# US 10,768,741 B2 · Semiconductor device, display device and method of operating the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,768,741 B2 - Document ID: US10768741B2 - Status: Granted - Kind: B2 - Application number: 15/982,628 - Filed: 2018-05-17 - Published: 2018-11-22 - Granted: 2020-09-08 - Earliest claimed: 2017-05-19 - Assignees: Creative Legend Semiconductor (Hong Kong) Limited - Applicants: Creative Legend Semiconductor (Hong Kong) Limited - Inventors: Kazuya Endo; Shinobu Nohtomi; Atsushi Shikata; Kentaro Suzuki - Web page: https://patentgrep.com/patent/US10768741B2 ## CPC - G09G 3/3614: {Control of polarity reversal in general} - 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 3/04184: {Synchronisation with the driving of the display or the backlighting unit to avoid interferences generated internally} - G09G 3/3688: {suitable for active matrices only} - G09G 2320/0219: Reducing feedthrough effects in active matrix panels, i.e. voltage changes on the scan electrode influencing the pixel voltage due to capacitive coupling - G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract A semiconductor device configured to drive a display panel in a display period, and perform touch sensing on the display panel in a touch sensing period after the display period. In a last horizontal sync period of the display period, the semiconductor device drives a first source line with a drive voltage of a first polarity, and a second source line with a drive voltage of a second polarity different from the first polarity. is the semiconductor is configured to output a first dummy pulse having first polarity and a voltage level based on the second display data to the first source line in a transition period between the display period and the touch sensing period. ## Claims ### Claim 1 A semiconductor device comprising: source output circuitry configured to: in a last horizontal sync period of a display period, drive a first source line of a plurality of source lines with a drive voltage having a first polarity based on first display data, and drive a second source line of the plurality of source lines with a drive voltage having a second polarity different from the first polarity based on second display data; and output a first dummy pulse having the first polarity to the first source line in a transition period between the display period and a touch sensing period, the first dummy pulse having a voltage level based on the second display data; and touch sensing circuitry configured to perform touch sensing in the touch sensing period after the display period. ### Claim 2 (depends on 1) The semiconductor device according to claim 1, wherein the source output circuitry is further configured to output a second dummy pulse having the second polarity to the second source line in the transition period, the second dummy pulse having a voltage level based on the first display data. ### Claim 3 (depends on 2) The semiconductor device according to claim 2, wherein the source output circuitry is further configured to drive the source lines to a predetermined potential in the transition period after outputting the first and second dummy pulses. ### Claim 4 (depends on 1) The semiconductor device according to claim 1, further comprising: dummy display data generator circuitry configured to generate first dummy display data specifying the voltage level of the first dummy pulse, based on display data associated with drive voltages having the second polarity, selected from display data specifying the drive voltages supplied to the first and second source lines in last M horizontal sync periods in the display period, where M is an integer of two or more. ### Claim 5 (depends on 4) The semiconductor device according to claim 4, wherein the source output circuitry is further configured to output a second dummy pulse having the second polarity to the second source line in the transition period, the second dummy pulse having a voltage level based on the first display data, and the dummy display data generator circuitry is further configured to generate second dummy display data specifying the voltage level of the second dummy pulse, based on display data associated with drive voltages having the first polarity, selected from the display data specifying the drive voltages supplied to the first and second source lines in the last M horizontal sync periods. ### Claim 6 (depends on 4) The semiconductor device according to claim 4, wherein the dummy display data generator circuitry is configured to calculate the first dummy display data as a first weighted average of the display data associated with drive voltages having the second polarity and selected from the display data specifying the drive voltages supplied to the first and second source lines in the last M horizontal sync periods. ### Claim 7 (depends on 6) The semiconductor device according to claim 6, wherein the source output circuitry is further configured to output a second dummy pulse having the second polarity to the second source line in the transition period, and the dummy display data generator circuitry is configured to calculate a second dummy display data as a second weighted average of the display data associated with drive voltages having the first polarity and selected from the display data specifying the drive voltages supplied to the first and second source lines in the last M horizontal sync periods. ### Claim 8 (depends on 7) The semiconductor device according to claim 7, wherein weighting factors applied to the display data associated with the drive voltages having the second polarity in the calculation of the first and second weighted averages are determined based on horizontal sync periods associated with the display data the weighting factors are applied. ### Claim 9 (depends on 4) The semiconductor device according to claim 4, wherein the dummy display data generator circuitry comprises: a counter configured to count horizontal sync periods in the display period; a line memory configured to store display data associated with one horizontal line; and processing circuitry configured to, in response to a counter value received from the counter: calculate processed display data by processing display data supplied to the processing circuitry in each horizontal sync period and display data stored in the line memory; and update the display data stored in the line memory to the processed display data, and wherein, in the transition period, the display data stored in the line memory and associated with the first source line is supplied to the source output circuitry as the first dummy display data. ### Claim 10 (depends on 1) The semiconductor device according to claim 1, further comprising: a register configured to store therein a register value; and dummy display data generator circuitry configured to generate first dummy display data specifying the voltage level of the first dummy pulse, based on display data associated with drive voltages having the second polarity, selected from display data specifying the drive voltages supplied to the first and second source lines in last M horizontal sync periods in the display period, where M is an integer of one or more specified by the register value. ### Claim 11 (depends on 10) The semiconductor device according to claim 10, wherein the source output circuitry is further configured to output a second dummy pulse having the second polarity to the second source line in the transition period, and the dummy display data generator circuitry is further configured to generate second dummy display data specifying the voltage level of the second dummy pulse, based on display data associated with drive voltages having the first polarity, selected from the display data specifying the drive voltages supplied to the first and second source lines in the last M horizontal sync periods. ### Claim 12 A display device, comprising: a display panel comprising a plurality of source lines; source output circuitry configured to: in a last horizontal sync period of a display period, drive a first source line of the plurality of source lines with a drive voltage having a first polarity based on first display data, and drive a second source line of the plurality of source lines with a drive voltage having a second polarity different from the first polarity based on second display data; and drive the first source line with a first dummy pulse having the first polarity in a transition period between the display period and a touch sensing period, the first dummy pulse having a voltage level based on the second display data; and touch sensing circuitry configured to perform touch sensing on the display panel in the touch sensing period after the display period. ### Claim 13 (depends on 12) The display device according to claim 12, wherein the source output circuitry is further configured to drive the second source line with a second dummy pulse having the second polarity in the transition period, the second dummy pulse having a voltage level based on the first display data. ### Claim 14 (depends on 13) The display device according to claim 13, wherein the source output circuitry is further configured to drive the source lines to a predetermined potential in the transition period after outputting the first and second dummy pulses. ### Claim 15 (depends on 12) The display device according to claim 12, further comprising: dummy display data generator circuitry configured to generate first dummy display data specifying the voltage level of the first dummy pulse, based on display data associated with drive voltages having the second polarity, selected from display data specifying the drive voltages supplied to the first and second source lines in last M horizontal sync periods in the display period, where M is an integer of two or more. ### Claim 16 (depends on 15) The display device according to claim 15, wherein the source output circuitry is further configured to output a second dummy pulse having the second polarity to the second source line in the transition period, the second dummy pulse having a voltage level based on the first display data, and the dummy display data generator circuitry is further configured to generate second dummy display data specifying the voltage level of the second dummy pulse, based on display data associated with drive voltages having the first polarity, selected from the display data specifying the drive voltages supplied to the first and second source lines in the last M horizontal sync periods. ### Claim 17 (depends on 15) The semiconductor display device according to claim 15, wherein the dummy display data generator circuitry is configured to calculate the first dummy display data as a first weighted average of the display data associated with drive voltages having the second polarity and selected from the display data specifying the drive voltages supplied to the first and second source lines in the last M horizontal sync periods. ### Claim 18 (depends on 12) The display device according to claim 12, further comprising: a register configured to store therein a register value; and dummy display data generator circuitry configured to generate first dummy display data specifying the voltage level of the first dummy pulse, based on display data associated with drive voltages having the second polarity, selected from display data specifying the drive voltages supplied to the first and second source lines in last M horizontal sync periods in the display period, where M is an integer of one or more specified by the register value. ### Claim 19 A method of operating a display device, the method comprising: supplying a first drive voltage having a first polarity to a first source line of a display panel of the display device in a final horizontal sync period of a display period, the first drive voltage having a voltage level based on first display data; supplying a second drive voltage having a second polarity different from the first polarity to a second source line of the display panel in the final horizontal sync period, the second drive voltage having a voltage level based on a second display data; outputting a first dummy pulse having the first polarity to the first source line in a transition period following the display period, the first dummy pulse having a voltage level based on the second display data; driving the first and second source lines to a predetermined potential after the transition period; and performing touch sensing on the display panel in a touch sensing period following the transition period. ### Claim 20 (depends on 19) The method according to claim 19, further comprising: outputting a second dummy pulse having the second polarity and a voltage level based on the first display data to the second source line in the transition period.