The present application claims priority to Chinese patent application No. 201810161083.0, filed on Feb. 27, 2018, the entire disclosure of which is incorporated herein by reference as part of the present application.
At least one embodiment of the present disclosure relates to an optical compensation method for a display panel and an optical compensation device.
Compared to a Liquid Crystal Display (LCD), an Organic Light-Emitting Diode (OLED) display apparatus has various advantages of high contrast, ultra thinness, bendability and the like, and thus is more and more widely applied to high-performance display. Currently, brightness non-uniformity and afterimages are two main difficult problems which the OLED faces. In order to solve the technical problems of brightness non-uniformity and afterimages in the OLED, in addition to improvement of the process, there is a compensation technology.
At least one embodiment of the present disclosure provides an optical compensation method for a display panel and an optical compensation device.
At least one embodiment of the present disclosure provides an optical compensation method for a display panel, the display panel comprises a main body region and an edge region located at a periphery of the main body region. The optical compensation method comprises: selecting a pixel block to be compensated in the edge region; and acquiring a pixel compensation parameter of at least one pixel block in the main body region as a pixel compensation parameter of the pixel block to be compensated.
For example, acquiring the pixel compensation parameter of the at least one pixel block in the main body region as the pixel compensation parameter of the pixel block to be compensated comprises: acquiring a pixel compensation parameter of a first pixel block in the main body region, which is the closest to a second pixel block to be compensated, as a pixel compensation parameter of the second pixel block.
For example, pixel blocks on the display panel are arranged along a row direction and a column direction, and acquiring the pixel compensation parameter of the at least one pixel block in the main body region as the pixel compensation parameter of the pixel block to be compensated further comprises: determining an alignment mode of the second pixel block and the first pixel block, the alignment mode comprising row alignment or column alignment; and using the pixel compensation parameter of the second pixel block as a pixel compensation parameter of a plurality of third pixel blocks to be compensated positioned in a same row or a same column with the second pixel block according to the alignment mode.
For example, before acquiring the pixel compensation parameter of the at least one pixel block in the main body region as the pixel compensation parameter of the pixel block to be compensated, the optical compensation method further comprises: judging whether a fourth pixel block to be compensated which is not in the row alignment or in the column alignment with the first pixel block in the main body region exists in the edge region; and determining a region where the fourth pixel block is positioned as a corner region of the edge region if the fourth pixel block exists in the edge region.
For example, the pixel compensation parameter of the first pixel block which is the closest to the corner region is used as a pixel compensation parameter of the fourth pixel block in the corner region, and the pixel compensation parameters of the fourth pixel blocks positioned in a same corner region are all the same.
For example, acquiring the pixel compensation parameter of the at least one pixel block in the main body region of the display panel comprises: acquiring picture data displayed by the display panel; identifying a color difference or brightness difference between the at least one pixel block in the main body region and at least one pixel block in a tested picture on the basis of color distribution or brightness distribution of the picture data; and acquiring the pixel compensation parameter of the at least one pixel block in the main body region by utilizing a compensation algorithm according to the color difference or brightness difference between the at least one pixel block in the main body region and the at least one pixel block in the tested picture.
For example, the pixel compensation parameter comprises an offset and a gain which are calculated according to the at least one pixel block in the main body region.
For example, acquiring the picture data displayed by the display panel comprises: adopting a camera to shoot to acquire the picture data displayed by the display panel.
For example, the compensation algorithm comprises an optical compensation algorithm.
For example, after acquiring the picture data displayed by the display panel, the optical compensation method further comprises: identifying the color difference or brightness difference between the pixel block in the display panel and the pixel block in the tested picture on the basis of the color distribution or brightness distribution of the picture data, and partitioning the display panel into the edge region and the main body region according to a size of the color difference or brightness difference. The color difference or brightness difference of the edge region is greater than that of the main body region.
For example, the optical compensation method further comprises: reading the pixel compensation parameter of the pixel block in the main body region of the display panel and a regulated pixel compensation parameter of the pixel block to be compensated in the edge region; and inputting the pixel compensation parameter of the main body region and the regulated pixel compensation parameter of the edge region into the display panel so as to compensate a display operation for the display panel.
For example, selecting the main body region and the edge region of the display panel comprises: acquiring a brightness test result of the display panel, and partitioning the display panel into the edge region with low brightness and the main body region with high brightness according to the test result; or partitioning the display panel into a plurality of regions in advance. The plurality of regions comprise at least one edge region and at least one main body region.
For example, the display panel comprises a curved screen, and the curved screen comprises a plane portion positioned in the main body region and a curved surface portion positioned in the edge region.
For example, the pixel block comprises N*M pixels, N is an integer between 1 and 10, and M is an integer between 1 and 10.
At least one embodiment of the present disclosure provides an optical compensation device, which comprises: a processor; and a memory configured to store a computer program instruction. The computer program instruction is applicable to be loaded by the processor and execute the optical compensation method for the display panel.
For example, the optical compensation device comprises a camera, configured to shoot a picture displayed by the display panel and send the picture into the processor so as to acquire the pixel compensation parameter of the at least one pixel block in the main body region of the display panel.
In order to clearly illustrate the technical solutions of the embodiments of the disclosure, the drawings of the embodiments will be briefly described in the following; it is obvious that the described drawings are only related to some embodiments of the disclosure and thus are not limitative to the disclosure.
In order to make objects, technical details and advantages of the embodiments of the disclosure apparent, the technical solutions of the embodiments will be described in a clearly and fully understandable way in connection with the drawings related to the embodiments of the disclosure. Apparently, the described embodiments are just a part but not all of the embodiments of the disclosure. Based on the described embodiments herein, those skilled in the art can obtain other embodiment(s), without any inventive work, which should be within the scope of the disclosure.
It should be noted that, the terms “first,” “second,” etc., which are used in the present disclosure, are not intended to indicate any sequence, amount or importance, but distinguish various components. It should be understood that the terms used as mentioned above can be interchanged in an appropriate circumstance so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms “comprise,” “comprising,” “include,” “including,” and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a series of steps or elements need not be limited to those steps or elements that are explicitly listed, but may include other steps or elements that are not explicitly listed or inherent to such process, method, product or apparatus.
Generally, electroluminescent display panels comprise an Active Matrix Organic Light-Emitting Diode (AMOLED) display panel, an Active Matrix Quantum dot Light-Emitting Diode (AMQLED) display panel, a Passive Matrix Organic Light-Emitting Diode (PMOLED) display panel and a Passive Matrix Quantum dot Light-Emitting Diode (PMQLED) display panel. The electroluminescent display panel is widely applicable to different fields. For example, in the field of commerce, the electroluminescent display panel can be applicable to a Point-Of-Sale (POS) machine, an Automatic Teller Machine (ATM) machine, a copier, a game machine and the like; in the field of communications, the electroluminescent display panel can be applicable to a mobile phone, a mobile network terminal and the like; in the field of a computer, the electroluminescent display panel can be applicable to a Personal Digital Assistant (PDA), a commercial Personal Computer (PC), a domestic PC, a notebook computer and the like; in the field of consumer electronic products, the electroluminescent display panel can be applicable to a sound device, a digital camera, a portable Digital Video Disc (DVD) and the like; in the field of industrial application, the electroluminescent display panel can be applicable to instruments and apparatus and the like; and in the field of traffic, the electroluminescent display panel can be applicable to a Global Positioning System (GPS), an aircraft instrument and the like.
For example, as shown in
For the OLED pixel circuit used in the small or medium-sized OLED display panel, due to limitation of a crystallization process for forming a polycrystalline silicon active layer of the thin film transistor, the low temperature polycrystalline silicon thin film transistors at different positions generally have non-uniformity in electrical parameters such as threshold voltage and mobility, and such non-uniformity can be converted into a current difference and a brightness difference of the OLED display panel and sensed by human eyes (i.e., a mura phenomenon). For the OLED pixel circuit used in the large-sized display panel, the oxide thin film transistor is relatively good in process uniformity, but a threshold voltage of the oxide thin film transistor can be drifted under long-time pressurization and high temperature. Due to different displayed pictures, the threshold drift amounts of thin film transistors at respective portions of the panel are different, which may cause a difference in display brightness. Such difference is related to a previously displayed image, and thus generally appears as an afterimage phenomenon, also known as afterimage.
In the current process, no matter whether it is the low temperature polycrystalline silicon thin film transistor or the oxide thin film transistor, there is a problem of non-uniformity or non-stability, and the OLED also may be attenuated in brightness along with increase of lighting time. Those problems are difficult to completely solve in process and have to be solved by various compensation technologies.
Currently, the technical problems of brightness non-uniformity and afterimage in the OLED display panel can be solved by an internal compensation technology or an external compensation technology. The internal compensation technology refers to a method for carrying out compensation inside a pixel by utilizing a compensation sub-circuit constructed by the thin film transistor. The external compensation technology refers to a method for carrying out compensation after sensing electrical or optical characteristics of the pixel by an external driving circuit or device.
In the study, an inventor of the application finds that: an optical compensation method for the electroluminescent display panel involves sensing optical characteristics of a pixel by an external driving circuit or device and then carrying out compensation. For example, in the optical compensation method, the electroluminescent display panel is shot by a camera, the optical characteristics of each pixel in the electroluminescent display panel are acquired by a shot image, and the optical compensation is performed on the basis of the optical characteristics of each pixel in the electroluminescent display panel, which are sensed by the camera. However, according to the optical compensation method, when the structure of the electroluminescent display panel is not flat, for example, when the display panel is a curved display panel, the curved display panel may have a phenomenon that brightness of an edge of the curved display panel may be higher than that of a non-edge portion of the curved display panel, after optical compensation.
At least one embodiment of the present disclosure provides an optical compensation system. The optical compensation system can be used for solving the problem that after optical compensation, the electroluminescent display panel has the phenomenon that brightness of the edge portion of the display panel is higher than that of the non-edge portion of the display panel. The optical compensation system is as shown in
For example, as shown in
At least one embodiment of the present disclosure is illustrated by taking the AMOLED display panel as an example. The AMOLED display panel may comprise a data decoding circuit, a timing controller (Tcon), a gate driving circuit, a data driving circuit, a storage apparatus (for example, a flash memory and the like) and the like, in addition to a pixel array. The data decoding circuit receives a display input signal and decodes the display input signal to obtain a display data signal; and the timing controller outputs a timing signal to control the gate driving circuit, the data driving circuit and the like to synchronously work, and can carry out gamma processing on the display data signal and input the processed display data signal to the data driving circuit to perform a display operation. For example, the timing controller, upon performing a gamma processing on the display data signal, can also simultaneously perform a compensation processing. For example, the timing controller can read a pre-stored pixel compensation parameter from the storage apparatus and further process the display data signal by adopting the pixel compensation parameter to obtain the compensated display data signal. And after the timing controller completing the gamma processing and the compensation processing, outputs the display data signal to the data driving circuit for the display operation. Or, the display panel also can comprise an independent gamma processing circuit which performs gamma processing, compensation processing and the like on the display data signal under the control of the timing controller.
In one embodiment, as shown in
For example, in at least one embodiment, as shown in
For example, as shown in
Illustration will be carried out below by taking bright compensation as an example, but the embodiments of the present disclosure do not make any limit thereto.
It should be noted that the camera 2021 comprises, but is not limited to, a charge coupled device (CCD) camera and a complementary metal oxide semiconductor (CMOS) camera. The camera 2021 herein, for example, is a CCD camera with high resolution and high accuracy.
However, the optical compensation method as mentioned above has the difficulty of how to accurately capture correct brightness of each pixel by the camera 2021, particularly when the structure of the display panel is not flat. For example, the display panel 201 can be a curved display panel, and for example, two side edges or four side edges of the curved display panel have a shape of a circular arc, so that a narrower frame can be implemented. When the curved display panel 201 is tested, the camera 2021 cannot accurately capture correct brightness of pixels at a curved edge portion of the display panel 201, and for the pixels at the curved edge portion, a brightness value obtained by shooting is lower than actual brightness values of those portions of the display panel 201, resulting in that after the optical compensation, the display panel 201 has a phenomenon that brightness of the edge portion is higher than that of a non-edge portion.
At least one embodiment of the present disclosure provides a flow chat of an optical compensation method for a display panel as shown in
S401: selecting a pixel block to be compensated in an edge region;
S402: acquiring a pixel compensation parameter of at least one pixel block in a main body region as a pixel compensation parameter of the pixel block to be compensated.
The pixel block as mentioned above comprises at least one pixel, i.e., the pixel block comprises N*M pixels. N is an integer between 1 and 10, and M is an integer between 1 and 10.
As shown in
For example, acquiring pixel compensation parameters of a plurality of pixel blocks on the display panel can comprise steps as follows. The OLED display panel receives a test image (e.g., a uniform gray scale image) sent out by a control unit of the optical compensation device. Upon the OLED display panel displaying a picture of the test image, the picture displayed by the OLED display panel is shot by a camera; and an image of the shot display picture is sent into a data processing unit to be processed and analyzed to acquire display parameters (e.g., color or brightness and the like) of corresponding pixels of the display panel, so as to acquire the pixel compensation parameter of each pixel block of the display panel.
For example, picture data of the test image displayed by the display panel is acquired; on the basis of color distribution or brightness distribution of the picture data, a color difference or brightness difference between each pixel block of the display panel and each pixel block in a target test picture is identified; and according to a size of the color difference or brightness difference between each pixel block of the display panel and each pixel block in the target test picture, the display panel is partitioned into the main body region and the edge region, and the color difference or brightness difference of the edge region is greater than that of the main body region. Then, according to the color difference or brightness difference between the pixel block in the main body region and the pixel block in the target test picture, the pixel compensation parameter of the pixel block in the main body region is acquired by utilizing a compensation algorithm.
The method of optical compensation can be performed with reference to the optical compensation device 202 in
After the pixel block to be compensated in the edge region is selected, the pixel compensation parameter of the pixel block in the main body region, which is acquired by the optical compensation device 202, is used as the pixel compensation parameter of the pixel block to be compensated.
The embodiments are not limited thereto. The pixel compensation parameter of the pixel block to be compensated in the edge region also can be acquired when the pixel compensation parameter of the pixel block in the main body region is acquired, and then the pixel compensation parameter of the pixel block to be compensated is regulated to be consistent with the pixel compensation parameter of the pixel block in the main body region.
In an example as shown in
Herein, selecting the edge region of the display panel further can be implemented in two modes as follows:
Mode I: acquiring a brightness test result of the picture data displayed by the display panel, partitioning the display panel into the edge region with low brightness and the main body region with high brightness according to the brightness test result, and selecting the edge region of the display panel on the basis of the partitioned edge region and main body region.
Mode II: partitioning the display panel into a plurality of regions in advance, as shown in
For example, n rows or m columns of pixels which are inwards from a side edge are selected as the edge region, n and m are integers greater than 1 and for example, are 5 to 15, and values of n and m can be selected based on experience or selected according to design parameters of the display panel.
After the pixel block to be compensated in the edge region is selected, the pixel compensation parameter of the pixel block in the main body region, which is the closest to the pixel block to be compensated, can be extracted from the acquired pixel compensation parameters of a plurality of pixel blocks in the main body region and used as the pixel compensation parameter of the pixel block to be compensated.
In the above-mentioned mode, the compensation parameter of the edge region of the curved display panel (i.e., a flexible screen) can be separately controlled, so that after the curved display panel is subjected to optical compensation, uniformity of brightness of the edge region and brightness of the main body region of the curved display panel is implemented, and the afterimage can be further weakened.
Moreover, according to an embodiment of the present disclosure, acquiring the pixel compensation parameter of at least one pixel block in the main body region as the pixel compensation parameter of the pixel block to be compensated comprises: acquiring a pixel compensation parameter of a first pixel block in the main body region, which is the closest to a second pixel block to be compensated, as a pixel compensation parameter of the second pixel block.
For example, as shown in
In another example, acquiring the pixel compensation parameter of at least one pixel block in the main body region as the pixel compensation parameter of the pixel block to be compensated further comprises: determining an alignment mode of the second pixel block and the first pixel block, the alignment mode comprising row alignment or column alignment; and using the pixel compensation parameter of the second pixel block as pixel compensation parameters of a plurality of third pixel blocks to be compensated positioned in the same row or the same column with the second pixel block according to the alignment mode.
For example, as shown in
S411: judging whether a fourth pixel block to be compensated which is not in the row alignment or in the column alignment with the first pixel block in the main body region exists in the edge region.
S412: determining a region where the fourth pixel block is positioned as the corner region of the edge region, if the fourth pixel block exists in the edge region.
For example, the edge regions comprise the edge region 501, the edge region 503, the edge region 505 and the edge region 507, the pixel compensation parameters of the fourth pixel blocks positioned in the same corner region (which means one of the four corner regions) are all the same and are equal to the pixel compensation parameter of the first pixel block which is the closest to the corner region.
For example, the fourth pixel block can be subjected to weight distribution, and according to weight distribution, the compensation parameter of the fourth pixel block in the edge region is regulated.
For example, performing weight distribution on the fourth pixel block in the edge region comprises: for each fourth pixel block, with respect to (the second pixel block) the third pixel block in row alignment or (the second pixel block) the third pixel block in column alignment, establishing a weight distribution coordinate system, the third pixel block herein being the closest to the fourth pixel block; and according to the weight distribution coordinate system, performing weight on the fourth pixel block in the edge region.
It should be noted that the fourth pixel block can be positioned in a plurality of corner regions, e.g., the edge region 501, the edge region 503, the edge region 505 and the edge region 507. In other words, each pixel block in the edge region 501, the edge region 503, the edge region 505 and the edge region 507 is not aligned with the pixel block in the main body region 509 in the row direction and the column direction.
For example, the weight distribution coordinate system as shown in
For example, as shown in
For example, as shown in
For example, after regulating the pixel compensation parameter of the edge region, the method further comprises: reading the pixel compensation parameter of the pixel block in the main body region of the display panel and the regulated pixel compensation parameter of the pixel block to be compensated in the edge region of the display panel; and inputting the pixel compensation parameter of the main body region and the regulated pixel compensation parameter of the edge region into the display panel so as to compensate a display operation for the display panel. Namely, the obtained pixel compensation parameter of the main body region and the obtained regulated pixel compensation parameter of the edge region are stored in the storage apparatus of the display panel for the display panel to retrieve when performing the display operation so as to compensate display data which is to be used for the display operation, and the compensated display data is used for the display operation.
For example, after the offset and gain values of each pixel block of the display panel are obtained, the control unit of the optical compensation device performs calculation, and optical compensation calculation is carried out by utilizing the Demura compensation algorithm, e.g., q=as+b, where q is an optical compensation output, s is an input, a is a value of gain, and b is a value of offset.
It should be noted that the pixel compensation parameters include, but are not limited to, the offset and the gain.
For example, the display panel in the embodiments of the present disclosure can be a flexible screen (a bendable display panel which is also called as a flexible display panel), and for example, the flexible screen can be curled and folded as required and can be relatively varied in appearance. The display panel also can adopt a plastic substrate, and by virtue of a thin film packaging technology, a protection film is adhered to the back of the display panel, so that the display panel becomes bendable and difficult to break. The flexible display panel can be very thin and be mounted on a flexible material such as plastic or a metal foil and the like.
For example,
In the above-mentioned mode, the compensation parameter of the curved surface portion, i.e., the edge region, included in the curved screen of the display panel can be separately controlled, so that after the display panel in the edge region is subjected to optical compensation, the display panel is relatively uniform in overall brightness, which further can be used for weakening the afterimage.
It should be noted that in order to simply describe, the embodiments of the above-mentioned system, method and display device are described as a series of action or module combinations, but those skilled in the art should know that the present disclosure is not limited to the described action sequence or module connection, because according to the present disclosure, some steps can be performed by adopting other sequences or simultaneously, and some modules can adopt other connection modes.
Those skilled in the art also should know that the embodiments described in the specification all belong to one embodiment, and the related actions and modules are not necessary for the present disclosure.
In the above-mentioned embodiments of the present disclosure, there are different emphases for description on each embodiment, and the part which is not described in detail in a certain embodiment can refer to related description in other embodiments.
In several embodiments provided by the present disclosure, it should be understood that the disclosed technical contents can be implemented in other modes. The apparatus embodiments described above merely are exemplary, for example, partitioning of the unit merely is logic functional partitioning and can adopt other partitioning modes in the actual implementing process, and for example, a plurality of units or components can be combined or can be integrated into another system, or some characteristics can be omitted or not executed. In addition, the displayed or discussed mutual coupling or direct coupling or communication connection may be indirect coupling or communication connection by some interfaces, units or modules, and may be in an electrical form or other forms.
The units illustrated as separation parts can be or also can be not physically separated, and the units as display parts can be or also can be not physical units, i.e., the units can be positioned in one place, or also can be distributed onto a plurality of network units. Part or all of units can be selected according to actual demands to fulfill the aim of the solutions of the embodiments.
In addition, each functional unit in each embodiment of the present disclosure can be integrated into one processing unit, or each unit can separately and physically exist, or two or more units also can be integrated into one unit. The integrated unit not only can be implemented in a form of hardware, but also can be implemented in a form of a software functional unit.
If the integrated unit is implemented in the form of the software functional unit and is sold or used as an independent product, the integrated unit can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present disclosure in essence or the part of the technical solutions, which makes contribution to the prior art, or all or part of the technical solutions can be reflected in a form of a software product, and the computer software product is stored in one storage medium and comprises a plurality of instructions for enabling one computer device (which may be a PC, a server or a network device and the like) to execute all or part of the steps in the method according to each embodiment of the present disclosure. The above-mentioned storage medium comprises a volatile storage medium or a non-volatile storage medium, e.g., various media capable of storing program codes, such as a U disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a mobile hard disk, a diskette or a compact disc and the like.
The above is only the preferred embodiment of the present disclosure, it should be pointed out that for a person of ordinary skill in the art, without departing from the principles of the present disclosure, several improvements and embellishments can also be made, and these improvements and embellishments should also be regarded as the scope of protection of the present disclosure.
Number | Date | Country | Kind |
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201810161083.0 | Feb 2018 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2018/122378 | 12/20/2018 | WO | 00 |