JP6923725B2 - Sensor controller - Google Patents

Description

The present invention relates to a stylus and a sensor controller, and more particularly to a stylus and a sensor controller constituting a position detection system in which the sensor controller detects the stylus by a burst signal transmitted from the stylus.

In the conventional stylus, a data signal including data such as pen pressure and stylus ID is transmitted following a burst signal for causing the sensor controller to detect itself and its position. The burst signal is a signal having a predetermined waveform known in advance between the stylus and the sensor controller (for example, an unmodulated signal having a predetermined frequency). On the other hand, the data signal is a signal modulated by the data to be transmitted. FIG. 7 of Patent Document 1 discloses an example of a stylus that transmits such a signal.

When the sensor controller is not detecting the stylus, it attempts to detect the burst signal by sequentially using all of the plurality of electrodes arranged side by side on the touch surface to perform the detection operation. When a burst signal is detected as a result, the data signal is tried to be detected by using only a part of the electrodes located in the vicinity of the electrode where the burst signal is detected.

International Publication No. 2015/11159

However, the conventional sensor controller has a problem that the detection may fail even though the burst signal reaches the touch surface, especially when the stylus is not yet in contact with the touch surface (during hovering). there were. This is because there is a distance between the stylus and the touch surface during hovering, so that the amplitude of the burst signal detected by the sensor controller becomes small and a sufficient S / N ratio cannot be obtained. On the other hand, it is conceivable to lengthen the detection operation time per electrode as one means for obtaining a sufficient S / N ratio even during hovering, but this time, the area in the touch surface is wide. It becomes difficult to detect the burst signal in the range. This is because the transmission of the burst signal ends before all the electrodes in the range are scanned.

Further, if the stylus and the sensor controller are approached to a distance where a sufficient S / N ratio can be obtained by performing a pen-down operation, the stylus is transmitting a data signal instead of a burst signal at that timing. The stylus detection by the sensor controller may fail.

Therefore, one of the objects of the present invention is to ensure that the burst signal can be detected in a wide range in the touch surface in order to identify the position of the undetected stylus, and the burst signal detection by the sensor controller can fail. An object of the present invention is to provide a stylus and a sensor controller that can reduce the performance.

The stylus according to one aspect of the present invention is a stylus capable of bidirectional communication with a sensor controller, and is based on a receiving unit that receives an uplink signal transmitted by the sensor controller and the uplink signal. A control unit that determines whether a signal having a predetermined waveform is continuously transmitted over a second time or a signal having a predetermined waveform is continuously transmitted over a first time longer than the second time, and the control. A transmission unit that continuously transmits a signal having the predetermined waveform over the first time or the second time based on the determination result of the unit is included.

The stylus according to the other aspect of the present invention is a stylus capable of bidirectional communication with the sensor controller, and is a receiving unit that receives an uplink signal transmitted by the sensor controller and the uplink signal. The control unit that determines the state of the sensor controller and the sensor controller in response to an instruction from the control unit when the uplink signal indicates that the sensor controller is in a stylus-undetected state. When a signal of a predetermined pattern known in advance is continuously transmitted for a predetermined time, and the uplink signal indicates that the sensor controller has already derived the position of the stylus, the signal of the predetermined pattern is transmitted. Includes a transmission unit that transmits a data signal that changes depending on the operating state of the stylus without continuously transmitting the above for a predetermined time.

The sensor controller according to one aspect of the present invention is a sensor controller configured so that the position of the stylus can be derived by detecting the signal transmitted from the stylus, and whether the stylus is undetected or detected. To instruct the stylus to continuously transmit a signal having the predetermined waveform over a second time according to the determination step and the determination that the stylus has been detected by the determination step. Depending on the step of transmitting the second uplink signal and the determination of the stylus not being detected by the determination step, a signal having a predetermined waveform is transmitted to the stylus for a first time longer than the second time. It is configured to perform a step of transmitting a first uplink signal instructing continuous transmission over time.

The sensor controller according to the other aspect of the present invention includes M first electrodes extending in the first direction and N electrodes extending in a second direction different from the first direction, respectively. A sensor controller connected to a matrix electrode including a second electrode, supplying a predetermined signal to each of the M first electrodes, and each of the N second electrodes. Using the finger touch detection step of performing finger touch detection by the predetermined signal detected in the above, and at least a part of the M first electrodes and at least a part of the N second electrodes, not yet. A full-range scan step that detects the stylus for detection and derives the position coordinates of the stylus, the first electrode that is less than the number of the first electrode used in the full-range scan step, and the full range. Using a smaller number of the second electrodes than the number of the second electrodes used in the scan step, a sector scan step for deriving the position coordinates of the already detected stylus is performed.

According to the present invention, the sensor controller can expect the stylus to transmit a long burst signal that lasts longer than a normal burst signal in a stylus undetected state where the stylus is likely to be hovering. Become. Therefore, it is possible to detect the burst signal by scanning more electrodes within the transmission duration of the long burst signal while making the detection operation time per electrode longer than that at the time of receiving the normal burst signal. It is possible to reduce the possibility of failure of burst signal detection by the sensor controller while ensuring a state in which burst signals can be detected in a wide range in the touch surface.

It is a figure which shows the structure of the electronic device 3 by embodiment of this invention, (a) shows the operation of the electronic device 3 when the touch by a finger F is detected, and (b) is the case where the stylus 2 is detected. The operation of the electronic device 3 is shown. It is a figure which shows the structure of the electronic device 3 by embodiment of this invention. It is a figure which shows the structure of the long burst signal, the burst signal, and the data signal transmitted by the stylus 2 by embodiment of this invention. It is a figure which shows the sequence of the signal transmission and reception between the stylus 2 and the sensor controller 31 when the stylus 2 is above the uplink detection height AH, and (a) shows the time when the pen start signal is transmitted by the sensor controller 31. (B) shows each case where the sensor controller 31 requests the transmission of the long burst signal. FIG. 5 is a diagram showing a sequence of signal transmission / reception between the stylus 2 and the sensor controller 31 at a stage where the stylus 2 is inside the sensing range SR and the sensor controller 31 has not yet specified the position of the stylus 2. ) Is the case where the sensor controller 31 transmits the pen activation signal, (b) is the case where the sensor controller 31 receives the long burst signal transmitted by the stylus 2, and (c) is the case where the stylus 2 receives the long burst signal. The case where the sensor controller 31 receives the transmitted long burst signal by using the linear electrode 30X is shown. It is a figure which shows the sequence of the signal transmission and reception between the stylus 2 and the sensor controller 31 after the stylus 2 is inside the sensing range SR, and after the sensor controller 31 has specified the position of the stylus 2, and is the burst signal by the stylus 2. And when the data signal is transmitted. It is a figure explaining the operation of the sensor controller 31 by embodiment of this invention, (a) shows the first half of a full range scan, (b) shows the latter half of a full range scan, and (c) shows a sector scan. ing. It is a figure which shows the structure of the stylus 2 by embodiment of this invention. It is a processing flow diagram which shows the whole operation of the sensor controller 31 by embodiment of this invention. It is a processing flow diagram which shows the stylus detection processing performed by the sensor controller 31 by embodiment of this invention. It is a processing flow diagram which shows the operation of the stylus 2 corresponding to FIG. It is a figure which shows the structure of the stylus 2 by the 1st modification of the Embodiment of this invention. It is a processing flow diagram which shows the operation of the stylus 2 by the 2nd modification of the Embodiment of this invention. It is a processing flow diagram which shows the operation of the sensor controller 31 by the 3rd modification of the Embodiment of this invention. It is a figure which shows the long burst signal transmitted by the stylus 2 by the 4th modification of embodiment of this invention. It is a processing flow diagram which shows the operation of the stylus 2 by the 5th modification of the Embodiment of this invention. It is a figure explaining the specific position exclusion process by the 6th modification of the Embodiment of this invention, (a) is a finger touch area detected by the finger touch detection process, (b) is (a). The positions of the stylus 2 derived by the stylus detection process executed immediately after the finger touch detection process are shown. It is a processing flow diagram which shows the operation of the sensor controller 31 by the 6th modification of the Embodiment of this invention.

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

FIG. 1 is a diagram showing a 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 is configured to include a sensor 30 and a sensor controller 31 as shown in the figure.

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

The sensor controller 31 uses the sensor 30 to detect a touch by the finger F (including deriving the position coordinates of the finger F in the touch surface) and detect the stylus 2 (position coordinates of the stylus 2 in the touch surface). It is a control unit that performs (including derivation) in time division.

FIG. 1A shows the operation of the electronic device 3 when the touch by the finger F is detected. As shown in the figure, the sensor controller 31 when detecting a touch by the finger F sequentially supplies a predetermined signal (hereinafter, referred to as “finger detection signal”) to each of the plurality of linear electrodes 30Y. At the same time, by sequentially scanning the potentials of each of the plurality of linear electrodes 30X, the finger detection signal that has arrived at each linear electrode 30X through the intersection with the linear electrodes 30Y is detected. The amplitude of the finger detection signal detected in this way is smaller when the finger F is approaching the vicinity of the intersection through which the finger detection signal has passed, as compared with the case where the finger F is not approaching. This is because a part of the current flowing on the linear electrodes 30X and 30Y flows out toward the human body through the capacitive coupling generated between the finger F and the linear electrodes 30X and 30Y. The sensor controller 31 detects the touch by the finger F by detecting such a change in amplitude.

FIG. 1B shows the basic operation of the electronic device 3 when detecting the stylus 2. As shown in the figure, the sensor controller 31 when detecting the stylus 2 uses, as a basic operation, each of the plurality of linear electrodes 30X and the plurality of linear electrodes 30Y as the receiving electrodes in sequence, and the stylus The detection operation of the signal transmitted by 2 (hereinafter, referred to as “downlink signal”) is performed. Then, the stylus 2 is detected based on the detection result. In the actual operation, the stylus 2 may be detected using only a part of the linear electrodes 30X and 30Y, which will be described later.

In order for the sensor controller 31 to detect the stylus 2, the stylus 2 needs to be close to the touch surface of the electronic device 3 to such an extent that the sensor controller 31 can receive the downlink signal. The illustrated sensing range SR schematically shows the range in which the sensor controller 31 can receive the downlink signal. When the stylus 2 enters the sensing range SR, the sensor controller 31 receives a downlink signal, whereby the stylus 2 can be detected. The movement of the stylus 2 to move from the outside to the inside of the sensing range SR is hereinafter referred to as "pen down". Pendown is usually performed by a user operation of bringing the stylus 2 closer to the touch surface of the electronic device 3. Further, a state in which the stylus 2 has entered the sensing range SR but has not yet come into contact with the touch surface is referred to as “during hovering”. When the stylus 2 goes into the hovering state through the pen down, the sensor controller 31 tries to detect the stylus 2 by detecting the downlink signal, but during the hovering, it is constant between the stylus 2 and the touch surface. Since there is a distance and it becomes difficult to secure a sufficient S / N ratio depending on the distance, the detection of the stylus 2 may fail as a result. Further, even if the stylus 2 is within the sensing range SR, the sensor controller 31 may fail to detect the stylus 2 during the period when the stylus 2 is transmitting a data signal instead of a burst signal. One of the objects of the present invention is to make it possible to avoid such a failure.

Here, the stylus 2 may be able to receive a signal (hereinafter, referred to as “uplink signal”) transmitted by the sensor controller 31 toward the stylus 2 even when it is outside the sensing range SR. This is because for some uplink signals (such as a pen activation signal to be described later and a command signal indicating a transmission instruction of a long burst signal), the entire surface of the touch surface (one or both of the all-linear electrode 30X and the all-linear electrode 30Y). This is because it is transmitted using. The illustrated uplink detection height AH 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 far from the touch surface).

FIG. 2 is a diagram showing a configuration of an electronic device 3 according to the present embodiment. The plurality of linear electrodes 30X and the plurality of linear electrodes 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 part of the current flowing from the sensor controller 31 to the linear electrode 30Y is absorbed by the finger F through this capacitive coupling. As a result, the amplitude of the finger detection signal detected by the linear electrode 30X becomes smaller as described above, so that the sensor controller 31 can detect the touch by the finger F. Further, the sensor 30 is configured to be capable of transmitting and receiving signals in both directions to and from the stylus 2 via the capacitive coupling.

As shown in FIG. 2, the sensor controller 31 includes a transmission unit 60, a selection unit 40, a reception unit 50, a logic unit 70, and an MCU 80.

The transmission unit 60 is a circuit that generates a finger detection signal at the timing of detecting the touch by the finger F and generates an uplink signal at the timing of detecting the stylus 2. The uplink signal includes a pen activation signal for notifying the stylus 2 of the existence of the sensor controller 31 and a command signal for indicating an instruction (command) to the stylus 2.

In the transmission unit 60 of FIG. 2, only the functional block related to the generation of the uplink signal is shown in detail. This functional block includes a pattern supply unit 61, a switch 62, a diffusion processing unit 63, a code string holding unit 64, and a transmission guard unit 65. Of these, the pattern supply unit 61 will be described as being included in the transmission unit 60 in the present embodiment, but may be included in the MCU 80.

The pen activation signal is composed of the repetition of the predetermined detection pattern c1 and the predetermined delimiter pattern STP arranged at the end.

The detection pattern c1 is a pattern of symbol values used by the stylus 2 to detect the presence of the sensor controller 31, and is known to the stylus 2 in advance (before the stylus 2 detects the sensor controller 31). There is. A symbol is a unit of information used for modulation in transmission processing (a unit of information expressed by a transmission signal), and is a unit of information obtained by demodulating one symbol which is a reception signal in reception processing. The symbol value is a value that is converted into a bit string (hereinafter referred to as "bit string compatible value") and a value that is not converted into a bit string by the stylus 2 that receives the symbol (hereinafter referred to as "bit string non-compatible value"). Can include. In a specific example, the detection pattern c1 is composed of a pattern "PM" composed of a combination of two types of bit string non-corresponding values "P" and "M".

The delimiter pattern STP is a symbol value pattern for notifying the stylus 2 of the end of the repetition period of the detection pattern c1, and is composed of a pattern that does not appear during the repetition of the detection pattern c1. The delimiter pattern STP is also known to the stylus 2 in advance (before the stylus 2 detects the sensor controller 31). As an example, when the detection pattern c1 is configured by the combination “PM” of two bit string non-corresponding values “P” and “M” as described above, the delimiter pattern STP sets the bit string non-corresponding value “P” twice. It can be configured by a continuous pattern "PP". The configuration of the delimiter pattern STP and the detection pattern c1 may be reversed, the delimiter pattern may be configured by "PM", and the detection pattern c1 may be configured by "PP".

The pattern supply unit 61 holds the detection pattern c1 and the delimiter pattern STP, and is configured to output these in a predetermined order according to the instruction of the control signal ctrl_t1 supplied from the logic unit 70. Specifically, the detection pattern c1 is continuously and repeatedly output during a predetermined continuous transmission period, and the delimiter pattern STP is output immediately after the end of the continuous transmission period. As a result, the transmission of the pen activation signal is realized. The delimiter pattern STP may be output at the beginning of a command signal (described later) indicating a transmission instruction of a long burst signal.

The switch 62 has a function of selecting one of the pattern supply unit 61 and the MCU 80 based on the control signal ctrl_t2 supplied from the logic unit 70, and supplying the selected output to the diffusion processing unit 63. When the switch 62 selects the pattern supply unit 61, the pattern supply unit 61 supplies the detection pattern c1 or the delimiter pattern STP to the diffusion processing unit 63. On the other hand, when the switch 62 selects the MCU 80, the control information c2 is supplied from the MCU 80 to the diffusion processing unit 63.

The control information c2 is information indicating an instruction (command) to the stylus 2 and is generated by the MCU80. The above-mentioned command signal is composed of the control information c2. The control information c2 includes a symbol value (for example, 0 to 15) associated with a variable-length bit string, and the value is not shared with the stylus 2 in advance. It's different.

The code string holding unit 64 has a function of generating and holding a diffusion code PN having a predetermined chip length having an autocorrelation characteristic based on the control signal ctrl_t3 supplied from the logic unit 70. The diffusion code PN held by the code string holding unit 64 is supplied to the diffusion processing unit 63.

The spreading processing unit 63 modulates the spreading code PN held by the code string holding unit 64 based on the value of the symbol (detection pattern c1, delimiter pattern STP, or control information c2) supplied via the switch 62. Therefore, it has a function of obtaining a transmission chip sequence having a predetermined chip length. The diffusion processing unit 63 is configured to supply the acquired transmission chip sequence to the transmission guard unit 65.

The transmission guard unit 65 is a guard required to switch between a transmission operation and a reception operation 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. It has a function to insert a period (a period in which both transmission and reception are not performed).

The receiving unit 50 is a circuit for receiving the finger detection signal transmitted by the transmitting unit 60 or the downlink signal transmitted by the stylus 2 based on the control signal ctrl_r of the logic unit 70. Specifically, it includes an amplifier circuit 51, a detection circuit 52, and an analog-to-digital (AD) converter 53.

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

The selection unit 40 includes switches 44x and 44y and conductor selection circuits 41x and 41y.

The switches 44x and 44y are 1-circuit, 2-contact switch elements configured so that the common terminal and any one of the T terminal and the R terminal are connected, respectively. The common terminal of the switch 44x is connected to the conductor selection circuit 41x, the T terminal is connected to the output terminal of the transmitting unit 60, and the R terminal is connected to the input terminal of the receiving unit 50. Further, the common terminal of the switch 44y is connected to the conductor selection circuit 41y, the T terminal is connected to the output terminal of the transmitting unit 60, and the R terminal is connected to the input terminal of the receiving unit 50.

The conductor selection circuit 41x is a switch element for selectively connecting M linear electrodes 30X to the common terminal of the switch 44x. The conductor selection circuit 41x is configured so that a part or all of the M linear electrodes 30X can be connected to the common terminal of the switch 44x at the same time.

The conductor selection circuit 41y is a switch element for selectively connecting N linear electrodes 30Y to the common terminal of the switch 44y. The conductor selection circuit 41y is also configured so that a part or all of the N linear electrodes 30Y can be connected to the common terminal of the switch 44y at the same time.

Four control signals sTRx, sTRy, selX, and selY are supplied to the selection unit 40 from the logic unit 70. Specifically, the control signal sTRx is supplied to the switch 44x, the control signal sTRy is supplied to the switch 44y, the control signal selX is supplied to the conductor selection circuit 41x, and the control signal selY is supplied to the conductor selection circuit 41y. The logic unit 70 controls the selection unit 40 by using these control signals sTRx, sTRy, selX, and selY to transmit and receive a finger detection signal and transmit an uplink signal including a pen activation signal and a command signal. And the reception of the downlink signal is realized. The control of the selection unit 40 by the logic unit 70 will be described in more detail later.

The logic unit 70 and the MCU 80 are control units that control the transmission / reception operation of the sensor controller 31 by controlling the transmission unit 60, the reception unit 50, and the selection unit 40. Specifically, the MCU 80 is a microprocessor that has a ROM and a RAM inside and operates based on a predetermined program. On the other hand, the logic unit 70 is configured to output each of the above-mentioned control signals based on the control of the MCU 80. The MCU 80 also derives coordinate data x, y, etc. indicating the position of the finger F or the stylus 2 based on the digital signal supplied from the AD converter 53, and outputs the coordinate data x, y, etc. to the system controller of the electronic device 3. When the digital signal supplied from the AD converter 53 indicates a data signal, the process of acquiring the data Res represented by the digital signal and outputting it to the system controller of the electronic device 3 is performed. It is composed.

Hereinafter, the control of the selection unit 40 by the logic unit 70 will be specifically described.

First, in the logic unit 70 when transmitting and receiving the finger detection signal, N linear electrodes 30Y are sequentially connected to the output ends of the transmitting unit 60, and M linear electrodes 30X are sequentially connected to the receiving unit 50. The selection unit 40 is controlled by using the control signals sTRx, sTRy, selX, and selY so that they are connected to the input terminal. As a result, as shown in FIG. 1, a finger detection signal is sequentially supplied to each of the N linear electrodes 30Y, and each linear electrode 30X passes through an intersection with the linear electrodes 30Y. Since it becomes possible for the receiving unit 50 to detect the finger detection signal that has arrived at, the touch detection by the finger F is realized.

The logic unit 70 when transmitting the uplink signal and receiving the downlink signal performs different processing depending on the detection state of the stylus 2 and the type of the downlink signal. Hereinafter, the types of downlink signals and the sequence of signal transmission / reception between the stylus 2 and the sensor controller 31 will be described first, and then the logic for transmitting the uplink signal and receiving the downlink signal. The operation of the unit 70 will be described in detail.

FIG. 3 is a diagram showing the types of downlink signals transmitted by the stylus 2 according to the embodiment of the present invention. As shown in the figure, the downlink signal includes a long burst signal, a burst signal, and a data signal. The long burst signal is a signal formed by continuously transmitting a signal having a predetermined waveform, which is a signal of a predetermined pattern known in advance between the stylus 2 and the sensor controller 31, for a predetermined time T1 (first time). be. The burst signal is a signal obtained by continuously transmitting a signal having the predetermined waveform over a predetermined time T2 (second time) shorter than the time T1. The data signal is a data signal obtained by modulating the signal having the predetermined waveform with data, and is transmitted following the burst signal within a time corresponding to the difference T1-T2 between the time T2 and the time T1. A predetermined gap signal (not shown) for indicating a separation from the burst signal is inserted at the head of the burst signal. The type of downlink signal transmitted by the stylus 2 is selected according to an instruction by a command signal transmitted by the sensor controller 31.

4 to 6 are diagrams showing a sequence of signal transmission / reception between the stylus 2 and the sensor controller 31, FIG. 4 shows the case where the stylus 2 is above the uplink detection height AH, and FIG. 5 shows the case where the stylus 2 is above the uplink detection height AH. In FIG. 6, the stylus 2 is inside the sensing range SR and the sensor controller 31 has not yet specified the position of the stylus 2 while the stylus 2 is inside the sensing range SR. Indicates after the position of the stylus 2 has been specified. Hereinafter, each case will be described in order.

<When the stylus 2 is above the uplink detection height AH>
FIG. 4A shows the case where the pen start signal is transmitted by the sensor controller 31, and FIG. 4B shows the case where the sensor controller 31 requests the transmission of the long burst signal.

First, as shown in FIG. 4A, the sensor controller 31 transmits the pen activation signal over the time T (= t1-t0) from the time t0 to the time t1. This transmission is performed when the sensor controller 31 has not yet detected the stylus 2. As described above, the pen activation signal is a signal including the repetition of the detection pattern c1 and the trailing delimiter pattern STP. The stylus 2 intermittently performs the detection operation of the detection pattern c1 by intermittently performing the detection operation of the symbols (“P” and “M” in the above example) constituting the detection pattern c1, but the stylus 2 itself is up. When the link detection height is above the AH, the detection pattern c1 cannot be detected even by this detection operation. Therefore, the stylus 2 simply repeats the detection operation of the detection pattern c1.

Following the transmission of the pen activation signal, the sensor controller 31 starts transmitting a command signal (denoted as "CMD" in FIGS. 4 to 6) at time t2 after time t1 as shown in FIG. 4 (b). .. The time required to transmit the command signal is T0, which is shorter than the above-mentioned time T. When the stylus 2 has not been detected yet, the sensor controller 31 transmits a command signal indicating a long burst signal transmission instruction. However, since the stylus 2 above the uplink detection height AH cannot receive this command signal, it does not transmit a long burst signal in response to the command signal and simply repeats the detection operation of the detection pattern c1. ..

The sensor controller 31 performs a long burst signal detection operation after transmitting a command signal indicating a long burst signal transmission instruction. This detection operation corresponds to the first half of the full-range scan described later, and is executed by sequentially using N linear electrodes 30Y. Details of the full range scan will be described later. Here, since the stylus 2 does not transmit the long burst signal, naturally, the long burst signal is not detected by the sensor controller 31. The time that can be used as the detection operation of the long burst signal is the time T1 (= T-T0) corresponding to the difference between the time T and the time T0, but the long burst signal is sequentially used by sequentially using N linear electrodes 30Y. When the detection operation of is performed, the detection operation of the long burst signal is temporarily completed at the time t3 before the time t4 (= t2 + T) when the time T1 elapses. Therefore, when the long burst signal is not detected during this detection operation, the sensor controller 31 goes into a sleep state from the time t3 to the time t4. As a result, the power consumption of the sensor controller 31 is reduced. After the time t4, the transmission of the pen activation signal is repeated.

<The stage where the stylus 2 is inside the sensing range SR and the sensor controller 31 has not yet specified the position of the stylus 2>
FIG. 5A shows a case where the sensor controller 31 transmits a pen activation signal, and FIG. 5B shows a case where the sensor controller 31 receives a long burst signal transmitted by the stylus 2 using the linear electrode 30Y. 5 (c) shows a case where the sensor controller 31 receives the long burst signal transmitted by the stylus 2 by using the linear electrode 30X.

When the pen-down operation (time t6) is performed as shown in FIG. 5A, the stylus 2 can detect the detection pattern c1 by the subsequent detection operation of the detection pattern c1 (time t7). The stylus 2 that has detected the detection pattern c1 in this way continues the detection operation until the delimiter pattern STP is detected. When the delimiter pattern STP is detected, it synchronizes with the sensor controller 31 based on the detection time. Specifically, this synchronization is performed by creating a transmission / reception schedule, which will be described later.

In FIG. 5A, the pen-down operation is performed at time t6 between the time t5 when the transmission of the pen activation signal is started and the time t8 (= t5 + T) when the transmission of the pen activation signal is finished, and the pen-down operation is performed at time t8. An example in which the stylus 2 detects the detection pattern c1 at the time t7 before the arrival is shown. For example, when the pen-down operation is performed when the sensor controller 31 is performing the long burst signal detection operation (for example, FIG. 5 (FIG. 5). Even at the time t6') shown in b), the same processing is executed only if the detection timing of the detection pattern c1 by the stylus 2 is slightly delayed.

Subsequently, as shown in FIG. 5B, when the sensor controller 31 starts transmitting a command signal indicating a long burst signal transmission instruction at time t9 after time t8, the stylus 2 receives this command signal and the time. The long burst signal is continuously transmitted over the time T1 up to t10 (= t9 + T). The sensor controller 31 detects the stylus 2 by detecting the long burst signal transmitted in this way.

Specifically, first, as shown in FIG. 5B, N linear electrodes 30Y are sequentially used to perform a long burst signal detection operation (the first half of the full range scan described later). At this time, since the long burst signal is detected by any one or more linear electrodes 30Y, the sensor controller 31 stores the detection intensity of the long burst signal in each linear electrode 30Y. Next, as shown in FIG. 5C, the sensor controller 31 restarts the transmission of the command signal indicating the transmission instruction of the long burst signal at the time t11 after the time t10, and performs the long burst signal detection operation at the end of the transmission. Do it again. This detection operation is carried out by sequentially using M linear electrodes 30X until the time t12 (= t11 + T) (the latter half of the full range scan described later). Since the long burst signal is detected by any one or more linear electrodes 30X by this detection operation, the sensor controller 31 stores the detection intensity of the long burst signal in each linear electrode 30X. Then, the position coordinates of the stylus 2 on the touch surface are derived based on the detection intensity of the long burst signal at each linear electrode 30Y stored earlier and the detection intensity of the long burst signal at each linear electrode 30X stored this time.

<After the stylus 2 is inside the sensing range SR and the sensor controller 31 identifies the position of the stylus 2>
FIG. 6 shows the time when the burst signal and the data signal are transmitted by the stylus 2. As shown in the figure, the sensor controller 31 that has specified the position of the stylus 2 starts transmitting a command signal indicating a data transmission instruction at the subsequent time t13. Upon receiving this, the stylus 2 first continuously transmits a burst signal over a time T2. The sensor controller 31 detects this burst signal and derives the position coordinates of the stylus 2 based on the detected burst signal. In the burst signal detection operation, only the M linear electrodes 30X and N linear electrodes 30Y that are indicated to be near the stylus 2 by the position coordinates of the stylus 2 derived immediately before are sequentially selected. Performed using (sector scan described below). The stylus 2 transmits a data signal including the indicated data following the burst signal. The sensor controller 31 receives the data signal and decodes it to acquire the data transmitted by the stylus 2. The reception of the data signal is performed using only one linear electrode 30X or linear electrode 30Y corresponding to the position coordinates of the stylus 2 derived immediately before.

Returning to FIG. 2, the operation of the logic unit 70 when detecting the stylus 2 and performing bidirectional communication with the stylus 2 will be described in detail.

When transmitting a command signal indicating a pen activation signal and a long burst signal transmission instruction (FIGS. 4 (a) (b) and 5 (a) (b) (c)), the logic unit 70 has M lines. The selection unit 40 is controlled so that all of the linear electrodes 30X and / or all of the N linear electrodes 30Y are used at the same time. Specifically, the control signals sTRx, sTRy, selX, selY so that the output end of the transmission unit 60 is simultaneously connected to one or both of the M linear electrodes 30X and the N linear electrodes 30Y. 40 is used to control the selection unit 40. As a result, each of the command signal indicating the transmission instruction of the pen activation signal and the long burst signal is transmitted over the entire touch surface, so that the stylus 2 can be anywhere within the sensing range SR shown in FIG. , These signals can be received.

The logic unit 70 when the long burst signal is received at the stage where the stylus 2 has not been detected (FIGS. 4 (b) and 5 (b)) is also shown in FIGS. 4 (b) and 5 (b). As described above, the selection unit 40 is controlled so that the N linear electrodes 30Y are sequentially used. Specifically, the selection unit 40 is controlled by using the control signals sTRy and selY so that the N linear electrodes 30Y are sequentially connected to the input terminals of the reception unit 50. This allows the sensor controller 31 to receive the long burst signal transmitted by the stylus 2 wherever the stylus 2 is within the sensing range SR shown in FIG. 1, thereby detecting the stylus 2.

FIG. 7A is a diagram illustrating the operation of the sensor controller 31 in this case. As shown in the figure, the sensor controller 31 in this case sequentially scans N linear electrodes 30Y. The reason why M linear electrodes 30X are not scanned at this stage is that the entire surface of the sensor 30 can be scanned by using only N linear electrodes 30Y, and one electrode per electrode. This is to increase the scanning time of.

After detecting the stylus 2 by receiving the long burst signal, when the long burst signal is received at the stage where the position coordinates of the stylus 2 have not been derived yet (FIG. 5 (c)), the logic unit 70 is shown in FIG. 5 (c). ), The selection unit 40 is controlled so that M linear electrodes 30X are sequentially used. Specifically, the selection unit 40 is controlled by using the control signals sTRx and selX so that the M linear electrodes 30X are sequentially connected to the input terminals of the reception unit 50. The sensor controller 31 derives the position coordinates of the stylus 2 on the touch surface as described above based on the result of this control and the detection result of the long burst signal by the N linear electrodes 30Y previously executed. do.

FIG. 7B is a diagram illustrating the operation of the sensor controller 31 in this case. As shown in the figure, the sensor controller 31 in this case sequentially scans M linear electrodes 30X. In the present specification, a scan (first half) in which N linear electrodes 30Y shown in FIG. 7 (a) are sequentially used and a scan in which M linear electrodes 30X shown in FIG. 7 (b) are sequentially used (a scan (first half). Together with the latter half), it is referred to as a "full range scan" (first scan).

When the command signal is transmitted at the stage after the position coordinates of the stylus 2 are derived (FIG. 6), the logic unit 70 is located near the stylus 2 among the M linear electrodes 30X and the N linear electrodes 30Y. The selection unit 40 is controlled so that only the ones in the above are used. Specifically, for example, assuming that the stylus 2 is located at the intersection of the j + 5th linear electrode 30X and the i + 5th linear electrode 30Y, for example, the range of 5 stylus 2 on each side, that is, the jth ~ The selection unit uses the control signals sTRx, sTRy, selX, and selY so that the j + 10th linear electrode 30X and the i-th to i + 10th linear electrodes 30Y are simultaneously connected to the output end of the transmission unit 60. 40 is controlled. As a result, the command signal can be transmitted using only the linear electrodes near the stylus 2, so that the power consumption required for transmitting the command signal can be reduced. Further, when the command signal is supplied to the equal hands placed on the touch surface, the ground potential supplied to the stylus 2 may increase, and as a result, the accuracy of detecting the uplink signal by the stylus 2 may decrease. However, by transmitting the command signal using only the linear electrode near the stylus 2 as described above, the possibility that the command signal is supplied to the equal hands is reduced, so that the uplink signal by the stylus 2 is reduced. It is possible to prevent a decrease in the detection accuracy of.

After deriving the position coordinates of the stylus 2, when receiving a normal burst signal that is not a long burst signal (FIG. 6), the logic unit 70 is of the M linear electrodes 30X and the N linear electrodes 30Y. The selection unit 40 is controlled so that only those near the stylus 2 are sequentially used. Specifically, for example, assuming that the stylus 2 is located at the intersection of the j + 5th linear electrode 30X and the i + 5th linear electrode 30Y, for example, as shown in FIG. That is, the control signals sTRx, sTRy, selX, so that the j-th to j + 10th linear electrodes 30X and the i-th to i + 10th linear electrodes 30Y are sequentially connected to the input ends of the receiving unit 50. The selection unit 40 is controlled using selY. As a result, the reception time per linear electrode can be lengthened, so that the burst signal can be received more reliably.

FIG. 7C is a diagram illustrating the operation of the sensor controller 31 in this case. Also in this example, it is assumed that the stylus 2 is located at the intersection of the j + 5th linear electrode 30X and the i + 5th linear electrode 30Y. The sensor controller 31 according to this example sequentially connects only the 11 linear electrodes 30X from the jth to the j + 10th and the 11 linear electrodes 30Y from the ith to the i + 10th among the M × N linear electrodes. The scan is performed, and the position coordinates of the stylus 2 are derived based on the result. Hereinafter, a scan for redistributing (updating) the position coordinates of the stylus 2 once derived using both a part of the M linear electrodes 30X and a part of the N linear electrodes 30Y in this way is performed as a “sector”. It is called "scan" (second scan).

When receiving the data signal (FIG. 6), the logic unit 70 selects to use only one linear electrode 30X or linear electrode 30Y corresponding to the position of the stylus 2 derived by the immediately preceding burst signal. The unit 40 is controlled. Specifically, the selection unit 40 is selected by using the control signals sTRx, sTRy, selX, and selY so that the one linear electrode 30X or the linear electrode 30Y is connected to the input end of the receiving unit 50. Control. This makes it possible to fully utilize the data signal transmission time (= T1-T2) for transmitting data from the stylus 2 to the sensor controller 31.

The operation of the logic unit 70 when detecting the stylus 2 and performing bidirectional communication with the stylus 2 has been described above.

FIG. 8 is a block diagram showing a functional block of the stylus 2 according to the present embodiment. As shown in the figure, the stylus 2 includes an electrode 21, a pen pressure detection sensor 23, and a signal processing unit 24.

The electrode 21 is a conductive member provided near the tip of the core of the stylus 2, serves as an antenna for transmitting a downlink signal, and is an uplink transmitted from the sensor controller 31 via a coupling capacitance. It also serves as an antenna for receiving signals.

The pen pressure detection sensor 23 is a pressure sensor for detecting the pressure (pen pressure) applied to the tip of the core of the stylus 2.

The signal processing unit 24 receives the uplink signal from the sensor controller 31 via the electrode 21, performs processing according to the content thereof, generates a downlink signal to be transmitted to the sensor controller 31, and sets the electrode 21. It has a function of transmitting to the sensor controller 31 via the sensor controller 31. Specifically, it functionally includes a switching unit 76, a receiving unit 71, a transmitting unit 75, and a control unit 90. Hereinafter, each of these functional blocks will be described in order.

The switching unit 76 is a switch element having one circuit and two contacts configured so that the common terminal and any one of the T terminal and the R terminal are connected. 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 receiving the uplink signal from the sensor controller 31, the control unit 90 controls the switching unit 76 by the control signal SWC so that the R terminal and the common terminal are connected. Further, when transmitting a downlink signal to the sensor controller 31, the switching unit 76 is controlled by the control signal SWC so that the T terminal and the common terminal are connected. The control unit 90 consumes the stylus 2 after fixing the switching unit 76 to the state in which the R terminal and the common terminal are connected until the initial state, that is, until the stylus 2 detects the detection pattern c1 described above. Go to sleep to reduce power consumption.

The receiving unit 71 is a circuit that receives the signal supplied from the switching unit 76 (the signal arriving at the electrode 21) and decodes the value of the symbol included in the received signal, and is a waveform reproducing unit 71a and a correlation calculator. It is configured to include 71b. The receiving unit 71 is configured to be able to detect each of the above-mentioned detection pattern c1, delimiter pattern STP, and control information c2 by this decoding. In order to reduce the power consumption of the stylus 2, the receiving unit 71 performs a receiving operation only intermittently until the detection pattern c1 is detected.

The waveform reproduction unit 71a binarizes the level of the electric charge (voltage) induced in the electrode 21 with a clock several times (for example, four times) the chip rate of the diffusion code PN described above, and binary sequences of positive and negative polar values (for example, four times). It is formatted into a chip string) and output. The correlation calculator 71b stores the chip sequence output by the waveform reproduction unit 71a in a register, and shifts sequentially with the clock to spread code PN (or at least one of inversion and cyclic shift with respect to the spread code PN). The value of the symbol contained in the received signal is decoded by performing the correlation operation with the code obtained by applying.

The receiving unit 71 sequentially determines whether or not the value of the symbol decoded by the correlation calculator 71b indicates the above-mentioned detection pattern c1. When the detection pattern c1 is detected as a result, the presence of the sensor controller 31 is detected, and an activation signal EN for enabling the control unit 90 to execute processing according to the command indicated by the command signal is set. Issue.

Further, when the detection pattern c1 is detected, the reception unit 71 continuously switches the reception operation from intermittent to continuous, and sequentially determines whether or not the value of the decoded symbol indicates the above-mentioned delimiter pattern STP. When the delimiter pattern STP is detected as a result, the receiving unit 71 outputs the detection time t2 to the control unit 90.

After detecting the delimiter pattern STP, the receiving unit 71 performs a command signal receiving operation to be transmitted by the sensor controller 31 according to scheduling (described later) by the control unit 90. Specifically, the values of a series of symbols decoded by the correlation calculator 71b during the reception operation are acquired as control information c2 and output to the control unit 90.

The control unit 90 is composed of a microprocessor (MCU) and is activated when the start signal EN is supplied from the reception unit 71, and then various signals are generated based on the detection time t2 supplied from the reception unit 71. Etc. to generate a transmission / reception schedule. Then, a process of generating a control signal SWC based on the generated transmission / reception schedule and supplying it to the switching unit 76, a process of controlling the receiving unit 71 so as to receive a command signal, and a control information c2 supplied from the receiving unit 71. The process of controlling the transmission unit 75 is performed based on the above. The control of the transmission unit 75 is to determine whether to transmit a long burst signal or a burst signal and a data signal based on the received command signal, and when transmitting a long burst signal or a burst signal. Includes instructing the transmission unit 75 to that effect, and, when transmitting a data signal, acquiring the data instructed to be transmitted by the control information c2 and supplying the data signal to the transmission unit 75. The data supplied to the transmission unit 75 includes data indicating the pen pressure detected by the pen pressure detection sensor 23.

The transmission unit 75 is a circuit that generates a signal to be transmitted to the sensor controller 31 and supplies it to the electrode 21, and is composed of a modulation unit 73 and a booster circuit 74.

The modulation unit 73 is a circuit that generates a carrier signal (square wave signal) having a predetermined frequency or a frequency that is controlled by the control unit 90, and outputs the signal as it is or after modulating it based on the control of the control unit 90. At the time of transmitting the long burst signal and the burst signal, the modulation unit 73 modulates and outputs the carrier signal as it is without modulating it or by modulating it with a pattern of known values shared with the sensor controller 31. As a result, the modulation unit 73 outputs a long burst signal before boosting and a burst signal before boosting. On the other hand, when the data signal is transmitted, the carrier signal is modulated (OK, PSK, etc.) by the data supplied from the control unit 90, and the resulting modulated signal is output. As a result, the data signal before boosting is output from the modulation unit 73.

The booster 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 constant amplitude. The long burst signal, burst signal, and data signal generated by the booster circuit 74 are transmitted from the electrode 21 to the space via the switching unit 76.

The configuration and operation of the sensor controller 31 and the stylus 2 according to the present embodiment have been described above. Next, each operation will be described in more detail with reference to the processing flow charts of the sensor controller 31 and the stylus 2.

First, FIG. 9 is a processing flow diagram showing the entire operation of the sensor controller 31. As shown in the figure, the sensor controller 31 performs four finger touch detection processes for each time Tr (for example, 16.67 ms, which is the reciprocal of 60 Hz) defined by the reciprocal of the display refresh rate of the liquid crystal display or the like. It is configured to repeat the same operation including (steps S1 and S2) and four stylus detection processes (step S3). The finger touch detection process and the stylus detection process are executed alternately, each finger touch detection process is continuously executed for a time Tf (for example, 1500 μs), and each stylus detection process is continuously executed for a time Ts (for example, 2500 μs). NS. The finger F is detected by using two finger touch detection processes (step S1 and step S2), which are executed discontinuously with the stylus detection process in between, as a position detection unit for one finger touch.

FIG. 10 is a processing flow diagram showing a stylus detection process performed by the sensor controller 31. Although not shown, the sensor controller 31 stores a state flag indicating its own state. The states indicated by the status flags include a stylus undetected and pen activation signal transmission waiting state (= 0), a stylus undetected and waiting for a response to the pen activation signal (= 1), and a stylus detected and position underived. A state (= 2) and a state in which the stylus position has been derived (= 3) are included. The sensor controller 31 first refers to this status flag (step S10).

When the state flag referred to in step S10 is "0", the sensor controller 31 transmits a pen activation signal over a predetermined time T (for example, 2500 μs, which is the same as the time Ts shown in FIG. 9) (step S11). .. Specifically, the repetition of the detection pattern c1 and the delimiter pattern STP are transmitted. The sensor controller 31 that has finished continuously transmitting the pen activation signal sets the status flag to "1" (step S12), and returns the process to step S10.

When the state flag referred to in step S10 is "1", the sensor controller 31 first transmits a command signal (first uplink signal) indicating a transmission instruction of the long burst signal (step S13). As shown in FIG. 10, it takes a maximum time T0 (for example, 200 μs) to transmit various command signals including this command signal. After that, the sensor controller 31 performs a long burst signal detection operation over time T1 (step S14). This detection operation is performed by the first half of the full range scan (first scan) described with reference to FIG. 7 (a).

When the time T1 elapses and the long burst signal detection operation is completed, the sensor controller 31 determines whether or not the long burst signal has been received (step S15). As a result, if it is determined that the signal has not been received, the status flag is set to "0" (step S16), and the process is returned to step S10. This step S16 is a process when the sensor controller 31 cannot receive the downlink signal because, for example, the stylus 2 is outside the sensing range SR shown in FIG. On the other hand, if it is determined that the signal has been received in step S15, the sensor controller 31 sets the status flag to "2" (step S17), then determines the command to be transmitted to the stylus 2 (step S18), and then determines the command to be transmitted. The process returns to step S10. The command determined here is an instruction to transmit a long burst signal.

When the state flag referred to in step S10 is "2", the sensor controller 31 first retransmits the command signal (first uplink signal) indicating the transmission instruction of the long burst signal (step S19). After that, the sensor controller 31 re-executes the long burst signal detection operation over the time T1 (step S20). This detection operation is performed by the latter half of the full range scan (first scan) described with reference to FIG. 7 (b). If the first half operation (step S14) and the second half operation (step S20) of the full range scan can be executed during one time T1, these two steps S14 and S20 are executed by one process. You may.

When the time T1 elapses and the long burst signal detection operation is completed, the sensor controller 31 determines whether or not the long burst signal has been received (step S21). As a result, if it is determined that the signal has not been received, the status flag is set to "0" (step S22), and the process is returned to step S10. This step S22 is a process when the sensor controller 31 cannot receive the downlink signal because, for example, the stylus 2 has moved out of the sensing range SR shown in FIG. On the other hand, when it is determined that the signal has been received in step S21, the sensor controller 31 sets the state flag to "3" (step S23), and also sets the detection result of the long burst signal in step S14 and the long burst in step S20. The position of the stylus 2 is derived based on the signal detection result (step S24). Then, after determining the command to be transmitted to the stylus 2 (step S25), the process returns to step S10. The command determined here is an instruction to transmit various data (stylus ID, data indicating pen pressure, etc.) and also plays a role of an instruction to transmit a burst signal over time T2.

When the state flag referred to in step S10 is "3", the sensor controller 31 transmits a command signal (second uplink signal) indicating the command determined in step S25 or step S32 described later (step S26). ). After that, the sensor controller 31 performs a burst signal detection operation for a time T2 shorter than the time T1 (step S27), and when the burst signal is detected, the stylus is based on the detection intensity at the linear electrodes 30X and 30Y. Derivation of the position coordinates of 2 is performed (step S28). The burst signal detection operation in step S27 is performed by the sector scan (second scan) described with reference to FIG. 7 (c).

When the time T2 elapses and the burst signal detection operation is completed, the sensor controller 31 then performs a data signal detection operation (step S29). This detection operation includes a data signal decoding process. The data signal detection operation is performed using one linear electrode 30X or linear electrode 30Y selected based on the position coordinates derived in the immediately preceding step S28. By doing so, it becomes possible to fully utilize the detection period of the data signal, and it becomes possible to receive more data from the stylus 2.

When the sensor controller 31 ends the data signal detection operation, the sensor controller 31 determines whether or not the burst signal or the data signal has been received (step S30). As a result, if it is determined that none of them have been received, the state flag is set to "0" (step S31), and the process is returned to step S10. This step S31 is a process when the sensor controller 31 cannot receive the downlink signal because, for example, the stylus 2 has moved out of the sensing range SR shown in FIG. On the other hand, if it is determined in step S30 that at least one of them has been received, the command to be transmitted to the stylus 2 is determined next (step S32), and then the process is returned to step S10. The command determined here is also an instruction to transmit various data (stylus ID, data indicating pen pressure, etc.) and also plays a role of an instruction to transmit a burst signal over time T2.

Next, FIG. 11 is a processing flow diagram showing the operation of the stylus 2 corresponding to FIG. 10. Although not shown, the stylus 2 also stores a state flag indicating its own state. The state indicated by the state flag includes a sensor controller undetected state (= 0) and a sensor controller detected state (= 1). The stylus 2 first refers to this state flag (step S40).

When the state flag referred to in step S40 is "0", the stylus 2 first enters the reception operation hibernation state (step S41). Then, after the predetermined time has elapsed, the detection of the above-mentioned detection pattern c1 is tried (step S42). The pause period in step S41 is provided in order to reduce the power consumption of the stylus 2 by intermittently performing the detection operation of the detection pattern c1.

The stylus 2 then determines whether or not the detection pattern c1 has been detected by the trial in step S42 (step S43). As a result, if it is determined that it has not been detected, the process returns to step S40. On the other hand, if it is determined that the stylus has been detected, the stylus 2 continues the detection operation of the detection pattern c1 and the symbols constituting the delimiter pattern STP until the delimiter pattern STP described above is detected (step S44). Then, when the delimiter pattern STP is detected, the process of synchronizing with the sensor controller 31 is performed based on the detection time (step S45), the state flag is set to "1" (step S46), and the state flag is set to "1" (step S46). Return the process. Specifically, the synchronization process in step S45 is a process of generating a transmission / reception schedule by the control unit 90 shown in FIG.

When the state flag referred to in step S40 is "1", the stylus 2 first performs a command signal detection operation (step S47). This detection operation is performed over time T0. Next, the stylus 2 determines whether or not the command signal is detected by the detection operation in step S47, and if so, what is the content indicated by the command signal (step S48). If it is determined that the command signal has not been detected, the status flag is set to "0" (step S49), and the process returns to step S40. This step S49 is a process when the stylus 2 cannot detect the uplink signal because, for example, the stylus 2 has left the sensing range SR shown in FIG.

On the other hand, when it is determined in step S48 that a command signal indicating a long burst signal transmission instruction is detected, the stylus 2 determines transmission of the long burst signal and performs a process of transmitting the long burst signal over time T1 (step). S50). Specifically, the signal of the predetermined waveform constituting the long burst signal is continuously transmitted over the time T1. After that, the process returns to step S40.

If it is determined in step S48 that a command signal indicating a data transmission instruction has been detected, the stylus 2 determines transmission of the burst signal and performs a process of transmitting the burst signal over time T2 (step S51). Specifically, the signal of the predetermined waveform constituting the burst signal is continuously transmitted over the time T2. Next, the stylus 2 performs a process of transmitting a data signal including the instructed data (step S52). After that, the process returns to step S40.

As described above, according to the present embodiment, the sensor controller 31 has a long stylus 2 that continues for a longer time than a normal burst signal in a stylus undetected state in which the stylus 2 is likely to be hovering. You can expect to send a burst signal. Therefore, while making the detection operation time per linear electrode longer than that during normal burst signal reception, more linear electrodes (all linear electrodes in the present embodiment) within the transmission duration of the long burst signal. Since it is possible to detect the burst signal by scanning 30Y or the linear electrode 30X), the burst signal detection by the sensor controller 31 fails while ensuring a state in which the burst signal can be detected in a wide range in the touch surface. It becomes possible to reduce the possibility of.

Further, according to the present embodiment, since the full range scan is used when the long burst signal is received, the detection operation time per linear electrode is secured while ensuring the state in which the burst signal can be detected in the entire area of the touch surface. Can be made even longer.

Further, according to the present embodiment, since the sensor controller 31 instructs the stylus 2 to transmit the long burst signal by the command signal indicating the transmission instruction of the long burst signal, the stylus 2 is instructed to transmit the long burst signal. You can clearly know when to send.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and the present invention can be implemented in various embodiments without departing from the gist thereof. Of course.

Hereinafter, the first to sixth modifications of the above embodiment will be described.

FIG. 12 is a diagram showing the configuration of the stylus 2 according to the first modification of the above embodiment. The sensor controller 31 and the stylus 2 according to this modification are different from the above-described embodiment in that they use wireless communication that does not use the electrostatic coupling method for transmitting the uplink signal. It is also different from the above embodiment in that the stylus 2 supports transmission of two types of downlink signals DS1 and DS2 having different carrier signal formats. The downlink signals DS1 and DS2 are both configured to be capable of transmitting the above-mentioned long burst signal, burst signal, and data signal, and the stylus 2 uses these properly according to the type of the approaching sensor controller 31. Hereinafter, the configuration of the stylus 2 according to this modification will be described in detail with reference to FIG.

As shown in FIG. 12, the stylus 2 according to this modification includes an electrode 21, a signal processing unit 24, a power supply 25, an amplification unit 26, and a reception unit 27.

The receiving unit 27 is a functional unit configured to enable communication by, for example, Bluetooth (registered trademark) as wireless communication. In this modification, the sensor controller 31 receives an uplink signal transmitted by Bluetooth (registered trademark). do.

The signal processing unit 24 is a functional unit having a function of selectively transmitting two types of downlink signals DS1 and DS2 and a function of receiving an uplink signal US via a receiving unit 27, and specifically, a functional unit having a function of receiving an uplink signal US via a receiving unit 27. , A control unit 91, a booster unit 92, an oscillation unit 93, and a switch unit 94.

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

The oscillating unit 93 has a function of generating an unmodulated sine wave signal (carrier signal) that vibrates at a predetermined frequency by performing an oscillating operation based on a DC voltage supplied from the power supply 25. The amplification unit 26 has a function of generating an unmodulated sine wave signal v2 by amplifying the sine wave signal generated by the oscillation unit 93 at a predetermined amplification factor. As shown in FIG. 12, the amplifier unit 26 is preferably configured by an amplifier circuit composed of a transformer and a capacitor.

The switch unit 94 is a switch element having one circuit and three contacts, and has a terminal a connected to the output end of the booster unit 92, a terminal b connected to the output end of the amplification unit 26, and a power supply wiring to which a ground potential is supplied. It is configured to have a terminal g connected to the electrode 21 and a common terminal c connected to the electrode 21.

The control unit 91 is an IC that supplies the control signal Ctrl for controlling the switch unit 94, controls the reception unit 27, and receives the uplink signal transmitted by the sensor controller 31, and is supplied from the power supply 25. It is configured to operate on power. In a specific example, the control unit 91 may be an ASIC or an MCU. The control unit 91 corresponds to the content of the uplink signal received via the reception unit 27 or the fact that the uplink signal is not received (the sensor controller 31 supports only one-way communication from the stylus 2 to the sensor controller 31). Case), it is determined which of the downlink signals DS1 and DS2 is used to transmit the long burst signal, the burst signal, and the data signal. Further, similarly to the control unit 90 shown in FIG. 8, the transmission / reception schedule of various signals and the like is determined, and the switch unit 94 is controlled based on the determined transmission / reception schedule.

The control unit 91 when transmitting the downlink signal DS1 controls the switch unit 94 so as to function as a first switch unit provided between the output end of the booster unit 92 and the electrode 21. That is, the process of switching the switch unit 94 is performed between the state in which the terminal a is connected to the common terminal c and the state in which the terminal g is connected to the common terminal c. The state where the terminal a is connected to the common terminal c corresponds to the state where the first switch part is on, and the state where the terminal g is connected to the common terminal c means that the first switch part is off. Corresponds to the state of being.

When a burst signal or a long burst signal is transmitted using the downlink signal DS1, the control unit 91 periodically performs switching control of the switch unit 94 at a predetermined cycle. When the terminal a is connected to the common terminal c, the DC voltage V1 becomes the output voltage of the switch unit 94. On the other hand, when the terminal g is connected to the common terminal c, the ground potential becomes the output voltage of the switch unit 94. Therefore, an unmodulated pulse train signal is output from the switch unit 94, which becomes a long burst signal or a burst signal.

On the other hand, when a data signal is transmitted using the downlink signal DS1, the control unit 91 uses the pen pressure level P and the switch information SW indicating on / off of the side switch (not shown) provided in the stylus 2 as data. The switching control of the switch unit 94 is performed accordingly. In addition, this data may include other information such as a stylus ID (identification information of the stylus 2). The control unit 91 generates a data signal, which is a pulse train signal modulated based on the data, by this switching control. As a specific method of modulation of the pulse train signal by the control unit 91, on-off modulation, frequency modulation, and the like can be considered.

The control unit 91 when transmitting the downlink signal DS2 controls the switch unit 94 so as to function as a second switch unit provided between the output end of the amplification unit 26 and the electrode 21. That is, the process of switching the switch unit 94 is performed between the state in which the terminal b is connected to the common terminal c and the state in which the terminal g is connected to the common terminal c. The state where the terminal b is connected to the common terminal c corresponds to the state where the second switch part is on, and the state where the terminal g is connected to the common terminal c means that the second switch part is off. Corresponds to the state of being.

When transmitting a burst signal or a long burst signal using the downlink signal DS2, the control unit 91 fixes the switch unit 94 on the terminal b side. Therefore, the switch unit 94 outputs an unmodulated sine wave signal v2, which becomes a long burst signal or a burst signal.

On the other hand, when a data signal is transmitted using the downlink signal DS2, 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. Even in this case, the data may include other information such as a stylus ID. The control unit 91 generates a data signal, which is a sine wave signal modulated based on the data, by this switching control. On-off modulation is adopted as a specific method for modulating the sinusoidal signal by the control unit 91.

As described above, according to this modification, Bluetooth (registered trademark) can be used for transmitting and receiving uplink signals. Although an example of using Bluetooth (registered trademark) has been described here, it goes without saying that proximity wireless communication other than Bluetooth (registered trademark) may be used for transmitting and receiving uplink signals.

Further, according to this modification, the stylus 2 can communicate with a plurality of different types of sensor controllers 31 in both directions or in one direction by properly using the downlink signals DS1 and DS2. ..

FIG. 13 is a processing flow diagram showing the operation of the stylus 2 according to the second modification of the above embodiment. The stylus 2 according to this modification determines that the sensor controller 31 transmits a long burst signal immediately after receiving some uplink signal at an undetected stage, and whether or not to transmit a burst signal immediately before the data signal. This is different from the above embodiment. Hereinafter, the operation of the stylus 2 according to this modification will be described in detail with reference to FIG.

As shown in FIG. 13, the stylus 2 according to this modification first performs an uplink signal detection operation (step S60). Then, it is determined whether or not the uplink signal is detected by this detection operation (step S61), and if it is determined that the uplink signal is not detected, the process returns to step S60 and the detection operation is repeated. On the other hand, if it is determined that it has been detected, a long burst signal is transmitted without waiting for the command signal (step S62). Specifically, the signal of the predetermined waveform described above is transmitted over the time T1.

After transmitting the long burst signal, the stylus 2 performs a command signal detection operation (step S63). Then, it is determined whether or not the command signal indicating the data transmission instruction is detected (step S64), and if it is determined that the command signal is not detected, the process returns to step S62 and the transmission of the long burst signal is repeated. On the other hand, if it is determined that it has been detected, it is determined whether or not to transmit the burst signal next (step S65). This determination is preferably made based on the content of the detected command signal. By doing so, it becomes possible to control from the sensor controller 31 whether or not the stylus 2 transmits a burst signal.

The process when it is determined in step S65 to transmit the burst signal is the same as in steps S51 and S52 shown in FIG. Specifically, the stylus 2 transmits a burst signal by transmitting a signal having a predetermined waveform over time T2 (step S66), and then indicates a command signal detected in step S63 over time T1-T2. A data signal including data based on the above is transmitted (step S67). On the other hand, when it is determined in step S65 that the burst signal is not transmitted, the stylus 2 transmits a data signal including data based on the instruction of the command signal detected in step S63 over the time T1 (step S68).

After transmitting the data signal in step S67 or step S68, the stylus 2 returns the process to step S63. As a result, it becomes possible to continuously transmit data according to the instruction from the sensor controller 31.

As described above, according to the present modification, the stylus 2 can transmit the long burst signal without waiting for the command signal including the instruction to transmit the long burst signal. Therefore, the long burst signal can be transmitted to the sensor controller 31 which does not particularly correspond to the long burst signal.

Further, since the stylus 2 determines whether or not to transmit the burst signal immediately before the data signal, the stylus 2 may use the stylus 2 when the sensor controller 31 does not need to transmit the burst signal from the stylus 2. It is possible to transmit a data signal (ie, transmit more data) over a longer period of time, and the sensor controller 31 will be able to acquire more data.

FIG. 14 is a processing flow diagram showing the operation of the sensor controller 31 according to the third modification of the above embodiment. The sensor controller 31 according to this modification is a command indicating a long burst signal transmission instruction following the transmission of the pen activation signal or the execution of the first half of the full range scan in one stylus detection process (step S3 in FIG. 9). It differs from the above embodiment in that a signal is transmitted. Hereinafter, the operation of the sensor controller 31 according to this modification will be described in detail with reference to FIG.

As shown in FIG. 14, the sensor controller 31 according to the modified example activates the pen for a shorter time (specifically, time T1) than the example of FIG. 10 when the state flag referred to in step S10 is “0”. A signal is transmitted (step S71). Next, the sensor controller 31 transmits a command signal (first uplink signal) indicating a transmission instruction of the long burst signal (step S72), then sets the state flag to "1" (step S12), and then steps S10. Return the process to.

When the state flag referred to in step S10 is "1", the sensor controller 31 according to this modification performs a long burst signal detection operation over time T1 (step S73), and then transmits the long burst signal. The command signal (first uplink signal) indicating the instruction is transmitted again (step S74). The point that the detection operation of step S73 is performed by the first half of the full range scan is the same as that of step S14 shown in FIG. Is reversed.

When the state flag referred to in step S10 is "2", the sensor controller 31 according to this modification performs a long burst signal detection operation over time T (step S63). The point that this detection operation is performed by the latter half of the full range scan is the same as in step S14 shown in FIG. 10, but as can be understood by comparing FIG. 10 and FIG. 14, the entire time T is a long burst signal. It is possible to use it for the detection operation of. Since the processing after this is the same as the example of FIG. 10, detailed description is omitted.

Here, in this modification, it is preferable that the transmission instruction of the long burst signal transmitted in steps S72 and S74 also includes information indicating the transmission duration of the long burst signal. The stylus 2 preferably controls the transmission duration of the long burst signal according to the transmission duration indicated by this information. By doing so, it is possible to match the period during which the sensor controller 31 detects the long burst signal with the period during which the stylus 2 transmits the long burst signal.

As described above, according to the present modification, the latter half of the full range scan can be performed over a longer period of time as compared with the above embodiment. Therefore, since the reception time per linear electrode 30X can be further lengthened, the sensor controller 31 can receive the burst signal more reliably than in the above embodiment.

FIG. 15 is a diagram showing a long burst signal transmitted by the stylus 2 according to the fourth modification of the above embodiment. The sensor controller 31 and the stylus 2 according to this modification differ from the above-described embodiment in the format of the long burst signal. Hereinafter, the format of the long burst signal according to this modification will be described in detail with reference to FIG.

As shown in FIG. 15, the long burst signal according to this modification is composed of a continuous pattern of a signal having a frequency f1 (first frequency) and a signal having a frequency f2 (second frequency) different from the frequency f1. Will be done. Specifically, the frequency of the first half is f1 and the frequency of the second half is f2.

Assuming that the frequency of the long burst signal is single over the entire section, 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 having a strong component near the frequency f1 as a long burst signal. On the other hand, according to the long burst signal according to the present modification, the sensor controller 31 determines that the received signal is a long burst signal based on the fact that two types of frequencies are detected in a known order. be able to. Therefore, according to this modification, it is possible to reduce the possibility that the sensor controller 31 misidentifies a signal that is not a long burst signal as a long burst signal and operates.

In this modification, the full range scan for detecting the long burst signal is executed so that, for example, the odd-numbered linear electrode 30Y is scanned first and the even-numbered linear electrode 30Y is scanned later. This is so that the sensor controller 31 can receive both the first half portion and the second half portion of the long burst signal. When the time T1 of the long burst signal can be sufficiently long, all the linear conductors 30Y may be sequentially scanned at the frequency f1, and then all the linear conductors 30Y may be sequentially scanned again at the frequency f2. good.

As described above, according to the present modification, it is possible to reduce the possibility that the sensor controller 31 misidentifies a signal that is not a long burst signal as a long burst signal and operates.

In this modified example, the long burst signal is provided with a feature that the frequency is different between the first half portion and the second half portion. However, the feature is that the sensor controller 31 can distinguish between the white noise and the long burst signal. If so, any feature may be provided in the long burst signal. For example, the long burst signal may be a signal in which L frequencies are changed in a predetermined sequence predetermined with the sensor controller 31. In this case, the sensor controller 31 may use N linear electrodes 30Y (or M linear conductors 30X) and perform the scanning operation L times repeatedly while changing the frequency.

FIG. 16 is a processing flow diagram showing the operation of the stylus 2 according to the fifth modification of the above embodiment. The sensor controller 31 and the stylus 2 according to the present modification are different from the above-described embodiment in that the stylus 2 determines that the stylus 2 has not yet been detected by the sensor controller 31 based on the uplink signal. Hereinafter, the operation of the stylus 2 according to this modification will be described in detail with reference to FIG.

As shown in FIG. 16, the stylus 2 according to this modification first goes into a sleep state (step S80). This sleep state is the same as the reception operation hibernation state (step S31) shown in FIG.

After entering the sleep state and the predetermined time has elapsed, the stylus 2 performs an uplink signal detection operation (step S81). Then, it is determined whether or not the uplink signal is detected by this detection operation (step S82), and if it is determined that the uplink signal is not detected, the process returns to step S80 and the sleep state is entered again. On the other hand, when it is determined that the stylus 2 has been detected, it is determined whether or not the uplink signal indicates that the sensor controller 31 has not yet detected the stylus 2 (in the undetected state) (step S83). ). This determination process is executed by the control unit 90 in the example of the stylus 2 shown in FIG. 8, and is executed by the control unit 91 in the example of the stylus 2 shown in FIG.

As a specific method for determining step S83, for example, the following can be considered. The first is the case where the sensor controller 31 explicitly transmits an uplink signal indicating that the stylus 2 is not detected. In this case, the stylus 2 may execute the determination in step S83 based on whether or not the uplink signal has been received. The second is a case where the sensor controller 31 transmits a command signal indicating a long burst signal transmission instruction, as described in the above embodiment. The sensor controller 31 transmits a command signal indicating a long burst signal transmission instruction when the sensor controller 31 has not yet detected the stylus 2, as described with reference to FIG. Therefore, the stylus 2 in this case can execute the determination in step S83 based on whether or not it has received the command signal indicating the transmission instruction of the long burst signal.

If a positive determination result is obtained in step S83, the stylus 2 transmits a long burst signal (step S84). Specifically, the signal of the predetermined waveform described above is transmitted over the time T1. Of course, the long burst signal transmitted in this case may be the long burst signal shown in FIG. 15 (a signal having a feature that makes it possible to distinguish between the white noise and the long burst signal).

On the other hand, if a negative determination result is obtained in step S83, the stylus 2 then determines whether or not to transmit the burst signal (step S85). Subsequent processes (steps S85 to S88) are the same as the processes of steps S65 to S68 described with reference to FIG. 13, so detailed description thereof will be omitted.

As described above, according to the present modification, the stylus 2 determines whether or not the sensor controller 31 has detected the stylus 2, and based on the result, transmits a long burst signal or a burst signal and It becomes possible to decide whether to transmit the data signal (or only the data signal).

FIG. 17 is a diagram illustrating a specific position exclusion process according to the sixth modification of the above embodiment. Further, FIG. 18 is a processing flow diagram showing the operation of the sensor controller 31 according to this modification. In this modification, the finger detected by the finger touch detection process (steps S1 and S2 in FIG. 9) from one or more positions of the stylus 2 derived as a result of the stylus detection process (step S3 in FIG. 9). It removes what is located in the touch area (information indicating the area touched by the finger F shown in FIG. 1). The details will be described below.

17 (a) shows the finger touch areas A1 and A2 detected by the finger touch detection process, and FIG. 17 (b) shows the stylus detection process executed immediately after the finger touch detection process of FIG. 17 (a). The positions B1 to B3 of the derived stylus 2 are shown.

In the finger touch areas A1 and A2 of FIG. 17A, as described above, a part of the current flowing on the linear electrode of the sensor 30 is generated through the capacitive coupling between the finger F and the linear electrodes 30X and 30Y. It was detected by flowing out toward the human body. In FIG. 17A, the area of the finger touch area A2 is significantly larger than the area of the finger touch area A1, but such a large area of the finger touch area A2 is usually at the fingertip. It is formed when the palm, fist, etc. come into contact with the touch surface. Therefore, it is usually invalidated by a separate process (palm rejection process) based on the size of the area. FIG. 17A shows the state before invalidation.

The positions B1 to B3 of the stylus 2 shown in FIG. 17B are derived, for example, in step S20 of FIG. 10 based on the detection intensity of the burst signal at the linear electrodes 30X and 30Y. The burst signal reaching the sensor 30 (see FIG. 2) goes through the hand holding the stylus 2 and the hand on the opposite side in addition to the components directly coming from the electrode 21 of the stylus 2 (see FIGS. 8 and 12). Contains the ingredients that arrive. Of the three positions B1 to B3 detected in FIG. 17B, only the position B3 is derived by the component directly coming from the electrode 21 of the stylus 2 to the sensor 30, and the other two are the positions B3. It is derived by the component that arrives at the sensor 30 via the hand holding the stylus 2 and the hand on the opposite side thereof.

Here, referring to FIG. 17A again, it is understood that the finger touch areas A1 and A2 are detected at the same positions as the positions B1 and B2. This is because the detection cause of the positions B1 and B2 is that the hand is close to the touch surface, and such a hand can also be detected by the finger touch detection process. The sensor controller 31 according to this modification utilizes such a relationship between the finger touch area and the stylus position, and the position of the stylus 2 derived by the stylus detection process by referring to the result of the finger touch detection process. Positions B1 and B2 are selected and removed (excluded) from B1 to B3. Hereinafter, the operation of the sensor controller 31 for realizing this will be described in detail with reference to FIG.

As shown in FIG. 18, the sensor controller 31 according to this modification first detects the finger touch area (step S90). This is a process performed in the finger touch detection process (steps S1 and S2) shown in FIG.

After that, when the process moves to the stylus detection process (step S3) shown in FIG. 9, the sensor controller 31 first acquires one or more stylus 2 position candidates by the process shown in step S20 of FIG. 10 (step). S91). Further, the sensor controller 31 acquires one or more finger touch areas detected in step S90 (step S92). When the above-mentioned palm rejection process is performed, the finger touch area acquired here is the one at the stage before receiving the palm rejection process.

Next, the sensor controller 31 repeats the processes after step S94 for each of the stylus 2 position candidates acquired in step S91. Specifically, first, it is determined whether or not the position indicated by the candidate is included in any one or more finger touch areas acquired in step S92 (step S94). If it is determined that the stylus is not included here, the position indicated by the candidate is recognized as the position of the stylus 2, and normal processing is performed (step S95). On the other hand, if it is determined that the candidate is included, the candidate is invalidated (step S96). The invalidated candidate will not be used at least as the position of the stylus 2 in the subsequent processing. This invalidation process may be realized by not outputting the position of the stylus 2 from the sensor controller 31 to the system controller of the electronic device 3, or after outputting the position of the stylus 2. The position may be realized by indicating that it is an invalid area with a flag or the like.

As described above, according to the present modification, the sensor controller 31 passes through the hand holding the stylus 2 and the hand on the opposite side from the plurality of positions of the stylus 2 derived by the stylus detection process. The position derived by the component of the burst signal arriving at the sensor 30 can be removed.

Further, in the above embodiment, it has been described that the full range scan is performed using all of the N linear electrodes 30Y and the M linear electrodes 30X, but the full range scan is compared with the sector scan. It is sufficient to perform many scans (that is, scans using a large number of linear electrodes), and it is not always necessary to use all of the N linear electrodes 30Y and the M linear electrodes 30X. That is, the full range scan may be performed by using the detection area of the first range which is the whole or a part of the touch surface, and the sector scan may perform the detection area of the selected range of the first range. You can use it. Further, in this case, the command signal (command signal indicating the transmission instruction of the long burst signal) performed before the full range scan may be transmitted from the first range, and the command signal (burst signal and the command signal) performed before the sector scan may be transmitted. The command signal indicating the transmission instruction of the data signal) may be transmitted from the above-selected range.

Further, in the above embodiment, the operation of the full range scan is divided into a scan in which N linear electrodes 30Y are sequentially used (first half) and a scan in which M linear electrodes 30X are sequentially used (second half). However, if the transmission duration T1 of the long burst signal can be secured sufficiently long, the position of the stylus 2 (two-dimensional coordinate position) can be determined by using the linear conductor 30X after the operation of the linear electrode 30Y. It may be specified.

Further, in the above embodiment, the example in which the data signal is not transmitted after the long burst signal is transmitted has been described, but the data signal may be transmitted after the long burst signal. The transmission duration of the data signal in this case may be shorter than the transmission duration of the data signal of the burst signal shown in FIG. This data signal is suitable for transmitting data that can indicate the state with a number of bits shorter than the writing pressure or the like, such as an on / off state of a switch provided in the housing of the stylus 2.

2 Stylus 3 Electronic equipment 21 Electrode 23 Pen pressure detection sensor 24 Signal processing unit 25 Power supply 26 Amplifier 27 Receiver 30 Sensor 30X, 30Y Linear electrode 31 Sensor controller 40 Selection 41x, 41y Conductor selection circuit 44x, 44y Switch 50 Reception Part 51 Amplifier circuit 52 Detection circuit 53 Converter 60 Transmission part 61 Pattern supply part 62 Switch 63 Diffusion processing part 64 Code string holding part 65 Transmission guard part 70 Logic part 71 Reception part 71a Wave reproduction part 71b Correlation calculator 73 Modulation part 74 Booster circuit 75 Transmission unit 76 Switching unit 90 Control unit 91 Control unit 92 Booster unit 93 Oscillation unit 94 Switch unit A1, A2 Finger touch areas B1 to B3 Stylus position DS1, DS2 Downlink signal EN Start signal F Finger P Pen pressure level Res Data SR sensing range SW switch information US uplink signal

Claims (5)

Connected to a matrix electrode including M first electrodes extending in the first direction and N second electrodes extending in a second direction different from the first direction, respectively. It is a sensor controller
A finger touch detection step in which a predetermined signal is supplied to each of the M first electrodes and finger touch detection is performed by the predetermined signal detected in each of the N second electrodes.
With at least a part of the M first electrodes and at least a part of the N second electrodes, a full-range scan step of detecting an undetected stylus and deriving the position coordinates of the stylus. ,
The number of the first electrodes is less than the number of the first electrodes used in the full range scan step, and the number of the second electrodes is less than the number of the second electrodes used in the full range scan step. Is configured to perform a sector scan step and perform a sector scan step that derives the position coordinates of the already detected stylus.
The full range scan step
A step of detecting the position of the stylus using the smaller of the M first electrode and the N second electrode, and
Further, a sensor controller including a step of deriving the position of the stylus by using the larger of the M first electrode and the N second electrode. Connected to a matrix electrode including M first electrodes extending in the first direction and N second electrodes extending in a second direction different from the first direction, respectively. It is a sensor controller
A finger touch detection step in which a predetermined signal is supplied to each of the M first electrodes and finger touch detection is performed by the predetermined signal detected in each of the N second electrodes.
With at least a part of the M first electrodes and at least a part of the N second electrodes, a full-range scan step of detecting an undetected stylus and deriving the position coordinates of the stylus. ,
The number of the first electrodes is less than the number of the first electrodes used in the full range scan step, and the number of the second electrodes is less than the number of the second electrodes used in the full range scan step. Using the sector scan step to derive the position coordinates of the already detected stylus,
A step of transmitting a command signal to the stylus using at least one of all of the M first electrodes and all of the N second electrodes before performing the full range scan step. ,
Before executing the sector scan step, a step of transmitting a command signal to the stylus using one or more of the first electrodes and one or more of the second electrodes used in the sector scan step is executed. A sensor controller configured to do so. The sector scan is performed using the M first electrode and the N second electrodes located in the vicinity of the position coordinates derived in the full range scan step. 2. The sensor controller according to 2. The finger touch detection step and the stylus detection step for detecting the stylus are configured to be executed alternately.
The sensor controller according to any one of claims 1 to 3, wherein either the full range scan step or the sector scan step is executed at each time of the stylus detection step. The finger touch detection step is configured to detect one or more finger touch areas, each indicating an area touched by a finger.
A determination step for determining whether or not each of the one or more position coordinates derived in the sector scan step is included in any of the one or more finger touch areas detected in the finger touch detection step. ,
The sensor controller according to any one of claims 1 to 4, further performing an invalidation step of invalidating the position coordinates determined to be included in the determination step.

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