Patent Application
20160049123
This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 10-2014-0104493, filed on Aug. 12, 2014, in the Korean Intellectual Property Office (KIPO), the disclosure of which is incorporated by reference herein in its entirety.
The present inventive concept relates to a display apparatus, and more particularly to a method of driving a display panel and a display apparatus performing the method.
As display resolution of a liquid crystal display (LCD) apparatus increases, the number of horizontal rows may increase and thus, a charging duration of a subpixel may be reduced. Thus, a precharge driving scheme has been developed to secure the charging duration of the subpixel. In the precharge driving scheme, a precharge voltage may be charged to the subpixel before a data voltage is charged to the subpixel. The precharge driving scheme may result in a display defect. Accordingly, a difference of luminance between subpixels may occur in a horizontal direction or a vertical direction due to the difference between a precharge voltage and a charging voltage, and thus, a horizontal or a vertical spot line may appear on a display panel.
According to an exemplary embodiment of the present inventive concept, a method of driving a display panel is provided. The method includes compensating first pixel data corresponding to a first pixel of a plurality of pixel in the display panel based on at least one of a first decision, a second decision, or a third decision and generating a first data voltage corresponding to the compensated first pixel data. The first data voltage is applied to the first pixel through a data line. The first decision includes determining, based on a position of the first pixel, whether compensation for the first pixel data is required. The second decision includes determining, based on previous subpixel data and present subpixel data for the first pixel, whether the compensation for the first pixel data is required. The third decision includes determining whether the first pixel data complies with a compensation avoidance condition.
The third decision may further include determining a first color displayed through the first pixel based on the first pixel data. The third decision may be performed to maintain the first pixel data when the first pixel displays one of three primary colors. The third decision may be performed to compensate the first pixel data when the first pixel displays a color other than the three primary colors.
The first pixel may include a first subpixel, a second subpixel, and a third subpixel. The first subpixel may operate based on first subpixel data. The second subpixel may operate based on the present subpixel data. The third subpixel may operate based on the previous subpixel data.
Determining the first color may include comparing the previous subpixel data with first threshold data, comparing the first subpixel data with the first threshold data, determining that the first pixel displays one of the three primary colors when a value of the previous subpixel data is smaller than a value of the first threshold data and when a value of the first subpixel data is smaller than the value of the first threshold data, and determining that the first pixel displays the color other than the three primary colors when the value of the previous subpixel data is equal to or greater than the value of the first threshold data or when the value of the first subpixel data is equal to or greater than the value of the first threshold data.
Compensating the first pixel data may further include adding a value of compensation data to a value of the present subpixel data when all of the first decision, the second decision, or the third decision indicate that the compensation for the first pixel data is required and maintaining the present subpixel data when at least one of the first decision, the second decision, or the third decision indicates that to the compensation for the first pixel data is not required.
Compensating first pixel data may further include determining a second color displayed through a second pixel adjacent to the first pixel after a first color displayed displayed through the first pixel is determined, and comparing a first maximum grayscale with a second maximum grayscale. The first maximum grayscale may be the greatest one of first grayscales of the first color. The second maximum grayscale may be the greatest one of second grayscales of the second color. The compensating first pixel data may further include comparing each of grayscales other than the first maximum grayscale among the first grayscales with a reference grayscale, decreasing the value of the compensation data when the second pixel displays one of three primary colors, and when the first maximum grayscale is substantially the same as the second maximum grayscale, and when each of the grayscales other than the first maximum grayscale among the first grayscales is smaller than the reference grayscale, and maintaining the value of the compensation data when the second pixel displays a color other than the three primary colors, or when the first maximum grayscale is different from the second maximum grayscale, or when each of the grayscales other than the first maximum grayscale among the first grayscales is equal to or greater than the reference grayscale. The first pixel and the second pixel may be disposed in a first horizontal line of the display panel.
The second decision may further include comparing the previous subpixel data with first threshold data and comparing the present subpixel data with second threshold data. The second decision may be performed to compensate the first pixel data when a value of the previous subpixel data is smaller than a value of the first threshold data and when a value of the present subpixel data is greater than a value of the second threshold data. The second decision may be performed to maintain the first pixel data when the value of the previous subpixel data is equal to or greater than the value of the first threshold data or when the value of the present subpixel data is equal to or smaller than the value of the second threshold data.
The second decision may further include comparing first difference data with first threshold data. The first difference data may correspond to a difference between the present subpixel data and the previous subpixel data. The second decision may be performed to compensate the first pixel data when a value of the first difference data is greater than a value of the first threshold data. The second decision may be performed to maintain the first pixel data when the value of the first difference data is equal to or smaller than the value of the first threshold data.
The second decision may further include comparing the previous subpixel data with first threshold data, comparing the present subpixel data with second threshold data, and comparing first difference data with third threshold data. The first difference data may correspond to a difference between the present subpixel data and the previous subpixel data. The second decision may be performed to compensate the first pixel data when a value of the previous subpixel data is smaller than a value of the first threshold data, and when a value of the present subpixel data is greater than a value of the second threshold data, and when a value of the first difference data is greater than a value of the third threshold data. The second decision may be performed to maintain the first pixel data when the value of the previous subpixel data is equal to or greater than the value of the first threshold data, or when the value of the present subpixel data is equal to or smaller than the value of the second threshold data, or when the value of the first difference data is equal to or smaller than the value of the third threshold data.
According to an exemplary embodiment of the present inventive concept, a display apparatus is provided. The display apparatus includes a display panel, a gate driver, a data driver, and a timing controller. The display panel includes a first pixel connected to a gate line and a data line. The gate driver is configured to apply a gate signal to the gate line. The gate signal has an active period corresponding to at least two successive horizontal periods. The data driver is configured to generate a first data voltage corresponding to first pixel data for the first pixel. The first data voltage is applied to the data line. The timing controller is configured to control the gate driver and the data driver, to perform a first decision, a second decision, or a third decision, and to compensate the first pixel data based on the first decision, the second decision, or the third decision. The first decision includes determining, based on a position of the first pixel in the display panel, whether the compensation for the first pixel data is required. The second decision includes determining, based on previous subpixel data and present subpixel data for the first pixel, whether the compensation for the first pixel data is required. The third decision includes determining whether the first pixel data complies with a compensation avoidance condition.
The timing controller may include a data compensation unit and a control signal generation unit. The data compensation unit may be configured to perform the at least one of the first decision, the second decision, or the third decision, and to compensate the first pixel data based on the at least one of the first decision, the second decision, or the third decision. The control signal generation unit may be configured to generate a first control signal for the gate driver and a second control signal for the data driver based on an input control signal.
The data compensation unit may be configured to perform the third decision to maintain the first pixel data when the first pixel displays one of three primary colors, or the data compensation unit may be configured to perform the third decision to compensate the first pixel data when the first pixel displays color other than the three primary colors.
The first pixel may include a first subpixel, a second subpixel, and a third subpixel. The first subpixel may be configured to operate based on first subpixel data. The second subpixel may be configured to operate based on the present subpixel data. The third subpixel may be configured to operate based on the previous subpixel data. The data compensation unit may determine that the first pixel displays one of the three primary colors when a value of the previous subpixel data is smaller than a value of first threshold data and when a value of the first subpixel data is smaller than the value of the first threshold data.
The data compensation unit may add a value of compensation data to a value of the present subpixel data when all of the first decision, the second decision, or the third decision result indicate that the compensation for the first pixel data is required.
The data compensation unit may change the compensation data.
The data compensation unit may reduce the value of the compensation data when a second pixel adjacent to the first pixel displays one of three primary colors, and when a greatest first grayscale among first grayscales of a first color displayed through the first pixel is substantially the same as a greatest second grayscales of second grayscales of a second color displayed through the second pixel, and when each of first grayscales other than the greatest first grayscale among the first grayscales is smaller than a reference grayscale. The first pixel and the second pixel may be disposed in a first horizontal line
According to an exemplary embodiment of the present inventive concept, a method of driving a display panel is provided. The method includes analyzing a plurality of pixel data for a plurality of pixels disposed in a first horizontal line of the display panel, selecting one of a first compensation method or a second compensation method, based on the analyzation result, for compensation on the plurality of pixel data. The first compensation method includes a first decision, based on a position of a first pixel in the display panel, as to whether compensation for first pixel data corresponding to the first pixel among the plurality of pixel data is required, performing a second decision, based on previous subpixel data and present subpixel data for the first pixel, as to whether the compensation for the first pixel data is required, performing a third decision as to whether the first pixel data complies with a compensation avoidance condition, and compensating the first pixel data based on at least one of the first decision, the second decision, or the third decision. The second compensation method includes performing the first decision and the second decision, and compensating the first pixel data based on at least one of the first decision or the second decision.
Analyzing the plurality of pixel data may include determining a plurality of colors displayed through the plurality of pixels based on the plurality of pixel data. The analyzation result may be generated to select the first compensation method for the compensation on the plurality of pixel data when the plurality of pixels display only at least one color selected from three primary colors or only at least one color selected from three mixed colors including cyan, magenta, and yellow colors. The analyzation result may be generated to select the second compensation method for the compensation on the plurality of pixel data when the plurality of pixels display both of the at least one color selected from the three primary colors and the at least one color selected from the three mixed colors.
Analyzing the plurality of pixel data may include determining a plurality of colors displayed through the plurality of pixels based on the plurality of pixel data and comparing a number of N pixels (where N is a natural number equal to or greater than two) among the plurality of pixels with a reference number. The N pixels may be successively disposed in the first horizontal line and may display only at least one color selected from three primary colors. The analyzation result may be generated to select the first compensation method for compensation on N pixel data for the N pixels when the number of the N pixels is smaller than or equal to the reference number. The analyzation result may be generated to select the second compensation method for the compensation on the N pixel data for the N pixels when the number of the N pixels is greater than the reference number.
According to an exemplary embodiment of the present inventive concept, a display apparatus is provided. The display apparatus includes a display panel and a data compensation unit. The display panel includes a plurality of pixels. The data compensation unit is configured to compensate first pixel data corresponding to a first pixel of the plurality of pixels. The first pixel includes a first subpixel, a second subpixel, and a third subpixel. The first subpixel and the second subpixel are connected to a first data line of the display panel. The first subpixel is configured to operate based on first subpixel data for the first pixel during a first period and a second period subsequent to the first period. The second subpixel is configured to operate based on second subpixel data for the first pixel during the second period and a third period subsequent to the second period. The compensating of the first pixel data includes changing a value of the second subpixel data for the first pixel based on at least a comparison result between the first subpixel data and the second subpixel data.
Illustrative, non-limiting exemplary embodiments of the present inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings:
Various exemplary embodiments of the present inventive concept will be described more fully with reference to the accompanying drawings, in which exemplary embodiments thereof are shown. This present inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Like reference numerals may refer to like elements throughout the specification and drawings.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present inventive concept. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
Unless otherwise defined, all terms (including technical and scientific terms) used
Referring to
The display panel 100 includes a plurality of gate lines GL, a plurality of data lines DL, and a plurality of pixels (not illustrated) connected to the gate lines GL and the data lines DL.
The gate lines GL extend in a first direction D1, and the data lines DL extend in a second direction D2 substantially perpendicular to the first direction D1. The plurality of pixels may be arranged in a matrix form. Each of the plurality of pixels may include at least two subpixels.
Each subpixel in each of the plurality of pixels may include a switching element (not illustrated), a liquid crystal capacitor (not illustrated), and a storage capacitor (not illustrated). The liquid crystal capacitor and the storage capacitor may be electrically connected to the switching element. The switching element may be a thin film transistor. The liquid crystal capacitor may include a first electrode connected to a pixel electrode and a second electrode connected to a common electrode. A data voltage may be applied to the first electrode of the liquid crystal capacitor. A common voltage may be applied to the second electrode of the liquid crystal capacitor. The storage capacitor may include a first electrode connected to the pixel electrode and a second electrode connected to a storage electrode. The data voltage may be applied to the first electrode of the storage capacitor. A storage voltage may be applied to the second electrode of the storage capacitor. The storage voltage may be substantially equal to the common voltage.
Each subpixel may have a rectangular shape. Each subpixel may have a relatively short side in the first direction D1 and a relatively long side in the second direction D2. The relatively short side of each subpixel may be substantially parallel to the gate lines GL. The relatively long side of each subpixel may be substantially parallel to the data lines DL. Detailed configurations of the pixels and the subpixels will be described below with reference to
The timing controller 200 receives input image data RGBD and an input control signal CONT from an external device (e.g., a host). The input image data RGBD may include a plurality of input pixel data for the plurality of pixels. Each input pixel data may include red grayscale data R, green grayscale data G, and blue grayscale data B for a respective one of the plurality of pixels. The input control signal CONT may include a master clock signal, a data enable signal, a vertical synchronization signal, a horizontal synchronization signal, etc.
The timing controller 200 generates output image data RGBD′, a first control signal CONT1, and a second control signal CONT2 based on the input image data RGBD and the input control signal CONT.
For example, the timing controller 200 may generate the first control signal CONT1 based on the input control signal CONT. The first control signal CONT1 may be provided to the gate driver 300, and a driving timing of the gate driver 300 may be controlled based on the first control signal CONT1. The first control signal CONT1 may include a vertical start signal, a gate clock signal, etc. The timing controller 200 may generate the second control signal CONT2 based on the input control signal CONT. The second control signal CONT2 may be provided to the data driver 500, and a driving timing of the data driver 500 may be controlled based on the second control signal CONT2. The second control signal CONT2 may include a horizontal start signal, a load signal, etc.
The timing controller 200 may generate the output image data RGBD′ based on the input image data RGBD. The output image data RGBD′ may be provided to the data driver 500. In an exemplary embodiment of the present inventive concept, the output image data RGBD′ may be substantially the same as the input image data RGBD. In an exemplary embodiment of the present inventive concept, the output image data RGBD′ may be compensated image data that is generated based on the input image data RGBD and compensation data. Similarly to the input image data RGBD, the output image data RGBD′ may include a plurality of output pixel data corresponding to the plurality of pixels, respectively. Detailed configurations and operations of the timing controller 200 will be described below with reference to
The gate driver 300 receives the first control signal CONT1 from the timing controller 200. The gate driver 300 generates gate signals for driving the gate lines GL in response to the first control signal CONT1. The gate driver 300 may sequentially output the gate signals to the gate lines GL.
In an exemplary embodiment of the present inventive concept, the gate driver 300 may be disposed, e.g., directly mounted, on the display panel 100, or may be connected to the display panel 100 in a tape carrier package (“TCP”) type. In an exemplary embodiment of the present inventive concept, the gate driver 300 may be integrated on the display panel 100.
The gamma reference voltage generator 400 generates a gamma reference voltage VGREF. The gamma reference voltage generator 400 provides the gamma reference voltage VGREF to the data driver 500. The gamma reference voltage VGREF may have values corresponding to grayscales of the plurality of output pixel data included in the output image data RGBD′.
In an exemplary embodiment of the present inventive concept, the gamma reference voltage generator 400 may include a resistor string circuit (not illustrated) having a plurality of resistors connected in series between a power supply voltage and a ground voltage. The gamma reference voltage generator generates the gamma reference voltage VGREF by dividing the power supply voltage based on the grayscales of the plurality of output pixel data included in the output image data RGBD′. Although not illustrated in
The data driver 500 receives the second control signal CONT2 and the output image data RGBD′ from the timing controller 200. The data driver 500 receives the gamma reference voltage VGREF from the gamma reference voltage generator 400. The data driver 500 generates analog data voltages based on the second control signal CONT2, the output image data RGBD′, and the gamma reference voltage VGREF. The data driver 500 may sequentially output the analog data voltages to the data lines DL.
In an exemplary embodiment of the present inventive concept, the data driver 500 may include a shift register (not illustrated), a latch (not illustrated), a signal processor (not illustrated), and a buffer (not illustrated). The shift register may output a latch pulse to the latch. The latch may temporarily store the output image data RGBD′, and may output the output image data RGBD′ to the signal processor. The signal processor may generate the analog data voltages based on the digital output image data RGBD′ and the gamma reference voltage VGREF, and may output the analog data voltages to the buffer. The buffer may output the analog data voltages to the data lines DL.
In an exemplary embodiment of the present inventive concept, the data driver 500 may be disposed, e.g., directly mounted, on the display panel 100, or may be connected to the display panel 100 in a tape carrier package (“TCP”) type. In an exemplary embodiment of the present inventive concept, the data driver 500 may be integrated on the display panel 100.
Referring to
The data compensation unit 210 may receive the input image data RGBD and may generate the output image data RGBD′ by selectively compensating the input image data RGBD. For example, as described above with reference to
In an exemplary embodiment of the present inventive concept, the data compensation unit 210 may include a single-line memory (not illustrated) that stores pixel data corresponding to a single subpixel row (e.g., a single horizontal line).
The control signal generation unit 220 may receive the input control signal CONT. The control signal generation unit 220 may generate the first control signal CONT1 for the gate driver 300 and the second control signal CONT2 for the data driver 500 based on the input control signal CONT. The control signal generation unit 220 may output the first control signal CONT1 to the gate driver 300 and may output the second control signal CONT2 to the data driver 500.
In an exemplary embodiment of the present inventive concept, the timing controller 200 may further include an adaptive color correction (ACC) unit (not illustrated) and/or a dynamic capacitance compensation (DCC) unit (not illustrated). The ACC unit may receive the input pixel data and may perform an ACC operation on the input pixel data. The ACC unit may compensate grayscales of the input pixel data using a gamma curve. The DCC unit may perform a DCC operation on the input pixel data. The DCC unit may compensate the grayscales of the input pixel data using previous frame image data and present frame image data. According to an exemplary embodiments, the ACC unit and/or the DCC unit may be located prior to or subsequent to the data compensation unit 210.
Referring to
Hereinafter, the present inventive concept will be described based on an example where one pixel includes three subpixels. However, the present inventive concept is not limited thereto.
Each of the plurality of subpixels SP1˜SP4, R11˜R44, G11˜G44, and B11˜B44 may be disposed in one of a plurality of subpixel rows and one of a plurality of subpixel columns.
For example, the subpixels SP1˜SP4 may be disposed in a first subpixel column. The red subpixels R11˜R41, R12˜R42, R13˜R43, and R14˜R44 may be disposed in a second subpixel column, a fifth subpixel column, an eighth subpixel column, and an eleventh subpixel column, respectively. The green subpixels G11˜G41, G12˜G42, G13˜G43, and G14˜G44 may be disposed in a third subpixel column, a sixth subpixel column, a ninth subpixel column, and a twelfth subpixel column, respectively. The blue subpixels B11˜B41, B12˜B42, and B13˜B43 may be disposed in a fourth subpixel column, a seventh subpixel column, and a tenth subpixel column, respectively.
The subpixels SP1, R11, G11, B11, R12, G12, B12, R13, G13, B13, R14, and G14 may be disposed in a first subpixel row. The subpixels SP2, R21, G21, B21, R22, G22, B22, R23, G23, B23, R24, and G24 may be disposed in a second subpixel row. The subpixels SP3, R31, G31, B31, R32, G32, B32, R33, G33, B33, R34, and G34 may be disposed in a third subpixel row. The subpixels SP4, R41, G41, B41, R42, G42, B42, R43, G43, B43, R44, and G44 may be disposed in a fourth subpixel row.
In addition, each of the plurality of subpixels SP1˜SP4, R11˜R44, G11˜G44, and B11˜B44 may be connected to one of a plurality of gate lines GL1˜GL8 and one of a plurality of data lines DL1˜DL7.
For example, subpixels SP1, G11, G12, B12, G13, and G14 in the first subpixel row may be connected to the first gate line GL1, and subpixels R11, B11, R12, R13, B13, and R14 in the first subpixel row may be connected to the second gate line GL2. Subpixels SP2, G21, G22, B22, G23, and G24 in the second subpixel row may be connected to the third gate line GL3, subpixels R21, B21, R22, R23, B23, and R24 in the second subpixel row may be connected to the fourth gate line GL4. Subpixels SP3, G31, G32, B32, G33, and G34 in the third subpixel row may be connected to the fifth gate line GL5, and subpixels R31, B31, R32, R33, B33, and R34 in the third subpixel row may be connected to the sixth gate line GL6. Subpixels SP4, G41, G42, B42, G43, and G44 in the fourth subpixel row may be connected to the seventh gate line GL7, and subpixels R41, B41, R42, R43, B43, and R44 in the fourth subpixel row may be connected to the eighth gate line GL8.
In addition, subpixels SP2, R21, SP4, and R41 in the first and second subpixel columns may be connected to the first data line DL1, and subpixels SP1, R11, SP3, and R11 in the first and second subpixel columns may be connected to the second data line DL2. Subpixels G21, B21, G41, and B41 in the third and fourth subpixel columns may be connected to the second data line DL2, and subpixels G11, B11, G11, and B11 in the third and fourth subpixel columns may be connected to the third data line DL3. Subpixels R22, G22, R42, and G42 in the fifth and sixth subpixel columns may be connected to the third data line DL3, and subpixels R12, G12, R32, and G32 in the fifth and sixth subpixel columns may be connected to the fourth data line DL4. Subpixels B22, R23, B42, and R43 in the seventh and eighth subpixel columns may be connected to the fourth data line DL4, and subpixels B12, R13, B32, and R33 in the seventh and eighth subpixel columns may be connected to the fifth data line DL5. Subpixels G23, B23, G43, and B43 in the ninth and tenth subpixel columns may be connected to the fifth data line DL5, and subpixels G13, B13, G33, and B33 in the ninth and tenth subpixel columns may be connected to the sixth data line DL6. Subpixels R24, G24, R44, and G44 in the eleventh and twelfth subpixel columns may be connected to the sixth data line DL6, and subpixels R14, G14, R34 and G34 in the eleventh and twelfth subpixel columns may be connected to the seventh data line DL7.
For example, subpixels in each subpixel row may be electrically connected to one of two gate lines, and subpixels of two adjacent subpixel columns may be electrically connected to two adjacent data lines.
Each of the data lines DL1˜DL7 may be, alternately in a column direction, connected to two subpixels at a left side with respect to each of the data lines DL1˜DL7 or may be connected to two subpixels at a right side with respect to each of the data lines DL1˜DL7. For example, the second data line DL2 may be sequentially connected to the subpixels SP1 and R11 (e.g., two subpixels at the left side of the data line DL2) in the first and second subpixel columns, the subpixels G21 and B21 (e.g., two subpixels at the right side of the data line DL2) in the third and fourth subpixel columns, the subpixels SP3 and R31 (e.g., two subpixels at the left side of the data line DL2) in the first and second subpixel columns, and the subpixels G41 and B41 (e.g., two subpixels at the right side of the data line DL2) in the third and fourth subpixel columns.
For example, subpixels in the two adjacent subpixel columns may be alternately connected to two adjacent data lines by a unit of two subpixels. For example, in the first and second subpixel columns, two subpixels SP1 and R11 in the first subpixel row may be connected to the second data line DL2, two subpixels SP2 and R21 in the second subpixel row may be connected to the first data line DL1, two subpixels SP3 and R31 of the third subpixel row may be connected to the second data line DL2, and two subpixels SP4 and 431 of the fourth subpixel row may be connected to the first data line DL1.
Data voltages (e.g., analog data voltage signals) may be applied to data lines DL1˜DL7 in a frame. Polarities of the data voltages may be inverted in a next frame.
For example, during a first frame, data voltages having a negative polarity (−) may be applied to the first, third, fifth, and seventh data lines DL1, DL3, DL5, and DL7, and data voltages having a positive polarity (+) may be applied to the second, fourth, and sixth data lines DL2, DL4, and DL6. Accordingly, data voltage applied with subpixels of the display panel 100 may have may be inverted in polarity for each row (e.g., referred to as a polarity pattern of a dot inversion). For example, each of the first and third subpixel rows may have a polarity pattern of “+, +, −, −, +, +, −, −, +, +, −, −”, and each of the second and fourth subpixel rows may have a polarity pattern of “−, −, +, +, −, −, +, +, −, −, +, +” which is opposite to two adjacent subpixels. Therefore, the display panel 100 may have a polarity pattern of a dot inversion where two adjacent subpixels in a subpixel row have the same polarity as each other and two adjacent subpixels are surrounded by subpixels having a polarity which is opposite to that of the two adjacent subpixels in the subpixel.
Although not illustrated in
Thus, using a column inversion method which provides data voltages having opposite polarities to adjacent data lines, the display panel 100 may have a dot inversion effect in which subpixels are inverted in polarity for every two columns in the first direction D1 (e.g., in a row direction) and subpixels are inverted in polarity for every row in the second direction D2 (e.g., in a column direction).
Referring to
For simplicity of explanation, four gate signals G1˜G4 applied to first four gate lines GL1˜GL4, respectively are described in
In
For example, the second gate signal G2 applied to the second gate line GL2 may have the ON level during two successive horizontal periods from a first horizontal period HP1 to a second horizontal period HP2. The first gate signal G1 applied to the first gate line GL1 may have the ON level during two successive horizontal periods from the second horizontal period HP2 to a third horizontal period HP3. The fourth gate signal G4 applied to the fourth gate line GL4 may have the ON level during two successive horizontal periods from the third horizontal period HP3 to a fourth horizontal period HP4. The third gate signal G3 applied to the third gate line GL3 may have the ON level during two successive horizontal periods from the fourth horizontal period HP4 to a fifth horizontal period HP5.
The subpixels connected to the second gate line GL2 may be precharged based on the precharge voltage during the first horizontal period HP1 and may be mainly charged based on the charging voltage during the second horizontal period HP2. The subpixels connected to the first gate line GL1 may be precharged based on the precharge voltage during the second horizontal period HP2 and may be mainly charged based on the charging voltage during the third horizontal period HP3. The subpixels connected to the fourth gate line GL4 may be precharged based on the precharge voltage during the third horizontal period HP3 and may be mainly charged based on the charging voltage during the fourth horizontal period HP4. The subpixels connected to the third gate line GL3 may be precharged based on the precharge voltage during the fourth horizontal period HP4 and may be mainly charged based on the charging voltage during the fifth horizontal period HP5.
In an exemplary embodiment of the present inventive concept, data in a subpixel stored by the precharge operation may correspond to previous subpixel data, and data in the subpixel stored by the charge operation (e.g., a main-charge operation) may correspond to present subpixel data.
Referring to
For example, data in the third subpixel B11 stored by the main-charge operation during the second horizontal period HP2 may be substantially the same as data in the second subpixel G11 stored by the precharge operation during the second horizontal period HP2. Thus, data in the second subpixel G11 stored by the main-charge operation during the third horizontal period HP3 may be referred to as present subpixel data of the first pixel the data in the third subpixel B11 stored by the main-charge operation during the second horizontal period HP2 may be referred to as previous subpixel data of the first pixel.
Hereinafter, a method of driving a display panel according to an exemplary embodiment of the present inventive concept will be described with reference to
Referring to
A second decision as to whether the compensation for the first pixel data is required may be made based on previous subpixel data and present subpixel data for the first pixel PIX1 (step S200). As described above with reference to
A third decision as to whether the first pixel data complies with a compensation avoidance condition may be made (step S300). The first pixel data is selectively compensated based on the first decision, the second decision and the third decision (step S400). For example, the first pixel data may be compensated by changing grayscales of the first pixel data.
A data voltage is generated based on the first pixel data to be applied to a data line (e.g., DL2 or DL3 in
In an exemplary embodiment of the present inventive concept, the steps S100, S200, S300, and S400 in
Although not illustrated in
In the method of driving the display panel 100 described above with reference to
Referring to
When the compensation for the first pixel data is required (step S110: YES), e.g., when the first pixel PIX1 is disposed in the compensation area and/or when the image displayed on the display panel 100 corresponds to the defect causable image, the first decision may be made to compensate the first pixel data (step S130).
When the compensation for the first pixel data is not required (step S110: NO), e.g., when the first pixel PIX1 is disposed in an area other than the compensation area and/or when the image displayed on the display panel 100 does not correspond to the defect causable image, the first decision may be made not to compensate (e.g., maintain) the first pixel data (step S150).
In an exemplary embodiment of the present inventive concept, the steps S110, S130, and S150 in
Referring to
The present subpixel data for operating the second subpixel G11 may be compared with second threshold data THH (step S230). The second threshold data THH may have a value corresponding to a relatively high grayscale that is greater than the middle grayscale. For example, the second threshold data THH may have a value close to a maximum grayscale. For another example, the second threshold data THH may correspond to a substantially white grayscale in the normal black mode. The second threshold data THH may be set by a user.
When a value of the previous subpixel data is smaller than a value of the first threshold data THL (step S210: YES), and when a value of the present subpixel data is greater than a value of the second threshold data THH (step S230: YES), the second decision may be made to compensate the first pixel data (step S270).
When the value of the previous subpixel data is equal to or greater than the value of the first threshold data THL (step S210: NO), or when the value of the present subpixel data is equal to or smaller than the value of the second threshold data THH (step S230: NO), the second decision may be made not to compensate (e.g., maintain) the first pixel data (step S290).
In an exemplary embodiment of the present inventive concept, the steps S210, S230, S270, and S290 in
Referring to
When a value of the first difference data is greater than a value (e.g., a grayscale) of the third threshold data THD (step S250: YES), the second decision may be made to compensate the first pixel data (step S270).
When the value of the first difference data is equal to or smaller than the value of the third threshold data THD (step S250: NO), the second decision may be made not to compensate (e.g., maintain) the first pixel data (step S290).
In an exemplary embodiment of the present inventive concept, the steps S250, S270, and S290 in
Referring to
When a value of the previous subpixel data is smaller than a value of the first threshold data THL (step S210: YES), when a value of the present subpixel data is greater than a value of the second threshold data THH (step S230: YES), and when a value of the first difference data is greater than a value of the third threshold data THD (step S250: YES), the second decision may be made to compensate the first pixel data (step S270).
When the value of the previous subpixel data is equal to or greater than the first threshold data THL (step S210: NO), when the value of the present subpixel data is equal to or smaller than the value of the second threshold data THH (step S230: NO), or when the value of the first difference data is equal to or smaller than the value of the third threshold data THD (step S250: NO), the second decision may be made not to compensate (e.g., maintain) the first pixel data (step S290).
In an exemplary embodiment of the present inventive concept, the steps S210, S230, S250, S270, and S290 in
Referring to
When the first pixel PIX1 displays one of the three primary colors (step S310: YES), e.g., when the first color corresponds to one (e.g., green) of the three primary colors, the third decision may be made not to compensate (e.g., maintain) the first pixel data (step S330). For example, when the first pixel PIX1 displays one of the three primary colors, it may represent that the first pixel data complies with the compensation avoidance condition.
When the first pixel PIX1 displays a color other than the three primary colors (step S310: NO), e.g., when the first color does not correspond to one of the three primary colors, the third decision may be made to compensate the first pixel data (step S350).
In an exemplary embodiment of the present inventive concept, the steps S310, S330, and S350 in
Referring to
When a value of the previous subpixel data is smaller than a value of the fourth threshold data THB (step S311: YES), and when a value of the first subpixel data is smaller than a value of the fourth threshold data THB (step S313: YES), it may be determined that the first pixel PIX1 displays one of the three primary colors, and thus, the third decision may be made not to compensate (e.g., maintain) the first pixel data (step S330). For example, when the value of the previous subpixel data is smaller than the value of the fourth threshold data THB, and when the value of the first subpixel data is smaller than the value of the fourth threshold data THB, it may represent that the first pixel data complies with the compensation avoidance condition. For example, when RGB grayscales of the first pixel data is (0, 128, 0), it may be determined that the first pixel PIX1 displays a green color that is one of the three primary colors.
When the value of the previous subpixel data is equal to or greater than the value of the fourth threshold data THB (step S311: NO), or when the value of the first subpixel data is equal to or greater than the value of the fourth threshold data THB (step S313: NO), it may be determined that the first pixel PIX1 displays a color other than the three primary colors, and thus, the third decision may be made to compensate the first pixel data (step S350).
In an exemplary embodiment of the present inventive concept, the steps S311, S313, S330, and S350 in
In the method of driving the display panel 100 described above with reference to
Referring to
When all of the first decision, the second decision, and the third decision indicate that the compensation for the first pixel data is not required (step S410: YES), the first pixel data may be compensated by adding compensation data to the present subpixel data (step S430). The compensation data may be determined based on a difference in grayscale between the present subpixel data and the previous subpixel data. For example, the data compensation unit 210 may use a conversion function and calculate a compensation grayscale based on the grayscale of the present subpixel data and the grayscale of the previous subpixel data. In an exemplary embodiment of the present inventive concept, the data compensation unit 210 may determine the compensation grayscale using a lookup table that stores the compensation grayscale based on a difference between the grayscale of the present subpixel data and the grayscale of the previous subpixel data.
When at least one of the first decision, the second decision, and the third decision is made that the compensation for the first pixel data is not required (step S410: NO), the first pixel data may not be compensated (for example, the first pixel data may be maintained) (step S450).
In an exemplary embodiment of the present inventive concept, the steps S410, S430, and S450 in
Referring to
When all of the first decision, the second decision, and the third decision indicate that the compensation for the first pixel data is required (step S410: YES), the compensation data may be selectively changed (step S420), and the first pixel data may be compensated by adding compensation data to the present subpixel data (step S430).
When at least one of the first decision, the second decision, and the third decision indicates that the compensation for the first pixel data is not required (step S410: NO), the first pixel data may not be compensated (for example, the first pixel data may be maintained) (step S450).
The steps S410, S430, and S450 in
In an exemplary embodiment of the present inventive concept, the steps S410, S420, S430, and S450 in
Referring to
A first maximum grayscale may be compared with a second maximum grayscale (step S423). The first maximum grayscale may be the greatest one of first grayscales of the first color displayed by the first pixel PIX1. The second maximum grayscale may be the greatest one of second grayscales of the second color displayed by the second pixel PIX2. For example, it may be determined whether the first maximum grayscale is substantially the same as the second maximum grayscale.
Grayscales other than the first maximum grayscale among the first grayscales may be compared with a reference grayscale (step S425). For example, it may be determined whether the grayscales other than the first maximum grayscale among the first grayscales are smaller than the reference grayscale. The reference grayscale may be set by a user.
When the second pixel PIX2 displays one (e.g., a green color) of the three primary colors (step S421: YES), and when the first maximum grayscale is substantially the same as the second maximum grayscale (step S423: YES), and when the grayscales other than the first maximum grayscale among the first grayscales are smaller than the reference grayscale (step S425: YES), a value (e.g., a grayscale) of the compensation data may be reduced (step S427). For example, when RGB grayscales of the first pixel data is (20, 128, 0), and when RGB grayscales of the second pixel data is (0, 128, 0), and when the reference grayscale may be about 30, a compensation grayscale corresponding to the value of the compensation data may be reduced.
When the second pixel displays PIX2 a color other than the three primary colors (step S421: NO), when the first maximum grayscale is different from the second maximum grayscale (step S423: NO), or when the grayscales other than the first maximum grayscale among the first grayscales are equal to or greater than the reference grayscale (step S425: NO), the value of the compensation data may be maintained (step S429).
In an exemplary embodiment of the present inventive concept, the steps S421, S423, S425, S427, and S429 in
Although
In the method of driving the display panel 100 described above with reference to
Referring to
Based on the first analyzation result, one of a first compensation method and a second compensation method is selected for the compensation on the plurality of pixel data (step S1200).
The first compensation method may correspond to the method illustrated in
The second compensation method may be similar to the method illustrated in
In an exemplary embodiment of the present inventive concept, the steps S1100 and S1200 in
Although not illustrated in
Although not illustrated in
In the method of driving the display panel 100 described above with reference to
Referring to
When each of the plurality of pixels displays only at least one color selected from the three primary colors or only at least one color selected from the three mixed colors (step S1110: NO), e.g., when each of the plurality of colors corresponds to only the at least one color selected from the three primary colors or only the at least one color selected from the three mixed colors, the first analyzation result may be generated to select the first compensation method, which includes the third decision result on whether the compensation avoidance condition is met, for the compensation on the plurality of pixel data (step S1150).
When each of the plurality of pixels displays both of the at least one color selected from the three primary colors and the at least one color selected from the three mixed colors (step S1110: YES), e.g., when each of the plurality of colors corresponds to both of the at least one color selected from the three primary colors and the at least one color selected from the three mixed colors, the first analyzation result may be generated to select the second compensation method, which does not include the third decision result on whether the compensation avoidance condition is met, for the compensation on the plurality of pixel data (step S1170).
In an exemplary embodiment of the present inventive concept, the steps S1110, S1150, and S1170 in
Referring to
The number of the N pixels may be compared with a reference number (step S1130). It may be determined whether a pattern displayed by the N pixels corresponds to a gamma test pattern or a normal pattern based on the reference number. The reference number may be set by a user.
When N is smaller than or equal to the reference number (step S1130: NO), the first analyzation result may be generated to select the first compensation method for the compensation on N pixel data corresponding to the N pixels (step S1155). For example, when N is smaller than or equal to the reference number, it may be determined that the pattern displayed by the N pixels corresponds to the normal pattern, and the first compensation method may be selected for the normal pattern.
When N is greater than the reference number (step S1130: YES), the first analyzation result may be generated to select the second compensation method for the compensation on the N pixel data corresponding to the N pixels (step S1175). For example, when N is greater than the reference number, it may be determined that the pattern displayed by the N pixels corresponds to the gamma test pattern, and the second compensation method may be selected for the gamma test pattern.
In addition, it may be determined whether the analysis on a plurality of pixels disposed in the first horizontal line is completed (step S1180).
When the analysis on the plurality of pixels disposed in the first horizontal line is not completed (step S1180: NO), e.g., when one of the first compensation method and the second compensation method is not selected for all of the plurality of pixels disposed in the first horizontal line, K pixels (K is a natural number equal to or greater than two) among the plurality of pixels may be further detected (step S1180). The K pixels may be disposed subsequent to the N pixels, may be successively disposed in the first horizontal line, and may display only at least one color selected from the three primary colors. The steps S1130, S1155, S1175, S1180, and S1190 may be repeated for each of the K pixels. The steps S1130, S1155, S1175, S1180, and S1190 may be repeated until the analysis on the plurality of pixels in the first horizontal line is completed.
When the analysis on the plurality of pixels in the first horizontal line is completed (step S1180: YES), e.g., when one of the first compensation method and the second compensation method is selected for the compensation on all of the plurality of pixels in the first horizontal line, the analysis on the plurality of pixels in the first horizontal line may be terminated.
In an exemplary embodiment of the present inventive concept, the steps S1120, S1130, S1155, S1175, S1180, and S1190 in
In the method of driving the display panel 100 described above with reference to
The above described exemplary embodiments of the present inventive concept may be used in a display panel, a display apparatus or a system including the display apparatus, such as a mobile phone, a smart phone, a personal digital assistant (PDA), a portable media player (PMP), a digital camera, a digital television, a set-top box, a music player, a portable game console, a navigation device, a personal computer (PC), a server computer, a workstation, a tablet computer, a laptop computer, a smart card, a printer, etc.
The foregoing is illustrative of exemplary embodiments of the present inventive concept and the present inventive concept should not to be construed as being limited to the exemplary embodiments disclosed herein. Although a few exemplary embodiments have been described, it will be understood that various modifications in forms and detail may be possible without materially departing from the spirit and scope of the present inventive concept as defined in the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2014-0104493 | Aug 2014 | KR | national |
