This application claims priority to Chinese Patent Application No. 201710425265.X, filed Jun. 7, 2017, the contents of which are incorporated by reference in the entirety.
The present invention relates to display technology, more particularly, to a method for driving a display panel to display image, a display apparatus thereof, and a driver enabled to perform the method for driving the display panel to display images.
Active Matrix Organic Light Emitting Diode (AMOLED) display is a typical OLED display apparatus having many advantages in ultra-thin panel thickness, ultra-high contrast ratio, ultra-wide range color gamut, ultra-fast response rate, ultra-wide viewing angle, and ultra-large curvature deflection and has been widely applied in the field. AMOLED display includes a display panel. The display panel includes a base substrate and gate lines, data lines, and arrays of subpixels arranged on the base substrate. Each subpixel includes thin-film transistors (TFT), an anode, an organic light-emitting cell, a cathode, a connection between the gate of TFT to the gate line, a connection between the source of TFT to the data line, a connection between the drain of ET to the cathode. The display panel is operated to use a control signal to turn TFT on through the gate line and apply voltage signals sequentially through the source, the drain and the anode to the organic light-emitting cell to drive light-emission thereof for image display per subpixel. In other words, the subpixel is displaying a subpixel image by converting an electrical signal to an optical signal. By increasing the electrical signal applied to one subpixel, a luminance value of the subpixel can be raised to enhance image contrast ratio of the subpixel image relative to neighboring subpixel images.
Yet, maintaining a high luminance value of a subpixel for a long time will result in degradation of electro-optical conversion efficiency of the subpixel. If so, when a displayed image changes from one frame to another, the subpixel may fail to effectively convert the electrical signal to corresponding optical signal causing a decrease of luminance value of the subpixel and the display panel to display a residual image distorted from an original one.
In an aspect, the present disclosure provides a method for driving a display panel to display image. The method includes determining multiple subpixels in a bright area of an image to be displayed by the display panel. The bright area is an image display area having a luminance value maintained greater than a threshold luminance value for a duration longer than a threshold duration. The method further includes driving the multiple subpixels to emit light alternatingly in a period of alternate light-emission for displaying the image. Additionally, the method includes driving at least one adjacent subpixel surrounding a first subpixel that is not emitting light during the period of alternate light-emission to provide luminance rendering to the first subpixel such that the luminance value of the bright area is greater than the threshold luminance value.
Optionally, the method of driving the multiple subpixels to emit light alternatingly in the period of alternate light-emission includes determining the first subpixel and second subpixels among the multiple subpixels in the bright area corresponding to each period of alternate light-emission. The second subpixels are adjacent subpixels surrounding the first subpixel. The method of driving the multiple subpixels further includes controlling the first subpixel to not emit light and the second subpixels to emit light with luminance values being increased for providing the luminance rendering to the first subpixel during each period of alternate limit-emission.
Optionally, the method of providing the luminance rendering to the first subpixel includes determining an original luminance value of the first subpixel. The original luminance value of the first subpixel is a luminance value when the first subpixel is controlled to emit light according to an original image display data. The method of providing the luminance rendering to the first subpixel further includes controlling the second subpixel to emit light and adjusting luminance values of the second subpixels based on the original luminance value of the first subpixel, wherein the luminance values of the second subpixels are increased to provide the luminance rendering to the first subpixel when the first subpixel is not emitting light. A luminance value of the first subpixel after the luminance rendering substantially equals to the original luminance value.
Optionally, the method of adjusting the luminance values of the second subpixels based on the original luminance value of the first subpixel includes calculating a target luminance value of each second subpixel using a subpixel rendering algorithm based on the original luminance value of the first subpixel and adjusting the luminance value of the each second subpixel based on the target luminance value.
Optionally, in any one period, of alternate light-emission, at least two second subpixels are driven to emit light and two subsequent periods of alternate light-emission are not associated with any second subpixel in common.
Optionally, the multiple subpixels constitute an array of repeating units. Each of the repeating units includes at least two of the multiple subpixels. Each of the repeating units is associated with at least one period of alternate light-emission. At least two periods of alternate light-emission are associated with different subpixels of the multiple subpixels in one of the repeating units.
Optionally, the first subpixels in the bright area in at least two periods of alternate light-emission are capable of emitting light of a same color.
Optionally, at least two first subpixels in the bright area are controlled not to emit light in each period of alternate light-emission.
Optionally, the display panel includes a plurality of subpixels being arranged in SPR form.
Optionally, the plurality of subpixels is arranged in an order based on color of emitted light thereof. The order includes a repeating unit of four sequential subpixels capable of emitting red-color, green-color, blue-color, and green-color in a row adapted to a subpixel rendering operation.
In another aspect, the present disclosure provides a driver for controlling image display operation of a display panel comprising at least a processor including a computer readable storage media. The computer readable storage media is configured to store computer-executable instructions. The processor is configured to execute the computer-executable instructions for controlling a display panel for displaying images. The computer-executable instructions include a first set of instructions for determining multiple subpixels in a bright area of an image to be displayed by the display panel. The bright area is an image display area having a luminance value maintained greater than a threshold luminance value for a duration longer than a threshold duration. The computer-executable instructions also include a second set of instructions for driving the multiple subpixels to emit light alternatingly in a period of alternate light-emission for displaying the image and driving at least one adjacent subpixel surrounding a first subpixel that is not emitting light during the period of alternate light-emission to provide luminance rendering to the first subpixel such that the luminance value of the bright area is greater than the threshold luminance value.
Optionally, the second set of instructions includes a first subset of instructions for determining the first subpixel and second subpixels among the multiple subpixels in the bright area corresponding to each period of alternate light-emission. The second subpixels are several adjacent subpixels surrounding the first subpixel. The second set of instructions also includes a second subset of instructions for controlling the first subpixel to not emit light and the second subpixels to emit light in each period of alternate light-emission so that luminance values of the second subpixels are increased to provide the luminance rendering to the first subpixel without emitting light.
Optionally, the second subset of instructions includes a first sub-subset of instructions for determining an original luminance value of the first subpixel. The original luminance value of the first subpixel is a luminance value when the first subpixel is controlled to emit light according to an original image display data. The second subset of instructions further includes a second sub-subset of instructions for controlling the second subpixels to emit light. The second subset of instructions additionally includes a third sub-subset of instructions for adjusting luminance values of the second subpixels based on the original luminance value of the first subpixel. The luminance values of the second subpixels are increased to provide the luminance rendering to the first subpixel when the first subpixel is not emitting light. A luminance value of the first subpixel after the luminance rendering substantially equals to the original luminance value.
Optionally, the third sub-subset of instructions includes an instruction for calculating a target luminance value of each second subpixel using a subpixel rendering algorithm based on the original luminance value of the first subpixel and adjusting the luminance value of the each second subpixel based on the target luminance value.
Optionally, in any one period of alternate light-emission, at least two second subpixels are driven to emit light alternatingly and two adjacent periods of alternate light-emission are not associated with any second subpixel in common.
Optionally, the multiple subpixels constitute an array of pixels. Each of which the array of pixels includes at least two of the multiple subpixels. Each of the array of pixels corresponds to at least one period of alternate light-emission. At least two periods of alternate light-emission correspond to different subpixels of the multiple subpixels in the each of the array of pixels.
Optionally, the first subpixels in the bright area in at least two periods of alternate light-emission are capable of emitting light of a same color.
Optionally, at least two first subpixels in the bright area are controlled not to emit light in each period of alternate light-emission.
Optionally, the display panel includes a plurality of subpixels being arranged in an order based on color of emitted light thereof. The order including a repeating unit of four sequential subpixels capable of emitting red-color, green-color, blue-color, and green-color in a row adapted to a subpixel rendering operation.
In another aspect, the present disclosure provides a display apparatus comprising a display panel and a driver described herein including a processor having a computer readable storage media to store computer-executable instructions and to execute the computer-executable instructions for driving the display panel to display images.
The following drawings are merely examples for illustrative purposes according to various disclosed embodiments and are not intended to limit the scope of the present invention.
The disclosure will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of some embodiments are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.
TV based on AMOLED display has been gradually implemented and has huge potential for future market success. Due to limitation of AMOLED device function, however, after displaying a static image with respective subpixels being maintained to a certain luminance values for a long time when the display panel changes to a next frame of image, the display panel is susceptible to displaying a residual image of the previous static image.
To solve the issue of residual image of the AMOLED display panel, an image processing technique using Subpixel Rendering (SPR) treatment is used in the present disclosure, in which an algorithm of performing the subpixel rendering based on array of subpixels arranged on the display panel in a special SPR arrangement is disclosed. Accordingly, the present disclosure provides, inter alia, a method of controlling image display of a display panel, a driver for implementing the method, and a display apparatus having the same that substantially obviate one or more of the problems due to limitations and disadvantages of the related art.
In one aspect, the present disclosure provides a display panel having a plurality of subpixels arranged in a special arrangement adapted to subpixel rendering operation.
In an embodiment, multiple subpixels arranged in a SPR arrangement with an order of RGBG form multiple repeating units 02. Referring to
Optionally, the array of subpixels can be arranged in other SPR arrangement with different orders. Different arrangement orders of R, G, B colored subpixels should not alter the nature of claims of the present disclosure.
In an aspect, the present disclosure provides a method for driving a display panel having a plurality of subpixels arranged with a certain SPR arrangement to display image.
Optionally, the threshold luminance value can be set according to particular display panel at particular situation of image display. For example, the threshold luminance value can be set based on a luminance value of the whole image to he displayed. The threshold luminance value usually is greater than the luminance value of the whole image to be displayed. Then the bright area can be a portion of the whole image to be displayed that has a high luminance value.
Optionally, the threshold duration can be set according to specific situation of image display and used to determine if an image to be displayed is a static image. For example, when a duration of maintaining a luminance value for an image to be displayed is longer than the threshold duration, the image to be displayed is considered as a static image. When the duration of maintaining luminance value for an image to be displayed is shorter than or equal to the threshold duration, the image to be displayed is considered to be a dynamic image.
In the embodiment, the image to be displayed is going to be displayed through the subpixels arranged in SPR arrangement on the display panel. In particular, the image is displayed by using a driver associated with the display panel to drive subpixels to emit light. The driver includes a driving circuit controlled and operated by a controller using a plurality of sets of computer-executable instructions stored in a memory device. Each subpixel includes a thin-film transistor (TFT), an anode, an organic light-emitting cell, a cathode, a connection between the gate of TFT to the gate line, the source of TFT being electrically connected to the data line, the drain of TFT being electrically connected to the cathode. The driving circuit of the driver is connected to the gate line and the data line associated with each subpixel. In particular, the driver is configured to control on or off of the TFT through the gate line and gate electrode of the TFT to turn the subpixel on or off. When the subpixel is turned on, the diver is configured to apply a driving voltage through the data line to the subpixel to drive organic light-emitting cell to emit light for displaying a subpixel image. A value of the driving voltage is used to determine a luminance value of the subpixel. In a condition without considering electro-optical conversion efficiency of the subpixel, the driving voltage is proportional to the luminance value of the subpixel.
Optionally, the driver is configured to determine a respective value of the driving voltage to be applied to each subpixel before driving the display panel to display an image. Based on the value of the driving voltage, the driver determines the corresponding luminance value of each subpixel. Additionally, the driver is configured to determine a respective length of duration of applying the driving voltage to each subpixel. The driver then is able to determine an image display area to be a bright area if all subpixels in the display area have luminance values greater than a threshold luminance value and the duration for applying the driving voltage to the corresponding subpixels longer than a threshold duration. Or, the driver is configured to determine a value of each driving voltage to be applied to each subpixel before the to-be-displayed image is displayed by the display panel, based on which the driver calculates different luminance values that need to maintain at different image display areas and determines a target display area where the luminance values to be maintained are larger than the threshold luminance. Further, the driver is configured to determine different durations of maintaining certain luminance values in the different target display areas based on different durations of applying respective driving voltages to respective subpixels in the different target display areas. Furthermore, the driver is able to determine an image display area to be a bright area if a duration of maintaining a luminance value greater than a threshold luminance value in the image display area among the different target display areas is longer than a threshold duration. Optionally, the bright area of an image displayed on the display panel can be determined alternatively using different methods.
In the embodiment, after determining the bright area, multiple subpixels associated with the bright area can be determined. Referring to
Referring to
In the embodiment, the driver associated With the display panel is configured to drive multiple subpixels in the bright area to alternatingly emit light. Optionally, the driver drives the multiple subpixels associated with the bright area to emit light periodically. In other words, a duration of one or more first subpixels of the multiple subpixels being driven to not emit light is a period of alternate light-emission. In each period of alternate light-emission, at least one subpixel is controlled to not emit light while other subpixels in the bright area are controlled to emit light. Optionally, in each period of alternate light-emission, at least two first subpixels are controlled to not emit light while other subpixels in the bright area are controlled to emit light. The length of the period of alternate light-emission is determined based on pixel electro-optical conversion function. Optionally, the period of alternate light-emission is set to 1 second or others.
In the embodiment, the driver is configured to randomly determine a first subpixel to not emit light among the multiple subpixels in each period of alternate light-emission. Optionally, the driver can be configured to determine the first subpixel based on a particular selection rule but not limited thereof For each period of alternate light-emission, all second subpixels as the adjacent subpixels surrounding the first subpixel can be determined once the first subpixel is determined.
Optionally, the multiple subpixels associated with the bright area are arranged to an array of multiple repeating units, each of which includes at least two subpixels. For two consecutive periods of alternate light-emission, the two respective first subpixels may or may not be in respective two adjacent repeating units. Yet, each repeating unit is associated with at least one period of alternate light-emission. When a repeating unit is associated with two periods of alternate light-emission, one earlier and one later, the two periods of alternate light-emission are associated with different subpixels in the repeating unit. In the embodiment, each period of alternate light-emission is associated with at least two second subpixels. Any two subsequent periods of alternate light-emission are not associated with a second subpixel in common. Any two periods of alternate light-emission are associated with respective two first subpixels with either a same color or different color. In any period of alternate light-emission, the bright area includes at least two first subpixels being controlled to not emit light.
Referring to
Optionally, in two consecutive periods of alternate light-emission, the first subpixel can be located in two adjacent repeating units (of subpixels) or non-adjacent repeating units. Optionally, each repeating unit in the bright area is associated with at least one period of alternate light-emission. Optionally, each repeating unit in the bright area is associated with at least two periods of alternate light-emission and the two periods of alternate light-emission are associated with different subpixels in the each repeating unit. For example, referring to
Optionally, any two periods of alternate light-emission are respectively associated with two first subpixels capable of emitting a same color or different colors. Optionally, each period of alternate light-emission is associated with at least two first subpixels in the bright area.
Referring back to
In the embodiment, the driver is configured, in every period of alternate light-emission after determining at least a corresponding first subpixel and several second subpixels, to control turning off the corresponding first subpixel to not emit light and turning on the corresponding second subpixels to emit light and to control increasing luminance values of the second subpixels to provide luminance rendering to the first subpixel to make the luminance value of the bright area to be greater than a threshold luminance.
Referring to
Further, the method includes adjusting luminance values of the second subpixels based on the original luminance value of the first subpixel. In particular the luminance values of the second subpixels are increased to provide the luminance rendering to the first subpixel when the first subpixel is not emitting light such that a luminance value of the first subpixel after the luminance rendering substantially equals to the original luminance value. In other words, a viewer simply cannot tell difference of the luminance value of the first subpixel in the displayed image before and after the luminance rendering.
In the embodiment, the multiple subpixels in the bright area are arranged in one of SPR orders. The driver associated with the display panel is configured to adjust luminance values of the second subpixels based on the original luminance value of the first subpixel stored in the memory device. In particular, the driver uses a Subpixel Rendering algorithm depended on the subpixel arrangement in one of SPR orders to calculate a luminance value of each second subpixel, based on which the luminance value of each second subpixel is adjusted. Optionally, after a luminance value is calculated for a second subpixel, the driver is able to determine a driving voltage corresponding to the calculated luminance value and to operate the driving circuit to apply the driving voltage through a data line connected to the second subpixel so that the second subpixel is able to emit light with the corresponding luminance value to achieve adjusting a luminance value of a second subpixel. The same method is applicable to adjusting luminance value of each other second subpixel. Each second subpixel may have different adjusted luminance value.
Optionally, in each period of alternate light-emission a corresponding first subpixel is controller to shut off, and all second subpixels are controlled to emit light with increasing luminance values to provide luminance rendering to the first subpixel.
In another aspect, the present disclosure provides a driver for controlling image display operation of a display panel. Referring to
Referring to
Further, referring to
Additionally, referring to
Optionally, the multiple subpixels in the bright area are arranged in a certain SPR order adapted for subpixel rendering operation. The processor 301, in order to execute the third sub-subset of instructions 3223 for adjusting luminance values of the second subpixels based on the original luminance value of the first subpixel, is to execute a first instruction for calculating a luminance value of each second subpixel using a SPR algorithm depended on the SPR order arrangement of the multiple subpixels. Then the processor 301 sends a control signal for controlling adjustment of the luminance value of the second subpixel based on the calculated luminance value. Optionally, any period of alternate light-emission is associated with at least two second subpixels for providing luminance rendering to the first subpixel. Optionally, any two consecutive periods of alternate light-emission are not associated with any second subpixel in common. Optionally, the multiple subpixels are arranged with multiple repeating units, each of which includes at least two subpixels. Optionally, any two consecutive periods of alternate light-emission are associated with respective two first subpixels located in two repeating units that are either adjacent to each other or not. Optionally, each repeating unit of the multiple subpixels is associated with at least one period of alternate light-emission. Optionally, each repeating unit of the multiple subpixels is associated with at least two periods of alternate light-emission, one earlier than another. The two periods of alternate light-emission are associated with different subpixels in each repeating unit. Optionally, any two periods of alternate light-emission are associated with respective two first subpixels capable of emitting a same color. Optionally, in each period of alternate light-emission at least two first subpixels are selected to not emit light in the bright area.
In another aspect, the present disclosure provides a display apparatus including a display panel and a driver described herein including a processor having a computer readable storage media to store computer-executable instructions and to execute the computer-executable instructions for driving the display panel to display images. The display panel is an OLED display panel. Optionally, the OLED display panel is an AMOLED display panel.
In an alternative aspect, the present disclosure provides a control terminal including a processor, a memory configured to store instructions executable by the processor. The processor is configured to determine multiple subpixels in a bright area of an image to be displayed by the display panel. Here the bright area is an image display area having a luminance value maintained greater than a threshold luminance value for a duration longer than a threshold duration. Additionally, the processor is configured to drive the multiple subpixels to emit light alternatingly in a period of alternate light-emission for displaying the image and drive all adjacent subpixels surrounding any one subpixel that is not emitting light during the period of alternate light-emission to provide luminance rendering to the one subpixel such that the luminance value of the bright area is greater than the threshold luminance value. Optionally, the control terminal can be one selected from a smart phone, a tablet computer, a smart TV, a laptop computer, a desktop computer. The processor disposed therein can be a chip containing integrated circuit.
In another alternative aspect, the present disclosure provides a computer executable storage media. The computer executable storage media stores commands and instructions. When the computer executable storage media is in operation within a computer associated with a display panel, the commands are executed and control signals are generated to drive the display panel to display image according to the instructions described herein.
The foregoing description of the embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form or to exemplary embodiments disclosed. Accordingly, the foregoing description should be regarded as illustrative rather than restrictive. Obviously, many modifications and variations will be apparent to practitioners skilled in this art. The embodiments are chosen and described in order to explain the principles of the invention and its best mode practical application, thereby to enable persons skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular use or implementation contemplated. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents in which all terms are meant in their broadest reasonable sense unless otherwise indicated. Therefore, the term “the invention”, “the present invention” or the like does not necessarily limit the claim scope to a specific embodiment, and the reference to exemplary embodiments of the invention does not imply a limitation on the invention, and no such limitation is to be inferred. The invention is limited only by the spirit and scope of the appended claims. Moreover, these claims may refer to use “first”, “second”, etc. following with noun or element. Such terms should be understood as a nomenclature and should not be construed as giving the limitation on the number of the elements modified by such nomenclature unless specific number has been given. Any advantages and benefits described may not apply to all embodiments of the invention. It should be appreciated that variations may be made in the embodiments described by persons skilled in the art without departing from the scope of the present invention as defined by the following claims. Moreover, no element and component in the present disclosure is intended to be dedicated to the public regardless of whether the element or component is explicitly recited in the following claims.
Number | Date | Country | Kind |
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201710425265.X | Jun 2017 | CN | national |
Filing Document | Filing Date | Country | Kind |
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PCT/CN2017/115442 | 12/11/2017 | WO | 00 |