JPH04296922A - Position detector - Google Patents

Abstract

PURPOSE:To increase the position detection speed by detecting the induced voltage of a sense-side coil due to the change of the magnetic flux of a position indicator to obtain a maximum value of the detected induced voltage. CONSTITUTION:A position detecting part 1 consisting of transmission coils TX-1... arranged in the position detecting direction at prescribed intervals and reception coils RX-1... which have coil pieces approximately orthogonal to transmission coils and are arranged at prescribed intervals and are so turned that the induced voltage generated by the change of the magnetic flux due to the current flowing to coil pieces of transmission coils is practically cancelled, an AC signal generating circuit 5 which supplies an AC signal to selected transmission coils, and a cursor 7 including a coil and a capacitor constituting a tuning circuit tuned to the frequency of the AC signal are provided. Reception coils are successively selected, and the AC signal is successively applied to transmission coils TX-1... during selection, and the induced voltage generated in the selected reception coil is detected, and the position of the position indicator is obtained in accordance with the position of the transmission coil which generates a maximum induced voltage.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device, and more particularly to a so-called cordless tablet in which a position indicator indicating a position on a position detecting section does not require a connection line to connect to the position detecting section. .

0002

2. Description of the Related Art A conventional position detection device of this type sequentially selects one loop coil from a plurality of loop coils arranged in parallel in the position detection direction and serves both the drive side and the sense side, and applies a predetermined value to the selected loop coil. A position indicator having a tuning circuit that tunes to the predetermined frequency receives the magnetic flux change that occurs in the selected loop coil by applying a signal at the predetermined frequency, and stops applying the signal of the predetermined frequency to the tuned coil of the tuning circuit. The induced voltage generated in the loop coil is detected by the magnetic flux change caused by the induced voltage generated in the loop coil, and this detection operation is sequentially repeated for each selected loop coil to determine the position where the induced voltage generated in the loop coil has the maximum value, that is, the position. It is configured to find the position of the indicator.

0003

[Problems to be Solved by the Invention] However, according to the above-mentioned conventional position detection device, the loop coil is provided in common on the drive side and the sense side. , the loop coil must be switched to the sensing side to detect the induced voltage, and since driving and sensing cannot be performed simultaneously, there is a problem that the position detection speed becomes slow. Furthermore, even if the drive-side loop coil and the sense-side loop coil are provided independently, the drive and sense become temporally independent due to the voltage induced in the sense-side loop coil by the current flowing through the drive-side loop coil. However, there was a problem that the position detection speed was slow.

The present invention provides a driving side coil arranged at predetermined intervals in the position detection direction, and a sensing side arranged almost orthogonally to the driving side coil and wound so as not to generate an induced voltage caused by energization of the driving side coil. A coil is provided, the drive side coil is scanned and an alternating current voltage is sequentially applied, the induced voltage of the sense side coil caused by the change in magnetic flux of the position indicator is detected, and the position where the detected induced voltage is the maximum value is determined. Accordingly, it is an object of the present invention to provide a position detection device that solves the above-mentioned problems and increases the speed of position detection.

[0005]

[Means for Solving the Problems] The position detection device of the present invention includes a drive side coil having a winding count of one turn or more and arranged at predetermined intervals in a position detection direction, and a wire ring side substantially perpendicular to the drive side coil. , a position detection unit consisting of a sense side coil arranged at a predetermined interval and wound so as to substantially cancel the induced voltage generated by a change in magnetic flux due to a current flowing through the wire ring of each drive side coil; , a selection means for sequentially selecting drive-side coils, an AC signal source that supplies an AC signal to the drive-side coil via the selection means, and a position indicator including a coil and a capacitor forming a tuning circuit tuned to the frequency of the AC signal. select the first sense side coil, and during the selection, drive the selection means to sequentially apply an alternating current signal to the drive side coil, and detect the induced voltage generated in the selected sense side coil. The present invention is characterized in that it includes a detection means for determining the position of the position indicator from the position of the drive-side coil generating the maximum induced voltage.

[0006] Furthermore, two position detecting sections are provided, the driving side coil of the first position detecting section is arranged in the X coordinate direction, and the driving side coil of the second position detecting section is arranged in the Y coordinate direction. , sequentially 1
During the selection, the selection means is driven to sequentially apply an alternating current signal to the drive side coils of the position detection section including the selected sense side coils. The generated induced voltage may be detected and the position of the position indicator may be determined from the position of the drive-side coil that generates the maximum induced voltage.

[0007]

[Operation] When using the position detection device of the present invention, an induced voltage is generated in the coil of the tuned circuit due to a change in magnetic flux due to a current flowing through the drive side coil to which an AC signal is applied. An induced voltage is generated in the sense side coil by the current flowing. This induced voltage is at its maximum when the drive-side coil located opposite the position indicator is energized. While the sense side coil 1 is selected, AC signals are sequentially applied to the drive side coil, during which the generated induced voltage is detected by the detection means in the sense side coil, and the drive side coil is selected when the detected induced voltage shows the maximum value. is detected, and the position of the position indicator is detected. In this case, since virtually no induced voltage is generated in the sense side coil due to the magnetic flux caused by the current flowing through the drive side coil, an induced voltage is generated in the sense side coil due to the energization of the drive side coil and the magnetic flux change from the position indicator. The detection of the induced voltage can be performed in parallel, increasing the position detection speed, and since the induced voltage of the sense side coil is not affected by the drive side coil, the position can be detected accurately.

[0008] Furthermore, two position detecting sections are provided, the driving side coil of the first position detecting section is arranged in the X coordinate direction, and the driving side coil of the second position detecting section is arranged in the Y coordinate direction. , 1, while selecting the sense side coil, the selection means is driven to sequentially apply an alternating current signal to the drive side coil, detect the induced voltage generated in the selected sense side coil, and generate the maximum induced voltage. When the position of the position indicator is determined from the drive side coil position, the two-dimensional position of the position indicator can be detected.

[0009]

[Examples] The present invention will be explained below with reference to Examples.

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. As shown in FIG. 2, the position detection unit 1 includes an Direction transmitting coil TX-1, TX-2
,...TX-n (n is a natural number) and the X-axis direction transmitting coil T
The transmitting coil is wound so that the coil sides are almost orthogonal to X-1, TX-2, ..., and TX-n, and the direction of the magnetic flux generated by the current flowing through each coil side of the X-axis direction drive coil is canceled out. X-axis direction receiving coils RX-1 and RX-2, which are X-axis direction sense side coils, are designed to prevent the generation of induced voltage caused by electromagnetic induction due to the current flowing in TX-1, TX-2, ... and TX-n. It is equipped with X-axis direction receiving coil RX-1 and X-axis direction receiving coil R
X-2 is arranged so as to be shifted at a constant pitch so that position detection can be performed over the entire surface.

[0011] X-axis direction transmitting coils TX-1, TX-2,
...and TX-n are connected to an X-axis direction transmitting coil selection circuit 2 consisting of, for example, an analog switch, etc., and are sequentially selected by the X-axis direction transmission coil selection circuit 2 to output an AC signal of a predetermined frequency. The output from the signal generation circuit 5 is applied. On the other hand, the X-axis direction receiving coils RX-1 and RX-2 are selectively connected to the X-axis direction receiving coils RX-1 and RX-2 through a receiving coil selection circuit 6 consisting of an analog switch or the like. The induced voltages of the receiving coils RX-1 and RX-2 are supplied to the signal processing circuit 3. The induced voltage of the selected X-axis receiving coil subjected to signal processing by the signal processing circuit 3 is supplied to the control calculation circuit 4.

The control calculation circuit 4 drives the X-axis transmitting coil selection circuit 2 and applies the output from the AC signal generating circuit 5 to the X-axis transmitting coils TX-1, TX-2, TX-3.
..., drives the receiving coil selection circuit 6 to sequentially select the induced voltages of the receiving coils RX-1 and RX-2 in the X-axis direction, and determines the position where the output from the signal processing circuit 3 has the maximum value. calculate.

The control calculation circuit 4 includes, for example, an A/D converter that converts the output from the signal processing circuit 3 into digital data;
receiving the output of the A/D converter and outputting a selection signal to the X-axis direction transmitting coil selection circuit 2 and receiving coil selection circuit 6;
It is equipped with a microcomputer that performs a calculation to determine the position of the maximum value of the output from the signal processing circuit 3. The cursor 7 as a position indicator has a coil 81 and a capacitor 82 that constitute a tuning circuit 8 tuned to the output AC signal frequency of the AC signal generation circuit 5, and a coil 81 and a capacitor 82 that are selectively connected in parallel to the capacitor 82 via a switch 83. A capacitor 84 is provided for shifting the phase of the current flowing through the tuning circuit 8 from the phase of the induced voltage generated by changes in magnetic flux from the transmitting coil.

Furthermore, the position detection unit 1 includes X-axis direction transmitting coils TX-1, TX-2,
...Y-axis direction transmitting coils TY-1, T with the number of windings of 1 turn or more arranged at predetermined intervals in the Y-axis direction perpendicular to TX-n.
Y-2, ..., TY-n and Y-axis direction transmitting coil TY-1
, TY-2, ...TY-n, the wire ring sides are approximately perpendicular to each other, and the transmitter coils TY-1, TY are wound so that the directions of the magnetic lines of force generated by the current flowing through each wire ring side are sequentially opposite directions.
Y-axis receiving coils RY-1 and RY-2 are provided to prevent generation of induced voltage caused by electromagnetic induction due to current flowing through -2, . . . , TY-n. The coil group for detecting the position in the X-axis direction and the coil group for detecting the position in the Y-axis direction are galvanically insulated. An AC signal of a predetermined frequency output from the AC signal generation circuit 5 is applied to the Y-axis direction transmission coils TY-1, TY-2, . . . , TY-n via the Y-axis direction transmission coil selection circuit 9.

On the other hand, the induced voltages of the Y-axis direction receiving coils RY-1 and RY-2 are selected by a receiving coil selection circuit 6 consisting of analog switches and the like and are supplied to the signal processing circuit 3. The induced voltage of the selected Y-axis receiving coil subjected to signal processing by the signal processing circuit 3 is supplied to the control calculation circuit 4.

The control calculation circuit 4 drives the Y-axis transmitting coil selection circuit 9 to apply the output signal from the AC signal generating circuit 5 to Y-axis transmitting coils TY-1, TY-2, . . .
In addition to selecting TY-n, the receiving coil selection circuit 6
is driven to select the Y-axis direction receiving coils RY-1 and RY-2, and the position where the output from the signal processing circuit 3 is maximum is determined and calculated.

The signal processing circuit 3 includes an amplifier 33 for amplifying the output from the receiving coil selection circuit 6, a rectifier circuit 34 for rectifying the output of the amplifier 33, an integrating circuit 35 for smoothing the rectified output and supplying it to the control calculation circuit 4, It is comprised of a phase detection circuit 36 that detects the phase of the output of the amplifier 33, and an integration circuit 37 that smoothes the phase detection output and supplies it to the control calculation circuit 4.

The AC signal generating circuit 5 receives the pulse γ output from the control calculation circuit 4 and outputs pulses a and b having a phase shift of 90° for setting the frequency of the sine wave signal and for phase detection. In response to the switching pulse δ output from the generation circuit 51 and the control calculation circuit 4, the switching circuit 52 is switched to select the output of the signal generation circuit 51 and is supplied to the phase detection circuit 36, and the output pulse from the signal generation circuit 51 In response to a, the X-axis direction transmitting coil selection circuit 2 and Y
A sine wave signal generation circuit 5 that outputs a sine wave signal to be supplied to the transmission coil via the axial transmission coil selection circuit 9
The output sine wave signal from the sine wave signal generation circuit 53 is switched by the XY axis switching signal β outputted from 3 and the control calculation circuit 4 to the X axis direction transmit coil selection circuit 2 and the Y axis direction transmission coil selection circuit 9. It is composed of a switching circuit 54 that selectively supplies the signal. In addition, the receiving coil selection circuit 6
is supplied with an XY-axis switching signal β to switch between the X-axis receiving coils (RX-1, RX-2) and the Y-axis receiving coils (RY-1, RY-2), and The pulse ε output from the control calculation circuit 4 is supplied, and
It is configured to switch between the axial receiving coils RX-1 and RX-2 and between the Y-axis receiving coils RY-1 and RY-2.

In this embodiment configured as described above,
First, position detection in the X-axis direction will be explained.

As shown in FIG. 3, the transmitting coil TX in the X-axis direction
Apply a sine wave signal to -i (i=1,...,n). When a current flows in the direction shown by the arrow in the wire ring side of the X-axis direction transmitting coil TX-i, magnetic fields are generated in alternating directions as shown in Figure 3, and current flows in the opposite direction. Similarly, magnetic fields are generated alternately in different directions, and the magnetic flux generated in the X-axis direction transmitting coil TX-i by the sine wave signal passes through the loop of the X-axis direction receiving coil RX-1, but the penetrating magnetic flux is The directions cancel each other out, and the X-axis direction transmitting coil TX
- Even if a sine wave signal is applied to i, the receiving coil R in the X-axis direction
No induced voltage is generated in X-1 due to the X-axis direction transmitting coil TX-i. The same applies to the X-axis direction receiving coil RX-2.

[0021] The energized X-axis direction transmitting coil TX-
1 induces a voltage in the tuned circuit 8 of the cursor 7. As shown in FIG. 4(a), when the position of the cursor 7 is moved in the A-A' direction and the B-B' direction with respect to the X-axis direction transmitting coil TX-i, facing the position detection unit 1. , the induced voltages generated in the tuning circuit 8 of the cursor 7 are as shown in FIGS. 4(b) and 4(c), respectively. The induced voltage induced in the tuned circuit 8 of the cursor 7 is proportional to the magnetic flux passing through the coil 81. A current accompanying this induced voltage flows into the tuned circuit 8, and the magnetic flux generated by this current passes through the receiving coil RX-i in the X-axis direction as shown in FIG. 5(a). Depending on the change, the X-axis direction receiving coil RX-1, R
An induced voltage is generated at X-2. X-axis direction receiving coil RX-
5(b) and 5(c) depending on the position of casa 7.
As shown in FIG. 2, an induced voltage proportional to the change in magnetic flux generated from the tuning circuit 8 is generated.

Therefore, for example, as shown in FIG. 6(a), the center position CTX in the X-axis direction of the X-axis direction transmitting coil TX-i
- When casa 7 is located opposite i,
When the X-axis direction transmitting coil TX-i is energized, Fig. 6 (
As shown in b), the induced voltage in the X-axis direction receiving coil RX-i is at the center position CTX- of the X-axis direction transmitting coil TX-i.
It shows the maximum value at i, and the X-axis direction transmitting coil TX-i
The induced voltage decreases as the distance from the center position CTX-i increases. Note that in FIG. 6(b), C written as CTX-ii is a symbol indicating the center of the transmitting coil. As a result, the X-axis direction transmitting coil selection circuit 2
By sequentially selecting the X-axis direction transmitting coils and detecting the X-axis direction transmitting coil generating the maximum induced voltage,
The position of the cursor 7 can be detected. This position detection is performed by the receiving coil RX as shown by the broken line in FIG. 6(b).
The induced voltage of −i can be approximated by a quadratic function, and the position of the maximum value can be determined by calculation. The same applies to the Y-axis side.

Next, the operation including the control calculation circuit 4 will be explained based on the flowcharts of FIGS. 8 and 9.

The control calculation circuit 4 outputs a pulse α, an XY axis switching signal β, a pulse γ, a pulse ε, and a switching pulse δ. In response to the pulse γ, the signal generation circuit 51 generates two-phase pulses having a 90° phase difference as shown in FIGS. 7(a) and (b), and in response to the pulse in FIG.
3 generates a sine wave signal shown in FIG. 7(c). Therefore, the sine wave signal output from the switching circuit 54 is also
) is the same waveform (FIG. 7(d)). In response to the pulse β, the switching circuit 54 is switched between the X-axis direction and the Y-axis direction, and in synchronization with the switching of the switching circuit 54, the receiving coil selection circuit 6
switches between the X-axis receiving coil side and the Y-axis receiving coil side. In response to the pulse ε, the receiving coil selection circuit 6 switches between the receiving coils RX-1 and RX-2 during the X-axis receiving coil selection, and switches the receiving coil RY between the receiving coils RX-1 and RX-2 during the Y-axis receiving coil selection.
Switch between -1 and RY-2. Therefore, on the receiving side, FIGS. 8(d), 8(e), 8(f), and 8(g)
As shown in the figure, the X-axis direction receiving coil RX-1, the X-axis direction receiving coil RX-2, the Y-axis direction receiving coil RY-1, and the Y-axis direction receiving coil RY-2 are selected in this order, and the induced voltage is applied to the amplifier. 33.

On the other hand, in response to the pulse α, the X-axis transmitting coil selection circuit 2 and the Y-axis transmitting coil selection circuit 9 select the receiving coils RX-1 and RX-2 as shown in FIG. 8(h).
is selected, the X-axis direction transmitting coil TX-1
~TX-n (abbreviated as X1 to Xn in FIG. 8)
are sequentially selected in whole or in part, and during the period when receiving coils RY-1 and RY-2 are selected, Y-axis direction transmitting coils TY-1 to TY-n (Y1 in FIG.
~Yn) are sequentially selected in whole or in part.

Therefore, when position detection is started, the X-axis direction receiving coil RX-1 is selected first, and during the period when the X-axis direction receiving coil RX-1 is selected, the X-axis direction transmitting coils TX-1 to TX-1 are selected. TX-n is sequentially selected, and a sine wave signal is sequentially applied to the X-axis direction transmitting coils TX-1 to TX-n. The amplified output of the amplifier 33 during this period is shown in FIG.
As shown in e). This amplified output is rectified by a rectifier circuit 34. The output of the rectifier circuit 34 is as shown in FIG. 7(g). The rectified output is smoothed by an integrating circuit 35 and supplied to the control calculation circuit 4. The output of the integrating circuit 35 is shown in Figure 7.
As shown in (i), the X-axis direction receiving coil RX-
1, RX-2 is schematically shown in FIG. 8(i). The output of the integrating circuit 35 is stored in the storage section of the microcomputer as position data in the X-axis direction. FIG. 8(a) shows an enlarged view of the sine wave signal waveform shown in FIG. 7(c), and FIGS. 8(b) and 8(c) show the period when the X-axis direction receiving coil RX-1 is selected. An enlarged view showing the selection of the X-axis direction transmitting coils TX-1 to TX-n and an enlarged view of the output of the integrating circuit 35 are shown in FIG.

Next, the X-axis receiving coil RX-2 is selected, and similarly the X-axis transmitting coils TX-1, . . . TX-
A sine wave signal is sequentially applied to the receiving coil R in the X-axis direction.
The induced voltage of X-2 is amplified by the amplifier 33. This amplified output is rectified by a rectifying circuit 34, smoothed by an integrating circuit 35, and then supplied to the control calculation circuit 4. The output of the integrating circuit 35 is stored in the storage section of the microcomputer as position data in the X-axis direction.

Next, the Y-axis direction receiving coil RY-1 is selected, and similarly, a sine wave signal is sequentially applied to the Y-axis direction transmitting coils TY-1, .
The output of the integrating circuit 35 based on the induced voltage of 1 is stored in the storage section as position data in the Y-axis direction. Next, the Y-axis direction receiving coil RY-2 is selected, and similarly, a sine wave signal is sequentially applied to the Y-axis direction transmitting coils TY-1, ...TY-n,
The output of the integrating circuit 35 based on the induced voltage of the Y-axis receiving coil RY-2 is stored in the storage section as Y-axis position data.

When the switch 83 in the cursor 7 is closed, the output of the amplifier 33 is shown in FIG. 7(f), the output of the rectifier circuit 34 is shown in FIG. 7(h), and the output of the integrating circuit 35 is shown in FIG. Each is shown in (j). Since the capacitor 84 is connected in parallel, the tuning frequency of the tuning circuit 8 is lowered by an amount corresponding to the capacitance of the capacitor 84, and FIG.
The phase is advanced by an amount corresponding to the capacitance of the capacitor 84 with respect to e), and the phase in FIG. 7(h) is advanced by an amount corresponding to the capacitance of the capacitor 84 with respect to FIG. I'm here.

Following the completion of storing the position data in the X-axis direction and the Y-axis direction, the maximum value of the stored X-axis integral output,
It is determined whether the maximum value of the integrated output of the Y-axis is above a predetermined level, respectively, and a predetermined number of front and back X-axis direction transmitting coils including the X-axis direction transmitting coil from which the maximum value is obtained among all the X-axis direction transmitting coils TX-1 to TX-n are determined. partial scanning to select only the X-axis direction transmitting coils and a predetermined number of front and rear Y-axis direction receiving coils including the Y-axis direction transmitting coil from which the maximum value was obtained among all the Y-axis direction transmitting coils TY-1 to TY-n. Perform a partial scan to select only the Determine whether the output of the integrating circuit 35 obtained in the partial scan is above a predetermined level, calculate the maximum value position in the X-axis direction and the maximum value position in the Y-axis direction, and obtain the position coordinates of the cursor 7. Stored in the storage unit.

On the other hand, in response to the switching pulse δ, the switching circuit 52
alternately selects the output of the signal generating circuit 51. The output from the amplifier 33 using the output of the selected signal generation circuit 51 is subjected to phase detection in the phase detection circuit 36. The phase detection output obtained by phase detection using pulse a shown in Fig. 7(a) is shown in Fig. 7(k).
The phase detection output obtained by phase detection using the pulse b shown in FIG. 7(b) is as shown in FIG. 7(m). The phase detection output is smoothed by an integrating circuit 37. Integrating circuit 3
The output waveforms of 7 are as shown in FIGS. 7(p) and 7(r), and the output level shown in FIG. 7(p) is Vφ0, and the output level shown in FIG. 7(r) is Vφ90. Figure 7 (p
) corresponds to FIG. 7(k), and FIG. 7(r) corresponds to FIG. 7(m). In addition, FIG. 7(l), FIG. 7(n), FIG. 7(q
) and FIG. 7(s) show the case where the switch 83 is closed, FIG. 7(l) corresponds to FIG. 7(k), and FIG. 7(n
) corresponds to FIG. 7(m), FIG. 7(q) corresponds to FIG. 7(p), and FIG. 7(s) corresponds to FIG. 7(r). Further, the output level shown in FIG. 7(q) is assumed to be Vφ0', and the output level shown in FIG. 7(s) is assumed to be Vφ90'.

When the position coordinates of the cursor 7 are obtained, after partial scanning, the X-axis receiving coil that was outputting the maximum induced voltage in the X-axis receiving coil and the X-axis transmitting coil at that time are selected. The outputs Vφ0 and Vφ90 from the integrating circuit 37 are supplied to the control calculation circuit 4.
is read, and the phase difference of the received induced voltage is calculated from the ratio of the output Vφ0 and the output Vφ90. The coordinate position data of the cursor 7 and the phase difference data of the received induced voltage obtained above are output from the control calculation circuit 4 to the outside. This coordinate data determines the XY coordinate position of the cursor 7, and this phase difference data determines whether the switch 83 is closed.

[0033]

As explained above, according to the present invention, the drive-side coil is wound so that the induced voltage generated in the sense-side coil is substantially canceled by the change in magnetic flux caused by the current flowing through each wire ring side of the drive-side coil. Because of this, substantially no induced voltage is generated in the sense coil due to the magnetic flux caused by the current flowing through the drive coil. Therefore, the energization of the drive side coil and the detection of the induced voltage generated in the sense side coil due to changes in magnetic flux from the position indicator can be performed in parallel. There is no need to switch between coils, which has the effect of increasing position detection speed. Furthermore, since there is no influence from the drive side coil on the induced voltage of the sense side coil, there is also the effect that position detection can be performed accurately.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a schematic diagram showing the arrangement of an X-axis receiving coil and an X-axis transmitting coil in an embodiment of the present invention.

FIG. 3 is a schematic diagram showing the direction of a magnetic field generated by energization of a transmitting coil in an embodiment of the present invention.

FIG. 4 is a waveform explanatory diagram showing an induced voltage generated in a tuning circuit of a cursor caused by a transmitting coil in an embodiment of the present invention.

FIG. 5 is a waveform explanatory diagram showing the induced voltage generated in the receiving coil by the induced voltage generated by the tuning circuit of the casser in one embodiment of the present invention.

FIG. 6 is a schematic diagram showing the distribution of the induced voltage in the receiving coil with respect to the cursor position in an embodiment of the present invention.

FIG. 7 is a waveform diagram for explaining the operation of an embodiment of the present invention.

FIG. 8 is a timing diagram for explaining the operation of an embodiment of the present invention.

FIG. 9 is a flowchart for explaining the operation of an embodiment of the present invention.

FIG. 10 is a flowchart for explaining the operation of an embodiment of the present invention.

[Explanation of symbols]

1...Position detection section 2...X-axis direction transmitting coil selection circuit 3...Signal processing circuit 4...Control calculation circuit 5...AC signal generation circuit 6...Receiving coil selection circuit 7…Casa 8... Tuning circuit 9...Y-axis direction transmitting coil selection circuit

Claims (2)

[Claims] Claim 1: A drive-side coil with a winding count of one turn or more arranged at a predetermined interval in the position detection direction, and a wire ring side substantially perpendicular to the drive-side coil, arranged at a predetermined interval, and each drive-side coil is arranged at a predetermined interval. a position detection unit comprising a sense side coil wound so that an induced voltage generated by a change in magnetic flux due to a current flowing through a wire ring of the coil is substantially canceled; and a selection means for sequentially selecting a drive side coil; An AC signal source that supplies an AC signal to the drive side coil through a selection means, a position indicator including a coil and a capacitor that constitute a tuning circuit tuned to the frequency of the AC signal, and a first sense side coil are selected in sequence. , during the selection, the selection means is driven to sequentially apply alternating current signals to the drive side coil, the induced voltage generated in the selected sense side coil is detected, and the drive side generates the maximum induced voltage; 1. A position detection device comprising: detection means for determining the position of a position indicator from a coil position. 2. A first drive-side coil with a winding count of one turn or more arranged at a predetermined interval in the X-coordinate direction; a coil side substantially perpendicular to the first drive-side coil and arranged at a predetermined interval; and a first sense side coil wound so as to substantially cancel out the induced voltage generated by a change in magnetic flux caused by a current flowing through the coil segments of each first drive side coil; a second drive-side coil with a winding count of one turn or more arranged at predetermined intervals in the Y-coordinate direction; a second position detection unit comprising a second sense side coil wound so that the induced voltage generated by a change in magnetic flux due to a current flowing in a wire ring piece of the side coil is substantially canceled; and a first drive side coil. and 1 from the second drive side coil.
a selection means for sequentially selecting one of the drive side coils; an AC signal source for supplying an AC signal to the drive side coil selected by the selection means; and a position including a coil and a capacitor forming a tuning circuit tuned to the frequency of the AC signal. indicator and
The first sense side coil is selected in sequence, and during the selection, the selection means is driven to sequentially apply an AC signal to the drive side coil of the position detection unit including the selected sense side coil, and the selected sense side coil is sequentially applied. 1. A position detection device comprising: detecting means for detecting an induced voltage generated in a coil and determining the position of a position indicator from the position of a drive-side coil generating a maximum induced voltage.