Abstract:
A driving method of a touch display panel includes: selectively operating in a display mode and a touch detecting mode; when operating in the display mode during a first frame period, processing a first frame to generate an image processing indicator of a second frame for indicating an image processing level of the second frame; when operating in the touch detecting mode during the first frame period, generating a control signal when a touch is detected; wherein when the control signal is generated, processing the second frame according to an image processing indicator of the first frame for indicating an image processing level of the first frame when operating in the display mode during a second frame period, instead of using the image processing indicator of the second frame.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a driving method, and more particularly, to an image processing driving method, a driver integrated circuit (IC) applying the driving method, and a touch display system. 
         [0003]    2. Description of the Prior Art 
         [0004]    Smartphone users may deal with a situation that requires changing a displayed image to another image by touching and swiping the display panel. The image here is not limited to a picture; it can be anything which is displayed on the touch display panel such as a webpage or an app. During the process of changing a displayed image to another, a conventional smartphone will process the image shown on the display panel dynamically. This kind of transient image process may cause severe quantization loss, however. For example, assuming that the display panel shows an image having a particular gray gradient, and the user changes the image to a wholly black image, as the image processor enhances the image processing level dynamically to optimize the display, the higher image processing level will result in greater quantization loss. Therefore, the user may sense a distortion in the image during this transient process. 
       SUMMARY OF THE INVENTION 
       [0005]    One of the objectives of the present invention is to provide an image processing driving method, a driver IC, and a touch display system to solve the aforementioned problem. 
         [0006]    According to an embodiment of the present invention, a touch display system is disclosed, comprising: an image processing unit, and a touch detecting unit. The image processing circuit is arranged to process a first frame during a display period of a first frame period to generate an image processing indicator of a second frame for indicating an image processing level of the second frame, wherein the second frame is displayed immediately after the first frame period. The touch detecting circuit coupled to the image processing unit is arranged to generate a control signal to the image processing unit when a touch is detected by the touch detecting unit during a touch detecting period of the first frame period; wherein when the image processing unit receives the control signal generated by the touch detecting unit, the image processing unit processes the second frame during a display period of a second frame period according to an image processing indicator of the first frame for indicating an image processing level of the first frame, instead of using the image processing indicator of the second frame. 
         [0007]    According to an embodiment of the present invention, a driver IC is disclosed, wherein the driver IC is arranged to selectively operate in a display mode and a touch detecting mode during a first frame period when the driver IC is coupled to a touch display panel. When the driver IC operates in the display mode during the first frame period, the driver IC processes a first frame to generate an image processing indicator of a second frame for indicating an image processing level of the second frame, and outputs the first frame to the touch display panel; when the driver IC operates in the touch detecting mode during the first frame period, a touch detecting circuit generates a control signal to the driver IC if a touch is detected by the touch detecting circuit during the first frame period; wherein when the driver IC receives the control signal generated by the touch detecting circuit, the driver IC processes the second frame according to an image processing indicator of the first frame for indicating an image processing level of the first frame when the driver IC operates in the display mode during a second frame period, instead of using the image processing indicator of the second frame. 
         [0008]    According to an embodiment of the present invention, a driving method of a touch display panel is disclosed, comprising: selectively operating in a display mode and a touch detecting mode; when operating in the display mode during a first frame period, processing a first frame to generate an image processing indicator of a second frame for indicating an image processing level of the second frame; when operating in the touch detecting mode during the first frame period, generating a control signal if a touch is detected; wherein when the control signal is generated, processing the second frame according to an image processing indicator of the first frame for indicating an image processing level of the first frame when operating in the display mode during a second frame period, instead of using the image processing indicator of the second frame. 
         [0009]    These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a diagram illustrating a touch display system according to an embodiment of the present invention. 
           [0011]      FIG. 2  is a diagram illustrating a synchronous signal and a touch enable signal according to an embodiment of the present invention. 
           [0012]      FIG. 3  is a diagram illustrating image processing indicators for frames when no touch is detected during a touch detecting period according to an embodiment of the present invention. 
           [0013]      FIG. 4  is a diagram illustrating image processing indicators for frames when a touch is detected during a touch detecting period according to an embodiment of the present invention. 
           [0014]      FIG. 5  is a flowchart illustrating a driving method of the touch display system according to an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    Certain terms are used throughout the description and following claims to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms “include” and “comprise” are used in an open-ended fashion, and thus should not be interpreted as a close-ended term such as “consist of”. Also, the term “couple” is intended to mean either an indirect or direct electrical connection. Accordingly, if one device is coupled to another device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections. 
         [0016]      FIG. 1  is a diagram illustrating a touch display system  100  according to an embodiment of the present invention. As shown in  FIG. 1 , the touch display system  100  comprises a driver IC  110  and a touch display panel  120 , wherein the driver IC  110  comprises an image processing unit  111 , and the touch display panel comprises a touch detecting unit  121 . The driver IC  110  generates a synchronous signal VSYNC and a touch enable signal TP_EN to the touch display panel  120 , wherein the synchronous signal VSYNC is arranged to define a time period for each frame, and the touch enable signal TP_EN is arranged to indicate whether the driver IC operates in a touch detecting mode or in a display mode during a frame period. Referring to  FIG. 2 , which is a diagram illustrating a synchronous signal VSYNC and a touch enable signal TP_EN according to an embodiment of the present invention, the synchronous signal VSYNC defines the time period for each frame, e.g. frame periods FP 1 -FP 4 . During the frame period FP 1 , the touch display system  100  processes and displays the frame F 1 ; during a frame period FP 2 , the touch display  100  processes and displays the frame F 2 , and so on. The driver IC  110  can selectively operate in the display mode and the touch detecting mode during each frame period. As shown in  FIG. 2 , during the frame period FP 1 , the driver IC  110  operates in the display mode when the touch enable signal TP_EN stays low (i.e. logic value ‘0’) and operates in the touch detecting mode when the touch enable signal TP_EN goes high (i.e. logic value ‘1’). Likewise, during the frame period FP 2 , the driver IC  110  operates in the display mode when the touch enable signal TP_EN stays low and operates in the touch detecting mode when the touch enable signal TP_EN goes high. 
         [0017]    Referring again to FIG. 1 , the image processing unit  111  is arranged to process display data of each frame when the driver IC  110  operates in the display mode, and generate an image processing indicator K for the next frame, wherein the image processing indicator K is for indicating an image processing level. For example, while the image processing unit  111  processes a frame F 1  based on an image processing indicator K 1  when the driver IC  110  operates in the display mode in a frame period FP 1  defined by the synchronous signal VSYNC, the image processing unit  111  generates an image processing indicator K 2  for a frame F 2  such that the image processing unit  111  could process the frame F 2  based on the image processing indicator K 2  when the driver IC operates in the display mode in a frame period FP 2  defined by the synchronous signal VSYNC. In this embodiment, the image processing level indicated by the image processing indicator is a backlight compensation level, but this is not a limitation of the present invention; the image processing level can represent any image processing operation such as luminance/color enhancement and/or luminance/color compensation. The touch detecting unit  121  is arranged to send a control signal CS to the driver IC  110  if a touch is detected by the touch detecting unit  121  when the driver IC  110  operates in the touch detecting mode. It should be noted that the touch detecting unit  121  is not limited to be integrated in the touch display panel  120 . In other embodiments, the touch detecting unit  121  can be integrated in the driver IC  110 . When the driver IC  110  receives the control signal CS from the touch detecting unit  121 , the image processing indicator for the next frame will be the same as the image processing indicator for the current frame. For example, while the image processing unit  111  processes the frame F 1  based on the image processing indicator K 1  when the driver IC  110  operates in the display mode in the frame period FP 1  defined by the synchronous signal VSYNC, the image processing unit  111  generates the image processing indicator K 2  for the frame F 2 . If the touch is detected by the touch detecting unit  121  when the driver IC  110  operates in the touch detecting mode in the frame period FP 1 , the image processing unit  111  controls the image processing indicator K 2  for the frame F 2  to be the same as the image processing indicator K 1  for the frame F 1 . Next, when the driver IC  110  operates in the display mode in the frame period FP 2 , the image processing unit  111  processes the frame F 2  based on the image processing indicator K 2  which is identical to the image processing indicator K 1 . 
         [0018]      FIG. 3  is a diagram illustrating image processing indicators for frames when no touch is detected during a touch detecting period according to an embodiment of the present invention. As shown in  FIG. 3 , the control signal CS stays low (i.e. logic value ‘0’) during frame period FP 1  to frame period FP 4 , meaning there is no touch detected during frame period FP 1  to frame period FP 4 . The image processing indicators for frames F 1  to F 5  may change from frame to frame. More specifically, when the driver IC  110  operates in the display mode in the frame period FP 1 , the image processing unit  111  processes the frame F 1  according to the image processing indicator K 1 , and the image processing unit  111  generates the image processing indicator K 2  for the frame F 2  according to the contents of the frame F 1 , and/or the image processing indicator K 1 , and/or other information. For example, the image processing indicator K 1 = 1  and the image processing indicator K 2 =2, wherein the numbers 1 and 2 mean a level of image processing. The numbers are only for illustrative purpose, and are not a limitation of the present invention. The touch detecting unit  121  detects no touch when the driver IC  110  operates in the touch detecting mode in the frame period FP 1 . When the driver IC  110  operates in the display mode in the frame period FP 2 , the image processing unit  111  processes the frame F 2  according to the image processing indicator K 2 , and the image processing unit  111  generates the image processing indicator K 3  for the frame F 3  according to the contents of the frame F 1 , and/or the image processing indicator K 2 , and/or other information; for example, the image processing indicator K 3 =3. The touch detecting unit  121  detects no touch when the driver IC operates in the touch detecting mode during the frame period FP 2 . The operation will therefore continue until a touch is detected by the touch detecting unit  121 . 
         [0019]      FIG. 4  is a diagram illustrating the operation when a touch is detected according to an embodiment of the present invention. As shown in  FIG. 4 , the control signal CS goes high when the driver IC  110  operates in the touch detecting mode during the frame periods FP 2  and FP 3 , meaning a touch is detected by the touch detecting unit  121  during the frame periods FP 2  and FP 3 . More specifically, when the driver IC  110  operates in the display mode during the frame period FP 1 , the image processing unit  111  processes the frame F 1  according to the image processing indicator K 1 , and the image processing unit  111  generates the image processing indicator K 2  for the frame F 2 . For example, the image processing indicator K 1 =1 and the image processing indicator K 2 =2. Next, the touch detecting unit  121  detects no touch when the driver IC operates in the touch detecting mode during the frame period FP 1 . Next, when the driver IC  110  operates in the display mode during the frame period FP 2 , the image processing unit  111  processes the frame F 2  according to the image processing indicator K 2 , and generates the image processing indicator K 3  for the frame F 3 ; for example, K 3 =3. Because a touch is detected by the touch detecting unit  121  when the driver IC  110  operates in the touch detecting mode during the frame period FP 2 , the image processing unit  111  controls/resets the image processing indicator K 3  to be the same as the image processing indicator K 2 , i.e. the image processing indicator K 3  is 2. Next, when the driver IC  110  operates in the display mode during the frame period FP 3 , the image processing unit  111  processes the frame F 3  according to the image processing indicator K 3  (which equals the image processing indicator K 2 ), and generates the image processing indicator K 4  for the frame F 4 . Then, because a touch is detected by the touch detecting unit  121  when the driver IC operates in the touch detecting mode during the frame period FP 3 , the image processing unit  111  also controls/resets the image processing indicator K 4  to be the same as the previous image processing indicator K 3 , so K 4  will also be 2. 
         [0020]    Next, when the driver IC  110  operates in the display mode during the frame period FP 4 , the image processing unit  111  processes the frame F 4  according to the image processing indicator K 4  (which equals the image processing indicator K 3 ), and generates the image processing indicator K 5  for the frame F 5 . The image processing indicator may be different from the image processing indicator K 4  (for example, K 5 =5) because the touch detecting unit  121  detects no touch when the driver IC operates in the touch detecting mode during the frame period FP 4 . In the end, when the driver IC  110  operates in the display mode during the frame period FP 5 , the image processing unit  111  processes the frame F 5  according to the image processing indicator K 5 . 
         [0021]      FIG. 5  is a flowchart illustrating a driving method of the touch display system  100  according to an embodiment of the present invention. Provided that the result is substantially the same, the steps are not required to be executed in the exact order shown in  FIG. 5 . The exemplary driving flow of the touch display system  100  is briefly summarized by the following steps. 
         [0022]    Step  500 : start. 
         [0023]    Step  502 : the driver IC  110  operates in the display mode, and the image processing unit  111  processes a frame, e.g. the frame F 1 , according to an image processing indicator of the frame, e.g. the image processing indicator K 1 , to generate an image processing indicator of a next frame, e.g. the image processing indicator K 2  of the frame F 2 . 
         [0024]    Step  504 : the driver IC  110  operates in the touch detecting mode, and determines whether a touch is detected by the touch detecting unit  121 ; if yes, go to step  506 ; otherwise, go to step  502 . 
         [0025]    Step  506 : the driver IC  110  controls the image processing indicator of the next frame to be the same as the image processing indicator of the frame, i.e. K 2 =K 1 . The flow returns to step  502 . 
         [0026]    As a person skilled in the art can readily understand details of each step shown in  FIG. 5  after reading the above paragraphs directed to the touch display system  100 , further description is omitted here for brevity. 
         [0027]    Briefly summarized, the present invention discloses an image processing driver method, a driver applying the method, and a touch display system to solve the problem of dynamically processing frames during a transient process between two images via keeping the image process still when a touch is detected, to thereby prevent an inconvenient experience for users. 
         [0028]    Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.