CN106990613A - A kind of backlight - Google Patents

Abstract

The embodiment of the present invention discloses a backlight source, including: an excitation light source, the excitation light source is a blue light excitation light source or a purple light excitation light source, used to generate excitation light; Quantum dots of more than one color are used to generate emission spectra under the irradiation of excitation light. By controlling the central wavelength of the excitation light source and the color coordinates of quantum dots of more than two colors, the backlight can achieve 80% to 110% NTSC color gamut range. An embodiment of the present invention provides a backlight source to achieve the effect of increasing the color gamut of the backlight source.

Description

a backlight

【Technical field】

Embodiments of the present invention relate to the field of display technology, and in particular to a backlight source.

【Background technique】

The backlight source is the light source provider of the Liquid Crystal Display (LCD). In the LCD, the liquid crystal display component itself does not emit light, but the backlight source located on the back of the LCD module provides the light source.

At present, the backlight generally uses light emitting diode (Light Emitting Diode, LED) as the light source. From the positional relationship between the light emitting direction of the light source and the light emitting surface of the backlight, it can be divided into direct type backlight and edge type backlight. Currently, the light source used in the backlight generally induces white light through blue LEDs and yellow phosphors.

The backlight uses blue LED and yellow phosphor to induce white light. The color gamut of the backlight can reach about 72% of the NTSC color gamut, but it is far from meeting the development of display technology requirements. The NTSC color gamut is (USA) The sum of colors under the National Television Standards Committee standard.

【Content of invention】

An embodiment of the present invention provides a backlight source to achieve the effect of increasing the color gamut of the backlight source.

The backlight source provided by the embodiment of the present invention includes:

An excitation light source, the excitation light source is a blue light excitation light source or a purple light excitation light source for generating excitation light;

The quantum dot diaphragm is arranged in the light-emitting direction of the excitation light, and includes quantum dots of more than two colors, and is used to generate an emission spectrum under the irradiation of the excitation light. By controlling the central wavelength of the excitation light source and the The color coordinates of the quantum dots of more than two colors, so that the backlight source can achieve an NTSC color gamut range of 80% to 110%.

Wherein, the central wavelength of the blue light excitation light source is between 450nm and 490nm; the central wavelength of the purple light excitation light source is between 380nm and 425nm.

The quantum dot film includes red quantum dots, green quantum dots and blue quantum dots. By controlling the central wavelength of the excitation light source and the color coordinates of the quantum dots of more than two colors, the backlight can realize 80%~110% NTSC color gamut range.

The color coordinates of the red quantum dots are R1 (x=0.63±0.05, y=0.33±0.05), R2 (x=0.65±0.05, y=0.32±0.05) or R3 (x=0.67±0.05, y=0.31 ±0.05);

The color coordinates of the green quantum dots are G1 (x=0.29±0.04, y=0.59±0.05), G2 (x=0.27±0.04, y=0.65±0.05) or G3 (x=0.20±0.04, y=0.71 ±0.05);

The color coordinates of the blue quantum dots are B1 (x=0.17±0.02, y=0.10±0.002), B2 (x=0.14±0.02, y=0.08±0.002) or B3 (x=0.15±0.02, y= 0.055±0.001).

Optionally, the excitation light source is a blue light excitation light source, the central wavelength of the blue light excitation light source is between 455nm and 490nm; the color coordinates of the red quantum dots are R1 (x=0.63±0.05, y=0.33±0.05 ), the color coordinates of the green quantum dots are G1 (x=0.29±0.04, y=0.59±0.05), and the color coordinates of the blue quantum dots are B1 (x=0.17±0.02, y=0.10±0.002) ; The backlight can achieve at least 90% of the NTSC color gamut range.

Optionally, the excitation light source is a blue light excitation light source, and the central wavelength of the blue light excitation light source is between 465nm and 475nm; the color coordinates of the red quantum dots are R2 (x=0.65±0.05, y=0.32±0.05 ), the color coordinates of the green quantum dots are G2 (x=0.27±0.04, y=0.65±0.05), and the color coordinates of the blue quantum dots are B2 (x=0.14±0.02, y=0.08±0.002) ; The backlight source can achieve at least 100% NTSC color gamut range.

Optionally, the excitation light source is a blue light excitation light source, the central wavelength of the blue light excitation light source is between 450nm and 465nm; the color coordinates of the red quantum dots are R3 (x=0.67±0.05, y=0.31±0.05 ), the color coordinates of the green quantum dots are G3 (x=0.20±0.04, y=0.71±0.05), and the color coordinates of the blue quantum dots are B3 (x=0.15±0.02, y=0.055±0.001) ; The backlight source can achieve an NTSC color gamut of 110%.

Optionally, the excitation light source is a purple light excitation light source, and the central wavelength of the purple light excitation light source is between 410nm and 425nm; the color coordinates of the red quantum dots are R1 (x=0.63±0.05, y=0.33±0.05 ), the color coordinates of the green quantum dots are G1 (x=0.29±0.04, y=0.59±0.05), and the color coordinates of the blue quantum dots are B1 (x=0.17±0.02, y=0.10±0.002) ; The backlight can achieve at least 90% of the NTSC color gamut range.

Optionally, the excitation light source is a purple light excitation light source, and the central wavelength of the purple light excitation light source is between 400nm and 410nm; the color coordinates of the red quantum dots are R2 (x=0.65±0.05, y=0.32±0.05 ), the color coordinates of the green quantum dots are G2 (x=0.27±0.04, y=0.65±0.05), and the color coordinates of the blue quantum dots are B2 (x=0.14±0.02, y=0.08±0.002) ; The backlight source can achieve at least 100% NTSC color gamut range.

Optionally, the excitation light source is a purple light excitation light source, and the central wavelength of the purple light excitation light source is between 380nm and 400nm; the color coordinates of the red quantum dots are R3 (x=0.67±0.05, y=0.31±0.05 ), the color coordinates of the green quantum dots are G3 (x=0.20±0.04, y=0.71±0.05), and the color coordinates of the blue quantum dots are B3 (x=0.15±0.02, y=0.055±0.001) ; The backlight source can achieve an NTSC color gamut of 110%.

An embodiment of the present invention provides a backlight, the quantum dot film is arranged in the light emitting direction of the excitation light source, and the quantum dot film includes quantum dots of more than two colors, and the blue light excitation light source or the purple light excitation light source is used to irradiate the quantum dots The diaphragm generates white light with a wide color gamut, which solves the problem in the prior art that the color gamut of white light cannot meet the requirements of display technology, and achieves the effect of improving the color gamut of the backlight source.

【Description of drawings】

FIG. 1 is a schematic diagram of the working mode of the backlight provided by Embodiment 1 of the present invention;

FIG. 2 is a partial structural schematic diagram of a direct-lit backlight provided by Embodiment 3 of the present invention;

FIG. 3 is a schematic structural diagram of a photometric backlight provided by Embodiment 3 of the present invention.

【detailed description】

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings but not all structures.

Embodiment one

The embodiment of the present invention provides a backlight source, which can be used as a backlight source for liquid crystal displays and the like, and can be applied to products or devices such as liquid crystal televisions, liquid crystal displays, mobile phones, and computer display screens.

The backlight source provided by the embodiment of the present invention includes an excitation light source and a quantum dot film. The excitation light source is a blue light excitation light source or a violet light excitation light source for generating excitation light. The quantum dot diaphragm is arranged in the light emitting direction of the excitation light, and includes quantum dots of more than two colors, and is used to generate an emission spectrum under the irradiation of the excitation light. By controlling the central wavelength of the excitation light source and the two or more colors The color coordinates of the quantum dots enable the backlight to achieve an NTSC color gamut range of 80% to 110%.

1 is a schematic diagram of the working mode of the backlight provided by the embodiment of the present invention. As shown in FIG. 1 , the excitation light 110 emitted by the excitation light source 11 is irradiated on the quantum dot film 12, and the quantum dot film 12 is excited to emit a new light beam 120.

Quantum dots are usually made of IIB-VIA or IIIA-VA group element materials in the periodic table of elements, and their particle size is usually 2-20nm. Due to the quantum confinement of electrons and holes, the continuous energy band structure of quantum dots becomes a discrete energy level structure with molecular characteristics, and can emit fluorescence after being excited. In recent years, quantum dots have been widely used in solar cells, light-emitting devices, optical biomarkers and other fields, and have special advantages in the field of LED display technology. First, the emission spectrum of quantum dots can be controlled by changing the size of quantum dots, and the emission spectrum can cover the entire visible light region. Taking CdTe (cadmium telluride) quantum dots as an example, when its particle size grows from 2.5nm to 4.0nm, their emission wavelength can move from 510nm to 660nm, and the corresponding color changes from red to green; second, Quantum dots have good photostability; third, quantum dots have a wide excitation spectrum and a narrow emission spectrum, even if the same excitation light source can be used to simultaneously excite quantum dots with different particle sizes to produce a variety of spectral wavelengths Fourth, the fluorescence lifetime of quantum dots is long, which is 3 to 4 times that of organic fluorescent dyes. Therefore, under the same excitation light, the brightness of white light induced by quantum dots can be increased by 10 compared with yellow phosphor powder. %~15%.

In the embodiment of the present invention, NTSC stands for (United States) National Television System Committee, and the NSTC color gamut is the sum of colors under the NTSC standard.

Optionally, the central wavelength of the blue light excitation light source is between 450nm and 490nm; the central wavelength of the purple light excitation light source is between 380nm and 425nm. The blue light excitation light source and the violet light excitation light source can be light emitting diodes. The quantum dot membrane includes red quantum dots, green quantum dots and blue quantum dots. The red quantum dot means that the color corresponding to the emission spectrum of the quantum dot is red. The green quantum dot means that the color corresponding to the emission spectrum of the quantum dot is green. The blue quantum dot means that the color corresponding to the emission spectrum of the quantum dot is blue. In other embodiments, the quantum dot film can also be set to include red quantum dots and green quantum dots, and the excitation light source is selected as a blue light excitation light source to make the backlight source generate white light.

The quantum dot diaphragm can be formed by mixing red quantum dots, green quantum dots and blue quantum dots in proportion, stirring them evenly with acrylic particles or silica gel, and then hot pressing at low temperature to form a quantum dot diaphragm.

Optionally, the color coordinates of the red quantum dots are R1 (x=0.63±0.05, y=0.33±0.05), R2 (x=0.65±0.05, y=0.32±0.05) or R3 (x=0.67±0.05, y =0.31±0.05); the color coordinates of green quantum dots are G1 (x=0.29±0.04, y=0.59±0.05), G2 (x=0.27±0.04, y=0.65±0.05) or G3 (x=0.20±0.04 , y=0.71±0.05); the color coordinates of blue quantum dots are B1(x=0.17±0.02, y=0.10±0.002), B2(x=0.14±0.02, y=0.08±0.002) or B3(x= 0.15±0.02, y=0.055±0.001). Wherein, the color coordinate of the red quantum dot refers to the coordinate value of the color corresponding to the emission spectrum of the red quantum dot in the chromaticity diagram, and the color coordinate of the green quantum dot refers to the coordinate value of the color corresponding to the emission spectrum of the green quantum dot in the chromaticity diagram. The color coordinates of the blue quantum dots refer to the coordinate values of the corresponding colors in the emission spectrum of the blue quantum dots in the chromaticity diagram.

Exemplarily, the blue primary color light emitted by the blue LED is irradiated on the quantum dot film containing red quantum dots, green quantum dots and blue quantum dots. The quantum dots are CdTe (cadmium telluride) quantum dots. Among them, when the blue primary color light from the blue LED is irradiated on the red quantum dots, the red quantum dots are excited to generate red light; when the blue primary color light from the blue LED is irradiated on the green quantum dots, the green quantum dots are excited to generate green light; When the blue primary color light emitted by the LED irradiates the blue quantum dots, the blue quantum dots are excited to generate blue light. The three colors of light emitted by the three color quantum dots are mixed to produce white light, and its color gamut value is determined by the color coordinates of the three colors of light in the chromaticity diagram.

In the embodiment of the present invention, by providing a backlight, the quantum dot film is arranged in the light emitting direction of the excitation light source, and the quantum dot film includes quantum dots of more than two colors, and the blue light excitation light source or the purple light excitation light source is used to irradiate The quantum dot diaphragm produces white light with a wide color gamut. Since quantum dots have good photostability, and have a wide excitation spectrum and a narrow emission spectrum, compared to using blue LEDs and yellow phosphors to induce white light, using the backlight provided by the embodiment of the present invention The generated white light has a wider color gamut, which solves the problem that the white light color gamut cannot meet the display technical requirements in the prior art, and realizes the effect of improving the color gamut of the backlight source.

Embodiment two

This embodiment is based on the above-mentioned embodiment, and the difference is that, on the basis of the above-mentioned embodiment, combination one, the excitation light source is selected as the blue light excitation light source or the purple light excitation light source, and the color of the red quantum dots is selected. The coordinates are R1, the color coordinates of green quantum dots are G1, and the color coordinates of blue quantum dots are B1, so that the backlight can achieve at least 90% of the NTSC color gamut range; combination 2, select the excitation light source as blue light excitation light source or purple light Excite the light source, select the color coordinates of the red quantum dots as R2, the color coordinates of the green quantum dots as G2, and the color coordinates of the blue quantum dots as B2, so that the backlight can achieve at least 100% of the NTSC color gamut range; combination three, Select the excitation light source as the blue light excitation light source or the purple light excitation light source, select the color coordinates of the red quantum dots as R3, the color coordinates of the green quantum dots as G3, and the color coordinates of the blue quantum dots as B3, so that the backlight can achieve 110% NTSC color gamut range.

Correspondingly, in combination one, the excitation light source is a blue light excitation light source with a center wavelength between 455nm and 490nm. The color coordinates of the red quantum dots, green quantum dots and blue quantum dots contained in the quantum dot film are R1(x=0.63±0.05, y=0.33±0.05), G1(x=0.29±0.04, y=0.59±0.05), respectively. 0.05) and B1 (x=0.17±0.02, y=0.10±0.002), it is also possible to use only red quantum dots with color coordinates R1 and green quantum dots with color coordinates G1.

The excitation light source can also be a violet excitation light source with a central wavelength between 410nm and 425nm. In this case, a quantum dot diaphragm containing three kinds of color quantum dots needs to be used to generate white light. The color coordinates of the red quantum dots are R1, the color coordinates of the green quantum dots are G1, and the color coordinates of the blue quantum dots are B1.

In combination two, the excitation light source is a blue light excitation light source with a central wavelength between 465nm and 475nm. The color coordinates of the red quantum dots, green quantum dots and blue quantum dots contained in the quantum dot film are R2 (x=0.65±0.05, y=0.32±0.05), G2 (x=0.27±0.04, y=0.65±0.05), respectively. 0.05) and B2 (x=0.14±0.02, y=0.08±0.002), it is also possible to use only red quantum dots with color coordinates R2 and green quantum dots with color coordinates G2.

The excitation light source can also be a purple light excitation light source with a center wavelength between 400nm and 410nm. In this case, a quantum dot diaphragm containing three kinds of color quantum dots needs to be used to generate white light. Wherein, the color coordinates of the red quantum dots are R2, the color coordinates of the green quantum dots are G2, and the color coordinates of the blue quantum dots are B2.

In combination three, the excitation light source is a blue light excitation light source with a central wavelength between 450nm and 465nm. The color coordinates of the red quantum dots, green quantum dots and blue quantum dots contained in the quantum dot film are R3 (x=0.67±0.05, y=0.31±0.05), G3 (x=0.20±0.04, y=0.71±0.05), respectively. 0.05) and B3 (x=0.15±0.02, y=0.055±0.001), it is also possible to use only red quantum dots with color coordinates R3 and green quantum dots with color coordinates G3.

The excitation light source can also be a purple light excitation light source with a center wavelength between 380nm and 400nm. In this case, a quantum dot diaphragm containing three colors of quantum dots needs to be used to generate white light. Wherein, the color coordinates of the red quantum dots are R3, the color coordinates of the green quantum dots are G3, and the color coordinates of the blue quantum dots are B3.

It should be noted that the above-mentioned laser source and the quantum dot film can also have various other combinations, for example, the excitation light source is a blue light excitation light source with a center wavelength between 455nm and 490nm. The color coordinates of the red quantum dots, green quantum dots and blue quantum dots contained in the quantum dot film are R2 (x=0.65±0.05, y=0.32±0.05), G2 (x=0.27±0.04, y=0.65±0.05), respectively. 0.05) and B2 (x=0.14±0.02, y=0.08±0.002).

In the backlight provided by the embodiment of the present invention, excitation light sources with different central wavelength ranges are combined with quantum dot films containing quantum dots with specific color coordinates. Correspondingly, the combination makes the backlight realize an NTSC color gamut of at least 90%. Combination 2 enables the backlight to achieve at least 100% of the NTSC color gamut range, and combination 3 enables the backlight to achieve a 110% NTSC color gamut range, so that the appropriate combination can be selected to meet the requirements of the display technology for the backlight Color gamut requirements.

Embodiment Three

This embodiment is based on the above-mentioned embodiment, and the difference is that, based on the above-mentioned embodiment, a blue LED with a specific wavelength is selected as the excitation light source, and a quantum dot film containing quantum dots with specific color coordinates is used. chips to produce white light.

Fig. 2 is a partial structural diagram of the direct-lit backlight provided by Embodiment 3 of the present invention. As shown in Fig. 2 , the backlight includes a backlight base plate 21, a light reflection film 22 is arranged on the back light base plate 21, and the excitation light source is a blue LED 24. The center wavelength of its emission spectrum is 455nm, and a plurality of blue light LED24 (not shown in Fig. 2) patch is arranged on the circuit board 23, and is electrically connected by the copper clad line on the circuit board 23, and a plurality of circuit boards 23 are arranged on the light reflective film 22 . An optical diaphragm group is arranged above the blue LED 24, and the optical diaphragm group includes a light diffusion sheet 25, a quantum dot diaphragm 26 and a light enhancement film 27 in sequence along the light emitting direction of the backlight, and the quantum dot diaphragm 26 contains red quantum dots. and green quantum dots, wherein the color coordinates of the red quantum dots are (x=0.63, y=0.33), and the color coordinates of the green quantum dots are (x=0.29, y=0.59). The light diffusion sheet 25, the quantum dot film 26 and the light enhancement film 27 are fixed by using the bracket 28 to cooperate with the bottom plate 21 to form a complete backlight module. Using the backlight can get 92% of the NTSC color gamut range.

3 is a schematic structural diagram of a photometric backlight provided by Embodiment 3 of the present invention. As shown in FIG. For the light source assembly 31, it includes a light source bracket 311, a first light reflection film 312, a circuit board 313, a blue LED314 and a quantum dot diaphragm 315, wherein the first light reflection film 312 is arranged on the light source bracket 311, and the excitation light source is a blue light LED314 , the central wavelength of its emission spectrum is 460nm, and a plurality of blue LED314 (not shown in Figure 3) patches are arranged on the strip circuit board 313, and the circuit board 313 and the blue LED314 are electrically connected by copper-clad lines. The circuit board 313 is disposed on the first light reflection film 312 . Fix the strip-shaped quantum dot film 315 above the blue LED314, and the quantum dot film 315 contains red quantum dots, green quantum dots and blue quantum dots, wherein the color coordinates of the red quantum dots are (x=0.65, y =0.32), the color coordinates of the green quantum dots are (x=0.27, y=0.65), and the color coordinates of the blue quantum dots are (x=0.14, y=0.08). The light guide plate assembly 32 includes a backlight bottom plate 321 , a second light reflection film 322 , a light guide plate 323 , a light diffusion sheet 324 and a light enhancement film 325 arranged in sequence along the light emitting direction of the backlight. The side of the light guide plate 323 near the backlight base plate 321 and the side of the non-incident light are all provided with a second light reflection film 322, and the side of the light guide plate 323 near the backlight base plate 321 is provided with dots (not shown in FIG. 3 ), these dots make The light incident from the side of the light guide plate 323 can be emitted from the required light-emitting surface after being refracted. Using the backlight can get 104% of the NTSC color gamut range.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention, and the present invention The scope is determined by the scope of the appended claims.

Claims (10)

1. a kind of backlight, it is characterised in that including：

Excitation source, the excitation source is blue light excitation source or purple light excited light source, for producing exciting light；

On quantum dot diaphragm, the light direction for being arranged on the exciting light, and include the quantum dot of two or more colors, for Under the irradiation of exciting light, emission spectrum is produced, by the centre wavelength and described two above colors that control the excitation source Quantum dot chromaticity coordinates so that the backlight realizes 80%~110% NTSC scope.

2. backlight according to claim 1, it is characterised in that the centre wavelength of the blue light excitation source is located at Between 450nm~490nm；The centre wavelength of the purple light excited light source is located between 380nm~425nm.

3. backlight according to claim 2, it is characterised in that the quantum dot diaphragm includes red quantum dot, green Quantum dot and blue quantum dot, by controlling the centre wavelength of the excitation source and the quantum dot of described two above colors Chromaticity coordinates, so that the backlight realizes 80%~110% NTSC scope.

4. backlight according to claim 3, it is characterised in that the chromaticity coordinates of the red quantum dot is R1 (x=0.63 ± 0.05, y=0.33 ± 0.05), R2 (x=0.65 ± 0.05, y=0.32 ± 0.05) or R3 (x=0.67 ± 0.05, y= 0.31±0.05)；

The chromaticity coordinates of the green quantum dot be G1 (x=0.29 ± 0.04, y=0.59 ± 0.05), G2 (x=0.27 ± 0.04, Y=0.65 ± 0.05) or G3 (x=0.20 ± 0.04, y=0.71 ± 0.05)；

The chromaticity coordinates of the blue quantum dot be B1 (x=0.17 ± 0.02, y=0.10 ± 0.002), B2 (x=0.14 ± 0.02, y=0.08 ± 0.002) or B3 (x=0.15 ± 0.02, y=0.055 ± 0.001).

5. backlight according to claim 4, it is characterised in that the excitation source is blue light excitation source, the indigo plant The centre wavelength in phot-luminescence source is located between 455nm~490nm；

The chromaticity coordinates of the red quantum dot be R1 (x=0.63 ± 0.05, y=0.33 ± 0.05), the green quantum dot Chromaticity coordinates be G1 (x=0.29 ± 0.04, y=0.59 ± 0.05), the chromaticity coordinates of the blue quantum dot for B1 (x=0.17 ± 0.02, y=0.10 ± 0.002)；

The backlight realization at least can reach 90% NTSC scope.

6. backlight according to claim 4, it is characterised in that the excitation source is blue light excitation source, the indigo plant The centre wavelength in phot-luminescence source is located between 465nm~475nm；

The chromaticity coordinates of the red quantum dot be R2 (x=0.65 ± 0.05, y=0.32 ± 0.05), the green quantum dot Chromaticity coordinates be G2 (x=0.27 ± 0.04, y=0.65 ± 0.05), the chromaticity coordinates of the blue quantum dot for B2 (x=0.14 ± 0.02, y=0.08 ± 0.002)；

The backlight realization at least can reach 100% NTSC scope.

7. backlight according to claim 4, it is characterised in that the excitation source is blue light excitation source, the indigo plant The centre wavelength in phot-luminescence source is located between 450nm~465nm；

The chromaticity coordinates of the red quantum dot be R3 (x=0.67 ± 0.05, y=0.31 ± 0.05), the green quantum dot Chromaticity coordinates be G3 (x=0.20 ± 0.04, y=0.71 ± 0.05), the chromaticity coordinates of the blue quantum dot for B3 (x=0.15 ± 0.02, y=0.055 ± 0.001)；

The backlight realization can reach 110% NTSC scope.

8. backlight according to claim 4, it is characterised in that the excitation source is purple light excited light source, the purple The centre wavelength in phot-luminescence source is located between 410nm~425nm；

The chromaticity coordinates of the red quantum dot be R1 (x=0.63 ± 0.05, y=0.33 ± 0.05), the green quantum dot Chromaticity coordinates be G1 (x=0.29 ± 0.04, y=0.59 ± 0.05), the chromaticity coordinates of the blue quantum dot for B1 (x=0.17 ± 0.02, y=0.10 ± 0.002)；

The backlight realization at least can reach 90% NTSC scope.

9. backlight according to claim 4, it is characterised in that the excitation source is purple light excited light source, the purple The centre wavelength in phot-luminescence source is located between 400nm~410nm；

The chromaticity coordinates of the red quantum dot be R2 (x=0.65 ± 0.05, y=0.32 ± 0.05), the green quantum dot Chromaticity coordinates be G2 (x=0.27 ± 0.04, y=0.65 ± 0.05), the chromaticity coordinates of the blue quantum dot for B2 (x=0.14 ± 0.02, y=0.08 ± 0.002)；

The backlight realization at least can reach 100% NTSC scope.

10. backlight according to claim 4, it is characterised in that the excitation source is purple light excited light source, the purple The centre wavelength in phot-luminescence source is located between 380nm~400nm；

The chromaticity coordinates of the red quantum dot be R3 (x=0.67 ± 0.05, y=0.31 ± 0.05), the green quantum dot Chromaticity coordinates be G3 (x=0.20 ± 0.04, y=0.71 ± 0.05), the chromaticity coordinates of the blue quantum dot for B3 (x=0.15 ± 0.02, y=0.055 ± 0.001)；

The backlight realization can reach 110% NTSC scope.