Control method of touch display device

Abstract

The present application relates to a control method of a touch display device. The control method of the touch display device comprises the following steps: dividing a whole screen touch operation into N touch detections; (A) when a vertical synchronization signal is received, performing N times of display scanning, and after each time of display scanning, performing touch detection; (B) when the N times of touch detection are completed, and before a next vertical synchronization signal is received, continuously performing touch detection; when the next vertical synchronization signal is received, returning to step (A) and step (B) to continuously perform display scanning and touch detection, wherein N is a natural number.

Description

Technical Field

[0001] This invention relates to a technology for a touch display panel, and more specifically, to a control method for a touch display device. Background Technology

[0002] With technological advancements, mobile devices are becoming increasingly prevalent, leading to a growing market demand for competitive video games. Currently, display devices generally employ a fixed refresh rate, based on standards set by the Video Electronics Standards Association (VESA). However, video games often experience a disconnect between the screen refresh rate and the display adapter's image updates. This asynchrony causes screen tearing, significantly impacting the gaming experience.

[0003] Therefore, dynamic refresh rate technologies (adaptive synchronization technologies) emerged, such as G-Sync, FreeSync, and Q-Sync. Previously, display adapters had to adaptively output frame images to the monitor according to its specifications; that is, the frame had to be output to the monitor immediately at the designated time. However, adaptive synchronization technology allows the monitor to adapt to the display adapter's frame rate to eliminate screen tearing. In other words, the monitor must be able to receive frame rates from the display adapter at different speeds and display them accordingly.

[0004] This technology is generally used in the gaming market, so it's applied to touchscreen displays and requires a high touch reporting rate to enhance game operability. However, current touch technologies lack adaptive synchronization for reporting, therefore, they currently still use integer multiples for reporting. Figure 1 As shown, Figure 1 This diagram illustrates the relationship between the display frame rate and touch reporting rate in existing technologies. As can be seen, at 30 frames per second, the touch reporting rate is 120 (4 touch points reported per frame). At 60 frames per second, the touch reporting rate is 60 (1 touch point reported per frame). Therefore, applying the method of using an integer multiple of the touch reporting rate to the display frame rate to non-integer dynamic display technologies results in significant fluctuations in the touch reporting rate. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to provide a control method for a touch display device, which utilizes the time before vertical synchronization is reached after scanning to perform touch detection again, so as to improve and stabilize the reporting rate.

[0006] This invention provides a control method for a touch display device, which includes the following steps: performing a display operation on the entire screen at a variable refresh rate; dividing the touch operation of the entire screen into N touch detection steps; (A) when a vertical synchronization signal is received, performing N display scans, and performing touch detection after each display scan; (B) when the Nth touch detection is completed, and before receiving the next vertical synchronization signal, continuing to perform touch detection; when the next vertical synchronization signal is received, returning to steps (A) and (B) to continue performing display scanning and touch detection, where N is a natural number.

[0007] According to the preferred embodiment of the present invention, the control method of the touch display device further includes the following steps: storing touch noise data during the first to Nth display scans; when performing touch detection after the Kth display scan is completed, using the touch noise data during the Kth display scan to determine the touch point, wherein K is a natural number, and K is less than or equal to N and K is greater than 0.

[0008] According to the preferred embodiment of the present invention, the control method of the touch display device further includes the following steps: storing touch noise data when there is no display scan; when performing the touch detection in step (B) after the Nth display scan is completed, using the touch noise data when there is no display scan to determine the touch point.

[0009] According to the control method of the touch display device of the preferred embodiment of the present invention, if a vertical synchronization signal is received before the current touch detection is completed during step (B), the touch detection is abandoned and the process returns to step (A). In a preferred embodiment, when steps (A) and (B) are completed, and before the next vertical synchronization signal is received, step (B) continues to be performed to perform touch detection.

[0010] According to a preferred embodiment of the control method for a touch display device of the present invention, step (A) includes: (A) when a vertical synchronization signal is received, performing N display scans, and performing touch detection after each display scan, wherein the first touch detection is performed after the first display scan. In a preferred embodiment, the number of touch detections is determined according to the number of steps (B), wherein the Jth touch detection is performed when performing the Jth step (B), wherein J is a natural number, and J is greater than 0 and less than or equal to N; the number of touch detections is determined according to the number of steps (B), wherein the LM*Nth touch detection is performed when performing the Lth step (B), wherein L is a natural number, and L is greater than N, wherein LM*N is a natural number, and LM*N is greater than 0 and less than or equal to N.

[0011] The spirit of this invention lies in the fact that, driven by a dynamic refresh rate, the touch display device utilizes screen scanning to complete the touch detection of one screen, and before the vertical synchronization signal arrives, performs at least one more touch detection. Thus, regardless of changes in the screen refresh rate, the touch reporting rate can be maintained within a certain range, resulting in smoother device operation. Furthermore, the touch display device provided by this invention can also store noise during the touch calibration stage and utilize and filter the stored noise during the touch detection stage.

[0012] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0013] Figure 1 This is a schematic diagram illustrating the relationship between the display frame rate and the touch reporting rate in existing technologies.

[0014] Figure 2 This is a timing diagram of a control method for a touch display device according to a preferred embodiment of the present invention.

[0015] Figure 3 This is a timing diagram of a control method for a touch display device according to a preferred embodiment of the present invention.

[0016] Figure 4 This is a flowchart of a control method for a touch display device according to a preferred embodiment of the present invention.

[0017] Figure 5 This is a flowchart of a sub-step of step S401 and the steps preceding step S401 in the control method of a touch display device according to a preferred embodiment of the present invention.

[0018] Figure 6 This is a flowchart of a sub-step of step S403 in the control method of a touch display device according to a preferred embodiment of the present invention.

[0019] Figure 7 This is a schematic diagram of the display frame rate versus touch reporting rate in a control method for a touch display device according to a preferred embodiment of the present invention.

[0020] Figure 8 This is a schematic diagram of the display frame rate versus touch reporting rate in a control method for a touch display device according to a preferred embodiment of the present invention.

[0021] Symbol explanation:

[0022] VSYNC: Indicates vertical synchronization signal

[0023] DT1: First scan

[0024] DT2: Second scan

[0025] DT3: Third scan

[0026] DT4: Fourth scan

[0027] N1, N2, N3, N4, NP: Represent the noise during touch detection.

[0028] TT1: First touch detection area

[0029] TT2: Second touch detection area

[0030] TT3: Third Touch Detection Area

[0031] TT4: Fourth Touch Detection Zone

[0032] blank: blank period

[0033] S401~S403: Steps of the embodiments of the present invention

[0034] S501~S505: Steps of the embodiments of the present invention

[0035] S601: Steps of the Embodiments of the Invention Detailed Implementation

[0036] Figure 2 This is a timing diagram of a control method for a touch display device according to a preferred embodiment of the present invention. Please refer to... Figure 2 VSYNC represents the vertical synchronization signal; DT1 to DT4 represent the first to fourth display scans of a frame, respectively; TT1 to TT4 represent the first to fourth touch detection areas on the screen. Additionally, N1, N2, N3, N4, and NP represent touch detection noise corresponding to different display scan segments, where noise N1 corresponds to the first display scan DT1; noise N2 corresponds to the second display scan DT2; noise N3 corresponds to the third display scan DT3; noise N4 corresponds to the fourth display scan DT4; and noise NP is the background noise when no display scan is performed. Since touch detection is highly sensitive to noise, in this embodiment, noise N1, N2, N3, N4, and NP are, for example, noise data pre-stored after initial touch calibration.

[0037] As can be seen from the timing diagram above, the interval between each vertical synchronization signal (VSYNC) is different. Because this design employs adaptive synchronization technology, the frame data is provided to the touch display panel only after the display adapter generates the frame. In this embodiment, the first frame is at 120Hz, the second at 96Hz, and the third at 120Hz. Since the display panel passively receives the frame data in adaptive synchronization technology, replacing the previous method of receiving the frame data at set times, each receipt of the vertical synchronization signal (VSYNC) indicates the start of display frame scanning.

[0038] In this embodiment, upon receiving the first vertical synchronization signal VSYNC, the first scan DT1 begins, followed by touch detection of the first touch detection area TT1 of a frame. This is followed by the second scan DT2, then touch detection of the second touch detection area TT2 of a frame, and so on. When touch detection of the fourth touch detection area TT4 of a frame is completed, the next vertical synchronization signal VSYNC is received, and the process continues with the next frame: the first scan DT1, touch detection of the first touch detection area TT1, the second scan DT2, touch detection of the second touch detection area TT2, the third scan DT3, touch detection of the third touch detection area TT3, the fourth scan DT4, and touch detection of the fourth touch detection area TT4. Afterwards, since the next vertical synchronization signal VSYNC has not yet been received, there is a blanking period before touch detection of the first touch detection area TT1 resumes. After completing the touch detection in the first touch detection area TT1, the system immediately receives the next vertical synchronization signal VSYNC, and thus begins the next frame's first scan DT1, touch detection in the second touch detection area TT2, second scan DT2, touch detection in the third touch detection area TT3, third scan DT3, touch detection in the fourth touch detection area TT4, fourth scan DT4, and touch detection in the first touch detection area TT1.

[0039] Furthermore, since noise has a significant impact on touch control, especially the noise of the display (generally a liquid crystal display, LCD), this embodiment records the touch detection noise caused by different display scanning sections (N1, N2, N3, N4, NP in the figure below). During the touch phase, the noise from the LCD at the corresponding position of the touch scanning section is eliminated. Figure 2For the first touch detection area TT1, there are different noise levels corresponding to different LCD scanning noises: N1 / N1 / NP / N4. During the touch calibration stage, this noise data generated by the display scanning is stored in the base data of the first touch detection area TT1. The base data represents the capacitive sensing data of the first touch detection area TT1 when there is no touch. When actual touch is detected, the actual touch data is obtained by subtracting the corresponding base data from the actual detected data of the first touch detection area TT1. In the touch detection section, different base data (N1, N2, N3, N4, or NP) are used according to the positions of the touch detection areas TT1, TT2, TT3, and TT4 and different touch detection times. This filters out the influence of the LCD noise section with asynchronous display frame rates.

[0040] Figure 3 This is a timing diagram of a control method for a touch display device according to a preferred embodiment of the present invention. Please refer to... Figure 3 Similarly, VSYNC represents the vertical synchronization signal; DT1 to DT4 represent the first to fourth scans of a frame, respectively; TT1 to TT4 represent the first to fourth touch detection areas of a screen. Additionally, N1, N2, N3, N4, and NP represent touch detection noise corresponding to different display scan segments, where noise N1 corresponds to the first display scan DT1; noise N2 corresponds to the second display scan DT2; noise N3 corresponds to the third display scan DT3; noise N4 corresponds to the fourth display scan DT4; and noise NP is the background noise when not scanning. Since touch detection is highly sensitive to noise, in this embodiment, noise N1, N2, N3, N4, and NP are, for example, noise data pre-stored after initial touch calibration.

[0041] In this embodiment, the first frame F1 is 120Hz; the second frame F2 is 96Hz; the third frame F3 is 96Hz; and the fourth frame F4 is 96Hz. Upon receiving the first vertical synchronization signal VSYNC, the first scan DT1 begins, followed by touch detection of the first touch detection area TT1 of a frame. This is followed by the second scan DT2, then touch detection of the second touch detection area TT2 of a frame, and so on. When touch detection of the fourth touch detection area TT4 of a frame is completed, the next vertical synchronization signal VSYNC is received, and the process continues with the next frame: the first scan DT1, touch detection of the first touch detection area TT1, the second scan DT2, touch detection of the second touch detection area TT2, the third scan DT3, touch detection of the third touch detection area TT3, the fourth scan DT4, and touch detection of the fourth touch detection area TT4. Afterwards, since the next vertical synchronization signal VSYNC has not yet been received, a blanking period is passed before touch detection of the fourth touch detection area TT4 continues.

[0042] After touch detection in the fourth touch detection area TT4 is completed, the next vertical sync signal VSYNC is immediately received, so the process continues with the first scan DT1, touch detection in the first touch detection area TT1, the second scan DT2, touch detection in the second touch detection area TT2, the third scan DT3, touch detection in the third touch detection area TT3, the fourth scan DT4, and touch detection in the fourth touch detection area TT4. Afterwards, since the next vertical sync signal VSYNC has not yet been received, there is a blanking period before touch detection in the third touch detection area TT3 resumes. This process continues, with the blanking period in the next frame during which touch detection in the second touch detection area TT2 resumes; and the blanking period in the next frame after that during which touch detection in the first touch detection area TT1 resumes.

[0043] In the above embodiments, by adjusting the scanning order of the touch detection areas, the order of the touch detection areas after the display scan is fixed (that is, the touch detection of the touch detection area TT1 is fixed after the first display scan DT1; the touch detection of the touch detection area TT2 is fixed after the second display scan DT2; the touch detection of the touch detection area TT3 is fixed after the third display scan DT3; and the touch detection of the touch detection area TT4 is fixed after the fourth display scan DT4). In this way, the noise generated by the gate signal of the liquid crystal display has a fixed relationship with the touch detection area (N1 corresponds to the touch detection area TT1; N2 corresponds to the touch detection area TT2; N3 corresponds to the touch detection area TT3; and N4 corresponds to the touch detection area TT4). Therefore, the noise of the liquid crystal display is fixed and predictable, and this part of the noise can be filtered out during the touch detection stage. The advantage of this is that, during the initial touch calibration, for the first display scan DT1, only the noise N1 corresponding to the touch detection area TT1 needs to be stored, without needing to store the noise N2 to N4 corresponding to the touch detection areas TT2 to TT4. This reduces memory usage. Furthermore, the noise of the LCD during the vertical blanking period is also fixed (background noise NP without display scan), and this noise NP is independent of the position of the touch during the vertical blanking period. Therefore, this part of the LCD noise can also be filtered out during the touch detection stage.

[0044] Figure 4 This is a flowchart illustrating a control method for a touch display device according to a preferred embodiment of the present invention. Please refer to... Figure 4 The control method for this touch display device includes the following steps:

[0045] Step S401: When the vertical synchronization signal VSYNC is received, perform four display scans DT1 to DT4. Between each display scan, perform touch detection TT1 to TT4 until the display scan and touch scan are completed.

[0046] Step S402: Determine whether the vertical synchronization signal VSYNC has been received. If the vertical synchronization signal VSYNC has not been received, proceed to step S403; if the vertical synchronization signal has been received, return to step S401.

[0047] Step S403: Continue the touch detection operation and return to step S402.

[0048] Furthermore, when performing step S403, if the current touch detection operation is not completed, i.e., the vertical synchronization signal VSYNC is received, the data of this touch operation is discarded, and the process returns to step S402 to continue executing this method.

[0049] Figure 5 This is a flowchart illustrating the sub-steps of step S401 and the steps preceding step S401 in the control method of a touch display device according to a preferred embodiment of the present invention. Please refer to... Figure 5 The following steps are included before step S401:

[0050] Step S501: Perform a touch calibration. This touch calibration includes, for example, storing the touch noise data (N1, N2, N3, N4) during the first display scan DT1 to the fourth display scan DT4, as described above, and storing the touch noise data (NP) during blanking.

[0051] Step S401 also includes the following sub-steps:

[0052] Step S502: After the first display scan DT1 is completed, when performing touch detection TT1, the touch noise data N1 from the first display scan DT1 is used to determine the touch point.

[0053] Step S503: After the second display scan DT2 is completed, when performing touch detection TT2, the touch noise data N2 from the second display scan DT2 is used to determine the touch point.

[0054] Step S504: After the third display scan DT3 is completed, when performing touch detection TT3, the touch noise data N3 from the third display scan DT3 is used to determine the touch point.

[0055] Step S505: After the fourth display scan DT4 is completed, when performing touch detection TT4, the touch noise data N4 from the fourth display scan DT4 is used to determine the touch point.

[0056] Figure 6 This is a flowchart illustrating a sub-step of step S403 in the control method of a touch display device according to a preferred embodiment of the present invention. Please refer to... Figure 6 Step S403 further includes the following steps:

[0057] S601: Uses touch noise data NP during scan without display to determine touch points.

[0058] Although the above embodiments use four display scans (DT1-DT4) and four touch detections (TT1-TT4) as examples, those skilled in the art should understand that the number of display scans and touch detections can be varied depending on the design. Therefore, this invention is not limited to the aforementioned four scans. Furthermore, the above embodiments use display frame rates of 120Hz and 96Hz as examples. Those skilled in the art should understand that a lower display frame rate allows for more touch detections; therefore, this invention is not limited to this. Moreover, when performing additional touch detection, if a vertical synchronization signal (VSYNC) is received, the current touch detection must be abandoned.

[0059] Figure 7 This is a schematic diagram illustrating the relationship between the display frame rate and the touch reporting rate in a control method for a touch display device according to a preferred embodiment of the present invention. Please refer to... Figure 7 Using a 120Hz display frame rate and four touch scanning zones as an example, we can see... Figure 7 The touch reporting frequency in the middle is relative to existing technologies ( Figure 1 There will be slight variations in the frequency range of 100Hz to 120Hz.

[0060] Figure 8 This is a schematic diagram illustrating the relationship between the display frame rate and the touch reporting rate in a control method for a touch display device according to a preferred embodiment of the present invention. Please refer to... Figure 8 In this embodiment, the method of the present invention is extended to the application of fixed touch reporting points under a limited dynamic display frame rate. In this example, the display frame rate is fixed at 30Hz, 32Hz, 40Hz, 48Hz, 60Hz, 80Hz, 96Hz, and 120Hz, and the touch reporting rate is fixed at 120Hz. Therefore, when applied to adaptive synchronization technology, the present invention can provide more stable touch reporting points than existing technologies, increasing operational stability.

[0061] Although the above embodiments do not mention displaying frame rates of 30Hz, 32Hz, 40Hz, 48Hz, and 60Hz, those skilled in the art should know that when the screen is divided into DT1 to DT4 and touch detection is divided into TT1 to TT4, a display frame rate of 30Hz can perform more than four touch detections in addition to the original four. That is, step S403 will be executed more than four times. Taking the above embodiment as an example, the fifth execution of step S403 will perform touch detection for TT1, the sixth execution will perform touch detection for TT2, and so on. Mathematically, LM*4 represents the number of touch detections performed, L is the number of times step S403 is performed more than four times, and M is L / 4 (not an integer). When L / 4 is divisible, the result must be subtracted by 1. The Lth execution of step S403 is performing LM*4 touch detections. Applying the above mathematical formula, the fifth execution of step S403 is 5-1*4, which is performing TT1 touch detection; the sixth execution of step S403 is 6-1*4, which is performing TT2 touch detection. This invention is not limited to the above embodiments.

[0062] In summary, the spirit of this invention lies in using a dynamic update rate-driven approach to perform at least one more touch detection during the time between screen scanning and the arrival of the vertical synchronization signal after a screen has been scanned and a touch detection has been completed. In this way, regardless of changes in the screen update rate, the touch reporting rate can be maintained within a certain range, making the device operation smoother.

[0063] The specific embodiments described in the detailed description of the preferred embodiments are only used to facilitate the illustration of the technical content of the present invention, and are not intended to narrowly limit the present invention to the above embodiments. Various modifications and implementations made without departing from the spirit of the present invention and the following claims are all within the scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A control method for a touch display device, characterized in that, include: The entire screen is displayed using a variable refresh rate, where the display device uses a variable refresh rate mode, and the update time of each frame is dynamically controlled by the image source, rather than being fixed within a constant vertical synchronization interval. The touch operation detection of the entire screen is divided into N touch detections; (A) Upon receiving a vertical synchronization signal, perform N display scans, and perform touch detection after each display scan; (B) When the Nth touch detection is completed, and before the next vertical synchronization signal is received, touch detection continues; Upon receiving the next vertical synchronization signal, return to steps (A) and (B) to continue display scanning and touch detection. Where N is a natural number, In step (B), if a vertical synchronization signal is received before the current touch detection is completed, the touch detection is abandoned and the process returns to step (A).

2. The control method for a touch display device as described in claim 1, characterized in that, Including: Store touch noise data from the first to Nth display scans; After the Kth display scan is completed, touch detection is performed using the touch noise data from the Kth display scan to determine the touch point. Where K is a natural number, and K is less than or equal to N, and K is greater than 0.

3. The control method for a touch display device as described in claim 1, characterized in that, Including: Store touch noise data during scans without a display; After the Nth display scan is completed, when performing step (B) touch detection, the touch noise data during the no-display scan is used to determine the touch point.

4. The control method for a touch display device as described in claim 1, characterized in that, Including: When steps (A) and (B) are completed, and before receiving the next vertical synchronization signal, step (B) continues to be performed to perform touch detection.

5. The control method for a touch display device as described in claim 1, characterized in that, Step (A) includes: (A) Upon receiving a vertical synchronization signal, perform N display scans, and perform touch detection after each display scan. Specifically, the I-th display scan is followed by the I-th touch detection. Where I is a natural number, and I is greater than 0 and less than or equal to N.

6. The control method for a touch display device as described in claim 5, characterized in that, Including: The number of touch detections is determined based on the number of steps (B). Specifically, the Jth touch detection is performed during the Jth step (B). Where J is a natural number, and J is greater than 0 and less than or equal to N.

7. The control method for a touch display device as described in claim 5, characterized in that, Including: The number of touch detections is determined based on the number of steps (B). Specifically, during the Lth step (B), the LM*Nth touch detection is performed. Where L is a natural number, and L is greater than N. Where M is a natural number, and M equals L / N rounded to the nearest integer. Wherein, LM*N is a natural number, and LM*N is greater than 0 and less than or equal to N.

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