Active Pen

Abstract

[Problem] To stop vibration of a haptic device immediately after a nib has separated from a panel surface. [Solution] An active pen 2 of the present invention comprises a haptic device 26, a pressure sensor 23 that detects a pressure applied to the nib, a nib electrode 21 provided in the nib, a communication unit 25 that performs near-field communication, and an integrated circuit 27 that transmits, from the nib electrode 21, a downlink signal DS including a writing pressure value indicating the magnitude of the pressure detected by the pressure sensor 23. The integrated circuit 27 starts to vibrate the haptic device 26 when receiving a control signal instructing the haptic device 26 to start vibration via the communication unit 25, whereas the integrated circuit 27 stops vibration of the haptic device 26 when the writing pressure value has fallen below a first predetermined value.

Description

Technical Field

[0001] The present invention relates to an active pen, and more particularly to an active pen incorporating a haptic element for providing a user with sensory feedback.

Background Art

[0002] A technique for reproducing the writing feel on paper by controlling a haptic element incorporated in an electronic pen from an electronic device such as a tablet terminal is known. Examples of this type of technique are disclosed in Patent Documents 1 to 3.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when controlling the haptic element in the electronic pen from an electronic device, there is a slight time lag in the control. Therefore, even after the pen tip is detached from the panel surface, the vibration of the haptic element does not stop immediately, which may give the user a sense of discomfort.

[0005] Therefore, one object of the present invention is to provide an active pen capable of quickly stopping the vibration of the haptic element after the pen tip is detached from the panel surface.

Means for Solving the Problems

[0006] The active pen according to the first aspect of the present invention includes a haptic element, a pressure sensor that detects the pressure applied to the pen tip, a pen tip electrode provided at the pen tip, a communication unit that performs short-range wireless communication, and a signal processing unit that transmits a downlink signal including a pen pressure value indicating the magnitude of the pressure detected by the pressure sensor from the pen tip electrode. When the signal processing unit receives a control signal instructing the start of vibration of the haptic element by the communication unit, the signal processing unit starts the vibration of the haptic element. On the other hand, when the pen pressure value falls below a first predetermined value, the signal processing unit stops the vibration of the haptic element.

[0007] The active pen according to the second aspect of the present invention includes a haptic element, a pressure sensor that detects the pressure applied to the pen tip, and a signal processing unit that starts the vibration of the haptic element in response to pen down and stops the vibration of the haptic element in response to pen up. When the pen pressure value indicating the magnitude of the pressure detected by the pressure sensor falls below a first predetermined value, the signal processing unit stops the vibration of the haptic element.

Advantages of the Invention

[0008] According to the present invention, since the vibration of the haptic element can be stopped according to the pen pressure value in the active pen, it becomes possible to quickly stop the vibration of the haptic element after the pen tip is detached from the panel surface.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0010] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0011] FIG. 1 is a diagram showing the configuration of a position detection system 1 according to an embodiment of the present invention. As shown in the figure, the position detection system 1 includes an active pen 2 and an electronic device 3 which is a position detection device for detecting the active pen 2.

[0012] The electronic device 3 is a computer having a panel surface 3a such as a tablet computer or a digitizer. Inside the electronic device 3, a sensor 30 disposed in the panel surface 3a, a sensor controller 31 connected to the sensor 30, a display 32 disposed so as to overlap the sensor 30, a wireless communication unit 33, and a host processor 34 for controlling each part of the electronic device 3 including these are provided.

[0013] The host processor 34 is a central processing unit of the electronic device 3, and is configured to read various programs from a memory (not shown) and execute them. The programs thus executed include various applications including the operating system and drawing applications of the electronic device 3. Among these, the drawing application is a program for generating digital ink based on the position and data supplied from the sensor controller 31, storing the digital ink in the memory in the electronic device 3, rendering the generated digital ink, and generating a video signal indicating the result and supplying it to the display 32. The display 32 is a device for displaying the video signal supplied from the host processor 34, and is constituted by, for example, a liquid crystal display or an organic EL display.

[0014] The sensor 30 is a device having a structure in which a plurality of sensor electrodes are arranged within the panel surface 3a. A part of the plurality of sensor electrodes constituting the sensor 30 can be used also as a common electrode of the display 32 (an electrode for supplying a ground potential commonly to each pixel). When this dual use is carried out, the electronic device 3 constitutes a so-called "in-cell type" position detection device. On the other hand, when the dual use is not carried out, the electronic device 3 constitutes a so-called "on-cell type" or "out-cell type" position detection device. The present invention can be suitably applied to any of the electronic devices 3.

[0015] The sensor controller 31 is an integrated circuit having a function of detecting the position of the active pen 2 within the panel surface 3a. In the present embodiment, an example in which this detection is executed by the active electrostatic method (AES) will be described, but the present invention can be suitably applied also when the position of the active pen 2 is detected by another method such as the electromagnetic induction method (EMR).

[0016] The sensor controller 31 corresponding to the active electrostatic method is configured to communicate bidirectionally with the active pen 2 through an electrostatic coupling between the sensor 30 and an electrode (a pen tip electrode 21 described later) within the active pen 2. Hereinafter, a signal transmitted from the sensor controller 31 to the active pen 2 by this communication is referred to as an "uplink signal US", and a signal transmitted from the active pen 2 to the sensor controller 31 is referred to as a "downlink signal DS".

[0017] The uplink signal US is a signal that is periodically transmitted by the sensor controller 31. The uplink signal US notifies the active pen 2 of the transmission timing of the downlink signal DS and the reception timing of the next uplink signal US, and also serves to transmit commands to the active pen 2. On the other hand, the downlink signal DS is a signal that includes a position signal which is an unmodulated carrier signal and a data signal which is a carrier signal modulated by data. The position signal is a signal for causing the sensor controller 31 to detect the position of the active pen 2. The sensor controller 31 is configured to derive the position of the active pen 2 within the panel surface 3a based on the distribution of the reception intensity of the position signal at each sensor electrode in the sensor 30. The data transmitted by the data signal includes, in addition to the switch information and pen pressure values described later, data instructed to be transmitted by a command. The sensor controller 31 acquires the data transmitted by the active pen 2 by demodulating the data signal. The position derived and the data acquired by the sensor controller 31 in this way are sequentially supplied from the sensor controller 31 to the host processor 34.

[0018] The wireless communication unit 33 is a communication device for performing short-range wireless communication such as Bluetooth (registered trademark), and is connected to the host processor 34. The host processor 34 performs short-range wireless communication with the active pen 2 and other devices (keyboard, mouse, speaker, headphones, etc.) via the wireless communication unit 33.

[0019] The signal transmitted by the host processor 34 to the active pen 2 through the wireless communication unit 33 includes a control signal for the haptics element 26, which will be described later. The host processor 34 detects pen-down when the pen pressure value supplied from the sensor controller 31 exceeds a predetermined value V2 (typically, V2 = 0), and transmits a control signal instructing the start of vibration of the haptics element 26. On the other hand, when the pen pressure value supplied from the sensor controller 31 reaches the predetermined value V2, the host processor 34 detects pen-up and transmits a control signal instructing the stop of vibration of the haptics element 26. This will be described in more detail later with reference to FIG. 2.

[0020] The active pen 2 is an electronic pen (stylus) corresponding to the active electrostatic method. As shown in FIG. 1, it includes a core body 20, a pen tip electrode 21, a side switch 22, a pressure sensor 23, a battery 24, a wireless communication unit 25, a haptics element 26, and an integrated circuit 27. The core body 20 is a member that constitutes the pen shaft of the active pen 2. The tip of the core body 20 constitutes the pen tip of the active pen 2, and the end abuts against the pressure sensor 23. The pen tip electrode 21 is a conductor disposed at the pen tip and is electrically connected to the integrated circuit 27. Note that a plurality of pen tip electrodes 21 may be provided in the active pen 2, and different pen tip electrodes 21 may be used for transmission and reception, for example.

[0021] The side switch 22 is a push-button type switch provided on the surface of the active pen 2 and is configured to be operable to be turned on and off by the user. The operation state (on / off state) of the side switch 22 is supplied to the integrated circuit 27 as, for example, 2-bit switch information. The pressure sensor 23 is a sensor that detects the pressure applied to the tip (pen tip) of the core body 20. The pressure detected by the pressure sensor 23 is supplied to the integrated circuit 27 as, for example, a 12-bit pen pressure value. The battery 24 serves to supply the power necessary for the integrated circuit 27 to operate.

[0022] The wireless communication unit 25 is a communication device for performing short-range wireless communication such as Bluetooth (registered trademark). The integrated circuit 27 performs short-range wireless communication with the host processor 34 of the electronic device 3 via this wireless communication unit 25. The signal received by the integrated circuit 27 from the host processor 34 through this short-range wireless communication includes the control signal of the haptics element 26 described above.

[0023] The haptics element 26 is a device for providing sensory feedback to the user of the active pen 2, and is constituted by, for example, a vibrator of an eccentric rotating mass method, a linear resonance actuator method, or a piezo (piezoelectric) actuator method. The haptics element 26 may be constituted by using a magnetic fluid whose hardness can be controlled by the frequency of the applied pulsed current. Hereinafter, the description will be continued on the premise that the haptics element 26 is constituted by a vibrator of the eccentric rotating mass method. In this case, the haptics element 26 is constituted by having a motor and an eccentric weight attached to the rotation axis of the motor.

[0024] The integrated circuit 27 is a circuit that executes various processes for communicating with the sensor controller 31 through the pen tip electrode 21 and for communicating with the host processor 34 through the wireless communication unit 25. Specifically, the integrated circuit 27 performs a process of receiving the uplink signal US by detecting a change in the potential of the pen tip electrode 21, a process of determining the transmission / reception schedule of the downlink signal DS and the next uplink signal US with the reception timing of the uplink signal US as a reference time, a process of generating the downlink signal DS in response to a command included in the uplink signal US, and a process of transmitting the generated downlink signal DS by changing the potential of the pen tip electrode 21 according to the determined transmission / reception schedule. Further, the integrated circuit 27 performs pairing with the host processor 34 through the wireless communication unit 25, receives various control signals from the paired host processor 34, and performs processing based on the received control signals.

[0025] The processing based on the received control signal includes processing for starting or stopping the vibration of the haptic element 26. Specifically, the integrated circuit 27 is configured to start or stop the vibration of the haptic element 26 in response to the control signal transmitted by the host processor 34. However, the integrated circuit 27 also performs a process of stopping the vibration of the haptic element 26 even when the pen pressure value supplied from the pressure sensor 23 becomes a value equal to or less than a predetermined value V1. The predetermined value V1 is a value greater than the above-described predetermined value V2 (the value used by the host processor 34 to detect pen down and pen up) (V1 > V2). In actual processing, the integrated circuit 27 stops the vibration of the haptic element 26 at the earlier of the timing of reception of the control signal instructing the stop of the vibration of the haptic element 26 by the wireless communication unit 25 and the timing when the pen pressure value supplied from the pressure sensor 23 falls below the predetermined value V1.

[0026] FIG. 2 is a diagram showing a sequence of processing executed in the position detection system 1. Only the processing related to the control of the haptic element 26 is extracted and shown in the figure. Hereinafter, with reference to FIG. 2, the processing performed by the active pen 2, the sensor controller 31, and the host processor 34 related to the control of the haptic element 26 will be described.

[0027] As shown in FIG. 2, first, when the active pen 2 transmits a downlink signal DS (step S1), the sensor controller 31 derives coordinates indicating the position of the active pen 2 in the panel surface 3a based on the position signal in the downlink signal DS, and acquires data such as the pen pressure value from the data signal in the downlink signal DS and supplies it to the host processor 34 (step S2). The processing of steps S1 and S2 is executed each time the active pen 2 transmits a downlink signal DS.

[0028] Subsequently, each time the host processor 34 receives the pen pressure value from the sensor controller 31, it determines whether pen down and pen up have occurred based on the series of pen pressure values supplied so far (steps S3, S4), and according to the result, it transmits a control signal for the haptic element 26 using short-range wireless communication (steps S5, S6). Specifically, when the pen pressure value changes from a value equal to or less than a predetermined value V2 (typically, V2 = 0) to a value greater than the predetermined value V2, the host processor 34 detects the occurrence of pen down (step S3) and transmits a control signal instructing the start of vibration of the haptic element 26 (step S5). Also, when the pen pressure value changes from a value greater than the predetermined value V2 to a value equal to or less than the predetermined value V2, the host processor 34 detects the occurrence of pen up (step S4) and transmits a control signal instructing the stop of vibration of the haptic element 26 (step S6).

[0029] The integrated circuit 27 of the active pen 2 that has received the control signal instructing the start of vibration of the haptic element 26 starts the vibration of the haptic element 26 (step S7). Specifically, the vibration of the haptic element 26 is started by applying a current in the first direction to the motor constituting the haptic element 26. As a result, when the user slides the active pen 2 on the panel surface 3a, the user can feel the same vibration as when sliding a real writing instrument such as a ballpoint pen on paper.

[0030] While the haptic element 26 is vibrating, the integrated circuit 27 performs a process of comparing the supplied pen pressure value with a predetermined value V1 each time the pen pressure value is supplied from the pressure sensor 23 (step S8). Then, when the integrated circuit 27 detects that the pen pressure value has become equal to or less than the predetermined value V1 as a result of the comparison, it stops the vibration of the haptic element 26 (step S9). The integrated circuit 27 also stops the vibration of the haptic element 26 when it receives a control signal instructing the stop of vibration of the haptic element 26 (step S10). Only the one that is executed earlier among step S9 and step S10 will be actually executed.

[0031] Here, when stopping the vibration of the haptics element 26 in step S9 or step S10, it is preferable that the integrated circuit 27 stops the vibration of the haptics element 26 by applying a current in a direction opposite to the above-described first direction to the motor and then stopping the application of the current to the motor. By doing so, it becomes possible to quickly stop the residual vibration of the haptics element 26 due to inertia as compared with the case where the application of the current to the motor is stopped without applying a current in a direction opposite to the first direction to the motor.

[0032] As described above, according to the position detection system 1 according to the present embodiment, in the active pen 2, the vibration of the haptics element 26 can be stopped according to the pen pressure value. Therefore, after the pen tip separates from the panel surface 3a, it becomes possible to quickly stop the vibration of the haptics element 26.

[0033] Further, according to the active pen 2 according to the present embodiment, since the vibration of the haptics element 26 is stopped when the pen pressure value falls below a predetermined value V1 that is generally larger than a predetermined value V2 used for determining pen down and pen up, even if there is residual vibration of the haptics element 26 due to inertia, it becomes possible to immediately stop the vibration of the haptics element 26 after the pen tip separates from the panel surface 3a.

[0034] However, the present invention can also be suitably applied when the predetermined value V1 is equal to the predetermined value V2. In this case, after the pen tip separates from the panel surface 3a, there may be residual vibration of the haptics element 26 due to inertia, but compared with the control from the electronic device 3, it is possible to quickly stop the vibration of the haptics element 26.

[0035] Further, according to the active pen 2 according to the present embodiment, when stopping the vibration of the haptics element 26, since a current in a direction opposite to the previous one is applied to the motor, it also becomes possible to quickly stop the residual vibration of the haptics element 26 itself due to inertia.

[0036] As described above, the preferred embodiments of the present invention have been explained. However, the present invention is not limited to such embodiments at all, and it goes without saying that the present invention can be implemented in various forms without departing from the gist thereof.

[0037] FIG. 3 is a diagram showing a sequence of processes executed in the position detection system 1 according to a modification of the present embodiment. This modification is different from the present embodiment in that, instead of the steps S3 to S6 shown in FIG. 2, the processes of steps S10 to S13 are executed.

[0038] Specifically, in this modification, the sensor controller 31 determines the presence or absence of pen-down and pen-up based on a series of pen pressure values acquired so far (steps S10, S11), and according to the result, transmits a control signal for the haptics element 26 using the uplink signal US (steps S12, S13). The specific processes of steps S10 to S13 are the same as those of steps S3 to S6, except that the uplink signal US is used instead of short-range wireless communication.

[0039] Even when the sensor controller 31 transmits a control signal for the haptics element 26 using the uplink signal US in this way, according to the present invention, in the active pen 2, the vibration of the haptics element 26 can be stopped according to the pen pressure value. Therefore, after the pen tip is detached from the panel surface 3a, it becomes possible to quickly stop the vibration of the haptics element 26.

Explanation of Reference Numerals

[0040] 1 Position detection system 2 Active pen 3 Electronic device 3a Panel surface 20 Core body 21 Pen tip electrode 22 Side switch 23 Pressure sensor 24 Battery 25 Wireless communication unit 26 Haptics element 27 integrated circuits 30 sensors 31 sensor controllers 32 displays 33 wireless communication units 34 host processors DS downlink signal US uplink signal

Claims

1. A haptic element, A pressure sensor that detects the pressure applied to the pen tip, A pen tip electrode provided at the pen tip, A communication unit that performs short-range wireless communication, An integrated circuit that transmits a downlink signal including a pen pressure value indicating the magnitude of the pressure detected by the pressure sensor from the pen tip electrode, and The integrated circuit, When receiving a control signal instructing the start of vibration of the haptic element by the communication unit, while starting the vibration of the haptic element, When the pen pressure value falls below a first predetermined value that is larger than a second predetermined value used as a reference for detecting pen down, stopping the vibration of the haptic element, An active pen.

2. The control signal is a signal generated by a host processor connected to a sensor controller that receives the downlink signal through electrostatic coupling between a sensor disposed in the panel surface and the pen tip electrode, When the pen pressure value supplied from the sensor controller exceeds the second predetermined value, the host processor transmits a control signal instructing the start of vibration of the haptic element through the short-range wireless communication, The active pen according to claim 1.

3. A haptic element including a motor, A pressure sensor that detects the pressure applied to the pen tip, A pen tip electrode provided at the pen tip, A communication unit that performs short-range wireless communication, An integrated circuit that transmits a downlink signal including a pen pressure value indicating the magnitude of the pressure detected by the pressure sensor from the pen tip electrode, and The integrated circuit, When receiving a control signal instructing the start of vibration of the haptic element by the communication unit, while starting the vibration of the haptic element by applying a current in a first direction to the motor, When the pen pressure value falls below the first predetermined value, after applying a current in a direction opposite to the first direction to the motor, stopping the application of current to the motor to stop the vibration of the haptic element, An active pen.

4. The control signal is a signal generated by a host processor connected to a sensor controller that receives the downlink signal through electrostatic coupling between a sensor disposed in the panel surface and the pen tip electrode, When the pen pressure value supplied from the sensor controller exceeds a second predetermined value, the host processor transmits a control signal instructing the start of vibration of the haptic element through the short-range wireless communication. The active pen according to claim 3.

5. The first predetermined value is greater than the second predetermined value. The active pen according to claim 4.

6. When the pen pressure value supplied from the sensor controller is less than the second predetermined value, the host processor transmits a control signal instructing the stop of vibration of the haptic element through the short-range wireless communication. The active pen according to claim 2, 4, or 5.

7. A haptic element; A pressure sensor that detects the pressure applied to the pen tip; An integrated circuit that starts the vibration of the haptic element in response to pen-down and stops the vibration of the haptic element in response to the pen pressure value indicating the magnitude of the pressure detected by the pressure sensor falling below a first predetermined value that is used as a reference for detecting the pen-down, where the first predetermined value is greater than a second predetermined value; An active pen including the above.

8. A pen tip electrode provided at the pen tip; Further including a communication unit that performs short-range wireless communication, The integrated circuit: Transmits a downlink signal including the pen pressure value indicating the magnitude of the pressure detected by the pressure sensor from the pen tip electrode, When receiving a control signal instructing the start of vibration of the haptic element from the communication unit, starts the vibration of the haptic element, The control signal is a signal generated by a host processor connected to a sensor controller that receives the downlink signal through electrostatic coupling between a sensor disposed in the panel surface and the pen tip electrode, The host processor: Detects the pen-down when the pen pressure value supplied from the sensor controller exceeds the second predetermined value, When detecting the pen-down, starts the vibration of the haptic element by transmitting a control signal instructing the start of vibration of the haptic element through the short-range wireless communication. The active pen according to claim 7.

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