KR101192797B1 - Liquid Crystal Display Device and Method of Driving the same - Google Patents

Abstract

The present invention provides a liquid crystal panel capable of improving luminance by adding a subpixel without a color filter to two subpixels having color filters of different colors, a liquid crystal display including the liquid crystal panel, and a driving method thereof. It is about.

According to an exemplary embodiment of the present invention, a liquid crystal panel includes: a first subpixel having a color filter of a first color; A second subpixel having a color filter of a second color different from the first color; The third subpixel includes no color filter.

With this configuration, in the present invention, since the color filter is not formed in the third subpixel, the light transmittance is increased, the luminance is improved, and the color reproduction range is widened.

4 primary colors, yellow, turquoise

Description

Liquid Crystal Display Device and Method of Driving the same

1 is a perspective view schematically showing a liquid crystal display according to the prior art.

2 is a timing diagram illustrating a method of driving a liquid crystal display according to the related art.

3 is an exploded perspective view schematically illustrating a liquid crystal display device having a field sequential driving method according to the related art.

4 is a timing diagram illustrating a field sequential driving method according to the related art.

5 is an exploded perspective view schematically illustrating a liquid crystal display according to the present invention.

6 is a graph showing the characteristics of the color filter and the light source of the liquid crystal display according to the present invention.

7 is a timing diagram for explaining the driving of the liquid crystal display according to the present invention.

8A to 8C schematically illustrate colors of each subpixel when driving the LCD according to the present invention based on FIGS. 6 and 7.

9 is an exploded perspective view schematically illustrating a liquid crystal display according to a second embodiment of the present invention.

10 is an exploded perspective view schematically illustrating a liquid crystal display according to a third exemplary embodiment of the present invention.

11 is an exploded perspective view schematically illustrating a liquid crystal display according to a fourth embodiment of the present invention.

12 is a color coordinate diagram schematically showing a color reproduction range by the liquid crystal display of the present invention.

13 is a block diagram schematically illustrating a driving unit of the liquid crystal display of the present invention.

14 is a block diagram schematically illustrating a data converter included in a timing controller.

15 is a block diagram schematically illustrating a five-color generating unit according to an embodiment of the present invention.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS FIG.

100: lower substrate 110: gate wiring

120: data wiring 130: thin film transistor

140: pixel electrode 200: upper substrate

210: black matrix 220: color filter layer

230: common electrode 320: backlight unit

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and a driving method thereof having improved luminance and color reproduction range.

Ultra-thin flat panel displays with a thickness of only a few centimeters (cm). Among them, liquid crystal displays have low operating voltages, which consume less power and can be used as portable devices. Applications range from ships to spacecraft to aircraft.

Hereinafter, a conventional liquid crystal display device will be described with reference to the drawings.

1 is a perspective view schematically showing a liquid crystal display according to the prior art.

As shown in FIG. 1, the liquid crystal display device includes a lower substrate 10, an upper substrate 20, and a liquid crystal layer (not shown) formed between the substrates 10 and 20.

Gate lines 11 and data lines 12 are formed on the lower substrate 10 so as to cross each other longitudinally and horizontally to define pixel regions. The thin film transistor 13 is formed as a switching element in an intersection region of the gate line 11 and the data line 12. A pixel electrode 14 is formed to be connected to the thin film transistor 13. The backlight unit 30 for irradiating light to the lower substrate 10 is located on the bottom of the lower substrate 10.

In addition, a light shielding layer 21 is formed on the upper substrate 20 to block light leakage from the gate wiring 11, the data wiring 12, and the thin film transistor 13. The color filter layer 22 is formed between the layers 21 to correspond to the pixel region, and the common electrode 23 is formed on the color filter layer 22.

Red, green, and blue color filters 22a, 22b, and 22c are formed in the color filter layer 22, and color display is possible by transmitting three primary colors of light in the visible region. Let's do it.

In addition, the color filters 22a, 22b, and 22c express colors by forming the size d of each subpixel, that is, the spatial period of the color to have a value equal to or less than the spatial resolution of time.

2 is a timing diagram illustrating a method of driving a liquid crystal display according to the related art.

In order to drive the liquid crystal display, as shown in FIG. 2, the backlight unit is continuously maintained in a lit state, and red, green, and blue image data are simultaneously supplied to the liquid crystal panel in units of frames.

However, such a liquid crystal display has a problem in that luminance is reduced because light transmittance is lowered due to light absorption of the color filter.

In order to solve this problem, a liquid crystal display device driven by a field sequential driving system has been developed.

3 is an exploded perspective view schematically illustrating a liquid crystal display device having a field sequential driving method according to the related art.

As can be seen in FIG. 3, in the field sequential driving type liquid crystal display, the color filter layer is not formed on the upper substrate 20, and the red light source 32R, the green light source 32G, and the blue light source ( 32B).

The liquid crystal display using the field sequential driving method removes the color filter to increase the light transmittance and reproduce the color in time, so that the temporal period T for the color reproduction has a value less than the temporal resolution of time. By forming, the color is expressed.

4 is a timing diagram illustrating a field sequential driving method according to the prior art.

As can be seen in Figure 4, the field sequential driving method according to the prior art separates the entire frame into three frames composed of red, green, and blue to drive each backlight with a time interval.

After the red data is charged in the liquid crystal cell during the data charging time T _d , the red light source 32R is turned on after the response time T _lc of the liquid crystal passes. After red is displayed in this way, green data is written, green light source 32G is turned on, blue data is written, and blue light source 32B is lighted sequentially, and green and blue are displayed.

By dividing the entire frame into three frames consisting of red, green, and blue, and illuminating each backlight with time intervals, the time to turn on the backlight is the data charging time (T _d ) and the liquid crystal response time (T _lc ). It is the time except the sum of the times. Since the backlight emits each color for a time except for the sum of the data charging time T _d and the liquid crystal response time T _lc , the backlight is configured to increase the luminance rather than configuring one frame.

In general, since the LCD has a frame period of 60 Hz, T _t = 16.7 msec.

As the number of frames increases, the time T _{bl for turning} on the backlight decreases, so that it is understood that the effect of increasing the luminance is less than that of the conventional method. Therefore, when driving the liquid crystal display, there is a limit to shortening the data charging time T _d , and when the response time T _lc of the liquid crystal is increased, the time for turning on the backlight T _bl is shortened. There is a problem that the brightness of the decrease.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems,

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal panel capable of improving luminance by adding a subpixel without a color filter to two subpixels having color filters of different colors.

In addition, another object of the present invention is to provide a liquid crystal display device including the liquid crystal panel, having at least two light sources, a wide color reproduction range and a driving method thereof.

In order to achieve the above object, the present invention provides a display device comprising: a first subpixel in which a color filter of a first color is formed; A second subpixel having a color filter of a second color different from the first color; And a third subpixel in which a color filter is not formed.

The present invention is characterized in that the first subpixel and the second subpixel in which color filters of different colors are formed, instead of the subpixels in which the three color filters of red, green, and blue are formed, respectively. And a third subpixel (white subpixel) in which the color filter is not formed constitutes the liquid crystal panel.

When the light emitted from the backlight unit passes through the color filter, its brightness is reduced to one third. Therefore, the brightness is improved due to the white subpixel in which the color filter is not formed.

In this case, the first color filter of the liquid crystal panel may be made of yellow, and the second color filter may be made of cyan.

The yellow color filter transmits red light and green light, and the cyan color filter transmits green light and blue light. Therefore, all colors can be realized through two color filters.

In addition, the first color filter of the liquid crystal panel may be formed of green, and the second color filter may be formed of magenta.

Since the magenta color filter transmits red light and blue light, all colors may be realized through two color filters.

In addition, the present invention, in order to achieve the above object, the above-mentioned liquid crystal panel; A backlight unit for irradiating light onto the liquid crystal panel; And a driving unit for driving the light source of the liquid crystal panel and the backlight unit.

The backlight unit may include at least two light sources.

In this case, the light source may be light yellow and light blue.

The light yellow light includes a component of red light and a component of green light, and the light blue light includes a component of green light and a component of blue light, thereby realizing all colors.

Since one frame is divided into two subframes and the light yellow and light blue light sources are sequentially driven in each subframe, the time for turning on the backlight is increased compared to the conventional field sequential driving method, thereby improving luminance.

In addition, the light source may be formed of red, first green, second green, and blue.

The second green light source is driven together when the red light source is driven, and the first green light source is driven together when the blue light source is driven.

The first green light source may have a longer wavelength of light than the second green light source.

When the red light source and the second green light source whose wavelengths of the light are shorter than the first green light source are turned on together, the light yellow light is turned on. When the blue light source and the first green light source whose wavelength is longer than the second green light source are turned on together, the light blue light is turned on. Becomes

In addition, the light source may be formed of red, green, and blue.

At this time, the red and green light sources are driven in the first subframe, and the green and blue light sources are driven in the second subframe.

That is, light yellow and light blue light are directly driven by using light yellow and light blue light sources, red, first green, second green and blue light sources, or red, green and blue light sources as described above. You can also make

In this case, the driver may include a data driver circuit for supplying a data signal to each of the sub pixels; A gate driving circuit supplying a scan pulse to each of the subpixels; A light source driving circuit for driving a light source according to a light source control signal supplied to each of the subpixels; A data converter for converting three-color source data into five-color data using a gain value; And a timing controller configured to supply data divided into at least two subframes to the data driving circuit and to control the gate driving circuit, the data driving circuit, and the light source driving circuit.

The data converter may include a first gamma correction unit configured to generate three-color input data by performing inverse gamma correction on the three color source data; A four-color conversion unit converting the three-color input data into four-color data; A gain value generation unit generating the gain value according to the four color data; A multiplier for multiplying the four-color data by the gain value to generate four-color amplified data; A five-color generator which extracts a common component of the four-color amplified data into white data and simultaneously generates and outputs five-color output data using the white data; A second gamma converter configured to gamma correct the five color output data to generate the fifth color data; And an output unit for sequentially selecting and outputting some of the five color data according to the subframe.

The five color generator extracts and outputs a common component of the four-color amplified data as white data; And a subtractor configured to generate and output four-color output data by subtracting the extracted white data from each of the four-color amplified data.

The output unit outputs two-color output data of the four-color output data, that is, red and cyan output data and white data in a first subframe, and the remaining two-color output data of the four-color output data, that is, green and blue output data. And white data is output in the second subframe.

In this case, the order of data output from the first subframe and the second subframe may be changed. However, when the red and cyan output data and the white data are output, the light yellow light source should be driven, and the green and blue outputs are output. When the data and the white data are output, the light blue light source must be driven.

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

5 is an exploded perspective view schematically illustrating a liquid crystal display according to the present invention.

As can be seen in FIG. 5, the liquid crystal display according to the present invention includes a lower substrate 100, an upper substrate 200, and a liquid crystal layer (not shown) formed between the substrates 100 and 200. .

The gate line 110 and the data line 120 are formed on the lower substrate 100 to cross each other longitudinally and horizontally to define a pixel area. The thin film transistor 130 is formed as a switching element in an intersection region of the gate line 110 and the data line 120. The pixel electrode 140 is formed and connected to the thin film transistor 130. The backlight unit 320 including light sources 320Y and 320C for irradiating light to the lower substrate 100 is disposed on the rear surface of the lower substrate 100.

In addition, a light blocking layer 210 is formed on the upper substrate 200 to block light leakage from the gate wiring 110, the data wiring 120, and the thin film transistor 130. The color filter layer 220 is formed between the layers 210 to correspond to the pixel region, and the common electrode 230 is formed on the color filter layer 220.

The common electrode 230 may be formed on the upper substrate 200 as described above, but may also be formed on the lower substrate 100.

In this case, a yellow color filter 220Y is formed in the first subpixel SP1 on the left side, and a cyan color filter 220C is formed in the second subpixel SP2 on the right side. In the middle of the third subpixel SP3, the color filter is not formed.

Since the subpixels SP1, SP2, and SP3 are formed such that the size of one subpixel, that is, the spatial period d of the color has a value equal to or less than the spatial resolution of vision, the first subpixel SP1 is formed. Even if the position is changed, such as being formed in the center and the third sub-pixel SP3 is formed on the left side, its function is not affected.

The backlight unit 320 includes a light yellow light source 320Y and a light blue light source 320C.

The yellow light source 320Y and the cyan light source 320C may be formed of a light emitting diode (LED) or a cold cathode tube fluorescent lamp (CCFL).

6 is a graph showing the characteristics of the color filter and the light source of the liquid crystal display according to the present invention.

As can be seen in FIG. 6, the yellow color filter transmits red light (R) and green light (G2) having a long wavelength, and the cyan color filter transmits blue light (B) and green light (G1) having a short wavelength. .

In addition, when the spectrum of the light source is analyzed, the light blue light source is composed of blue light (B) and green light (G2) having a long wavelength, and the light yellow light source is composed of red light (R) and green light (G1) with short wavelength. have.

Therefore, when the light blue light source is irradiated with the liquid crystal panel, green light G2 having a long wavelength is transmitted through the yellow color filter, blue light B is transmitted through the blue color filter, and the light filter is not formed. All incident light is transmitted.

Further, when the light yellow light source is irradiated with the liquid crystal panel, red light R is transmitted through the yellow color filter, and green light G1 having a short wavelength is transmitted through the blue color filter.

7 is a timing diagram for explaining the driving of the liquid crystal display according to the present invention.

As shown in FIG. 7, one frame is divided into two subframes, and in the first subframe, after filling data into the liquid crystal cell for the data charging time T _d , the response time T _lc of the liquid crystal has passed. Next, the light yellow light source 320Y is turned on.

Thereafter, in the second subframe, data is charged into the liquid crystal cell again during the data charging time T _d , and then the light blue light source 320C is turned on after the response time T _lc of the liquid crystal passes.

Since the light source is driven by dividing one frame into two subframes, the driving burden is smaller than that of driving the light source by dividing one frame into three subframes, and the time to turn on the backlight is reduced. The brightness is improved by increasing.

As described above, the present invention introduces the driving method by the conventional color filter and the field sequential driving method together, thereby simplifying the driving of the liquid crystal display and improving the luminance.

8A to 8C schematically illustrate colors of each subpixel when driving the LCD according to the present invention based on FIGS. 6 and 7.

As shown in FIG. 8A, the unit pixel of the liquid crystal display according to the present invention may include a first subpixel SP1 having a yellow color filter, a second subpixel SP2 having a cyan color filter, and no color filter. The third subpixel SP3 is included.

As shown in FIG. 8B, the light yellow light source 320Y is turned on and irradiated to the pixel in the first subframe, so that the first subpixel SP1 transmits only the light R in the red region among the light yellow light.

In addition, the second subpixel SP2 transmits only the light G1 having a short wavelength among the light yellow light, and the third subpixel SP3 has a red light R and a light having a short wavelength. It transmits all (G1).

As shown in FIG. 6, when the light yellow light is composed of red light (R) and green light (G1) having a short wavelength, the yellow color filter includes red light (R) and green light (G2) having a long wavelength. This is because the cyan color filter passes blue light B and short green light G1.

As can be seen in FIG. 8C, after the yellow light source 320Y is turned off, the light blue light source 320C is turned on and irradiated to the pixel in the second subframe, whereby the first subpixel SP1 has a green region having a long wavelength among light blue light. Only light G2 is transmitted.

In addition, the second subpixel SP2 transmits only the light B in the blue region among the light blue light, and the third subpixel SP3 transmits the light B in the blue region and the light G2 in the green region having a long wavelength. Transmit all of them.

Similar to the case where the light yellow light source is turned on, the yellow color filter has red light (R) and green light (G2) having a long wavelength, and the blue color filter has blue light (B) and green light (G1) with short wavelength. This is because light blue light is composed of blue light (B) and green light (G2) having a long wavelength.

In the first subframe, red light (R) and green light (G2) with long wavelengths are transmitted. In the second subframe, blue light (B) and green light (G2) with short wavelengths are transmitted. The desired color can be displayed by transmitting light of red color, green color with long wavelength, green color with short wavelength, and blue color.

9 is an exploded perspective view schematically illustrating a liquid crystal display according to a second exemplary embodiment of the present invention.

9, the liquid crystal display according to the second exemplary embodiment of the present invention is the same as the liquid crystal display according to the first exemplary embodiment except for the color filter layer 220.

A green color filter 220G is formed in the first subpixel SP1 of the liquid crystal display according to the second embodiment of the present invention, and a magenta color filter (Magenta) is formed in the second subpixel SP2. 220M is formed, and the color filter is not formed in the third subpixel SP3.

The magenta color filter 220M transmits red light (R) and blue light (B).

Therefore, when the light blue light source 320C is irradiated with the liquid crystal panel, green light is transmitted through the green color filter 220G, blue light is transmitted through the magenta color filter 220M, and incident light is applied to a portion where the color filter is not formed. All light is transmitted.

When the light yellow light source 320Y is irradiated with the liquid crystal panel, green light is transmitted through the green color filter 220G, and red light is transmitted through the magenta color filter 220M.

Since green light and blue light are transmitted through the first subframe, and green light and red light are transmitted through the second subframe, the desired color can be displayed by transmitting red, green, and blue light for one frame.

10 is an exploded perspective view schematically illustrating a liquid crystal display according to a third exemplary embodiment of the present invention.

As can be seen in FIG. 10, the liquid crystal display according to the third exemplary embodiment of the present invention is the same as the liquid crystal display according to the first exemplary embodiment except for the backlight unit 320.

The backlight unit 320 according to the third embodiment of the present invention includes a red light source 320R, a first green color 320G1, a second green color 320G2, and a blue light source 320B.

The red 320R, first green 320G1, second green 320G2, and blue 320B light sources may include a light emitting diode (LED) or a cold cathode tube fluorescent lamp (CCFL).

In this case, the second green light source 320G2 has a longer wavelength of light than the first green light source 320G1.

As described in the first embodiment, the light yellow light is composed of red light 320R and short green light 320G1, and the light blue light is blue light 320B and the long green light 320G2. Since the four light sources red 320R, the first green 320G1, the second green 320G2, and the blue 320B as described above, the same effects as in the first embodiment can be obtained.

However, in order to obtain light yellow light, the red light source 320R and the first green light source 320G1 must be driven together. To obtain light blue light, the second green light source 320G2 is driven together when the blue light source 320B is driven. Should be.

That is, the light yellow and light blue light sources may be used directly, but the light yellow light may be driven by using the red (320R), the first green (320G1), the second green (320G2), and the blue light source (320B) as described above. And light blue light.

11 is an exploded perspective view schematically illustrating a liquid crystal display according to a fourth embodiment of the present invention.

As can be seen in FIG. 11, the liquid crystal display according to the fourth embodiment of the present invention is the same as the liquid crystal display according to the first embodiment except for the backlight unit 320.

The backlight unit 320 according to the fourth embodiment of the present invention includes a red light source 320R, a green light 320G, and a blue light 320B.

The red 320R, green 320G, and blue 320B light sources may include a light emitting diode (LED) or a cold cathode fluorescent lamp (CCFL).

In the first subframe, the red light source 320R and the green light source 320G are driven together, and in the second subframe, the green light source 320G and the blue light source 320B are driven together.

That is, the green light source 320G maintains a lighting state in both the first subframe and the second subframe.

The green light source 320G preferably uses a light source including both the spectra of the first green light source and the second green light source of the third embodiment.

Although the green light source 320G includes both the spectra of the first green light source and the second green light source, the yellow color filter 220Y and the cyan color filter 220C selectively transmit the first green light and the second green light. Since the light yellow and light blue light sources are used, almost similar effects can be obtained.

Accordingly, the liquid crystal display device according to the present invention is a liquid crystal display device by taking advantage of the conventional two methods by forming a color filter to separate the color spatially, and driving the light source sequentially to separate the color in time.

12 is a color coordinate diagram schematically showing a color reproduction range by the liquid crystal display of the present invention.

As can be seen in Figure 12, the liquid crystal display device according to the prior art has a triangular color reproduction range by using three primary colors of light. On the other hand, according to the present invention, by using the four primary colors of red, green with a long wavelength, green with a short wavelength, and blue, the color reproduction range forms a rectangle.

As the area of the rectangle is larger than the area of the triangle, it can be seen that the color reproduction range of the liquid crystal display according to the present invention is wider than that of the prior art.

Hereinafter, the driving of the liquid crystal display according to the exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

13 is a block diagram schematically illustrating a driving unit of the liquid crystal display of the present invention.

As shown in FIG. 13, the driving unit of the liquid crystal display according to the exemplary embodiment of the present invention includes a liquid crystal panel 105 having n gate lines G1 to Gn and m data lines D1 to Dm, and n units. A gate driving circuit 115 for supplying a scan pulse to the gate lines G1 to Gn, a data driving circuit 125 for supplying a video data signal to the m data lines D1 to Dm, and driving a light source A light source driving circuit 325 for generating a gate control signal GCS and a data converter 405 for converting three-color source data into five-color data using the gain value and supplying the five-color data to the timing controller 400. Timing for controlling the driving circuit 115, generating a data control signal DCS to control the data driving circuit 125, and simultaneously generating a light source control signal LCS to control the light source driving circuit 325. Including the controller 400 Eojinda.

In the liquid crystal panel 105, a thin film transistor TFT is formed at an intersection area of the n gate lines G1 to Gn and the m data lines D1 to Dm.

The thin film transistor TFT supplies a data signal from the data lines D1 to Dm to the liquid crystal cell in response to a scan pulse from the gate lines G1 to Gn. The liquid crystal cell is composed of a common electrode facing each other with a liquid crystal interposed therebetween and a pixel electrode connected to the thin film transistor TFT, and thus may be equivalently represented as a liquid crystal capacitor Clc.

The liquid crystal cell includes a storage capacitor Cst to maintain the data signal charged in the liquid crystal capacitor Clc until the next data signal is charged.

The gate driving circuit 115 includes a shift register that sequentially generates scan pulses, that is, gate high pulses, in response to the gate control signal GCS from the timing controller 400. In response to this scan pulse, the thin film transistor is turned on.

The data driving circuit 125 converts the three-color data arranged from the timing controller 400 into a video data signal, which is an analog signal, according to the data control signal DCS supplied from the timing controller 400, and thus the gate wiring G1. To Gn), a video data signal for one horizontal line is supplied to the data lines D1 to Dm every one horizontal period to which the scan pulse is supplied.

The data converter 405 converts three-color source data RGB input from the outside into five-color data RCGBW, and then selects some of the five-color data according to subframes, and sequentially performs the timing controller 400. To feed.

The timing controller 400 uses the main clock MCLK, the data enable signal DE, and the horizontal and vertical synchronization signals Hsync and Vsync, which are input from the outside, to the data control signal DCS and the gate control signal GCS. And generating a light source control signal LCS to control each of the gate driving circuit 115, the data driving circuit 125, and the light source driving circuit 325, and subframes the five-color data received from the data converter 405. As a result, the data driving circuit 125 is sequentially supplied to the data driving circuit 125.

14 is a block diagram schematically illustrating a data converter.

As can be seen in FIG. 14, the data converter 405 includes a first gamma converter 410, a four-color converter 420, a gain value generator 430, a multiplier 440, and a five-color generator ( 450, a second gamma converter 460, and an output unit 470.

The first gamma converter 410 converts externally input three-color source data RGB into linearized three-color input data RI, GI, and BI.

Since the three-color source data RGB input from the outside is a gamma correction signal considering the output characteristics of the cathode ray tube, it should be linearized using Equation 1 below.

The four-color conversion unit 420 converts the three-color input data (RI, GI, BI) into four-color input data (rI, cI, gI, bI), that is, red (r), cyan (c) and green (g). ), Blue (b) is converted into input data.

The cyan input data cI is generated by the ratio of the green and blue input data gI, bI.

Since the liquid crystal display according to the present invention reproduces different colors in four colors using two color filters and two light sources, a four color conversion unit 420 is required.

The gain value generator 430 uses the maximum luminance value Ymax and the minimum luminance value Ymin of the four-color input data rI, cI, gI, and bI converted by the four color converter 420. Generate a gain value (G). In order to extract the maximum luminance value Ymax and the minimum luminance value Ymin of the converted four-color input data rI, cI, gI, and bI, a vertical synchronization signal Vsync or / and a data enable signal DE Use The gain value usually has a value between 1 and 2. In the method of generating the gain value G by the gain value generator 430, a known technique of compensating for the color temperature and adjusting the gain value to linearly convert the luminance of the data may be applied. . For example, the gain value generator 430 is disclosed in Korean Patent Laid-Open Publication No. 10-2004-0110014 (December 29, 2004), Korean Patent Publication No. 10-2006-0004426 (January 12, 2006) Gains disclosed in Japanese Patent Application Laid-Open No. 10-2005-0100530 (October 19, 2005), Korean Patent Publication No. 10-2005-0100209 (October 18, 2005), and Japanese Patent Publication No. 10-2005-0059521 (June 21, 2005). The gain value G may be generated using a value adjustment method.

The multiplier 440 converts the gain value G from the gain value generator 430 into four-color input data rI, cI, gI, and bI from the four-color converter 420 as shown in Equation 2 below. ), Multi-color amplification data rA, cA, gA, and bA are generated and supplied to the five-color generating unit 450.

15 is a block diagram schematically illustrating a five-color generating unit according to an embodiment of the present invention.

As can be seen in Figure 15, the five-color generation unit 450 according to an embodiment of the present invention is white data for extracting the common component of the four color amplification data (rA, cA, gA, bA) as white data (w) Extraction unit 451; And a subtraction unit configured to subtract the extracted white data w from each of the four color amplification data rA, cA, gA, and bA to generate and output four color output data (ro, co, go, bo).

The white data extractor 451 extracts a common component from the multi-color amplification data rA, cA, gA, and bA from the multiplier 440 as white data w according to Equation 3 below. To 452.

As can be seen from Equation 3, the white data extraction unit 451 extracts the minimum value from the four-color amplification data rA, cA, gA, and bA as a common component, and subtracts the extracted component as white data (w). It supplies to the part 451.

If four-color data amplifier (rA, cA, gA, bA ) are both greater than 2 ^n, the extract is 2 ⁿ by the common component. Where n represents the number of bits, which is 255 for 8-bit data. In the case of 8 bits, since the gray scale cannot exceed 255, if the four-color amplified data (rA, cA, gA, bA) multiplied by the gain value exceeds 255, the maximum gray scale 255 is extracted as a common component.

The subtractor 453 subtracts the white data w from the white data extractor 451 from the four-color amplified data rA, cA, gA, and bA from the multiplier 440 to output the four-color output data ( ro, co, go, bo).

Therefore, the subtractor 453 outputs five colors so as to realize accurate colors in the subpixels by subtracting the white data w respectively contributing to the luminance of the four primary colors from the four color amplification data rA, cA, gA, and bA. The data is generated and output.

The gamma converter 460 includes five color output data (ro, co, go, and the like) including four color output data (rA, cA, gA, bA) and white data (w) from the five color generator 450. bo, w) is supplied, and gamma corrected according to Equation 4 below to convert into five final output data.

The output unit 470 uses a vertical sync signal Vsync and / or a data enable signal DE to generate red, gamma corrected red color data among the five color final output data Ro, Co, Go, Bo, and W. The cyan and white data Ro, Co, and W are output in the first subframe, and the green, blue, and white data of the five color final output data Ro, Co, Go, Bo, and W are gamma-corrected. Bo, W) is output in the second subframe.

The order of the signals output from the first subframe and the second subframe may be changed. However, when the red, cyan and white data (Ro, Co, W) are output, the light source driving circuit must be driven to light up the light yellow light source. When the green, blue, and white data (Go, Bo, W) is output, the light source driving circuit must be driven so that the light blue light source is turned on.

According to the present invention having the above-described configuration, since the color filter is not formed in the third subpixel, the light absorption by the color filter is reduced, so that the light transmittance is increased and the luminance is improved.

In addition, when light yellow and light blue light are sequentially irradiated to subpixels having yellow and cyan color filters, the color reproduction range is widened by using four primary colors of light.

In the conventional field sequential driving method, the time to turn on the backlight by shortening one frame into three subframes is short. However, in the present invention, the time to turn on the backlight is long because the backlight is turned on by dividing into two subframes. The brightness is improved compared with the prior art. In addition, since one frame is driven by dividing into two subframes, the burden on driving is less than that of the conventional method of dividing and driving one frame into three subframes.

Claims (22)

A liquid crystal panel including a first subpixel having a color filter of a first color, a second subpixel having a color filter of a second color different from the first color, and a third subpixel having no color filter; ; A backlight unit for irradiating light onto the liquid crystal panel; A driving unit for driving a light source of the liquid crystal panel and the backlight unit; The driving unit A data driver circuit for supplying a data signal to each of the sub pixels; A gate driving circuit which supplies a scan pulse to each of the sub pixels; A light source driving circuit for driving a light source according to a light source control signal supplied to each of the subpixels; A data converter for converting three-color source data into five-color data and selecting and outputting some of the five-color data; And a timing controller for dividing the five-color data provided from the data converter into two subframes and supplying the data to the data driving circuit and controlling the gate driving circuit, the data driving circuit and the light source driving circuit. A liquid crystal display device. The method of claim 1, The first color is yellow, And the second color is cyan. The method of claim 1, The first color is green, The second color is magenta (Magenta) characterized in that the liquid crystal display. delete The method of claim 1, The backlight unit, A liquid crystal display comprising at least two light sources. The method of claim 5, And the light source is light yellow and light blue. The method of claim 5, And the light source is red, first green, second green and blue. The method of claim 7, wherein The first green light source has a longer wavelength than the second green light source. The method of claim 5, And the light source is red, green, or blue. delete The method of claim 1, The data conversion unit A first gamma correction unit generating inverse gamma correction of the three color source data to generate three color input data; A four-color conversion unit converting the three-color input data into four-color data; A gain value generation unit generating a gain value according to the four colors of data; A multiplier for multiplying the four-color data by the gain value to generate four-color amplified data; A five-color generator which extracts a common component of the four-color amplified data into white data and simultaneously generates and outputs five-color output data using the white data; A second gamma converter configured to gamma correct the five color output data to generate the five color data; And And an output unit configured to sequentially select and output some of the five color data according to the subframe. 12. The method of claim 11, Four-color data converted by the four-color conversion unit Liquid crystal display, characterized in that the red, cyan, green and blue data. 12. The method of claim 11, The five color generator A white data extracting unit extracting and outputting common components of the four-color amplified data as white data; And And a subtractor configured to generate and output four-color output data by subtracting the extracted white data from each of the four-color amplified data. 14. The method of claim 13, The four-color output data output from the five color generator is And a red, cyan, green and blue output data. The method of claim 14, The output unit outputs red, cyan output data and white data among the four color output data in the first subframe, and outputs green, blue output data and white data, which are the remaining two colors of the four color output data, in the second subframe. Liquid crystal display characterized in that. The method of claim 14, The output unit outputs green, blue output data and white data among the four color output data in the first subframe, and outputs red and cyan output data and white data, which are the remaining two colors of the four color output data, in the second subframe. Liquid crystal display characterized in that. Dividing a frame into two subframes; Converting three-color source data from the outside into five-color data; Selecting a part of the five color data according to the subframe and sequentially supplying some of the five color data to a liquid crystal panel; And irradiating light to the liquid crystal panel by driving a backlight having at least two light sources according to the subframe. 18. The method of claim 17, Converting three-color source data from the outside into five-color data Inverse gamma correction of the three color source data to generate three color input data; Converting the three-color input data into four-color data; Generating a gain value according to the four color data; Generating four-color amplified data by multiplying the four-color data by the gain value; Extracting common components of the four-color amplified data into white data and simultaneously generating and outputting five-color output data using the white data; And And gamma correcting the five color output data to generate the five color data. 19. The method of claim 18, The four colors of data A method of driving a liquid crystal display device, characterized in that the data is red, cyan, green and blue. 19. The method of claim 18, Generating and outputting the five color output data Extracting and outputting a common component of the four-color amplified data as white data; And And generating and outputting four-color output data by subtracting the extracted white data from each of the four-color amplified data. 18. The method of claim 17, Selecting part of the five color data according to the subframe and sequentially supplying to the liquid crystal panel Supplying red, cyan and white data to the first subframe; And And supplying green, blue, and white data to the second sub frame. 22. The method of claim 21, And driving a light yellow light source to the first subframe and a light blue light source to the second subframe.

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