JPH02162410A - Coordinate input device and its input pointor - Google Patents

Abstract

PURPOSE:To omit a cable, etc., for an input pointor containing a tuning circuit by producing the radio waves to the pointor via a position detecting part to obtain the coordinate value of a position pointed by the pointor from the radio waves reflected from the turning circuit and at the same time to obtain the change of a tuning frequency as the change of a phase. CONSTITUTION:When the radio waves are produced from a radio wave generating means 7 of a tablet, a tuning circuit of an input pointor 2 reflects the radio waves. The reflected radio waves are detected by a radio wave detecting means 14 of the tablet and sent to a coordinate detecting means. Then this detecting means detects the coordinate value of a point pointed by the pointor 2 in both X and Y directions. In this case, the radio waves detected by the means 14 have the frequency and phase errors in response to the operations of the pointor 2. These errors are detected by a phase detecting means of the tablet as the phase change. Then this phase information and the information obtained from the coordinate value of the pointed position are displayed on a display device. Thus it is not required to connect a cable, etc., to the pointor 2.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention detects information on a pond along with coordinate values of a designated position,
The present invention relates to a coordinate input device that displays information obtained from these devices and an input indicator thereof.

(Prior Art) This conventional heel coordinate input device includes a pressure-sensitive sensor provided in an input indicator equipped with a configuration for detecting a designated position, or a configuration for detecting a designated position. By installing a pressure-sensitive sensor over the entire coordinate input range of the equipped tablet, the pen pressure applied to the input indicator is detected, and the information obtained from this and the coordinate value of the indicated position is CR
There were some that were displayed on display devices such as T.

(Problem to be Solved by the Invention) However, when a pressure sensor is provided in an input indicator, a cable, etc. is indispensable for extracting the pressure-sensitive information from the manual indicator, and therefore In addition, if the pressure sensor is provided over the entire coordinate input range of the tablet, it is difficult to make the characteristics of the pressure sensor uniform over the entire coordinate input range. There is a problem in that it is difficult to accurately detect pen pressure in all the ranges mentioned above.

The present invention solves the above problems, eliminates the need to connect a cable or the like to the input indicator, and can accurately detect other information such as pen pressure over the entire coordinate input range. An object of the present invention is to provide a coordinate input device and an input indicator thereof that can display information obtained from the coordinate values of the indicated position and the information obtained from the coordinate values of the indicated position.

(Means for Solving the Problem) In order to achieve the above object, the present invention provides an input indicator having a tuning circuit whose tuning frequency changes around a predetermined frequency according to the operation, and a radio wave of the predetermined frequency. radio wave generating means for generating radio waves reflected from the tuning circuit; radio wave detecting means for detecting the radio waves reflected from the tuning circuit; coordinates for determining the coordinate values of the position indicated by the input indicator based on the radio waves detected by the radio wave detecting means. A coordinate input device comprising a detection means and a tablet having a phase detection means for detecting a change in the tuning frequency in the tuning circuit as a change in phase with respect to the predetermined frequency based on the radio waves detected by the radio wave detection means. a coordinate input device equipped with a display device that displays information obtained from coordinate values, phases, etc. of the detected indicated position; A coordinate input device equipped with an input indicator having a tuning circuit that changes to a position detection unit having a Y-direction loop coil group formed by arranging loop coils in parallel in the Y-direction; an X-direction selection means for sequentially selecting one loop coil from the X-direction loop coil group of the tablet; Y-direction selection means for sequentially selecting one loop coil from a group of loop coils in the Y-direction of the tablet; signal generation means for generating an alternating current signal of the predetermined frequency; and a signal for detecting the alternating current signal of the predetermined frequency. a detection means and an X direction and a Y direction selected by the X direction and Y direction selection means;
connection switching means for alternately connecting the signal generating means and the signal detecting means to each loop coil in the direction;
coordinate detection means for determining coordinate values in the X direction and Y direction of the position indicated by the input indicator based on AC signals detected by the signal detection means from each loop coil in the X direction and the Y direction; phase detection means for detecting a change in the tuning frequency in the tuning circuit of the input indicator as a change in phase with respect to the predetermined frequency based on an alternating current signal detected by the signal detection means from one loop coil in the Y direction; A coordinate input device consisting of a coordinate input device that uses a planar display device in these coordinate input devices and superimposes it on a tablet, and a figure that indicates a position indicating a phase in these coordinate input devices A coordinate input device that converts the phase into spread information and displays it, or a coordinate input device that converts the phase into density information of a predetermined color at the indicated position and displays it.
Alternatively, it has a coordinate input device that converts the phase into hue information at a designated position and displays it, and a core supported movably in the axial direction of a pen-shaped housing, and a pen applied to the core. It has an input indicator equipped with a tuning circuit in which the tuning frequency changes around a predetermined frequency according to the pressure, and a manually operable regulator, and the tuning frequency is set to a predetermined value according to the operation of the regulator. An input indicator equipped with a tuned circuit that changes around the frequency of We propose an indicator or an input indicator using a dial-operated regulator.

(Function) According to the coordinate input device of the present invention, when a radio wave is generated by the radio wave generating means of the tablet, the radio wave is tuned to, or received by, the tuning circuit of the input indicator that specifies a position on the tablet. , the tuned circuit that receives the radio wave transmits or reflects a similar radio wave.

The reflected radio waves are detected by the radio wave detection means of the tablet, and the detected radio waves are further sent to the coordinate detection means of the tablet, and the coordinate values in the X and Y directions of the position indicated by the input indicator are detected. be done.

In addition, at this time, the radio waves detected by the radio wave detection means of the tablet are accompanied by a shift in frequency and phase depending on the operation of the input indicator, but this is detected as a change in phase by the phase detection means of the tablet, Further, information obtained from the phase information and the coordinate values of the indicated position is displayed on the display device.

Further, according to the coordinate input device of the present invention, the phase information detected by the phase detection means of the tablet becomes a value that continuously changes according to the operation, and the continuously changing phase information and the coordinate value of the indicated position. The information obtained is displayed on the display device.

Further, according to the coordinate input device of the present invention, the position detection section
The signal generating means is connected to the loop coil selected by the selection means in the X direction from the group of loop coils in the direction through the connection switching means, and when an alternating current signal of a predetermined frequency is applied, A radio wave is generated, and the radio wave excites a coil of a tuned circuit of the input indicator on the position detection section, causing the tuned circuit to generate an induced voltage of the predetermined frequency.

Thereafter, when the signal generating means is disconnected from the first loop coil by the connection switching means and the signal detecting means is connected instead, radio waves are no longer generated from the first loop coil, but instead, the signal generating means is disconnected from the first loop coil. Radio waves are generated from the coil of the tuned circuit based on the generated induced voltage, and the radio waves reversely excite the first loop coil to generate an alternating current signal, that is, an induced voltage.

Transmission and reception of the radio waves is performed for all the loop coils in the X and Y directions by the X and Y direction selection means and the connection switching means, and the corresponding induced voltages are detected by the signal detection means. Since the voltage value of the induced voltage is a value that depends on the distance between each loop coil and the tuning circuit, that is, the input indicator, based on these, the coordinate detection means determines the X direction and the position indicated by the input indicator. A coordinate value in the Y direction is calculated.

Further, the induced voltage at this time is accompanied by a frequency and phase shift depending on the operation of the input indicator, but this is detected as a change in phase by the phase detection means, and the phase information and the coordinate value of the indicated position are detected by the phase detection means. The information obtained is displayed on the display device.

Further, according to the coordinate input device of the present invention, since the flat display device is superimposed on the tablet, a figure indicating the indicated position is displayed at the display position of the display device corresponding to the indicated position by the input indicator, for example. It can be displayed.

Further, according to the coordinate input device of the present invention, the phase is converted into the spread information of the figure indicating the indicated position and displayed, so that the figure having the spread corresponding to the operation of the input indicator is displayed. An image drawn at a position corresponding to the coordinate values of the position indicated by the input indicator is displayed on the display device.

Further, according to the coordinate input device of the present invention, since the phase is converted into density information of a predetermined color at the indicated position and displayed, the density of the predetermined color corresponding to the operation of the input indicator is displayed. The information it has is displayed on the display device.

Further, according to the coordinate input device of the present invention, since the phase is converted into hue information at the indicated position and displayed, information having a hue corresponding to the operation of the input indicator is displayed on the display device. Ru.

Further, according to the input indicator of the present invention, when the pen pressure applied to the core changes, the phase detected by the coordinate input device changes, and for example, the spread of the figure indicating the indicated position changes according to the pen pressure. displayed as it changes.

Further, according to the input indicator of the present invention, when the operation on the adjuster is changed, the phase detected on the coordinate input device side changes, and for example, the spread of the figure indicating the indicated position changes depending on the operation on the adjuster. displayed as it changes.

Furthermore, according to the input indicator of the present invention, when the operation of the rotary-operated regulator, slide-operated regulator, or dial-operated regulator is changed, the phase detected by the coordinate input device changes. For example, the extent of a graphic indicating the indicated position is displayed as it changes depending on the operation of each adjuster.

(Embodiment) FIG. 1 shows an outline of an embodiment of the coordinate input device and its input indicator of the present invention, and in the figure, 1 is a tablet;
2 is an input indicator, for example an input pen; 3 is a display device; 4
is the host computer.

FIG. 2 shows the details of the tablet 1 together with a tuning circuit for the input vent 2, which will be described later. In the figure, 5 is a position detection section, 6 is a control circuit, 7 is a signal generation means (circuit),
8 and 9 are selection means (circuits) for the X direction and the Y direction. Further, 10.11 is a transmission/reception switching circuit, 12 is an XY switching circuit, and 13 is a reception timing switching circuit, which constitute a connection switching means. In addition, 14 is a bandpass filter (B
PF), which constitutes the signal detection means.

Further, 15 is a detector, and 16 is a low-pass filter (LPF), which together with the control circuit 6 and a program to be described later constitute coordinate detection means. In addition, 17.18 is a phase detector (PSD), and 19.20 is a low-pass filter (LP
F), which constitute phase detection means together with the control circuit 6 and a program to be described later. Also, 21.22
is a drive circuit, and 23 and 24 are amplifiers. Note that all of these are housed in a case 1a made of a non-metallic material.

FIG. 3 shows details of the loop coil group 5x in the X direction and the loop coil group 5y in the Y direction, which constitute the position detection section 5. The loop coil group 5x in the X direction includes a large number, for example, 48 loop coils 5X-1, 5X-2, . . . arranged parallel to each other and overlapping each other along the X direction.
. . 5x - 48, and the Y-direction loop coil group 5y is a large number of similarly 48 loop coils 5 arranged parallel to each other and overlapping along the Y-direction.
Consisting of y-1, 5y-2, ...5y-48,
The loop coil n 5 x in the X direction and the loop coil group 5y in the Y direction are closely overlapped with each other (however, in the drawing, they are drawn apart for easy understanding). Although each loop coil is configured with one turn here, it may be configured with multiple turns as necessary.

FIG. 4 shows the specific structure of the human-powered pen 2, which includes a pen shaft 25 made of a non-metallic material such as synthetic resin, a core body 27 equipped with a ferrite chip 26, and a core body 27 that is slid inside. It consists of a coil 28 that can be housed in a movable manner, a lead holder 29 that holds the rear end of the lead body 27, a spring 30 that supports the lead holder 29 so as to be slightly displaceable with respect to the pen shaft 25, and a capacitor 31. ing.

As shown in FIG. 2, the coil 28 and capacitor 31 are connected in series to form a well-known open circuit 32, and the inductance of the coil 28 and the capacitance of the capacitor 31 are The tuning (resonance) frequency is set to approximately a predetermined frequency fO. Here, when the core body 27 is held in the core holder 29, the ferrite chip 26 is located at the end of the coil 28, and when the input ben 2 is operated on the input surface etc., the current pen pressure is Accordingly, the core body 27, that is, the ferrite chip 26 moves, and thereby the inductance of the coil 28 changes continuously, so that the tuning frequency in the above-mentioned tuning circuit 32 changes slightly and continuously.

The display device 3 is, for example, a planar type in which a reflective layer that allows radio waves to pass is provided on the back side of a well-known matrix type liquid crystal display panel in which a liquid crystal medium is interposed between a plurality of crossed horizontal electrodes and vertical electrodes. It is overlaid and integrated on the case 1a of the tablet 1. The reflective layer is formed by coating a white pigment such as titanium oxide or by attaching a white plastic plate such as polyethylene terephthalate. Moreover, the display area of the display device 3 is
For example, it is set to be approximately equal to the input range in the position detection section 5 of the tablet 1, and is superimposed on the tablet 1 so that its display position coincides with the input position in the position detection section 5.

The host computer 4 receives the coordinate values and phase information of the designated position sent from the tablet 1, performs predetermined data processing, and sends the obtained information to the display device 3 for display.

Next, the operation of the device will be explained along with its configuration.
First, we will explain how radio waves are transmitted and received between the tablet 1 and the input pen 2, and the signals obtained at this time.
This will be explained according to the diagram.

The control circuit 6 is composed of a well-known microprocessor or the like, and controls the signal generation circuit 7 and also controls the switching of each loop coil of the position detection section 5 via the selection circuits 8 and 9 according to the flowchart shown in FIG. Also, X
It controls switching of the coordinate detection direction for the Y switching circuit 12 and the reception timing switching circuit 13, and also performs analog-to-digital (A/D) conversion on the output values from the low-pass filters 16, 19, and 20, which will be described later. The CPU 2 executes arithmetic processing to determine the coordinate values of the position indicated by the input sensor 2, detects the phase of the received signal, which will be described later, and sends these to the host computer 4.

The selection circuit 8 sequentially selects one loop coil from the X-direction loop coil group 5x, and the selection circuit 9 sequentially selects one loop coil from the Y-direction loop coil group 5y. Yes, each control circuit 6
Operate according to information from.

The transmission/reception switching circuit 10 alternately connects the selected J loop coil in the X direction to the drive circuit 21 and the amplifier 23, and the transmission/reception switching circuit 11 connects the selected J loop coil in the Y direction alternately. are alternately connected to the drive circuit 22 and the amplifier 24, and these operate according to a transmission/reception switching signal, which will be described later.

The signal generation circuit 7 has a predetermined frequency fO1, for example, 500kHz.
z rectangular wave signal A1, a signal B obtained by delaying the phase of the rectangular wave signal A by 90'', and a predetermined frequency fk.

For example, a 15.625 kHz transmission/reception switching signal C and a reception timing signal are generated. The rectangular wave signal A is sent as it is to the phase detector 17, and is converted into a sine wave signal E by a low-pass filter (not shown), and further converted into a sine wave signal E.
The rectangular wave signal B is sent to either the drive circuit 21 or 22 via the Y switching circuit 12, and the rectangular wave signal B is sent to the phase detector 1.
8, and the transmission/reception switching signal C is sent to the transmission/reception switching circuit 1.
0 and 11, and furthermore, a reception timing signal is sent to the reception timing switching circuit 13.

Now, assuming that information for selecting the X direction is input from the control circuit 6 to the XY switching circuit 12 and the reception timing switching circuit 13, the sine wave signal E is sent to the drive circuit 21, converted to a balanced signal, and further The signal is sent to the transmission/reception switching circuit 10, but since the transmission/reception switching circuit 10 switches and connects either the drive circuit 21 or the amplifier 23 based on the transmission/reception switching signal C, the signal is output from the transmission/reception switching circuit 10 to the selection circuit 8. The signal is a signal F that outputs and does not output a 500 kHz signal every 32 μsec for a time T (−1/2 fk ).

The signal F is passed through the selection circuit 8 to one loop coil 5x-i (i-1°2,...
-48), and the loop coil 5x-i generates a radio wave based on the signal F.

At this time, if the input pen 2 is held on the tablet 1 via the display device 3 in a substantially upright state, that is, in a used state,
The radio wave excites the coil 28 of the input pen 2, causing its tuning circuit 32 to generate an induced voltage G synchronized with the signal F.

Thereafter, when the signal F enters a no-signal period, that is, a reception period, and the loop coil 5x-i is switched to the amplifier 23 side, the radio wave from the loop coil 5x-i immediately disappears, but the induced voltage G It gradually attenuates depending on the loss within the tuning circuit 32.

On the other hand, the current flowing through the tuning circuit 32 based on the induced voltage G causes the coil 28 to emit radio waves.

The radio wave is transmitted through the loop coil 5x-L connected to the amplifier 23.
In order to excite the loop coil 5X-i in the opposite direction, an induced voltage due to the radio waves from the coil 28 is generated in the loop coil 5X-i. The induced voltage is transferred from the transmission/reception switching circuit 10 to the amplifier 23 only during the reception period.
The received signal H is then amplified and sent to the reception timing switching circuit 13.

The reception timing switching circuit 13 receives either X-direction or Y-direction selection information, here X-direction selection information,
A reception timing signal R which is essentially an inverted signal of the transmission/reception switching signal C is input, and the reception signal H is output during the period when the signal is at the high (H) level, and the reception timing signal R is output when the signal is at the low (L) level. Since nothing is output, the signal I (substantially the same as the received signal H) is obtained at its output.

The signal (2) is sent to a bandpass filter 14, which is a ceramic filter whose natural frequency is the frequency fO, and a signal J having an amplitude corresponding to the energy of the acid component at the frequency fO in the signal (2). (Strictly speaking, in a state in which several signals I are input to the bandpass filter 14 and converged) are sent to the detector 15 and phase detectors 17 and 18.

The signal J input to the detector 15 is detected and rectified,
After being converted into a signal, it is converted by a low-pass filter 16 with a sufficiently low cutoff frequency into a DC signal having a voltage value corresponding to approximately 1/2 of the amplitude, for example, Vx, and sent to the control circuit 6.

The signal voltage 1mVx is a value that depends on the distance between the input pen 2 and the loop coil 5x-i, and in the case of 22, it is approximately inversely proportional to the fourth power of the distance.
Since it changes when i is switched, the control circuit 6 converts the voltage value VX obtained for each loop coil into a digital value, and performs the arithmetic processing described below on these values, so that The coordinate value of the direction is determined.

Incidentally, the coordinate value in the X direction of the position indicated by the input bench 2 is also obtained in the same manner.

On the other hand, the rectangular wave signals A and B are input to the phase detectors 17 and 18 as detection signals, and at this time, the signal J
Assuming that the phase of the square wave signal A almost matches that of the rectangular wave signal A, the phase detector 17 outputs a signal Ml (substantially the same as the signal) which is the positive inversion of the signal J, and the phase The detector 18 outputs a signal M2 having a symmetrical waveform on the positive and negative sides.

The signal Ml is passed through the same low-pass filter 19 as the signal J.
The signal M2 is converted into a DC signal Nl (substantially the same as the signal) having a voltage value corresponding to approximately 1/2 of the amplitude of VX, and sent to the control circuit 6. The signal M2 from the phase detector 18 is converted into a DC signal N2 and sent to the control circuit 6. Here, since the positive and negative components of the signal M2 from the phase detector 18 are the same, the voltage value of the output of the low-pass filter 20 is It becomes 0 [v].

The control circuit 6 converts the output values of the low-pass filters 19 and 20, in this case the signals Nl and N2, into digital values, and further uses these digital values to perform calculation processing according to the following equation (1), and then converts the output values of the low-pass filters 19 and 20 into digital values. The phase difference θ between the signal added to signal 18, here J, and the rectangular wave signal A is determined.

θ--jan-' (VQ/VP)
...11) However, vP indicates a digital value corresponding to the output of the low-pass filter 19, and VQ indicates a digital value corresponding to the output of the low-pass filter 20. for example,
In the case of the signal J described above, the voltage value of the signal N1 is Vx, but the voltage value of the signal N2 is 0 [V], that is, VQ-0, so the phase difference is θ-0''.

By the way, the phase of the signal J is determined by the tuning circuit 3 of the input Ben 2.
2 varies depending on the tuning frequency at 2. That is, when the tuned frequency in the tuned circuit 32 matches the predetermined frequency fO, an induced voltage of the frequency fO is generated in the tuned circuit 32 during both the signal transmission period and the signal reception period, and an induced current synchronized with this flows, the frequency and phase of the received signal H (or I) match those of the rectangular wave signal A, and the phase of the signal J also matches those of the rectangular wave signal A.

On the other hand, if the tuned frequency in the tuned circuit 32 does not match the predetermined frequency fO, for example, if the frequency is slightly lower than the frequency fO, for example fl, the tuned circuit 32 receives an induced voltage at the frequency fO during the signal transmission period. However, at that time, an induced current with a phase delay flows through the tuned circuit 32, and an induced voltage of approximately frequency fl and an induced current synchronized with this flow during the signal reception period, so that the received signal H The frequency of (or I) is the square wave signal A
The frequency is slightly lower than that of , and its phase is also slightly delayed. As mentioned above, since the bandpass filter 14 has only the frequency fO as its frequency, the frequency shift toward the lower side of the input signal is outputted as a phase lag, and therefore the phase of the signal J is the received signal H
It is even later than (or ■).

Conversely, if the tuning frequency in the tuning circuit 32 is slightly higher than the predetermined frequency fO, for example f2,
During the signal transmission period, the tuning circuit 32 has a frequency fO
An induced voltage of f2 is generated, but at that time, an induced current with a phase lead flows through the tuned circuit 32, and an induced voltage of approximately frequency f2 and an induced current synchronized with this flow during the signal reception period. The received signal H (or its frequency is slightly higher than the frequency of the rectangular wave signal A, and
Its phase is also slightly advanced. In the bandpass filter 14, a shift in the frequency of the input signal toward the higher side is outputted as a phase lead, contrary to the case described above, and therefore, the phase of the signal J is higher than that of the received signal H (or I). It becomes even more advanced.

As mentioned above, the tuning frequency of the tuning circuit 32 is
Since it changes continuously according to the pen pressure applied to the (1)
) The phase difference θ determined by the formula changes continuously according to the pen pressure. In this embodiment, the phase difference θ is set in advance so that when no writing pressure is applied to the human pen 2, the phase difference θ is approximately 160@, and when the maximum writing pressure is applied, it is approximately 60@.

The submerged phase difference θ is added by 40″ and becomes 20″ to 1
The phase information is converted into phase information with a value in the range of 00'' and sent to the host computer 4 along with the coordinate values of the indicated position in the X and Y directions. You may do so.)

Next, with reference to FIGS. 6 to 10, a detailed description will be given of the coordinate detection operation, the phase detection operation, and how image data is created based on the coordinate values and phase information of the indicated position.

First, when the entire device is powered on and enters the measurement start state, the control circuit 6 sends information for selecting the X direction to the XY switching circuit 12 and reception timing switching circuit 13, and also Loop coil 5x-1~5
Information for selecting the first loop coil 5x-1 among x-48 is sent to the selection circuit 8, and the loop coil 5x-1 is connected to the transmission/reception switching circuit 10.

The transmission/reception switching circuit 10 switches the loop coil 5x-1 to the drive circuit 21 and the amplifier 2 based on the transmission/reception switching signal C described above.
3 alternately, but in this case, the drive circuit 21 is connected to 32μ
sec, 16 sine wave signals of 500kHz as shown in FIG. 7(a) are transmitted to the loop coil 5.
(Only five of them are shown in FIG. 5 for convenience of drawing.)

The switching between transmission and reception is repeated seven times for one loop coil, here 5x-1, as shown in FIG. 7(b). These seven transmission and reception repetition periods correspond to one loop coil selection period (448 μsec).

At this time, an induced voltage is obtained at the output of the amplifier 23 for one loop coil every seven reception periods, but this induced voltage is passed through the reception timing switching circuit 13 to the bandpass filter 14 as described above. It is sent out, averaged, and sent to detector 1.
5. Phase detector 17゜18 and low pass filter 16, 19
．． The signal is sent to the control circuit 6 via 20.

The control circuit 6 inputs the output value of the low-pass filter 16 after A/D conversion, and temporarily stores it as a detected voltage, for example, Vxl, which depends on the distance between the input pen 2 and the loop coil 5x-1.

Next, the control circuit 6 sends information for selecting the loop coil 5x-2 to the selection circuit 8, connects the loop coil 5x-2 to the transmission/reception switching circuit 10, and connects the input vent 2 and the loop coil 5x.
'-2, the detection voltage VX2 that depends on the distance from the loop coil 5x-3 to 5x-48 is obtained and stored.
are sequentially connected to the transmission/reception switching circuit 10, and the detection voltage Vxl-Vx4g depending on the distance in the X direction from the input bend 2 for each loop coil as shown in FIG. c), only a part of which is shown in analog representation) is stored.

As shown in FIG. 8, the actual detected voltage is obtained only in several loop coils around the position (xp) where the input vent 2 is placed.

The control circuit 6 checks whether the voltage value of the memorized detection voltage is above a certain detection level, and if it is below the certain detection level, selects each loop coil in the X direction and performs voltage detection again. Repeatedly, if the detection level is above a certain level, proceed to the next process.

Next, the control circuit 6 sends selection information in the Y direction to the XY switching circuit 12 and the reception timing switching circuit 13, and switches the selection circuit 9 and the transmission/reception switching circuit 11 in the same manner as described above, thereby controlling the low frequency range when transmitting and receiving radio waves. Input Ben 2 obtained by A/D converting the output value of the filter 16 and each loop coil 5 in the Y direction
The detected voltage depending on the distance to y-1 to 5y-48 is temporarily stored. After that, a level check is performed in the same manner as above, and if it is below a certain detection level, the process returns to selection of each loop coil in the X direction and voltage detection, and if it is above a certain detection level, the above memorized From the electric value, as described later, the X direction and Y direction of the position indicated by the input ben 2
Calculate the coordinate values of the direction.

Next, the control circuit 6 controls the loop coil 5x-1 in the X direction.
~5x-48 (or Y-direction loop coil 5y-1~
5y-48), the selection circuit 8(
or 9), and repeats the transmission and reception of the radio waves a plurality of times, for example, 7 times. At that time, the output values obtained from the low-pass filters 19 and 20 are A/D converted, and the phase difference θ is calculated as described above. Calculate.

The phase difference θ is added by 40° and is transferred to the host computer 4 together with the X- and Y-direction coordinate values of the position indicated by the input bench 2 described above.

When the first coordinate detection operation and phase detection operation are completed in this way, the control circuit 6 starts the second coordinate detection operation and the phase detection operation as shown in FIG.
As the coordinate detection operation after the first time, a certain number of loop coils, for example, 10 loop coils, around the loop coil from which the maximum detection voltage was obtained among the loop coils 5x-1 to 5x-48 in the X direction, are used. The information for selecting only the
Among 1 to 5y-48, centering on the loop coil where the maximum detection voltage was obtained, a certain number of 10
The information for selecting only the main loop coil is sent to the selection circuit 9, the output value is obtained in the same manner as described above, and the coordinate detection operation in the X direction and Y direction and the phase detection operation are performed for the input Ben 2, and the obtained instruction is The position coordinates/values and phase information are transferred to the host computer 4, and these steps are repeated hereafter.

To explain the level check mentioned above in detail, it checks whether the maximum value of the detection voltage has reached the detection level and which loop coil has the maximum detection voltage, and then checks whether the maximum value of the detection voltage has reached the detection level. If the position has not been reached, the subsequent coordinate calculations etc. are stopped, and the center of the loop coil to be selected in the next coordinate detection operation and position detection operation is set.

As one calculation method for determining the coordinate value in the X direction or the Y direction, for example, the coordinate value xp, the detection voltages Vxl to V
There is a method of approximating the waveform near the maximum value of x48 by an appropriate function and finding the coordinates of the maximum value of the function.

For example, in FIG. 7(C), the maximum detection voltage VX3
By approximating the detected voltages Vx2 and Vx4 on both sides by a quadratic function, it can be calculated as follows (however, the coordinate values of the center position of each loop coil 5x-1 to 5x-48 are x48, and the interval is ΔX.)
. First, from each voltage and coordinate value, Vx2-a(x2-xp) +b -(2)
VX3-a(x3-xp) +b -'-
(3) VX4-a (x4-xp) +b
-=14). Here, a and b are constants (ago
).

Also, x3−x2−Δx −−−−−−(
5) x4 −x2 −2 Δx
--------(B). Substituting equations (5) and (Q) into equations <3) and (4), we get xp-x2+Δx/2 ((3VX2-4Vx3+
Vx4)/ (Vx2-2 Vx3+ Vx4)1・
...(7) becomes.

Therefore, from each of the detection voltages Vxl to Vx48, the maximum detection voltage obtained during the level check and the detection voltages before and after it are extracted, and these and the detection voltage of the loop coil from which the maximum detection voltage was obtained are extracted. The coordinate value xp of the input bend 2 can be calculated by performing an operation corresponding to the above-mentioned equation (7) from the coordinate value (known) of the previous loop coil.

On the other hand, the host computer 4 stores, as valid data, only data in which the phase information is 1° or more among the data sent from the control circuit 6 according to the flowchart shown in FIG. The spread information of the figure indicating the point) is converted into, for example, the diameter of a circle (for example, converted into a value proportional to the phase information), and the coordinate position based on the coordinate values in the X and Y directions in an image memory (not shown) is converted. A circle shape having a diameter is drawn and sent to the display device 3, where it is displayed on the screen.

The above processing is performed while data is being transferred from the control circuit 6.
Since this is repeated, when the input pen 2 is moved while changing the writing pressure, circular shapes 34 with different diameters are lined up in a continuous manner along the trajectory 33 of the indicated position as shown in FIG. An image with arbitrary line thickness can be obtained like this.

FIGS. 12(a) and 12(b) show other examples of images displayed by this device. FIG. (bl) is “
This is an image obtained by inputting the kanji ``effort'' and then filling in the inside of the circle.

Note that the obtained image can be made into a hard copy using a printer (not shown) or the like, if necessary, or can be transmitted to another device via a telephone line or the like.

Further, in the above embodiment, the phase information is converted into the diameter of the circle indicating the indicated position, but by changing the program of the host computer 4, it is possible to convert the phase information into the diameter of the circle indicating the indicated position.
It can be converted into the major axis of an ellipse, the length of a rectangle, etc.

Furthermore, as shown in FIG. 13, in a rectangular figure 35 whose length changes depending on the phase information, if a "partially broken rectangle 35'" is inserted corresponding to a predetermined range of phase information, " An image 36 expressing "fading" can be obtained.

In addition, by changing the program of the host computer 4, the phase information can be changed to the density of the selected predetermined color of the point indicating the indicated position or the predetermined area including the indicated position (
It can also be converted into information representing brightness), hue, etc.
It can also be applied to various designs.

FIGS. 14 and 15 show flowcharts corresponding to the programs of the host computer 4 when converting phase information into the aforementioned density information and into hue information.

FIGS. 16(a) and 16(b) show another example of an input indicator, in which a pen shaft 37, a core body 38, and a core body 38 made of a non-metallic material such as synthetic resin are inserted. A ferrite core 39 that can be accommodated in a freely movable manner, a coil spring 40, and a plastic core 39. Shuswitch 41. It consists of a tuning circuit 45 consisting of a coil 42 wound around a ferrite core 39, a capacitor 43, and a variable capacitor (variable capacitor) 44, and a rotary operating knob 46 attached to the shaft of the variable capacitor 44.

As shown in FIG. 17, the coil 42 and capacitor 43 are connected in series to form a well-known resonant circuit, and the inductance of the coil 42 and the capacitance of the capacitor 43 are determined by the resonance (tuning). ) The frequency is set to approximately the above-mentioned frequency fO.

Further, the variable capacitor 44' is connected to both ends of the capacitor 43 via the bush switch 41.

When the bush switch 41 is pressed into the pen shaft 37 by holding the pen shaft 37 with a hand or the like and pressing the tip of the core body 38 onto an input surface etc., the coil spring 4 is activated by the rear end.
The capacitance value of the variable capacitor 44 can be changed continuously by rotating a knob 46.

According to the input indicator described above, arbitrary phase information can be sent to the tablet 1 side by operating the variable capacitor 44, and the thickness of the line or the density or hue of a predetermined color can be changed. can.

FIG. 18 shows still another embodiment of the input indicator, in which the variable capacitor 44 is operated by a slide-operated knob instead of the rotary-operated knob 46 in the input indicator shown in FIG. It is designed to be operated.

That is, in the figure, reference numeral 47 denotes a slide-operated knob, which is attached to the side surface near the tip of the pen shaft 48 so as to be slidable along the axial direction, and rotates the aforementioned variable capacitor 44 via a mechanism (not shown). It seems to be moving. According to this input indicator, it is possible to change the phase information by operating the knob 47 with one hand while indicating the position on the tablet 1 side. Note that the other configurations and operations are similar to the embodiment shown in FIG. 16.

FIG. 19 shows yet another embodiment of the input indicator, in which the housing 49 is made of a non-metallic material such as synthetic resin, and one end of the casing 49 is made of a transparent material such as plastic with a "+" indicator provided on the bottom. An index device 50 is attached, and a bush switch 5 w l is mounted on the top surface.

s w 2 , s w 3 , s w 4 and a variable capacitor dial 51 to be described later are attached,
Further, a coil L is provided around the indicator 50 so as to surround it, and a tuning circuit, which will be described later, is built inside the casing 49.

FIG. 20 shows the configuration of the tuning circuit built into the housing 49, which includes the above-mentioned coil and bush switch s w.
1 to sw4 as well as capacitor cl.

C2, C3, C4 and variable capacitor (varicon) C5
It consists of Each of the bushing switches swl to sw3 is connected in series via its normally closed contact NC and common contact C. That is, the contact NC of the switch s w l is connected to the contact C of the switch s w 2, and the contact NG of the switch s w 2 is connected to the contact C of the switch s w 3. Further, the contact C of the switch s w l is connected to one end of the coil L, and the other end of the coil L is connected to one end of the capacitors 01 to C4. Also,
capacitor cl.

The other ends of C2 and C3 are connected to normal oven contact No. of switches swl and sw2°sw3, respectively.

The other end of capacitor C4 is the contact N of switch sw3.
Connected to C. Also, the variable capacitor c5 is switch s
It is connected to both ends of the capacitor c4 via w4.

The inductance of the coil L and the capacitance value of the capacitor c4 have a resonance (tuning) frequency approximately equal to the above-mentioned frequency f.
The value is set to O. Also, capacitor C1*
c2. The capacitance value of c3 is set to such a value that, when combined with the coil L, its resonance (tuning) frequency is slightly different from the frequency fO. In addition, the capacitance value of variable capacitor c5 is such that when it is connected to capacitor c4 via switch sw4, its resonance (tuning) frequency is slightly different from frequency fO (however, when coil L and capacitor C1 or C2 or C3 (a frequency within a range different from the frequency when the dial 51 is combined) is set to a value that changes continuously in accordance with the operation of the dial 51.

Therefore, according to this input indicator, the switch s w
By operating switches 1, sw2, or sw3, preset phase information can be sent to the tablet 1 side, and when switches s and w4 are operated, continuous phase information can be sent according to the operation of the dial 51. Can send information.

Note that the number of loop coils and the arrangement thereof in the embodiments are merely examples, and it goes without saying that the present invention is not limited thereto.

(Effects of the Invention) As explained above, according to the coordinate input device of the present invention, the position detection unit A radio wave having the predetermined frequency is generated, and at this time, the radio wave reflected from the tuning circuit is also detected by the position detection section, and from the detected radio wave, the coordinate value of the position indicated by the manual indicator is determined. Find the change in tuning frequency in radio waves as a change in phase with respect to a given frequency,
Since the information obtained from these is displayed on the display device, the input indicator only needs to be equipped with a tuning circuit, eliminating the need for cables, and also eliminating the need for heavy parts such as batteries and magnets. It has good operability during work, and there is no need to provide pressure-sensitive sensors etc. throughout the coordinate input range as in the past, and other information can be accurately detected at any part of the coordinate input range. Therefore, information obtained from the coordinate values of the position indicated by the input indicator and other information can be accurately displayed on the display device.

Further, according to the coordinate input device of the present invention, the phase information can be continuously changed according to the operation, and the continuously changing phase information and the information obtained from the coordinate values of the indicated position can be displayed on the display device. can be displayed.

Further, according to the coordinate input device of the present invention, radio waves are transmitted and received between one of the loop coil groups in the X direction and the Y direction and a tuned circuit in the input indicator, and at this time, the one loop coil in the X direction and the Y direction The AC signal generated in the loop coil is detected and this is repeated for all the loop coils, so no matter where the input indicator is on the position detection section, the coordinates and phase of the indicated position, i.e. Other information can be obtained with high accuracy.

Further, according to the coordinate input device of the present invention, since the flat display device is superimposed on the tablet, a figure indicating the indicated position is displayed at the display position of the display device corresponding to the indicated position by the input indicator, for example. In addition, at this time, information corresponding to the operation on the input indicator can be displayed, and the user can work while confirming the operation on the input indicator.

Further, according to the coordinate input device of the present invention, the phase is converted into the spread information of the figure indicating the indicated position and displayed, so that the figure having the spread corresponding to the operation of the input indicator is displayed. It can be displayed at a display position on the display device corresponding to the coordinate values of the position indicated by the input indicator.

Further, according to the coordinate input device of the present invention, since the phase is converted into density information of a predetermined color at the indicated position and displayed, the density of the predetermined color corresponding to the operation of the input indicator is displayed. The information that it has can be displayed on the display device.

Further, according to the coordinate input device of the present invention, since the phase is converted into hue information at the indicated position and displayed, information having a hue corresponding to the operation of the input indicator is displayed on the display device. be able to.

Furthermore, according to the input indicator of the present invention, it is possible to change the phase detected by the coordinate input device by simply changing the pressure applied to the core. It can be changed according to the pressure, and an image similar to that when using a brush can be displayed by simply operating the input indicator on the tablet as if using a normal brush.

Furthermore, according to the input indicator of the present invention, it is possible to change the phase detected by the coordinate input device by simply changing the operation on the adjuster. It can be changed and displayed according to the operation.

Furthermore, according to the input indicator of the present invention, the phase detected by the coordinate input device can be changed simply by operating the rotary type adjuster, slide type adjuster, or dial type adjuster. For example, there is an advantage that the spread of a figure indicating the designated position can be changed and displayed in accordance with the operation of the switch.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an overview of an embodiment of the coordinate input device and its input indicator of the present invention, Fig. 2 is a block diagram showing details of the tablet as well as the tuning circuit of the human pen, and Fig. 3 is the position A detailed configuration diagram of the loop coil group in the X and Y directions of the detection unit, Figure 4 is a cross-sectional view of the input pen, Figure 5 is a signal waveform diagram of each part of Figure 2, and Figure 6 is the processing in the control circuit. 7(a), (b), and (c) are timing diagrams showing the basic coordinate detection operation in the control circuit, and FIG. 8 shows the timing diagram obtained from each loop coil during the first coordinate detection operation. Figure 9 is a diagram showing the detection voltage; Figure 9 is a timing diagram showing the coordinate detection operation and phase detection operation from the second time onwards;
Figure 11 is a flowchart of processing in the host computer.
The figure shows the displayed image when the input pen is moved while changing the pen pressure, Figures 12(a) and (b) are diagrams showing other examples of the displayed image, and Figure 13 shows the display image corresponding to the phase information. An explanatory diagram showing another example of a figure showing a changing indicated position and an example of a display image drawn by this figure, FIG. 14 corresponds to a host computer program when converting phase information into density information of a predetermined color. FIG. 15 is a flowchart of the process corresponding to the host computer program when phase information is converted to hue information, and FIG. 16(a) is a sectional view showing another embodiment of the input indicator. , Figure 16 (b
) is an enlarged side view of the main part of the input indicator in FIG. 16(a),
FIG. 17 is a block diagram of the tuning circuit of the input indicator shown in FIG. 16, FIG. 18 is a side view of main parts showing still another embodiment of the input indicator, and FIG. 19 is a further diagram of the input indicator. FIG. 20, a perspective view showing another embodiment, is a configuration diagram of a tuning circuit of the manual indicator shown in FIG. 19. DESCRIPTION OF SYMBOLS 1...Tablet, 2...Input pen, 3...Display device, 4...Host computer, 5...Position detection unit, 5x...X direction loop coil group, 5y... Y
direction loop coil group, 6... control circuit, 7... signal generation circuit, 8... X direction selection circuit, 9... Y direction selection circuit, 10.11... transmission/reception switching circuit , 12・
...XY switching circuit, 13... Reception timing switching circuit, 14... Bandpass filter, 15... Detector, 16° 19.20... Low pass filter, 17.18... place)
1 detector, 28... coil, 31... capacitor,
32...tuned circuit.

Claims (12)

[Claims] (1) An input indicator having a tuning circuit whose tuning frequency changes around a predetermined frequency according to the operation, a radio wave generating means for generating radio waves of the predetermined frequency, and a radio wave reflected from the tuning circuit. a radio wave detection means for detecting; a coordinate detection means for determining the coordinate values of the position indicated by the input indicator based on the radio waves detected by the radio wave detection means; A coordinate input device comprising: a tablet having a phase detection means for detecting a change in the tuning frequency in the tuning circuit as a change in phase with respect to the predetermined frequency; A coordinate input device comprising a display device that displays information. (2) The coordinate input device according to claim (1), further comprising an input indicator having a tuning circuit whose tuning frequency changes continuously around a predetermined frequency in response to an operation. (3) A position detection unit having a tablet with a loop coil group in the X direction, which is formed by arranging a large number of loop coils in parallel in the X direction, and a loop coil group in the Y direction, which is formed by arranging a large number of loop coils in parallel in the Y direction. , X-direction selection means for sequentially selecting one loop coil from a group of loop coils in the X direction of the tablet, and Y-direction selection means for sequentially selecting one loop coil from a group of loop coils in the Y direction of the tablet. and signal generating means for generating an alternating current signal of the predetermined frequency; signal detecting means for detecting the alternating current signal of the predetermined frequency; and the X direction and Y direction selected by the X direction and Y direction selection means. connection switching means for alternately connecting the signal generating means and the signal detecting means to each loop coil in the X direction and the Y direction, based on the AC signal detected by the signal detecting means from each of the loop coils in the X direction and Y direction, coordinate detection means for obtaining coordinate values in the X direction and Y direction of a position indicated by the input indicator; and input based on an AC signal detected by the signal detection means from one loop coil in the X direction or Y direction and a phase detection means for detecting a change in the tuning frequency in the tuning circuit of the indicator as a change in phase with respect to the predetermined frequency.
2) The coordinate input device described above. (4) Claim (1) characterized in that a flat display device is used as the display device and is superimposed on a tablet.
The coordinate input device according to any one of (3) to (3). (5) Claim (1) characterized in that the phase is converted into spread information of a figure indicating the indicated position and displayed.
The coordinate input device according to any one of (4) to (4). (6) Claim (6) characterized in that the phase is converted into density information of a predetermined color at the indicated position and displayed.
1) The coordinate input device according to any one of (4). (7) Claims (1) to (7) characterized in that the phase is converted into hue information at the indicated position and displayed.
4) Any coordinate input device. (8) It has a core supported movably in the axial direction of a pen-shaped housing, and is equipped with a tuning circuit whose tuning frequency changes around a predetermined frequency in accordance with the pen pressure applied to the core. An input indicator characterized by: (9) An input indicator characterized by having a manually operable adjuster, and a tuning circuit whose tuning frequency changes around a predetermined frequency in accordance with the operation of the adjuster. (10) The input indicator according to claim (9), characterized in that a rotary actuated regulator is used. (11) The input indicator according to claim (9), characterized in that a slide-operated adjuster is used. (12) The input indicator according to claim (9), characterized in that a dial-operated regulator is used.