KR100707028B1 - LCD Display - Google Patents

Abstract

The present invention relates to a liquid crystal display that improves brightness and contrast ratio by expressing colors by using complementary color relationships between RGBCMY 6 colors and by configuring and controlling a light source for each pixel. The apparatus comprises a liquid crystal panel comprising R, G, B, C, M, and Y pixels and comprising a plurality of subpixels driven by a pair of gate lines; A plurality of light sources respectively positioned under the plurality of subpixels; And a plurality of light source controllers respectively determining luminances of the plurality of light sources, wherein pixels of complementary colors among R, G, B, C, M, and Y pixels on the subpixels are connected to the same data line, The R, G, and B pixels are connected to a first gate line, and the C, M, and Y pixels are connected to a second gate line.

Description

Liquid crystal display

1 is a view showing a color reproduction range of an RGB three-color liquid crystal display device.

2 is a view showing a color reproduction range of the RGBCMY 6-color liquid crystal display according to the prior art.

3 is a conceptual diagram of a liquid crystal display according to the present invention.

4 is a conceptual diagram of a subpixel according to the present invention;

5 is a cross-sectional view of a liquid crystal display device according to the present invention.

6 is a timing diagram of signals used in the liquid crystal panel according to the present invention;

7 is a view showing a relationship between expression colors according to the present invention.

8 is a waveform diagram of a signal according to a charging voltage value of a subpixel.

9 and 10 are diagrams showing magnitudes of color signals of respective pixels.

11 and 12 are diagrams illustrating brightness expression using a light source.

Explanation of symbols on the main parts of the drawings

200: liquid crystal panel 210: subpixel

211: R (Red) pixel 212: G (Green) pixel

213: B (Blue) pixel 214: C (Cyan) pixel

215: M (Magenta) pixel 216: Y (Yellow) pixel

217: light source

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device capable of improving color reproducibility and maintaining luminance characteristics by using a color filter of RGBCMY.

In general, a liquid crystal display device uses a color filter of R (Red), G (Green), and B (Blue), and uses an RGB three-color system that expresses color by a combination thereof. The conventional liquid crystal display device using the RGB three-color system has a limitation of color reproduction, that is, color reproduction.

1 shows a color reproduction range of an RGB three-color liquid crystal display device.

As shown, the color reproduction range 10 of the liquid crystal display device using the RGB three-color system has a color reproduction range of about 70% based on the color reproduction range 11 of the NTSC (National Television System) system. Have CIE 12 here represents an international standard for color specifications. In order to overcome the limitation of the color reproduction of the RGB three-color method, conventionally, color filters of red, green, blue, cyan, magenta, and yellow are used to increase the color reproduction range than the RGB three-color method. RGBCMY 6-color method is proposed to express colors by the combination.

2 shows a color reproduction range of the RGBCMY 6-color liquid crystal display according to the prior art.

As shown, the color reproduction range 13 of the liquid crystal display device using the RGBCMY 6-color system has a color reproduction range of hexagonal color, so that the color reproduction range substantially matches the color reproduction range 11 of the NTSC system. Have Conventional liquid crystal display devices using the RGBCMY 6-color system need a rendering system that converts signals in order to generate CMY color data in addition to RGB colors. Referring to US Patent Publication No. 6570584 B1, in order to implement RGBCMY 6 colors, the liquid crystal display is provided with a color conversion unit (color transformation) separately, and receives normal RGB color data to calculate and convert the 6 colors It can be seen that it is implemented. However, in order to implement a rendering system such as the color conversion unit, an additional cost is generated in the configuration of the liquid crystal display.

In the related art, the brightness of the liquid crystal display is expressed by operating the light source at the same luminance on the back of the transmissive liquid crystal display and controlling the light transmittance only by the operation of the liquid crystal. However, such a method has a problem in implementing a high-quality liquid crystal display because the contrast ratio is lowered because the control of the liquid crystal is not perfect when expressing a color that must completely block light such as normally black.

Accordingly, the present invention was created to solve the problems inherent in the prior art as described above, and an object of the present invention is to express colors using complementary color relations between RGBCMY 6 colors and to configure a light source for each pixel. The present invention provides a liquid crystal display that can improve the brightness and contrast ratio by controlling this.

In order to achieve the above object, according to an aspect of the present invention, a liquid crystal display device is provided: a plurality of subpixels including R, G, B, C, M, and Y pixels and driven by a pair of gate lines; A liquid crystal panel comprising; A plurality of light sources respectively positioned under the plurality of subpixels; And a plurality of light source controllers respectively determining luminances of the plurality of light sources, wherein pixels of complementary colors among R, G, B, C, M, and Y pixels on the subpixels are connected to the same data line, The R, G, and B pixels are connected to the first gate line, and the C, M, and Y pixels are connected to the second gate line.

According to another aspect of the invention, the subpixels are driven once the data line is driven. The first and second gate lines are sequentially driven.

According to another aspect of the present invention, the light source controller drives the light source to have a luminance proportional to the sum of pixel data input to the R, G, and B pixels of the subpixel.

(Example)

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a conceptual diagram of a liquid crystal display according to the present invention.

In the liquid crystal display according to the present invention, R (211), G (212), B (213), C (214), M (215), and Y pixel (216) are defined as one subpixel (210). The liquid crystal panel 200 includes a plurality of subpixels 210, and an individual light source 217 disposed under each subpixel 210. In the present exemplary embodiment, a white organic light emitting diode OLED is used as the light source 217, and the luminance of each subpixel 210 is adjusted using the OLED.

4 shows a conceptual diagram of a subpixel according to the present invention.

The subpixel according to the present invention includes the thin film transistor 218 in each of the R 211, the G 212, the B 213, the C 214, the M 215, and the Y pixel 216. Here, the consecutively arranged R 211, G 212, and B pixels 213 are connected to the first gate line 219, and C 214, M 215, and Y pixels 216. Is connected to the second gate line 220, and the on / off driving of the thin film transistor 218 included in each pixel is performed, and the subpixel having six colors by the data signal transmitted to the data line 221. Adjust the transmittance of

5 is a cross-sectional view of a liquid crystal display device according to the present invention.

As described above, the liquid crystal display according to the present invention includes a plurality of R (211), G (212), B (213), C (214), M (215), and Y pixels 216, respectively A liquid crystal panel 200 including subpixels, a light source 217 provided in each of the plurality of subpixels, and a light source controller 222 for adjusting the luminance of the light source 217 is provided. The light source controller 222 converts the luminance data of the R 211, the G 212, and the B 213 to determine the luminance of the white organic light emitting element, and has the luminance determined by the light source controller 222. Light emitted from the light source 217 passes through the liquid crystal panel 200 to display an image.

Hereinafter, the operation of the liquid crystal display according to the present invention will be described with reference to FIGS. 6 to 12.

6 shows a timing diagram of signals used in the liquid crystal panel according to the present invention.

In the subpixel according to the present invention, R is sequentially arranged by applying a first gate signal gate 0 to the first gate line 219 and a second gate signal gate 1 to the second gate line 220 in this order. The thin film transistors 218 provided in the C (214), the M (215), and the Y pixel (216) arranged in series with the (211), G (212), and B pixels 213 are sequentially driven. In addition, the data signal data uses the data used for the conventional RGB three-color system as it is. Therefore, the liquid crystal display device according to the present invention does not generate separate data applied to the C 214, the M 215, and the Y pixel 216, and R 211, G 212, and The data applied to the B pixel 213 is shared and used. Thus, there is no need for an additional device for converting RGB signals to CMY signals. In addition, the common voltage vcom has a frequency twice as large as that of the data signal data, so that when the data signal data is input once, successively arranged R 211, G 212, and B ( 213 The C (214), M (215), and Y (216) pixels which are arranged in series with each other are driven to represent colors.

The subpixels according to the present invention arrange R, 211, G 212, and B by arranging pixels of complementary colors (Red-Cyan, Green-Magenta, Blue-Yellow) on one data line 221, respectively. C (Cyan), M (Magenta), and Y (Yellow) can be expressed using the pixel 213, and R (using C (214), M 215, and Y pixel 216) can be expressed. Expressions of Red), G (Green), and B (Blue) are also possible. Figure 7 shows the relationship between the representation colors according to the present invention. As shown in the figure, the larger the portion occupied by C (Cyan), the smaller the specific gravity of R (RED). In addition, the relationship between R (RED) and C (Cyan) as described above is similarly established in the relationship of "G (Green) -M (Magenta)" and "B (Blue) -Y (Yellow)". Referring to FIG. 8, the charging voltage value of the subpixel according to the relational expression has one period during the half period of the data signal data. At this time, if the size of "A" is determined, the size of "B" is determined in inverse proportion to the size. The same applies to the next half period of the data signal data, so that when the size of "A '" is determined, the size of "B'" is determined in inverse proportion to the size. That is, as shown in FIG. 9, when color signals are given in magnitudes of 0.6 for the R pixel 211, 1.0 for the G pixel 212, and 0.2 for the B pixel 213, respectively, they have a complementary color relationship with them. It can be seen that the relationship between the expression colors shown in FIG. 7 is satisfied by automatically converting signals of magnitudes 0.4 for the C pixel 214, 0 for the M pixel 215, and 0.8 for the Y pixel 216. have.

Next, looking at the brightness expression using the light source 217 in the sub-pixel unit, as shown in FIG. 10, the magnitudes of the color signals input to the R 211, the G 212, and the B pixel 213 are all zero. In the black or black state, R (211), G (212), and B pixel 213 and C (214), M (215), and Y pixel (216) are all gray with the same saturation and hue. (gray), but in terms of brightness, R 211, G 212, and B pixels 213 represent black, and C 214, M 215, and Y pixels 216 are white. Will be represented. Therefore, as for the color expressed by six colors, white rather than black appears. At this time, by controlling the luminance of the light source 217 in the sub-pixel unit, it is possible to express the correct color by adjusting the brightness. Referring to FIG. 11, the luminance of the white organic light emitting element used as the light source 217 is determined by adding only the magnitudes of the color signals input to the R 211, the G 212, and the B pixel 213. In other words, as can be seen from FIG. 12, when the magnitudes of the color signals input to the R 211, the G 212, and the B pixel 213 are all "0" values, that is, black, the light source 217 is turned on. The luminance also becomes "0". Therefore, the final color represents black. In addition, although the white organic light emitting diode is used as the light source 217 in the embodiment of the present invention, it may be replaced with another light source such as an LED.

As we have seen above. The liquid crystal display device according to the present invention using the RGBCMY 6-color system has a color reproduction range that substantially matches that of the NTSC system by having a hexagonal color reproduction range. In addition, by making the light source 217 into a non-current state, that is, a state where the luminance is "0", the contrast ratio is significantly reduced compared to the conventional method of blocking light only by driving the liquid crystal when implementing black. Can be raised. In addition, since six colors can be implemented using only the RGB signal, a rendering system for generating CMY color data is unnecessary. Therefore, the cost according to the configuration of the rendering system can be reduced.

According to the configuration as described above of the present invention, by using the complementary color relationship between the RGBCMY 6 colors to each other, the brightness and contrast ratio can be improved by configuring and controlling the light source for each pixel.

While the invention has been shown and described with reference to certain preferred embodiments, the invention is not so limited, and the invention is not limited to the spirit and scope of the invention as set forth in the following claims. It will be readily apparent to those skilled in the art that these various modifications and variations can be made.

Claims (3)

In the liquid crystal display device, Liquid crystals containing a plurality of subpixels including R (Red), G (Green), B (Blue), C (Cyan), M (Magenta), and Y (Yellow) pixels and driven by a pair of gate lines panel; A plurality of light sources respectively positioned under the plurality of subpixels; And And a plurality of light source controllers for determining luminance of the plurality of light sources, respectively. Complementary color pixels among the R, G, B, C, M, and Y pixels on the subpixel are connected to the same data line, and the R, G, and B pixels are connected to the first gate line, and C, M and And the Y pixel is connected to the second gate line. The method of claim 1, The subpixel is, When the data line is driven once. And the first and second gate lines are sequentially driven. The method of claim 1, The light source control unit, And driving the light source to have a luminance proportional to the sum of the pixel data input to the R, G, and B pixels of the sub-pixel.

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