# US 10,481,745 B2 · Method and apparatus for determining touch position of capacitive screen > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,481,745 B2 - Document ID: US10481745B2 - Status: Granted - Kind: B2 - Application number: 15/984,428 - Filed: 2018-05-21 - Published: 2018-09-20 - Granted: 2019-11-19 - Earliest claimed: 2016-11-17 - Assignees: Shenzhen Goodix Technology Co., Ltd. - Applicants: Shenzhen Goodix Technology Co., Ltd. - Inventors: Shuang Wu; Huafei Li - Web page: https://patentgrep.com/patent/US10481745B2 ## CPC - G06F 3/04186: {Touch location disambiguation} - G06F 3/044: by capacitive means - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract Embodiments of the present application provide a method and apparatus for determining a touch position of a capacitive screen. The method includes: acquiring an output signal of each capacitor node, and orthogonally demodulating the output signal to acquire a corresponding orthogonal component Q; judging whether corresponding orthogonal components Q of some of the capacitor nodes increase relative to a reference orthogonal component Q in an underwater mode, and whether corresponding orthogonal components Q of some other capacitor nodes decrease relative to the reference orthogonal component Q in the underwater mode; and determining that the capacitive screen is touched, and determining the touch position according to coordinates of the capacitor node whose orthogonal component Q decreases if the judgment indicates a positive result. ## Claims ### Claim 1 A method for determining a touch position of a capacitive screen, comprising: acquiring an output signal of each capacitor node of the capacitive screen, and orthogonally demodulating the output signal to acquire a corresponding orthogonal component Q; judging whether corresponding orthogonal components Q of some of the capacitor nodes increase relative to a reference orthogonal component Q in an underwater mode, and whether corresponding orthogonal components Q of some other capacitor nodes decrease relative to the reference orthogonal component Q in the underwater mode to obtain a positive result or a negative result; and determining that the capacitive screen is touched, and determining the touch position according to coordinates of the capacitor node whose orthogonal component Q decreases if the judgment indicates a positive result. ### Claim 2 (depends on 1) The method according to claim 1, wherein the orthogonally demodulating the output signal to acquire a corresponding orthogonal component Q comprises: pre-processing the output signal of each capacitor node, and acquiring a denoised output signal for the orthogonal demodulating. ### Claim 3 (depends on 1) The method according to claim 1, wherein when there is no touch underwater, the output signal of the capacitor node is orthogonally demodulated to acquire the reference orthogonal component Q in the underwater mode. ### Claim 4 (depends on 1) The method according to claim 1, further comprising: acquiring a capacitance of each capacitor node, and judging whether the capacitive screen enters the underwater mode according to the capacitance; and if the capacitive screen enters the underwater mode, judging whether corresponding orthogonal components Q of some of the capacitor nodes increase relative to a reference orthogonal component Q in an underwater mode, and whether corresponding orthogonal components Q of some other capacitor nodes decrease relative to the reference orthogonal component Q in the underwater mode. ### Claim 5 (depends on 4) The method according to claim 4, further comprising: orthogonally demodulating the output signal to acquire a corresponding in-phase component I; wherein the acquiring a capacitance of each capacitor node, and judging whether the capacitive screen enters the underwater mode according to the capacitance comprises: calculating the capacitance of each capacitor node according to the in-phase component I and the orthogonal component Q; and determining that the capacitive screen is in the underwater mode if the capacitance of each capacitor node decreases relative to a reference capacitance obtained when there is no touch in a non-underwater mode. ### Claim 6 (depends on 5) The method according to claim 5, wherein the calculating the capacitance of each capacitor node according to the in-phase component I and the orthogonal component Q comprises: calculating moduli of the in-phase component I and the orthogonal component Q to acquire the capacitance of each capacitor node. ### Claim 7 (depends on 5) The method according to claim 5, wherein upon determining that the capacitive screen is in the underwater mode, the method further comprises: comparing the capacitance of each capacitor node with the reference capacitance obtained when there is no touch in the underwater mode to judge whether there is a capacitor node whose capacitance decreases; and determining all of the capacitor nodes whose capacitances decrease to judge, among all of the capacitor nodes whose capacitances decrease, whether there are a portion of capacitor nodes whose corresponding orthogonal components Q increase relative to the reference orthogonal component Q in the underwater mode, and whether there are a portion of capacitor nodes whose corresponding orthogonal components Q decrease relative to the reference orthogonal component Q in the underwater mode. ### Claim 8 (depends on 1) The method according to claim 1, wherein the judging whether corresponding orthogonal components Q of some of the capacitor nodes increase relative to a reference orthogonal component Q in an underwater mode, and whether corresponding orthogonal components Q of some other capacitor nodes decrease relative to the reference orthogonal component Q in the underwater mode comprises: judging, according to an envelop curve, whether there are a portion of capacitor nodes whose corresponding orthogonal components Q increase relative to the reference orthogonal component Q in the underwater mode, and whether there are a portion of capacitor nodes whose corresponding orthogonal components Q decrease relative to the reference orthogonal component Q in the underwater mode. ### Claim 9 An apparatus for determining a touch position of a capacitive screen, comprising: a signal demodulating module, configured to acquire an output signal of each capacitor node, and orthogonally demodulate the output signal of each capacitor node to acquire a corresponding orthogonal component Q; a touch judging module, configured to judge whether there are a portion of capacitor nodes whose corresponding orthogonal components Q increase relative to a reference orthogonal component Q in an underwater mode, and whether there are a portion of capacitor nodes whose corresponding orthogonal components Q decrease relative to the reference orthogonal component Q in the underwater mode; and a position determining module, configured to determine that the capacitive screen is touched, and determine the touch position according to coordinates of the capacitor node whose orthogonal component Q decreases if it is judged that the capacitive screen is touched. ### Claim 10 (depends on 9) The apparatus according to claim 9, further comprising: a pre-processing module, configured to pre-process the output signal of each capacitor node to acquire a denoised output signal for the orthogonal demodulating. ### Claim 11 (depends on 9) The apparatus according to claim 9, further comprising: an underwater judging module, configured to acquire a capacitance of each capacitor node, and judge whether the capacitive screen enters the underwater mode according to the capacitance. ### Claim 12 (depends on 9) The apparatus according to claim 9, wherein the touch judging module is further configured to compare a capacitance of each capacitor node with a reference capacitance obtained when there is no touch in the underwater mode, and judge whether there is a capacitor node whose capacitance decreases; if there is a capacitor node whose capacitance decreases, determine all the capacitor nodes whose capacitances decrease to judge, among all the capacitor nodes whose capacitances decrease, whether there are a portion of capacitor nodes whose corresponding orthogonal components Q increase relative to the reference orthogonal component Q in the underwater mode, and whether there are a portion of capacitor nodes whose corresponding orthogonal components Q decrease relative to the reference orthogonal component Q in the underwater mode. ### Claim 13 A non-volatile computer storage medium, storing a computer-executable instruction, wherein the computer-executable instruction, when being executed, is configured to cause a computing device to perform a method comprising: acquiring an output signal of each capacitor node of a capacitive screen, and orthogonally demodulating the output signal to acquire a corresponding orthogonal component Q; judging whether corresponding orthogonal components Q of some of the capacitor nodes increase relative to a reference orthogonal component Q in an underwater mode, and whether corresponding orthogonal components Q of some other capacitor nodes decrease relative to the reference orthogonal component Q in the underwater mode to obtain a positive result or a negative result; and determining that the capacitive screen is touched, and determining the touch position according to coordinates of the capacitor node whose orthogonal component Q decreases if the judgment indicates a positive result. ### Claim 14 (depends on 13) The non-volatile computer storage medium according to claim 13, wherein the orthogonally demodulating the output signal to acquire a corresponding orthogonal component Q comprises: pre-processing the output signal of each capacitor node, and acquiring a denoised output signal for the orthogonal demodulating. ### Claim 15 (depends on 13) The non-volatile computer storage medium according to claim 13, wherein when there is no touch underwater, the output signal of the capacitor node is orthogonally demodulated to acquire the reference orthogonal component Q in the underwater mode. ### Claim 16 (depends on 13) The non-volatile computer storage medium according to claim 13, further comprising: acquiring a capacitance of each capacitor node, and judging whether the capacitive screen enters the underwater mode according to the capacitance; and if the capacitive screen enters the underwater mode, judging whether corresponding orthogonal components Q of some of the capacitor nodes increase relative to a reference orthogonal component Q in an underwater mode, and whether corresponding orthogonal components Q of some other capacitor nodes decrease relative to the reference orthogonal component Q in the underwater mode. ### Claim 17 (depends on 16) The non-volatile computer storage medium according to claim 16, further comprising: orthogonally demodulating the output signal to acquire a corresponding in-phase component I; wherein the acquiring a capacitance of each capacitor node, and judging whether the capacitive screen enters the underwater mode according to the capacitance comprises: calculating the capacitance of each capacitor node according to the in-phase component I and the orthogonal component Q; and determining that the capacitive screen is in the underwater mode if the capacitance of each capacitor node decreases relative to a reference capacitance obtained when there is no touch in a non-underwater mode. ### Claim 18 (depends on 17) The non-volatile computer storage medium according to claim 17, wherein the calculating the capacitance of each capacitor node according to the in-phase component I and the orthogonal component Q comprises: calculating moduli of the in-phase component I and the orthogonal component Q to acquire the capacitance of each capacitor node. ### Claim 19 (depends on 17) The non-volatile computer storage medium according to claim 17, wherein upon determining that the capacitive screen is in the underwater mode, the method further comprises: comparing the capacitance of each capacitor node with the reference capacitance obtained when there is no touch in the underwater mode to judge whether there is a capacitor node whose capacitance decreases; and determining all of the capacitor nodes whose capacitances decrease to judge, among all of the capacitor nodes whose capacitances decrease, whether there are a portion of capacitor nodes whose corresponding orthogonal components Q increase relative to the reference orthogonal component Q in the underwater mode, and whether there are a portion of capacitor nodes whose corresponding orthogonal components Q decrease relative to the reference orthogonal component Q in the underwater mode. ### Claim 20 (depends on 13) The non-volatile computer storage medium according to claim 13, wherein the judging whether corresponding orthogonal components Q of some of the capacitor nodes increase relative to a reference orthogonal component Q in an underwater mode, and whether corresponding orthogonal components Q of some other capacitor nodes decrease relative to the reference orthogonal component Q in the underwater mode comprises: judging, according to an envelop curve, whether there are a portion of capacitor nodes whose corresponding orthogonal components Q increase relative to the reference orthogonal component Q in the underwater mode, and whether there are a portion of capacitor nodes whose corresponding orthogonal components Q decrease relative to the reference orthogonal component Q in the underwater mode.