JP6549360B2 - Display device - Google Patents

Description

  The present invention relates to a display device.

  Recently, instead of a cathode ray tube display (Cathode Ray Tube, CRT), a liquid crystal display (LCD), a plasma display panel (PDP), an organic light emitting display (OLED) Flat panel displays such as Display are rapidly developing. Unlike the flat panel display, the liquid crystal display does not emit light by itself unlike the plasma display and the like, and a light source is required. At this time, a point light source such as a light emitting diode (LED) is generally used as such a light source, an electroluminescent lamp (EL), a cold cathode fluorescent lamp (Cold Cathode Fluorescent Lamp) Use linear light sources like CCFL). Among the light sources, light emitting diodes are widely used as light sources for backlight units.

  Recently, there is interest in Dimming technology aimed at improving contrast ratio (CR) and reducing power consumption, with a focus on products that use backlight units that use light emitting diodes as light sources. It is rising. That is, the entire screen area is divided into a large number of blocks having uniform sizes, and the gamma curve distortion caused by the light leakage phenomenon of the panel is corrected by luminance dimming separately for each block to improve the contrast ratio and power consumption. Reduce the number.

  Recently, as the light source, red, green and blue light emitting diodes are adopted, not only the luminance but also the dimming drive technology for each hue has been developed. The above-described dimming drive technique for each hue has the advantage of reducing distortion of the hue when making a block-by-block determination, but color distortion may occur when making a determination for each pixel within each block. Improvement points still remain in Japan.

  The problem to be solved by the present invention is to provide a light source driving method for improving color reproducibility and reducing color distortion, and a display device for performing the same.

  The problems of the present invention are not limited to the above-mentioned technical problems, and other technical problems which are not mentioned will be clearly understood by those skilled in the art from the following description.

  According to an embodiment of the present invention, there is provided a display apparatus including a light source module including a plurality of light emitting blocks, a plurality of pixels, and an image divided into a plurality of video blocks corresponding to the light emitting block. A display panel to be displayed, a video signal is divided into the video blocks, a color dimming signal corresponding to a first video block among the video blocks is generated, the first video block is analyzed, and the pixels are divided. A pixel distortion value and a pixel improvement value corresponding to each are acquired, and based on the pixel distortion value and the pixel improvement value, color dimming of a first light emission block corresponding to the first image block among the light emission blocks And a light source module control unit for driving the first light emission block.

  Specific contents of the other embodiments are included in the detailed description and the drawings.

According to the embodiment of the present invention, at least the following effects can be obtained.
According to the present invention, it is possible to provide a light source drive method for improving display quality and a display device for performing the same.
Further, according to the present invention, it is possible to provide a light source drive method for improving color reproducibility and reducing color distortion, and a display device for performing the same.
The effects of the present invention are not limited by the contents exemplified above, and various additional effects are included in the present specification.

FIG. 1 is a schematic block diagram of a display device according to an embodiment of the present invention. It is a top view which shows the display panel and light source module which are shown in FIG. 1 roughly. FIG. 5 is a flow chart schematically illustrating a light source driving method according to an embodiment of the present invention. FIG. 5 is a flow chart schematically showing an operation according to an embodiment of step S30 in the light source driving method shown in FIG. 3. FIG. 5 is a flow chart schematically showing an operation according to an embodiment of step S50 in the light source driving method shown in FIG. 3. FIG. 6 is a flow chart schematically showing an operation according to an embodiment of step S70 in the light source driving method shown in FIG. 3. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention. FIG. 6 is an exemplary view for explaining a light source driving method in a display device according to an embodiment of the present invention.

The advantages and features of the invention, and the manner of achieving them, will be apparent in the embodiments described in detail below in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but is realized in various forms different from each other, and the present embodiment merely completes the disclosure of the present invention, and the present invention It is provided to fully inform the scope of the invention to the person skilled in the art to which it belongs, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout the specification. The sizes and relative sizes of layers and regions shown in the drawings may be exaggerated for clarity of illustration.
It is needless to say that although the first, second, etc. are used to describe various elements and components, these elements and components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, it goes without saying that the first component mentioned below can be the second component within the technical concept of the present invention. As used herein, singular forms also include plural forms unless the context clearly indicates otherwise. As used herein, “comprise” and / or “have” refers to the presence of one or more of the components, steps, operations and / or elements referred to in the component, step, operation and / or elements. Do not exclude additions.

  The terms "parts" or "modules" used in the present embodiment are given or mixed for ease of description, and do not themselves have any meaning or role to distinguish them from each other.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic block diagram of a display device according to an embodiment of the present invention. FIG. 2 is a plan view schematically showing the display panel and the light source module shown in FIG.

  Referring to FIG. 1, the display device 10 according to the present embodiment may include a display panel 100 for displaying an image, a timing control unit 110, a panel drive unit 130, and a light source device BLU.

  The display panel 100 may display a video corresponding to a video signal ID provided from the outside, and may include a plurality of pixels P for displaying the video. The pixel P may include a red unit pixel PR, a green unit pixel PG, and a blue unit pixel PB, and may further include a white unit pixel although not shown in the drawing. Although not shown in the drawings, each pixel P may include a switching element TR connected to the gate line GL and the data line DL crossing each other, a liquid crystal capacitor CLC connected to the switching element TR, and a storage capacitor CST. Such a display panel 100 can display an image divided into a plurality of image blocks DB as described later.

  The timing control unit 110 receives the control signal CS and the video signal ID from an external device (not shown). The control signal CS may include a vertical synchronization signal, a horizontal synchronization signal, a clock signal, a data enable signal, etc., and generates a timing control signal (T_Cont) for controlling the drive timing of the panel driver 130 using the control signal Cont. Do. Here, the timing control signal (T_Cont) may be a first control signal (T_Cont_1) for controlling the drive timing of the data driver 132 and a second control signal (T_Cont2) for controlling the drive timing of the gate driver 134. May be included. For example, the timing control unit 110 converts the data format of the video signal ID according to the interface specification with the data drive unit 132 of the panel drive unit 130, and outputs the converted video signal (ID ') to the data drive unit 132. . The timing control unit 110 also outputs the first control signal (T_Cont1) to the data driver 132 and the second control signal (T_Cont2) to the gate driver 134. In an exemplary embodiment, the first control signal (T_Cont1) may include an output start signal, a horizontal start signal, a clock signal, etc., and the second control signal (T_Cont2) may include a vertical start signal, a gate clock signal and an output enable signal. Although it may contain, it is not limited to this.

  The panel driving unit 130 may drive the display panel 100 using the timing control signal (T_Cont) received from the timing control unit 110 and the converted video signal (ID ′), and the data driving unit 132 and the gate driving unit May be included.

  The gate driver 134 receives the gate-on voltage and the gate-off voltage, and sequentially outputs gate signals having the gate-on voltage in response to a second control signal (T_Cont2) provided from the timing controller 110. The gate signals are sequentially applied to the gate lines GL of the display panel 100 to sequentially scan the gate lines GL. Although not shown in the drawings, the display device 10 may further include a regulator that converts an input voltage into the gate on voltage and the gate off voltage and outputs the voltage.

  The data driver 132 operates in response to an analog drive voltage, and generates a plurality of gray scale voltages using the gamma voltage provided from the gamma voltage generator (not shown). The data driver 132 is a gray scale voltage corresponding to the converted video signal (ID ') among the gray scale voltages generated in response to the first control signal (T_Cont1) provided from the timing control unit 110. Is selected, and the selected gray scale voltage is applied to the data line (DL) of the display panel 210 as a data signal.

  When the gate signal is sequentially applied to the gate line GL, the data signal is applied to the data line (DL) in synchronization with this. When the corresponding gate signal is applied to the selected gate line, the thin film transistor TR connected to the selected gate line is turned on in response to the corresponding gate signal. When a data signal is applied to a data line connected to the turned on thin film transistor TR, the applied data signal is charged in the liquid crystal capacitor CLC and the storage capacitor CST through the turned on thin film transistor TR. The liquid crystal capacitor CLC adjusts the light transmittance of the liquid crystal according to the charged voltage. The storage capacitor CST stores a data signal when the thin film transistor TR is turned on, and applies the data signal stored when the thin film transistor TR is turned on to the liquid crystal capacitor CLC to maintain the charge of the liquid crystal capacitor CLC. The display panel 100 displays an image by such a method.

  The light source device BLU may include a light source module 200 and a light source module controller 300.

  The light source module 200 is disposed adjacent to the display panel 100 to supply light to the display panel 100. Such a light source module 200 may include a plurality of light emitting blocks B. For example, the light source module 200 may be divided into M * N (M and N are natural numbers) light emitting blocks B. Each light emitting block B corresponds to the image displayed on the display panel 100 by the dimming method, and can be individually driven. For example, each light emitting block B corresponds to the image block DB of the image displayed on the display panel 100 Corresponding and can be driven individually.

  FIG. 2 is a plan view schematically showing the display panel and the light source module shown in FIG. 1, and more specifically, light emission of a portion of the display panel corresponding to one video block and the light source module corresponding to the video block. It is a top view which expands a block roughly and shows it.

  1 and 2, each light emitting block B of the light source module 200 may include a plurality of unit light emitting blocks 210, and each unit light emitting block 210 may emit a first light source 211 emitting a first color light and a second color light And a third light source 215 for emitting a third color light. A plurality of first light sources 211 and a plurality of second light sources 213 may be included. Here, the first to third colors may be different from each other. For example, the first color may be any one of green, blue and red, and the second color may be different from the first color of green, blue and red; The color may be different from the first color and the second color among green, blue and red. Hereinafter, for convenience of explanation, the first color is red, the second color is green, and the third color is blue, but this is an example, and the first to third colors are It can be changed in many ways.

  The first light source 211 may be a light emitting diode, and in an exemplary embodiment may be a red light emitting diode that emits red light as the first color. Similarly, the second light source 213 may be a light emitting diode, and in an exemplary embodiment may be a green light emitting diode that emits green light as the second color. Also, the third light source 215 may be a light emitting diode, and in an exemplary embodiment may be a blue light emitting diode that emits blue light as the third color. The wavelength of red light emitted from the first light source 211 is about 580 nm to 700 nm, the wavelength of green light emitted from the second light source 213 is about 460 nm to 630 nm, and the wavelength of red light emitted from the third light source 215 is The wavelength may be about 400 nm to 500 nm, but is not limited thereto.

  The plurality of unit light emission blocks 210 included in the light emission block B are provided to correspond to the pixels P of the display panel 100. For example, the drawing shows the case where one unit light emitting block 210 and four pixels P correspond to each other. That is, two unit pixels in the row direction and two unit pixels in the column direction correspond to one unit light emitting block 210. However, this is only an example, and unit light emission blocks 210 may be provided to correspond to the respective pixels P one by one. That is, the correspondence ratio between the unit light emission block 210 and the pixel P is not limited.

  The plurality of first light sources 211, the second light sources 213, and the third light sources 215 included in one light emission block B are driven independently of the light sources belonging to the other light emission blocks. Also, the plurality of first light sources 211, the second light sources 213, and the third light sources 215 included in the same light emitting block B may be independently driven according to the colors of the light sources. Furthermore, each of the first light source 211, the second light source 213, and the third light source 215 belonging to one unit light emitting block 210 may be individually driven.

  Meanwhile, although not shown, the light source module 200 may further include a circuit board on which a plurality of first light sources 211, second light sources 213 and third light sources 215 are mounted. The circuit board is provided with circuit wiring for transmitting a driving current to the first light source 211, the second light source 213 and the third light source 215. Such a circuit board may be a printed circuit board (PCB), and may be a metal core printed circuit board (MCPCB) for improving heat dissipation efficiency, but is not limited thereto.

  Referring back to FIG. 1, the light source module control unit 300 is a part that controls the exceptional driving of each of the light emitting blocks B of the light source module 200.

  The light source module control unit 300 may include an image analysis unit 310, a color coordinate calculation unit 330, an operation unit 350, a mode determination unit 370, and a light source module drive unit 390.

  The video analysis unit 310 may divide the video signal ID into a plurality of video blocks DB corresponding to the light emission block B, analyze the video blocks DB, and generate a color dimming signal for controlling the hue of each video block DB. it can. For example, the video analysis unit 310 analyzes an arbitrary video block (hereinafter referred to as "first video block") selected from the plurality of video blocks DB, determines a representative hue of the first video block, and determines the representative hue. And generates a color dimming signal for driving a light emitting block (hereinafter referred to as "first light emitting block") corresponding to the first video block. An example of the detailed operation of the image analysis unit 310 generating the color dimming signal will be described later.

  Also, the image analysis unit 310 may determine a representative luminance value of the first image block, and may further generate a luminance dimming signal for driving the first light emitting block based on the representative luminance value.

  The color coordinate calculation unit 330 calculates color coordinates in units of pixels for each of the video blocks DB. For example, the color coordinate calculation unit 330 analyzes the first video block of the plurality of video blocks DB in units of pixels to obtain pixel data, and performs color dimming based on the color dimming signal for each pixel. The color coordinates of the case (or color dimming color coordinates) and the color coordinates without color dimming (or non-dimming color coordinates) are calculated. Here, the calculated color dimming color coordinates and the non-dimming color coordinates may be color coordinates located within a color coordinate system that has already been determined.

  The calculation unit 350 calculates data for each pixel, and more specifically, calculates a pixel distortion value and a pixel improvement value for each pixel data. For example, the calculation unit 350 calculates data for each pixel based on each pixel color dimming color coordinates and non-dimming color coordinates calculated by the color coordinate calculation unit 330, and each calculated pixel data is subjected to pixel distortion. It is determined which of the value and the pixel improvement value corresponds to.

  The mode determination unit 370 determines whether or not the color dimming drive of each light emitting block B is possible. For example, the mode determining unit 370 receives the pixel distortion value and pixel improvement value of the first image block from the operation unit 350, and based on this, performs color dimming driving of the first light emitting block corresponding to the first image block. Decide whether to

  For example, when the color determining drive of the first light emitting block is determined as a result of the determination of the mode determining unit 370, the mode determining unit 370 provides the light source module driving unit 390 with the color dimming signal generated by the image analysis unit 310. In addition, when the image analysis unit 310 further generates a luminance light control signal, the mode determination unit 370 provides the light control signal with the color dimming signal to the light source module drive unit 390.

  On the other hand, when the mode determination unit 370 determines that the first light emitting block is not to be color dimmed, the mode determination unit 370 does not provide the light source module drive unit 390 with the color dimming signal generated by the image analysis unit 310. May be In addition, when the image analysis unit 310 further generates a luminance dimming signal, the mode determining unit 370 may provide only the luminance dimming signal to the light source module driving unit 390.

  The light source module driving unit 390 drives the light emitting block B of the light source module 200, and the light emitting block B of the light source module 200 or a plurality of light sources (211, 213, Drive 215).

  FIG. 3 is a flow chart schematically showing a light source driving method according to an embodiment of the present invention, and more specifically, a flow chart schematically showing the operation of the light source device shown in FIG. FIG. 4 is a flow chart schematically illustrating the operation of one embodiment of step S30 shown in FIG. FIG. 5 is a flow chart schematically showing the operation of the light source driving method shown in FIG. 3 according to an embodiment of step S50. FIG. 6 is a flow chart schematically showing the operation of the light source driving method shown in FIG. 3 according to an embodiment of step S70. 7 to 14 are exemplary views for explaining a method of driving a light source in a display device according to an embodiment of the present invention, wherein FIG. 10 is an enlarged view of a first image block shown in FIG. is there.

  Referring to FIG. 3, in the light source driving method according to an embodiment of the present invention, the image analysis unit 310 analyzes the image signal and divides it into a plurality of image blocks (S10). The color dimming signal corresponding to the first image block is generated (S30), and the operation unit 350 generates the first image based on the pixel-by-pixel color dimming color coordinates and the non-dimming color coordinates calculated by the color coordinate calculation unit 330. The block is analyzed to obtain a pixel distortion value and a pixel improvement value corresponding to each of the pixels (S50), and the mode determining unit 370 generates a first image corresponding to the first image block based on the pixel distortion value and the pixel improvement value. It is determined whether or not color dimming of the light emission block is possible (or whether or not color dimming can be driven) (S70), and the light source module drive unit 390 determines based on the determination. It may include the step (S90) for driving the first light emitting block.

  The process of analyzing the video signal and dividing it into a plurality of video blocks (S10) is as follows.

  Referring to FIGS. 1 to 3 and FIGS. 7 and 8, when a video signal as shown in FIG. 7 is input, the video analysis unit 310 analyzes the input video signal and outputs a plurality of video signals as shown in FIG. Divided into video block DB. In the following, for convenience of explanation, it is assumed that the video signal is a video signal having four colors as shown in FIG. 7 and FIG. 8. Specifically, the video signal is blue region IB, white region IW, green region IG And it is assumed that the video signal has a yellow area IY.

  A process (S30) of generating a color dimming signal corresponding to the first video block among the plurality of video blocks is as follows.

  Referring to FIGS. 1 to 4 and FIGS. 9 and 10, in the exemplary embodiment, step S30 extracts color information corresponding to each pixel in the first image block (S31), and the color corresponding to each of the pixels is extracted. The hue classes of information are classified (S32), each hue class is mapped to the color coordinate system already determined (S33), and the representative hue of the first video block is determined (S34), the determined representative The method may include the step of generating a color dimming signal based on the hue (S35).

  More specifically, the light source device BLU or the display device 10 may store already set hue class table information, and the plurality of hue class table information may be stored in a separate storage unit or video analysis unit 310. The hue class table information may include information on hue classes. One hue class of hue gradations in a proximity region where it is difficult for a person to distinguish among red, green, and blue B divided into respective predetermined hue gradations, for example, 256 hue gradations. Define by In the exemplary embodiment, as shown in FIG. 9, hue gradations divided into 256 gradations are grouped into hue gradations having the same or similar visibility, and four hue classes of red, green and blue respectively. Divided into That is, by grouping the hue gradations of the red, green and blue hue classes into 0 to 63 gradations, 64 to 127 gradations, 128 to 191 gradations and 192 to 255 gradations, red and green are obtained. , Blue are divided into four hue classes. As a result, in the present embodiment, there are a total of 256 × 256 × 256 gradations, and the number of hue classes is 4 × 4 × 4. On the other hand, in the present embodiment, red R, green G, and blue B are divided into four hue classes (Class R1 to Class R4, Class G1 to Class G4, Class B1 to Class B4), but this is one example. That is, since each hue class has similar visibility or defines the same hue range in one area, the number of hue classes of each hue can be changed variously. Further, the number of hue classes may be the same or may not be the same, and the sizes of the divided hue classes also differ depending on the hue tone. Also, hue class table information, which is information of such a hue class, may be stored in advance in a separate storage unit or image analysis unit 310.

  The video analysis unit 310 divides the video signal ID from the timing control unit 110 into a plurality of video blocks DB, and among the video blocks DB, any first video block DB1 corresponds to each pixel P of the display panel 100. The color information of the pixel data Px is acquired. For example, the video signal ID includes color information for each pixel P. Then, the image analysis unit 310 compares the acquired color information with the above-described hue class table information to classify the hue class of each pixel data Px. Here, color information of the pixel data Px may include gradation information (GRAY INFORMATION) of red, green and blue. Also, the image analysis unit 310 maps the classified hue class in advance to a color coordinate system in which a plurality of hue regions are divided. In an exemplary embodiment, the color coordinate system may be a CIE 1976 color coordinate system. Also, in the exemplary embodiment, each of the hue regions divided into the color coordinate system may be a region defined by hue tones having similar visibility. Furthermore, a plurality of hue regions are tabulated to form color coordinate system table information, and the color coordinate system table information is stored in advance in a separate storage unit or image analysis unit 310 so as to be similar to the hue class table information. It can be done. Alternatively, after acquiring the color information of the pixel data Px, the image analysis unit 310 may omit the separate hue class classification process, and may map directly to the hue area of the color coordinate system. That is, for example, although the first video block DB1 has color information for each pixel P, the first video block DB1 may be formed by a hue region defined by hue tones having similar visibility. Then, the hue area of the first video block DB1 is mapped in the color coordinate system based on color coordinate system table information indicating the relationship between the hue area and the color coordinates.

  Thereafter, the image analysis unit 310 determines the hue region having the largest value among the hue classes mapped to the color coordinate system as the representative hue of the first image block DB1. Alternatively, the image analysis unit 310 may map one hue class having the largest value among the hue classes to the color coordinate system to determine the representative hue of the first image block DB1. Furthermore, when the separate hue class classification process is omitted, the image analysis unit 310 may determine the hue region to which the largest value is mapped as the representative hue of the first image block DB1. In the case of the first video block DB1, for example, the number of pixels P corresponding to the blue area IB or the number of pixel data Px corresponding to the blue area IB corresponds to the number of pixels P corresponding to the white area IW or the white area IW. The representative hue of the first video block DB1 may be determined to be blue because the number is larger than the number of corresponding pixel data Px.

  Thereafter, the image analysis unit 310 generates a color dimming signal based on the determined representative hue. Here, the color dimming signal is a signal for driving a light emitting block for a video block. The image analysis unit 310 generates a color dimming signal according to, for example, the magnitude of the luminance of the representative hue. For example, the video analysis unit 310 generates a color dimming signal to reduce the luminance in the light emitting block in the case of the representative hue with high luminance. Conversely, the image analysis unit 310 generates a color dimming signal that increases the brightness of the light emitting block in the case of a representative hue with low brightness.

  However, the above-described content is one example, and the image analysis unit 310 may generate the color dimming signal corresponding to the first image block by various methods.

  Meanwhile, in some embodiments, the image analysis unit 310 may generate luminance dimming information as well as color dimming information. For example, the video analysis unit 310 can also generate a luminance light adjustment signal based on the representative luminance value extracted and extracted from the representative luminance value of the first video block DB1. For example, when the representative luminance value is high, the image analysis unit 310 generates a color dimming signal to reduce the luminance in the light emission block. Conversely, when the representative luminance value is low, the image analysis unit 310 generates a color dimming signal that increases the luminance in the light emission block.

  The process of analyzing the first video block to obtain pixel distortion values and pixel improvement values corresponding to the respective pixels (S50) is as follows.

  1 to 5 and 10 to 12, in an exemplary embodiment, the step S50 analyzes the first image block to calculate color dimming color coordinates and non-dimming color coordinates corresponding to each of the pixels. (S51), it is determined whether the non-dimming color coordinates are located within the color area including the already set reference coordinates (S52), and as a result, it is determined that the non-dimming color coordinates include the already set reference coordinates. In the case of being located inside, a step of calculating the first distance between the color dimming color coordinates and the non-dimming color coordinates (S53) and determining the calculated first distance as a pixel distortion value (S57) may be included. . Also, if it is determined in step S52 that the non-dimming color coordinates are not located within the color area including the already set reference coordinates, the first distance between the color dimming color coordinates and the non-dimming color coordinates, the reference coordinates, and the color The second distance between the dimming color coordinates and the third distance between the reference coordinates and the non-dimming color coordinates are calculated (S54), and the second distance calculated in the step S54 is the third distance or more In the step S55, if the second distance is greater than or equal to the third distance, it may include the step of determining the first distance as the pixel improvement value (S56), and the determination result of the step S55. If the second distance is less than the third distance, it is determined that the first distance is a pixel distortion value (S57).

  Step S51 described above is performed by the color coordinate calculator 330.

  More specifically, the color coordinate calculation unit 330 analyzes the first image block DB1 and calculates color dimming color coordinates and non-dimming color coordinates from pixel data Px corresponding to each of the pixels P.

  The color dimming color coordinates and the non-dimming color coordinates may be coordinates located in a color coordinate system 90 which has already been set as shown in FIG. The color coordinate system 90 already set in the exemplary embodiment may be the CIE 1976 color coordinate system. The advantage of the CIE 1976 color coordinate system is that there is a correlation between the geometrical distance between the color coordinates in this coordinate system and the color difference perceived by the person.

  A reference area 910, a reference coordinate W, and a judgment area 930 are defined in the color coordinate system 90 which has already been set.

  The reference area 910 means a color area that can be expressed when the display device 10 does not perform the dimming drive (or performs the non-dimming drive). Alternatively, the reference area 910 may mean a National Television System Committee (NTSC) reference color area.

  The reference coordinate W may be a coordinate at which red, green and blue gradation values all indicate the same part. In other words, the reference coordinates W may be color coordinates with respect to white.

  The determination area 930 is an area including the reference coordinate W inside as an area serving as one reference for calculating the pixel improvement value and the pixel distortion value. In the judgment area 930, when any pixel data has Rg as a red tone value, Gg as a green tone value, and Bg as a blue tone value, a region satisfying all the conditions of Equations 1, 2 and 3 below Defined as

［式２］

［式３］

[Equation 1]

[Formula 2]

[Equation 3]

  Here, in Formulas 1 to 3, C1 to C3 may have integer values of 0 or more and 255 or less.

  That is, in the judgment area 930, the absolute value for the difference between the red tone value and the green tone value is the first setting value C1 or less, and the absolute value for the difference between the green tone value and the blue tone value is the second set. It is defined as a region that does not exceed the value C2 and that the absolute value for the difference between the blue tone value and the red tone value satisfies the condition of the third set value C3 or less. Here, the first set value to the third set value may be individually changed in the range of 0 to 255, respectively. Such a determination area 930 may be set and stored in the display device 10 or the light source device BLU.

  If the arbitrary pixel data located in the blue region IB among the plurality of pixel data Px shown in FIG. 10 is the first pixel data Pxa, the color coordinate calculation unit 330 sets the first pixel data Px in the color coordinate system 90 as shown in FIG. Non-dimming color coordinates CPxa1 and color dimming color coordinates CPxa2 of one pixel data Pxa can be calculated. Here, the color coordinate calculation unit 330 analyzes the first video block of the plurality of video blocks DB in pixel units to obtain pixel data, and performs color dimming based on the color dimming signal for each pixel. The color coordinates (or color dimming color coordinates) and the color coordinates without color dimming (or non-dimming color coordinates) are calculated. As described above in the exemplary embodiment, in the case of the first image block DB1, since the representative hue is determined to be blue, the color dimming color coordinates CPxa2 of the first pixel data Pxa are relative to the non-dimming color coordinates CPxa1. , And may be located outside the reference area 910, as shown in FIG.

  Similarly, if the arbitrary pixel data located in the white area IW among the plurality of pixel data Px shown in FIG. 10 is the second pixel data Pxb, the color coordinate calculation unit 330 determines the color coordinate system as shown in FIG. At 90, the non-dimming color coordinates CPxb1 and the color dimming color coordinates CPxb2 of the second pixel data Pxb can be calculated. As described above in the exemplary embodiment, in the case of the first image block DB1, since the representative hue is determined to be blue, the color dimming color coordinates CPxb2 of the second pixel data Pxb are relative to the non-dimming color coordinates CPxb1. Can be positioned adjacent to the blue B part.

  The operation S <b> 52 to S <b> 57 may be performed by the operation unit 350.

  More specifically, referring to FIG. 14, the computing unit 350 determines whether the non-dimming color coordinates CPxa1 of the first pixel data Pxa calculated by the color coordinate calculating unit 330 are located in the judgment area 930. As shown in FIG. 14, since the non-dimming color coordinates CPxa1 of the first pixel data Pxa are located outside the determination area 930 and not located within the determination area 930, the computing unit 350 calculates the color dimming color coordinates CPxa2 and the non-dimming color coordinates. A first distance da1 to CPxa1 is calculated. Further, the calculation unit 350 calculates a second distance da2 between the reference coordinate W and the color dimming color coordinate CPxa2, and a third distance da3 between the reference coordinate W and the non-dimming color coordinate CPxa1. In addition, the calculation unit 350 determines whether the second distance da2 is equal to or more than the third distance da3, and determines that the first distance da1 is a pixel improvement value when the second distance da2 is equal to or more than the third distance da3. If the second distance da2 is less than the third distance da3, the first distance da1 is determined to be a pixel distortion value. In an exemplary embodiment, FIG. 14 illustrates the case where the second distance da2 is larger than the third distance da3, and the computing unit 350 determines that the first distance da1 is a pixel improvement value with respect to the first pixel data Pxa. Do.

  The coordinates located outside the determination area 930 have relatively strong color characteristics because the difference between the red tone value, the green tone value, and the blue tone value is relatively clear. When color dimming is performed on pixel data having such coordinates, if color dimming color coordinates move to the side of the reference coordinates W, it may be determined that the color characteristics decrease despite the color dimming being performed. Therefore, the distance between the color dimming color coordinates and the non-dimming color coordinates is determined to be a pixel distortion value. On the other hand, when color dimming is performed, if the color coordinates of color dimming move in the direction away from the reference coordinate W, it can be determined that the color characteristics increase according to the execution of color dimming. Therefore, in such a case, the distance between the color dimming color coordinates and the non-dimming color coordinates is determined to be the pixel improvement value.

  Similarly, referring to FIG. 15, the computing unit 350 determines whether the non-dimming color coordinates CPxb1 of the second pixel data Pxb calculated by the color coordinate calculating unit 330 are located in the determination area 930. As shown in FIG. 15, since the non-dimming color coordinates CPxb1 of the second pixel data Pxb are located in the judgment area 930, the computing unit 350 calculates the first distance DB1 between the color dimming color coordinates CPxb2 and the non-dimming color coordinates CPxb1. Calculate In addition, the calculation unit 350 determines that the first distance DB1 is a pixel distortion value for the second pixel data Pxb.

  The coordinates located in the judgment area 930 have relatively weak color characteristics and correspond to coordinates relatively close to white because the difference between the red tone value, the green tone value, and the blue tone value is relatively small. When color dimming is performed on pixel data having such coordinates, there is a high possibility that distortion of the hue occurs in the image displayed on the display panel 100. Therefore, when the non-dimming color coordinates are located in the determination area 930, the distance between the color dimming color coordinates and the non-dimming color coordinates is determined to be a pixel distortion value.

  The process of determining whether or not color dimming of the first light emitting block corresponding to the first image block is performed (or whether or not color dimming driving is performed) based on the pixel distortion value and the pixel improvement value is as follows.

  Referring to FIGS. 1 to 6 and 16, in the example embodiment, the step S70 adds pixel distortion values, calculates a block distortion value (S71), adds pixel improvement values, and calculates a block improvement value. The method may include determining whether the color dimming of the first light emitting block is possible (or whether or not the color dimming drive is possible) based on the block distortion value and the block improvement value (S73). Here, the steps S71 and S72 may be performed in the reverse order, or both steps may be performed simultaneously.

  The above-described step S70 is performed by the mode determination unit 370.

  FIG. 16 is a table exemplarily showing values acquired for each pixel data Px of the first video block DB1 shown in FIG. 10, and as a result of the determination of the calculation unit 350, the acquired values corresponding to the white region IW in FIG. It is assumed that the acquired value corresponding to the blue region IB is determined to be a pixel improvement value, which is determined to be a distortion value.

  The mode determination unit 370 adds the pixel improvement value and the pixel distortion value to calculate a block improvement value and a block distortion value. For example, if the block improvement value is Ba and the block distortion value is Bd, the mode determination unit 370 calculates the Ba and Bd values. Here, Ba has a value obtained by adding a1 to a52, a54, a55, a57 to a63, a70 to a76, a78, a79, and a81 to a108. Similarly, Bd has a value obtained by adding a53, a56, a64 to a69, a77 and a80.

  Thereafter, the mode determining unit 370 determines whether to perform color dimming of the first light emitting block corresponding to the first image block DB1 in the light source module 200 based on the block distortion value Bd and the block improving value Ba.

  In an exemplary embodiment, if the block distortion value Bd is larger than the block improvement value Ba, the mode determination unit 370 may determine not to perform the color dimming drive on the first light emission block, thereby the mode determination unit 370 may The color dimming signal for the first light emission block generated by the image analysis unit 310 may not be provided to the light source module drive unit 390. Meanwhile, if the image analysis unit 310 further generates a luminance dimming signal, the mode determining unit 370 may provide the light source module driving unit 390 with only the luminance dimming signal for the first light emitting block.

  In an exemplary embodiment, if the block distortion value Bd is less than the block improvement value Ba, the mode determining unit 370 may determine to drive the first light emission block by color, which causes the mode determining unit 370 to generate an image. The color dimming signal for the first light emitting block generated by the analysis unit 310 may be provided to the light source module driving unit 390. Meanwhile, if the image analysis unit 310 further generates a luminance dimming signal, the mode determining unit 370 may provide the light source module driving unit 390 with both the color dimming signal and the luminance dimming signal for the first light emitting block.

  However, the above-described content is one example, and the determination criterion of the mode determination unit 370 can be variously changed. For example, a weight is added to at least one of the block distortion value Bd and the block improvement value Ba to generate a conversion value, and based on the generated conversion value, it is determined whether or not color dimming of the first light emission block is possible. You can also That is, the determination criteria of the mode determination unit 370 can be appropriately changed as needed, and the scope of the present invention is not limited to the above-described embodiment.

  According to the present invention described above, the pixel distortion value and the pixel improvement value are acquired separately for each pixel before performing the color dimming drive, and the possibility of the color dimming drive is determined based on the acquired pixel distortion value and the pixel improvement value. The present invention has the advantage of reducing color distortion that may occur during color dimming drive.

  Further, color reproducibility is improved by reducing color distortion as compared to the case of performing color dimming drive without making a separate determination, in order to determine whether or not color dimming drive is possible by reflecting color information for each pixel. Can be obtained, which has the advantage of improving the display quality of the display.

  Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments, and can be manufactured in various forms different from one another, and the technical field to which the present invention belongs Those skilled in the art will understand that the present invention can be practiced in other specific forms without changing the technical idea or essential features of the present invention. Accordingly, the above embodiments are to be understood in all respects as illustrative and not restrictive.

DESCRIPTION OF SYMBOLS 10 display apparatus 100 display panel 110 timing control part 130 panel drive part 132 data drive part 134 gate drive part DB image block 200 light source module B light emission block 210 unit light emission block 211, 213, 215 1st, 2nd, 3rd light source 300 Light source module control unit 310 Image analysis unit 330 Color coordinate calculation unit 350 Operation unit 370 Mode determination unit 390 Light source module drive unit

Claims (6)

A light source module including a plurality of light emitting blocks;
A display panel that displays a video including a plurality of pixels and divided into a plurality of video blocks corresponding to the light emission block;
A video signal is divided by the video block, a color dimming signal corresponding to a first video block among the video blocks is generated, the first video block is analyzed, and pixel distortion values and pixels corresponding to the respective pixels are analyzed. Based on the pixel distortion value and the pixel improvement value, the improvement value is acquired, and whether or not color dimming of the first light emission block corresponding to the first image block is determined among the light emission blocks is determined, and the first light emission block is driven. A light source module control unit
Only including,
The light source module control unit
A video analysis unit that analyzes the video signal and divides it into the plurality of video blocks, analyzes a first video block among the plurality of video blocks, and generates a color dimming signal;
A color coordinate calculation unit which analyzes the first video block among the video blocks and calculates color dimming color coordinates and non-dimming color coordinates corresponding to each of the pixels in the color coordinate system already determined;
An arithmetic unit that calculates the pixel distortion value and the pixel improvement value based on the color dimming color coordinates and the non-dimming color coordinates;
A mode determining unit configured to determine whether or not color dimming of the first light emitting block is possible based on the pixel distortion value and the pixel improvement value;
A light source module drive unit which drives the light source module for each light emitting block based on the determination of the mode determination unit;
Including
The arithmetic unit is
Determining whether the non-dimming color coordinates are located within a judgment area including reference coordinates already set in the color coordinate system;
As a result of the determination, when the non-dimming color coordinates are located within the determination area, a first distance between the color dimming color coordinates and the non-dimming color coordinates is calculated, and the first distance is determined as the pixel distortion. Judged as a value,
As a result of the determination, when the non-dimming color coordinates are not located within the determination region,
A first distance between the color dimming color coordinates and the non-dimming color coordinates, a second distance between the reference coordinates and the color dimming color coordinates, and a second distance between the reference coordinates and the non-dimming color coordinates 3 Calculate the distance,
If the second distance is greater than or equal to the third distance, the first distance is determined to be the pixel improvement value;
The display apparatus which judges that the said 1st distance is the said pixel distortion value, when the said 2nd distance is less than the said 3rd distance . Each of the light emission blocks is
Contains one or more unit light emission blocks,
The unit light emission block is
The display device according to claim 1, comprising a first light source emitting a first color light, a second light source emitting a second color light, and a third light source emitting a third color light. The previously determined color coordinate system is
The display device according to claim 1 , which is a CIE 1976 color coordinate system. The reference coordinates are
The display device according to any one of claims 1 to 3 , wherein the red tone value, the green tone value, and the blue tone value have the same coordinates. The judgment area is
The absolute value of the difference between the red tone value and the green tone value is less than or equal to the first set value,
The absolute value of the difference between the green tone value and the blue tone value is less than or equal to the second set value,
The display device according to any one of claims 1 to 4, which is a region in which the absolute value of the difference between the blue tone value and the red tone value satisfies a condition equal to or less than a third set value. The mode determination unit
Calculating a block distortion value of the first video block by summing the pixel distortion values;
Calculating the block improvement value of the first video block by summing the pixel improvement values;
The display device according to any one of claims 1 to 5, wherein the dimming drive mode of the first light emitting block is determined based on the block distortion value and the block improvement value.

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