# US 12,216,863 B2 · Position detection circuit, position detection method, and position detection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,216,863 B2 - Document ID: US12216863B2 - Status: Granted - Kind: B2 - Application number: 18/596,481 - Filed: 2024-03-05 - Published: 2024-06-27 - Granted: 2025-02-04 - Earliest claimed: 2022-06-15 - Assignees: Wacom Co., Ltd. - Applicants: Wacom Co., Ltd. - Inventors: Yoshio Nomura - Web page: https://patentgrep.com/patent/US12216863B2 ## CPC - G06F 3/04166: {Details of scanning methods, e.g. sampling time, grouping of sub areas or time sharing with display driving (Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally G06F3/04184)} - G06F 3/044: by capacitive means - G06F 3/0446: {using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Provided is a position detection circuit that uses a touch sensor of a capacitance type including sensor electrodes to detect a first position indicated by a first indicator that communicates with the touch sensor to indicate the first position and a second position indicated by a second indicator that indicates the second position without communicating with the touch sensor, the position detection circuit including a first detection circuit that detects a touch of the second indicator to an input surface arranged on the touch sensor, a second detection circuit that detects the first indicator when proximity information indicating a proximity of the first indicator to the touch sensor is equal to or greater than a threshold, and a changing circuit that changes the threshold to a larger value when the first detection circuit detects the touch compared to when the first detection circuit does not detect the touch. ## Claims ### Claim 1 A position detection circuit that is connected to a capacitive sensor to detect a position of a stylus that communicates with a touch sensor and a position of a touch, the position detection circuit comprising: a touch detection circuit that, in operation, detects a touch to an input surface arranged on the capacitive sensor; a stylus detection circuit that, in operation, detects the stylus based on proximity information that indicates proximity of the stylus to the capacitive sensor, wherein the stylus detection circuit detects the stylus if the proximity information is greater than or equal to a threshold; and wherein the position detection circuit, in operation, changes the threshold based on a detection result of the touch detection circuit. ### Claim 2 (depends on 1) The position detection circuit according to claim 1, wherein: the position detection circuit, in operation, changes the threshold to a larger value when the touch detection circuit detects the touch, and the larger value is larger than a value of the threshold when the touch detection circuit does not detect the touch. ### Claim 3 (depends on 1) The position detection circuit according to claim 1, wherein: the proximity information is a reception strength at the touch sensor of a downlink signal transmitted from the stylus. ### Claim 4 (depends on 1) The position detection circuit according to claim 1, wherein: the proximity information is an amount of change in capacitance generated by capacitive coupling of the stylus and the touch sensor. ### Claim 5 (depends on 1) The position detection circuit according to claim 1, wherein: the position detection circuit, in operation, changes the threshold according to a distance between the input surface and the touch sensor. ### Claim 6 (depends on 1) The position detection circuit according to claim 1, wherein: the position detection circuit, in operation, does not change the threshold or changes the threshold in a direction of a pre-change value when predetermined conditions are satisfied. ### Claim 7 (depends on 1) The position detection circuit according to claim 1, further comprising: a reception circuit that, in operation, receives a designation of a detectable range on the touch sensor in which the stylus not in contact with the input surface is able to be detected according to a user input, wherein the position detection circuit, in operation, changes the threshold such that the stylus is detected when a distance between the stylus and the touch sensor is within the detectable range. ### Claim 8 A method of detecting a position of a stylus that communicates with a touch sensor and a position of a touch, the method comprising: detecting a touch to an input surface arranged on a capacitive sensor; detecting the stylus based on proximity information that indicates proximity of the stylus to the touch sensor, wherein the stylus is detected if the proximity information is greater than or equal to a threshold; and changing the threshold based on whether the touch has been detected by the detecting the touch. ### Claim 9 (depends on 8) The method according to claim 8, wherein: the changing includes changing the threshold to a larger value when the touch is detected by the detecting the touch, and the larger value is larger than a value of the threshold when the touch is not detected by the detecting the touch. ### Claim 10 (depends on 8) The method according to claim 8, wherein: the proximity information is a reception strength at the touch sensor of a downlink signal transmitted from the stylus. ### Claim 11 (depends on 8) The method according to claim 8, wherein: the proximity information is an amount of change in capacitance generated by capacitive coupling of the stylus and the touch sensor. ### Claim 12 (depends on 8) The method according to claim 8, wherein: the changing includes changing the threshold according to a distance between the input surface and the touch sensor. ### Claim 13 (depends on 8) The method according to claim 8, wherein: the changing includes changing the threshold in a direction of a pre-change value or not changing the threshold when predetermined conditions are satisfied. ### Claim 14 (depends on 8) The method according to claim 8, further comprising: receiving a designation of a detectable range on the touch sensor in which the stylus not in contact with the input surface is able to be detected according to a user input, wherein the changing includes changing the threshold such that the stylus is detected when a distance between the stylus and the touch sensor is within the detectable range. ### Claim 15 A position detection system, comprising: a stylus that communicates with a touch sensor; and a position detection circuit that is connected to a capacitive sensor to detect a position of the stylus and a position of a touch, wherein the position detection circuit includes: a touch detection circuit that, in operation, detects a touch to an input surface arranged on a capacitive sensor; a stylus detection circuit that, in operation, detects the stylus based on proximity information that indicates proximity of the stylus to the touch sensor, wherein the stylus detection circuit detects the stylus if the proximity information is greater than or equal to a threshold; and wherein the position detection circuit, in operation, changes the threshold based on a detection result of the touch detection circuit. ### Claim 16 (depends on 15) The position detection system according to claim 15, wherein: the position detection circuit, in operation, changes the threshold to a larger value when the touch detection circuit detects the touch, and the larger value is larger than a value of the threshold when the touch detection circuit does not detect the touch. ### Claim 17 (depends on 15) The position detection system according to claim 15, wherein: the proximity information is a reception strength at the touch sensor of a downlink signal transmitted from the stylus. ### Claim 18 (depends on 15) The position detection system according to claim 15, wherein: the proximity information is an amount of change in capacitance generated by capacitive coupling of the stylus and the touch sensor. ### Claim 19 (depends on 15) The position detection system according to claim 15, wherein: the position detection circuit, in operation, changes the threshold according to a distance between the input surface and the touch sensor. ### Claim 20 (depends on 15) The position detection system according to claim 15, wherein: the position detection circuit, in operation, does not change the threshold or changes the threshold in a direction of a pre-change value when predetermined conditions are satisfied.