Active pen and position detection system

Abstract

To provide an active pen and a position detection system that can execute various functions according to status of a power remaining amount of the active pen.SOLUTION: An active pen (12) includes a control unit (40) that controls operations of a receiving circuit (46), a transmitting circuit (48), or an attendant function circuit (50) according to a plurality of kinds of operation modes including a normal mode and a low consumption mode. The low consumption mode is the operation mode in which execution frequency of a specific driving operation relating to at least one of reception of an uplink signal (US), transmission of a downlink signal DS, and the attendant function is relatively low, or an execution amount of the specific driving operation is relatively small.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to an active pen and position detection system. [Background technology]

[0002] Conventionally, a position detection system that includes an active electronic pen (hereinafter, referred to as an "active pen"), which is a position indicator with a built-in power source, and an electronic device including a touch sensor has been known. In this type of system, signals are transmitted and received between the active pen and the electronic device to exchange data or synchronize control (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6473554 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the user continues to use the active pen when the remaining power supply is low, the active pen may not be able to perform the desired operation due to insufficient power.

[0005] The present invention has been made in consideration of the above-mentioned problems, and its object is to provide an active pen and a position detection system that can execute various functions according to the remaining power supply status of the active pen. [Means for solving the problem]

[0006] The active pen in a first aspect of the present invention is a pen used with an electronic device comprising a capacitive touch sensor having a plurality of sensor electrodes arranged in a planar shape, and comprises a receiving circuit for receiving an uplink signal from the electronic device, a transmitting circuit for transmitting a downlink signal to the electronic device, an auxiliary function unit for performing an auxiliary function other than the reception of the uplink signal and the transmission of the downlink signal, and a control unit for controlling the operation of the receiving circuit, the transmitting circuit, or the auxiliary function unit according to a plurality of operating modes including a normal mode and a low consumption mode, wherein the normal mode is an operating mode in which a specific driving operation relating to at least one of the reception of the uplink signal, the transmission of the downlink signal, and the auxiliary function is executed relatively frequently or the specific driving operation is executed in a relatively large amount, and the low consumption mode is an operating mode in which the specific driving operation is executed relatively infrequently or the specific driving operation is executed in a relatively small amount.

[0007] A position detection system in a second aspect of the present invention comprises an electronic device including a capacitive touch sensor having a plurality of sensor electrodes arranged in a planar shape, and an active pen used together with the electronic device, the active pen comprising a pen side receiving circuit that receives an uplink signal from the electronic device, a pen side transmitting circuit that transmits a downlink signal corresponding to the uplink signal to the electronic device, and a pen side control unit that controls driving operations by the pen side receiving circuit or the pen side transmitting circuit according to a plurality of operating modes including a normal mode and a low consumption mode, the normal mode being an operating mode in which transmission of the downlink signal is continued, and the low consumption mode being an operating mode in which transmission of the downlink signal is stopped and the active pen functions as a passive pointer.

[0008] A position detection system in a third aspect of the present invention comprises an electronic device including a capacitive touch sensor having a plurality of sensor electrodes arranged in a planar shape, an active pen used together with the electronic device, and an alarm means provided on the electronic device or the active pen and for explicitly or implicitly alarming a user that the active pen has a low power supply, the active pen comprising a receiving circuit for receiving an uplink signal from the electronic device, a transmitting circuit for transmitting a downlink signal to the electronic device, an auxiliary function unit for performing an auxiliary function other than the reception of the uplink signal and the transmission of the downlink signal, and a control unit for controlling the operation of the receiving circuit, the transmitting circuit, or the auxiliary function unit in accordance with a plurality of operating modes including a normal mode and a low consumption mode, the normal mode being an operating mode in which a frequency of execution of a specific driving operation relating to at least one of the reception of the uplink signal, the transmission of the downlink signal, and the auxiliary function is relatively high, or the amount of execution of the specific driving operation is relatively large, and the low consumption mode being an operating mode in which the frequency of execution of the specific driving operation is relatively low, or the amount of execution of the specific driving operation is relatively small. Effect of the Invention

[0009] According to the present invention, it is possible to execute various functions according to the remaining power status of the active pen. [Brief description of the drawings]

[0010] [Figure 1] 1 is an overall configuration diagram of a position detection system common to each embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the active pen shown in FIG. [Diagram 3] FIG. 2 is a block diagram of a pen-side controller included in the active pen in the first embodiment. [Figure 4] FIG. 4 is a functional block diagram of the pen-side MCU shown in FIG. [Diagram 5]5 is a flowchart showing an example of a mode switching operation by the pen side controller of FIGS. 3 and 4. [Figure 6] FIG. 2 is a diagram illustrating a first sharing method of a mode flag. [Figure 7] FIG. 11 is a diagram illustrating a second sharing method of the mode flag. [Figure 8] FIG. 11 is a diagram showing an example of a selection result of an operation mode. [Figure 9] 5A to 5C are diagrams illustrating differences in drive operations between operation modes in the first embodiment. [Figure 10] FIG. 11 is a diagram showing an example of an internal configuration of an electronic device according to a second embodiment. [Figure 11] FIG. 11 is a functional block diagram of a sensor side controller shown in FIG. [Figure 12] 12 is a flowchart showing an example of a mode switching operation by the sensor side controller of FIGS. 10 and 11. [Figure 13] 13A to 13C are diagrams illustrating a first difference in drive operation between operation modes in the second embodiment. [Figure 14] 13A and 13B are diagrams illustrating a second difference in drive operation between operation modes in the second embodiment. [Figure 15] FIG. 11 is a first block diagram of a pen-side controller provided in an active pen in a second embodiment. [Figure 16] FIG. 2 is a diagram showing an example of a signal waveform of a downlink signal. [Figure 17] FIG. 13 is a diagram showing a main part of a circuit configuration for realizing pseudo-activation. [Figure 18] FIG. 11 is a second block diagram of the pen side controller of the active pen in the second embodiment. [Figure 19] FIG. 11 is a schematic configuration diagram of a position detection system according to a third embodiment. [Figure 20] 20 is a diagram showing an example of a method of displaying the position of the active pen in FIG. 19. [Figure 21] 11A and 11B are diagrams illustrating an example of a method for changing the display mode of a cursor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The active pen and the position detection system according to the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the embodiments and modifications described below, and can be freely modified without departing from the spirit of the present invention. Alternatively, the respective configurations may be combined in any manner as long as no technical contradiction occurs. Alternatively, the order of execution of each step constituting the flow chart may be changed as long as no technical contradiction occurs.

[0012] [Description of location detection system 10] <Overall composition> 1 is a diagram showing the overall configuration of a position detection system 10 common to all of the embodiments of the present invention. The position detection system 10 basically comprises an active pen 12 and an electronic device 14 used together with the active pen 12.

[0013] The active pen 12 is a pen-shaped pointing device configured to be capable of one-way or two-way communication with the electronic device 14. In this embodiment, the active pen 12 is an "active type" stylus that actively generates a signal from electrical energy stored in itself and transmits this signal as a downlink signal DS to the electronic device 14. In the case of an active electrostatic coupling type (AES) or a capacitive type, the active pen 12 and the electronic device 14 are capacitively coupled to each other by a capacitance Cpen.

[0014] The electronic device 14 is a computer owned by a user, and is composed of, for example, a tablet terminal with or without a display function, a smartphone, a personal computer, etc. Specifically, the electronic device 14 is composed of a host processor, a memory, a communication module, or a display panel (none of which are shown) in addition to the touch sensor 16 and the sensor-side controller 18. The host processor performs digital ink generation processing, pointer display processing, etc., using position data sequentially output from the sensor-side controller 18.

[0015] The touch sensor 16 is, for example, a capacitance type (more specifically, a mutual capacitance type or a self-capacitance type) sensor in which a plurality of sensor electrodes are arranged in a planar shape. Each sensor electrode may be made of a transparent conductive material including ITO (Indium Tin Oxide), or may be made of a wire mesh sensor. The touch sensor 16 may be a "built-in type" (further classified as an on-cell type or an in-cell type) sensor that is integrally formed with a display panel (not shown), or may be an "external type" (or an out-cell type) sensor that is attached to the display panel from the outside.

[0016] The sensor-side controller 18 is connected to the touch sensor 16 and is a control circuit for controlling communication with the active pen 12 via the touch sensor 16. Specifically, the sensor-side controller 18 transmits an uplink signal US to the active pen 12 and receives a downlink signal DS from the active pen 12 to detect the pointing position of the active pen 12.

[0017] <Device configuration of active pen 12> Fig. 2 is an exploded perspective view of the active pen 12 shown in Fig. 1. The active pen 12 includes a core 20, a tip electrode 22 (corresponding to a "pen electrode"), a ring electrode 24 (corresponding to a "pen electrode"), a writing pressure sensor 26, a pen-side controller 28, a power supply module 30 (corresponding to a "power supply"), and a housing 32.

[0018] The core 20 is a rod-shaped member disposed along the pen shaft of the active pen 12. The tip electrode 22 and the ring electrode 24 are each made of or contain a conductive material such as a metal. Specifically, the tip electrode 22 is a cone-shaped electrode attached to the tip of the core 20. The ring electrode 24 is a tapered annular electrode whose diameter gradually decreases toward the tip side.

[0019] The writing pressure sensor 26 is physically connected to the lead 20 and is configured to be able to detect the amount of writing pressure acting on the tip side (i.e., the pen tip) of the lead 20. The detection method of the writing pressure sensor 26 may be, for example, a capacitance method, a film resistance method, a piezoelectric element method, an optical method, or a MEMS (Micro Electro-Mechanical System) method.

[0020] The pen-side controller 28 is composed of a single or multiple boards that configure an electric circuit for operating the active pen 12. The power supply module 30 is composed of, for example, a battery or a capacitor, and supplies driving power to electronic components or electronic elements on the pen-side controller 28. The housing 32 is configured to be capable of housing each of the above-mentioned components.

[0021] [First embodiment] First, a position detection system 10A in the first embodiment will be described with reference to Fig. 3 to Fig. 9. The position detection system 10A corresponds to one aspect of the position detection system 10 shown in Fig. 1. This position detection system 10A includes an active pen 12A and an electronic device 14A.

[0022] <Block diagram of the pen side controller 28a> 3 is a block diagram of the pen side controller 28a of the active pen 12A in the first embodiment. The pen side controller 28a includes a microcontroller unit (hereinafter referred to as the "pen side MCU 40"), a first switch 42, a second switch 44, a pen side receiving circuit 46, a pen side transmitting circuit 48, and an additional function unit 50.

[0023] The pen side MCU 40 (corresponding to a "pen side control unit") is a unit that performs overall control over each part of the active pen 12A. The pen side MCU 40 is configured to be able to receive an uplink signal US from the electronic device 14A by performing desired reception control on the pen side receiving circuit 46. The pen side MCU 40 is configured to be able to transmit a downlink signal DS to the electronic device 14B by performing desired digital signal processing on the data supplied from the pen side receiving circuit 46 and performing desired transmission control on the pen side transmitting circuit 48.

[0024] The first switch 42 is a switch element configured such that a common terminal is connected to either an R terminal or a T terminal. The common terminal of the first switch 42 is connected to the tip electrode 22, the R terminal is connected to an input terminal of the pen side receiving circuit 46, and the T terminal is connected to an output terminal of the pen side transmitting circuit 48. The pen side MCU 40 supplies a first switch control signal SWC1 to the first switch 42 to perform switching control, thereby selectively receiving an uplink signal US and transmitting a downlink signal DS.

[0025] The second switch 44 is a switch element configured such that a common terminal is connected to either an R terminal or a T terminal. The common terminal of the second switch 44 is connected to the ring electrode 24, the R terminal is connected to an input terminal of the pen side receiving circuit 46, and the T terminal is connected to an output terminal of the pen side transmitting circuit 48. The pen side MCU 40 supplies a second switch control signal SWC2 to the second switch 44 to perform switching control, thereby selectively receiving an uplink signal US and transmitting a downlink signal DS.

[0026] The pen side receiving circuit 46 is a circuit that demodulates the uplink signal US induced to the tip electrode 22 or the ring electrode 24, and outputs the demodulated data to the pen side MCU 40. The ground terminal of the pen side receiving circuit 46 is grounded (or connected to ground) to the housing 32 of the active pen 12A. More specifically, the pen side receiving circuit 46 is configured to include a waveform regenerator 52 and a correlation calculator 54.

[0027] Waveform regenerator 52 binarizes the level of the voltage induced in tip electrode 22 or ring electrode 24 with a clock of a predetermined rate, shapes it into a binary string of positive and negative polarity values ​​(i.e., a chip string), and outputs it. This clock frequency is set, for example, to an integer multiple of the chip rate of the spreading code.

[0028] The correlation calculator 54 stores the chip sequence from the waveform regenerator 52 in a register, and performs correlation calculations with the spreading code while sequentially shifting the chip sequence with the clock, thereby decoding the chip sequence contained in the uplink signal US.

[0029] The pen side transmission circuit 48 is a circuit that generates the downlink signal DS under the control of the pen side MCU 40. When the downlink signal DS is a "position signal", the pen side transmission circuit 48 outputs a carrier signal without modulation, and when the downlink signal DS is a "data signal", the pen side transmission circuit 48 modulates the carrier signal using transmission data and outputs the modulated carrier signal. More specifically, the pen side transmission circuit 48 is configured to include a modulator 56 and a boost circuit 58.

[0030] The modulator 56 generates a carrier signal such as a square wave or a triangular wave, and outputs the carrier signal modulated or as is, under the control of the pen side MCU 40. When transmitting a burst signal, the modulator 56 outputs the carrier signal as is, without modulating it, in accordance with the instructions of the pen side MCU 40. On the other hand, when transmitting a data signal, the modulator 56 modulates (OOK, PSK, etc.) the carrier signal with data supplied from the pen side MCU 40, and outputs the resulting modulated signal.

[0031] The boost circuit 58 generates a downlink signal DS by boosting the output signal supplied from the modulator 56 to a certain amplitude. The downlink signal DS generated by the boost circuit 58 is sent to the outside from the tip electrode 22 via the first switch 42 or from the ring electrode 24 via the second switch 44.

[0032] The additional function unit 50 is configured to be able to perform a function (hereinafter referred to as an "additional function") that is additional to the basic function related to the pen input, which is a function other than the reception of the uplink signal US or the transmission of the downlink signal DS. The additional function unit 50 may be a part of the configuration of the pen-side controller 28a, or may be a configuration separate from the pen-side controller 28a instead of or in addition to the pen-side controller 28a.

[0033] <Function block diagram> Fig. 4 is a functional block diagram of the pen side MCU 40 shown in Fig. 3. The pen side MCU 40 includes a mode switching unit 60, an operation control unit 62, a data writing unit 64, and a data storage unit 66 (corresponding to "memory"). In addition to the above-mentioned pen pressure sensor 26 (Fig. 2), pen side receiving circuit 46, and pen side transmitting circuit 48 (Fig. 3), a communication chip 72, a pen switch 74, a vibration device 76, and a power management integrated circuit (hereinafter referred to as "PMIC 78") are connected to the pen side MCU 40. Here, the pen pressure sensor 26, the communication chip 72, the pen switch 74, the vibration device 76, and the data writing unit 64 correspond to an additional function unit 50 that executes various additional functions.

[0034] The mode switching unit 60 switches between a plurality of types of operation modes using mode information including a mode flag. The types of operation modes are classified into, for example, [1] a "first operation mode group" that switches depending on the detection result of the active pen 12A or the passive pointer, and [2] a "second operation mode group" that switches depending on the remaining amount of power provided in the active pen 12A.

[0035] The first operating mode group includes, for example, [1] an “STP (Simultaneous Pen Touch) mode” in which the positions of the active pen 12A and the passive pointer are detected in a time-division manner, or [2] an “exclusive mode” in which detection of the passive pointer is temporarily stopped and the position of only the active pen 12A is detected.

[0036] The second operation mode group includes a normal mode or a low-consumption mode. Here, the "normal mode" refers to an operation mode in which the power consumption associated with the drive operation related to at least one of the reception of the uplink signal US, the transmission of the downlink signal DS, and the associated functions (hereinafter referred to as "specific drive operation"). Also, the "low-consumption mode" refers to an operation mode in which the power consumption associated with the specific drive operation is relatively low. For example, in the "normal mode", the frequency of execution of the specific drive operation may be relatively high, or the amount of execution of the specific drive operation may be relatively large. Also, in the "low-consumption mode", the frequency of execution of the specific drive operation may be relatively low, or the amount of execution of the specific drive operation may be relatively small.

[0037] The mode switching unit 60 may detect the operation mode of the electronic device 14A based on the uplink signal US received via the pen-side receiving circuit 46, and switch the operation mode of the active pen 12A in accordance with the detection result. For example, when the mode switching unit 60 detects that the electronic device 14A is executing the low-consumption mode, the mode switching unit 60 may transition to the low-consumption mode in cooperation with the electronic device 14A. Alternatively, when the mode switching unit 60 detects that the electronic device 14A has returned to the normal mode from the low-consumption mode, the mode switching unit 60 may return to the normal mode in cooperation with the electronic device 14A.

[0038] The operation control unit 62 performs operation control on the pen side receiving circuit 46, the pen side transmitting circuit 48, and the additional function unit 50 according to the operation mode selected by the mode switching unit 60. The operation control unit 62 performs operation control while changing drive parameters related to a specific drive operation according to the selected operation mode. Examples of the "specific drive operation" include [1] a boost operation of the downlink signal DS, [2] a transmission operation of the downlink signal DS, [3] a frequency hopping operation of the downlink signal DS, [4] a reception operation of the uplink signal US, or [5] various operations related to the additional functions. The operation control unit 62 may change its behavior triggered by the reception of the uplink signal US between when the normal mode is being executed and when the low consumption mode is being executed.

[0039] The data writing unit 64 performs a function (hereinafter, writing function) of writing necessary data (e.g., firmware) supplied by communication with the electronic device 14A to the data storage unit 66. This data may be acquired through reception of an uplink signal US or through reception of a wireless signal WS. The driving parameters include [1] permission / prohibition of writing, and [2] time, memory area, and data amount allocated for writing.

[0040] The pen-side receiving circuit 46 executes a receiving function to receive an uplink signal US from the electronic device 14A. The driving parameters include [1] enabling / disabling of receiving, or [2] receiving frequency. This "disabling of receiving" includes stopping the receiving operation or stopping the processing of received data.

[0041] The pen-side transmitting circuit 48 executes a transmitting function of transmitting a downlink signal DS to the electronic device 14A. The driving parameters include [1] enabling / disabling transmission, [2] transmitting voltage (voltage value, with or without boosting), [3] rectangular pulse width, [4] transmitting frequency, [5] continuing / stopping frequency hopping, and [6] clock frequency. This "disabling of transmission" includes stopping the generation of the downlink signal DS or stopping the transmitting operation.

[0042] The pen pressure sensor 26 executes a pen pressure detection function that detects the pen pressure acting on the pen tip. Examples of the driving parameters include [1] enable / disable of detection, and [2] frequency of pen pressure detection. This "disable of detection" includes stopping the output of the detection signal or stopping the transmission of the pen pressure value.

[0043] The communication chip 72 executes a communication function to communicate with the electronic device 14A using a communication method (wired or wireless) different from the electrostatic coupling method. Examples of the communication method include USB (Universal Serial Bus), Bluetooth (registered trademark), and near field communication (NFC). Examples of the driving parameters include [1] continuation / stop of communication, or [2] type of communication mode.

[0044] The pen switch 74 executes an operation detection function for detecting an operation state by a user. Examples of the driving parameters include [1] valid / invalid of the operation, or [2] identification information of a switch whose operation is valid.

[0045] The vibration device 76 executes a vibration function that vibrates the active pen 12A to reproduce an analog-like writing feel. Examples of the driving parameters include [1] enabling / disabling vibration, and [2] vibration time and vibration level.

[0046] The PMIC 78 is an integrated circuit for monitoring the state of the power supply module 30 (FIG. 2) and supplying power to the pen-side controller 28a. The PMIC 78 successively measures the remaining power of the power supply module 30 and supplies the remaining power to the pen-side controller 28a.

[0047] <Explanation of operation> The position detection system 10A in the first embodiment is configured as described above. Next, the operation of the position detection system 10A will be described with reference to Figures 5 to 9. Figure 5 is a flow chart showing an example of a mode switching operation by the pen side controller 28a of Figures 3 and 4.

[0048] In step SP10, the pen side controller 28a checks whether or not a signal has been received from the electronic device 14. If a signal has not been received (step SP10: NO), the pen side controller 28a remains in step SP10 until a signal is received. On the other hand, if a signal has been received (step SP10: YES), the pen side controller 28a proceeds to the next step SP12.

[0049] In step SP12 of FIG. 5, the mode switching section 60 acquires the mode flag contained in the signal received in step SP10.

[0050] 6 is a diagram showing a first sharing method of the mode flag. The first sharing method corresponds to a method in which the electronic device 14A generates a mode flag and then provides the mode flag to the active pen 12A. Here, the touch sensor 16, the sensor side controller 18a, the host processor 34, and the wireless module 36 are shown as components of the electronic device 14A. Also, the pen side receiving circuit 46, the pen side transmitting circuit 48, and the communication chip 72 are shown as components of the active pen 12A.

[0051] First, the host processor 34 of the electronic device 14A acquires data including the remaining power supply of the active pen 12A through communication with the active pen 12A, and generates a mode flag indicating the operation mode to be executed.

[0052] When communication using the active electrostatic coupling method is used, the sensor-side controller 18a of the electronic device 14A generates an uplink signal US modulated by data including a mode flag, and transmits the uplink signal US from the sensor electrode of the touch sensor 16. Then, the active pen 12A receives the uplink signal US via the pen-side receiving circuit 46, and obtains data including the mode flag by demodulating the uplink signal US. In this manner, the active pen 12A obtains the mode flag.

[0053] When a wireless communication other than the active electrostatic coupling method is used, the sensor-side controller 18a of the electronic device 14A generates a wireless signal WS modulated by data including a mode flag, and transmits the wireless signal WS from the wireless module 36. The active pen 12A then receives the wireless signal WS via the communication chip 72, and acquires the data including the mode flag through demodulation of the wireless signal WS. In this manner, the active pen 12A acquires the mode flag.

[0054] 7 is a diagram illustrating a second sharing method of the mode flag. The second sharing method corresponds to a method in which the active pen 12A generates a mode flag and then provides the mode flag to the electronic device 14A.

[0055] First, the active pen 12A obtains its own remaining power supply and generates a mode flag indicating an operation mode to be executed. Then, the active pen 12A supplies the mode flag to the host processor 34 of the electronic device 14A through transmission of a downlink signal DS or a wireless signal WS modulated by data including the mode flag. Note that at this point, the active pen 12A does not yet switch the operation mode.

[0056] When communication using the active electrostatic coupling method is used, the sensor-side controller 18a of the electronic device 14A generates an uplink signal US modulated by data including a mode flag, and transmits the uplink signal US from the sensor electrode of the touch sensor 16. Then, the active pen 12A receives the uplink signal US via the pen-side receiving circuit 46, and obtains data including the mode flag by demodulating the uplink signal US. In this manner, the active pen 12A obtains the mode flag.

[0057] When a wireless communication other than the active electrostatic coupling method is used, the sensor-side controller 18a of the electronic device 14A generates a wireless signal WS modulated by data including a mode flag, and transmits the wireless signal WS from the wireless module 36. The active pen 12A then receives the wireless signal WS via the communication chip 72, and acquires the data including the mode flag through demodulation of the wireless signal WS. In this manner, the active pen 12A acquires the mode flag.

[0058] 5, the mode switching unit 60 refers to the value of the mode flag acquired in step SP12 and selects one operation mode from among the multiple operation modes. If the "normal mode" is selected (step SP14: normal mode), the mode switching unit 60 proceeds to the next step SP16.

[0059] In step SP16, the operation control section 62 controls the operations of each section in accordance with the normal mode selected in step SP14. Thereafter, the pen-side controller 28a returns to step SP10, and repeatedly executes steps SP10, SP12, SP14, and SP16 while the normal mode continues.

[0060] Returning to step SP14, if the "low consumption mode" is selected (step SP14: low consumption mode), the mode switching section 60 proceeds to the next step SP18.

[0061] In step SP18, the operation control unit 62 controls the operations of each unit in accordance with the low-consumption mode selected in step SP14. Thereafter, the pen-side controller 28a returns to step SP10, and repeatedly executes steps SP10, SP12, SP14, and SP18 while the low-consumption mode continues.

[0062] In this way, the pen-side controller 28a dynamically switches the operation mode of the active pen 12A by repeatedly executing steps SP10 to SP18 in FIG.

[0063] FIG. 8 is a diagram showing an example of the selection result of the operation mode. The horizontal axis of the graph indicates time t (unit: minute), and the vertical axis of the graph indicates the remaining battery level (unit: %). Here, it is assumed that the threshold of the remaining battery level for switching the operation mode is set to "50%".

[0064] First, while the remaining battery level is above 50% at t < t1, the normal mode is executed. After that, by continuously using the active pen 12A, when the remaining battery level drops to 50% at t = t1, the mode switches from the normal mode to the low-power consumption mode. As the remaining battery level gradually decreases and reaches a low level (t = t2), the charging of the power module 30 is started. When the remaining battery level recovers to 50% at t = t3, the mode switches from the low-power consumption mode to the normal mode.

[0065] After that, after the remaining battery level reaches 100% (t = t4), the use of the active pen 12A is resumed (t = t5). While the remaining battery level is above 50% at t5 < t < t6, the normal mode is executed. After that, by continuously using the active pen 12A, when the remaining battery level drops to 50% at t = t6, the mode switches from the normal mode to the low-power consumption mode. In this way, even when the use of the active pen 12A is continued while the remaining battery level is low, by automatically shifting to the low-power consumption mode, the active pen 12A can be used for a longer time.

[0066] <Comparison between the normal mode and the low-power mode> FIG. 9 is a diagram schematically showing differences in driving operations between operation modes in the first embodiment. [1] In the boosting operation of the downlink signal DS, in the normal mode, the voltage after boosting is set to Vs1, while in the low power consumption mode, the voltage after boosting is set to Vs2 (<Vs1). [2] In the transmission operation of the downlink signal DS, in the normal mode, the transmission rate is set to R1, while in the low power consumption mode, the transmission rate is set to R2 (<R1). [3] In the frequency hopping operation of the downlink signal DS, in the normal mode, the frequency hopping is set to "ON", while in the low power consumption mode, the frequency hopping is set to "OFF". [4] In the reception operation of the uplink signal US, in the normal mode, the reception is set to "ON" (bidirectional mode), while in the low power consumption mode, the reception is set to "OFF" (unidirectional mode).

[0067] [5] In the wireless communication operation, in the normal mode, the wireless communication is set to "ON", while in the low power consumption mode, the wireless communication is set to "OFF". [6] In the pen pressure detection operation of the active pen 12, in the normal mode, the detection is set to "ON", while in the low power consumption mode, the detection is set to "OFF". [7] In the angle detection operation of the active pen 12, in the normal mode, the angle detection is set to "ON", while in the low power consumption mode, the angle detection is set to "OFF". [8] In the operation reception operation of the pen switch 74, in the normal mode, the operation is set to "valid", while in the low power consumption mode, the operation is set to "invalid". [9] In the data writing operation, in the normal mode, the writing is "permitted", while in the low power consumption mode, the writing is "restricted".

[0068] Note that the change of the above-described driving parameters is not limited to one, and two or more combinations may be performed simultaneously as long as there is no technical contradiction. Further, the low power consumption mode may be set by the level of the remaining power amount (that is, the remaining amount level), and in this case, the number of changes of the driving parameters may be increased step by step according to the remaining amount level.

[0069] <Summary of the First Embodiment> As described above, the position detection system 10A in the first embodiment includes an electronic device 14A including a capacitive touch sensor 16 formed by arranging a plurality of sensor electrodes in a planar shape, and an active pen 12A used together with the electronic device 14A. The active pen 12A includes a receiving circuit (here, a pen side receiving circuit 46) for receiving an uplink signal US from the electronic device 14A, a transmitting circuit (i.e., a pen side transmitting circuit 48) for transmitting a downlink signal DS to the electronic device 14A, an additional function unit 50 for performing additional functions other than receiving the uplink signal US and transmitting the downlink signal DS, and a control unit (here, a pen side MCU 40) for controlling the operation of the pen side receiving circuit 46, the pen side transmitting circuit 48, or the additional function unit 50 according to a plurality of types of operation modes including a normal mode and a low consumption mode.

[0070] The normal mode is an operation mode in which the power consumption associated with a specific driving operation related to at least one of the reception of the uplink signal US, the transmission of the downlink signal DS, and the auxiliary functions is relatively high (e.g., an operation mode in which the execution frequency of the specific driving operation is relatively high or the execution amount of the specific driving operation is relatively large). The low consumption mode is an operation mode in which the power consumption associated with the specific driving operation is relatively low (e.g., an operation mode in which the execution frequency of the specific driving operation is relatively low or the execution amount of the specific driving operation is relatively small).

[0071] With this configuration, it is possible to execute various functions according to the remaining power of the active pen 12A. Specifically, by selecting the normal mode when the remaining power is high and the low consumption mode when the remaining power is low, it is possible to extend the operating time of the active pen 12A.

[0072] In addition, when the specific driving operation is a boost operation of the downlink signal DS, the pen side MCU 40 may control the boost operation by the pen side transmission circuit 48 so as to [1] boost the transmission voltage of the downlink signal DS to a first voltage in normal mode, and [2] boost the downlink signal DS to a second voltage lower than the first voltage, or stop boosting the downlink signal DS in low consumption mode.

[0073] Furthermore, when the specific drive operation is a boost operation of a downlink signal DS consisting of multiple rectangular pulses, the pen side MCU 40 may control the boost operation by the pen side transmission circuit 48 so that [1] in normal mode, the degree of slowing of the rise or fall of the rectangular pulses of the boosted downlink signal DS is relatively small, and [2] in low consumption mode, the degree of slowing of the rise or fall of the rectangular pulses of the boosted downlink signal DS is relatively large.

[0074] In addition, when the specific driving operation is a transmission operation of a downlink signal DS, the pen side MCU 40 may control the transmission operation by the pen side transmitting circuit 48 so that [1] in normal mode, the transmission frequency of the downlink signal DS is relatively high, and [2] in low consumption mode, the transmission frequency of the downlink signal DS is relatively low.

[0075] In addition, when the specific driving operation is a frequency hopping operation that performs frequency hopping to switch the transmission frequency of the downlink signal DS, the pen side MCU 40 may control the frequency hopping operation by the pen side transmission circuit 48 so as to: [1] in normal mode, continue frequency hopping by relatively increasing the frequency of switching the transmission frequency; and [2] in low consumption mode, continue frequency hopping by relatively decreasing the frequency of switching the transmission frequency, or stop frequency hopping.

[0076] In addition, when the specific driving operation is a transmission operation of transmitting a downlink signal DS by switching the clock frequency related to the generation or transmission of the downlink signal DS, the pen side MCU 40 may control the transmission operation by the pen side transmitting circuit 48 so as to [1] transmit the downlink signal DS at a relatively high clock frequency in normal mode, and [2] transmit the downlink signal DS at a relatively low clock frequency in low consumption mode.

[0077] In addition, when the specific driving operation is a receiving operation of the uplink signal US, the pen side MCU 40 may control the receiving operation by the pen side receiving circuit 46 so as to: [1] continue receiving the uplink signal US in normal mode; and [2] receive the uplink signal US intermittently or disable reception of the uplink signal US in low consumption mode.

[0078] In addition, in the low consumption mode, the pen side MCU 40 may control the transmission operation of the pen side transmission circuit 48 so as to transmit the downlink signal DS at a predetermined transmission period while disabling reception of the uplink signal US.

[0079] The additional functions include at least one of a communication function for communicating with the electronic device 14A using a method other than the active electrostatic coupling method, a pen pressure detection function for detecting the pen pressure acting on the pen tip of the active pen 12A, an operation detection function for detecting the operation state of a switch of the active pen 12A, a vibration function for vibrating the active pen 12A, and a writing function for writing data supplied from the electronic device 14A to a memory. In this case, the pen-side MCU 40 may control the operation of the additional function unit 50 so as to [1] continue the additional function in the normal mode, and [2] intermittently execute the additional function or stop execution of the additional function in the low-consumption mode.

[0080] Furthermore, the pen side MCU 40 may behave differently when the normal mode is being executed and when the low consumption mode is being executed, in response to reception of the uplink signal US.

[0081] Furthermore, the electronic device 14A may select an operation mode for the active pen 12A based on the remaining capacity of a power source (here, the power source module 30) mounted on the active pen 12A, and generate a mode flag indicating the operation mode. In this case, the pen-side MCU 40 acquires the mode flag through reception from the electronic device 14A, and switches between the normal mode and the low-consumption mode according to the value of the mode flag.

[0082] The pen-side MCU 40 may also switch between the normal mode and the low-consumption mode based on the remaining capacity of the power source (here, the power source module 30) mounted on the active pen 12A. In this case, the pen-side transmission circuit 48 transmits a downlink signal DS including a mode flag indicating the currently executed operation mode to the electronic device 14A.

[0083] [Second embodiment] Next, a position detection system 10B in the second embodiment will be described with reference to Fig. 10 to Fig. 18. The position detection system 10B corresponds to one aspect of the position detection system 10 shown in Fig. 1. This position detection system 10B includes an active pen 12B and an electronic device 14B.

[0084] <Internal configuration of electronic device 14B> 10 is a diagram showing an example of the internal configuration of an electronic device 14B in the second embodiment. The electronic device 14B includes a touch sensor 16, a sensor-side controller 18b, and a host processor .

[0085] The touch sensor 16 is a capacitance type (more specifically, mutual capacitance type) sensor in which a plurality of sensor electrodes 16X and 16Y are arranged in a planar shape. The touch sensor 16 includes a plurality of sensor electrodes 16X for detecting a position in an X direction (X coordinate) and a plurality of sensor electrodes 16Y for detecting a position in a Y direction (Y coordinate). The linear sensor electrodes 16X are provided extending in the Y direction and are arranged at equal intervals while being spaced apart from each other along the X direction. The linear sensor electrodes 16Y are provided extending in the X direction and are arranged at equal intervals while being spaced apart from each other along the Y direction. The sensor electrodes 16X and 16Y are insulated from each other by an insulating substrate (not shown) made of glass or resin.

[0086] The sensor side controller 18b is connected to the touch sensor 16 and includes a micro control unit (hereinafter, sensor side MCU 100), a logic circuit 101, sensor side transmission circuits 102 and 103, a sensor side reception circuit 104, and a selector circuit 105.

[0087] The sensor-side MCU 100 and the logic circuit 101 control the transmission and reception operations of the sensor-side controller 18b by controlling the sensor-side transmission circuits 102 and 103, the sensor-side reception circuit 104, and the selector circuit 105. The sensor-side MCU 100 is a control unit that selectively performs the following operations by reading and executing a program from its own memory: [1] supplying a pixel drive voltage Vcom to the selector circuit 105, [2] controlling the sensor-side transmission circuit 102 to transmit a finger detection signal FDS, [3] controlling the sensor-side reception circuit 104 to receive the finger detection signal FDS, [4] controlling the sensor-side transmission circuit 103 to transmit an uplink signal US to the active pen 12B, and [5] controlling the sensor-side reception circuit 104 to receive a downlink signal DS from the active pen 12B. Furthermore, the logic circuit 101 is configured to generate control signals for the sensor side transmission circuits 102 and 103, the sensor side reception circuit 104, and the selector circuit 105 in response to the control of the sensor side MCU 100.

[0088] When the downlink signal DS is a "position signal" indicating the position of the active pen 12B, the sensor-side MCU 100 calculates the position coordinates (x, y) of the active pen 12B on the touch surface from the reception strength at each of the multiple sensor electrodes 16X, 16Y, and outputs it to the host processor 34. On the other hand, when the downlink signal DS is a "data signal" including transmission data, the sensor-side MCU 100 obtains response data Res (specifically, a unique ID, writing pressure, on / off information of the pen switch, etc.) included in this data signal and outputs it to the host processor 34.

[0089] The sensor-side transmission circuit 102 generates a finger detection signal FDS under the control of the sensor-side MCU 100, and supplies the signal to each sensor electrode 16X via a selector circuit 105. The finger detection signal FDS is, for example, K signals s1 to s2 each consisting of K pulses represented by "1" or "-1". K The signals s1 to s K Each nth (n=1~K) pulse is a part of pulse group p n and one pulse group p n The pulses constituting the signal are input in parallel from the sensor side transmission circuit 102 through the selector circuit 105 to each sensor electrode 16X.

[0090] The sensor side transmission circuit 103 has a function of generating an uplink signal US under the control of the sensor side MCU 100 and the logic circuit 101. Specifically, the sensor side transmission circuit 103 is configured to include a code sequence holding unit 110, a diffusion processing unit 111, and a transmission guard unit 112.

[0091] The code sequence holding unit 110 has a function of generating and holding a spreading code of a predetermined chip length having autocorrelation characteristics, based on a control signal ctrl_t3 supplied from the logic circuit 101. The spreading code held by the code sequence holding unit 110 is supplied to a spreading processing unit 111.

[0092] The spreading processing unit 111 has a function of acquiring a transmission chip sequence of a predetermined chip length by modulating the spreading code held by the code sequence holding unit 110 based on the command COM supplied via the sensor-side MCU 100. The spreading processing unit 111 supplies the acquired transmission chip sequence to the selector circuit 105 via the transmission guard unit 112.

[0093] The transmission guard unit 112 has the function of inserting a guard period (i.e., a period during which neither transmission nor reception is performed) required to switch between the transmission period of the uplink signal US and the reception period of the downlink signal DS based on a control signal ctrl_t4 supplied from the logic circuit 101.

[0094] The sensor side receiving circuit 104 receives the finger detection signal FDS transmitted by the sensor side transmitting circuit 102 or the downlink signal DS transmitted by the active pen 12B based on the control signal ctrl_r of the logic circuit 101. Specifically, the sensor side receiving circuit 104 includes an amplifier circuit 115, a detection circuit 116, and an analog-to-digital (AD) converter 117.

[0095] The amplifier circuit 115 amplifies and outputs the finger detection signal FDS or the downlink signal DS supplied from the selector circuit 105. The detector circuit 116 generates a voltage corresponding to the level of the output signal of the amplifier circuit 115. The AD converter 117 generates a digital signal by sampling the voltage output from the detector circuit 116 at predetermined time intervals. The digital signal output by the AD converter 117 is supplied to the sensor-side MCU 100.

[0096] The selector circuit 105 is connected to the touch sensor 16, and performs a switching operation in response to a control signal from the logic circuit 101. Specifically, the selector circuit 105 includes two switches 118x and 118y, and two electrode selection circuits 119x and 119y.

[0097] Each of the switches 118x and 118y is configured such that a common terminal is connected to one of the T1 terminal, the T2 terminal, the R terminal, and the D terminal. The common terminal of the switch 118x is connected to the electrode selection circuit 119x, the T1 terminal to the output terminal of the sensor side transmission circuit 102, the T2 terminal to the output terminal of the sensor side transmission circuit 103, the R terminal to the input terminal of the sensor side reception circuit 104, and the D terminal to the output terminal of the sensor side MCU 100. The common terminal of the switch 118y is connected to the electrode selection circuit 119y, the T terminal to the output terminal of the sensor side transmission circuit 103, and the R terminal to the input terminal of the sensor side reception circuit 104.

[0098] The electrode selection circuit 119x is a switch element for selectively connecting the multiple sensor electrodes 16X to a common terminal of the switch 118x. That is, the electrode selection circuit 119x is configured to be able to simultaneously connect at least some of the multiple sensor electrodes 16X to the common terminal of the switch 118x. The electrode selection circuit 119y is a switch element for selectively connecting the multiple sensor electrodes 16Y to the common terminal of the switch 118y. That is, the electrode selection circuit 119y is configured to be able to simultaneously connect at least some of the multiple sensor electrodes 16Y to the common terminal of the switch 118y.

[0099] Four control signals sTRx, sTRy, selX, and selY are supplied to the selector circuit 105 from the logic circuit 101. Specifically, the control signal sTRx is supplied to the switch 118x, the control signal sTRy is supplied to the switch 118y, the control signal selX is supplied to the electrode selection circuit 119x, and the control signal selY is supplied to the electrode selection circuit 119y. The logic circuit 101 performs switching control of the selector circuit 105 through the four control signals sTRx, sTRy, selX, and selY to selectively perform [1] transmission and reception of a finger detection signal FDS, or [2] transmission of an uplink signal US and reception of a downlink signal DS.

[0100] The host processor 34 is configured with an arithmetic processing device including a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and an MPU (Micro-Processing Unit). The host processor 34 executes a program stored in a memory (not shown) to execute an operating system of the electronic device 14B and various applications such as drawing software. The drawing software includes a function of generating stroke data based on coordinates successively supplied from the sensor-side controller 18b, rendering the data, and displaying the data on a display, and a function of adjusting the rendering result based on data such as a pen pressure value supplied from the sensor-side controller 18b (for example, a function of adjusting a line width according to a pen pressure value).

[0101] <Function block diagram> Fig. 11 is a functional block diagram relating to the sensor-side MCU 100 shown in Fig. 10. The sensor-side MCU 100 includes a mode switching unit 130, a position detection unit 132, and an output processing unit 134.

[0102] The mode switching unit 130 switches between a plurality of types of operation modes that combine touch scanning or pen scanning. As in the first embodiment, the types of operation modes are classified into [1] a "first operation mode group" that switches depending on the detection result of the active pen 12B or the passive pointer, and [2] a "second operation mode group" that switches depending on the remaining amount of power provided in the active pen 12B. As in the first embodiment, the first operation mode group includes the STP mode or the exclusive mode, and the second operation mode group includes the normal mode or the low-consumption mode.

[0103] In the second embodiment, the low-consumption mode is divided into [1] an "active mode" that maintains the pen function of the active pen 12B, and [2] a "passive mode" that stops transmission of the downlink signal DS and causes the active pen 12B to function as a passive pointer. During execution of the active mode or the passive mode, the sensor-side controller 18b executes at least one of [1] a fallback operation, [2] a touch priority operation, [3] a passivation operation, [4] a pseudo-passivation operation, and [5] a signal reflection operation. Each operation will be described in detail later.

[0104] The mode switching unit 130 refers to the remaining power information supplied from the active pen 12B and selects an operation mode according to the magnitude relationship between the remaining power and a predetermined threshold. This "remaining power information" means a quantitative or qualitative value indicating the remaining power of the active pen 12B. For example, the mode switching unit 130 selects the "normal mode" when the current remaining power exceeds the threshold (50%), and selects the "low consumption mode" when the current remaining power is equal to or less than the threshold. Note that two or more remaining power thresholds may be provided, and a low consumption mode (or a sub-mode) that consumes less power may be selected in stages as the remaining power decreases.

[0105] The position detection unit 132 detects the position of the active pen 12B or a passive pointer (for example, finger F in FIG. 10) according to the operation mode selected by the mode switching unit 130. The position detection unit 132 performs a drive operation while changing drive parameters related to a specific drive operation according to the selected operation mode. Examples of the "specific drive operation" include [1] a transmission operation of an uplink signal US, [2] a reception operation of a downlink signal DS, [3] an angle calculation operation of the active pen 12B, or [4] various operations related to the scan operation of the touch sensor 16.

[0106] Specifically, the position detection unit 132 includes a scan control unit 136 , a signal transmission unit 138 , a signal acquisition unit 140 , a touch detection unit 142 , and a pen detection unit 144 .

[0107] The scan control unit 136 repeatedly executes a plurality of types of scan processing in a time-division manner via the touch sensor 16. The plurality of types of scan processing includes [1] a "touch scan" for detecting a passive pointer (e.g., a finger F) that does not transmit a signal, and [2] a "pen scan" for detecting an active pen 12B that transmits a downlink signal DS. The touch scan and the pen scan may be executed in a ratio of 1:1, or in a ratio of n:m (n ≠ m).

[0108] The above-mentioned touch scan is executed to detect a change in capacitance in the sensor electrodes 16X and 16Y. This touch scan may be, for example, [1] a scan based on a "mutual capacitance method" in which a finger detection signal FDS is transmitted from the sensor electrode 16X and the sensor electrode 16Y receives the signal FDS to detect a change in mutual capacitance between the sensor electrodes 16X and 16Y, or [2] a scan based on a "self-capacitance method" in which a change in capacitance of each of the sensor electrodes 16X and 16Y is detected.

[0109] The scan control unit 136 performs a scan operation according to drive parameters corresponding to the operation mode selected by the mode switching unit 130. Examples of the drive parameters include [1] the length of a time slot assigned to a touch scan (hereinafter also referred to as "touch time length"), or [2] the length of a time slot assigned to a pen scan (hereinafter also referred to as "pen time length").

[0110] The signal transmitting unit 138 transmits a desired signal for performing a touch scan or a pen scan from the sensor electrodes 16X, 16Y in response to transmission control by the scan control unit 136. The signal transmitting unit 138 generates a finger detection signal FDS for detecting a finger F while performing a touch scan, and outputs and transmits this finger detection signal FDS to a transmission electrode (here, one or more sensor electrodes 16X). The signal transmitting unit 138 generates an uplink signal US for detecting the active pen 12B while performing a pen scan, and outputs and transmits this uplink signal US to a transmission electrode (here, one or more sensor electrodes 16X, 16Y).

[0111] The signal transmission unit 138 performs the transmission operation of the uplink signal US according to the driving parameters corresponding to the operation mode selected by the mode switching unit 130. Examples of the driving parameters include [1] enabling / disabling the transmission, [2] the transmission voltage (voltage value, whether or not the voltage is boosted), or [3] the transmission frequency of the uplink signal US. This "disabling of the transmission" includes stopping the generation of the uplink signal US or stopping the transmission operation.

[0112] The signal acquisition unit 140 receives or acquires a desired signal for performing a touch scan or a pen scan from the sensor electrodes 16X, 16Y in response to reception control by the scan control unit 136. The signal acquisition unit 140 receives a finger detection signal FDS from the transmitting electrode from a receiving electrode (here, one or more sensor electrodes 16Y) during execution of a touch scan, and acquires a detection signal (or a first detection signal) for detecting the presence or absence or the position of a finger F. The signal acquisition unit 140 receives a downlink signal DS from the active pen 12B from a receiving electrode (here, one or more sensor electrodes 16X, 16Y) during execution of a pen scan, and acquires a detection signal (or a second detection signal) for detecting the presence or absence or the position of the active pen 12B.

[0113] The signal acquisition unit 140 performs the receiving operation of the downlink signal DS according to the driving parameters corresponding to the operation mode selected by the mode switching unit 130. Examples of the driving parameters include [1] enabling / disabling reception, or [2] the frequency of receiving the downlink signal DS. This "disabling of reception" includes stopping the receiving operation, or stopping the processing of received data.

[0114] The touch detection unit 142 detects the presence or absence or position of a passive pointer (hereinafter, collectively referred to as "touch position") by applying various signal processing to the first detection signal acquired by the signal acquisition unit 140. This signal processing includes [1] "threshold processing" for detecting the presence or absence of a finger F from the magnitude relationship between the signal value for each position indicated by the signal distribution and a threshold value, [2] "identification processing" for identifying the type of touch (e.g., finger F, palm, or other object) based on the size or shape of the area detected by the threshold processing, and [3] "position calculation processing" for calculating the touch position by applying an interpolation calculation or an approximation calculation to the signal distribution.

[0115] The pen detection unit 144 detects the presence or absence or position of the active pen 12B (hereinafter collectively referred to as "pen position") by applying various signal processing to the second detection signal acquired by the signal acquisition unit 140. This signal processing includes [1] "threshold processing" that detects the presence or absence of the active pen 12B from the magnitude relationship between the signal level for each position indicated by the signal distribution and a threshold, and [2] "position calculation processing" that detects the pen position by applying an interpolation calculation or an approximation calculation to the signal distribution.

[0116] The pen detection unit 144 performs the detection operation of the pen position according to the driving parameters corresponding to the operation mode selected by the mode switching unit 130. An example of the driving parameters is a threshold value used in threshold processing.

[0117] The output processing unit 134 generates position information including the pen position or touch position calculated by the position detection unit 132, and then outputs data including the position information to the host processor 34 (FIG. 10). The output processing unit 134 may output data at a predetermined cycle (e.g., 120 Hz). In addition to the position information of the active pen 12B, this data may include: [1] information provided by the active pen 12B (e.g., pen ID, writing pressure, on / off information of a pen switch, etc.); [2] information calculated from the position information (e.g., tilt angle, direction, speed, acceleration); and [3] identification information of the currently executed operation mode.

[0118] The output processing unit 134 is configured to be able to output data in accordance with driving parameters corresponding to the operation mode selected by the mode switching unit 130. Examples of the driving parameters include [1] the presence or absence of each data item, or [2] the frequency of outputting data.

[0119] <Explanation of operation> The position detection system 10B in the second embodiment is configured as described above. Next, the operation of the position detection system 10B will be described with reference to Fig. 12 to Fig. 18. Fig. 12 is a flow chart showing an example of a mode switching operation by the sensor side controller 18b in Figs.

[0120] 12, the sensor-side controller 18b checks whether the detection timing has arrived. If the detection timing has not yet arrived (step SP30: NO), the sensor-side controller 18b remains in step SP30 until the detection timing arrives. On the other hand, if the detection timing has arrived (step SP30: YES), the sensor-side controller 18b proceeds to the next step SP32.

[0121] In step SP32, the mode switching section 130 acquires the most recent remaining power supply amount supplied from the active pen 12b.

[0122] In step SP34, the mode switching section 130 selects the operation mode to be executed based on the remaining power level acquired in step SP32.

[0123] In step SP36, the mode switching unit 130 checks the operation mode selected in step SP34. If the normal mode is selected (step SP36: normal mode), the mode switching unit 130 supplies a mode flag indicating the "normal mode" to the position detection unit 132, and proceeds to the next step SP38.

[0124] In step SP38, the position detection unit 132 performs detection processing for the active pen 12b in accordance with the normal mode. After that, the sensor-side controller 18b returns to step SP30, and repeatedly executes steps SP30, SP32, SP34, SP36, and SP38 while the normal mode continues.

[0125] Returning to step SP36, if the low consumption mode is selected (step SP36: low consumption mode), the mode switching section 130 supplies a mode flag indicating the "low consumption mode" to the position detection section 132, and proceeds to the next step SP40.

[0126] In step SP40, the position detection unit 132 performs detection processing for the active pen 12b in accordance with the low consumption mode. After that, the sensor-side controller 18b returns to step SP30, and repeatedly executes steps SP30, SP32, SP34, SP36, and SP40 while the low consumption mode continues.

[0127] In this way, the sensor-side controller 18b repeatedly executes steps SP30 to SP40 in FIG. 12, thereby performing the detection operation of the active pen 12b in real time.

[0128] <Examples of low consumption mode> Next, a specific example of the low consumption mode will be described with reference to FIGS.

[0129] (First Example: Fallback Operation) As a first example of the low power consumption mode, the fallback operation of the position detection system 10B will be described. This "fallback operation" means an operation to maintain the operation of the active pen 12B while partially stopping the functions or performance of the position detection system 10B.

[0130] FIG. 13 is a diagram showing a first example of a comparison of drive operations between the normal mode and the low power mode. [1] In the transmission operation of the uplink signal US, transmission is set to "ON" in the normal mode, while transmission is set to "OFF" in the low power consumption mode. [2] In the reception operation of the downlink signal DS, reception is set to "ON" in the normal mode, while reception is set to "OFF" in the low power consumption mode. [3] In the threshold determination operation of the reception level, the threshold is set to Th1 in the normal mode, while the threshold is set to Th2 (<Th1) in the low power consumption mode. [4] In the angle detection operation of the active pen 12B, detection is set to "ON" in the normal mode, while detection is set to "OFF" in the low power consumption mode.

[0131] Note that the above-described changes in the drive parameters may differ depending on [1] whether it is the active mode or the passive mode, or [2] the behavior of the active pen 12B in the low power consumption mode. For example, in the low power consumption mode, transmission of the uplink signal US or reception of the downlink signal may be set to "ON". In this case, the active pen 12B can realize the low power consumption mode by spontaneously stopping the transmission of the downlink signal DS or stopping the transmission of the downlink signal DS corresponding to the uplink signal US through blocking the detection of the uplink signal US.

[0132] (Second Example: Touch Priority Operation) As a second example of the low power consumption mode, the touch priority operation of the position detection system 10B will be described. This "touch priority operation" means an operation to prioritize touch scanning when performing touch scanning and pen scanning in a time-division manner.

[0133] Fig. 14 is a diagram showing a second example of a comparison of drive operations between the normal mode and the low power mode. More specifically, Fig. 14 shows a schematic time schedule of the scan operation by the scan control unit 136 of Fig. 11. Note that the rectangles in the drawing correspond to the time slots assigned to each scan.

[0134] The normal mode is an operation mode for executing one touch scan (TS) and one pen scan (PS) in a time-sharing manner. The touch scan time slot is assigned a time length of T1 (unit: ms). The pen scan time slot is assigned a time length of T2 (unit: ms). In other words, [1] one touch scan with a time length of T1 and [2] one pen scan with a time length of T2 constitute one operation unit (period: Tc1 = T1 + T2).

[0135] The low power mode corresponds to an operation mode in which two touch scans (TS) and one pen scan (PS) are executed in a time-division manner. The touch scan time slot is assigned a time length of T1 (unit: ms). The pen scan time slot is assigned a time length of T2 (unit: ms). In other words, [1] two touch scans with a time length of 2·T1 and [2] one pen scan with a time length of T2 constitute one operation unit (period: Tc2=2·T1+T2).

[0136] Here, if the pen output rates in the normal mode and the low consumption mode are R1 and R2 [Hz], respectively, R1 and R2 are calculated according to the following formulas (1) and (2). R1=1000 / Ts1=1000 / (T1+T2) ‥‥(1) R2=1000 / Ts2=1000 / (T1+2·T2)‥‥(2)

[0137] Here, when T2 is a positive value, the relationship R1>R2 is satisfied. In this way, by performing touch scanning preferentially in the low power consumption mode, the response frequency of the active pen 12B is relatively reduced, and the power consumption of the active pen 12B is accordingly reduced.

[0138] (Third example: Passivation operation) As a third example of the low-consumption mode, a passivation operation of the position detection system 10B will be described. This "passivation operation" refers to an operation for making the active pen 12B function as a "passive pointer."

[0139] 15 is a first block diagram of the pen side controller 28b of the active pen 12B in the second embodiment. The pen side controller 28b includes a pen side MCU 160, a first switch 42, a second switch 44, a pen side receiving circuit 46, a pen side transmitting circuit 48, an additional function unit 50, and a third switch 162.

[0140] The pen-side MCU 160 is a unit that performs overall control over each part of the active pen 12B, similar to the pen-side MCU 40 shown in Fig. 3. The pen-side MCU 160 performs switching control of the first switch 42, the second switch 44, and the third switch 162 according to the currently executed operation mode.

[0141] The third switch 162 is a switch element configured to connect the common terminal side of the first switch 42 and the common terminal side of the second switch 44. The pen-side MCU 160 supplies a third switch control signal SWC3 to the third switch 162 to perform switching control, thereby selectively shorting the tip electrode 22 and the ring electrode 24 and releasing the short circuit.

[0142] Next, the switching control associated with switching between the normal mode and the low consumption mode will be described. During execution of the normal mode, the pen-side MCU 160 performs switching control so that the third switch 162 is kept in the "open" state, and performs operation control of each part in the same manner as in the first embodiment.

[0143] Thereafter, when the normal mode is switched to the low-consumption mode, the pen-side MCU 160 performs switching control so that the first switch 42 and the second switch 44 are kept in the "open" state, and the third switch 162 is kept in the "closed" state. This shorts the tip electrode 22 and the ring electrode 24. The increase in the volume of the conductor portion that forms the capacitance with the touch sensor 16 makes it easier to stabilize the detection of the active pen 12B as a passive pointer.

[0144] 15 shows an example in which tip electrode 22 and ring electrode 24 are short-circuited, but the present invention is not limited to this configuration. For example, three or more pen electrodes may be short-circuited, or one pen electrode may be short-circuited between housing 32. When tip electrode 22 and housing 32 are short-circuited, third switch 162 is provided between the common terminal side of first switch 42 and the ground line connected to housing 32.

[0145] <Example 4: Pseudo activation behavior> As a fourth example of the low-consumption mode, a pseudo-activation operation of the position detection system 10B will be described. This "pseudo-activation operation" refers to an operation for pseudo-detecting the operating state of the active pen 12B as "active" even though the operating state is "passive".

[0146] 16 is a diagram showing an example of a signal waveform of the downlink signal DS. This downlink signal DS is composed of [1] a position detection signal, [2] a start signal, and [3] a data signal. The position detection signal is a burst signal for detecting the position of the active pen 12B. The start signal is a timing signal for determining the start point of the data signal. The data signal is a signal in which data including a pen pressure value is coded by the presence or absence (binary) of a burst signal.

[0147] For example, assume that the sensor-side controller 18 receives a common downlink signal DS regardless of whether the normal mode or the low power mode is selected. If the operating state of the active pen 12B is "passive", the downlink signal DS is not transmitted, and therefore the active pen 12B is not detected by the sensor-side controller 18. Therefore, by devising the circuit configuration of the sensor-side controller 18, it is possible to detect the active pen 12B as pseudo-"active" even though the operating state is "passive".

[0148] 17 is a diagram showing the main part of the circuit configuration for realizing pseudo activation. The sensor-side controller 18c includes a sensor-side receiving circuit 104, a sensor-side MCU 170, an oscillator circuit 172 (corresponding to a "signal generating circuit"), and a fourth switch 174 (corresponding to a "switch").

[0149] The sensor-side MCU 170 is a unit that performs overall control over each part of the sensor-side controller 18c, similar to the sensor-side MCU 100 shown in Fig. 10. The sensor-side MCU 170 performs switching control of the fourth switch 174 according to the operation mode being executed.

[0150] The oscillator circuit 172 generates a continuous or intermittent burst signal according to enable control by the sensor-side MCU 170. This burst signal has the same waveform shape (i.e., the same time length and frequency) as the "position detection signal" of the downlink signal DS shown in FIG.

[0151] The fourth switch 174 is a switch element provided between the reference potential (i.e., GND) side of the sensor side receiving circuit 104 and the output side of the oscillation circuit 172. The sensor side MCU 170 supplies a fourth switch control signal SWC4 to the fourth switch 174 to perform switching control, thereby selectively connecting and disconnecting the sensor side receiving circuit 104 and the oscillation circuit 172.

[0152] Next, the switching control associated with switching between the normal mode and the low consumption mode will be described. During execution of the normal mode, the sensor-side MCU 170 supplies an "OFF" enable signal to the oscillator circuit 172 and performs switching control so that the fourth switch 174 is kept in the "open" state.

[0153] Thereafter, when the normal mode is switched to the low-consumption mode, the sensor-side MCU 170 supplies an "ON" enable signal to the oscillator circuit 172 and performs switching control so that the fourth switch 174 is kept in the "closed" state. Then, the burst signal generated by the oscillator circuit 172 is superimposed on the reference potential of the sensor-side receiving circuit 104. This allows the sensor-side MCU 170 to receive the downlink signal DS including only the position detection signal through the sensor-side receiving circuit 104, thereby enabling it to virtually detect the active pen 12B.

[0154] 17 shows an example in which the burst signal is superimposed on the reference potential (GND) of the sensor side receiving circuit 104, but the present invention is not limited to this configuration. For example, the burst signal may be superimposed on the power supply potential (Vcc) of the sensor side receiving circuit 104. In this case, the fourth switch 174 is provided between the Vcc side of the sensor side receiving circuit 104 and the output side of the oscillation circuit 172.

[0155] <5th Example: Signal reflection operation> As a fifth example of the low-consumption mode, a signal reflection operation of the position detection system 10B will be described. This "signal reflection operation" refers to an operation in which the active pen 12B reflects the uplink signal US, so that the electronic device 14B detects it as being in a pseudo "active state."

[0156] 18 is a second block diagram of the pen side controller 28c of the active pen 12B in the second embodiment. The pen side controller 28c includes a pen side MCU 180, a first switch 42, a second switch 44, a pen side receiving circuit 182, a pen side transmitting circuit 48, and an additional function unit 50.

[0157] The pen-side MCU 180 is a unit that performs overall control over each part of the active pen 12B, similar to the pen-side MCU 40 shown in Fig. 3. The pen-side MCU 160 performs switching control of the first switch 42, the second switch 44, and a fifth switch 186 (described later) according to the currently executed operation mode.

[0158] The pen side receiving circuit 182 is a circuit that demodulates the uplink signal US induced to the tip electrode 22 or the ring electrode 24, and outputs the demodulated data to the pen side MCU 180. Specifically, the pen side receiving circuit 182 is configured to include an amplifier circuit 184, a fifth switch 186, and a decoding processor 188.

[0159] The amplifier circuit 184 is a circuit that amplifies the uplink signal US induced in the tip electrode 22 or the ring electrode 24. The input terminal of the amplifier circuit 184 is connected to the R terminals of the first switch 42 and the second switch 44, and the ground terminal of the amplifier circuit 184 is connected to the housing 32.

[0160] The fifth switch 186 is a switch element configured such that a common terminal is connected to either an R terminal or a T terminal. The common terminal of the fifth switch 186 is connected to the amplifier circuit 184, the R terminal is connected to the decoding processor 188, and the T terminal is connected to the first switch 42 and the second switch 44. The pen-side MCU 180 supplies a fifth switch control signal SWC5 to the fifth switch 186 to perform switching control, thereby selectively performing reception and mirror transmission of the uplink signal US.

[0161] The decoding processor 188 performs a process of decoding the uplink signal US amplified by the amplifier circuit 184. The decoding processor 188 has, for example, the same functions as the waveform regenerator 52 and the correlation calculator 54 (FIG. 3) in the first embodiment.

[0162] Next, switching control associated with switching between the normal mode and the low-consumption mode will be described. During execution of the normal mode, for example, the pen-side MCU 180 performs switching control so that the first switch 42 is connected to the T terminal, the second switch 44 is connected to the R terminal, and the fifth switch 186 is connected to the R terminal. Then, the pen-side controller 28c receives an uplink signal US via the ring electrode 24 and transmits a downlink signal DS via the tip electrode 22.

[0163] Thereafter, when the normal mode is switched to the low-consumption mode, the pen side MCU 180 performs switching control so that the first switch 42 is connected to the T terminal, the second switch 44 is connected to the R terminal, and the fifth switch 186 is connected to the T terminal. Then, the pen side controller 28c mirror-transmits the uplink signal US induced in the ring electrode 24 via the second switch 44, the amplifier circuit 184, the fifth switch 186, and the first switch 42, and then via the tip electrode 22. This makes it possible to block the supply of data to the pen side MCU 180, and accordingly reduces the amount of processing calculations by the pen side MCU 180.

[0164] <Summary of the second embodiment> As described above, the position detection system 10B in the second embodiment includes an electronic device 14B including a capacitive touch sensor 16 formed by arranging a plurality of sensor electrodes 16X, 16Y in a planar shape, and an active pen 12B used together with the electronic device 14B. The active pen 12B includes a pen side receiving circuit 46 that receives an uplink signal US from the electronic device 14B, a pen side transmitting circuit 48 that transmits a downlink signal DS corresponding to the uplink signal US to the electronic device 14B, and a pen side control unit (here, pen side MCU 40, 160, 180) that controls the driving operation by the pen side receiving circuit 46 or the pen side transmitting circuit 48 in accordance with a plurality of types of operation modes including a normal mode and a low consumption mode.

[0165] The normal mode is an operation mode in which the transmission of the downlink signal DS continues, and the low-consumption mode is an operation mode in which the transmission of the downlink signal DS is stopped and the active pen 12B functions as a passive pointer. This configuration makes it possible to execute various functions according to the state of the remaining power of the active pen 12B. Specifically, by selecting the normal mode when the remaining power is high and the low-consumption mode when the remaining power is low, the operating time of the active pen 12B can be extended.

[0166] In addition, in the low-consumption mode, the pen side MCU 40 may voluntarily stop transmitting the downlink signal DS, or may stop transmitting the downlink signal DS corresponding to the uplink signal US by cutting off detection of the uplink signal US.

[0167] In addition, if the active pen 12B further includes two or more pen electrodes (here, the tip electrode 22 and the ring electrode 24) for receiving an uplink signal US or transmitting a downlink signal DS, and a switch (here, the third switch 162) provided between the connection lines connecting the two or more pen electrodes, the pen side MCU 160 may perform switching control so that the third switch 162 is in an open state in the normal mode and in a closed state in the low consumption mode.

[0168] In addition, if the active pen 12B further comprises a housing 32 that accommodates at least a pen side receiving circuit 46, a pen side transmitting circuit 48, and a pen side MCU 160, a pen electrode (here, the tip electrode 22 or the ring electrode 24) for receiving an uplink signal US or transmitting a downlink signal DS, and a switch provided between the connecting line connecting the pen electrode and the housing 32, the pen side MCU 160 may perform switching control so as to open the switch in the normal mode and close the switch in the low consumption mode.

[0169] In addition, if the electronic device 14B further includes a sensor side controller 18b that controls the driving operation of the touch sensor 16, the sensor side controller 18b may perform a receiving operation of a common downlink signal DS regardless of whether the normal mode or the low consumption mode is selected.

[0170] The sensor side controller 18b may also include a sensor side receiving circuit 104 that receives a downlink signal DS via the sensor electrodes 16X, 16Y, a signal generating circuit (here, an oscillator circuit 172) that generates a simulated signal that simulates the downlink signal DS, a switch (here, a fourth switch 174) that is provided between the power supply potential side of the sensor side receiving circuit 104 and the output side of the oscillator circuit 172, or between the power supply potential side of the sensor side receiving circuit 104 and the output side of the oscillator circuit 172, and a sensor side control unit (here, the sensor side MCU 170) that performs switching control so as to open the fourth switch 174 in the normal mode and close the fourth switch 174 in the low consumption mode.

[0171] In addition, if the active pen 12B further includes a switch (here, a fifth switch 186) for switching the output destination of the pen side receiving circuit 46 to the pen side MCU 180 or the pen side transmitting circuit 48, the pen side MCU 180 may perform switching control so that the output destination of the fifth switch 186 is connected to the pen side MCU 180 in normal mode, and to the pen side transmitting circuit 48 in low consumption mode.

[0172] [Third embodiment] Next, a position detection system 10C in a third embodiment will be described with reference to Fig. 19 to Fig. 21. The position detection system 10C corresponds to one aspect of the position detection system 10 shown in Fig. 1. This position detection system 10C includes an active pen 12C and an electronic device 14C.

[0173] <Configuration and operation> 19 is a schematic configuration diagram of a position detection system 10C in the third embodiment. At least one of the active pen 12C and the electronic device 14C is provided with a notification means 200 that explicitly or implicitly notifies the user that the remaining power of the active pen 12C is low.

[0174] The active pen 12C has an internal configuration similar to that of the first embodiment (active pen 12A) or the second embodiment (active pen 12B), for example. In the example of Fig. 19, the active pen 12C further includes an exposed output device 202 and a built-in output device 204. Here, the output devices 202 and 204 correspond to the above-mentioned notification means 200.

[0175] The exposed output device 202 outputs visible information that appeals to the user's vision. The output device 202 is composed of, for example, a display panel or a lamp. Examples of the display panel include a transmissive liquid crystal panel, a reflective liquid crystal panel, an organic EL (Electro Luminescence) panel, and electronic paper. In particular, by using electronic paper, it is possible to maintain the display content even when the power supply is stopped in the low-consumption mode.

[0176] The built-in output device 204 outputs audible information that appeals to the user's hearing or tactile information that appeals to the user's touch. The output device 204 is, for example, a sound generator including a speaker, or a vibration device including a vibrator. Examples of output sounds include a buzzer, a jingle, music, and voice guidance.

[0177] The electronic device 14C has an internal configuration similar to that of the first embodiment (electronic device 14A) or the second embodiment (electronic device 14B), for example. In the example of FIG. 19, the electronic device 14C includes a touch sensor 16, a sensor side controller 18c, a wireless module 36 of any configuration, a host processor 206, and a display panel 208. Here, the display panel 208 corresponds to the above-mentioned notification means 200. Examples of the display panel include a liquid crystal panel, an organic EL panel, and electronic paper.

[0178] Next, a notification operation associated with switching between the normal mode and the low-consumption mode will be described. Hereinafter, a state in which the remaining power exceeds a threshold value will be referred to as a "normal state," and a state in which the remaining power is equal to or less than the threshold value will be referred to as a "low remaining power state." In the third embodiment, a state in which the normal mode is being executed corresponds to the "normal state," and a state in which the low-consumption mode is being executed corresponds to the "low remaining power state."

[0179] The position detection system 10C does not notify the user through the notification means 200 while the normal mode is being executed, but does notify the user through the notification means 200 explicitly or implicitly while the low consumption mode is being executed. In other words, the notification means 200 starts notifying the user when the normal mode is switched to the low consumption mode, and the notification means 200 stops notifying the user when the low consumption mode is switched to the normal mode.

[0180] Here, "explicit notification" means to give the user an awareness by outputting various information in the low-consumption mode that was not output in the normal mode. Examples of "explicit notification" include displaying a message, displaying a fuel gauge, turning on / flashing a lamp, outputting an alarm sound, or generating a vibration. Moreover, "implicit notification" means to give the user an awareness by changing the output mode of various information depending on whether the mode is the normal mode or the low-consumption mode. An example of "implicit notification" is to change the display mode of the cursor 214 (FIG. 20) displayed on the electronic device 14C.

[0181] Fig. 20 is a diagram showing an example of a method for displaying the position of the active pen 12C in Fig. 19. The electronic device 14C is configured to display a cursor 214 (corresponding to a "mark") indicating the position 212 of the active pen 12C within a display area 210 of a display panel 208 as the active pen 12 approaches. Specifically, when the height of the active pen 12C based on the touch surface 12s (hereinafter also referred to as "hover height Hh") is greater than a height threshold, the cursor 214 is not displayed, but when the hover height Hh becomes smaller than the height threshold, the cursor 214 is displayed.

[0182] 21 is a diagram showing an example of a method for changing the display mode of the cursor 214. The horizontal axis of the graph indicates the hover height Hh (unit: mm), and the vertical axis of the graph indicates the visibility of the cursor 214. This visibility is defined such that the larger the value, the higher the visibility, and the smaller the value, the lower the visibility. A visibility value of zero indicates a state in which the user cannot see the cursor 214 (i.e., the cursor 214 is not displayed). The visibility is adjusted in various ways, including, for example, [1] the brightness and saturation of the color of the cursor 214, [2] the size and shape, or [3] the presence or absence of an outline.

[0183] Here, in the normal mode (shown by a solid line), the height threshold is set to h1, whereas in the low consumption mode (shown by a dashed line), the height threshold is set to h2. Here, since the magnitude relationship of h1>h2 is satisfied, the appearance sensitivity of the cursor 214 is relatively low in the low consumption mode. In other words, when the mode shifts from the normal mode to the low consumption mode, the user can recognize that the remaining power of the active pen 12C has decreased through the decrease in the appearance sensitivity of the cursor 214.

[0184] In addition, in Fig. 21, the height threshold is changed according to the operation mode being executed, but the effect of the display mode is not limited to this. For example, the height threshold may be kept constant, and the visibility may be gradually increased as the value of the hover height Hh decreases. Even when the visibility of the cursor 214 is changed transiently, it is possible to implicitly notify that the remaining power of the active pen 12C is low.

[0185] In addition, in reality, the active pen 12C or the electronic device 14C is not provided with a distance measurement sensor for measuring the hover height Hh. Therefore, for this threshold determination, instead of the hover height Hh, [1] the reception strength of the uplink signal US or [2] the reception strength of the downlink signal DS, which are physical quantities correlated with the hover height Hh, are used. In this case, in the low consumption mode, the reception sensitivity of the uplink signal US by the active pen 12C or the reception sensitivity of the downlink signal DS by the electronic device 14C is relatively lowered, thereby making it possible to reproduce the change in the display mode shown in FIG. 21.

[0186] <Summary of the third embodiment> As described above, the position detection system 10C in the third embodiment includes an electronic device 14C including a capacitive touch sensor 16 having a plurality of sensor electrodes arranged in a planar shape, an active pen 12C used together with the electronic device 14C, and a notification means 200 provided in the electronic device 14C or the active pen 12C, and which explicitly or implicitly notifies a user that the remaining power supply in the active pen 12C is low.

[0187] The active pen 12C comprises a receiving circuit (here, the pen side receiving circuit 46) that receives an uplink signal US from the electronic device 14C, a transmitting circuit (i.e., the pen side transmitting circuit 48) that transmits a downlink signal DS to the electronic device 14C, an additional function unit 50 that performs additional functions other than receiving the uplink signal US and transmitting the downlink signal DS, and a control unit (here, the pen side MCU 40) that controls the operation of the pen side receiving circuit 46, the pen side transmitting circuit 48, or the additional function unit 50 in accordance with a number of operating modes including a normal mode and a low consumption mode.

[0188] In this way, by providing the notification means 200 in the electronic device 14C or the active pen 12C, it is possible to notify the user when the remaining power of the active pen 12C is low, and to prompt the user to take measures such as charging or replacing the power source.

[0189] Furthermore, when the notification means 200 is a display panel 208 that displays a cursor 214 at the indication position 212 of the active pen 12C, the display panel 208 may, in a normal state (or while the normal mode is being executed), display a mark (here, the cursor 214) according to the magnitude relationship between the distance between the active pen 12C and the touch sensor 16 or a physical quantity correlated to the distance, and a first threshold value, and, in a low remaining charge state (or while the low consumption mode is being executed), display the cursor 214 according to the magnitude relationship between the distance or physical quantity, and a second threshold value that is smaller than the first threshold value.

[0190] Furthermore, if the notification means 200 is a display panel 208 that displays a cursor 214 at the indication position 212 of the active pen 12C, the display panel 208 may display a mark (here, the cursor 214) in different ways depending on whether the indicator is in a normal state or a low remaining amount state.

[0191] Furthermore, when the notification means 200 is an output device 202, 204 provided in the active pen 12C, the output device 202, 204 may output information that appeals to the visual, auditory, or tactile senses in a low remaining state. Furthermore, the output device 202 may be electronic paper that displays visible information.

[0192] [Other embodiments] When the remaining power supply of the active pen 12 becomes low, the following measures may be taken.

[0193] A first possible solution is to add a power source for the active pen 12. Specifically, the active pen 12 may be configured so that it can be switched from the power source module 30 (FIG. 2) that is the main power source to a sub-power source such as a solar cell. Alternatively, the active pen 12 may be provided with a vibration power generator that can generate power by vibration of the pen body.

[0194] As a second measure, it is possible to provide a mechanical structure that enables operation even when the remaining battery power is low. Specifically, the active pen 12 may be provided with a position adjustment mechanism (e.g., a screw adjustment mechanism) that moves the pen electrode for transmitting the downlink signal DS closer to the pen tip. Alternatively, the active pen 12 may be provided with a replacement core module for increasing capacitance or signal strength. [Explanation of symbols]

[0195] 10, 10A, 10B, 10C...position detection system, 12, 12A, 12B, 12C...active pen, 14, 14A, 14B, 14C...electronic device, 16...touch sensor, 18, 18a, 18b, 18c...sensor side controller, 28, 28a, 28b, 28c...pen side controller, 40, 160, 180...pen side MCU (pen side control unit), 46, 182...pen side receiving circuit, 48...pen side transmitting circuit, 100, 170...sensor side MCU (sensor side control unit), DS...downlink signal, US...uplink signal

Claims

1. An active pen used with an electronic device including a capacitive touch sensor having a plurality of sensor electrodes arranged in a planar shape, A receiving circuit for receiving an uplink signal from the electronic device; a transmitter circuit for transmitting a downlink signal to the electronic device; an additional function unit that performs an additional function other than the reception of the uplink signal and the transmission of the downlink signal; a control unit that controls an operation of the receiving circuit, the transmitting circuit, or the additional function unit according to a plurality of operation modes including a normal mode and a low-power mode; The normal mode is an operation mode in which a frequency of execution of a specific driving operation related to at least one of the reception of the uplink signal, the transmission of the downlink signal, and the auxiliary function is relatively high, or an amount of execution of the specific driving operation is relatively large, The low consumption mode is an operation mode in which the specific drive operation is performed relatively low in frequency or the specific drive operation is performed relatively small in amount.

2. the specific driving operation is a boosting operation of the downlink signal, The control unit In the normal mode, a transmission voltage of the downlink signal is boosted to a first voltage. In the low consumption mode, the downlink signal is boosted to a second voltage lower than the first voltage, or the boosting of the downlink signal is stopped. Controlling the boosting operation by the transmission circuit; The active pen of claim 1 .

3. the specific driving operation is a boosting operation of the downlink signal consisting of a plurality of rectangular pulses; The control unit In the normal mode, the degree of blunting of the rising or falling edges of the rectangular pulse of the boosted downlink signal is relatively small. In the low consumption mode, the degree of blunting of the rising or falling edge of the rectangular pulse of the boosted downlink signal becomes relatively large. Controlling the boosting operation by the transmission circuit; The active pen of claim 1 .

4. the specific driving operation is a transmission operation of the downlink signal, The control unit In the normal mode, the downlink signal is transmitted relatively frequently. In the low consumption mode, the downlink signal is transmitted relatively less frequently. Controlling the transmission operation by the transmission circuit; The active pen of claim 1 .

5. the specific driving operation is a frequency hopping operation that performs frequency hopping to switch a transmission frequency of the downlink signal, The control unit In the normal mode, the frequency of switching the transmission frequency is relatively increased to continue the frequency hopping. In the low consumption mode, the frequency of switching the transmission frequency is relatively low to continue the frequency hopping, or to stop the frequency hopping. controlling the frequency hopping operation by the transmitting circuit; The active pen of claim 1 .

6. the specific driving operation is a transmission operation of transmitting the downlink signal by switching a clock frequency related to generation or transmission of the downlink signal, The control unit to transmit the downlink signal at the relatively high clock frequency in the normal mode; transmitting the downlink signal at a relatively low clock frequency in the low consumption mode; Controlling the transmission operation by the transmission circuit; The active pen of claim 1 .

7. the specific driving operation is a receiving operation of the uplink signal, The control unit In the normal mode, to continue receiving the uplink signal. In the low consumption mode, the uplink signal is received intermittently or the reception of the uplink signal is disabled. Controlling the receiving operation by the receiving circuit; The active pen of claim 1 .

8. the control unit controls the transmission operation by the transmission circuit so as to transmit the downlink signal at a predetermined transmission period while disabling reception of the uplink signal in the low consumption mode. The active pen of claim 7.

9. The additional functions are: A communication function for communicating with the electronic device using a method other than electrostatic coupling; a pen pressure detection function for detecting a pen pressure acting on the pen tip of the active pen; an operation detection function for detecting an operation state of a switch of the active pen; A vibration function that vibrates the active pen; and A write function for writing data supplied from the electronic device into the memory. and The control unit In the normal mode, the auxiliary function is continued. In the low consumption mode, the additional function is executed intermittently or the execution of the additional function is stopped. Controlling the operation of the auxiliary function unit. The active pen of claim 1 .

10. the control unit causes a behavior triggered by reception of the uplink signal to differ between a case in which the normal mode is being executed and a case in which the low consumption mode is being executed. The active pen of claim 1 .

11. the electronic device selects an operation mode of the active pen based on a remaining amount of a power source mounted in the active pen, and generates a mode flag indicating the operation mode; The control unit acquires the mode flag through reception from the electronic device, and switches to the normal mode or the low-consumption mode according to a value of the mode flag. The active pen of claim 1 .

12. The control unit switches between the normal mode and the low-power mode based on a remaining capacity of a power source mounted in the active pen, The transmitter transmits the downlink signal to the electronic device, the downlink signal including a mode flag indicating an active operation mode. The active pen of claim 1 .

13. An electronic device including a capacitive touch sensor having a plurality of sensor electrodes arranged in a planar shape; an active pen for use with the electronic device; Equipped with The active pen is a pen-side receiving circuit for receiving an uplink signal from the electronic device; a pen-side transmitting circuit for transmitting a downlink signal corresponding to the uplink signal to the electronic device; a pen-side control unit for controlling the driving operation of the pen-side receiving circuit or the pen-side transmitting circuit in accordance with a plurality of operation modes including a normal mode and a low-power mode; Equipped with the normal mode is an operation mode in which the transmission of the downlink signal continues; The low consumption mode is an operation mode in which the transmission of the downlink signal is stopped and the active pen functions as a passive pointer.

14. The pen side control unit stops transmitting the downlink signal in the low consumption mode, or stops transmitting the downlink signal corresponding to the uplink signal by blocking detection of the uplink signal. The location detection system of claim 13.

15. The active pen is two or more pen electrodes for receiving the uplink signal or transmitting the downlink signal; a switch provided between connection lines connecting the two or more pen electrodes; Further equipped with the pen-side control unit performs switching control so as to open the switch in the normal mode and close the switch in the low-power mode. The location detection system of claim 13.

16. The active pen is a housing that houses at least the pen side receiving circuit, the pen side transmitting circuit, and the pen side control unit; a pen electrode for receiving the uplink signal or for transmitting the downlink signal; a switch provided between a connection line connecting the pen electrode and the housing; Further equipped with the pen-side control unit performs switching control so as to open the switch in the normal mode and close the switch in the low-power mode. The location detection system of claim 13.

17. The electronic device further includes a sensor side controller that controls a drive operation of the touch sensor, the sensor-side controller performs a common operation of receiving the downlink signal regardless of whether the normal mode or the low consumption mode is selected; The location detection system of claim 13.

18. The sensor side controller includes: a sensor side receiving circuit for receiving the downlink signal via the sensor electrode; a signal generating circuit that generates a simulation signal that simulates the downlink signal; a switch provided between a reference potential side of the sensor-side receiving circuit and an output side of the signal generating circuit, or between a power supply potential side of the sensor-side receiving circuit and an output side of the signal generating circuit; a sensor-side control unit that performs switching control so as to open the switch in the normal mode and close the switch in the low consumption mode; Equipped with 20. The location detection system of claim 17.

19. the active pen further includes a switch for switching an output destination of the pen side receiving circuit to the pen side control unit or the pen side transmitting circuit; the pen side control unit performs switching control so that an output destination of the switch is connected to the pen side control unit in the normal mode and is connected to the pen side transmission circuit in the low consumption mode. The location detection system of claim 13.

20. An electronic device including a capacitive touch sensor having a plurality of sensor electrodes arranged in a planar shape; an active pen for use with the electronic device; a notification means provided in the electronic device or the active pen for explicitly or implicitly notifying a user that the remaining power of the active pen is low; Equipped with The active pen is A receiving circuit for receiving an uplink signal from the electronic device; a transmitter circuit for transmitting a downlink signal to the electronic device; an additional function unit that performs an additional function other than the reception of the uplink signal and the transmission of the downlink signal; a control unit that controls an operation of the receiving circuit, the transmitting circuit, or the additional function unit according to a plurality of operation modes including a normal mode and a low-power mode; The normal mode is an operation mode in which a frequency of execution of a specific driving operation related to at least one of the reception of the uplink signal, the transmission of the downlink signal, and the auxiliary function is relatively high, or an amount of execution of the specific driving operation is relatively large, The low consumption mode is an operation mode in which the specific drive operation is performed relatively infrequently or the specific drive operation is performed relatively in small amounts.

21. the notification means is a display panel that displays a mark at a position indicated by the active pen, The display panel includes: In the normal mode, the cursor is displayed according to a magnitude relationship between a distance between the active pen and the touch sensor or a physical quantity correlated with the distance, and a first threshold value; in the low consumption mode, the cursor is displayed according to a magnitude relationship between the distance or the physical amount and a second threshold value that is smaller than the first threshold value.

21. The location detection system of claim 20.

22. the notification means is a display panel that displays a mark at a position indicated by the active pen, the display panel changes the display mode of the mark between the normal mode and the low consumption mode.

21. The location detection system of claim 20.

23. the notification means is an output device provided in the active pen, the output device outputs visual, auditory, or tactile information in the low battery state.

22. The location detection system of claim 21.

24. The output device is electronic paper that displays visual information.

24. The location detection system of claim 23.

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