Display device and method for preventing image retention therein

Abstract

To provide a display apparatus and a method for preventing image burn-in thereof.SOLUTION: A display apparatus is provided, which includes a display panel and a display controller. The display controller calculates an image average brightness of each image in a video signal. When an absolute difference between a first image average brightness of a current image in the video signal and a second image average brightness of a previous image in the video signal is smaller than a predetermined value, the display controller activates a timer to obtain a timer value. When the timer value reaches a first duration, the display controller reduces brightness of each pixel in the current image of the video signal displayed on the display panel by a first ratio. When the timer value reaches a second duration, the display controller reduces the brightness of each pixel in the current image of the video signal displayed on the display panel by a second ratio. The second duration is longer than the first duration, and the second ratio is higher than the first ratio.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] This application claims priority to Taiwan Patent Application No. 110148049, filed on December 22, 2021, all of which are incorporated herein by reference.

[0002] The present invention relates to a display device, and more particularly to a display device and a method for preventing image burn-in therein. [Background technology]

[0003] With the advancement of technology, computer users spend more and more time using their monitors. In some applications, the host plays static images on the display panel at high brightness levels for long periods of time, which can easily cause the pixel components of the display panel to deteriorate and result in image burn-in. This is especially problematic for organic light-emitting diode (OLED) panels. Summary of the Invention [Problem to be solved by the invention]

[0004] In view of the above, an electronic device and a method for preventing image burn-in therein are provided that solve the aforementioned problems. [Means for solving the problem]

[0005] In an exemplary embodiment, a display device is provided that includes a display panel and a display controller. The display controller is configured to receive a video signal from a host and display the video signal on the display panel. The display controller calculates an image average luminance of each image in the video signal. In response to an absolute difference between a first image average luminance of a current image in the video signal and a second image average luminance of a previous image in the video signal being less than a predetermined value, the display controller activates a timer and obtains a timer value. In response to the timer value reaching a first duration, the display controller reduces the luminance of each pixel of the current image of the video signal displayed on the display panel by a first rate. In response to the timer value reaching a second duration, the display controller reduces the luminance of each pixel of the current image of the video signal displayed on the display panel by a second rate. The second duration is longer than the first duration, and the second rate is higher than the first rate.

[0006] In some embodiments, in response to the timer value being greater than or equal to a third duration, the display controller reduces to 0 a brightness of each pixel of a current image of the video signal displayed on the display panel, the third duration being greater than the second duration.

[0007] In some embodiments, the display controller calculates the average luminance values ​​of the red, green, and blue subpixels of each pixel of each image in the video signal, calculates the sum of the average luminance values ​​of all pixels in each image, and divides the calculated sum by the resolution of the display panel to obtain an average image luminance for each image.

[0008] In some embodiments, in response to the absolute difference being less than a predetermined value, the display controller determines that the current image and the previous image are substantially the same.

[0009] In some embodiments, in response to the absolute difference being greater than a predetermined value, the display controller determines that the current image and the previous image are different images and resets a timer value of the timer.

[0010] In some embodiments, the display controller further dynamically adjusts the predetermined value according to an average image luminance of the current image.

[0011] In some embodiments, when the image average luminance of the current image is in a first luminance interval, the display controller sets the predetermined value to a first predetermined value. When the image average luminance of the current image is in a second luminance interval, the display controller sets the predetermined value to a second predetermined value. When the image average luminance of the current image is in a third luminance interval, the display controller sets the predetermined value to a third predetermined value. The first luminance interval is higher than the second luminance interval and the second luminance interval is higher than the third luminance interval. The first predetermined value is greater than the second predetermined value and the second predetermined value is greater than the third predetermined value.

[0012] In another exemplary embodiment, a method for preventing image burn-in for use in a display device is provided. The display device includes a display panel and a display controller. The method includes the steps of: receiving a video signal from a host and displaying the video signal on the display panel using the display controller; calculating an image average luminance of each image in the video signal using the display controller; activating a timer using the display controller in response to an absolute difference between a first image average luminance of a current image in the video signal and a second image average luminance of a previous image in the video signal being less than a predetermined value, activating a timer using the display controller to obtain a timer value; reducing a luminance of each pixel of the current image of the video signal displayed on the display panel by a first rate in response to the timer value reaching a first duration; and reducing a luminance of each pixel of the current image of the video signal displayed on the display panel by a second rate in response to the timer value reaching a second duration, the second duration being longer than the first duration. The second rate being higher than the first rate. [Brief description of the drawings]

[0013] The present invention can be more fully understood from the following detailed description taken in conjunction with the accompanying drawings, in which: [Figure 1] FIG. 1 is a block diagram of a computer system according to an embodiment of the present invention. [Figure 2A] FIG. 2A is a diagram illustrating reduction in screen brightness according to an embodiment of the present invention. [Figure 2B] FIG. 2B is a diagram illustrating the reduction in screen brightness according to an embodiment of the present invention. [Figure 2C] FIG. 2C is a diagram illustrating the reduction in screen brightness according to an embodiment of the present invention. [Figure 2D] FIG. 2D is a diagram illustrating reduction in screen brightness according to an embodiment of the present invention. [Diagram 3] FIG. 3 is a flow chart of a method for preventing image burn-in according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] The following description is made for the purpose of illustrating the general principles of the invention and is not to be taken in a limiting sense, the scope of the invention being determined with reference to the appended claims.

[0015] FIG. 1 is a block diagram of a computer system according to an embodiment of the present invention. The computer system 10 may be, for example, a personal computer or a server equipped with a display device. As shown in FIG. 1, the computer system 10 includes a host 100 and a display device 200, and the host 100 has a signal connection to the display device 200. For example, the host 100 may include a processing unit 110, a graphics processing unit (GPU) 120, a memory unit 130, a storage device 140, one or more transmission interfaces 150, and one or more peripheral devices 160. The processing unit 110, the graphics processing unit 120, the memory unit 130, the storage device 140, the transmission interface 150, and the peripheral devices 160 may be coupled to each other via a system bus 111. The processing unit 110 may be, for example, a central processing unit (CPU), a general-purpose processor, etc., but the present invention is not limited thereto. The graphics processing unit 120 may be, for example, a graphics processing unit on a video adapter, or may be integrated into the processing unit 110.

[0016] The memory unit 130 may be a random access memory such as a static random access memory (SRAM) or a dynamic random access memory (DRAM), but the present invention is not limited thereto. The storage device 140 may be a non-volatile memory such as a hard disk drive, a solid state disk (SSD), a flash memory, or a read-only memory (ROM), but the present invention is not limited thereto.

[0017] The transmission interface 150 may include a wired transmission interface and / or a wireless transmission interface. The wired transmission interface may include a High-Definition Multimedia Interface (HDMI), a DisplayPort (DP) interface, an Embedded DisplayPort (eDP) interface, a Universal Serial Bus (USB) interface, a USB Type-C interface, a Thunderbolt interface, a Digital Video Interface (DVI), a Video Graphics Array (VGA) interface, a General Purpose Input / Output (GPIO) interface, a Universal Asynchronous Receiver / Transmitter (UART) interface, a Serial Peripheral Interface (SPI), an Inter-Integrated Circuit (I2C) interface, or a combination thereof. The wireless transmission interface may include, but is not limited to, a Bluetooth, a Wi-Fi, a Near Field Communication (NFC) interface, and the like. The peripheral device 160 may include, but is not limited to, an input device, such as a keyboard, a mouse, a touchpad, and the like.

[0018] For example, the storage device 140 can store one or more applications 141 and an operating system 142 (e.g., Windows®, Linux®, MacOS®, etc.). The processing unit 110 can load the operating system 142 and the applications 141 into the memory unit 130 and execute them. The graphics processing unit 120 can, for example, perform graphics processing for the applications being executed by the processing unit 110, generate an image signal including one or more images, and transmit the image signal to the display device 200 via the transmission interfaces 150 and 250 (e.g., an HDMI or DisplayPort interface).

[0019] The display device 200 may be, for example, a flat panel display, a television, a projector, or a computer monitor, but the invention is not limited thereto. The display device 200 includes a display controller 210, a display panel 220, a storage unit 230, an image buffer 240, one or more transmission interfaces 250, and an input interface 260.

[0020] The transmission interface 250 may include a wired transmission interface and / or a wireless transmission interface. The wired transmission interface may include a High-Definition Multimedia Interface (HDMI), a DisplayPort (DP) interface, an Embedded DisplayPort (eDP) interface, a Universal Serial Bus (USB) interface, a USB Type-C interface, a Thunderbolt interface, a Digital Video Interface (DVI), a Video Graphics Array (VGA) interface, a General Purpose Input / Output (GPIO) interface, a Universal Asynchronous Receiver / Transmitter (UART) interface, a Serial Peripheral Interface (SPI), an Inter-Integrated Circuit (I2C) interface, or a combination thereof. The wireless transmission interface may include, but is not limited to, Bluetooth, Wi-Fi, a Near Field Communication (NFC) interface, and the like. The peripheral device 160 may include, but is not limited to, an input device, such as a keyboard, a mouse, a touchpad, and the like.

[0021] The display controller 210 may be implemented by, for example, an application specific integrated circuit (ASIC), a system on a chip (SoC), a processor, or a microcontroller, but the invention is not limited thereto.

[0022] The display panel 220 may be, for example, a liquid crystal display panel, a light emitting diode (LED) panel, or an organic light emitting diode (OLED) panel, although the present invention is not limited to the aforementioned three types of display panels.

[0023] Storage unit 230 can be, for example, a non-volatile memory such as a read only memory (ROM), an erasable programmable read only memory (EPROM), an electrically erasable programmable read only memory (EEPROM), etc., but the invention is not limited thereto. Storage unit 230 is configured to store firmware 231 and 232 associated with display device 200, and one or more on-screen display (OSD) interfaces 233. Storage unit 230 may be located external to display controller 210, or alternatively may be integrated into display controller 210.

[0024] Firmware 231 may include, for example, Extended Display Identification Data (EDID) and display settings of display device 200, as well as one or more On Screen Display (OSD) interfaces 233. EDID may include, for example, information such as the manufacturer, product name, resolution, and frames per second (FPS) of display device 200. Display settings of display device 200 may include brightness, contrast, sharpness, and color temperature of display device 200. Firmware 232 may include instructions or program code for image burn-in prevention functions of display device 200.

[0025] In one embodiment, the display controller 210 can read the program codes of the firmware 231 and 232 and the OSD interface 233 stored in the storage unit 230 via a bus (e.g., an I2C bus) to configure corresponding display parameters. In addition, the display controller 210 can transmit the EDID of the display device 200 to the host 100 via one of the transmission interfaces 250 (which can be, for example, an image transmission channel or a data transmission channel), and the processing unit 110 and the graphics processing unit 120 in the host 100 can configure the resolution and corresponding synchronization signal of the output image signal based on the EDID. The OSD interface 233 can include, for example, an OSD menu and corresponding options, an information dashboard, a timer, a counter, a crosshair, a specific symbol, a specific color, a specific text, or a combination thereof, but the present invention is not limited thereto.

[0026] The image buffer 240 can be, for example, a volatile memory (e.g., DRAM) or a non-volatile memory (e.g., flash memory) configured to store the output image displayed on the display panel 220, and the host 100 or the display controller 210 overwrites certain areas of the image signal stored in the image buffer 240 with one or more OSD interfaces 233 according to an OSD enable signal generated by the host 100.

[0027] The input interface 260 is configured to control an OSD menu of the display device 200. The input interface 260 can be implemented by one or more physical buttons 261 or a five-way joystick 262 to perform instructions such as up, down, left, right, and confirm.

[0028] In one embodiment, when a user operates one direction of the five-way joystick 262 (or presses one of the physical buttons 261), the display controller 210 can read the firmware 231, the program code or firmware of the OSD menu, and the corresponding options of the OSD interface 233 from the storage unit 230, and display the OSD menu and the corresponding options on the display panel 220. In one embodiment, a user can operate on the input interface 260 to control the OSD menu of the display device to adjust brightness, contrast, sharpness, color temperature, or activate or deactivate other interfaces of the OSD interface 233. In another embodiment, for example, the activation and deactivation of the OSD interface 233 and the content displayed on the OSD interface 233 can be controlled by the peripheral device 160 of the host 100, which will be described in more detail below.

[0029] For example, firmware 231 may be considered the default firmware for display device 200, and a user may control settings of an OSD interface 233 displayed on display device 200 via a five-way joystick 262 (or physical buttons 261).

[0030] In one embodiment, the display controller 210 may include an image scalar 211 and a timing controller 212. The display controller 210 may receive an image signal from the host 100 and / or another signal from another host via one of the transmission interfaces 250, and the image scalar 211 may perform an image scaling process and / or an image overlay process on the received image signal to fit the resolution of the display panel 220, and store the image (e.g., output image) generated by the image scaling process in the image buffer 240. The timing controller 212 may control the display panel 220 to read and display the output image from the image buffer 240.

[0031] In another embodiment, the display controller 210 may include a timing controller 212, and the resolution of the image signal from the host 100 may be adapted to the resolution of the display panel 220. Therefore, the display controller 210 may directly store the received image signal from the host 100 in the image buffer 240 without performing an image scaling process. The timing controller 212 may read the output image stored in the image buffer 240, and control the display panel 220 to display the output image.

[0032] 2A to 2D are diagrams illustrating a decrease in screen luminance according to an embodiment of the present invention. Please refer to Fig. 2A to Fig. 2D.

[0033] In one embodiment, the display controller 210 can calculate the number of pixels that have a change between a current image (e.g., time N) and a previous image (e.g., time N-1) of the video signal. For example, when the absolute value of the luminance difference of a particular pixel at the same position in the current image (e.g., time N) and the previous image (e.g., time N-1) is greater than 0 (or greater than a preset value), the display controller 210 can determine that the particular pixel has changed. In some embodiments, the luminance difference is a difference value between the gray levels of the particular pixel. In some other embodiments, the luminance difference can be the sum of the differences of the red subpixel, the green subpixel, and the blue subpixel of the particular pixel, but the present invention is not limited thereto.

[0034] For example, as shown in Figure 2A, the video signal transmitted from the host 100 to the display device 200 may include image 21, which is a still image, and image 21 may include a time toolbar 201 with a current time of 3:15 PM. The host 100 may also periodically update the time displayed in the time toolbar 201, such as once per minute. Thus, at 3:16 PM, the video signal transmitted from the host 100 to the display device 200 may include image 22, as shown in Figure 2B.

[0035] Assuming that the display panel 220 plays 60 frames per second, image 21 will be maintained for one minute (i.e., 60 frames) and image 22 will also be maintained for one minute (i.e., 60 frames). The display controller 210 calculates the average luminance Y of all pixels of each image in the video signal as shown in equation (1):

number

[0036] Here, M denotes the resolution of the display panel 220, K denotes a single pixel, and Z denotes the average luminance value of the red subpixel, the green subpixel, and the blue subpixel in the single pixel. For example, if the resolution of the display panel 220 is 1920x1080, M=1920x1080=2073600 pixels. If the luminances of the red subpixel, the green subpixel, and the blue subpixel in the single pixel are represented by BR, BG, and BB, respectively, Z=(BR+BG+BB) / 3.

[0037] The display controller 210 then calculates the image average brightness Y N and Y N-1 Calculate the average image brightness Y N and Y N-1 Calculate the absolute difference A between the two, and the absolute difference A is calculated using the formula (2):

number

[0038] When the absolute difference A is between 0 and a predetermined value TH (for example, but not limited to, 1), the image average brightness Y of the current image (i.e., time N) and the previous image (i.e., time N-1) is N and Y N-1are very close, display controller 210 determines that the current image (i.e., time N) and the previous image (i.e., time N-1) are two substantially identical images. At this time, if a timer (not shown in FIG. 1) is not activated, display controller 210 activates the timer and calculates the duration of the still image. If the timer is activated, display controller 210 continues to accumulate the timer value of the timer.

[0039] If the absolute difference A is equal to or greater than a predetermined value TH, the image average luminance Y N and Y N-1 Note that to indicate that a significant change has occurred between the current image (i.e., time N) and the previous image (i.e., time N-1), the display controller 210 determines that the current image (i.e., time N) and the previous image (i.e., time N-1) are different images and resets the timer value of the timer. In this embodiment, the display controller uses a fixed predetermined value TH to determine whether the current image and the previous image are substantially the same image.

[0040] Because image 21 in FIG. 2A and image 22 in FIG. 2B are still images, and the only difference between images 21 and 22 is the time displayed by the time toolbar 201, the mechanism performed by the display controller 210 to determine whether the current image and the previous image are substantially the same image already includes a tolerance that can allow for small changes on the screen, such as a time jump on the time toolbar 201, or a flickering cursor on a text editor.

[0041] Specifically, when the timer value of the timer reaches a first duration, the display controller 210 activates a mechanism for preventing burn-in of the screen of the display device 200, and reduces the brightness of each pixel of the current image of the video signal displayed by the display panel 220 by a first ratio, to indicate that the video signal displayed on the display device 200 has been maintained as a still image for a certain period of time. For example, the first duration is 5 minutes, and the first ratio is 50%, but the present invention is not limited thereto. For example, the image 22 in FIG. 2B at 3:16 PM starts to maintain a still state. At 3:21 PM, the display controller 210 determines that the timer value of the timer has reached a first duration (e.g., 5 minutes), so the display controller 210 reduces the brightness of each pixel of the current image of the video signal displayed on the display panel 220 by 50%, as shown in FIG. 2C.

[0042] Then, since the video signal from the host 100 still maintains a still image, when the timer value reaches a second duration (e.g., 10 minutes), indicating that the video signal displayed on the display device 200 continues to maintain a still image for a longer time, the display controller 210 can reduce the brightness of each pixel of the current image of the video signal displayed on the display device 200 by a second ratio, the second duration can be 10 minutes, and the second ratio can be 70%, but the present invention is not limited thereto. For example, the image 22 in FIG. 2B starts to maintain a still state at 3:16 PM. At 3:26 PM, the display controller 210 can determine that the timer value of the timer reaches a second duration (e.g., 10 minutes), and the display controller 210 can reduce the brightness of each pixel of the current image of the video signal displayed on the display panel 220 by 70%, as shown in FIG. 2D.

[0043] Since the video signal from the host 100 still maintains a static state, when the timer value of the timer reaches a third duration (e.g., 15 minutes), which indicates that the video signal displayed on the display device 200 has been maintained in a static state for a very long time, the display controller 210 can reduce the brightness of each pixel of the current image of the video signal displayed on the display device 200 to 0 (e.g., a black screen is displayed), and the third duration can be 15 minutes, but the present invention is not limited thereto. In addition, the display controller 210 can read the OSD interface 233 corresponding to a notification message from the firmware 231, and display the notification message on the display panel 220 to notify the user that the display device 200 has entered a screen burn-in prevention mode.

[0044] In another embodiment, the display controller 210 can dynamically adjust the predetermined value TH according to the average luminance of the current image of the video signal, thereby determining whether the current image and the previous image are substantially the same image. For example, when the average luminance of the current image of the video signal is between 100% and 70% (e.g., a first luminance interval) of the maximum luminance (e.g., 255) of each pixel, the display controller 210 can set the aforementioned predetermined value TH to a predetermined value TH1, where the predetermined value TH1 is, for example, 0.00005. This means that when the average luminance of the current image is high luminance, the display controller 210 can set a lower predetermined value TH1 (i.e., a tolerance ratio) to determine whether the current image and the previous image are substantially the same image.

[0045] When the average luminance of the current image of the video signal is between 70% and 30% (e.g., a second luminance interval) of the maximum luminance (e.g., 255) of each pixel, the display controller 210 can set the aforementioned predetermined value TH to a predetermined value TH2, where the predetermined value TH2 is, for example, 0.0001. This means that when the average luminance of the current image is medium luminance, the display controller 210 can set a medium predetermined value TH2 (i.e., a tolerance ratio) to determine whether the current image and the previous image are substantially the same image.

[0046] When the average luminance of the current image of the video signal is between 30% and 10% (e.g., the third luminance interval) of the maximum luminance (e.g., 255) of each pixel, the display controller 210 can set the aforementioned predetermined value TH to a predetermined value TH3, where the predetermined value TH3 is, for example, 0.0002. This means that when the average luminance of the current image is low, the display controller 210 can set a higher predetermined value TH3 (i.e., the tolerance ratio) to determine whether the current image and the previous image are substantially the same image.

[0047] 3 is a flow chart of a method for preventing image burn-in according to an embodiment of the present invention. Please refer to FIG.

[0048] In step S310, the display controller 210 receives a video signal from the host 100 and displays the video signal on the display panel 220.

[0049] In step S320, the display controller 210 calculates the average luminance of each image in the video signal. For example, the display controller 210 calculates the average luminance value Z of the red subpixel, the green subpixel, and the blue subpixel of each pixel in each image of the video signal, calculates the sum of the average luminance values ​​of all pixels in each image, and divides the calculated sum by the resolution (i.e., the total number of pixels) of the display panel 220 to obtain the average luminance Y of each image, as shown in formula (1).

[0050] In step S330, when the absolute difference between the first image average luminance of the current image and the second image average luminance of the previous image in the video signal is less than a predetermined value, the display controller 210 activates a timer and obtains a timer value. For example, the image average luminance values ​​of the current image (i.e., time N) and the previous image (i.e., time N-1) are Y and Y, respectively. N and Y N-1 and the absolute difference A is shown in Equation (2). When the absolute difference A is between 0 and a predetermined value TH (for example, but not limited to, 1), the image average brightness Y N and Y N-1 are very close, display controller 210 determines that the current image (ie, time N) and the previous image (ie, time N-1) are two substantially identical images.

[0051] In step S340, when the timer value reaches the first duration, the display controller 210 reduces the luminance of each pixel of the current image of the video signal displayed on the display panel 220 by a first rate.

[0052] In step S350, when the timer value reaches a second duration, the display controller 210 reduces the luminance of each pixel of the current image of the video signal displayed on the display panel 220 by a second rate, where the second duration is longer than the first duration and the second rate is higher than the first rate.

[0053] In step S360, when the timer value reaches a third duration (e.g., equal to or greater than the third duration), the luminance of each pixel of the current image of the video signal displayed on the display panel 220 is reduced to 0, where the third duration is longer than the second duration. For example, when the absolute difference A is between 0 and a predetermined value TH (e.g., but not limited to, 1), the image average luminance Y of the current image (i.e., time N) and the previous image (i.e., time N-1) is reduced to 0. N and Y N-1are very close, the display controller 210 determines that the current image (i.e., time N) and the previous image (i.e., time N-1) are two substantially identical images. At this time, if a timer (not shown in FIG. 1) is not activated, the display controller 210 activates the timer and calculates the duration of the still image. If the timer is activated, the display controller 210 continues to accumulate the timer value of the timer. If the aforementioned absolute difference A is equal to or greater than the predetermined value TH, the image average brightness Y of the current image (i.e., time N) and the previous image (i.e., time N-1) is calculated. N and Y N-1 To indicate that a significant change has occurred between time N and time N-1, display controller 210 determines that the current image (i.e., time N) and the previous image (i.e., time N-1) are different images and resets the timer value of the timer.

[0054] In view of the above, a display device is provided that can determine whether a current image and a previous image in a video signal from a host are substantially the same, and determine the duration of the same image, and a method for preventing burn-in on the screen thereof. When determining that the video image is a still image, the display device can accumulate a timer value, and further reduce the brightness of each pixel of the current pixel of the video signal according to the timer value, thereby reducing the overall brightness of the display panel when displaying the still image. This can reduce the possibility of the burn-in phenomenon occurring on the display panel.

[0055] The use of terms such as "first," "second," and "third" in the claims is used to modify elements in the claims and is not used to indicate a priority, precedence relationship, or precedence of one element over another, or a chronological order in performing method steps, but is used only to distinguish between similarly named elements.

[0056] While the present invention has been described by way of example and in terms of a preferred embodiment, it is not intended to be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements which will be apparent to those skilled in the art. Thus, the scope of the appended claims should be accorded the broadest interpretation to encompass all such modifications and similar arrangements. [Explanation of symbols]

[0057] 10. Computer Systems 21~24 Images 100 hosts 110 Processing Unit 111 System Bus 120 Graphics Processing Unit (GPU) 130 Memory Unit 140 Storage device 141 Applications 142 Operating Systems 150 Transmission Interface 160 Peripheral Devices 200 Display device 201 Time Toolbar 210 Display Controller 211 Image Scalar 212 Timing Controller 220 Display Panel 230 Storage Unit 231, 232 Firmware 233 On-Screen Display (OSD) Interface 240 Image Buffer 250 Transmission Interface 260 Input Interface 261 Physical Buttons 262 5-way joystick S310~S360 Step

Claims

1. Display panel, and a display controller configured to receive a video signal from a host and display the video signal on the display panel; the display controller calculating an average image luminance for each image in the video signal; in response to an absolute difference between a first image average luminance of a current image in the video signal and a second image average luminance of a previous image in the video signal being less than a predetermined value, the display controller activates a timer, obtains a timer value, and In response to the timer value reaching a first duration, the display controller reduces a luminance of each pixel of the current image of the video signal displayed on the display panel by a first rate; in response to the timer value reaching a second duration, the display controller reduces a luminance of each pixel of the current image of the video signal displayed on the display panel by a second rate, the second duration being longer than the first duration and the second rate being greater than the first rate; The display controller further comprises: dynamically adjusting the predetermined value according to the average image luminance of the current image; when the image average luminance of the current image is higher than a first luminance, the display controller sets the predetermined value to a first predetermined value; when the image average luminance of the current image is between the first luminance and a second luminance lower than the first luminance, the display controller sets the predetermined value to a second predetermined value; when the image average luminance of the current image is between the second luminance and a third luminance lower than the second luminance, the display controller sets the predetermined value to a third predetermined value; A display device, wherein the first predetermined value is smaller than the second predetermined value, and the second predetermined value is smaller than the third predetermined value.

2. 2. The display device of claim 1, wherein in response to the timer value being equal to or greater than a third duration, the display controller reduces to zero a luminance of each pixel of the current image of the video signal displayed on the display panel, the third duration being greater than the second duration.

3. 2. The display device of claim 1, wherein the display controller calculates average luminance values ​​of red, green, and blue subpixels of each pixel of each image in the video signal, calculates a sum of the average luminance values ​​of all pixels in each image, and divides the calculated sum by the resolution of the display panel to obtain the average image luminance for each image.

4. 2. The display device of claim 1, wherein in response to the absolute difference being less than the predetermined value, the display controller determines that the current image and the previous image are substantially the same.

5. The display device of claim 1 , in response to the absolute difference being equal to or greater than the predetermined value, the display controller determines that the current image and the previous image are different images and resets the timer value of the timer.

6. A method for preventing image burn-in used in a display device including a display panel and a display controller, comprising: receiving a video signal from a host using the display controller and displaying the video signal on the display panel; calculating, using said display controller, an average image luminance for each image in said video signal; activating a timer using the display controller and obtaining a timer value in response to an absolute difference between a first image average luminance of a current image in the video signal and a second image average luminance of a previous image in the video signal being less than a predetermined value; responsive to the timer value reaching a first duration, decreasing, with the display controller, a luminance of each pixel of the current image of the video signal displayed on the display panel by a first rate; and responsive to the timer value reaching a second duration, decreasing, with the display controller, a luminance of each pixel of the current image of the video signal displayed on the display panel by a second rate. wherein the second duration is longer than the first duration and the second ratio is higher than the first ratio; using the display controller to dynamically adjust the predetermined value according to the average image luminance of the current image; dynamically adjusting, using the display controller, the predetermined value according to an average image luminance of the current image, setting, using the display controller, the predetermined value to a first predetermined value when the average image luminance of the current image is greater than a first luminance; setting, using the display controller, the predetermined value to a second predetermined value when the image average luminance of the current image is between the first luminance and a second luminance lower than the first luminance; and setting, using the display controller, the predetermined value to a third predetermined value when the image average luminance of the current image is between the second luminance and a third luminance lower than the second luminance; The first predetermined value is less than the second predetermined value, and the second predetermined value is less than the third predetermined value.

7. 7. The method of claim 6, further comprising, in response to the timer value being equal to or greater than a third duration, using the display controller to reduce to zero a luminance of each pixel of the current image of the video signal displayed on the display panel, the third duration being greater than the second duration.

8. Calculating, using the display controller, an average image luminance for each pixel of each image in the video signal, 7. The method of claim 6, further comprising using the display controller to calculate average luminance values ​​of red, green and blue subpixels of each pixel of each image in the video signal, to calculate a sum of the average luminance values ​​of all pixels in each image, and to divide the calculated sum by a resolution of the display panel to obtain the average image luminance for each image.

9. 7. The method of claim 6, further comprising the step of determining, with the display controller, that the current image and the previous image are substantially the same in response to the absolute difference being less than the predetermined value.

10. 7. The method of claim 6, further comprising the step of: in response to the absolute difference being greater than or equal to the predetermined value, determining, using the display controller, that the current image and the previous image are different images and resetting the timer value of the timer.

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