Sensor controller, method of controlling signal transmission, and electronic device

Abstract

The invention relates to a sensor controller, a method of controlling signal transmission, and an electronic device. The present invention prevents the touch pen (2) from being unable to detect an uplink signal and the uplink signal from affecting the operation of other devices. A sensor controller (13) is connected to a sensor electrode group (12) constituting a surface. A sensor controller (13) supplies a predetermined AC signal to one or more AC signal transmission electrodes comprising at least some of a plurality of sensor electrodes constituting a sensor electrode group (12). A cancel signal is transmitted from a cancel signal transmission electrode that is different from the AC signal transmission electrode, said cancel signal suppressing occurrence of a signal transmitted from the AC signal transmission electrode at a ground terminal of a detection circuit of the stylus (2).

Description

[0001] This application is a divisional application of the application with PCT application number PCT / JP2017 / 040877, international application date November 14, 2017, Chinese application number 201780093248.9, and invention name “Sensor Controller”, which entered the Chinese national phase on January 16, 2020. Technical Field

[0002] 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

[0003] Among tablet terminals that support pen input, some are configured to transmit an uplink signal from a sensor controller that detects the stylus's position to the stylus (see, for example, Patent Document 1). The uplink signal is used to transmit information from the sensor controller to the stylus, and the stylus performs processing such as starting an action and transmitting a pen signal based on this uplink signal.

[0004] The sensor controller detects the stylus by detecting pen signals. However, it is preferable to detect a new stylus before the stylus comes into contact with the panel surface. To this end, the stylus is configured to detect uplink signals even when not in contact with the panel surface (hovering), and transmit pen signals based on uplink signal detection.

[0005] Considering the situation where the stylus approaches the panel surface quickly, it is desirable to enable the stylus to detect the uplink signal from a certain distance away from the panel surface. To this end, attempts have been made to shorten the uplink signal transmission period, increase the uplink signal transmission output, improve the stylus's detection sensitivity, and reduce noise that interferes with the uplink signal.

[0006] Prior art literature

[0007] Patent Literature

[0008] Patent Document 1: International Publication No. 2017 / 029836 Summary of the Invention

[0009] Problems to be solved by the invention

[0010] The stylus detects uplink signals via the electrostatic capacitance formed between the sensor electrode on the panel surface and the tip electrode located at the tip of the stylus. The stylus detects uplink signals by monitoring changes in the tip electrode's potential relative to the ground potential. The ground potential is typically the same as the human body potential, which is where the stylus is located.

[0011] However, this detection method sometimes fails to detect the uplink signal, requiring improvement. Specifically, if a user holds the stylus in their right hand and places their left hand on the panel, the uplink signal will also be detected in their left hand due to the static capacitance formed between the left hand and the sensor electrode. This causes the body's potential (i.e., the stylus's ground potential) to change in the same manner as the uplink signal, canceling out the potential change at the stylus tip electrode. Consequently, the stylus cannot detect the uplink signal.

[0012] Therefore, one object of the present invention is to provide a sensor controller that can prevent the stylus 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.

[0013] Furthermore, in tablet terminals, not only sensor electrodes but also display electrodes (common electrodes and pixel electrodes, hereinafter collectively referred to as "display electrodes") are located on the panel surface. Electrostatic capacitance forms between the sensor electrodes and the display electrodes, so uplink signals transmitted from the sensor electrodes are detected by the display electrodes through this capacitance. As a result, the display content on the display device may become distorted. Similarly, other devices located near the panel surface, such as speakers, NFC communication devices, CMOS cameras, and wireless LAN antennas, may experience operational disturbances due to detection of uplink signals by their respective electrodes.

[0014] Therefore, another object of the present invention is to provide a sensor controller that can prevent an uplink signal from affecting the operation of other devices.

[0015] Solutions to Problems

[0016] 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.

[0017] 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.

[0018] Effects of the Invention

[0019] 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.

[0020] According to another aspect of the present invention, an AC signal (uplink signal) can be prevented 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

[0021] Figure 1 1 and 2 are diagrams showing a usage state of the tablet terminal 1 and the stylus pen 2 according to the first embodiment of the present invention.

[0022] Figure 2 It shows 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.

[0023] Figure 3 It shows Figure 2 The internal structure of the sensor electrode group 12 and the sensor controller 13 is shown.

[0024] Figure 4 3 is a diagram showing the structure of the uplink signal US.

[0025] Figure 5 2 is a diagram showing examples of waveforms of the uplink signal US and the cancel signal CA.

[0026] Figure 6 It shows Figure 1 The internal structure of the stylus pen 2 is shown.

[0027] Figure 7 yes Figure 2 FIG. 1 is a flowchart of a process performed by the sensor controller 13 .

[0028] Figure 8 yes Figure 7 Detailed flowchart of pen scanning is shown.

[0029] Figure 9 yes Figure 8 Detailed flowchart of global scanning is shown.

[0030] Figure 10 It shows Figure 9 FIG. 1 is a diagram showing the usage status of the sensor electrode group 12 during global scanning.

[0031] Figure 11 It shows Figure 8 FIG. 1 is a diagram showing the usage status of the sensor electrode group 12 during sector scanning.

[0032] Figure 12 This is a flowchart of the processing performed by the stylus pen 2.

[0033] Figure 13 It is a diagram showing a modified example of how the sensor electrode group 12 is used in global scanning.

[0034] Figure 14 1 is a diagram showing a usage state of the sensor electrode group 12 during a global scan performed when the sensor electrode group 12 is of a self-capacitive type.

[0035] Figure 15 This is a detailed flowchart of the global scan according to the second embodiment of the present invention.

[0036] Figure 16 1 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.

[0037] Figure 17 1 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.

[0038] Figure 18 It shows Figure 17 A sequence diagram of the processing of the logic unit 51 is shown. DETAILED DESCRIPTION

[0039] Below, with reference to the attached Figure 1 The embodiments of the present invention will be described in detail.

[0040] Figure 1 : is a diagram showing the usage state of the tablet terminal 1 and the stylus pen 2 according to the first embodiment of the present invention. Figure 2 It shows 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.

[0041] 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 controls the entire tablet terminal 1, and the operations of various components within the tablet terminal 1 described below are executed under the control of the host processor 10.

[0042] 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 liquid crystal displays, organic EL displays, and electronic paper can be used as the display device 11. Although not shown in the figure, the display device 11 is configured to include 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. Figure 1 It is provided for the entire panel surface 1a shown.

[0043] 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 1 a , thereby enabling the position of a pointer such as the stylus pen 2 or the user's finger to be detected over the entire panel surface 1 a .

[0044] The sensor controller 13 uses the sensor electrode group 12 to detect the position of a pointer, such as the stylus pen 2 or a user's finger, within the panel surface 1a and to receive data transmitted from the stylus pen 2. The sensor controller 13 is configured to output the detected position and data received from the stylus pen 2 to the host processor 10.

[0045] 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 sensor controller 13 transmits an uplink signal US to the stylus pen 2 and receives a pen signal DS from the stylus pen 2. The pen signal DS is transmitted by the stylus pen 2 in response to the uplink signal US. It consists of a pulse train signal, an unmodulated carrier signal, and a data signal, a carrier signal modulated with data transmitted by a command COM (described later) included in the uplink signal US. The sensor controller 13 calculates the position of the stylus pen 2 based on the received position of the pulse train signal and receives the data transmitted by the stylus pen 2 by decrypting the received data signal.

[0046] 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 pen tip electrode. pen_tip The sensor electrode group 12 is electrically connected to the housing via the electrostatic capacitor C shown in the figure. 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 via the electrostatic capacitor C shown in the figure. displayThe sensor electrode group 12 is electrically connected to the display electrodes 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 electrodes in the display device 11. palm It is also electrically connected to the human body 3.

[0047] In addition, the human body 3 is connected to the electrostatic capacitor C human_GND The 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.

[0048] 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. 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 stylus pen 2 is electrically connected to the sensor electrode group 12. pen_GND 、C human_GND And grounded.

[0049] 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 transmits it to the detection unit 41. pen_tip This signal is generated not only when the tip of the stylus pen 2 is in contact with the panel surface 1a, but also when they are somewhat separated. Therefore, the stylus pen 2 can receive the uplink signal US even when its tip is separated from the panel surface 1a (in a hovering state). Taking advantage of this, the sensor controller 13 is configured to detect the stylus pen 2 before it comes into contact with the panel surface 1a. Figure 1 The position P shown indicates the position of the stylus pen 2 in the hovering state detected in this manner.

[0050] Here, if Figure 1 As shown in the example, the user sometimes holds 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 shown in FIG, the area Palm 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 1In 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_GND The uplink signal USa is then supplied to the ground terminal of the detection unit 41. Consequently, the uplink signal US is supplied to both the input terminal and the ground terminal, making it difficult for the detection unit 41 to detect the uplink signal USa. This phenomenon can occur not only when another hand is placed on the panel surface 1a, but also when, for example, a hand holding the stylus pen 2 is in contact with or close to the panel surface 1a, the uplink signal USa is received by that hand.

[0051] In addition, the uplink signal US sent from the sensor electrode group 12 is not only detected by the stylus pen 2, but also detected by the stylus pen 2. Figure 2 The electrostatic capacitance C shown display The signal is detected by the display electrodes in the display device 11. This causes fluctuations in the potential of the display electrodes, disrupting the display content of the display device 11. In particular, the common electrode is significantly affected by the uplink signal US because it is provided over the entire panel surface 1a as described above.

[0052] The present embodiment aims to address these issues. Specifically, it prevents the uplink signal US from causing a change in the potential of the ground terminal of the stylus pen 2, thereby preventing the stylus pen 2 from being unable to detect the uplink signal US, and also prevents the uplink signal US from affecting the operation of the display device 11. The structure used to achieve this goal is described in detail below.

[0053] Figure 3 1 is a diagram showing the internal structure of the sensor electrode group 12 and the sensor controller 13 .

[0054] 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) perpendicular 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 although an example is shown here in which the sensor electrodes 12X and 12Y are both composed of linear conductors, 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 two-dimensionally in a manner capable of detecting the two-dimensional coordinates of the stylus 2 (see the following description). Figure 14 ).

[0055] One of the sensor electrodes 12X and 12Y can also be used as a common electrode within the display device 11. A tablet terminal 1 that uses one of the sensor electrodes 12X and 12Y as a common electrode within the display device 11 is, for example, called an "in-cell" type. On the other hand, a tablet terminal 1 that includes both the sensor electrodes 12X and 12Y and a common electrode within the display device 11 is, for example, called an "out-cell" or "on-cell" type. The following description assumes that the tablet terminal 1 is an in-cell type, but the present invention is equally applicable to both out-cell and on-cell tablet terminals. Furthermore, the following description assumes that the sensor electrode 12X is used as the common electrode, but the sensor electrode 12Y can also be used as the common electrode.

[0056] When the display device 11 is driving pixels, it is necessary to maintain the potential of the common electrode at a predetermined value (specifically, the common potential Vcom described above). Therefore, in the embedded tablet terminal 1, the sensor controller 13 cannot communicate with the stylus 2 or detect a finger while the display device 11 is driving pixels. Therefore, the host processor 10 uses the horizontal and vertical loop intervals, during which pixel driving is not occurring, to instruct the sensor controller 13 to communicate with the stylus 2 and detect a finger. Specifically, the horizontal and vertical loop intervals are treated as time slots, and the sensor controller 13 is controlled so that communication with the stylus 2 and finger detection are performed during these time slots.

[0057] like Figure 3 As shown, the sensor controller 13 includes an MCU 50 , a logic unit 51 , transmission units 52 and 53 , a reception unit 54 , and a selection unit 55 .

[0058] The MCU 50 and logic unit 51 are control units that control the sensor controller 13's transmission and reception operations by controlling the transmitters 52 and 53, the receiver 54, and the selector 55. Specifically, the MCU 50 is a microprocessor with internal ROM and RAM that operates by executing programs stored in these memory units. The MCU 50 also outputs a common potential Vcom and a command COM indicating a command to the stylus 2. Meanwhile, the logic unit 51 is configured to output control signals ctrl_t1 to ctrl_t5, ctrl_r, sTRx, sTRy, selX, and selY based on control by the MCU 50.

[0059] The transmitter 52 is a circuit that generates a finger detection signal FDS for finger detection under the control of the MCU 50. As will be described in detail later, in this embodiment, the finger detection signal FDS detects not only the user's fingers but also the user's hand (palm). The finger detection signal FDS can be, for example, an unmodulated pulse train signal or a sine wave signal.

[0060] The transmission unit 53 is a circuit that generates the uplink signal US and the 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 here is a brief description. The uplink signal US of this embodiment is a signal that includes the preamble PRE for causing 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 from being transmitted to the detection unit 41 (see Figure 1 ) is a signal appearing at the ground terminal of the uplink signal US, for example.

[0061] like Figure 3 As shown, the transmitter 53 includes a preamble supply unit 61, a switch 62, a code string storage unit 63, an expansion processing unit 64, a transmission protection unit 65, and a cancel signal generation unit 66. It should be noted that the preamble supply unit 61 may also be included in the MCU 50.

[0062] The preamble supply unit 61 holds a 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.

[0063] Figure 4 is a diagram illustrating the structure of an uplink signal US. As shown in the figure, the uplink signal US is configured with a preamble PRE at the beginning, followed by a command COM (data portion). To enable detection of stylus pen 2, the contents of the preamble PRE are known in advance to stylus pen 2. Meanwhile, as mentioned above, command COM is data indicating a command to stylus pen 2. Specific examples of the contents of commands based on command COM include transmission of pen pressure data indicating the pressure applied to the pen tip, transmission of data indicating the pressed state of a switch (not shown) provided on the surface of stylus pen 2, and transmission of a stylus pen ID previously stored in stylus pen 2.

[0064] 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 respectively correspond to 4-bit bit strings of "0000" to "1111". 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 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 is continued based on this premise.

[0065] return Figure 3 The switch 62 has the 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.

[0066] 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 a 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.

[0067] 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, for example, by a cyclic shift as described in Patent Document 1. In this case, as a result of the modulation, a spreading code having a length of 12 chips is output for each symbol.

[0068] The spreading code output from the spreading processing unit 64 is sequentially supplied to the transmission protection unit 65 and the cancel signal generating unit 66. The transmission protection unit 65 has a function of inserting a guard period, a period in which neither transmission nor reception is performed, between the transmission period of the uplink signal US and the period in which the reception unit 54, described later, is receiving, based on the control signal ctrl_t5 supplied from the logic unit 51.

[0069] The cancel signal generator 66 is a functional unit that generates a cancel signal CA based on the spread code output from the spread processing unit 64. The cancel signal generator 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 generator 66 is configured to output the cancel signal CA only during the period indicated by the control signal ctrl_t4.

[0070] Figure 5 is a diagram showing an example of the waveforms of the uplink signal US and the cancel signal CA. As shown in the figure, the uplink signal US after spread coding becomes an AC signal with a rectangular wave that can take on either 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 its changing direction) 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 its changing direction) compared to the uplink signal US. The signal with the potential difference amplified compared to 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, the cancel signal CA is preferably a differential signal or an integrated signal of the inverted signal of the uplink signal US. Furthermore, since a potential difference between the input terminal of the detection unit 41 of the stylus pen 2 and the ground terminal is sufficient compared to the case where the uplink signal US is transmitted to all electrodes, a predetermined AC signal may be transmitted in the uplink signal US, and a signal at a predetermined potential (e.g., ground potential) may be used as the cancel signal.

[0071] return Figure 3 The receiving unit 54 is a circuit for receiving the pen signal DS transmitted by the stylus pen 2 or the finger detection signal FDS transmitted 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 .

[0072] Amplifier circuit 70 amplifies and outputs the pen signal DS or finger detection signal FDS supplied from selector 55. Detector circuit 71 generates a voltage corresponding to the level of the output signal from amplifier circuit 70. A / D converter 72 generates a digital signal by sampling the voltage output from detector circuit 71 at predetermined time intervals. The digital signal output by A / D converter 72 is supplied to MCU 50. Based on the supplied digital signal, MCU 50 detects the position of stylus 2 or finger (or palm) and retrieves data Res sent by stylus 2. MCU 50 sequentially outputs the x and y coordinates representing the detected position and the retrieved data Res to host processor 10.

[0073] The selection unit 55 is configured to include switches 68 x and 68 y and conductor selection circuits 69 x and 69 y .

[0074] Switch 68y is a switching element configured so that its common terminal is connected to either the T terminal or the R terminal. The common terminal of switch 68y is connected to conductor selection circuit 69y, with the T terminal connected to the output of transmitter 53 and the R terminal connected to the input of receiver 54. Switch 68x is a switching element configured so that its common terminal is connected to either the T1 terminal, T2 terminal, D terminal, or R terminal. The common terminal of switch 68x is connected to conductor selection circuit 69x, with the T1 terminal connected to the output of transmitter 53, the T2 terminal connected to the output of transmitter 52, the D terminal connected to the output of MCU 50 that outputs the common potential Vcom, and the R terminal connected to the input of receiver 54.

[0075] The conductor selection circuit 69x is a switching 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 some or all of the plurality of sensor electrodes 12X to the common terminal of the switch 68x.

[0076] Conductor selection circuit 69y is a switching element for selectively connecting multiple sensor electrodes 12Y to the common terminal of switch 68y or the output terminal of cancel signal CA of transmitter 53. Conductor selection circuit 69y is configured to simultaneously connect some or all of the multiple sensor electrodes 12Y to the common terminal of switch 68y or the output terminal of cancel signal CA of transmitter 53. Control by logic unit 51, described later, prevents a single sensor electrode 12Y from being simultaneously connected to both the common terminal of switch 68y and the output terminal of cancel signal CA of transmitter 53.

[0077] The selector 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 selector 55 using these control signals sTRx, sTRy, selX, and selY to transmit the uplink signal US or the finger detection signal FDS, apply the common potential Vcom, and receive the pen signal DS or the finger detection signal FDS. Furthermore, the logic unit 51 controls the operation of the cancel signal generator 66 using the control signal ctrl_t4, thereby transmitting the cancel signal CA.

[0078] 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 finger and palm detection is performed, when 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.

[0079] First, when detecting fingers and palms, the logic unit 51 controls switch 68x to connect the T2 terminal to the common terminal and switches 68y to connect the R terminal to the common terminal. Furthermore, the conductor selection circuits 69x and 69y are controlled so that combinations of the multiple sensor electrodes 12X and 12Y are sequentially selected. In this way, the finger detection signals FDS that pass through each of the multiple intersections formed by the multiple sensor electrodes 12X and 12Y are sequentially received by the receiving unit 54. This control is hereinafter referred to as "touch scanning." The MCU 50 detects the positions of the fingers and palms on the panel surface 1a based on the reception strength of the finger detection signals FDS sequentially received through touch scanning. More specifically, the MCU 50 calculates the area of a continuous region formed by intersections where the reception strength of the finger detection signal FDS exceeds a specified value. If the obtained area is below the specified value, the finger position is detected; otherwise, the palm position is detected. It should be noted that the palm position is not represented by a point, but rather by an extended area.

[0080] Next, when executing pixel drive operations, the logic unit 51 controls the switch 68x to connect the D terminal to the common terminal, and controls the conductor selection circuit 69x to simultaneously connect all of the multiple sensor electrodes 12X to the switch 68x. This supplies the common potential Vcom from the MCU 50 to each sensor electrode 12X, enabling the display device 11 to execute pixel drive operations. 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.

[0081] Next, when transmitting the uplink signal US and cancel signal CA, the logic unit 51 controls switch 68x to connect the R terminal to the common terminal and controls switch 68y to connect the T terminal to the common terminal. Consequently, the uplink signal US output from the transmitter 53 is supplied to the conductor selection circuit 69y. The logic unit 51 further instructs the conductor selection circuit 69y to sequentially connect a predetermined number of sensor electrodes 12Y to the common terminal of switch 68y. This allows the uplink signal US to be transmitted from the predetermined number of sensor electrodes 12Y connected to the common terminal of switch 68y, ultimately transmitting the uplink signal US from all sensor electrodes 12Y.

[0082] The logic unit 51 also performs processing to transmit the cancel signal CA simultaneously with the transmission of the uplink signal US. Specifically, at the timing of transmitting 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 predetermined number of sensor electrodes 12Y to the output end of the cancel signal CA of the transmitting 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 transmitting unit 53. Thus, the transmission of the cancel signal CA is achieved simultaneously with the transmission of the uplink signal US. This will be discussed later with reference to the processing flow. Figure 1 Explain in more detail.

[0083] Finally, when receiving the pen signal DS, the logic unit 51 controls the switches 68x and 68y so that the R terminal is connected to the common terminal. The control method of the conductor selection circuits 69x and 69y is different when detecting the position of the stylus pen 2 and when receiving the data signal sent by the stylus pen 2. The former will be discussed later. Figure 8 Details will be described later. In the latter case, the logic unit 51 controls the conductor selection circuits 69x and 69y so that only a predetermined number (e.g., one) of the multiple sensor electrodes 12X and 12Y located near 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 demodulates and decrypts the supplied data signals to obtain the aforementioned data Res.

[0084] 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.

[0085] The electrode 21 is a conductive member that constitutes the tip of the stylus pen 2. The electrode 21 functions as an antenna for transmitting the stylus 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 stylus tip may be provided independently of the electrode 21. Alternatively, the electrode for transmitting the stylus signal DS and the electrode for receiving the uplink signal US may be provided separately.

[0086] The switch 22 is a switch that can be switched between on and off by user 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 (writing pressure) applied to the tip of the stylus pen 2. Specifically, the pen pressure detection sensor 23 can be constructed using known technologies, such as a variable capacitance capacitor whose capacitance changes in response to pressure, or a pressure sensor whose resistance changes in response to pressure.

[0087] 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 of the uplink signal US, generating a pen signal DS to be transmitted to the sensor controller 13, and transmitting the pen signal DS to the sensor controller 13 via the electrode 21. Specifically, the functional structure includes a switching unit 40, a detection unit 41, a control unit 44, and a transmission unit 46. Each of these is described below in order.

[0088] The switch unit 40 is a 1-circuit, 2-contact switching element with a common terminal connected to either the T terminal or the 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 using the control signal SWC so that the R terminal is connected to the common terminal. Furthermore, when transmitting the pen signal DS to the sensor controller 13, the switch unit 40 is controlled using the control signal SWC so that the T terminal is connected to the common terminal.

[0089] The detection unit 41 is a circuit that detects the signal supplied from the switching unit 40 (the signal reaching the electrode 21) and decodes the code string contained in the detected signal. In this example, the detection unit 41 is configured to include a waveform regeneration unit 42 and a correlation operator 43. The detection unit 41 is configured to detect the preamble PRE and the command COM described above through this decoding.

[0090] The waveform regeneration unit 42 binarizes the charge (voltage) level induced at the electrode 21 using a clock that is a multiple (e.g., 4) of the chip rate of the spreading code used by the sensor controller 13 to spread the uplink signal US. This binary string (chip string) is then transformed into a positive and negative polarity binary string (chip string) and outputted. The correlation operator 43 stores the chip string output by the waveform regeneration unit 42 in a register and, while sequentially shifting the chip string using the clock, performs correlation operations with each of the multiple spreading codes that the sensor controller 13 may have transmitted, thereby decoding the chip string contained in the received signal. This decoding results in the symbols P and M and one of the 16 types of symbols D.

[0091] The detection unit 41 sequentially detects the preamble code PRE based on the decoding results of the correlation calculator 43. Specifically, this detection operation determines whether two consecutive symbols P have been obtained. Furthermore, the detection unit 41 also determines whether two consecutive symbols M have been detected. If the result of any of these determinations is affirmative, the detection unit 41 detects the presence of the sensor controller 13 and issues an activation signal EN to the control unit 44.

[0092] The detection unit 41, having issued the start signal EN, then performs a detection operation for the command COM. Specifically, the series of symbols D obtained sequentially through decoding are sequentially demodulated into a bit string, ultimately obtaining a 16-bit bit string and outputting it 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 during the reception operation of the preamble PRE, the chip string output from the waveform regeneration unit 42 is inverted and then supplied to the correlation operator 43. In this way, the uplink signal US can be correctly received even if it is inverted, and even when a cancellation signal CA (for example, an inverted signal of the uplink signal US) is received, it can be received as the uplink signal US.

[0093] The control unit 44 is comprised of a microprocessor (MCU) and is activated upon receipt of a start signal EN from the detection unit 41. After activation, the control unit 44 performs the operations instructed by the command COM supplied from the detection unit 41. This operation includes causing the transmitter 46 to transmit the pen signal DS. Specifically, the control unit 44 causes the transmitter 46 to transmit an unmodulated carrier signal, thereby causing the transmitter 46 to transmit a pulse train signal. Furthermore, the control unit 44 obtains the data instructed to be transmitted by the command COM and supplies this data to the transmitter 46, causing the transmitter 46 to transmit the data signal. Consequently, the pen signal DS transmitted from the transmitter 46 includes the data instructed to be transmitted by the command COM.

[0094] The transmitting unit 46 is a circuit that generates a 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 modulating unit 47 and a boosting circuit 48 .

[0095] The modulator 47 is a circuit that generates a carrier signal (e.g., a rectangular wave signal) at a predetermined frequency or a frequency controlled by the control unit 44. Based on the control unit 44's control, the modulator 47 outputs the carrier signal as is or after modulating it. When transmitting a pulse train signal, the modulator 47 outputs the carrier signal as is, without modulating it, in accordance with the control unit 44's instructions. It should be noted that a signal modulated using a pattern of known values can also be used as the pulse train signal. In this case, the modulator 47 modulates the carrier signal using this known pattern of values and outputs it. On the other hand, when transmitting a data signal, the modulator 47 modulates the carrier signal (e.g., using OOK, PSK, etc.) using data supplied by the control unit 44 and outputs the resulting modulated signal.

[0096] The boost circuit 48 is a circuit that generates a pen signal DS by boosting the output signal of the modulation unit 47 to a constant amplitude. The pen signal DS generated by the boost circuit 48 is sent from the electrode 21 to the space via the switching unit 40 .

[0097] 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 While explaining in detail.

[0098] Figure 7 2 is a flowchart of the processing performed by the sensor controller 13. This figure shows only the processing related to the position detection of the finger, palm, and stylus pen 2.

[0099] 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 the fingers and palms on the panel surface 1 a based on the results (step S2 ). The specific contents of these processes are as described above.

[0100] Next, the sensor controller 13 substitutes 1 into the variable m (step S3), and then performs pen scanning (step S4). Pen scanning is a process for detecting the stylus pen 2, which will be referred to later. Figure 8 Let's explain in detail.

[0101] After completing the pen scan, the sensor controller 13 adds 1 to the variable m (step S5) and then determines whether the variable m exceeds 4. If it is determined that it has not exceeded 4, the process returns to step S4 and performs the pen scan again. On the other hand, if it is determined that it has exceeded 4, the process returns to step S1 and performs the touch scan.

[0102] According to the above processing, the sensor controller 13 repeatedly performs these processes using a step of performing four pen scans after performing one touch scan. It should be noted that this step is only an example, and these processes can also be repeated using other steps (for example, a step of performing one pen scan after performing one touch scan). Figure 7 Although not shown in the figure, when the stylus pen 2 is detected by the execution of the pen scan, the actual sensor controller 13 performs a data signal reception operation and obtains the data sent by the stylus pen 2.

[0103] 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 ).

[0104] Figure 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 is referred to as a sensor electrode 12Y. n (n is a natural number from 1 to 24.) However, the sensor electrode group 12 may of course include fewer than 24 sensor electrodes 12Y or 25 or more sensor electrodes 12Y.

[0105] 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. Hereinafter, following Figure 9 Let's explain in detail.

[0106] like Figure 9 As shown, the sensor controller 13 first substitutes 1 into the variable n (step S20), then substitutes n and n+8 into the variables Y1 and Y2, respectively (step S21). The sensor controller 13 then determines whether the variable Y2 is equal to or greater than 21 (step S22). If so, the sensor controller 13 subtracts 16 from the variable Y2 (step S23).

[0107] 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, a cancel signal CA is sent from each of them (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 a cancel signal CA to the sensor electrode 12Y. Y2 ~12Y Y2+7 's respective supplies, thereby executing step S24.

[0108] Note that, at this time, the sensor controller 13 does not supply signals to the sensor electrodes 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.

[0109] The sensor controller 13 that has finished transmitting the uplink signal US and the cancel signal CA performs a reception operation of the pen signal DS (step S25). Figure 3 As explained in detail, logic unit 51 controls switches 68x and 68y to connect their R terminals to the common terminal. This control then uses control signals selX and selY to control conductor selection circuits 69x and 69y, sequentially selecting one of the plurality of sensor electrodes 12X and 12Y. This sequentially connects each of the plurality of sensor electrodes 12X and 12Y to the input terminal of receiver unit 54, and receiver unit 54 sequentially provides MCU 50 with the received strength of pen signal DS at each sensor electrode 12X and 12Y.

[0110] 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 scan process is terminated and the process returns to step S26. Figure 8 On the other hand, if it is determined that no data has 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 does not exceed 17, the process returns to step S21 and continues. On the other hand, if it is determined that it exceeds 17, the process of global scanning is terminated and the process returns to step S21. Figure 8 processing.

[0111] Figure 10 It shows Figure 9The sensor electrodes 12Y shown in the figure are sensor electrodes 12Y1 to 12Y1 in order from the left side of the figure. 24 .

[0112] Figure 10 (a) shows the 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 uplink signal US is transmitted from the sensor electrodes 12Y9 to 12Y10. 16 Each sends a cancellation signal CA.

[0113] Figure 10 (b) shows the 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 sends a cancellation signal CA.

[0114] Figure 10 (c) shows the case where the variable n is 9. As shown in the figure, in this case, the sensor electrodes 12Y9 to 12Y 16 Each of them sends an uplink signal US, from the sensor electrode 12Y 17 ~12Y 24 Each sends a cancellation signal CA.

[0115] Figure 10 (d) shows a case where the variable n is 13. As shown in the figure, in this case, the sensor electrode 12Y 13 ~12Y 20 Each of them sends an uplink signal US, from the sensor electrodes 12Y5~12Y 12 Each sends a cancellation signal CA.

[0116] Figure 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 them sends an uplink signal US, from sensor electrodes 12Y9~12Y 16 Each sends a cancellation signal CA.

[0117] Thus, according to the global scan performed by the sensor controller 13 of this embodiment, the cancellation 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 (e.g., the hand holding stylus 2) can be a mixed signal of the cancel signal CA and the uplink signal US. This prevents the uplink signal US from causing a change in the potential of the ground terminal of stylus 2, which could cause the stylus 2 to lose detection of the uplink signal US. Furthermore, since both the uplink signal US and the cancel signal CA are supplied to the common electrode of display device 11, they cancel each other out, preventing the uplink signal US from affecting the operation of display device 11.

[0118] Furthermore, the global scan performed by the sensor controller 13 in this embodiment sequentially transmits the uplink signal US from portions of the panel surface 1a, not from the entire panel surface 1a. This reduces the likelihood that the hand not holding the stylus pen 2 will receive the uplink signal US. This also prevents the stylus pen 2 from being unable to detect the uplink signal US due to a change in the potential of the ground terminal of the stylus pen 2 caused by the uplink signal US.

[0119] 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.

[0120] 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) performed 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 Figure 7 processing.

[0121] If the sensor controller 13 determines that the stylus signal DS has been received in step S11, it performs a sector scan near the location where the stylus signal DS was received (step S12). Sector scanning is a process for specifically determining the location of the stylus signal DS through calculation. It is performed while the stylus pen 2 continues to transmit a burst signal in response to the uplink signal US.

[0122] Figure 11 FIG is a diagram showing the use of the sensor electrodes 12X and 12Y in sector scanning. Figure 3 , while describing in detail the receiving operation performed by the sensor controller 13 in the sector scan.

[0123] First, the MCU 50 selects one sensor electrode close to the stylus 2 from each of the plurality of sensor electrodes 12X and 12Y based on the results of the global scan. This selection is performed based on the reception intensity of the pen signal DS at each sensor electrode 12X and 12Y supplied from the receiving unit 54 to the MCU 50. Next, the logic unit 51 sequentially selects a predetermined number of sensor electrodes 12X and 12Y (in the range of 1 to 20) from the sensor electrodes close to the sensor electrodes 12X and 12Y selected by the MCU 50. Figure 11 12X and 12Y are shown with mesh lines in the diagram. After that, logic unit 51 controls switches 68x and 68y to connect their R terminals to the common terminal. This control then controls conductor selection circuits 69x and 69y using control signals selX and selY to sequentially select a predetermined number of sensor electrodes 12X and 12Y. Consequently, each of the predetermined number of selected sensor electrodes 12X and 12Y is sequentially connected to the input terminal of receiver unit 54. Receiver unit 54 then sequentially provides MCU 50 with the received strength of pen signal DS at each sensor electrode 12X and 12Y.

[0124] return Figure 8 The sensor controller 13 that has finished the sector scan determines whether the pen signal DS is received in the receiving operation performed in the sector scan (step S13). If it is determined that the pen signal DS is not received, the pen scan process is terminated and the process returns to step S13. Figure 7 processing.

[0125] If it is determined that the touch signal has been received in step S13, 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, including linear interpolation) based on the reception strength of the pen signal DS at each sensor electrode 12X, 12Y supplied from the receiving unit 54. The position of the stylus pen 2 is specifically determined by the process of step S14. The determined position is transmitted from the sensor controller 13 to the touch screen. Figure 3 The host processor 10 is shown supplying.

[0126] Figure 12This is a flowchart illustrating the processing performed by stylus pen 2. As shown in the figure, stylus pen 2 continuously receives the uplink signal US (steps S30 and S31) until it receives the uplink signal US. As described above, even if stylus pen 2 receives the cancel signal CA, it can still receive it as the uplink signal US. It should be noted that stylus pen 2 can also intermittently receive the uplink signal US to reduce power consumption. Upon receiving the uplink signal US, stylus pen 2 transmits a pen signal DS (step S32) consisting of the aforementioned pulse train signal and data signal, and then returns to step S30 to wait for reception of the uplink signal US.

[0127] As described above, according to the sensor controller 13 of the present embodiment, the uplink signal US can be prevented 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.

[0128] Furthermore, since the uplink signal US can be prevented from appearing on the display electrodes (particularly 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 .

[0129] It should be noted that the use of the sensor electrode 12Y in the global scan is not limited to the reference Figure 10 For example, the sensor controller 13 may select the sensor electrodes 12Y used as the AC signal transmitting electrodes and the sensor electrodes 12Y used as the cancel signal transmitting electrodes so that the AC signal transmitting electrodes and the cancel signal transmitting electrodes are alternately arranged a predetermined number of times along the Y direction, and further, may select the sensor electrodes 12Y used as the AC signal transmitting electrodes and the sensor electrodes 12Y used as the cancel signal transmitting electrodes so that the AC signal transmitting electrodes and the cancel signal transmitting electrodes partially overlap and slide along the Y direction each time the uplink signal US is transmitted.

[0130] Figure 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. Figure 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, Figure 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, Figure 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 sends a cancellation signal CA.

[0131] In this example, a predetermined number of AC signal transmission electrodes and cancel signal transmission electrodes are alternately arranged along the Y direction. Furthermore, 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 achieving the same effects 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 2 failing to receive the uplink signal US is reduced. Furthermore, since the boundary between the AC signal transmission electrodes and the cancel signal transmission electrodes is not fixed, the formation of areas on the panel surface 1a where the stylus 2 cannot receive the uplink signal US is avoided.

[0132] In addition, in this embodiment, the case where the sensor electrode group 12 is of mutual capacitance type (i.e., the case where the stylus 2 or the finger is detected based on the change in capacitance generated between the sensor electrodes 12X and 12Y) is described as an example, but the present invention can also be applied to the case where the sensor electrode group 12 is of self-capacitance type.

[0133] Figure 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. Figure 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.

[0134] Figure 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. Specifically, Figure 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.

[0135] In addition, the sensor controller 13 controls the signals sent from each sensor electrode 12a so that the sensor electrode units 12U partially overlap and slide along the Y direction. Figure 14 In (a), the sensor controller 13 controls the signals transmitted from the sensor electrodes 12 a so that the sensor electrode unit 12U at the upper left is moved by two sensor electrodes 12 a in the Y direction each time the uplink signal US is transmitted.

[0136] according to Figure 14 In addition to being able to obtain the same effects as in the present embodiment, Figure 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 the stylus pen 2 failing to receive the uplink signal US can be reduced. Furthermore, since the boundary between the AC signal transmission electrode and the cancel signal transmission electrode is not fixed, the formation of an area on the panel surface 1a where the stylus pen 2 cannot receive the uplink signal US can be avoided.

[0137] Next, the second embodiment of the present invention will be described. This embodiment differs 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 palm position." 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.

[0138] Figure 15This is a detailed flowchart of the global scan of the second embodiment of the present invention. As shown in the figure, after starting the global scan, the sensor controller 13 of this embodiment first determines whether a palm is detected (step S40). If it is determined that no palm is detected, the process moves to Figure 8 In step S20 shown, a global scan is performed as described in the first embodiment.

[0139] On the other hand, in step S40, 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 to be used as the cancel signal transmission electrode. Then, the cancel signal CA is transmitted from the selected sensor electrode 12Y, and the uplink signal US is transmitted from the other sensor electrodes 12Y (step S41). Figure 8 In the step S25 shown, the pen signal DS is received in the same manner (step S42 ).

[0140] 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.

[0141] Next, a third embodiment of the present invention will be described. This embodiment differs 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 a 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.

[0142] Figure 16 This figure shows the internal structure of the sensor electrode group 12 and sensor controller 13 in this embodiment. The cancel signal transmitting electrode 1b shown in this figure is provided at a location where a user operating the stylus pen 2 would contact the device. For example, it is provided on the entire back surface (opposite to the panel surface 1a) of the tablet terminal 1 or a portion thereof (for example, the portion contacted by the hand not holding the stylus pen 2 when the tablet terminal 1 is held and the stylus pen 2 is operated).

[0143] In this embodiment, the output end of the cancel signal generator 66 is connected to the cancel signal transmitting electrode 1b. Thus, 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 can be the same as that of the first embodiment.

[0144] According to this embodiment, it is also possible to provide the user's body 3 (see Figure 2 ) provides a cancel signal CA. As in the first embodiment, this prevents the stylus pen 2 from being unable to detect the uplink signal US due to a 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 the user's hand is in contact with the panel surface 1a, and the uplink signal US is being supplied from there to the human body 3, 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, thereby preventing the uplink signal US from being supplied to the ground terminal of the stylus pen 2.

[0145] Next, the fourth embodiment of the present invention will be described. This embodiment is similar to the third embodiment in that electrodes different from the multiple sensor electrodes 12X and 12Y that constitute the sensor electrode group 12 are used as cancel signal transmission electrodes. However, it differs from the third embodiment in that display electrodes are used as these electrodes. Since the fourth embodiment is similar to the third embodiment in other respects, the following description will focus on the differences from the third embodiment.

[0146] Figure 17 1 is a diagram showing the internal structure of the sensor electrode group 12 and the sensor controller 13 in this embodiment. As shown in this diagram, in this embodiment, the output end of the cancel signal generating unit 66 is connected to the D terminal of the switch 68x.

[0147] In this embodiment, sensor controller 13 controls switch 68x using control signal sTRx to connect the common terminal to the D terminal at the timing of transmitting the uplink signal US. Furthermore, at this time, conductor selection circuit 69x is controlled using control signal selX to simultaneously connect all or some of the multiple sensor electrodes 12X to the common terminal of switch 68x. This cancels out the uplink signal US and cancel signal CA in sensor electrodes 12X, which serve as the common electrode. Consequently, according to this embodiment, as in the first embodiment, it is possible to prevent the uplink signal US from affecting the operation of display device 11.

[0148] It should be noted that, because the display device 11 does not drive pixels while the uplink signal US is being transmitted, the common potential Vcom from the MCU 50 and the cancel signal CA from the cancel signal generator 66 are not simultaneously supplied to the sensor electrodes 12X. Furthermore, according to this embodiment, while the uplink signal US is less likely to be transmitted from the panel surface 1a, it does not completely prevent it from being transmitted. Therefore, the sensor controller 13 is not unable to detect the stylus 2. This embodiment is particularly effective when it is desired to minimize the impact on the operation of the display device 11.

[0149] Figure 18 is a sequence diagram illustrating the processing of the logic unit 51 of this embodiment. As shown in this diagram, the logic unit 51 of this embodiment is configured to simultaneously supply an uplink signal US to each sensor electrode 12Y and a cancel signal CA to each sensor electrode 12X. This cancels the uplink signal US and the cancel signal CA in the sensor electrode 12X, which serves as the common electrode, as described above.

[0150] It should be noted that in Figure 17 While the example of a built-in tablet terminal 1 is shown, this embodiment can also be applied to embedded or plug-in tablet terminals. In this case, the output end of cancel signal generator 66 is connected to a common electrode provided within display device 11. Furthermore, sensor controller 13 causes cancel signal generator 66 to output cancel signal CA at the same timing as when uplink signal US is transmitted. Thus, as in this embodiment, the uplink signal US and cancel signal CA can be canceled at the common electrode of display device 11, thereby preventing the uplink signal US from affecting the operation of display device 11.

[0151] While preferred embodiments of the present invention have been described above, the present invention is not limited to these 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.

[0152] For example, in the first embodiment described above, a portion of the plurality of sensor electrodes 12Y is always selected as electrodes for transmitting AC signals, and another portion of the plurality of sensor electrodes 12Y is selected as electrodes for transmitting cancel signals. However, each time an uplink signal US is transmitted, a first mode may be switched between selecting a portion of the plurality of sensor electrodes 12Y as electrodes for transmitting AC signals and selecting another portion of the plurality of sensor electrodes 12Y as electrodes for transmitting cancel signals, and selecting a portion of the plurality of sensor electrodes 12X as electrodes for transmitting AC signals and selecting another portion of the plurality of sensor electrodes 12X as electrodes for transmitting cancel signals. This further reduces the possibility of the stylus pen 2 failing to receive the uplink signal US.

[0153] Furthermore, when the position of stylus pen 2 is already determined, for example, when an uplink signal US is transmitted to notify stylus pen 2 of a new command COM, the cancellation signal CA need not be transmitted. In this case, uplink signal US only needs to be transmitted from some sensor electrodes 12Y located near the position of stylus pen 2. Therefore, the possibility of stylus pen 2 being unable to detect uplink signal US due to a change in the potential of the ground terminal of stylus pen 2 caused by uplink signal US is reduced. Therefore, it can be said that not transmitting cancellation signal CA is not a problem.

[0154] 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 impact on these devices can also be prevented.

[0155] While the above embodiment uses the stylus pen 2 as an example, the present invention can also be applied to transmitting signals to a device held by a hand, equipped with predetermined electrodes and a detection unit 41, which receives the uplink signal US at a sensor. The device is not limited to a stylus pen; it can also take the form of an electronic ruler, a computer mouse, a card, or a VR (Virtual Reality) controller that moves in 3D space.

[0156] Furthermore, in the above embodiment, an example is described in which the uplink signal US is composed of an AC signal (modulated spreading code) having a rectangular wave with either a high or low value. However, the uplink signal US can be any AC signal. For example, the uplink signal US can be a sine wave or a rectangular wave, and can be modulated or unmodulated.

[0157] Description of labels

[0158] 1 Tablet terminal

[0159] 1a Panel surface

[0160] 1b Cancel signal sending electrode

[0161] 2 stylus

[0162] 3 Human body

[0163] 10 Host processor

[0164] 11 Display device

[0165] 12 sensor electrode groups

[0166] 12U sensor electrode unit

[0167] 12X, 12Y, 12a sensor electrodes

[0168] 13 Sensor Controller

[0169] 21 electrodes

[0170] 22 Switch

[0171] 23 Pen pressure detection sensor

[0172] 24 Signal Processing Unit

[0173] 40 Switching unit

[0174] 41 Testing Department

[0175] 42 Waveform regeneration unit

[0176] 43 Correlation Operator

[0177] 44 Control Department

[0178] 46 Sending Department

[0179] 47 Modulation Department

[0180] 48 Boost Circuit

[0181] 51 Logic Department

[0182] 52, 53 Sending Department

[0183] 54 Receiving Department

[0184] 55 Selection Department

[0185] 61 Preamble code supply unit

[0186] 62 switches

[0187] 63 Code string holding unit

[0188] 64 Extended Processing Unit

[0189] 65 Send Protection Department

[0190] 66 Cancel signal generation unit

[0191] 68x, 68Y switches

[0192] 69x, 69Y conductor selection circuit

[0193] 70 amplifier circuit

[0194] 71 Detection Circuit

[0195] 72 Analog-to-digital converter

[0196] COM instructions

[0197] ctrl_t1~ctrl_t5, ctrl_r, sTRx, sTRy, selX, selY, SWC control signals

[0198] DS pen signal

[0199] EN start signal

[0200] FDS finger detection signal

[0201] PRE preamble

[0202] US, USa uplink signal

[0203] Vcom common potential.

Claims

1. A sensor controller connected to a sensor electrode group constituting a panel surface, wherein The sensor controller supplies an uplink signal to be transmitted from the panel surface to the stylus pen to an alternating current (AC) signal transmitting electrode constituting a part of the sensor electrodes included in the sensor electrode group, and The sensor controller transmits a cancel signal configured to suppress the uplink signal transmitted from the AC signal transmitting electrode from appearing at the ground terminal of the detection circuit of the stylus pen from a cancel signal transmitting electrode that is another part of the sensor electrodes included in the sensor electrode group and is different from the AC signal transmitting electrode. At least one of the AC signal transmitting electrodes is positioned between two sub-portions of the cancel signal transmitting electrode in the first direction of the panel face. 2 . The sensor controller according to claim 1 , wherein the cancel signal is an inverted signal of the uplink signal. 3 . The sensor controller according to claim 1 , wherein the sensor electrodes extend in a second direction orthogonal to the first direction of the panel surface. 4 . The sensor controller according to claim 1 , wherein at least one of the AC signal transmitting electrodes is positioned between two sub-portions of the cancel signal transmitting electrode in a second direction of the panel surface orthogonal to the first direction of the panel surface. 5 . The sensor controller according to claim 4 , wherein the sensor electrodes are arranged in a matrix in the first direction and in the second direction. The sensor controller according to claim 5 , wherein the sensor electrodes are square electrodes.

7. The sensor controller according to claim 4, wherein: Between two instances of the uplink signal transmission from the panel surface to the stylus, the sensor controller switches between a first mode and a second mode, wherein the first mode selects the AC signal transmission electrode and the cancel signal transmission electrode from the sensor electrodes positioned in the first direction, and the second mode selects the AC signal transmission electrode and the cancel signal transmission electrode from the sensor electrodes positioned in the second direction.

8. The sensor controller according to claim 1, wherein: Between two instances of the uplink signal transmission from the panel surface to the stylus, the sensor controller changes at least some of the sensor electrodes selected as electrodes for transmitting the AC signal and changes at least some of the sensor electrodes selected as electrodes for transmitting the cancel signal.

9. The sensor controller according to claim 8, wherein: The sensor controller slides the AC signal transmission electrode and the cancel signal transmission electrode along the first direction between two instances of the uplink signal transmission from the panel surface to the stylus pen.

10. The sensor controller according to claim 1, wherein: After supplying the uplink signal to the AC signal transmission electrode, the sensor controller performs a reception operation using the sensor electrode.

11. The sensor controller according to claim 10, wherein The uplink signal is a signal for causing the stylus pen to transmit a signal, and The receiving action is an action for detecting a signal sent by the stylus.

12. The sensor controller according to claim 11, wherein: The sensor controller determines a position of the stylus pen within the panel surface based on a result of the receiving operation. 13 . The sensor controller according to claim 1 , wherein the uplink signal is a signal including a preamble and data.

14. The sensor controller according to claim 1, wherein: The sensor controller electrically connects the AC signal transmission electrode and the cancel signal transmission electrode for a determined period of time when the polarity of the uplink signal and the polarity of the cancel signal are reversed.

15. A method for controlling signal transmission from a sensor controller to a stylus, wherein the sensor controller is connected to a sensor electrode group constituting a panel surface, the method comprising: An uplink signal to be transmitted from the panel surface to the stylus pen is supplied to an AC signal transmitting electrode constituting a portion of the sensor electrodes included in the sensor electrode group, and transmitting a cancel signal configured to suppress the uplink signal transmitted from the AC signal transmitting electrode from appearing at a ground terminal of the detection circuit of the stylus pen from a cancel signal transmitting electrode that is another part of the sensor electrodes included in the sensor electrode group and is different from the AC signal transmitting electrode; Here, at least one of the AC signal transmitting electrodes is positioned between two sub-portions of the cancel signal transmitting electrode in the first direction of the panel surface. The method according to claim 15 , wherein the cancellation signal is an inverted signal of the uplink signal. 17 . The method according to claim 15 , wherein at least one of the AC signal transmitting electrodes is positioned between two sub-portions of the cancel signal transmitting electrode in a second direction orthogonal to the first direction of the panel surface.

18. The method according to claim 17, comprising: Between two instances of the uplink signal transmission from the panel surface to the stylus, switching is performed between a first mode and a second mode, wherein the first mode selects the AC signal transmission electrode and the cancel signal transmission electrode from the sensor electrode positioned in the first direction, and the second mode selects the AC signal transmission electrode and the cancel signal transmission electrode from the sensor electrode positioned in the second direction.

19. The method according to claim 15, comprising: Between two instances of the uplink signal transmission from the panel surface to the stylus pen, at least some of the sensor electrodes selected as the AC signal transmission electrodes are changed, and at least some of the sensor electrodes selected as the cancel signal transmission electrodes are changed.

20. The method according to claim 19, comprising: The sensor controller slides the AC signal transmission electrode and the cancel signal transmission electrode along the first direction between two instances of the uplink signal transmission from the panel surface to the stylus pen.

21. The method according to claim 15, comprising: After the uplink signal is supplied to the AC signal transmission electrode, a reception operation is performed using the sensor electrode to receive the signal transmitted from the stylus pen.

22. An electronic device comprising: monitor, a sensor electrode group constituting the sensor electrodes on the panel surface, and The sensor controller is connected to the sensor electrode group and is configured as follows: An uplink signal to be transmitted from the panel surface to a stylus pen is supplied to an AC signal transmitting electrode constituting a portion of the sensor electrodes included in the sensor electrode group, and A cancel signal is sent from a cancel signal sending electrode which is another part of the sensor electrodes included in the sensor electrode group and is different from the AC signal sending electrode, and is configured to suppress the uplink signal sent from the AC signal sending electrode from appearing at the ground end of the detection circuit of the stylus pen, wherein at least one of the AC signal sending electrodes is positioned between two sub-parts of the cancel signal sending electrode in the first direction of the panel surface.

23. The electronic device according to claim 22, wherein the cancellation signal is an inverted signal of the uplink signal. 24 . The electronic device according to claim 22 , wherein at least one of the AC signal transmitting electrodes is positioned between two sub-portions of the cancel signal transmitting electrode in a second direction orthogonal to the first direction of the panel surface.

25. A sensor controller connected to a sensor electrode group constituting a panel surface, wherein: The sensor controller supplies an uplink signal to be transmitted from the panel surface to the stylus pen to one or more alternating current (AC) signal transmitting electrodes constituting a portion of the plurality of sensor electrodes included in the sensor electrode group; the sensor controller transmitting, from one or more cancel signal transmitting electrodes different from the AC signal transmitting electrodes, a cancel signal for suppressing the uplink signal transmitted from the AC signal transmitting electrodes from appearing at a ground terminal of the detection circuit of the stylus pen; the sensor controller selecting some of the plurality of sensor electrodes as the AC signal transmitting electrodes and selecting other ones of the plurality of sensor electrodes as the cancel signal transmitting electrodes; and The sensor controller moves the selected AC signal sending electrodes in the sensor electrode group, changes at least some of the one or more sensor electrodes selected as the AC signal sending electrodes, and changes at least some of the one or more sensor electrodes selected as the cancel signal sending electrodes. 26 . The sensor controller of claim 25 , wherein the cancellation signal generates a potential difference between an input terminal of the detection circuit of the stylus and the ground terminal. The sensor controller according to claim 26 , wherein the cancel signal is an inverted signal of the uplink signal. 28 . The sensor controller according to claim 26 , wherein the cancellation signal is a fixed prescribed potential signal to generate a potential difference between the input terminal of the detection circuit of the stylus pen and the ground terminal. 29 . The sensor controller according to claim 25 , wherein the sensor electrode comprises a plurality of rectangular conductive bodies two-dimensionally arranged so as to be able to detect a two-dimensional coordinate of the stylus pen.

30. The sensor controller of claim 29, wherein the sensor electrode group is a self-capacitive type electrode group.

31. The sensor controller according to claim 29, wherein the selected AC signal transmission electrode constitutes one sensor electrode unit for transmitting the uplink signal.

32. The sensor controller of claim 31, wherein the uplink signal is sent to a location of the stylus, and the cancel signal is sent to a location of a palm of a user holding the stylus.

33. A sensor controller connected to a sensor electrode group constituting a panel surface, wherein: The sensor controller includes a plurality of rectangular conductive bodies arranged two-dimensionally so as to be capable of detecting the two-dimensional coordinates of the stylus pen; The sensor controller supplies an uplink signal to be transmitted from the panel surface to the stylus pen to one or more alternating current (AC) signal transmitting electrodes constituting a portion of the plurality of sensor electrodes included in the sensor electrode group; The sensor controller selects some of the plurality of rectangular conductive bodies as the AC signal transmitting electrodes; The sensor controller moves the selected AC signal transmitting electrode in the sensor electrode group and changes at least some of the one or more rectangular conductors selected as the AC signal transmitting electrode; and The sensor controller transmits a cancel signal configured to suppress the uplink signal transmitted from the AC signal transmitting electrode from appearing at a ground terminal of the detection circuit of the stylus pen from one or more cancel signal transmitting electrodes different from the AC signal transmitting electrode.

34. The sensor controller of claim 33, wherein the sensor electrode group is a self-capacitive type electrode group.

35. The sensor controller of claim 33, wherein the uplink signal is transmitted from the rectangular conductive body adjacent to a location of the stylus. 36 . The sensor controller of claim 35 , wherein the cancel signal is transmitted from the rectangular conductive body adjacent to a palm of a user holding the stylus. 37 . The sensor controller of claim 33 , wherein the cancellation signal generates a potential difference between an input terminal of the detection circuit of the stylus and the ground terminal. The sensor controller according to claim 37 , wherein the cancel signal is an inverted signal of the uplink signal. 39 . The sensor controller according to claim 37 , wherein the cancellation signal is a fixed prescribed potential signal to generate a potential difference between the input terminal of the detection circuit of the stylus pen and the ground terminal.

40. A method for controlling signal transmission from a sensor controller to a stylus, wherein the sensor controller is connected to a sensor electrode group constituting a panel surface, the method comprising: supplying an uplink signal to be transmitted from the panel surface to a stylus pen to an alternating current (AC) signal transmitting electrode constituting a portion of the sensor electrodes included in the sensor electrode group; transmitting, from a cancel signal transmitting electrode constituting another part of the sensor electrodes included in the sensor electrode group and different from the AC signal transmitting electrode, a cancel signal for suppressing the uplink signal transmitted from the AC signal transmitting electrode from appearing at a ground terminal of a detection circuit of the stylus pen; selecting some of the plurality of sensor electrodes as the AC signal transmitting electrodes, and selecting other some of the plurality of sensor electrodes as the cancel signal transmitting electrodes; and The selected AC signal transmitting electrodes in the sensor electrode group are moved, at least some of the one or more sensor electrodes selected as the AC signal transmitting electrodes are changed, and at least some of the one or more sensor electrodes selected as the cancel signal transmitting electrodes are changed. 41 . The method of claim 40 , wherein the cancellation signal generates a potential difference between an input terminal of the detection circuit of the stylus and the ground terminal.

42. The method of claim 40, wherein the cancellation signal is an inverted signal of the uplink signal. 43 . The method according to claim 40 , wherein the cancellation signal is a fixed prescribed potential signal to generate a potential difference between the input terminal of the detection circuit of the stylus and the ground terminal.

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