Sensor Controller

Abstract

The invention prevents the stylus pen (2) from being unable to detect the uplink signal and the uplink signal from affecting the operation of other devices. The invention is a sensor controller (13) connected to the sensor electrode group (12) constituting the surface. The sensor controller (13) supplies a predetermined AC signal to one or more AC signal sending electrodes constituted by at least a part of the plurality of sensor electrodes constituting the sensor electrode group (12), and sends a cancel signal from a cancel signal sending electrode different from the AC signal sending electrode to suppress the signal sent from the AC signal sending electrode from appearing at the ground end of the detection circuit of the stylus pen (2).

Description

Technical Field

[0001] The present invention relates to a sensor controller, and more particularly to a sensor controller having a function of transmitting an uplink signal. Background Art

[0002] Among tablet terminals that support pen input using a stylus pen, there are tablet terminals that are configured to be able to send an uplink signal from a sensor controller that detects the position of the stylus pen to the stylus pen (for example, see Patent Document 1). The uplink signal is a signal for sending information from the sensor controller to the stylus pen, and the stylus pen performs processing such as starting an action and sending a pen signal based on the uplink signal.

[0003] The sensor controller detects the stylus by detecting the pen signal, but the detection of a new stylus is preferably completed before the stylus contacts the panel surface. For this reason, the stylus is configured to perform the uplink signal detection operation even when it is not in contact with the panel surface (hovering state), and transmit the pen signal based on the detection of the uplink signal.

[0004] If the stylus pen approaches the panel surface at a fast speed, it is desirable that the stylus pen can detect the uplink signal from the stage where the stylus pen is away from the panel surface to a certain extent. To this end, in the past, attempts have been made to shorten the transmission period of the uplink signal, increase the transmission output of the uplink signal, improve the detection sensitivity of the stylus pen, and reduce the noise interfering with the uplink signal.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: International Publication No. 2017 / 029836 Summary of the invention

[0008] Problems to be solved by the invention

[0009] The stylus detects the uplink signal via the electrostatic capacitance formed between the sensor electrode disposed on the panel surface and the pen tip electrode disposed at the pen tip of the stylus. During the detection, the stylus detects the uplink signal by detecting the change in the potential of the pen tip electrode relative to the ground potential. The ground potential is usually the potential of the human body holding the stylus.

[0010] However, in such a detection method, the detection of the uplink signal sometimes fails and needs to be improved. In detail, for example, when the user holds the stylus in the right hand and places the left hand on the panel surface, the uplink signal is also detected in the left hand via the static capacitance formed between the left hand and the sensor electrode. As a result, the potential of the human body (i.e., the ground potential of the stylus) changes in the same way as the uplink signal, so the change in the potential of the pen tip electrode is offset. As a result, the stylus cannot detect the uplink signal.

[0011] Therefore, one object of the present invention is to provide a sensor controller that can prevent the stylus pen from being unable to detect the uplink signal due to a change in the ground potential of the stylus pen caused by the uplink signal.

[0012] In addition, in a tablet terminal, not only sensor electrodes but also electrodes for a display device (common electrodes and pixel electrodes, hereinafter collectively referred to as "display electrodes") are arranged on the panel surface. An electrostatic capacitance is also formed between the sensor electrode and the display electrode, so the uplink signal sent from the sensor electrode is detected by the display electrode through the electrostatic capacitance. As a result, sometimes the display content of the display device becomes disordered. Similarly, in other devices arranged near the panel surface, such as speakers, NFC communication devices, CMOS cameras, wireless LAN antennas, etc., there are also cases where the operation is disordered due to the detection of uplink signals at their respective electrodes.

[0013] Therefore, another object of the present invention is to provide a sensor controller capable of preventing an uplink signal from affecting the operation of other devices.

[0014] Solutions to Solve Problems

[0015] The sensor controller of the present invention is a sensor controller connected to a sensor electrode group constituting a surface, wherein a prescribed AC signal is supplied to one or more AC signal sending electrodes constituted by at least a part of a plurality of sensor electrodes constituting the sensor electrode group, and a cancel signal is sent from a cancel signal sending electrode different from the AC signal sending electrode to suppress the signal sent from the AC signal sending electrode from appearing at the ground end of the detection circuit of the stylus.

[0016] Furthermore, a sensor controller according to another aspect of the present invention is the sensor controller described above, wherein the cancel signal is an inverted signal of the AC signal.

[0017] Effects of the Invention

[0018] According to the present invention, it is possible to prevent a predetermined AC signal (uplink signal) from changing the ground potential of the stylus pen, thereby preventing the stylus pen from being unable to detect the uplink signal.

[0019] According to another aspect of the present invention, it is possible to prevent an AC signal (uplink signal) from appearing on electrodes of other devices such as a display device, thereby preventing the uplink signal from affecting the operation of other devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a diagram showing a usage state of the tablet terminal 1 and the stylus pen 2 according to the first embodiment of the present invention.

[0021] Figure 2 It is shown Figure 1 The diagram shows the internal structure of the tablet terminal 1 and the equivalent circuit of the tablet terminal 1 and the stylus pen 2 .

[0022] Figure 3 It is shown Figure 2 The diagram shows the internal structure of the sensor electrode group 12 and the sensor controller 13.

[0023] Figure 4 It is a diagram showing the structure of the uplink signal US.

[0024] Figure 5 2 is a diagram showing an example of the waveforms of the uplink signal US and the cancel signal CA.

[0025] Figure 6 It is shown Figure 1 FIG. 2 is a diagram showing the internal structure of the stylus pen 2 .

[0026] Figure 7 yes Figure 2 Flowchart of the processing performed by the sensor controller 13 shown.

[0027] Figure 8 yes Figure 7 Detailed flowchart of pen scanning is shown.

[0028] Fig. 9 yes Figure 8 Detailed flowchart of global scanning is shown.

[0029] Fig.10 It is shown Fig. 9 FIG. 1 is a diagram showing a usage status of the sensor electrode group 12 during a global scan.

[0030] Fig.11 It is shown Figure 8 FIG. 1 is a diagram showing a usage status of the sensor electrode group 12 in sector scanning.

[0031] Fig.12 4 is a flowchart of the process performed by the stylus pen 2 .

[0032] Fig.13 It is a diagram showing a modified example of the use of the sensor electrode group 12 in the global scan.

[0033] Fig.14 FIG. 1 is a diagram showing a use status of the sensor electrode group 12 in a global scan performed when the sensor electrode group 12 is of a self-capacitive type.

[0034] Fig.15 This is a detailed flowchart of the global scan according to the second embodiment of the present invention.

[0035] Fig.16 It is a diagram showing the internal structure of the sensor electrode group 12 and the sensor controller 13 according to the third embodiment of the present invention.

[0036] Fig.17 It is a diagram showing the internal structure of the sensor electrode group 12 and the sensor controller 13 according to the fourth embodiment of the present invention.

[0037] Fig.18 It is shown Fig.17 A sequence diagram of the processing of the logic unit 51 is shown. DETAILED DESCRIPTION

[0038] Below, while referring to the attached Figure 1 Embodiments of the present invention will be described in detail.

[0039] Figure 1 1 is a diagram showing a usage state of the tablet terminal 1 and the stylus pen 2 according to the first embodiment of the present invention. Figure 2 It is shown Figure 1 The internal structure of the tablet terminal 1 and the equivalent circuit diagram of the tablet terminal 1 and the stylus pen 2 are shown. Figure 1 The outline of the present invention will be described below.

[0040] like Figure 2 As shown, the tablet terminal 1 includes a host processor 10, a display device 11, a sensor electrode group 12, and a sensor controller 13. The host processor 10 is a processor that controls the entire tablet terminal 1. The operations of various components in the tablet terminal 1 described below are executed under the control of the host processor 10.

[0041] The display device 11 is a display that can display arbitrary information according to the control of the host processor 10. Various displays such as a liquid crystal display, an organic EL display, and an electronic paper can be used as the display device 11. Although not shown in the figure, the display device 11 is configured to have the above-mentioned display electrodes (common electrodes and pixel electrodes). The common electrode among the display electrodes is an electrode for supplying a common potential Vcom to each pixel, and is distributed throughout the display device 11. Figure 1The entire panel surface 1a shown is provided.

[0042] The sensor electrode group 12 is composed of a plurality of transparent conductors (described later) arranged on the display surface of the display device 11. Figure 3 The sensor electrode group 12 is also provided over the entire panel surface 1a, thereby being able to detect the position of a pointer such as the stylus pen 2 or a user's finger over the entire panel surface 1a.

[0043] The sensor controller 13 is a device that uses the sensor electrode group 12 to detect the position of the stylus pen 2 or a user's finger or other indicator within the panel surface 1a and receives data sent by the stylus pen 2. The sensor controller 13 is configured to output the detected position and the data received from the stylus pen 2 to the host processor 10.

[0044] If the part of the processing of the sensor controller 13 related to the stylus pen 2 is briefly described, the sensor controller 13 uses the sensor electrode group 12 as an antenna. Figure 1 As shown, the uplink signal US is sent to the stylus pen 2 and the pen signal DS is received from the stylus pen 2. Here, the pen signal DS is a signal sent by the stylus pen 2 in response to the uplink signal US, and is composed of a pulse train signal, which is a non-modulated carrier signal, and a data signal, which is a carrier signal modulated by the data to be sent indicated by the command COM (described later) included in the uplink signal US. The sensor controller 13 is configured to calculate the position of the stylus pen 2 based on the receiving position of the received pulse train signal, and receive the data sent by the stylus pen 2 by decrypting the received data signal.

[0045] like Figure 2 As shown, the various components in the tablet terminal 1, the stylus pen 2, and the user's body 3 holding the stylus pen 2 are electrically connected to each other via electrostatic coupling. Specifically, first, the stylus pen 2 is electrically connected to the stylus pen 2 via the electrostatic capacitance C shown in the figure at the tip electrode. pen_tip The sensor electrode group 12 is electrically connected to the housing via the electrostatic capacitor C pen_GND The sensor electrode group 12 is electrically connected to the human body 3. In addition to the stylus pen 2, the sensor electrode group 12 is also connected to the human body 3 through the electrostatic capacitor C shown in the figure. display The sensor electrode group 12 is electrically connected to the display electrode in the display device 11. When a part of the human body 3 (typically a hand) is in contact with or close to the panel surface 1a, the sensor electrode group 12 is electrically connected to the display electrode in the display device 11. palm And it is also electrically connected to the human body 3.

[0046] In addition, the human body 3 is connected to the electrostatic capacitor C human_GNDThe sensor controller 13 and the display device 11 are connected to the ground via the electrostatic capacitance C generated between the ground end of the housing and the earth. system_GND And common ground.

[0047] like Figure 1 As shown, a detection unit 41 (detection circuit) having a function of detecting the uplink signal US is provided inside the stylus pen 2. The details of the detection unit 41 will be referred to later. Figure 6 The input end of the detection unit 41 is connected to the pen tip electrode through the wiring in the stylus pen 2, so the electrostatic capacitance C pen_tip The sensor electrode group 12 is electrically connected to the ground terminal of the detection unit 41. In addition, the ground terminal of the detection unit 41 is connected to the housing of the stylus pen 2. Therefore, the static capacitance C pen_GND , C human_GND And grounded.

[0048] The uplink signal US sent from the sensor electrode group 12 is transmitted via the electrostatic capacitor C pen_tip and the pen tip electrode and transmitted to the detection unit 41. Static capacitance C pen_tip The uplink signal US is formed not only when the tip of the stylus pen 2 is in contact with the panel surface 1a, but also when they are separated to some extent. Therefore, the stylus pen 2 can receive the uplink signal US even when the tip of the stylus pen 2 is separated from the panel surface 1a (hovering state). Taking advantage of this, the sensor controller 13 is configured to detect the stylus pen 2 before the stylus pen 2 is in contact with the panel surface 1a. Figure 1 The position P shown indicates the position of the stylus pen 2 in the hovering state thus detected.

[0049] Here, if Figure 1 As shown in the example, the user may hold the stylus pen 2 in one hand (in Figure 1 The right hand is in the middle and the other hand (in Figure 1 The touch pen 2 is placed on the panel surface 1a to input to the tablet terminal 1. Figure 1 In the example of , the area Palm shown in the figure represents the contact portion between the left hand and the panel surface 1a. In this case, not only the pen tip electrode of the stylus pen 2 but also the other hand placed on the panel surface 1a receives the uplink signal US. Figure 1 In order to distinguish the uplink signal US detected by the pen tip electrode from the uplink signal US, the uplink signal US is recorded as the uplink signal USa. Figure 1 As shown, the uplink signal USa passes through the human body 3 and the static capacitor C pen_GNDThe uplink signal USa is supplied to the ground terminal of the detection unit 41. As a result, the uplink signal US is supplied to both the input terminal and the ground terminal, and it is difficult for the detection unit 41 to detect the uplink signal USa. The same phenomenon may occur not only when the other hand is placed on the panel surface 1a, but also when the hand holding the stylus pen 2 is in contact with or close to the panel surface 1a, because the uplink signal USa is received by the hand.

[0050] In addition, the uplink signal US sent from the sensor electrode group 12 is not only detected by the stylus pen 2, but also transmitted through the Figure 2 The static capacitance C shown display The signal is detected by the display electrodes in the display device 11. This causes the potential of the display electrodes to fluctuate, causing disturbances in the display content of the display device 11. In particular, the common electrode is provided over the entire panel surface 1a as described above, and is therefore greatly affected by the uplink signal US.

[0051] The purpose of this embodiment is to solve these problems. Specifically, it is to prevent the stylus pen 2 from being unable to detect the uplink signal US due to the change in the potential of the ground end of the stylus pen 2 caused by the uplink signal US, and to prevent the uplink signal US from affecting the operation of the display device 11. The structure for achieving this purpose is described in detail below.

[0052] Figure 3 1 is a diagram showing the internal structure of the sensor electrode group 12 and the sensor controller 13 .

[0053] The sensor electrode group 12 constitutes a mutual capacitance type touch sensor, and has a structure in which a plurality of sensor electrodes 12X (second sensor electrodes) are transparent conductors extending in the Y direction (first direction) and arranged at equal intervals in the X direction (second direction) orthogonal to the Y direction, and a plurality of sensor electrodes 12Y (first sensor electrodes) are transparent conductors extending in the X direction and arranged at equal intervals in the Y direction, respectively. It should be noted that an example in which the sensor electrodes 12X and 12Y are both composed of linear conductors is shown here, but the sensor electrode group 12 can also be composed of conductors of other shapes. For example, the sensor electrode group 12 can also be composed of a plurality of rectangular conductors arranged in two dimensions in a manner that can detect the two-dimensional coordinates of the stylus 2 (see the later described structure). Fig.14 ).

[0054] One of the sensor electrodes 12X and 12Y can also be used as a common electrode in the display device 11. The type of tablet terminal 1 that uses one of the sensor electrodes 12X and 12Y as a common electrode in the display device 11 is called, for example, an "in-cell type". On the other hand, the type of tablet terminal 1 that separately provides the sensor electrodes 12X and 12Y and the common electrode in the display device 11 is called, for example, an "out-cell type" or an "on-cell type". Hereinafter, the tablet terminal 1 will be described as an in-cell type, but the present invention can be similarly applied to an out-cell type or an on-cell type tablet terminal. In addition, the following description will be described as using the sensor electrode 12X as a common electrode, but the sensor electrode 12Y can also be used as a common electrode.

[0055] When the display device 11 performs pixel driving processing, it is necessary to maintain the potential of the common electrode at a specified value (specifically, the common potential Vcom mentioned above). Therefore, in the embedded tablet terminal 1, during the period when the display device 11 performs pixel driving processing, the sensor controller 13 cannot communicate with the stylus 2 or detect the finger. Therefore, the host processor 10 uses the horizontal loop interval and the vertical loop interval in which the pixel driving processing is not performed to make the sensor controller 13 perform communication with the stylus 2 and detect the finger. Specifically, the horizontal loop interval and the vertical loop interval are regarded as time slots, and the sensor controller 13 is controlled in such a way that communication with the stylus 2 and detection of the finger are performed within the time slot.

[0056] like Figure 3 As shown, the sensor controller 13 is configured to include an MCU 50 , a logic unit 51 , transmission units 52 , 53 , a reception unit 54 , and a selection unit 55 .

[0057] MCU50 and logic unit 51 are control units that control the sending and receiving actions of sensor controller 13 by controlling sending units 52, 53, receiving unit 54, and selecting unit 55. Specifically, MCU50 is a microprocessor that has ROM and RAM inside and operates by executing programs stored in them. MCU50 also has a function of outputting a common potential Vcom and a command COM indicating a command to the stylus pen 2. On the other hand, logic unit 51 is configured to output control signals ctrl_t1 to ctrl_t5, ctrl_r, sTRx, sTRy, selX, and selY based on the control of MCU50.

[0058] The transmitting unit 52 is a circuit that generates a finger detection signal FDS used for detecting a finger according to the control of the MCU 50. As will be described in detail later, in this embodiment, in addition to the user's fingers, the user's hand (palm) also becomes the object of detection of the finger detection signal FDS. The finger detection signal FDS can be, for example, a non-modulated pulse train signal or a sine wave signal.

[0059] The transmission unit 53 is a circuit that generates an uplink signal US and a cancel signal CA according to the control of the MCU 50 and the logic unit 51. The details of the uplink signal US and the cancel signal CA will be described later, but the outline is described here. The uplink signal US of this embodiment is a signal that includes a preamble PRE for the stylus pen 2 to detect the uplink signal US in addition to the above-mentioned command COM. In addition, the cancel signal CA is a signal that suppresses the uplink signal US in the detection unit 41 (refer to Figure 1 ) appears at the ground terminal, for example, an inverted signal of the uplink signal US.

[0060] like Figure 3 As shown, the transmission unit 53 includes a preamble supply unit 61, a switch 62, a code string holding unit 63, an extension processing unit 64, a transmission protection unit 65, and a cancel signal generating unit 66. It should be noted that the preamble supply unit 61 may also be included in the MCU 50.

[0061] The preamble supply unit 61 holds the preamble PRE and has a function of outputting the preamble PRE in accordance with the instruction of the control signal ctrl_t1 supplied from the logic unit 51. The preamble PRE output by the preamble supply unit 61 is supplied to the switch 62. The switch 62 is also supplied with a command COM from the MCU 50.

[0062] Figure 4 is a diagram showing the structure of the uplink signal US. As shown in the figure, the uplink signal US is configured to have a structure in which a preamble PRE is configured at the beginning and a command COM (data part) is configured next. In order to enable detection of the stylus 2, the content of the preamble PRE is known in advance to the stylus 2. On the other hand, as described above, the command COM is data representing a command to the stylus 2. As the content of the command based on the command COM, specifically, for example, there can be cited the sending of pen pressure data representing the pressure applied to the pen tip, the sending of data representing the pressed state of a switch (not shown) provided on the surface of the stylus 2, the sending of the stylus ID pre-stored in the stylus 2, and the like.

[0063] The preamble PRE and the command COM are respectively composed of a combination of the values ​​of multiple symbols. A symbol is a unit of information corresponding to one extension code, including symbols corresponding to a bit string and symbols not corresponding to a bit string. The former symbol is composed of, for example, any one of 16 symbols corresponding to different extension codes, and these 16 symbols correspond to 4-bit bit strings of "0000" to "1111", respectively. Hereinafter, such symbols are collectively referred to as symbols D. In addition, the latter symbol is composed of any one of two symbols corresponding to mutually inverted extension codes. Hereinafter, these two symbols are respectively referred to as symbols P and symbols M. In Figure 4 In the example, the preamble PRE is composed of two consecutive symbols P, and the command COM is composed of four consecutive symbols D (that is, 16-bit data). The following description will be continued based on this premise.

[0064] return Figure 3 The switch 62 has a function of selecting either the preamble supply unit 61 or the MCU 50 according to the control signal ctrl_t2 supplied from the logic unit 51 and supplying the output of the selected one to the extension processing unit 64. When the switch 62 selects the preamble supply unit 61, the preamble PRE is supplied to the extension processing unit 64. On the other hand, when the switch 62 selects the MCU 50, the command COM is supplied to the extension processing unit 64.

[0065] The code string holding unit 63 has a function of generating and holding a spreading code having an autocorrelation characteristic, for example, of 11 chips in length, based on the control signal ctrl_t3 supplied from the logic unit 51. The spreading code held by the code string holding unit 63 is supplied to the spreading processing unit 64.

[0066] The spreading processing unit 64 has a function of modulating the spreading code held by the code string holding unit 63 based on the value of the symbol supplied via the switch 62. This modulation is performed by, for example, a cyclic shift as described in Patent Document 1, and in this case, as a result of the modulation, a spreading code of 12 chips is output for each symbol.

[0067] The spread code output from the spread processing unit 64 is sequentially supplied to the transmission protection unit 65 and the cancel signal generating unit 66. The transmission protection unit 65 plays a role of inserting a period in which neither transmission nor reception is performed, i.e., a protection period, between the transmission period of the uplink signal US and the period in which the receiving unit 54 described later performs a reception operation based on the control signal ctrl_t5 supplied from the logic unit 51.

[0068] The cancel signal generating unit 66 is a functional unit that generates the cancel signal CA based on the extension code output from the extension processing unit 64. The cancel signal generating unit 66 is configured to output the cancel signal CA based on the control signal ctrl_t4 supplied from the logic unit 51. More specifically, the cancel signal CA is output only during the period in which the control signal ctrl_t4 indicates output.

[0069] Figure 5 : is a diagram showing an example of the waveform of the uplink signal US and the cancel signal CA. As shown in the figure, the uplink signal US after extension coding becomes an AC signal of a rectangular wave that takes a high or low value. The cancel signal CA is a signal that amplifies the potential difference between the potential generated at the input end (or the direction of change) of the detection unit 41 (on the pen tip electrode side) of the stylus 2 and the potential generated at the ground end of the detection unit 41 (or the direction of change) compared with the uplink signal US. The signal that amplifies the potential difference compared with the uplink signal US is typically as follows: Figure 5 However, depending on the specific structure of the transmitting circuit of the tablet terminal 1 and the receiving circuit of the stylus pen 2, the received signal of the stylus pen 2 may become a differential signal or an integral signal of the uplink signal US. In this case, Figure 5 As shown, it is preferable to make the cancellation signal CA a differential signal or an integral signal of the inverted signal of the uplink signal US. In addition, since it is sufficient to generate a potential difference between the input end and the ground end of the detection unit 41 of the stylus 2 compared with the case where the uplink signal US is sent to all electrodes, it is also possible to send a predetermined AC signal in the uplink signal US and use a signal of a predetermined potential (for example, a ground potential) as the cancellation signal.

[0070] return Figure 3 The receiving unit 54 is a circuit for receiving the pen signal DS sent by the stylus pen 2 or the finger detection signal FDS sent by the transmitting unit 52 based on the control signal ctrl_r of the logic unit 51. Specifically, it includes an amplifier circuit 70, a detector circuit 71 and an analog-to-digital (AD) converter 72.

[0071] The amplifier circuit 70 amplifies and outputs the pen signal DS or the finger detection signal FDS supplied from the selection unit 55. The detector circuit 71 is a circuit that generates a voltage corresponding to the level of the output signal of the amplifier circuit 70. The AD converter 72 is a circuit that generates a digital signal by sampling the voltage output from the detector circuit 71 at a predetermined time interval. The digital signal output by the AD converter 72 is supplied to the MCU 50. Based on the digital signal supplied in this way, the MCU 50 detects the position of the stylus pen 2 or the finger (and palm) and obtains the data Res sent by the stylus pen 2. The MCU 50 outputs the coordinates x, y representing the detected position and the obtained data Res to the host processor 10 one by one.

[0072] The selection unit 55 is configured to include switches 68x and 68y and conductor selection circuits 69x and 69y.

[0073] The switch 68y is a switch element configured such that a common terminal is connected to either the T terminal or the R terminal. The common terminal of the switch 68y is connected to the conductor selection circuit 69y, the T terminal is connected to the output end of the transmission unit 53, and the R terminal is connected to the input end of the receiving unit 54. In addition, the switch 68x is a switch element configured such that a common terminal is connected to any one of the T1 terminal, the T2 terminal, the D terminal, and the R terminal. The common terminal of the switch 68x is connected to the conductor selection circuit 69x, the T1 terminal is connected to the output end of the transmission unit 53, the T2 terminal is connected to the output end of the transmission unit 52, the D terminal is connected to the output end of the MCU 50 that outputs the common potential Vcom, and the R terminal is connected to the input end of the receiving unit 54.

[0074] The conductor selection circuit 69x is a switch element for selectively connecting the plurality of sensor electrodes 12X to the common terminal of the switch 68x. The conductor selection circuit 69x is configured to simultaneously connect a part or all of the plurality of sensor electrodes 12X to the common terminal of the switch 68x.

[0075] The conductor selection circuit 69y is a switch element for selectively connecting the plurality of sensor electrodes 12Y to the common terminal of the switch 68y or the output end of the cancel signal CA of the transmission unit 53. The conductor selection circuit 69y is configured to simultaneously connect a part or all of the plurality of sensor electrodes 12Y to the common terminal of the switch 68y or the output end of the cancel signal CA of the transmission unit 53. It should be noted that the control of the logic unit 51 described later prevents one sensor electrode 12Y from being simultaneously connected to both the common terminal of the switch 68y and the output end of the cancel signal CA of the transmission unit 53.

[0076] The selection unit 55 is supplied with four control signals sTRx, sTRy, selX, and selY from the logic unit 51. Specifically, the control signal sTRx is supplied to the switch 68x, the control signal sTRy is supplied to the switch 68y, the control signal selX is supplied to the conductor selection circuit 69x, and the control signal selY is supplied to the conductor selection circuit 69y. The logic unit 51 controls the selection unit 55 using these control signals sTRx, sTRy, selX, and selY to realize the transmission of the uplink signal US or the finger detection signal FDS, the application of the common potential Vcom, and the reception of the pen signal DS or the finger detection signal FDS. In addition, the logic unit 51 also realizes the transmission of the cancel signal CA by further controlling the operation of the cancel signal generation unit 66 using the control signal ctrl_t4.

[0077] The following describes in detail the control contents of the logic unit 51 over the selection unit 55 and the cancel signal generation unit 66 and the actions of the MCU 50 that receives the control contents, including when the finger and palm detection is performed, when the pixel driving action is performed, when the uplink signal US and the cancel signal CA are sent, and when the pen signal DS is received.

[0078] First, the logic unit 51 controls the switch 68x in the detection of fingers and palms so that the T2 terminal is connected to the common terminal, and controls the switch 68y in the connection of the R terminal to the common terminal. Furthermore, the conductor selection circuits 69x and 69y are controlled so that the combination of the plurality of sensor electrodes 12X and 12Y is selected in sequence. In this way, the finger detection signals FDS of each of the plurality of intersections formed by the plurality of sensor electrodes 12X and 12Y are received in sequence by the receiving unit 54. Hereinafter, this control is referred to as "touch scanning". The MCU50 detects the positions of the fingers and palms on the panel surface 1a based on the receiving intensity of the finger detection signals FDS received in sequence by touch scanning. More specifically, the MCU50 calculates the area of ​​the region formed by the continuous intersections where the receiving intensity of the finger detection signal FDS is greater than a specified value, detects the position of the finger when the obtained area is less than the specified value, and detects the position of the palm when it is not. It should be noted that the position of the palm is not represented by a point, but by an extended area.

[0079] Next, the logic unit 51 controls the switch 68x so that the D terminal is connected to the common terminal when the pixel driving operation is executed, and controls the conductor selection circuit 69x so that all of the plurality of sensor electrodes 12X are simultaneously connected to the switch 68x. Thus, the common potential Vcom is supplied from the MCU 50 to each sensor electrode 12X, so that the display device 11 can execute the pixel driving operation. It should be noted that the MCU 50 causes the logic unit 51 to execute the above control at a timing based on a timing signal supplied from the host processor 10.

[0080] Next, the logic unit 51 controls the switch 68x so that the R terminal is connected to the common terminal, and controls the switch 68y so that the T terminal is connected to the common terminal when the uplink signal US and the cancel signal CA are transmitted. Thus, the uplink signal US output from the transmission unit 53 is supplied to the conductor selection circuit 69y. The logic unit 51 further causes the conductor selection circuit 69y to sequentially connect the sensor electrodes 12Y to the common terminal of the switch 68y in a predetermined number of ways each time. Thus, the uplink signal US is transmitted from the predetermined number of sensor electrodes 12Y connected to the common terminal of the switch 68y, and finally the uplink signal US is transmitted from all the sensor electrodes 12Y.

[0081] The logic unit 51 also performs processing to send the cancel signal CA simultaneously with the sending of the uplink signal US. Specifically, at the timing of sending the uplink signal US, the cancel signal generating unit 66 is controlled to output the cancel signal, and the conductor selection circuit 69y is controlled to connect a specified number of sensor electrodes 12Y to the output end of the cancel signal CA of the sending unit 53. However, the logic unit 51 controls the conductor selection circuit 69y in such a way that the sensor electrode 12Y connected to the common terminal of the switch 68y is not connected to the output end of the cancel signal CA of the sending unit 53. Thus, the sending of the cancel signal CA is achieved simultaneously with the sending of the uplink signal US. This will be discussed later with reference to the processing flow. Figure 1 Explain in more detail.

[0082] Finally, the logic unit 51 controls the switches 68x and 68y respectively in such a way that the R terminal is connected to the common terminal when receiving the pen signal DS. The control method of the conductor selection circuits 69x and 69y is different when the position of the stylus pen 2 is detected and when the data signal sent by the stylus pen 2 is received. The former will be described later. Figure 8 In the latter case, the logic unit 51 controls the conductor selection circuits 69x and 69y so that only a predetermined number (e.g., 1) of the plurality of sensor electrodes 12X and 12Y that are located around the most recently detected position are selected. The data signals received by the selected predetermined number of sensor electrodes are supplied to the MCU 50 via the receiving unit 54. The MCU 50 obtains the above-mentioned data Res by demodulating and decrypting the data signals supplied in this way.

[0083] Figure 6 2 is a diagram showing the internal structure of the stylus pen 2. As shown in the figure, the stylus pen 2 includes an electrode 21, a switch 22, a writing pressure detection sensor 23, and a signal processing unit 24.

[0084] The electrode 21 is a conductive member constituting the pen tip of the stylus pen 2. The electrode 21 functions as an antenna for transmitting the pen signal DS, and also functions as an antenna for receiving the uplink signal US transmitted from the sensor controller 13 via the sensor electrode group 12. It should be noted that the member constituting the pen tip may be provided independently of the electrode 21. In addition, the electrode for transmitting the pen signal DS and the electrode for receiving the uplink signal US may be provided separately.

[0085] The switch 22 is a switch that can be turned on or off by a user's operation, such as a side switch provided on the side of the stylus pen 2 or a tail switch provided at the rear end. The pen pressure detection sensor 23 is a pressure sensor for detecting the pressure (pen pressure) applied to the tip of the stylus pen 2. Specifically, the pen pressure detection sensor 23 can be configured using a known technology such as a variable capacitance capacitor whose electrostatic capacitance changes according to pressure or a pressure sensor whose resistance value changes according to pressure.

[0086] The signal processing unit 24 has the following functions: receiving the uplink signal US from the sensor controller 13 via the electrode 21, performing processing corresponding to the content thereof, and generating a pen signal DS to be sent to the sensor controller 13, and sending the pen signal DS to the sensor controller 13 via the electrode 21. Specifically, the function is constituted to include a switching unit 40, a detection unit 41, a control unit 44, and a sending unit 46. Hereinafter, each of them will be described in turn.

[0087] The switch unit 40 is a switch element having a 1-circuit 2-contact structure in which a common terminal is connected to either a T terminal or an R terminal. The common terminal of the switch unit 40 is connected to the electrode 21, the T terminal is connected to the output terminal of the transmitter 46, and the R terminal is connected to the input terminal of the detector 41. The state of the switch unit 40 is controlled by a control signal SWC from the control unit 44. When receiving the uplink signal US from the sensor controller 13, the control unit 44 controls the switch unit 40 by using the control signal SWC so that the R terminal is connected to the common terminal. In addition, when sending the pen signal DS to the sensor controller 13, the switch unit 40 is controlled by using the control signal SWC so that the T terminal is connected to the common terminal.

[0088] The detection unit 41 is a circuit that detects the signal supplied from the switching unit 40 (the signal that reaches the electrode 21) and decodes the code string contained in the detected signal, and in this example, is configured to include a waveform regeneration unit 42 and a correlation operator 43. The detection unit 41 is configured to be able to detect each of the above-mentioned preamble PRE and the command COM through the decoding.

[0089] The waveform regeneration unit 42 converts the level of the charge (voltage) induced at the electrode 21 into a binary value at a clock that is several times (e.g., 4 times) the chip rate of the spreading code used when the sensor controller 13 spreads the uplink signal US, and forms a binary string (chip string) of positive and negative polarity values ​​and outputs it. The correlation operator 43 stores the chip string output by the waveform regeneration unit 42 in a register, and performs correlation operations with each of the multiple spreading codes that the sensor controller 13 may send while sequentially shifting using the above clock, thereby decoding the chip string included in the received signal. As a result of this decoding, any of the above symbols P, M, and 16 types of symbols D is obtained.

[0090] The detection unit 41 successively performs the detection operation of the preamble code PRE based on the decoding result of the correlation operator 43. This detection operation is specifically an operation of determining whether two consecutive symbols P are obtained. In addition, the detection unit 41 also determines whether two consecutive symbols M are detected while making this determination. When the result of any one of these determinations becomes positive, the detection unit 41 detects the presence of the sensor controller 13 and issues a start signal EN for starting the control unit 44 to the control unit 44.

[0091] The detection unit 41 that has issued the start signal EN then performs the detection operation of the command COM. Specifically, a series of symbols D obtained in sequence through decoding are demodulated into a bit string one by one, and finally a 16-bit bit string is obtained and output to the control unit 44. In this case, the detection unit 41 demodulates the command COM with reference to the previously received preamble PRE. Specifically, when two consecutive symbols M are detected in the reception operation of the preamble PRE, the code chip string output from the waveform regeneration unit 42 is inverted and supplied to the correlation operator 43. In this way, the uplink signal US can be correctly received even if the uplink signal US is inverted, and when the cancellation signal CA (for example, the inverted signal of the uplink signal US) is received, it can be received as the uplink signal US.

[0092] The control unit 44 is composed of a microprocessor (MCU), and is started when a start signal EN is supplied from the detection unit 41. After being started, the control unit 44 performs the action indicated by the command COM supplied from the detection unit 41. This action includes the process of causing the transmission unit 46 to send the pen signal DS. Specifically, the control unit 44 causes the transmission unit 46 to send a pulse train signal by causing the transmission unit 46 to send a non-modulated carrier signal. In addition, the data instructed to be sent by the command COM is obtained, and the data is supplied to the transmission unit 46 to cause the transmission unit 46 to send a data signal. As a result, the pen signal DS sent from the transmission unit 46 becomes a signal including the data instructed to be sent by the command COM.

[0093] The transmission unit 46 is a circuit that generates the pen signal DS under the control of the control unit 44 and supplies the pen signal DS to the electrode 21 , and is composed of a modulation unit 47 and a booster circuit 48 .

[0094] The modulator 47 is a circuit that generates a carrier signal (e.g., a rectangular wave signal) of a specified frequency or a frequency controlled by the controller 44, and directly outputs the carrier signal or modulates the carrier signal before outputting it based on the control of the controller 44. When a pulse train signal is transmitted, the modulator 47 directly outputs the carrier signal without modulating it according to the instruction of the controller 44. It should be noted that a signal modulated using a pattern of known values ​​may also be used as a pulse train signal. In this case, the modulator 47 modulates the carrier signal using the pattern of the known values ​​and then outputs it. On the other hand, when a data signal is transmitted, the modulator 47 modulates the carrier signal (OOK, PSK, etc.) using the data supplied from the controller 44, and outputs the modulated signal obtained as a result.

[0095] The booster circuit 48 is a circuit that generates a pen signal DS by boosting the output signal of the modulator 47 to a certain amplitude. The pen signal DS generated by the booster circuit 48 is sent from the electrode 21 to the space via the switch 40 .

[0096] Next, regarding the transmission of the uplink signal US and the cancel signal CA in this embodiment, referring to the processing flow of the sensor controller 13, Figure 1 Explain in detail.

[0097] Figure 7 2 is a flowchart of the processing performed by the sensor controller 13. In this figure, only the processing related to the position detection of the finger, the palm, and the stylus pen 2 is shown.

[0098] like Figure 7 As shown, the sensor controller 13 first performs touch scanning for detecting fingers and palms (step S1), and detects the positions of fingers and palms on the panel surface 1a based on the results (step S2). The specific contents of these processes are as described above.

[0099] Next, the sensor controller 13 substitutes 1 into the variable m (step S3), and then performs pen scanning (step S4). The pen scanning is a process for detecting the stylus pen 2, which will be referred to later. Figure 8 Let me explain in detail.

[0100] After the pen scan is completed, the sensor controller 13 adds 1 to the variable m (step S5), and determines whether the variable m exceeds 4. If it is determined that it has not exceeded, the process returns to step S4 and performs pen scan again. On the other hand, if it is determined that it has exceeded, the process returns to step S1 and performs touch scan.

[0101] According to the above processing, the sensor controller 13 repeatedly performs these processings by performing a step of performing four pen scans after performing one touch scan. It should be noted that this step is only an example, and other steps (for example, a step of performing one pen scan after performing one touch scan) can also be used to repeatedly perform these processings. Figure 7 Although not shown in the figure, when the stylus pen 2 is detected by the execution of pen scanning, the actual sensor controller 13 performs a data signal receiving operation to obtain the data sent by the stylus pen 2.

[0102] Figure 8 Detailed flowchart of pen scanning As shown in the figure, the sensor controller 13 first performs a global scan, which is a process for determining the sensor electrodes 12X and 12Y closest to the stylus pen 2 one by one (step S10 ).

[0103] Fig. 9 It is a detailed flowchart of the global scan. It should be noted that in the following description, it is assumed that the sensor electrode group 12 has 24 sensor electrodes 12Y, and each of them is referred to as the sensor electrode 12Y. n (n is a natural number of 1 to 24.) However, the sensor electrode group 12 may of course include less than 24 sensor electrodes 12Y or 25 or more sensor electrodes 12Y.

[0104] In this global scan, the sensor controller 13 selects a part of the plurality of sensor electrodes 12Y as electrodes for transmitting AC signals, and selects another part of the plurality of sensor electrodes 12Y as electrodes for transmitting cancel signals. Then, the sensor controller 13 is configured to supply an uplink signal US to the electrodes for transmitting AC signals, and to transmit a cancel signal CA from the electrodes for transmitting cancel signals. In addition, the sensor controller 13 is configured to change at least a part of one or more sensor electrodes 12Y selected as electrodes for transmitting AC signals and at least a part of one or more sensor electrodes 12Y selected as electrodes for transmitting cancel signals each time the uplink signal US is transmitted. Next, the following is described. Fig. 9 Let me explain in detail.

[0105] like Fig. 9 As shown, the sensor controller 13 first substitutes 1 into the variable n (step S20), and then substitutes n and n+8 into the variables Y1 and Y2, respectively (step S21). Then, the sensor controller 13 determines whether the variable Y2 is greater than 21 (step S22), and if it is determined to be greater than 21, 16 is subtracted from the variable Y2 (step S23).

[0106] Next, the sensor controller 13 selects eight sensor electrodes 12Y Y1 ~12Y Y1+7As the AC signal transmission electrode, an uplink signal US is transmitted from each of the eight sensor electrodes 12Y. Y2 ~12Y Y2+7 As the cancel signal sending electrode, the cancel signal CA is sent from each electrode (step S24). Figure 3 As described above, the uplink signal US is transmitted to the sensor electrode 12Y under the control of the logic unit 51. Y1 ~12Y Y1+7 and sends the cancel signal CA to the sensor electrode 12Y. Y2 ~12Y Y2+7 ’s respective supplies, thereby executing step S24.

[0107] It should be noted that at this time, the sensor controller 13 does not supply a signal to each sensor electrode 12X. This is to prevent the uplink signal US (or cancel signal CA) sent from the sensor electrode 12Y and the cancel signal CA (or uplink signal US) sent from the sensor electrode 12X from canceling each other.

[0108] The sensor controller 13 that has completed the transmission of the uplink signal US and the cancel signal CA performs a reception operation of the pen signal DS (step S25). Figure 3 As described in detail, after the logic unit 51 controls each of the switches 68x and 68y so that the R terminal is connected to the common terminal, the conductor selection circuits 69x and 69y are controlled by the control signals selX and selY so that one of the plurality of sensor electrodes 12X and 12Y is sequentially selected. Thus, the plurality of sensor electrodes 12X and 12Y are sequentially connected to the input end of the receiving unit 54 one by one, and the receiving unit 54 sequentially supplies the receiving strength of the pen signal DS at each sensor electrode 12X and 12Y to the MCU 50.

[0109] After executing step S25, the sensor controller 13 determines whether the pen signal DS is received as a result of the receiving operation (step S26). If it is determined that the pen signal DS is received, the global scanning process is terminated and the process returns to step S26. Figure 8 On the other hand, if it is determined that it has not been received, 4 is added to the variable n (step S27). Then, it is determined whether the added variable n exceeds 17 (step S28). If it is determined that it has not exceeded, the process returns to step S21 to continue. On the other hand, if it is determined that it has exceeded, the process of global scanning is terminated and the process returns to step S21. Figure 8 processing.

[0110] Fig.10 It is shown Fig. 9FIG. 1 is a diagram showing the use of the sensor electrodes 12X and 12Y in the global scan. The sensor electrodes 12Y shown in the diagram are sensor electrodes 12Y1 to 12Y2 in order from the left side of the diagram. 24 .

[0111] Fig.10 (a) shows a case where the variable n is 1. As shown in the figure, in this case, the uplink signal US is transmitted from each of the sensor electrodes 12Y1 to 12Y8, and the sensor electrodes 12Y9 to 12Y 16 Each of them sends a cancellation signal CA.

[0112] Fig.10 (b) shows a case where the variable n is 5. As shown in the figure, in this case, the sensor electrodes 12Y5 to 12Y 12 Each of them sends an uplink signal US, from the sensor electrode 12Y 13 ~12Y 20 Each of them sends a cancellation signal CA.

[0113] Fig.10 (c) shows a case where the variable n is 9. As shown in the figure, in this case, sensor electrodes 12Y9 to 12Y 16 Each of them sends an uplink signal US, from the sensor electrode 12Y 17 ~12Y 24 Each of them sends a cancellation signal CA.

[0114] Fig.10 (d) shows the case where the variable n is 13. As shown in the figure, in this case, from the sensor electrode 12Y 13 ~12Y 20 Each of the sensor electrodes 12Y5 to 12Y 12 Each of them sends a cancellation signal CA.

[0115] Fig.10 (e) shows a case where the variable n is 17. As shown in the figure, in this case, the sensor electrode 12Y 17 ~12Y 24 Each of the sensor electrodes 12Y9 to 12Y 16 Each of them sends a cancellation signal CA.

[0116] In this way, according to the global scan performed by the sensor controller 13 of this embodiment, the cancel signal CA is transmitted from the sensor electrode group 12 together with the uplink signal US. Figure 1The uplink signal USa shown is replaced with the cancel signal CA, or the uplink signal USa received by another hand (for example, the hand holding the stylus pen 2) can be made into a mixed signal of the cancel signal CA and the uplink signal US, thereby preventing the stylus pen 2 from failing to detect the uplink signal US due to the change in the potential of the ground end of the stylus pen 2 caused by the uplink signal US. In addition, since both the uplink signal US and the cancel signal CA are supplied to the common electrode of the display device 11, they cancel each other, so the uplink signal US can be prevented from affecting the operation of the display device 11.

[0117] In addition, according to the global scan performed by the sensor controller 13 of the present embodiment, the uplink signal US is not sent from the entire panel surface 1a but from each part of the panel surface 1a in sequence. Therefore, the possibility of the hand that does not hold the stylus pen 2 receiving the uplink signal US is reduced, and thus, from this point of view, it is also possible to prevent the stylus pen 2 from being unable to detect the uplink signal US due to the change in the potential of the ground end of the stylus pen 2 caused by the uplink signal US.

[0118] Furthermore, according to the global scanning performed by the sensor controller 13 of this embodiment, since the boundary between the AC signal transmitting electrode and the cancel signal transmitting electrode is not fixed, it is possible to avoid forming an area on the panel surface 1 a where the stylus pen 2 cannot receive the uplink signal US.

[0119] return Figure 8 The sensor controller 13 that has completed the global scan determines whether the pen signal DS (step S11) is received in the receiving operation (step S25) implemented in the global scan. If it is determined that the pen signal DS is not received, the pen scan process is terminated and the process returns to step S25. Figure 7 processing.

[0120] If it is determined in step S11 that the signal is received, the sensor controller 13 performs a sector scan near the position where the pen signal DS is received (step S12). The sector scan is a process for specifically determining the position of the pen signal DS by calculation, and is performed while the stylus pen 2 continues to transmit the pulse train signal in response to the uplink signal US.

[0121] Fig.11 FIG. 1 is a diagram showing the use of the sensor electrodes 12X and 12Y in sector scanning. Figure 3 , while describing in detail the receiving action performed by the sensor controller 13 in the sector scan.

[0122] First, MCU50 selects one sensor electrode close to the stylus pen 2 from each of the plurality of sensor electrodes 12X and 12Y based on the result of the global scan. This selection is performed based on the reception strength of the pen signal DS at each sensor electrode 12X and 12Y supplied from the receiving unit 54 to the MCU50. Next, the logic unit 51 sequentially selects a predetermined number of sensor electrodes 12X and 12Y (in the case of the stylus pen 2) from the sensor electrodes close to the sensor electrodes 12X and 12Y selected by the MCU50. Fig.11 After that, the logic unit 51 controls the switches 68x and 68y so that the R terminal is connected to the common terminal, and then controls the conductor selection circuits 69x and 69y using the control signals selX and selY so that the selected predetermined number of sensor electrodes 12X and 12Y are selected in sequence. Thus, the selected predetermined number of sensor electrodes 12X and 12Y are connected to the input end of the receiving unit 54 one by one, and the receiving unit 54 sequentially supplies the receiving strength of the pen signal DS at each sensor electrode 12X and 12Y to the MCU 50.

[0123] return Figure 8 The sensor controller 13 that has completed the sector scanning determines whether the pen signal DS is received in the receiving operation performed in the sector scanning (step S13). As a result, if it is determined that the pen signal DS is not received, the pen scanning process is terminated and the process returns to step S14. Figure 7 processing.

[0124] If it is determined in step S13 that the touch signal has been received, the sensor controller 13 detects the position of the touch pen 2 (step S14). Figure 3 The MCU 50 shown in FIG. 1 performs calculations (for example, calculations including linear interpolation) based on the reception strengths of the pen signals DS at the sensor electrodes 12X and 12Y supplied from the receiving unit 54. The position of the stylus pen 2 is specifically determined by the processing of step S14. The determined position is transmitted from the sensor controller 13 to the touch screen 2. Figure 3 The host processor 10 is shown supplying.

[0125] Fig.12: is a flowchart showing the processing performed by the stylus pen 2. As shown in the figure, the stylus pen 2 continues to perform the receiving action of the uplink signal US (steps S30, S31) until the uplink signal US is received. As described above, even when the stylus pen 2 receives the cancel signal CA, it can receive it as the uplink signal US. It should be noted that the stylus pen 2 can also be set to intermittently perform the receiving action of the uplink signal US in order to reduce power consumption. And, when the uplink signal US is received, the stylus pen 2 sends a pen signal DS including the above-mentioned pulse train signal and data signal (step S32), and returns to step S30 again to wait for the reception of the uplink signal US.

[0126] As described above, according to the sensor controller 13 of the present embodiment, it is possible to prevent the uplink signal US from changing the ground potential of the stylus pen 2 , thereby preventing the stylus pen 2 from being unable to detect the uplink signal US.

[0127] In addition, since the uplink signal US can be prevented from appearing on the display electrodes (especially the common electrodes) of the display device 11 , it is possible to prevent the uplink signal US from affecting the operation of the display device 11 .

[0128] It should be noted that the use of the sensor electrode 12Y in the global scan is not limited to the reference Fig.10 For example, the sensor controller 13 may select the sensor electrode 12Y used as the AC signal sending electrode and the sensor electrode 12Y used as the cancel signal sending electrode in such a manner that the AC signal sending electrode and the cancel signal sending electrode are alternately arranged a predetermined number of times along the Y direction, and may select the sensor electrode 12Y used as the AC signal sending electrode and the sensor electrode 12Y used as the cancel signal sending electrode in such a manner that the AC signal sending electrode and the cancel signal sending electrode partially overlap and slide along the Y direction each time the uplink signal US is sent.

[0129] Fig.13 FIG. 1 is a diagram showing a modified example of the use of the sensor electrode 12Y in the global scan. In this modified example, first, as shown in FIG. Fig.13 As shown in (a), from sensor electrodes 12Y5 to 12Y8, 12Y 13 ~12Y 16 , 12Y 21 ~12Y 24 Each of the sensor electrodes 12Y1 to 12Y4, 12Y9 to 12Y 12 , 12Y 17 ~12Y 20Each of them sends a cancellation signal CA. Then, Fig.13 As shown in (b), from the sensor electrodes 12Y1 to 12Y2, 12Y7 to 12Y 10 , 12Y 15 ~12Y 18 , 12Y 23 ~12Y 24 Each of the sensor electrodes 12Y3 to 12Y6, 12Y 11 ~12Y 14 , 12Y 19 ~12Y 22 Each of them sends a cancellation signal CA. Finally, Fig.13 As shown in (c), from the sensor electrodes 12Y1 to 12Y4, 12Y9 to 12Y 12 , 12Y 17 ~12Y 20 Each of the sensor electrodes 12Y5 to 12Y8, 12Y 13 ~12Y 16 , 12Y 21 ~12Y 24 Each of them sends a cancellation signal CA.

[0130] In this example, the AC signal transmission electrodes and the cancel signal transmission electrodes are alternately arranged in a predetermined number along the Y direction, and each time the uplink signal US is transmitted, the AC signal transmission electrodes and the cancel signal transmission electrodes partially overlap and slide along the Y direction. Therefore, in addition to being able to obtain the same effect as the present embodiment, since either the uplink signal US or the cancel signal CA is always transmitted from the entire panel surface 1a, the possibility of the stylus pen 2 failing to receive the uplink signal US can be reduced. In addition, since the boundary between the AC signal transmission electrode and the cancel signal transmission electrode is not fixed, it is possible to avoid forming an area on the panel surface 1a where the stylus pen 2 cannot receive the uplink signal US.

[0131] In addition, in this embodiment, the case where the sensor electrode group 12 is a mutual capacitance type (i.e., the case where the stylus 2 and the finger are detected based on the change in capacitance generated between the sensor electrodes 12X and 12Y) is used as an example for explanation, but the present invention can also be applied to the case where the sensor electrode group 12 is a self-capacitance type.

[0132] Fig.14 FIG. 1 is a diagram showing a usage state of the sensor electrodes 12a in a global scan performed when the sensor electrode group 12 is a self-capacitive type. Fig.14As shown, the sensor electrode group 12 in this case has a structure in which a plurality of sensor electrodes 12 a , each of which is a square electrode, are arranged in a matrix.

[0133] Fig.14 The sensor controller 13 of the example is configured to transmit the uplink signal US and the cancel signal CA by treating the 4×4 sensor electrodes 12a as one sensor electrode unit 12U. Fig.14 As shown, the signal transmitted from each sensor electrode 12a is controlled so that different signals are transmitted between adjacent sensor electrode units 12U.

[0134] In addition, the sensor controller 13 controls the signals sent from the sensor electrodes 12a so that the sensor electrode units 12U partially overlap and slide along the Y direction. Fig.14 In (a), for the sensor electrode unit 12U located on the upper left, the sensor controller 13 controls the signal transmitted from each sensor electrode 12a so as to move the sensor electrode unit 12U by two sensor electrodes 12a in the Y direction each time the uplink signal US is transmitted.

[0135] according to Fig.14 In addition to being able to obtain the same effects as in the present embodiment, Fig.13 Similarly, since either the uplink signal US or the cancel signal CA is always transmitted from the entire panel surface 1a, the possibility of failure of the stylus pen 2 in receiving the uplink signal US can be reduced. In addition, since the boundary between the AC signal transmission electrode and the cancel signal transmission electrode is not fixed, it is possible to avoid forming an area on the panel surface 1a where the stylus pen 2 cannot receive the uplink signal US.

[0136] Next, a second embodiment of the present invention is described. This embodiment is different from the first embodiment in that "when the position of the palm is detected by touch scanning performed prior to the execution of the global scan, one or more sensor electrodes 12Y selected as electrodes for sending a cancel signal are determined based on the detected position of the palm." Figure 3 The internal structure of the sensor electrode group 12 and the sensor controller 13 shown in FIG. Figure 6 The other aspects of the internal structure of the stylus pen 2 shown are the same as those of the first embodiment, and therefore the following description will focus on the differences from the first embodiment.

[0137] Fig.15Detailed flowchart of global scanning of the second embodiment of the present invention. As shown in the figure, after starting global scanning, the sensor controller 13 of this embodiment first determines whether a palm is detected (step S40). As a result, if it is determined that a palm is not detected, the processing is transferred to Figure 8 In step S20 shown, a global scan is performed as described in the first embodiment.

[0138] On the other hand, the sensor controller 13 determines that the detected Figure 7 The palm position obtained in step S2 is used to select one or more sensor electrodes 12Y used as the cancel signal sending electrode. Then, after the cancel signal CA is sent from the selected sensor electrode 12Y and the uplink signal US is sent from the other sensor electrodes 12Y (step S41), Figure 8 In step S25 shown, the receiving operation of the pen signal DS is similarly performed (step S42).

[0139] According to this embodiment, it is possible to Figure 1 The possibility of replacing the uplink signal USa with the cancel signal CA is higher than that in the first embodiment. Therefore, it is possible to more reliably prevent the stylus pen 2 from failing to detect the uplink signal US due to a change in the potential of the ground end of the stylus pen 2 caused by the uplink signal US.

[0140] Next, a third embodiment of the present invention will be described. This embodiment is different from the first embodiment in that an electrode different from the plurality of sensor electrodes 12X and 12Y constituting the sensor electrode group 12 is used as the cancel signal transmitting electrode. Figure 6 The other aspects of the internal structure of the stylus pen 2 shown are the same as those of the first embodiment, and therefore the following description will focus on the differences from the first embodiment.

[0141] Fig.16 1 is a diagram showing the internal structure of the sensor electrode group 12 and the sensor controller 13 of the present embodiment. The cancel signal sending electrode 1b shown in the figure is an electrode provided at a position where a user who operates the stylus pen 2 is assumed to touch, for example, provided on the entire or a part of the back side (opposite to the panel surface 1a) of the tablet terminal 1 (for example, a part touched by a hand that is not holding the stylus pen 2 when the stylus pen 2 is operated while the tablet terminal 1 is held).

[0142] In this embodiment, the output end of the cancel signal generating unit 66 is connected to the cancel signal transmitting electrode 1b. Therefore, the sensor controller 13 of this embodiment is configured to transmit the cancel signal CA from the cancel signal transmitting electrode 1b. The transmission timing of the cancel signal CA may be the same as that of the first embodiment.

[0143] According to this embodiment, it is also possible to provide the user's body 3 (see Figure 2 ) provides a cancel signal CA, so as in the first embodiment, it is possible to prevent the stylus pen 2 from being unable to detect the uplink signal US due to the change in the potential of the ground terminal of the stylus pen 2 caused by the uplink signal US. It should be noted that even if it is assumed that the user's hand is in contact with the panel surface 1a and the uplink signal US is supplied to the human body 3 from there, according to this embodiment, since the cancel signal CA is supplied to the human body 3 from other parts of the human body 3, the uplink signal US and the cancel signal CA cancel each other in the human body 3, which can prevent the uplink signal US from being supplied to the ground terminal of the stylus pen 2.

[0144] Next, the fourth embodiment of the present invention is described. This embodiment is the same as the third embodiment in that an electrode different from the plurality of sensor electrodes 12X and 12Y constituting the sensor electrode group 12 is used as the cancel signal transmission electrode, but is different from the third embodiment in that a display electrode is used as the electrode. Other aspects are the same as the third embodiment, so the following description focuses on the differences from the third embodiment.

[0145] Fig.17 1 is a diagram showing the internal structure of the sensor electrode group 12 and the sensor controller 13 of the present embodiment. As shown in the figure, in the present embodiment, the output end of the cancel signal generating unit 66 is connected to the D terminal of the switch 68x.

[0146] The sensor controller 13 of this embodiment uses the control signal sTRx to control the switch 68x so that the common terminal is connected to the D terminal at the timing of sending the uplink signal US. In addition, at this time, the conductor selection circuit 69x is controlled by using the control signal selX so that all or part of the plurality of sensor electrodes 12X are simultaneously connected to the common terminal of the switch 68x. As a result, the uplink signal US and the cancel signal CA are canceled in the sensor electrode 12X serving as the common electrode. Therefore, according to this embodiment, as in the first embodiment, it is possible to prevent the uplink signal US from affecting the operation of the display device 11.

[0147] It should be noted that, since the display device 11 does not perform pixel driving operation when the uplink signal US is transmitted, the common potential Vcom from the MCU 50 and the cancel signal CA from the cancel signal generating unit 66 are not supplied to the sensor electrode 12X at the same time. In addition, according to the present embodiment, although the uplink signal US is difficult to come out of the panel surface 1a, it does not completely not come out, so the sensor controller 13 is not unable to detect the stylus 2. This embodiment is particularly effective when it is desired to reduce the influence on the operation of the display device 11.

[0148] Fig.18 : is a sequence diagram showing the processing of the logic unit 51 of the present embodiment. As shown in the figure, the logic unit 51 of the present embodiment is configured to supply the uplink signal US to each sensor electrode 12Y and supply the cancel signal CA to each sensor electrode 12X. As described above, in the sensor electrode 12X as a common electrode, the cancellation of the uplink signal US and the cancel signal CA is realized.

[0149] It should be noted that in Fig.17 , the example of the case where the tablet terminal 1 is an embedded type is shown, but the present embodiment can also be applied to an embedded or plug-in type tablet terminal. In this case, the output end of the cancel signal generating unit 66 is connected to the common electrode provided in the display device 11. And, the sensor controller 13 causes the cancel signal generating unit 66 to output the cancel signal CA at the timing of sending the uplink signal US. Thus, as in the present embodiment, the uplink signal US and the cancel signal CA can be canceled in the common electrode of the display device 11, and as a result, the uplink signal US can be prevented from affecting the operation of the display device 11.

[0150] Although preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments at all, and the present invention can of course be implemented in various forms within the scope not departing from the gist of the present invention.

[0151] For example, in the first embodiment described above, a part of the plurality of sensor electrodes 12Y is always selected as the electrodes for transmitting AC signals, and another part of the plurality of sensor electrodes 12Y is selected as the electrodes for transmitting cancel signals, but the first mode and the second mode may be switched each time the uplink signal US is transmitted, wherein the first mode is a mode in which a part of the plurality of sensor electrodes 12Y is selected as the electrodes for transmitting AC signals and another part of the plurality of sensor electrodes 12Y is selected as the electrodes for transmitting cancel signals, and the second mode is a mode in which a part of the plurality of sensor electrodes 12X is selected as the electrodes for transmitting AC signals and another part of the plurality of sensor electrodes 12X is selected as the electrodes for transmitting cancel signals. In this way, the possibility of the stylus pen 2 failing to receive the uplink signal US can be further reduced.

[0152] In addition, when the position of the stylus pen 2 is already determined, for example, when the uplink signal US is sent to notify the stylus pen 2 of a new command COM, the cancellation signal CA may not be sent. In this case, the uplink signal US only needs to be sent from some sensor electrodes 12Y located near the position of the stylus pen 2, so the possibility that the stylus pen 2 cannot detect the uplink signal US due to the change in the potential of the ground end of the stylus pen 2 caused by the uplink signal US becomes low. Therefore, it can be said that it is okay not to send the cancellation signal CA.

[0153] In addition, in the above-mentioned embodiments, the display device 11 is cited as a specific example of a device whose action is affected by the uplink signal US, but other types of devices such as speakers, NFC communication devices, CMOS cameras, wireless LAN antennas, etc. may also be affected. According to the above-mentioned embodiments, the influence on these devices can also be prevented.

[0154] In addition, in the above embodiment, the stylus pen 2 is used as an example, but the present invention can be applied to send a signal to the following device, which is held by a hand, has a predetermined electrode and a detection unit 41, and receives the uplink signal US on the sensor. The device is not limited to the shape of a stylus pen, and may also be in the shape of an electronic ruler, a computer mouse, a card, or a controller for VR (Virtual Reality) moving in 3D space.

[0155] In addition, in the above-mentioned embodiment, an example is described in which the uplink signal US is composed of an AC signal (modulated extension code) of a rectangular wave having any value of high or low, but the uplink signal US can be any AC signal. For example, the uplink signal US does not matter whether it is a sine wave or a rectangular wave, and can be modulated or unmodulated.

[0156] Description of symbols

[0157] 1 Tablet terminal

[0158] 1a Panel surface

[0159] 1b Cancel signal sending electrode

[0160] 2 Stylus

[0161] 3 Human body

[0162] 10 Host processor

[0163] 11 Display device

[0164] 12 Sensor electrode groups

[0165] 12U Sensor Electrode Unit

[0166] 12X, 12Y, 12a sensor electrodes

[0167] 13 Sensor Controller

[0168] 21 Electrode

[0169] 22 Switch

[0170] 23 Pen pressure detection sensor

[0171] 24 Signal Processing Unit

[0172] 40 Switching unit

[0173] 41. Inspection Department

[0174] 42 Waveform regeneration unit

[0175] 43 Correlation operator

[0176] 44 Control Department

[0177] 46 Sending Department

[0178] 47 Modulation Department

[0179] 48 Boost Circuit

[0180] 51 Logic Department

[0181] 52, 53 Sending Department

[0182] 54 Receiving Department

[0183] 55 Selection Department

[0184] 61 Preamble code supply unit

[0185] 62 Switch

[0186] 63 Code string holding unit

[0187] 64 Extended Processing Unit

[0188] 65 Send Protection Department

[0189] 66 Cancel signal generation unit

[0190] 68x, 68Y switch

[0191] 69x, 69Y conductor selection circuit

[0192] 70 Amplifier Circuit

[0193] 71 Detection circuit

[0194] 72 Analog-to-digital converter

[0195] COM Instructions

[0196] ctrl_t1~ctrl_t5, ctrl_r, sTRx, sTRy, selX, selY, SWC control signals

[0197] DS pen signal

[0198] EN start signal

[0199] FDS Finger Detection Signal

[0200] PRE Preamble

[0201] US, USa Uplink signal

[0202] Vcom Common potential.

Claims

1. A sensor controller connected to a sensor electrode group constituting a surface, wherein: supplying a predetermined AC signal to one or more AC signal transmitting electrodes formed by at least a part of a plurality of sensor electrodes forming the sensor electrode group, and a cancel signal for suppressing the signal transmitted from the AC signal transmitting electrode from appearing at a ground terminal of a detection circuit provided in the stylus pen, from a cancel signal transmitting electrode different from the AC signal transmitting electrode; selecting a part of the plurality of sensor electrodes as the AC signal transmitting electrodes, and selecting another part of the plurality of sensor electrodes as the cancel signal transmitting electrodes, The plurality of sensor electrodes include a plurality of first sensor electrodes extending in a second direction within the plane and a plurality of second sensor electrodes extending in a first direction within the plane orthogonal to the second direction. selecting a part of the plurality of first sensor electrodes as the AC signal transmitting electrodes, and selecting another part of the plurality of first sensor electrodes as the cancel signal transmitting electrodes, A part of the plurality of first sensor electrodes used as the AC signal sending electrodes and another part of the plurality of first sensor electrodes used as the cancel signal sending electrodes are selected so that the AC signal sending electrodes and the cancel signal sending electrodes are alternately arranged a predetermined number of times along the second direction, A portion of the plurality of first sensor electrodes used as the AC signal sending electrodes and another portion of the plurality of first sensor electrodes used as the cancel signal sending electrodes are selected in such a manner that the AC signal sending electrode and the cancel signal sending electrode partially overlap and slide along the second direction each time the AC signal is sent.

2. The sensor controller according to claim 1, The cancel signal is an inverted signal of the AC signal.

3. The sensor controller according to claim 1, At least a portion of the one or more sensor electrodes selected as the AC signal transmitting electrodes and at least a portion of the one or more sensor electrodes selected as the cancel signal transmitting electrodes are changed every time the AC signal is transmitted.

4. The sensor controller according to claim 1, While the AC signal is supplied to the AC signal transmitting electrode and the cancel signal is transmitted from the cancel signal transmitting electrode, the signal is not supplied to the plurality of second sensor electrodes.

5. The sensor controller according to claim 1, After the AC signal is supplied to the one or more AC signal transmitting electrodes, a receiving operation is performed using the plurality of sensor electrodes.

6. The sensor controller according to claim 5, The AC signal is a signal used to make the stylus pen send a signal. The receiving action is an action for detecting a signal sent by the stylus pen.

7. The sensor controller according to claim 6, The position of the stylus within the plane is determined based on the result of the receiving action.

8. The sensor controller according to claim 7, When the AC signal is sent after the position of the stylus pen is determined, the cancel signal is not sent.

9. The sensor controller according to claim 7 or 8, The plurality of sensor electrodes include a plurality of first sensor electrodes extending in a second direction within the plane and a plurality of second sensor electrodes extending in a first direction within the plane orthogonal to the second direction. After the position of the stylus pen is determined, the receiving operation is performed using a predetermined number of the first sensor electrodes determined based on the position.

10. The sensor controller according to claim 1, The one or more sensor electrodes selected as the cancel signal transmitting electrodes are determined based on the position of the palm obtained by a predetermined calculation.

11. The sensor controller according to claim 10, The palm position is obtained by performing the calculation on the touch detection result.

12. The sensor controller according to claim 1, The AC signal is a signal including a preamble and a data portion.

13. The sensor controller according to claim 12, The detection circuit is configured to demodulate the data portion with reference to the preamble.

14. The sensor controller according to claim 1 or 2, The cancel signal transmitting electrode is an electrode different from any of the plurality of sensor electrodes constituting the sensor electrode group.

15. The sensor controller according to claim 14, The cancel signal transmission electrode is provided at a position where a user operating the stylus pen is expected to touch.

16. A sensor controller connected to a sensor electrode group constituting a surface, wherein: supplying a predetermined AC signal to one or more AC signal transmitting electrodes formed by at least a part of a plurality of sensor electrodes forming the sensor electrode group, and a cancel signal for suppressing the signal transmitted from the AC signal transmitting electrode from appearing at a ground terminal of a detection circuit provided in the stylus pen, from a cancel signal transmitting electrode different from the AC signal transmitting electrode; selecting a part of the plurality of sensor electrodes as the AC signal transmitting electrodes, and selecting another part of the plurality of sensor electrodes as the cancel signal transmitting electrodes, The sensor electrode group includes a plurality of first sensor electrodes extending in a second direction within the plane and a plurality of second sensor electrodes extending in a first direction within the plane orthogonal to the second direction. The first mode and the second mode are switched each time the AC signal is sent, the first mode being a mode in which a part of the plurality of first sensor electrodes is selected as the electrodes for sending the AC signal and another part of the plurality of first sensor electrodes is selected as the electrodes for sending the cancellation signal, and the second mode being a mode in which a part of the plurality of second sensor electrodes is selected as the electrodes for sending the AC signal and another part of the plurality of second sensor electrodes is selected as the electrodes for sending the cancellation signal.

17. A sensor controller connected to a sensor electrode group constituting a surface, wherein: supplying a predetermined AC signal to one or more AC signal transmitting electrodes formed by at least a part of a plurality of sensor electrodes forming the sensor electrode group, and a cancel signal for suppressing the signal transmitted from the AC signal transmitting electrode from appearing at a ground terminal of a detection circuit provided in the stylus pen, from a cancel signal transmitting electrode different from the AC signal transmitting electrode; The cancel signal transmitting electrode is a display electrode arranged to overlap with the sensor electrode group.

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