is constructed, it goes without saying that other materials may be used.

When the vibrating pen 3 is left on the vibration transmitting plate 8, the housing of the vibrating pen 3 and the vibration transmitting plate 8 are in line contact with each other. Therefore, in this case, the vibration generated in the vibrating pen 3 is
It is input to the vibration transmission plate 8 by line contact through the pen tip protection member 133 and the housing 131. Therefore, in this case, the waveform of the detection signal output from each sensor is a composite wave of the vibrations incident at a large number of points, unlike the case where the vibrations are incident through the pen tip 12 in a point contact manner. In this case, the delay time of this composite wave detected as described above and the linear distances da to d calculated from the calculation result thereof.
d has no geometrical meaning (vibration transmission plate 8
Because the vibration that is incident on is not incident at a point). Therefore, if it is possible to determine the state in which the vibration is incident by the line contact in this way, whether the vibration pen 3 is actually used to input the coordinates or the vibration pen 3 is left on the vibration transmission plate 8. It can be distinguished whether or not it is in the state. Hereinafter, a method of determining such a state will be described.

Now, the coordinate values calculated and output by the above equations (10) and (11) are defined as (α, β). From these α and β, it is possible to geometrically obtain the distances da ′ to dd ′ from the geometrically output coordinate values (α · β) to each sensor. If the vibration is incident on the vibration transmission plate 8 at a point, the distance d between the input point and each sensor is d.
When a to dd are accurately calculated, the distances da ′ to dd ′ from each coordinate value (α, β) calculated from the result to each sensor are equal to da to dd.
However, when vibration is input due to line contact, the signals detected by the sensors are distorted, and as a result, the above da to d
d and da 'to dd' are not equal. Therefore, da to d
By comparing the values of d and da ′ to dd ′, the output coordinate values are in a state in which vibration is input via the pen tip 12, that is, an operator's operation is performed for the purpose of inputting coordinates. It is possible to determine whether or not the vibration pen 3 is left on the vibration transmission plate 8.

The above description will be described in detail with reference to FIG.

As described above, in this embodiment, the coordinates are detected by using four sensors, and the X-direction coordinates and the Y-direction coordinates of the output coordinate values are detected independently. ing. In order to simplify the description, in the case where the vibration pen 3 is left on the vibration transmission plate 8, the vibration is incident by the line contact, and the vibration is input at two points (point a and point b) on the line. Will be described. It is assumed that the X-direction coordinate (α) is calculated by the vibration from the point a and the Y-direction coordinate (β) is output by the vibration from the point b. The coordinates C (α, β) at this time are as shown in FIG. Using this coordinate C (α, β), the distance to the sensor 6a is calculated back by the following equation (only the distance to the sensor 6a is shown).

Da ′ ² = (X / 2 + α) ² + β ² (12) The distances da ′ and da, and the distance db ′ to each sensor.
~ Dd 'and the distances db to dd are compared to determine whether the coordinates are input by the operator or the vibration pen 3 is left on the vibration transmission plate 8. Can be determined.
Here, for simplification of description, the state of the geometrical calculation has been described in the state where the vibration is input at two points on the line where the vibration pen 3 and the vibration transmission plate 8 are in line contact. , Because the vibration is actually input at multiple points on the line,
The detection signal output from each sensor is detected as a composite wave, and is distorted as compared with the output signal waveform of the signal input by point contact with the pen tip 12 of the vibrating pen 3. Therefore,
In this case, the calculated distances from each sensor da to d
Since d has a large error, it has no geometrical meaning. When the distance to each sensor is calculated back from the coordinate values output in such a state according to the equation (12), the state as described above occurs and the state of the vibrating pen can be determined (in FIG. 7, Due to the distorted signal waveform, it happens that da, db (a
Point), and a state in which dc and dd (point b) are detected).

Although the above description has been made in the case of using four vibration sensors, at least three vibration sensors are used.
Similar effects can be obtained by calculating coordinate values in the X and Y directions with different combinations of sensors. Moreover, using the distance between the input pen and the above-mentioned two sensors, which is calculated based on the propagation time of the wave using two of the three sensors,
It is also possible to calculate the position of the input pen, calculate the distance from this input pen position to the remaining one sensor,
It can also be determined by comparing with the distance to the remaining one sensor calculated based on the propagation time of the wave.
Further, in this embodiment, the pen tip protection member 133 and the housing 13
1 shows that the waveform is distorted due to the line contact with the vibration transmission plate 8 to cause an error in the detection position. In the present embodiment, the vibration is input at a point and the vibration is input at a certain area. However, the shape of the housing or the like is not particularly specified.

<Description of Coordinate Output Flowchart (FIG. 8)> Next, the microcomputer 3 of the arithmetic control circuit 1
The process of outputting the coordinate value and the system control signal according to No. 1 will be described with reference to the flowchart of FIG.
The control program for executing this processing is the ROM 31a.
Remembered in.

First, in step S1, when the arithmetic control circuit 1 outputs a start signal 38 for driving the vibrator driving circuit 2, the vibrator driving circuit 2 starts driving the vibrating pen 3. This start signal 38 causes the timer 3
The time counting by 3 is started, and the timer 33 sets a predetermined time (for example, in an effective area where coordinates can be input,
When the coordinates are input at a position where the distance between the vibration pen 3 and the sensor is maximum, before the time taken for the vibration wave to propagate between them is measured, each sensor is incident on the vibration transmission plate 8. When a vibration detection signal is output, step S3
Proceed to. In step S3, it is determined that the vibration from the vibrating pen 3 has been input to the vibration transmitting plate 8, and the positions da and dd to the position indicated by the vibrating pen 3 and each sensor are calculated, and then in step S4, The indicated coordinate value (α,
β) is calculated.

Next, in step S5, the distances to the respective sensors are calculated back based on the calculated coordinate values (α, β) indicated by the vibrating pen 3. When the distances da 'to dd' are obtained in this way, the process proceeds to step S6 and is compared with each of the distances da to dd calculated in step S3. If the compared values are equal in step S6, the process proceeds to step S7, and the coordinate values (α, β)
Is output as a determined value to the external circuit via the I / O port 37, and the process returns to the start. On the other hand, if the values compared in step S6 are different, the process proceeds to step S8, the coordinate values (α, β) are not output, and a signal (for example, a reset signal) for controlling the system is output and the process returns to step S1. When outputting the signal for controlling this system, it is detected that the vibrating pen 3 is left on the vibration transmitting plate 8 by the above-described method. In this case, for example, an unnecessary circuit is sent. In order to execute processing such as cutting off the power supply in order to cut off the power supply of the above, for example, a signal for branching a program operating on the system to a subroutine or the like for the processing.

Although not shown in the flow chart of FIG. 8, when the coordinate values (α, β) are output as fixed values, the system control signal may be reset to return to the normal state. It goes without saying that the number of times the signal for controlling the system in step S8 is output (how many times step S8 is executed) may be counted and the system state may be changed based on the counted value.

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

As described above, according to the present embodiment, whether the vibration input pen 3 is left on the vibration transmission plate 8 which is the coordinate input surface, or the vibration pen 3 is operated by the operator and the vibration is generated. It is possible to determine whether the position is designated on the transmission plate 8. As a result, for example,
When the vibration input pen 3 is left on the vibration transmission plate 8 and the operator thinks without instructing the position, the operator does not have to take action such as turning off the switch. Processing such as cutoff of power supply to unnecessary circuits is automatically performed. Further, when the operator restarts the position pointing operation on the vibration transmission plate 8,
The power supply to the circuit, which had been powered off until then, is automatically restarted, and normal processing can be performed. In this way, power consumption can be prevented without disturbing the operator's thinking. This is particularly advantageous when the system is operated by a battery such as a battery, which can prolong the usage time.

It is also possible to detect that the vibrating pen 3 is left on the vibration transmitting plate 8 and branch the software (application program or the like) operating on the system to other processing. . In this way, the vibration input pen 3 for indicating the coordinate position by the operator is attached to the vibration transmission plate 8
The excellent effect that the operating state of the system can be changed (serving as a switch) can be obtained only by a very natural operation of leaving it in an arbitrary place above.

[0058]

As described above, according to the present invention, it is possible to determine whether or not the detected position information of the vibration input pen is valid, and whether or not the actual coordinate input operation is performed. An excellent effect can be obtained in that the operator can automatically make a judgment only by a very natural operation of leaving a pen for inputting coordinates at an arbitrary place on the vibration transmission plate.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing the structure of a vibration input pen of this embodiment.

FIG. 2 is a block diagram showing a schematic configuration of a coordinate input device of this embodiment.

FIG. 3 is a block diagram showing a configuration of an arithmetic control circuit of the coordinate input device according to the present embodiment.

FIG. 4 is a timing chart showing the timing of signal processing in the signal waveform detection circuit of the coordinate input device of this embodiment.

FIG. 5 is a block diagram showing a configuration of a signal waveform detection circuit of this embodiment.

FIG. 6 is an explanatory diagram for calculating coordinate positions.

FIG. 7 is a diagram illustrating a method of calculating a distance between a position designated by a vibrating pen and each sensor.

FIG. 8 is a flowchart showing coordinate value output and system control signal output processing in the arithmetic control circuit of the coordinate input device according to the present embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 arithmetic control circuit 2 vibrator drive circuit 3 vibrating pen 4 vibrator 5 vibration transmission member 6a to 6d sensor 7 vibration isolator 8 vibration transmission plate 9 signal waveform detection circuit 10 display drive circuit 11 display 12 nib 31 microcomputer 31a ROM 33 timer 34a-34d latch circuit 38 start signal 131 pen housing 133 pen tip protection member

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Jun Tanaka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yuichiro Yoshimura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Kiyoshi Kaneko 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A coordinate input device for detecting and outputting a coordinate position on the vibration transmission plate designated by the vibration input pen based on elastic wave vibration from the vibration input pen input to the vibration transmission plate. And a plurality of sensors provided on the vibration transmission plate for detecting a vibration wave incident from the vibration input pen and propagated through the vibration transmission plate, and detected by each of the plurality of sensors. A calculation unit that calculates each distance to each of the plurality of sensors and the vibration input pen based on a signal, and a position detection unit that detects the position of the vibration input pen based on each distance calculated by the calculation unit And a distance from the position of the vibration input pen detected by the position detecting means to each of the plurality of sensors, and the distances calculated by the calculating means. By comparing, the determination unit that determines whether the position of the vibration input pen detected by the position detection unit is valid, and the determination unit determines when the position of the vibration input pen is valid, Output the coordinate information indicating the position,
A coordinate input device comprising: output means for outputting information indicating invalidity without outputting coordinate information indicating the position when it is determined that the position of the vibration input pen is not valid. 2. A coordinate input method for detecting and outputting a coordinate position on the vibration transmission plate designated by the vibration input pen based on elastic wave vibration from the vibration input pen input to the vibration transmission plate. There, provided with the vibration transmission plate, each of the plurality of sensors based on a signal detected by each of a plurality of sensors for detecting a vibration wave that is incident from the vibration input pen and propagated through the vibration transmission plate. A step of calculating each distance to the vibration input pen, a step of detecting the position of the vibration input pen based on each calculated distance, and a step of detecting the plurality of positions from the detected position of the vibration input pen. Calculating a distance to each of the sensors and comparing the distance with each of the distances calculated by the calculating step to determine whether or not the position of the vibration input pen is valid. Coordinate input wherein the.