JP6154696B2 - Coordinate detection device - Google Patents

Description

  The present invention relates to a coordinate detection device, and more particularly to a coordinate detection device capable of detecting an indicator by either an electromagnetic induction method or a capacitance method.

  Coordinate input devices that perform input detection with a hand or a finger are now mainly in the capacitive type, which allows easy detection of simultaneous input by a plurality of indicators, so-called multi-touch detection. In the capacitive coordinate input device, the input position is detected by utilizing a minute change in capacitance, so that the detection resolution is not high and the detection accuracy of the input coordinates is poor. For this reason, an electromagnetic induction type coordinate input device with higher detection accuracy is used for drawing characters and pictures. In the electromagnetic induction method, a pointing element is detected by detecting an induced electromotive force from a coil of a pointer driven by a driving line provided on a detection surface with a detection line. is there.

  For example, in Patent Document 1, an electromagnetic induction pen detection unit and a capacitance finger detection unit are stacked with a display device sandwiched therebetween, so that an indicator can be detected by either an electromagnetic induction method or a capacitance method. A coordinate detection device is disclosed.

  Patent Document 2 discloses an apparatus that can detect the position of an oscillation pen as a digitizer and can detect the position of a finger as a touch panel. During the digitizer operation, a predetermined carrier signal is oscillated from the oscillation pen, and this carrier signal is detected from each electrode line. Further, during the touch panel operation, a carrier signal similar to the carrier signal of the oscillation pen is given to an arbitrary electrode line. Then, an electric field is generated by the capacitive coupling between the orthogonal electrode lines. The finger is detected by using a change in capacity caused by the signal absorbed by the finger when the finger approaches.

JP 2011-186550 A Japanese Patent Laid-Open No. 8-179871

  In the apparatus of Patent Document 1, since two types of detection units are provided, there is a problem that the apparatus becomes expensive and becomes large and heavy. Furthermore, if the distance between the detection surface and the detection unit becomes too long, there is a possibility that the actual input position and the detected position are misaligned.

  Further, in the apparatus of Patent Document 2, when used as a digitizer, the indicator needs to use an oscillation pen that oscillates a predetermined carrier signal. That is, the indicator requires a power source such as a battery, and since the device can detect only the electrostatic capacity, the electromagnetic induction pen cannot be detected.

  In view of such circumstances, the present invention is intended to provide a coordinate detection device that can detect an indicator with a simple structure and at a low cost both by an electromagnetic induction method and a capacitance method.

  In order to achieve the above-described object of the present invention, a coordinate detection device according to the present invention is arranged in parallel with a plurality of drive lines arranged along one of the XY coordinate axes and a plurality of parallel along the other of the XY coordinate axes. A detection line, a drive circuit connected to one end of the drive line and driving the drive line by inputting a predetermined drive voltage to the drive line, and a signal connected to one end of the detection line to detect a signal from the detection line, and an indicator A detection circuit for calculating the designated position coordinates, a drive line loop means connected to the other end of the plurality of drive lines and selectively functioning so that the two drive lines become a loop-like drive line from the open, and a loop Drive line connecting means for connecting to a drive circuit so that a current flows through the drive line, and a drive line selection unit connected to the other end of the plurality of detection lines and selectively opening the two detection lines Detection line loop that functions as a loop detection line A detection line selection unit including a stage and a detection line connection unit connected to the detection circuit so as to detect a current or potential difference flowing in the loop-shaped detection line, and a predetermined drive line and a detection line as a drive circuit and a detection circuit. The drive line selection unit and the detection line selection unit are respectively controlled so as to be sequentially connected to each other, and when detecting the indicator by the electromagnetic induction method, it is driven so as to become a loop-like drive line and a loop-like detection line. When controlling the line selection unit and the detection line selection unit and detecting the indicator by the capacitance method, it becomes an open drive line and an open detection line, or a loop drive line and an open state And a control unit for controlling the drive line selection unit and the detection line selection unit so as to be the detection lines.

  Here, the drive line loop means of the drive line selection unit functions so that the odd-numbered and even-numbered drive lines become loop-like drive lines with a predetermined interval, and the detection line loop means of the detection line selection unit Any function may be used as long as it functions so that the odd-numbered and even-numbered detection lines become loop-shaped detection lines with a predetermined interval.

  The drive line loop unit of the drive line selection unit and / or the detection line loop unit of the detection line selection unit may be any one of a resistance element, a capacitor, a coil, a diode, an analog switch, or a combination thereof.

  Further, the detection line loop means of the detection line selection section is composed of a diode, and further includes detection line bias means for setting the detection line to a predetermined bias potential, and the control section further controls the detection line bias means. May be.

  Further, the drive line loop means of the drive line selection section is composed of a diode, and further includes drive line bias means for setting the drive line to a predetermined bias potential, and the control section further controls the drive line bias means. May be.

  The control unit may also control the drive voltage of the drive circuit.

  Furthermore, a sheet base material is provided, the drive line and / or the detection line are arranged on the sheet base material, and the drive line loop means and / or the detection line loop means are installed on the sheet base material. Also good.

  The coordinate detection device according to the present invention is connected to a plurality of drive lines arranged in parallel along one of the XY coordinate axes, a plurality of detection lines arranged in parallel along the other of the XY coordinate axes, and one end of the drive line. The drive circuit that drives the drive line by inputting a predetermined drive voltage to the drive line, and the signal from the detection line connected to one end of the detection line are detected, and the indicator is identified by increasing or decreasing the detected signal. A detection circuit for calculating the indicated position coordinates of the indicator, and connected to the other end of the plurality of drive lines, and selectively interposed between the two drive lines to form a loop-like drive line. Drive line selection means including a high drive line loop means and a drive line connection means for connecting to a drive circuit so that a current flows in the loop-like drive line, and selectively connected to the other ends of the plurality of detection lines So that two detection lines become loop-shaped detection lines. A detection line selection unit including a detection line loop unit having a resistance value higher than that of the detection line, and a detection line connection unit connected to a detection circuit so as to detect a current or potential difference flowing in the loop-shaped detection line; And a control unit that controls the drive line selection unit and the detection line selection unit so as to sequentially connect the drive line and the detection line to the drive circuit and the detection circuit, respectively.

  Furthermore, the coordinate detection apparatus according to the present invention is connected to a plurality of drive lines arranged in parallel along one of the XY coordinate axes, a plurality of detection lines arranged in parallel along the other of the XY coordinate axes, and one end of the drive line. A driving circuit that drives the driving line by inputting a predetermined driving voltage to the driving line; a detection circuit that is connected to one end of the detection line, detects a signal from the detection line, and calculates a pointing position coordinate of the indicator; Drive line GND potential connection means connected to the other end of the plurality of drive lines and functioning to be selectively connected to the GND potential; drive line connection means connecting to the drive circuit so that current flows through the drive lines; , A detection line GND potential connecting means connected to the other end of the plurality of detection lines and functioning to be selectively connected to the GND potential, and a current or potential difference flowing through the detection line is detected. Connect to the detection circuit A detection line selection unit including a detection line connection unit; and the drive line selection unit and the detection line selection unit are respectively controlled so as to sequentially connect a predetermined drive line and a detection line to the drive circuit and the detection circuit. When the indicator is detected by the guidance method, the drive line selection unit and the detection line selection unit are controlled so as to connect the drive line and the detection line to the GND potential, and when the indicator is detected by the capacitance method. A control unit that controls the drive line selection unit and the detection line selection unit so that the drive line is open and the detection line is open, or the drive line is connected to the GND potential and the detection line is open. And may be provided.

  The coordinate detection apparatus of the present invention has an advantage that a pointer can be detected by an electromagnetic induction method or a capacitance method at a low cost with a simple structure.

FIG. 1 is a schematic block diagram for explaining a coordinate detection apparatus of the present invention. FIG. 2 is a schematic circuit diagram for explaining a more specific configuration of the coordinate detection apparatus of the present invention. FIG. 3 is a schematic diagram for explaining an example of an electromagnetic induction pen having a capacitor and a coil. FIG. 4 is a schematic circuit diagram for explaining another example of the drive line loop means and the detection line loop means of the coordinate detection apparatus of the present invention. FIG. 5 is a schematic circuit diagram for explaining another example of the coordinate detection apparatus of the present invention. FIG. 6 is a schematic circuit diagram for explaining still another example of the coordinate detection apparatus of the present invention. FIG. 7 is a schematic block diagram for explaining still another example of the coordinate detection apparatus of the present invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described together with illustrated examples. FIG. 1 is a schematic block diagram for explaining a coordinate detection apparatus of the present invention. As shown in the figure, the coordinate detection apparatus of the present invention includes a drive line 10, a detection line 20, a drive circuit 30, a detection circuit 40, a drive line selection unit 50, a detection line selection unit 60, and a control unit 70. Consists mainly of. FIG. 2 is a schematic circuit diagram for explaining a more specific configuration of the coordinate detection apparatus of the present invention.

  A plurality of drive lines 10 are arranged in parallel along one of the XY coordinate axes, for example, the Y coordinate axis in the illustrated example. The drive line 10 may be made of a conductive member such as a copper wire or a line pattern.

  A plurality of detection lines 20 are arranged in parallel along one of the XY coordinate axes, for example, the X coordinate axis in the illustrated example. The detection line 20 may be made of a conductive member such as a copper wire or a line pattern.

  The drive line 10 and the detection line 20 may be disposed in an insulated state on the substrate. Moreover, you may arrange | position on flexible sheet base materials, such as a flexible substrate.

  The drive circuit 30 is connected to one end of the drive line 10 and drives the drive line 10 by inputting a predetermined drive voltage to the drive line 10. In the illustrated example, the drive circuit 30 is connected to the lower end of the drive line 10. Here, the predetermined drive voltage is, for example, an output signal having a predetermined frequency from an oscillator. The drive circuit 30 includes a drive amplifier, for example, and amplifies the signal from the oscillator and applies the amplified signal to the drive line 10.

  The detection circuit 40 is connected to one end of the detection line 20 and detects a signal from the detection line 20. In the illustrated example, a detection circuit 40 is connected to the left end of the detection line 20. Here, the signal from the detection line 20 is a current that flows based on electromagnetic coupling or electrostatic coupling. The detection circuit 40 has an amplifier circuit such as an operational amplifier, and measures the current or potential difference flowing through the detection line 20.

  The drive line selection unit 50 includes drive line loop means 51 and drive line connection means 52. The drive line loop means 51 is connected to the other ends of the plurality of drive lines 10 and selectively functions so that the two drive lines 10 become the loop-like drive lines 10 from the open state. The drive line connecting means 52 is for connecting a drive circuit to the drive line so that a current flows through the loop-like drive line 10. In the example of FIG. 1, the drive line loop means 51 is connected so that the odd-numbered and even-numbered drive lines 10 are loop-shaped drive lines with a predetermined interval. More specifically, the two drive lines 10 are connected via the drive line loop means 51 with an interval between the four drive lines 10. However, the present invention is not limited to this, and it is only necessary that the two drive lines 10 be connected via the drive line loop means 51. The drive line connection means 52 switches the drive voltage from the drive circuit 30 to the drive line 10 in order.

  The detection line selection unit 60 includes a detection line loop unit 61 and a detection line connection unit 62. The detection line loop means 61 is connected to the other ends of the plurality of detection lines 20 and selectively functions so that the two detection lines 20 change from open to loop-like detection lines. The detection line connecting means 62 is for connecting to the detection circuit 40 so as to detect a current or potential difference flowing in the loop-shaped detection line 20. In the example of FIG. 1, the detection line loop means 61 is connected so that the odd-numbered and even-numbered detection lines 20 are loop-shaped detection lines with a predetermined interval. More specifically, the two detection lines 20 are connected via the detection line loop means 61 with an interval between the four detection lines 20. However, the present invention is not limited to this, as long as the two detection lines 20 are connected via the detection line loop means 61. The detection line connecting means 62 switches the connection or switching of the current or potential difference flowing through the detection line 20 to the detection circuit 40 in sequence.

  The control unit 70 controls the drive line selection unit 50 and the detection line selection unit 60 so as to sequentially connect the predetermined drive line 10 and the detection line 20 to the drive circuit 30 and the detection circuit 40, respectively. When the indicator is detected by the electromagnetic induction method, the drive line selection unit 50 and the detection line selection unit 60 are controlled so that the loop drive line 10 and the loop detection line 20 are obtained. Further, the control unit 70 sets the drive line selection unit 50 and the detection line selection unit 60 so that the detection line 20 is opened and the detection line 20 is opened when the indicator is detected by the capacitance method. Control. Furthermore, the drive line selection unit 50 and the detection line selection unit 60 may be controlled so that the drive line 10 is in the loop state and the detection line 20 is in the open state.

  Here, it demonstrates in detail using FIG. As shown in FIG. 2, in this example, the drive line loop means 51 and the detection line loop means 61 are resistance elements. The drive circuit 30 includes a drive amplifier 31 for amplifying the drive voltage. The detection circuit 40 includes an operational amplifier 41 for amplifying the detection signal. The driving line loop means 51 and the detection line loop means 61 are respectively looped so that a current flows through the driving line 10 and the detection line 20 so that the driving line 10 and the detection line 20 are electromagnetically coupled. In this example, the resistance value of the drive line 10 and the detection line 20 is low, and the resistance value of the resistance element as the loop means is higher than those lines. Drive line connection means 52 for connecting the drive circuit 30 so that a current flows through the loop-like drive line 10 is provided. Similarly, a detection line connecting means 62 for connecting the detection circuit 40 so as to detect a current or potential difference flowing in the loop detection line 20 is provided. The control unit 70 controls the drive line selection unit 50 and the detection line selection unit 60 so that the predetermined drive line 10 and the detection line 20 are sequentially selected and connected to the drive circuit 30 and the detection circuit 40, respectively. . That is, when the resistance value of the drive line 10 is low, the drive line loop means 51 is opened due to the resistance of the resistance element of the drive line loop means 51, and all the drive lines other than the selected drive line 10 are kept at the GND potential. be able to. Similarly, when the resistance value of the detection line 20 is low, the detection line loop unit 61 is opened due to the resistance of the resistance element of the detection line loop unit 61, and all the detection lines other than the selected detection line 20 are opened. Can keep. That is, in FIG. 2, the drive voltage from the drive line 10 connected to the drive circuit 30 flows to the detection line 20 through the electrostatic coupling capacitance of C1. This signal is detected from the detection line 20 connected to the detection circuit 40. At this time, when the input side of the operational amplifier 41 is viewed as DC or AC, it is at a GND potential, so only the current flowing therethrough can be detected, so that it is independent of the other electrostatic coupling capacitors C2, C3 and C4. The current or potential difference from C1 can be detected. If the resistance value of the drive line or the detection line is high, it becomes difficult to keep the potential of the unselected drive line at the GND potential. Thus, for example, a current flowing from C2 is mixed. In addition, a current flowing through C3 and C4 is mixed from the detection line that is not selected through the detection loop unit. Therefore, in this example, the resistance value of the drive line or the detection line may be configured to be sufficiently lower than the drive line loop means or the detection line loop means.

  In the example illustrated in FIG. 2, the control unit 70 connects the drive circuit 30 to the drive line 10 using, for example, the drive line connection unit 52 so that current flows through the selected loop-shaped drive line 10. At the same time, the unselected drive line 10 is fixed to the GND potential. Further, the selected detection line 20 is connected to the detection circuit 40 by using the detection line connecting means 62, and the unselected detection line 20 is fixed to the GND potential. By sequentially connecting the drive line 10 and the detection line 20, it is possible to determine from which intersection the signal is detected by the combination of the selected drive line and detection line. Coordinates are detected. An indicator that can be detected using the coordinate detection apparatus configured as described above will be described with reference to FIG. FIG. 3 is a schematic diagram for explaining an example of an electromagnetic induction pen having a capacitor and a coil. As shown in the drawing, the electromagnetic induction pen is composed of a resonance circuit having a capacitor and a coil. In the illustrated example, the coil is wound around a ferrite core, and the ferrite core is a nib. When detecting the input coordinates of such an electromagnetic induction pen (electromagnetic induction method), the detection line and the drive line controlled as described above are in a loop shape and a current flows. When the electromagnetic induction pen approaches the drive line or the detection line, the degree of electromagnetic coupling between the drive line and the detection line which are orthogonally coupled to each other and become stronger becomes stronger. Therefore, the signal detected by the detection circuit 40 becomes large. On the other hand, when detecting the input coordinates of a finger as an indicator (electrostatic coupling method), an open state is realized by a resistance element as in the example of FIG. When the finger is input, the electrostatic coupling becomes weak, and the signal detected by the detection circuit 40 becomes small. As described above, the detection circuit 40 can calculate the pointing position coordinates of the pointer, and can identify the pointer by increasing or decreasing the detected signal. That is, it is possible to identify whether the indicator is an electromagnetic induction pen or a finger.

  As described above, the coordinate detection apparatus of the present invention can detect an indicator such as an electromagnetic induction pen and a finger with a simple structure and at a low cost by either the electromagnetic induction method or the electrostatic coupling method. Moreover, since the detected frequency and phase change by making the resonance frequencies and phases of the plurality of electromagnetic induction pens different, it is possible to identify each pen using this. Furthermore, it is possible to provide additional functions such as writing pressure detection and switches by phase detection.

  In the above illustrated example, the example in which the resistance element is used as the drive line loop unit or the detection line loop unit has been described, but the present invention is not limited to this. For example, when the drive voltage of the drive circuit is an AC signal, a coil or a capacitor can be used as an impedance element as well as a resistance element.

  FIG. 4 is a schematic circuit diagram for explaining another example of the drive line loop means and the detection line loop means. As the drive line loop means and the detection line loop means, for example, an analog switch can be used as shown in FIG. This is particularly effective when the resistance values of the drive line 10 and the detection line 20 are large. In the case of the electrostatic capacity method, the analog switch is opened, and the unselected drive line 10 can be reliably opened. Similarly, in the case of the electromagnetic induction method, it is possible to reliably keep the unselected detection line 20 at the GND potential by closing the analog switch. The analog switch may be turned on during the detection time slot of the electromagnetic induction pen when the controller 70 detects the indicator by the electromagnetic induction method.

  As described above, when the indicator is detected by the electromagnetic induction method, the drive line loop means and the detection line loop means are controlled to be turned on so that the loop drive line and the loop detection line are obtained. Further, when the indicator is detected by the electrostatic capacity method, the drive line loop means and the detection line loop means are controlled to be off so that the open drive line and the open detection line are obtained.

  Further, diodes may be used as the drive line loop means and the detection line loop means. As shown in FIG. 4B, for example, a Zener diode may be used. Specifically, the anodes of the Zener diodes are connected via a resistance element. By using the reverse voltage of the Zener diode, it is possible to eliminate the induced current to the drive line and the detection line that are not selected.

  Furthermore, as shown in FIG. 4C, the drive line loop means and / or the detection line loop means may be, for example, a silicon diode. Specifically, a resistance element is connected in series to a silicon diode connected in parallel in the reverse direction. By using the forward voltage of the silicon diode, it is possible to eliminate the induced current to the drive line 10 and the detection line 20 that are not selected, as in the case of the Zener diode described above.

  Further, as shown in FIG. 4D, a silicon diode and a resistor element connected in series can be used as the drive line loop means and / or the detection line loop means. In the coordinate detection apparatus of the present invention, as described above, any one of a resistance element, a capacitor, a coil, a diode, an analog switch, or the like, or a combination thereof can be used as a drive line loop unit or a detection line loop unit.

  Here, the coordinate detection apparatus of the present invention using the drive line loop means and the detection line loop means shown in FIGS. 4B and 4C will be described more specifically with reference to FIG. FIG. 5 is a schematic circuit diagram for explaining another example of the coordinate detection apparatus of the present invention. In the figure, the same reference numerals as those in FIG. 2 denote the same parts. As shown in the figure, in this example, the drive line loop means using the Zener diode shown in FIG. 4B is used, and the detection line loop means using the silicon diode shown in FIG. 4C. Is used. In a general silicon diode, the AC impedance is high when the voltage at both ends is 0.6 V or less, and the AC impedance is low when the voltage is 0.8 V or more. Using this phenomenon, the loop can be controlled on and off. That is, a detection line bias unit 81 for setting the detection line 20 to a predetermined bias potential is provided. The detection line bias unit 81 is configured to be capable of on / off control by the control unit 70 so as to have a predetermined potential via a resistor. When it is desired to turn off the detection line loop means 61 made of a silicon diode, that is, when the indicator is detected by the electrostatic capacity method, the detection line bias means 81 is turned off to make the DC bias voltage 0.6 V or less. As a result, the impedance of the detection line loop means 61 is increased to open it. On the other hand, when the indicator is detected by the electromagnetic induction method, the detection line bias unit 81 is turned on and the DC bias voltage is set to 0.8 V or more, so that the impedance of the detection line loop unit 61 is lowered and the conduction state is established. And

  The drive line bias means 82 for providing a predetermined bias potential is also provided for the drive line 10. For example, the drive line bias unit 82 can control the drive voltage of the drive amplifier 31 by the control unit 70. When the indicator is detected by the electrostatic capacity method, the drive line loop means 51 is turned off and the drive line 10 is selected in the open state by lowering the drive voltage of the drive amplifier 31. On the other hand, when the indicator is detected by the electromagnetic induction method, the drive voltage of the drive amplifier 31 is increased to turn on the drive line loop means 51 and make it conductive. It is of course possible to perform the same on / off control by controlling the drive voltage itself of the drive circuit 30 by the control unit 70.

  Next, the coordinate detection apparatus of the present invention using the drive line loop means and the detection line loop means shown in FIG. 4 (d) will be described more specifically with reference to FIG. FIG. 6 is a schematic circuit diagram for explaining still another example of the coordinate detection apparatus of the present invention. In the figure, the same reference numerals as those in FIG. 2 denote the same parts. As shown in the figure, in this example, the drive line loop means and the detection line loop means using the silicon diode shown in FIG. 4D are used. In this example, when the drive line loop means 51 is turned off, the drive line connection means 52 is connected to the drive circuit 30 and the unselected drive lines 10 connected via the drive line loop means 51 are set to a positive potential. Switch to. As a result, a reverse voltage is applied to the diodes constituting the drive line loop means 51 to open the diode. On the other hand, when the drive line loop means 51 is turned on, the drive line connection means 52 is connected to the drive circuit 30 and the drive line 10 connected via the drive line loop means 51 is switched to the GND potential. As a result, a forward voltage is applied to the diode constituting the drive line loop means 51 and the diode becomes conductive.

  Similarly, when the detection line loop unit 61 is turned off, the detection line bias unit 81 for setting the selected detection line 20 to a predetermined bias potential is turned off and the detection line loop unit 61 is not selected. By turning on the bias potential of the detection line 20 by using the detection line bias unit 81, a reverse voltage is applied to the diode constituting the detection line loop unit 61, thereby opening the detection line. On the other hand, when the detection line loop unit 61 is turned on, the detection line bias unit 81 for setting the selected detection line 20 to a predetermined bias potential is turned on, and the unselected detection connected via the detection line loop unit 61 is performed. By turning off the bias potential of the line 20, a forward voltage is applied to the diodes constituting the detection line loop means 61 and the conductive state is established.

  Thus, in this example as well, when the indicator is detected by the electromagnetic induction method, the drive line loop means and the detection line loop means are set so as to form a loop-like drive line and a loop-like detection line. Turn on control. Further, when the indicator is detected by the electrostatic capacity method, the drive line loop means and the detection line loop means are controlled to be off so that the open drive line and the open detection line are obtained. Thereby, it is possible to detect with either an electromagnetic induction pen or a finger.

  Next, still another example of the coordinate detection apparatus of the present invention will be described with reference to FIG. FIG. 7 is a schematic block diagram for explaining still another example of the coordinate detection apparatus of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same parts. As shown in the figure, in this example, instead of the drive line loop means and the detection line loop means, the drive line GND potential connection means and the detection line GND potential function to connect the other end of the drive line and the detection line to the GND potential. It has a connection means. That is, in the examples so far, the drive lines are looped through the other drive lines so as to have the GND potential. However, in the illustrated example, each of the drive lines 10 and the detection lines 20 has one end. The other end is connected to the drive circuit 30 and the detection circuit 40, and the other end is connected to the common GND via the drive line GND potential connection means 55 and the detection line GND potential connection means 65, so that a current flows through each line. ing. The control unit 70 controls the drive line selection unit 50 and the detection line selection unit 60 so as to connect the drive line 10 and the detection line 20 to the GND potential when the indicator is detected by the electromagnetic induction method. When the indicator is detected by the capacitance method, the open drive line 10 and the open detection line 20 are connected, or the drive line 10 is connected to the GND potential and the open detection line 20 is connected. The drive line selection unit and the detection line selection unit are controlled so that The drive line GND potential connection means 55 and the detection line GND potential connection means 65 may be any one of a resistance element, a capacitor, a coil, a diode, an analog switch, or a combination thereof, as described above. .

  Even with such a configuration, as in the previous examples, when an indicator (electromagnetic induction pen) is detected by, for example, an electromagnetic induction method, a current flows through the drive line 10 and the detection line 20, and the electromagnetic The detection circuit 40 can detect that the degree of coupling becomes strong. Further, when the indicator (finger) is detected by the capacitive method, the electrostatic coupling becomes weak and the signal detected by the detection circuit 40 becomes small, so that the finger pointing position can be detected.

  In addition, by controlling the drive voltage of the drive circuit 30, it is possible to reduce the drive voltage and reduce the current consumption in the case of the electromagnetic induction method. In the case of the electromagnetic induction method, a current flows through a connection to the GND potential. Therefore, it is possible to reduce power consumption by lowering the drive voltage to some extent.

  Here, the drive line and the detection line may be disposed on a flexible sheet base material such as a flexible substrate. For example, a pattern of drive lines and detection lines may be printed on the sheet base material with conductive ink. And a detection surface can be easily formed by superimposing a sheet base material so that it may become 90 degrees, respectively. Further, it is also possible to install drive line loop means and detection line loop means on the sheet base material. For example, when the drive line loop means and the detection line loop means are resistance elements, the resistance element pattern may be printed on the sheet base material with conductive ink. With this configuration, it is possible to manufacture a coordinate detection device that can detect an indicator with a simple structure and at a low cost by either an electromagnetic induction method or a capacitance method.

  It should be noted that the coordinate detection apparatus of the present invention is not limited to the illustrated examples described above, and it is needless to say that various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Drive line 20 Detection line 30 Drive circuit 31 Drive amplifier 40 Detection circuit 41 Operational amplifier 50 Drive line selection part 51 Drive line loop means 52 Drive line connection means 55 Drive line GND electric potential connection means 60 Detection line selection part 61 Detection line loop means 62 Detection line connection means 65 Detection line GND potential connection means 70 Control unit 81 Detection line bias means 82 Drive line bias means

Claims (4)

A coordinate detection device for detecting a pointing position coordinate of a pointer, the coordinate detection device,
A plurality of drive lines arranged in parallel along one of the XY coordinate axes;
A plurality of detection lines arranged in parallel along the other of the XY coordinate axes;
A drive circuit connected to one end of the drive line and driving the drive line by inputting a predetermined drive voltage to the drive line;
A detection circuit connected to one end of the detection line for detecting a signal from the detection line and calculating the pointing position coordinates of the pointer;
A diode connected to the other end of the plurality of drive lines and selectively connected so that the two drive lines become open-loop drive lines and drive line biasing means for setting the drive lines to a predetermined bias potential are used. A drive line selection unit including a drive line loop unit configured as described above, and a drive line connection unit configured to connect to a drive circuit so that a current flows through the loop-shaped drive line,
A diode connected to the other end of the plurality of detection lines and selectively connected so that the two detection lines become open loop detection lines and detection line bias means for setting the detection lines to a predetermined bias potential are used. A detection line selection unit including a detection line loop unit configured to detect a current or a potential difference flowing in the loop-shaped detection line, and a detection line connection unit connected to the detection circuit.
The drive line selection unit and the detection line selection unit are controlled so that predetermined drive lines and detection lines are sequentially connected to the drive circuit and the detection circuit, respectively. Control the drive line bias means and drive line selection unit and the detection line bias means and detection line selection unit so that the drive line and the loop detection line become a detection line. The drive line bias means, the drive line selection section , the detection line bias means, and the detection line selection section are arranged so that the drive line and the detection line in the open state or the drive line in the loop state and the detection line in the open state are detected. A control unit to control,
A coordinate detection apparatus comprising: 2. The coordinate detection apparatus according to claim 1, wherein the drive line loop means of the drive line selection unit drives the loop by connecting a diode between the odd-numbered and even-numbered drive lines with a predetermined interval therebetween. Function as a line,
The detection line loop means of the detection line selection unit functions to become a loop-like detection line by connecting a diode between the odd-numbered and even-numbered detection lines with a predetermined interval between them.
A coordinate detection apparatus characterized by that. In the coordinate detecting device according to claim 1 or claim 2, wherein the control unit, the coordinate detecting apparatus characterized by the drive voltage of the drive circuit is also controlled. The coordinate detection device according to any one of claims 1 to 3 , further comprising a sheet base material,
The drive line and / or the detection line are disposed on a sheet base material,
The drive line loop means and / or the detection line loop means are installed on a sheet base material.
A coordinate detection apparatus characterized by that.