JP2007166147A - Coil drive method, coil driver, and position detection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase a dynamic range in coil driving. <P>SOLUTION: Switches 102a, 115a only are closed, a first half positive half wave signal S1 of a drive signal is given to a terminal 101, and a latter half positive half wave signal S2 of the drive signal is given to a terminal 117, then a drive circuit 103a and a drive circuit 116a are alternately switched and driven, a position detection signal is transmitted from a first region 108 to a position indicator at the first half of the drive signal, and the position detection signal is transmitted from a second region 111 to the position indicator at the latter half of the drive signal, resulting in that the driving is similar to driving a whole coil 105. Other coils 106, 107 are similarly driven. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a coil driving method suitable for driving a coil that is magnetically coupled to a coil of an indicator and transmits a signal to the coil, a coil driving device used in the coil driving method, and the coil driving device. Used as an input device for CAD (Computer Aided Design), computer, personal digital assistant (PDA), mobile phone, PHS (Personal Handyphone System), etc., and has at least one coil for indicating the position The present invention relates to a position detection device that detects a position indicated by the indicator by transmitting and receiving signals to and from the indicator by electromagnetic coupling.

Conventionally, as a CAD input device, a computer input system, or the like, a position detection device that transmits and receives signals by electromagnetic coupling with an indicator and detects the indication position of the indicator has been used ( For example, see Patent Documents 1 and 2).
The position indicator has at least one coil. The position detection device includes a coil for transmitting a position detection signal to the position indicator, and a coil driving device for driving the coil.

  On the position detecting device side, the coil driving device drives the coil to transmit a position detection signal from the coil. On the position indicator side, the position detection signal is received by electromagnetic coupling and a position indication signal is returned. The position detecting device receives the position indicating signal. The position detection device calculates the indicated position by the position indicator by performing a predetermined calculation process after performing the above operation a predetermined number of times.

JP 2003-202955 A JP 2003-204231 A

  However, the conventional coil driving device has a problem that the dynamic range cannot be expanded unless the circuit configuration is a complicated positive / negative two power supply configuration, and the dynamic range is narrowed when driving at a low voltage with a single power source. Further, when a dynamic range is required, there is a problem that it is particularly difficult to transmit a large current.

An object of the present invention is to increase the dynamic range in a coil driving method. Another object of the present invention is to enable easy driving in a coil driving method.
An object of the present invention is to increase the dynamic range of a coil drive device. Moreover, this invention makes it the subject to simplify the structure of a coil drive device.
An object of the present invention is to increase a dynamic range in a position detection device. Moreover, this invention makes it a subject to simplify a structure in a position detection apparatus.

According to the present invention, in the coil driving method of transmitting a signal from the first coil means to the second coil means by electromagnetic coupling by supplying a driving current to the first coil means, the first coil means is the first coil means. There is provided a coil driving method which is configured to have a region and a second region, and wherein the driving means switches between the first region and the second region by a drive signal and drives them.
The first coil means is configured to have a first area and a second area, and the driving means drives the first area and the second area by switching between them with a drive signal.

Here, the first region is constituted by a coil wound in a first direction, and the second region is constituted by a coil wound in a second direction opposite to the first direction. You may comprise.
Further, the driving means has a suction circuit, and pulls up the boundary between the first region and the second region with a positive power supply voltage, and the first region and the second region are switched to each other by the suction circuit. You may comprise so that it may drive.

Further, the driving means has a discharge circuit, pulls down the boundary between the first region and the second region to a reference potential, and drives the first region and the second region by switching to each other by the discharge circuit. You may comprise as follows.
The driving means may include a transistor for supplying a current to the first coil means, and the transistor may be directly connected to the first coil means.
The first coil means may be constituted by a plurality of coils intersecting each other, and the coil driving means may be configured to simultaneously drive corresponding regions of the plurality of coils.

Further, according to the present invention, in the coil driving apparatus for transmitting a signal from the first coil means to the second coil means by electromagnetic coupling by supplying a driving current to the first coil means, the first coil means There is provided a coil drive device comprising a drive means configured to have a first area and a second area, and to switch and drive the first area and the second area with a drive signal. The
The driving means drives the first area and the second area of the first coil means by switching between them with a drive signal.

Here, the first region is constituted by a coil wound in a first direction, and the second region is constituted by a coil wound in a second direction opposite to the first direction. You may comprise.
Further, the driving means has a suction circuit, and pulls up the boundary between the first region and the second region with a positive power supply voltage, and the first region and the second region are switched to each other by the suction circuit. You may comprise so that it may drive.

Further, the driving means has a discharge circuit, pulls down the boundary between the first region and the second region to a reference potential, and drives the first region and the second region by switching to each other by the discharge circuit. You may comprise as follows.
The driving means may include a transistor for supplying a current to the first coil means, and the transistor may be directly connected to the first coil means.
The first coil means may be constituted by a plurality of coils intersecting each other, and the coil driving means may be configured to simultaneously drive corresponding regions of the plurality of coils.

  Further, according to the present invention, the first coil means and a coil driving device for driving the first coil means are provided, and the first coil means is driven by the coil driving device so that at least one coil is used. In the position detection device for detecting the indicated position of the position indicator by transmitting a signal by electromagnetic coupling to the position indicator having the second coil means, any one of the above as the coil driving device. There is provided a position detecting device comprising the coil driving device described above.

Here, the first coil means may be configured to be a transmission-dedicated coil for transmitting a position detection signal.
Further, it may be configured to include detection means for detecting an indication position of the position indicator based on a signal from the first coil means received by the second coil means.
In addition, the first coil means may be configured to be a coil that serves both for transmitting a position detection signal and for detecting a position instruction signal from the position indicator.

According to the present invention, the dynamic range can be increased in the coil driving method. In addition, in the coil driving method, it is possible to drive easily.
Further, according to the present invention, it is possible to increase the dynamic range of the coil driving device. In addition, the configuration of the coil driving device can be simplified.
Further, according to the present invention, it is possible to increase the dynamic range in the position detection device. In addition, there is an effect that the configuration of the position detection device can be simplified.

FIG. 1 is a block diagram of a coil driving device used in the position detection device according to the first embodiment of the present invention.
In FIG. 1, the coil drive device includes a first switch circuit 102 having a plurality of open / close switches 102a to 102c, one end of which is connected in parallel to a terminal 101, and a plurality of drive circuits connected to the other ends of the switches 102a to 102c. First drive circuit 103 having 103a to 103c, a plurality of coils 105 to 107 having one end side connected to drive circuits 103a to 103c via connection terminals 104a to 104c, and a plurality of connection terminals 104d to 104f. The second drive circuit 116 having a plurality of drive circuits 116a to 116c connected to the other ends of the coils 105 to 107, and a plurality of open / close switches 115a to 115c having the other ends connected to the drive circuits 116a to 116c. The 2nd switch circuit 115 which has is provided. One end side of each of the switches 115a to 115c is connected in parallel to the terminal 117.

The central portions 114a to 114c of the coils 105 to 107 are connected to a positive power source (+ V) having a predetermined voltage by pull-up connection. Coils 105-107 are divided into a plurality of regions (first region 108-110 and second region 111-113 in this embodiment) by central portions 114a-114c.
The first regions 108 to 110 of the coils 105 to 107 are configured by coils wound in a first direction (clockwise or counterclockwise), and the second regions 111 to 113 are first in the direction opposite to the first direction. It is constituted by a coil wound in two directions (counterclockwise or clockwise). The coils constituting the first region 108 to 110 and the second region 111 to 113 are wound n (positive number) in the first direction and the second direction, respectively.
The switches 102a to 102c and 115a to 115c are controlled to be opened and closed by control means (not shown).

The drive circuits 103a to 103c and 116a to 116c have transistors for supplying current to the coils 105 to 107, and the transistors are configured to be directly connected to the coils 105 to 107.
The coils 105 to 107 may be dedicated coils for transmitting a position detection signal, and serve both for transmitting a position detection signal and for receiving a position instruction signal from a position indicator (not shown) ( It may be a coil for both transmission and reception.

In the case of a transmission-dedicated coil, a plurality of coils 105 to 107 may be used, or a single coil may be provided.
Further, in the case of the coils for transmitting and receiving, the coils 105 to 107 may be arranged in plural in the X direction and Y direction so that the plurality of transmitting and receiving coils are orthogonal to each other.
In FIG. 1, the coils 105 to 107 are shown in a substantially U shape. However, the coils 105 to 107 are configured to be wound a plurality of times, and the central portion is connected to a power source (+ V) and divided into two equal parts. You may comprise so that it may divide | segment into.

The operation of the coil driving device configured as described above will be described in detail.
First, the control means selects a coil that transmits a position detection signal to a position indicator (not shown).
For example, when a position detection signal is transmitted from the coil 105, the switch 102a in the first switch circuit 102 and the switch 115a in the second switch circuit 115 are closed and the other switches 102b, 102c, 115b, and 115c are turned on. In the open state, the positive half-wave signal S1 of the first half of the drive signal is input to the terminal 101, and the positive half-wave signal S2 of the second half of the drive signal is input to the terminal 117. As a result, the drive circuit 103a in the first drive circuit 103 and the drive circuit 116a in the second drive circuit 116 are alternately switched and driven (that is, the push-pull operation of the drive circuits 103a and 116a is performed).

As a result, in the first half of the drive signal, a current flows from the power source (+ V) through the first region 108 and the drive circuit 103a of the coil 105, and a position detection signal is sent from the first region 108 to the position indicator. Sent.
In the latter half of the drive signal, a current flows from the power source (+ V) through the second region 111 of the coil 105 and the drive circuit 116a, and position detection is performed from the second region 111 of the coil 105 to the position indicator. A signal is transmitted.
In this way, by switching and driving a plurality of areas of one coil, the same effect as that obtained by driving the entire coil can be obtained.

  Similarly, when transmitting a position detection signal from the coil 106, the switch 102b in the first switch circuit 102 and the switch 115b in the second switch circuit 115 are closed and the other switches 102a, 102c, 115a, 115c are closed. In the open state, the positive half-wave signal S1 of the first half of the drive signal is input to the terminal 101, and the positive half-wave signal S2 of the second half of the drive signal is input to the terminal 117. As a result, the drive circuit 103b in the first drive circuit 103 and the drive circuit 116b in the second drive circuit 116 are alternately switched and driven (that is, the push-pull operation of the drive circuits 103b and 116b is performed).

  As a result, in the first half of the drive signal, a current flows from the power source (+ V) through the first region 109 of the coil 106 and the drive circuit 103b, and a position detection signal is sent from the first region 109 to the position indicator. Sent. In the latter half of the drive signal, a current flows from the power source (+ V) through the second region 112 of the coil 106 and the drive circuit 116b, and position detection is performed from the second region 112 of the coil 106 to the position indicator. A signal is transmitted.

  When transmitting a position detection signal from the coil 107, the switch 102c in the first switch circuit 102 and the switch 115c in the second switch circuit 115 are closed and the other switches 102a, 102b, 115a, 115b are turned on. In the open state, the positive half-wave signal S1 of the first half of the drive signal is input to the terminal 101, and the positive half-wave signal S2 of the second half of the drive signal is input to the terminal 117. Accordingly, the drive circuit 103c in the first drive circuit 103 and the drive circuit 116c in the second drive circuit 116 are alternately switched and driven (that is, the push-pull operation of the drive circuits 103c and 116c is performed).

  Thereby, in the first half of the drive signal, a current flows from the power source (+ V) through the first region 110 and the drive circuit 103c of the coil 107, and a position detection signal is sent from the first region 110 to the position indicator. Sent. In the second half of the drive signal, a current flows from the power source (+ V) through the second region 113 of the coil 107 and the drive circuit 116c, and position detection is performed from the second region 113 of the coil 107 to the position indicator. A signal is transmitted.

When the coils 105 to 107 are both transmitting and receiving coils, the control means selects a coil that receives a position indication signal from the position indicator from the coils 105 to 107, and both terminals 104a to 104a of the selected coil are selected. An input section of a differential amplifier (not shown) is connected between 104c and 104d to 104f. Thereby, a detection signal corresponding to the position indication signal from the position indicator is output from the differential amplifier. The control means calculates the indicated position by the position indicator based on the detection signal control unit output from the differential amplifier, and obtains the indicated position by the position indicator.
When the coils 105 to 107 are dedicated coils for transmitting position detection signals, a position instruction signal is received by scanning a plurality of separate reception coils, and the position indicated by the position indicator is calculated.

  Thus, a single power supply (+ V), a plurality of drive circuits 103a to 103c functioning as a suction circuit, drive circuits 103 and 116 having 116a to 116c, a plurality of switches 102a to 102c, a switch circuit 102 having 115a to 115c, 115, the coils 105 to 107 are configured to have the first regions 108 to 110 and the second regions 111 to 113, and the first regions 108 to 110 and the second regions 111 to 113 are alternately switched and driven alternately. Thus, the dynamic range can be increased, and the coils 105 to 107 can be driven with a large current even in the case of low voltage driving. Further, since the single power supply configuration is used, there is an effect that the circuit configuration is simplified.

FIG. 2 is a block diagram of a coil driving device used in the position detecting device according to the second embodiment of the present invention, and the same parts as those in FIG.
The difference between the second embodiment and the first embodiment is that, in the first embodiment, the switches 102a to 102c and the drive circuits 103a to 103c correspond to the coils 105 to 107, respectively. While a series circuit and a series circuit of switches 115a to 115c and drive circuits 116a to 116c are provided, common drive circuits 203 and 216 are provided for the coils 105 to 107. Is a point.

  That is, in FIG. 2, the coil drive device includes a drive circuit 203 as a first drive means connected to the terminal 101, and a first switch circuit having a plurality of open / close switches 202 a to 202 c connected in parallel to the drive circuit 203 on one end side. 202, a second coil having a plurality of coils 105 to 107 connected at one end thereof to the other ends of the switches 202a to 202c and a plurality of open / close switches 215a to 215c connected to the other ends of the coils 105 to 107. A switch circuit 215 and a drive circuit 216 as a second drive means in which the switches 215a to 215c are connected in parallel are provided. The drive circuit 216 is connected to the terminal 117.

  When transmitting the position detection signal to the position indicator, the switches 202a to 202c included in the switch circuits 202 and 215 are switched to be divided into the first half and the second half of the drive signal as in the first embodiment. 215a to 215c are selectively opened and closed by the control means to select the first regions 108 to 110 and the second regions 111 to 113 of the coils 105 to 107 to be driven, and half-waves are applied to the terminals 101 and 117. Drive signals S1 and S2 are input. As a result, a position detection signal is output from the selected coil.

  For example, when a position detection signal is transmitted from the coil 105, the switch 202a and the switch 215a are closed and the other switches 202b, 202c, 215b, and 215c are opened, and the positive polarity of the first half of the drive signal is applied to the terminal 101. The half-wave signal S1 is input, and the positive half-wave signal S2 of the second half of the drive signal is input to the terminal 117. As a result, the drive circuit 203 and the drive circuit 216 are alternately switched and driven (that is, the push-pull operation of the drive circuits 203 and 216 is performed).

As a result, in the first half of the drive signal, a current flows from the power source (+ V) to the drive circuit 203 through the first region 108 and the switch 202a of the coil 105, and the position is detected from the first region 108 to the position indicator. Signal is transmitted.
In the second half of the drive signal, a current flows from the power source (+ V) to the drive circuit 216 through the second region 111 of the coil 105 and the switch 215a, and the second region 111 of the coil 105 passes the position indicator. A position detection signal is transmitted.
In this way, by switching and driving a plurality of areas of one coil, the same effect as that obtained by driving the entire coil can be obtained.

Similarly, a coil to be driven is selected by controlling the switch circuits 202 and 215, and a position detection signal is transmitted from the selected coil. Detection of the indicated position of the position indicator can be performed in the same manner as in the first embodiment.
In the second embodiment, not only the same effect as the first embodiment but also the number of drive circuits can be reduced, so that the configuration can be simplified and the configuration can be made inexpensively. .

FIG. 3 is a diagram showing a coil arrangement of the coil driving apparatus according to the embodiment of the present invention. The example of FIG. 3 is an example of a transmission / reception coil that combines transmission of a position detection signal and reception of a position instruction signal.
In FIG. 3, the coil 301 has a plurality of X direction coils 302 disposed in the X direction and a plurality of Y direction coils 303 disposed in the Y direction so as to be orthogonal to the coils 302. As in the previous embodiment, the central portion of each coil 302, 303 is connected to a single power source, and each terminal 304 of each coil 302, 303 is connected to a switch circuit, a drive circuit, a detection circuit or the like (not shown). Have been used.

In this case, both the X direction coil 302 and the Y direction coil 303 may be used as a transmission / reception coil, and one of the X direction coil 302 and the Y direction coil 303 is used as a transmission / reception coil, and the other coil is a reception dedicated coil. It is possible to make various modifications such as
FIG. 4 shows an example in which each of the position detection signal transmission coil and the position instruction signal reception coil is configured as a dedicated coil.

In FIG. 4, a position detection signal transmission dedicated coil 401 is disposed around the position indicator detection region. As described in the above implementation, the central portion of the transmission-only coil 401 is connected to a single power source. The transmission-dedicated coil 401 may be configured to be wound a plurality of times.
A position indicator reception-dedicated coil 402 is disposed inside the transmission-dedicated coil 401. The reception-only coil 402 includes a plurality of X-direction coils 403 disposed in the X direction and a plurality of Y-direction coils 404 disposed in the Y direction so as to be orthogonal to the coils 403.

  A drive circuit or the like is connected to the terminal 405 of the transmission coil 401 as in the above embodiment. Further, a detection circuit or the like is connected to the terminal 406 of the reception coil 402 and used. When the position detection signal is transmitted from the transmission coil 401 to the position indicator, the position indicator signal is returned from the position indicator. The position indication signal is received by sequentially scanning the receiving coils 403 and 404, and the indication position by the position indicator is calculated.

The example of FIG. 5 is also an example in which each of the position detection signal transmission coil and the position instruction signal reception coil is configured as a dedicated coil, and the same parts as those in FIG. In the example of FIG. 4, only one transmission coil is provided, but in this example, a plurality (two in FIG. 5) of transmission coils are provided.
In FIG. 5, a plurality of position detection signal transmission coils 401 and 501 are arranged around the position indicator detection region. As described in the above implementation, the central portions of the transmission-only coils 401 and 501 are each connected to a single power source. The transmission-only coils 401 and 501 may be configured to be wound a plurality of times.

A position indicator reception-dedicated coil 402 is disposed inside the transmission-dedicated coils 401 and 501. The reception-only coil 402 includes a plurality of X-direction coils 403 disposed in the X direction and a plurality of Y-direction coils 404 disposed in the Y direction so as to be orthogonal to the coils 403.
Similarly to the above-described embodiment, a switch circuit, a drive circuit, and the like are connected to the terminals 405 and 502 of the transmission coils 401 and 501, respectively. Further, a detection circuit or the like is connected to the terminal 406 of the reception coil 402 and used.

When a position detection signal is transmitted from the coils 401 and 501 to the position indicator by simultaneously driving the transmission coils 401 and 501, a position indication signal is returned from the position indicator. The position indication signal is received by sequentially scanning the receiving coils 403 and 404, and the indication position by the position indicator is calculated.
As in the present embodiment, by simultaneously driving a plurality of transmission coils, it becomes possible to transmit a low-voltage and high-energy position detection signal to the position indicator, thereby improving the position detection accuracy. It becomes possible.
Note that a plurality of transmission coil coils 401 and 501 may be provided in the X direction and the Y direction, respectively.

  As described above, the coil driving apparatus according to the embodiment of the present invention supplies the driving current to the first coil means (coils 105 to 107, 301, 401, 501), thereby electromagnetically coupling the first coil device. In a coil driving apparatus for transmitting a signal from one coil means to a second coil means comprising at least one coil of a position indicator, the first coil means is placed in the first areas 108 to 110 and the second areas 111 to 113. A driving means (switch circuits 102 and 115, driving circuits 103 and 116) that divides and drives the first areas 108 to 110 and the second areas 111 to 113 alternately by switching to each other with driving signals S1 and S2 is provided. It is characterized by that.

Therefore, a single power supply configuration can be achieved, and the dynamic range can be increased. Therefore, the coil can be driven with a large current even when driven at a low voltage. In addition, since a single power supply configuration is possible, the configuration can be simplified.
The first coil means (coils 105 to 107, 301, 401, 501) and a coil driving device for driving the first coil means are provided, and the first coil means is driven by the coil driving device. In the position detection device for detecting the indicated position of the position indicator by performing transmission and reception of signals by electromagnetic coupling with the position indicator having the second coil means composed of at least one coil, as a coil driving device By using the coil driving device, it is possible to increase the dynamic range, and therefore it is possible to drive the coil with a large current even in low voltage driving. In addition, the configuration can be simplified.

In each of the above embodiments, the drive circuits 103, 116, 203, and 216 are configured by suction circuits. However, by using a negative single power source, the drive circuits 103, 116, 203, and 216 can be configured by discharge circuits.
That is, in each of the above-described embodiments, the driving means is configured to have a suction circuit (drive circuits 103a to 103c, 116a to 116c, 203, 216), and the first regions 108 to 110 of the transmission coils 105 to 107 are The boundary between the second regions 111 to 113 is pulled up with a positive power supply voltage (+ V), and the first region 108 to 110 and the second region 111 to 113 are switched and driven by the suction circuit. However, the drive means is configured to have a discharge circuit, the boundaries between the first regions 108 to 110 and the second regions 111 to 113 are pulled down to a reference potential, and the first regions 108 to 110 are pulled down by the discharge circuit. In addition, the second regions 111 to 113 may be switched and driven. The reference potential includes a ground potential.

Further, the transmission coil may be provided at the same position as the reception coil.
Further, the position detection device may be configured such that the indicator receives a signal from the transmission coil by electromagnetic coupling and performs position detection based on the received signal.
That is, a first coil means and a coil driving device for driving the first coil means, and the first coil means is driven by the coil driving device to form a second coil means comprising at least one coil. In the position detection device for detecting the indicated position of the position indicator by transmitting a signal by electromagnetic coupling to the position indicator having, using any of the coil drive devices described above as the coil drive device, You may comprise so that the detection means which detects the indication position of the said position indicator based on the signal from the said 1st coil means received by the said 2nd coil means may be comprised. In this case, the detecting means is not necessarily arranged on the coil driving device side (that is, the position detecting device main body side), but is arranged on the indicator side or as another independent component. It may be configured.

  The present invention can be applied to a coil driving method for driving a coil for transmitting various signals such as a data signal and a power signal to another coil by magnetic coupling. Further, the present invention can be applied to various coil driving devices that transmit signals from one coil to the other coil by magnetic coupling. In addition, it is used as an input device for CAD (Computer Aided Design), computer, personal digital assistant (PDA), mobile phone, PHS (Personal Handyphone System), etc., and has an instruction to indicate a position having at least one coil The present invention can be applied to a position detection device that detects a position indicated by the indicator by transmitting / receiving a signal to / from the indicator by electromagnetic coupling.

It is a block diagram of the coil drive device used for the position detection apparatus which concerns on the 1st Embodiment of this invention. It is a block diagram of the coil drive device used for the position detection apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows coil arrangement | positioning of the coil drive device which concerns on embodiment of this invention. It is a figure which shows other coil arrangement | positioning of the coil drive device which concerns on embodiment of this invention. It is a figure which shows other coil arrangement | positioning of the coil drive device which concerns on embodiment of this invention.

Explanation of symbols

101, 104a to 104f, 117, 304, 405, 406, 502... Terminal 102... First switch circuits 102a to 102c, 115a to 115c, 202a to 202c, 215a to 215c. Switch 103... First drive circuits 103 a to 103 c, 116 a to 116 c, 203, 216... Drive circuits 105 to 107, 303... Coils 108 to 110 as first coil means. First region 111 to 113, second region 115, 215, second switch circuit 116 constituting drive means, second drive circuit 203, 216, constituting drive means, drive means Configured drive circuits 401, 501 ... Coil for transmission 402 as first coil means ... Coil for reception only

Claims (16)

In a coil driving method for transmitting a signal from the first coil means to the second coil means by electromagnetic coupling by supplying a driving current to the first coil means,
A coil driving method characterized in that the first coil means has a first area and a second area, and the driving means switches the first area and the second area to each other by a driving signal. .   The first region is constituted by a coil wound in a first direction, and the second region is constituted by a coil wound in a second direction opposite to the first direction. The coil driving method according to claim 1.   The driving means has a suction circuit, pulls up the boundary between the first region and the second region with a positive power supply voltage, and drives the first region and the second region by switching to each other by the suction circuit. The coil driving method according to claim 1 or 2, characterized in that   The drive means has a discharge circuit, pulls down the boundary between the first region and the second region to a reference potential, and drives the first region and the second region to be switched to each other by the discharge circuit. The coil driving method according to claim 1 or 2, characterized in that:   5. The drive means according to claim 1, further comprising a transistor for supplying a current to the first coil means, wherein the transistor is directly connected to the first coil means. The coil driving method described.   The said 1st coil means is comprised by the some coil which mutually cross | intersects, The said coil drive means drives each corresponding area | region of these coils simultaneously, The one of Claim 1 thru | or 5 characterized by the above-mentioned. The coil drive method as described in one. In the coil drive device for transmitting a signal from the first coil means to the second coil means by electromagnetic coupling by supplying a drive current to the first coil means,
The first coil means is configured to have a first area and a second area, and includes a driving means for switching the first area and the second area to be driven by a driving signal. Coil drive device.   The first region is constituted by a coil wound in a first direction, and the second region is constituted by a coil wound in a second direction opposite to the first direction. The coil drive device according to claim 7.   The driving means has a suction circuit, pulls up the boundary between the first region and the second region with a positive power supply voltage, and drives the first region and the second region by switching to each other by the suction circuit. The coil drive device according to claim 7 or 8, wherein   The drive means has a discharge circuit, pulls down the boundary between the first region and the second region to a reference potential, and drives the first region and the second region to be switched to each other by the discharge circuit. The coil drive device according to claim 7 or 8, characterized in that   11. The driving means includes a transistor for supplying a current to the first coil means, and the transistor is directly connected to the first coil means. The coil drive device described.   The said 1st coil means is comprised by the some coil which mutually cross | intersects, The said coil drive means drives each corresponding area | region of these coils simultaneously, The one of Claim 7 thru | or 11 characterized by the above-mentioned. The coil drive device described in 1. A position having a first coil means and a coil driving device for driving the first coil means, and driving the first coil means by the coil driving device to have a second coil means comprising at least one coil. In the position detection device for detecting the indicated position of the position indicator by transmitting a signal to the indicator by electromagnetic coupling,
A position detection device comprising the coil drive device according to any one of claims 7 to 12 as the coil drive device.   14. The position detection apparatus according to claim 13, wherein the first coil means is a transmission-dedicated coil for transmitting a position detection signal.   15. The position detection apparatus according to claim 14, further comprising detection means for detecting an indication position of the position indicator based on a signal from the first coil means received by the second coil means.   14. The position detecting device according to claim 13, wherein the first coil means is a coil that serves both for transmitting a position detecting signal and for detecting a position indicating signal from the position indicator.

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