Sensor controller, electronic device, electronic pen, control method for sensor controller, and position detection system

Abstract

This provides a sensor controller that can calculate the pressure applied to a pen sensor by an electronic pen with high precision. [Solution] The sensor controller (20) includes an acquisition unit (22) that acquires a position signal indicating the position of the electronic pen (2) from a pen sensor (10) that detects the position of the electronic pen (2). The sensor controller also includes a pressure calculation unit (23) that calculates a pressure value relating to the pressure applied by the electronic pen to the pen sensor based on the change in the signal level of the position signal acquired by the acquisition unit.

Description

Technical Field

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[0001] The present invention relates to a sensor controller, an electronic device, an electronic pen, a control method for a sensor controller, and a position detection system, and particularly to an electronic device, an electronic pen, a sensor controller, a control method for a sensor controller, and a position detection system that receive a position instruction by an electronic pen and display it on a screen.

Background Art

[0002] Conventionally, an electronic device including a pen sensor that detects a position instruction by an electronic pen and a display unit that performs screen display according to the detection by the pen sensor is known. Regarding such an electronic device, a technique for detecting the pen pressure of an electronic pen with respect to the pen sensor is known.

[0003] Regarding this, Patent Document 1 discloses a sensor controller (electronic device) that corrects the pen pressure indicated by a pen pressure signal transmitted from an electronic pen having a pen pressure detection unit according to the reception intensity of a downlink signal transmitted from the electronic pen to the sensor and a sensor that detects an instruction position by the electronic pen.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Electronic pens with a function to detect pen pressure may experience variations in the accuracy of pen pressure calculation due to factors such as manufacturing variations in the pen pressure switch used to detect pen pressure. In the technology described in Patent Document 1, when variations occurred in the accuracy of pen pressure calculation of the electronic pen, the accuracy of contact detection with the pen sensor and the calculation of high or low pen pressure decreased.

[0006] Furthermore, in electronic pens that have a function to detect pen pressure, the pressure applied to the pen pressure switch for detecting pen pressure may change depending on the degree of tilt of the electronic pen relative to the pen sensor. In the technology described in Patent Document 1, when the tilt of the electronic pen relative to the pen sensor was large, the contact detection of the electronic pen with the pen sensor became sluggish.

[0007] This invention has been made in view of these problems, and its objective is to provide a sensor controller, electronic device, electronic pen, control method for the sensor controller, and position detection system that can calculate the pressure applied to a pen sensor by an electronic pen with high precision. [Means for solving the problem]

[0008] To solve the above problems, the first sensor controller according to the present invention includes an acquisition unit that acquires a position signal indicating the position of the electronic pen from a pen sensor that detects the position of the electronic pen, and a pen pressure calculation unit that calculates a pen pressure value relating to the pen pressure applied to the pen sensor based on the change in the signal level of the position signal acquired by the acquisition unit.

[0009] Furthermore, in the second sensor controller according to the present invention, the signal level is an electric potential, and the pen pressure calculation unit determines that the operating state has transitioned to a first state in which the electronic pen is pressing the pen sensor when the electric potential of the position signal rises to a first electric potential or higher within a predetermined time, and calculates the pen pressure value as the first value.

[0010] Furthermore, in the third electronic device according to the present invention, the pressure calculation unit determines that the operating state has transitioned to a second state in which the electronic pen is separated from the pen sensor when the potential of the position signal drops to a second potential or more within a predetermined time, and calculates the pressure value as a second value different from the first value.

[0011] Furthermore, in the fourth sensor controller according to the present invention, the pen pressure calculation unit calculates the pen pressure value such that it changes stepwise from the first value to the second value when the operating state transitions from the second state to the first state.

[0012] Furthermore, in the fifth sensor controller according to the present invention, the signal level is an electric potential, the acquisition unit acquires a pressure signal from the pen sensor that is transmitted from the electronic pen to the pen sensor and indicates the pressure of the electronic pen on the pen sensor, and the pressure calculation unit calculates the pressure value by correcting the pressure indicated by the pressure signal based on the change in the electric potential of the position signal.

[0013] Furthermore, in the sixth sensor controller according to the present invention, the pressure calculation unit determines that the operating state has transitioned to a first state in which the electronic pen is pressing the pen sensor when the potential of the position signal rises to a first potential or higher within a predetermined time, and calculates the pressure value as a first value. If the pressure signal acquired by the acquisition unit before determining that the operating state has transitioned to the first state indicates that the electronic pen is pressing the pen sensor, the pressure calculation unit determines that the pressure signal is showing an abnormal value and calculates the pressure value as a second value different from the first value.

[0014] Furthermore, in the seventh sensor controller according to the present invention, the pressure calculation unit determines that the operating state has transitioned to a second state in which the electronic pen is separated from the pen sensor when the potential of the position signal drops to a second potential or more within a predetermined time, and calculates the pressure value as the second value. If the pressure signal acquired by the acquisition unit before determining that the operating state has transitioned to the second state indicates that the electronic pen is separated from the pen sensor, the pressure value is maintained as an abnormal value because the pressure signal indicates an abnormal value.

[0015] Furthermore, the eighth control method for a sensor controller according to the present invention is a control method for a sensor controller connected to a pen sensor, and includes acquiring a position signal indicating the position of the electronic pen from the pen sensor which detects the position of the electronic pen, and calculating a pen pressure value relating to the pen pressure of the electronic pen to the pen sensor based on the change in the signal level of the acquired position signal.

[0016] Furthermore, the ninth electronic device according to the present invention is an electronic device equipped with a sensor controller according to the first invention, further comprising: a display panel for displaying an object to be displayed; and a pen sensor provided so as to overlap the display area of ​​the display panel in a plan view and for detecting the position of the electronic pen.

[0017] Furthermore, the tenth electronic pen according to the present invention is an electronic pen that provides position instructions to a pen sensor, comprising: a pen tip provided at the tip so as to be reciprocal along the axial direction and having an electrode that transmits and receives signals to and from the pen sensor; a pen controller that calculates a pen pressure value related to pen pressure based on a change in the signal level of an uplink signal transmitted from the pen sensor via the electrode; and a transmitting unit that transmits a pen pressure signal indicating the pen pressure value calculated by the pen controller and a position signal indicating the instruction position to the pen sensor to the pen sensor via the electrode.

[0018] Furthermore, in the eleventh electronic pen according to the present invention, the signal level is an electric potential, and the pen controller determines that the operating state has transitioned to a first state in which the pen sensor is being pressed when the electric potential of the uplink signal rises to a first electric potential or higher within a predetermined time, and calculates the pen pressure value as a first value.

[0019] Furthermore, in the twelfth electronic pen according to the present invention, the pen controller determines that the operating state has transitioned to a second state in which it is separated from the pen sensor when the potential of the uplink signal drops to a second potential or more within a predetermined time, and calculates the pen pressure value as a second value different from the first value.

[0020] Furthermore, the thirteenth electronic pen according to the present invention further comprises a pressure sensor for detecting the pressure applied to the pen tip, wherein the signal level is an electric potential, and the pen controller calculates the pen pressure value by correcting the pressure detected by the pressure sensor based on the change in the signal level of the uplink signal.

[0021] Furthermore, in the fourteenth electronic pen according to the present invention, the signal level is an electric potential, and the pen controller determines that the operating state has transitioned to a first state in which the pen sensor is being pressed when the electric potential of the uplink signal rises to a first electric potential or higher within a predetermined time, and calculates the pen pressure value as a first value. If the pen pressure signal indicates that the pen sensor is being pressed before it is determined that the operating state has transitioned to the first state, the pen controller determines that the pen pressure signal is showing an abnormal value and calculates the pen pressure value as a second value different from the first value.

[0022] Furthermore, in the electronic pen according to the fifteenth specification of the present invention, the pen controller determines that the operating state has transitioned to a second state in which the pen is separated from the pen sensor when the potential of the uplink signal drops to a second potential or more within a predetermined time, and calculates the pen pressure value as the second value. If the pen pressure signal indicates that the pen is separated from the pen sensor before it is determined that the operating state has transitioned to the second state, the pen controller maintains the pen pressure value as indicating that the pen pressure signal is showing an abnormal value.

[0023] Also, a sixteenth position detection system according to the present invention is a position detection system including an electronic pen according to the tenth present invention, and includes a display panel that displays a display target, a pen sensor that is provided so as to overlap the display area of the display panel in a plan view, transmits the uplink signal to the electronic pen, and detects the pen pressure signal and the position signal transmitted from the electronic pen, and an electronic device having a sensor controller that performs display control of the display panel according to the pen pressure signal and the position signal detected by the pen sensor.

[0024] Also, a seventeenth sensor controller according to the present invention includes an acquisition unit that acquires, from a pen sensor that detects the position of an electronic pen, a first signal transmitted from a first electrode of the electronic pen to the pen sensor, a second signal transmitted from a second electrode different from the first electrode of the electronic pen to the pen sensor, and a pen pressure signal indicating the pen pressure of the electronic pen, and a pen pressure calculation unit that calculates a pen pressure value regarding the pen pressure of the electronic pen with respect to the pen sensor based on changes in signal levels of the first signal and the second signal acquired by the acquisition unit and the pen pressure signal.

[0025] Also, in an eighteenth sensor controller according to the present invention, the pen pressure calculation unit calculates the pen pressure value such that the pen pressure value increases as the inclination angle of the electronic pen with respect to the detection surface of the pen sensor increases, and the pen pressure value decreases as the inclination angle decreases.

[0026] Also, in a nineteenth sensor controller according to the present invention, the signal level is a potential, and when the potential of the first signal or the second signal rises above a first potential within a predetermined time, the pen pressure calculation unit determines that the operating state has shifted to a first state in which the electronic pen is pressing the pen sensor, and calculates the pen pressure value as a first value.

[0027] Furthermore, in the 20th sensor controller according to the present invention, the signal level is an electric potential, and the pen pressure calculation unit determines that the operating state has transitioned to a first state in which the electronic pen is pressing the pen sensor when the potential difference between the first signal and the second signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as a first value.

[0028] Furthermore, in the 21st sensor controller according to the present invention, the pen pressure calculation unit calculates the movement speed of the electronic pen relative to the pen sensor from the position signal, and determines the value of the first potential according to the calculated movement speed.

[0029] Furthermore, in the 22nd sensor controller according to the present invention, the pen pressure calculation unit determines the value of the first potential to be the value of the third potential when the movement speed is equal to or greater than the speed threshold, and determines the value of the first potential to be the value of the fourth potential which is greater than the third potential when the movement speed is less than the speed threshold.

[0030] Furthermore, in the 23rd sensor controller according to the present invention, the pressure calculation unit determines the value of the first potential such that the value of the first potential is proportional to the movement speed.

[0031] Furthermore, in the 24th sensor controller according to the present invention, the pen pressure calculation unit calculates the movement speed of the electronic pen relative to the pen sensor from the position signal and determines the first value according to the calculated movement speed.

[0032] Furthermore, in the 25th sensor controller according to the present invention, the pen pressure calculation unit calculates the pen pressure value when predetermined conditions are not met, and the predetermined conditions are that the time elapsed since the last calculation of the pen pressure value is less than the reference time and the distance the electronic pen has moved since the last calculation of the pen pressure value is less than the reference distance.

[0033] Furthermore, in the 26th sensor controller according to the present invention, the pen pressure calculation unit, when the predetermined conditions are met, executes a waiting process that waits for a waiting time before processing if it has not been executed since the previous determination of the predetermined conditions, and calculates the pen pressure value if it has been executed since the previous determination of the predetermined conditions.

[0034] Furthermore, the 27th electronic pen according to the present invention is an electronic pen that provides position instructions to a pen sensor, and comprises a pen tip that has electrodes for sending and receiving signals with the pen sensor and can be housed in a storage member, and a pen controller that sends and receives signals with the pen sensor via the electrodes, determines the state in which the pen tip is housed in the storage member, notifies the pen sensor when it is determined that the pen tip is housed in the storage member, and stops transmitting the signal in response to the notification transmitted from the pen sensor.

[0035] Furthermore, in the electronic pen according to the 28th aspect of the present invention, the pen controller notifies the pen sensor when the storage state changes from a state in which the pen tip is stored in the storage member to a state in which the pen tip is not stored in the storage member, and starts transmitting the signal in response to the notification transmitted from the pen sensor.

[0036] Furthermore, the 29th electronic pen according to the present invention further comprises a storage member which is a cylindrical housing, and a retractable member which allows the pen tip to extend and retract from one opening of the housing.

[0037] Furthermore, in the 30th electronic pen according to the present invention, the retractable member is a knock mechanism that allows the pen tip to extend and retract from one opening of the housing, and further comprises a switch member whose state changes in accordance with the sliding movement of a sliding member that slides in conjunction with the knocking operation of the knock mechanism, and the pen controller determines the retracted state based on the state of the switch member.

[0038] Furthermore, in the 31st electronic pen according to the present invention, the retractable member has a retractable mechanism that allows the pen tip to extend and retract from one opening of the housing by the rotation of a member rotatably coupled to the housing with the center line of the housing as the axis of rotation, and further comprises a detection member whose state switches in accordance with the rotational movement of the retractable mechanism which is linked to the rotation of the member rotatably coupled to the housing, and the pen controller determines the retracted state based on the state of the detection member.

[0039] Furthermore, in the 32nd electronic pen according to the present invention, the storage member is a cap that is detachably attached to the housing on which the pen tip is provided, so as to cover the pen tip.

[0040] Furthermore, in the 33rd electronic pen according to the present invention, the storage member is a housing of an electronic device having a hole into which the pen tip can be inserted.

[0041] Furthermore, the 34th electronic pen according to the present invention further comprises a detection member that detects changes in the electric field, magnetic field, or capacitance of the space including the pen tip, and the pen controller determines the storage state based on the detection result of the detection member.

[0042] Furthermore, the 35th electronic pen according to the present invention further comprises a detection member for detecting a change in the electrical conductivity between the pen tip and the storage member, and the pen controller determines the storage state based on the detection result of the detection member.

[0043] Furthermore, in the 36th electronic pen according to the present invention, the electrode is a first electrode, which transmits and receives signals with the pen sensor and is capable of receiving signals transmitted from the first electrode, and further comprises a second electrode different from the first electrode, and the pen controller determines whether or not the pen tip is housed in the housing member based on the amount of change in the signal level of the signal transmitted from the first electrode to the second electrode. [Effects of the Invention]

[0044] According to the present invention, the sensor controller can calculate the pressure applied to the pen sensor by an electronic pen with high precision. [Brief explanation of the drawing]

[0045] [Figure 1] This figure shows an example of a position detection system according to the first embodiment. [Figure 2] This figure shows an example of a specific configuration of an electronic pen according to the first embodiment. [Figure 3] This figure shows an example of the functional configuration of a sensor controller according to the first embodiment. [Figure 4] This graph shows an example of the relationship between the change in the position signal level and the pen pressure value in the first embodiment. [Figure 5] This graph shows another example of the relationship between the change in the position signal level and the pen pressure value in the first embodiment. [Figure 6] This flowchart shows an example of a series of processing steps performed by an electronic device according to the first embodiment. [Figure 7] This figure shows an example of a specific configuration of the electronic device according to the second embodiment. [Figure 8] This graph shows an example of the relationship between the change in the levels of the position signal and the pressure signal, and the pressure value, in the second embodiment. [Figure 9] A flowchart showing an example of a series of processing steps performed by an electronic device according to the second embodiment. [Figure 10A] This is a cross-sectional view of the position detection system according to the third embodiment, along line XX. [Figure 10B] Figure 10A is a cross-sectional view of the position detection system when the electronic pen is tilted relative to the electronic device. [Figure 11] This graph shows an example of the relationship between the change in the uplink signal level and the pen pressure value when the electronic pen is tilted significantly, according to the third embodiment. [Figure 12A]This figure shows an example of the signal level distribution when the electronic pen is not in contact with the electronic device and has a small tilt, according to the fourth embodiment. [Figure 12B] This figure shows an example of the signal level distribution when the electronic pen is in contact with an electronic device and the tilt is small, according to the fourth embodiment. [Figure 12C] This figure shows an example of the signal level distribution when the electronic pen is not in contact with the electronic device and has a large tilt, according to the fourth embodiment. [Figure 12D] This figure shows an example of the signal level distribution when the electronic pen is in contact with an electronic device and is tilted significantly, according to the fourth embodiment. [Figure 13] A flowchart showing an example of a series of processing steps performed by an electronic device according to the fourth embodiment. [Figure 14] This flowchart shows an example of a series of processing steps performed by an electronic device according to the fifth embodiment. [Figure 15] This flowchart shows an example of a series of processing steps performed by an electronic device according to the sixth embodiment. [Figure 16A] This figure shows the pen tip of the retractable electronic pen according to the seventh embodiment, housed within the hollow part of the casing. [Figure 16B] This figure shows the pen tip of the retractable electronic pen according to the seventh embodiment protruding from the opening of the casing. [Figure 17A] This figure shows the state in which the pen tip of the rotary electronic pen according to the seventh embodiment is housed within the hollow part of the casing. [Figure 17B] This figure shows the pen tip of the rotary electronic pen according to the seventh embodiment protruding from the opening of the housing. [Figure 18A] This figure shows an example of the configuration of a cap-type electronic pen according to the seventh embodiment. [Figure 18B] This figure shows another example of the configuration of a cap-type electronic pen according to the seventh embodiment. [Figure 18C]This figure shows an example of the configuration of an electronic pen and an electronic device capable of housing the electronic pen according to the seventh embodiment. [Figure 19] A flowchart illustrating an example of the processing flow using an electronic pen according to the seventh embodiment. [Modes for carrying out the invention]

[0046] Hereinafter, embodiments of the present invention (hereinafter referred to as "First Embodiment," "Second Embodiment," "Third Embodiment," "Fourth Embodiment," "Fifth Embodiment," "Sixth Embodiment," or "Seventh Embodiment") will be described with reference to the attached drawings. To facilitate understanding of the description, the same reference numerals are used for identical components and steps in each drawing whenever possible, and redundant explanations are omitted.

[0047] ---First Embodiment--- First, let me describe the first embodiment.

[0048] <Overall Structure> Figure 1 is a diagram showing an example of the specific configuration of the position detection system 5 according to the first embodiment. As shown in Figure 1, the position detection system 5 is composed of an electronic device 1A and an electronic pen 3. The electronic device 1A is a computer owned by the user, such as a tablet, smartphone, or personal computer. The electronic device 1A is composed of, for example, a pen sensor 10, a sensor controller 20, a host processor 30, and a display panel 40. The electronic device 1A is equipped with memory, a communication module, etc., although not shown. In Figure 1, the electronic pen 3 is an AES (Active Electrostatic) stylus. The user can draw pictures and write characters on the display panel 40 of the electronic device 1A by pressing the tip of the electronic pen 3, which is a pen-type pointing device, against the display panel 40 of the electronic device 1A and moving it. In the first embodiment, the electronic pen 3 is an active touch pen, but it may also be a non-active touch pen. Furthermore, in the first embodiment, the electronic pen 3 is configured to enable bidirectional communication with the electronic device 1A, but is not limited to this, and may be configured to enable unidirectional communication only in the direction from the electronic pen 3 to the electronic device 1A. Also, in the first embodiment, when viewing the display panel 40 of the electronic device 1A from the front, the upward direction is defined as the Y-axis direction, the rightward direction as the X-axis direction, and the front direction as the Z-axis direction.

[0049] The pen sensor 10 is, for example, a capacitive sensor in which multiple detection electrodes are arranged in a planar manner. The pen sensor 10 is provided so as to overlap the display area of ​​the display panel 40 in a planar view and detects the position of the electronic pen 3. The pen sensor 10 is composed of, for example, multiple linear detection electrodes 11 for detecting the position on the X axis of the sensor coordinate system and multiple linear detection electrodes 12 for detecting the position on the Y axis. The detection electrodes 11 and 12 may be made of a transparent conductive material containing ITO (Indium Tin Oxide) or may be made of a wire mesh sensor. In addition, the pen sensor 10 may be a self-capacitive sensor in which block-shaped electrodes are arranged in a two-dimensional grid, instead of the mutual-capacitive sensor described above. Furthermore, although the pen sensor 10 is a capacitive sensor in this embodiment, it is not limited to this, and may be, for example, a loop coil antenna used in the EMR (Electro Magnetic Resonance) method.

[0050] The sensor controller 20 controls the operation of the electronic pen 3 by the pen sensor 10 to detect its position and pressure. The sensor controller 20 also performs bidirectional communication between the electronic pen 3 and the sensor controller 20 by controlling the reception and transmission of signals to the pen sensor 10. The sensor controller 20 also communicates with the host processor 30. The sensor controller 20 may also perform unidirectional communication, receiving signals transmitted from the electronic pen 3 via the pen sensor 10 and not transmitting signals to the electronic pen 3 via the pen sensor 10. The sensor controller 20 is composed of, for example, a communication device, a storage device, a CPU (Central Processing Unit), and memory. The sensor controller 20 functions in various functional configurations described later by the CPU executing a predetermined program stored in the memory or storage device. The communication device consists of a communication interface for communicating with external devices. The storage device consists of a hard disk or the like and stores various programs, various information, and processing result information necessary for executing processing in the sensor controller 20.

[0051] The host processor 30 is composed of a processing unit including a CPU, a GPU (Graphics Processing Unit), and an MPU (Micro-Processing Unit). The host processor 30 is responsible for executing the operating system of the electronic device 1A and various applications such as drawing software by executing programs stored in memory (not shown). The drawing software includes a function to generate stroke data based on coordinates sequentially supplied from the sensor controller 20, render it, and display it on the display. The drawing software also includes a function to adjust the rendering results based on data such as pen pressure values ​​supplied from the sensor controller 20 (for example, a function to adjust the line width according to the pen pressure value).

[0052] The display panel 40 is configured to display content including text, images, and videos. Specifically, the display panel 40 can display monochrome or color images and is composed of, for example, a liquid crystal panel, an organic EL (Electro-Luminescence) panel, electronic paper, or a quantum dot panel. The liquid crystal panel may be a backlight type, a mini-LED (Light Emitting Diode) type, or a micro-LED type. The display panel 40 displays content in response to detection of the electronic pen 3 by the pen sensor 10, according to the control of the host processor 30. As shown in Figure 2, the display panel 40 is located above the pen sensor 10 (in the Z-axis direction).

[0053] The specific configuration of the electronic pen 3 will be described with reference to Figure 2. Figure 2 is a diagram showing an example of the specific configuration of the electronic pen 3 according to the first embodiment. As shown in Figure 2, the electronic pen 3 is composed of, for example, a power supply 31, an information manager 32, a data manager 33, a sensor 34, a button 35, a pen controller 36, a communication module 361, electrodes 37 and 38, and an electrode switch 39. The electronic pen 3 has the button 35 and electrodes 37 and 38 provided on the surface of the housing, while the power supply 31, information manager 32, data manager 33, sensor 34, communication module 361, electrode switch 39, and pen controller 36 are provided inside the housing.

[0054] Power supply 31 is any type of power supply, such as a battery or a rechargeable power supply, that supplies power to the electronic pen 3.

[0055] The information manager 32 stores the pen function information of the electronic pen 3. The pen function information includes, for example, information about the predetermined functions of the electronic pen 3 and setting information about the user-adjustable settings of the electronic pen 3. The information manager 32 updates the setting information whenever the user changes the settings of the electronic pen 3, such as the color or line width of the electronic pen 3.

[0056] The data manager 33 manages the operation data of the electronic pen 3. The operation data indicates the operating status of the electronic pen 3, such as the pressure at the tip of the electronic pen 3, the rotation state of the electronic pen 3, and the battery level. The operation data is generated by the sensor 34. The sensor 34 includes a pressure sensor configured to detect the pressure applied to the tip of the electronic pen 3 and a rotation sensor configured to detect the rotation of the electronic pen 3.

[0057] The pen controller 36 controls the operation of the communication module 361 and the electrode switch 39 in bidirectional communication with the sensor controller 20 of the electronic device 1A. Specifically, the pen controller 36 controls the electrode switch 39 to set electrodes 37 and 38 to a transmission mode that transmits pen function information and operation data to the sensor controller 20 via the communication module 361 and electrode 37.

[0058] The communication module 361 is a module that performs bidirectional communication with the electronic device 1A. The communication module 361 is configured to include a transmit (TX) circuit and a receive (RX) circuit that communicate with the electronic device 1A via at least one of electrodes 37 and 38. Electrodes 37 and 38 are used to communicate with the electrodes of the pen sensor 10 of the electronic pen 3.

[0059] Electrodes 37 and 38 are positioned at different locations on the housing of the electronic pen 3. Specifically, electrode 37 is located at the tip of the electronic pen 3. Electrode 37 is used for indicating coordinate values ​​on the display panel 40 of the electronic pen 3 and for communication with the sensor controller 20. Electrode 38 is located above electrode 37 and below the gripping portion where the user holds the electronic pen 3, spaced apart from electrode 37. Electrode 38 is a ring electrode formed in an annular shape and is positioned to cover the outer circumference of the electronic pen 3. Electrode 38 is used to measure the attitude of the electronic pen 3. The attitude includes, for example, a tilt value indicating the inclination of the electronic pen 3 and an orientation value indicating the orientation of the electronic pen 3 on the display panel 40. The orientation value indicates the orientation of the tip of the electronic pen 3 when the display panel 40 is viewed from the Z-axis direction. The tilt value is the angle of the electronic pen 3 in the Z-axis direction with respect to the display surface of the display panel 40.

[0060] The electrode switch 39 is a switch that switches the operation of electrodes 37 and 38 between transmission mode and reception mode.

[0061] <Functional configuration> Next, the functional configuration of the sensor controller 20 of the electronic device 1A will be described with reference to Figure 3. Figure 3 is a diagram showing an example of the functional configuration of the sensor controller 20 according to the first embodiment. As shown in Figure 3, the sensor controller 20 is functionally configured to include, for example, a storage unit 21, an acquisition unit 22, and a pen pressure calculation unit 23. The functional means other than the storage unit 21 are realized by the CPU of the sensor controller 20 executing a program stored in the storage device of the sensor controller 20.

[0062] The memory unit 21 has a functional configuration that stores various values ​​and conditions used by the pen pressure calculation unit 23 in calculating pen pressure. Specifically, the memory unit 21 stores pen pressure reference data 211, pen pressure condition data 212, and operation status data 213.

[0063] The pen pressure reference data 211 is data used by the pen pressure calculation unit 23 in calculating pen pressure. Specifically, the pen pressure reference data 211 includes a value for a first potential, a value for a second potential, a value for a predetermined time indicating the period for determining whether the potential of the position signal rises or falls, a first value, and a second value. The first potential is a potential used to determine whether the operating state has transitioned to a first state, where the electronic pen 3 is pressing against the pen sensor 10. The second potential is a potential used to determine whether the operating state has transitioned to a second state, where the electronic pen 3 is separated from the pen sensor 10. The second potential may be the same as the first potential or a different potential. The predetermined time is the period for determining whether the potential of the position signal rises or falls. The first value is the set value of the pen pressure value in the first state. The second value is the set value of the pen pressure value in the second state and is a different value from the first value. Note that the pen pressure reference data 211 may store the first signal level and the second signal level, respectively, instead of the first potential and the second potential. The signal level is a level that correlates with the received strength of the position signal. The signal level may be, for example, a potential value, a current value, a power value, or a digital value of a digital signal.

[0064] The pen pressure condition data 212 is data relating to the conditions used by the pen pressure calculation unit 23 to determine whether the electronic pen 3 is pressing against the pen sensor 10 or whether the electronic pen 3 is separated from the pen sensor 10. Examples of the conditions indicated by the pen pressure condition data 212 will be explained later, so their explanation is omitted here.

[0065] The operating status data 213 is data indicating the current operating status. The operating status data 213 indicates whether the current operating status is the first state or the second state.

[0066] The acquisition unit 22 acquires a position signal indicating the position of the electronic pen 3 from the pen sensor 10. Specifically, the acquisition unit 22 acquires the position signal transmitted from the detection electrode 11 and the position signal transmitted from the detection electrode 12 from the pen sensor 10.

[0067] The pressure calculation unit 23 calculates a pressure value related to the pressure applied by the electronic pen 3 to the pen sensor 10 based on the change in the potential of the position signal acquired by the acquisition unit 22. Specifically, the pressure calculation unit 23 refers to the potential of the position signal acquired by the acquisition unit 22 and the pressure reference data 211 and pressure condition data 212 stored in the storage unit 21. The pressure calculation unit 23 determines that the operating state has transitioned to the first state if the potential of the position signal rises by a first potential or more within a predetermined time. The pressure calculation unit 23 then calculates the pressure value as the first value. The pressure calculation unit 23 also determines that the operating state has transitioned to the second state if the potential of the position signal falls by a second potential or more within a predetermined time. The pressure calculation unit 23 then calculates the pressure value as the second value. Furthermore, if the potential of the position signal does not meet the above conditions, the pressure calculation unit 23 determines that the operating state has not changed and maintains the pressure value. The pressure sensitivity calculation unit 23 stores the determined current operating state in the operating state data 213 of the storage unit 21. When the pressure sensitivity calculation unit 23 determines whether the potential of the position signal has risen or fallen, it determines that the potential has risen or fallen if both the position signal transmitted from the detection electrode 11 and the position signal transmitted from the detection electrode 12 satisfy the conditions. In the first to seventh embodiments, the pressure sensitivity calculation unit 23 uses potential in calculating the pressure sensitivity value, but it is not limited to potential. The pressure sensitivity calculation unit 23 may use the above-mentioned signal level instead of potential in calculating the pressure sensitivity value.

[0068] Here, an example of how the pressure is calculated by the pressure calculation unit 23 will be described with reference to Figure 4. Figure 4 is a graph showing an example of the relationship between the change in the position signal level and the pressure value in the first embodiment. In Figure 4, the vertical axis shows the detection level, which is converted from the potential to a common scale by a predetermined conversion formula. Also in Figure 4, the horizontal axis shows the elapsed time [ms]. The graph in Figure 4 shows data showing the difference in the detection level of the detection electrode 11 from the previous time, data showing the difference in the detection level of the detection electrode 12 from the previous time, and data showing the level of the pressure value. Also in Figure 4, the detection levels associated with the first potential and the second potential are both assumed to be 200. Also in Figure 4, the predetermined time is assumed to be 10 ms. Also in Figure 4, the first value is assumed to be 1000. Also in Figure 4, the second value is assumed to be 0. Note that the change in level is the amount that the level value has changed per unit time. Specifically, the change in level can be, for example, the rate of increase or decrease in the level, or the derivative obtained by differentiating the level value with respect to time.

[0069] At an elapsed time of 0 ms, the acquisition unit 22 acquires the potential from the position signal. From an elapsed time of 0 ms to an elapsed time of 473 ms, the change in the detection level of the detection electrodes 11 and 12 (difference from the previous time) is approximately 0 for both. From an elapsed time of 0 ms to an elapsed time of 473 ms, the pen pressure calculation unit 23 checks the detection level every 10 ms and determines that the detection level has not fluctuated by more than 200 and the operating state remains in the second state, and calculates the pen pressure value while maintaining it at 0. The host processor 30 assumes that the electronic pen 3 is separated from the pen sensor 10 according to the pen pressure value of 0 transmitted from the pen pressure calculation unit 23 and performs display control operations of the display panel 40.

[0070] After 500ms, the change in the detection level of the detection electrode 11 is approximately 1000. Also after 500ms, the change in the detection level of the detection electrode 12 is approximately 700. After 500ms, the pressure calculation unit 23 determines that the detection level has risen by 200 or more and that the operating state has transitioned from the second state to the first state, and calculates the pressure value as 1000.

[0071] After 525ms, the pressure sensitivity calculation unit 23 corrects the pressure sensitivity to the calculated value of 1000 and transmits the corrected pressure sensitivity to the host processor 30. The host processor 30 then performs the display control operation of the display panel 40, assuming that the electronic pen 3 is pressing the pen sensor 10 with a force equivalent to a pressure sensitivity of 1000, according to the pressure sensitivity value 1000 transmitted from the pressure sensitivity calculation unit 23.

[0072] From an elapsed time of 530ms to an elapsed time of 1260ms, the change in the detection level of detection electrodes 11 and 12 is approximately 0. From an elapsed time of 530ms to an elapsed time of 1260ms, the pen pressure calculation unit 23 checks the detection level every 10ms and determines that the detection level has not fluctuated by more than 200 and the operating state remains in the first state, and maintains the pen pressure value at 1000.

[0073] After 1290ms, the change in the detection level of the detection electrode 11 is approximately -2000. Also after 1290ms, the change in the detection level of the detection electrode 12 is approximately -1300. After 1290ms, the pressure calculation unit 23 determines that the detection level has dropped by 200 or more and that the operating state has transitioned from the first state to the second state, and calculates the pressure value as 0.

[0074] After 525ms, the pressure sensitivity calculation unit 23 corrects the pressure sensitivity to 0 and transmits the corrected pressure sensitivity to the host processor 30. The host processor 30, in accordance with the pressure sensitivity of 0 transmitted from the pressure sensitivity calculation unit 23, assumes that the electronic pen 3 is separated from the pen sensor 10 and performs the display control operation of the display panel 40.

[0075] The functional configuration of the sensor controller 20 has been described above. Next, the specific processing flow of the electronic device 1A will be explained in detail. Figure 6 is a flowchart showing an example of a series of processing steps performed by the electronic device 1A. Note that the content and order of the following steps can be changed as appropriate.

[0076] (Step SP10) The electronic device 1A acquires a position signal from the electronic pen 3 to the pen sensor 10 via the pen sensor 10, indicating the position of the electronic pen 3. Then, the process proceeds to step SP12.

[0077] (Step SP12) The electronic device 1A acquires position signals transmitted from the detection electrodes 11 and 12 of the pen sensor 10 using the acquisition unit 22. Then, the process proceeds to step SP14.

[0078] (Step SP14) The electronic device 1A uses the pressure sensitivity calculation unit 23 to refer to the operating state data 213 of the memory unit 21 and determines whether the current operating state is the second state. If the determination is positive, the process proceeds to step SP16. Conversely, if the determination is negative, the electronic device 1A determines that the current operating state is the first state, and the process proceeds to step SP22.

[0079] (Step SP16) The electronic device 1A uses the pressure sensitivity calculation unit 23 to determine whether the potential of the position signal has risen to a first potential or higher within a predetermined time. Alternatively, the electronic device 1A may use the pressure sensitivity calculation unit 23 to determine whether the potential of the position signal has risen to a first potential or higher from the previously acquired potential of the position signal. If the determination is positive, the process proceeds to step SP18. If the determination is negative, the process proceeds to step SP28.

[0080] (Step SP18) The electronic device 1A determines, via the pressure sensitivity calculation unit 23, that its operating state has transitioned from the second state to the first state. The electronic device 1A updates the operating state data 213 in the storage unit 21, via the pressure sensitivity calculation unit 23, to indicate that the current operating state is the first state. Then, the process proceeds to step SP20.

[0081] (Step SP20) The electronic device 1A calculates a pen pressure value as a first value using the pen pressure calculation unit 23. The electronic device 1A then transmits the calculated pen pressure value to the host processor 30 using the pen pressure calculation unit 23. The process then proceeds to step SP28.

[0082] (Step SP22) The electronic device 1A uses the pressure sensitivity calculation unit 23 to determine whether the potential of the position signal has dropped by two potentials or more within a predetermined time. Alternatively, the electronic device 1A may use the pressure sensitivity calculation unit 23 to determine whether the potential of the position signal has dropped by two potentials or more from the potential of the previously acquired position signal. If the determination is positive, the process proceeds to step SP24. If the determination is negative, the process proceeds to step SP28.

[0083] (Step SP24) The electronic device 1A determines, via the pressure sensitivity calculation unit 23, that its operating state has transitioned from the first state to the second state. The electronic device 1A updates the operating state data 213 in the storage unit 21 to indicate that the current operating state is the second state. Then, the process proceeds to step SP26.

[0084] (Step SP26) The electronic device 1A calculates the pen pressure value as a second value using the pen pressure calculation unit 23. The electronic device 1A then transmits the calculated pen pressure value to the host processor 30 using the pen pressure calculation unit 23. The process then proceeds to step SP28.

[0085] (Step SP28) The electronic device 1A controls the display of the display panel 40 according to the pen pressure indicated by the pen pressure value transmitted from the pen pressure calculation unit 23 by the host processor 30. Then, the series of processes shown in Figure 6 are completed.

[0086] <Effects> In the first embodiment described above, the sensor controller 20 includes an acquisition unit 22 that acquires a position signal indicating the position of the electronic pen 3 from a pen sensor 10 that detects the position of the electronic pen 3. The sensor controller 20 also includes a pressure calculation unit 23 that calculates a pressure value relating to the pressure applied by the electronic pen 3 to the pen sensor 10 based on the change in the signal level of the position signal acquired by the acquisition unit 22. With this configuration, since the sensor controller 20 calculates the pressure value based on the change in the signal level of the position signal, the influence of variations in the signal level of the position signal due to manufacturing variations of the electronic pen 3 is reduced. Therefore, the sensor controller 20 can calculate the pressure applied by the electronic pen 3 to the pen sensor 10 with high accuracy.

[0087] Furthermore, in the first embodiment, the pressure calculation unit 23 determines that the operating state has transitioned to a first state in which the electronic pen 3 is pressing against the pen sensor 10 when the potential of the position signal rises to a first potential or higher within a predetermined time, and calculates the pressure value as the first value. Here, the signal level is potential. Therefore, since the sensor controller 20 calculates the pressure value according to the amount of rise in the position signal, it can determine the pressure of the electronic pen 3 against the pen sensor 10 with a simple configuration and high accuracy, and calculate the pressure value according to that pressure.

[0088] Furthermore, in the first embodiment, the pressure calculation unit 23 determines that the operating state has transitioned to a second state in which the electronic pen 3 is separated from the pen sensor 10 when the potential of the position signal drops by a second potential or more within a predetermined time, and calculates the pressure value as a second value different from the first value. Therefore, since the sensor controller 20 calculates the pressure value according to the amount of decrease in the position signal, it can determine the separation of the electronic pen 3 from the pen sensor 10 with a simple configuration and high accuracy, and calculate the pressure value according to that separation.

[0089] ---Second Embodiment--- Next, a second embodiment will be described.

[0090] <Overall Structure> Figure 7 shows an example of the specific configuration of the electronic device 1B according to the second embodiment. As shown in Figure 7, the electronic device 1B according to the second embodiment is composed of a pen sensor 100, a touch sensor 101, a touch sensor controller 51, a pen sensor controller 52, a host processor 30, and a display panel 40. Note that the display panel 40 and the host processor 30 are the same as in the first embodiment, so their description is omitted.

[0091] The electronic pen 300 is a stylus equipped with a resonant circuit used in the EMR (Electromagnetic Resonance) method. The electronic pen 300 receives a magnetic field generated from the pen sensor 100, drives the resonant circuit according to the received magnetic field, and transmits a position signal indicating the indicated position of the electronic pen 300 to the pen sensor 100. The electronic pen 300 also has a pressure sensor that detects the pressure applied to the pen tip. The pressure sensor is composed of a capacitor and a coil whose capacitance is variable according to the pressure applied. The electronic pen 300 transmits a pressure signal indicating the pressure applied to the electronic pen 300 to the pen sensor 100 in accordance with the driving of the resonant circuit.

[0092] The touch sensor 101 is similar to the pen sensor 10, and is, for example, a capacitive sensor in which multiple detection electrodes 11 and 12 are arranged in a planar manner. The touch sensor 101 detects the indicated position of the user's finger 2. In this embodiment, the touch sensor 101 is an "external type" sensor that is attached to the outside of the display panel 40, but it is not limited to this. The touch sensor 101 may also be an "internal type" (further classified as on-cell type or in-cell type) sensor that is integrated with the display panel 40.

[0093] The pen sensor 100 is a loop coil antenna used in the EMR system. The pen sensor 100 is composed of multiple loop coils for detecting the position in the X-axis direction and multiple loop coils for detecting the position in the Y-axis direction. The pen sensor 100 detects the indicated position of the electronic pen 300 by generating a magnetic field from the coil antenna and receiving a position signal transmitted from a resonant circuit provided in the electronic pen 300. The pen sensor 100 also detects the pressure applied by the electronic pen 300 to the pen sensor 100 by generating a magnetic field from the coil antenna and receiving a pen pressure signal transmitted from a resonant circuit provided in the electronic pen 300.

[0094] The touch sensor controller 51 controls the operation of finger position detection and pen pressure detection by the touch sensor 101. The touch sensor controller 51 also communicates with the host processor 30.

[0095] The pen sensor controller 52 controls the operation of the electronic pen 300's position detection and pressure detection using the pen sensor 100. The pen sensor controller 52 also controls the transmission of signals from the pen sensor 100 to the electronic pen 300 and the reception of position signals and pressure signals transmitted from a resonant circuit that is driven by the signals transmitted from the pen sensor 100. The pen sensor controller 52 also communicates with the host processor 30.

[0096] The touch sensor controller 51 and the pen sensor controller 52 are configured to include, for example, a communication device, a storage device, a CPU, and memory. The touch sensor controller 51 and the pen sensor controller 52 function as described later by the CPU executing a predetermined program stored in memory or the storage device. The communication device consists of a communication interface for communicating with external devices. The storage device consists of a hard disk or the like and stores various programs, various information, and processing result information necessary for executing processing in the touch sensor controller 51 or the pen sensor controller 52.

[0097] <Functional configuration> Next, the functional configuration of the pen sensor controller 52 of the electronic device 1B will be described. Note that the memory unit 21 is the same as the sensor controller 20 of the first embodiment, so its description will be omitted. Similarly, the functional configuration of the touch sensor controller 51 is the same as the sensor controller 20 of the first embodiment, so its description will also be omitted.

[0098] The acquisition unit 22 acquires a position signal from the pen sensor 100 indicating the position of the electronic pen 300. Specifically, the acquisition unit 22 acquires from the pen sensor 100 a position signal transmitted from a loop coil for detecting the position in the X-axis direction and a position signal transmitted from a loop coil for detecting the position in the Y-axis direction. The acquisition unit 22 also acquires a pressure signal from the pen sensor 100 indicating the pressure applied by the electronic pen 300.

[0099] The pressure calculation unit 23 calculates the pressure value by correcting the pressure indicated by the pressure signal acquired by the acquisition unit 22 based on the change in the potential of the position signal acquired by the acquisition unit 22. Specifically, the pressure calculation unit 23 refers to the potentials of the position signal and pressure signal acquired by the acquisition unit 22, and the pressure reference data 211 and pressure condition data 212 stored in the storage unit 21. The pressure calculation unit 23 determines that the operating state has transitioned to the first state when the potential of the position signal rises to a first potential or higher within a predetermined time. Then, the pressure calculation unit 23 calculates the pressure value by correcting the pressure indicated by the pressure signal with a first value. Specifically, the pressure calculation unit 23 corrects the pressure by, for example, multiplying, adding, subtracting, or dividing the pressure value indicated by the pressure signal by a first value, or by substituting the first value and the pressure value indicated by the pressure signal into a predetermined relational expression. Furthermore, the pressure calculation unit 23 may, for example, compare the magnitude relationship between the first value and the pressure indicated by the pressure signal, select the larger value, and correct the pressure. Alternatively, the pressure calculation unit 23 may calculate the pressure value as the first value.

[0100] Furthermore, the pressure calculation unit 23 determines that the operating state has transitioned to the second state if the potential of the position signal drops by a second potential or more within a predetermined time. The pressure calculation unit 23 then calculates the pressure value by correcting the pressure indicated by the pressure signal with the second value. Specifically, the pressure calculation unit 23 corrects the pressure by, for example, multiplying, adding, subtracting, or dividing the pressure value indicated by the pressure signal by the second value, or by substituting the second value and the pressure value indicated by the pressure signal into a predetermined relational expression. The pressure calculation unit 23 may also calculate the pressure value as the second value. In addition, if the potential of the position signal does not meet the above conditions, the pressure calculation unit 23 determines that the operating state has not changed and maintains the pressure value. The pressure calculation unit 23 stores the determined current operating state in the operating state data 213 of the storage unit 21.

[0101] Furthermore, if the pressure calculation unit 23 determines that the pressure signal acquired by the acquisition unit 22 indicates that the electronic pen 300 is pressing the pen sensor 100 before determining that the operating state has transitioned from the second state to the first state, it determines that the pressure signal is showing an abnormal value. If the pressure calculation unit 23 determines that an abnormal value is showing, it corrects the pressure indicated by the pressure signal with a second value. Alternatively, if the pressure calculation unit 23 determines that an abnormal value is showing, it may calculate the pressure indicated by the pressure signal as the second value.

[0102] Furthermore, if the pressure calculation unit 23 determines that the operating state has transitioned from the first state to the second state, and the pressure signal acquired by the acquisition unit 22 indicates that the pen sensor 100 is separated from the electronic pen 300, the unit maintains the pressure value, treating the pressure signal as an abnormal value.

[0103] Here, with reference to Figure 8, an example of how the pressure is calculated by the pressure calculation unit 23 in the second embodiment will be described. Figure 8 is a graph showing an example of the relationship between the change in the levels of the position signal and the pressure signal and the pressure value in the second embodiment. In Figure 8, the vertical axis shows the detection level, which is converted to a common scale by a predetermined conversion formula. Also in Figure 8, the horizontal axis shows the elapsed time [ms]. The graph shown in Figure 8 shows data indicating the difference from the previous detection level of the loop coil in the X-axis direction, data indicating the difference from the previous detection level in the Y-axis direction, data indicating the level of the pressure value, and the potential of the pressure signal. Also in Figure 8, the detection levels associated with the first potential and the second potential are both assumed to be 200. Also in Figure 8, the predetermined time is assumed to be 10 ms. Also in Figure 8, the first value is assumed to be 1000. Also in Figure 8, the second value is assumed to be 0. Note that in Figure 8, the pressure calculation unit 23 calculates the pressure value as either the first value or the second value.

[0104] As shown in Figure 8, the pressure calculation unit 23 calculates a first pressure value faster than the pressure signal indicates that the electronic pen 300 is pressing against the pen sensor 100, and transmits the pressure value to the host processor 30. The pressure calculation unit 23 also calculates a second pressure value immediately after the pressure signal indicates that the electronic pen 300 has moved away from the pen sensor 100.

[0105] The functional configuration of the pen sensor controller 52 has been described above. Next, the specific processing flow in the electronic device 1B will be described in detail. Figure 9 is a flowchart showing an example of a series of processing steps by the electronic device 1B according to the second embodiment. Note that the content and order of the following steps can be changed as appropriate.

[0106] (Step SP50) The electronic device 1B acquires a pressure signal from the electronic pen 300, indicating the pressure applied by the electronic pen 300 to the pen sensor 100, via the pen sensor 100. Then, the process proceeds to step SP52.

[0107] (Step SP52) The electronic device 1B acquires the position signal transmitted from the loop coil of the pen sensor 100 using the acquisition unit 22. Then, the process proceeds to step SP54.

[0108] (Step SP54) The electronic device 1B uses the pressure sensitivity calculation unit 23 to refer to the operating state data 213 of the memory unit 21 and determines whether the current operating state is the second state. If the determination is positive, the process proceeds to step SP56. Conversely, if the determination is negative, the electronic device 1B determines that the current operating state is the first state, and the process proceeds to step SP64.

[0109] (Step SP56) The electronic device 1B uses a pressure calculation unit 23 to determine whether the pressure signal indicates that the electronic pen 300 is pressing against the pen sensor 100. If the determination is positive, the process proceeds to step SP58. If the determination is negative, the process proceeds to step SP62.

[0110] (Step SP58) The electronic device 1B determines, using the pressure calculation unit 23, that the pressure signal indicates an abnormal value. Then, the process proceeds to step SP60.

[0111] (Step SP60) The electronic device 1B calculates the pen pressure value as a second value using the pen pressure calculation unit 23. The electronic device 1B then transmits the calculated pen pressure value to the host processor 30 using the pen pressure calculation unit 23. The process then proceeds to step SP72.

[0112] (Step SP62) The electronic device 1B determines, using the pressure calculation unit 23, that its operating state remains in the second state. The electronic device 1B then calculates the pressure value as the second value using the pressure calculation unit 23. Alternatively, the electronic device 1B may calculate the pressure value by correcting the pressure indicated by the pressure signal using the second value using the pressure calculation unit 23. The process then proceeds to step SP72.

[0113] (Step SP64) The electronic device 1B uses a pressure calculation unit 23 to determine whether the pressure signal indicates that the electronic pen 300 is separated from the pen sensor 100. If the determination is positive, the process proceeds to step SP66. If the determination is negative, the process proceeds to step SP70.

[0114] (Step SP66) The electronic device 1B determines, using the pressure calculation unit 23, that the pressure signal is showing an abnormal value. Then, the process proceeds to step SP68.

[0115] (Step SP68) The electronic device 1B maintains the pen pressure value at the previously calculated value using the pen pressure calculation unit 23. The electronic device 1B also transmits the calculated pen pressure value to the host processor 30 using the pen pressure calculation unit 23. Then, the process proceeds to step SP72.

[0116] (Step SP70) The electronic device 1B determines, using the pressure calculation unit 23, that its operating state remains in the first state. The electronic device 1B then calculates the pressure value as the first value using the pressure calculation unit 23. Alternatively, the electronic device 1B may calculate the pressure value by correcting the pressure indicated by the pressure signal using the first value using the pressure calculation unit 23. The process then proceeds to step SP72.

[0117] (Step SP72) The electronic device 1B controls the display of the display panel 40 according to the pen pressure indicated by the pen pressure value transmitted from the pen pressure calculation unit 23 by the host processor 30. Then, the series of processes shown in Figure 9 are completed.

[0118] <Effects> In the second embodiment described above, the acquisition unit 22 acquires a pressure signal from the electronic pen 300 that is transmitted from the electronic pen 300 to the pen sensor 100 and indicates the pressure applied by the electronic pen 300 to the pen sensor 100. The pressure calculation unit 23 calculates the pressure value by correcting the pressure indicated by the pressure signal based on the change in the potential of the position signal. Therefore, the pen sensor controller 52 (sensor controller) can calculate the pressure applied by the electronic pen 300 to the pen sensor 100 with high accuracy, even when using an electronic pen 300 that has a function to detect pressure.

[0119] In the second embodiment, the pressure calculation unit 23 determines that the operating state has transitioned to a first state in which the electronic pen 300 is pressing the pen sensor 100 when the potential of the position signal rises to a first potential or higher within a predetermined time, and calculates the pressure value as a first value. Furthermore, if the pressure calculation unit 23 determines that the operating state has transitioned to the first state, and the pressure signal acquired by the acquisition unit 22 indicates that the electronic pen 300 is pressing the pen sensor 100, it determines that the pressure signal is an abnormal value and calculates the pressure value as a second value different from the first value. Here, the signal level is potential. Therefore, the pen sensor controller 52 (sensor controller) can determine that a false detection of pressure by the electronic pen 300's pressure sensor is abnormal, and thus can calculate the pressure applied to the pen sensor 100 by the electronic pen 300 with even greater accuracy.

[0120] Furthermore, in the second embodiment, the pressure calculation unit 23 determines that the operating state has transitioned to a second state in which the electronic pen 300 is separated from the pen sensor 100 when the potential of the position signal drops to a second potential or higher within a predetermined time, and calculates the pressure value as the second value. Also, if the pressure calculation unit 23 determines that the operating state has transitioned to the second state, and the pressure signal acquired by the acquisition unit 22 indicates that the electronic pen 300 is separated from the pen sensor 100, it maintains the pressure value as an abnormal value.Therefore, the pen sensor controller 52 (sensor controller) can determine that the erroneous detection of separation by the pressure sensor of the electronic pen 300 is abnormal, and thus can calculate the pressure applied by the electronic pen 300 to the pen sensor 100 with even greater accuracy.

[0121] ---Third Embodiment--- Next, the third embodiment will be described.

[0122] In the first and second embodiments, the sensor controller 20 provided in the electronic device 1A or the pen sensor controller 52 provided in the electronic device 1B calculated the pen pressure value. The third embodiment differs from the first and second embodiments in that the electronic pen 3, rather than the electronic devices 1A and 1B, calculates the pen pressure value.

[0123] Figure 10A is a cross-sectional view of the position detection system 5 according to the third embodiment along line XX. Figure 10B is a cross-sectional view of the position detection system 5 shown in Figure 10A when the electronic pen 3 is tilted relative to the electronic device 1A. In Figures 10A and 10B, it is assumed that a pressure Fa is applied to the tip of the electronic pen 3 in the direction normal to the upward direction from the display panel 40 of the electronic device 1A. In Figure 10B, when the pressure Fa vector is decomposed into the axial direction of the electronic pen 3 and the direction perpendicular to the axial direction, the axial component of the electronic pen 3 is defined as pressure Fb, and the component perpendicular to the axial direction is defined as pressure Fc. As shown in Figure 10B, it can be seen that the larger the tilt α of the electronic pen 3 with respect to the display surface of the electronic device 1A, the smaller the pressure Fb applied to the tip of the electronic pen 3 in the axial direction.

[0124] As shown in Figure 10A, the electronic pen 3 has a pen tip that can reciprocate along the axial direction of the electronic pen 3. The electronic pen 3 also has a gap between the pen tip and the sensor 34, and a cushioning material 371 is provided in this gap to transmit the pressure applied to the pen tip to the sensor 34. The pen tip has an electrode 37 at its tip or the pen tip itself functions as an electrode 37. The sensor 34 is configured to include a capacitor switch whose capacitance changes according to the pressure. The sensor 34 detects pressure by changing its capacitance in response to the pressure applied from the pen tip via the cushioning material 371, and transmits the detected pressure as a pen pressure signal to the pen controller 36 via the data manager 33.

[0125] The pen controller 36 calculates a pen pressure value based on the change in the potential of the uplink signal transmitted from the pen sensor 10 via the electrode 37. Specifically, the pen controller 36 determines that the operating state has transitioned to the first state when the potential of the uplink signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as the first value. The pen controller 36 also determines that the operating state has transitioned to the second state when the potential of the uplink signal falls to a second potential or higher within a predetermined time, and calculates the pen pressure value as the second value. The pen controller 36 may also calculate the pen pressure value by correcting the pressure detected by the sensor 34 based on the change in the potential of the uplink signal.

[0126] Further details regarding the operation of the pen controller 36 are the same as in the first or second embodiment, except that the pressure sensitivity is calculated or corrected based on the change in the potential of the uplink signal instead of the position signal, so the explanation is omitted.

[0127] An example of how the pen controller 36 calculates pen pressure will be explained with reference to Figure 11. Figure 11 is a graph showing an example of the relationship between the change in the level of the uplink signal and the pen pressure value when the tilt α of the electronic pen 3 is large in the third embodiment. In Figure 11, the vertical axis shows the detection level, which is obtained by converting the potential to a common scale using a predetermined conversion formula. Also in Figure 11, the horizontal axis shows the elapsed time [ms]. The graph shown in Figure 11 shows data showing the difference in the level of the uplink signal transmitted from the detection electrode 11 from the previous time, data showing the difference in the level of the uplink signal transmitted from the detection electrode 12 from the previous time, and data showing the pen pressure value and the level of the pen pressure signal. Also in Figure 11, the detection levels associated with the first potential and the second potential are both assumed to be 200. Also in Figure 11, the predetermined time is assumed to be 10 ms. Also in Figure 11, the first value is assumed to be 1000. Also in Figure 11, the second value is assumed to be 0.

[0128] As shown in Figure 11, the pen controller 36 calculates the pressure value as a first value considerably earlier than the uplink signal indicates that the electronic pen 3 is pressing against the pen sensor 10, and transmits the pressure value to the host processor 30. The pen controller 36 also calculates the pressure value as a second value immediately after the pressure signal indicates that the electronic pen 3 has moved away from the pen sensor 10.

[0129] In the third embodiment, the electronic pen 3 is equipped with a sensor 34 for detecting pen pressure and transmits a pen pressure signal, but it is not limited to this. The electronic pen 3 does not need to have a sensor 34. Furthermore, the electronic pen 3 may simply calculate a pen pressure value based on the signal level of the uplink signal.

[0130] <Effects> In the third embodiment described above, the electronic pen 3 is an electronic pen 3 that provides position instructions to the pen sensor 10. The electronic pen 3 has a pen tip having an electrode 37 that is provided at the tip so as to be reciprocal along the axial direction and transmits and receives signals to and from the pen sensor 10, a pen controller 36, and a transmitter TX. The pen controller 36 calculates a pen pressure value related to pen pressure based on the change in potential of the uplink signal transmitted from the pen sensor 10 via the electrode 37. The transmitter TX transmits a pen pressure signal indicating the pen pressure value calculated by the pen controller 36 and a position signal indicating the instruction position to the pen sensor 10 to the pen sensor 10 via the electrode 37.

[0131] With this configuration, the electronic pen 3 calculates the pressure value based on changes in the signal level of the uplink signal, thus reducing the influence of variations in the signal level of the position signal due to manufacturing variations in the electronic pen 3. Furthermore, because the electronic pen 3 uses the uplink signal to calculate the pressure value, the influence of the degree of tilt of the electronic pen 3 relative to the pen sensor 10 on the sensor 34 is reduced. Therefore, the electronic pen 3 can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with high accuracy.

[0132] In the third embodiment, the pen controller 36 determines that the operating state has transitioned to a first state in which the pen sensor 10 is being pressed when the potential of the uplink signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as the first value. Here, the signal level is the potential.

[0133] Therefore, since the electronic pen 3 calculates the pen pressure value according to the increase in the potential of the uplink signal, it can determine the pressure applied by the electronic pen 3 to the pen sensor 10 with a simple configuration and high accuracy, and calculate the pen pressure value according to that pressure.

[0134] In the third embodiment, the pen controller 36 determines that the operating state has transitioned to a second state in which it is separated from the pen sensor 10 when the potential of the uplink signal drops to a second potential or higher within a predetermined time, and calculates the pen pressure value as a second value different from the first value.

[0135] Therefore, since the electronic pen 3 calculates the pressure value according to the decrease in the potential of the uplink signal, it can determine the distance between the pen 3 and the pen sensor 10 with a simple configuration and high accuracy, and calculate the pressure value according to that distance.

[0136] In the third embodiment, the electronic pen 3 further includes a sensor 34 (pressure sensor) that detects the pressure applied to the pen tip. The pen controller 36 calculates the pen pressure value by correcting the pressure detected by the sensor 34 based on the change in the signal level of the uplink signal. Here, the signal level is the electric potential.

[0137] Therefore, the electronic pen 3 can calculate the pen pressure applied to the pen sensor 10 with high accuracy by correcting the pressure detected by the sensor 34.

[0138] In the third embodiment, the pen controller 36 determines that the operating state has transitioned to the first state when the potential of the uplink signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as the first value. Conversely, if the pen controller 36 determines that the operating state has transitioned to the first state, and the pen pressure signal indicates that the pen sensor 10 is being pressed, it determines that the pen pressure signal is showing an abnormal value and calculates the pen pressure value as the second value. Here, the signal level is the potential.

[0139] Therefore, the electronic pen 3 can determine that a false detection of pressure by the sensor 34 is an anomaly, and thus can calculate the pen pressure applied to the pen sensor 100 by the electronic pen 3 with even greater accuracy.

[0140] In the third embodiment, the pen controller 36 determines that the operating state has transitioned to the second state when the potential of the uplink signal drops to a second potential or higher within a predetermined time, and calculates the pen pressure value as the second value. On the other hand, if the pen controller 36 indicates that the pen pressure signal is separated from the pen sensor 10 before determining that the operating state has transitioned to the second state, it maintains the pen pressure value as an abnormal value.

[0141] Therefore, the electronic pen 3 can determine any erroneous detection of distance between the pen and the pen as an anomaly based on the pressure sensor of the electronic pen 3, thus enabling the calculation of the pressure applied to the pen sensor 10 by the electronic pen 3 with even greater accuracy.

[0142] ---Fourth Embodiment--- Next, the fourth embodiment will be described.

[0143] In the fourth embodiment, the sensor controller 20 of the electronic device 1A differs from the first embodiment in that it calculates the pressure value of the electronic pen 3 based on a first signal transmitted from the electrode 37 of the electronic pen 3 and a second signal transmitted from the electrode 38 of the electronic pen 3. Furthermore, in the fourth embodiment, the electronic pen 3 is assumed to have the sensor 34 (pressure sensor) described in the third embodiment.

[0144] Figure 12A shows an example of the signal level distribution in the fourth embodiment when the electronic pen 3 is not in contact with the electronic device 1A and has a small tilt. In Figure 12A and Figures 12B to 12D described later, the vertical axis of the graph shows the signal level (potential, etc.) of the first signal and the second signal. The horizontal axis of the graph shows the coordinate value in the X-axis direction on the pen sensor 10. In Figures 12A and 12B, the tilt of the electronic pen 3 relative to the pen sensor 10 (i.e., the angle between the normal to the detection surface of the pen sensor 10 and the axis direction of the electronic pen 3) is assumed to be 0°. In the fourth embodiment, the electronic pen 3 transmits a first signal toward the pen sensor 10 that includes information about the indicated position, such as the coordinate value of the electronic pen 3 on the pen sensor 10. The first signal may also include information about the pressure detected by the sensor 34, i.e., the writing pressure of the electronic pen 3 toward the pen sensor 10. The electronic pen 3 also transmits a second signal toward the pen sensor 10 that includes an attitude value relating to the orientation of the electronic pen 3 on the pen sensor 10.

[0145] As shown in Figure 12A, the pen sensor 10 receives the first signal transmitted from the electrode 37. The first signal has the highest signal level at coordinate x4 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and its value is V1. Similarly, the second signal has the highest signal level at coordinate x4 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and its value is V3. Note that the level of the second signal is generally lower than that of the first signal because the distance between the pen sensor 10 and the electrode 38 is longer than the distance between the pen sensor 10 and the electrode 37. Also, in Figure 12A, because the tilt of the electronic pen 3 relative to the pen sensor 10 is small, the coordinate value where the signal level of the first signal is at its maximum coincides with the coordinate value where the signal level of the second signal is at its maximum.

[0146] Figure 12B shows an example of the signal level distribution in the fourth embodiment when the electronic pen 3 is in contact with the electronic device 1A and the tilt is small. In Figure 12B, the first signal has the highest signal level at coordinate x4 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and the value V2 is greater than the value V1. It can be seen that the signal level of the first signal is higher than in the non-contact case because the electronic pen 3 is in contact with the pen sensor 10. The second signal has the highest signal level at coordinate x4 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and the value V3. In reality, the level of the second signal is slightly higher than the value V3 because the distance between the electrode 38 and the pen sensor 10 is shorter compared to the case when the electronic pen 3 is not in contact with the pen sensor 10, but the change is within a negligible range, so for convenience it is set to value V3. In Figure 12B, similar to Figure 12A, the tilt of the electronic pen 3 relative to the pen sensor 10 is small, so the coordinate value at which the signal level of the first signal is at its maximum value coincides with the coordinate value at which the signal level of the second signal is at its maximum value.

[0147] Figure 12C shows an example of the signal level distribution in the fourth embodiment when the electronic pen 3 is not in contact with the electronic device 1A and has a large tilt. In Figure 12C, the tilt of the electronic pen 3 relative to the pen sensor 10 (i.e., the angle between the normal to the detection surface of the pen sensor 10 and the axis direction of the electronic pen 3) is assumed to be 90°-α. Also in Figure 12C, the first signal has the highest signal level at coordinate x4 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and the value is V1. The second signal has the highest signal level at coordinate x6 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and the value is V4, which is greater than the value V3. The second signal shows that the electronic pen 3 has a large tilt relative to the pen sensor 10, and the distance between the electrode 38 and the pen sensor 10 is closer compared to the case where the tilt is small, so the signal level is higher than in the non-contact case. In Figure 12C, because the tilt of the electronic pen 3 relative to the pen sensor 10 is large, the coordinate value at which the signal level of the first signal is at its maximum value does not match the coordinate value at which the signal level of the second signal is at its maximum value.

[0148] Figure 12D shows an example of the signal level distribution in the fourth embodiment when the electronic pen 3 is in contact with the electronic device 1A and has a large tilt. In Figure 12D, the tilt of the electronic pen 3 relative to the pen sensor 10 (i.e., the angle between the normal to the detection surface of the pen sensor 10 and the axis direction of the electronic pen 3) is assumed to be 90°-α. In Figure 12D, the first signal has the highest signal level at coordinate x4 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and the value is V2. The second signal has the highest signal level at coordinate x6 among the coordinate values ​​(x1 to x7) in the X-axis direction on the pen sensor 10, and the value is V4. It can be seen that the signal level of the first signal is higher than in the non-contact case because the electronic pen 3 is in contact with the pen sensor 10. Furthermore, the second signal shows an increased signal level compared to the non-contact case because the electronic pen 3 is tilted significantly relative to the pen sensor 10, and the distance between the electrode 38 and the pen sensor 10 is shorter compared to the case where the tilt is smaller. Figure 12D shows that because the electronic pen 3 is tilted significantly relative to the pen sensor 10, the coordinate value at which the signal level of the first signal is at its maximum does not match the coordinate value at which the signal level of the second signal is at its maximum. Note that while Figures 12A to 12D use coordinate values ​​in the X-axis direction as an example, coordinate values ​​in the Y-axis direction should be treated in the same way as coordinate values ​​in the X-axis direction.

[0149] Next, the method for calculating pen pressure in the fourth embodiment will be described. In the fourth embodiment, the acquisition unit 22 acquires a first signal transmitted from the electrode 37 (first electrode) of the electronic pen 3 to the pen sensor 10 from the pen sensor 10. The acquisition unit 22 also acquires a second signal transmitted from the electrode 38 (second electrode), which is different from the electrode 37 of the electronic pen 3, to the pen sensor 10 from the pen sensor 10. The acquisition unit 22 also acquires a pen pressure signal from the pen sensor 10 that indicates the pen pressure of the electronic pen 3. The pen pressure signal is assumed to be transmitted from the electrode 37 of the electronic pen 3. The acquisition unit 22 also stores the information indicated by the acquired first signal, second signal, and pen pressure signal in the storage unit 21.

[0150] In the fourth embodiment, the storage unit 21 stores a correction table for correcting or calculating pen pressure according to the tilt angle of the electronic pen 3 relative to the pen sensor 10 (i.e., the angle between the normal to the detection surface of the pen sensor 10 and the axial direction of the electronic pen 3). The correction table, for example, associates calculated values ​​obtained from the signal distributions of the first signal and the second signal with a correction coefficient. The correction coefficient is basically a value that increases the pen pressure value indicated by the pen pressure signal (for example, a value greater than 1), but is not limited to this, and may also be a value that decreases the pen pressure value indicated by the pen pressure signal (for example, a value less than 1). Alternatively, instead of a correction table, the storage unit 21 may store a predetermined arithmetic formula or function in which values ​​related to the signal distribution of the first signal and values ​​related to the signal distribution of the second signal are input variables and the correction coefficient is the output variable.

[0151] The correction table associates calculated values ​​with correction coefficients such that the smaller the calculated value, the larger the correction coefficient. This indicates that as the electronic pen 3 is tilted relative to the pen sensor 10, the electrode 38 moves closer to the pen sensor 10, and therefore the signal level of the second signal becomes larger relative to the signal level of the first signal. The correction table may also associate the difference between the coordinate value on the pen sensor 10 at which the statistical value (preferably the maximum value) of the signal level of the first signal was detected and the coordinate value at which the statistical value (preferably the maximum value) of the signal level of the second signal was detected with a correction coefficient. In this example, the tilt of the electronic pen 3 relative to the pen sensor 10 is calculated based on the difference in the coordinate values ​​at which the maximum value was detected. As the electronic pen 3 is tilted relative to the pen sensor 10, the difference between the coordinate value indicating the maximum value of the signal level of the first signal and the coordinate value indicating the maximum value of the signal level of the second signal becomes larger. The correction table may also associate the difference between the acceleration vector detected by the acceleration sensor pre-installed on the electronic pen 3 and the acceleration vector detected by the acceleration sensor pre-installed on the electronic device 1A with a correction coefficient. In this example, the difference between the acceleration applied to the electronic pen 3 and the acceleration applied to the electronic device 1A is used as a calculated value to indicate the tilt of the electronic pen 3 relative to the pen sensor 10.

[0152] The pressure calculation unit 23 calculates a pressure value relating to the pressure applied by the electronic pen 3 to the pen sensor 10 based on the change in potential of the first signal, the change in potential of the second signal, and the pressure signal acquired by the acquisition unit 22. Specifically, the pressure calculation unit 23 determines that the operating state has transitioned to the first state if the potential difference between the first signal and the second signal rises to the first potential or higher within a predetermined time. The pressure calculation unit 23 also determines that the operating state has transitioned to the second state if the potential difference between the first signal and the second signal falls to the second potential or higher within a predetermined time. The pressure calculation unit 23 uses statistical values ​​of the signal distribution of the first signal and the signal distribution of the second signal to calculate the potential difference between the first and second signals. The statistical values ​​of the signal distribution include, for example, the maximum value, median value, and mean value of the signal level. The pressure calculation unit 23 then calculates the pressure value according to the signal distribution of the first and second signals and the pressure signal. Furthermore, if the potentials of the first signal and the second signal do not meet the above-described conditions, the pressure calculation unit 23 determines that the operating state has not changed and maintains the pressure value. The pressure calculation unit 23 stores the determined current operating state in the operating state data 213 of the storage unit 21.

[0153] The pressure sensitivity calculation unit 23 calculates the pressure sensitivity in the first and second states such that the pressure sensitivity increases as the tilt angle of the electronic pen 3 with respect to the pen sensor 10 increases, and decreases as the tilt angle decreases. Specifically, the pressure sensitivity calculation unit 23 calculates a value by subtracting the maximum value of the signal level of the second signal from the maximum value of the signal level of the first signal. The pressure sensitivity calculation unit 23 refers to the correction table stored in the memory unit 21 and obtains the correction coefficient associated with the calculated value. Then, the pressure sensitivity calculation unit 23 corrects the pressure sensitivity by multiplying the pressure sensitivity indicated by the pressure sensitivity signal by the obtained correction coefficient. Note that in the first state, if the pressure sensitivity signal indicates that the electronic pen 3 is not pressing against the pen sensor 10, the pressure sensitivity calculation unit 23 may calculate the pressure sensitivity as a first value indicating that the electronic pen 3 is pressing against the pen sensor 10.

[0154] Furthermore, the pressure sensitivity calculation unit 23 may use the potential of the first signal or the second signal instead of the potential difference between the first signal and the second signal when determining the operating state. Specifically, the pressure sensitivity calculation unit 23 may determine that the operating state has transitioned to the first state if, in the second state, the potential of the first signal or the second signal rises to a first potential or higher within a predetermined time. Also, the pressure sensitivity calculation unit 23 may determine that the operating state has transitioned to the second state if, in the first state, the potential of the first signal or the second signal falls to a second potential or higher within a predetermined time. In addition, the pressure sensitivity calculation unit 23 may use the ratio of the potentials instead of the potential difference between the first signal and the second signal when determining the operating state. Furthermore, the pressure sensitivity calculation unit 23 may use the area of ​​the signal distribution of the first signal or the area of ​​the signal distribution of the second signal when determining the operating state. Furthermore, the pressure sensitivity calculation unit 23 may use the area ratio of the signal distribution of the second signal to the signal distribution of the first signal when determining the operating state. Furthermore, the pressure calculation unit 23 may use the overlapping area between the signal distribution of the first signal and the signal distribution of the second signal when determining the operating state.

[0155] Furthermore, the pressure sensitivity calculation unit 23 may calculate the tilt angle of the electronic pen 3 relative to the pen sensor 10 instead of the calculated value. In addition, the correction table may associate the tilt angle with a correction coefficient. The tilt angle is calculated, for example, from the coordinate value at which the maximum value of the signal level of the first signal is detected, the coordinate value at which the maximum value of the signal level of the second signal is detected, and the distance between electrodes 37 and 38 that are stored in advance, but is not limited to this.

[0156] The functional configuration of the sensor controller 20 according to the fourth embodiment has been described above. Next, the specific processing flow of the electronic device 1A according to the fourth embodiment will be described in detail. Figure 13 is a flowchart showing an example of a series of processing steps performed by the electronic device 1A according to the fourth embodiment. Note that the content and order of the following steps can be changed as appropriate.

[0157] (Step SP80) The electronic device 1A acquires a first signal and a second signal transmitted from the electronic pen 3 to the pen sensor 10 via the pen sensor 10. The first signal is transmitted from the electrode 37 of the electronic pen 3 and indicates the indicated position of the electronic pen 3 on the pen sensor 10. The first signal may also include a pressure value relating to the pressure applied by the electronic pen 3 to the pen sensor 10. The second signal is transmitted from the electrode 38 of the electronic pen 3 and indicates the tilt of the electronic pen 3 on the pen sensor 10. The process then proceeds to step SP82.

[0158] (Step SP82) The electronic device 1A acquires position signals transmitted from the detection electrodes 11 and 12 of the pen sensor 10 using the acquisition unit 22. Then, the process proceeds to step SP84.

[0159] (Step SP84) The electronic device 1A uses the pressure sensitivity calculation unit 23 to refer to the operating state data 213 of the memory unit 21 and determines whether the current operating state is the second state. If the determination is positive, the process proceeds to step SP86. Conversely, if the determination is negative, the electronic device 1A determines that the current operating state is the first state, and the process proceeds to step SP92.

[0160] (Step SP86) The electronic device 1A uses the pressure-sensitive pen pressure calculation unit 23 to determine whether the potential difference between the first signal and the second signal has risen to a first potential or higher within a predetermined time. Alternatively, the electronic device 1A may use the pressure-sensitive pen pressure calculation unit 23 to determine whether the potential difference between the first signal and the second signal has risen to a first potential or higher from the previously acquired potential difference. If the determination is positive, the process proceeds to step SP88. If the determination is negative, the process proceeds to step SP98.

[0161] (Step SP88) The electronic device 1A determines, via the pressure sensitivity calculation unit 23, that its operating state has transitioned from the second state to the first state. The electronic device 1A updates the operating state data 213 in the storage unit 21 to indicate that the current operating state is the first state. Then, the process proceeds to step SP90.

[0162] (Step SP90) The electronic device 1A calculates a pen pressure value based on the signal distribution of the first signal and the second signal using the pen pressure calculation unit 23. The electronic device 1A then transmits the calculated pen pressure value to the host processor 30 using the pen pressure calculation unit 23. The process then proceeds to step SP28.

[0163] (Step SP92) The electronic device 1A uses a pressure-sensitive pen pressure calculation unit 23 to determine whether the potential difference between the first signal and the second signal has dropped by two potentials or more within a predetermined time. Alternatively, the electronic device 1A may use the pressure-sensitive pen pressure calculation unit 23 to determine whether the potential difference between the first signal and the second signal has dropped by two potentials or more from the previously acquired potential difference. If the determination is positive, the process proceeds to step SP94. If the determination is negative, the process proceeds to step SP98.

[0164] (Step SP94) The electronic device 1A determines, via the pressure sensitivity calculation unit 23, that its operating state has transitioned from the first state to the second state. The electronic device 1A updates the operating state data 213 in the storage unit 21 to indicate that the current operating state is the second state. Then, the process proceeds to step SP96.

[0165] (Step SP96) The electronic device 1A calculates a pen pressure value based on the signal distribution of the first signal and the second signal using the pen pressure calculation unit 23. The electronic device 1A then transmits the calculated pen pressure value to the host processor 30 using the pen pressure calculation unit 23. The process then proceeds to step SP28.

[0166] (Step SP98) The electronic device 1A controls the display of the display panel 40 according to the pen pressure indicated by the pen pressure value transmitted from the pen pressure calculation unit 23 by the host processor 30. Then, the series of processes shown in Figure 13 are completed.

[0167] <Effects> In the fourth embodiment described above, the sensor controller 20 includes an acquisition unit 22 and a pen pressure calculation unit 23. The acquisition unit 22 acquires a first signal transmitted from the electrode 37 (first electrode) of the electronic pen 3 to the pen sensor 10, which detects the position of the electronic pen 3. The acquisition unit 22 also acquires a second signal transmitted from the electrode 38 (second electrode) of the electronic pen 3 to the pen sensor 10, which is different from the electrode 37. The acquisition unit 22 also acquires a pen pressure signal indicating the pressure applied by the electronic pen 3. The pen pressure calculation unit 23 calculates a pen pressure value relating to the pressure applied by the electronic pen 3 to the pen sensor 10 based on the changes in the signal levels of the first and second signals acquired by the acquisition unit 22, as well as the pen pressure signal.

[0168] In this configuration, the sensor controller 20 uses a first signal transmitted from electrode 37 and a second signal transmitted from electrode 38, which is different from electrode 37, to calculate the pen pressure value. Therefore, even when the tilt of the electronic pen 3 relative to the pen sensor 10 is large and the accuracy of pen pressure detection by the electronic pen 3 decreases, the sensor controller 20 can calculate the pen pressure value applied to the pen sensor 10 by the electronic pen 3 with high accuracy. Furthermore, unlike the conventional configuration described in Patent Document 2, the sensor controller 20 does not necessarily need to calculate the angle of the electronic pen 3 relative to the pen sensor 10. Therefore, the sensor controller 20 can calculate the pen pressure value related to the pen pressure of the electronic pen 3 applied to the pen sensor 10 without calculating the angle of the electronic pen 3 relative to the pen sensor 10.

[0169] Furthermore, the pressure calculation unit 23 calculates the pressure value such that the pressure value increases as the tilt angle of the electronic pen 3 with respect to the detection surface of the pen sensor 10 increases, and decreases as the tilt angle decreases.

[0170] In this configuration, the sensor controller 20 corrects the pressure value in cases where the pressure detected by the electronic pen 3 decreases as the tilt angle of the electronic pen 3 relative to the pen sensor 10 increases. Therefore, the sensor controller 20 can calculate the pressure value applied to the pen sensor 10 by the electronic pen 3 with high accuracy even when the electronic pen 3 is tilted relative to the pen sensor 10.

[0171] Furthermore, the pressure calculation unit 23 determines that the operating state has transitioned to a first state in which the electronic pen 3 is pressing the pen sensor 10 when the potential of the first signal or the second signal rises to a first potential or higher within a predetermined time, and calculates the pressure value as the first value. Here, the signal level is the potential.

[0172] Therefore, the sensor controller 20 can calculate the pressure value for the pen sensor 10 with high accuracy even when the accuracy of pressure detection by the electronic pen 3 is reduced.

[0173] Furthermore, the pressure calculation unit 23 determines that the operating state has transitioned to a first state in which the electronic pen 3 is pressing the pen sensor 10 when the potential difference between the first signal and the second signal rises to a first potential or higher within a predetermined time, and calculates the pressure value as the first value. Here, the signal level is the potential.

[0174] Therefore, the sensor controller 20 can calculate the pressure value for the pen sensor 10 with high accuracy even when the accuracy of pressure detection by the electronic pen 3 is reduced.

[0175] ---Fifth Embodiment--- Next, the fifth embodiment will be described.

[0176] In the fifth embodiment, the sensor controller 20 determines a criterion for determining whether the operating state has transitioned according to the movement speed of the electronic pen 3. In the fifth embodiment, the storage unit 21 stores a speed threshold related to the movement speed of the electronic pen 3 relative to the pen sensor 10. The storage unit 21 also stores a third potential and a fourth potential related to the first potential. The third potential is the value of the potential determined as the first potential when the movement speed of the electronic pen 3 is equal to or greater than the speed threshold. The fourth potential is the value of the potential determined as the first potential when the movement speed of the electronic pen 3 is less than the speed threshold. The fourth potential is a value greater than the third potential. Furthermore, the storage unit 21 also stores a fifth potential and a sixth potential related to the second potential. The fifth potential is the value of the potential determined as the second potential when the movement speed of the electronic pen 3 is equal to or greater than the speed threshold. The sixth potential is the value of the potential determined as the second potential when the movement speed of the electronic pen 3 is less than the speed threshold. The sixth potential is a value greater than the fifth potential. In other words, the third and fifth potentials are the values ​​of the first and second potentials, respectively, when the criteria for determining whether or not the operating state has transitioned are relaxed. The fourth and sixth potentials are the values ​​of the first and second potentials, respectively, when the criteria for determining whether or not the operating state has transitioned are not relaxed.

[0177] Here, with reference to Figure 14, the specific processing flow of the electronic device 1A in the fifth embodiment will be described. Figure 14 is a flowchart showing an example of a series of processing steps by the electronic device 1A according to the fifth embodiment. Note that in Figure 14, the processing of steps SP110 and SP112 is the same as the processing of steps SP10 and SP12 in the first embodiment, so their explanation is omitted here. Also, in Figure 14, the processing of steps SP122 to SP136 is the same as the processing of steps SP14 to SP28 in the first embodiment, so their explanation is omitted here.

[0178] (Step SP114) The electronic device 1A calculates the movement speed of the electronic pen 3 relative to the pen sensor 10 from the position signal acquired by the acquisition unit 22 using the pressure sensitivity calculation unit 23. Specifically, the electronic device 1A extracts coordinate values ​​indicating the position of the electronic pen 3 on the pen sensor 10 from the position signal acquired by the acquisition unit 22 using the pressure sensitivity calculation unit 23. The electronic device 1A stores the extracted coordinate values ​​in the storage unit 21 using the pressure sensitivity calculation unit 23. The coordinate values ​​include coordinate values ​​in the X-axis direction and coordinate values ​​in the Y-axis direction of the pen sensor 10. The electronic device 1A calculates the difference between the coordinate values ​​extracted this time and the coordinate values ​​extracted last time using the pressure sensitivity calculation unit 23. The electronic device 1A divides the calculated difference by the time elapsed from the extraction of the previous coordinate values ​​to the extraction of the current coordinate values ​​using the pressure sensitivity calculation unit 23, and the result of the division is taken as the movement speed. Then, the process moves on to step SP116.

[0179] (Step SP116) The electronic device 1A determines whether the calculated movement speed by the pressure sensitivity calculation unit 23 is equal to or greater than the speed threshold. If the determination is positive, the process proceeds to step SP118. If the determination is negative, the process proceeds to step SP120.

[0180] (Step SP118) The electronic device 1A, using the pressure sensitivity calculation unit 23, sets the value of the first potential to the value of the third potential (a relaxed value). The electronic device 1A also sets the value of the second potential to the value of the fifth potential (a relaxed value) using the pressure sensitivity calculation unit 23. In other words, the pressure sensitivity calculation unit 23 relaxes the criteria (first potential and second potential) for determining whether the operating state has transitioned. Then, the process proceeds to step SP122.

[0181] (Step SP118) The electronic device 1A, using the pressure sensitivity calculation unit 23, sets the value of the first potential to the value of the fourth potential (the normal value). The electronic device 1A, using the pressure sensitivity calculation unit 23, sets the value of the second potential to the value of the sixth potential (the normal value). In other words, the pressure sensitivity calculation unit 23 does not relax the criteria (first potential and second potential) for determining whether the operating state has changed, and keeps them as normal. Then, the process moves on to step SP122.

[0182] <Effects> In the fifth embodiment described above, the pressure sensitivity calculation unit 23 calculates the movement speed of the electronic pen 3 relative to the pen sensor 10 from the position signal. The pressure sensitivity calculation unit 23 also determines the value of the first potential according to the calculated movement speed.

[0183] In this configuration, the sensor controller 20 determines a first potential value that determines whether the operating state has transitioned to a first state in which the electronic pen 3 is pressing against the pen sensor 10, according to the movement speed of the electronic pen 3 relative to the pen sensor 10. Therefore, the sensor controller 20 can calculate the pressure applied by the electronic pen 3 to the pen sensor 10 with high accuracy, even when the accuracy of position detection of the electronic pen 3 by the pen sensor 10 changes depending on the magnitude of the movement speed of the electronic pen 3.

[0184] Furthermore, the pressure sensitivity calculation unit 23 determines the value of the first potential to be the value of the third potential when the movement speed is equal to or greater than the speed threshold. Also, the pressure sensitivity calculation unit 23 determines the value of the first potential to be the value of the fourth potential, which is greater than the third potential, when the movement speed is less than the speed threshold.

[0185] The accuracy of position signal detection by detection electrodes 11 and 12 may decrease when the electronic pen 3 moves at a speed exceeding the speed threshold. This decrease in detection accuracy occurs because, when the electronic pen 3 is moving rapidly, it may be positioned in the exact gap between multiple detection electrodes 11 or detection electrodes 12 at the time of position signal detection. With this configuration, the sensor controller 20 sets the value of the first potential to the value of the third potential, which is smaller than the fourth potential, when the electronic pen 3 is moving on the pen sensor 10 at a speed exceeding the speed threshold and the accuracy of position signal detection by the pen sensor 10 decreases. In other words, the sensor controller 20 relaxes the criteria for determining whether the operating state has transitioned to the first state. Therefore, the sensor controller 20 can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with high accuracy even when the movement speed of the electronic pen 3 is above the speed threshold.

[0186] In the fifth embodiment, the sensor controller 20 determines the first and second potentials according to whether the movement speed of the electronic pen 3 is equal to or greater than a speed threshold, but is not limited to this. The sensor controller 20 may store multiple speed thresholds with respect to the movement speed of the electronic pen 3 in the storage unit 21. The sensor controller 20 may also determine the first and second potentials according to the conditions determined by the multiple speed thresholds. Here, we will explain using the case where the storage unit 21 stores two speed thresholds as an example.

[0187] The memory unit 21 stores a first velocity threshold and a second velocity threshold that is greater than the first velocity threshold. The memory unit 21 also stores, with respect to the first potential, the potential when it is less than the first velocity threshold, the potential when it is greater than or equal to the first velocity threshold but less than the second velocity, and the potential when it is greater than or equal to the second velocity threshold. The memory unit 21 also stores, with respect to the second potential, the potential when it is less than the first velocity threshold, the potential when it is greater than or equal to the first velocity threshold but less than the second velocity, and the potential when it is greater than or equal to the second velocity threshold.

[0188] The pressure sensitivity calculation unit 23 determines which of the multiple conditions defined by the first speed threshold and the second speed threshold the movement speed of the electronic pen 3 satisfies. If the movement speed of the electronic pen 3 is less than the first speed threshold, the pressure sensitivity calculation unit 23 determines the values ​​of the first potential and the second potential to be those corresponding to the case where the movement speed is less than the first speed threshold. If the movement speed of the electronic pen 3 is greater than or equal to the first speed threshold and less than the second speed threshold, the pressure sensitivity calculation unit 23 determines the values ​​of the first potential and the second potential to be those corresponding to the case where the movement speed of the electronic pen 3 is greater than or equal to the second speed threshold. If the movement speed of the electronic pen 3 is greater than or equal to the second speed threshold, the pressure sensitivity calculation unit 23 determines the values ​​of the first potential and the second potential to be those corresponding to the case where the movement speed is greater than or equal to the second speed threshold.

[0189] In this configuration, the sensor controller 20 adjusts the degree of relaxation of the criteria for determining whether or not an operating state has changed in three or more stages, according to the movement speed of the electronic pen 3. Therefore, the sensor controller 20 can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with even greater accuracy according to the movement speed of the electronic pen 3.

[0190] Furthermore, the sensor controller 20 determines the values ​​of the first and second potentials depending on whether the movement speed of the electronic pen 3 satisfies the conditions determined by the speed threshold, but is not limited to this. The sensor controller 20 may substitute the movement speed of the electronic pen 3 into a function defined for the first potential and set the output result of the function as the first potential. The sensor controller 20 may also substitute the movement speed of the electronic pen 3 into a function defined for the second potential and set the output result of the function as the second potential. The function is, for example, a linear function. Specifically, the sensor controller 20 may determine the first potential in proportion to the movement speed of the electronic pen 3 using the pressure sensitivity calculation unit 23. The sensor controller 20 may also determine the second potential in proportion to the movement speed of the electronic pen 3 using the pressure sensitivity calculation unit 23.

[0191] With this configuration, the sensor controller 20 can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with even greater precision according to the movement speed of the electronic pen 3.

[0192] Furthermore, the sensor controller 20 determines the values ​​of the first and second potentials according to the movement speed of the electronic pen 3, but is not limited to this. The sensor controller 20 may determine the first value according to the movement speed of the electronic pen 3 using the pressure sensitivity calculation unit 23. The sensor controller 20 may also determine the second value according to the movement speed of the electronic pen 3 using the pressure sensitivity calculation unit 23. Specifically, if the movement speed of the electronic pen 3 is greater than or equal to the speed threshold, the pressure sensitivity calculation unit 23 determines the first value to the third value (a relaxed value). Furthermore, if the movement speed of the electronic pen 3 is less than the speed threshold, the pressure sensitivity calculation unit 23 determines the first value to the fourth value (a normal value) which is smaller than the third value. Furthermore, if the movement speed of the electronic pen 3 is greater than or equal to the speed threshold, the pressure sensitivity calculation unit 23 determines the second value to the fifth value (a relaxed value). Furthermore, if the movement speed of the electronic pen 3 is less than the speed threshold, the pressure sensitivity calculation unit 23 determines the second value to a sixth value (the normal value), which is smaller than the fifth value.

[0193] In this configuration, the sensor controller 20 determines a first or second value to be used as the result of calculating the pen pressure value, depending on the movement speed of the electronic pen 3 relative to the pen sensor 10. Specifically, the sensor controller 20 calculates the pen pressure value such that it is larger when the movement speed of the electronic pen 3 is greater than or equal to the speed threshold, compared to when the movement speed of the electronic pen 3 is less than the speed threshold. Therefore, the sensor controller 20 can calculate the pen pressure applied to the pen sensor 10 by the electronic pen 3 with high accuracy, even when the accuracy of position detection of the electronic pen 3 by the pen sensor 10 changes depending on the magnitude of the movement speed of the electronic pen 3.

[0194] ---Sixth Embodiment--- Next, the sixth embodiment will be described.

[0195] In the sixth embodiment, the sensor controller 20 performs a standby process if the distance traveled by the electronic pen 3 is short and the elapsed time is short since the last calculation of the electronic pen pressure value. Specifically, the pressure calculation unit 23 calculates the distance traveled by the electronic pen 3 since the last calculation of the electronic pen pressure value. The pressure calculation unit 23 also measures the time elapsed since the calculation of the pressure value. Then, if the distance traveled by the electronic pen 3 is less than the reference distance and the elapsed time is less than the reference time since the last calculation of the electronic pen pressure value, the pressure calculation unit 23 performs a standby process for a predetermined standby time. The standby process is a process that stops the series of processes related to the calculation of the pressure value for a predetermined time. The storage unit 21 stores the values ​​of the reference time, the reference distance, and the standby time.

[0196] Here, with reference to Figure 15, the specific processing flow of the electronic device 1A in the sixth embodiment will be described. Figure 15 is a flowchart showing an example of a series of processing steps by the electronic device 1A according to the sixth embodiment. Note that in Figure 15, the processing of steps SP140 to SP146 and step SP168 is the same as the processing of steps SP10 to SP16 and step SP22 in the first embodiment, so the explanation is omitted here. Also in Figure 15, the processing of steps SP158 to SP160 is the same as the processing of steps SP24 to SP26 in the first embodiment, so the explanation is omitted here. Also in Figure 15, the processing of steps SP168 and SP190 is the same as the processing of steps SP22 and SP28 in the first embodiment, respectively, so the explanation is omitted here. Also in Figure 15, the processing of steps SP170 to SP178 is the same as the processing of steps SP148 to SP156 which will be described later, so the explanation is omitted here. Furthermore, the processing of steps SP180 to SP182 in Figure 15 is the same as the processing of steps SP24 to SP26 in the first embodiment, so its explanation is omitted. Also, the processing of steps SP184 to SP188 in Figure 15 is the same as the processing of steps SP162 to SP166 described later, so its explanation is omitted.

[0197] (Step SP148) The electronic device 1A uses a pressure sensitivity calculation unit 23 to calculate the distance the electronic pen 3 moves relative to the pen sensor 10 from the position signal acquired by the acquisition unit 22. Specifically, the electronic device 1A performs the same processing as in step SP114 of the fifth embodiment and calculates the difference between the coordinate value of the electronic pen 3 on the pen sensor 10 extracted from the position signal this time and the coordinate value extracted last time. The electronic device 1A uses the pressure sensitivity calculation unit 23 to determine the distance moved. Then, the process moves on to step SP150.

[0198] (Step SP150) The electronic device 1A uses the pressure sensitivity calculation unit 23 to calculate the elapsed time since the last pressure sensitivity calculation. The starting time for the elapsed time is determined in the process of step SP162, which will be described later. If the electronic device 1A has not performed the process of calculating the pressure sensitivity even once, the process of calculating the elapsed time is omitted. Then, the process proceeds to the process of step SP152.

[0199] (Step SP152) The electronic device 1A uses a pressure-sensing unit 23 to determine whether the distance the electronic pen 3 has moved since the last pressure-sensing value was calculated is less than the reference distance and whether the time elapsed since the last pressure-sensing value was calculated is less than the reference time. If the determination is positive, the process proceeds to step SP154. If the determination is negative, the process proceeds to step SP158.

[0200] (Step SP154) The electronic device 1A determines whether or not the standby process has been executed by the pressure sensitivity calculation unit 23. Specifically, the electronic device 1A determines whether or not the standby process execution flag is turned on by the pressure sensitivity calculation unit 23. The standby process execution flag is stored, for example, in the storage unit 21. If the determination is positive, the process proceeds to step SP158. Conversely, if the determination is negative, the process proceeds to step SP156.

[0201] (Step SP156) The electronic device 1A performs a standby process using the pressure sensitivity calculation unit 23. Specifically, the electronic device 1A pauses a series of processing operations for a standby period of time using the pressure sensitivity calculation unit 23. Subsequently, the electronic device 1A turns on the standby process completion flag using the pressure sensitivity calculation unit 23. Then, the process proceeds to step SP190.

[0202] (Step SP162) The electronic device 1A initializes the count for measuring the elapsed time since the last calculation of the pen pressure value using the pen pressure calculation unit 23. Specifically, if the electronic device 1A is measuring the elapsed time since the last calculation of the pen pressure value using the pen pressure calculation unit 23, it terminates that time measurement. Next, the electronic device 1A starts measuring the elapsed time since the current pen pressure value was calculated, using the current time as the starting time, using the pen pressure calculation unit 23. Then, the process moves on to step SP164.

[0203] (Step SP164) The electronic device 1A updates the position of the electronic pen 3 on the pen sensor 10 using the pressure sensitivity calculation unit 23. Specifically, the electronic device 1A updates the coordinate values ​​of the position of the electronic pen 3 at the time of the pressure sensitivity calculation process using the current coordinate values ​​of the electronic pen 3 extracted in step SP148. Then, the process moves on to step SP166.

[0204] (Step SP166) The electronic device 1A turns off the standby process completion flag using the pen pressure calculation unit 23. If the standby process completion flag is already off, the electronic device 1A keeps the standby process completion flag off. Then, the process proceeds to step SP190.

[0205] <Effects> In the sixth embodiment described above, the pen pressure calculation unit 23 calculates a pen pressure value when the predetermined conditions are not met. Here, the predetermined conditions are that the time elapsed since the last calculation of the pen pressure value is less than the reference time and the distance the electronic pen 3 has moved since the last calculation of the pen pressure value is less than the reference distance.

[0206] In this configuration, the sensor controller 20 calculates a pen pressure value if the distance the electronic pen 3 has moved since the calculation of the pen pressure value is long, or if a long time has elapsed since the calculation of the pen pressure value. As a result, the sensor controller 20 does not calculate a pen pressure value when the electronic pen 3 moves only vertically (normal to the detection surface) on the pen sensor 10 in a short amount of time. Therefore, the sensor controller 20 can prevent the calculation of a pen pressure value when the electronic pen 3 is simply shaking on the pen sensor 10 due to hand tremors or habits while the user is drawing with the electronic pen 3. In addition, the sensor controller 20 does not calculate a pen pressure value if the movement deviates from human-possible movements, such as when the signal level changes in a short amount of time, as this is considered a false detection of the electronic pen 3 by the pen sensor 10. Therefore, the sensor controller 20 can calculate the pen pressure applied to the pen sensor 10 by the electronic pen 3 with higher accuracy.

[0207] Furthermore, in the sixth embodiment, if the predetermined conditions are met, the pen pressure calculation unit 23 executes a waiting process, which waits for a predetermined period of time, if it has not executed a waiting process after the previous determination of the predetermined conditions. Conversely, if the predetermined conditions are met, the pen pressure calculation unit 23 calculates the pen pressure value if it has executed a waiting process after the previous determination of the predetermined conditions.

[0208] In this configuration, the sensor controller 20 performs a standby process when predetermined conditions are met (when the distance the electronic pen 3 has moved since the pressure value was calculated is short and the time elapsed since the pressure value was calculated is short). As a result, even if the amount of change in the signal level fluctuates in approximately the same position in a short period of time, the sensor controller 20 determines that it is either a false detection or due to the user's hand tremor or habits, and puts the calculation of the pressure value into standby mode. Therefore, the sensor controller 20 can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with higher accuracy.

[0209] The sensor controller 20 may change whether or not to calculate the pen pressure value depending on the vertical position (normal direction to the detection surface) of the electronic pen 3 relative to the pen sensor 10. Specifically, the sensor controller 20 uses a pen pressure calculation unit 23 to extract coordinate values ​​from the position signal that indicate the position (i.e., height) of the electronic pen 3 relative to the pen sensor 10 in the normal direction to the detection surface. The sensor controller 20 uses the pen pressure calculation unit 23 to calculate the pen pressure value if the extracted coordinate values ​​are less than the reference height. Conversely, the sensor controller 20 does not calculate the pen pressure value if the extracted coordinate values ​​are greater than or equal to the reference height. The reference height is stored, for example, in a storage unit 21.

[0210] With this configuration, the sensor controller 20 does not calculate the pen pressure value regardless of the amount of change in the signal level when the position of the electronic pen 3 is higher than the pen sensor 10. Therefore, the sensor controller 20 suppresses false detections when the electronic pen 3 is at a height where it should not be in contact with the pen sensor 10 and the amount of change in the signal level is large. Consequently, the sensor controller 20 can calculate the pen pressure applied to the pen sensor 10 by the electronic pen 3 with higher accuracy.

[0211] ---Seventh Embodiment--- Next, the seventh embodiment will be described.

[0212] Figure 16A shows the state in which the pen tip 375 of the electronic pen 3 according to the seventh embodiment is housed in the hollow portion 3000a of the housing 3000. Figure 16B shows the state in which the pen tip 375 of the electronic pen 3 according to the seventh embodiment protrudes from the opening 3000b of the housing 3000. In Figures 16A and 16B, the electronic pen 3 is shown with its housing 3000 made of transparent synthetic resin, allowing the inside of the housing 3000 to be seen. The housing 3000 functions as a storage member for housing the pen tip 375. In Figures 16A and 16B, the housing 3000 and the knock mechanism 303 provided inside the housing 3000 are configured in the same way as well-known commercially available retractable ballpoint pens.

[0213] The knock mechanism 303 is a retractable member that allows the pen tip 375 to extend and retract from one opening 3000b of the housing 3000. The knock mechanism 303 is composed of a cam body 3031, a knock rod 3032, and a rotor 3033. The cam body 3031 is formed on the inner wall surface of the cylindrical housing 3000. The knock rod 3032 is configured to accept the user's knock operation of the electronic pen 3. Its end portion 3032a is provided to protrude from the opening 3000c of the housing 3000 on the side opposite to the pen tip 375. The rotor 3033 has a fitting portion 3033a into which the rear end portion of the main body 301 on the side opposite to the pen tip 375 is fitted. The cam body 3031 and the rotor 3033 function as sliding members that slide in response to the knock operation on the knock rod 3032.

[0214] In the state shown in Figure 16A, when the end 3032a of the knocking rod 3032 of the electronic pen 3 is pressed, the knocking mechanism 303 locks the main body 301 within the housing 3000 to the state shown in Figure 16B. That is, the pen tip 375 of the main body 301 protrudes from the opening 3000b of the housing 3000. Furthermore, when the end 3032a of the knocking rod 3032 is pressed again from the state shown in Figure 16B, the knocking mechanism 303 releases the lock. As a result, the position of the main body 301 within the housing 3000 returns to the state shown in Figure 16A by the return spring 320. Note that the detailed configuration and operation of the knocking mechanism 303 are well known, so their explanation is omitted here.

[0215] Furthermore, the electronic pen 3 is equipped with a switch member 3040 for determining whether or not the pen tip 375 is housed inside the housing 3000. The switch member 3040 is provided on the inner wall of the housing 3000. The switch member 3040 has a movable part (not shown) that can move along the axial direction of the electronic pen 3. The movable part moves in conjunction with the axial movement of the fitting part 3033a or the rotor 3033. The state of the switch member 3040 is switched when the movable part moves in conjunction with the sliding movement of the fitting part 3033a caused by the knocking operation on the knock mechanism 303.

[0216] The electronic pen 3 is equipped with a pen controller 36 inside the main body 301. The pen controller 36 determines the retracted state based on the switching state of the switch member 3040. Specifically, when the movable part of the switch member 3040 is located on the pen tip 375 side, the pen controller 36 determines that the pen tip 375 is not retracted, as shown in Figure 16A. Conversely, when the movable part of the switch member 3040 is located on the knock rod 3032 side, the pen controller 36 determines that the pen tip 375 is retracted, as shown in Figure 16B. The electrical conduction state of the switch member 3040 switches between on and off depending on the position of the movable part. The pen controller 36 then determines the on / off state of the electrical conduction state of the switch member 3040 by applying a potential to the switch member 3040 and measuring the current value and resistance value. In this way, the pen controller 36 determines the state of the switch member 3040.

[0217] Furthermore, the pen controller 36 transmits and receives signals such as position signals to and from the pen sensor 10 via electrodes 37 or 38 provided on the pen tip 375. The signal transmitted from the electronic pen 3 to the pen sensor 10 is a downlink signal to the pen sensor 10. The signal transmitted from the pen sensor 10 to the electronic pen 3 is an uplink signal. The pen controller 36 determines the state of the switch member 3040. When the state of the switch member 3040 changes, the pen controller 36 notifies the pen sensor 10 of the determination result via electrodes 37 or 38. The pen controller 36 also receives a response from the pen sensor 10 to this notification via electrodes 37 or 38. Then, the pen controller 36 stops transmitting signals to the pen sensor 10.

[0218] Here, the operation of the pen sensor 10 and sensor controller 20 in the seventh embodiment will be described. The pen sensor 10 transmits and receives signals with the electronic pen 3 according to the operation control of the sensor controller 20. The sensor controller 20 controls the position detection operation by the pen sensor 10. The sensor controller 20 receives a notification from the electronic pen 3 when the storage state of the pen tip 375 in the storage member (housing 3000 in this example) changes. If the notification indicates that the storage state of the pen tip 375 has changed to a state where it is stored in the storage member, the sensor controller 20 responds to the electronic pen 3 to stop transmitting a downlink signal to the pen sensor 10. Conversely, if the notification indicates that the storage state of the pen tip 375 has changed to a state where it is not stored in the storage member, the sensor controller 20 responds to the electronic pen 3 to start transmitting a downlink signal to the pen sensor 10. The sensor controller 20 performs this response by transmitting an uplink signal from the pen sensor 10 to the electronic pen 3.

[0219] Returning to the explanation of the pen controller 36, when the pen controller 36 sends a notification to the pen sensor 10 indicating that the pen tip 375 has been retracted, it receives a response from the pen sensor 10 indicating that it will stop transmitting signals to the pen sensor 10. The pen controller 36 then stops transmitting signals to the pen sensor 10. Also, when the pen controller 36 sends a notification to the pen sensor 10 indicating that the pen tip 375 has not been retracted, it receives a response from the pen sensor 10 indicating that it will start transmitting signals to the pen sensor 10. The pen controller 36 then starts transmitting signals to the pen sensor 10.

[0220] The electronic pen 3 uses, but is not limited to, downlink and uplink signals to send notifications to the pen sensor 10 and to receive responses from the pen sensor 10 to those notifications. The electronic pen 3 may also send and receive signals using short-range wireless communication such as Bluetooth® instead of uplink and downlink signals for sending notifications and receiving responses to those notifications.

[0221] Now, with reference to Figure 19, the specific processing flow of the electronic pen 3 in the seventh embodiment will be described. Figure 19 is a flowchart showing an example of a series of processing steps performed by the electronic pen 3 according to the seventh embodiment.

[0222] (Step SP200) The electronic pen 3 undergoes initialization processing by the pen controller 36. During the initialization process, the electronic pen 3 is, for example, initially set to normal mode. The electronic pen 3 has two operating modes, for example, normal mode and power-saving mode, and operates in one of these modes. Power-saving mode is an operating mode that suppresses the power consumption of the electronic pen 3. Normal mode is an operating mode that does not suppress the power consumption of the electronic pen 3 compared to power-saving mode. Then, the process moves on to step SP202.

[0223] (Step SP202) The electronic pen 3 is controlled by the pen controller 36 to determine whether its operating mode is power-saving mode. If the determination is positive, the process proceeds to step SP204. If the determination is negative, the process proceeds to step SP206.

[0224] (Step SP204) The electronic pen 3 performs operation processing in power-saving mode. In power-saving mode, the electronic pen 3 stops transmitting signals to the pen sensor 10, for example. Also, in power-saving mode, the electronic pen 3 reduces the frequency of signal transmission to the pen sensor 10 compared to normal mode. The electronic pen 3 also receives signals from the pen sensor 10. When the electronic pen 3 is transmitting signals to the pen sensor 10, it transmits information about the position and pressure of the electronic pen 3 to the pen sensor 10 through the transmission and reception of signals between the electronic pen 3 and the pen sensor 10. Then, the process moves on to the processing of step SP208.

[0225] (Step SP206) The electronic pen 3 performs operation processing in normal mode. In normal mode, the electronic pen 3 transmits signals to the pen sensor 10 at predetermined intervals, for example. Also in normal mode, the electronic pen 3 receives signals from the pen sensor 10. Through the transmission and reception of signals with the pen sensor 10, the electronic pen 3 transmits information about the position of the electronic pen 3 and the pressure applied to the pen sensor 10. Then, the process moves on to the processing in step SP208.

[0226] (Step SP208) The electronic pen 3 uses a pen controller 36 to determine whether the pen tip 375 is stored in the storage member. If the determination is positive, the process proceeds to step SP210. If the determination is negative, the process proceeds to step SP212.

[0227] (Step SP210) When the electronic pen 3 is in normal mode, the pen controller 36 sends a notification to the pen sensor 10 indicating that the pen tip 375 is stored in the storage member. Subsequently, the electronic pen 3 receives a response from the pen sensor 10 to this notification via the pen controller 36. The response sent from the pen sensor 10 to the electronic pen 3 includes a control command to switch the electronic pen 3's operating mode from normal mode to power-saving mode. The electronic pen 3 switches its operating mode from normal mode to power-saving mode according to the control command indicated by the response received from the pen sensor 10. Note that if the electronic pen 3 is already in power-saving mode, it does not send a notification to the pen sensor 10. Also, if the electronic pen 3 is already in power-saving mode, it maintains the operating mode in power-saving mode. Then, the process moves on to step SP214.

[0228] (Step SP212) If the electronic pen 3 is in power-saving mode, the pen controller 36 sends a notification to the pen sensor 10 indicating that the pen tip 375 is not stored in the storage member. Subsequently, the electronic pen 3 receives a response from the pen sensor 10 to this notification via the pen controller 36. The response sent from the pen sensor 10 to the electronic pen 3 includes a control command to switch the electronic pen 3's operating mode from power-saving mode to normal mode. The electronic pen 3 switches its operating mode from power-saving mode to normal mode according to the control command indicated by the response received from the pen sensor 10. Note that if the electronic pen 3 is already in normal mode, it does not send a notification to the pen sensor 10. Also, if the electronic pen 3 is already in normal mode, it maintains the operating mode in normal mode. Then, the process proceeds to step SP214.

[0229] (Step SP214) The pen controller 36 determines whether or not it has received a command to stop the operation of the electronic pen 3, based on user input or signals transmitted from the pen sensor 10. Stopping the operation means, for example, turning off the power to the electronic pen 3. If the determination is negative, the process returns to step SP202. On the other hand, if the determination is positive, the pen controller 36 stops the operation of the electronic pen 3. Then, the series of processes shown in Figure 19 ends.

[0230] Another example relating to the electronic pen 3 according to the seventh embodiment will be described. Figure 17A shows the state in which the pen tip 375 of the rotary electronic pen 3 according to the seventh embodiment is housed in the hollow part of the housing 3000. Figure 17B shows the state in which the pen tip 375 of the rotary electronic pen 3 according to the seventh embodiment is protruding from the opening 3000b of the housing 3000.

[0231] As shown in Figures 17A and 17B, the electronic pen 3 comprises a housing 3001 and a housing 3002 that is rotatably fitted to the housing 3001 with the center line O of the housing 3001 as the axis of rotation. The housing 3001 functions as a storage member capable of housing the pen tip 375. The housing 3001 also includes a retractable mechanism 3050 that rotates to extend and retract the pen tip 375 of the main body 301. The main body 301 is inserted into the retractable mechanism 3050 and is further held by the retractable mechanism 3050. The housing 3002 is fitted to the retractable mechanism 3050 and has a configuration that allows it to rotate relative to the retractable mechanism 3050. Note that in Figures 17A and 17B, the main body 301 has a fitting portion that is fixed to the retractable mechanism 3050 by being inserted into it.

[0232] The housing 3001 is provided with a detection member 3051 located close to the housing 3002. The housing 3002 is provided with a detection member 3052 located close to the housing 3001. The detection member 3051 is, for example, a magnet. The detection member 3052 is, for example, a magnetic sensor. As shown in Figure 17A, when the pen tip 375 of the electronic pen 3 is housed in the housing 3001, the detection member 3052 of the housing 3002 is separated from the detection member 3051 of the housing 3001. In this case, the sensor output of the detection member 3052 becomes low because the detection level of the magnetic force emitted from the detection member 3051 is weakened. In contrast, as shown in Figure 17B, when the pen tip 375 of the electronic pen 3 is not housed in the housing 3001, the detection member 3052 of the housing 3002 is in close proximity to the detection member 3051 of the housing 3001. In this case, the sensor output of the detection member 3052 becomes high level upon detecting the strong magnetic force emitted from the detection member 3051.

[0233] The electronic pen 3 is equipped with a pen controller 36 on its main body 301. The pen controller 36 determines whether the pen tip 375 is housed in the housing 3001 based on the sensor output value of the detection member 3052. The processing flow by the pen controller 36 is as described above, so its explanation is omitted here.

[0234] Another example relating to the electronic pen 3 according to the seventh embodiment will be described. Figure 18A is a diagram showing an example of the configuration of a cap-type electronic pen 3A according to the seventh embodiment. As shown in Figure 18A, the electronic pen 3A has a housing 3000 and a cap 350. The cap 350 is a storage member capable of housing the pen tip 375. Specifically, the cap 350 is a storage member that is detachably attached to the housing 3000, which is provided with the pen tip 375 so as to cover the pen tip 375 of the electronic pen 3A.

[0235] In Figure 18A, the housing 3000 has a detection member 3053 that detects whether or not the pen tip 375 is housed in the cap 350. The detection member 3053 is provided on the outer circumference of the housing 3000. The detection member 3053 is provided on the outer circumference of the housing 3000 at a position that contacts a detection member 3054 provided on the inner wall of the cap 350 when the cap 350 is attached to the housing 3000.

[0236] The cap 350 has a detection member 3054 that detects whether or not the pen tip 375 is housed in the cap 350. The detection member 3054 is provided on the outer circumference of the housing 3000. The detection member 3054 is provided on the inner circumference of the cap 350 at a position that contacts the detection member 3053 of the housing 3000 when the cap 350 is attached to the housing 3000.

[0237] The detection members 3053 and 3054 are, for example, physical switch members, electrodes, magnets, etc. The case where the detection members 3053 and 3054 are switch members will be described below. The detection member 3053 has a button that can be pressed in the direction normal to the outer circumference of the housing 3000. The detection member 3054 is formed as a protrusion extending from the inner circumference of the cap 350 toward the inside of the cap 350. When the cap 350 is attached to the housing 3000, the detection member 3053 is pressed by the detection member 3054. Conversely, when the cap 350 is removed from the housing 3000, the press by the detection member 3054 is released. The pen controller 36 of the electronic pen 3A determines whether the pen tip 375 is retracted into the cap 350 depending on whether the button of the detection member 3053 is pressed or not. The determination of the button press state of the detection member 3053 is performed by measuring the current flowing through the detection electrical circuit formed between the pen controller 36 and the button.

[0238] The case where detection members 3053 and 3054 are electrodes will be described below. Detection member 3053 has, for example, an electrode that functions as an input terminal and an electrode that functions as an output terminal. Detection member 3054 has one electrode that contacts the input terminal and output terminal of detection member 3053 when the cap 350 is attached to the housing 3000. When the cap 350 is attached to the housing 3000, a current path is established from the output terminal of detection member 3053 to the input terminal of detection member 3053 via the electrode of detection member 3054. In contrast, when the cap 350 is attached to the housing 3000, the current path from the output terminal of detection member 3053 to the input terminal of detection member 3053 via the electrode of detection member 3054 is blocked. The pen controller 36 of the electronic pen 3A applies a potential from the pen controller 36 toward the output terminal of detection member 3053 in order to determine whether or not the pen tip 375 is retracted. The pen controller 36 measures the current and potential at the input terminal of the detection member 3053. The pen controller 36 determines whether the pen tip 375 is housed in the cap 350 based on the magnitude of the measured values.

[0239] Furthermore, the detection member 3053 may be an electrode of a capacitive sensor. The detection member 3053 is connected to a capacitive detection sensor circuit provided in the electronic pen 3A. In this case, the detection member 3054 is, for example, metal. The pen controller 36 detects the capacitance around the detection member 3053 using the detection sensor circuit. When the cap 350 is attached to the housing 3000 and the detection member 3053 is close to or in contact with the detection member 3054, the sensor output value of the detection sensor becomes large. Conversely, when the cap 350 is detached from the housing 3000 and the detection member 3053 is far from the detection member 3054, the sensor output value of the detection sensor becomes small. The pen controller 36 determines whether the pen tip 375 is housed in the cap 350 based on the magnitude of the sensor output of the detection sensor, etc.

[0240] The case where the detection member 3053 is a magnet and the detection member 3054 is a magnetic sensor will be described. The pen controller 36 measures the sensor output of the magnetic sensor of the detection member 3054. Note that the determination by the pen controller 36 as to whether or not the pen tip 375 is housed in the cap 350 is the same as when the detection member 3053 is an electrode of a capacitive sensor, except that the object being measured is different, so the explanation is omitted here.

[0241] Next, further examples of the electronic pen 3 according to the seventh embodiment will be described. Figure 18B shows another example of the configuration of the cap-type electronic pen 3B according to the seventh embodiment.

[0242] As shown in Figure 18B, the electronic pen 3B has electrodes 37 and 38. Furthermore, the inner circumference of the cap 350 is formed to conform to the shape of the pen tip 375 so that the space volume between the inner circumference of the cap 350 and the pen tip 375 is reduced when the cap is attached to the housing 3000.

[0243] The pen controller 36 in the electronic pen 3B transmits a signal from electrode 37 to electrode 38 to determine whether the pen tip 375 is housed in the cap 350. The pen controller 36 receives the signal transmitted from electrode 37 via electrode 38. The pen controller 36 detects whether the pen tip 375 is housed in the cap 350 based on the change in the signal level of the signal received by electrode 38. When the cap 350 is removed from the housing 3000, there is no shield between electrode 37 and electrode 38 to obstruct signal propagation except for the housing 3000. Therefore, when the cap 350 is removed from the housing 3000, the signal level received by electrode 38 increases. When the cap 350 is attached to the housing 3000, signal propagation is obstructed by the cap 350 located between electrode 37 and electrode 38. Therefore, when the cap 350 is attached to the housing 3000, the signal level received by electrode 38 decreases. The pen controller 36 determines that the retracted state of the pen tip 375 has changed if the amount of change in the signal level received by the electrode 38 is large. Specifically, the pen controller 36 determines that the retracted state of the pen tip 375 has changed to a state where it is not retracted into the cap 350 if the value of the signal level received by the electrode 38 increases rapidly. Conversely, the pen controller 36 determines that the retracted state of the pen tip 375 has changed to a state where it is retracted into the cap 350 if the value of the signal level received by the electrode 38 decreases rapidly.

[0244] In the seventh embodiment, the electronic pens 3A and 3B have a cap 350 as a storage member for housing the pen tip 375, but are not limited to this. The storage member is not limited to the cap 350, but can be any member that can house the pen tip 375. The storage member may be, for example, a housing with a hole for housing the electronic pen 3 provided in a laptop computer or the like. The above example will be explained with reference to Figure 18C. Figure 18C is a diagram showing an example of the configuration of the electronic pen 3A and the electronic device 1C capable of housing the electronic pen 3A according to the seventh embodiment.

[0245] Electronic device 1C is, for example, an information processing device such as a laptop computer, tablet, or smartphone. While it is desirable that electronic device 1C be an easily portable information processing device, it may also be an information processing device that is not easily portable, such as a desktop computer. Electronic device 1C is equipped with a housing having a hole 1050 capable of housing an electronic pen 3A. A detection member 3054, similar to the one provided on the inner circumference of the cap 350 in Figure 18A, is provided on the inner circumference of the hole 1050. When the electronic pen 3A is housed in the hole 1050 of electronic device 1C, the detection member 3053 detects that the pen tip 375 is housed in the storage member. Conversely, when the electronic pen 3A is removed from the hole 1050 of electronic device 1C, the detection member 3053 detects that the pen tip 375 is no longer housed in the storage member.

[0246] <Effects> In the seventh embodiment described above, the electronic pen 3 comprises a pen tip 375 that can be stored in a storage member and a pen controller 36. The pen tip 375 has an electrode 37 that transmits and receives signals to and from the pen sensor 10. The pen controller 36 transmits and receives signals to and from the pen sensor 10 via the electrode 37. The pen controller 36 also determines the storage state of the pen tip 375 in the storage member. The pen controller 36 notifies the pen sensor 10 when it determines that the pen tip 375 is stored in the storage member. The pen controller 36 also stops transmitting signals in response to the notification transmitted from the pen sensor 10.

[0247] According to this configuration, the electronic pen 3 stops transmitting signals only in response to the response from the pen sensor 10 after notifying the pen sensor 10, without the electronic pen 3 independently stopping signal transmission. Therefore, the electronic pen 3 shares the storage state of the pen tip 375 with respect to the storage member with the pen sensor 10, and can improve the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10. In addition, the electronic pen 3 can reduce power consumption by stopping signal transmission when the pen tip 375 is stored and the electronic pen 3 is not used by the user.

[0248] Further, when the storage state changes from the state where the pen tip 375 is stored in the storage member to the state where the pen tip 375 is not stored in the storage member, the pen controller 36 notifies the pen sensor 10. In addition, the pen controller 36 starts signal transmission in response to the response to the notification transmitted from the pen sensor 10.

[0249] According to this configuration, the electronic pen 3 starts transmitting signals only in response to the response from the pen sensor 10 after notifying the pen sensor 10, without the electronic pen 3 independently starting signal transmission. Therefore, the electronic pen 3 shares the storage state of the pen tip 375 with respect to the storage member with the pen sensor 10, and can improve the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10. In addition, since the electronic pen 3 starts signal transmission when the pen tip 375 is taken out of the storage member and the electronic pen 3 can be used by the user, the user does not need to perform an operation deliberately, and the convenience can be improved.

[0250] In addition, the electronic pen 3 further includes a storage member that is a cylindrical housing 3000 and an emerging member that allows the pen tip 375 to emerge from and retract into one opening 3000b of the housing 3000.

[0251] Therefore, even when the pen tip 375 is housed in the cylindrical housing 3000, the electronic pen 3 can improve the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10. Also, the electronic pen 3 can reduce power consumption even when the pen tip 375 is housed in the cylindrical housing 3000.

[0252] Also, the protruding / retracting member is a knock mechanism 303 that enables the pen tip 375 to protrude and retract from one opening 3000b of the housing. Further, the electronic pen 3 further includes a switch member 3040 whose state is switched according to the sliding movement of a sliding member (cam body 3031 and rotor 3033) that slides and moves in conjunction with the knocking operation of the knock mechanism 303. Also, the pen controller 36 determines the housed state based on the state of the switch member 3040.

[0253] Therefore, even when the pen tip 375 is protruded and retracted by the knock mechanism 303, the electronic pen 3 can improve the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10. Also, the electronic pen 3 can reduce power consumption even when the pen tip 375 is protruded and retracted by the knock mechanism 303.

[0254] Also, the protruding / retracting member has a protruding / retracting mechanism 3050 that enables the pen tip 375 to protrude and retract from one opening 3000b of the housing 3001 by the rotation of a member (housing 3002) that is rotatably coupled to the housing 3001 with the center line O of the housing 3001 as the rotation axis. Further, the electronic pen 3 further includes detection members 3051 and 3052 whose states are switched according to the rotational movement that is interlocked with the rotation of a member (housing 3002) that is rotatably coupled to the housing 3001 of the protruding / retracting mechanism 3050. Also, the pen controller 36 determines the housed state based on the states of the detection members 3051 and 3052.

[0255] Therefore, even when the electronic pen 3 extends and retracts its pen tip 375 by the rotational movement of a component (housing 3002) rotatably connected to the housing 3001, the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10 can be improved. Furthermore, even when the electronic pen 3 extends and retracts its pen tip 375 by the rotational movement of a component (housing 3002) rotatably connected to the housing 3001, power consumption can be reduced.

[0256] Furthermore, the storage component is a cap 350 that is detachably attached to the housing 3000, which is provided with the pen tip 375, so as to cover the pen tip 375.

[0257] Therefore, even when the storage member is the cap 350, the electronic pen 3 can improve the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10. In addition, the electronic pen 3 can reduce power consumption even when the storage member is the cap 350.

[0258] Furthermore, the storage component is the housing of an electronic device 1C having a hole 1050 into which the pen tip 375 can be inserted.

[0259] Therefore, even when the electronic pen 3 is an electronic device 1C in which the storage member has a hole 1050 into which the pen tip 375 can be inserted, the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10 can be improved. Furthermore, even when the electronic pen 3 is an electronic device 1C in which the storage member has a hole 1050 into which the pen tip 375 can be inserted, power consumption can be reduced.

[0260] Furthermore, the electronic pen 3 further includes detection members 3053 and 3054 or 3051 and 3052 that detect changes in the electric field, magnetic field, or capacitance of the space including the pen tip 375. The pen controller 36 determines the storage state based on the detection results of the detection members 3053 and 3054 or 3051 and 3052.

[0261] Therefore, the electronic pen 3 can utilize various detection members to improve the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10. In addition, the electronic pen 3 can utilize various detection members to reduce power consumption.

[0262] Furthermore, the electronic pen 3 further includes detection members 3053 and 3054 that detect changes in the electrical conductivity between the pen tip 375 and the storage member. The pen controller 36 determines the storage state based on the detection results of the detection members 3053 and 3054.

[0263] Therefore, the electronic pen 3, with its simple configuration, can improve the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10. In addition, the electronic pen 3, with its simple configuration, can reduce power consumption.

[0264] Furthermore, electrode 37 is the first electrode (electrode 37). The electronic pen 3 also transmits and receives signals with the pen sensor 10 and is capable of receiving signals transmitted from the first electrode, and further includes a second electrode (electrode 38) which is different from the first electrode. The pen controller 36 determines whether or not the pen tip 375 is housed in the housing member based on the amount of change in the signal level of the signal transmitted from the first electrode to the second electrode.

[0265] Therefore, the electronic pen 3 can improve the processing efficiency of the processing performed by the pen sensor 10 on the electronic pen 3 with a small number of parts, without adding any components solely for the purpose of determining the retracted state of the pen tip 375. Furthermore, the electronic pen 3 can reduce power consumption with a small number of parts, without adding any components solely for the purpose of determining the retracted state of the pen tip 375.

[0266] ---Revised Version--- It should be noted that the present invention is not limited to the embodiments described above. That is, any design modifications made to the above embodiments by those skilled in the art are also included within the scope of the present invention, as long as they retain the features of the present invention. Furthermore, the elements of the above embodiments and the modifications described later can be combined to the extent that it is technically possible, and any combination thereof is also included within the scope of the present invention, as long as it retains the features of the present invention.

[0267] For example, in the first embodiment, the pressure calculation unit 23 calculated the pressure value according to the fluctuations in the potential of both the position signal transmitted from the detection electrode 11 and the position signal transmitted from the detection electrode 12, but it is not limited to this. The pressure calculation unit 23 may also calculate the pressure value according to the fluctuations in the potential of either the position signal transmitted from the detection electrode 11 or the position signal transmitted from the detection electrode 12. The same applies to the second embodiment. With this configuration, the sensor controller 20 can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with higher sensitivity.

[0268] Furthermore, in the first and second embodiments, the pressure calculation unit 23 used either the amount of change within a predetermined time or the difference from the previously acquired potential to determine the amount of change in the potential of the position signal, but is not limited to these. The pressure calculation unit 23 may calculate the difference of the potential of the position signal acquired this time to the moving average of the potential of the position signal acquired a predetermined number of times in the past, and calculate the pressure value according to the fluctuation of said difference. With this configuration, the sensor controller 20 calculates the pressure value according to the difference from the moving average of past position signals, so it can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with higher accuracy.

[0269] Furthermore, in the first embodiment, the pen pressure calculation unit 23 calculated the pen pressure value to be one of the first value and the second value, but it is not limited to this. For example, when the operating state transitions between the first state and the second state, the pen pressure calculation unit 23 may calculate the pen pressure value to change in steps from the first value to the second value or from the second value to the first value.

[0270] Here, while referring to FIG. 5, another example regarding the calculation of the pen pressure value will be described. FIG. 5 is a graph showing another example of the relationship between the amount of change in the level of the position signal and the pen pressure value in the first embodiment. As shown in FIG. 5, when the pen pressure calculation unit 23 determines that the operation state has shifted from the second state to the first state, the pen pressure calculation unit 23 calculates the pen pressure value so as to gradually shift from the second value to the first value over time. Further, when the pen pressure calculation unit 23 determines that the operation state has shifted from the first state to the second state, the pen pressure calculation unit 23 calculates the pen pressure value so as to gradually shift from the first value to the second value over time. Note that the pen pressure calculation unit 23 shifts the pen pressure value according to, for example, a predetermined functional formula having the elapsed time as a variable. Further, the pen pressure calculation unit 23 shifts the pen pressure value by, for example, the amount indicated by a predetermined change rate or change amount in the elapsed time.

[0271] According to this configuration, since the sensor controller 20 calculates the pen pressure value so that the pen pressure calculation unit 23 shifts stepwise between the first value and the second value, it is possible to reduce the abruptness and unnaturalness of drawing that may occur due to a sudden change in the pen pressure value.

[0272] Also, in the second embodiment, although the pen pressure calculation unit 23 calculates the pen pressure value according to the position signal transmitted from the chip electrode provided at the tip of the electronic pen 300 and received by the pen sensor 100, the present invention is not limited to this. The pen pressure calculation unit 23 may calculate the pen pressure value according to the amount of change in the potential of the attitude signal including the attitude value of the electronic pen 300 transmitted from the ring electrode of the electronic pen 300. According to this configuration, the sensor controller 20 can calculate the pen pressure value according to the amount of change in the potential of another signal regardless of the position signal of the electronic pen 300.

[0273] Furthermore, the pressure calculation unit 23 may change the correction amount for correcting the pressure signal according to the position signal, in accordance with the change in the potential of the attitude signal. Specifically, the pressure calculation unit 23 may increase the correction amount for the pressure signal when the change in the potential of the attitude signal is greater than or equal to the reference potential, and decrease the correction amount for the pressure signal when the change in the potential of the attitude signal is less than the reference potential. Alternatively, the pressure calculation unit 23 may decrease the correction amount for the pressure signal when the change in the potential of the attitude signal is greater than or equal to the reference potential, and increase the correction amount for the pressure signal when the change in the potential of the attitude signal is less than the reference potential. With this configuration, the pen sensor controller 52 can calculate the pressure value with even higher accuracy because it changes the correction amount according to the attitude signal of the electronic pen 300.

[0274] Furthermore, in the fourth embodiment, the pressure sensitivity calculation unit 23 determines the operating state of the electronic pen 3 based on whether the change in the potential difference between the first signal and the second signal is greater than or equal to a predetermined value, but is not limited to this. The pressure sensitivity calculation unit 23 may also determine the operating state of the electronic pen 3 based on whether the ratio of the change in the potential of the second signal to the change in the potential of the first signal is greater than or equal to a predetermined ratio. The ratio of the change in the potential of the second signal to the change in the potential of the first signal is, that is, the result of dividing the change in the potential of the first signal by the change in the potential of the second signal level. The predetermined ratio is, for example, 2 or 3.

[0275] When the operating state of the electronic pen 3 transitions from the second state to the first state, the potential of the first signal detected by the pen sensor 10 rises sharply. Conversely, when the operating state of the electronic pen 3 transitions from the first state to the second state, the potential of the first signal detected by the pen sensor 10 falls sharply. This phenomenon occurs because the air layer that exists between the electronic pen 3 and the pen sensor 10 when the electrode 37 of the electronic pen 3 is not in contact with the pen sensor 10 disappears when the electrode 37 of the electronic pen 3 comes into contact with the pen sensor 10. Regarding the potential of the second signal, since it is unlikely that the electrode 38 that transmits and receives the second signal will come into contact with the pen sensor 10, the same phenomenon as with the first signal is unlikely to occur. This modified example is based on the principle that the operating state can be determined by determining whether the change in the potential of the first signal and the change in the potential of the second signal satisfy predetermined conditions, taking the above phenomena into account.

[0276] Here, with reference to Figure 13, the details of the above modified example will be explained. Note that the processes other than those in step SP86 and step SP92 are the same as in the fourth embodiment, so their explanation will be omitted here.

[0277] (Step SP86) The pen pressure calculation unit 23 determines whether the ratio of the change in potential of the second signal to the change in potential of the first signal is greater than or equal to a first ratio. The first ratio is a ratio used to determine whether the operating state has transitioned to a first state in which the electronic pen 3 is pressing against the pen sensor 10. If the determination is positive, the process proceeds to step SP88. If the determination is negative, the process proceeds to step SP98.

[0278] (Step SP92) The pen pressure calculation unit 23 determines whether the ratio of the change in potential of the second signal to the change in potential of the first signal is greater than or equal to the second ratio. The second ratio is a ratio used to determine whether the operating state has transitioned to the second state, in which the electronic pen 3 is separated from the pen sensor 10. The second ratio may be the same as the first ratio or a different ratio. If the determination is positive, the process proceeds to step SP94. If the determination is negative, the process proceeds to step SP98.

[0279] Furthermore, the sensor controller 20 is not limited to the examples described above. For example, it may store model data showing the time transition of the potential change of the first signal and the potential change of the second signal when the operating state of the electronic pen 3 changes from the first state to the second state. The sensor controller 20 may also store model data showing the time transition of the potential change of the first signal and the potential change of the second signal when the operating state of the electronic pen 3 changes from the second state to the first state. The sensor controller 20 may refer to the model data regarding changes in the operating state of the electronic pen 3 and determine that the operating state has changed if it matches or nearly matches the model data.

[0280] In this configuration, the sensor controller 20 determines the operating state of the electronic pen 3 based on whether the change in the potential of the first signal and the change in the potential of the second signal satisfy predetermined conditions. Therefore, the sensor controller 20 can calculate the pressure applied to the pen sensor 10 by the electronic pen 3 with high accuracy, even when the absolute values ​​of the potentials of the first and second signals fluctuate due to differences in the models of the electronic pen 3 and pen sensor 10, or manufacturing variations.

[0281] Furthermore, in the first to fourth embodiments, the position detection system 5 performed the determination of the change in potential and the calculation of the pen pressure value using the same device (for example, electronic device 1A, electronic device 1B, electronic pen 3, etc.), but it is not limited to this. The position detection system 5 may perform the determination of the change in potential and the calculation of the pen pressure value using different devices. A specific example will be explained again with reference to Figure 6. Note that the processing of steps SP10 to SP16, step SP22 and step SP28 is the same as in the first embodiment, so their explanation will be omitted.

[0282] (Step SP18) The electronic device 1A determines, via the pressure calculation unit 23, that its operating state has transitioned from the second state to the first state. The electronic device 1A updates the operating state data 213 in the storage unit 21 to indicate that the current operating state is the first state. Furthermore, the electronic device 1A transmits an uplink signal to the electronic pen 3, which includes a control command to calculate the pressure value. The electronic device 1A may transmit the control command to the electronic pen 3 via short-range wireless communication such as Bluetooth® instead of an uplink signal. Then, the process proceeds to step SP20.

[0283] (Step SP20) The electronic pen 3 receives an uplink signal from the electronic device 1A via the pen controller 36. The electronic pen 3 performs a pressure pressure calculation process according to a control command from the pen controller 36 that calculates the pressure pressure value included in the uplink signal. In the pressure pressure calculation process, the electronic pen 3 calculates the pressure pressure value as a first value, for example. In the pressure pressure calculation process, the electronic pen 3 also calculates the pressure detected by a sensor 34 provided on the electronic pen 3 as the pressure pressure value. The electronic pen 3 transmits a downlink signal containing the calculated pressure pressure value to the electronic device 1A. The electronic pen 3 may also transmit the pressure pressure value to the electronic device 1A via short-range wireless communication such as Bluetooth® instead of a downlink signal. Then, the process moves on to step SP28.

[0284] (Step SP24) The electronic device 1A determines, via the pressure-sensing unit 23, that its operating state has transitioned from the first state to the second state. The electronic device 1A updates the operating state data 213 in the storage unit 21 to indicate that the current operating state is the second state. Furthermore, the electronic device 1A transmits an uplink signal to the electronic pen 3, which includes a control command to calculate the pressure value. The electronic device 1A may transmit the control command to the electronic pen 3 via short-range wireless communication such as Bluetooth® instead of an uplink signal. The process then proceeds to step SP26.

[0285] (Step SP26) The electronic pen 3 receives an uplink signal from the electronic device 1A via the pen controller 36. The electronic pen 3 performs a pressure pressure calculation process according to a control command from the pen controller 36 that calculates the pressure pressure value included in the uplink signal. In the pressure pressure calculation process, the electronic pen 3 calculates the pressure pressure as a second value, for example. In addition, the electronic pen 3 calculates the pressure detected by a sensor 34 provided on the electronic pen 3 as the pressure pressure value. The electronic pen 3 transmits a downlink signal containing the calculated pressure pressure value to the electronic device 1A. The electronic pen 3 may also transmit the pressure pressure value to the electronic device 1A via short-range wireless communication such as Bluetooth® instead of a downlink signal. Then, the process moves on to step SP28.

[0286] In this configuration, the position detection system 5 performs the detection of changes in potential using the electronic device 1A, and the pressure sensitivity calculation process is performed by the electronic pen 3 when a control command is transmitted from the electronic device 1A. Therefore, since the position detection system 5 performs the pressure sensitivity calculation process only when a control command is transmitted from the electronic device 1A, power consumption associated with the pressure sensitivity calculation process and a decrease in processing speed can be suppressed.

[0287] Furthermore, in the seventh embodiment, the electronic pen 3 may, when it determines that the state has changed to one in which the pen tip 375 is stored in the storage member, switch its operating mode from normal mode to power-saving mode in response to a response transmitted from the pen sensor 10, but is not limited to this. The electronic pen 3 may also completely turn off its power and stop its operation in response to a response transmitted from the pen sensor 10 when it determines that the state has changed to one in which the pen tip 375 is stored in the storage member. In other words, the electronic pen 3 may stop the operation of internal circuits such as the pen controller 36.

[0288] In this configuration, the electronic pen 3 notifies the pen sensor 10 according to the storage state of the pen tip 375 within the storage member. The electronic pen 3 also stops operating in response to the notification from the pen sensor 10. Therefore, the electronic pen 3 stops operating simply by storing the pen tip 375, without requiring any user input, thus improving the convenience of the electronic pen 3. Furthermore, the processing efficiency of the processing related to the electronic pen 3 performed by the pen sensor 10 can be improved.

[0289] Furthermore, the electronic pen 3 switches its operating mode from normal mode to power-saving mode in response to a response transmitted from the pen sensor 10 when it determines that the state has changed to one in which the pen tip 375 is stored in the storage member, but is not limited to this. The sensor controller 20, which controls the transmission and reception operations of the pen sensor 10, may change the scan mode when the pen sensor 10 receives a notification indicating that the state has changed to one in which the pen tip 375 is stored in the storage member.

[0290] The scan modes will now be explained. The sensor controller 20 has, for example, four types of scan modes as shown below. The sensor controller 20 usually switches between these modes in the order shown below to perform position detection processing for the electronic pen 3, finger 2, etc.

[0291] The first mode is for detecting the position of finger 2. In this mode, the sensor controller 20 temporarily suspends the transmission and reception of signals with the electronic pen 3 to detect the position indication of finger 2 to the pen sensor 10. The second mode is for transmitting an uplink signal to the electronic pen 3. The third mode is for receiving a downlink signal from the electronic pen 3 to detect the indicated position of the electronic pen 3. The fourth mode is for receiving a downlink signal from the electronic pen 3 to acquire various information about the electronic pen 3. In other words, the second to fourth modes are modes for transmitting and receiving signals with the electronic pen 3.

[0292] When the pen sensor 10 receives a notification indicating that the pen tip 375 has been retracted into the storage member, the sensor controller 20 may switch the scan mode from sequentially switching between the first to fourth modes to repeating the first mode. In other words, when the pen tip 375 of the electronic pen 3 is retracted into the storage member, the sensor controller 20 stops transmitting and receiving signals with the electronic pen 3 and changes the process to detect the position indication of the finger 2.

[0293] Furthermore, if the pen sensor 10 receives a notification indicating that the pen tip 375 has changed state to one where it is not stored in the storage member, the sensor controller 20 may switch the scan mode from repeating the first mode to sequentially switching between the first to fourth modes. In other words, if the pen tip 375 of the electronic pen 3 changes state to one where it is not stored in the storage member, the sensor controller 20 changes its processing to detect the position indication of the finger 2 and transmit and receive signals between it and the electronic pen 3 as usual.

[0294] In this configuration, the position detection system 5, which includes an electronic pen 3 and a sensor controller 20, switches the scan mode of the sensor controller 20 according to the storage state of the pen tip 375 of the electronic pen 3 within the storage member. Therefore, the position detection system 5 stops transmitting and receiving signals between the pen sensor 10 and the electronic pen 3 when the pen tip 375 of the electronic pen 3 is stored, thereby reducing the power consumption of the electronic pen 3 and the sensor controller 20. Furthermore, the position detection system 5 can improve the processing efficiency of the sensor controller 20. [Explanation of symbols]

[0295] 1A...Electronic device, 1B...Electronic device, 3...Electronic pen, 10...Pen sensor, 20...Sensor controller, 21...Acquisition unit, 23...Pen pressure calculation unit, 40...Display panel

Claims

1. An acquisition unit that acquires a position signal indicating the position of the electronic pen from a pen sensor that detects the position of the electronic pen, A pressure calculation unit calculates a pressure value relating to the pressure applied by the electronic pen to the pen sensor based on the change in the signal level of the position signal acquired by the acquisition unit, A sensor controller equipped with the following features.

2. The aforementioned signal level is electric potential. The pen pressure calculation unit determines that the operating state has transitioned to a first state in which the electronic pen is pressing the pen sensor when the potential of the position signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as the first value. The sensor controller according to claim 1.

3. The pen pressure calculation unit determines that the operating state has transitioned to a second state in which the electronic pen is separated from the pen sensor when the potential of the position signal drops to a second potential or higher within a predetermined time, and calculates the pen pressure value as a second value different from the first value. The sensor controller according to claim 2.

4. The pen pressure calculation unit calculates the pen pressure value so that it changes in steps from the first value to the second value when the operating state transitions from the second state to the first state. The sensor controller according to claim 3.

5. The aforementioned signal level is electric potential. The acquisition unit acquires from the pen sensor a pressure signal that is transmitted from the electronic pen to the pen sensor and indicates the pressure applied by the electronic pen to the pen sensor. The pen pressure calculation unit calculates the pen pressure value by correcting the pen pressure indicated by the pen pressure signal based on the change in the potential of the position signal. The sensor controller according to claim 1.

6. The pressure calculation unit determines that the operating state has transitioned to a first state in which the electronic pen is pressing the pen sensor when the potential of the position signal rises to a first potential or higher within a predetermined time, and calculates the pressure value as a first value. If the pressure signal acquired by the acquisition unit before determining that the operating state has transitioned to the first state indicates that the electronic pen is pressing the pen sensor, the unit determines that the pressure signal indicates an abnormal value and calculates the pressure value as a second value different from the first value. The sensor controller according to claim 5.

7. The pressure calculation unit determines that the operating state has transitioned to a second state in which the electronic pen is separated from the pen sensor when the potential of the position signal drops to a second potential or higher within a predetermined time, and calculates the pressure value as the second value. If the pressure signal acquired by the acquisition unit before determining that the operating state has transitioned to the second state indicates that the electronic pen is separated from the pen sensor, the pressure value is maintained as an abnormal value because the pressure signal indicates an abnormal value. The sensor controller according to claim 6.

8. A method for controlling a sensor controller connected to a pen sensor, The process involves obtaining a position signal indicating the position of the electronic pen from the pen sensor that detects the position of the electronic pen, Based on the change in the signal level of the acquired position signal, the pressure value related to the pressure applied by the electronic pen to the pen sensor is calculated, A control method for a sensor controller, including the sensor controller.

9. An electronic device comprising a sensor controller as described in claim 1, A display panel that displays the items to be displayed, The pen sensor is provided so as to overlap the display area of ​​the display panel in a plan view, and detects the position of the electronic pen, Electronic devices that also have additional features.

10. An electronic pen that provides positional instructions to a pen sensor, A pen tip having an electrode that is provided at the tip so as to be reciprocable along the axial direction and transmits and receives signals with the pen sensor, A pen controller that calculates a pen pressure value related to pen pressure based on a change in the signal level of the uplink signal transmitted from the pen sensor via the electrodes, A transmitting unit that transmits a pressure signal indicating the pressure value calculated by the pen controller and a position signal indicating the instruction position for the pen sensor to the pen sensor via the electrodes to the pen sensor. An electronic pen equipped with [a specific feature].

11. The aforementioned signal level is electric potential. The pen controller determines that the operating state has transitioned to a first state in which the pen sensor is pressed when the potential of the uplink signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as a first value. The electronic pen according to claim 10.

12. The pen controller determines that the operating state has transitioned to a second state, where it is separated from the pen sensor, when the potential of the uplink signal drops to a second potential or higher within a predetermined time, and calculates the pen pressure value as a second value different from the first value. The electronic pen according to claim 11.

13. The pen tip is further equipped with a pressure sensor that detects the pressure applied to it. The aforementioned signal level is electric potential. The pen controller calculates the pen pressure value by correcting the pressure detected by the pressure sensor based on the change in the potential of the uplink signal. The electronic pen according to claim 10.

14. The aforementioned signal level is electric potential. The pen controller determines that the operating state has transitioned to a first state in which the pen sensor is being pressed when the potential of the uplink signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as a first value. If the pen pressure signal indicates that the pen sensor is being pressed before it is determined that the operating state has transitioned to the first state, the pen controller determines that the pen pressure signal is showing an abnormal value and calculates the pen pressure value as a second value different from the first value. The electronic pen according to claim 10.

15. The pen controller determines that the operating state has transitioned to a second state, where it is separated from the pen sensor, when the potential of the uplink signal drops to a second potential or higher within a predetermined time, and calculates the pen pressure value as the second value. If the pen pressure signal indicates that it is separated from the pen sensor before the determination that the operating state has transitioned to the second state, the pen controller maintains the pen pressure value, treating the pen pressure signal as an abnormal value. The electronic pen according to claim 14.

16. A position detection system comprising an electronic pen as described in claim 10, An electronic device comprising: a display panel for displaying an object to be displayed; a pen sensor provided so as to overlap the display area of ​​the display panel in a plan view with respect to the electronic pen, which transmits the uplink signal to the electronic pen and detects the pressure signal and position signal transmitted from the electronic pen; and a sensor controller which controls the display of the display panel according to the pressure signal and position signal detected by the pen sensor. A position detection system further equipped with features.

17. An acquisition unit that acquires, from a pen sensor that detects the position of the electronic pen, a first signal transmitted from the first electrode of the electronic pen to the pen sensor, a second signal transmitted from a second electrode different from the first electrode of the electronic pen to the pen sensor, and a pressure signal indicating the pressure of the electronic pen, A pressure calculation unit calculates a pressure value relating to the pressure of the electronic pen on the pen sensor based on the changes in the signal levels of the first signal and the second signal acquired by the acquisition unit, and the pressure signal. A sensor controller equipped with the following features.

18. The pressure calculation unit calculates the pressure value such that the pressure value increases as the tilt angle of the electronic pen with respect to the detection surface of the pen sensor increases, and decreases as the tilt angle decreases. The sensor controller according to claim 17.

19. The aforementioned signal level is electric potential. The pen pressure calculation unit determines that the operating state has transitioned to a first state in which the electronic pen is pressing the pen sensor when the potential of the first signal or the second signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as the first value. The sensor controller according to claim 17 or 18.

20. The aforementioned signal level is electric potential. The pen pressure calculation unit determines that the operating state has transitioned to a first state in which the electronic pen is pressing the pen sensor when the potential difference between the first signal and the second signal rises to a first potential or higher within a predetermined time, and calculates the pen pressure value as the first value. The sensor controller according to claim 17 or 18.

21. The pressure sensitivity calculation unit calculates the movement speed of the electronic pen relative to the pen sensor from the position signal, and determines the value of the first potential according to the calculated movement speed. The sensor controller according to claim 2.

22. The pressure-pen calculation unit determines the value of the first potential to be the value of the third potential when the movement speed is equal to or greater than the speed threshold, and determines the value of the first potential to be the value of the fourth potential which is greater than the third potential when the movement speed is less than the speed threshold. The sensor controller according to claim 21.

23. The pen pressure calculation unit determines the value of the first potential such that the value of the first potential is proportional to the movement speed. The sensor controller according to claim 21.

24. The pen pressure calculation unit calculates the movement speed of the electronic pen relative to the pen sensor from the position signal, and determines the first value according to the calculated movement speed. The sensor controller according to claim 2.

25. The pen pressure calculation unit calculates the pen pressure value when the predetermined conditions are not met. The predetermined conditions are that the time elapsed since the previous calculation of the pen pressure value is less than the reference time, and the distance the electronic pen has moved since the previous calculation of the pen pressure value is less than the reference distance. The sensor controller according to claim 1.

26. The pen pressure calculation unit, when the predetermined conditions are met, executes a waiting process that waits for a waiting time, if it has not been executed since the previous determination of the predetermined conditions, and calculates the pen pressure value if it has been executed since the previous determination of the predetermined conditions. The sensor controller according to claim 25.

27. An electronic pen that provides positional instructions to a pen sensor, A pen tip that has electrodes for transmitting and receiving signals with the aforementioned pen sensor and is housed in a storage member, A pen controller that transmits and receives the signal to and from the pen sensor via the electrode, determines the storage state of the pen tip in the storage member, notifies the pen sensor if it is determined that the pen tip is stored in the storage member, and stops transmitting the signal in response to the notification transmitted from the pen sensor. An electronic pen equipped with [a specific feature].

28. The pen controller notifies the pen sensor when the storage state changes from a state in which the pen tip is stored in the storage member to a state in which the pen tip is not stored in the storage member, and starts transmitting the signal in response to the notification transmitted from the pen sensor. The electronic pen according to claim 27.

29. The storage member, which is a cylindrical housing, The housing further comprises a retractable member that allows the pen tip to extend and retract from one of the openings of the housing. The electronic pen according to claim 27.

30. The retractable member is a knock mechanism that allows the pen tip to extend and retract from one of the openings in the housing. The device further includes a switch member whose state changes in accordance with the sliding movement of a sliding member that slides in conjunction with the knocking operation of the knocking mechanism, The pen controller determines the storage state based on the state of the switch member. The electronic pen according to claim 29.

31. The retractable member has a retractable mechanism that allows the pen tip to extend and retract from one opening of the housing by the rotation of a member that is rotatably connected to the housing with the center line of the housing as the axis of rotation. The retractable mechanism further comprises a detection member whose state switches in accordance with rotational movement linked to the rotation of the member rotatably coupled to the housing, The pen controller determines the storage state based on the state of the detection member. The electronic pen according to claim 29.

32. The storage member is a cap that is detachably attached to the housing on which the pen tip is provided, so as to cover the pen tip. The electronic pen according to claim 28.

33. The storage member is a housing for an electronic device having a hole into which the pen tip can be inserted. The electronic pen according to claim 28.

34. The device further comprises a detection member for detecting changes in the electric field, magnetic field, or capacitance of the space including the pen tip, The pen controller determines the storage state based on the detection result of the detection member. The electronic pen according to claim 32 or 33.

35. The system further includes a detection member for detecting changes in the electrical conductivity between the pen tip and the storage member, The pen controller determines the storage state based on the detection result of the detection member. The electronic pen according to claim 32 or 33.

36. The electrode is the first electrode, It transmits and receives signals with the pen sensor and is capable of receiving signals transmitted from the first electrode, and further comprises a second electrode different from the first electrode, The pen controller determines whether the pen tip is housed in the storage member based on the amount of change in the signal level of the signal transmitted from the first electrode to the second electrode. The electronic pen according to claim 32 or 33.

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