Stylus, sensor controller, integrated circuit, and method performed by stylus

Abstract

The present application provides a stylus, a sensor controller, an integrated circuit, and a method performed by the stylus. It is ensured that the state of the burst signal can be detected in a wide range within the touch surface, and the possibility of failure of the burst signal detection of the sensor controller is reduced. The stylus (2) is capable of bidirectional communication with the sensor controller, including: a receiving unit (71) for receiving an uplink signal sent by the sensor controller; a control unit (90) for determining whether to continuously send a signal of a predetermined waveform for a second time or continuously send the signal of the predetermined waveform for a first time longer than the second time based on the uplink signal; and a sending unit (75) for continuously sending the signal of the predetermined waveform for the first time or the second time based on the determination result of the control unit (90).

Description

[0001] This application is a divisional application of the application filed on December 25, 2018, with application number 201680087118.X, entitled "Stylus Pen and Sensor Controller". Technical Field

[0002] This invention relates to styluses and sensor controllers, and more particularly to styluses and sensor controllers constituting a position detection system in which the sensor controller detects the stylus by means of a burst signal sent from the stylus. Background Technology

[0003] Conventional styluses transmit data signals, including pen pressure and stylus ID, after receiving a burst signal that enables a sensor controller to detect the stylus and its position. The burst signal is a signal with a predetermined waveform (e.g., an unmodulated signal of a predetermined frequency) known in advance between the stylus and the sensor controller. The data signal, on the other hand, is a signal modulated from the data of the object being transmitted. (Patent Document 1) Figure 7 An example of a stylus that sends such signals was disclosed.

[0004] Before the stylus is detected, the sensor controller attempts to detect burst signals by sequentially performing detection actions using all of the multiple electrodes arranged side-by-side on the touch surface. If a burst signal is detected as a result, the controller attempts to detect data signals using only a subset of the electrodes located near the electrode where the burst signal was detected.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: International Publication No. 2015 / 111159 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, conventional sensor controllers have encountered the following problem: especially when the stylus is not yet in contact with the touch surface (during hovering), sometimes the detection fails even though the burst signal reaches the touch surface. This is because during hovering, due to the distance between the stylus and the touch surface, the amplitude of the burst signal detected by the sensor controller becomes smaller, resulting in an insufficient signal-to-noise ratio (S / N ratio). One approach to achieving a sufficient S / N ratio even during hovering is to extend the detection time of each electrode. However, this makes it difficult to detect burst signals over a large area within the touch surface. This is because the transmission of the burst signal ends before all electrodes within the area have been scanned.

[0010] Furthermore, even when the stylus and sensor controller approach each other at a distance sufficient for a sufficient signal-to-noise ratio during a pen stroke, if the stylus sends a data signal instead of a burst signal at that timing, the sensor controller may fail to detect the stylus.

[0011] Therefore, one of the objectives of this invention is to provide a stylus and sensor controller that can ensure the detection of burst signals over a large area within the touch surface in order to determine the position of an undetected stylus and reduce the possibility of burst signal detection failure by the sensor controller.

[0012] Solution for solving the problem

[0013] The stylus of one side of the present invention is a stylus capable of bidirectional communication with a sensor controller, comprising: a receiving unit for receiving an uplink signal sent by the sensor controller; a control unit for determining, based on the uplink signal, whether to continuously send a signal of a predetermined waveform for a second time or to continuously send the signal of the predetermined waveform for a first time longer than the second time; and a sending unit for continuously sending the signal of the predetermined waveform for the first time or the second time based on the decision result of the control unit.

[0014] Another aspect of the present invention is a stylus capable of bidirectional communication with a sensor controller, comprising: a receiving unit for receiving uplink signals sent by the sensor controller; a control unit for determining the state of the sensor controller based on the uplink signals; and a transmitting unit that, when the uplink signals indicate that the sensor controller is in a state where the stylus has not been detected, continuously transmits signals of a predetermined pattern known in advance between the sensor controller and the sensor controller for a predetermined time according to the instructions of the control unit; on the other hand, when the uplink signals indicate that the sensor controller is in a state where the stylus has been detected, does not continuously transmit signals of the predetermined pattern for the predetermined time, but instead transmits data signals that change according to the operating state of the stylus.

[0015] One aspect of the sensor controller of the present invention is configured to derive the position of a stylus by detecting a signal transmitted from a stylus. The controller is configured to perform: a determination step of determining whether a stylus has been detected or not; a step of sending a second uplink signal to the stylus, instructing it to continuously transmit a signal of a predetermined waveform for a second time, corresponding to the determination step determining that a stylus has been detected; and a step of sending a first uplink signal to the stylus, instructing it to continuously transmit a signal of a predetermined waveform for a first time longer than the second time, corresponding to the determination step determining that a stylus has not been detected.

[0016] Another aspect of the invention is a sensor controller connected to a matrix electrode, which is configured to include M first electrodes extending in a first direction and N second electrodes extending in a second direction different from the first direction. The sensor controller is configured to perform: a finger touch detection step, supplying a predetermined signal to each of the M first electrodes and detecting a finger touch using the predetermined signal detected at each of the N second electrodes; a full-range scanning step, using at least a portion of the M first electrodes and at least a portion of the N second electrodes to detect an undetected stylus and derive the position coordinates of the stylus; and a partial scanning step, using a smaller number of first electrodes and a smaller number of second electrodes than those used in the full-range scanning step to derive the position coordinates of detected styluses.

[0017] Invention Effects

[0018] According to the present invention, when the stylus is in a state of inactivity, where the stylus is likely to be hovering, the sensor controller can anticipate that the stylus will send a long burst signal that lasts for a longer period than a typical burst signal. Therefore, the detection action time of each electrode can be longer than the typical burst signal reception time, and more electrodes can be scanned to detect the burst signal during the duration of the long burst signal transmission. This ensures that the state of burst signal detection can be achieved over a large area within the touch surface, and reduces the possibility of burst signal detection failure by the sensor controller. Attached Figure Description

[0019] Figure 1 This is a diagram showing the structure of an electronic device 3 according to an embodiment of the present invention. (a) shows the operation of the electronic device 3 when detecting the touch of a finger F, and (b) shows the operation of the electronic device 3 when detecting a stylus 2.

[0020] Figure 2 This is a diagram illustrating the structure of an electronic device 3 according to an embodiment of the present invention.

[0021] Figure 3 This is a diagram illustrating the structure of the long burst signal, burst signal, and data signal transmitted by the stylus 2 according to an embodiment of the present invention.

[0022] Figure 4 This is a diagram showing the sequence of signal transmission and reception between the stylus 2 and the sensor controller 31 when the stylus 2 is positioned above the upward detection height AH. (a) shows the case where the sensor controller 31 sends a pen start signal, and (b) shows the case where the sensor controller 31 requests the transmission of a long burst signal.

[0023] Figure 5 This is a diagram showing the sequence of signal transmission and reception between the stylus 2 and the sensor controller 31 during the stage when the stylus 2 is inside the sensing range SR and the sensor controller 31 has not yet determined the position of the stylus 2. (a) shows the case where the sensor controller 31 sends a pen start signal, (b) shows the case where the sensor controller 31 uses the linear electrode 30Y to receive the long burst signal sent by the stylus 2, and (c) shows the case where the sensor controller 31 uses the linear electrode 30X to receive the long burst signal sent by the stylus 2.

[0024] Figure 6 This diagram illustrates the sequence of signal transmission and reception between the stylus 2 and the sensor controller 31 after the stylus 2 is inside the sensing range SR and the sensor controller 31 has determined the position of the stylus 2. It shows the situation where the stylus 2 sends burst signals and data signals.

[0025] Figure 7 This is a diagram illustrating the operation of the sensor controller 31 according to an embodiment of the present invention. (a) shows the first half of the full-range scan, (b) shows the second half of the full-range scan, and (c) shows a partial scan.

[0026] Figure 8 This is a diagram showing the structure of the stylus 2 according to an embodiment of the present invention.

[0027] Figure 9 This is a flowchart illustrating the overall operation of the sensor controller 31 according to an embodiment of the present invention.

[0028] Figure 10 This is a flowchart illustrating the stylus detection process performed by the sensor controller 31 according to an embodiment of the present invention.

[0029] Figure 11 It is shown that... Figure 10 The corresponding flowchart for the actions of stylus 2.

[0030] Figure 12is a diagram showing the configuration of a stylus 2 according to a first modified example of the embodiment of the present invention.

[0031] Figure 13 is a processing flowchart showing the operation of the stylus 2 according to a second modified example of the embodiment of the present invention.

[0032] Figure 14 is a processing flowchart showing the operation of the sensor controller 31 according to a third modified example of the embodiment of the present invention.

[0033] Figure 15 is a diagram showing a long burst signal transmitted by the stylus 2 according to a fourth modified example of the embodiment of the present invention.

[0034] Figure 16 is a processing flowchart showing the operation of the stylus 2 according to a fifth modified example of the embodiment of the present invention.

[0035] Figure 17 is a diagram for explaining specific position exclusion processing according to a sixth modified example of the embodiment of the present invention, where (a) shows a finger touch area detected by finger touch detection processing, and (b) shows the position of the stylus 2 derived by stylus detection processing executed immediately after the finger touch detection processing in (a).

[0036] Figure 18 is a processing flowchart showing the operation of the sensor controller 31 according to the sixth modified example of the embodiment of the present invention. Detailed Description of the Embodiments

[0037] Hereinafter, the embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0038] Figure 1 is a diagram showing the configuration of an electronic device 3 according to the present embodiment. The electronic device 3 is a computer having a touch surface, such as a tablet terminal, and as shown in this diagram, is configured to include a sensor 30 and a sensor controller 31.

[0039] The sensor 30 is configured by a matrix electrode including M linear electrodes 30X (first electrodes) and N (N<M) linear electrodes 30Y (second electrodes) arranged inside the touch surface. In a specific example, M=72 and N=46. The M linear electrodes 30X are arranged to extend at equal intervals in a first direction parallel to the touch surface. Further, the N linear electrodes 30Y are arranged to extend at equal intervals in a second direction that is parallel to the touch surface and orthogonal to the first direction. Each of the linear electrodes 30X and each of the linear electrodes 30Y are connected to the sensor controller 31, respectively.

[0040] The sensor controller 31 is a control unit that uses the sensor 30 to detect the touch of the finger F (including the derivation of the position coordinates of the finger F within the touch surface) and the stylus 2 (including the derivation of the position coordinates of the stylus 2 within the touch surface) in a time-division manner.

[0041] Figure 1 (a) illustrates the operation of the electronic device 3 when detecting the touch of finger F. As shown in the figure, when detecting the touch of finger F, the sensor controller 31 detects the finger detection signal that has reached each of the multiple linear electrodes 30X by sequentially supplying predetermined signals (hereinafter referred to as "finger detection signals") to each of the multiple linear electrodes 30Y and sequentially scanning the potentials of each of the multiple linear electrodes 30X. The amplitude of the detected finger detection signal decreases when finger F approaches the vicinity of the intersection point through which the finger detection signal passes compared to when it does not approach. This is because, through the capacitive coupling generated between finger F and the linear electrodes 30X and 30Y, a portion of the current flowing on the linear electrodes 30X and 30Y flows towards the human body. The sensor controller 31 detects the touch of finger F by detecting this change in amplitude.

[0042] Figure 1 (b) illustrates the basic operation of the electronic device 3 when detecting the stylus 2. As shown in the figure, as a basic operation, the sensor controller 31 sequentially uses multiple linear electrodes 30X and multiple linear electrodes 30Y, each as a receiving electrode, to detect the signal (hereinafter referred to as the "downlink signal") transmitted by the stylus 2. Furthermore, the stylus 2 is detected based on this detection result. It should be noted that in actual operation, sometimes only a portion of the linear electrodes 30X and 30Y are used to detect the stylus 2, but this will be discussed later.

[0043] For the sensor controller 31 to detect the stylus 2, the stylus 2 needs to come close to the touch surface of the electronic device 3 to a point where the sensor controller 31 can receive downlink signals. The sensing range SR shown in the figure schematically illustrates the range within which the sensor controller 31 can receive downlink signals. When the stylus 2 enters this sensing range SR, the sensor controller 31 can receive downlink signals and thus detect the stylus 2. Hereinafter, the action of the stylus 2 moving from outside the sensing range SR into the sensing range SR will be referred to as "pen placement". Pen placement is usually performed by the user's operation of bringing the stylus 2 close to the touch surface of the electronic device 3. In addition, the state in which the stylus 2 has entered the sensing range SR but has not yet made contact with the touch surface is referred to as "hovering period". When the stylus 2 is in the hovering period state after pen placement, the sensor controller 31 needs to detect the stylus 2 by detecting downlink signals. However, during the hovering period, there is a certain distance between the stylus 2 and the touch surface. Due to this distance, it is difficult to ensure a sufficient signal-to-noise ratio. Therefore, as a result, the detection of the stylus 2 sometimes fails. Furthermore, even when the stylus 2 enters the sensing range SR, the sensor controller 31 may sometimes fail to detect the stylus 2 during the period when the stylus 2 is sending a data signal instead of a burst signal. One of the objectives of this invention is to enable the avoidance of such failures.

[0044] Here, even when the stylus 2 is outside the sensing range SR, it can sometimes receive signals (hereinafter referred to as "uplink signals") sent towards the stylus 2 by the sensor controller 31. This is because a portion of the uplink signals (such as the pen activation signal and the instruction signal indicating the transmission of a long burst signal, described later) are transmitted using the entire surface of the touch surface (one or both of all linear electrodes 30X and all linear electrodes 30Y). The uplink detection height AH shown in the figure indicates the limit of the height (distance from the touch surface) at which the stylus 2 can receive these uplink signals. The uplink detection height AH is a position higher than the upper limit of the sensing range SR (a position farther from the touch surface).

[0045] Figure 2 This diagram illustrates the structure of the electronic device 3 according to this embodiment. The plurality of linear electrodes 30X and 30Y constituting the sensor 30 are configured to be capacitively coupled to the stylus 2 and the finger F. When the finger F approaches the sensor 30, a portion of the current flowing from the sensor controller 31 to the linear electrodes 30Y via this capacitive coupling is absorbed by the finger F. Therefore, as described above, the amplitude of the finger detection signal detected by the linear electrodes 30X decreases, thus enabling the sensor controller 31 to detect the touch of the finger F. Furthermore, the sensor 30 is configured to bidirectionally transmit and receive signals with the stylus 2 via the aforementioned capacitive coupling.

[0046] like Figure 2 As shown, the sensor controller 31 is configured to have a transmitting unit 60, a selecting unit 40, a receiving unit 50, a logic unit 70, and an MCU 80.

[0047] The transmitting unit 60 is a circuit that generates a finger detection signal when the touch of finger F is detected, and generates an uplink signal when the stylus 2 is detected. The uplink signal includes a pen activation signal for notifying the sensor controller 31 of the presence of stylus 2, and an instruction signal indicating an instruction (command) for stylus 2.

[0048] Figure 2 The transmitting unit 60 is shown in detail only for the functional blocks related to the generation of uplink signals. These functional blocks include a mode supply unit 61, a switch 62, a diffusion processing unit 63, a code string holding unit 64, and a transmission protection unit 65. It should be noted that, in particular, the mode supply unit 61 is described as being included within the transmitting unit 60 in this embodiment, but it could also be included within the MCU 80.

[0049] The pen start signal consists of repeated specified detection mode c1 and specified interval mode STP configured at the end.

[0050] Detection mode c1 is a mode for the values ​​of symbols used by the stylus 2 to detect the presence of the sensor controller 31. This mode is known to the stylus 2 beforehand (before the stylus 2 detects the sensor controller 31). In the transmission process, a symbol is a unit of information used for modulation (a unit of information represented by the transmitted signal). In the reception process, it is a unit of information obtained by demodulating the 1 symbol, which is the received signal. The value of a symbol can include values ​​converted into bit strings (hereinafter referred to as "bit string corresponding values") and values ​​converted into bit strings by the stylus 2 that are not received (hereinafter referred to as "bit string non-corresponding values"). In a specific example, detection mode c1 is composed of a mode "PM" that combines two types of bit string non-corresponding values, "P" and "M".

[0051] The Segmentation Pattern (STP) is a pattern of symbol values ​​used to notify the stylus 2 of the end of the repetition period of detection pattern c1. It consists of patterns that do not appear during the repetition of detection pattern c1. The STP is also known to the stylus 2 beforehand (before the stylus 2 detects the sensor controller 31). For example, if detection pattern c1 is constructed as described above using a combination of two non-corresponding bit string values ​​"P" and "M" called "PM", the STP can be constructed as a pattern "PP" formed by repeating the non-corresponding bit string value "P" twice consecutively. Alternatively, the structure of the STP and detection pattern c1 can be reversed, with the STP constructed using "PM" and the detection pattern c1 constructed using "PP".

[0052] The mode supply unit 61 holds the detection mode c1 and the partition mode STP, configured to output them in a predetermined order according to the instruction of the control signal ctrl_t1 supplied from the logic unit 70. Specifically, it is configured to continuously and repeatedly output the detection mode c1 during a predetermined continuous transmission period, and output the partition mode STP immediately after the end of the continuous transmission period. This realizes the transmission of the pen start signal. It should be noted that the partition mode STP can also be set to be output before the instruction signal (described later) indicating the transmission instruction of a long burst signal.

[0053] Switch 62 has the function of selecting either mode supply unit 61 or MCU 80 based on the control signal ctrl_t2 supplied from logic unit 70, and supplying the output of the selected one to diffusion processing unit 63. When switch 62 selects mode supply unit 61, detection mode c1 or separation mode STP is supplied from mode supply unit 61 to diffusion processing unit 63. On the other hand, when switch 62 selects MCU 80, control information c2 is supplied from MCU 80 to diffusion processing unit 63.

[0054] Control information c2 is information indicating instructions (commands) to stylus 2, generated by MCU 80. The aforementioned instruction signal is constituted by this control information c2. Control information c2 differs from detection mode c1 and separation mode STP in that it includes a value (e.g., 0-15) corresponding to a variable-length bit string, and this value is not previously shared with stylus 2.

[0055] The code string holding unit 64 has the function of generating and holding an extended code PN of a specified chip length with autocorrelation characteristics based on the control signal ctrl_t3 supplied from the logic unit 70. The extended code PN held by the code string holding unit 64 is supplied to the diffusion processing unit 63.

[0056] The diffusion processing unit 63 has the function of obtaining a transmit chip string of a predetermined chip length by modulating the extended code PN held by the code string holding unit 64 based on the value of the symbol supplied via the switch 62 (detection mode c1, separation mode STP, or control information c2). The diffusion processing unit 63 is configured to supply the obtained transmit chip string to the transmit protection unit 65.

[0057] The transmission protection unit 65 has the function of inserting a protection period (the period during which neither transmission nor reception is performed) between the transmission period of the uplink signal and the reception period of the downlink signal based on the control signal ctrl_t4 supplied from the logic unit 70, which is required to switch the transmission and reception operations.

[0058] The receiving unit 50 is a circuit used to receive the finger detection signal sent by the transmitting unit 60 or the downlink signal sent by the stylus 2 based on the control signal ctrl_r from the logic unit 70. Specifically, it is configured to include an amplifier circuit 51, a detector circuit 52, and an analog-to-digital (AD) converter 53.

[0059] Amplifier circuit 51 amplifies and outputs the signal (finger detection signal or downlink signal) supplied from selection unit 40. Detector circuit 52 is a circuit that generates a voltage corresponding to the level of the output signal of amplifier circuit 51. AD converter 53 is a circuit that generates a digital signal by sampling the voltage output from detector circuit 52 at predetermined time intervals. The digital signal output by AD converter 53 is supplied to MCU 80.

[0060] The selection unit 40 is configured to include switches 44x and 44y and conductor selection circuits 41x and 41y.

[0061] Switches 44x and 44y are switching elements configured as a 1-circuit 2-contact circuit, each connected to either a common terminal or either a T terminal or an R terminal. The common terminal of switch 44x is connected to conductor selection circuit 41x, its T terminal is connected to the output terminal of transmitting unit 60, and its R terminal is connected to the input terminal of receiving unit 50. Similarly, the common terminal of switch 44y is connected to conductor selection circuit 41y, its T terminal is connected to the output terminal of transmitting unit 60, and its R terminal is connected to the input terminal of receiving unit 50.

[0062] The conductor selection circuit 41x is a switching element for selectively connecting M linear electrodes 30X to the common terminal of the switch 44x. The conductor selection circuit 41x is also configured to simultaneously connect some or all of the M linear electrodes 30X to the common terminal of the switch 44x.

[0063] The conductor selection circuit 41y is a switching element used to selectively connect N linear electrodes 30Y to the common terminal of the switch 44y. The conductor selection circuit 41y is also configured to simultaneously connect some or all of the N linear electrodes 30Y to the common terminal of the switch 44y.

[0064] The logic unit 70 supplies four control signals, sTRx, sTRy, selX, and selY, to the selection unit 40. Specifically, control signal sTRx is supplied to switch 44x, control signal sTRy is supplied to switch 44y, control signal selX is supplied to conductor selection circuit 41x, and control signal selY is supplied to conductor selection circuit 41y. The logic unit 70 uses these control signals sTRx, sTRy, selX, and selY to control the selection unit 40 to transmit and receive finger detection signals, transmit uplink signals including pen start signals and command signals, and receive downlink signals. The control of the selection unit 40 by the logic unit 70 will be explained in detail later.

[0065] The logic unit 70 and MCU 80 are control units that control the transmission and reception operations of the sensor controller 31 by controlling the transmitting unit 60, the receiving unit 50, and the selection unit 40. Specifically, the MCU 80 is a microprocessor that has internal ROM and RAM and operates based on a predetermined program. On the other hand, the logic unit 70 is configured to output the aforementioned control signals based on the control of the MCU 80. Furthermore, the MCU 80 is configured to perform the following processing: derive coordinate data (x, y, etc.) representing the position of the finger F or the stylus 2 based on the digital signal supplied from the AD converter 53, and output this data to the system controller of the electronic device 3; when the digital signal supplied from the AD converter 53 represents a data signal, acquire the data Res represented by that digital signal, and output this data to the system controller of the electronic device 3.

[0066] The following is a detailed explanation of the control of the selection unit 40 by the logic unit 70.

[0067] First, the logic unit 70, which transmits and receives signals for finger detection, connects N linear electrodes 30Y sequentially to the output of the transmitting unit 60 and M linear electrodes 30X sequentially to the input of the receiving unit 50, and controls the selection unit 40 using control signals sTRx, sTRy, selX, and selY. Thus, as... Figure 1 As shown, finger detection signals can be sequentially supplied to N linear electrodes 30Y, and the receiving unit 50 can detect the finger detection signals that arrive at each linear electrode 30X through the intersection with the linear electrodes 30Y, thus enabling the detection of finger F touch.

[0068] The logic unit 70, which transmits uplink signals and receives downlink signals, performs different processing depending on the detection state of the stylus 2 and the type of downlink signal. Hereinafter, the types of downlink signals and the signal transmission and reception sequence between the stylus 2 and the sensor controller 31 will be explained first, followed by a detailed explanation of the operation of the logic unit 70 during uplink signal transmission and downlink signal reception.

[0069] Figure 3 This diagram illustrates the types of downlink signals transmitted by the stylus 2 according to an embodiment of the present invention. As shown in the diagram, the downlink signals include long burst signals, burst signals, and data signals. A long burst signal is a signal formed by continuously transmitting a signal of a predetermined waveform, known in advance between the stylus 2 and the sensor controller 31, for a predetermined time T1 (first time). A burst signal is a signal formed by continuously transmitting the aforementioned signal of the predetermined waveform for a predetermined time T2 (second time), shorter than time T1. The data signal is a data signal modulated by data onto the aforementioned signal of the predetermined waveform, and is transmitted after the burst signal within a time interval corresponding to the difference between time T2 and time T1, T1-T2. It should be noted that a predetermined gap signal (not shown) is inserted before the burst signal to indicate a separation from the burst signal. The type of downlink signal transmitted by the stylus 2 is selected according to the instruction signal sent by the sensor controller 31.

[0070] Figures 4-6 This is a diagram showing the sequence of signal transmission and reception between the stylus 2 and the sensor controller 31. Figure 4 This shows the situation where the stylus 2 is positioned above the upward detection height AH. Figure 5 This shows the stage where the stylus 2 is inside the sensing range SR and the sensor controller 31 has not yet determined the position of the stylus 2. Figure 6 This is shown after the stylus 2 is inside the sensing range SR and the sensor controller 31 has determined the position of the stylus 2. The following sections will explain each case in turn.

[0071] <When stylus 2 is positioned above the upward detection height AH>

[0072] Figure 4 (a) shows the sensor controller 31 sending a pen start signal. Figure 4 (b) shows the case where the sensor controller 31 requests the transmission of a long burst signal.

[0073] First, such as Figure 4As shown in (a), the sensor controller 31 sends a pen activation signal during the time T (=t1-t0) from time t0 to time t1. This transmission is performed before the sensor controller 31 detects the stylus 2. As described above, the pen activation signal is a signal that includes the repetition of detection mode c1 and the final interval mode STP. The stylus 2 intermittently performs the detection action of detection mode c1 by intermittently performing the detection action of the symbols constituting detection mode c1 (in the example above, "P" and "M"), but when it is above the upward detection height AH, it cannot detect detection mode c1 even through this detection action. Therefore, the stylus 2 simply repeats the detection action of detection mode c1.

[0074] The sensor controller 31 is connected after the pen start signal is sent, such as... Figure 4 As shown in (b), the command signal begins at time t2 after time t1 (in Figures 4-6 The transmission of the command signal (referred to as "CMD") takes a shorter time than the time T mentioned above, T0. Before the stylus 2 is detected, the sensor controller 31 sends a command signal indicating a long burst signal transmission instruction. However, the stylus 2, located above the upward detection height AH, cannot receive this command signal and therefore will not send a long burst signal according to the command signal; it simply repeats the detection action of detection mode c1.

[0075] After sending a command signal indicating a long burst signal transmission instruction, the sensor controller 31 performs a long burst signal detection operation. This detection operation corresponds to the first half of the full-range scan described later, and is performed sequentially using N linear electrodes 30Y. Details of the full-range scan will be described later. Here, since the stylus 2 does not transmit long burst signals, the sensor controller 31 will not detect them. The time available for long burst signal detection is time T1 (=T-T0), which is the difference between time T and time T0. However, when performing long burst signal detection using N linear electrodes 30Y sequentially, the detection is temporarily completed at time t3, which is earlier than time t4 (=t2+T) after time T1 has elapsed. Therefore, since no long burst signal is detected during this detection operation, the sensor controller 31 enters a sleep state between time t3 and time t4. As a result, the power consumption of the sensor controller 31 is reduced. After time t4, the pen activation signal is repeatedly transmitted.

[0076] <The stage where stylus 2 is inside the sensing range SR and the sensor controller 31 has not yet determined the position of stylus 2>

[0077] Figure 5(a) shows the sensor controller 31 sending a pen start signal. Figure 5 (b) shows the sensor controller 31 using a linear electrode 30Y to receive long burst signals sent by the stylus 2. Figure 5 (c) shows the situation where the sensor controller 31 uses the linear electrode 30X to receive long burst signals sent by the stylus 2.

[0078] When Figure 5 After the pen stroke is performed as shown in (a) (time t6), the stylus 2 can detect detection mode c1 through the subsequent detection action of detection mode c1 (time t7). The stylus 2, having detected detection mode c1, continues the detection action until the segmentation mode STP is detected. Furthermore, after the segmentation mode STP is detected, synchronization is performed with the sensor controller 31 based on this detection time. Specifically, this synchronization is performed through the creation of the transmit / receive schedule described later.

[0079] It should be noted that, Figure 5 (a) illustrates an example where a pen stroke is performed at time t6, between the start of the pen activation signal transmission (t5) and the end of the pen activation signal transmission (t8) (=t5+T), and the stylus 2 detects detection mode c1 at time t7 before reaching time t8. However, this also applies to cases where a pen stroke is performed, for example, while the sensor controller 31 is performing a long burst signal detection operation (e.g. Figure 5 (b) The time t6' shown is just a slight delay in the timing of the stylus 2's detection of detection mode c1, and the same processing will be performed.

[0080] Next, as Figure 5 As shown in (b), after the sensor controller 31 sends an instruction signal indicating the transmission of a long burst signal at time t9 after time t8, the stylus 2 receives the instruction signal and continuously transmits long burst signals for a period of time T1 until time t10 (=t9+T). The sensor controller 31 detects the stylus 2 by detecting the long burst signals transmitted in this way.

[0081] Specifically, firstly, as Figure 5 As shown in (b), N linear electrodes 30Y are used sequentially to detect long burst signals (the first half of the full-range scan described later). Since the long burst signals are detected by any one or more linear electrodes 30Y, the sensor controller 31 stores the detection intensity of the long burst signals at each linear electrode 30Y. Next, as... Figure 5As shown in (c), the sensor controller 31 resumes transmitting the instruction signal indicating the transmission of a long burst signal at time t11 after time t10, and performs the long burst signal detection operation again after the transmission ends. This detection operation is performed sequentially using M linear electrodes 30X up to time t12 (=t11+T) (the latter half of the full-range scan described later). Through this detection operation, the long burst signal is detected by any one or more linear electrodes 30X, and therefore the sensor controller 31 stores the detection intensity of the long burst signal at each linear electrode 30X. Then, based on the previously stored detection intensity of the long burst signal at each linear electrode 30Y and the currently stored detection intensity of the long burst signal at each linear electrode 30X, the position coordinates of the stylus 2 on the touch surface are derived.

[0082] <After the stylus 2 is inside the sensing range SR and the sensor controller 31 determines the position of the stylus 2>

[0083] Figure 6 The diagram illustrates the transmission of burst signals and data signals by the stylus 2. As shown, the sensor controller 31, having determined the position of the stylus 2, begins transmitting a command signal indicating data transmission at time t13. Upon receiving this signal, the stylus 2 first continuously transmits burst signals within time T2. The sensor controller 31 detects these burst signals and derives the position coordinates of the stylus 2 based on the detected burst signals. The burst signal detection operation is performed sequentially using only the electrodes from the M linear electrodes 30X and N linear electrodes 30Y that indicate the vicinity of the stylus 2 based on the previously derived position coordinates of the stylus 2 (local scanning described later). Following the burst signals, the stylus 2 transmits a data signal including the indicated data. The sensor controller 31 obtains the data transmitted by the stylus 2 by receiving and decoding this data signal. The reception of the data signal is performed using only one linear electrode 30X or linear electrode 30Y corresponding to the previously derived position coordinates of the stylus 2.

[0084] return Figure 2 The operation of the logic unit 70 during the detection of the stylus 2 and bidirectional communication with the stylus 2 is explained in detail.

[0085] When sending the instruction signal indicating the pen start signal and the long burst signal ( Figure 4 (a)(b) Figure 5The logic unit 70 of (a)(b)(c) controls the selection unit 40 by simultaneously using all of the M linear electrodes 30X, all of the N linear electrodes 30Y, or both. Specifically, the selection unit 40 is controlled using control signals sTRx, sTRy, selX, and selY, such that the output terminal of the transmitting unit 60 is simultaneously connected to one or both of the M linear electrodes 30X and the N linear electrodes 30Y. Thus, instruction signals indicating the pen activation signal and the long burst signal are respectively transmitted to the entire touch surface, so the stylus 2, regardless of its position... Figure 1 These signals can be received anywhere within the sensing range SR shown.

[0086] like Figure 4 (b) and Figure 5 As shown in (b), when a long burst signal is received before the stylus 2 is detected ( Figure 4 (b) Figure 5 (b) The logic unit 70 controls the selection unit 40 by sequentially using N linear electrodes 30Y. Specifically, the selection unit 40 is controlled by control signals sTRy and selY, with the N linear electrodes 30Y sequentially connected to the input terminals of the receiving unit 50. Thus, regardless of whether the stylus 2 is in the position of the input terminal, the selection unit 40 is controlled by these signals. Figure 1 Wherever the sensor controller 31 is within the sensing range SR shown, it can receive the long burst signal sent by the stylus 2 and thereby detect the stylus 2.

[0087] Figure 7 (a) is a diagram illustrating the operation of the sensor controller 31 in this case. As shown in the diagram, the sensor controller 31 scans the N linear electrodes 30Y sequentially in this case. The reason why the M linear electrodes 30X are not scanned in this stage is that the entire surface of the sensor 30 can be scanned using only the N linear electrodes 30Y, and also to extend the scanning time for each electrode.

[0088] Also Figure 5 As shown in (c), after the stylus 2 is detected by receiving the long burst signal, when the long burst signal is received in the stage before the position coordinates of the stylus 2 are derived ( Figure 5 (c) The logic unit 70 controls the selection unit 40 by sequentially using M linear electrodes 30X. Specifically, the selection unit 40 is controlled by control signals sTRx and selX, with the M linear electrodes 30X sequentially connected to the input terminals of the receiving unit 50. Based on the result of this control and the detection results of long burst signals by the previously implemented N linear electrodes 30Y, the sensor controller 31 derives the position coordinates of the stylus 2 on the touch surface as described above.

[0089] Figure 7(b) is a diagram illustrating the operation of the sensor controller 31 in this situation. As shown in the diagram, the sensor controller 31 sequentially scans the M linear electrodes 30X in this situation. In this specification, Figure 7 (a) shows the sequential scanning (first half) using N linear electrodes 30Y and Figure 7 (b) The scans (second half) using M linear electrodes at 30X as shown are collectively referred to as the “full-range scan” (first scan).

[0090] When sending command signals in the stage after exporting the position coordinates of stylus 2 ( Figure 6 The logic unit 70 controls the selection unit 40 using only the electrodes near the stylus 2 from among the M linear electrodes 30X and N linear electrodes 30Y. Specifically, assuming, for example, that the stylus 2 is located at the intersection of the (j+5)th linear electrode 30X and the (i+5)th linear electrode 30Y, the selection unit 40 is controlled using control signals sTRx, sTRy, selX, and selY, such that the range of five linear electrodes extending outwards from this point (i.e., the jth to j+10th linear electrodes 30X and the ith to i+10th linear electrodes 30Y) is simultaneously connected to the output of the transmitting unit 60. This allows the command signal to be transmitted using only the linear electrodes near the stylus 2, thus reducing the power consumption for transmitting the command signal. Furthermore, if a command signal is supplied to a hand or other object placed on the touch surface, the ground potential supplied to the stylus 2 will rise. As a result, the stylus 2 may decrease its detection accuracy of the uplink signal. However, by using only the linear electrode located near the stylus 2 to send the command signal as described above, the possibility of supplying the command signal to a hand or other object is reduced, thus preventing the stylus 2 from decreasing its detection accuracy of the uplink signal.

[0091] After exporting the position coordinates of stylus 2, when receiving a normal burst signal that is not a long burst signal ( Figure 6 The logic unit 70 controls the selection unit 40 by sequentially using only the electrodes located near the stylus 2 from among the M linear electrodes 30X and N linear electrodes 30Y. Specifically, for example, assuming the stylus 2 is located at the intersection of the (j+5)th linear electrode 30X and the (i+5)th linear electrode 30Y, then, for example... Figure 6 As shown, with five linear electrodes 30X (jth to j+10th) and five linear electrodes 30Y (ith to i+10th) extending outwards from this point to the input terminal of the receiving unit 50, the selection unit 40 is controlled using control signals sTRx, sTRy, selX, and selY. This extends the reception time of each linear electrode, thus enabling more reliable reception of burst signals.

[0092] Figure 7(c) is a diagram illustrating the operation of the sensor controller 31 in this case. In this example, the stylus 2 is also assumed to be located at the intersection of the (j+5)th linear electrode 30X and the (i+5)th linear electrode 30Y. In this example, the sensor controller 31 only sequentially scans the 11 linear electrodes 30X from the jth to the (j+10)th of the M×N linear electrodes and the 11 linear electrodes 30Y from the ith to the (i+10)th, and derives the position coordinates of the stylus 2 based on this result. Hereinafter, the scan that uses both a portion of the M linear electrodes 30X and a portion of the N linear electrodes 30Y to derive (update) the position coordinates of the stylus 2 derived once is called a "partial scan" (second scan).

[0093] When receiving data signals ( Figure 6 The logic unit 70 controls the selection unit 40 using only one linear electrode 30X or linear electrode 30Y corresponding to the position of the stylus 2 derived from the previous burst signal. Specifically, the selection unit 40 is controlled using control signals sTRx, sTRy, selX, and selY, with the linear electrode 30X or linear electrode 30Y connected to the input terminal of the receiving unit 50. This allows the data signal transmission time (=T1-T2) to be fully utilized for transmitting data from the stylus 2 to the sensor controller 31.

[0094] The above describes the operation of the logic unit 70 during the detection of the stylus 2 and the bidirectional communication with the stylus 2.

[0095] Figure 8 This is a block diagram showing the functional blocks of the stylus 2 according to this embodiment. As shown in the figure, the stylus 2 is configured to have an electrode 21, a pen pressure detection sensor 23, and a signal processing unit 24.

[0096] Electrode 21 is a conductive component located near the top of the core of stylus 2. It serves as an antenna for transmitting downlink signals and also as an antenna for receiving uplink signals transmitted from sensor controller 31 via coupling capacitor.

[0097] The pen pressure sensor 23 is a pressure sensor used to detect the pressure (pen pressure) applied to the tip of the core of the stylus 2.

[0098] The signal processing unit 24 has the following functions: receiving uplink signals from the sensor controller 31 via electrode 21, performing processing corresponding to the signals, and generating downlink signals to be sent to the sensor controller 31, which are then sent to the sensor controller 31 via electrode 21. Specifically, it is functionally configured to include a switching unit 76, a receiving unit 71, a transmitting unit 75, and a control unit 90. These functional blocks will be described in turn below.

[0099] The switching unit 76 is a switching element configured as a circuit 2 contact connected to either the common terminal or the T terminal and the R terminal. The common terminal of the switching unit 76 is connected to the electrode 21, the T terminal is connected to the output terminal of the transmitting unit 75, and the R terminal is connected to the input terminal of the receiving unit 71. The state of the switching unit 76 is controlled by the control signal SWC from the control unit 90. When the control unit 90 receives an uplink signal from the sensor controller 31, it controls the switching unit 76 by connecting the R terminal to the common terminal using the control signal SWC. In addition, when a downlink signal is sent to the sensor controller 31, it controls the switching unit 76 by connecting the T terminal to the common terminal using the control signal SWC. In the initial state, that is, during the period before the stylus 2 detects the above-mentioned detection mode c1, the control unit 90 fixes the switching unit 76 in the state where the R terminal is connected to the common terminal, and puts it into a sleep state in order to reduce the power consumption of the stylus 2.

[0100] The receiving unit 71 is a circuit that receives the signal supplied from the switching unit 76 (the signal that has arrived at the electrode 21) and decodes the value of the symbol contained in the received signal. It is configured to include a waveform regeneration unit 71a and a correlation arithmetic unit 71b. The receiving unit 71 is configured to detect the detection mode c1, the segmentation mode STP, and the control information c2 respectively through this decoding. In order to reduce the power consumption of the stylus 2, the receiving unit 71 only performs receiving operations intermittently during the period until the detection mode c1 is detected.

[0101] The waveform regeneration unit 71a binarizes the level of the charge (voltage) induced by the electrode 21 at a clock frequency several times (e.g., 4 times) of the chip rate of the aforementioned extended code PN, shaping it into a binary string (chip string) of positive and negative extreme values, and outputs it. The correlation unit 71b stores the chip string output by the waveform regeneration unit 71a in a register, and performs correlation operations with the extended code PN (or, symbols obtained by flipping and cyclically shifting the extended code PN) while sequentially shifting the aforementioned clock, thereby decoding the value of the symbol contained in the received signal.

[0102] The receiving unit 71 sequentially determines whether the value of the symbol decoded by the correlation arithmetic unit 71b represents the aforementioned detection mode c1. When detection mode c1 is detected as a result, the sensor controller 31 is detected and issues a start signal EN to the control unit 90 to enable the execution of processing corresponding to the instruction represented by the instruction signal.

[0103] Furthermore, when the detection mode c1 is detected, the receiving unit 71 switches the receiving operation from intermittent to continuous, and successively determines whether the value of the decoded symbol represents the aforementioned STP (Separation Mode Phenomenon). When the STP is detected as a result, the receiving unit 71 outputs the detection time t2 to the control unit 90.

[0104] After detecting the Segmentation Mode (STP), the receiving unit 71 performs the receiving operation of the command signal sent by the sensor controller 31 according to the scheduling of the control unit 90 (described later). Specifically, it obtains the values ​​of a series of symbols decoded by the correlation arithmetic unit 71b during the receiving operation as control information c2 and outputs them to the control unit 90.

[0105] The control unit 90, comprised of a microprocessor (MCU), is activated upon receiving a start signal EN from the receiving unit 71. It then generates a transmission schedule for various signals based on a detection time t2 provided by the receiving unit 71. Next, it performs processing to generate a control signal SWC based on the generated transmission schedule and supply it to the switching unit 76; controls the receiving unit 71 to receive command signals; and controls the transmitting unit 75 based on control information c2 provided by the receiving unit 71. The control of the transmitting unit 75 includes: determining whether to transmit a long burst signal, a burst signal, or a data signal based on the received command signal; instructing the transmitting unit 75 to transmit the command when a long burst signal or a burst signal is transmitted; and acquiring the data instructed to be transmitted by the control information c2 and supplying it to the transmitting unit 75 when a data signal is transmitted. The data supplied to the transmitting unit 75 includes data representing the pen pressure detected by the pen pressure detection sensor 23.

[0106] The transmitting unit 75 is a circuit that generates signals to be transmitted to the sensor controller 31 and supplies them to the electrode 21. It consists of a modulation unit 73 and a boost circuit 74.

[0107] The modulation unit 73 is a circuit that generates a carrier signal (rectangular wave signal) at a predetermined frequency or at a frequency controlled by the control unit 90 and outputs it directly, or outputs it after modulation based on the control of the control unit 90. When transmitting long burst signals and burst signals, the modulation unit 73 outputs the carrier signal directly without modulation, or modulates it in a mode with a known value shared with the sensor controller 31 and outputs it. Thus, the long burst signal and the burst signal before boost are output from the modulation unit 73. On the other hand, when transmitting data signals, the carrier signal (OOK, PSK, etc.) is modulated using data supplied from the control unit 90, and the resulting modulated signal is output. Thus, the data signal before boost is output from the modulation unit 73.

[0108] The boost circuit 74 is a circuit that generates a long burst signal, a burst signal, and a data signal by boosting the output signal of the modulation unit 73 to a certain amplitude. The long burst signal, the burst signal, and the data signal generated by the boost circuit 74 are sent out from the electrode 21 to space via the switching unit 76.

[0109] The structure and operation of the sensor controller 31 and stylus 2 in this embodiment have been described above. Next, referring to the processing flowcharts of the sensor controller 31 and stylus 2, the operation of each will be described in more detail.

[0110] first, Figure 9 This is a flowchart illustrating the overall operation of the sensor controller 31. As shown in the figure, the sensor controller 31 is configured to repeatedly perform the same operation, including four finger touch detection processes (steps S1 and S2) and four stylus detection processes (step S3), at intervals defined by a time Tr (e.g., the reciprocal of 60Hz, i.e., 16.67ms), for example, every time interval. The finger touch detection process and the stylus detection process are executed alternately, with each finger touch detection process continuously executed for a time Tf (e.g., 1500μs) and each stylus detection process continuously executed for a time Ts (e.g., 2500μs). It should be noted that the detection of finger F is performed as one finger touch position detection unit, consisting of two finger touch detection processes (steps S1 and S2) that are executed discontinuously, separated by the stylus detection process.

[0111] Figure 10 This is a flowchart illustrating the stylus detection process performed by the sensor controller 31. Although not shown, the sensor controller 31 stores status flags indicating its own state. The states indicated by the status flags include: stylus not detected and stylus activation signal waiting state (=0), stylus not detected and response to stylus activation signal waiting state (=1), stylus detected and position not derived state (=2), and stylus position derived state (=3). The sensor controller 31 first refers to this status flag (step S10).

[0112] When the referenced status flag in step S10 is "0", the sensor controller 31 will, at a predetermined time T (e.g., with...), Figure 9 Within the same 2500μs time Ts shown, a pen start signal is sent (step S11). Specifically, the repeated and interval mode STP of detection mode c1 is sent. After the continuous transmission of the pen start signal ends, the sensor controller 31 sets the status flag to "1" (step S12), and the process returns to step S10.

[0113] If the status flag referenced in step S10 is "1", the sensor controller 31 first sends a command signal (first uplink signal) indicating a transmission indication for a long burst signal (step S13). The transmission of various command signals, including this command signal, is as follows: Figure 10 The maximum required time T0 is shown (e.g., 200 μs). Afterwards, the sensor controller 31 performs a long burst signal detection operation within time T1 (step S14). This detection operation is performed by referring to... Figure 7 (a) The first half of the full-range scan (first scan) is performed as described.

[0114] After the sensor controller 31 terminates the detection of the long burst signal after time T1, it determines whether a long burst signal has been received (step S15). If it determines that no signal has been received, it sets the status flag to "0" (step S16), causing the process to return to step S10. Step S16 is, for example, when the stylus 2 is in... Figure 1 This refers to the handling of situations where the sensor controller 31 cannot receive the downlink signal due to reasons such as being outside the sensing range SR shown. On the other hand, if it is determined in step S15 that a signal has been received, the sensor controller 31 sets the status flag to "2" (step S17), then determines the instruction to be sent to the stylus 2 (step S18), and then returns the processing to step S10. The instruction determined here becomes the instruction to send a long burst signal.

[0115] If the referenced status flag in step S10 is "2", the sensor controller 31 first sends again the instruction signal (first uplink signal) indicating the transmission indication of a long burst signal (step S19). Then, the sensor controller 31 executes the long burst signal detection action within time T1 again (step S20). This detection action is based on the reference... Figure 7 (b) The second half of the full-range scan (first scan) is performed as described. It should be noted that if the first half of the full-range scan (step S14) and the second half of the full-range scan (step S20) can be performed in one time T1, these two steps S14 and S20 can also be performed in one process.

[0116] After the sensor controller 31 terminates the detection of the long burst signal after time T1, it determines whether a long burst signal has been received (step S21). If it determines that no signal has been received, it sets the status flag to "0" (step S22), causing the process to return to step S10. Step S22 occurs, for example, when the stylus 2 is removed from the stylus. Figure 1This refers to the handling of situations where the sensor controller 31 becomes unable to receive downlink signals due to reasons such as being outside the sensing range SR shown. On the other hand, if it is determined in step S21 that a signal has been received, the sensor controller 31 sets the status flag to "3" (step S23), and derives the position of the stylus 2 based on the detection results of the long burst signal in step S14 and step S20 (step S24). Then, after determining the instruction to be sent to the stylus 2 (step S25), the process returns to step S10. The instruction determined here is an instruction to send various data (data representing stylus ID, pen pressure, etc.), and also serves as an instruction to send burst signals within time T2.

[0117] If the referenced status flag in step S10 is "3", the sensor controller 31 sends a command signal (second uplink signal) indicating the command determined in step S25 or step S32 (described later) (step S26). Then, the sensor controller 31 performs a burst signal detection operation within a time T2 shorter than time T1 (step S27), and if a burst signal is detected, it derives the position coordinates of the stylus 2 based on the detection intensity at each linear electrode 30X, 30Y (step S28). The burst signal detection operation in step S27 is performed by referring to... Figure 7 (c) The local scan (second scan) described is performed.

[0118] After the sensor controller 31 finishes detecting the burst signal after time T2, it proceeds to detect the data signal (step S29). This detection action includes decoding the data signal. The data signal detection is performed using either a linear electrode 30X or a linear electrode 30Y selected based on the position coordinates derived in the previous step S28. This allows for full utilization of the data signal detection period, thus enabling the reception of more data from the stylus 2.

[0119] After the sensor controller 31 finishes detecting the data signal, it determines whether a burst signal or a data signal has been received (step S30). If it determines that neither has been received, it sets the status flag to "0" (step S31), causing the process to return to step S10. Step S31 occurs, for example, when the stylus 2 is disengaged. Figure 1This refers to the handling of situations where the sensor controller 31 becomes unable to receive downlink signals due to reasons such as being outside the sensing range SR. On the other hand, if it is determined in step S30 that at least one signal has been received, then after determining the instruction to be sent to the stylus 2 (step S32), the process returns to step S10. The instruction determined here is also an instruction to send various data (data representing stylus ID, pen pressure, etc.), and also serves as an instruction to send burst signals within time T2.

[0120] then, Figure 11 It is shown that... Figure 10 The flowchart shows the processing of the corresponding actions of the stylus 2. Although not shown, the stylus 2 also stores a status flag indicating its own state. The states indicated by the status flag include a sensor controller not detected state (=0) and a sensor controller detected state (=1). The stylus 2 first refers to this status flag (step S40).

[0121] When the referenced status flag in step S40 is "0", the stylus 2 first enters the receiving action pause state (step S41). Then, after a predetermined time, it attempts to perform the detection mode c1 described above (step S42). The pause period in step S41 is set to reduce the power consumption of the stylus 2 by intermittently performing the detection action of detection mode c1.

[0122] Next, the stylus 2 determines whether detection mode c1 has been detected through the attempt in step S42 (step S43). If it is determined that no detection has been made, the process returns to step S40. On the other hand, if it is determined that detection has been made, the stylus 2 continues the detection operation of the symbols constituting detection mode c1 and the partition mode STP until the partition mode STP is detected (step S44). Then, if the partition mode STP is detected, a synchronization process with the sensor controller 31 based on the detection time is performed (step S45), and then the status flag is set to "1" (step S46), returning the process to step S40. Specifically, the synchronization process in step S45 is... Figure 8 The control unit 90 shown is responsible for generating and processing the send / receive schedule.

[0123] If the status flag referenced in step S40 is "1", the stylus 2 first performs a command signal detection operation (step S47). This detection operation is performed within time T0. Next, the stylus 2 determines whether a command signal was detected through the detection operation in step S47, and if so, what the command signal indicates (step S48). If it is determined that no command signal was detected, the status flag is set to "0" (step S49), and the process returns to step S40. This step S49 is, for example, when the stylus 2 is disengaged from... Figure 1 This refers to the handling of situations where the stylus 2 becomes unable to detect the uplink signal due to reasons such as being outside the sensing range SR shown.

[0124] On the other hand, if it is determined in step S48 that an instruction signal indicating the transmission of a long burst signal has been detected, the stylus 2 determines to transmit the long burst signal and performs the transmission of the long burst signal process within time T1 (step S50). Specifically, within time T1, the signal constituting the aforementioned predetermined waveform of the long burst signal is continuously transmitted. Afterwards, the process returns to step S40.

[0125] Furthermore, if it is determined in step S48 that an instruction signal indicating data transmission is detected, the stylus 2 decides to transmit a burst signal and performs the transmission of the burst signal processing within time T2 (step S51). Specifically, within time T2, the aforementioned predetermined waveform constituting the burst signal is continuously transmitted. Next, the stylus 2 performs the transmission of a data signal including the indicated data (step S52). Afterward, the processing returns to step S40.

[0126] As explained above, according to this embodiment, when the stylus 2 is in a state where it is highly likely to be in a hovering state and therefore undetected, the sensor controller 31 can expect the stylus 2 to send a long burst signal that lasts longer than a normal burst signal. Therefore, the detection action time of each linear electrode can be longer than the normal burst signal reception time, and more linear electrodes (in this embodiment, all linear electrodes 30Y or 30X) can be scanned during the duration of the long burst signal transmission to detect the burst signal. This ensures that the burst signal can be detected over a large area of ​​the touch surface and reduces the possibility of burst signal detection failure by the sensor controller 31.

[0127] Furthermore, according to this embodiment, since full-range scanning is used when receiving long burst signals, it is possible to ensure that the state of the burst signal can be detected over the entire touch surface, and to extend the detection time of each linear electrode.

[0128] Furthermore, according to this embodiment, since the stylus 2 is instructed to send a long burst signal from the sensor controller 31 via an instruction signal indicating the transmission of a long burst signal, the stylus 2 can clearly know the timing when the long burst signal should be sent.

[0129] While preferred embodiments of the present invention have been described above, the present invention is not limited to such embodiments in any way, and can of course be implemented in various ways without departing from its spirit.

[0130] Hereinafter, the first to sixth variations of the above embodiments will be described.

[0131] Figure 12 This diagram illustrates the structure of the stylus 2 in a first variation of the above-described embodiment. This variation differs from the above embodiment in that the sensor controller 31 and stylus 2 use wireless communication without electrostatic coupling for uplink signal transmission. Furthermore, it differs from the above embodiment in that the stylus 2 transmits two downlink signals DS1 and DS2, which correspond to different carrier signal forms. Both downlink signals DS1 and DS2 are configured to transmit the aforementioned long burst signal, burst signal, and data signal; the stylus 2 uses them separately depending on the type of sensor controller 31 that is nearby. Hereinafter, refer to... Figure 12 The structure of the stylus 2 in this modified example will be described in detail.

[0132] like Figure 12 As shown, the stylus 2 of this modified example is configured to have an electrode 21, a signal processing unit 24, a power supply 25, an amplification unit 26, and a receiving unit 27.

[0133] The receiving unit 27 is a functional unit configured to perform communication such as Bluetooth (registered trademark) as wireless communication. In this modified example, it receives the uplink signal sent by the sensor controller 31 using Bluetooth (registered trademark).

[0134] The signal processing unit 24 is a functional unit that has the function of selectively transmitting two downlink signals DS1 and DS2 and receiving uplink signal US via the receiving unit 27. Specifically, it is configured to have a control unit 91, a boost unit 92, an oscillation unit 93, and a switching unit 94.

[0135] The boost unit 92 has the function of generating a DC voltage V1 by boosting the DC voltage supplied from the power supply 25. In a specific example, the boost unit 92 is composed of a DC-DC converter or a charge pump circuit.

[0136] The oscillation unit 93 has the function of generating an unmodulated sinusoidal wave signal (carrier signal) vibrating at a predetermined frequency by oscillating based on the DC voltage supplied from the power supply 25. The amplification unit 26 has the function of generating an unmodulated sinusoidal wave signal v2 by amplifying the sinusoidal wave signal generated by the oscillation unit 93 at a predetermined amplification rate. Figure 12 As shown, the amplification section 26 is preferably composed of an amplification circuit, which consists of a transformer and a capacitor.

[0137] The switching unit 94 is a 1-circuit 3-contact switching element, configured to have a terminal a connected to the output terminal of the boost unit 92, a terminal b connected to the output terminal of the amplification unit 26, a terminal g connected to the power supply line supplied with ground potential, and a common terminal c connected to the electrode 21.

[0138] The control unit 91 is an IC that supplies the control signal Ctrl for controlling the switch unit 94 and controls the receiver unit 27 to receive the uplink signal sent by the sensor controller 31. It is configured to operate using power supplied from the power supply 25. In a specific example, the control unit 91 can be an ASIC or a MCU. Based on the content of the uplink signal received via the receiver unit 27, or the fact that it does not receive the uplink signal (the sensor controller 31 only handles one-way communication from the stylus 2 to the sensor controller 31), the control unit 91 determines which of the downlink signals DS1 and DS2 to use to send the long burst signal, burst signal, and data signal. Furthermore, with... Figure 8 Similarly, the control unit 90 shown determines the transmission and reception schedule of various signals, and controls the switching unit 94 based on the determined transmission and reception schedule.

[0139] When transmitting the downlink signal DS1, the control unit 91 controls the switch unit 94 in a manner that functions as a first switch unit located between the output terminal of the boost unit 92 and the electrode 21. That is, it performs a process of switching the switch unit 94 between the state where terminal a is connected to the common terminal c and the state where terminal g is connected to the common terminal c. The state where terminal a is connected to the common terminal c corresponds to the state where the first switch unit is on, and the state where terminal g is connected to the common terminal c corresponds to the state where the first switch unit is off.

[0140] When transmitting burst signals or long burst signals using the downlink signal DS1, the control unit 91 periodically controls the switching unit 94 to switch at a predetermined interval. When terminal a is connected to the common terminal c, the DC voltage V1 becomes the output voltage of the switching unit 94. Conversely, when terminal g is connected to the common terminal c, the ground potential becomes the output voltage of the switching unit 94. Therefore, an unmodulated pulse train signal is output from the switching unit 94, which becomes a long burst signal or a burst signal.

[0141] On the other hand, when transmitting data signals using the downlink signal DS1, the control unit 91 performs switching control of the switch unit 94 based on data such as the pen pressure level P and switch information SW indicating the on / off state of the side switch (not shown) set on the stylus 2. It should be noted that this data may also include other information such as the stylus ID (identification information of the stylus 2). The control unit 91 generates a pulse train signal, i.e., a data signal, based on data modulation, through this switching control. As for the specific method of modulation of the pulse train signal by the control unit 91, on / off modulation, frequency modulation, etc., can be considered.

[0142] When transmitting downlink signal DS2, the control unit 91 controls the switch unit 94 in a manner that functions as a second switch unit located between the output terminal of the amplifier unit 26 and the electrode 21. That is, it performs a process of switching the switch unit 94 between the state where terminal b is connected to the common terminal c and the state where terminal g is connected to the common terminal c. The state where terminal b is connected to the common terminal c corresponds to the state where the second switch unit is on, and the state where terminal g is connected to the common terminal c corresponds to the state where the second switch unit is off.

[0143] When using the downlink signal DS2 to transmit a burst signal or a long burst signal, the control unit 91 fixes the switch unit 94 to the terminal b side. Therefore, an unmodulated sine wave signal v2 is output from the switch unit 94, which becomes a long burst signal or a burst signal.

[0144] On the other hand, when using the downlink signal DS2 to transmit data signals, the control unit 91 performs switching control of the switch unit 94 based on data such as the pen pressure level P and the switch information SW. It should be noted that in this case, the data may also include other information such as the stylus ID. The control unit 91 generates a data signal based on a modulated sine wave signal through this switching control. As a specific method for the control unit 91 to modulate the sine wave signal, on-off modulation is employed.

[0145] As explained above, according to this variation, Bluetooth (registered trademark) can be used for uplink signal transmission and reception. It should be noted that while an example using Bluetooth (registered trademark) has been described here, other short-range wireless communications besides Bluetooth (registered trademark) can certainly be used for uplink signal transmission and reception.

[0146] Furthermore, according to this variant, the stylus 2 can communicate bidirectionally or unidirectionally between multiple sensor controllers 31 of different types by using downlink signals DS1 and DS2 separately.

[0147] Figure 13This is a flowchart illustrating the operation of the stylus 2 in a second variation of the above-described embodiment. The stylus 2 in this variation differs from the above-described embodiment in that it immediately sends a long burst signal after receiving certain uplink signals during the stage before the sensor controller 31 is detected, and in determining whether to send the burst signal before the data signal. Hereinafter, refer to... Figure 13 The operation of the stylus 2 in this modified example will be described in detail.

[0148] like Figure 13 As shown, in this modified example, the stylus 2 first performs an uplink signal detection operation (step S60). Then, it determines whether an uplink signal has been detected through this detection operation (step S61). If it is determined that no uplink signal has been detected, it returns to step S60 and repeats the detection operation. On the other hand, if it is determined that an uplink signal has been detected, a long burst signal is sent without waiting for a command signal (step S62). Specifically, the signal with the aforementioned predetermined waveform is sent within time T1.

[0149] After sending a long burst signal, the stylus 2 performs a command signal detection operation (step S63). It then determines whether a command signal indicating data transmission has been detected (step S64). If no signal is detected, the process returns to step S62 and the long burst signal is sent repeatedly. Conversely, if a signal is detected, it then determines whether to send a burst signal (step S65). This determination is based on the content of the detected command signal. In this way, the stylus 2 can be controlled by the sensor controller 31 to determine whether to send a burst signal.

[0150] The processing in step S65 when a burst signal is determined to be sent. Figure 11 Steps S51 and S52 shown are the same. Specifically, the stylus 2 sends a burst signal by transmitting a signal of a predetermined waveform within time T2 (step S66), and then sends a data signal including data based on the instruction signal detected in step S63 within the subsequent time T1-T2 (step S67). On the other hand, if it is determined in step S65 that no burst signal will be sent, the stylus 2 sends a data signal including data based on the instruction signal detected in step S63 within time T1 (step S68).

[0151] After sending the data signal in step S67 or S68, the stylus 2 returns the processing to step S63. Thereafter, data corresponding to the instruction from the sensor controller 31 can be sent.

[0152] As explained above, according to this variation, the stylus 2 can send a long burst signal without waiting for an instruction signal that includes a sending indication of a long burst signal. Therefore, it is also possible to send a long burst signal for a sensor controller 31 that does not specifically correspond to a long burst signal.

[0153] Furthermore, since the stylus 2 determines whether to send a burst signal before the data signal, the stylus 2 can send data signals for a longer period (i.e., send more data) when the sensor controller 31 does not need to send a burst signal from the stylus 2, and the sensor controller 31 can acquire more data.

[0154] Figure 14 This is a flowchart illustrating the operation of the sensor controller 31 in the third variation of the above-described embodiment. In this variation, the sensor controller 31 performs one stylus detection process ( Figure 9 The difference from the above embodiment lies in step S3), where the instruction signal indicating the transmission of a long burst signal is sent after the transmission of the pen start signal or the execution of the first half of the full-range scan. Hereinafter, refer to... Figure 14 The operation of the sensor controller 31 in this modified example will be described in detail.

[0155] like Figure 14 As shown, in this modified example, when the state flag referenced by the sensor controller 31 in step S10 is "0", the comparison... Figure 10 For example, the pen start signal is sent within a short time (specifically time T1) (step S71). Next, the sensor controller 31 sends an instruction signal (first uplink signal) indicating a transmission indication of a long burst signal (step S72), then sets the status flag to "1" (step S12), and then returns the process to step S10.

[0156] Furthermore, if the status flag referenced in step S10 is "1", the sensor controller 31 of this modified example performs a long burst signal detection operation within time T1 (step S73), and then sends again a command signal (first uplink signal) indicating the transmission of the long burst signal (step S74). The detection operation in step S73 is performed through the first half of a full-range scan. Figure 10 The steps shown in step S14 are the same, but if they are the same as... Figure 10 Comparing the examples, the detection action of the long burst signal and the sending order of the command signal are reversed.

[0157] Furthermore, when the status flag referenced in step S10 is "2", the sensor controller 31 of this modified example performs a long burst signal detection operation within time T (step S63). This detection operation is performed during the latter half of the full-range scan, which is consistent with... Figure 10 The steps shown in step S14 are the same, but if... Figure 10 and Figure 14 A comparison reveals that the entire time frame T can be used for detecting long burst signals. This subsequent processing and... Figure 10 The examples are the same, so detailed explanations are omitted.

[0158] In this modified example, it is preferable that the transmission indication of the long burst signal transmitted in steps S72 and S74 also includes information indicating the transmission duration of the long burst signal. Furthermore, the stylus 2 preferably controls the transmission duration of the long burst signal based on the transmission duration indicated by this information. This ensures that the period during which the sensor controller 31 performs the long burst signal detection operation coincides with the period during which the stylus 2 transmits the long burst signal.

[0159] As explained above, according to this variation, the latter half of the full-range scan can be performed over a longer period of time than in the above-described embodiment. Therefore, the reception time for each linear electrode 30X can be extended, thus enabling the sensor controller 31 to receive burst signals more reliably compared to the above-described embodiment.

[0160] Figure 15 This diagram illustrates a long burst signal transmitted by the stylus 2 in the fourth variation of the above-described embodiment. The sensor controller 31 and stylus 2 in this variation differ from those in the above-described embodiment in the format of the long burst signal. Hereinafter, refer to... Figure 15 The format of the long burst signal in this variation is explained in detail.

[0161] like Figure 15 As shown, the long burst signal in this variation consists of a continuous pattern of a signal at frequency f1 (first frequency) and a signal at frequency f2 (second frequency), which is different from frequency f1. Specifically, the frequency of the first half is f1, and the frequency of the second half is f2.

[0162] If the frequency of a long burst signal is uniform across the entire range, the sensor controller 31 cannot obtain any information from the received long burst signal. Therefore, the sensor controller 31 may mistakenly receive, for example, simple white noise or frequency-selective noise with a strong component near frequency f1, as a long burst signal. In contrast, according to this modification, the sensor controller 31 can determine that the received signal is a long burst signal based on the fact that two frequencies are detected in a known order. Therefore, according to this modification, the possibility of the sensor controller 31 mistaking a signal that is not a long burst signal for a long burst signal and operating accordingly can be reduced.

[0163] In this modified example, the full-range scan for detecting long burst signals is performed, for example, as follows: first scan the odd-numbered linear electrodes 30Y, then scan the even-numbered linear electrodes 30Y. This is to enable the sensor controller 31 to receive both the first and second halves of the long burst signal. It should be noted that when the duration T1 of the long burst signal is sufficiently long, all linear conductors 30Y can also be scanned sequentially at frequency f1, and then all linear conductors 30Y can be scanned sequentially again at frequency f2.

[0164] As explained above, according to this modified example, the possibility that the sensor controller 31 may mistakenly identify a signal that is not a long burst signal as a long burst signal and thus perform an action can be reduced.

[0165] It should be noted that this modified example illustrates the feature of setting different frequencies in the first and second halves of a long burst signal. However, any feature that can distinguish between white noise and long burst signals in the sensor controller 31 can be set for the long burst signal. For example, a long burst signal can also be a signal that changes L frequencies in a predetermined sequence with respect to the sensor controller 31. In this case, the sensor controller 31 can also use N linear electrodes 30Y (or M linear conductors 30X) to perform L repeated scanning operations while changing the frequency.

[0166] Figure 16 This is a flowchart illustrating the operation of the stylus 2 in the fifth variation of the above-described embodiment. The sensor controller 31 and stylus 2 in this variation differ from those in the above-described embodiment in that the stylus 2 determines that the sensor controller 31 has not yet detected the stylus 2 based on the uplink signal. Hereinafter, refer to... Figure 16 The operation of the stylus 2 in this modified example will be described in detail.

[0167] like Figure 16 As shown, in this modified example, the stylus 2 first enters a sleep state (step S80). This sleep state is related to... Figure 11 The receiving action pause state shown is the same as step S31.

[0168] After entering sleep mode and waiting for a predetermined time, the stylus 2 performs an uplink signal detection operation (step S81). Then, it is determined whether an uplink signal has been detected through this detection operation (step S82). If it is determined that no uplink signal has been detected, the process returns to step S80 and re-enters sleep mode. On the other hand, if it is determined that an uplink signal has been detected, it is determined whether the uplink signal indicates that the sensor controller 31 has not yet detected the stylus 2 (is in an undetected state) (step S83). This determination process, for example... Figure 8 In the example shown, the stylus 2 is executed by the control unit 90. Figure 12 In the example shown, the stylus 2 is controlled by the control unit 91.

[0169] As a specific method for determining step S83, the following methods can be considered for example. The first is when the sensor controller 31 is explicitly sending an uplink signal indicating that the stylus 2 is not detected. In this case, the stylus 2 performs the determination in step S83 based on whether it receives the uplink signal. The second is when the sensor controller 31 sends a command signal indicating a transmission indication of a long burst signal, as described in the above embodiment. (Refer to...) Figure 10 As explained above, the situation where the sensor controller 31 sends the instruction signal indicating the transmission of a long burst signal occurs when the sensor controller 31 has not yet detected the stylus 2. Therefore, in this situation, the stylus 2 can perform the determination in step S83 based on whether it has received the instruction signal indicating the transmission of a long burst signal.

[0170] If a positive result is obtained in step S83, the stylus 2 sends a long burst signal (step S84). Specifically, the signal with the specified waveform described above is sent for a duration T1. The long burst signal sent in this case can, of course, also be... Figure 15 The long burst signal shown is a signal with characteristics that can distinguish it from white noise.

[0171] On the other hand, if a negative determination result is obtained in step S83, the stylus 2 then determines whether to send a burst signal (step S85). Subsequent processing (steps S85-S88) is the same as in... Figure 13 The processes described in steps S65 to S68 are the same, so detailed explanations are omitted.

[0172] As explained above, according to this variation, the stylus 2 can determine whether the sensor controller 31 has detected the stylus 2, and based on the result, decide whether to send a long burst signal or send a burst signal and a data signal (or only send a data signal).

[0173] Figure 17 This diagram illustrates the specific location exclusion process in the sixth variation of the above-described embodiment. Additionally, Figure 18 This is a flowchart illustrating the operation of the sensor controller 31 in this modified example. This modified example involves processing as a stylus detection... Figure 9 The result of step S3) is used to remove the stylus 2 from one or more locations located in the finger touch detection processing. Figure 9 The finger touch area detected in steps S1 and S2) (represented by the finger touch area detected in steps S1 and S2) Figure 1 The location within the area touched by finger F (as shown) is explained in detail below.

[0174] Figure 17 (a) shows finger touch areas A1 and A2 detected by finger touch detection processing. Figure 17 (b) shows how by Figure 17 (a) The position B1 to B3 of stylus 2 is derived from stylus detection processing performed immediately after finger touch detection processing.

[0175] As mentioned above, Figure 17 (a) The finger-touched areas A1 and A2 are detected because a portion of the current flowing on the linear electrodes of sensor 30 flows towards the human body through capacitive coupling generated between the finger F and the linear electrodes 30X and 30Y. It should be noted that in Figure 17 In (a), the area of ​​the finger-touched area A2 is much larger than that of the finger-touched area A1. However, such a large finger-touched area A2 is usually formed by the palm, fist, etc. (rather than the fingertip) contacting the touch surface. Therefore, it is usually invalidated by another processing based on the size of the area (palm accidental touch processing). Figure 17 (a) shows the state before invalidation.

[0176] Figure 17 (b) The positions B1 to B3 of the stylus 2 shown are, for example, in Figure 10 The position derived in step S20 is based on the detection intensity of the burst signal at each linear electrode 30X, 30Y. Upon reaching sensor 30 (reference...) Figure 2 In the burst signal of ), besides the signal from electrode 21 of stylus 2 (refer to) Figure 8 , Figure 12 In addition to the components that arrive directly, there are also components that arrive via the hand holding the stylus 2 or the hand on the opposite side. Figure 17 Of the three locations B1 to B3 detected in (b), only location B3 is derived from the component of the sensor 30 directly from the electrode 21 of the stylus 2. The other two are derived from the component of the sensor 30 via the hand holding the stylus 2 or the hand on the opposite side.

[0177] Here, refer again Figure 17 (a) It can be seen that finger touch areas A1 and A2 are detected at the same locations as positions B1 and B2. This is based on the following reason: the detection at positions B1 and B2 is due to the hand approaching the touch surface, and such a hand can also be detected through finger touch detection processing. In this modified example, the sensor controller 31 utilizes the relationship between such finger touch areas and stylus positions, and selects and removes (excludes) positions B1 and B2 from the positions B1 to B3 of the stylus 2 derived through stylus detection processing by referring to the result of finger touch detection processing. Hereinafter, refer to Figure 18The operation of the sensor controller 31 used to implement this process will be described in detail.

[0178] like Figure 18 As shown, in this modified example, the sensor controller 31 first detects the finger touch area (step S90). This is in Figure 9 The processing performed in the finger touch detection process shown (steps S1 and S2).

[0179] Afterwards, when moving towards Figure 9 After the stylus detection process shown (step S3), the sensor controller 31 passes through... Figure 10 In step S20, the process first obtains one or more candidate positions for the stylus 2 (step S91). Additionally, the sensor controller 31 obtains one or more finger touch areas detected in step S90 (step S92). It should be noted that, in the case of the aforementioned palm touch error handling, the finger touch area obtained here is the area from the stage before the palm touch error handling was performed.

[0180] Next, the sensor controller 31 repeatedly performs the processing after step S94 on each candidate position of the stylus 2 obtained in step S91. Specifically, it first determines whether the position represented by the candidate is included in any of the more than one finger touch area obtained in step S92 (step S94). Here, if it is determined that it is not included, the position represented by the candidate is identified as the position of the stylus 2, and normal processing is performed (step S95). On the other hand, if it is determined that it is included, the candidate is invalidated (step S96). The invalidated candidate will not be used as the position of the stylus 2 in subsequent processing. It should be noted that this invalidation process can be implemented by preventing the sensor controller 31 from outputting the position of the stylus 2 to the system controller of the electronic device 3, or it can be implemented by indicating that the position is an invalid area after outputting the position of the stylus 2 using a flag or the like.

[0181] As explained above, according to this variation, the sensor controller 31 can remove the component of the burst signal from the sensor 30 that is obtained by the hand holding the stylus 2 or the hand on the opposite side from the multiple positions of the stylus 2 derived by the stylus detection processing.

[0182] Furthermore, in the above embodiment, it is described that a full-range scan is performed using all of the N linear electrodes 30Y and M linear electrodes 30X. However, in a full-range scan, it is sufficient to perform more scans than a partial scan (i.e., scans using many linear electrodes), and it is not necessary to use all of the N linear electrodes 30Y and M linear electrodes 30X. In other words, a full-range scan can be performed using the entire or a portion of the touch surface, i.e., the detection area of ​​the first range, while a partial scan can be performed using the detection area of ​​a selected range within the first range. In addition, in this case, the command signal (the command signal indicating the transmission instruction of a long burst signal) issued before the full-range scan can be transmitted from the first range, and the command signal (the command signal indicating the transmission instruction of both the burst signal and the data signal) issued before the partial scan can be transmitted from the selected range.

[0183] Furthermore, in the above embodiment, the full-range scanning operation is described as being divided into scanning using N linear electrodes 30Y sequentially (first half) and scanning using M linear electrodes 30X sequentially (second half). However, if the transmission duration T1 of the long burst signal can be ensured to be sufficiently long, it can also be set to determine the position (two-dimensional coordinate position) of the stylus 2 using the linear conductor 30X after the operation of the linear electrodes 30Y.

[0184] Furthermore, while the above embodiment exemplifies an example where no data signal is transmitted after a long burst signal, it is also possible to transmit a data signal immediately after a long burst signal. In this case, the transmission duration of the data signal can be longer than... Figure 3 The data signal transmitted in the burst signal shown has a short transmission duration. This data signal is suitable for transmitting data such as the on / off state of a switch located on the housing of the stylus 2, which can be represented by a shorter number of bits than the pen pressure.

[0185] Label Explanation

[0186] 2. Stylus

[0187] 3 Electronic devices

[0188] 21 electrodes

[0189] 23 Pen pressure detection sensor

[0190] 24 Signal Processing Department

[0191] 25 Power Supply

[0192] 26 Enlarged section

[0193] 27 Receiving Department

[0194] 30 sensors

[0195] 30X, 30Y linear electrodes

[0196] 31 Sensor Controller

[0197] 40 Selection Department

[0198] 41x, 41y conductor selection circuit

[0199] 44x, 44y switches

[0200] 50 Receiving Department

[0201] 51 Amplifier Circuit

[0202] 52 Detector Circuit

[0203] 53 Converter

[0204] 60. Sending Department

[0205] 61 Model Supply Department

[0206] 62 switches

[0207] 63 Diffusion Processing Department

[0208] 64 Code String Preservation Section

[0209] 65 Send Protection Department

[0210] 70 Logic Department

[0211] 71 Receiving Department

[0212] 71a Waveform Regeneration Section

[0213] 71b Related Arithmetic Unit

[0214] 73 Modulation Section

[0215] 74 Boost Circuit

[0216] 75. Sending Department

[0217] 76 Switching Unit

[0218] 90 Control Department

[0219] 91 Control Department

[0220] 92. Boost Unit

[0221] 93 Oscillation section

[0222] 94 Switching Section

[0223] A1, A2 Finger Touch Area

[0224] B1~B3 Stylus Position

[0225] DS1 and DS2 downlink signals

[0226] EN start signal

[0227] F refers to

[0228] P Pen Pressure Level

[0229] Res data

[0230] SR sensing range

[0231] SW switch information

[0232] US uplink signal.

Claims

1. A stylus capable of bidirectional communication with a sensor controller, comprising: The receiving unit receives the uplink signal sent by the sensor controller; Control unit, the control unit In response to the data of the uplink signal indicating a request for a data signal, it is determined to send a normal burst signal in the second time period T2, the normal burst signal having a predetermined pattern known in advance between the stylus and the sensor controller; and In response to the data of the uplink signal indicating a request for a long burst signal having the specified pattern and used to identify the position of the stylus, it is determined to send the long burst signal within a first time period T1 that is longer than the second time period T2; as well as The transmitting unit transmits the normal burst signal or the long burst signal based on the decision of the control unit to transmit the normal burst signal or the long burst signal, respectively.

2. The stylus according to claim 1, wherein, When the control unit decides to send the normal burst signal, the sending unit sends the data signal within a time period corresponding to the difference between the second time period T2 and the first time period T1.

3. The stylus according to claim 1, wherein The data of the uplink signal varies depending on whether the sensor controller has detected the presence or position of the stylus. When the data in the uplink signal indicates that the sensor controller has not detected the presence or location of the stylus, the control unit decides to send the long burst signal.

4. The stylus according to claim 1, wherein, The control unit decides whether to send the normal burst signal or the long burst signal regardless of whether the stylus is in a hovering or contact state.

5. The stylus according to claim 1, wherein, The normal burst signal and the long burst signal have the specified pattern, and the specified pattern has a specified frequency.

6. A stylus capable of bidirectional communication with a sensor controller, comprising: The receiving unit receives the uplink signal sent by the sensor controller; The control unit determines the state of the sensor controller based on the uplink signal; as well as The transmitting unit, the transmitting unit In response to the control unit determining, based on the uplink signal, that the sensor controller has not detected the stylus, it continuously sends long burst signals within a specified time period. These long burst signals are used to identify the position of the stylus and have a pre-known predetermined pattern between the stylus and the sensor controller. In response to the control unit determining, based on the uplink signal, that the sensor controller has located the stylus, the control unit sends a data signal indicating the stylus's operating state within the specified time period, instead of continuously sending the long burst signal with the specified pattern.

7. The stylus according to claim 6, wherein, The specified pattern is a pattern that includes a series of signals having a first frequency and signals having a second frequency different from the first frequency.

8. The stylus according to claim 6, wherein, In response to the control unit determining, based on the uplink signal, that the sensor controller has located the position of the stylus, the transmitting unit continuously transmits signals having the predetermined pattern within a time period shorter than the predetermined time period, and also transmits the data signal.

9. The stylus according to claim 6, wherein, The operating state of the stylus is determined by the pen pressure level sensed by a pressure sensor.

10. The stylus according to claim 6, wherein, The transmitting unit determines whether to send the long burst signal or the data signal regardless of whether the stylus is in a hovering or contact state.

11. The stylus according to claim 6, wherein, The long burst signal has the specified pattern, and the specified pattern has a specified frequency.

12. A sensor controller capable of deriving the position of a stylus by detecting signals transmitted from a stylus, the sensor controller being configured to perform: The decision-making steps for determining whether the stylus has been detected or not; In response to the determination in the decision step that the stylus has been detected, a step of sending a second uplink signal instructing the stylus to continuously send a signal having a predetermined waveform during a second time period; as well as In response to the determination in the decision step that the stylus was not detected, a first uplink signal is sent instructing the stylus to continuously transmit a signal having the specified waveform for a first time period longer than the second time period.

13. The sensor controller according to claim 12, wherein, The sensor controller is configured to further perform: In response to the determination step that the stylus was not detected, a first scan is performed to perform a detection operation that uses a detection area of ​​a first range to detect a signal having the specified waveform; as well as In response to the determination step that the stylus has been detected, a second scan is performed to perform a detection operation that uses a detection area within a selected range of the first range to detect a signal having the specified waveform.

14. The sensor controller according to claim 13, wherein, The decision step is in response to the sensor controller detecting a signal with the specified waveform in the first scan and determining that the stylus has been detected.

15. The sensor controller according to claim 13, wherein, The first uplink signal is transmitted from the first range, and the second uplink signal is transmitted from the selected range.

16. The sensor controller according to claim 12, wherein, The second uplink signal indicates an instruction for the stylus to send specified data.

17. An integrated circuit configured to control a stylus, wherein the stylus is capable of bidirectional communication with a sensor controller, the integrated circuit comprising: A receiving circuit that receives the uplink signal sent by the sensor controller during operation; Control circuit, the control circuit In response to the data of the uplink signal indicating a request for a data signal, it is determined to send a normal burst signal in the second time period T2, the normal burst signal having a predetermined pattern known in advance between the stylus and the sensor controller; and In response to the data of the uplink signal indicating a request for a long burst signal having the specified pattern and used to identify the position of the stylus, it is determined to send the long burst signal within a first time period T1 that is longer than the second time period T2; as well as The transmitting circuit transmits the normal burst signal or the long burst signal based on the decision of the control circuit to transmit the normal burst signal or the long burst signal, respectively.

18. The integrated circuit according to claim 17, wherein, When the control circuit decides to send the normal burst signal, the sending circuit sends the data signal within the time period corresponding to the difference between the second time period T2 and the first time period T1.

19. The integrated circuit according to claim 17, wherein The data of the uplink signal varies depending on whether the sensor controller has detected the presence or position of the stylus. When the data in the uplink signal indicates that the sensor controller has not detected the presence or location of the stylus, the control circuit decides to send the long burst signal.

20. The integrated circuit according to claim 17, wherein, The control circuit determines whether to send the normal burst signal or the long burst signal, regardless of whether the stylus is in a hovering or contact state.

21. The integrated circuit according to claim 17, wherein, The normal burst signal and the long burst signal have the specified pattern, and the specified pattern has a specified frequency.

22. An integrated circuit configured to control a stylus, wherein the stylus is capable of bidirectional communication with a sensor controller, the integrated circuit comprising: A receiving circuit that receives the uplink signal sent by the sensor controller during operation; A control circuit that determines the state of the sensor controller based on the uplink signal during operation; as well as Transmitting circuit, the transmitting circuit In response to the control circuit determining, based on the uplink signal, that the sensor controller has not detected the stylus, it continuously sends long burst signals within a specified time period. These long burst signals are used to identify the position of the stylus and have a pre-known predetermined pattern between the stylus and the sensor controller. In response to the control circuit determining, based on the uplink signal, that the sensor controller has derived the position of the stylus, it sends a data signal indicating the operating state of the stylus within the specified time period, instead of continuously sending the long burst signal with the specified pattern.

23. The integrated circuit according to claim 22, wherein, The specified pattern is a pattern that includes a series of signals having a first frequency and signals having a second frequency different from the first frequency.

24. The integrated circuit according to claim 22, wherein, In response to the control circuit determining, based on the uplink signal, that the sensor controller has derived the position of the stylus, the transmitting circuit continuously transmits signals having the predetermined pattern within a time period shorter than the predetermined time period, and also transmits the data signal.

25. The integrated circuit according to claim 22, wherein, The operating state of the stylus is determined by the pen pressure level sensed by a pressure sensor.

26. The integrated circuit according to claim 22, wherein, The transmitting circuit determines whether to send the long burst signal or the data signal, regardless of whether the stylus is in a hovering or contact state.

27. The integrated circuit according to claim 22, wherein, The long burst signal has the specified pattern, and the specified pattern has a specified frequency.

28. A method performed by a stylus, the stylus being configured to communicate bidirectionally with a sensor controller, the method comprising: Receive the uplink signal sent by the sensor controller; In response to the data of the uplink signal indicating a request for a data signal, it is determined to send a normal burst signal in the second time period T2, the normal burst signal having a predetermined pattern known in advance between the stylus and the sensor controller; and In response to the data of the uplink signal indicating a request for a long burst signal having the specified pattern and used to identify the position of the stylus, it is determined to send the long burst signal within a first time period T1 that is longer than the second time period T2; as well as The normal burst signal or the long burst signal is transmitted based on the decision to transmit the normal burst signal or the long burst signal.

29. The method of claim 28, comprising: Based on the decision to send the normal burst signal, the data signal is sent within the time period corresponding to the difference between the second time period T2 and the first time period T1.

30. The method according to claim 28, wherein, The data of the uplink signal varies depending on whether the sensor controller has detected the presence or position of the stylus. When the data in the uplink signal indicates that the sensor controller has not detected the presence or location of the stylus, it decides to send the long burst signal.

31. The method of claim 28, comprising: The decision to send either the normal burst signal or the long burst signal is made regardless of whether the stylus is in a hovering or contact state.

32. The method according to claim 28, wherein, The normal burst signal and the long burst signal have the specified pattern, and the specified pattern has a specified frequency.

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