Position detection device

Abstract

Provided is a position detection device capable of sharing the entire area of a sensor in both an electromagnetic induction mode and an electrostatic coupling mode. The present invention is provided with: a sensor in which a plurality of first electrodes are arranged in a first direction and a plurality of second electrodes are arranged in a second direction intersecting the first direction; and a signal processing circuit that detects the pointing positions of the plurality of pointing bodies on the sensor. The first electrode and the second electrode are respectively formed as annular electrodes. A selection circuit of a signal processing circuit selects a first electrode and a second electrode so that an induced current is induced in each of the first electrode and the second electrode, thereby detecting an indicated position of a first indicator on a sensor by means of electromagnetic induction. The first electrode and the second electrode are selected so that an induced current is not induced in each of the first electrode and the second electrode, thereby detecting the pointing position of the second pointing body on the sensor by electrostatic coupling.

Description

[0001] This application is a divisional application of the application filed on May 8, 2020, with application number 201880072381.0 and invention name “Position detection device and position detection method based on electromagnetic induction coupling and electrostatic coupling”. Technical Field

[0002] The present invention relates to a position detection device capable of detecting an indicated position of an indicator based on electromagnetic induction coupling and an indicated position of an indicator based on electrostatic coupling using a common position detection sensor. Background Art

[0003] There is known a position detection device that uses an electrostatic coupling method position detection sensor to detect the indicated position of a stylus pen (electronic pen) corresponding to the electrostatic coupling method and can detect the touch position of a human finger. However, in the case of this position detection device, if a human body such as a hand is in contact with the position detection sensor surface when detecting the indicated position of the stylus pen, there is a problem that it is difficult to accurately detect the indicated position of the stylus pen.

[0004] In this regard, the above-mentioned problem can be solved by using an electromagnetic induction type position detection sensor to detect the indicated position of the stylus pen and using an electrostatic coupling type position detection sensor to detect the touched position of a human finger.

[0005] However, if an electromagnetic induction type position detection sensor and an electrostatic coupling type position detection sensor are independently provided in a position detection device, there is a problem that the structure becomes complicated.

[0006] To solve this problem, Patent Document 1 (Japanese Patent No. 5702511) and Patent Document 2 (Japanese Patent No. 5819565) propose position detection devices that implement electromagnetic induction position detection and electrostatic coupling position detection using a single common position detection sensor.

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent No. 5702511

[0010] Patent Document 2: Japanese Patent No. 5819565 Summary of the invention

[0011] Problems to be solved by the invention

[0012] However, the position detection sensor of the position detection device proposed in Patent Document 1 is configured such that a plurality of linear conductors (X-axis body and Y-axis body) extending in mutually orthogonal directions are provided on the surface and back of a substrate, and switch circuits are provided on one end side and the other end side of the X-axis body and the Y-axis body, respectively, to form a ring coil for electromagnetic induction coupling and switch the ring coil, and to switch the X-axis body and the Y-axis body for electrostatic coupling. Therefore, there is a problem that the structure becomes complicated.

[0013] In addition, in the position detection sensor of the position detection device proposed in Patent Document 2, a plurality of linear conductors (X-axis body and Y-axis body) extending in mutually orthogonal directions are provided on the surface and back of a substrate, and each of the plurality of X-axis body and the plurality of Y-axis body is divided into a linear body used in an electromagnetic induction method and a linear body used in an electrostatic coupling method. Therefore, in the position detection sensor, the area that can be detected in an electromagnetic induction method and the area that can be detected in an electrostatic coupling method exist separately, and there is a problem that the entire area of ​​the position detection sensor cannot be shared by the electromagnetic induction method and the electrostatic coupling method.

[0014] An object of the present invention is to provide a position detection device that can solve the above-mentioned problems.

[0015] Means for solving problems

[0016] In order to solve the above-mentioned problems, a position detection device is provided, comprising: a sensor having a plurality of first electrodes arranged in a first direction and a plurality of second electrodes arranged in a second direction intersecting the first direction; and a signal processing circuit connected to the sensor to detect respective positions indicated by a plurality of indicators on the sensor.

[0017] It is characterized in that

[0018] The first electrodes and the second electrodes are respectively formed as ring electrodes, and the signal processing circuit has a selection circuit for selecting the plurality of first electrodes and the plurality of second electrodes.

[0019] The first electrode and the second electrode are selected by the selection circuit in such a manner that an induced current is induced in each of the first electrode and the second electrode, thereby detecting the position indicated by the first indicator on the sensor by utilizing electromagnetic induction coupling between the first indicator and the sensor, and,

[0020] The selection circuit selects the first electrode and the second electrode in such a manner that no induced current is induced in each of the first electrode and the second electrode, thereby detecting the position indicated by the second indicator on the sensor by utilizing electrostatic coupling between the second indicator and the sensor.

[0021] In the sensor of the position detection device of the above structure, a plurality of first electrodes and a plurality of second electrodes are arranged as annular electrodes in the first direction and the second direction intersecting each other. And, by selecting the annular electrodes arranged on the sensor by the selection circuit in a manner of inducing induced currents respectively, it is possible to couple with the first indicator by electromagnetic induction, and the indicated position of the first indicator can be detected by electromagnetic induction. In addition, by selecting the annular electrodes arranged on the sensor by the selection circuit in a manner of not inducing induced currents respectively, it is possible to couple with the second indicator by electrostatic coupling, and the indicated position of the second indicator can be detected by electrostatic coupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a diagram showing a configuration example of a first embodiment of a position detection device according to the present invention.

[0023] Figure 2 It is a diagram for explaining the operation state of the position detection device in the electromagnetic induction mode according to the first embodiment.

[0024] Figure 3 It is a diagram for explaining the operation state of the position detection device in the electrostatic coupling mode according to the first embodiment.

[0025] Figure 4 It is a diagram showing a configuration example of a second embodiment of the position detection device of the present invention.

[0026] Figure 5 This is a diagram for explaining the selection control of the annular electrode by the selection circuit in the electromagnetic induction mode in the position detection device of the first example of the second embodiment.

[0027] Figure 6 This is a diagram for explaining the operation in the electromagnetic induction mode in the position detection device of the first example of the second embodiment.

[0028] Figure 7 This is a diagram showing an example of arrangement of loop coils of a position detection sensor equivalent to the position detection sensor of the position detection device of the first example of the second embodiment.

[0029] Figure 8 This is a diagram for explaining the operation in the electromagnetic induction mode in the position detection device of the second example of the second embodiment.

[0030] Fig. 9 This is a diagram for explaining the operation in the electromagnetic induction mode in the position detection device of the second example of the second embodiment.

[0031] Fig.10It is a diagram showing an example of arrangement of loop coils of a position detection sensor equivalent to the position detection sensor of the position detection device of the second example of the second embodiment.

[0032] Fig.11 It is a diagram showing a configuration example of a third embodiment of the position detection device of the present invention.

[0033] Fig.12 It is a diagram for explaining the operation state of the position detection device in the electromagnetic induction mode according to the third embodiment.

[0034] Fig.13 It is a diagram for explaining another example of the position detection sensor of the position detection device of the present invention. DETAILED DESCRIPTION

[0035] [First embodiment]

[0036] Figure 1 1 is a diagram showing a configuration example of a position detection device 1 according to a first embodiment of the present invention. In the position detection device 1 according to this embodiment, an electronic pen (stylus pen) as an example of a first indicator and a human finger as an example of a second indicator can be used, and the coordinates (X, Y) of the indicated position of each indicator can be detected regardless of which indicator indicates the position.

[0037] In the following example, Figure 2 As shown, the electronic pen 2, which is the first indicator to be detected by the position detection device of the first embodiment, has a coil 202 wound around a magnetic core 201, and has a structure for transmitting a signal from a signal generating circuit 203 as electromagnetic induction energy to the position detection device 1 through the coil 202. It should be noted that the electronic pen 2 has a battery (omitted in the figure) for driving the signal generating circuit 203.

[0038] like Figure 1 As shown, the position detection device 1 of this embodiment is composed of a position detection sensor 10 and a signal processing circuit 20 connected to the position detection sensor 10. In this example, the position detection sensor 10 is configured as a transparent sensor arranged on a display screen of a display device such as a liquid crystal display.

[0039] That is, in the position detection sensor 10 of this example, the lateral direction of a transparent substrate 11 such as a rectangular glass substrate is set as the X-axis direction (an example of a first direction) and the longitudinal direction orthogonal to the lateral direction of the transparent substrate 11 is set as the Y-axis direction (an example of a second direction), and a metal mesh electrode obtained by combining fine wires of ITO (Indium Tin Oxide) or silver, copper, etc. is used on the transparent substrate 11 to form a group of elongated annular electrodes arranged at fixed intervals in a manner that does not overlap each other.

[0040] The annular electrode group, for example, has a double-layer structure of an X annular electrode group 12 composed of a plurality of annular electrodes X as an example of a first electrode and a Y annular electrode group 13 composed of a plurality of annular electrodes Y as an example of a second electrode. In this example, on the surface side of the transparent substrate 11, a plurality of annular electrodes X in the length direction of the elongated ring in the Y-axis direction are arranged at fixed intervals in a state of not overlapping each other in the X-axis direction to form the X annular electrode group 12. In addition, on the back side of the transparent substrate 11, a plurality of annular electrodes Y in the length direction of the elongated ring in the X-axis direction are arranged at fixed intervals in a state of not overlapping each other in the Y-axis direction to form the Y annular electrode group 13. In this example, the X annular electrode group 12 is composed of 40 annular electrodes X (X1 to X40), and the Y annular electrode group 13 is composed of 30 annular electrodes Y (Y1 to Y30).

[0041] It should be noted that in the following description, when there is no need to distinguish each of the annular electrodes X1 to X40, they are simply recorded as annular electrode X. Similarly, when there is no need to distinguish each of the annular electrodes Y1 to Y30, they are simply recorded as annular electrode Y.

[0042] The arrangement pitch of the annular electrode X and the annular electrode Y is preferably 3 to 6 mm, which is equivalent to the size of the contact area when a finger touches the position detection sensor 10. In addition, in order to efficiently receive the signal from the electronic pen 2, the width of the annular coil is preferably wide. Figure 1 As shown in FIG. 1 , the interval between the adjacent annular electrodes of the annular electrodes X and the annular electrodes Y is preferably as narrow as possible. Therefore, in this example, the adjacent annular electrodes of the annular electrodes X and the annular electrodes Y are arranged in close proximity to each other. Therefore, the width of the ring in the arrangement direction of each of the annular electrodes X and the annular electrodes Y is slightly smaller than the arrangement pitch.

[0043] In this example, the signal processing circuit 20 connected to the position detection sensor 10 is configured to include a selection circuit 21 for selecting one annular electrode X from the X annular electrode group 12, a selection circuit 22 for selecting one annular electrode Y from the Y annular electrode group 13, a mode switching circuit 23 for switching between detection of a first indicator based on electromagnetic induction coupling and detection of a second indicator based on electrostatic coupling, a pen signal receiving circuit 24 that is an example of a first detection circuit for detecting an indicated position of a first indicator by electromagnetic induction coupling, a touch detection control circuit 25 that is an example of a second detection circuit for detecting an indicated position of a second indicator by electrostatic coupling, and a processing control circuit 26 composed of a computer.

[0044] The selection circuit 21 is composed of two multiplexers 211 and 212. The winding start ends (X1a to X40a) of the plurality of annular electrodes X (X1 to X40) are connected to one of the multiplexers 211, and the winding end ends (X1b to X40b) are connected to the other of the multiplexers 212. The two multiplexers 211 and 212 are linked to each other by the selection control signal SEx from the processing control circuit 26, and the selection circuit 21 selects the annular electrodes X one by one from the X annular electrode group 12.

[0045] Furthermore, the winding start end of a ring electrode X selected by the selection control signal SEx in the X ring electrode group 12 is selected by the multiplexer 211 and connected to the common terminal XA of the multiplexer 211, and the winding end end of the same ring electrode X is selected by the multiplexer 212 and connected to the common terminal XB of the multiplexer 212.

[0046] In addition, the selection circuit 22 is composed of two multiplexers 221 and 222, and the winding start ends (Y1a to Y30a) of the plurality of annular electrodes Y (Y1 to Y30) are respectively connected to one of the multiplexers 221, and the winding end ends (Y1b to Y30b) are respectively connected to the other of the multiplexers 222. And, the two multiplexers 221 and 222 are linked to the selection control signal SEy from the processing control circuit 26, and the selection circuit 22 selects the annular electrodes Y one by one from the Y annular electrode group 13 in sequence.

[0047] Furthermore, the winding starting end of a ring electrode Y selected by the selection control signal SEy in the Y ring electrode group 13 is selected by the multiplexer 221 and connected to the multiplexer 221 and the common terminal YA, and the winding ending end of the same ring electrode Y is selected by the multiplexer 222 and connected to the common terminal YB of the multiplexer 222.

[0048] The mode switching circuit 23 includes switching circuits 23XA and 23XB for the annular electrode X and switching circuits 23YA and 23YB for the annular electrode Y. The common terminal XA of the multiplexer 211 is connected to the movable terminal of the switching circuit 23XA of the mode switching circuit 23, and the common terminal XB of the multiplexer 212 is connected to the movable terminal of the switching circuit 23XB of the mode switching circuit 23. The common terminal YA of the multiplexer 221 is connected to the movable terminal of the switching circuit 23YA of the mode switching circuit 23, and the common terminal YB of the multiplexer 222 is connected to the movable terminal of the switching circuit 23YB of the mode switching circuit 23.

[0049] Furthermore, one fixed terminal P of the switching circuits 23XA, 23XB, 23YA, and 23YB of the mode switching circuit 23 is connected to the pen signal receiving circuit 24 , and the other fixed terminal F is connected to the touch detection control circuit 25 .

[0050] Furthermore, a fixed terminal P of the switching switch circuit 23XA of the mode switching circuit 23 is connected to one input terminal (inverting input terminal in the example) of the X-side differential input amplifier 24X of the pen signal receiving circuit 24, and a fixed terminal P of the switching switch circuit 23XB is connected to the other input terminal (non-inverting input terminal in the example) of the X-side differential input amplifier 24X. Furthermore, a fixed terminal P of the switching switch circuit 23YA of the mode switching circuit 23 is connected to one input terminal (inverting input terminal in the example) of the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24, and a fixed terminal P of the switching switch circuit 23YB is connected to the other input terminal (non-inverting input terminal in the example) of the Y-side differential input amplifier 24Y.

[0051] Although not shown in the figure, an X-axis signal receiving circuit and a Y-axis signal receiving circuit are provided at the subsequent stages of the X-side differential input amplifier 24X and the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24, respectively. These X-axis signal receiving circuit and the Y-axis signal receiving circuit detect the reception level of the pen signal (the signal received from the electronic pen 2) detected by the annular electrode X and the annular electrode Y, and supply the information of the detected reception level to the processing control circuit 26. The processing control circuit 26 detects the coordinates (X, Y) of the indicated position of the electronic pen 2 on the position detection sensor 10 based on the information from the pen signal receiving circuit 24.

[0052] In this example, the other fixed terminal F of the switching circuit 23XA and the other fixed terminal F of the switching circuit 23XB are connected to each other, and the connection point is connected to the input end of the touch signal detection amplifier 251 of the touch detection control circuit 25. In addition, the other fixed terminal F of the switching circuit 23YA and the other fixed terminal F of the switching circuit 23YB are connected to each other, and the connection point is connected to the output end of the transmission output driver 252 of the touch detection control circuit 25. Therefore, both ends of the annular electrode X and the annular electrode Y are short-circuited, and thus each operates as one electrode line.

[0053] An oscillation circuit 253 is connected to the front stage of the transmission output driver 252, and a frequency signal of a predetermined frequency f from the oscillation circuit 253 is transmitted to the position detection sensor 10 through the transmission output driver 252. In addition, a touch detection circuit (not shown) is provided at the rear stage of the touch signal detection amplifier 251 of the touch detection control circuit 25, and the touch detection circuit detects the level of the signal transmitted to the position detection sensor 10 through the transmission output driver 252 and received by the position detection sensor 10, and supplies information on the level of the detected signal to the processing control circuit 26.

[0054] The processing control circuit 26 detects the coordinates (X, Y) of the pointed position of the finger on the position detection sensor 10 using the fact that the level of the signal from the touch detection control circuit 25 changes at the position pointed by the finger.

[0055] The processing control circuit 26 detects the coordinates of the indicated position of each indicator as described above based on the reception information from the pen signal receiving circuit 24 and the touch detection control circuit 25 , and supplies a timing control signal to these pen signal receiving circuit 24 and the touch detection control circuit 25 .

[0056] In addition, the processing control circuit 26 supplies a selection control signal SEx to the multiplexers 211 and 212 of the selection circuit 21 to control the selection of one annular electrode X in sequence from the X annular electrode group 12, and supplies a selection control signal SEy to the multiplexers 221 and 222 of the selection circuit 22 to control the selection of one annular electrode Y in sequence from the Y annular electrode group 13.

[0057] Moreover, the processing control circuit 26 supplies a mode switching signal MD to the mode switching circuit 23 for switching between a state in which the movable terminal of the switching switch circuit 23XA, 23XB, 23YA, and 23YB is connected to the fixed terminal P (electromagnetic induction mode) and a state in which the movable terminal of the switching switch circuit 23XA, 23XB, 23YA, and 23YB is connected to the fixed terminal F (electrostatic coupling mode).

[0058] In this embodiment, the processing control circuit 26 switches the mode switching circuit 23 alternately between the fixed terminal P side and the fixed terminal F side at predetermined time intervals using the mode switching signal MD, thereby switching the position detection device 1 between the electromagnetic induction mode and the electrostatic coupling mode in a time-division manner.

[0059] [Operation of Position Detection Device 1 of First Embodiment]

[0060] In this embodiment, the processing control circuit 26 uses the mode switching signal MD to connect the movable terminals of the switching switch circuits 23XA, 23XB, 23YA, and 23YB of the mode switching circuit 23 to the fixed terminal P during a predetermined time period, and drives the pen signal receiving circuit 24 to switch to the electromagnetic induction mode. Furthermore, during the electromagnetic induction mode, the processing control circuit 26 controls the multiplexers 211 and 212 of the selection circuit 21 so that the annular electrodes X are all selected one by one in sequence from the X annular electrode group 12, and controls the multiplexers 221 and 222 of the selection circuit 22 so that the annular electrodes Y are all selected one by one in sequence from the Y annular electrode group 13.

[0061] Therefore, in the position detection device 1 in the electromagnetic induction mode, as shown in FIG. Figure 2 As shown, both ends of the annular electrode X selected by the selection circuit 21 are connected to the inverting input terminal and the non-inverting input terminal of the X-side differential input amplifier 24X of the pen signal receiving circuit 24. Similarly, both ends of the annular electrode Y selected by the selection circuit 22 are connected to the inverting input terminal and the non-inverting input terminal of the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24.

[0062] At this time, if the electronic pen 2 indicates a position on the position detection sensor 10, the induced current induced in the annular electrode X and the annular electrode Y according to the signal from the electronic pen 2 is amplified by the X-side differential input amplifier 24X and the Y-side differential input amplifier 24Y, and is supplied to the X-axis signal receiving circuit and the Y-axis signal receiving circuit of the subsequent stage to detect the level thereof.

[0063] The processing control circuit 26 detects the coordinates (X, Y) of the indicated position of the electronic pen 2 on the position detection sensor as described above based on the switching timing of the selection control signal SEx and the selection control signal SEy of the multiplexers 211 and 212 of the selection circuit 21 and the multiplexers 221 and 222 of the selection circuit 22 and the reception detection output of the signal sent from the electronic pen 2 from the pen signal receiving circuit 24.

[0064] Furthermore, when the period of the electromagnetic induction mode ends, in this embodiment, the processing control circuit 26 uses the mode switching signal MD to connect the movable terminals of the switching switch circuits 23XA, 23XB, 23YA, and 23YB of the mode switching circuit 23 to the fixed terminal F, and drives the touch detection control circuit 25 to switch to the electrostatic coupling mode. Furthermore, during the electrostatic coupling mode, the processing control circuit 26 also switches the selection circuit 21 and the selection circuit 22 using the selection control signal Sex and the selection control signal SEy, and controls the selection of the annular electrodes X from the X annular electrode group 12 one by one, and controls the selection of the annular electrodes Y from the Y annular electrode group 13 one by one.

[0065] In the position detection device 1 in the electrostatic coupling mode, as Figure 3 As shown, the annular electrode Y selected by the selection circuit 22 and connected to the common terminal XA of the winding start end and the common terminal YA of the winding end end is connected to each other and functions as one electrode line, and the signal of the predetermined frequency from the oscillation circuit 253 is sequentially supplied through the transmission output driver 252 of the touch detection control circuit 25. In addition, the annular electrode X selected by the selection circuit 21 and connected to the common terminal YA of the winding start end and the common terminal YB of the winding end end is connected to each other and functions as one electrode line, and is connected to the input end of the touch signal detection amplifier 251 of the touch detection control circuit 25.

[0066] At this time, the signal transmitted to the short-circuited annular electrode Y by the transmission output driver 252 is received by the short-circuited annular electrode X, and its reception level is supplied to the touch signal detection amplifier 251. However, when the finger 3 touches the position detection sensor 10, part of the signal transmitted to the annular electrode Y flows through the finger 3 and the human body, so the signal transmitted from the annular electrode Y at the finger touch position to the annular electrode X is reduced. The processing control circuit 26 detects the coordinates of the finger touch position by detecting the change in the reception signal level from the touch detection control circuit 25.

[0067] When the electrostatic coupling mode period ends, in this embodiment, the processing control circuit 26 switches to the electromagnetic induction mode as described above using the mode switching signal MD. Thereafter, the electromagnetic induction mode and the electrostatic coupling mode are repeated in a similar manner in a time-division manner.

[0068] As described above, in the position detection device 1 of the first embodiment described above, the position detection sensor 10 formed with the X annular electrode group 12 and the Y annular electrode group 13 is used, which can detect the coordinates of the indicated position of the electronic pen 2 by electromagnetic induction, and can detect the coordinates of the indicated position of the finger 3 by electrostatic coupling.

[0069] Furthermore, in the position detection device 1 of the first embodiment, since the X annular electrode group 12 and the Y annular electrode group 13 are formed in the position detection sensor 10 instead of linear electrodes, it is not necessary to connect the linear electrodes at the ends to form annular electrodes. Therefore, the position detection device 1 can be set to a simple structure using the selection circuit 21 and the selection circuit 22, which each selects the annular electrode X from the X annular electrode group 12 and the annular electrode Y from the Y annular electrode group 13, and the mode switching circuit 23.

[0070] [Second embodiment]

[0071] In the position detection device 1 of the first embodiment described above, the ring electrodes X and Y are selected one by one in sequence in both the electromagnetic induction mode and the electrostatic coupling mode in the selection circuits 21 and 22. However, it is possible to configure a wide ring coil to more efficiently detect the signal from the electronic pen 2 by simultaneously selecting a plurality of adjacent ring electrodes from the X ring electrode group 12 and the Y ring electrode group 13 in the electromagnetic induction mode. The second embodiment described below is configured in this way. It should be noted that in the following description, the operation in the electrostatic coupling mode is the same as that in the first embodiment, so the operation in the electromagnetic induction mode will be mainly described.

[0072] <First Example of Second Implementation>

[0073] Figure 4~Figure 7 This is a diagram for explaining a configuration example of a position detection device 1A according to the second embodiment configured to simultaneously select two adjacent annular electrodes X and two adjacent annular electrodes Y. FIG.

[0074] Figure 4 FIG. 1 is a diagram showing a configuration example of a position detection device 1A according to a second embodiment. Figure 4 As shown, instead of the selection circuits 21 and 22 in the position detection device 1 of the first embodiment, selection circuits 21A and 22A are provided, and instead of the processing control circuit 26, a processing control circuit 26A is provided. The rest is the same structure as the position detection device 1 of the first embodiment. Figure 4 In the present invention, the same components as those of the position detection device 1 according to the first embodiment described above are denoted by the same reference numerals, and description thereof will be omitted.

[0075] In the second embodiment, the selection circuit 21A is composed of a selection switch 211A and a selection switch 212A. Figure 4As shown, the selection switch 211A and the selection switch 212A have switches corresponding to the number of the annular electrodes X (X1 to X40), and the winding start ends X1a to X40a of the annular electrodes X (X1 to X40) are respectively connected to one end of each switch of the selection switch 211A, and the winding end ends X1b to X40b are respectively connected to one end of each switch of the selection switch 212A.

[0076] Furthermore, the other ends of the multiple switches of the selection switch 211A are connected in common and connected to the common terminal XA' of the selection switch 211A. Similarly, the other ends of the multiple switches of the selection switch 212A are connected in common and connected to the common terminal XB' of the selection switch 212A. The common terminal XA' of the selection switch 211A is connected to the movable terminal of the switching switch circuit 23XA of the mode switching circuit 23, and the common terminal XB' of the selection switch 212A is connected to the movable terminal of the switching switch circuit 23XB of the mode switching circuit 23.

[0077] Furthermore, in the first example of the second embodiment, in the electromagnetic induction mode, the selection switch 211A and the selection switch 212A are controlled by the selection control signal SEMx from the processing control circuit 26A so as to select two adjacent annular electrodes X from the X annular electrode group 12 at a time and sequentially shift the selected two annular electrodes X one by one.

[0078] Figure 5 1A is a diagram for explaining the selection control of a plurality of switches of the selection switches 211A and 212A in the electromagnetic induction mode in the position detection device 1A of the first example of the second embodiment. Figure 5 The switching states of the switches connected to the respective annular electrodes X1 to X40 of the X annular electrode group 12 in the selection switches 211A and 212A are shown in chronological order, with "1" indicating that the switch is turned on and "0" indicating that the switch is turned off. In the electromagnetic induction mode, the switching states are repeatedly performed by selecting the control signals SEMx and SEMy. Figure 5 Select controls shown.

[0079] That is, the selection switch 211A and the selection switch 212A of the selection circuit 21A sequentially select the same two adjacent annular electrodes X, but first, the two switches connected to the annular electrodes X1 and X2 are turned on, and the annular electrodes X1 and X2 are connected to the common terminals XA' and XB'. Next, the two switches connected to the annular electrodes X2 and X3 are turned on, and the annular electrodes X2 and X3 are connected to the common terminals XA' and XB'. And, as the annular electrodes X3 and X4, X4 and X5, and X5 and X6, the selected annular electrodes X are shifted one by one, and the two annular electrodes X are connected to the common terminals XA' and XB'.

[0080] Since the common terminals XA' and XB' are connected to the X-side differential input amplifier 24X of the pen signal receiving circuit 24 via the fixed terminal P side of the mode switching circuit 23, the pen signal receiving circuit 24 detects the reception level of the pen signal for each of the two selected annular electrodes X.

[0081] When two adjacent annular electrodes X are selected at the same time, Figure 6 As shown, the two coils are connected in parallel and are supplied to the X-side differential input amplifier 24X. In this case, if the currents induced by electromagnetic induction coupling with the electronic pen 2 at two adjacent annular electrodes Xn and Xn+1 (where n=1, 2, . . . , 39) are respectively defined as i1 and i2, the X-side differential input amplifier 24X obtains an output α (i1+i2) corresponding to the added value of the currents induced at the two annular electrodes Xn and Xn+1.

[0082] As described above, the selection switches 211A and 212A are set to Figure 5 The order shown in the figure selects two adjacent annular electrodes X in turn to detect the signal from the electronic pen 2 and the Figure 7 This is equivalent to a well-known detection method in the electromagnetic induction method of sequentially selecting the overlapping loop coils 14. In this example, by simultaneously selecting two adjacent loop electrodes, a loop coil having a width twice the arrangement pitch of the loop electrodes can be formed.

[0083] Although the selection circuit 21A for the X annular electrode group 12 for obtaining the X coordinate has been described above, the selection circuit 22A for the Y annular electrode group 13 for obtaining the Y coordinate can be configured similarly.

[0084] That is, in the second embodiment, the selection circuit 22A is composed of a selection switch 221A and a selection switch 222A having the same number of switches as the annular electrodes Y (Y1 to Y30). Figure 4 As shown, the winding start ends Y1a to Y30a of each annular electrode Y (Y1 to Y30) are connected to one end of each switch of the selection switch 221A, and the winding end ends Y1b to Y30b are connected to one end of each switch of the selection switch 222A.

[0085] Furthermore, the other ends of the multiple switches of the selection switch 221A are connected in common to the common terminal YA' of the selection switch 221A, and the other ends of the multiple switches of the selection switch 222A are connected in common to the common terminal YB' of the selection switch 222A. Furthermore, the common terminal YA' of the selection switch 221A is connected to the movable terminal of the switching switch circuit 23YA of the mode switching circuit 23, and the common terminal YB' of the selection switch 222A is connected to the movable terminal of the switching switch circuit 23YB of the mode switching circuit 23.

[0086] Furthermore, in the first example of the second embodiment, in the electromagnetic induction mode, the selection switch 221A and the selection switch 222A are controlled by the selection control signal SEMy from the processing control circuit 26A in the same manner as the selection control for selecting two adjacent annular electrodes X each time from the X annular electrode group 12 described above, in such a manner that the selected two annular electrodes Y are sequentially shifted one by one while being selected.

[0087] Therefore, regarding the annular electrode Y, Figure 6 Similarly to the operation shown, the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24 obtains an output α (i1+i2) corresponding to the sum of the currents induced in the two annular electrodes Ym and Xm+1 (m=1, 2, . . . , 29). In addition, regarding the Y annular electrode group 13, it is also equivalent to a well-known detection method in the electromagnetic induction method of sequentially selecting annular coils arranged overlapping each other.

[0088] It should be noted that, as described above, in the electrostatic coupling mode, in the second embodiment, the selection switches 211A and 212A, and the selection switches 221A and 222A are also controlled so as to select the annular electrode X and the annular electrode Y one by one. Therefore, in the electrostatic coupling mode, SECx and SECy for turning on a plurality of switches one by one are supplied from the processing control circuit 26A to the selection switches 211A and 212A, and the selection switches 221A and 222A, respectively.

[0089] <Second Example of Second Implementation>

[0090] The first example described above simultaneously selects multiple (two in this example) adjacent annular electrodes X and annular electrodes Y in the electromagnetic induction mode, but it is also possible to simultaneously select two or more adjacent annular electrodes X and annular electrodes Y. The second example is an example of this case, and the following describes three cases.

[0091] That is, in the case of the second example, the structure of the position detection device is also directly used. Figure 4Furthermore, in the position detection device of the second example, the selection control signals SEMx and SEMy supplied from the processing control circuit 26A to the two selection switches 211A and 212A of the selection circuit 21A and the two selection switches 221A and 222A of the selection circuit 22A in the electromagnetic induction mode are different from those of the first example.

[0092] Figure 8 This is a diagram for explaining selection control of a plurality of switches of selection switches 211A and 212A in the electromagnetic induction mode in the position detection device 1A of the second example of the second embodiment.

[0093] In this example, the selection switch 211A and the selection switch 212A of the selection circuit 21A sequentially select the same three adjacent annular electrodes X, but first, the three switches connected to the annular electrodes X1, X2, and X3 are turned on, and these annular electrodes X1, X2, and X3 are connected to the common terminals XA' and XB'. Next, the three switches connected to the annular electrodes X2, X3, and X4 are turned on, and these annular electrodes X2, X3, and X4 are connected to the common terminals XA' and XB'. And, the selected annular electrodes X are connected to the common terminals XA' and XB' while shifting one by one, such as the annular electrodes X3, X4, X5, X4, X5, X6, X5, X6, and X7.

[0094] When three adjacent annular electrodes X are selected at the same time, Fig. 9 As shown in FIG. 1 , three annular electrodes X (coils) are connected in parallel and are supplied to the X-side differential input amplifier 24X. In this case, if the currents induced by electromagnetic induction coupling with the electronic pen 2 in each of the three adjacent annular electrodes Xn, Xn+1, and Xn+2 (where n=1, 2, . . . , 38) are denoted as i1, i2, and i3, the X-side differential input amplifier 24X obtains an output α (i1+i2+i3) corresponding to the sum of the currents induced in the three annular electrodes Xn, Xn+1, and Xn+2.

[0095] As described above, the selection switches 211A and 212A are set to Figure 8 The adjacent three annular electrodes X are selected in the order shown in the figure to detect the signal from the electronic pen 2 and the Fig.10 In this example, by selecting three adjacent annular electrodes at the same time, an annular coil having a width three times the arrangement pitch of the annular electrodes X can be formed.

[0096] The selection circuit 22A for the Y annular electrode group 13 for obtaining the Y coordinate can be configured in the same manner, and three coils are connected in parallel to be supplied to the Y-side differential input amplifier 24Y.

[0097] [Third Embodiment]

[0098] In the position detection device 1A of the second embodiment described above, in the electromagnetic induction mode, in the selection circuit 21A and the selection circuit 22A, as shown in FIG. Figure 6 and Fig. 9 As shown, the plurality of annular electrodes X and the plurality of annular electrodes Y are connected in parallel for selection, but the selection circuit may be configured such that the annular electrodes (coils) are connected in series when the adjacent plurality of annular electrodes X and the plurality of annular electrodes Y are selected. The third embodiment is an example of this case.

[0099] Fig.11 1B is a diagram for explaining a configuration example of a position detection device 1B according to the third embodiment. In the following description, the operation in the electromagnetic induction mode of the position detection device 1B according to the third embodiment will be mainly described.

[0100] In the position detection device 1B of the third embodiment, as shown in FIG. Fig.11 As shown in FIG. 1 , selection circuits 21B and 22B are provided in place of selection circuits 21 and 22 in the position detection device 1 of the first embodiment, and a processing control circuit 26B is provided in place of the processing control circuit 26. The rest is the same configuration as the position detection device 1 of the first embodiment. Fig.11 In the embodiment, the same parts as those of the position detection device 1 of the first embodiment are denoted by the same reference numerals and their description is omitted. Fig.11 In the figure, the pen signal receiving circuit 24 and the touch detection control circuit 25 are omitted.

[0101] In the third embodiment, the selection circuit 21B is composed of multiplexers 211B and 212B having the same structure as the multiplexers 211 and 212 of the first embodiment and a plurality of (in this example, the number is 39, which is one less than the number of annular electrodes X (X1 to X40)) three-terminal switches SX1 to SX39. The three-terminal switch is a switch having three terminals, namely, a first terminal, a second terminal, and a third terminal, and can be set by a setting control signal so as to connect any two terminals from among the three terminals.

[0102] Furthermore, each of the winding end ends X1b to X39b of the annular electrodes X (X1 to X39) is connected to the first terminal of each of the three-terminal switches SX1 to SX39, and each of the winding start ends X2a to X40a of the annular electrodes X (X2 to X40) is connected to the second terminal of each of the three-terminal switches SX1 to SX39. Furthermore, the third terminal of each of the three-terminal switches SX1 to SX39 is connected to multiplexers 211B and 212B. However, the winding start end X1a of the annular electrode X1 is directly connected to the multiplexer 212B, and the winding end end X40b of the annular electrode X40 is directly connected to the multiplexer 211B.

[0103] Furthermore, in this embodiment, in addition to the mode switching signal MD, the processing control circuit 26B also sends a setting control signal CTx for controlling the setting of each of the three-terminal switches SX1~SX39, and sends a selection control signal SExA to the multiplexer 211B and a selection control signal SExB to the multiplexer 212B.

[0104] For example, when two adjacent annular electrodes X are connected in series, first, the winding end X1b of the annular electrode X1 is connected to the three-terminal switch SX1 of the first terminal so as to connect the first terminal to the second terminal, and the winding end X2b of the adjacent annular electrode X2 is connected to the three-terminal switch SX2 of the first terminal so as to connect the first terminal to the third terminal. Furthermore, the multiplexer 211B is controlled so as to select the three-terminal switch SX2, and the multiplexer 212B is controlled so as to select the winding start end X1a of the annular electrode X1.

[0105] Next, the three-terminal switch SX1 is set and controlled so as to connect the first terminal to the third terminal, and the adjacent three-terminal switch SX2 is set and controlled so as to connect the first terminal to the second terminal, and the adjacent three-terminal switch SX3 is set and controlled so as to connect the first terminal to the third terminal. Furthermore, the multiplexer 211B is selected and controlled so as to select the three-terminal switch SX3 connected to the first terminal and the third terminal, and the multiplexer 212B is similarly selected and controlled so as to select the three-terminal switch SX1 connected to the first terminal and the third terminal.

[0106] Next, the adjacent three-terminal switches SXn to SXn+2 are sequentially set and controlled by shifting one of the three-terminal switches at a time. Furthermore, among the adjacent three-terminal switches SXn to SXn+2, the three-terminal switches SXn and SXn+2 at both ends are set and controlled so that the first terminal is connected to the third terminal, and the three-terminal switch SXn+1 in the middle is set and controlled so that the first terminal is connected to the second terminal. Furthermore, the multiplexers 211B and 212B are controlled so that the three-terminal switches SXn+2 and SXn at both ends are selected.

[0107] When the selection circuit 21B is selected and controlled in this way, Fig.12 As shown, two annular electrodes X (coils) are connected in series and are supplied to an X-side differential input amplifier 24X, and an output corresponding to a sum of induced currents in the two annular electrodes X is obtained in the X-side differential input amplifier 24X.

[0108] It should be noted that the present invention is not limited to the case where two annular electrodes X are connected in series at a time, and three adjacent annular electrodes X may be connected in series, and the group of the three annular electrodes X may be controlled in a manner of shifting one at a time. In the case of more than three annular electrodes X, the winding start ends of the annular electrodes X at both ends are connected to the multiplexers 211B and 212B, and the winding end ends and the winding start ends of the adjacent annular electrodes are connected by the middle annular electrode X sandwiched between the two ends, and each of the three-terminal switches connected to the plurality of annular electrodes X is controlled.

[0109] The above is an explanation of the X annular electrode group 12, but the selection circuit 22B for the Y annular electrode group 13 can also be configured in the same manner, and similarly controlled in a manner of connecting a plurality of annular electrodes Y in series each time. That is, the selection circuit 22B is composed of multiplexers 221B and 222B having the same configuration as the multiplexers 221 and 222 of the first embodiment, and a plurality of (in this example, the number is 29, which is one less than the number of annular electrodes Y (Y1 to Y30)) three-terminal switches SY1 to SY29.

[0110] Furthermore, these multiplexers 221B and 222B and the three-terminal switches SY1 to SY29 of the selection circuit 22B are controlled by the selection control signals SEyA and SEyB and the setting control signal CTy from the processing control circuit 26B, so that a plurality of adjacent annular electrodes Y can be sequentially connected in series and selected in the same manner as in the case of the X annular electrode group 12.

[0111] In the electrostatic coupling mode of the third embodiment, similarly to the second embodiment, one annular electrode X and one annular electrode Y are selected by the selection circuit 21B and the selection circuit 22B.

[0112] [Other embodiments]

[0113] In the above-mentioned embodiment, the position detection sensor 10 forms the annular electrode X and the annular electrode Y on the transparent substrate 11 using a substantially transparent conductive material such as a metal mesh electrode formed by combining fine wires of ITO, silver, copper, etc. Therefore, the wires constituting the electrodes of the position detection sensor 10 are formed as a pattern having a predetermined width of, for example, about 1 mm. If the position detection sensor using such wires of electrodes is used for touch detection, the inner part of the width of the annular electrode X and the width of the annular electrode Y will become an electrical void, so the capacitance with the human body such as a finger is reduced at the central part of the annular electrode X and the annular electrode Y, making it difficult to accurately obtain the indicated position of the finger.

[0114] In order to solve such a problem, a protrusion that protrudes from the pattern of the line constituting the annular electrode X and the annular electrode Y to the inside of the width of the annular electrode X and the inside of the width of the annular electrode Y may be formed. Fig.13 (A) and (B) are examples of protrusions that protrude from the pattern of the lines constituting the electrodes of the annular electrode X and the annular electrode Y toward the inside of the width of the annular electrode X and the inside of the width of the annular electrode Y.

[0115] like Fig.13 As shown in (A) and (B), in the position detection sensor, the annular electrode X and the annular electrode Y are arranged to intersect each other orthogonally, so that the width of the annular electrode X and the width of the annular electrode Y form a rectangular cavity region 16 .

[0116] exist Fig.13 In the example of (A), two mutually opposing protrusions 17a and 17b are formed from the electrode line pattern of the annular electrode X at a position toward the center of the rectangular hollow region 16 and protrude in a direction orthogonal to and intersecting the electrode line pattern. In addition, two mutually opposing protrusions 18a and 18b are formed from the electrode line pattern of the annular electrode Y at a central position of the rectangular hollow region 16 and protrude in a direction orthogonal to and intersecting the electrode line pattern.

[0117] In addition, Fig.13 In the example of (B), the protrusions 17c and 17d protruding in the direction orthogonal to and intersecting the electrode line pattern of the annular electrode X are also formed, but in this example, these protrusions 17c and 17d are formed so as to face positions deviated from the center of the rectangular hollow region 16 and not face each other. Similarly, the protrusions 18c and 18d protruding in the direction orthogonal to and intersecting the electrode line pattern of the annular electrode Y are formed, but in this example, these protrusions 18c and 18d are formed so as to face positions deviated from the center of the rectangular hollow region 16 and not face each other.

[0118] According to the above Fig.13 In the position detection sensor having an electrode pattern as shown in (A) and (B), even when a finger touches the rectangular hollow area 16, since the protrusions 17a, 17b and protrusions 18a, 18b or the protrusions 17c, 17d and protrusions 18c, 18d are present in the hollow area 16, the finger is actually in contact with the annular electrode X and the annular electrode Y, making it easier to detect the finger touch.

[0119] Even if the protrusions 17a, 17b and 18a, 18b or the protrusions 17c, 17d and 18c, 18d are provided on the inner side of the annular electrodes X, Y, the magnetic field radiated from the electronic pen is radiated to a sufficiently wide area compared to the line width of the protrusions. Therefore, during the pen signal receiving operation, the protrusions 17a, 17b and 18a, 18b or the protrusions 17c, 17d and 18c, 18d have almost no influence on the reception of the magnetic field signal from the electronic pen.

[0120] [Other embodiments or modifications]

[0121] It should be noted that in the above-mentioned embodiment, in the electrostatic coupling mode, each of the annular electrode X and the annular electrode Y connects the winding start end and the winding end end to be short-circuited, but one of the winding start end and the winding end end may be opened (set as an open end) and the other may be set as an end for connection to the touch detection control circuit 25.

[0122] In addition, in the above-mentioned embodiment, the position detection sensor 10 is configured as a transparent sensor structure in which annular electrodes X and annular electrodes Y are formed on a transparent substrate 11 using a metal mesh electrode formed by combining fine wires of ITO, silver, copper, etc., but for purposes other than being configured on a display screen of a display device, it can of course also be an opaque sensor structure.

[0123] In the above-described embodiment, the amplifier circuits for the X-side input and the Y-side input of the pen signal receiving circuit 24 are configured as differential amplifiers, but may be configured such that one end of each of the annular electrode X and the annular electrode Y is connected to a fixed potential and the other end is supplied to an amplifier having a single input.

[0124] In addition, in the above-mentioned embodiment, the position detection device 1, 1A, 1B switches the electromagnetic induction mode and the electrostatic coupling mode in a manner executed by time division through the mode switching signal MD from the processing control circuit 26, 26A, 26B. However, the switching between the electromagnetic induction mode and the electrostatic coupling mode can of course also be manually switched by the user. In this case, a switching switch or a push button switch that enables the user's switching operation is provided in the position detection device, and for example, the processing control circuit switches the electromagnetic induction mode and the electrostatic coupling mode according to the switching state of the switching switch or the push button switch.

[0125] Alternatively, the position detection device may be switched to the electromagnetic induction mode when receiving a signal from the electronic pen via the position detection sensor, and may be switched to the electrostatic coupling mode when receiving a signal from the electronic pen without using the position detection sensor.

[0126] In addition, a short-range wireless communication circuit, such as a Bluetooth (registered trademark) standard, may be provided on both the electronic pen and the position detection device. The short-range wireless communication circuit of the position detection device may switch the position detection device to an electromagnetic induction mode when receiving a signal from the electronic pen, and may switch to an electrostatic coupling mode when not receiving a signal from the electronic pen.

[0127] It should be noted that, in the above-mentioned embodiment, the second indicator as the object to be detected in the electrostatic coupling mode is set to a human finger, but it may also be an electronic pen of a passive electrostatic mode. In addition, it may also be an electronic pen of an active electrostatic coupling mode. In the case of an electronic pen of an active electrostatic coupling mode, a circuit that receives a signal from an electronic pen of an active electrostatic coupling mode with respect to each of the annular electrode X and the annular electrode Y and detects the level thereof is provided instead of the touch detection control circuit 25.

[0128] In the above-mentioned embodiment, in the electromagnetic induction mode, the position indicated by the electronic pen 2 is detected by receiving a signal from the electronic pen 2 having an oscillation circuit. However, the present invention is not limited to this, and the following structure may be adopted: as the electronic pen, an electronic pen having a resonant circuit composed of a coil and a capacitor is used, and in the electromagnetic induction mode, an AC signal is sent from the position detection device to the electronic pen by electromagnetic induction coupling, and the position indicated by the electronic pen is detected by receiving a signal fed back through the resonant circuit of the electronic pen. In this case, the means for sending the AC signal to the electronic pen may use the X annular electrode group 12 and the Y annular electrode group 13, or a ring coil may be provided separately for transmission.

[0129] Description of symbols

[0130] 1, 1A, 1B…position detection device, 2…electronic pen, 3…finger, 10…position detection sensor, 11…transparent substrate, 12…X ring electrode group, 13…Y ring electrode group, 17a, 17b, 17c, 17d…protrusion, 18a, 18b, 18c, 18d…protrusion, 21, 21A, 21B…X ring electrode selection circuit, 22, 22A, 22B…Y ring electrode selection circuit, 23…mode switching circuit, 24…pen signal receiving circuit, 25…touch detection control circuit.

Claims

1. A position detection device, characterized in that: In a sensor having a plurality of first electrodes arranged in a first direction, Each of the electrodes formed as a plurality of first loop coil groups has a protrusion that protrudes toward the inside of the loop coil.

2. The position detection device according to claim 1, comprising: A sensor having a plurality of first electrodes arranged in a first direction; a signal processing circuit coupled to the sensor for detecting various positions on the sensor indicated by a plurality of indicators; as well as a selection circuit for selecting the plurality of first electrodes, It is characterized in that the following steps are performed: The first electrodes are selected by the selection circuit in such a manner that an induced current is induced in each of the first electrodes, thereby detecting the position on the sensor indicated by the first indicator by utilizing electromagnetic induction coupling between the first indicator and the sensor; and The first electrodes are selected by the selection circuit in such a manner that no induced current is induced in each of the first electrodes, thereby detecting a position on the sensor indicated by the second indicator by utilizing electrostatic coupling between the second indicator and the sensor.

3. The position detection device according to claim 2, The position detection device includes a first detection circuit that, when in a state of electromagnetic induction coupling with a pointer, simultaneously selects a plurality of first electrodes adjacent to each other from the plurality of first electrodes to detect a position indicated by the pointer.

4. The position detection device according to claim 3, The first common terminal and the second common terminal of the first detection circuit are connected to a part of the plurality of first electrodes. When in a state of electromagnetic induction coupling with an indicator, the first terminal of one electrode among a plurality of first electrodes adjacent to each other and the first terminal of another electrode are connected to the first common terminal, and the second terminal of the one electrode and the second terminal of the other electrode are connected to the second common terminal.

5. The position detection device according to claim 4, An amplifier circuit is provided for adding the currents induced in a plurality of first electrodes selected simultaneously by electromagnetic induction coupling.

6. The position detection device according to claim 2, The first common terminal and the second common terminal of the first detection circuit are connected to a part of the plurality of first electrodes. When in a state of electromagnetic induction coupling with an indicator, the first terminal of one electrode among a plurality of first electrodes adjacent to each other is connected to the first common terminal, the second terminal of the one electrode is connected to the first terminal of another electrode, and the second terminal of the other electrode is connected to the second common terminal.

7. The position detection device according to claim 6, In a sensor having a plurality of first electrodes arranged in a first direction, When the indicator is in electromagnetic induction coupling, At a first timing, a Kth first electrode and a K+1th first electrode adjacent to each other are simultaneously selected from the plurality of first electrodes to detect the indicated position of the indicator, At the second timing, the K+1th first electrode and the K+2th first electrode adjacent to each other are simultaneously selected from the plurality of first electrodes to detect the indicated position of the indicator.

8. The position detection device according to claim 2, The first common terminal and the second common terminal of the first detection circuit are connected to the first terminal and the second terminal of each of the plurality of first electrodes, respectively, when in a state of electromagnetic induction coupling with the indicator.

9. The position detection device according to claim 1, When the first electrode is selected, both ends of the ring electrode forming the first electrode are short-circuited, thereby detecting the position portion indicated by the second indicator on the sensor by utilizing electrostatic coupling between the second indicator and the sensor.

10. The position detection device according to claim 1, When the first electrode is selected, one end of the ring electrode forming the first electrode is set as an open end, so that the position indicated by the second indicator on the sensor is detected by utilizing electrostatic coupling between the second indicator and the sensor.

11. The position detection device according to claim 1, The protrusion increases the mutual capacitance.

12. The position detection device according to claim 1, The invention comprises: a sensor having a plurality of first electrodes arranged in a first direction and a plurality of second electrodes arranged in a second direction intersecting the first direction; and a signal processing circuit connected to the sensor and detecting respective positions indicated by a plurality of indicators on the sensor, The first electrode and the second electrode are respectively formed as ring electrodes, and a selection circuit for selecting the plurality of first electrodes and the plurality of second electrodes is provided in the signal processing circuit. The first electrode and the second electrode are selected by the selection circuit in such a manner that an induced current is induced in each of the first electrode and the second electrode, thereby detecting the position indicated by the first indicator on the sensor by utilizing electromagnetic induction coupling between the first indicator and the sensor, and, The selection circuit selects the first electrode and the second electrode in such a manner that no induced current is induced in each of the first electrode and the second electrode, thereby detecting the position indicated by the second indicator on the sensor by utilizing electrostatic coupling between the second indicator and the sensor.

13. The position detection device according to claim 12, The protrusion of the first electrode and the protrusion of the second electrode are arranged to face each other, and the first electrode is orthogonal to the second electrode.

14. The position detection device according to claim 12, The protrusion of the first electrode and the protrusion of the second electrode are arranged not to face each other, and the first electrode is orthogonal to the second electrode.

15. The position detection device according to claim 1, comprising: A plurality of first annular electrodes are arranged in the first direction without overlapping each other; and A plurality of second annular electrodes are arranged in a second direction intersecting the first direction without overlapping each other.

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