# US 2017/0285771 A1 · Active stylus pen and touch sensing system including the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0285771 A1 - Document ID: US20170285771A1 - Status: Published application - Kind: A1 - Application number: 15/392,783 - Filed: 2016-12-28 - Published: 2017-10-05 - Earliest claimed: 2016-03-31 - Assignees: LG Display Co., Ltd. - Applicants: LG Display Co., Ltd. - Inventors: Doyoung JUNG; Cheolse KIM; Buyeol LEE; Hyunguk JANG; Sanghyuck BAE - Web page: https://patentgrep.com/patent/US20170285771A1 ## CPC - G06F 3/0383: {Signal control means within the pointing device} - G06F 3/03545: {Pens or stylus} - G06F 3/038: Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry - G06F 3/0412: {Digitisers structurally integrated in a display} - G06F 3/04162: {for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware} - G06F 3/0441: {using active external devices, e.g. active pens, for receiving changes in electrical potential transmitted by the digitiser, e.g. tablet driving signals} - G06F 3/0442: {using active external devices, e.g. active pens, for transmitting changes in electrical potential to be received by the digitiser} - G06F 3/0443: {using a single layer of sensing electrodes} - G06F 3/0446: {using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes} - 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: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) ## Abstract An active stylus pen is insensitive to external noise and has enhanced sensing performance with respect to an uplink signal input from a touch screen. The active stylus pen includes a housing connected to a ground, a conductive tip protruding outwardly from one side of the housing and brought into contact with a touch screen, a conductor layer surrounding an outer surface of the housing with an insulator interposed therebetween, a pen driving circuit connected to the conductor layer, and a switch connecting the conductor layer and the pen driving circuit. The pen driving circuit is cased by the housing, receives an uplink signal and a touch sensor driving signal from the touch screen, generates a pen driving signal synchronized with the touch sensor driving signal and outputs the generated pen driving signal to the touch screen through the conductive tip. ## Claims ### Claim 1 An active stylus pen, comprising: a housing coupled to an electrical ground; a conductive tip protruding outwardly from an end of the housing, the conductive tip being operable to contact a touch screen; a conductor layer surrounding an outer surface of the housing with an insulator interposed therebetween; a pen driving circuit configured to receive an uplink signal and a touch sensor driving signal from the touch screen, to generate a pen driving signal synchronized with the touch sensor driving signal and to output the generated pen driving signal to the touch screen through the conductive tip, the pen driving circuit being housed within the housing; and a switch configured to selectively couple the conductor layer to the pen driving circuit. ### Claim 2 (depends on 1) The active stylus pen of claim 1, wherein at least one touch period of one frame is allocated to drive the touch screen, and the switch is switched on during a reception section of the touch period for inputting the uplink signal, to couple the conductor layer to the pen driving circuit, and the switch is switched off during a transmission section of the touch period for outputting the pen driving signal, to decouple the conductor layer and the pen driving circuit. ### Claim 3 (depends on 2) The active stylus pen of claim 2, wherein the conductive tip is operably coupled to the touch screen through a pen capacitance, and the conductor layer is operably coupled to the touch screen through a human capacitance. ### Claim 4 (depends on 3) The active stylus pen of claim 3, wherein, during the reception section, the pen driving circuit receives the uplink signal through at least one of the conductive tip and the conductor layer. ### Claim 5 (depends on 1) The active stylus pen of claim 1, wherein when at least one touch period of one frame is allocated to drive the touch screen and the uplink signal is continuously applied in in-phase to the touch screen during the touch period, the switch is switched on during a reception section of the touch period for inputting the uplink signal, and when the uplink signal is input in out-of-phase to the pen driving circuit within the reception section, the switch is switched off. ### Claim 6 (depends on 1) The active stylus pen of claim 1, wherein when at least one touch period of one frame is allocated to drive the touch screen and the uplink signal is alternately applied in in-phase and out-of-phase to the touch screen during the touch period, the switch is maintained in an ON state during a reception section of the touch period for inputting the uplink signal. ### Claim 7 A touch sensing system, comprising: a touch screen; a touch driving device configured to apply an uplink signal and a touch sensor driving signal to the touch screen; and an active stylus pen configured to generate a pen driving signal synchronized with the touch sensor driving signal and to output the generated pen driving signal to the touch screen, wherein the active stylus pen includes: a housing connected to an electrical ground; a conductive tip protruding outwardly from the housing, the conductive tip being operable to contact the touch screen; a conductor layer surrounding an outer surface of the housing with an insulator interposed therebetween; a pen driving circuit configured to receive the uplink signal and the touch sensor driving signal from the touch screen, and to output the pen driving signal to the touch screen through the conductive tip, the pen driving circuit being housed within the housing; and a switch configured to selectively couple the conductor layer to the pen driving circuit. ### Claim 8 (depends on 7) The touch sensing system of claim 7, wherein at least one touch period of one frame is allocated to drive the touch screen, and the switch is switched on during a reception section of the touch period for inputting the uplink signal, to couple the conductor layer to the pen driving circuit, and the switch is switched off during a transmission section of the touch period for outputting the pen driving signal, to decouple the conductor layer and the pen driving circuit. ### Claim 9 (depends on 8) The touch sensing system of claim 8, wherein the conductive tip is operably coupled to the touch screen through a pen capacitance, and the conductor layer is operably coupled to the touch screen through a human capacitance. ### Claim 10 (depends on 9) The touch sensing system of claim 9, wherein, during the reception section, the pen driving circuit receives the uplink signal through at least one of the conductive tip and the conductor layer. ### Claim 11 (depends on 7) The touch sensing system of claim 7, wherein when at least one touch period of one frame is allocated to drive the touch screen and the uplink signal is continuously applied in in-phase to the touch screen during the touch period, the switch is switched on during a reception section of the touch period for inputting the uplink signal, and when the uplink signal is input in out-of-phase to the pen driving circuit within the reception section, the switch is switched off. ### Claim 12 (depends on 7) The touch sensing system of claim 7, wherein when at least one touch period of one frame is allocated to drive the touch screen and the uplink signal is alternately applied in in-phase and out-of-phase to the touch screen during the touch period, the switch is maintained in an ON state during a reception section of the touch period for inputting the uplink signal. ### Claim 13 A method, comprising: applying an uplink signal and a touch sensor driving signal to a touch screen; contacting the touch screen by a conductive tip of an active stylus pen; receiving, by a pen driving circuit housed within a housing of the active stylus pen, the uplink signal and the touch sensor driving signal; generating, by the pen driving circuit, a pen driving signal synchronized with the touch sensor driving signal; outputting the generated pen driving signal to the touch screen; and controlling a switch to selectively couple a conductor layer that at least partially surrounds the housing of the active stylus pen to the pen driving circuit. ### Claim 14 (depends on 13) The method of claim 13, wherein controlling the switch to selectively couple the conductor layer to the pen driving circuit includes: turning the switch on during a reception section of a touch period for inputting the uplink signal, to couple the conductor layer to the pen driving circuit, and turning the switch off during a transmission section of the touch period for outputting the pen driving signal, to decouple the conductor layer and the pen driving circuit. ### Claim 15 (depends on 14) The method of claim 14, further comprising: coupling the capacitive tip to the touch screen through a pen capacitance; and coupling the conductor layer to the touch screen through a human capacitance. ### Claim 16 (depends on 15) The method of claim 15, wherein, during the reception section, the pen driving circuit receives the uplink signal through at least one of the conductive tip and the conductor layer.