# US 2020/0401293 A1 · Touch-and-display device and sensing system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0401293 A1 - Document ID: US20200401293A1 - Status: Published application - Kind: A1 - Application number: 16/662,009 - Filed: 2019-10-23 - Published: 2020-12-24 - Earliest claimed: 2019-06-18 - Assignees: Himax Technologies Limited - Applicants: Himax Technologies Limited - Inventors: Hui-Min WANG; Ren-Hao YE - Web page: https://patentgrep.com/patent/US20200401293A1 ## CPC - G06F 3/04162: {for exchanging data with external devices, e.g. smart pens, via the digitiser sensing hardware} - G02F 1/13338: {Input devices, e.g. touch panels} - G02F 1/133512: {Light shielding layers, e.g. black matrix (G02F1/136209 takes precedence)} - G06F 3/03545: {Pens or stylus} - G06F 3/0412: {Digitisers structurally integrated in a display} - 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: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS ## Abstract A touch-and-display device operated with an active stylus is provided. The touch-and-display device includes a touch-and-display panel and a circuit. In a touch sensing period, the circuit transmits a touch sensing signal to multiple sensing electrodes and determines at least one touched electrode and at least one untouched electrode of the sensing electrodes based on capacitance of the sensing electrodes. In a stylus sensing period, the circuit transmits an uplink signal to the untouched electrodes and applies a direct current voltage to the touched electrodes. The uplink signal is a time-varying signal. ## Claims ### Claim 1 A touch-and-display device operated with an active stylus, the touch-and-display device comprising: a touch-and-display panel, comprising a plurality of sensing electrodes, wherein the sensing electrodes are electrically insulated with each other; and a circuit, electrically connected to the sensing electrodes through a plurality of sensing lines, wherein in a display period, the circuit applies a common voltage to the sensing electrodes through the sensing lines, wherein in a touch sensing period, the circuit transmits a touch sensing signal to the sensing electrodes through the sensing lines, and determines at least one touched electrode and at least one untouched electrode of the sensing electrodes based on capacitance of the sensing electrodes, wherein in a stylus sensing period, the circuit transmits an uplink signal only to the at least one untouched electrode and simultaneously applies a direct current voltage only to the at least one touched electrode, and the circuit receives a downlink signal from the active stylus through the sensing electrodes, and determines a stylus location corresponding to the active stylus according to the downlink signal, wherein the uplink signal is a time-varying signal. ### Claim 2 (depends on 1) The touch-and-display device of claim 1, wherein the touch-and-display panel further comprises a plurality of pixel structures, a plurality of gate lines, and a plurality of data lines, and each of the gate lines is connected to corresponding ones of the pixel structures, and each of the data lines is connected to corresponding ones of the pixel structures, wherein in the stylus sensing period, the circuit transmits the uplink signal to the gate lines and the data lines. ### Claim 3 (depends on 2) The touch-and-display device of claim 2, wherein the circuit is a touch and display driver integration (TDDI) circuit. ### Claim 4 (depends on 1) The touch-and-display device of claim 1, wherein the uplink signal is configured to carry synchronization information. ### Claim 5 (depends on 1) The touch-and-display device of claim 1, wherein the downlink signal is configured to carry pressure information, tilt information, or button information. ### Claim 6 A sensing system comprising: an active stylus, comprising a case and a conductive tip; and a touch-and-display device, comprising a touch-and-display panel and a circuit, wherein the touch-and-display panel comprises a plurality of sensing electrodes which are electrically insulated with each other, and the circuit is electrically connected to the sensing electrodes through a plurality of sensing lines, wherein in a display period, the circuit applies a common voltage to the sensing electrodes through the sensing lines, wherein in a touch sensing period, the circuit transmits a touch sensing signal to the sensing electrodes through the sensing lines, and determines at least one touched electrode and at least one untouched electrode of the sensing electrodes based on capacitance of the sensing electrodes, wherein in a stylus sensing period, the circuit transmits an uplink signal only to the at least one untouched electrode and simultaneously applies a direct current voltage only to the at least one touched electrode, and the circuit receives a downlink signal from the active stylus through the sensing electrodes, and determines a stylus location corresponding to the active stylus according to the downlink signal, wherein the uplink signal is a time-varying signal. ### Claim 7 (depends on 6) The sensing system of claim 6, wherein the touch-and-display panel further comprises a plurality of pixel structures, a plurality of gate lines, and a plurality of data lines, and each of the gate lines is connected to corresponding ones of the pixel structures, and each of the data lines is connected to corresponding ones of the pixel structures, wherein in the stylus sensing period, the circuit transmits the uplink signal to the gate lines and the data lines. ### Claim 8 (depends on 7) The sensing system of claim 7, wherein the circuit is a touch and display driver integration (TDDI) circuit. ### Claim 9 (depends on 6) The sensing system of claim 6, wherein the downlink signal is configured to carry pressure information, tilt information, or button information. ### Claim 10 (depends on 6) The sensing system of claim 6, wherein the uplink signal is transmitted to the conductive tip through the at least one untouched electrode, and the direct current voltage is transmitted to the case through the at least one touched electrode, wherein the active stylus further comprises a signal processing circuit taking a voltage of the case as a ground voltage and analyzing a differential signal between the uplink signal from the conductive tip and the ground voltage. ### Claim 11 (depends on 10) The sensing system of claim 10, wherein the signal processing circuit detects one of a period, a duty cycle, a number of pulses, a rising edge, and a falling edge of the uplink signal. ### Claim 12 (depends on 11) The sensing system of claim 11, wherein the uplink signal is configured to carry synchronization information.