Abstract: A sensor controller includes a transmitter configured to transmit an uplink signal including a first partial signal and a second partial signal. The transmitter is configured to transmit the first partial signal by direct spreading using a first spread code and transmit the second partial signal by direct spreading using a second spread code which is different from the first spread code and which has an identical chip time length to the first spread code. An active stylus includes a receiver configured to receive an uplink signal including a first partial signal and a second partial signal. The receiver is configured to synchronize with the uplink signal by detecting the first partial signal using a first spread code and thereafter detect the second partial signal using a second spread code, which is different from the first spread code and has an identical chip time length to the first spread code.

Abstract: A touch detection method is performed by a controller of a touch sensor of a capacitive type including sensor electrodes. The touch detection method includes acquiring detection values at crossing positions of the sensor electrodes, acquiring capacitance values for the crossing positions, calculating difference values for the crossing positions, each of the detection values being obtained by subtracting the moving average for one of the crossing positions from one of the difference values for the one of the crossing positions, acquiring a maximum value among the detection values at the crossing positions, determining a first threshold value by subtracting a subtraction value, which is a fixed value or a value that decreases as the maximum value increases, from the maximum value, and deriving a position of the indicator based on the detection values at the crossing positions with reference to the first threshold value.

Abstract: An active stylus includes an elongated body, an electrode provided at a tip end of the elongated body, an indicator, and a controller coupled to the electrode and the indicator. The controller is configured to operate, in a mutually exclusive manner, either in a first mode of operation to transmit a signal of a first system via the electrode and to receive an uplink signal transmitted from a sensor which detects, based on the signal of the first system, a position of the active stylus, or in a second mode of operation to transmit a signal of a second system via the electrode. The controller is configured to control the indicator responsive to a detection of the uplink signal.

Abstract: A sensor controller is provided for use in a position detector for detecting a position of a position indicator on a touch surface. The sensor controller includes a microprocessor for outputting a value of a symbol to be sent to the position indicator. The sensor controller includes a transmitter coupled to the microprocessor for generating a transmission signal including a chip string CN1 produced by cyclically shifting a code string PNa having autocorrelation characteristics by a shift quantity based on the value of the symbol to be sent, and sending the generated transmission signal to the position indicator via the touch surface. A higher bit rate can be obtained for a given chip rate compared with the prior art in which only 1 bit can be expressed by one code string.

Abstract: A method of using an active stylus and a sensor controller is provided including generally four steps. The active stylus, in response to a trigger indicative of a pen lowering operation, sends replaceable pen tip information indicating a type of a replaceable pen tip that forms a pen tip of the active stylus. The sensor controller receives the replaceable pen tip information and identifies the replaceable pen tip type of the active stylus. The active stylus repeatedly sends a data signal including a pen pressure value applied to the replaceable pen tip. The sensor controller derives a position of the active stylus based on the data signal using a position deriving method that corresponds to the replaceable pen tip information.

Abstract: A stylus includes a cylindrical housing, a tip portion provided on a tip side of the housing and including a tip electrode, a tail portion provided on a tail side of the housing and including a tail electrode, a power circuit provided in the housing, a first transmission circuit which, in operation, receives power from the power circuit and generates a first downlink signal that is transmitted toward an outside of the housing through the tip electrode, a second transmission circuit which, in operation, receives power from the power circuit and generates a second downlink signal that is transmitted toward the outside of the housing through the tail electrode, the second downlink signal being different from the first downlink signal, and a control circuit which, in operation, controls the first transmission circuit and the second transmission circuit according to a plurality of transmission modes.

Abstract: A method carried out in a system including an active stylus and a sensor controller includes: transmitting, by the sensor controller, an uplink signal including a first partial signal and a second partial signal; and receiving, by the active stylus, the uplink signal. The transmitting includes transmitting the first partial signal by direct spreading using a first spread code and transmitting the second partial signal by direct spreading using a second spread code, wherein the second spread code is different from the first spread code and has a chip time length that is identical to a chip time length of the first spread code. The receiving includes, while the active stylus is synchronized with the uplink signal, detecting the first partial signal using the first spread code and subsequently detecting the second partial signal using the second spread code.

Abstract: A touch detection method is performed by a controller of a touch sensor of a capacitive type including sensor electrodes. The touch detection method includes acquiring detection values at crossing positions of the sensor electrodes, each detection value corresponding to a capacitance between an indicator and the touch sensor at one of the crossing positions, acquiring a maximum value among the detection values at the crossing positions, determining a first threshold value by subtracting a subtraction value, which is a fixed value or a value that decreases as the maximum value increases, from the maximum value, and deriving a position of the indicator based on the detection values at the crossing positions with reference to the first threshold value.

Abstract: A system includes a stylus and a sensor controller couplable to a sensor capable of detecting the stylus. The sensor controller is configured to continuously transmit, via the sensor, first uplink control signals (US_c1) during a continuous transmission period (TCP), which is longer than an interval (WPa) at which the stylus performs a reception operation Rx of an uplink signal from the sensor. The sensor controller is configured to, after the TCP, control a reception operation at the sensor of a downlink signal (DS) from the stylus during a reception period (RDS). The sensor controller is configured to, depending on a result of detection of the DS during the RDS, determine whether or not the stylus is detected by the sensor.

Abstract: A method implemented in a system for deriving a position of a pen on a sensor panel by transmitting and receiving signals via capacitive coupling between a pen tip electrode of the pen and the sensor panel, includes: transmitting a first signal indicating a reference time of one frame period via the sensor panel, from a sensor controller that performs a pen detecting operation only at one or more specific time periods in the one frame period; and transmitting a burst signal that does not include a data signal indicating an operating state of the pen, from the pen that has detected the first signal, at each of the one or more specific time periods in the frame period indicated by the first signal.

Abstract: A method is provided to interface an active stylus with a sensor controller, wherein the sensor controller is coupled to a sensor configured to receive input from the active stylus. In the method the sensor controller caches stylus capability information of the active stylus. The stylus capability information includes setting information for inking used by an application program executed to display input from the active stylus on the sensor. The active stylus generates a hash value of the stylus capability information and transmits the hash value to the sensor controller when the active stylus enters a sensing zone of the sensor controller.

Abstract: A sensor controller is provided for use in a position detector for detecting a position of a position indicator on a touch surface. The sensor controller includes a microprocessor for outputting a value of a symbol to be sent to the position indicator. The sensor controller includes a transmitter coupled to the microprocessor for generating a transmission signal including a chip string CN1 produced by cyclically shifting a code string PNa having autocorrelation characteristics by a shift quantity based on the value of the symbol to be sent, and sending the generated transmission signal to the position indicator via the touch surface. A higher bit rate can be obtained for a given chip rate compared with the prior art in which only 1 bit can be expressed by one code string.

Abstract: A method of using an active stylus and a sensor controller is provided including generally four steps. The active stylus, in response to a trigger indicative of a pen lowering operation, sends replaceable pen tip information indicating a type of a replaceable pen tip that forms a pen tip of the active stylus. The sensor controller receives the replaceable pen tip information and identifies the replaceable pen tip type of the active stylus. The active stylus repeatedly sends a data signal including a pen pressure value applied to the replaceable pen tip. The sensor controller derives a position of the active stylus based on the data signal using a position deriving method that corresponds to the replaceable pen tip information.

Abstract: A method is carried out by a stylus, wherein the stylus is a dual stylus configured to be capable of transmitting signals pursuant to both a first system and a second system and receiving at least a signal pursuant to the first system. The dual stylus has a detection function of detecting a writing pressure applied to a stylus (pen) tip. The method includes detecting contact between the stylus and a touch surface based on the writing pressure detected by the detection function, activating a signal reception operation pursuant to the first system for a predetermined time period, and, responsive to reception of a signal pursuant to the first system in the predetermined time period, setting an operation mode of the stylus to a first operation mode, in which signals are transmitted and received pursuant to the first system.

Abstract: A method performed by a device (e.g., touch controller) includes deriving a pen position, and transmitting a report indicating the derived pen position to a host computer. The report includes a first area storing position data indicating the derived position and a second area storing non-position data different from the position data. The method includes securing a buffer area for retaining a plurality of the reports in a memory, deriving the pen position at each determined scanning time, and generating a report including the position data indicating the derived position. The method includes storing the report in the buffer area and, in response to obtaining the non-position data, writing the non-position data in the second area of each of one or more of the reports stored in the buffer area. The method includes transmitting the plurality of the reports stored in the buffer area to the host computer.

Abstract: A position indicator includes a pen-shaped body; control circuitry housed in the pen-shaped body and configured to generate position detection signals and generate additional information about the position indicator; a first receiver; a second receiver different from the first receiver; a first transmitter provided near a distal end of the pen-shaped body and configured to transmit the position detection signals to a sensor of a position detection system; and a second transmitter, which is different from the first transmitter and configured to transmit wireless signals to the position detection system. The control circuitry, in response to a control signal from the position detection system received by the first receiver or the second receiver, controls transmission of the position detection signals and transmission of the additional information via a transmitter selected from the first transmitter and the second transmitter, to the position detection system.

Abstract: A method carried out in a system including an active stylus and a sensor controller includes: transmitting, by the sensor controller, an uplink signal including a first partial signal and a second partial signal; and receiving, by the active stylus, the uplink signal. The transmitting includes transmitting the first partial signal by direct spreading using a first spread code and transmitting the second partial signal by direct spreading using a second spread code, wherein the second spread code is different from the first spread code and has a chip time length that is identical to a chip time length of the first spread code. The receiving includes, while the active stylus is synchronized with the uplink signal, detecting the first partial signal using the first spread code and subsequently detecting the second partial signal using the second spread code.

Abstract: A position indicator that can be used with a plurality of types of position detection systems. The position indicator includes a first transmitter, a second transmitter, an input circuit which, in operation, accepts an input from outside of the position indicator, a signal generation circuit which, in operation, generates a position detecting signal, a plurality of additional information generation circuits which, in operation, generate a plurality of types of additional information, and a controller. The controller controls, based on the input accepted by the input circuit, transmission of the position detecting signal through the first transmitter and controls, based on the input accepted by the input circuit, transmission of additional information generated by the plurality of additional information generation circuits from the first transmitter or the second transmitter.

Abstract: A method carried out in a system having an active stylus and a sensor controller includes establishing frame synchronization between the controller and the stylus, selecting a first variable-length command from among multiple variable-length commands each including data of a variable number of bits, transmitting the first command in a first portion of a frame using an uplink signal having a variable time length that depends on a number of bits of the first command, receiving the uplink signal having the variable time length, detecting the first command by decoding the uplink signal up to a tail of the uplink signal, and transmitting a downlink signal that depends on the first command in a second portion of the first frame that is different from the first portion of the first frame.

Abstract: A method is provided for using an active stylus and a sensor controller that engage in two-way communication with each other. The sensor controller sends a beacon signal BS indicating reference time of a frame F. After detecting the beacon signal BS, the active stylus sends, included in a response signal to the beacon signal BS, a hash value CP_Hash associated with capability information indicating the type of one or more pieces of interactive data DF that can be obtained by the active stylus. The active stylus periodically sends data signals DF1,DF2, and so on, which include at least part of the one or more pieces of interactive data DF and which are configured in a format determined based on the one or more pieces of interactive data DF.