Touch driving circuit and display device

Abstract

A touch driving circuit according to an embodiment of the present specification may: generate a reset signal for initializing an internal sensing circuit and a first touch driving signal synchronized with the reset signal; generate a second touch driving signal by adjusting a phase of the first touch driving signal; transmit the second touch driving signal to a plurality of touch driving electrodes of a touch panel through a transmission line to supply a third touch driving signal to each of the plurality of touch driving electrodes; and perform touch sensing on the basis of the third touch driving signal. Touch performance at a touch point that is farthest from the touch driving circuit in the touch panel can be sufficiently improved, and overall touch performance can be enhanced.

Description

Touch driving circuit and display device

[0001] The present specification relates to a touch driving circuit and a display device, and more specifically, to a touch driving circuit and a display device that improves touch performance by adjusting the phase of a touch driving signal.

[0002] As the information society develops, the demand for display devices to display images is increasing in various forms, and various types of display devices such as Liquid Crystal Displays (LCDs), Plasma Displays, and Organic Light Emitting Displays (OLEDs) are being utilized. Among these diverse types of display devices, OLEDs are currently gaining popularity because they utilize self-emissive elements, offer excellent response speed, viewing angle, and color reproduction, and can be implemented in a thin form factor.

[0003] A display device can operate in response to input signals received through various input devices such as keyboards and mice. The display device can intuitively and conveniently receive user commands by touching the screen using a touch panel. More specifically, the touch panel is placed on the screen of the display device, and when a user touches a specific point on the screen using a finger or a ballpoint pen-shaped touch pen, the touch panel recognizes the contact point to execute the user's command or move the cursor position. Since such touch panels tend to be embedded in the display device and integrated with it, it is important to satisfy touch recognition conditions, such as touch sensitivity and touch duration, for proper operation.

[0004] The touch detection function of a touch panel can be implemented through touch driving electrodes. Touch driving electrodes are placed in the touch area and receive touch driving signals from a touch driving circuit via connecting wiring, and can transmit signals generated by the touch to the touch driving circuit. In the case of a large touch panel, deviations in the touch driving signals supplied to the electrodes occur due to differences in distance between the electrodes receiving the signals from the touch driving circuit; this causes a degradation in touch performance at points far from the touch driving circuit on the touch panel.

[0005] The present specification provides a touch driving circuit and a display device that improve touch performance by adjusting the phase of a touch driving signal to improve the prior art.

[0006] The problem to be solved according to the embodiments of the present specification is to provide a touch driving circuit and a display device that adjust the phase of a touch driving signal generated in a touch driving circuit to lead a reference.

[0007] The problem to be solved according to the embodiments of the present specification is to provide a touch driving circuit and a display device in which a touch driving signal is generated by overlapping with the generation of a reset signal that initializes the touch driving circuit by adjusting the phase of the touch driving signal to lead a reference.

[0008] The problem to be solved according to the embodiments of the present specification is to provide a touch driving circuit and a display device that adjust the phase of a touch driving signal to lead a reference within a predetermined range so that the touch performance at the point furthest from the touch driving circuit is sufficiently improved.

[0009] The problems described in this specification are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0010] A touch driving circuit according to one embodiment of the present specification generates a reset signal that initializes an internal sensing circuit and a first touch driving signal synchronized with the reset signal, generates a second touch driving signal by adjusting the phase of the first touch driving signal, transmits the second touch driving signal to a plurality of touch driving electrodes of a touch panel through a transmission line to supply a third touch driving signal to each of the plurality of touch driving electrodes, and performs touch sensing based on the third touch driving signal.

[0011] A display device according to one embodiment of the present specification comprises a display panel, a touch panel connected to the display panel and including a plurality of touch driving electrodes, and a touch driving circuit for driving the touch panel. The touch driving circuit generates a reset signal that initializes a sensing circuit of the touch driving circuit and a first touch driving signal synchronized with the reset signal, generates a second touch driving signal by adjusting the phase of the first touch driving signal, transmits the second touch driving signal to a plurality of touch driving electrodes through a transmission line connected to the touch panel to supply a third touch driving signal to each of the plurality of touch driving electrodes, and performs touch sensing based on the third touch driving signal.

[0012] Specific details of other embodiments are included in the detailed description and drawings.

[0013] According to the embodiments of this specification, the phase of a touch driving signal synchronized with a reset signal that initializes a touch driving circuit can be adjusted to lead a reference so that the maximum possible voltage change is measured at the touch driving electrodes furthest from the touch driving circuit during a sensing time corresponding to the off-level interval of one cycle of the reset signal. Accordingly, the touch performance of the touch point furthest from the touch driving circuit on the touch panel can be improved to a sufficient degree, and the overall touch performance can be enhanced.

[0014] The effects of this specification are not limited to those mentioned above, and other unmentioned effects will be clearly understood by a person skilled in the art from the description below.

[0015] FIG. 1 is a block diagram of a display device according to one embodiment of the present specification.

[0016] FIG. 2 is a circuit diagram of a touch panel and a touch driving circuit according to one embodiment of the present specification.

[0017] Figure 3 is a waveform diagram of the signals used in the circuit of Figure 2.

[0018] FIG. 4 is a waveform diagram of a reset signal and a touch driving signal generated in a touch driving circuit according to one embodiment of the present specification.

[0019] FIG. 5 is a drawing illustrating a touch panel and a touch driving circuit according to one embodiment of the present specification.

[0020] FIG. 6 is an equivalent circuit diagram in which RC modeling is taken for a transmission line inside a touch panel according to one embodiment of the present specification.

[0021] FIGS. 7a and 7b are waveform diagrams of touch driving signals supplied to each touch point of a touch panel according to one embodiment of the present specification.

[0022] FIGS. 8A and FIGS. 8B are drawings illustrating a method for measuring a voltage change amount when performing touch sensing based on a touch driving signal according to one embodiment of the present specification.

[0023] FIG. 9 is a diagram illustrating a method for adjusting the phase of a touch driving signal according to one embodiment of the present specification.

[0024] FIG. 10 is a waveform diagram of a reset signal and a phase-adjusted touch driving signal generated in a touch driving circuit according to one embodiment of the present specification.

[0025] FIGS. 11a and FIGS. 11b are waveforms of phase-adjusted touch driving signals supplied to each touch point of a touch panel according to one embodiment of the present specification.

[0026] FIGS. 12a and FIGS. 12b are drawings illustrating a method for measuring a voltage change amount when performing touch sensing based on a phase-adjusted touch driving signal according to one embodiment of the present specification.

[0027] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0028] Shapes, sizes, ratios, angles, numbers, etc. disclosed in the drawings for explaining embodiments of the present invention are exemplary, and therefore the present invention is not limited to the depicted details. Throughout the specification, the same reference numerals refer to the same components. Furthermore, in describing the present invention, if it is determined that a detailed description of related prior art may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Where terms such as "includes," "has," or "is made up" are used in this specification, other parts may be added unless "only" is used. Where a component is expressed in the singular, it includes cases where it is included in the plural unless specifically stated otherwise.

[0029] In interpreting the components, they are interpreted to include a margin of error even in the absence of a separate explicit statement.

[0030] In the case of describing positional relationships, for example, when the positional relationship between two parts is described using expressions such as 'on,' 'upper,' 'lower,' or 'next to,' one or more other parts may be located between the two parts unless 'immediately' or 'directly' is used.

[0031] In the case of an explanation of a temporal relationship, for example, when a temporal sequence is explained using 'after', 'following', 'next', 'before', etc., it may include cases where the sequence is not continuous unless 'immediately' or 'directly' is used.

[0032] As used in this specification, the term "part" refers to a unit that processes at least one function or operation, and may mean, for example, software or a hardware component. The function provided by the "part" may be performed separately by a plurality of components or may be integrated with other additional components. The "part" in this specification may be implemented through a single circuit or a plurality of circuits, or through a single device or a plurality of devices.

[0033] The features of each of the embodiments of this specification may be combined or combined with one another, either partially or wholly, and may technically enable various interlocking and operation. Each embodiment may be implemented independently of one another or may be implemented together in an associated relationship.

[0034] Hereinafter, a touch driving circuit and a display device according to an embodiment of the present specification will be described with reference to the attached drawings.

[0035] FIG. 1 is a block diagram of a display device according to one embodiment of the present specification.

[0036] As illustrated in FIG. 1, a display device according to one embodiment of the present invention may include a host system (110), a timing controller (120), a gate driving circuit (130), a data driving circuit (140), a display panel (DIS), a touch panel (TSP), and a touch driving circuit (150).

[0037] The host system (110) performs image processing on the data signal and outputs it along with a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, and a clock signal. The host system (110) supplies the vertical synchronization signal, the horizontal synchronization signal, the data enable signal, the clock signal, and the data signal to the timing controller (120). Additionally, the host system (110) executes an application program associated with the coordinate values ​​of the touch data (TDATA) input from the touch driving circuit (150).

[0038] The timing controller (120) receives data signals, etc. from the host system (110) and outputs a gate timing control signal (GDC) for controlling the operation timing of the gate driving circuit (130) and a data timing control signal (DDC) for controlling the operation timing of the data driving circuit (140). The timing controller (120) supplies a data signal (DATA) to the data driving circuit (140) along with the data timing control signal (DDC).

[0039] The timing controller (120) is a component that transmits control signals to various components of the display device. The timing controller (120) receives timing signals, such as a vertical synchronization signal, a horizontal synchronization signal, a data enable signal, and a dot clock, through a receiving circuit, such as an LVDS or TMDS interface connected to the video board. The timing controller (120) generates control signals to control the operation timing of the gate driving circuit (130) and the data driving circuit (140) based on the input timing signals.

[0040] The gate driving circuit (130) outputs a gate signal while shifting the level of the gate voltage in response to a gate timing control signal (GDC) supplied from the timing controller (120). The gate driving circuit (130) includes a level shifter and a shift register.

[0041] The gate driving circuit (130) supplies gate signals to subpixels included in the display panel (DIS) through gate lines (GL1~GLm). The gate driving circuit (130) can be formed in the display panel (DIS) in a gate-in-panel manner or as an integrated circuit (IC). The part of the gate driving circuit (130) formed in a gate-in-panel manner is a shift register.

[0042] The data driving circuit (140) samples and latches a data signal (DATA) in response to a data timing control signal (DDC) supplied from the timing controller (120), and converts the digital signal into an analog signal corresponding to the gamma voltage and outputs it. The data driving circuit (140) supplies the data signal to subpixels included in the display panel (DIS) through data lines (DL1~DLn). The data driving circuit (140) may be formed in the form of an integrated circuit (IC).

[0043] The data driving circuit (140) converts the pixel data of the input image, which is digital data, into a digital-to-analog converter (hereinafter referred to as "DAC") to generate an analog data voltage. The DAC receives the pixel data, which is digital data, and receives a gamma reference voltage from the gamma voltage generation circuit of the power supply. The data driving circuit (140) uses a voltage divider circuit to generate the gamma reference voltage into a gamma compensation voltage corresponding to each of the grayscale levels of the pixel data. The DACs placed in each of the channels of the data driving circuit (140) convert the pixel data into a gamma compensation voltage and output a data voltage through a switch element array that selects a voltage corresponding to the bit of the pixel data.

[0044] A display panel (DIS) displays an image in response to a gate signal and a data signal output from driving circuits including a gate driving circuit (130) and a data driving circuit (140). Depending on the material of the substrate, the display panel (DIS) is implemented in a flat shape, a curved shape, or a flexible shape. The display panel (DIS) includes a display area defined by a plurality of pixels and a non-display area where various signal lines or pads are formed. In the display area of ​​the display panel (DIS), a plurality of pixels defined by a plurality of data lines (DL1~DLn) and a plurality of gate lines (GL1~GLm) are arranged, and a plurality of subpixels are included in one pixel. The subpixels include a red subpixel, a green subpixel, and a blue subpixel, or a white subpixel, a red subpixel, a green subpixel, and a blue subpixel. The subpixels may have one or more different light-emitting areas depending on their light-emitting characteristics.

[0045] A pixel array of a display panel (DIS) may be provided with a plurality of horizontal pixel lines, and a plurality of pixels that are horizontally adjacent and commonly connected to gate lines may be arranged on each horizontal pixel line. Here, each of the horizontal pixel lines may not be a physical signal line, but may refer to a pixel block of one line implemented by horizontally adjacent pixels.

[0046] A touch panel (TSP) may include a plurality of transmission lines (TX lines, TX1 to TXn) through which a touch driving signal is transmitted from a touch driving circuit (150), a plurality of receiving lines (RX lines, RX1 to RXm) that intersect the transmission lines and receive the touch signal detected by the touch driving circuit (150), and a plurality of touch driving electrodes (or touch sensors) formed at the intersection points of the transmission lines (TX1 to TXn) and the receiving lines (RX1 to RXm). Each of the touch driving electrodes may include mutual capacitance.

[0047] The touch driving circuit (150) may include a transmitting driving circuit (151), a receiving driving circuit (152), and a touch controller (153).

[0048] The transmission driving circuit (151) selects a transmission channel (TX channel) to output a touch driving signal in response to a transmission setup signal input from the touch controller (153), and applies the touch driving signal to the transmission lines (TX1 to TXn) connected to the selected transmission channel. The transmission lines (TX1 to TXn) are charged during the high-potential period of the touch driving signal to supply charge to the touch driving electrodes, and are discharged during the low-potential period of the touch driving signal. The touch driving signal can be continuously supplied to each of the transmission lines (TX1 to TXn) through the reception lines (RX1 to RXm) so that the voltage of the touch driving electrodes can be accumulated in the integrator within the reception driving circuit (152).

[0049] The receiving driving circuit (152) selects receiving lines (RX1~RXm) to receive the voltage of the touch driving electrodes in response to a receiving setup signal input from the touch controller (153). The receiving driving circuit (152) samples the voltage of the touch driving electrodes received through the receiving lines (RX1~RXm) and accumulates it in an integrator. Then, the receiving driving circuit (152) uses an analog-to-digital converter (hereinafter referred to as "ADC") connected to the output terminal of the integrator to convert the voltage accumulated in the integrator into digital data and output touch raw data.

[0050] The touch controller (153) generates a transmission setup signal for setting a transmission channel to which a touch driving signal is output from the transmission driving circuit (151), and a reception setup signal for setting a reception channel to receive the voltage of the touch driving electrodes from the reception driving circuit (152), so that the sensing operation of the transmission driving circuit (151) and the reception driving circuit (152) can be synchronized. In addition, the touch controller (153) generates timing control signals to control the operation timing of the sampling and integrator of the reception driving circuit (152) and the operation timing of the ADC.

[0051] The touch controller (153) receives a horizontal synchronization signal (Hsync) from the host system (110) and, based on this, drives the transmitting driving circuit (151) and the receiving driving circuit (152) during the display period and the time-divided touch sensing period. The transmitting driving circuit (151) and the receiving driving circuit (152) can sense the voltage of the touch driving electrodes during the touch sensing period allocated within the low logic period of the horizontal synchronization signal (Hsync) under the control of the touch controller (153).

[0052] In one embodiment, the touch controller (153) can execute a preset touch recognition algorithm to compare raw touch data received from the receiving driving circuit (152) with a preset threshold. The touch recognition algorithm determines that raw touch data above the threshold is data input from the touch driving electrodes of the touch (or proximity) input location and calculates the coordinates of each of the touch (or proximity) input locations. The touch controller (153) can then transmit the touch data (TDATA) to the host system (110) at a touch report rate with a frequency higher than the display frame rate. The touch data may be generated after the presence of touch input for all touch driving electrodes within the touch panel is determined by a processor performing touch recognition, and may include coordinate information for each of the touch (or proximity) input locations.

[0053] FIG. 2 is a circuit diagram of a touch panel and a touch driving circuit according to one embodiment of the present specification, and FIG. 3 is a waveform diagram of signals used in the circuit of FIG. 2.

[0054] In one embodiment, the sensing portion of the touch driving circuit (Touch IC) may include an amplifier and a capacitor (Cf). The inverting input terminal (-) of the amplifier is connected to the touch driving electrode (Cm) through a receiving channel, the non-inverting input terminal (+) of the amplifier is connected to the input terminal of the reference voltage (VREF), and the output terminal (VOUT) of the amplifier may be connected to the inverting input terminal (-) through the capacitor (Cf).

[0055] In the sensing section as shown in FIG. 2, the amplifier can operate as an inverting amplifier. The output voltage (VOUT) of the sensing section can be expressed as shown in the following mathematical formula.

[0056]

[0057] In Equation 1, the reference voltage (VREF) is a DC level, VTX represents the voltage of the touch driving signal applied to the touch driving electrode (Cm), Cm represents the mutual capacitance of the touch driving electrode (Cm), and Cf represents the capacitance of the sensing capacitor (Cf). The output voltage (VOUT), which represents the change in charge of the touch driving electrode (Cm), may have a phase opposite to that of the voltage of the touch driving signal (VTX).

[0058] In FIG. 2, the circuit of the touch panel (TSP) is an equivalent circuit diagram of an example in which RC modeling is taken inside the touch panel, and represents the resistance (Rout_Tx) and capacitance (Cp_Tx) by the transmitting line connected to the touch driving electrode (Cm), and the resistance (Rout_Rx) and capacitance (Cp_Rx) by the receiving line. In FIG. 3, IO_TX represents a touch driving signal applied to the touch driving electrode, RX_IN represents a touch signal detected by the touch driving electrode transmitted to the touch driving circuit through the receiving line, RST represents a reset signal that initializes the sensing unit, and VOUT represents the output voltage of the sensing unit.

[0059] FIG. 4 is a waveform diagram of a reset signal and a touch driving signal generated in a touch driving circuit according to one embodiment of the present specification.

[0060] To summarize based on the above, basically, the signal sensed for touch detection in the touch driving circuit can be the result of the waveform of the touch driving signal (IO_TX) supplied to the touch driving electrode.

[0061] According to one embodiment of the present specification, a signal generator of a touch driving circuit may generate a reset signal (RST) that initializes a sensing unit of the touch driving circuit and a touch driving signal (IO_TX) that drives a touch driving electrode. The touch driving signal (IO_TX) may be generated in synchronization with the reset signal (RST). The signal generator may set the driving timing of the generated reset signal (RST) and the touch driving signal (IO_TX).

[0062] The reset signal (RST) and the touch driving signal (IO_TX) may be signals having on pulses at regular time intervals as shown in FIG. 4. The touch driving signal (IO_TX) may be generated in synchronization with the reset signal (RST), and more specifically, the on pulse of the touch driving signal (IO_TX) may be a signal having a rising edge after a predetermined time (e.g., after a first time) at the falling edge timing of the first on pulse of the reset signal (RST), and having a falling edge after the same time as the predetermined time (i.e., after a first time) at the falling edge timing of the second on pulse, which is the next on pulse of the first on pulse.

[0063] In one embodiment, touch sensing may be performed by measuring the amount of change during the sensing time for a signal that the touch driving circuit senses for touch detection. Here, the sensing time may be the time from the falling edge timing of the first on pulse of the reset signal (RST) to the rising edge timing of the second on pulse, which is the next on pulse of the first on pulse (in other words, the time for the off-level interval of one cycle of the reset signal). In addition, the settling time, which is the time required for the touch driving signal supplied to the touch driving electrode to reach and sustain within a predetermined range of the final voltage value (e.g., the sensed voltage magnitude (VTX)), may be as shown in FIG. 4.

[0064] FIG. 5 is a drawing illustrating a touch panel and a touch driving circuit according to one embodiment of the present specification, and FIG. 6 is an equivalent circuit diagram in which RC modeling is taken for a transmission line inside the touch panel.

[0065] When the size of the touch panel (TSP) is large, a deviation in the touch driving signal supplied to the touch driving electrodes occurs due to the difference in distance between the touch driving electrodes receiving the touch driving signal from the touch driving circuit (150), and this can cause the touch performance at points far from the touch driving circuit on the touch panel to degrade. Referring to FIG. 6, as the size of the touch panel increases, the overall resistance and capacitance values ​​related to the transmission line increase. Referring to FIG. 5 as well, among the multiple touch driving electrodes of the touch panel (TSP), a difference in waveform, etc. occurs between the point (BP) closest to the touch driving circuit (150) and the point (WP) farthest from the touch driving circuit (150). Therefore, a method is required to compensate for the difference in the magnitude of the detected touch signal caused by the difference in the load of the transmission line due to the increase in the size of the touch panel.

[0066] FIGS. 7a and 7b are waveform diagrams of touch driving signals supplied to each touch point of a touch panel according to one embodiment of the present specification.

[0067] Basically, the signal sensed for touch detection in the touch driving circuit can be the result of the waveform of the touch driving signal (IO_TX) supplied to the touch driving electrode.

[0068] FIG. 7a shows the waveform of a touch driving signal (IO_TX) supplied at the point (BP) closest to the touch driving circuit (150) among the multiple touch driving electrodes of the touch panel (TSP). In this case, the voltage magnitude (VTX) sensed based on the touch driving signal supplied to the touch driving electrode can be VTX_BP as shown in FIG. 7a. FIG. 7b shows the waveform of a touch driving signal (IO_TX) supplied at the point (WP) farthest from the touch driving circuit (150) among the multiple touch driving electrodes of the touch panel (TSP). In this case, the voltage magnitude (VTX) sensed based on the touch driving signal supplied to the touch driving electrode can be VTX_WP as shown in FIG. 7b.

[0069] Due to the difference in distance from the touch driving circuit (150), waveform differences may occur between the touch driving signals supplied to the touch driving electrode through the transmission line, and based on this, the voltage magnitude (VTX) sensed may also differ as VTX_BP and VTX_WP. Due to such differences, the touch performance of the touch point (WP) that is furthest from the touch driving circuit on the touch panel may be degraded, and since the overall touch performance of the touch panel is determined by the touch performance of the furthest touch point (WP), it may result in a degradation of the overall touch performance of the touch panel.

[0070] FIGS. 8A and FIGS. 8B are drawings illustrating a method for measuring a voltage change amount when performing touch sensing based on a touch driving signal according to one embodiment of the present specification.

[0071] In the embodiments of the present specification, the sensing time may be the time from the falling edge timing of the first on pulse of the reset signal (RST) to the rising edge timing of the second on pulse, which is the next on pulse of the first on pulse (in other words, the time for the off-level interval of one cycle of the reset signal).

[0072] Referring to FIG. 8a, when the voltage change amount of a touch driving signal supplied to a touch driving electrode at a point (BP) closest to the touch driving circuit (150) among a plurality of touch driving electrodes of a touch panel (TSP) is measured during a sensing time, the voltage change amount, that is, the sensed voltage magnitude, can be VTX_BP. Since this is the voltage change amount at the point with the best touch performance, it can be seen as corresponding to 100% of the voltage magnitude.

[0073] Referring to FIG. 8b, when the voltage change amount of a touch driving signal supplied to a touch driving electrode at the point (WP) furthest from the touch driving circuit (150) among a plurality of touch driving electrodes of a touch panel (TSP) is measured during a sensing time, the voltage change amount, that is, the sensed voltage magnitude, can be VTX_WP. This is the voltage change amount at the point where touch performance is the worst, and in one embodiment, it may correspond to 60% of the voltage magnitude sensed at the point where touch performance is best.

[0074] Hereinafter, a method to improve the touch performance of the touch point furthest from the touch driving circuit in a touch panel according to an embodiment of the present specification is described.

[0075] FIG. 9 is a diagram illustrating a method for adjusting the phase of a touch driving signal according to one embodiment of the present specification.

[0076] In one embodiment of the present specification, the touch driving circuit (150) transmits the touch driving signal (IO_TX) initially generated from the signal generator to the phase adjustment unit, and adjusts the phase of the touch driving signal initially generated to apply the phase-adjusted touch driving signal to the transmission line (TX line) of the touch panel.

[0077] In one embodiment of the present specification, the phase of the phase-adjusted touch driving signal may be adjusted so that the phase is ahead of the initial generated touch driving signal. Referring to FIG. 9, the phase of the phase-adjusted touch driving signal indicated by the dotted line may be set to be ahead of the initial generated touch driving signal indicated by the solid line.

[0078] Based on the rising edge (ref) of the on pulse of the initially generated touch driving signal, the phase-adjusted touch driving signal may be phase-adjusted to have a leading phase (D). For reference, in this specification, the initially generated touch driving signal may be referred to as the 'first touch driving signal', and the phase-adjusted touch driving signal may be referred to as the 'second touch driving signal'. Additionally, the touch driving signal that is applied to the transmission line and transmitted to the touch driving electrode, i.e., the touch driving signal in which a difference in waveform, etc. occurs depending on the distance from the touch driving circuit (150), may be referred to as the 'third touch driving signal'.

[0079] FIG. 10 is a waveform diagram of a reset signal and a phase-adjusted touch driving signal generated in a touch driving circuit according to one embodiment of the present specification.

[0080] Referring again to FIG. 4, the reset signal (RST) and the touch driving signal (IO_TX) may be signals having an ON pulse at a certain time interval. The touch driving signal (IO_TX) may be generated in synchronization with the reset signal (RST), and more specifically, the ON pulse of the touch driving signal (IO_TX) may be a signal having a rising edge after a predetermined time (e.g., after a first time) at the falling edge timing of the first ON pulse of the reset signal (RST), and having a falling edge after the same time as the predetermined time (i.e., after a first time) at the falling edge timing of the second ON pulse, which is the ON pulse next to the first ON pulse.

[0081] Referring to FIG. 10, the ON pulse of the phase-adjusted touch driving signal (IO_TX) may occur while the first ON pulse of the reset signal (RST) is being generated. That is, the rising edge of the ON pulse of the phase-adjusted touch driving signal (IO_TX) may be included in the first ON pulse interval of the reset signal (RST).

[0082] In the case of the settling time, which is the time required for the touch driving signal supplied to the touch driving electrode to reach and sustain within a predetermined range of the final voltage value, it can be secured as the time from the rising edge timing of the on pulse of the touch driving signal (IO_TX) until the start of the second on pulse of the reset signal (RST) having an initialization function. Therefore, if a phase-adjusted touch driving signal is used as shown in FIG. 10, the settling time of the touch driving signal can be secured more.

[0083] FIGS. 11a and FIGS. 11b are waveforms of phase-adjusted touch driving signals supplied to each touch point of a touch panel according to one embodiment of the present specification.

[0084] Basically, the signal sensed for touch detection in the touch driving circuit can be the result of the waveform of the touch driving signal (IO_TX) supplied to the touch driving electrode.

[0085] FIG. 11a shows the waveform of a phase-adjusted touch driving signal (IO_TX) supplied at the point (BP) closest to the touch driving circuit (150) among the plurality of touch driving electrodes of the touch panel (TSP). In this case, the voltage magnitude (VTX) sensed based on the touch driving signal supplied to the touch driving electrode can be VTX_BP as in FIG. 11a. FIG. 11b shows the waveform of a phase-adjusted touch driving signal (IO_TX) supplied at the point (WP) farthest from the touch driving circuit (150) among the plurality of touch driving electrodes of the touch panel (TSP). In this case, the voltage magnitude (VTX) sensed based on the touch driving signal supplied to the touch driving electrode can be VTX_WP as in FIG. 11b.

[0086] Comparing FIG. 11a and FIG. 7a, in one embodiment, at the point (BP) closest to the touch driving circuit (150) among the plurality of touch driving electrodes of the touch panel (TSP), the difference between when an initial touch driving signal is applied and when a phase-adjusted touch driving signal is applied may be small.

[0087] Comparing FIG. 11b and FIG. 7b, in one embodiment, at the point (WP) furthest from the touch driving circuit (150) among the plurality of touch driving electrodes of the touch panel (TSP), the waveform distortion according to the distance from the touch driving circuit (150) can be reduced when a phase-adjusted touch driving signal is applied compared to when an initial touch driving signal is applied.

[0088] In summary, when using a phase-adjusted touch driving signal, compared to when using an initially generated touch driving signal, the magnitude of the touch driving signal supplied to the touch driving electrode at the point (BP) closest to the touch driving circuit (150) is slightly reduced, and the magnitude of the touch driving signal at the point (WP) furthest from the touch driving circuit (150) is slightly increased.

[0089] FIGS. 12a and FIGS. 12b are drawings illustrating a method for measuring a voltage change amount when performing touch sensing based on a phase-adjusted touch driving signal according to one embodiment of the present specification.

[0090] Referring to FIG. 12a, when the voltage change amount of a phase-adjusted touch driving signal supplied to a touch driving electrode at a point (BP) closest to the touch driving circuit (150) among a plurality of touch driving electrodes of a touch panel (TSP) is measured during a sensing time, the voltage change amount, that is, the sensed voltage magnitude, can be VTX_BP. If the voltage change amount at the point with the best touch performance when using the basic touch driving signal of FIG. 8a is defined as 100% voltage magnitude, then VTX_BP, the sensed voltage magnitude of FIG. 12a, may correspond to 80% in one embodiment.

[0091] Referring to FIG. 12b, when the voltage change amount of a phase-adjusted touch driving signal supplied to the touch driving electrode at the point (WP) furthest from the touch driving circuit (150) among the multiple touch driving electrodes of the touch panel (TSP) is measured during the sensing time, the voltage change amount, that is, the sensed voltage magnitude, can be VTX_WP. This is the voltage change amount at the point where touch performance is worst. If the voltage change amount at the point where touch performance is best when using the basic touch driving signal of FIG. 8a is considered as 100% voltage magnitude, then VTX_WP, the sensed voltage magnitude of FIG. 12b, may correspond to 70% in one embodiment.

[0092] At the point (WP) furthest from the touch driving circuit (150), in the case of FIG. 8b using a basic touch driving signal, the voltage change amount during the sensing time is 60% of the voltage change amount when maximum performance is used, and in the case of FIG. 12b using a phase-adjusted touch driving signal, the voltage change amount during the sensing time is 70% of the voltage change amount when maximum performance is used, so that the touch performance of the touch point (WP) furthest from the touch driving circuit (150) on the touch panel (TSP) can be improved to a sufficient degree.

[0093] At the point (BP) closest to the touch driving circuit (150), the touch performance is best when using a basic touch driving signal, so the voltage change amount is 100% of the voltage magnitude. In the case of FIG. 12a, where a phase-adjusted touch driving signal is used, the voltage change amount during the sensing time is 80% of the voltage change amount when the maximum performance is achieved, so the touch performance may decrease slightly. Nevertheless, since the touch performance at the point where the touch performance is worst is sufficiently improved, the overall touch performance can be improved.

[0094] As described above, the phase-adjusted touch driving signal can be adjusted so that its phase leads the initially generated touch driving signal. Additionally, touch sensing can be performed based on a first voltage, which is the amount of voltage change of the touch driving signal supplied to the touch driving electrode (i.e., the third touch driving signal) measured during the sensing time.

[0095] In one embodiment of the present specification, the phase of the phase-adjusted touch driving signal can be adjusted such that the limit is the moment when the first voltage measured at the touch driving electrodes at the point (WP) furthest from the touch driving circuit among the plurality of touch driving electrodes (i.e., the amount of voltage change of the touch driving signal supplied to the touch driving electrodes measured during the sensing time) becomes equal to the first voltage measured at the touch driving electrodes at the point (BP) closest to the touch driving circuit among the plurality of touch driving electrodes.

[0096] As described above, the touch driving circuit and display device according to one embodiment of the present specification can be configured such that the phase of a touch driving signal synchronized with a reset signal that initializes the touch driving circuit is set to lead a reference, thereby allowing the maximum possible voltage change to be measured at the touch driving electrodes furthest from the touch driving circuit during a sensing time corresponding to the off-level interval of one cycle of the reset signal. Accordingly, the touch performance of the touch point furthest from the touch driving circuit on the touch panel can be improved to a sufficient degree, and the overall touch performance can be enhanced.

[0097] Although embodiments of the present invention have been described in more detail with reference to the attached drawings, the present invention is not necessarily limited to these embodiments and may be modified in various ways within the scope of the technical spirit of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical spirit of the present invention, and the scope of the technical spirit of the present invention is not limited by these embodiments. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of protection of the present invention shall be interpreted by the claims, and all technical spirits within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

[0098] [Explanation of the symbol]

[0099] 110: Host System

[0100] 120: Timing Controller

[0101] 130: Gate driving circuit

[0102] 140: Data driving circuit

[0103] 150: Touch driving circuit

[0104] DIS: Display Panel

[0105] TSP: Touch Panel

Claims

1. Generate a first touch driving signal synchronized with a reset signal that initializes an internal sensing circuit, and A second touch driving signal is generated by adjusting the phase of the first touch driving signal, and The second touch driving signal is transmitted to a plurality of touch driving electrodes of a touch panel through a transmission line, and a third touch driving signal is supplied to each of the plurality of touch driving electrodes. A touch driving circuit that performs touch sensing based on the above third touch driving signal.

2. In Paragraph 1, The above reset signal and the above first touch driving signal are signals having an ON pulse at a regular time interval, and A touch driving circuit in which the on pulse of the first touch driving signal has a rising edge after a first time at the falling edge timing of the first on pulse of the reset signal, and has a falling edge after the first time at the falling edge timing of the second on pulse, which is the next on pulse of the first on pulse.

3. In Paragraph 2, A touch driving circuit in which the second touch driving signal is adjusted to have a phase leading the first touch driving signal.

4. In Paragraph 3, The waveform of the third touch driving signal changes according to the distance between each of the plurality of touch driving electrodes disposed on the touch panel and the touch driving circuit, and The above touch sensing is performed based on a first voltage, which is the amount of voltage change of the third touch driving signal measured during the sensing time, and A touch driving circuit in which the range in which the phase of the second touch driving signal is adjusted is limited to the moment when the first voltage measured at the touch driving electrodes furthest from the touch driving circuit among the plurality of touch driving electrodes becomes equal to the first voltage measured at the touch driving electrodes closest to the touch driving circuit among the plurality of touch driving electrodes.

5. In Paragraph 3, A touch driving circuit in which touch sensing is performed during a sensing time, which is the time from the falling edge timing of the first on pulse of the reset signal to the rising edge timing of the second on pulse.

6. In Paragraph 3, The ON pulse of the second touch driving signal is a touch driving circuit that is generated while the first ON pulse of the reset signal is being generated.

7. Display panel; A touch panel connected to the above-mentioned display panel and comprising a plurality of touch driving electrodes; and It includes a touch driving circuit that drives the above touch panel, and The above touch driving circuit is, A first touch driving signal synchronized with a reset signal that initializes the sensing circuit of the above touch driving circuit is generated, and A second touch driving signal is generated by adjusting the phase of the first touch driving signal, and The second touch driving signal is transmitted to the plurality of touch driving electrodes through a transmission line connected to the touch panel, and a third touch driving signal is supplied to each of the plurality of touch driving electrodes. A display device that performs touch sensing based on the above third touch driving signal.

8. In Paragraph 7, The above reset signal and the above first touch driving signal are signals having an ON pulse at a regular time interval, and A display device in which the on pulse of the first touch driving signal has a rising edge after a first time at the falling edge timing of the first on pulse of the reset signal, and has a falling edge after the first time at the falling edge timing of the second on pulse, which is the next on pulse of the first on pulse.

9. In Paragraph 8, A display device in which the second touch driving signal is adjusted to have a phase leading the first touch driving signal.

10. In Paragraph 9, The waveform of the third touch driving signal changes according to the distance between each of the plurality of touch driving electrodes disposed on the touch panel and the touch driving circuit, and The above touch sensing is performed based on a first voltage, which is the amount of voltage change of the third touch driving signal measured during the sensing time, and A display device in which the range in which the phase of the second touch driving signal is adjusted is limited to the moment when the first voltage measured at the touch driving electrodes furthest from the touch driving circuit among the plurality of touch driving electrodes becomes equal to the first voltage measured at the touch driving electrodes closest to the touch driving circuit among the plurality of touch driving electrodes.

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