CN101256311B - LCD Monitor - Google Patents

Abstract

A liquid crystal display comprises a backlight module and a liquid crystal display panel. The backlight module is provided with at least one white light source, and the light-emitting spectrum of the backlight module has relatively maximum brightness peak values respectively between the wavelength of 430 nanometers and 470 nanometers and between the wavelength of 520 nanometers and 620 nanometers. The liquid crystal display panel is arranged above the backlight module and comprises two substrates and a liquid crystal layer positioned between the two substrates, wherein one of the two substrates is provided with a red filter layer, a green filter layer and a blue filter layer, the x coordinate value and the y coordinate value of the red filter layer on a CIE 1931 color coordinate are Rx and Ry respectively under a CIE standard light source C, wherein Rx is more than or equal to 0.65, and Ry is less than or equal to 0.32. The invention can improve the red saturation of the liquid crystal display and improve the phenomenon that the red of a display picture shows a orange color.

Description

LCD Monitor

technical field

The present invention relates to a display, and in particular to a liquid crystal display.

Background technique

Liquid Crystal Display (LCD), which has superior characteristics such as high image quality, good space utilization efficiency, low power consumption, and no radiation, has gradually become the mainstream of displays. With the popularization of liquid crystal displays, an important indicator for consumers when purchasing liquid crystal displays is high color reproduction (color reproduction). Several high color reproducibility technologies exist to meet consumer demand for high color reproducibility.

The liquid crystal display is mainly composed of a liquid crystal display panel and a backlight module that provides a light source for the liquid crystal display panel. The liquid crystal display panel includes, for example, an active element array substrate, a color filter substrate, and a liquid crystal layer, wherein the color filter substrate has a red filter layer, a green filter layer and a blue filter layer. Generally speaking, the light source in the backlight module can be a cold-cathode fluorescent lamp (Cold-Cathode Fluorescent Lamp, CCFL), a light-emitting diode or other types of light sources.

For the color performance of LCD monitors, the color saturation of the monitor is usually measured by the standards set by the National Television System Committee (NTSC). On the other hand, those with ordinary knowledge in the art usually use the sRGB or EBU specification as a reference for color adjustment when adjusting the red saturation, green saturation, and blue saturation of a liquid crystal display. According to the sRGB specification, red coordinates, green coordinates, and blue coordinates are expressed in CIE1931 as red specification (Rx, Ry) = (0.640, 0.330), green specification (Gx, Gy) = (0.300, 0.600) and blue specification (Bx, By) = (0.150, 0.060).

In the development of high-color technology, the type of backlight module plays an important role. Currently, the type of white light emitting diode (Light Emitting Diode, LED) is the most popular. White light emitting diodes have been widely used in portable backlight modules due to their advantages of power saving, fast response, small size, long life, simple structure, and non-toxicity. Among the backlight modules of white light emitting diodes widely used in the market at present, one of them is a combination of blue light emitting diodes and yellow phosphor to form white light.

FIG. 1 is a schematic diagram of a known CIE1931 chromaticity coordinate using a liquid crystal display. Please refer to FIG. 1, the white light provided by the backlight module in the liquid crystal display 10 is composed of a combination of blue light-emitting diodes and yellow phosphor powder. As shown in FIG. There is still a gap in the red coordinate, so the above-mentioned light source composed of blue light-emitting diodes and yellow phosphors has the disadvantage of poor color rendering. More specifically, the red color of the liquid crystal display 10 tends to be orange, which causes the red saturation of the liquid crystal display 10 to be unsatisfactory, thereby affecting the overall display color performance of the liquid crystal display 10 .

Contents of the invention

The invention provides a liquid crystal display, which can improve the red saturation and improve the disadvantage that the red color of the display screen is more orange.

The invention provides a liquid crystal display, which includes a backlight module and a liquid crystal display panel. Wherein, the backlight module has at least one white light source, and the emission spectrum of the backlight module has relatively maximum brightness peaks between wavelengths of 430 nm to 470 nm and wavelengths of 520 nm to 620 nm. The liquid crystal display panel is arranged above the backlight module, and the liquid crystal display panel includes two substrates and a liquid crystal layer located between the substrates, one of the two substrates has a red filter layer, a green filter layer and a blue filter layer, The red filter layer is under CIE standard light source C, and the x-coordinate and y-coordinate values on the CIE 1931 color coordinates are Rx and Ry respectively, where Rx≥0.65 and Ry≤0.32.

In one embodiment of the present invention, the white light source is a light emitting diode. In one embodiment, the light emitting diode includes a blue light diode and phosphor material on the inner wall of the blue light diode.

In one embodiment of the present invention, the transmittance of the red filter layer in the yellow light band is substantially less than or equal to 40%. In one embodiment, the wavelength of the yellow light band is between 585 nm and 605 nm. In another embodiment, the yellow light band is, for example, 595 nm.

In one embodiment of the present invention, the transmittance of the red filter layer in the yellow light band is substantially greater than or equal to 30%.

In one embodiment of the present invention, the backlight module is, for example, a direct-lit backlight module or a side-lit backlight module.

In an embodiment of the present invention, the composition of the red filter layer includes, for example, three pigments of PR254, PR177 and PY150.

In one embodiment of the present invention, the liquid crystal display is suitable for displaying a red picture, and the y-coordinate value of the chromaticity of the red picture on the CIE 1931 color coordinate is Ry', wherein Ry'≤0.335.

In summary, in the liquid crystal display of the present invention, by controlling the relative maximum brightness peak distribution in the luminous spectrum of the backlight module, and then matching it with a color filter layer that satisfies a specific relationship on the CIE chromaticity coordinates, the liquid crystal display can be improved. Improve the red saturation of the display screen, and improve the phenomenon that the red color of the display screen is more orange.

In order to make the above and other objects, features and advantages of the present invention more comprehensible, preferred embodiments are specifically cited below and described in detail with accompanying drawings.

Description of drawings

FIG. 1 is a schematic diagram of a known CIE1931 chromaticity coordinate using a liquid crystal display.

FIG. 2 is a schematic diagram of a liquid crystal display according to an embodiment of the present invention.

FIG. 3 shows the emission spectrum of the backlight module of the liquid crystal display and the transmittance spectrum performance of the red filter layer in one embodiment of the present invention.

Fig. 4 is a comparison chart of CIE 1931 chromaticity coordinates of a liquid crystal display of the present invention and a known liquid crystal display.

Wherein, the reference signs are explained as follows:

10, 100: LCD display

110: Backlight module

120: LCD display panel

112: white light source

122: Color filter substrate

122R: Red filter layer

122G: Green filter layer

122B: blue filter layer

124: Thin film transistor array substrate

126: liquid crystal layer

A, B, C: Spectrum

Rx: the x-axis chromaticity coordinate value of the red filter layer

Ry: the x-axis chromaticity coordinate value of the green filter layer

Rx': the x-axis chromaticity coordinate value of the liquid crystal display

Ry': the y-axis chromaticity coordinate value of the green filter layer

P1: Maximum brightness peak between wavelengths 430 nm to 470 nm in the luminescence spectrum

P2: Maximum brightness peak between wavelengths 520nm and 620nm in the emission spectrum

Detailed ways

FIG. 2 is a schematic diagram of a liquid crystal display according to an embodiment of the present invention. Referring to FIG. 2 , the liquid crystal display 100 includes a backlight module 110 and a liquid crystal display panel 120 , wherein the backlight module 110 is, for example, a direct-lit backlight module or a side-lit backlight module. The backlight module 110 has at least one white light source 112, wherein the light emitted by the white light source 112 is suitable for providing the liquid crystal display panel 120, and in this embodiment, the white light source 112 is an example of a light emitting diode that can provide white light.

Please continue to refer to FIG. 2 , the liquid crystal display panel 120 is disposed above the backlight module 110 . The liquid crystal display panel 120 is mainly composed of two substrates and a liquid crystal layer 126 between the two substrates. As shown in Figure 2, the aforementioned two substrates can be a thin film transistor array substrate 124 and a color filter substrate 122 respectively, wherein the color filter substrate 122 has a red filter layer 122R, a green filter layer 122G and a blue filter layer 122B . Of course, in other embodiments, the aforementioned two substrates may also be a color filter layer on a matrix substrate (color filter on array; COA) substrate and an opposite substrate with a common electrode, or a matrix layer on a color filter on array substrate respectively. An array on color filter (AOC) substrate and an opposite substrate with a common electrode.

FIG. 3 is a schematic diagram showing the emission spectrum of the backlight module of the liquid crystal display and the transmittance spectrum of the red filter layer thereof in an embodiment of the present invention. Please refer to FIG. 3. Spectrum A is the emission spectrum of the backlight module 110, which has relatively maximum brightness peaks between the wavelengths of 430 nm to 470 nm and the wavelengths of 520 nm to 620 nm, such as P1 and P1 of the spectrum A in the figure. P2. Specifically, the inner wall of the white light source 112 has a variety of phosphor materials for adjusting the optical properties such as brightness and chromaticity of the white light source. Appropriate phosphor material, such as yellow phosphor.

It is worth noting that the red color filter layer 122R with proper color performance can be effectively improved when the backlight module 110 with the above-mentioned emission spectrum is combined with the poor red performance of the known liquid crystal display 10 . Specifically, when the red filter layer 122R of this embodiment is measured using the standard illuminant (C light source) stipulated by the International Commission on Illumination CIE, the red filter layer 122R will satisfy the following relationship: Rx≥0.65, and Ry≤0.32, where Rx and Ry are respectively defined as the x-coordinate value and y-coordinate value of the red filter layer 122R under the C light source on the CIE 1931 color coordinate.

Please continue to refer to FIG. 3 , the transmittance T of the red filter layer 122R in the yellow light band of this embodiment satisfies, for example, the relational expression 30%≦T≦40%, but the present invention is not limited thereto. Specifically, the wavelength of the above-mentioned yellow light band is, for example, between 585 nm and 605 nm. In this embodiment, the calculation of the transmittance T of the red filter layer 122R is based on 595 nm as an example and known compared to. Spectrum B is the transmittance spectrum of the red filter layer in the known liquid crystal display 10 under the C light source, and spectrum C is the transmittance spectrum of the red filter layer 122R of the present invention under the C light source. As can be seen from the figure, It is known that the transmittance of the red filter layer 122R in the liquid crystal display 10 at a wavelength of 595 nm is about 57.5%, while the transmittance of the red filter layer 122R of the present invention at a wavelength of 595 nm is about 33.4%. In other words, when the light transmittance at the edge of the red band after passing through the red filter layer 122R is less than a specific value, the red saturation of the light passing through the LCD 100 can be greatly improved, and the transmittance of the LCD 100 can be maintained to a certain extent. This enables the liquid crystal display 100 to greatly improve the performance of the red color under the condition of a slight change in brightness.

It is worth mentioning that in practice, when making the red filter layer 122R that meets the above conditions, three kinds of pigments, PR254, PR177 and PY150, can be used. Of course, the material of the red filter layer 122R can also be formulated with other materials. , the present invention is not limited thereto. Among them, the above-mentioned pigment numbers PR254, PR177 and PY150 belong to the international standard material codes in the art.

Fig. 4 is a comparison chart of CIE 1931 chromaticity coordinates of a liquid crystal display of the present invention and a known liquid crystal display. Please refer to FIG. 4 , it is known that the liquid crystal display 10 and the liquid crystal display 100 of this embodiment have obvious differences in red saturation in the chromaticity coordinate diagram. Specifically, the backlight module 110 in the liquid crystal display 100 has relatively maximum brightness peaks P1 and P2 respectively in the emission spectrum between wavelengths of 430 nm to 470 nm and between wavelengths of 520 nm to 620 nm (shown in FIG. 3 ). In the present invention, for example, by adjusting the transmittance of the red filter layer 122R at the edge of the red band, when the liquid crystal display panel 120 with the red filter layer 122R satisfying Rx≥0.65 and Ry≤0.32 is matched with the above-mentioned backlight module 110, When the light source provided by the backlight module 110 passes through the liquid crystal display panel 120 , it can have high color saturation performance, especially excellent performance in red saturation. Some data will be listed below to assist in explaining the color performance of the liquid crystal display 100 .

Table I

In detail, Table 1 shows the actual measurement data of the chromaticity coordinates of the known liquid crystal display 10 and the liquid crystal display 100 in this embodiment. Please refer to Table 1, the chromaticity coordinate values (Rx, Ry) of the red filter layer used by the known liquid crystal display 10 on the CIE chromaticity coordinates are, for example, (0.660, 0.330), and the The chromaticity coordinate value (Rx, Ry) of the red filter layer 122R used by the liquid crystal display 100 on the CIE chromaticity coordinates is, for example, (0.657, 0.320). The present invention utilizes the liquid crystal display of the red filter layer 122R satisfying the above relationship Panel 120, and after it is matched with the above-mentioned backlight module 110 having relatively maximum brightness peaks P1 and P2, the overall color performance of the liquid crystal display 100 can be optimized, and the performance of red saturation can be closer to sRGB The red standard in the standard can effectively improve the phenomenon that the known liquid crystal display 10 is reddish to orange when displaying.

Please refer to FIG. 4 and Table 1 at the same time. When the liquid crystal display 100 displays a red picture, the chromaticity coordinate values (Rx', Ry') of the chromaticity of the red picture on the CIE 1931 color coordinates are about (0.644, 0.333). Compared with (0.646, 0.343) of the red chromaticity coordinate values (Rx', Ry') displayed by the known liquid crystal display 10, the liquid crystal display 100 is closer to the red specification (Rx, Ry)=( 0.640, 0.330). In other words, when the backlight module 110 that satisfies the above-mentioned specific relationship is matched with the liquid crystal display panel 120, the color performance of the liquid crystal display 100 can be improved, and the problem of poor color purity when the liquid crystal display 100 displays red is effectively improved, thereby improving the performance of the liquid crystal display. 100 display quality.

To sum up, when adjusting the overall color saturation of the LCD, it is necessary to consider the luminous spectrum distribution of the backlight module and the color performance of the corresponding red filter layer, so as to effectively improve the phenomenon of reddish orange and ensure the color of each color. The color saturation does not interfere with each other, effectively improving the overall color saturation of the LCD display.

Although the present invention has been disclosed above with the embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope is to be determined as defined by the appended claims.

Claims (9)

1. A liquid crystal display, comprising: A backlight module with at least one white light source, wherein the emission spectrum of the backlight module has a relatively maximum brightness peak between wavelengths of 430 nm to 470 nm and wavelengths of 520 nm to 620 nm; and A liquid crystal display panel is arranged above the backlight module, and the liquid crystal display panel includes two substrates and a liquid crystal layer between the two substrates, wherein one of the two substrates has a red filter layer, a green filter layer Optical layer and blue filter layer, the red filter layer under CIE standard light source C, the x-coordinate values and y-coordinate values on CIE 1931 color coordinates are Rx and Ry respectively, where Rx≥0.65, and Ry≤0.32 . 2. The liquid crystal display as claimed in claim 1, wherein the white light source is a light emitting diode. 3. The liquid crystal display as claimed in claim 2, wherein the light emitting diode comprises a blue light diode and a phosphor material on an inner wall of the blue light diode. 4. The liquid crystal display as claimed in claim 1, wherein the transmittance of the red filter layer in the yellow light band is less than or equal to 40% and greater than or equal to 30%. 5. The liquid crystal display as claimed in claim 4, wherein the wavelength of the yellow light band is between 585 nm and 605 nm. 6. The liquid crystal display as claimed in claim 4, wherein the wavelength range of the yellow light is 595 nm. 7. The liquid crystal display as claimed in claim 1, wherein the backlight module comprises a direct type backlight module or an edge type backlight module. 8. The liquid crystal display as claimed in claim 1, wherein the composition of the red filter layer comprises three kinds of pigments: PR254, PR177 and PY150. 9. The liquid crystal display as claimed in claim 1, wherein the liquid crystal display is suitable for displaying a red picture, and the y-coordinate value of the chromaticity of the red picture on the CIE 1931 color coordinate is Ry', wherein Ry'≤0.335.

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