Touch display device, touch driving circuit and touch driving method thereof

Abstract

Embodiments of the present disclosure relate to a touch display device, a touch driving circuit, and a touch driving method, and more particularly, to a touch display device, a touch driving circuit, and a touch driving method for improving the signal-to-noise ratio (SNR) and sensitivity of touch sensing by implementing a code division sensing effect for a self-capacitance sensing scheme.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority from Korean Patent Application No. 10-2019-0179283 filed on December 31, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure relates to a touch display device, a touch driving circuit, and a touch driving method. Background Art

[0004] As the information society develops, various demands on display devices for displaying images increase. Recently, various types of display devices have been utilized, such as liquid crystal display (LCD) devices, plasma display panels (PDP), and organic light emitting display devices.

[0005] Additionally, touch display devices have been utilized that include touch-based input mechanisms implemented in these display devices and allow users to input information or commands intuitively and conveniently relative to typical input mechanisms such as buttons, keyboards, and mice.

[0006] In order for such a touch display device to provide a touch-based input interface, the touch display device is required to have the ability to accurately detect the presence of a touch from a user and detect the touch coordinates.

[0007] Touch display devices typically use a common electrode for driving each pixel as a touch electrode for touch sensing. Therefore, during the display drive period, a common voltage is supplied to the thin film transistor, and during the touch sensing period, a touch drive signal is supplied to the touch electrode.

[0008] To this end, among various types of touch sensing schemes, a capacitance-based touch sensing scheme has been widely used, which includes detecting touch presence, touch coordinates, etc. based on changes in capacitance formed across a plurality of touch electrodes arranged in a display panel.

[0009] Such capacitance-based touch sensing schemes may include a mutual capacitance sensing scheme and a self capacitance sensing scheme.

[0010] In the case of a mutual capacitance sensing scheme, the multiple touch electrodes include: one or more drive electrodes, to which one or more touch drive signals are applied via one or more touch drive lines; and one or more sense electrodes, which are used to sense the one or more touch sense signals via the one or more touch sense lines and form capacitance with the one or more drive electrodes. In this scheme, the presence of a touch, touch coordinates, etc. can be detected based on changes in the mutual capacitance formed between the drive electrode and the sense electrode according to the presence or absence of a pointer such as a finger, an active pen, or a passive pen.

[0011] Meanwhile, in the case of a self-capacitance sensing scheme, each touch electrode serves as both a drive electrode and a sense electrode. That is, a touch drive signal is applied to each touch electrode, and a touch sense signal is received by the touch electrode to which the touch drive signal is applied. In this scheme, the presence of a touch, touch coordinates, and other information can be detected based on changes in the capacitance formed between the touch electrode and a pointer such as a finger, active pen, or passive pen.

[0012] Recently, in a mutual capacitance sensing scheme, in order to improve the signal-to-noise ratio (SNR) and sensitivity of touch sensing, a method has been provided in which a touch drive signal is applied to a drive electrode as a time-varying code-division waveform.

[0013] However, in the case of the self-capacitance sensing scheme, since both the touch driving signal and the touch sensing signal are provided through one touch line connected to one touch electrode, the touch driving signal cannot be applied as various waveforms varying with time. Summary of the Invention

[0014] According to embodiments of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method are provided for enabling improvement of the signal-to-noise ratio (SNR) and sensitivity of touch sensing by implementing a code division sensing effect for a self-capacitance sensing scheme.

[0015] Furthermore, according to embodiments of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method are provided for enabling a code division sensing effect for a self-capacitance sensing scheme to be implemented by sensing a plurality of touch electrodes in a code division form.

[0016] In addition, according to an embodiment of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method are provided, which are used to enable the magnitude and power consumption of a touch driving signal for driving touch electrodes to be reduced by sensing multiple touch electrodes in a code division form.

[0017] In addition, according to an embodiment of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method are provided, which are used to reduce noise and perform stable touch driving by applying a multi-frequency sensing scheme and a self-capacitance sensing scheme in which multiple touch electrodes are sensed in a code division form.

[0018] In addition, according to an embodiment of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method are provided, which are used to effectively prevent saturation of the touch driving circuit by controlling the level of the touch driving signal for driving the touch electrode to a level different from the reference voltage.

[0019] According to one aspect of the present disclosure, a touch display device is provided, which includes: a touch panel, which includes a plurality of touch electrodes and a plurality of touch lines; a multiplexer, which is connected to the touch electrodes through the touch lines and outputs a code-division sensing signal obtained by adding touch sensing signals provided by a plurality of touch electrodes selected by a code-division control signal in a code-division form; and a touch sensing circuit, which calculates the capacitance in the touch electrodes based on the code-division sensing signal from the multiplexer and detects the presence of a touch or touch coordinates.

[0020] The touch panel of the touch display device may allow implementation of self-capacitance sensing, in which a touch drive signal and a touch sensing signal are provided through one touch line connected to one touch electrode.

[0021] The multiplexer of the touch display device may include a plurality of multiplexers, and a plurality of touch electrodes are connected as a group to each multiplexer.

[0022] The touch sensing circuit of the touch display device may include: a preamplifier circuit, which includes: an operational amplifier, which receives a code-division sensing signal through an inverting input terminal and receives a touch drive signal through a non-inverting input terminal; a feedback capacitor, which is connected in parallel between the inverting input terminal and the output terminal of the operational amplifier, and a feedback switch; an integration circuit, which includes multiple switches and multiple capacitors to accumulate the output voltage of the preamplifier circuit; and a sampling circuit, which provides the output signal of the integration circuit at any time.

[0023] The touch driving signal in the touch display device may be one or more sinusoidal wave signals including multiple frequency components.

[0024] A touch driving signal in a touch display device may have a peak-to-peak value different from a no-load driving signal applied to a plurality of touch electrodes through a multiplexer.

[0025] The touch sensing circuit of the touch display device may calculate the capacitance across one or more touch electrodes using the decoded code corresponding to the inverse matrix of the code-division control signal.

[0026] According to another aspect of the present disclosure, there is provided a touch drive circuit including: a multiplexer connected to touch electrodes through touch lines and outputting a code-division sensing signal obtained by adding, in a code-division form, touch sensing signals provided by a plurality of touch electrodes selected by a code-division control signal; and a touch sensing circuit calculating capacitance in the touch electrodes based on the code-division sensing signals from the multiplexer and detecting touch presence or touch coordinates.

[0027] According to another aspect of the present disclosure, a touch driving method is provided, which receives touch sensing signals from multiple touch electrodes arranged in a touch panel and detects the presence of touch or touch coordinates, the method including: applying a code division control signal to a multiplexer connected to the multiple touch electrodes through multiple touch lines; outputting, through the multiplexer, a code division sensing signal obtained by adding, in a code division form, touch sensing signals provided by the multiple touch electrodes selected by the code division control signal; and detecting the presence of touch or touch coordinates by calculating the capacitance in the touch electrodes based on the code division sensing signal from the multiplexer.

[0028] According to another aspect of the present disclosure, a touch display device is provided, the touch display device comprising: a touch panel including a plurality of touch electrodes and a plurality of touch lines; and a touch drive circuit for sensing the touch electrodes through the touch lines. The touch drive circuit includes a first multiplexer, the first multiplexer including n touch line channel ports (n is a natural number greater than or equal to 3), the first multiplexer electrically connected to the n touch electrodes through the n touch lines, and during a first cycle of the touch panel, simultaneously applying touch drive signals to (nk) touch electrodes (k is a number less than n by 1 or more) of the touch electrodes connected to the n touch line channel ports, and simultaneously applying a no-load drive signal having the same phase as the touch drive signal to the k touch electrodes.

[0029] According to embodiments of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method for enabling improvement of the signal-to-noise ratio (SNR) and sensitivity of touch sensing by implementing a code division sensing effect for a self-capacitance sensing scheme may be provided.

[0030] Furthermore, according to embodiments of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method for enabling a code division sensing effect for a self-capacitance sensing scheme to be implemented by sensing a plurality of touch electrodes in a code division form may be provided.

[0031] In addition, according to an embodiment of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method can be provided, which are used to reduce the magnitude and power consumption of a touch driving signal for driving touch electrodes by sensing multiple touch electrodes in a code division form.

[0032] In addition, according to an embodiment of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method can be provided, which are used to reduce noise and perform stable touch driving by applying a multi-frequency sensing scheme and a self-capacitance sensing scheme in which multiple touch electrodes are sensed in a code division form.

[0033] In addition, according to an embodiment of the present disclosure, a touch display device, a touch driving circuit and a touch driving method can be provided, which are used to effectively prevent saturation of the touch driving circuit by controlling the level of the touch driving signal used to drive the touch electrode to a level different from the reference voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A touch display device according to an embodiment of the present disclosure is shown.

[0035] Figure 2 An example of touch driving and sensing operations in a touch display device according to an embodiment of the present disclosure is shown.

[0036] Figure 3 is a plan view illustrating a touch panel in a touch display device to which a self-capacitance sensing scheme is applied according to an embodiment of the present disclosure.

[0037] Figure 4 A method of sensing a touch sensing signal in a code division form in a touch display device according to an embodiment of the present disclosure is shown.

[0038] Figure 5 An example of a cyclic code and a decoding matrix used as a code division control signal in a touch display device according to an embodiment of the present disclosure is shown.

[0039] Figure 6 A touch driving circuit of a touch display device according to an embodiment of the present disclosure is shown.

[0040] Figure 7 is a graph comparing a voltage output from a touch driving circuit when a plurality of touch electrodes are sensed in a code division form in a touch display device according to an embodiment of the present disclosure with a voltage in a typical case.

[0041] Figure 8 An example is shown in which a reference voltage for comparison with a code-division sensing signal in a touch display device according to an embodiment of the present disclosure is composed of sinusoidal waves of multiple frequencies.

[0042] Figure 9 A touch driving circuit according to an embodiment of the present disclosure is shown when a reference voltage of a preamplifier circuit different from a peak-to-peak value of a touch driving signal is applied in a touch display device. DETAILED DESCRIPTION

[0043] In the following description of examples or embodiments of the invention, reference will be made to the accompanying drawings in which specific examples or embodiments that may be implemented are shown by way of illustration, and in the accompanying drawings, the same reference numerals may be used to designate the same or similar components even if those reference numerals are shown in different drawings from one another. In addition, in the following description of examples or embodiments of the invention, when it is determined that a detailed description of well-known functions and components herein may make the subject matter of certain embodiments of the invention rather unclear, that description will be omitted. Terms such as "including," "having," "comprising," "consisting of," "composed of," and "formed" as used herein are generally intended to allow for the addition of additional components unless the term is used with the term "only." As used herein, the singular is intended to include the plural unless the context clearly indicates otherwise.

[0044] Terms such as "first," "second," "A," "B," "(A)," or "(B)" may be used herein to describe elements of the present invention. Each of these terms is not used to define the nature, order, sequence, or quantity of the elements, but is only used to distinguish the corresponding element from other elements.

[0045] When it is mentioned that a first element is “connected or coupled”, “contacting or overlapping”, etc. with a second element, it should be interpreted that not only the first element can be “directly connected or coupled” or “directly contacting or overlapping” with the second element, but also a third element can be “interposed” between the first and second elements, or the first and second elements can be “connected or coupled”, “contacting or overlapping” each other via a fourth element, etc. Here, the second element can be included in at least one of the two or more elements that are “connected or coupled”, “contacting or overlapping”, etc. with each other.

[0046] When time relative terms such as “after,” “successively after,” “next,” “before,” etc. are used to describe a process or operation of an element or construction, or a flow or step in an operation, process, or manufacturing method, these terms may be used to describe non-sequential or non-sequential processes or operations unless used with the terms “directly” or “immediately.”

[0047] Furthermore, when referring to any dimension, relative size, etc., it should be considered that the numerical value of the element or feature or corresponding information (e.g., level, range, etc.) includes a tolerance or error range that may be caused by various factors (e.g., process factors, internal or external influences, noise, etc.), even if no relevant description is specified. In addition, the term "may" fully encompasses all meanings of the term "can."

[0048] Figure 1 A touch display device according to an embodiment of the present disclosure is shown.

[0049] refer to Figure 1 , the display device 100 according to an embodiment of the present disclosure may have a function of displaying an image and a function of sensing a touch from a user or a conductive object.

[0050] To simultaneously implement both image display and touch sensing functions, the touch display device 100 may include: a display panel 110 on which a plurality of data lines and a plurality of gate lines are arranged; a display driving circuit 120 for driving the display panel 110; and the like.

[0051] In terms of functions, the display driving circuit 120 may include: a data driving circuit for driving data lines; a gate driving circuit for driving gate lines; a controller for controlling the data driving circuit and the gate driving circuit; etc. The display driving circuit 120 may be implemented as one or more integrated circuits.

[0052] The touch display device 100 may include: a touch panel TSP on which a plurality of touch electrodes TE for touch sensing are arranged; a touch driving circuit 200 for driving the touch panel TSP and processing touch sensing; and the like.

[0053] The touch panel TSP in the touch display device 100 may be an external type in which the touch panel TSP is manufactured separately from the display panel 110 and then bonded to the display panel 110, or the touch panel TSP may be an embedded type in which the touch panel TSP is manufactured together with the display panel 110 when the display panel 110 is manufactured and located inside the display panel 110.

[0054] Therefore, the touch panel TSP in the touch display device 100 according to an embodiment of the present disclosure may be an independent panel having a touch sensing function, or may represent a display panel 110 having both a display function and a touch sensing function.

[0055] To drive the display panel 110 , the touch driving circuit 200 may provide a touch driving signal to the display panel 110 , receive a touch sensing signal from the display panel 110 , and detect touch presence or touch coordinates based thereon.

[0056] The touch driving circuit 200 may include a touch sensing circuit that provides a touch driving signal and receives a touch sensing signal, and a touch controller that detects touch presence or touch coordinates.

[0057] The touch driving circuit 200 may be implemented as one or more components (eg, one or more integrated circuits), or may be implemented separately from the display driving circuit 120 .

[0058] In addition, all or at least a portion of the touch driving circuit 200 may be implemented by integrating with the display driving circuit 120 or a circuit within the display driving circuit 120. For example, the touch sensing circuit of the touch driving circuit 200 may be implemented as an integrated circuit by integrating with the data driving circuit of the display driving circuit 120.

[0059] Meanwhile, the touch display device 100 may sense touch presence or touch coordinates based on capacitance formed by the touch electrodes TE.

[0060] The touch display device 100 may sense a touch using a mutual capacitance sensing scheme or a self capacitance sensing scheme as a capacitance-based touch sensing scheme.

[0061] In the case of a mutual capacitance sensing scheme, the plurality of touch electrodes TE may include: a driving electrode to which a touch sensing signal is applied via a driving line; and a sensing electrode configured to provide a sensing signal via a sensing line and form a capacitance with the driving electrode. Here, the driving line and the sensing line may be referred to as a touch line TL.

[0062] In case of a mutual capacitance sensing scheme, touch presence and touch coordinates may be detected based on a change in mutual capacitance formed between a driving electrode and a sensing electrode according to the presence or absence of a pointer such as a finger, a pen, or the like.

[0063] In the case of a self-capacitance sensing scheme, each touch electrode serves as both a drive electrode and a sense electrode. That is, a touch drive signal is applied to the touch electrode TE via a touch line, and a touch sense signal provided from the touch electrode to which the touch drive signal was applied is received via the same touch line. Therefore, in the case of a self-capacitance sensing scheme, there is no distinction between drive electrodes and sense electrodes, or between drive lines and sense lines.

[0064] In case of a self-capacitance sensing scheme, touch presence and touch coordinates may be detected based on a change in capacitance formed between a pointer such as a finger, a pen, etc., and a touch electrode.

[0065] Therefore, the touch display device 100 may sense a touch using a mutual capacitance sensing scheme or a self capacitance sensing scheme.

[0066] In addition, the touch display device 100 may be various types of display devices, such as a liquid crystal display device, an organic light emitting display device, a plasma display panel, a quantum dot display, and the like.

[0067] For example, when the touch display device 100 according to an embodiment of the present disclosure is a liquid crystal display device, the plurality of touch electrodes TE may be arranged on the display panel 110 and be common electrodes to which a common voltage for display driving is applied.

[0068] Figure 2 An example of touch driving and sensing operations in a touch display device according to an embodiment of the present disclosure is shown.

[0069] refer to Figure 2 , the touch display device 100 according to an embodiment of the present disclosure includes: a plurality of touch electrodes TE, which serve as touch sensors providing a touch sensing function; a touch driving circuit 200, which senses touch by sequentially driving the touch electrodes TE; and the like.

[0070] The touch driving circuit 200 may detect touch presence and touch coordinates by sequentially driving and sensing the plurality of touch electrodes TE in a touch sensing period in which touch sensing is performed.

[0071] More specifically, the touch drive circuit 200 can select one or more of the plurality of touch electrodes TE as touch electrodes TE to be sensed, and provide a touch drive signal TDS to the selected touch electrodes TEs. Thereafter, the touch drive circuit 200 can detect the presence of a touch or touch coordinates by determining a capacitance change (or voltage change, charge amount change, etc.) of each touch electrode TE based on the touch sensing signal TSS received from each selected touch electrode TEs and each unselected touch electrode TEo.

[0072] The touch drive circuit 200 may include, for example: a touch controller 220, which controls the generation of signals related to touch sensing and performs a process for detecting the presence of touch and calculating touch coordinates; a touch sensing circuit 210, which provides a touch drive signal TDS to the display panel 110, detects a touch sensing signal TSS from the touch electrode TE to which the touch drive signal TDS is provided, and provides the detected signal to the touch controller 220, etc.

[0073] Here, a touch sensing period in which touch sensing is performed may be temporally separated from a display driving period in which an image is displayed on the display panel 110 , or performed simultaneously with the display driving period.

[0074] In addition, by providing an AC signal having the same phase and amplitude as the touch drive signal TDS to at least one data line and at least one gate line of the display panel 110 during the touch sensing period, a no-load drive for reducing a parasitic capacitance formed by at least one touch electrode TE can be performed, and in this case, the touch drive signal TDS can correspond to a no-load drive signal.

[0075] Figure 3 A touch panel in a touch display device to which a self-capacitance sensing scheme is applied according to an embodiment of the present disclosure is illustrated.

[0076] refer to Figure 3 According to an embodiment of the present disclosure, a touch display device 100 to which a self-capacitance sensing scheme is applied includes: a display panel 110 on which a plurality of touch electrodes TE and a plurality of touch lines TL are arranged; and a touch driving circuit 200, which provides a touch driving signal TDS to the touch electrodes TE and receives a touch sensing signal TSS from the touch electrodes TE.

[0077] The touch display device 100 may include an active area AA in which a plurality of touch electrodes (TE11-TE54) are arranged and an inactive area outside the active area AA, such as a frame area BA. The touch driving circuit 200 is located on the inactive area.

[0078] Here, an example of the touch electrodes TE being arranged in 5 rows and 4 columns in the display panel 110 is discussed; however, this is merely an example for ease of description. For example, the touch electrodes TE may be arranged in various structures in the display panel 110.

[0079] A plurality of touch electrodes (TE11-TE54) are arranged in a first direction x and a second direction y intersecting the first direction x in the active area AA, and a plurality of touch lines (TL11-TL54) are respectively connected to the plurality of touch electrodes (TE11-TE54). The plurality of touch lines (TL11-TL54) extend from the active area AA to the frame area BA in the second direction y and are connected to the touch drive circuit 200.

[0080] More specifically, the 1-1 touch line TL11 is connected to the touch electrode TE11 in the first row and the first column. The 1-1 touch line TL11 extends from the active area AA to the border area BA in the second direction y and is connected to the touch drive circuit 200. In addition, the 2-1 touch line TL21 is connected to the touch electrode TE21 in the second row and the first column. The 2-1 touch line TL21 extends from the active area AA to the border area BA in parallel with the 1-1 touch line and is connected to the touch drive circuit 200. Similarly, the 3-1 touch line TL31 connected to the touch electrode TE31 in the third row and the first column, the 4-1 touch line TL41 connected to the touch electrode TE41 in the fourth row and the first column, and the 5-1 touch line TL51 connected to the touch electrode TE51 in the fifth row and the first column extend from the active area AA to the border area BA in parallel with the 1-1 touch line TL11 and the 2-1 touch line TL21 and are connected to the touch drive circuit 200.

[0081] Similarly, the touch electrode TE12 in the first row and the second column to the touch electrode TE52 in the fifth row and the second column arranged in the second column are respectively connected to the 1-2 touch line TL12 to the 5-2 touch line TL52. The 1-2 touch line TL12 to the 5-2 touch line TL52 extend parallel to each other from the active area AA to the border area BA and are connected to the touch drive circuit 200.

[0082] In addition, the touch electrode TE13 in the first row and third column to the touch electrode TE53 in the fifth row and third column arranged in the third column are also connected to the 1-3 touch line TL13 to the 5-3 touch line TL53, respectively. The 1-3 touch line TL13 to the 5-3 touch line TL53 extend parallel to each other from the active area AA to the border area BA and are connected to the touch drive circuit 200.

[0083] In addition, the touch electrode TE14 in the first row and fourth column to the touch electrode TE54 in the fifth row and fourth column arranged in the fourth column are also connected to the 1-4 touch line TL14 to the 5-4 touch line TL54, respectively. The 1-4 touch line TL14 to the 5-4 touch line TL54 extend parallel to each other from the active area AA to the border area BA and are connected to the touch drive circuit 200.

[0084] Such a touch display device 100 can be implemented as an organic light-emitting display device. The organic light-emitting display device includes a plurality of sub-pixels defined by a plurality of gate lines and a plurality of data lines. Each sub-pixel includes a self-luminous organic light-emitting diode (OLED), and the organic light-emitting diode (OLED) includes an anode electrode, a cathode electrode, and an organic compound layer interposed therebetween. The organic compound layer may also include a hole-related layer, an electron-related layer, and an emission layer. The hole-related layer may include a hole injection layer HIL and a hole transport layer HTL, and the electron-related layer may include an electron injection layer EIL and an electron transport layer ETL.

[0085] In the case where the touch display device 100 according to an embodiment of the present disclosure is an organic light emitting display device, the display panel 110 may have a top emission structure in which light is guided to travel upward or a bottom emission structure in which light is guided to travel downward.

[0086] In the case of the touch display device 100 as an organic light emitting display device, a plurality of touch electrodes TE are included in the display panel 110 and can be arranged on an encapsulation layer located above transistors and organic light emitting diodes. This arrangement of touch electrodes TE may be more suitable for a top emission structure.

[0087] In the case of the touch display device 100 as an organic light-emitting display device, multiple touch electrodes TE can be arranged on the substrate of the display panel 110, on which thin film transistors (TFTs) are provided. For example, the multiple touch electrodes TE can be anode electrodes of an organic light-emitting diode included in the display panel 110, electrodes formed on the same layer as the anode electrode, or electrodes on at least one of various layers located above or below the anode. In this way, a configuration in which the touch electrodes TE are arranged on a substrate on which thin film transistors are formed is more suitable for a case in which the display panel 110 has a bottom emission structure.

[0088] To improve the luminous efficiency of the sub-pixels SP, the multiple touch electrodes TE included in the touch display device 100 according to an embodiment of the present disclosure can be formed into a plate type without openings or a grid type with openings. The multiple touch electrodes TE can be transparent electrodes, or one or more transparent electrodes can be included to improve the luminous efficiency of the sub-pixels SP. The multiple touch electrodes TE included in the touch display device 100 according to an embodiment of the present disclosure can be dedicated electrodes for touch sensing, or can be electrodes used for both display driving and touch sensing.

[0089] According to an embodiment of the present disclosure, a touch display device, a touch driving circuit, and a touch driving method are provided, which can reduce power consumption and sensing time by sensing touch sensing signals TSS provided from multiple touch electrodes TE through multiple touch lines TL in a code division form in a self-capacitance sensing scheme.

[0090] Figure 4 A method of sensing a touch sensing signal in a code division form in a touch display device according to an embodiment of the present disclosure is shown.

[0091] refer to Figure 4 The touch display device 100 according to an embodiment of the present disclosure uses a self-capacitance sensing scheme, and each touch electrode TE functions as both a drive electrode and a sense electrode. That is, by applying a touch drive signal TDS to the touch electrode TE via a touch line TL and receiving a touch sense signal TSS provided from the touch electrode TE to which the touch drive signal TDS has been applied via the same touch line TL, the touch display device 100 can detect the presence of a touch, touch coordinates, etc. based on changes in capacitance formed between a pointer such as a finger or pen and the touch electrode TE.

[0092] The plurality of touch electrodes TE are connected to one multiplexer MUX through corresponding touch lines TL, and a touch sensing signal TSS from the touch electrode TE connected to the touch line TL selected by the multiplexer MUX is provided to a sensing unit of the touch sensing circuit 210 .

[0093] To this end, the multiplexer MUX may include a plurality of touch line channel ports TLP to which the plurality of touch lines TL are connected to be electrically connected with the plurality of touch electrodes TE.

[0094] In the touch display device 100 according to an embodiment of the present disclosure, by controlling the multiplexer MUX connected to the plurality of touch electrodes TE using mutually orthogonal signals over time, the code-division sensing signal can be provided to the touch sensing circuit 210 through the multiplexer MUX.

[0095] For example, assume that four touch electrodes (TE11, ..., TE41) corresponding to the first to fourth touch electrodes TE11 to TE41 and arranged in the first column are distributed and connected to the touch line channel ports (TLP11, ..., TLP41) of the 4X1 multiplexer MUX through 4 touch lines TL.

[0096] The multiplexer MUX is connected to the four touch electrodes (TE11, ..., TE41), and during the touch sensing period, the touch drive signal TDS is applied to the touch electrodes (TE11, ..., TE41) through the multiplexer MUX. According to the control of the multiplexer MUX, the touch sensing signal TSS generated from the four touch electrodes (TE11, ..., TE41) is provided to the touch sensing circuit 210.

[0097] Here, the touch electrodes TE to which the touch driving signal TDS is applied and the touch electrodes TE receiving the touch sensing signal TSS therefrom through the multiplexer MUX are controlled with code division mode signals over time.

[0098] For example, by applying the code division control signal CD_MUX of [0, 1, 1, 1] to the multiplexer MUX during the first time period T1, the touch drive signal TDS may be applied to the first touch electrode TE11 and the touch sensing signal TDS provided from the second touch electrode TE21 to the fourth touch electrode TE41 may be provided to the touch sensing circuit 210. Here, the code division control signal CD_MUX of "0" applied to the multiplexer MUX is a control signal for applying the touch drive signal TDS to the corresponding touch line TL, and the code division control signal CD_MUX of "1" applied to the multiplexer MUX corresponds to a control signal for providing the touch sensing signal TSS from the corresponding touch line TL to the touch sensing circuit 210.

[0099] Accordingly, when the code division control signal of [0, 1, 1, 1] is applied to the multiplexer MUX during the first time period Tl, the sum of the touch sensing signals TSS provided from the second touch electrode TE21 to the fourth touch electrode TE41 is output as the code division sensing signal CDS of the multiplexer MUX and provided to the touch sensing circuit 210.

[0100] At this time, if the self-capacitances formed by the first to fourth touch electrodes TE11 to TE41 are respectively referred to as Cs1 to Cs4, the code division sensing signal CDS1 provided to the touch sensing circuit 210 through the multiplexer MUX during the first time period T1 may be (Cs2+Cs3+Cs4)×Vex. Here, Vex is the peak-to-peak value of the touch drive signal TDS.

[0101] After the first time period T1 in which the code division control signal CD_MUX of [0, 1, 1, 1] has been applied to the multiplexer MUX, a code division control signal CD_MUX of [1, 0, 1, 1] orthogonal to the code division control signal CD_MUX in the first time period T1 can be applied to the multiplexer MUX during the second time period T2.

[0102] As a result, the sum of the touch sensing signals TSS provided from the first touch electrode TE11, the third touch electrode TE31, and the fourth touch electrode TE41 through the multiplexer MUX during the second time period T2 is provided to the touch sensing circuit 210 as the code division sensing signal CDS of the multiplexer MUX. Therefore, the code division sensing signal CDS2 provided to the touch sensing circuit 210 through the multiplexer MUX during the second time period T2 may become (Cs1+Cs3+Cs4)×Vex.

[0103] Furthermore, during the third time period T3 , a code division control signal CD_MUX of [1, 1, 0, 1] orthogonal to the code division control signal CD_MUX in the second time period T2 may be applied to the multiplexer MUX.

[0104] As a result, the sum of the touch sensing signals TSS provided from the first touch electrode TE11, the second touch electrode TE21, and the fourth touch electrode TE41 through the multiplexer MUX during the third time period T3 is provided to the touch sensing circuit 210 as the code division sensing signal CDS of the multiplexer MUX. Therefore, the code division sensing signal CDS3 provided to the touch sensing circuit 210 through the multiplexer MUX during the third time period T3 may become (Cs1+Cs2+Cs4)×Vex.

[0105] Furthermore, during the fourth time period T4 , a code division control signal CD_MUX of [1, 1, 1, 0] orthogonal to the code division control signal CD_MUX in the third time period T3 may be applied to the multiplexer MUX.

[0106] As a result, the sum of the touch sensing signals TSS provided from the first touch electrode TE11, the second touch electrode TE21, and the third touch electrode TE31 through the multiplexer MUX during the fourth time period T4 is provided to the touch sensing circuit 210 as the code division sensing signal CDS of the multiplexer MUX. Therefore, the code division sensing signal CDS4 provided to the touch sensing circuit 210 through the multiplexer MUX during the fourth time period T4 may become (Cs1+Cs2+Cs3)×Vex.

[0107] Therefore, the code-division sensing signal provided to the touch sensing circuit 210 through the multiplexer MUX during the first to fourth time periods T1 to T4 is represented as follows.

[0108] CDS1=(Cs2+Cs3+Cs4)×Vex

[0109] CDS2=(Cs1+Cs3+Cs4)×Vex

[0110] CDS3=(Cs1+Cs2+Cs4)×Vex

[0111] CDS4=(Cs1+Cs2+Cs3)×Vex

[0112] These can be expressed as matrices as follows, and the code division control signal (CD_MUX) can be regarded as a coding matrix with an orthogonal relationship.

[0113]

[0114] Therefore, the self-capacitances of the first to fourth touch electrodes TE11 to TE41 may be calculated as follows.

[0115]

[0116] That is, the self-capacitance of the first touch electrode TE11 to the fourth touch electrode TE41 can be calculated based on the peak-to-peak value Vex of the touch drive signal TDS provided to the touch sensing circuit 210 during the corresponding time period (T1, ..., T4), the magnitude of the code division sensing signal (CDS1, ..., CDS4), and the inverse matrix of the code division control signal CD_MUX.

[0117] In particular, the inverse matrix of the code division control signal CD_MUX corresponds to a Hadamard matrix as a decoding matrix for calculating the self-capacitance of the touch electrodes (TE11, ..., TE41), and the value of its main diagonal (from the upper left to the lower right) is -2. The Hadamard matrix is ​​a square matrix in which all components have values ​​of +1 or -1, and any two row vectors are orthogonal to each other. Since the value of the main diagonal is -2, the value corresponding to -2 can be obtained by shifting a bit by one in the binary base.

[0118] Therefore, by using the inverse matrix of the code division control signal CD_MUX as a decoding matrix, the self-capacitance (Cs1, ..., Cs4) of the corresponding touch electrodes (TE11, ..., TE41) can be easily obtained from the code division sensing signals (CDS1, ..., CDS4) provided to the touch sensing circuit 210 over time.

[0119] That is, by applying code division control signals CD_MUX that are orthogonal to each other over time to a multiplexer MUX connected to a plurality of touch electrodes (TE11, ..., TE41), and sensing the touch sensing signals TSS generated from the touch electrodes (TE11, ..., TE41) in a code division scheme, the self-capacitances (Cs1, ..., Cs4) of the corresponding touch electrodes (TE11, ..., TE41) can be easily calculated based on this.

[0120] As a result, since the magnitude of the code division sensing signal CDS provided to the touch sensing circuit 210 through the multiplexer MUX can be increased, the signal-to-noise ratio can be improved and the sensitivity of touch sensing can be increased even when a self-capacitance sensing scheme is used.

[0121] In addition, since the code division sensing signal CDS provided to the touch sensing circuit 210 through the multiplexer MUX is based on the sum of the touch sensing signals TSS provided from the plurality of touch electrodes TE, even if the peak-to-peak value of the touch drive signal TDS is reduced, the sensitivity of touch sensing can be maintained or increased; thus, the advantage of reducing the power consumption of the touch display device 100 can be provided.

[0122] Furthermore, since the plurality of touch electrodes TE are sensed simultaneously, even if noise is included in the touch sensing signal TSS, the noise can be easily removed from the code-division sensing signal CDS, and there is an effect of reducing a sensing difference between the touch electrodes TE.

[0123] In addition, when the touch electrodes TE arranged in separate positions are individually sensed, the loads of the touch electrodes differ depending on the distances spaced apart from the touch drive circuit 200, and therefore, there is a problem of a difference caused by a time delay in providing the touch drive signal TDS or the touch sensing signal TSS. However, since the touch display device 100 herein simultaneously senses the touch electrodes TE having different loads while simultaneously sensing a plurality of touch electrodes TE, an effect of reducing the difference caused by the time delay can be produced.

[0124] The touch display device 100 according to an embodiment of the present disclosure can simultaneously apply a touch drive signal TDS to a preconfigured number of touch electrodes TE selected for touch sensing among a plurality of touch electrodes TE connected to one multiplexer MUX through the touch lines TL during a first time period T1. In addition, a no-load drive signal can be simultaneously applied to at least one touch electrode TE that does not perform touch sensing among the plurality of touch electrodes TE connected to the multiplexer MUX through at least one touch line TL.

[0125] In addition, a no-load driving signal may be applied to at least one of the plurality of touch electrodes TE connected to the multiplexer MUX to which the touch driving signal TDS has been applied in the first time period T1 during the second time period T2. In addition, the touch display device 100 according to an embodiment of the present disclosure may apply the touch driving signal TDS to at least one of the plurality of touch electrodes TE connected to the multiplexer MUX to which the no-load driving signal has been applied in the first time period T1 during the second time period T2.

[0126] In other words, a plurality of touch electrodes TE can be sensed simultaneously by one multiplexer MUX, and while the number of touch electrodes TE to be sensed is maintained at a predetermined number, sensing can be performed while changing the touch electrodes TE to be sensed. In addition, since the touch electrodes TE to be sensed are changed, the accuracy of touch sensing can be improved by applying a no-load drive signal to at least one touch electrode TE on which sensing is not performed.

[0127] Here, the touch drive signal TDS and the no-load drive signal may have different amplitudes. For example, the amplitude of the touch drive signal TDS may be 1V, and the amplitude of the no-load drive signal may be 3V. For another example, the amplitude of the touch drive signal TDS may be 1V, and the amplitude of the no-load drive signal may be 0.5V.

[0128] In addition, the touch display device 100 according to an embodiment of the present disclosure may further include a display panel 110, which includes a plurality of data lines and a plurality of gate lines. During a first time period T1 in the touch display device 100, a gate no-load drive signal having the same phase as the touch drive signal may be applied to the gate lines overlapping the plurality of touch electrodes TE to which the touch drive signal TDS is applied. Furthermore, during the first time period T1 in the touch display device 100, a data no-load drive signal having the same phase as the touch drive signal may be applied to the data lines overlapping the plurality of touch electrodes TE to which the touch drive signal TDS is applied.

[0129] Here, the touch drive signal TDS and the gate no-load drive signal may have different amplitudes. For example, the amplitude of the touch drive signal TDS may be 1V, and the amplitude of the gate no-load drive signal may be 3V. For example, the amplitude of the touch drive signal TDS may be 1V, and the amplitude of the gate no-load drive signal may be 0.5V.

[0130] Here, the touch drive signal TDS and the data no-load drive signal may have different amplitudes. For example, the amplitude of the touch drive signal TDS may be 1V, and the amplitude of the data no-load drive signal may be 3V. For example, the amplitude of the touch drive signal TDS may be 1V, and the amplitude of the data no-load drive signal may be 0.5V.

[0131] Meanwhile, the Hadamard matrix has a structure of 2×2, 4×4, 8×8, or 16×16. In some instances, a 10×1 multiplexer MUX may be used depending on the type of the touch display device 100. In this case, it may be difficult to use the Hadamard matrix to calculate the self-capacitances (Cs1, ..., Cs4) of the corresponding touch electrodes (TE1, ..., TE4) based on the code division sensing signals CDS.

[0132] In this way, when the multiplexer MUX having the same structure as the Hadamard matrix is ​​not used, the self-capacitance Cs of the touch electrode TE can be easily calculated by using the cyclic code as the code division control signal CD_MUX.

[0133] Figure 5 An example of a cyclic code and a decoding matrix used as a code division control signal in a touch display device according to an embodiment of the present disclosure is shown.

[0134] refer to Figure 5 The touch display device 100 according to an embodiment of the present disclosure can use code division control signals CD_MUX that are orthogonal to each other as an encoding matrix to control the operation of the multiplexer MUX connected to the plurality of touch electrodes TE, and use an inverse matrix of the code division control signal CD_MUX as a decoding matrix, which is used to calculate the self-capacitance Cs of the touch electrode TE based on the code division sensing signal CDS provided from the multiplexer MUX by the code division control signal CD_MUX.

[0135] Here, since the number of multiplexers connected to the touch electrode TE may differ depending on the type of the touch display device 100, when the number of multiplexers MUX corresponds to a Hadamard matrix, the Hadamard matrix may be used as a decoding matrix; when the number of multiplexers MUX does not correspond to the Hadamard matrix, the decoding matrix may be configured to be similar to the Hadamard matrix by configuring the code division control signal CD_MUX applied to the multiplexer MUX as a cyclic code.

[0136] That is, when the code division control signal CD_MUX is configured as Figure 5 For the 10×10 cyclic code shown in (a), the inverse matrix of the cyclic code has the following formula: Figure 5 (b) The structure shown.

[0137] At this time, the value 5 other than 1 in the inverse matrix of the cyclic code can be obtained by adding the value shifted by 2 bits based on the binary number system (the value increased by 4) to its own value, and 19 can be obtained by adding the value shifted by 4 bits based on the binary number system (the value increased by 16) and the value shifted by 1 bit (the value increased by 2) to its own value.

[0138] In this way, even when the number of multiplexers MUX does not correspond to the Hadamard matrix, the self-capacitance Cs can be effectively calculated from the code-division sensing signal CDS provided by the multiplexer MUX when the code-division control signal CD_MUX is configured as a cyclic code.

[0139] Figure 6 A touch driving circuit of a touch display device according to an embodiment of the present disclosure is shown.

[0140] refer to Figure 6 , the touch driving circuit 200 of the touch display device 100 according to an embodiment of the present disclosure may perform touch sensing using a switched capacitor circuit in a charge transfer method.

[0141] The touch driving circuit 200 may include a multiplexer MUX, a preamplifier circuit (PreAmp, 212 ), an integration circuit 214 , a sampling circuit 216 , and a charge remover 218 .

[0142] An analog-to-digital converter ADC for converting the sense voltage Sout into a digital value may be connected to an output terminal of the sampling circuit 216 .

[0143] The multiplexer MUX is connected to the plurality of touch electrodes TE arranged in the display panel 110 through the plurality of touch lines TL, and adds the plurality of touch sensing signals (TSS1, ..., TSSn) provided from the plurality of touch electrodes TE through the plurality of touch line channel ports (TLP1, ..., TLPn) in a code-division form by the code-division control signal CD_MUX which is orthogonal to each other over time, and then outputs them as the code-division sensing signal CDS.

[0144] The preamplifier circuit 212 may include an operational amplifier that receives the code-division sensing signal CDS via its inverting input terminal (-), a feedback capacitor Cfb connected in parallel between the inverting input terminal (-) and an output terminal of the operational amplifier, and a feedback switch SWfb. A reference voltage Vref for comparison with the code-division sensing signal CDS is applied to the non-inverting input terminal (+) of the operational amplifier, and an output voltage Vout1 from the preamplifier circuit 212 is provided to the integration circuit 214.

[0145] At this time, the reference voltage Vref applied to the operational amplifier of the preamplifier circuit 212 can be a sine wave or a square wave in the form of a pulse with a constant frequency. Here, the peak-to-peak value Vp of the reference voltage Vref can be equal to or different from the peak-to-peak value Vex of the touch drive signal TDS.

[0146] The integration circuit 214 may include a plurality of switches and at least one capacitor to accumulate the output voltage Vout1 from the preamplifier circuit 212 , and the switches and the capacitors may be changed into various structures.

[0147] The sampling circuit 216 may include a capacitor for charging the output signal Vout2 from the integration circuit 214 , and provides the voltage charged in the capacitor as the sensing voltage Vout to the analog-to-digital converter ADC by controlling at least one switch inside the sampling circuit.

[0148] Furthermore, the touch drive circuit 200 may include a charge remover 218 to remove initial charge remaining in the inverting input terminal (-) of the preamplifier circuit 212. When the number of touch electrodes TE or the capacitance of the touch electrodes TE increases due to a large display panel 110, the output voltage Vout1 of the preamplifier circuit 212 increases; therefore, the touch drive circuit 200 may saturate beyond a specified range. In this case, the charge remover 218 for removing saturated charge may be connected to the front of the preamplifier circuit 212.

[0149] The charge remover 218 may be implemented as a structure in which a plurality of capacitors Ccr are connected in parallel to each other, and a charge removing pulse voltage Vcr may be applied to the plurality of capacitors Ccr.

[0150] Figure 7 is a graph comparing a voltage output from a touch driving circuit when a plurality of touch electrodes are sensed in a code division form in a touch display device according to an embodiment of the present disclosure with a voltage in a typical case.

[0151] refer to Figure 7 In the touch display device 100 according to an embodiment of the present disclosure, when the touch sensing signals TSS generated from the plurality of touch electrodes TE in a code-division form are sensed and the code-division sensing signal CDS is generated, since the touch sensing signals TSS generated from the plurality of touch electrodes TE are added in a code-division form, even if a lower peak-to-peak value Vex of the touch drive signal TDS applied to the display panel 110 is set, a sensing signal Vout equal to that in the case of sensing the touch sensing signal TSS from one touch electrode TE can be obtained.

[0152] For example, Figure 7 (a) shows a typical case when the peak-to-peak value Vex of the touch drive signal TDS is set to 3 V. The touch sensing signal TSS provided from one touch electrode TE is amplified to Vout1 by the preamplifier circuit 212. The amplified signal Vout1 is accumulated by the integration circuit 214 and provided as the output signal Vout2.

[0153] on the contrary, Figure 7 (b) shows that when the peak-to-peak value Vex of the touch drive signal TDS is set to correspond to Figure 7 In the case of 1 / 3 of the voltage in the typical case shown in (a), the touch sensing signals TSS provided from the four touch electrodes (TE1, ..., TE4) are added in a code-division form over time, and the code-division sensing signal CDS is generated.

[0154] like Figure 7As shown in FIG. 2( b ), in the touch display device 100 according to an embodiment of the present disclosure, when the touch sensing signals TSS provided from the four touch electrodes (TE1, ..., TE4) are added in a code-division manner and then the code-division sensing signal CDS is generated, it can be seen that the signal Vout1 output from the preamplifier circuit 212 increases by approximately three times compared to a typical case. It can be understood that this is because the code-division sensing signal CDS is generated by adding all the touch sensing signals TSS provided from the three touch electrodes TE within one time period.

[0155] Here, it should be noted that although the peak-to-peak value Vex of the touch drive signal TDS applied in the touch display device 100 according to the embodiment of the present disclosure is 1V, in a typical case the peak-to-peak value Vex of the touch drive signal TDS is 3V; therefore, the voltage Vout2 accumulated by the integration circuit 214 has a difference of approximately three times.

[0156] However, in the case of the touch display device 100 according to an embodiment of the present disclosure, since the code division sensing signal CDS provided by the multiplexer MUX has a value approximately 3 times larger than that of a typical case in which the touch sensing signal TSS is received from one touch electrode TE, even if the peak-to-peak value Vex of the touch drive signal TDS has a level of 1 / 3 of the value corresponding to the typical case, the sensing voltage Vout output by the touch drive circuit 200 during the same time period shows almost the same value.

[0157] In this way, in the touch display device 100 according to an embodiment of the present disclosure, since the peak-to-peak value Vex of the touch drive signal TDS is configured to be reduced, the sensing voltage Vout of the touch drive circuit 200 is increased while reducing power consumption, and thus, the effect of obtaining excellent touch sensing sensitivity can be provided.

[0158] Furthermore, by generating the code division sensing signal CDS by code-divisionally adding the touch sensing signals TSS provided from the plurality of touch electrodes TE, a signal-to-noise ratio may be improved and a difference between the touch sensing signal TSS and a sensing time may be reduced.

[0159] Meanwhile, in the touch display device 100 according to an embodiment of the present disclosure, by using sine waves of various frequencies as the reference voltage Vref compared to the code division sensing signal CDS at the preamplifier circuit 212, noise generated due to harmonic components can be reduced while avoiding noise in a specific frequency band.

[0160] Figure 8 An example is shown in which a reference voltage for comparison with a code-division sensing signal in a touch display device according to an embodiment of the present disclosure is composed of sinusoidal waves of multiple frequencies.

[0161] refer to Figure 8 In the touch display device 100 according to an embodiment of the present disclosure, the code division sensing signal CDS provided to the preamplifier circuit 212 is compared with the reference voltage Vref applied to the non-inverting input terminal (+) of the operational amplifier. In this case, a pulsed square wave or a sine wave of multiple frequencies may be applied as the reference voltage Vref.

[0162] For example, the reference voltage Vref applied to the non-inverting input terminal (+) of the operational amplifier can be composed of sine waves of different frequencies (f1, f2, f3, f4); when the sine waves of corresponding frequencies (f1, f2, f3, f4) are orthogonal to each other, effective touch sensing can be performed because the corresponding frequency components can be easily separated.

[0163] At this time, the touch driving circuit 200 may separate the self-capacitance Cs of each touch electrode TE for each frequency by comparing between the code-divided sensing signal CDS and the reference voltage Vref using a signal processing algorithm such as Fast Fourier Transform (FFT).

[0164] Thereafter, the presence of a touch on the display panel 110 may be determined based on the separated self-capacitance Cs for each frequency, and the coordinates of the touch electrode TE where the touch has occurred may be generated from the frequency at which the touch is determined to have occurred.

[0165] In this way, by using sine waves of various frequencies as the reference voltage Vref compared with the code-divided sensing signal CDS at the preamplifier circuit 212, noise due to harmonic components can be reduced while avoiding noise in a specific frequency band.

[0166] At the same time, the touch display device 100 may include a charge remover 218 to prevent saturation and remove the initial charge remaining at the inverting input terminal (-) of the preamplifier circuit 212; however, in the touch display device 100, since the peak-to-peak value Vp of the reference voltage Vref applied to the preamplifier circuit 212 is configured to be different from the peak-to-peak value Vex of the touch drive signal TDS, in the absence of a separate charge remover 218, saturation can be prevented and the initial charge remaining at the preamplifier circuit 212 can be removed.

[0167] Figure 9 A touch driving circuit according to an embodiment of the present disclosure is shown when a reference voltage of a preamplifier circuit different from a peak-to-peak value of a touch driving signal is applied in a touch display device.

[0168] refer to Figure 9In the touch display device 100 according to an embodiment of the present disclosure, by setting the peak-to-peak value Vp of the reference voltage Vref applied to the preamplifier circuit 212 and the peak-to-peak value Vex of the touch drive signal TDS to be different from each other, the charge remover 218 may not be provided inside the touch drive circuit 200.

[0169] At this time, the reference voltage Vref having a value different from the touch driving signal TDS is used to remove the charge of the preamplifier circuit 212; therefore, it may be referred to as a charge control signal.

[0170] For example, when the charge remover 218 is located in front of the preamplifier circuit 212 , the voltage Vout1 output from the preamplifier circuit 212 may be expressed as follows.

[0171]

[0172] However, when the peak-to-peak value Vp of the reference voltage Vref compared with the code-division sensing signal CDS at the preamplifier circuit 212 is set to a value having a different peak-to-peak value Vex from the code-division sensing signal CDS, saturation can be prevented and the initial charge remaining at the preamplifier circuit 212 can be removed even if a separate charge remover 218 is not provided.

[0173] That is, when the peak-to-peak value Vp of the reference voltage Vref compared with the code-division sensing signal CDS at the preamplifier circuit 212 is set to have a value different from the peak-to-peak value Vex of the code-division sensing signal CDS, the output value Vout1 of the preamplifier circuit 212 can be adjusted as follows, and thus, the touch drive circuit 200 can be prevented from being saturated beyond a limited range.

[0174]

[0175] Here, k is the number of touch electrodes TE that simultaneously receive the touch sensing signal TSS through the code division control signal CD_MUX, and m is the number of multiplexers MUX connected to the preamplifier circuit 212. In addition, Cc is the coupling capacitance between the node to which the touch drive signal TDS is applied and the touch line, and Cp represents the capacitance formed by one or more touch electrodes TE.

[0176] At this time, during the first time period T1, the touch display device 100 according to an embodiment of the present disclosure may apply a gate charge control signal to a gate line overlapping with the plurality of touch electrodes TE to which the touch drive signal TDS is applied. Furthermore, during the first time period T1, the touch display device 100 according to an embodiment of the present disclosure may apply a data charge control signal to a data line overlapping with the plurality of touch electrodes TE to which the touch drive signal TDS is applied. Furthermore, during the first time period T1, the touch display device 100 according to an embodiment of the present disclosure may apply a touch charge control signal to other touch electrodes TE overlapping with the plurality of touch lines TL connected to the plurality of touch electrodes TE to which the touch drive signal TDS is applied.

[0177] In addition, the touch display device 100 according to an embodiment of the present disclosure can apply a charge control signal to other electrodes adjacent to the multiple touch electrodes TE sensed during the touch sensing period in order to perform the typical charge remover 218 function. That is, when the touch drive signal TDS is applied to the multiple touch electrodes TE to be sensed, the amount of charge present in the multiple touch electrodes TE to be sensed can be controlled by applying a charge control signal having an amplitude different from the amplitude of the touch drive signal TDS or a DC voltage signal of a predetermined level to the data line or gate line arranged adjacent to the multiple touch electrodes TE to be sensed. In other words, by controlling the capacitance formed between the multiple touch electrodes TE to be sensed and the other electrodes arranged adjacent thereto, the amount of charge in the multiple touch electrodes TE to be sensed can be controlled.

[0178] The above description has been given to enable any person skilled in the art to implement and use the technical ideas of the present invention, and has been provided in the context of specific applications and their requirements. Various modifications, additions and substitutions to the described embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. The above description and accompanying drawings provide examples of the technical ideas of the present invention for illustrative purposes only. That is, the disclosed embodiments are intended to illustrate the scope of the technical ideas of the present invention. Therefore, the scope of the present invention is not limited to the embodiments shown, but is in the widest scope consistent with the claims. The scope of protection of the present invention should be interpreted based on the appended claims, and all technical ideas within their equivalent scope should be interpreted as being included within the scope of the present invention.

Claims

1. A touch display device, comprising: A touch panel including a plurality of touch electrodes and a plurality of touch lines; a multiplexer comprising n touch line channel ports connected to n touch electrodes in the same column of the touch electrodes through n touch lines among the touch lines, the multiplexer being configured to allow a touch drive signal to be provided at a time to (nk) touch electrodes among the n touch electrodes in the same column based on a code-division control signal that varies with time, where k is a natural number that is 1 or more less than n, and to output a code-division sensing signal in a code-division form in which touch sensing signals provided from k touch electrodes among the n touch electrodes in the same column are added; as well as A touch sensing circuit configured to: calculating capacitances in the plurality of touch electrodes based on the code-divided sensing signals from the multiplexer, and Detect touch presence or touch coordinates, Among the n touch electrodes in the same column, the touch electrode to which the touch driving signal is applied is different from the k touch electrodes providing the touch sensing signal, and Wherein, the touch sensing circuit includes: A preamplifier circuit comprising: an operational amplifier configured to receive the code-division sensing signal through an inverting input terminal of the operational amplifier, and configured to receive the touch drive signal through a non-inverting input terminal of the operational amplifier; a feedback capacitor connected in parallel between the inverting input terminal and an output terminal of the operational amplifier; and Feedback switch; an integration circuit comprising a plurality of switches and a plurality of capacitors, the integration circuit being configured to accumulate an output voltage from the preamplifier circuit; and A sampling circuit is configured to provide the output signal from the integration circuit at any time.

2. The touch display device according to claim 1, wherein: The touch panel is configured to operate based on a self-capacitance touch sensing method, wherein a touch driving signal and a touch sensing signal are provided through a same touch line among the plurality of touch lines connected to a touch electrode among the plurality of touch electrodes.

3. The touch display device according to claim 1, wherein: The multiplexer includes a plurality of multiplexers, and a sub-plurality of touch electrodes from among the plurality of touch electrodes is connected as a group to each of the plurality of multiplexers.

4. The touch display device according to claim 1, wherein: The touch driving signal is a sine wave signal including a plurality of frequency components.

5. The touch display device according to claim 1, wherein: The touch driving signal has a first peak-to-peak value different from a second peak-to-peak value of a no-load driving signal applied to the plurality of touch electrodes through the multiplexer. The touch display device according to claim 1 , wherein: The touch sensing circuit is configured to calculate capacitances in the plurality of touch electrodes using decoded codes corresponding to an inverse matrix of the code-division control signal.

7. The touch display device according to claim 1, in, During a first period, the touch drive signal is simultaneously applied to the (nk) touch electrodes among the n touch electrodes connected to the n touch line channel ports, and a no-load drive signal having the same phase as the touch drive signal is simultaneously applied to the k touch electrodes.

8. The touch display device according to claim 7, wherein: During a second period of the touch panel, the no-load drive signal is applied to at least one of the (nk) touch electrodes to which the touch drive signal has been applied, and the touch drive signal is applied to at least one of the k touch electrodes to which the no-load drive signal has been applied.

9. The touch display device according to claim 7, wherein: An amplitude of the touch driving signal is different from an amplitude of the no-load driving signal.

10. The touch display device according to claim 7, further comprising a display panel, wherein the display panel comprises a plurality of data lines and a plurality of gate lines. in, During the first cycle, a gate no-load drive signal having the same phase as the touch drive signal is applied to a gate line among the multiple gate lines overlapping with the (nk) touch electrodes to which the touch drive signal is applied, or during the first cycle of the touch panel, a data no-load drive signal having the same phase as the touch drive signal is applied to a data line among the multiple data lines overlapping with the (nk) touch electrodes to which the touch drive signal is applied.

11. The touch display device according to claim 10, wherein: The amplitude of the gate no-load driving signal is different from the amplitude of the touch driving signal, or the amplitude of the data no-load driving signal is different from the amplitude of the touch driving signal.

12. The touch display device according to claim 7, wherein: During the first period, a gate charge control signal is applied to a gate line overlapping the (nk) touch electrodes to which the touch drive signal is applied; Alternatively, during the first cycle of the touch panel, a data charge control signal is applied to a data line overlapping with the (nk) touch electrodes to which the touch drive signal is applied; or during the first cycle of the touch panel, a touch charge control signal is applied to other touch electrodes overlapping with (nk) touch lines among the multiple touch lines connected to the (nk) touch electrodes to which the touch drive signal is applied.

13. The touch display device according to claim 12, wherein: The amplitude of the gate charge control signal is different from the amplitude of the touch drive signal or the amplitude of the predetermined DC voltage, The amplitude of the data charge control signal is different from the amplitude of the touch drive signal or the amplitude of the predetermined DC voltage, and The amplitude of the touch charge control signal is different from the amplitude of the touch drive signal or the amplitude of the predetermined DC voltage.

14. A touch driving circuit, comprising: a multiplexer comprising n touch line channel ports connected to n touch electrodes in the same column of the plurality of touch electrodes through n touch lines among the plurality of touch lines, the multiplexer being configured to allow a touch drive signal to be provided at a time to (nk) touch electrodes among the n touch electrodes in the same column based on a code-division control signal that varies with time, where k is a natural number that is 1 or more less than n, and to output a code-division sensing signal in a code-division form in which touch sensing signals provided from k touch electrodes among the n touch electrodes in the same column are added; as well as a touch sensing circuit configured to calculate capacitances in the plurality of touch electrodes based on the code-divided sensing signals from the multiplexer and detect touch presence or touch coordinates, Among the n touch electrodes in the same column, the touch electrode to which the touch driving signal is applied is different from the k touch electrodes providing the touch sensing signal, and Wherein, the touch sensing circuit includes: A preamplifier circuit comprising: an operational amplifier, the operational amplifier receiving the code-division sensing signal through an inverting input terminal of the operational amplifier when in operation; a feedback capacitor connected in parallel between the inverting input terminal and an output terminal of the operational amplifier; and Feedback switch, wherein the touch drive signal is applied to the non-inverting input terminal of the operational amplifier; an integrating circuit comprising a plurality of switches and a plurality of capacitors, the integrating circuit operative to integrate an output voltage from the preamplifier circuit; and A sampling circuit, which when operational provides an output signal from the integrating circuit at any time.

15. The touch driving circuit according to claim 14, wherein: The multiplexer includes a plurality of multiplexers, and a sub-plurality of touch electrodes from among the plurality of touch electrodes is connected as a group to each of the plurality of multiplexers.

16. A touch driving method, comprising: applying a code division control signal to a multiplexer, the multiplexer including n touch line channel ports, the n touch line channel ports being connected to n touch electrodes in the same column of the plurality of touch electrodes through n touch lines among the plurality of touch lines, and the multiplexer allowing a touch drive signal to be provided to (nk) touch electrodes among the n touch electrodes in the same column at a time based on the code division control signal that varies with time, where k is a natural number that is 1 or more less than n; outputting a code-division sensing signal through the multiplexer in a code-division form in which touch sensing signals provided from k touch electrodes among the n touch electrodes in the same column are added; as well as detecting touch presence or touch coordinates using a touch sensing circuit by calculating capacitance in the plurality of touch electrodes based on the code-divided sensing signals from the multiplexer, Among the n touch electrodes in the same column, the touch electrode to which the touch driving signal is applied is different from the k touch electrodes providing the touch sensing signal, and Wherein, the touch sensing circuit includes: A preamplifier circuit comprising: an operational amplifier, the operational amplifier receiving the code-division sensing signal through an inverting input terminal of the operational amplifier when in operation; a feedback capacitor connected in parallel between the inverting input terminal and an output terminal of the operational amplifier; and Feedback switch, wherein the touch drive signal is applied to the non-inverting input terminal of the operational amplifier; an integrating circuit comprising a plurality of switches and a plurality of capacitors, the integrating circuit operative to integrate an output voltage from the preamplifier circuit; and A sampling circuit, which when operational provides an output signal from the integrating circuit at any time.

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