Patent Application
20210035498
BACKGROUND
The invention relates to a display device and more particularly, to a panel control device and an operation method thereof.
Some types of display panels have a phenomenon of image sticking. For example, in an organic light emitting diode (OLED) display panel, the phenomenon of image sticking may occur to the OLED display panel after displaying a static object for a time period, and this phenomenon is a so-called burn-in (or referred to as burn-down) phenomenon. The OLED display panel has an organic compound film. As the OLED display panel is used for a longer duration and generates heat, the organic material thereof is gradually aged. The image sticking of the OLED display panel actually refers to a same still image displayed by some pixels at a certain fixed position on a screen for a long time, which causes the organic compound film corresponding to the pixels to be aged in a faster speed than pixels in other positions. These rapidly aged pixels leave the image sticking on the screen. Generally, the burn-in phenomenon is irreversible. How to prevent the occurrence of the bum-in phenomenon is an important subject to the technical field related to display devices.
A panel control device receives video data from a former stage device and then, drives a display panel according to the video data. Generally, the panel control device has to perform image analysis on several (or dozens) frames in the video data, so as to judge whether a current frame is a still image. When a judgment result indicates that the current frame is a still image, the panel control device performs an anti-burn-in process on the video data, thereby preventing the burn-in phenomenon from occurring to the display panel. In order to judge whether the current frame is the still image, the panel control device spends a considerably lone time for performing the image analysis.
It should be noted that the contents of the section of “Description of Related Art” is used for facilitating the understanding of the invention. A part of the contents (or all of the contents) disclosed in the section of “Description of Related Art” may not pertain to the conventional technology known to the persons with ordinary skilled in the art. The contents disclosed in the section of “Description of Related Art” do not represent that the contents have been known to the persons with ordinary skilled in the art prior to the filing of this invention application.
The invention provides a panel control device and an operation method thereof to dynamically adjust a processing degree of an anti-burn-in process according to a panel self-refresh command issued by a former stage device.
According to an embodiment of the invention, a panel control device configured to drive a display panel is provided. The panel control device includes a first display port and a control circuit. The first display port is configured to receive video data from a second display port of a former stage device. The control circuit is coupled to the first display port. The control circuit is configured to perform an anti-burn-in process on the video data according to a processing degree. After the former stage device issues a panel self-refresh entering command to the panel control device, the panel control device enters a panel self-refresh mode, and the control circuit increases the processing degree according to the panel self-refresh entering command, so as to perform the anti-burn-in process on the video data according to the increased processing degree.
According to an embodiment of the invention, an operation method of a panel control device is provided. The operation method includes: receiving video data from a second display port of a former stage device by a first display port of the panel control device, wherein the panel control device is configured to drive a display panel; performing an anti-bum-in process on the video data according to a processing degree by a control circuit of the panel control device; and after the former stage device issues a panel self-refresh entering command to the panel control device, entering a panel self-refresh mode by the panel control device, and increasing the processing degree according to the panel self-refresh entering command by the control circuit, so as to perform the anti-burn-in process on the video data according to the increased processing degree.
According to an embodiment of the invention, a panel control device configured to drive a display panel is provided. The panel control device includes a first display port and a control circuit. The first display port is configured to receive video data from a second display port of a former stage device. The control circuit is coupled to the first display port. The control circuit is configured to perform an anti-burn-in process on the video data according to a processing degree. After the former stage device issues a panel self-refresh exiting command to the panel control device, the panel control device exits a panel self-refresh node, and the control circuit reduces the processing degree according to the panel self-refresh exiting command, so as to perform the anti-burn-in process on the video data according to the reduced processing degree.
According to an embodiment of the invention, an operation method of a panel control device is provided. The operation method includes: receiving video data from a second display port of a former stage device by a first display port of the panel control device, wherein the panel control device is configured to drive a display panel; performing an anti-burn-in process on the video data according to a processing degree by a control circuit of the panel control device; and after the former stage device issues a panel self-refresh exiting command to the panel control device, exiting a panel self-refresh mode by the panel control device, and reducing the processing degree according to the panel self-refresh exiting command by the control circuit, so as to perform the anti-burn-in process on the video data according to the reduced processing degree.
Based on the above, the panel control device and the operation method provided by the embodiments of the invention can receive the video data and the panel self-refresh command (e.g., the panel self-refresh entering command and/or the panel self-refresh exiting command) from the former stage device. For example, after the former stage device issues the panel self-refresh entering command to the panel control device, the control circuit can increase the processing degree of the anti-burn-in process according to the panel self-refresh entering command. Moreover, in another example, after the former stage device issues the panel self-refresh exiting command to the panel control device, the control circuit can reduce the processing degree of the anti-burn-in process according to the panel self-refresh exiting command. Thus, the control circuit can dynamically adjust the processing degree of the anti-burn-in process according to the panel self-refresh command issued by the former stage device.
In order to make the aforementioned and other features and advantages of the invention more comprehensible, several embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
The term “couple (or connect)” throughout the specification (including the claims) of this application are used broadly and encompass direct and indirect connection or coupling means. For example, if the disclosure describes a first apparatus being coupled (or connected) to a second apparatus, then it should be interpreted that the first apparatus can be directly connected to the second apparatus, or the first apparatus can be indirectly connected to the second apparatus through other devices or by a certain coupling means. In addition, terms such as “first” and “second” mentioned throughout the specification (including the claims) of this application are only for naming the names of the elements or distinguishing different embodiments or scopes and are not intended to limit the upper limit or the lower limit of the number of the elements not intended to limit sequences of the elements. Moreover, elements/components/steps with same reference numerals represent same or similar parts in the drawings and embodiments. Elements/components/notations with the same reference numerals in different embodiments may be referenced to the related description.
Some types of display panels may have a phenomenon of image sticking. For example, in an organic light emitting diode (OLED) display panel, the phenomenon of image sticking may occur to the OLED display panel after displaying a static object for a long time period, and this phenomenon is a so-called burn-in (or referred to as burn-down) phenomenon. How to prevent the occurrence of the burn-in phenomenon is an important subject to the technical field related to display devices.
In some embodiments, for a pixel which the burn-in phenomenon likely occurs to, the probability of the occurrence of the burn-in phenomenon may be effectively reduced by adaptively reducing a brightness of the pixel. The lower the brightness is, the less heat the pixel generates. Thereby, the probability of the occurrence of the burn-in phenomenon may be reduced. In anyway, the reduction of the pixel brightness means the reduction of image brightness. For a still image scene, a reduction extent (i.e., a processing degree) of the pixel brightness may be increased. For a motion video, the reduction extent (i.e., the processing degree) of the pixel brightness may be decreased, or even the pixel brightness may be recovered to a normal brightness (i.e., the brightness is riot reduced).
Consequently, in the PSR mode, the panel control device 100 can be configured to increase the processing degree according to the panel self-refresh entering command, so as to perform the anti-burn-in process on the video data according to the increased processing degree. In other words, the former stage device 10 can be utilized to take or share the responsibility of judging whether a current frame has a still image (a part or whole of the frame), thus increasing the efficiency of burn-prevention.
For example, the panel control device 100 further includes a control circuit 110 and a frame buffer 120. The control circuit 110 is coupled to a display port 101 to receive the video data 12. The control circuit 110 may perform an anti-bum-in process on the video data 12 according to a processing degree and then drive the display panel 20 according to the video data processed by the anti-burn-in process to display the image. In the PSR mode, the panel control device 100 can be configured to increase the processing degree according to the panel self-refresh entering command, so as to perform the anti-burn-in process on the video data according to the increased processing degree. In addition, the frame buffer 120 may store the video data 12 in the PSR mode. In the PSR mode, data transmission between a display port 11 and the display port 101 may be turned off, and the control circuit 110 may generate a plurality of frames according to the video data stored by the frame buffer 120 in the PSR mode. The PSR mode is a conventional technique and thus, will not be repeatedly described. It is also noted that other kinds of commands and/or modes can be also implemented in other embodiments.
Based on a design requirement, the data transmission between the display port 11 and the display port 101 may use any data transmission protocol. For example, the protocol used by the data transmission between the display port 11 and the display port 101 may include an. embedded display port (eDP) transmission protocol. Namely, the display port 11 is an eDP port (e.g., an eDPTX port), and the display port 101 is another eDP port (e.g., an eDPRX port). The eDP transmission protocol is a conventional technique and thus, will not be repeatedly described.
In step S220, whether the former stage device 10 issues the PSR entering command to the panel control device 100 may be determined. In a condition that the former stage device 10 does not issue the PSR entering command to the panel control device 100 (i.e., the determination result of step S220 is “No”), the control circuit 110 may perform the anti-burn-in process on the video data 12 according to a processing degree corresponding to a motion image (step S250). For example, in the condition that the former stage device 10 does not issue the PSR entering command to the panel control device 100, a reduction extent of a pixel brightness (i.e., a processing degree of the anti-burn-in process) may be zero, i.e., the pixel brightness of the video data 12 is reduced.
After the former stage device 10 issues the PSR entering command to the panel control device 100 (i.e., the determination result of step S220 is “Yes”), the panel control device 100 may enter the PSR mode (step S230), and the control circuit 110 may increase the processing degree of the anti-burn-in process according to the PSR entering command (step S240), so as to perform the anti-burn-in process on the video data 12 according to the increased processing degree (step S250).
For example, after the former stage device 10 issues the PSR entering command to the panel control device 100, the control circuit 110 may increase the reduction extent of the pixel brightness (i.e., the processing degree of the anti-burn-in process) according to the PSR entering command. The control circuit 110 may reduce the pixel brightness of the video data 12 (i.e., perform the anti-burn-in process on the video data 12) according to the new reduction extent (i.e., the increased processing degree). Thus, the control circuit 100 may perform the anti-burn-in process on the video data 12 immediately and adaptively without spending more time, thereby preventing the burn-in phenomenon from occurring to the display panel 20. It is noted that numerous approaches capable of preventing burn-in phenomenon can be adopted by the control circuit 110.
After the former stage device 10 issues the PSR entering command to the panel control device, the control circuit 110 can instantly increase the processing degree of the anti-burn-in process to a predetermined level instead of gradually increasing the level of the processing degree. The predetermined level may be defined based on a design requirement. For example, the predetermined level may be a maximum level. Taking the embodiment as illustrated in
In other embodiments, the anti-burn-in process should not be limited to the description set forth above. For example, in some embodiments, the anti-burn-in process includes a brightness control operation, and the processing degree includes a brightness control degree. Referring to
In some other embodiments, the anti-burn-in operation includes a smooth filter operation, and the processing degree includes an edge smoothing degree. After the former stage device 10 issues the PSR entering command to the panel control device 100, the control circuit 110 may adjust the edge smoothing degree of the smooth filter operation to a maximum level at a certain increasing speed. The control circuit 100 may perform the smooth filter operation on the video data 12 according to the edge smoothing degree.
In yet other embodiments, the anti-burn-in process includes a dynamic chromatic control operation, and the processing degree includes a dynamic chromatic control degree. After the former stage device 10 issues the PSR entering command to the panel control device 100, the control circuit 110 may adjust the dynamic chromatic control degree of the dynamic chromatic control operation to a maximum level at a certain increasing speed. The control circuit 110 may perform the dynamic chromatic control operation on the video data 12 according to the dynamic chromatic control degree to dim a blue brightness of the video data 12.
In some other embodiments, the anti-burn-in process includes an image orbit operation, and the processing degree includes a moving distance. After the former stage device 10 issues the PSR entering command to the panel control device 100, the control circuit 110 may adjust the moving distance of the image orbit operation to a maximum level at a certain increasing speed. The control circuit 110 may perform the image orbit operation on the video data 12 according to the moving distance to move the image of the video data 12.
Referring to
The control circuit 110 may reduce a processing degree corresponding to the partial update region 520 in the PSR mode, for example, by reducing the processing degree of the anti-burn-in process performed on the partial update region 520 to L0. The processing degree L0 may be determined according to a design requirement. For example, in the PSR mode, the control circuit 110 may set the processing degree L0 corresponding to the partial update region 520 to be zero.
The control circuit 110 may increase the processing degree of the anti-burn-in process performed on the static image regions 510 and 530. The static image region 510 (and/or the static image region 530) may be divided into one or more sub static regions according to a design requirement. The control circuit 110 may set processing degrees corresponding to different sub static regions to be different values. Taking the embodiment as illustrated in
After the former stage device 10 issues the PSR exiting command to the panel control device 100 (i.e., the determination result of step S620 is “Yes”), the panel control device 100 may exit the PSR mode (step S630), and the control circuit 110 may reduce the processing degree of the anti-burn-in process according to the PSR exiting command (step S640), so as to perform the anti-burn-in process on the video data 12 according to the reduced processing degree (step S650).
For example, after the former stage device 10 issues the PSR entering command to the panel control device 100, the control circuit 110 may increase the reduction extent of the pixel brightness (i.e., the processing degree of the anti-burn-in process) according to the PSR entering command. The control circuit 110 may reduce the pixel brightness of (i.e., perform the anti-burn-in process on) the video data 12 according to a new reduction extent (i.e., an increased processing degree). After the former stage device 10 issues the PSR exiting command to the panel control device 100, the control circuit 110 may decrease the reduction extent (i.e., the processing degree) of the pixel brightness according to the PSR exiting command. The control circuit 110 may perform the anti-burn-in process on the video data 12 according to the new reduction extent (i.e., the reduced processing degree). For example, after the former stage device 10 issues the PSR exiting command to the panel control device 100, the control circuit 110 may decrease the reduction extent to zero (i.e., does not reduce the pixel brightness), so as to recover the pixel brightness to the normal brightness.
The control circuit 110 may reduce the processing degree of the anti-burn-in process by any method. In some embodiments, the control circuit 110 may dynamically (or statically) determine a reducing speed for the processing degree. For example, after the former stage device 10 issues the PSR exiting command to the panel control device 100, the control circuit 10 may calculate an image change degree of the current frame of the video data 12 according to a previous frame, and the control circuit 110 may determine the reducing speed of reducing the processing degree according to the image change degree.
In some other embodiments, the control circuit 110 may determine the reducing speed of reducing the processing degree by comparing the image change degree with a threshold. The threshold value may be determined based on a design requirement. When the image change degree is greater than the threshold, the control circuit 110 may rapidly reduce the processing degree of the anti-burn-in process at a first reducing speed. The first reducing speed may be determined based on a design requirement.
Referring to
Table 1 below illustrates the process of adjusting the processing degree of the anti-burn-in process at different positions in the display panel 20 according to the embodiments of the invention. The horizontal axis in Table 1 represent the time, wherein T1-T9 represent different time points. The vertical axis in Table 1 represents the positions in the display panel 20, wherein PL1-PL7 represent different positions in the display panel 20.
Referring to
After the time point T3, the former stage device 10 issues a panel self-refresh 2 (PSR2) entering command to the panel control device 100, such that the panel control device 100 enters a PSR2 mode. It is assumed that the position PL6 belongs to a partial update region (which may be inferred with reference to the description related to the partial update region 520 illustrated in
At the time point T5, the control circuit 110 may reduce the processing degree of the anti-burn-in process performed at the position PL6 (the partial update region) from L1 to L0. For the positions PL5 and PL7 which are nearer the position PL6, the processing degrees of the anti-burn-in process thereof are reduced from L2 to L1. According to a distance from the partial update region, the processing degree at the position PL4 is reduced from L3 to L2, and the processing degrees at the positions PL1-PL3 are maintained at L3 (it is assumed herein that L3 is the maximum level).
After the time point T5, the former stage device 10 issues a panel self-refresh 2 (PSR2) exiting command to the panel control device 100, such that the panel control device 100 exits the PSR2 mode (but is till in the PSR mode). At the time point T6, based on the PSR entering command, the control circuit 110 may increase the processing degrees at the positions PL1-PL7. For example, the control circuit 110 may increase the processing degree at the position PL6 from L0 to L1, increase the processing degrees at the positions PL5 and PL7 from L1 to L2, and increase the processing degree at the position PL4 from L2 to L3. Because the processing degrees at the positions PL1-PL3 have reached the maximum level, the processing degrees at the positions PL1-PL3 are maintained at L3.
After the time point T6, the former stage device 10 issues a PSR exiting command to the panel control device 100, such that the panel control device 100 exits the PSR mode. At the time point T7, the control circuit 110 may reduce the processing degrees at the positions PL1-PL7 according to the PSR exiting command. For example, the control circuit 110 may reduce the processing degrees at the positions PL1-PL4 from L3 to L2, reduce the processing degrees at the positions PL5 and PL7 from L2 to L1, and reduce the processing degree at the position PL6 from L1 to L0. By deducing in the same way, at the time point T9, the control circuit 110 may reduce the processing degrees at the positions PL1-PL7 to L0.
Based on different design demands, the blocks of the the panel control device and/or the control circuit 110 may be implemented in a form of hardware, firmware, or in a combination of both of the aforementioned forms.
In terms of the hardware form, the blocks of the panel control device 100 and/or the control circuit 110 may be implemented as logic circuits on an integrated circuit. Related functions of the panel control device 100 and/or the control circuit 110 may be implemented in a form of hardware by utilizing hardware description languages (e.g., Verilog HDL or VHDL) or other suitable programming languages. For example, the panel control device 100 and/or the control circuit 110 may be implemented in one or more controllers, micro-controllers, microprocessors, application-specific integrated circuits (ASICs), digital signal processors (DSPs), field programmable gate arrays (FPGAs) and/or various logic blocks, modules and circuits in other processing units.
In terms of the firmware form, the panel control device 100 and/or the control circuit 110 may be implemented as programming codes. For example, the panel control device 100 and/or the control circuit 110 may be implemented by using general programming languages (e.g., C or C++) or other suitable programming languages. The programming codes may be recorded/stored in recording media, and the aforementioned recording media include, for example, a read only memory (ROM), a storage device and/or a random access memory (RAM). Additionally, the programming codes may be accessed from the recording medium and executed by a computer, a central processing unit (CPU), a controller, a micro-controller or a microprocessor to accomplish the related functions. As for the recording medium, a non-transitory computer readable medium, such as a tape, a disk, a card, a semiconductor memory or a programming logic circuit, may be used. In addition, the programs may be provided to the computer (or the CPU) through any transmission medium (e.g., communication network or radio waves). The communication network is, for example, the Internet, wired communication., wireless communication or other communication media.
Based on the above, the panel control device and the operation method provided by the embodiments of the invention can receive the video data and the PSR command from the former stage device (e.g., the PSR entering command and/or the PSR exiting command) from the former stage device. After the former stage device issues the PSR entering command to the panel control device, the control circuit can increase the processing degree of the anti-burn-in process according to the PSR entering command. After the former stage device issues the PSR exiting command to the panel control device, the control circuit can reduce the processing degree of the anti-burn-in process according to the PSR exiting command. Thus, the control circuit can dynamically adjust the processing degree of the anti-burn-in process according to the panel self refresh command issued by the former stage device.
It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the disclosed embodiments without departing from the scope or spirit of the disclosure. In view of the foregoing, it is intended that the disclosure cover modifications and variations of this disclosure provided they fall within the scope of the following claims and their equivalents.
