Touch circuit and method for controlling touch circuit

Abstract

This disclosure relates to touch circuits and methods for controlling touch circuits. An embodiment provides a touch circuit comprising: a touch driving circuit that supplies touch driving signals to touch electrodes; a touch sensing circuit that senses capacitance changes of the touch electrodes via touch sensing lines; and multiplexers connected to the touch sensing lines, each multiplexer transmitting capacitance changes of the touch electrodes to the touch sensing circuit. Some of the touch electrodes in the touch circuit are selectively short-circuited according to the driving mode of the touch circuit, and the touch electrodes are electrically connected to each other via the connection of nodes of the touch electrodes.

Description

Technical Field

[0001] This embodiment relates to a touch integrated circuit and a display device including the touch integrated circuit, and more specifically, to a touch circuit and its driving method for transmitting touch driving signals to touch electrodes and sensing changes in the capacitance of the touch electrodes. Prior Technology

[0002] The technology that identifies external objects approaching or touching a touch panel is called touch sensing technology. The touch panel is placed on a flat surface in the same position as the display panel, so the user can input user operation signals to the touch panel while viewing an image on the display panel. Compared to other previous user operation signal input methods (such as mouse input or keyboard input), the method used to generate such user operation signals provides remarkably intuitive user feedback.

[0003] Based on these advantages, touch sensing technology has been applied to various electronic devices, including display panels. Touch circuits can sense the touch or proximity of external objects by supplying drive signals to drive electrodes arranged on the touch panel and receiving response signals formed on sensing electrodes. The touch panel creates capacitance between the drive electrodes and the sensing electrodes, and changes in capacitance can indicate the touch or proximity of external objects.

[0004] At the same time, in order to sense the touch or proximity of external objects relative to all areas of the touch panel, a continuous drive signal should be supplied to all drive electrodes, which may lead to continuous power consumption on the touch panel even if no touch or proximity of an object is sensed. Summary of the Invention

[0005] In this context, one aspect of the present disclosure is to provide a touch circuit and a display device including the touch circuit, which can reduce the power consumed in the touch panel by changing the pattern of the drive signal supplied to the drive electrodes according to the drive mode of the touch panel.

[0006] Another aspect of this disclosure is to provide a touch circuit and a display device including the touch circuit, which can optimize the performance load of the system by preventing unnecessary system driving in the parts where touch sensing technology is not used and selectively controlling the internal operation of the touch panel.

[0007] In one aspect, an embodiment may provide a touch circuit comprising: a touch driving circuit that supplies touch driving signals to touch electrodes; a touch sensing circuit that senses capacitance changes of the touch electrodes via touch sensing lines; and multiplexers respectively connected to the touch sensing lines, each multiplexer transmitting capacitance changes of the touch electrodes to the touch sensing circuit, wherein some of the touch electrodes are selectively short-circuited according to the driving mode of the touch circuit, and the touch electrodes are electrically connected to each other via the connection of nodes of the touch electrodes.

[0008] In another embodiment, an embodiment may provide a touch circuit comprising: a touch driving circuit that transmits touch driving signals to a first touch electrode and a second touch electrode via touch driving lines; and a touch sensing circuit that receives touch signals transmitted from the first touch electrode and the second touch electrode, wherein a switch is arranged between the first touch electrode and the second touch electrode, the switch selectively short-circuiting the first touch electrode or the second touch electrode according to the driving mode of the touch circuit.

[0009] In another aspect, embodiments may provide a method for controlling a touch circuit, comprising: generating a control signal for a switch disposed among a plurality of touch electrodes; transmitting the control signal for the switch to a readout circuit via a serial peripheral interface communication method, i.e., an SPI communication method; and the readout circuit selectively short-circuiting the plurality of touch electrodes in response to the control signal for the switch.

[0010] As is evident from the above, according to the embodiments, since touch or no touch can be determined using only one multiplexer by shorting between the touch electrodes based on the driving mode of the touch panel, the power consumption in the touch panel can be reduced.

[0011] According to this embodiment, since the internal operating procedures of the touch panel can be simplified, the amount of data transmitted and the data processing speed can be reduced, and the load generated during data processing can be reduced.

[0012] According to this embodiment, a touch sensing method can be used to prevent continuous touch sensing of the touch panel by responding to the driving mode of the touch panel, and the touch panel driving can be optimized by reducing unnecessary signal output. Simple Explanation of the Diagram

[0013] Figure 1 is a configuration diagram of a typical display device.

[0014] Figure 2 is a diagram illustrating the touch sensing processing of a stylus and a finger according to an embodiment.

[0015] Figure 3 is a diagram illustrating a communication method of a touch circuit according to an embodiment.

[0016] Figure 4 is a first example diagram illustrating the operation of the touch circuit according to an embodiment.

[0017] Figure 5 is a second example diagram illustrating the operation of the touch circuit according to an embodiment.

[0018] Figure 6 is a third example diagram illustrating the operation of the touch circuit according to an embodiment.

[0019] Figure 7 is a fourth example diagram illustrating the operation of the touch circuit according to an embodiment.

[0020] Figure 8 is a diagram illustrating the operation of the switch between the touch electrodes according to an embodiment.

[0021] Figure 9 is a diagram illustrating the time-division driving of the touch circuit according to an embodiment.

[0022] Figure 10 is a diagram illustrating the process of driving the touch circuit in normal mode according to an embodiment.

[0023] Figure 11 is a diagram illustrating the process of driving the touch circuit in low-power mode according to an embodiment.

[0024] Figure 12 is a diagram illustrating the pen / finger scanning process of the touch circuit according to an embodiment.

[0025] Figure 13 is a diagram illustrating operation via a driving mode of the touch circuit according to an embodiment.

[0026] Figure 14 is a diagram illustrating the short-circuit handling between channels between touch electrodes in a touch circuit according to an embodiment. Implementation

[0027] Figure 1 is a configuration diagram of a typical display device.

[0028] Referring to Figure 1, the display device 100 may include a panel 110, a data driving circuit 120, a gate driving circuit 130, a touch circuit 140, and a control circuit 150.

[0029] On panel 110, a plurality of data lines DL connected to data driving circuit 120 can be formed, and a plurality of gate lines GL connected to gate driving circuit 130 can be formed. In addition, on panel 110, a plurality of pixels P corresponding to the intersection points of the plurality of data lines DL and the plurality of gate lines GL can be defined.

[0030] On each pixel P, a transistor can be formed such that a first electrode (e.g., a source electrode or a drain electrode) is connected to a data line DL, a gate electrode is connected to a gate line GL, and a second electrode (e.g., a drain electrode or a source electrode) is connected to a display electrode.

[0031] Furthermore, on panel 110, multiple touch electrodes TE can be further formed to be spaced apart from each other. In the area where the touch electrodes TE are located, one pixel P can be positioned, or multiple pixels P can be positioned.

[0032] Panel 110 may include a display panel and a touch panel (touchscreen panel (TSP)), and the display panel and touch panel may share some constituent elements. For example, multiple touch electrodes TE may be a configuration of the display panel (e.g., a common electrode for applying a common voltage) and simultaneously a configuration of the touch panel (touch electrodes for sensing touch). In-cell panels are known as a type of panel that shares some constituent elements of the display panel and touch panel, but this is merely an example of the panel 110 described above, and the panels to which this disclosure applies are not limited to such in-cell panels.

[0033] The data driving circuit 120 supplies data signals to the data lines DL to display images on the individual pixels P of the panel 110. The data driving circuit 120 may include, but is not limited to, at least one data driver integrated circuit and may be implemented in various ways.

[0034] The gate drive circuit 130 sequentially supplies scan signals to the gate line GL to turn on / off the transistors located on each pixel P. The gate drive circuit 130 may include, but is not limited to, at least one gate driver integrated circuit, and may be implemented in various ways.

[0035] Touch circuit 140 applies drive signals to all or part of a plurality of touch electrodes TE connected to the sensing line SL. Touch circuit 140 can be defined as a touch / data driver circuit (touch and driver IC (TDDI)) or a touch / display driver circuit (touch and display driver IC (TDDI)). Touch circuit 140 may include source readout circuitry (source readout driver IC (SRIC)) and a microprocessor (microprocessor unit (MCU)) and can perform touch sensing based on the touch electrodes TE.

[0036] Touch / display driver circuits (TDDI) can drive an electrode in a time-division multiplexing manner based on display driving periods and touch driving periods, thus reducing circuit size. Electrodes used in touch / display driver circuits can be defined as common electrodes or touch electrodes.

[0037] When the data driving circuit 120 and the touch circuit 140 form an integrated touch / data driving circuit (TDDI), image data can be acquired by forming several blocks of common electrodes to which a common voltage is applied during the display driving period for image display, and touch data can be acquired by using several blocks of common electrodes as multiple touch electrodes TE.

[0038] In order for the touch circuit 140 to apply a drive signal to all or part of the plurality of touch electrodes TE, it may be necessary to connect sensing lines SL to the respective touch electrodes of the plurality of touch electrodes TE. Therefore, the sensing lines SL connected to the respective touch electrodes TE to transmit touch drive signals may be formed on the panel 110 along a first direction (e.g., vertical direction) or a second direction (e.g., horizontal direction).

[0039] On the other hand, the display device 100 may employ a capacitive touch method that detects the approach or touch of an object by transmitting capacitance changes via the touch electrode TE. The capacitive touch method may be a mutual capacitance touch method or a self-capacitance touch method.

[0040] Mutual capacitance touch, as a capacitive touch method, applies a driving signal to one touch electrode (Tx electrode) and senses another touch electrode (Rx electrode) coupled to the Tx electrode. In the mutual capacitance touch method, the sensed value on the Rx electrode varies depending on the proximity or touch of an object such as a finger or pen, and the mutual capacitance touch method detects whether a touch or touch coordinate is being performed by using the sensed value on the Rx electrode.

[0041] In the self-capacitance touch method, which is another capacitive touch method, there is no distinction between the Tx electrode and the Rx electrode, and after a drive signal is applied to a touch electrode TE, the corresponding touch electrode TE is sensed again.

[0042] The control circuit 150 can supply various control signals to the data driving circuit 120, the gate driving circuit 130, and the touch circuit 140. The control circuit 150 can transmit data control signals (DCS) for controlling the data driving circuit 120 to supply data voltage to each pixel P to match the timing, and can transmit gate control signals (GCS) to the gate driving circuit 130, or can transmit sensing signals to the touch circuit 140.

[0043] The control circuit 150 may include a timing controller for further control functions.

[0044] Figure 2 is a diagram illustrating the touch sensing processing of a stylus and a finger according to an embodiment.

[0045] Referring to Figure 2, in the touch sensing system 200, the display device 100, touch panel 110, or touch circuit 140 can transmit uplink (UL) signals using an object (e.g., a stylus or finger).

[0046] Touch circuit 140 may include touch driving circuit 141 and touch sensing circuit 142, wherein touch driving circuit 141 transmits touch driving signal (STX) to touch electrode, and touch sensing circuit 142 receives touch sensing signal SRX in response to capacitance change on touch electrode, and if necessary, all or some configurations of touch circuit 140 may be defined as readout circuit (readout integrated circuit (ROIC)).

[0047] The touch driving circuit 141 of the touch circuit 140 can transmit an uplink (UL) signal to the stylus 20 via the touch electrodes. If the stylus 20 touches or approaches the panel 110 including the touch electrodes within a predetermined distance, the stylus 20 can receive the uplink (UL) signal. The uplink (UL) signal can be transmitted from a portion or all of the touch panel 110 to the stylus 20.

[0048] The uplink (UL) signal transmitted from the touch circuit 140 to the stylus 20 may include information related to the touch panel (e.g., touch panel status information, touch panel identification information, and touch panel type information), information related to the touch panel's driving mode (e.g., stylus search mode or stylus driving mode identification information), and stylus signal characteristic information (e.g., touch panel driving frequency, stylus transmission frequency, and signal pulse count).

[0049] The touch sensing circuit 142 of the touch circuit 140 can receive downlink (DL) signals from the stylus 20 via touch electrodes. If the stylus 20 receives an uplink (UL) signal, the stylus 20 can transmit the downlink (DL) signal. The downlink (DL) signal can be transmitted to the touch electrodes located at or near the point touched by the stylus.

[0050] If a downlink (DL) signal enters the touch circuit 140, the touch circuit 140 can continuously send data to and receive data from the stylus 20. If the downlink (DL) signal does not enter the touch circuit 140 from a certain point in time, the touch sensing device can search for the active pen again. That is, the touch circuit 140 can repeat the above process by sending an uplink (UL) signal to the stylus again.

[0051] The touch circuit 140 can determine whether a touch is made, the touch position, the touch intensity, and the touch interval based on the capacitance change of the touch electrode that is touching or near the object (OBJ) 10.

[0052] Furthermore, regardless of whether the information is based on the touch or proximity of an object, the touch circuit 140 can receive downlink (DL) signals generated by the stylus 20 itself.

[0053] Downlink (DL) signals may include information related to the state of the stylus (for example, the state of the stylus may include stylus power information, stylus frequency information, stylus protocol information, stylus movement speed, position and tilt information).

[0054] The downlink (DL) signal transmitted by the stylus 20 can use a frequency different from the frequency of the drive signal, and the processor (not shown) or frequency selection circuit (not shown) inside the stylus 20 can use the frequency by taking into account information related to the state of the stylus 20.

[0055] The touch circuit 140 can distinguish between signals generated by capacitance changes of the touch electrodes due to an object approaching the panel and signals generated by downlink signals transmitted due to an object approaching the panel.

[0056] The touch circuit 140 in Figure 2 illustrates mutual capacitance touch sensing, but the technical concept of this disclosure is not limited thereto and can also be applied to self-capacitance touch sensing.

[0057] Figure 3 is a diagram illustrating a communication method of a touch circuit according to an embodiment.

[0058] Referring to Figure 3, the display device 300 may include a panel 310, a source readout circuit 340, a microprocessor 360, a power supply circuit 370, and a backlight circuit 380.

[0059] Panel 310 can be the panel shown in Figure 1 above, or it can be implemented as a display panel or a touch panel (touch screen panel (TSP)) that is separate or integrated.

[0060] The source readout circuit (source readout integrated circuit (SRIC)) 340 may include an analog unit 341 and a digital unit 342.

[0061] The analog unit 341 may be a circuit that transmits analog signals (e.g., touch drive signals or touch sensing signals) to the panel 310 and receives analog signals (e.g., touch drive signals or touch sensing signals) from the panel 310, and may receive analog signals, convert analog signals into digital signals, and transmit digital signals to the digital unit 342.

[0062] The digitizing unit 342 can receive digital signals converted by the analog unit 341, or it can convert digital signals into analog signals to transmit analog signals to the analog unit 341. Furthermore, the digitizing unit 342 can transmit digital signals (e.g., panel control signals or switch control signals) to and receive digital signals (e.g., panel control signals or switch control signals) from the microprocessor 360. For example, communication between the digitizing unit 342 and the microprocessor 360 can be Serial Peripheral Interface (SPI) type communication.

[0063] The microprocessor 360 may include a touch computing algorithm circuit 361 and a communication protocol circuit 362.

[0064] The touch calculation algorithm circuit 361 can calculate touch coordinates and touch intensity based on touch information transmitted from the digital unit 342, and can perform such calculations using an algorithm configured therein or an algorithm transmitted from an external source.

[0065] The communication protocol circuit 362 may be a circuit that generates or controls a Universal Serial Bus (USB) communication protocol, a Pen Communication Protocol, or a Serial Peripheral Interface (SPI) communication protocol with the host 390.

[0066] The communication protocol circuit 362 can send data to and receive data from the digital unit 342 of the touch circuit 340 via SPI communication, or it can transmit and receive signals for controlling the digital unit 342.

[0067] A pen communication protocol can be a communication protocol used to transmit uplink signals from a touch panel to a pen and receive downlink signals from the pen.

[0068] The power supply circuit 370 can be a circuit that supplies power to the touch circuit 340 and the microprocessor 360. The power supply circuit 370 can reduce the power consumption of each circuit by adjusting the supplied current or voltage differently in accordance with the operation of the touch circuit 340 or the microprocessor 360.

[0069] The backlight circuit 380 may be a circuit that controls the operation of the light-emitting diode (LED) used when the panel 310 is a liquid crystal display (LCD), and may selectively include the backlight circuit 380 depending on the type of panel 310.

[0070] The host 390 can be an external device (such as a laptop, monitor, or tablet).

[0071] Figure 4 is a first example diagram illustrating the operation of the touch circuit according to an embodiment.

[0072] Figure 5 is a second example diagram illustrating the operation of the touch circuit according to an embodiment.

[0073] Referring to Figures 4 and 5, the touch circuit can transmit the touch driving signal from the touch driving circuit 441 to the touch electrode, and the touch sensing circuit 442 can receive the touch sensing signal related to the capacitance change of the touch electrode by means of one or more multiplexers (MUX) 445.

[0074] The touch driving circuit 441 can transmit touch driving signals to the touch electrode by means of a plurality of sensing lines SL connected to the touch driving circuit 441, and the touch sensing circuit 442 can receive touch sensing signals transmitted from the touch electrode by means of a plurality of sensing lines SL connected to the touch sensing circuit 442 which is different from the above-mentioned touch sensing circuit 442.

[0075] One or more multiplexers 445 may be further arranged between the touch electrodes and the touch sensing circuitry 442.

[0076] The multiplexer 445 can select one of the signals related to the capacitance change generated on the touch electrode from multiple sensing lines SL, and can transmit the selected signal to the touch sensing circuit 442. N (N is a natural number equal to or greater than 1) sensing lines can be connected to N (N is a natural number equal to or greater than 1) touch electrodes, and the touch sensing signals generated from each touch electrode can be transmitted to the touch sensing circuit 442 by the multiplexer 445.

[0077] The multiplexer 445 can form a multiplexer group consisting of multiple multiplexers, and one end of each multiplexer can be connected to a touch electrode via a sensing line.

[0078] For example, as shown in FIG4, the first multiplexer 445-1 can be connected to nodes formed on the first to fourth touch electrodes 411-1, 411-2, 411-3, and 411-4 via four signal lines for the first to fourth touch electrodes 411-1, 411-2, 411-3, and 411-4. In this case, the first to fourth touch electrodes 411-1, 411-2, 411-3, and 411-4 can be defined as a first touch group 411, and the first multiplexer 445-1 can be defined as connected to the first touch group 411. The second to sixth multiplexers (not shown) can also be connected to the second to sixth touch groups 412, 413, 414, 415, and 416, respectively.

[0079] For example, as shown in FIG5, the first multiplexer 445-1 can be connected to nodes formed on the first to eighth touch electrodes (not shown) via eight signal lines for the first to eighth touch electrodes (not shown). In this case, the first to fourth touch electrodes can be defined as the first touch group 411, and the fifth to eighth touch electrodes can be defined as the second touch group 412. The first multiplexer 445-1 can be defined as connected to the first touch group 411 and the second touch group 412.

[0080] As shown in Figures 4 and 5, when the touch driving circuit 441 supplies touch driving signals to all touch electrodes and senses the capacitance changes of each touch electrode, all touch electrodes sense the capacitance changes in real time, thus increasing the power consumption consumed in the touch panel driving process. Furthermore, when all multiplexers 445-1, 445-2, 445-3, 445-4, 445-5, and 445-6 corresponding to each touch electrode or each touch electrode group are operating, the power consumption consumed in the touch panel driving process is further increased.

[0081] Figure 6 is a third example diagram illustrating the operation of the touch circuit according to an embodiment.

[0082] Referring to Figure 6, the first touch group 511 can be short-circuited to other touch groups 512, 513, 514, 515 and 516, and the connection status can be identified.

[0083] The short-circuit state of the touch electrode can be explained by the connection relationship of some electrodes (e.g., the first touch electrode 511-1, the second touch electrode 512-1, the third touch electrode 513-1, the fourth touch electrode 514-1, the fifth touch electrode 515-1, and the sixth touch electrode 516-1).

[0084] A touch group can be defined as a specific group of touch electrodes connected to a multiplexer, and is not limited to the method shown in FIG6. The first touch group 511 can be a group of touch electrodes connected by a signal line connected to the first multiplexer 545-1, and the second touch group 512 to the sixth touch group 516 can also be defined in the same way.

[0085] The sixth touch electrode 516-1 of the sixth touch group 516 can be electrically connected to the first touch electrode 511-1 of the first touch group 511, the second touch electrode 512-1 of the second touch group 512, the third touch electrode 513-1 of the third touch group 513, the fourth touch electrode 514-1 of the fourth touch group 514, and the fifth touch electrode 515-1 of the fifth touch group 515. All or some of the individual touch electrodes can be selectively short-circuited by signal lines between nodes and can be electrically connected to each other.

[0086] In this configuration, the first to sixth touch electrodes 511-1 to 516-1 can be short-circuited to form a touch group 517, and simplified information (such as whether a touch is being made) can be sensed without sensing all positional information of the touch panel. For example, since the second touch electrode 512-1 is short-circuited to the sixth touch electrode 516-1, a touch sensing signal generated by an object near the second touch electrode 512-1 can be transmitted to the sixth touch electrode 516-1. Furthermore, since the sixth touch electrode 516-1 is short-circuited to the first touch electrode 511-1, the signal transmitted to the sixth touch electrode 516-1 can be transmitted to the first touch electrode 511-1. The first touch electrode 511-1 can transmit the touch sensing signal to the multiplexer via a sensing line SL connected to the multiplexer. When multiple touch electrodes are electrically connected as described above, the touch sensing signal can be sequentially transmitted to a specific touch electrode via signal lines, and the touch sensing signal can be transmitted in a desired direction or position.

[0087] The touch electrodes 511-1 to 516-1 present in the touch group 517 can be treated as a virtual touch electrode and can be selectively short-circuited according to the driving mode of the touch panel or the setting value of the touch circuit.

[0088] When touch data is collected by forming a touch group 517, touch data in the touch group 517 can be selectively collected, integrated, and managed, reducing the amount of data transmitted. Furthermore, when the touch circuit's driving mode is low-power mode, only information needed to determine whether to wake up the system is required, and this circuit structure can be utilized when the touch circuit's driving mode is low-power mode.

[0089] The data collected by the touch group 517 can be transmitted to the first multiplexer 545-1 via a sensing line SL.

[0090] In the same manner as described above, all touch sensing signals relating to capacitance changes on the second to sixth touch electrodes 512-1 to 516-1 can be transmitted to the first touch electrode 511-1. The touch sensing signals transmitted to the first touch electrode 511-1 can be transmitted to the first multiplexer 545-1 and can also be transmitted to the touch sensing circuit (not shown).

[0091] In this case, the second to sixth multiplexers 545-2 to 545-6 can be electrically disconnected from the touch electrodes. Exemplarily, the second to sixth multiplexers 545-2 to 545-6 can remain in an open-circuit state without being connected to the sensing line SL by a switch (not shown). With the first multiplexer 545-1 selected as the reference multiplexer without altering the touch panel structure and the remaining multiplexers 545-2 to 545-6 open-circuited, only one multiplexer is used, thus improving the efficiency of internal power usage. When all multiplexers are controlled, due to the increased computational load and complexity of the internal processor, some multiplexers can be switched off to simplify touch sensing operations.

[0092] The touch group can be opened or short-circuited by opening / closing an internal switch (not shown), and the operation of the switch (not shown) can selectively open or short-circuit according to the driving mode of the touch circuit.

[0093] When the internal operation varies depending on whether the touch circuit's driving mode is normal or low power, the operation described above in Figure 4 can be defined as operation in normal mode, and the operation in Figure 6 can be defined as operation in low power mode.

[0094] Figure 7 is a fourth example diagram illustrating the operation of the touch circuit according to an embodiment.

[0095] Referring to Figure 7, a multiplexer can be connected to the sensing line SL to receive touch sensing signals in the first touch group 511 and the second touch group 512.

[0096] As shown in Figure 7, when a multiplexer is connected to multiple touch groups, the number of multiplexers can be reduced, thereby reducing the size of the touch panel. For example, two channels (e.g., the first touch group 511 and the second touch group 512) can be configured to be connected to a single multiplexer.

[0097] The first touch group 511 can be electrically connected to the third touch group 513, and the third touch group 513 can be electrically connected to the fifth touch group 515. By analogy, the connection relationships of each touch group can be formed into an integrated touch group.

[0098] In the same manner, the second touch group 512 can be electrically connected to the fourth touch group 514, and the fourth touch group 514 can be electrically connected to the sixth touch group 516.

[0099] Since operating an internal switch (not shown) to short-circuit some touch groups instead of operating an internal switch (not shown) to short-circuit all touch groups reduces power consumption, one or more integrated touch groups can be formed by optionally defining the short-circuit area, as shown in FIG7. The technical concept of this disclosure is not limited to the technical concept shown in FIG7.

[0100] The first touch group 511, the third touch group 513, or the fifth touch group 515 can be defined as an odd-numbered touch group integrating an odd number of channels. In this case, the touch sensing signals generated by the first touch group 511, the third touch group 513, and the fifth touch group 515 can be transmitted to the multiplexer 545-1 via the touch electrodes of the first touch group 511.

[0101] The touch group can be opened or short-circuited by opening / closing an internal switch (not shown), and the operation of the switch (not shown) can selectively open or short-circuit according to the driving mode of the touch circuit.

[0102] The aforementioned touch group can be defined as forming a channel. Furthermore, the aforementioned operation can be defined as a short-circuit state between multiple channels.

[0103] When the internal operation differs depending on whether the touch circuit's driving mode is normal or low power, the operation described above in Figure 5 can be defined as an operation in normal mode, and the operation in Figure 7 can be defined as an operation in low power mode.

[0104] Figure 8 is a diagram illustrating the operation of the switch between the touch electrodes according to an embodiment.

[0105] Referring to Figure 8, switches (SW) 646-1 and 646-2 can be connected between multiple touch electrodes 611, 612 and 613.

[0106] A first node (node ​​1) formed on the first touch electrode 611 can be electrically connected to a second node (node ​​2) formed on the second touch electrode 612, and this can be a physical or virtual connection.

[0107] The first switch 646-1 can be arranged between the first node and the second node, and can selectively short-circuit the first touch electrode 611 and the second touch electrode 612 in response to external or internal control signals.

[0108] For example, the first signal line L1 formed between the first touch electrode 611 and the second touch electrode 612 can be opened or short-circuited by the first switch 646-1.

[0109] The second node (node ​​2) formed on the second touch electrode 612 and the third node (node ​​3) formed on the third touch electrode 613 can be electrically connected to each other in the same way.

[0110] The second switch 646-2 can be arranged between the second node and the third node, and can selectively short-circuit the second touch electrode 612 and the third touch electrode 613 in response to external or internal control signals.

[0111] For example, the second signal line L2 formed between the second touch electrode 612 and the third touch electrode 613 can be opened or shorted by the second switch 646-2.

[0112] The first signal line L1 and the second signal line L2 can be a single line or separate lines.

[0113] The first switch 646-1 and the second switch 646-2 can operate simultaneously or at different times, and the signals controlling each switch can be transmitted independently.

[0114] The first switch 646-1 and the second switch 646-2 can be selectively short-circuited or open-circuited depending on the driving mode of the touch circuit (e.g., normal mode or low power mode) to connect the nodes of the touch electrodes.

[0115] The operation of the first switch 646-1 and the second switch 646-2 can be limited and changed by receiving control signals from internal or external switches.

[0116] Furthermore, the operation of the first switch 646-1 and the second switch 646-2 can be limited and changed according to the setting value of the internal register of the readout circuit (not shown). This can be a change in the physical connection state of the internal integrated circuit, and can be used to open or short-circuit each node according to the change in the setting value of the internal register within the integrated circuit.

[0117] The first switch 646-12 and the second switch 646-2 can be synchronized with a signal for controlling the operation of a multiplexer (not shown) connected to the sensing line SL, or can be synchronized with a control signal for a switch (not shown) for controlling the electrical connection relationship of the multiplexer (not shown).

[0118] The first switch 646-1 and the second switch 646-2 can be arranged between the touch electrodes, or between the touch driving circuit and the touch sensing circuit.

[0119] The connection relationship between the touch electrode and the switch as shown in Figure 8 above is for illustrative purposes only. The technical concept of this disclosure is not limited thereto, and the touch electrode, sensing line, and switch can have various connection relationships or arrangement relationships.

[0120] Figure 9 is a diagram illustrating the time-division driving of the touch circuit according to an embodiment.

[0121] Referring to Figure 9, according to the touch sensing method 700, the panel can be driven by dividing the driving period of the display device 100 into a display driving period or a touch sensing period. If necessary, the touch sensing period can be defined as the period for transmitting touch driving signals or receiving touch sensing signals.

[0122] The display driving period (DP) and the touch sensing period (TP) are time-divided periods that can alternate with each other.

[0123] When multiple objects are touched or brought near, the touch sensing time periods for each object can be divided in time, and the touch sensing time periods for each object can be sensed individually.

[0124] For example, during the touch sensing period, the touch sensing period T1 of the first stylus, the touch sensing period T2 of the finger, and the touch sensing period T3 of the second stylus can be separate and can be performed sequentially.

[0125] To independently sense finger touch, first stylus touch, and second stylus touch, the frequency bands of the corresponding sensing signals can be defined as a first frequency, a second frequency, and a third frequency for sensing. For more accurate touch sensing, the first to third frequencies can be selected as different frequencies, but they can also be selected as the same frequency as needed.

[0126] Figure 10 is a diagram illustrating the process of driving the touch circuit in normal mode according to an embodiment.

[0127] Referring to Figure 10, if the driving mode of the touch circuit is normal mode, the driving method 800 may have one or more time slots.

[0128] The touch circuitry is capable of transmitting touch drive signals in a manner that has multiple time slots during a time period defined as a frame, and can receive touch sensing signals. For example, a frame may include 16 time slots.

[0129] For example, if the driving mode of the touch circuit is normal mode, the first time slot can be a time slot used to transmit a beacon signal. The beacon signal can be a signal used to identify whether an object has been identified.

[0130] For example, if the driving mode of the touch circuit is normal mode, the second time slot, the sixth time slot, the tenth time slot, and the fourteenth time slot can be time slots used to receive pen position information.

[0131] For example, if the touch circuit's driving mode is normal, then the third and fourth time slots can be time slots where no signals are transmitted or received. These two can be defined as deactivated time slots.

[0132] For example, if the driving mode of the touch circuit is normal mode, the fifth and thirteenth time slots can be time slots used to receive pen tilt information.

[0133] For example, if the driving mode of the touch circuit is normal mode, then the seventh, eighth, fifteenth, and sixteenth time slots can be time slots used to receive data transmitted from the pen.

[0134] For example, if the driving mode of the touch circuit is normal mode, then the ninth, eleventh, and twelfth time slots can be time slots used to sense finger touch.

[0135] By combining one or more time slots as described above, a communication protocol for communication between the touch panel and the object can be defined.

[0136] The signal transmitted or received in a time slot can be the signal described above in Figure 1, and the style, number, and timing of the communication protocol used for touch can be defined to be different from the style, number, and timing of the communication protocol used for sensing.

[0137] Figure 11 is a diagram illustrating the process of driving the touch circuit in low-power mode according to an embodiment.

[0138] Referring to Figure 11, if the driving mode of the touch circuit is a low-power mode, the driving method 900 may have one or more time slots.

[0139] For example, if the driving mode of the touch circuit is a low-power mode, the first time slot can be a time slot used to transmit beacon signals.

[0140] For example, if the driving mode of the touch circuit is a low-power mode, then the second to fourteenth time slots can be time slots where no signals are transmitted or received. These time slots can be defined as deactivated time slots.

[0141] For example, if the driving mode of the touch circuit is a low-power mode, the fifteenth time slot can be a time slot used to sense finger touch.

[0142] For example, if the driving mode of the touch circuit is a low-power mode, the sixteenth time slot can be a time slot used to receive pen position information.

[0143] Compared to the normal driving mode of the touch circuit, when the driving mode of the touch circuit is in low-power mode, the operation of each time slot of the protocol can be selectively omitted or changed to achieve efficient system use.

[0144] For example, if the driving mode of the touch circuit is a low-power mode, only the time slots for transmitting beacon signals, receiving pen position information, and sensing finger touches can be used. In this case, since the time slots do not receive pen tilt information or data transmitted from the pen, the operation of the touch circuit can be simplified, and the power consumed in the touch panel can be reduced.

[0145] For example, when the driving mode of the touch circuit is in low power mode, compared to the case where the driving mode of the touch circuit is in normal mode, the number of disabled time slots can be increased and the types of time slots used can be reduced.

[0146] By changing the driving mode of the touch circuit to the normal mode, the power consumption of the touch panel can be minimized by changing the type, quantity, and style of the signals transmitted to the touch panel and the internal operation of the touch panel.

[0147] As shown in Figure 11, by simplifying the protocols used in touch sensing processing, the problems of reduced energy efficiency and microprocessor data processing overload that occur in continuous touch sensing processing can be solved. Furthermore, for example, in low-power mode, unnecessary system drives can be prevented in areas where objects are not detected approaching.

[0148] Unlike the operation described above with reference to Figure 11, according to the technical concept of this disclosure, the number and order of time slots in a frame can be changed differently.

[0149] Figure 12 is a diagram illustrating the pen / finger scanning process of the touch circuit according to an embodiment.

[0150] Referring to Figure 12, the pen / finger scanning method 1000 for the touch circuit may include the following steps: system initialization (S1001), touch sensing start (S1003), system status check (S1005), determining the driving mode of the touch circuit (S1007), and pen / finger scanning (S1009).

[0151] The system initialization step (S1001) can also be a step to initialize the state of the internal arithmetic unit or storage unit.

[0152] The touch sensing start step (S1003) can be a step of transmitting a touch drive signal or receiving a touch sensing signal from a touch electrode using the method described above. Furthermore, communication between the object and the touch panel can be performed.

[0153] The system state check step (S1005) can be a step to identify whether an object is near after touch sensing begins and the system state depending on the state of the object. In order to identify the system state, the system state can be continuously identified using a polling method.

[0154] The step of determining the driving mode of the touch circuit (S1007) may be a step of determining the driving mode of the touch circuit as a normal mode or a low-power mode.

[0155] For example, if the system status is checked and it is determined that an object has not approached the touch panel during a predetermined time period, the driving mode of the touch circuit can be determined to be or changed to a low-power mode. As another example, if the system status is checked and it is determined that an object has approached the touch panel, the driving mode of the touch circuit can be determined to be or changed to a normal mode.

[0156] The driving mode can be changed from normal mode to low power mode when there is no touch input in the system during a predetermined time period, and the driving mode can be changed from low power mode to normal mode when there is touch input a predetermined number of times or for a predetermined time.

[0157] The pen / finger scanning step (S1009) can be a step of scanning whether an object such as a pen or finger is nearby, corresponding to the driving mode of the touch circuit. The above-described protocol of Figures 10 and 11 can be used in the process of scanning whether the object is nearby.

[0158] If the touch circuit is in normal mode, the touch drive signal can be supplied to all touch electrodes of the system, and the touch sensing signal can be received by some sensing lines connected to the touch electrodes and the multiplexer.

[0159] If the driving mode of the touch circuit is low power mode, the touch driving signal can be supplied to all or some of the touch electrodes of the system, and the touch sensing signal can be received by some sensing lines connected to the touch electrodes and the multiplexer.

[0160] If the touch circuit's driving mode is low power mode, it can determine whether the system is awake, and if an object approaches, the touch circuit's driving mode can be changed back to normal mode.

[0161] Furthermore, in the pen / finger scanning step (S1009), the status information of the pen or finger can be received, and the pen / finger scanning can be temporarily stopped according to the driving mode of the touch circuit. Under predetermined conditions, the operation can be changed back to the touch sensing start step (S1003).

[0162] Figure 13 is a diagram illustrating the operation of the driving mode of the touch circuit according to an embodiment.

[0163] Referring to Figure 13, the operation method 1100 using the driving mode of the touch circuit may include the following steps: system initialization (S1101), outputting the driving signal of the panel and communicating (S1102), outputting the touch / pen identification signal (S1103), identifying whether the touch / pen is identified (S1104), receiving and calculating the touch / pen status information (S1105), system status check (S1106), determining whether the driving mode of the touch circuit is a low-power mode (S1107), and simplifying the touch / pen identification signal (S1108).

[0164] The system initialization step (S1101) can be the system initialization steps described above with reference to Figure 12.

[0165] The step of outputting the drive signal of the panel and communicating (S1102) may be the step of transmitting the touch drive signal to the panel and communicating.

[0166] The step of outputting the touch / pen recognition signal (S1103) may be the step of transmitting the uplink signal to the object.

[0167] The step of identifying whether a touch / pen has been recognized (S1104) may be a step of receiving a downlink signal from an object. Alternatively, this step may be a step of receiving a touch sensing signal related to a capacitance change based on the proximity of an object and determining whether a touch / pen has been recognized.

[0168] The step of receiving and calculating touch / pen status information (S1105) may be a step of receiving touch / pen status information from the data obtained in the step of identifying whether the touch / pen is recognized (S1104) and calculating the information in the form of necessary data.

[0169] The system status check step (S1106) can be the system status check step as described above with reference to Figure 12.

[0170] The step (S1107) of determining whether the driving mode of the touch circuit is a low-power mode can be a step of determining whether the driving mode of the touch circuit is a low-power mode based on the above-mentioned basis or other predetermined basis as referenced in FIG12.

[0171] If the driving mode of the touch circuit is normal mode, the step can return to the step of receiving and calculating touch / pen status information (S1105), and the step of receiving and calculating touch / pen status information can be repeated.

[0172] If the driving mode of the touch circuit is low power mode, the step of simplifying touch / pen recognition information can be performed (S1108).

[0173] The step of simplifying touch / pen recognition information (S1108) can be the step of simplifying the communication protocol as described above with reference to Figures 10 and 11.

[0174] Figure 14 is a diagram illustrating the short-circuit handling between channels between touch electrodes in a touch circuit according to an embodiment.

[0175] Referring to Figure 14, the short-circuit method 1200 between channels of the touch circuit may include the following steps: transmitting data by a microprocessor (S1201), receiving data from a digital unit (S1202), issuing commands by the controller of the digital unit (S1203), changing the state of the internal switch of the touch panel (S1204), and short-circuiting the channels of the touch panel (S1205).

[0176] The step of transferring data by the microprocessor (S1201) can be the step of the microprocessor MCU generating data and transferring the data to an external integrated circuit (IC).

[0177] A microprocessor (MCU) can generate signals to control the digitizing unit and transmit these signals to the digitizing unit in a source driver integrated circuit (SRIC). Communication between the microprocessor and the digitizing unit can be achieved via SPI communication.

[0178] The step of receiving data from the digital unit (S1202) may be the step of receiving external control signals or data.

[0179] The step of giving commands by the controller of the digital unit (S1203) may be a step in which the controller of the digital unit (not shown) transmits and commands a control signal for changing the state of a switch (not shown).

[0180] The step (S1204) of changing the state of the internal switch of the touch panel can change the connection relationship between the touch electrodes in accordance with the controller (not shown). For example, the internal switch can selectively open or short-circuit the touch electrodes.

[0181] The step of short-circuiting the channels of the touch panel (S1205) can be a step of selectively short-circuiting the channels defined as touch electrodes or touch electrode groups by operation corresponding to the internal switch of the touch panel.

[0182] Cross-references to related applications

[0183] This application claims priority to Korean Patent Application 10-2021-0102612, filed on August 4, 2021, the entire contents of which are incorporated herein by reference.

[0184] 10:Object 20: Stylus, Pen 100: Display device 110: Panel, Touch Panel 120: Data drive circuit 130: Gate drive circuit 140: Touch circuit 141: Touch driving circuit 142: Touch sensing circuit 150: Control Circuit 200: Touch Sensing System 300: Display device 310: Panel 340: Source readout circuit 341: Analog Unit 342: Digital Unit 360: Microprocessor 361: Touchscreen Calculation Algorithm Circuit 362: Communication Protocol Circuit 370: Power supply circuit 380: Backlight circuit 390: Host 411: First Touch Group 411-1: First touch electrode 411-2: Second touch electrode 411-3: Third touch electrode 411-4: Fourth touch electrode 412: Second Touch Group 413: Third Touch Group 414: Fourth Touch Group 415: Fifth Touch Group 416: Sixth Touch Group 441: Touch driving circuit 442: Touch sensing circuit 445: Multiplexer 445-1: First multiplexer, multiplexer 445-2: Multiplexer 445-3: Multiplexer 445-4: Multiplexer 445-5: Multiplexer 445-6: Multiplexer 511: First Touch Group 511-1: First touch electrode, touch electrode 512: Touch group, second touch group 512-1: Second touch electrode, touch electrode 513: Touch group, third touch group 513-1: Third touch electrode, touch electrode 514: Touch group, fourth touch group 514-1: Fourth touch electrode, touch electrode 515: Touch group, fifth touch group 515-1: Fifth touch electrode, touch electrode 516: Touch group, sixth touch group 516-1: Sixth touch electrode, touch electrode 517: Touch Group 545-1: First multiplexer, multiplexer 545-2: Second multiplexer, multiplexer 545-3: Third multiplexer, multiplexer 545-4: Fourth Multiplexer, Multiplexer 545-5: Fifth multiplexer, multiplexer 545-6: Sixth Multiplexer, Multiplexer 611: Touch electrode, first touch electrode 612: Touch electrode, second touch electrode 613: Touch Electrode 646-1: Switch, First Switch 646-2: Switch, Second Switch 700: Touch Sensing Method 800: Driver Method 900: Driver Method 1000: Pen / Finger Scanning Method 1100: Operating Instructions 1200: Short-circuit method DL: Data Line GL: Gate line L1: First signal line L2: Second signal line MUX: Multiplexer OBJ: Object P: pixel S1001: Steps S1003: Steps S1005: Steps S1007: Steps S1009: Steps S1101: Steps S1102: Steps S1103: Steps S1104: Steps S1105: Steps S1106: Steps S1107: Steps S1108: Steps S1201: Steps S1202: Steps S1203: Steps S1204: Steps S1205: Steps SL: Sensing line SRX: Touch sensing signal STX: Touch drive signal SW: Switch T1: Touch sensing period T2: Touch sensing period T3: Touch sensing period TE: Touch Electrode

Claims

1. A touch circuit, comprising: A touch driving circuit that supplies touch driving signals to the touch electrodes; A touch sensing circuit that senses changes in capacitance of the touch electrodes via touch sensing lines; The circuit includes multiplexers connected to the touch sensing lines, each multiplexer transmitting capacitance changes of the touch electrodes to the touch sensing circuit. Some of the touch electrodes are selectively short-circuited according to the driving mode of the touch circuit, and the touch electrodes are electrically connected to each other via node connections. The multiplexers include a first multiplexer and a second multiplexer. The touch electrodes include a first touch group and a second touch group, the first touch group including a first plurality of touch electrodes, and the second touch group including a second plurality of touch electrodes. In a first driving mode of the touch circuit, the first multiplexer is connected to the first plurality of touch electrodes of the first touch group, and the second multiplexer is connected to the second plurality of touch electrodes of the second touch group. In a second driving mode of the touch circuit, the first multiplexer is connected to the first plurality of touch electrodes of the first touch group, the second multiplexer is not connected to the second plurality of touch electrodes of the second touch group, and each of the first plurality of touch electrodes is connected to a corresponding one of the second plurality of touch electrodes.

2. The touch circuit according to claim 1, wherein, In the second driving mode of the touch circuit, the touch electrode includes a plurality of touch groups, the plurality of touch groups including the first touch group and the second touch group, and the plurality of touch groups are connected to each other by internal switches and wires in the plurality of touch groups.

3. The touch circuit according to claim 1, wherein, When the second driving mode of the touch circuit is a low-power mode, the first touch group and the second touch group are short-circuited.

4. The touch circuit according to claim 1, wherein, In the first driving mode of the touch circuit, the multiplexer is connected to a plurality of touch groups including the touch electrodes, and each multiplexer selects and outputs one of the touch sensing signals transmitted from the plurality of touch groups.

5. The touch circuit according to claim 1, wherein, In the first driving mode, the touch sensing line is connected to the first multiplexer and the second multiplexer, and in the second driving mode, the touch sensing line that was connected to the second multiplexer in the first driving mode is disconnected from the second multiplexer.

6. The touch circuit according to claim 1, wherein, The method of transmitting the touch drive signal to the touch electrode is changed according to the driving mode of the touch circuit.

7. The touch circuit according to claim 1, wherein, When the driving mode of the touch circuit is the second driving mode, the signal received by the touch electrode is a signal related to the position of the object.

8. The touch circuit according to claim 1, wherein, The driving mode of the touch circuit is determined based on the setting value stored in the touch circuit, and the operation of the switch used to determine the connection state of the touch electrode is changed in response to the change of the setting value.

9. A touch circuit, comprising: A touch driving circuit transmits touch driving signals to a first plurality of touch electrodes disposed in a first touch group and a second plurality of touch electrodes disposed in a second touch group via touch driving lines; a touch sensing circuit receives touch signals transmitted from one or more of the first plurality of touch electrodes and the second plurality of touch electrodes; and a multiplexer connected to a plurality of touch sensing lines connected to the touch sensing circuit, each multiplexer selecting and outputting one of the signals transmitted from the plurality of touch sensing lines, wherein a plurality of switches are respectively arranged between the first plurality of touch electrodes in the first touch group and the second plurality of touch electrodes in the second touch group, each of the plurality of switches selectively short-circuiting between the first plurality of touch electrodes and the second plurality of touch electrodes according to the driving mode of the touch circuit; When the driving mode of the touch circuit is low power mode, the multiplexer includes a reference multiplexer and an open-circuit multiplexer. The reference multiplexer is connected to some of the multiple touch sensing lines connected to the first plurality of touch electrodes disposed in the first touch group, and the open-circuit multiplexer is not connected to the multiple touch sensing lines connected to the second plurality of touch electrodes disposed in the second touch group. When the driving mode of the touch circuit is low power mode, each of the plurality of switches forms a short circuit between the first plurality of touch electrodes and the second plurality of touch electrodes, and each of the first plurality of touch electrodes is connected to a corresponding one of the second plurality of touch electrodes. When the driving mode of the touch circuit is low power mode, the reference multiplexer is used to sense changes in the charge of one or more of the first plurality of touch electrodes and the second plurality of touch electrodes.

10. The touch circuit according to claim 9, wherein, Each of the plurality of switches responds to a switch control signal from the microcontroller unit to change the connection state between the first plurality of touch electrodes and the second plurality of touch electrodes, respectively.

11. The touch circuit according to claim 9, wherein, Each of the plurality of switches responds to the timing of the control signals transmitted via serial peripheral interface communication to determine the short-circuit timing of the first plurality of touch electrodes and the second plurality of touch electrodes, respectively.

12. The touch circuit according to claim 9, wherein, When the driving mode of the touch circuit changes from the normal mode to the low power mode, the number of time slots used in a frame is changed.

13. The touch circuit according to claim 9, wherein, When the driving mode of the touch circuit is the low-power mode, the time slots used for pen data communication are switched off.

14. A method for controlling a touch circuit as described in claim 1, comprising: Generate control signals for switches arranged between multiple touch electrodes; The control signal used for switching is transmitted to the readout circuit via a serial peripheral interface communication method; The readout circuit selectively short-circuits the plurality of touch electrodes in response to the control signal for switching.

15. The method according to claim 14, wherein, The first multiplexer and the second multiplexer each select a touch sensing signal and output the touch sensing signal to an external circuit, and wherein, in the second driving mode of the touch circuit, the method further includes transmitting the touch sensing signal to the first multiplexer via the touch sensing line connected between the first multiplexer and the first plurality of touch electrodes of the first touch group when the touch sensing signal is generated in the second plurality of touch electrodes of the second touch group.

16. The method according to claim 14, wherein, The switch changes its operation in response to the driving mode of the touch circuit, and selectively short-circuits the plurality of touch electrodes when the driving mode of the touch circuit is the second driving mode.

17. The method according to claim 14, wherein, The method of transmitting touch drive signals to the plurality of touch electrodes is changed in response to the control signal used for the switch.

18. The method according to claim 17, wherein, When the control signal used for the switch is used to selectively short-circuit the plurality of touch electrodes, the number of time slots used to transmit the touch drive signal to the plurality of touch electrodes is changed.

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