The present invention illustrates an image display method and an image display system, and more particularly, an image display method and an image display system capable of stabilizing image brightness and reducing image flickers.
Liquid crystal display (LCD) and organic light-emitting diode (OLED) display devices have been widely used for applying to multimedia products, mobile phones, personal digital assistants, computer monitors, or flat-screen TVs since they have advantages of low power consumption, no radiation, and slim bodies.
Nowadays, many advanced display devices are often used for displaying images of video games or movies. For the video games or movies, their images include a lot of motion objects. Therefore, in order to provide a satisfactory quality of visual experience, the advanced display devices can perform a function of “Dynamic Accuracy (DyAc)”. The DyAc function can be used for enhancing sharpness of a dynamic motion image. Therefore, the DyAc function is helpful for mitigating severe image vibrations, especially in images of video games or movies. Further, the advanced display devices also have a function of dynamically refreshing a frame rate (i.e., such as a free sync function). The free sync function can be used for displaying images by dynamically adjusting the frame rate according to video data rendered by a game console or a graphics card. In other words, when the display device receives the video data having a non-constant frame rate (30-240 Hertz), it can use the free sync function for displaying the images.
However, when the free sync function and the DyAc function are enabled for enhancing the sharpness of the dynamic motion images transmitted by using the non-constant frame rate, human eyes easily perceive image flickers, especially in the frame rate lower than 100 Hertz. Further, when the free sync function is enabled, since the frame rate is varied over time, image brightness may be unstable. Therefore, for current display devices, after the free sync function and the DyAc function are enabled, since the image flickers are severe and the image brightness is unstable when the frame rate is low, the quality of visual experience may be decreased.
In an embodiment of the present invention, an image display method is disclosed. The image display method comprises setting a plurality of frame rate intervals and a plurality of backlight driving signal adjustment modes, acquiring a data clock signal, detecting a first frame rate of the data clock signal, adjusting a first power distribution of a backlight driving signal according to a first backlight driving signal adjustment mode of the plurality of backlight driving signal adjustment modes when the first frame rate falls into a first frame rate interval of the plurality of frame rate intervals, and displaying an image according to at least the data clock signal and the backlight driving signal.
In another embodiment of the present invention, an image display system is disclosed. The image display system comprises a display panel, a driving circuit, a processor, a backlight device, and a memory. The display panel comprises a plurality of pixels and is configured to display an image. The driving circuit is coupled to the display panel and configured to drive the plurality of pixels. The processor is coupled to the driving circuit and configured to control the driving circuit. The backlight device is coupled to the processor and configured to generate a backlight signal. The memory is coupled to the processor and configured to save data of a plurality of frame rate intervals and data of a plurality of backlight driving signal adjustment modes. After the processor acquires a data clock signal transmitted from a signal source, the processor detects a first frame rate of the data clock signal. The processor adjusts a first power distribution of a backlight driving signal according to a first backlight driving signal adjustment mode of the plurality of backlight driving signal adjustment modes when the first frame rate falls into a first frame rate interval of the plurality of frame rate intervals. The backlight device generates the backlight signal according to the backlight driving signal. The driving circuit drives the display panel for displaying the image according to at least the data clock signal and the backlight driving signal.
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.
In the display system 100, after the processor 12 acquires the data clock signal transmitted from the signal source 15, the processor 12 can detect a first frame rate of the data clock signal. The processor 12 can adjust a first power distribution of a backlight driving signal according to a first backlight driving signal adjustment mode of the plurality of backlight driving signal adjustment modes saved in the memory 14 when the first frame rate falls into a first frame rate interval of the plurality of frame rate intervals. Then, the backlight device 13 can generate the backlight signal according to the backlight driving signal. The driving circuit 11 can drive the display panel 10 for displaying the image according to at least the data clock signal and the backlight driving signal. Further, the image display system 100 can provide a function of dynamically refreshing the frame rate (say, “a free sync function” hereafter). Therefore, the first frame rate of the data clock signal is varied over time. For example, a range of the first frame rate can be 30-240 Hertz. The plurality of frame rate intervals and the plurality of backlight driving signal adjustment modes saved in the memory 14 can be illustrated in Table T1.
However, decision boundaries and intervals listed in Table T1 are the embodiment of the display system 100. Any reasonable frame rate interval modification or backlight driving signal adjustment mode falls into the scope of the present invention. Details of each backlight driving signal adjustment mode are illustrated below.
In other words, for the first frame rate R1 of the data clock signal DLK, the processor 12 can adjust the first frequency Freq1 of the backlight driving signal BL according to the first backlight driving signal adjustment mode (i.e., as shown in Table T1) of the plurality of backlight driving signal adjustment modes saved in the memory 14. The processor 12 can adjust the first frequency Freq1 of the backlight driving signal BL to approach N times of the first frame rate R1 of the data clock signal DLK according to the first backlight driving signal adjustment mode. N is a positive integer. Further, when the first frame rate R1 of the data clock signal DLK is increased, the processor 12 can decrease a value of N. As shown in Table T1, when the first frame rate R1 falls into a frame interval of “FR≤40 Hertz”, N is set to 3. When the first frame rate R1 falls into a frame interval of “40 Hertz<FR<100 Hertz”, N is set to 2. When the first frame rate R1 falls into a frame interval of “FR≥100 Hertz”, N is set to 1. A frequency adjustment method of the backlight driving signal BL according to the second frame rate R2 is similar to the frequency adjustment method of the backlight driving signal BL according to the first frame rate R1. Thus, their details are omitted here.
Further, the image display system 100 can adjust a waveform of the backlight driving signal BL. The processor 12 can adjust a first power distribution of the backlight driving signal BL according to the first backlight driving signal adjustment mode of the plurality of backlight driving signal adjustment modes saved in the memory 14. For example, as previously mentioned, during the first frame F1 interval, the first frequency Freq1 of the backlight driving signal BL can be adjusted to approach triple first frame rates R1 (3×R1=3×40=120 Hertz). Further, the processor 12 can adjust the power E11, the power E12, and the power E13 of a plurality of first rectangular waveforms S1 of the backlight driving signal BL during the first frame F1 interval. Similarly, during the Qth frame FQ interval, the second frequency Freq2 of the backlight driving signal BL can be adjusted to approach double second frame rates R2 (2×R2=2×75=150 Hertz). Further, the processor 12 can adjust the power E21 and the power E22 of a plurality of second rectangular waveforms S2 of the backlight driving signal BL during the Qth frame FQ interval. Therefore, by adjusting the rectangular waveforms of the backlight driving signal BL, the display system 100 can reconfigure the power distribution of the backlight driving signal BL during each frame interval. Further, the power values of the backlight driving signal BL during all frame intervals of the data clock signal DLK are substantially identical. For example, the power values of the backlight driving signal BL can satisfy a condition of E11+E12+E13≈E21+E22. By doing so, since the power values of the backlight driving signal BL during all frame intervals are substantially identical, the image brightness can be stabilized, leading to satisfactory quality of visual experience.
Further, as previously mentioned, the processor 12 can adjust the power distribution of the backlight driving signal BL. Therefore, after the power distribution of the backlight driving signal BL is adjusted, the power values of the backlight driving signal BL during all frame intervals of the data clock signal DLK are substantially identical, leading to stabilized image brightness. In other words, in
In the image display system 100, the processor 12 can adjust the frequency of the backlight driving signal BL and/or can adjust the rectangular waveforms of the backlight driving signal BL according to an appropriate backlight driving signal adjustment mode of the plurality of backlight driving signal adjustment modes saved in the memory 14. When the frequency of the backlight driving signal BL is increased, the image flicks can be avoided. When the rectangular waveforms of the backlight driving signal BL are adjusted, power values of the backlight driving signal BL during all frame intervals are substantially identical, thereby leading to high stability of the image brightness. However, the power distributions of the backlight driving signal BL are not limited to satisfying E11+E12+E13≈E21+E22 or E11≈E12≈E13. Any reasonable technology for stabilizing the image brightness falls into the scope of the present invention.
Further, the method of adjusting the power distribution of the backlight driving signal BL is not limited to technologies in
In the image display system 100, the processor 12 can adjust the power distribution and the frequency of the backlight driving signal BL for avoiding the image flickers and stabilizing the image brightness. However, the image display system 100 can introduce hybrid modes for further enhancing the visual quality. For example, in the image display system 100, the memory 14 can save data of a plurality of over drive modes (OD modes). When the first frame rate R1 falls into the first frame rate interval of the plurality frame rate intervals, the processor 12 can use one OD mode of the plurality of OD modes to accelerate driving pixels. When the plurality of OD modes are introduced to the image display system 100, a plurality of hybrid modes can be generated by integrating the backlight driving signal adjustment modes with the OD modes, as illustrated in Table T2.
Here, the image display system 100 can introduce the plurality of OD modes for setting the pixel driving voltage. When an intensity of the pixel driving voltage is large, it implies that a transient time length of refreshing liquid crystal molecules of the pixel is short. Therefore, when the first frame rate R1 of the data clock signal DLK is small (i.e., for example, the first frame rate R1 is smaller than 40 Hertz), it implies that the signal source 15 generates a static image or an image having slow motion objects, such as an image of text documents. Therefore, the OD mode can be set to a “weak” mode. Then, the processor 12 can use a pixel driving voltage having a small intensity for driving the display panel 10. When the first frame rate R1 of the data clock signal DLK is large (i.e., for example, the first frame rate R1 is greater than 100 Hertz), it implies that the signal source 15 generates a dynamic image or an image having fast motion objects, such as an image of video games. Therefore, the OD mode can be set to a “strong” mode. Then, the processor 12 can use a pixel driving voltage having a large intensity for driving the display panel 10. After the display panel 10 is driven by the pixel driving voltage having the large intensity, an image sticking effect can be mitigated. Therefore, after the image display system 100 adjusts the power distribution of the backlight driving signal BL and introduces the plurality of OD modes, the image display system 100 can reduce the image flickers, stabilize the image brightness, and mitigate the image sticking effect. Thus, the image display system 100 can greatly improve the quality of visual experience.
Details of step S501 to step S505 are previously illustrated. Therefore, they are omitted here. By adjusting the backlight driving signal BL, the image display system 100 can avoid generating the image flickers and can stabilize the image brightness. In other words, even if the image display system 100 performs the free sync function, the frequency of the backlight driving signal BL can be dynamically adjusted. The adjusted frequency is greater than a threshold (i.e., greater than 100 Hertz) for any frame rate. Therefore, the image flickers can be avoided. By doing so, the image display system 100 can increase the quality of visual experience.
To sum up, the present invention illustrates an image display method and an image display system. The image display system can dynamically adjust a frequency of a backlight driving signal according to frame rate variability of a data clock signal. When the frame rate of the data clock signal is very low, the image display system can increase the frequency of the backlight driving signal to avoid perceiving image flickers by human eyes. Further, the image display system can also adjust a height and/or a width of rectangular waveforms of the backlight driving signal for optimizing power distribution of the backlight driving signal during all image frames, thereby leading to high stability of the image brightness. Further, the image display system can also introduce a plurality of OD modes for mitigating an image sticking effect. Therefore, the image display system 100 can reduce the image flickers, stabilize the image brightness, and mitigate the image sticking effect. Thus, the image display system 100 can greatly improve the quality of visual experience.
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.
Number | Date | Country | Kind |
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201910215269.4 | Mar 2019 | CN | national |
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