Position indicator

Abstract

To provide a position indicator with excellent operability.SOLUTION: A position indicator 1 that is used with respect to a position detection sensor 9 for detecting a position based on a change in capacitance, comprises: a cylindrical first shield electrode 8; a first electrode 31 provided within the first shield electrode 8 and having a tip portion protruding from the first shield electrode 8; and a second electrode 32 provided with a contact portion 322 located on the tip side of the first electrode 31 and in contact with the position detection sensor 9. The position indicator receives an AC signal V1 of the position detection sensor 9 via the second electrode 32 and transmits an output signal V2 to the position detection sensor 9 via the first electrode 31.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This invention relates to a position indicator. [Background technology]

[0002] For example, Patent Document 1 describes a position indicator used with a position detection sensor that performs position detection by detecting changes in capacitance. This position indicator includes a first electrode for receiving an AC signal from the position detection sensor, a signal augmentation processing circuit for performing predetermined signal augmentation processing on the AC signal received via the first electrode, and a second electrode to which the signal output from the signal augmentation processing circuit is supplied. The position indicator then indicates the position by forming a signal augmented signal having a predetermined correlation with the AC signal from the position detection sensor received via the first electrode, and simultaneously sending the signal augmented signal from the second electrode to the position detection sensor. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2012-128556 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, in a position indicator with this configuration, the AC signal from the position detection sensor is received by the first electrode, and the signal, which has been augmented by a signal augmentation processing circuit, is sent to the position detection sensor from the second electrode. Therefore, the first and second electrodes must be spaced apart from each other to avoid electrical conductivity. Consequently, in a configuration where signal reception and transmission are performed by different electrodes, there is a discrepancy between the position where the AC signal is received from the position detection sensor and the position where the signal augmentation processing circuit sends the augmented signal to the position detection sensor. This results in a discrepancy between the position indicated by the position indicator and the position detected by the position detection sensor. Therefore, the position indicator in Patent Document 1 cannot achieve excellent operability.

[0005] The present invention has been made in view of the above, and aims to provide a position indicator with excellent operability by reducing the discrepancy between the position from which a signal is received from the position detection sensor and the position from which a signal is sent to the position detection sensor. [Means for solving the problem]

[0006] These objectives are achieved by the present invention described in (1) below.

[0007] (1) A position indicator used for a position detection sensor in which position detection is performed based on a change in capacitance, A cylindrical first shield electrode, The first shield electrode is provided, and the tip portion is The aforementioned A first electrode protruding from the first shield electrode, before It has a second electrode with a contact portion that contacts the position detection sensor, The contact portion of the second electrode is located closer to the tip than the first electrode. The first electrode has a notch facing the tip surface of the first electrode, A position indicator characterized by receiving an AC signal from the position detection sensor via the second electrode and sending an output signal to the position detection sensor via the first electrode. [Effects of the Invention]

[0008] In the position indicator of the present invention, since the portion of the first electrode other than the tip portion is covered by the first shield electrode, capacitive coupling between the relevant portion and the position detection sensor can be effectively suppressed. Therefore, it is possible to receive an AC signal from the position detection sensor via the tip portion of the first electrode, or to transmit an output signal to the position detection sensor. As a result, the first electrode is substantially close to the second electrode, and the amount of deviation between the reception position at which the AC signal is received from the position detection sensor and the transmission position at which the output signal is transmitted from the position indicator to the position detection sensor can be kept small. Accordingly, the position indicator can exhibit excellent operability. Brief Description of the Drawings

[0009] [Figure 1] It is an overall configuration diagram showing the position indicator and the position detection sensor according to the first embodiment. [Figure 2] It is a block diagram showing the configuration of the position detection sensor. [Figure 3] It is a cross-sectional view showing the configuration of the position detection sensor. [Figure 4] It is a cross-sectional view of the position indicator. [Figure 5] It is a plan view of the position indicator viewed from the upper side. [Figure 6] It is a cross-sectional view showing the electrode structure of the position indicator. [Figure 7] It is a diagram showing a state where the position indicator is brought into contact with the position detection sensor. [Figure 8] It is a diagram showing a state where the position indicator is brought into contact with the position detection sensor. [Figure 9] It is a circuit diagram showing the circuit configuration of the position indicator. [Figure 10] It is a cross-sectional view showing the electrode structure of the position indicator according to the second embodiment. [Figure 11] It is a plan view of the electrode structure of Fig. 10 viewed from the side. [Figure 12] It is a plan view of the electrode structure of Fig. 10 viewed from the tip side. [Figure 13] It is a diagram showing a state where the position indicator is brought into contact with the position detection sensor. [Figure 14] This is a plan view of the electrode structure of the position indicator according to the third embodiment, as seen from the tip side. [Figure 15] This diagram shows the position indicator in contact with the position detection sensor. [Figure 16] This diagram shows the position indicator in contact with the position detection sensor. [Figure 17] This diagram shows the position indicator in contact with the position detection sensor. [Modes for carrying out the invention]

[0010] The position indicator of the present invention will be described in detail below based on preferred embodiments shown in the accompanying drawings.

[0011] <First Embodiment> Figure 1 is an overall configuration diagram showing the position indicator and position detection sensor according to the first embodiment. Figure 2 is a block diagram showing the configuration of the position detection sensor. Figure 3 is a cross-sectional view showing the configuration of the position detection sensor. Figure 4 is a cross-sectional view of the position indicator. Figure 5 is a plan view of the position indicator seen from above. Figure 6 is a cross-sectional view showing the electrode structure of the position indicator. Figures 7 and 8 show the position indicator in contact with the position detection sensor, respectively. Figure 9 is a circuit diagram showing the circuit configuration of the position indicator.

[0012] The position indicator 1 shown in Figure 1 is used in combination with the position detection sensor 9. When the position indicator 1 touches the input screen of the position detection sensor 9, it indicates the position by sending an augmented output signal V2, which has a predetermined correlation with the AC signal V1 from the position detection sensor 9, to the position detection sensor 9. The position detection sensor 9 detects the contact position of the position indicator 1 on the input screen based on the output signal V2 sent from the position indicator 1. First, before describing the position indicator 1, we will briefly explain the position detection sensor 9.

[0013] ≪Position detection sensor 9≫ The position detection sensor 9 is a mutual capacitance type position detection sensor that detects the position of a touch point contacted by the position indicator 1 based on a change in coupling capacitance.

[0014] As shown in FIG. 2, the position detection sensor 9 includes a sensor unit 90, a transmission unit 91, and a reception unit 92. Note that, in the following description, for convenience of explanation, the horizontal direction of the instruction input surface is defined as the X-axis direction, and the vertical direction is defined as the Y-axis direction. The sensor unit 90 includes a plurality (64 in FIG. 2) of transmission conductors 9Y1, 9Y2, ..., 9Y that extend in the X-axis direction of the instruction input surface and are arranged side by side at equal intervals in the Y-axis direction 64 and a plurality (64 in FIG. 2) of reception conductors 9X1, 9X2, ..., 9X that extend in the Y-axis direction of the instruction input surface and are arranged side by side at equal intervals in the X-axis direction 64 . In addition, the transmission conductors 9Y1 to 9Y 64 are connected to the transmission unit 91, and the reception conductors 9X1 to 9X 64 are connected to the reception unit 92.

[0015] Note that, in the present specification, when there is no need to distinguish which one of the 64 transmission conductors 9Y1 to 9Y 64 it is, it is simply referred to as "transmission conductor 9Y", and similarly, when there is no need to distinguish which one of the 64 reception conductors 9X1 to 9X 64 it is, it is simply referred to as "reception conductor 9X".

[0016] The transmission conductors 9Y1 to 9Y 64 and the reception conductors 9X1 to 9X 64 are formed, for example, separately on the upper surface and the lower surface of a substrate, and are arranged so as to be orthogonal to each other and overlap each other in a plan view. The transmission conductors 9Y1 to 9Y 64 and the reception conductors 9X1 to 9X 64 have cross points CP formed at the portions where they overlap. As shown in FIG. 3, at each cross point CP, the transmission conductor 9Y and the reception conductor 9X are coupled via a capacitance C1.

[0017] As shown in Figure 2, the transmitting unit 91 supplies an AC signal V1 to each transmitting conductor 9Y. The waveform of the AC signal V1 is not particularly limited and can be any waveform, such as a square wave signal or a sine wave signal. The transmitting unit 91 also supplies the same AC signal to multiple transmitting conductors 9Y1 to 9Y 64 Alternatively, one wire may be supplied to each in sequence, or multiple different AC signals may be transmitted to multiple transmitting conductors 9Y1~9Y 64 They may be supplied simultaneously. Also, multiple transmitting conductors 9Y1~9Y 64 The devices may be divided into multiple groups, and a different AC signal may be supplied to each group.

[0018] On the other hand, the receiving unit 92 detects the AC signal V1 supplied to each receiving conductor 9X via capacitance C1. If the coupled capacitance between the transmitting conductor 9Y and the receiving conductor 9X is equal at all crossover points CP, then when the position indicator 1 is not on the sensor unit 90, the receiving unit 92 detects a received signal of the same level from all receiving conductors 9X. In contrast, when the position indicator 1 comes into contact with the sensor unit 90, a new coupled capacitance is formed at the contact point, the capacitance C1 changes at the crossover point where the contact occurs, and the received signal level obtained from the receiving conductor 9X changes accordingly.

[0019] The position detection sensor 9 detects the cross point CP to which the position indicator 1 is in contact by detecting the transmitting conductor 9Y that supplies the AC signal and the receiving conductor 9X where there has been a change in the received signal level. This makes it possible to detect the touch point to which the position indicator 1 has made contact.

[0020] The position detection sensor 9 has been briefly explained. Next, the position indicator 1 will be described.

[0021] ≪Position indicator 1≫ The position indicator 1 indicates the position by sending an augmented output signal V2, which has a predetermined correlation with the AC signal V1 from the position detection sensor 9, to the position detection sensor 9.

[0022] Furthermore, the position indicator 1 is stylus-shaped and, as shown in Figure 4, comprises a housing 2 that also serves as a first shield electrode 8, an electrode structure 3 provided in the housing 2, a wiring board 5 housed within the housing 2, a signal processing circuit 6 formed on the wiring board 5, and a battery 7 as a power source.

[0023] Furthermore, the electrode structure 3 includes a rod-shaped second electrode 32, a cylindrical first electrode 31 surrounding the second electrode 32, a second shield electrode 33 provided between the first electrode 31 and the second electrode 32, an insulating layer 34 provided between the first electrode 31 and the second shield electrode 33, and an insulating layer 35 provided between the second electrode 32 and the second shield electrode 33. In other words, in the electrode structure 3, the second electrode 32, insulating layer 35, second shield electrode 33, insulating layer 34, and first electrode 31 are arranged in that order from the center, and are provided concentrically with respect to each other.

[0024] In a position indicator 1 with this configuration, the AC signal V1 from the position detection sensor 9 is received via the second electrode 32, the signal processing circuit 6 generates an output signal V2 from the AC signal V1, and the output signal V2 is sent to the position detection sensor 9 via the first electrode 31.

[0025] The housing 2 is rod-shaped and has a substantially cylindrical shape. The housing 2 is made of a metal material and is conductive. In this embodiment, the housing 2 is made of aluminum. This results in a housing 2 that is lightweight and has high strength. Such a housing 2 is electrically connected to the ground conductor of the wiring board 5. The housing 2 also comes into contact with the operator when the operator grasps the position indicator 1. When the housing 2 comes into contact with the operator, the ground conductor of the wiring board 5 is connected to ground. As a result, the housing 2 functions as the first shield electrode 8. The constituent material of the housing 2 is not particularly limited as long as it is conductive.

[0026] Furthermore, the tip of the housing 2 is a tapered portion 23 that gradually narrows. By making the tip of the housing 2 a tapered portion 23, the position indicator 1 can be easily tilted relative to the input surface of the position detection sensor 9, thereby improving the operability of the position indicator 1. The electrode structure 3 is provided within this tapered portion 23. An insulating layer 24 is formed on the inner circumferential surface of the tapered portion 23 to provide insulation from the first electrode 31 located on the outermost periphery of the electrode structure 3. In this embodiment, the insulating layer 24 is made of aluminum oxide. The insulating layer 24 is formed, for example, by anodizing the inner circumferential surface of the tapered portion 23. However, the constituent materials and formation method of the insulating layer 24 are not particularly limited.

[0027] In this embodiment, the tapered portion 23 is constructed separately from the portion closer to the base end, but this is not limited to this configuration, and they may be integrally formed. Furthermore, the shape of the housing 2, particularly the cross-sectional shape, is not limited to a circle, but may be a polygon such as a triangle, square, pentagon, or hexagon, or an ellipse, oblong, or other irregular shape.

[0028] A battery 7 is housed in the housing 2. The battery 7 supplies voltage to the signal processing circuit 6. A charging receptacle 28, electrically connected to the battery 7, is provided on the base end face of the housing 2. By connecting a charging cable to the receptacle 28, the battery 7 can be charged. In this embodiment, the receptacle 28 is USB Type-C. This allows for a smaller receptacle 28, and thus enables miniaturization of the position indicator 1.

[0029] However, the receptacle 28 is not limited to this. Also, charging may be done by wireless power supply such as contactless power supply instead of by wired power supply via the receptacle 28. Furthermore, instead of the rechargeable battery 7, for example, a battery may be used as the power source for the signal processing circuit 6.

[0030] Furthermore, as shown in Figure 5, the housing 2 is provided with a switch element 25 and a light-emitting element 26. The switch element 25 is exposed outside the housing 2 and has a sliding operator 251 relative to the housing 2. The power is switched ON / OFF by the user sliding the operator 251. When the power is ON, voltage is applied from the battery 7 to the signal processing circuit 6, and the signal processing circuit 6 is driven. Conversely, when the power is OFF, the application of voltage from the battery 7 to the signal processing circuit 6 is stopped, and the operation of the signal processing circuit 6 is stopped.

[0031] Furthermore, the light-emitting element 26 lights up when the power is turned ON, and turns off when the power is turned OFF. The housing 2 is provided with a window 27, through which light from the light-emitting element 26 is emitted to the outside of the housing 2. In this way, by turning the light-emitting element 26 on and off in response to the power ON / OFF, the user can be notified of the power ON / OFF more reliably and easily. The light-emitting element 26 is not particularly limited, but for example, an LED (Light Emitting Diode) can be used. However, the method of turning the power ON / OFF and the method of notifying the user are not particularly limited.

[0032] Next, the electrode structure 3 provided within the tapered portion 23 will be described. As mentioned above, the electrode structure 3 includes a rod-shaped second electrode 32, a cylindrical first electrode 31 surrounding the second electrode 32, a second shield electrode 33 provided between the first electrode 31 and the second electrode 32, an insulating layer 34 provided between the first electrode 31 and the second shield electrode 33, and an insulating layer 35 provided between the second electrode 32 and the second shield electrode 33. This electrode structure 3 is provided concentrically with the central axis J of the housing 2.

[0033] As shown in Figure 6, the second electrode 32 is a rod-shaped central electrode extending along the central axis J of the housing 2. The second electrode 32 also has a rod-shaped base 321 and a contact portion 322 provided at the tip of the base 321. The base 321 is provided inside the first electrode 31, and its tip protrudes from the first electrode 31. The base 321 functions as part of the wiring that electrically connects the contact portion 322 and the signal processing circuit 6.

[0034] Furthermore, the contact portion 322 is located closer to the tip than the first electrode 31 and is exposed to the outside of the position indicator 1. The contact portion 322 is located at the very front of the position indicator 1 and constitutes the contact portion with the position detection sensor 9. This allows the AC signal V1 from the position detection sensor 9 to be received via the contact portion 322. Each part of the electrode structure 3 is arranged to fit inside the tangent L between the contact portion 322 and the tapered portion 23. This makes it easier to tilt the position indicator 1 relative to the input surface of the position detection sensor 9, improving the operability of the position indicator 1.

[0035] Furthermore, the contact portion 322 has a roughly hemispherical shape (dome shape) that is larger in diameter than the base portion 321. The dimensions of the contact portion 322 are not particularly limited, but for example, the diameter can be about 2 mm to 3 mm and the height about 1 mm to 1.5 mm. This makes the contact portion 322 an appropriate size. As a result, the position indicator 1 can exhibit excellent operability.

[0036] The second electrode 32, having this configuration, is made of various metal materials such as aluminum or copper.

[0037] The configuration of the second electrode 32 is not particularly limited. For example, the contact portion 322 may be covered with an elastic protective conductor. This prevents damage to the indicator input surface of the position detection sensor 9 when the position indicator 1 is brought into contact with the position detection sensor 9, and also increases the contact area with the indicator input surface. The protective conductor can be made of, for example, conductive elastic rubber. Alternatively, the base portion 321 may be omitted, and instead of the base portion 321, wiring that electrically connects the contact portion 322 and the signal processing circuit 6 may be placed inside the first electrode 31.

[0038] The first electrode 31 has a cylindrical shape, with its tip protruding from the tapered portion 23. Hereinafter, the portion protruding from the tapered portion 23 will also be referred to as the "protruding portion 310". By covering the base end of the first electrode 31 with the tapered portion 23, which functions as the first shield electrode 8, the amount of deviation D between the receiving position Pin, which receives the AC signal V1 from the position detection sensor 9, and the sending position Pout, which sends the output signal V2 from the position indicator 1 to the position detection sensor 9, can be kept small. As a result, the position indicator 1 has excellent operability. The principle of this is briefly explained below.

[0039] Figure 7 shows the case where the tapered portion 23 does not function as the first shield electrode 8. In this state, the output signal V2 is sent from the entire first electrode 31 to the position detection sensor 9, so the peak of the electric field strength of the output signal V2 is shifted significantly toward the base end of the position indicator 1 relative to the contact portion 322. As a result, the amount of deviation D between the receiving position Pin and the transmitting position Pout becomes large.

[0040] In contrast, in this embodiment, as shown in Figure 8, the tapered portion 23 (first shield electrode 8) suppresses capacitive coupling between the portion of the first electrode 31 other than the protruding portion 310 and the position detection sensor 9. As a result, the output signal V2 is sent to the position detection sensor 9 from substantially only the protruding portion 310. This reduces the peak bias of the electric field strength distribution of the output signal V2 with respect to the contact portion 322 compared to the configuration in Figure 7. Consequently, the amount of deviation D between the receiving position Pin and the transmitting position Pout can be kept small. As a result, a position indicator 1 with excellent operability is obtained.

[0041] The length of the protrusion 310 (the amount of protrusion from the tapered portion 23) is not particularly limited, but it is preferably about 0.5 mm to 2 mm. This makes it possible to reduce the amount of displacement D while ensuring sufficient strength of the output signal V2.

[0042] As shown in Figure 6, the inner diameter of the first electrode 31 is larger than the outer diameter of the contact portion 322. Therefore, in a plan view of the electrode structure 3 (a plan view from the direction along the central axis J), the contact portion 322 is located inside the first electrode 31. This configuration suppresses the overlap between the first electrode 31 and the second electrode 32, thereby suppressing their capacitive coupling. As a result, crosstalk between the first electrode 31 and the second electrode 32 is suppressed, and the intrusion of noise into the AC signal V1 and the output signal V2 can be suppressed.

[0043] Such a first electrode 31 is made of various metal materials such as aluminum or copper.

[0044] The second shield electrode 33 is cylindrical and is provided between the first electrode 31 and the second electrode 32. The second shield electrode 33 is electrically connected to the ground conductor of the wiring board 5 and is connected to ground when the position indicator 1 is grasped by the operator. Therefore, the capacitive coupling between the first electrode 31 and the second electrode 32 can be suppressed by the second shield electrode 33. As a result, crosstalk between the first electrode 31 and the second electrode 32 is suppressed, and the intrusion of noise into the AC signal V1 and the output signal V2 can be effectively suppressed.

[0045] In particular, in this embodiment, the tip of the second shield electrode 33 protrudes from the first electrode 31, and the second shield electrode 33 is also located between the contact portion 322 and the first electrode 31. Therefore, capacitive coupling between the first electrode 31 and the second electrode 32 can be suppressed more effectively. Consequently, crosstalk between the first electrode 31 and the second electrode 32 can be suppressed more effectively, and the intrusion of noise into the AC signal V1 and the output signal V2 can be suppressed more effectively.

[0046] As will be described later, the insulating layer 35 is provided to fill the step between the base portion 321 and the contact portion 322. Therefore, the second shield electrode 33 provided on the outer surface of the insulating layer 35 is located outside the contact portion 322 in a plan view of the electrode structure 3. Consequently, it becomes easier to position the second shield electrode 33 between the contact portion 322 and the first electrode 31.

[0047] Furthermore, the tip of the second shield electrode 33 is tapered, gradually narrowing towards the end. This makes it easier to tilt the position indicator 1 relative to the input surface of the position detection sensor 9, thereby improving the operability of the position indicator 1.

[0048] Such a second shield electrode 33 is made of various metal materials such as aluminum or copper.

[0049] The insulating layer 34 is cylindrical and is provided between the first electrode 31 and the second shield electrode 33. This insulating layer 34 insulates the first electrode 31 from the second shield electrode 33. The insulating layer 35 is also cylindrical and is provided between the second electrode 32 and the second shield electrode 33. This insulating layer 35 insulates the second electrode 32 from the second shield electrode 33. The insulating layer 35 covers the entire base 321 of the second electrode 32, with its tip protruding from the first electrode 31. The insulating layer 35 does not cover the contact portion 322. In other words, the contact portion 322 is exposed from the insulating layer 35. The insulating layer 35 has a thickness approximately equal to the step between the contact portion 322 and the base 321, and is provided to fill this step. Therefore, as described above, it becomes easier to position the second shield electrode 33 between the contact portion 322 and the first electrode 31.

[0050] The constituent materials of such insulating layers 34 and 35 are not particularly limited, and various resin materials can be used, for example.

[0051] Next, the signal processing circuit 6 will be described. As shown in Figure 9, the signal processing circuit 6 includes a power supply circuit section 61 and a signal processing section 62. The power supply circuit section 61 is equipped with a DC / DC converter 611, which generates a power supply voltage Vcc from the voltage of the battery 7 and supplies it to the signal processing section 62. In the power supply circuit section 61, a switch element 25 is provided between the DC / DC converter 611 and the battery 7. In addition, a series circuit of a resistor 612 and a light-emitting element 26 is connected between the output terminal of the DC / DC converter 611 and the ground conductor of the wiring board 5.

[0052] In this power supply circuit 61, when the switch element 25 is operated and the power is turned ON, the voltage from the battery 7 is supplied to the DC / DC converter 611, generating a power supply voltage Vcc, and at the same time the light-emitting element 26 lights up to notify the user that the power is ON. Conversely, when the switch element 25 is operated and the power is turned OFF, the supply of voltage from the battery 7 to the DC / DC converter 611 is stopped, the generation of the power supply voltage Vcc stops, and at the same time the light-emitting element 26 turns off to notify the user that the power is OFF. However, the configuration of the power supply circuit 61 is not particularly limited.

[0053] The signal processing unit 62 constitutes a signal augmentation processing circuit, generating an output signal V2 by inverting and amplifying the AC signal V1 from the position detection sensor 9, and sending the output signal V2 to the position detection sensor 9. Such a signal processing unit 62 includes an amplification circuit 64 and an inverting amplification circuit 65.

[0054] The amplification circuit 64 includes an operational amplifier 641 and resistors 642 and 643 connected between the inverting input terminal and output terminal of the operational amplifier 641. The second electrode 32 is connected to the non-inverting input terminal of the operational amplifier 641, with a coupling capacitor in between. When the position indicator 1 is on the position detection sensor 9, the second electrode 32 and the position detection sensor 9 are coupled via capacitance C2, and the AC signal V1 flowing through the position detection sensor 9 is input to the amplification circuit 64 as a current signal via capacitance C2 and the second electrode 32. The amplification circuit 64 then amplifies the input AC signal V1 and outputs it to the inverting amplification circuit 65.

[0055] The inverting amplifier circuit 65 inverts and amplifies the signal output from the amplifier circuit 64 and outputs it to the first electrode 31. The inverting amplifier circuit 65 includes an operational amplifier 651 and resistors 652 and 653 connected between the non-inverting input terminal and the output terminal of the operational amplifier 651. In addition, the output terminal of operational amplifier 641 is connected to the inverting input terminal of operational amplifier 651, with a coupling capacitor in between.

[0056] The configuration of the position indicator 1 has been described above. Next, the method of using the position indicator 1 will be described. When the position indicator 1 is powered ON, the power supply voltage Vcc is supplied from the power supply circuit 61 to the signal processing unit 62, and the signal processing unit 62 is driven. In this state, when the contact part 322 of the position indicator 1 is brought into contact with the position indicator surface of the position detection sensor 9, the second electrode 32 and the position detection sensor 9 are coupled via the capacitance C2, and the AC signal V1 flowing through the position detection sensor 9 is input to the signal processing unit 62 via the capacitance C2 and the second electrode 32, and after amplitude amplification in the amplification circuit 64 and phase inversion amplification in the inverting amplifier circuit 65, it becomes the output signal V2, and this output signal V2 is sent (feeded back) to the position detection sensor 9 via the first electrode 31 and the capacitance C3.

[0057] As mentioned above, the output signal V2 sent to the position detection sensor 9 is an augmented signal in the opposite phase to the AC signal V1 supplied to the transmitting conductor 9Y. Therefore, the position indicator 1 functions to further increase the change in the received signal level obtained from the receiving conductor 9X. Consequently, the position detection sensor 9 can detect the contact position of the position indicator 1 with high sensitivity. In particular, in the position indicator 1, the ground conductor of the wiring board 5 is connected to ground when the housing 2 is touched by the operator, which further stabilizes the detection operation of the position detection sensor 9.

[0058] Furthermore, as mentioned above, the signal processing circuit 6 performs predetermined signal processing on the AC signal V1 to generate the output signal V2. By generating the output signal V2 from the AC signal V1 in this way, it becomes easy to generate an output signal V2 that has a correlation with the AC signal V1.

[0059] <Second Embodiment> Figure 10 is a cross-sectional view showing the electrode structure of the position indicator according to the second embodiment. Figure 11 is a plan view of the electrode structure of Figure 10 seen from the side. Figure 12 is a plan view of the electrode structure of Figure 10 seen from the tip side. Figure 13 is a diagram showing the position indicator in contact with the position detection sensor.

[0060] The position indicator 1 of this embodiment is the same as the position indicator 1 of the first embodiment described above, except that the configuration of the first electrode 31 is different. Therefore, in the following description, this embodiment will be described mainly for the differences from the previously described embodiment, and similar matters will not be described. In addition, in each figure of this embodiment, the same reference numerals are used for components that are the same as those in the previously described embodiment.

[0061] As shown in Figures 10 to 12, in the position indicator 1 of this embodiment, a notch 311 is formed in the protruding portion 310 of the first electrode 31. The notch 311 extends along the central axis J, and its tip faces the tip surface of the first electrode 31. In other words, the notch 311 opens at its tip to the tip surface of the first electrode 31. By having such a notch 311, the amount of deviation D between the receiving position Pin and the transmitting position Pout can be reduced even further than in the first embodiment described above. Therefore, the position indicator 1 has excellent operability. The principle of this will be briefly explained below.

[0062] As shown in Figure 13, when the position indicator 1 is used with the notch 311 facing downwards (facing the input screen of the position detection sensor 9), the output signal V2 is not sent from the notch 311. Therefore, the bias of the peak electric field strength of the output signal V2 relative to the contact portion 322 becomes even smaller compared to the first embodiment described above. Consequently, the amount of deviation D between the receiving position Pin and the transmitting position Pout can be kept even smaller. As a result, the position indicator 1 has excellent operability.

[0063] In particular, in this embodiment, the notch 311 extends from the tip surface of the first electrode 31 to the portion overlapping with the tapered portion 23. In other words, the notch 311 is provided by traversing the protruding portion 310 longitudinally. As a result, the bias of the peak of the electric field strength of the output signal V2 with respect to the contact portion 322 is reduced, and the amount of deviation D between the receiving position Pin and the transmitting position Pout can be reduced.

[0064] Here, the central angle θ of the notch 311 is not particularly limited, but it is preferably, for example, 60° or more and 90° or less. This allows the notch 311 to be made sufficiently large, and the above-mentioned effects become more pronounced. In addition, even if the orientation of the position indicator 1 changes during use, the notch 311 can be easily maintained facing the input screen of the position detection sensor 9. Furthermore, excessive damage to the first electrode 31 due to the notch 311 is prevented, and the strength of the output signal V2 sent from the first electrode 31 can be sufficiently secured with less power.

[0065] In this embodiment, the notch 311 is rectangular, but the shape of the notch 311 is not particularly limited. For example, the width of the notch 311 (the circumferential length of the first electrode 31) may be tapered, gradually increasing towards the base end, or conversely, tapered, gradually decreasing towards the base end.

[0066] However, if the position of the notch 311 is unknown, there is a risk that the position indicator 1 may be used in a position where the notch 311 does not face downwards (a position where it does not face the input screen of the position detection sensor 9). If the position indicator 1 is used in such a position, the above-mentioned effects may not be fully realized. Therefore, in the position indicator 1 of this embodiment, as shown in Figures 10 and 11, a marker 29 is provided on the housing 2 to inform the user of the position of the notch 311. As a result, the user can confirm the position of the notch 311 based on the marker 29 and then use the position indicator 1 in a position where the notch 311 faces downwards.

[0067] The configuration of the marker portion 29 is not particularly limited as long as it can perform its function, but in this embodiment, it consists of a marker 291 displayed at a position opposite the notch portion 311 of the tapered portion 23, prompting the user to use it with the marker 291 facing upwards. This ensures that the position indicator 1 is used with the notch portion 311 facing downwards more reliably. Note that a switch element 25 or a light-emitting element 26 may be used as the marker portion 29, or if the position indicator 1 has a clip for fixing it to an object, this clip may be used as the marker portion 29. Furthermore, the housing 2 may be shaped so that the position indicator 1 is easiest to grip when the notch portion 311 is facing downwards.

[0068] The second embodiment described above can also achieve the same effects as the first embodiment described above.

[0069] <Third Embodiment> Figure 14 is a plan view of the electrode structure of the position indicator according to the third embodiment, as seen from the tip side. Figures 15 to 17 show the position indicator in contact with the position detection sensor, respectively.

[0070] The position indicator 1 of this embodiment is the same as the position indicator 1 of the second embodiment described above, except that the configuration of the first electrode 31 is different. Therefore, in the following description, the differences between this embodiment and the previously described embodiment will be the focus, and similar matters will not be described. In addition, in the figures of this embodiment, the same reference numerals are used for components that are the same as those in the previously described embodiment.

[0071] As shown in Figure 14, the first electrode 31 of this embodiment has a plurality of notches 311. The plurality of notches 311 are provided at equal intervals along the circumferential direction of the first electrode 31. Furthermore, each notch 311 faces another portion of the first electrode 31 that does not have a notch 311, via the central axis J. In other words, the notches 311 are configured so that they do not face each other via the central axis J. Even with a position indicator 1 configured in this way, as shown in Figure 15, by using the position indicator 1 with the notches 311 facing downwards (facing the input screen of the position detection sensor 9), the amount of deviation D between the receiving position Pin and the transmitting position Pout can be reduced.

[0072] In this embodiment, three notches 311 are provided at 120° intervals. By having three notches 311, and arranging multiple notches 311 at equal intervals, it is easy to configure the device so that the first electrode 31 is located at a point opposite each notch 311 across the central axis J. In other words, it is possible to configure the device so that the notches 311 do not face each other across the central axis J. However, the number of notches 311 is not particularly limited, as long as there are two or more.

[0073] Furthermore, the position indicator 1 of this embodiment can also provide the following effects. For example, as shown in Figure 16, when the position indicator 1 of the second embodiment described above is positioned perpendicular to the input screen of the position detection sensor 9, the peak of the electric field strength of the output signal V2 is shifted and distributed on the opposite side of the notch 311 from the contact portion 322. As a result, a slight shift D occurs between the receiving position Pin and the transmitting position Pout.

[0074] In contrast, as shown in Figure 17, in the position indicator 1 of this embodiment, the notches 311 are arranged at equal intervals in the circumferential direction of the first electrode 31, so that there is virtually no bias in the peak of the electric field strength of the output signal V2 with respect to the contact portion 322. Therefore, the amount of deviation D between the receiving position Pin and the transmitting position Pout can be made smaller, and substantially zero. Thus, according to the position indicator 1 of this embodiment, the amount of deviation D between the receiving position Pin and the transmitting position Pout can be made smaller when the position detection sensor 9 is in an upright position relative to the input screen.

[0075] Here, the central angle θ of each notch 311 is not particularly limited and varies depending on the number of notches 311, but in the case of three notches 311 as in this embodiment, it is preferable that it be, for example, 45° or more and 60° or less. This makes it possible to more reliably ensure that the notches 311 do not face each other via the central axis J. Furthermore, each notch 311 can be made sufficiently large, and the above-mentioned effects can be more reliably achieved. In addition, even if the orientation of the position indicator 1 changes during use, the state in which the notches 311 face the input screen of the position detection sensor 9 can be easily maintained. Furthermore, excessive damage to the first electrode 31 due to the notches 311 is prevented, and the strength of the output signal V2 sent from the first electrode 31 can be sufficiently secured with less power.

[0076] The third embodiment described above can also achieve the same effects as the first embodiment described above.

[0077] Although the position indicator of the present invention has been described above based on the illustrated embodiment, the present invention is not limited thereto, and the configuration of each part can be replaced with any configuration having a similar function. Furthermore, any other components may be added to the present invention. [Explanation of Symbols]

[0078] 1…Position indicator 2…Housing 23…Tapered section 24…Insulating layer 25…Switch element 251…Operator 26…Light-emitting element 27…Window section 28…Receptacle 29…Marker section 291…Marker 3…Electrode structure 31…First electrode 310…Protrusion 311…Notch 32…Second electrode 321…Base 322…Contact section 33…Second shield electrode 34,35…Insulating layer 5…Wiring board 6…Signal processing circuit 61…Power supply circuit section 611…DC / DC converter 612…Resistor 62…Signal processing section 64…Amplifier circuit 641…Operational amplifier 642…Resistor 643…Resistor 65…Inverting amplifier circuit 651…Operational amplifier 652…Resistor 653…Resistor 7…Battery 8…First shield electrode 9…Position detection sensor 9X, 9X1~9X 64 ...receiving conductors 9Y, 9Y1~9Y 64 …Transmitting conductor 90…Sensor section 91…Transmitting section 92…Receiving section C1, C2, C3…Capacitance CP…Cross point D…Amount of deviation J…Central axis L…Tangential Pin…Receiving position Pout…Transmitting position V1…AC signal V2…Output signal Vcc…Power supply voltage θ…Central angle

Claims

1. A position indicator used for a position detection sensor that performs position detection based on changes in capacitance, A cylindrical first shield electrode, A first electrode provided within the first shield electrode, the tip of which protrudes from the first shield electrode, It has a second electrode with a contact portion that contacts the position detection sensor, The contact portion of the second electrode is located closer to the tip than the first electrode. The first electrode has a notch facing the tip surface of the first electrode, A position indicator characterized by receiving an AC signal from the position detection sensor via the second electrode and sending an output signal to the position detection sensor via the first electrode.

2. The position indicator according to claim 1, wherein the notch extends from the tip surface to the portion overlapping with the first shield electrode.

3. The position indicator according to claim 1, wherein the central angle of the notch is 60° or more and 90° or less.

4. The position indicator according to claim 1, wherein the notches are formed in multiple locations along the circumferential direction of the first electrode.

5. The position indicator according to claim 4, wherein each of the aforementioned notches faces a portion where no other aforementioned notches are formed.

6. The first electrode has three of the aforementioned notches, The position indicator according to claim 5, wherein the central angle of each of the aforementioned notches is 45° or more and 60° or less.

7. The position indicator according to claim 1, further comprising a second shield electrode disposed between the first electrode and the second electrode.

8. The position indicator according to claim 1, further comprising a signal processing circuit that performs predetermined signal processing on the AC signal and generates the output signal.

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