JP2796606B2 - Position input device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position input device for inputting position information to an electronic device such as a computer, and more particularly to a wireless position input device utilizing an electromagnetic induction phenomenon.

[0002]

2. Description of the Related Art Conventionally, this type of position input device excites a sense line with an excitation signal generated from an excitation circuit, and resonates a resonance circuit provided in the position indicator by a magnetic field generated from the sense line. The generated magnetic field is detected by another sense line, and this detection signal is amplified to obtain position information from the amplitude of the detection signal.

Further, as means for detecting the setting state of state setting means such as a switch provided in the position indicator on the main body side,
The resonance frequency of the resonance circuit provided in the position indicator is slightly changed by the state setting means, and the position input device body is set by detecting the phase difference between the reference excitation signal and the detection signal from the sense line. Detection was realized.

In addition, a large number of switches are mounted on the position indicator,
When a large number of status settings are required or when the status indicator needs to be extended, such as by providing a pen pressure detection function on the position indicator, slight changes in phase can be detected accurately and stably on the main unit. A detection circuit that can perform the detection is secured, and the resonance frequency of the resonance circuit is accurately adjusted during the manufacture of the position indicator. This has been achieved by using parts with good stability to obtain high stability.

[0005]

However, the conventional position input device of this type requires an excitation circuit and a phase difference detection circuit, and the circuit becomes more and more required to expand the state setting such as multiple switches. High precision and stability have been demanded, and such demands have complicated the circuit on the main body side and made miniaturization difficult.

Further, the position indicator has a problem that the adjustment work in the manufacturing process is increased and the cost is increased. As a result, it is difficult to expand the state setting means such as multi-switching and pen pressure detection. Was. An object of the present invention is to eliminate the excitation circuit and the phase difference detection circuit without using the conventional method of exciting the resonance circuit by a reference signal such as an excitation signal and detecting a response thereof, thereby simplifying the circuit. Moreover, it is an object of the present invention to provide a position input device which can easily obtain expandability of the state setting means. More specifically
Aims to: (1) Excitation circuit and phase difference detection circuit are eliminated to simplify the circuit
Oscillation amplitude information of the formed oscillation circuit
From which the position information of the position indicator can be easily obtained from
To implement a remote input device. (2) Excitation circuit and phase difference detection circuit are eliminated to simplify the circuit
It is possible to use multiple switches on the position indicator
Position where the status of the status setting means can be detected
To realize an input device. (3) Excitation circuit and phase difference detection circuit are eliminated to simplify the circuit
And any of the position indicators indicate
A position input device that can detect
thing. (4) As a combination of these purposes,
Circuit and phase difference detection circuit are eliminated to simplify the circuit.
Detect which of multiple position indicators is pointing
Yes, with multiple switches on the position indicator
Input that can detect the status of the status setting means
To realize the device.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned problems
To, in a first configuration of a position input device according to the present invention, amplification
A circuit; first coupling means connected to the output of the amplifier circuit;
Second coupling means connected to the input of the amplifier circuit;
Means and a position indicator having a resonance circuit.
The oscillation circuit is connected to both the first coupling means and the second coupling means.
By having magnetic coupling, the amplifier circuit and the first coupling hand
Form a feedback loop with the stage and the second coupling means,
An oscillation circuit that oscillates at a frequency corresponding to the resonant frequency of the
Forming and position detecting means, the position indicator and the first coupling means
And the distance between the second coupling means and the oscillation circuit of the oscillation circuit.
The relationship between the width and the amplitude information based on the width is stored in advance.
Refer to the table for oscillation amplitude information
Input device to obtain position information of position indicator
Was configured. Also, the second position input device of the present invention
In the configuration, in the position input device of the first configuration,
The first connecting means is parallel to one of the XY rectangular coordinate axes,
And multiple sense lines laid at equal intervals
A first sense line group and a first sense line group
The next selection circuit, which is connected to the output of the amplification circuit
One scanning circuit, and the second coupling means comprises the other axis.
Multiple sense licenses laid in parallel to each other and at equal intervals
A second sense line group consisting of
A circuit that sequentially selects the power supply group and is connected to the input of the amplifier circuit
A second scanning circuit, and the position detecting means
The oscillation of the oscillation signal obtained by scanning the first and second scanning circuits
Position indicator by referring to the table with width information
The position input device is configured so as to obtain the position information. Ma
In the third configuration of the position input device according to the present invention,
In the position input device of the first or second configuration, the resonance circuit
State setting means for changing the resonance frequency of the circuit;
Detects the state set by the state setting means from wave number information
The position input device is constituted by providing a state detecting means for performing the operation.

Further, the position input device according to the fourth aspect of the present invention.
Configuration, the amplifier circuit and the second circuit connected to the output of the amplifier circuit
One coupling means and a second coupling connected to the input of the amplifier circuit.
Means and a plurality of switches connected in parallel to the resonance circuit and the resonance circuit.
Position indicator having state setting means having a switch
Connected to the input or output side of the amplifier circuit to indicate the position
Position detection means for obtaining information on the position indicated by the detector,
Road input or output Connected to the side and the state of the state setting means
And a state detecting means for detecting
It is electromagnetically coupled to both the first coupling means and the second coupling means.
Thus, the amplifier circuit, the first coupling means, and the second coupling
Form a feedback loop with the combination means, set the resonance circuit and state
Oscillates at the resonance frequency determined by the means
An oscillation circuit is formed, and the position detecting means is provided with an oscillation signal of the oscillation circuit.
The position information of the position indicator is obtained from the amplitude information of the
The stage is set by the state setting means from the frequency information of the oscillation signal.
The position input device was configured to detect the fixed state.
In the fifth configuration of the position input device according to the present invention,
Width circuit and first coupling means connected to the output of the amplifier circuit
And second coupling means connected to the input of the amplifier circuit;
Multiple position indicators with circuit and input side of amplifier circuit
Alternatively, it is connected to the output side and information on the position indicated by the position indicator
Position detection means for obtaining information and the input or output of the amplifier circuit.
Connects to the force side and indicates any one of multiple position indicators
And status detection means for detecting whether the device is instructing
And the resonance circuit includes first coupling means and second coupling means.
The electromagnetic coupling with both of the above, the amplification circuit and the first
Form a feedback loop with the coupling means and the second coupling means;
Oscillates at the resonance frequency determined by the resonance circuit
An oscillation circuit, and the position detection means
Obtain the position information of the position indicator from the amplitude information of the signal and detect the state
The means may include a plurality of position indicators based on frequency information of the oscillation signal.
To detect which position indicator is pointing.
A position input device was constructed. Also, according to the present invention,
In a sixth configuration of the force device, the amplifier circuit and the output of the amplifier circuit
And the first coupling means connected to the input of the amplifier circuit.
Connected to the resonance circuit and the resonance circuit in parallel with the second coupling means.
And state setting means having a plurality of switches.
A plurality of position indicators, the resonance circuit and the state setting means;
The resonance frequency determined by each position indicator
Position indicators set differently from each other
Connected to the input or output side of the amplifier circuit to indicate the position
Position detection means for obtaining information on the position indicated by the detector,
Connected to the input or output side of the road
Which position indicator is pointing and the status
And state detecting means for detecting the state of the setting means.
And the resonance circuit includes the first coupling means and the second coupling means.
By electromagnetically coupling with both, the amplifier circuit and the first Result
Form a feedback loop with the combining means and the second combining means,
Oscillates at the resonance frequency determined by the oscillation circuit
An oscillation circuit is formed, and the position detecting means is provided with an oscillation signal of the oscillation circuit.
The position information of the position indicator is obtained from the amplitude information of the
The stage is based on the frequency information of the oscillation signal.
Which position indicator is pointing and the status setting
Position input device to detect the state set by the step
Was configured. In addition, the position input device according to the seventh aspect of the present invention.
In the configuration, the position input device according to any one of the fourth to sixth configurations is provided.
In addition, the first coupling means includes at least an XY orthogonal coordinate axis.
A plurality of cells laid parallel to one axis and equally spaced from each other
A first sense line group including sense lines and a first sense line group.
This is a circuit for sequentially selecting a set of
A first scanning circuit connected to the input and a second coupling
The means is at least parallel to the other of the XY rectangular coordinate axes.
And multiple sense lines laid at equal intervals
The second sense line group and the second sense line group
The next selection circuit, which is connected to the input of the amplification circuit
The position input device is composed of two scanning circuits.
Was.

Further, an eighth aspect of the position input device according to the present invention.
In the configuration of the above, in the position input device of the seventh configuration,
The first sense line group includes n sense lines.
And the second sense line group is composed of m sense lines.
Selected when the oscillation amplitude information indicates the maximum value.
Senses in the selected first and second sense line groups
If the lines are i-th and j-th, respectively,
And the selected combination of the second sense line group is
{(I-1) th, jth} and ｛(i + 1) th respectively
Eye, j-th, {i-th, (j-1) -th}, #i
Eye, (j + 1) th} and {ith, jth}
Information of the five oscillations and the first and second scanning times
Position indication based on each scanning signal for scanning the road
The position input device was configured to obtain the position information of the vessel. Sa
Furthermore, in the ninth configuration of the position input device according to the present invention,
Is a position input device having the first to eighth configurations,
Select a particularly high-performance amplifier that constitutes the present invention
Amplification so that there is no need to
Degree and phase characteristics The range of resonance frequency that shows stable characteristics
I used it. That is, the resonance circuit or
Frequency determined by the oscillation circuit and the state setting means
Range from 100 kHz to 1 MHz.
An input device was constructed.

[0010]

In the position input device according to the present invention, when there is a distance between the first and second coupling means and the resonance circuit, that is, when there is no magnetic coupling between the first and second coupling means and the resonance circuit, the feedback between the input and output of the amplifier circuit is not performed. It is not configured and does not oscillate. However, when the distance between the first and second coupling means and the resonance circuit is reduced and magnetic coupling occurs with each other, the output of the amplification circuit, the first coupling means, the resonance circuit, the second coupling means, and the amplification circuit A positive feedback loop having a series of input paths is formed, and oscillation occurs at the resonance frequency of the resonance circuit. The oscillation amplitude appearing in the positive feedback loop changes according to the feedback amount determined by the distance between the first and second coupling means and the resonance circuit. The closer the distance, the larger the feedback amount and the larger the oscillation amplitude. As the distance increases, the feedback amount decreases and the oscillation amplitude decreases. Therefore, the position detecting means can obtain the position information of the position indicator provided with the resonance circuit from the oscillation amplitude. Up
In the first to third configurations, the position indicator and the first
The distance between the coupling means and the second coupling means;
The relationship with the oscillation amplitude that appears in the return loop is stored in advance.
Table. Therefore, the oscillation amplitude information
When input to the table, it corresponds to the oscillation amplitude information.
Data is obtained. Based on that data,
Location information can be obtained.

Further, in the fourth configuration, a state setting means for changing a resonance frequency of the resonance circuit is provided,
When the resonance frequency of the resonance circuit is changed by the setting means,
As a result, the oscillation frequency that appears in the positive feedback loop
Change as well. Therefore, the state detection means uses this frequency information
To detect the state set by the state setting means.
Can be In the fifth configuration, a plurality of
Circuit with different resonance frequency for each position indicator
Are provided, and when indicated by each position indicator, the finger
Oscillation for each position indicator shown appearing in the positive feedback loop
The frequency changes as well. Therefore, the state detection means
Detects wave number information and indicates which position indicator is pointing
Can be detected. Further, in the sixth configuration,
Have a different resonance frequency for each of the plurality of position indicators
Provide a resonance circuit and change the resonance frequency of the resonance circuit.
Condition setting means for each position indicator.
The resonance frequency of the resonance circuit by the state setting means.
Changes the status setting for each indicated position indicator.
Appears in the positive feedback loop for each state set by the
The oscillation frequency changes in the same manner. Therefore, the state detection means
This frequency information is detected, and any
Status and the status set by the status setting means.
Can be detected.

In the seventh configuration , the first coupling means is a first sense line group, the second coupling means is a second sense line group, and the first and second scanning circuits are respectively provided. When provided, the resonance circuit forms a positive feedback loop by coupling both the sense lines sequentially selected by the first scanning circuit and the sense lines sequentially selected by the second scanning circuit, For example, the first
When the sense line selected by the scanning circuit is located immediately below the resonance circuit and the sense line selected by the second scanning circuit is located immediately below the resonance circuit, the maximum oscillation amplitude is obtained and selected. As the sense line becomes farther from the resonance circuit, the oscillation amplitude becomes smaller. The position detecting means can obtain the position information of the position indicator from the amplitude information of the oscillation signal obtained by scanning the first and second scanning circuits. In the eighth configuration, the five oscillation signals
By comparing and calculating the
It is possible to obtain detailed positional information finer than that of the first position. Ma
In the ninth configuration, the amplifier constituting the present invention is
There is no need to select a high performance one,
Since characteristics can be used in a stable range, it is easy to design
An input / output device can be realized.

An AG for controlling the degree of amplification of the amplifier circuit
In the case where the C circuit is provided, the amplification degree of the amplifier circuit is sufficiently secured in a state where the resonance circuit is not coupled to the first and second coupling means, and the resonance circuit is connected to the first and second coupling means. When the oscillation approaches the means, the AGC circuit controls the amplification degree of the amplifier circuit to limit the output amplitude. This stabilizes the oscillation and the output amplitude of the amplifier circuit becomes constant thereafter. When the distance between the resonance circuit and the first and second coupling means is further reduced, the control signal output from the AGC circuit and the input signal of the amplifier circuit change according to the distance. Position information of the position indicator can be obtained from amplitude information of oscillation obtained from a control signal output from the circuit or an input signal of the amplifier circuit.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a basic principle diagram of the present invention. In the figure,
3 is an amplifier circuit, 1 is a first amplifier connected to the output of the amplifier circuit 3.
Is a second coupling means connected to the input of the amplifier circuit 3, and 4 is a first coupling means 1 and a second coupling means 2
, A position indicator having a resonance circuit 4, 101 is an oscillation signal output from the amplification circuit 3, 102 is an input signal of the amplification circuit 3, and 6 is an amplitude signal of the oscillation signal 101. Position detecting means for detecting position information of the position indicator 5, M1 is electromagnetic coupling between the first coupling means 1 and the resonance circuit 4, and M2 is electromagnetic coupling between the second coupling means and the resonance circuit 4.

In FIG. 1, when the position indicator 5 is located at a position separated from the first coupling means 1 and the second coupling means 2,
When there is no electromagnetic coupling between the resonance circuit 4 and the first coupling means 1 and the second coupling means 2, no feedback occurs and no oscillation occurs. However, the position indicator 5 is located near the first coupling means 1 and the second coupling means 2, and the electromagnetic coupling M1 is provided between the resonance circuit 4 and the first coupling means 1 and the second coupling means 2.
And M2 occur, the output of the amplification circuit 3, the first coupling means 1, the electromagnetic coupling M1, the resonance circuit 4, the electromagnetic coupling M2, the second coupling means 2, and the input of the amplification circuit 3 are set as a series of paths, and A feedback loop is formed, and oscillation occurs at the resonance frequency of the resonance circuit 4. Oscillation is noise generated by the amplifier circuit 3,
It is excited by natural noise and the like, and is a well-known phenomenon in this kind of oscillation.

Here, when the resonance circuit 4 and the first coupling means 1 and the second coupling means 2 are further approached, the oscillation frequency does not change, but the amount of feedback changes according to the distance. The feedback amount increases and a large oscillation amplitude is obtained. As the distance increases, the feedback amount decreases and the oscillation amplitude decreases. In this way, an oscillation signal 101 having an amplitude corresponding to the position of the position indicator 5 is obtained from the output of the amplifier circuit 3, and the position detector 6
Can obtain position information from the amplitude of the oscillation signal 101.

The first and second coupling means may have any form as long as direct feedback is not applied through the first and second coupling means when there is no coupling with the resonance circuit. May be. Although the absolute value of the amplitude is small, position information can be obtained from the input signal 102 of the amplifier circuit 3 in the same manner. Next, a first embodiment of the present invention will be described with reference to FIGS.

FIG. 2 is a configuration diagram of the present embodiment. 1a is a first sense line, 2a is a second sense line, 3 is an amplifying circuit, 4 is a resonance circuit, 5 is a position indicator, 6a is a position detecting means, 101 is an oscillation signal, 102 is an input signal, and 102 is an input signal. B and C are positions indicated by the position indicator 5. FIG.
It is a block diagram of a position detection means 6a. 51 is a rectifier circuit, 5
2 is a smoothing circuit, 53 is an AD conversion circuit, 54a is a control circuit composed of a general CPU circuit, 101 is an oscillation signal,
Reference numeral 151 denotes an oscillation signal before AD conversion.

FIG. 4 is a diagram showing an example of a change in the amplitude of the oscillation signal 151 of FIG. The vertical axis is the amplitude of the oscillation signal 151,
The horizontal axis is the position indicated by the position indicator 5 in FIG.
C corresponds to positions A, B, and C in FIG. FIG. 5 shows a second configuration example of the first sense line 1a and the second sense line 2a shown in FIG. 1b is a first sense line, 2b is a second sense line, 5 is a position indicator, and 4 is a resonance circuit.

FIG. 6 shows a third configuration example of the first sense line 1a and the second sense line 2a shown in FIG.
1c is a first sense line, 2c is a second sense line, 5 is a position indicator, and 4 is a resonance circuit. Hereinafter, the operation of this embodiment will be described. In FIG. 2, a first sense line 1a and a second sense line 2a correspond to the first coupling means 1 and the second coupling means 2 shown in the basic principle diagram of FIG. The first sense line 1a is connected to the output of the amplifier circuit 3, and the second sense line 2a is connected to the input of the amplifier circuit 3. ing. As described above, when the first sense line 1a and the second sense line 2a are orthogonal to each other, there is no coupling between them, and if there is no position indicator 5, no feedback occurs and no oscillation occurs.

However, when the position indicator 5 is moved near the intersection of the first sense line 1a and the second sense line 2a, the resonance circuit 4 causes the first sense line 1a and the second
Oscillation occurs when the positive feedback loop is formed and the oscillation signal 101
Is obtained. The oscillation signal 101 is rectified by the rectifier circuit 51 in the position detecting means 6a, that is, in FIG.
2, digitized by the AD conversion circuit 53, and processed by the control circuit 54 a.

Here, in FIG. 2, when the height from each sense line to the position indicator 5 is fixed and the position indicator 5 is moved from the position A to the position C, for example, the oscillation signal 151 in FIG. FIG. 4 shows an example of a change in the amplitude of the previous oscillation signal. In FIG. 4, the amplitude increases from the position A to the position B, decreases from the position B to the position C, and a symmetrical change is obtained in which the position B, which is the center of the intersection of each sense line, is maximized. Therefore, in FIG. 3, the control circuit 54a obtains the position B from the table for associating the amplitude of the oscillation signal with the amplitude and the distance prepared in advance.
From the position indicator 5 to the position indicator 5.

The amplifying circuit 3 can be realized by a known operational amplifier or the like, and may be an inverting type or a non-inverting type as long as a positive feedback loop can be formed by the winding direction of the sense line and the connection polarity. In addition, as the coupling means that satisfies the condition that there is no coupling when there is no resonance circuit, and that each of them is coupled to the resonance circuit when the resonance circuit is in the vicinity, the first sense line 1a shown in FIG.
In addition to the configuration like the sense line 2a, a configuration in which one of the sense lines is inverted halfway as shown in FIG. 5, and a configuration in which both the sense lines are three-dimensionally crossed as shown in FIG. And so on.

Next, as a second embodiment of the present invention, an embodiment in which the first and second coupling means are constituted by a plurality of sense lines and scanning circuits will be described with reference to FIGS.
FIG. 7 is a configuration diagram of the present embodiment. In the figure, 5 is a position indicator, 1d is first coupling means, 2d is second coupling means, 3 is an amplifier circuit, 6b is position detection means, and S1 is a first sense line having sense lines y1 to yn. Group, 61
Is connected to the output of the amplifier circuit 3 and the first sense line group S
1 is a first scanning circuit for sequentially selecting 1, S2 is a second sense line group having sense lines x1 to xm, 62 is a second scan line connected to the input of the amplifier circuit 3 and sequentially selecting the second sense line group S2. Scanning circuit, 101 is an oscillation signal, 102
Is an input signal, 103 is a selection signal for selecting the first sense line group S1, and 104 is a selection signal for selecting the second sense line group S2.

Although not shown, the position indicator 5 has a resonance circuit similar to that of FIG. FIG. 8 shows the first
Is a configuration example of the coupling means 1d. S1 is a first sense line group, 61 is a first scanning circuit, 201 is a decoder, 2
11 to 21n are analog switches, 101 is an amplifier circuit 3
An oscillation signal 103 is connected from the output of the control unit 103. Reference numeral 103 denotes a selection signal output from the position detection unit 6b. Although the details of the second coupling means 2d are not shown, they have the same configuration as the first coupling means 1d, except that the first coupling means 1d is connected to the output of the amplifier circuit 3. , The second coupling means 2 d is connected to the input of the amplifier circuit 3.

FIG. 9 shows an example of the configuration of the position detecting means 6b. 51 is a rectifier circuit, 52 is a smoothing circuit, 53 is an AD converter circuit, and 54b is a control circuit composed of a general CPU circuit. 10 and 11 are a waveform diagram of an oscillation signal and an explanatory diagram for calculating coordinates. Hereinafter, the operation of this embodiment will be described. In FIG. 7, the case where the position indicator 5 is located at the intersection of the sense line x4 and the sense line y4 (A in FIG. 7) will be described.

The first scanning circuit 61 first selects the sense line y1 of the first sense line group S1 according to the selection signal 103 output from the position detecting means 6b. That is, in FIG. 8, the decoder 201 turns on the analog switch 211 by the selection signal 103, and connects the output of the amplifier circuit to the first sense line y1. On the other hand, the second scanning circuit 62 sets the second sense line group S2 to x1, by the selection signal 104 output from the position detection means 6b during this time.
x2... xm are sequentially selected. Then, once the scanning of the second sense line group is completed, the first
The scanning circuit 61 selects the sense line y2 of the first sense line group S1 according to the selection signal 103 output from the position detection means 6b, and the second scanning circuit 62 selects the detection line output from the position detection means 6b during this time. The second signal
, X2,... Xm are sequentially selected. Thereafter, the scanning is repeated in the same manner, and finally, the first scanning circuit 61 selects the sense line yn of the first sense line group S1, and the second scanning circuit 62 changes the second sense line group S2 to x1 during this period. , X2... Xm.

The position detecting means 6b controls the oscillation signal 1 obtained by sequentially selecting the second sense line group S2.
The waveform of 01 is shaped by a rectifier circuit 51 and a smoothing circuit 52 shown in FIG. 9, the magnitude (amplitude) is sequentially digitized by an AD conversion circuit 53, and further processed by a control circuit 54b. Here, the size of the oscillation signal 101 will be described in detail with reference to FIG. FIG. 10 is a waveform diagram when the position indicator 5 is located at the portion A in FIG. 7, and the selection signals 103 and 104 input to the first scanning circuit 61 and the second scanning circuit 62 and the position detection In the means 6b, AD
10 shows an oscillation signal (signal 151 in FIG. 9) before being converted.

A is an oscillation signal immediately below the portion A, that is, when the first sense line y4 and the second sense line x4 are selected, and is the largest signal among signals generated during scanning. The reason is that the first sense line group S1
Of the sense line y4 closest to the position indicator 5
Is selected, the degree of coupling between the resonance circuit of the position indicator 5 and the sense line y4 is the largest, and similarly, the sense line x4 closest to the position indicator 5 is selected from the second sense line group S2. This is because the degree of coupling between the resonance circuit of the position indicator 5 and the sense line x4 is also the largest, and the greatest amount of feedback is obtained by maximizing the coupling between the two.

B and c are the left and right sides of the portion A, that is, when the first sense line y4 and the second sense line x3 are selected, and when the first sense line y4 and the second sense line x5 are selected. The oscillation signal at the time. In this case, the resonance circuit of the position indicator 5 and the first sense line y4
Are the same, but the magnitudes of the oscillation signal b and the oscillation signal c are smaller than the oscillation signal a due to the distance between the position indicator 5 and the selected second sense line.

D and e are above and below the portion A, that is, when the first sense line y3 and the second sense line x4 are selected, and when the first sense line y5 and the second sense line x4 are selected. It is an oscillation signal at the time of. In this case, the degree of coupling between the resonance circuit of the position indicator 5 and the second sense line x4 is the same, but the oscillation signal b is equal to the distance between the position indicator 5 and the selected first sense line. And the magnitude of the oscillation signal c becomes smaller than the oscillation signal a.

The oscillation signals a to e have been described above. For other signals, the position of the sense line selected from the first sense line group S1 and the second sense line group S2 and the position indicator 5 are also described. The size is determined by the positional relationship of. In addition, as described in the first embodiment,
First sense line group S1 and second sense line group S2
Are orthogonal to each other, there is basically no coupling between the first sense line group S1 and the second sense line group S2,
Oscillation does not occur when the position indicator 5 is not present. Therefore, as described above, the magnitude of the oscillation signal is considered based on the positional relationship between the position of the position indicator 5 and the position of the sense line selected from the first sense line group S1 and the second sense line group S2. Can be. Here, a method of calculating coordinates will be described, focusing on the five oscillation signals a to e.

First, a method of calculating the X coordinate will be described with reference to FIG.
The following description focuses on the oscillation signals a, b, and c based on the above. FIG.
(1) is an enlarged view of a portion around A shown in FIG.
Consider a case where the position indicator 5 moves on the center of the sense line y4 from the center L0 of the sense line x4 to the midpoint L1 between the sense line x4 and the sense line x5. FIG.
(2) and (3) show that the position indicators 5 are L0 and L1.
Are shown for the oscillation signals a, b, and c when the oscillation signal is located at the position shown in FIG.

First, the position indicator 5 shown in FIG.
Is located at L0. As described above, the oscillation signal a is applied to the sense line x4 while the sense line y4 is selected, and the oscillation signal b is applied to the sense line x3
And the oscillation signal c is a signal when the sense line x5 is selected. At this time, the oscillating signal a has the largest value, and the oscillating signals b and c correspond to the position indicator 5 and the sense line x.
3 and the distance between the position indicator 5 and the sense line x5 are equal to each other.

Next, the position indicator 5 shown in FIG.
Is located at L1. At this time, the oscillation signals a and c are equal because the distance between the position indicator 5 and the sense line x4 and the distance between the position indicator 5 and the sense line x5 are the same. Here, the coordinates can be calculated by applying the method proposed by the present applicant (JP-A-55-96411). That is, a calculation defined by the following equation is performed based on the oscillation signal.

Q = (Vp−Vp + 1) / (Vp−Vp−1) (Expression-1) where Vp + 1> Vp−1 In the above equation, the oscillation signal a is Vp, the oscillation signal is b to Vp-
1 and the oscillation signal c is substituted for Vp + 1.
FIG. 11D shows a change in Q shown in (Equation 1) when the movement from 0 to L1 is performed. It is clear from the above description that Q = 1 when the position indicator 5 is at the position L0 and Q = 0 when the position indicator 5 is at the position L1. When the position indicator 5 is located between L0 and L1, Q takes a value in the range of 0 <Q <1 corresponding to this position on a one-to-one basis. Therefore, the characteristics of the Q are experimentally determined in advance to calculate the Q from the oscillation signals a, b, and c, and the detailed position of the position indicator 5 between L0 and L1 on the sense line is calculated from the Q. Can be requested. Further, the X coordinate can be obtained from the Q and the position of the sense line where the oscillation signal a is detected. The details of this coordinate calculation method are described in JP-A-55-964.
Since it is described in Japanese Patent Publication No. 11-A, it is omitted here.

Next, a method of calculating the Y coordinate will be described with reference to FIG. 11, focusing on the oscillation signals a, d, and e. The Y coordinate can be considered in the same manner as the X coordinate described above. In FIG. 11A, the position indicator 5 has a sense line x4
Is moved from the center L0 of the sense line y4 to the midpoint L2 between the sense line y4 and the sense line y5. 11 (5) and (6) show the position indicator 5
Are located at L0 and L2, the oscillation signal a,
This is for d and e.

First, the position indicator 5 shown in FIG.
Is located at L0. As described above, the oscillation signal a is applied to the sense line x4 while the sense line y4 is selected, the oscillation signal d is applied to the sense line x4 while the sense line y3 is selected, and the oscillation signal e is applied to the sense line y5. Is a signal when the sense line x4 is selected while is selected. At this time, the oscillation signal a has the largest value, and the oscillation signals d and e are equal because the distance between the position indicator 5 and the sense line y3 and the distance between the position indicator 5 and the sense line y5 are the same.

Next, the position indicator 5 shown in FIG.
Is located at L2. At this time, the oscillation signals a and e are equal because the distance between the position indicator 5 and the sense line y4 and the distance between the position indicator 5 and the sense line y5 are the same. Therefore, Q when moving the position indicator 5 from L0 to L2 as in the case of the X coordinate described above.
11 (7) is obtained by substituting the oscillation signal a into Vp, the oscillation signal d into Vp-1 and the oscillation signal e into Vp + 1 based on (Equation-1). . This is shown in FIG.
Characteristics similar to the characteristics in the case of the X coordinate of (4) are obtained, and the Y coordinate can be obtained using the characteristic of the Q similarly to the case of the X coordinate. The above processing is performed in the control circuit 54b (described in FIG. 9) configured by a general CPU circuit.

Next, as a third embodiment of the present invention, an embodiment provided with a state setting means and a state detection means will be described with reference to FIGS. FIG. 12 is a configuration diagram of the present embodiment. In the figure, 3 is an amplification circuit, 1 is a first coupling means, 2 is a second coupling means, 4 is a resonance circuit, 5 is a position indicator, 6 is a position detection means, 101 is an oscillation signal, and 102 is an input signal. , M1 and M2 are electromagnetic couplings between the first and second coupling means and the resonance circuit 4, 7 is a state setting means for changing the resonance frequency of the resonance circuit 4, SW1 is a first switch, SW
Reference numeral 2 denotes a second switch, and reference numeral 8 denotes state detecting means for detecting the state set by the state setting means 7 from the frequency of the oscillation signal 101.

FIG. 13 shows an example of the configuration of the state detecting means 8. In the figure, 55 is a waveform shaping circuit, 56 is a frequency counter circuit, and 54c is a frequency identification circuit composed of a general CPU circuit. Hereinafter, the operation of this embodiment will be described. 12, when the first switch SW1 and the second switch SW2 are turned off, the resonance frequency of the resonance circuit 4 is 300 kHz, and the first switch SW1 is turned off.
The resonance frequency when N is set to 280 kHz, and the resonance frequency when the second switch SW2 is turned on is 260 kHz.
When set to z, the amplification circuit 3
Is 300 kHz when the first switch SW1 and the second switch are turned off, and the first switch S
An oscillation signal 10 of 280 kHz when W1 is turned on and 260 kHz when the second switch SW2 is turned on
1 is obtained, and the oscillation signal 101 is output to the state setting means 8.

In FIG. 13, the oscillation signal 101 is shaped by the waveform shaping circuit 55, and the frequency counter circuit 5
6, and the obtained frequency is 300 kHz, 280 kHz and 2
The setting state of the first switch SW1 and the second switch SW2 can be detected by identifying which frequency corresponds to 60 kHz.

In the frequency identification, 270 kHz
From the first switch SW1 in the range from
If the ranges are provided and the identification is performed as in the case where is ON, fluctuations in the resonance frequency due to temperature changes and variations in component constants can be absorbed. In the present embodiment, an example in which two switches are mounted on the position indicator 5 has been described, but the oscillation frequency, that is, the resonance frequency depends on the phase characteristics of the amplifier circuit 3,
Within the range where the degree of amplification is guaranteed, specifically, 100 kHz to
1 MHz is preferable, and it can be set arbitrarily as long as it is within this band, so that it is possible to mount more switches on the position indicator 5 and identify them. For example, it is possible to divide the frequency range from 300 kHz to 500 kHz into 10 and assign 10 switches for every 20 kHz. These frequency assignments take into account the range of variation of the resonance frequency due to temperature changes and variations in component constants. Can be set. At this time,
In another circuit 54c, from 300 kHz to 500 kHz
Threshold that divides the frequency range of
That is, 300 kHz, 320 kHz, 340 kHz, 3
60kHz, ···, 480kHz, 500kHz of teeth
Thresholds are set so that the detected frequency depends on these thresholds.
To determine which frequency band is divided by
To determine which of the ten switches was operated.
Try to separate.

It is also possible to use a plurality of position indicators and assign a specific frequency range to each of the position indicators, thereby realizing individual identification of the position indicators simultaneously with identification of the state setting. For example, if you have two switches
When two position indicators are provided, the first position indicator
Resonance frequency of 300kHz, 320kHz, 340k
Hz and the resonance frequency of the second position indicator is 400 kHz.
z, 420 kHz and 440 kHz. This way
When instructed by the position indicator (1), it starts in the 300 kHz band.
400 kHz when shaking and instructing with the second position indicator
Oscillates in the z-band, so the oscillation frequency
Can identify multiple position indicators individually.
You. Switch identification is a detailed frequency identification within that band
In the same manner as described above. In the present embodiment, a capacitor is connected in parallel to the resonance circuit as a state setting means for changing the frequency of the resonance circuit, and the resonance frequency is reduced when the switch is pressed. There are many other means for changing the resonance frequency of the resonance circuit, such as continuously changing the frequency with a writing pressure sensor and detecting the writing pressure with the state detection means, and can be realized by other embodiments. Needless to say, Further, the configuration of the position detecting means may be any configuration as long as it can detect a change in frequency, and is not limited to the present embodiment.
Further, the first and second coupling means may be any as long as those described in the above-described embodiment. Also, switch
When one switch is mounted or when no switch is mounted
Are within the above frequency range (100 kHz to 1 MHz).
It is desirable that the frequency be selected at the resonance frequency
Needless to say.

Next, as a fourth embodiment of the present invention, an embodiment in which an AGC circuit for controlling the amplification degree of the amplifier circuit is provided will be described with reference to FIG.
This will be described with reference to FIGS. FIG. 14 is a configuration example of this embodiment. In the figure, 3a is an amplifier circuit whose amplification degree can be controlled, 1 is first coupling means, 2 is second coupling means,
4 is a resonance circuit, 5 is a position indicator, 6 is position detecting means, 1
01 is an oscillation signal, 102 is an input signal, M1 and M2 are electromagnetic coupling between the first and second coupling means and the resonance circuit 4, 9 is an AGC circuit for controlling the amplification degree of the amplifier circuit 3a, and 103 is an AGC circuit. This is a control signal to be output.

FIG. 15 shows an example of the configuration of the AGC circuit 9.
In the figure, 57 is a rectifier circuit, 58 is an integration circuit, 59 is a comparison circuit, 60 is an amplitude set value, 101 is an oscillation signal,
3 is a control signal. FIG. 16 shows a configuration example in the case where position information is obtained from the input signal 102. Hereinafter, the operation of this embodiment will be described. In FIG. 14, in a state where the resonance circuit 4 is not coupled to the first coupling means 1 and the second coupling means 2, a sufficient amplification degree of the amplifier circuit 3a is secured in advance, and the resonance circuit 4 When the oscillation starts by approaching the coupling means 1 and the second coupling means 2, the AGC circuit 9 controls the amplification degree of the amplifier circuit 3a to limit the amplitude of the oscillation signal 101. That is, the AGC circuit 9 rectifies the oscillation signal 101 in FIG. 15 with the rectifier circuit 57, integrates the integration signal with the integration circuit 58, and compares the amplitude of the oscillation signal with the amplitude set value 60 by the comparison circuit 59, thereby obtaining the oscillation signal 101. Is set to the amplitude set value 60
The control signal 103 is output to the amplifier circuit 3a so as to be constant at the amplitude set in step (1).

Here, as the distance between the resonance circuit 4 and the first coupling means 1 and the second coupling means 2 is further reduced, AG
The control signal 103 output from the C circuit 9 changes according to the distance, and the position detection means 6 obtains the position information of the position indicator 5 from the amplitude information of the oscillation obtained from the control signal 103 output from the AGC circuit 9. be able to. Thus AGC
Oscillation is stabilized by control by the circuit 9, the amplitude of the oscillation signal 101 becomes constant even when the position of the resonance circuit 4 changes, and position information can be obtained from the control signal 103 output from the AGC circuit 9.

Although the absolute value is small as shown in FIG. 16, position information can be obtained from the input signal 102 of the amplifier circuit 3a in the same manner. Also, in the combination of the state setting means and the state detection means shown in the third embodiment, the oscillation signal 101 having a constant amplitude can be used, and more stable detection can be performed. The amplifying circuit 3a of the present embodiment can be realized by a well-known device such as a VCA capable of changing the amplification degree from the outside. For example, TL026 (TI)
and so on.

[0048] As described above, in this embodiment, the AGC circuit for controlling the amplification degree of the amplifier circuit is provided, to take wider detectable distance range of the position indicator by effectively utilizing the dynamic range of the amplifier circuit And a more stable oscillation can be obtained. Further, the first and second coupling means may be any as long as those described in the above-described embodiment.

[0049]

As described above, according to the present invention, the resonance frequency of the resonance circuit is directly converted into the oscillation signal by the simple structure of inserting the resonance circuit of the position indicator into the positive feedback loop of the amplification circuit. Since elements such as excitation and phase difference detection are not required, the circuit can be simplified. Further, since the resonance frequency can be arbitrarily set, there is an effect that scalability of the state setting means such as multiple switches and pen pressure detection can be easily obtained. By providing the AGC circuit, the oscillation signal of the positive feedback loop is stabilized, and there is also an effect that the detectable distance range of the position indicator can be made wider. More specifically, the following effects are obtained. (1) Excitation circuit and phase difference detection circuit are eliminated to simplify the circuit
Oscillation amplitude information of the formed oscillation circuit
From which the position information of the position indicator can be easily obtained from
An input / output device can be realized. (2) Excitation circuit and phase difference detection circuit are eliminated to simplify the circuit
It is possible to use multiple switches on the position indicator
Position where the status of the status setting means can be detected
An input device can be realized. (3) Excitation circuit and phase difference detection circuit are eliminated to simplify the circuit
And any of the position indicators indicate
A position input device that can detect
be able to. (4) As a combination of these purposes,
Circuit and phase difference detection circuit are eliminated to simplify the circuit.
Detect which of multiple position indicators is pointing
Yes, with multiple switches on the position indicator
Input that can detect the status of the status setting means
The device can be realized.

[Brief description of the drawings]

FIG. 1 is a basic principle diagram of a position input device of the present invention.

FIG. 2 is a configuration diagram showing a first embodiment of the position input device of the present invention.

FIG. 3 shows a position detecting means 6 according to the first embodiment of the present invention.
It is a block diagram of a.

FIG. 4 is a diagram illustrating an example of a change in amplitude of an oscillation signal 151 in FIG. 3;

FIG. 5 is a diagram showing a second configuration example of the first sense line 1a and the second sense line 2a shown in FIG. 2;

FIG. 6 is a diagram illustrating a third configuration example of the first sense line 1a and the second sense line 2a illustrated in FIG. 2;

FIG. 7 is a configuration diagram showing a second embodiment of the position input device of the present invention.

FIG. 8 is a configuration diagram of a first coupling unit 1d according to a second embodiment of the present invention.

FIG. 9 shows a position detecting means 6 according to a second embodiment of the present invention.
It is a block diagram of b.

FIG. 10 is a waveform diagram of an oscillation signal according to the second embodiment of the present invention.

FIG. 11 is an explanatory diagram for calculating coordinates in the second embodiment.

FIG. 12 is a configuration diagram showing a third embodiment of the position input device of the present invention.

FIG. 13 is a configuration diagram of a state detection unit 8 according to a third embodiment of the present invention.

FIG. 14 is a configuration diagram showing a fourth embodiment of the position input device of the present invention.

FIG. 15 shows an AGC circuit 9 according to a fourth embodiment of the present invention.
FIG.

FIG. 16 shows an input signal 10 according to a fourth embodiment of the present invention.
FIG. 3 is a configuration diagram in a case where position information is obtained from No. 2;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first coupling means 2 second coupling means 3 amplifier circuit 4 resonance circuit 5 position indicator 6 position detection means 7 state setting means 8 state detection means 9 AGC circuit

Claims (9)

(57) [Claims] 1. A position indicator having an amplifier circuit, first coupling means connected to an output of the amplifier circuit, second coupling means connected to an input of the amplifier circuit, position detection means, and a resonance circuit. The resonance circuit has an electromagnetic coupling with both the first coupling means and the second coupling means, so that the amplification circuit, the first coupling means and the second coupling means Forming a feedback loop with the means, forming an oscillation circuit that oscillates at a frequency corresponding to the resonance frequency of the resonance circuit, wherein the position detection means is provided in front of the position indicator.
The distance between the first coupling means and the second coupling means;
And amplitude information based on the oscillation amplitude of the oscillation circuit
A position input device having a table in which the position information of the position indicator is obtained by referring to the table with the oscillation amplitude information. 2. The position input device according to claim 1, wherein the first coupling means comprises a plurality of sense lines laid in parallel to one of the XY orthogonal coordinate axes and at equal intervals. A sense line group, and a circuit for sequentially selecting the first sense line group, the first scan circuit being connected to the output of the amplifier circuit, wherein the second coupling means is parallel to the other axis. A second sense line group consisting of a plurality of sense lines laid at equal intervals and a circuit for sequentially selecting the second sense line group, the second scan being connected to an input of the amplifier circuit Consisting of a circuit,
The position detecting means refers to the table with amplitude information of an oscillation signal obtained by scanning the first and second scanning circuits .
A position input device characterized by obtaining position information of a position indicator by performing the above operation . 3. The position input device according to claim 1, wherein said state setting means changes a resonance frequency of said resonance circuit, and said state detection means detects a state set by said state setting means from oscillation frequency information. And a position input device. 4. An amplifier circuit connected to an output of the amplifier circuit.
First coupling means connected to an input of the amplifier circuit.
2, a resonance circuit and the resonance circuit. Connected in parallel to the road
And state setting means having a plurality of switches.
To the input or output side of the amplifier circuit.
A position detection for obtaining information on the position indicated by the position indicator
Output means and connected to the input side or output side of the amplifier circuit
A state detecting means for detecting a state of the state setting means;
Wherein the resonance circuit comprises the first coupling means and
By electromagnetic coupling with both of the second coupling means,
Amplifying circuit, the first coupling means, and the second coupling means
Form a feedback loop together with the resonance circuit and the state setting.
Oscillation at the resonance frequency determined by the
Forming an oscillation circuit, wherein the position detecting means includes the oscillation circuit.
From the amplitude information of the oscillation signal of the position indicator
The state detection means obtains the frequency information of the oscillation signal from the
Detecting a state set by the state setting means.
Position input device characterized by the above-mentioned. 5. An amplifying circuit and an output connected to the amplifying circuit.
First coupling means connected to an input of the amplifier circuit.
Plural position indicators provided with two coupling means and a resonance circuit
Connected to the input side or the output side of the amplification circuit,
Position detecting means for obtaining information on the position indicated by the position indicator
Connected to the input side or the output side of the amplification circuit,
Which of the multiple position indicators indicates
State detecting means for detecting whether the
The oscillation circuit is a combination of the first coupling means and the second coupling means.
The above-mentioned amplifier circuit and the above-mentioned second
Feedback loop together with the first coupling means and the second coupling means
The resonance frequency determined by the resonance circuit
Therefore, an oscillation circuit that oscillates is formed, and the position detection means
The position indicator is obtained from amplitude information of an oscillation signal of the oscillation circuit.
And the state detection means obtains the position information of the oscillation signal.
From the wave number information, the position of any of the plurality of position indicators
Position for detecting whether the indicator is pointing
Input device. 6. An amplifier circuit connected to an output of the amplifier circuit.
First coupling means connected to an input of the amplifier circuit.
2, a resonance circuit and a resonance circuit connected in parallel to the resonance circuit.
And state setting means having a plurality of switches.
A number of position indicators, said resonance circuit and said state setting
The resonance frequency determined by the means
Multiple positions set differently for each indicator
Indicator and connected to the input or output side of the amplifier circuit
Position detection for obtaining information on the position indicated by the position indicator
Means and an input side or an output side of the amplifier circuit.
Which one of the plurality of position indicators indicates
And the state of the state setting means is detected.
And a state detecting means, wherein the resonance circuit
Electromagnetic coupling with both the coupling means and the second coupling means
Thereby, the amplification circuit, the first coupling means, and the
The second coupling means forms a feedback loop and the resonance
A source that oscillates at the resonance frequency determined by the circuit
Forming an oscillation circuit, wherein the position detecting means emits light from the oscillation circuit.
Obtain the position information of the position indicator from the amplitude information of the vibration signal,
The state detecting means is configured to calculate the
Which of the multiple position indicators indicates
Or the state set by the state setting means.
A position input device for detecting. 7. The apparatus according to claim 1, wherein the first coupling means includes at least XY.
Lay parallel to one of the Cartesian axes and at equal intervals
First sense line group including a plurality of sense lines
And a circuit for sequentially selecting the first sense line group.
The first scanning circuit connected to the output of the amplification circuit
And the second coupling means includes at least an XY orthogonal seat.
Multiple laying parallel to the other axis of the benchmark and equally spaced from each other
A second sense line group including a plurality of sense lines;
A circuit for sequentially selecting a second sense line group,
And a second scanning circuit connected to the input of the amplifier circuit.
7. The position according to claim 4, wherein
Input device. 8. The apparatus according to claim 1, wherein said first sense line group comprises n sensor lines.
And the second sense line group is m
And the amplitude of the oscillation
The first and second selected when the information indicates the maximum value
Are the i-th sense line in the sense line group,
If it is the j-th, the first and second sense licenses
The selected combination of the component groups is represented by ｛(i−1), respectively.
Th, j th｝, {(i + 1) th, j th｝, ｛i th
Eye, (j-1) th, {ith, (j + 1) th}
And the amplitudes of the five oscillations at {i-th and j-th}
Scanning information and the first and second scanning circuits
The position information of the position indicator based on the scanning signal
The position input device according to claim 7, which is obtained. 9. The resonance circuit or the resonance circuit,
Range of the resonance frequency determined by the state setting means.
The frequency range is 100 kHz to 1 MHz.
The position input device according to claim 1, wherein the position input device performs the operation.