JP2625479B2 - Coordinate detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coordinate detecting device for detecting the coordinates of the position of an indicator such as a stylus pen or a cursor for indicating an arbitrary position on a tablet.

[Conventional technology]

There are various types of coordinate detection devices.In general, a lead wire is arranged in a meandering shape, and a selector line that divides a coordinate area at a predetermined interval is provided. In addition to detecting the position by scanning the selector line, the position in the section is detected based on the voltage induced on the conductor by the indicator, thereby detecting the coordinates of the indicator. However, there is a problem that a complicated circuit is required to scan the selector line, and the time required for scanning is long. To solve this problem, a coordinate detecting device which does not use a selector line has been proposed in Japanese Patent Application No. 58-159191. Hereinafter, an outline of the coordinate detecting device will be described with reference to the drawings.

FIGS. 4 (a) and 4 (b) are layout diagrams of X-axis coordinate detection conducting wires laid on a tablet of the coordinate detection device. Note that the Y-axis coordinate detection conductor is laid orthogonal to the X-axis coordinate detection conductor, but the form of the lay is the same as that of the X-axis coordinate detection conductor, and a description thereof will be omitted. Hereinafter, only the X-axis coordinate detection conductor will be described.

In FIG. 4 (a), reference numeral 1 denotes a single conductor arranged in a meandering shape, and its pitch is indicated by p. Reference numeral 2 denotes a conductor arranged in a meandering manner at the same pitch p as that of the conductor 1, and 1 /
It is staggered by 4 pitches. 11,11 'is conductor 1
, 12 and 12 ′ are terminals at both ends of the conductor 2.

In FIG. 4 (b), reference numeral 3 denotes one lead wire arranged in a meandering shape, and its pitch is indicated by q. The pitch q is a pitch different from the pitch p.
Is selected to be larger than the pitch p. 4 is the conductor 3
Are arranged on the meandering line with the same pitch q, and are displaced from the conductor 3 by 1/4 pitch. 13,
13 'is a terminal at both ends of the conductor 3, and 14 and 14' are terminals at both ends of the conductor 4.

Each conductor 1, 2, 3, 4 is arranged in a state insulated from each other,
In addition, the conductors 1 and 2 and the conductors 3 and 4 are arranged so as to overlap. An X-axis detection base is formed by the superposed wires, and a tablet is formed together with the Y-axis detection base having the same configuration. When the conductors 1, 2 and the conductors 3, 4 overlap,
A line forming both side edges of the conductor 1 and a line forming both side edges of the conductor 3 are matched up and down. The pitch p of the conductive wire 1 and the pitch q of the conductive wire 3 are selected so as to have a certain relationship expressed by the following equation. That is, the distance between lines forming both side edges is l,
Assuming that the pitch number is n, the following relationship is established between these numerical values.

1 = np = (n-1) q (1) In the case of the figure, the pitch number n is 5. Although the actual pitch number is much larger than this, equation (1) still holds.

Now, consider a case where the indicator 6 is placed at the illustrated position a in such an X-axis detection base. The position a is the second position of the conductor 1 in the X-axis direction (horizontal direction in the drawing).
Th the pitch is a position apart a distance r from the line 1 ₂ is started. This position is seen from the conductor 3 is in the position of the first second pitch start line 3 ₂ from the distance s. Pointer 6
Excitation, the terminals 11 and 11 ', the terminals 12 and 12', the terminal 1
3, 13 'and between terminals 14 and 14' FIG. 5, respectively between (a), the voltage _{E 11, E 12, E 13} , E 14 is generated as shown in (b). Here, if the voltage E ₁ applied to the cursor 6 is E ₁ = A ₁ cosωt (2) (A ₁ is a peak value), the above voltages E ₁₁ , E ₁₂ , E ₁₃ , E ₁₄
Is represented by the following equation.

E ₁₁ = A ₂ cos (2π · r / p) cosωt (3) E ₁₂ = A ₂ sin (2π · r / p) cosωt (4) E ₁₃ = A ₂ cos (2π · s / q _{) cosωt ...... (5) E 14} = a 2 sin (2π · s / q) cosωt ...... (6) provided that, a ₂ are coefficients.

Thus, terminals 11, 11 ', 12, 12', 13, 13 ', 14, 14'
Using the voltage signals E ₁₁ , E ₁₂ , E ₁₃ and E ₁₄ output from the
The X-axis coordinates of the pointer 6 are detected by the circuit shown in FIG.

FIG. 6 is a block diagram of a conventional coordinate detecting device. In the figure, 17 is a clock oscillator that outputs high-frequency pulses, 18
Is a frequency divider for dividing the high frequency output signal of the clock oscillator 17, and 19 is a filter for amplifying the output of the frequency divider 18 and converting it to a sine wave. The output of the filter 19 is supplied to the indicator 6 to excite it. 21 is a tablet comprising an X-axis detection base and a Y-axis detection base, and 21X and 21Y are X-axis output terminals and Y-axis output terminals (terminals 11, 11 'to 14, 14').
Is shown. Reference numeral 22 denotes a switching circuit for switching and inputting the output signal of each terminal, 23 and 24 denote amplifiers, 25 denotes an integrator, and 26 denotes an adder. 27 is a waveform converter for converting the sine wave output from the adder 26 into a rectangular wave corresponding to the sine wave, and 28 is a comparator for comparing the output signal of the frequency divider 18 with the main signal of the waveform converter 27 to obtain required data. Is a data processing device that obtains the coordinates of the pointer 6 based on the input data. A height detector 30 detects the height of the indicator 6 from the surface of the tablet 21 based on the output voltage of the adder 26, and its output is input to the data processor 29.

Next, an outline of the operation of the coordinate detector will be described. In accordance with a command from the data processing device 29, the switching circuit 22 sequentially outputs terminals.
The output signals of 11,11 'to 14,14' are input. Now, terminals 11,1
'When the inputs the voltage signal E _11, the signal is amplified by the amplifier 23, is integrated by the integrator 25 with respect to time t and the signal E _11' 1 is input to Do connexion adder 26 and. On the other hand, terminal 1
2,12 voltage signal E ₁₂ 'of the switching circuit 22, via the amplifier circuit 24 is directly input to the adder 26. The adder 26 outputs a signal E ₁₀ obtained by adding the two signals. Signal E ₁₀ is expressed by the following equation.

E ₁₀ = E ₁₁ ′ + E ₁₂ = A ₂ sin (ωt + 2π · r / P) (7) As is apparent from the above equation, the signal E ₁₀ is a phase modulation signal proportional to the distance r, and the excitation signal E _The distance r can be obtained by comparing the phase with ₁ and obtaining the phase difference φ1.

Therefore, the comparator 28 receives the set signal as the frequency divider 18 as a set signal.
Output signal is input and the waveform converter is used as a reset signal.
27 output signals are input. Time interval of the input time of the input time and the reset signal of the excisional signal is proportional to the phase difference phi _1. Therefore, until the input of the excisional signal, inputs the output pulses of the clock oscillator 17, by counting the number of pulses, the number of the pulses is the number which is proportional to the phase difference phi _1.
The distance r can be obtained by the following equation using a phase difference phi _1.

r = p · φ ₁ / 2π (8) The output signal E ₁₃ at the terminals 13 and 13 ′ is exactly the same as the above means.
And Treatment of the output signal E ₁₄ of the terminals 14, 14 'can be obtained by the phase difference phi ₂ the distance s by the following equation.

s = q · φ ₂ / 2π (9) Next, the operation of the data processing device 29 will be described with reference to FIG.
This will be described with reference to the graph shown in FIG. 7A and 7B, the horizontal axis indicates the position of the indicator 6, and the vertical axis indicates the number of pulses output from the comparator 28. The same number F (for example, 1000 pulses) is given to each of the pitches p and q as shown in FIG. 7 (a). now,
When the indicator 6 is at the position a as shown in FIG. 7 (a), the output of the comparator 28 is the pulse number with respect to the lead of the pitch p.
F _{1 is} the pulse number F ₂ for the lead q. Then, the number of pulses F ₁ is a distance r, the number of pulses F ₂ is proportional to the distance s. The data processing device 29 calculates the pitch number K in accordance with the following equation in order to determine at what pitch the conductor 6 is located.

Next, the coordinate value N of the pointer 6 is calculated by the following equation. G is a coefficient.

N = (F · K + F ₁ ) · G (11) In addition to the calculation by the above equation (10), there is also a method of obtaining the pitch number K by the following means. That is, the pulse numbers F ₁ and F ₂
Are compared, and if F ₁ > F ₂ , ΔF = F ₁ −F ₂ …… (12) If F ₁ <F ₂ , ΔF = F + F ₁ −F ₂ …… (13) The pitch number corresponding to the value .DELTA.F obtained by the expression (12) or (13) is extracted based on the relation table between the number of pitches and the value .DELTA.F. (12), (13)
The value ΔF obtained by the equation becomes a proportional straight line as shown in FIG. 7 (b).

[Problems to be solved by the invention]

The pitches p and q of the conventional coordinate detecting device are determined by the diameter of the electromagnetic coil housed in the indicator 6 and the distance between the indicator 6 and the conductor. In general, the indicator 6 is generally used in a state of being in contact with the surface of the tablet 21, and the pitches p and q are also determined based on this state. In such a coordinate detecting device, when the indicator 6 and the surface of the tablet 21 are separated from each other, the output voltage of each of the leads 1 to 4 becomes a clean sine wave as shown in FIGS. 5 (a) and 5 (b). Instead, it becomes a distorted sine wave. As a result, undulation occurs in the straight line portion of the graph in FIG. 7 (a), and the coordinate detection accuracy is greatly reduced. In an extreme case, the calculation of the equation (10) becomes erroneous and is detected as coordinates skipped by one pitch. There is. Further, the further apart the indicator 6 and the surface of the tablet 21 are, the greater the possibility that the output voltages of the conductors 1 to 4 include noise is increased. Therefore, the above-described conventional coordinate detecting device is provided with a height detector 30. When the pointer 6 is separated from the surface of the tablet 21 by a predetermined range (for example, 3 mm) or more, a data processing device is provided by an input signal of the height detector 30. 30 determines this and stops the detection operation to prevent incorrect coordinate detection.

However, in recent years, in use of the coordinate detection device,
The use of the indicator 6 considerably away from the surface of the tablet 21 has increased, and in contrast, a device capable of detecting coordinates in such a use has been required.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a coordinate detecting device capable of detecting coordinates even when there is a considerable distance between the pointer and the coordinate detecting plate.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a conductor set consisting of two conductors having a first pitch and different phases from each other and a conductor set consisting of two conductors having a second pitch and different phases from each other. A coordinate detection plate in which a configured wiring group is wired for each coordinate axis; an indicator having electromagnetic means for indicating an arbitrary position on the coordinate detection plate; Detecting means for detecting that the pointer is within the height range, and based on each output signal of the lead wire of the first pitch and the lead wire of the second pitch only when the indicator is within the predetermined height range. In a coordinate detecting apparatus comprising: first calculating means for calculating the number of pitches at which the pointer is present; and second calculating means for calculating the coordinate value of the pointer based on the number of pitches, the pointer has a predetermined value. A defined height that is continuous to the height range Another detecting means for detecting that the distance is within the range, and when the pointer is within the predetermined height range, the first value obtained from the lead wire having the first pitch is the second pitch. When the value of the difference is larger than a second value obtained from the lead wire, the value of the difference is multiplied by a predetermined coefficient. When the first value is smaller than the second value, the maximum set value of the two and the value of the difference are calculated. Third calculating means for obtaining the coordinate value of the pointer by multiplying the sum by the coefficient.

Further, in order to achieve the above object, the present invention provides a conductor set comprising two conductors having a first pitch and different phases from each other and a conductor consisting of two conductors having a second pitch and different phases from each other. A coordinate detection plate in which a wiring group composed of a set is wired for each coordinate axis, an indicator having electromagnetic means for indicating an arbitrary position on the coordinate detection plate, and the indicator being the coordinate detection plate And a detecting means for detecting that the pointer is within a predetermined height range allowing coordinate detection, wherein the pointer is at least one outside the predetermined height range.
Other detection means to detect that the
At least one conductor set having another pitch larger than the first pitch and the second pitch, which is added to each of the coordinate widths corresponding to the set height range, is provided. In the former invention described above, when the detection means detects that the distance between the pointer and the coordinate detection plate is within a predetermined height range, the output of each lead wire is the same as in the conventional coordinate detection device. Based on the signal, first, the number of pitches at which the pointer is located is determined by the first calculating means, and then, the second calculating means calculates the coordinate value by adding the distance of the pointer within the pitch to the number of pitches. On the other hand, if the other detecting means detects that the distance between the pointer and the coordinate detecting plate is within a predetermined height range exceeding the predetermined height range, the pitch number is not determined. , The coordinate value is directly obtained from the output signal of each conductor by the third calculating means. That is, when the first value obtained from the conductor of the first pitch is larger than the second value obtained from the conductor of the second pitch, the value of the difference between them is multiplied by a predetermined coefficient, and the first value becomes When the value is smaller than the second value, the sum of the maximum setting value and the difference between the two values is multiplied by the above coefficient to obtain the coordinate value of the pointer. If the pointer is at a height beyond the range determined by the other detection means, no coordinate detection is performed.

Further, in the latter invention, one or a plurality of set height ranges are provided by another detecting means, and the pitch of each of the existing wire sets on the coordinate detection plate corresponding to the provided set height range is provided. Add a wire set with a larger pitch. Then, when the distance between the pointer and the coordinate detection plate is within a predetermined height range of the existing detecting means, the coordinate value of the pointer is obtained using each existing wire pair. On the other hand, when the indicator is located at a height of a certain set range set in the other detecting means outside the predetermined height range, one of the wire set corresponding to the set height range and the existing wire set, or Two sets of conductors are provided corresponding to the set height range, and the coordinate value of the pointer is determined. In the present invention, the coordinate value of the pointer is obtained based on the pitch number as in the prior art.

〔Example〕

 Hereinafter, the present invention will be described with reference to the illustrated embodiments.

FIG. 1 is a block diagram of a coordinate detecting device according to an embodiment of the present invention. In the figure, the same parts as those shown in FIG. 6 are denoted by the same reference numerals, and description thereof will be omitted. Reference numeral 31 denotes a data processing device, which partially differs in function from the data processing device 29 of the conventional device. Reference numeral 32 denotes a height detector, which is a reference voltage setting device 32.
e, a switch 32s and a differential amplifier 32a. The switch 32s includes switching elements s ₁ and s ₂ , and the switching elements s ₁ and s ₂ are sequentially switched by a command from the data processing device 31.

Next, the operation of this embodiment will be described. When the indicator 6 is positioned at an arbitrary position on the tablet 21, a voltage corresponding to the output is output from the adder 26 as described above, and this voltage is shaped by the waveform converter 27 and output from the comparator 28. The number of pulses proportional to the phase difference is output. On the other hand, the output voltage from the adder 26 is input to the differential amplifier 32a of the height detector 32. At this time, the data processing device 31 outputs a command signal and outputs the switching elements s ₁ and s ₂ of the switch 32 s of the height detector 32.
(This switching will be described later). Thus, the other end of the differential amplifier 32a has a sequentially determined reference voltage e.
₁ and e ₂ (voltages generated when the respective switching elements s ₁ and s ₂ are closed) are input.

By the way, the voltage induced in each of the wires 1 to 4 is
４4 and the distance between the pointer 6 are almost inversely proportional. Therefore, the output of the adder 26 is also inversely proportional to the interval, and as a result,
By comparing the output voltage of the adder 26 with the reference voltages e ₁ and e _{2 by the} differential amplifier 32a, the distance of the indicator 6 from the surface of the tablet 21 can be determined. In this case, since two switching elements are provided, the distance D of the indicator 6 from the surface of the tablet 21 is divided into three ranges (D ₁ , D ₂ , D ₃ ). This indicator is determined in response to the performance of the coordinate detecting device, range D ₁ is the distance that can detect coordinates with a high precision, the distance range D ₂ is capable of detecting coordinate values below which accuracy, range D ₃ Is a distance for which detection is prohibited because the detection accuracy of coordinate values is too low. An example of such a range D ₁ to D _3, and then shows the relationship between the output voltage E ₁₀ and the reference voltage e _1, e ₂ of the adder 26 at that time.

The data processing device 31 with respect to the height detector 32, first output signal to close the switching-element s _1. Now, E
From the differential amplifier 32a when ₁₀ ≧ e ₁ and the high level signal is outputted, the data processing device 31 switching-element s ₁
Looking at the input signal from the height detector 32 when is closed, when this is at a high level, E ₁₀ ≧ e ₁ , that is, in the example above, if the height of the indicator 6 is within 3 mm to decide.
Then, the same means as in the related art, that is, the number of pitches where the pointer 6 exists is determined, and then the coordinate value is calculated and output.

On the other hand, when the input signal from the height detector 32 is a low-level signal, the data processing device 31
the s ₂ Close to output a signal. Here, assuming that a high-level signal is output from the differential amplifier 32a when E ₁₀ ≧ e ₂ , the data processing device 31 uses the above-described example when the input signal is a high-level signal at this time, Pointer 6 is 3m high
Judge that it is more than m and within 20mm. When the judgment is made in this manner, the number of pulses F ₁ and F ₂ output from the comparator 28 are compared as described above, and if F ₁ > F ₂ , the operation of equation (12) is performed, and ₁ <for F ₂ performs calculation of the expression (13) the value ΔF
Get. As described above, and as shown in the graph of FIG. 7B, the value ΔF is proportional to the coordinate value of the indicator 6. While the conventional coordinate detecting device uses the value ΔF for pitch number determination, in the present embodiment, the data processing device 31
Performs a process of multiplying the value ΔF by a predetermined coefficient to directly calculate and output the coordinate value of the pointer 6.

As described above, the means for directly calculating the coordinate value from the value ΔF adds the voltage detection error in each of the conductors 1 to 4, and therefore has a higher accuracy than the conventional means for calculating the coordinate value after determining the pitch number. The decline cannot be avoided. However, it is possible to surely avoid a large error of detecting coordinates by skipping one pitch which occurs when using the conventional means.

Next, when the signal of closing the switching-element s ₂ is a low level signal, i.e., the pointer 6 in the example above 20mm
If the height exceeds the height, the data processing device 31 stops the coordinate value detection operation. This is the tablet 21 of the indicator 6
If the height from the surface exceeds 20 mm, the influence of the aforementioned undulations and noise increases, and even if the detection is performed using the value ΔF, the detection accuracy is greatly reduced.

As described above, in this embodiment, the height of the pointer is divided into three parts by the height detector, and when the height is small, the means for calculating the coordinate value by the number of pitches is executed to execute the height. A coordinate value is output with high accuracy. If the height is large, the detecting operation is prohibited. If the height is halfway between the two, a means for calculating the coordinate value without calculating the pitch number is executed. Since the coordinate values are output in such a manner, it is possible to detect the coordinate values of the intermediate height, which cannot be obtained in the conventional device, and by expanding the allowable range of the height of the pointer, It is easy to use and the range of application of the device can be increased.

FIG. 2 is a block diagram of the coordinate detecting device according to the embodiment of the present invention. In the figure, the same parts as those shown in FIG. Numeral 34 denotes a tablet according to the present embodiment, which differs from the tablet 21 shown in FIG. The wiring configuration of the tablet 34 will be described later. 34X and 34Y are the X-axis output terminal of the tablet 34 and Y
Indicates the shaft output terminal. Reference numerals 35 and 36 denote a switching circuit and a data processing circuit corresponding to the switching circuit 22 and the data processing circuit 31 shown in FIG. 1, respectively.

FIG. 3 is a layout view of a part of the X-coordinate detecting conductor of the tablet wiring shown in FIG. In the figure, the same parts as those shown in FIGS. 4 (a) and 4 (b) are denoted by the same reference numerals. In FIG. 3, the dimensions in the horizontal direction are further expanded with respect to the layout shown in FIGS. 4 (a) and 4 (b), and the conductors 1 and 2 are solid lines and the conductors 3 and 4 are Indicated by broken lines. Reference numerals 8 and 9 denote conductors separately added to the conductors 1 to 4, which are drawn by dashed lines in the figure. 15,15 'is conductor 8
, 16 and 16 ′ are terminals of the conductor 9. c is the pitch of the conductors 8 and 9 and is selected to be larger than the pitches p and q. The Y-axis wiring configuration is the same as the X-axis wiring configuration described above.

Next, the operation of this embodiment will be described. Data processing unit 36
Outputs a signal to the switching circuit 35, first inputs the signals of the conductors 1 to 4 as in the conventional device, introduces the output of the adder 26 to the height detector 32, and outputs the signal from the surface of the tablet 34 of the indicator 6 Detect height. At this time, based on the height also the data processing device when the range D ₁ is a conventional device 36 signal conductors 1-4, determine pitch number, calculates the coordinate value by the above formula (11) . Further, when the height is in the range D _3, stops the detection operation.

On the other hand, if the above-mentioned height is in the range D ₂ is detected, the data processing unit 36 outputs a command signal to the switching circuit 35, Komu takes a signal conductor 3, 4 and conductors 8,9. That is, in the conventional device, signals of the conductors 8 and 9 are input instead of signals of the conductors 1 and 2. Hereinafter, exactly like the conventional device,
The data processing device 36 determines the number of pitches of the pointer 6 based on the signals of the conductors 3, 4, 8, and 9, calculates the coordinate value by the equation (11), and outputs the coordinate value.

Here, the conductors 8 and 9 will be described. In general, it is known that an optimal numerical range exists between the height of the pointer and the pitch of the coordinate detection conductor based on the distribution of the magnetic flux generated by the pointer and the linkage area of the coordinate detection conductor loop. I have. For example, in a certain height range of the indicator 6, the conducting wire
If the pitch p of 1,2 is optimal, for a certain height range above that, if the pitch of the conductors 1,2 is selected to be 1.5 to 2p, the induced voltage and the amplitude characteristics with respect to position will be better. Things. In this embodiment, the conductors 8, 9 having the pitch c larger than the pitches p, q are laid based on this, and the pitch c is a combination of the conductors 3, 4 and the conductors 8, 9, They are selected to best way coordinate detection in the high range D _2. Thus, it is possible to detect the coordinate value based on the pitch number, it is possible to detect the coordinate values without significantly lowering the detection accuracy in the height range D ₁ in the high range D _2.

In the description of the above embodiment, an example in which one set of conductors (conductors 8, 9) is added for one axis has been described. However, the present invention is not limited to this, and two sets of conductors are added,
It may be used the 2 pairs of wires to the coordinate detection in the high range D _2. In this case, a total of four sets of conductive wires are laid. As an example, these two sets of conductors are referred to as the conductors 8 and 9 and the other conductors 8 'and 9', and the total length is l = 200 m.
The following table shows the case where m is used and the counter used is a 1000-counter counter.

Further, as described above, not only three or four sets but also five or more sets can be laid, and an optimum combination is selected from these sets to adapt to various height ranges of the indicator. Can be done. In this case, of course, the magnitude and the number (the number of switching elements) of the reference voltage of the height detector are selected in accordance with the combination of the above-mentioned conductor sets. Normally, the number of conductor sets, their pitches, and the height range of the height detector can be arbitrarily selected according to the usage of the pointer of the coordinate detecting device and the required detection accuracy.

In this manner, in the present embodiment, a set of conductors having a large pitch is added to the tablet, and a combination of the set of conductors of the tablet is selected according to the height range of the pointer.
Means for determining the number of pitches to obtain a coordinate value can be employed, whereby the coordinate value can be detected with high accuracy even when the pointer is at a considerable height.

〔The invention's effect〕

As described above, according to the present invention, when a height range defined by one detecting means is detected, coordinate detection based on the pitch number is performed, and a higher height range defined by the other detecting means is detected. In this case, coordinate detection is performed directly from the output signal of each lead wire regardless of the number of pitches, so that coordinate detection can be performed without fear of jumping pitch even when the pointer is in a considerably high height range.

Further, in the present invention, at least one conductor set having a large pitch is added, and the combination of the conductor sets is selected according to the detected height range of the indicator. In this case, coordinate detection based on the number of pitches can be performed, thereby enabling highly accurate detection.

[Brief description of the drawings]

1 and 2 are block diagrams of a coordinate detecting apparatus according to an embodiment of the present invention, respectively. FIG. 3 is a layout diagram of the X-axis coordinate detecting lead wire of the tablet shown in FIG. 2, and FIG. 4 (a). ,
5 (b) is a layout diagram of the X-axis coordinate detecting wire in the conventional coordinate detecting device, FIGS. 5 (a) and 5 (b) are waveform diagrams of the induced voltage of the conductive wire, and FIG. 6 is a block diagram of the conventional coordinate detecting device. FIGS. 7A and 7B are characteristic diagrams of the number of pulses with respect to the position of the pointer. 1,2,3,4,8,9 ... conductor, 6 ... indicator, 21, 34 ... tablet, 22, 35 ... switching circuit, 31, 36 ... data processing device,
32 ... Height detector.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yukitoshi Muramatsu 2100 Kamiimaizumi, Ebina City, Kanagawa Prefecture Inside Hitachi Seiko Co., Ltd. References JP-A-60-103443 (JP, A) JP-A-59-55586 (JP, A)

Claims (2)

(57) [Claims] A first pitch having different phases from each other;
A coordinate detection plate in which a wiring group composed of a conductor set composed of two conductors and a conductor set composed of two conductors having a second pitch and having different phases is arranged for each coordinate axis, and electromagnetic means. An indicator for designating an arbitrary position on the coordinate detection plate; a detection unit for detecting that the indicator is within a predetermined height range from the coordinate detection plate; and First computing means for determining the number of pitches at which the pointer is present based on the output signals of the first pitch conductor and the second pitch conductor only when
A second step of obtaining coordinate values of the pointer based on the pitch number
A coordinate detecting device comprising: a detecting means for detecting that the pointer is within a predetermined height range continuous with the predetermined height range; and When the first value obtained from the conductor of the first pitch is larger than the second value obtained from the conductor of the second pitch, the value of the difference between the first pitch and the second pitch is determined by a predetermined coefficient. Multiplying the first value is smaller than the second value by multiplying the sum of the maximum set value of the two and the value of the difference by the coefficient to obtain the coordinate value of the pointer And a coordinate detecting device. 2. A method according to claim 1, wherein the first pitch and the second pitch are different from each other.
A coordinate detection plate in which a wiring group composed of a conductor set composed of two conductors and a conductor set composed of two conductors having a second pitch and having different phases is arranged for each coordinate axis, and electromagnetic means. A coordinate detection device comprising: a pointer for designating an arbitrary position on the coordinate detection plate; and detection means for detecting that the pointer is within a predetermined height range allowing coordinate detection from the coordinate detection plate. In the above, another detection means for detecting that the indicator is within at least one set height range outside the predetermined height range, and the detection means added to each of the coordinate axes corresponding to the set height range At least one having a pitch of 1 and another pitch greater than the second pitch
A coordinate detecting device, comprising: a pair of conductive wires;