Position detector

Abstract

To provide a position detector capable of sharing the entire area of a sensor for both electromagnetic induction type and electrostatic coupling type.SOLUTION: The position detector comprises a sensor including a plurality of first electrodes arrayed in a first direction. Each of the first electrodes is formed as loop electrode and the loop electrode includes a projection part projecting inside the loop electrode. When a finger touches a cavity region of the loop electrode, the finger substantially comes into contact with the loop electrode as the cavity region includes the projection part, thus finger touch can be easily detected.SELECTED DRAWING: Figure 13

Description

[Technical Field]

[0001] The present invention relates to a position detection device that can detect a position indicated by a pointer by electromagnetic induction coupling and a position indicated by a pointer by electrostatic coupling using a common position detection sensor. [Background technology]

[0002] A position detection device is known that uses an electrostatic coupling type position detection sensor to detect the position indicated by a stylus (electronic pen) that is compatible with the electrostatic coupling type, and also detects the position touched by a human finger. However, with this position detection device, there is a problem in that when detecting the position indicated by the stylus, if a human body such as a hand touches the surface of the position detection sensor, it becomes difficult to accurately detect the position indicated by the stylus.

[0003] In this regard, the above problem can be solved by using an electromagnetic induction type position detection sensor to detect the position indicated by the stylus, and using an electrostatic coupling type position detection sensor to detect the position touched by a human finger.

[0004] However, if a position detection device is provided with an electromagnetic induction type position detection sensor and an electrostatic coupling type position detection sensor separately, the configuration becomes complicated.

[0005] To solve this problem, Patent Document 1 (Patent Publication No. 5702511) and Patent Document 2 (Patent Publication No. 5819565) propose a position detection device that uses a single common position detection sensor to achieve position detection using an electromagnetic induction method and position detection using an electrostatic coupling method. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5702511 [Patent Document 2] Patent No. 5819565 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the position detection sensor of the position detection device proposed in Patent Document 1 has multiple linear conductors (X-axis line bodies and Y-axis line bodies) extending in mutually perpendicular directions on the front and back surfaces of the substrate, and switch circuits are provided on one end and the other end of each of the X-axis line bodies and Y-axis line bodies to form loop coils for electromagnetic induction coupling and switch between the loop coils, or to switch between the X-axis line bodies and Y-axis line bodies for electrostatic coupling applications. This has resulted in a problem of a complex configuration.

[0008] Furthermore, in the position detection sensor of the position detection device proposed in Patent Document 2, a plurality of linear conductors (X-axis line bodies and Y-axis line bodies) extending in mutually orthogonal directions are provided on the front and back surfaces of a substrate, and each of the plurality of X-axis line bodies and the plurality of Y-axis line bodies is configured to be divided into those used for the electromagnetic induction method and those used for the electrostatic coupling method. As a result, the position detection sensor has separate areas that can be detected by the electromagnetic induction method and those that can be detected by the electrostatic coupling method, which poses a problem that the entire area of ​​the position detection sensor cannot be used for both the electromagnetic induction method and the electrostatic coupling method.

[0009] SUMMARY OF THE INVENTION An object of the present invention is to provide a position detection device that can solve the above problems. [Means for solving the problem]

[0010] To solve the above problems, a sensor having a plurality of first electrodes arranged in a first direction; each of the first electrodes is formed as a loop electrode; The loop electrode has a protrusion that protrudes toward the inside of the loop electrode. The present invention provides a position detection device characterized by the above.

[0011] In the position detection device having the above-described configuration, even when a finger touches the hollow area of ​​the loop electrode, a protrusion is present within the hollow area, so the finger essentially comes into contact with the loop electrode, making it easier to detect the finger touch. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a diagram illustrating an example of the configuration of a position detection device according to a first embodiment of the present invention. [Figure 2] 3A and 3B are diagrams for explaining an operating state in an electromagnetic induction mode of the position detection device according to the first embodiment. [Figure 3] 4A and 4B are diagrams for explaining an operating state in an electrostatic coupling mode of the position detection device according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of the configuration of a second embodiment of a position detection device according to the present invention. [Figure 5] 10A and 10B are diagrams illustrating the selection control of loop electrodes by a selection circuit in an electromagnetic induction mode in a position detection device as a first example of a second embodiment. [Figure 6] 10A and 10B are diagrams for explaining the operation of the position detection device of the first example of the second embodiment in an electromagnetic induction mode. [Figure 7] 10 is a diagram showing an example of an 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; FIG. [Figure 8] 10A and 10B are diagrams for explaining the operation in an electromagnetic induction mode in the position detection device of the second example of the second embodiment. [Figure 9] 10A and 10B are diagrams for explaining the operation in an electromagnetic induction mode in the position detection device of the second example of the second embodiment. [Figure 10] FIG. 10 is a diagram illustrating an example of an arrangement of loop coils of a position detection sensor equivalent to the position detection sensor of the position detection device in the second example of the second embodiment. [Figure 11] FIG. 10 is a diagram illustrating an example of the configuration of a position detection device according to a third embodiment of the present invention. [Figure 12] 10A and 10B are diagrams for explaining an operating state in an electromagnetic induction mode of the position detection device according to the third embodiment. [Figure 13] 10A and 10B are diagrams for explaining another example of a position detection sensor of the position detection device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] [First embodiment] 1 is a diagram showing an example of the configuration of a position detection device 1 according to a first embodiment of the present invention. The position detection device 1 of this embodiment can use an electronic pen (stylus) as an example of a first indicator and a human finger as an example of a second indicator, and when a position is indicated by either indicator, the coordinates (X, Y) of the position indicated by each indicator can be detected.

[0014] In the example described below, electronic pen 2, which is a first indicator to be detected in the position detection device of this first embodiment, includes coil 202 wound around magnetic core 201, as shown in Fig. 2, and is configured to transmit a signal from signal generation circuit 203 to position detection device 1 as electromagnetic induction energy through coil 202. Note that electronic pen 2 includes a battery (not shown) for driving signal generation circuit 203.

[0015] 1, the position detection device 1 of this embodiment comprises 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 that is placed on the display screen of a display device such as a liquid crystal display.

[0016] That is, in this example of the position detection sensor 10, the horizontal direction of a transparent substrate 11 such as a rectangular glass substrate is the X-axis direction (an example of a first direction), and the vertical direction perpendicular to the horizontal direction of the transparent substrate 11 is the Y-axis direction (an example of a second direction), and a group of loop electrodes arranged at regular intervals on the transparent substrate 11 are formed using a metal mesh electrode made of ITO (Indium Tin Oxide) or a combination of thin wires such as silver or copper so that the long, thin loop electrodes do not overlap each other.

[0017] The loop electrode group has a two-layer structure, for example, consisting of an X loop electrode group 12 consisting of a plurality of loop electrodes X as an example of a first electrode, and a Y loop electrode group 13 consisting of a plurality of loop electrodes Y as an example of a second electrode. In this example, the X loop electrode group 12 is formed on the front side of the transparent substrate 11 by arranging a plurality of loop electrodes X, the longitudinal direction of which is elongated in the Y-axis direction, at regular intervals in the X-axis direction without overlapping each other. On the other hand, the Y loop electrode group 13 is formed on the back side of the transparent substrate 11 by arranging a plurality of loop electrodes Y, the longitudinal direction of which is elongated in the X-axis direction, at regular intervals in the Y-axis direction without overlapping each other. In this example, the X loop electrode group 12 consists of 40 loop electrodes X (X1 to X40), and the Y loop electrode group 13 consists of 30 loop electrodes Y (Y1 to Y30).

[0018] In the following description, when there is no need to distinguish between the loop electrodes X1 to X40, they will be referred to simply as loop electrode X, and similarly, when there is no need to distinguish between the loop electrodes Y1 to Y30, they will be referred to simply as loop electrode Y.

[0019] The arrangement pitch of the loop electrodes X and loop electrodes Y is preferably, for example, 3 to 6 mm, which corresponds to the size of the contact area when a finger touches the position detection sensor 10. Since a wider loop coil is preferable for efficient reception of signals from the electronic pen 2, the spacing between adjacent loop electrodes X and Y should be as narrow as possible, as shown in FIG. 1. Therefore, in this example, adjacent loop electrodes X and Y are arranged close to each other. Therefore, the loop width in the arrangement direction of each of the loop electrodes X and Y is slightly smaller than the arrangement pitch.

[0020] In this example, the signal processing circuit 20 connected to the position detection sensor 10 includes a selection circuit 21 for selecting one loop electrode X from the X loop electrode group 12, a selection circuit 22 for selecting one loop electrode Y from the Y loop electrode group 13, a mode switching circuit 23 that switches between detecting a first indicator by electromagnetic induction coupling and detecting a second indicator by electrostatic coupling, a pen signal receiving circuit 24 that constitutes an example of a first detection circuit for detecting a position indicated by the first indicator that is electromagnetically coupled, a touch detection control circuit 25 that constitutes an example of a second detection circuit for detecting a position indicated by the second indicator that is electrostatically coupled, and a processing control circuit 26 consisting of a computer.

[0021] The selection circuit 21 is composed of two multiplexers 211 and 212, with the winding start ends (X1a to X40a) of each of the plurality of loop electrodes X (X1 to X40) connected to one multiplexer 211, and the winding end ends (X1b to X40b) connected to the other multiplexer 212. The two multiplexers 211 and 212 are linked and selected and controlled by a selection control signal SEx from the processing control circuit 26, whereby the selection circuit 21 sequentially selects the loop electrodes X one by one from the X loop electrode group 12.

[0022] Then, the winding start end of one loop electrode X selected by the selection control signal SEx from the X loop electrode group 12 is selected by the multiplexer 211 and connected to the common terminal XA of this multiplexer 211, and the winding end end of the same loop electrode X is selected by the multiplexer 212 and connected to the common terminal XB of this multiplexer 212.

[0023] The selection circuit 22 is composed of two multiplexers 221 and 222, with the winding start ends (Y1a to Y30a) of the plurality of loop electrodes Y (Y1 to Y30) each connected to one multiplexer 221, and the winding end ends (Y1b to Y30b) each connected to the other multiplexer 222. The two multiplexers 221 and 222 are linked and selected and controlled by a selection control signal SEy from the processing control circuit 26, so that the selection circuit 22 sequentially selects the loop electrodes Y one by one from the Y loop electrode group 13.

[0024] Then, the winding start end of one loop electrode Y selected by the selection control signal SEy from the Y loop electrode group 13 is selected by the multiplexer 221 and connected to the common terminal YA of this multiplexer 221, and the winding end end of the same loop electrode Y is selected by the multiplexer 222 and connected to the common terminal YB of this multiplexer 222.

[0025] The mode switching circuit 23 includes changeover switch circuits 23XA and 23XB for the loop electrode X, and changeover switch circuits 23YA and 23YB for the loop electrode Y. The common terminal XA of the multiplexer 211 is connected to a movable terminal of the changeover switch circuit 23XA of the mode switching circuit 23, and the common terminal XB of the multiplexer 212 is connected to a movable terminal of the changeover switch circuit 23XB of the mode switching circuit 23. The common terminal YA of the multiplexer 221 is connected to a movable terminal of the changeover switch circuit 23YA of the mode switching circuit 23, and the common terminal YB of the multiplexer 222 is connected to a movable terminal of the changeover switch circuit 23YB of the mode switching circuit 23.

[0026] One fixed terminal P of each of the changeover switch circuits 23XA, 23XB, 23YA, and 23YB of the mode changeover 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.

[0027] One fixed terminal P of the changeover switch circuit 23XA of the mode changeover circuit 23 is connected to one input terminal (inverting input terminal in the illustrated example) of the X-side differential input amplifier 24X of the pen signal receiving circuit 24, and one fixed terminal P of the changeover switch circuit 23XB is connected to the other input terminal (non-inverting input terminal in the illustrated example) of the X-side differential input amplifier 24X. One fixed terminal P of the changeover switch circuit 23YA of the mode changeover circuit 23 is connected to one input terminal (inverting input terminal in the illustrated example) of the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24, and one fixed terminal P of the changeover switch circuit 23YB is connected to the other input terminal (non-inverting input terminal in the illustrated example) of the Y-side differential input amplifier 24Y.

[0028] Although not shown, an X-axis signal receiving circuit and a Y-axis signal receiving circuit are provided downstream of the X-side differential input amplifier 24X and the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24. These X-axis signal receiving circuit and Y-axis signal receiving circuit detect the reception levels of the pen signals (signals received from the electronic pen 2) detected by the loop electrodes X and Y, and supply information on the detected reception levels to the processing control circuit 26. From the information from the pen signal receiving circuit 24, the processing control circuit 26 detects the coordinates (X, Y) of the position indicated on the position detection sensor 10 by the electronic pen 2.

[0029] In this example, the other fixed terminal F of the changeover switch circuit 23XA and the other fixed terminal F of the changeover switch circuit 23XB are connected to each other, and the connection point thereof is connected to an input terminal of a touch signal detection amplifier 251 of the touch detection control circuit 25. The other fixed terminal F of the changeover switch circuit 23YA and the other fixed terminal F of the changeover switch circuit 23YB are connected to each other, and the connection point thereof is connected to an output terminal of a transmission output driver 252 of the touch detection control circuit 25. Therefore, both ends of the loop electrode X and the loop electrode Y are short-circuited, and each operates as a single electrode line.

[0030] An oscillator circuit 253 is connected in the preceding stage of the transmission output driver 252, and a frequency signal of a predetermined frequency f from this oscillator circuit 253 is transmitted to the position detection sensor 10 through the transmission output driver 252. In addition, in the subsequent stage of the touch signal detection amplifier 251 of the touch detection control circuit 25, a touch detection circuit (not shown) is provided which detects the level of a signal transmitted to the position detection sensor 10 through the transmission output driver 252 and received through the position detection sensor 10, and supplies information on the detected signal level to the processing control circuit 26.

[0031] The processing control circuit 26 detects the coordinates (X, Y) of the position pointed to by the finger on the position detection sensor 10 by using the fact that the level of the signal from the touch detection control circuit 25 changes at the position pointed to by the finger.

[0032] The processing control circuit 26 detects the coordinates of the position indicated by each of the above-mentioned pointers based on the information received from the pen signal receiving circuit 24 and the touch detection control circuit 25, and supplies timing control signals to the pen signal receiving circuit 24 and the touch detection control circuit 25.

[0033] The processing control circuit 26 also supplies a selection control signal SEx to the multiplexers 211 and 212 of the selection circuit 21 to control them to sequentially select one loop electrode X from the X loop electrode group 12, and supplies a selection control signal SEy to the multiplexers 221 and 222 of the selection circuit 22 to control them to sequentially select one loop electrode Y from the Y loop electrode group 13.

[0034] Furthermore, the processing control circuit 26 supplies the mode switching circuit 23 with a mode switching signal MD for switching between a state in which the movable terminals of the switching switch circuits 23XA, 23XB, 23YA, and 23YB are connected to the fixed terminal P (electromagnetic induction mode) and a state in which the movable terminals of the switching switch circuits 23XA, 23XB, 23YA, and 23YB are connected to the fixed terminal F (electrostatic coupling mode).

[0035] 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 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.

[0036] [Operation of the position detection device 1 of the first embodiment] In this embodiment, the processing control circuit 26 connects the movable terminals of the changeover switch circuits 23XA, 23XB, 23YA, and 23YB of the mode switching circuit 23 to the fixed terminal P in response to the mode switching signal MD for a predetermined long period of time, and also drives the pen signal receiving circuit 24 to switch to the electromagnetic induction mode. During this electromagnetic induction mode period, the processing control circuit 26 controls the multiplexers 211 and 212 of the selection circuit 21 to select all of the loop electrodes X from the X loop electrode group 12 one by one in sequence, and also controls the multiplexers 221 and 222 of the selection circuit 22 to select all of the loop electrodes Y from the Y loop electrode group 13 one by one in sequence.

[0037] 2, in the position detection device 1 in this electromagnetic induction mode, both ends of one loop electrode X selected by the selection circuit 21 are connected to the inverting input terminal and non-inverting input terminal of the X-side differential input amplifier 24X of the pen signal receiving circuit 24. Similarly, both ends of the loop electrode Y selected by the selection circuit 22 are connected to the inverting input terminal and non-inverting input terminal of the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24.

[0038] At this time, when a position is indicated on the position detection sensor 10 by the electronic pen 2, an induced current is induced in the loop electrode X and the loop electrode Y in response to a signal from the electronic pen 2. The induced current is amplified by the X-side differential input amplifier 24X and the Y-side differential input amplifier 24Y, and is supplied to the downstream X-axis signal receiving circuit and Y-axis signal receiving circuit, where its level is detected.

[0039] The processing control circuit 26 detects the coordinates (X, Y) of the position indicated by the electronic pen 2 on the position detection sensor as described above, based on the switching timing of the selection control signals SEx and 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.

[0040] Then, when the period of the electromagnetic induction mode ends, in this embodiment, the processing control circuit 26 connects the movable terminals of the changeover switch circuits 23XA, 23XB, 23YA, and 23YB of the mode switching circuit 23 to the fixed terminal F using the mode switching signal MD, and drives the touch detection control circuit 25 to switch to the electrostatic coupling mode. Then, even during this period of the electrostatic coupling mode, the processing control circuit 26 switches the selection circuit 21 and the selection circuit 22 using the selection control signal SEx and the selection control signal SEy, and controls them to select the loop electrodes X from the X loop electrode group 12 one by one in sequence, and controls them to select the loop electrodes Y from the Y loop electrode group 13 one by one in sequence.

[0041] 3, in the position detection device 1 in the electrostatic coupling mode, a signal of a predetermined frequency is sequentially supplied from an oscillator circuit 253 via a transmission output driver 252 of the touch detection control circuit 25 to the loop electrodes Y selected by the selection circuit 22 and having a common terminal XA connected to its winding start end and a common terminal YA connected to its winding end, which act as a single electrode line. Also, the loop electrode X selected by the selection circuit 21 and having a common terminal YA connected to its winding start end and a common terminal YB connected to its winding end, which act as a single electrode line, is connected to the input terminal of a touch signal detection amplifier 251 of the touch detection control circuit 25.

[0042] At this time, the signal transmitted to the shorted loop electrode Y through the transmission output driver 252 is received by the shorted loop electrode X, and the reception level is supplied to the touch signal detection amplifier 251. However, when the position detection sensor 10 is touched by a finger 3, part of the signal transmitted to the loop electrode Y flows through the finger 3 and the human body, and therefore the signal transmitted from the loop electrode Y at the finger touch position to the loop electrode X decreases. The processing control circuit 26 detects a change in the reception signal level from the touch detection control circuit 25, thereby detecting the coordinates of the finger touch position.

[0043] Then, when the electrostatic coupling mode period ends, in this embodiment, the processing control circuit 26 switches to the electromagnetic induction mode in accordance with the mode switching signal MD as described above. Thereafter, the electromagnetic induction mode and the electrostatic coupling mode are repeated in a time-division manner in the same manner.

[0044] As described above, the position detection device 1 of the first embodiment described above can detect the coordinates of the position indicated by the electronic pen 2 by the electromagnetic induction method using the position detection sensor 10 in which the X loop electrode group 12 and the Y loop electrode group 13 are formed, and can also detect the coordinates of the position indicated by the finger 3 by the electrostatic coupling method.

[0045] In the position detection device 1 of the first embodiment, the position detection sensor 10 is formed with the X loop electrode group 12 and the Y loop electrode group 13 instead of linear electrodes, so there is no need to connect linear electrodes at their ends to form loop electrodes. Therefore, the position detection device 1 can have a simple configuration using selection circuits 21 and 22 that select the loop electrodes X from the X loop electrode group 12 and the loop electrode Y from the Y loop electrode group 13, and a mode switching circuit 23.

[0046] [Second embodiment] In the position detection device 1 of the first embodiment described above, the selection circuits 21 and 22 sequentially select one each of the loop electrodes X and loop electrodes Y in both the electromagnetic induction mode and the electrostatic coupling mode. However, in the electromagnetic induction mode, multiple adjacent electrodes from the X loop electrode group 12 and the Y loop electrode group 13 are simultaneously selected to equivalently configure a wide loop coil, enabling more efficient detection of signals from the electronic pen 2. The second embodiment described below is configured in this manner. Note that, in the following description, the operation in the electrostatic coupling mode is the same as in the first embodiment, so the operation in the electromagnetic induction mode will be mainly described.

[0047] <First Example of Second Embodiment> 4 to 7 are diagrams for explaining an example of the configuration of a position detecting device 1A of the second embodiment, which is configured to simultaneously select two adjacent loop electrodes X and two adjacent loop electrodes Y. FIG.

[0048] Fig. 4 is a diagram showing an example of the configuration of a position detection device 1A of the second embodiment. In this position detection device 1A of the second embodiment, as shown in Fig. 4, selection circuits 21A and 22A are provided instead of the selection circuits 21 and 22 in the position detection device 1 of the first embodiment, and a processing control circuit 26A is provided instead of the processing control circuit 26. The rest of the configuration is the same as that of the position detection device 1 of the first embodiment. In Fig. 4, the same parts as those in the position detection device 1 of the first embodiment described above are given the same reference numerals, and their description will be omitted.

[0049] In the second embodiment, the selection circuit 21A is made up of a select switch 211A and a select switch 212A. As shown in Fig. 4, the select switches 211A and 212A include switches equal in number to the number of loop electrodes X (X1 to X40), with winding start ends X1a to X40a of each loop electrode X (X1 to X40) connected to one end of the select switch 211A, and winding end ends X1b to X40b of each loop electrode X (X1 to X40) connected to one end of the select switch 212A.

[0050] The other ends of the multiple switches of select switch 211A are connected together and connected to a common terminal XA' of select switch 211A. Similarly, the other ends of the multiple switches of select switch 212A are connected together and connected to a common terminal XB' of select switch 212A. The common terminal XA' of select switch 211A is connected to a movable terminal of changeover switch circuit 23XA of mode switching circuit 23, and the common terminal XB' of select switch 212A is connected to a movable terminal of changeover switch circuit 23XB of mode switching circuit 23.

[0051] In the first example of the second embodiment, in the electromagnetic induction mode, the select switch 211A and the select switch 212A are controlled by a selection control signal SEMx from the processing control circuit 26A to select two adjacent loop electrodes X from the X loop electrode group 12, while sequentially shifting the two selected loop electrodes X one by one.

[0052] Fig. 5 is a diagram for explaining the selection control of the multiple switches of the select switches 211A and 212A in the electromagnetic induction mode in the position detection device 1A of the first example of the second embodiment. Fig. 5 shows the on / off switching states of the switches in the select switches 211A and 212A to which each of the loop electrodes X1 to X40 of the X loop electrode group 12 is connected, in order of the passage of time, with "1" meaning switch on and "0" meaning switch off. In the electromagnetic induction mode, the selection control shown in Fig. 5 is repeatedly performed by the selection control signals SEMx and SEMy.

[0053] That is, the select switch 211A and the select switch 212A of the selection circuit 21A sequentially select the same two adjacent loop electrodes X. First, the two switches connected to the loop electrodes X1 and X2 are turned on to connect these loop electrodes X1 and X2 to the common terminals XA' and XB'. Next, the two switches connected to the loop electrodes X2 and X3 are turned on to connect these loop electrodes X2 and X3 to the common terminals XA' and XB'. Furthermore, the selected loop electrodes X are shifted one by one, such as loop electrodes X3 and X4, X4 and X5, and X5 and X6, and two loop electrodes X are connected to the common terminals XA' and XB'.

[0054] The common terminals XA' and XB' are connected to the X-side differential input amplifier 24X of the pen signal receiving circuit 24 through the fixed terminal P side of the mode switching circuit 23, so that the pen signal receiving circuit 24 detects the reception level of the pen signal for each of the selected two loop electrodes X.

[0055] When two adjacent loop electrodes X are selected simultaneously in this way, the two coils are connected in parallel and supplied to the X-side differential input amplifier 24X, as shown in Fig. 6. In this case, if the currents induced in the two adjacent loop electrodes Xn and Xn+1 (where n = 1, 2, . . . , 39) by electromagnetic inductive coupling with the electronic pen 2 are i1 and i2, respectively, the X-side differential input amplifier 24X will obtain an output α(i1 + i2) corresponding to the sum of the currents induced in these two loop electrodes Xn and Xn+1.

[0056] As described above, detecting a signal from the electronic pen 2 by using the select switch 211A and the select switch 212A to sequentially select two adjacent loop electrodes X in the order shown in Fig. 5 is equivalent to a well-known detection method in the electromagnetic induction system in which loop coils 14 arranged so as to overlap each other are sequentially selected, as shown in Fig. 7. In this example, by simultaneously selecting two adjacent loop electrodes, it is possible to form a loop coil having a width twice the arrangement pitch of the loop electrodes.

[0057] The selection circuit 21A for the X loop electrode group 12 for determining the X coordinate has been described above, but the selection circuit 22A for the Y loop electrode group 13 for determining the Y coordinate can also be configured in the same way.

[0058] That is, in this second embodiment, the selection circuit 22A is composed of a select switch 221A and a select switch 222A that have switches equal to the number of loop electrodes Y (Y1 to Y30), and as shown in Figure 4, each of the winding start ends Y1a to Y30a of each loop electrode Y (Y1 to Y30) is connected to one end of each switch of the select switch 221A, and each of the winding end ends Y1b to Y30b is connected to one end of each switch of the select switch 222A.

[0059] The other ends of the multiple switches of the select switch 221A are connected together and connected to a common terminal YA' of the select switch 221A, and the other ends of the multiple switches of the select switch 222A are connected together and connected to a common terminal YB' of the select switch 222A. The common terminal YA' of the select switch 221A is connected to a movable terminal of the changeover switch circuit 23YA of the mode changeover circuit 23, and the common terminal YB' of the select switch 222A is connected to a movable terminal of the changeover switch circuit 23YB of the mode changeover circuit 23.

[0060] In the first example of the second embodiment, in the electromagnetic induction mode, the select switch 221A and the select switch 222A are controlled by the selection control signal SEMy from the processing control circuit 26A to select two loop electrodes Y by sequentially shifting them one by one, in the same manner as the selection control of two adjacent loop electrodes X from the X loop electrode group 12 described above.

[0061] 6, the Y-side differential input amplifier 24Y of the pen signal receiving circuit 24 outputs an output α(i1+i2) corresponding to the sum of the currents induced in the two loop electrodes Ym and Xm+1 (m=1, 2, . . . , 29). The Y loop electrode group 13 is also equivalent to a well-known detection method in the electromagnetic induction system, in which overlapping loop coils are selected in order.

[0062] As described above, in the electrostatic coupling mode, also in the second embodiment, the select switches 211A and 212A, and the select switches 221A and 222A are controlled to select one each of the loop electrodes X and Y. For this reason, in the electrostatic coupling mode, the processing control circuit 26A supplies SECx and SECy to the select switches 211A and 212A, and the select switches 221A and 222A, respectively, which turn on one each of a plurality of switches.

[0063] <Second Example of Second Embodiment> In the first example described above, in the electromagnetic induction mode, a plurality of adjacent loop electrodes X and loop electrodes Y (two in this example) are selected simultaneously, but it is also possible to simultaneously select two or more adjacent loop electrodes X and loop electrodes Y. The second example is an example of such a case, and the case of three electrodes will be described below.

[0064] That is, in the case of this second example as well, the configuration of the position detection device uses the same configuration as the position detection device 1A shown in Fig. 4. In the position detection device of this second example, the selection control signals SEMx and SEMy supplied from the processing control circuit 26A to the two select switches 211A and 212A of the selection circuit 21A and the two select switches 221A and 222A of the selection circuit 22A in the electromagnetic induction mode are different from those in the first example.

[0065] FIG. 8 is a diagram for explaining selection control of a plurality of switches, namely, select switches 211A and 212A, in the electromagnetic induction mode in a position detection device 1A of the second example of the second embodiment.

[0066] In this example, the select switch 211A and the select switch 212A of the selection circuit 21A sequentially select the same three adjacent loop electrodes X. First, the three switches connected to loop electrodes X1, X2, and X3 are turned on to connect these loop electrodes X1, X2, and X3 to common terminals XA' and XB'. Next, the three switches connected to loop electrodes X2, X3, and X4 are turned on to connect these loop electrodes X2, X3, and X4 to common terminals XA' and XB'. Furthermore, the selected loop electrodes X are shifted one by one, such as loop electrodes X3, X4, and X5, X4, X5, and X6, and X5, X6, and X7, and the three loop electrodes X are connected to the common terminals XA' and XB'.

[0067] When three adjacent loop electrodes X are selected simultaneously in this way, the three loop electrodes X (coils) are connected in parallel and supplied to the X-side differential input amplifier 24X, as shown in Fig. 9. In this case, if the currents induced in the three adjacent loop electrodes Xn, Xn+1, and Xn+2 (where n = 1, 2, . . . , 38) by electromagnetic inductive coupling with the electronic pen 2 are i1, i2, and i3, respectively, the X-side differential input amplifier 24X will obtain an output α (i1 + i2 + i3) corresponding to the sum of the currents induced in these three loop electrodes Xn, Xn+1, and Xn+2.

[0068] In this way, detecting a signal from the electronic pen 2 by using the select switch 211A and the select switch 212A to sequentially select three adjacent loop electrodes X in the order shown in Fig. 8 is equivalent to a well-known detection method in the electromagnetic induction system in which loop coils 15 arranged so as to overlap each other are sequentially selected, as shown in Fig. 10. In this example, by simultaneously selecting three adjacent loop electrodes, it is possible to form a loop coil with a width three times the arrangement pitch of the loop electrodes X.

[0069] The selection circuit 22A for the Y loop electrode group 13 for determining the Y coordinate can be configured in a similar manner, with three coils connected in parallel and supplied to the Y-side differential input amplifier 24Y.

[0070] [Third embodiment] In the position detection device 1A of the second embodiment described above, in the electromagnetic induction mode, the selection circuits 21A and 22A are configured to select a plurality of loop electrodes X and a plurality of loop electrodes Y by connecting them in parallel, as shown in Fig. 6 and Fig. 9, but the selection circuits can also be configured so that when adjacent plurality of loop electrodes X and a plurality of loop electrodes Y are selected, the loop electrodes (coils) are connected in series. The third embodiment is an example of such a case.

[0071] 11 is a diagram for explaining a configuration example of a position detection device 1B according to the third embodiment. The following explanation will focus on the operation of the position detection device 1B according to the third embodiment in the electromagnetic induction mode.

[0072] In the position detection device 1B of the third embodiment, as shown in Fig. 11, the selection circuits 21 and 22 in the position detection device 1 of the first embodiment are replaced by selection circuits 21B and 22B, and the processing control circuit 26 is replaced by a processing control circuit 26B. The rest of the configuration is the same as that of the position detection device 1 of the first embodiment. In Fig. 11, the same parts as those in the position detection device 1 of the first embodiment described above are given the same reference numerals, and their description will be omitted. Note that the pen signal receiving circuit 24 and touch detection control circuit 25 are not shown in Fig. 11.

[0073] In this third embodiment, the selection circuit 21B is composed of multiplexers 211B and 212B having the same configuration as the multiplexers 211 and 212 in the first embodiment, and a plurality of three-terminal switches SX1 to SX39, in this example, 39, which is one less than the number of loop electrodes X (X1 to X40). The three-terminal switch has three terminals, a first terminal, a second terminal, and a third terminal, and can be set to connect any two of the three terminals using a setting control signal.

[0074] The winding end ends X1b to X39b of the loop electrodes X (X1 to X39) are connected to first terminals of the three-terminal switches SX1 to SX39, respectively, and the winding start ends X2a to X40a of the loop electrodes X (X2 to X40) are connected to second terminals of the three-terminal switches SX1 to SX39, respectively. The third terminals of the three-terminal switches SX1 to SX39 are connected to multiplexers 211B and 212B. However, the winding start end X1a of the loop electrode X1 is directly connected to the multiplexer 212B, and the winding end end X40b of the loop electrode X40 is directly connected to the multiplexer 211B.

[0075] In this embodiment, in addition to the mode switching signal MD, the processing control circuit 26B sends a setting control signal CTx to each of the three-terminal switches SX1 to SX39 to control their settings, and also sends a selection control signal SExA to the multiplexer 211B and a selection control signal SExB to the multiplexer 212B.

[0076] For example, when two adjacent loop electrodes X are connected in series, first, the three-terminal switch SX1, the winding end X1b of the loop electrode X1 being connected to its first terminal, is set and controlled so that its first and second terminals are connected, and the three-terminal switch SX2, the winding end X2b of the adjacent loop electrode X2 being connected to its first terminal, is set and controlled so that its first and third terminals are connected. Then, the multiplexer 211B selects the three-terminal switch SX2, and the multiplexer 212B selects the winding start end X1a of the loop electrode X1.

[0077] Next, three-terminal switch SX1 is set and controlled so that its first terminal and third terminal are connected, and the adjacent three-terminal switch SX2 is set and controlled so that its first terminal and second terminal are connected, and the further adjacent three-terminal switch SX3 is set and controlled so that its first terminal and third terminal are connected. Then, multiplexer 211B selects three-terminal switch SX3 whose first terminal and third terminal are connected, and multiplexer 212B is similarly controlled to select three-terminal switch SX1 whose first terminal and third terminal are connected.

[0078] Subsequently, sets of three adjacent three-terminal switches SXn to SXn+2 are sequentially shifted by one three-terminal switch and are set and controlled. Of the three adjacent three-terminal switches SXn to SXn+2, the three-terminal switches SXn and SXn+2 on both ends are set and controlled so that their first terminals are connected to their third terminals, and the central three-terminal switch SXn+1 is set and controlled so that its first terminal is connected to its second terminal. Then, multiplexers 211B and 212B are controlled to select the three-terminal switches SXn+2 and SXn on both ends.

[0079] When the selection circuit 21B is selected and controlled in this manner, as shown in FIG. 12, the two loop electrodes X (coils) are connected in series and supplied to the X-side differential input amplifier 24X, and an output corresponding to the sum of the currents induced in the two loop electrodes X is obtained from the X-side differential input amplifier 24X.

[0080] Note that the present invention is not limited to connecting two loop electrodes in series, but three adjacent loop electrodes X can be connected in series and the sets of three loop electrodes X can be controlled to be shifted by one. In the case of three or more loop electrodes, the winding start ends of the loop electrodes X at both ends are connected to the multiplexers 211B and 212B, and the loop electrodes X sandwiched between the two ends are adjacent, but the winding end and winding start ends of the loop electrodes X are connected by controlling the three-terminal switches to which the plurality of loop electrodes X are connected.

[0081] The above has been a description of the X loop electrode group 12, but the selection circuit 22B for the Y loop electrode group 13 is similarly configured and can similarly control each of the loop electrodes Y to be connected in series. That is, the selection circuit 22B is made up of multiplexers 221B and 222B having the same configuration as the multiplexers 221 and 222 of the first embodiment, and a plurality of three-terminal switches SY1 to SY29, which in this example is 29, the number of which is one less than the number of loop electrodes Y (Y1 to Y30).

[0082] These multiplexers 221B and 222B and three-terminal switches SY1 to SY29 of the selection circuit 22B are controlled by selection control signals SEyA and SEyB and setting control signal CTy from the processing control circuit 26B, so that multiple adjacent loop electrodes Y can be connected in series and selected in sequence, similar to the case of the X loop electrode group 12.

[0083] In the electrostatic coupling mode of the third embodiment, similarly to the second embodiment, one each of the loop electrodes X and Y is selected by the selection circuit 21B and the selection circuit 22B.

[0084] [Other embodiments] In the above-described embodiment, the position detection sensor 10 has the loop electrodes X and Y formed from a conductive material that can be made substantially transparent, such as a metal mesh electrode made by combining thin wires of ITO, silver, copper, or the like with the transparent substrate 11. Therefore, the electrode lines that make up the position detection sensor 10 are formed as a pattern with a predetermined width, for example, about 1 millimeter. When a position detection sensor using such electrode lines is used for touch detection operation, the inside portions of the loop electrodes X and Y become electrically hollow, and therefore the capacitance with the human body, such as a finger, decreases at the center of the loop electrodes X and Y, making it difficult to accurately determine the position pointed by the finger.

[0085] To solve this problem, it is sufficient to form protrusions that protrude from the electrode line patterns that make up the loop electrodes X and Y to the inside of the width of the loop electrodes X and Y. Figures 13(A) and (B) show examples of protrusions that protrude from the electrode line patterns that make up the loop electrodes X and Y to the inside of the width of the loop electrodes X and Y.

[0086] As shown in Figures 13(A) and (B), in the position detection sensor, the loop electrodes X and Y are arranged so as to intersect at right angles, so that a rectangular cavity region 16 is formed by the width of the loop electrodes X and Y.

[0087] 13(A), two opposing protrusions 17a, 17b are formed from the electrode line pattern of loop electrode X at positions toward the center of rectangular hollow region 16, protruding in a direction perpendicular to and intersecting with the electrode line pattern. Also, two opposing protrusions 18a, 18b are formed from the electrode line pattern of loop electrode Y at the center of rectangular hollow region 16, protruding in a direction perpendicular to and intersecting with the electrode line pattern.

[0088] 13(B), protrusions 17c and 17d are formed so as to protrude in a direction perpendicular to and intersecting with the electrode line pattern of loop electrode X, but in this example, these protrusions 17c and 17d are formed so as not to face each other and toward positions shifted from the center of rectangular hollow region 16. Similarly, protrusions 18c and 18d are formed so as to protrude in a direction perpendicular to and intersecting with the electrode line pattern of loop electrode Y, but in this example, these protrusions 18c and 18d are formed so as not to face each other and toward positions shifted from the center of rectangular hollow region 16.

[0089] According to the position detection sensor having the electrode pattern configured as shown in Figures 13(A) and (B) above, even when a finger touches rectangular hollow area 16, protrusions 17a, 17b and protrusions 18a, 18b or protrusions 17c, 17d and protrusions 18c, 18d are present within hollow area 16, so the finger essentially comes into contact with loop electrode X and loop electrode Y, making it easier to detect the finger touch.

[0090] Even if protrusions 17a, 17b and protrusions 18a, 18b or protrusions 17c, 17d and protrusions 18c, 18d are provided inside loop electrodes X, Y in this way, the magnetic field emitted from the electronic pen is emitted over an area that is sufficiently wide compared to the line width of the protrusions, so that when receiving a pen signal, protrusions 17a, 17b and protrusions 18a, 18b or protrusions 17c, 17d and protrusions 18c, 18d have almost no effect on receiving the magnetic field signal from the electronic pen.

[0091] [Other embodiments or modifications] In the above-described embodiment, in the electrostatic coupling mode, the loop electrode X and the loop electrode Y are each short-circuited by connecting the winding start end and the winding end, but one of the winding start end and the winding end may be open (released end), and the other may be an end for connection to the touch detection control circuit 25.

[0092] Furthermore, in the above-described embodiment, the position detection sensor 10 is configured as a transparent sensor in which the loop electrodes X and Y are formed from metal mesh electrodes in which thin wires of ITO, silver, copper, or the like are combined with the transparent substrate 11. However, for applications other than those in which the sensor is placed on the display screen of a display device, the sensor may of course be configured as an opaque sensor.

[0093] In the above 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 one end of each of the loop electrodes X and Y may be connected to a fixed potential, and the other end may be supplied to a single-input amplifier.

[0094] In the above-described embodiment, the position detection devices 1, 1A, and 1B are configured to switch between the electromagnetic induction mode and the electrostatic coupling mode in a time-division manner in response to the mode switching signal MD from the processing control circuits 26, 26A, and 26B. However, the user may manually switch between the electromagnetic induction mode and the electrostatic coupling mode. In this case, the position detection device is provided with a switch or push button switch that can be operated by the user, and the processing control circuit, for example, switches between the electromagnetic induction mode and the electrostatic coupling mode depending on the switching state of the switch or push button switch.

[0095] In addition, when the position detection device is in a state where it receives a signal from the electronic pen through the position detection sensor, the position detection device may be switched to electromagnetic induction mode, and when it is not in a state where it receives a signal from the electronic pen through the position detection sensor, it may be switched to electrostatic coupling mode.

[0096] In addition, both the electronic pen and the position detection device may be provided with a short-range wireless communication circuit, for example, conforming to the Bluetooth (registered trademark) standard, and the short-range wireless communication circuit of the position detection device may switch the position detection device to electromagnetic induction mode when it receives a signal from the electronic pen, and switch to electrostatic coupling mode when it does not receive a signal from the electronic pen.

[0097] In the above-described embodiment, the second indicator to be detected in the electrostatic coupling mode is a human finger, but it may be a passive electrostatic electronic pen. It may also be an active electrostatic electronic pen. In the case of an active electrostatic electronic pen, instead of the touch detection control circuit 25, a circuit is provided that receives signals from the active electrostatic electronic pen for each of the loop electrode X and the loop electrode Y and detects the levels of the signals.

[0098] In the above-described embodiment, in the electromagnetic induction mode, the position pointed by the electronic pen 2 is detected by receiving a signal from the electronic pen 2 that includes an oscillator circuit. However, this is not limited to this. An electronic pen that includes a resonant circuit consisting of a coil and a capacitor can be used, and in the electromagnetic induction mode, an AC signal can be transmitted from the position detection device to the electronic pen by electromagnetic induction coupling, and the position pointed by the electronic pen can be detected by receiving the signal that is fed back via the resonant circuit of the electronic pen. In this case, the means for transmitting the AC signal to the electronic pen may be the X loop electrode group 12 and the Y loop electrode group 13, or a separate loop coil may be provided for transmission. [Explanation of symbols]

[0099] 1, 1A, 1B...position detection device, 2...electronic pen, 3...finger, 10...position detection sensor, 11...transparent substrate, 12...X loop electrode group, 13...Y loop electrode group, 17a, 17b, 17c, 17d...projection portion, 18a, 18b, 18c, 18d...projection portion, 21, 21A, 21B...X loop electrode selection circuit, 22, 22A, 22B...Y loop electrode selection circuit, 23...mode switching circuit, 24...pen signal receiving circuit, 25...touch detection control circuit

Claims

1. a sensor having a plurality of first electrodes arranged in a first direction; each of the first electrodes is formed as a loop electrode; The loop electrode has a protrusion that protrudes toward the inside of the loop electrode. A position detection device characterized by:

2. a signal processing circuit coupled to the sensor for detecting a position indicated by each of a plurality of indicators on the sensor; a selection circuit that selects the plurality of first electrodes; Equipped with the selection circuit selects the plurality of first electrodes so that an induced current is induced in each of the plurality of first electrodes, thereby allowing a position pointed by a first indicator on the sensor to be detected by electromagnetic inductive coupling between the sensor and the first indicator; The first electrode is selected by a selection circuit so as not to induce a detection current in the first electrode, and a position indicated by a second indicator on the sensor is detected by utilizing electrostatic coupling between the second indicator and the sensor.

2. The position detection device according to claim 1.

3. a detection circuit, which simultaneously selects a plurality of first electrodes adjacent to each other from a plurality of first electrodes for detecting a position pointed by the pointer in a state where the detection circuit is electromagnetically inductively coupled with the pointer; 3. The position detection device according to claim 2.

4. the detection circuit has a first common terminal and a second common terminal connected to some of the plurality of first electrodes; In a state where the indicator and the sensor are electromagnetically inductively coupled, first terminals of the plurality of first electrodes adjacent to each other are connected to the first common terminal, and second terminals of the plurality of first electrodes adjacent to each other are connected to the second common terminal.

4. The position detection device according to claim 3.

5. a first amplifier circuit that adds and amplifies induced currents that flow through the plurality of first electrodes adjacent to each other due to electromagnetic inductive coupling with the indicator; 5. The position detection device according to claim 4.

6. the detection circuit has a first common terminal and a second common terminal connected to some of the plurality of first electrodes; When the indicator and the sensor are electromagnetically inductively coupled, a first terminal of one of a plurality of first electrodes adjacent to each other is connected to the first common terminal, a second terminal of the one of the first electrodes is connected to the first terminal of the other one of the first electrodes, and a second terminal of the other one of the first electrodes is connected to the second common terminal.

4. The position detection device according to claim 3.

7. In a state in which the pointer and the sensor are electromagnetically inductively coupled, a Kth first electrode and a (K+1)th first electrode that are adjacent to each other are simultaneously selected from the plurality of first electrodes at a first timing to detect a position pointed by the pointer, and a (K+1)th first electrode and a (K+2)th first electrode that are adjacent to each other are simultaneously selected from the plurality of first electrodes at a second timing to detect a position pointed by the pointer.

7. The position detection device according to claim 6.

8. A first common terminal and a second common terminal of the detection circuit are connected to the first terminals and the second terminals of the plurality of first electrodes, respectively, in a state in which the indicator and the sensor are electromagnetically inductively coupled.

4. The position detection device according to claim 3.

9. When the first electrode is selected, both ends of the loop electrode are short-circuited, and the position indicated by the second indicator on the sensor is detected by utilizing electrostatic coupling between the second indicator and the sensor.

2. The position detection device according to claim 1.

10. When the first electrode is selected, one end of the loop electrode is left open, and the position on the sensor pointed to by the second indicator is detected by utilizing the electrostatic coupling between the second indicator and the sensor.

2. The position detection device according to claim 1.

11. The protrusions increase the electrostatic coupling between the indicator and the protrusions.

2. The position detection device according to claim 1.

12. a sensor in which the plurality of first electrodes are arranged in a first direction and the plurality of second electrodes are arranged in a second direction intersecting the first direction; and a signal processing circuit connected to the sensor for detecting individual positions indicated by a plurality of indicators on the sensor; the first electrode and the second electrode are each formed as a loop electrode; the signal processing circuit includes a selection circuit that selects the plurality of first electrodes and the plurality of second electrodes; selecting the first electrode and the second electrode by the selection circuit so that an induced current is induced in each of the first electrode and the second electrode, thereby detecting a position on the sensor indicated by the first indicator using electromagnetic inductive coupling between the first indicator and the sensor; The selection circuit selects the first electrode and the second electrode so 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 electrostatic coupling between the second indicator and the sensor.

2. The position detection device according to claim 1.

13. The protrusions of the first electrode and the second electrode are configured to face each other, and the first electrode and the second electrode are perpendicular to each other.

13. The position detection device according to claim 12.

14. The protrusions of the first electrode and the protrusions of the second electrode are configured to face each other at a distance, and the first electrode is perpendicular to the second electrode.

13. The position detection device according to claim 12.

15. a plurality of first loop electrodes configured by the plurality of first electrodes arranged so as not to overlap one another in the first direction, and a plurality of second loop electrodes configured by the plurality of first electrodes arranged so as not to overlap one another in a second direction intersecting the first direction; 2. The position detection device according to claim 1, further comprising:

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