Touch display driving apparatus and touch display driving method

Abstract

This application relates to a touch display driving device and a touch display driving method. According to one aspect of this disclosure, a touch display driving device can maintain a constant touch coordinate reporting rate even in a low-speed driving mode with a reduced display refresh rate. The touch display driving device includes: a touch driver that performs a touch scan for acquiring real touch coordinates when a touch synchronization signal for a touch scan period and a display driving period is at a first level; and a touch microcontroller unit that reports virtual touch coordinates at the end of a processing time for calculating real touch coordinates, detects the level of the touch synchronization signal in various touch reporting cycles determined according to a predetermined touch coordinate reporting rate after the end of the processing time, and reports either the virtual touch coordinates or the real touch coordinates based on the detected level of the touch synchronization signal.

Description

Technical Field

[0001] This disclosure relates to display devices, and more specifically, to an embedded touch display. Background Technology

[0002] With the development of information technology, various display devices capable of visualizing information are being developed. Liquid crystal displays (LCDs), organic light-emitting diode (OLED) displays, and plasma display panel (PDP) displays are examples of displays that have been developed or are under development. These display devices are evolving to be able to appropriately display high-resolution images.

[0003] Display panels in various electronic devices (e.g., televisions, laptops, mobile devices, etc.) often employ touch functionality. In such cases, the display panel can be implemented as a flat panel display, and touch functionality can be achieved through a touch panel combined with the display panel. A touch panel refers to a panel that has the function of operating electronic devices or executing programs when a user presses text, images, icons, etc., with their fingers or a stylus.

[0004] For example, a touch panel can be configured to perform touch recognition capacitively; an example of a touch panel implementing capacitive touch recognition has been proposed as a "mutual capacitance type touch sensing device." For instance, the touch panel may have a configuration independent of the display panel and can be manufactured separately and combined with the display panel. As mentioned above, the configuration of combining the touch panel and the display panel leads to various difficulties such as process complexity and increased manufacturing costs.

[0005] To this end, the development of devices in which components for display and components for touch recognition can be shared is being promoted, with the embedded method being a representative example. The embedded method refers to implementing touch recognition using a configuration that implements touch functionality through pixels of a display panel. Pixels implemented using the embedded method perform both display and touch recognition. For example, in a device that provides both touch and display functionality (hereinafter referred to as a "touch display device"), touch operations and display operations can be operated in a time-division manner via display drive signals and touch drive signals.

[0006] When the screen remains unchanged, touch display devices can operate in a low-speed drive mode (e.g., LRR: low refresh rate) with a reduced display refresh rate to reduce power consumption. For accurate touch detection, the touch coordinate reporting rate used to obtain touch coordinates should remain constant even when the display refresh rate decreases, regardless of the refresh rate change. However, in typical touch display devices, the touch coordinate reporting rate can also decrease when the display refresh rate decreases. For example, in a typical touch display device, when the display refresh rate decreases from 60Hz to 30Hz, the touch coordinate reporting rate also decreases from 60Hz to 30Hz, leading to reduced touch detection accuracy and consequently, degraded touch performance. Summary of the Invention

[0007] This disclosure aims to solve the above-mentioned problems and to provide a touch display driving device and a touch display driving method that can maintain the touch coordinate reporting rate at a constant level in a low-speed driving mode with a reduced display refresh rate.

[0008] Furthermore, this disclosure aims to provide a touch display driving device and a touch display driving method, which can report virtual touch coordinates or real touch coordinates to the host according to the level of the touch synchronization signal in each touch reporting cycle determined according to the touch coordinate reporting rate.

[0009] In addition, this disclosure aims to provide a touch display driving device and a touch display driving method that can report touch coordinates in each constant period, regardless of the number of touches.

[0010] A touch display driving device according to one aspect of the present disclosure for addressing the aforementioned technical problem includes: a touch driver that performs a touch scan for acquiring real touch coordinates when a touch synchronization signal for determining a touch scan period and a display driving period is at a first level; and a touch microcontroller unit that reports virtual touch coordinates at the end of a processing time for calculating real touch coordinates, detects the level of the touch synchronization signal in each touch reporting cycle determined according to a predetermined touch coordinate reporting rate after the end of the processing time, and reports either the virtual touch coordinates or the real touch coordinates based on the detected level of the touch synchronization signal.

[0011] A touch display driving method according to one aspect of this disclosure for addressing the aforementioned technical problem includes the following steps: performing a touch scan to generate raw touch data during a touch sensing period in which a touch synchronization signal is maintained at a first level; generating real touch coordinates using the raw touch data; reporting virtual touch coordinates at the time point in which the real touch coordinates are generated; detecting the level of the touch synchronization signal within each touch reporting period determined according to a predetermined touch coordinate reporting rate; and reporting either the virtual touch coordinates or the real touch coordinates based on the detected level. Attached Figure Description

[0012] The accompanying drawings are included to provide a further understanding of this disclosure and are incorporated in and constitute a part of this application. The drawings illustrate embodiments of the disclosure and, together with the description, serve to illustrate the principles of the disclosure. In the drawings:

[0013] Figure 1 This is a block diagram of a touch display system including a touch display driving device according to one embodiment of the present disclosure;

[0014] Figure 2 This is a schematic diagram illustrating an example of an embedded touch panel using the mutual capacitance method;

[0015] Figure 3 This is a schematic diagram illustrating an example of an embedded touch panel using a self-capacitance method;

[0016] Figure 4 It is shown Figure 1 A block diagram showing the configuration of the touch microcontroller unit;

[0017] Figure 5 It is used to describe when the display refresh rate and touch scan rate are at the first frequency. Figure 1 The timing diagram of the operation of the touch display driver shown; and

[0018] Figure 6 It is used to describe when the display refresh rate and touch scan rate are reduced to the third frequency according to the low-speed drive mode. Figure 1 The timing diagram shown illustrates the operation of the touch display driver. Detailed Implementation

[0019] The advantages and features of this disclosure and its implementation methods will be illustrated by the following exemplary embodiments described with reference to the accompanying drawings. However, this disclosure may be embodied in various forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these exemplary embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art. Furthermore, this disclosure is limited only by the scope of the claims.

[0020] Throughout this disclosure, the same reference numerals denote substantially the same elements. In the following description, detailed descriptions of relevant known functions or configurations will be omitted where it is determined that such descriptions would unnecessarily obscure the essence of this disclosure. Furthermore, the element names used in the following description are illustrative and may differ from the names of the actual products corresponding to those elements.

[0021] In the context of the use of “comprising,” “having,” and “including” as described in this disclosure, an additional part may be added. Unless otherwise stated, singular terms may include plural forms.

[0022] When interpreting components, even if not explicitly described, the components are interpreted as including a range of error.

[0023] It will be understood that although the terms “first,” “second,” etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. Therefore, without departing from the scope of this disclosure, the first element referred to below may be called the second element.

[0024] The term "at least one" should be understood to include any and all combinations of one or more of the related listed items. For example, "at least one of the first, second, and third items" means each of the first, second, and third items, as well as all combinations of two or more items derived from the first, second, and third items.

[0025] Those skilled in the art will fully understand that the features of the various exemplary embodiments of this disclosure may be partially or wholly linked or combined with each other, and may interoperate or be combined and technically driven with each other in various ways. The exemplary embodiments of this disclosure may be implemented independently of each other, or may be implemented together in a mutually dependent manner.

[0026] In the following, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0027] Figure 1 This is a block diagram of a touch display system including a touch display driving device according to one embodiment of the present disclosure. Figure 1 The touch display system 100 shown performs display and touch scanning (or touch sensing) in a time-division manner. Although the components for display and the components for touch scanning can be shared in an embedded manner, this embodiment is not limited to a time-division method or an embedded method. For example, the touch display driver device of the following embodiment can also be implemented according to an external method or an embedded method of the overlay surface method.

[0028] According to various embodiments, the display and touch scanning of the touch display driving device can be implemented as separate operations. Here, display means representing a desired image by driving pixels on the display panel, and touch scanning means identifying the touch position on the display panel. Furthermore, the time-division method means that display and touch recognition are performed sequentially in an alternating manner according to the time domain. In one embodiment, touch scanning can be performed during a vertical blank period within a frame time period.

[0029] An embedded method refers to an implementation that enables simultaneous display and touch scanning of pixels in a display panel. For this purpose, a shared component capable of providing capacitance for touch scanning can be used, and at least a connection point of the component may be included. An example of a connection point could be a node (COM) that applies a common voltage, but is not limited to this; various components may be used as connection points depending on the manufacturer's intent.

[0030] Furthermore, the touch display system 100 according to this disclosure can be used in smartphones, tablet computers, laptops, etc., and can provide a thin and lightweight design while achieving high-definition images. According to an embodiment, the touch display system 100 according to this disclosure can be a vertical blanking (VBS) system.

[0031] like Figure 1 As shown, a touch display system 100 according to one embodiment of the present disclosure performs display functions and touch scanning functions, and may include a flat panel display such as a liquid crystal display (LCD) or an organic light-emitting diode display (OLED).

[0032] In one embodiment, the touch display system 100 according to this disclosure may include a capacitive touchscreen integrally implemented therein for sensing touch by contact with a conductive object such as a finger or an active pen. The touchscreen may be configured independently of the display panel used to implement the display, or it may be embedded in the pixel array of the display panel.

[0033] like Figure 1 As shown, a touch display system 100 according to one embodiment of the present disclosure includes a touch display driver 110 and a panel 120 (hereinafter, described as a concept including a touch screen and a display panel). The touch display driver 110 may include a timing controller 210, a gate driver 220, a data driver 230, a touch driver 235, and a touch microcontroller unit 240.

[0034] Panel 120 displays a specific grayscale image or receives touch input from a hand (or finger) or a stylus (or electronic pen). Multiple data lines D1 to Dn connected to data driver 230 and multiple gate lines G1 to Gm connected to gate driver 220 may be formed on panel 120. For example, the multiple data lines D1 to Dn may be arranged in rows or columns, and the multiple gate lines G1 to Gm may be arranged in columns or rows. In the following description, for ease of description, it is assumed that the multiple data lines D1 to Dn are arranged in rows and the multiple gate lines G1 to Gm are arranged in columns.

[0035] Furthermore, multiple pixels P can be defined at the intersection of multiple data lines D1 to Dn and multiple gate lines G1 to Gm.

[0036] Each pixel P can be composed of red (R), green (G), blue (B), and white (W) sub-pixels. In one embodiment, the sub-pixels can be repeatedly formed in the row direction, or they can be formed in a 2*2 matrix form. In this case, a color filter corresponding to each color is provided in each of the red (R), green (G), and blue (B) sub-pixels, while no separate color filter is provided in the white (W) sub-pixels. In one embodiment, the red (R), green (G), blue (B), and white (W) sub-pixels can be formed with the same area ratio, but the red (R), green (G), blue (B), and white (W) sub-pixels can also be formed with different area ratios.

[0037] Each of the multiple pixels P can be a liquid crystal display (LCD) pixel or an organic light-emitting diode (OLED) pixel, but is not limited thereto.

[0038] In one embodiment, panel 120 may be a panel with an embedded touch-type structure using a capacitive method. According to the embodiment, components for display and components for touch scanning may be shared in an embedded manner. For example, a touch electrode TE for detecting touches on a touchscreen may be used as a common voltage electrode to supply a common voltage from the display panel to it. Although embedded panels are known to be an integrated form of a display panel and a touchscreen combination, this is merely an example of the panel 120 described above, and panels applying this disclosure are not limited to embedded panels.

[0039] In one embodiment, panel 120 may be an embedded touch panel using a self-capacitance method or an embedded touch panel using a mutual capacitance method.

[0040] In the following text, refer to Figure 2 and Figure 3 The following will describe in more detail the in-wall touch panel using the mutual capacitance method and the in-wall touch panel using the self-capacitance method.

[0041] Figure 2This is a schematic diagram illustrating an example of an embedded touch panel using a mutual capacitance method. (See diagram for example.) Figure 2 As shown, panel 120 includes touch driving lines TX1 to TXm (m is a natural number greater than or equal to 2), a plurality of touch electrodes TE, and touch sensing lines RX1 to RXn (n is a natural number greater than or equal to 2).

[0042] Touch drive lines TX1 to TXm transmit touch drive signals to each touch electrode TE. Each touch electrode TE may include mutual capacitors. Touch sensing lines RX1 to RXn transmit the voltage (or charge) of each touch electrode TE to the touch driver 235.

[0043] The touch sensing lines RX1 to RXn can refer to the sensing lines of panel 120, or they can also be called touch sensing channels.

[0044] Figure 3 This diagram schematically illustrates an example of an embedded touch panel using a self-capacitance method. In the self-capacitance touch method, which is another type of capacitive touch method, the supply of the touch drive signal and the reception of the capacitance generated by the user's touch or the touch of a stylus are achieved through one of the touch lines T1 to Tk.

[0045] In this self-capacitance touch method, the value sensed at the corresponding touch electrode TE changes according to the touch or proximity of an object such as a finger or pen, and the self-capacitance touch method can use the sensed value to detect the presence or absence of a touch, touch coordinates, etc.

[0046] Refer to Figure 1 Panel 120 can operate in display driving mode and touch scanning mode. Panel 120 can display images during display driving mode and be used as a touch panel for touch scanning during touch scanning mode.

[0047] The timing controller 210 controls the operation of the data driver 230, the gate driver 220, the touch driver 235, and the touch microcontroller unit 240 to enable display and touch scanning to be performed in a time-division manner.

[0048] First, the timing controller 210 controls the data driver 230 and the gate driver 220 for display. The timing controller 210 can control the data driver 230 and the gate driver 220 by supplying various control signals DCS and GCS required for the driving operation of the data driver 230 and the gate driver 220.

[0049] The timing controller 210 starts scanning according to the timing implemented in each frame, converts the externally input image data Idata into the data signal format used by the data driver 230, outputs the converted image data (R / G / B), and drives the scan control data according to the timing.

[0050] The timing controller 210 receives various timing signals TS from an external source (e.g., a host system) along with image data (R / G / B), including vertical synchronization signal Vsync, horizontal synchronization signal Hsync, input data enable (DE) signal, clock signal CLK, etc.

[0051] The timing controller 210 converts externally input image data Idata into the data signal format used by the data driver 230 and outputs the converted image data (R / G / B). In addition, in order to control the data driver 230 and the gate driver 220, the timing controller 210 receives timing signals TS such as vertical synchronization signal Vsync, horizontal synchronization signal Hsync, input data enable (DE) signal, clock signal CLK, etc., generates various control signals, and outputs various control signals to the data driver 230 and the gate driver 220.

[0052] The timing controller 210 can be implemented as a component separate from the data driver 230, or it can be integrated with the data driver 230 and implemented as an integrated circuit.

[0053] The timing controller 210 generates a touch synchronization signal Tsync and sends it to the touch driver 235 and the touch microcontroller unit 240 to control touch operations. The touch synchronization signal Tsync defines the display driving period for displaying the image and the touch scanning period for performing the touch scan. In one embodiment, the period during which the touch synchronization signal Tsync is maintained at a first level (e.g., high level H) can be defined as the display driving period DDT, and the period during which the touch synchronization signal Tsync is maintained at a second level (e.g., low level L) can be defined as the touch scanning period TST.

[0054] According to the implementation, when the touch synchronization signal Tsync is at a first level (e.g., high level H), that is, during the display driving period DDT, the gate driver 220 and the data driver 230 can use a plurality of pixels P included in the panel 120 to display an image corresponding to the image data (R / G / B) according to the control of the timing controller 210.

[0055] The timing controller 210 can send the aforementioned touch synchronization signal Tsync to the general purpose input / output (GPIO) pin of the touch microcontroller unit 240.

[0056] In one implementation, the timing controller 210 can detect the display refresh rate based on the vertical synchronization signal Vsync, generate a touch synchronization signal Tsync according to the detection result, and send the touch synchronization signal Tsync to the GPIO pin of the touch microcontroller unit 240.

[0057] For example, such as Figure 5 As shown, when the display refresh rate is a first frequency (e.g., 60Hz), the timing controller 210 can generate a touch synchronization signal Tsync corresponding to the first frequency (60Hz) display refresh rate.

[0058] As another example, such as Figure 6 As shown, when the display refresh rate is reduced to the third frequency (30Hz), the timing controller 210 can generate a touch synchronization signal Tsync corresponding to the third frequency (e.g., 30Hz) display refresh rate.

[0059] Gate driver 220 supplies scan signals to gate lines G1 to Gm to turn switches (e.g., transistors) located at each pixel P on and off. Depending on the driving method, gate driver 220 may be configured as follows: Figure 1 The image shown is located only on one side of panel 120, or it can be divided into two and located on both sides of panel 120.

[0060] Gate driver 220 may include at least one gate driver integrated circuit. The at least one gate driver integrated circuit may be connected to bonding pads of panel 120 using a tape-on-board (TAB) method or a chip-on-glass (COG) method, or may be implemented as a gate-in-panel (GIP) type and formed directly on panel 120, and in some cases, may be formed by integration into panel 120. Furthermore, gate driver 220 may be implemented using a chip-on-film (COF) method.

[0061] Gate driver 220 can receive a gate control signal GCS, generate a gate drive signal corresponding to the gate control signal GCS, and provide the gate drive signal to pixel P of panel 120. According to one embodiment, gate driver 220 may include an input buffer, a shift register, a level shifter, and an output buffer. The input buffer can receive the gate control signal GCS and output the gate control signal GCS to the shift register, and the shift register can control the sequential generation of scan pulses as gate signals sent through the input buffer, column by column, of panel 120. The level shifter has the function of changing the output voltage level of the shift register to a level that enables thin-film transistors (TFTs) configured as switches to be turned on and off, and the output buffer can change the signal output from the level shifter and output the signal as a gate drive signal capable of driving gate lines G1 to Gm with RC loads.

[0062] Data driver 230 supplies data voltage to data line DL to display images on individual pixels P of panel 120. Data driver 230 may include at least one source driver integrated circuit (SDIC). At least one SDIC may be connected to bonding pads of panel 120 using tape auto-bonding (TAB) or chip-on-glass (COG) methods, or may be formed directly on panel 120, and in some cases, may be formed by integration into panel 120. Furthermore, data driver 230 may be implemented using chip-on-film (COF) methods.

[0063] The SDIC can be configured to generate a source drive signal based on the data control signal (DCS) and provide the source drive signal to the pixel P of the panel 120. The SDIC typically includes a latch, a digital-to-analog converter (DAC), and an output buffer. Here, the latch stores image data according to the display control signal and provides the image data to the DAC, and the DAC can output an analog signal of the voltage corresponding to the input image data. The output buffer transmits the output of the DAC as a source drive signal to the pixel P of the panel 120 via data lines D1 to Dn.

[0064] In one implementation, such as Figure 5 As shown, when the display refresh rate is a first frequency (e.g., 60Hz), the SDIC displays an image corresponding to the image data (R / G / B) input from the timing controller 210 during the period when the touch synchronization signal Tsync is at a first level (e.g., high level) within a frame time period.

[0065] Subsequently, as the touch display system 100 operates in low refresh rate (LRR) mode, such as Figure 6 As shown, when the display refresh rate is reduced to a third frequency (e.g., 30Hz), the SDIC displays an image corresponding to the image data input from the timing controller 210 during the first time period P1, which is within a frame time period when the touch synchronization signal Tsync is at a first level (e.g., high level). However, during the second time period P2, which is separate from the first time period P1, no image corresponding to the new image data is output, and the previously output image is maintained. Since no new image is output and the previous image is maintained, the second time period P2 can be defined as a dummy blank period.

[0066] Touch driver 235 uses touch drive signals to drive a plurality of touch electrodes TE disposed on panel 120. Touch driver 235 may include touch sensing circuitry for controlling the operation of the plurality of touch electrodes TE included on panel 120. Touch driver 235 can sense the touch or proximity of an external object to panel 120 based on response signals formed at the touch electrodes TE in response to the touch drive signals. In this case, touch driver 235 can identify the proximity or touch of an object by detecting the capacitance or capacitance change of the touch electrodes TE. Touch driver 235 receives the sensed values ​​of the touch electrodes TE to generate touch raw data RawD. Touch driver 235 sends the generated touch raw data RawD to touch microcontroller unit 240.

[0067] In one implementation, the touch driver 235 may be implemented using multiple touch readout integrated circuits (ROICs). Furthermore, when the touch driver 235 is implemented using multiple ROICs, the SDIC and ROIC may be implemented as a single chip (SRIC: source driver and touch readout IC).

[0068] The touch microcontroller unit 240 can receive a touch synchronization signal Tsync from the timing controller 210 and control the touch scan timing of the touch driver 235 based on the touch synchronization signal Tsync. Furthermore, the touch microcontroller unit 240 uses the raw touch data RawD sent from the touch driver 235 to calculate the actual touch coordinates. The touch microcontroller unit 240 sends (or reports) the calculated actual touch coordinates to another device (e.g., a host, controller, or processor).

[0069] In one implementation, the touch microcontroller unit 240 can detect the level of the touch synchronization signal Tsync during each touch reporting cycle generated based on the touch coordinate reporting rate, and output either virtual touch coordinates or real touch coordinates to the host according to the detected level.

[0070] Figure 5 It is used to describe when the display refresh rate and touch scan rate are at the first frequency (e.g., 60Hz). Figure 1 The diagram shows the timing of the operation of the touch display system.

[0071] Reference Figure 1 and Figure 5 When the display refresh rate is a first frequency (e.g., 60Hz), the touch scan rate (or touch sensing rate) for obtaining the actual touch coordinates is a first frequency (e.g., 60Hz), and the touch coordinate reporting rate is a second frequency (e.g., 120Hz).

[0072] In this context, the touch coordinate reporting rate (e.g., 120Hz) according to this disclosure is defined as the rate at which either virtual touch coordinates or real touch coordinates are output within each touch reporting cycle (e.g., the reciprocal of 120Hz, i.e., 8.33ms). For ease of description, times (e.g., 16.66ms, 8.33ms, and 33.33ms) are expressed to only two decimal places in this specification.

[0073] When the touch synchronization signal Tsync is at the second level (e.g., low level L), that is, during the touch scan period TST, the touch microcontroller unit 240 controls the touch driver 235 to cause the touch driver 235 to perform a touch scan operation.

[0074] The touch driver 235 generates touch raw data RawD corresponding to the response signal generated by the touch electrode TE included in the panel 120, and sends the touch raw data RawD to the touch microcontroller unit 240 under the control of the touch microcontroller unit 240.

[0075] The touch microcontroller unit 240 first outputs the first virtual touch coordinate VTCi (i=1) to the host, and then detects the level of the touch synchronization signal Tsync in each touch reporting cycle generated according to the touch coordinate reporting rate and outputs either the virtual touch coordinate or the real touch coordinate to the host based on the detected level.

[0076] Therefore, such as Figure 4 As shown, the touch microcontroller unit 240 includes a level detection unit 242, a virtual touch coordinate generation unit 244, a real touch coordinate generation unit 246, and a selection unit 248. In one embodiment, the level detection unit 242, the virtual touch coordinate generation unit 244, the real touch coordinate generation unit 246, and the selection unit 248 may be implemented as software executed by the touch microcontroller unit 240. In another embodiment, the level detection unit 242, the virtual touch coordinate generation unit 244, the real touch coordinate generation unit 246, and the selection unit 248 may be implemented as hardware performing the functions described in this specification.

[0077] The level detection unit 242 uses a timer in the touch microcontroller unit 240 to calculate the touch reporting cycle and detects the level of the touch synchronization signal Tsync within each calculated touch reporting cycle. The operation of the selection unit 248 can be controlled based on the detection results. The timer can use the output signal of a clock generator (or oscillator) to calculate the touch reporting cycle.

[0078] The virtual touch coordinate generation unit 244 can generate each of the virtual touch coordinates VTC1 and VTC2. For example, the virtual touch coordinate generation unit 244 can generate virtual touch coordinates by interpolating previous real touch coordinates.

[0079] When the touch synchronization signal Tsync is low, the real touch coordinate generation unit 246 can use the raw touch data RawD output from the touch driver 235 to calculate the real touch coordinates RTC.

[0080] Selection unit 248 can output either virtual touch coordinates VTC1 or VTC2 and real touch coordinates RTC to the host based on the level of the touch synchronization signal Tsync detected by level detection unit 242 in each touch reporting cycle.

[0081] Selection unit 248 outputs a first virtual touch coordinate (VTCi, i=1) to the host at a first time point T1. The first time point T1 is the point in time at which the maximum processing time PT_max, between the minimum processing time PT_min and the maximum processing time PT_max required to generate the real touch coordinates using the raw touch data RawD corresponding to the response signal output from the touch electrodes TE included in the panel 120, has elapsed during the touch scanning period TST. In one embodiment, the maximum processing time PT_max can be defined as the time to add a predetermined blank time BT to the minimum processing time PT_min.

[0082] In this disclosure, selection unit 248 outputs first virtual touch coordinates at a first time point T1, which is the time point when the maximum processing time PT_max has elapsed. Since the processing time can vary depending on the number of touches, when the touch coordinates are reported based on the actual processing time, the interval between the touch coordinates (e.g., virtual touch coordinates or real touch coordinates) reported for each frame may not be maintained at a constant level.

[0083] Therefore, when calculating the maximum processing time PT_max, since the selection unit 248 of this disclosure outputs the first virtual touch coordinates at the first time point T1 after the calculated maximum processing time PT_max has elapsed, and then outputs touch coordinates (e.g., virtual touch coordinates or real touch coordinates) at specific time intervals (e.g., 8.33ms) thereafter (e.g., at the second time point T2 and the third time point T3), the time interval for reporting touch coordinates (e.g., virtual touch coordinates or real touch coordinates) for each frame can be maintained uniformly.

[0084] For example, the selection unit 248 outputs the first virtual touch coordinate VTC1 generated by the virtual touch coordinate generation unit 244 as the output signal MUXO at the first time point T1, where the first time point T1 is the time point when the maximum processing time PT_max has elapsed.

[0085] The level detection unit 242 detects the level of the touch synchronization signal Tsync at the first time point T1 of the output first virtual touch coordinate VTC1 according to the touch report period calculated by the timer (e.g., 8.33ms), that is, at the second time point T2. Since the level of the touch synchronization signal Tsync is the second level (low level L) at the second time point T2, the selection unit 248 selects the real touch coordinate RTC generated by the real touch coordinate generation unit 246 as the output signal MUXO according to the control output of the level detection unit 242.

[0086] The level detection unit 242 detects the level of the touch synchronization signal Tsync at the second time point T2 of the output real touch coordinate RTC according to the touch report period calculated by the timer (e.g., 8.33ms), that is, at the third time point T3. Since the level of the touch synchronization signal Tsync is the first level (high level H) at the third time point T3, the selection unit 248 selects the second virtual touch coordinate VTCi (i=2) generated by the virtual touch coordinate generation unit 244 as the output signal MUXO according to the control output of the level detection unit 242.

[0087] In addition, such as Figure 6 As shown, when the touch display system 100 operates in a low-speed drive mode where the display refresh rate decreases from 60Hz to 30Hz, the touch scan rate also decreases from 60Hz to 30Hz. However, according to this disclosure, since the touch microcontroller unit 240 can report either the virtual touch coordinate or the real touch coordinate within each predetermined touch reporting cycle from the time point at which the first virtual touch coordinate VTC1 is reported, the touch coordinate reporting rate (e.g., 120Hz) can be maintained at a constant level regardless of changes in the display refresh rate and the touch scan rate.

[0088] See also the following text. Figure 4 and Figure 6 The operation of the touch display system 100 in low-speed drive mode will be described in more detail.

[0089] Figure 6 This is used to describe the operation of a touch display system in a low-speed drive mode where the display refresh rate and touch scan rate are reduced to a third frequency (e.g., 30Hz). Figure 1 The diagram shows the timing of the operation of the touch display system.

[0090] and Figure 5 In comparison, Figure 6 In this case, even though the display refresh rate is reduced to a third frequency (e.g., 30Hz) and the touch scan rate for performing the touch scan to obtain the actual touch coordinates is also reduced to a third frequency (e.g., 30Hz), it can be seen that regardless of the changes in the display refresh rate and the touch scan rate, the touch coordinate reporting rate remains at a constant level at a second frequency (e.g., 120Hz).

[0091] As described above, the touch coordinate reporting rate (e.g., 120Hz) according to this disclosure is defined as the rate at which either virtual touch coordinates or real touch coordinates are output within each touch reporting cycle (e.g., the reciprocal of 120Hz, i.e., 8.33ms).

[0092] When the touch synchronization signal Tsync is at the second level (low level L), that is, during the touch scan period TST, the touch microcontroller unit 240 generates a control signal for controlling the touch driver 235 based on the touch synchronization signal Tsync with the second level (low level L).

[0093] The touch microcontroller unit 240 can first output a first virtual touch coordinate VTC1 at a first time point T1, and then detect the level of the touch synchronization signal Tsync within a touch reporting period (e.g., 8.33ms) generated based on the touch coordinate reporting rate (e.g., 120Hz) and output either the virtual touch coordinate or the real touch coordinate according to the detected level.

[0094] The virtual touch coordinate generation unit 244 can generate each of the virtual touch coordinates VTC1, VTC2, VTC3, and VTC4. For example, the virtual touch coordinate generation unit 244 can generate each of the virtual touch coordinates VTC1, VTC2, VTC3, and VTC4 by interpolating at least two previous real touch coordinates.

[0095] like Figure 6 As shown, the selection unit 248 outputs the first virtual touch coordinate VTCi (i=1) generated by the virtual touch coordinate generation unit 244 as the output signal MUXO at the first time point T1 according to the control of the level detection unit 242. The first time point T1 is the time point when the maximum processing time PT_max has elapsed.

[0096] The level detection unit 242 detects the level of the touch synchronization signal Tsync at the first time point T1 of the output first virtual touch coordinate VTC1 according to the touch report period calculated by the timer (e.g., 8.33ms), that is, at the second time point T2. Since the level of the touch synchronization signal Tsync is the first level (high level H) at the second time point T2, the selection unit 248 selects the second virtual touch coordinate VTCi (i=2) generated by the virtual touch coordinate generation unit 244 according to the control of the level detection unit 242 as the output signal MUXO.

[0097] The level detection unit 242 detects the level of the touch synchronization signal Tsync at the second time point T2 according to the touch reporting period calculated by the timer (e.g., 8.33ms), that is, at the third time point T3. Since the level of the touch synchronization signal Tsync at the third time point T3 is the dummy blank period DBLANK, that is, the first level (high level H), the selection unit 248 outputs the third virtual touch coordinate VTCi (i=3) generated by the virtual touch coordinate generation unit 244 according to the control of the level detection unit 242 as the output signal MUXO.

[0098] The level detection unit 242 detects the level of the touch synchronization signal Tsync at the third time point T3 according to the touch reporting period calculated by the timer (e.g., 8.33ms), that is, at the fourth time point T4. Since the level of the touch synchronization signal Tsync is the second level (low level L) at the fourth time point T4, the selection unit 248 outputs the real touch coordinates RTC generated by the real touch coordinate generation unit 246 as the output signal MUXO according to the control of the level detection unit 242.

[0099] The level detection unit 242 detects the level of the touch synchronization signal Tsync at the fourth time point T4 according to the touch reporting period calculated by the timer (e.g., 8.33ms), that is, at the fifth time point T5. Since the level of the touch synchronization signal Tsync is the first level (high level H) at the fifth time point T5, the selection unit 248 outputs the fourth virtual touch coordinate VTCi (i=4) generated by the virtual touch coordinate generation unit 244 according to the control of the level detection unit 242 as the output signal MUXO.

[0100] like Figure 6 As shown, even when the touch scan rate is reduced to 30Hz according to the operation in low-speed drive mode, the touch display system 100 can stably maintain the touch coordinate report rate (e.g., 120Hz) because the touch microcontroller unit 240 outputs virtual touch coordinates and real touch coordinates in each touch report cycle determined according to the touch coordinate report rate (e.g., 120Hz).

[0101] According to this disclosure, since virtual touch coordinates or real touch coordinates can be reported to the host in each touch reporting cycle determined according to a predetermined touch coordinate reporting rate, regardless of the display refresh rate, the touch coordinate reporting rate can be maintained at a constant level even in a low-speed drive mode where the display refresh rate is reduced.

[0102] Furthermore, according to this disclosure, since either the virtual touch coordinates or the real touch coordinates can be periodically reported to the host based on the level detection results of the touch synchronization signal that determines the touch scanning period and the display driving period, it has the effect that a stable touch coordinate reporting rate can be maintained even in low-speed driving mode, thus improving touch performance.

[0103] Furthermore, according to this disclosure, since the virtual touch coordinates are reported based on the endpoint of the maximum processing time required to calculate the touch coordinates according to the number of touches, and either the virtual touch coordinates or the real touch coordinates are reported at a constant period from the time point when the first virtual touch coordinates are reported, it has the effect that touch reporting can be performed at a constant period even when the processing time varies according to the number of touches.

[0104] It will be apparent to those skilled in the art that various modifications and variations can be made to this disclosure without departing from the spirit or scope thereof. Therefore, this disclosure is intended to cover such modifications and variations.

[0105] The various embodiments described above can be combined to provide further embodiments. Based on the above description, these and other changes can be made to the embodiments. Generally, the terminology used in the following claims should not be construed as limiting the claims to the specific embodiments disclosed in the specification and claims, but should be interpreted to include all possible embodiments and the full scope of equivalents enjoyed by these claims. Therefore, these claims are not limited by this disclosure.

[0106] Cross-references to related applications

[0107] This application claims the benefit of Korean Patent Application No. 10-2025-0003751, filed on January 9, 2025, which is incorporated herein by reference as fully set forth herein.

Claims

1. A touch display driving device, the touch display driving device comprising: The touch driver performs a touch scan to obtain the actual touch coordinates when the touch synchronization signal for the touch scanning period and the display driving period is at a first level. as well as A touch microcontroller unit reports virtual touch coordinates at the end of the processing time for calculating the real touch coordinates, detects the level of the touch synchronization signal in each touch reporting cycle determined according to a predetermined touch coordinate reporting rate after the end of the processing time, and reports either the virtual touch coordinates or the real touch coordinates according to the detected level of the touch synchronization signal.

2. The touch display driving device according to claim 1, wherein, When the detected touch synchronization signal level is the second level, the touch microcontroller unit reports the virtual touch coordinates; and when the detected touch synchronization signal level is the first level, the touch microcontroller unit reports the actual touch coordinates. The first level is either a low level or a high level, and The second level is the other of the low level and the high level.

3. The touch display driving device according to claim 1, wherein, When the display refresh rate and touch scan rate used to obtain the actual touch coordinates are at a first frequency, the touch microcontroller unit sets the touch coordinate reporting rate to a second frequency higher than the first frequency, and when the display refresh rate and the touch scan rate are reduced to a third frequency lower than the first frequency according to the low-speed drive mode, the touch microcontroller unit maintains the touch coordinate reporting rate at the second frequency.

4. The touch display driving device according to claim 1, wherein, The touch driver generates raw touch data for obtaining the actual touch coordinates from multiple touch electrodes included in the embedded panel. During the touch scanning period when the touch synchronization signal is maintained at the first level, the touch driver generates raw touch data corresponding to the response signals output from the plurality of touch electrodes, and The touch microcontroller unit includes a true touch coordinate generation unit that uses the raw touch data to generate the true touch coordinates.

5. The touch display driving device according to claim 4, wherein, The processing time includes the first time for calculating the actual touch coordinates using the raw touch data and the blank time determined based on the maximum processing time required to calculate the actual touch coordinates.

6. The touch display driving device according to claim 1, wherein, The touch microcontroller unit includes: A level detection unit that detects the level of the touch synchronization signal during each touch reporting cycle; A virtual touch coordinate generation unit that generates the virtual touch coordinates using multiple previously calculated real touch coordinates; and The selection unit outputs either the virtual touch coordinates or the real touch coordinates based on the detection result of the level detection unit.

7. The touch display driving device according to claim 1, further comprising: A data driver that displays an image during the display driving period when the touch synchronization signal is maintained at the second level; as well as A timing controller that generates the touch synchronization signal and sends image data to the data driver. Wherein, when the display refresh rate is the first frequency, the data driver displays an image corresponding to the image data input from the timing controller during the period when the touch synchronization signal is at the second level within a unit frame time period, and When the display refresh rate decreases from a first frequency to a third frequency, the data driver displays an image corresponding to input image data from an external source during a first time period in the time period during which the touch synchronization signal is at the second level within a unit frame time period, and maintains the previous image during the remaining second time period excluding the first time period.

8. The touch display driving device according to claim 7, wherein, The touch driver and the data driver are implemented as a single chip.

9. A touch display driving method, the touch display driving method comprising the following steps: A touch scan is performed during the touch sensing period when the touch synchronization signal is maintained at the first level to generate raw touch data; Use the raw touch data to generate real touch coordinates; Report the virtual touch coordinates at the time point at which the actual touch coordinates are generated; The level of the touch synchronization signal is detected within each touch reporting cycle determined according to a predetermined touch coordinate reporting rate; as well as Report either the virtual touch coordinates or the real touch coordinates based on the detected level.

10. The touch display driving method according to claim 9, wherein, When reporting either the virtual touch coordinates or the actual touch coordinates When the detected touch synchronization signal level is the second level, the virtual touch coordinates are reported; and when the detected touch synchronization signal level is the first level, the real touch coordinates are reported. The first level is either a low level or a high level, and The second level is the other of the low level and the high level.

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