CN103278961A - Liquid crystal display device - Google Patents

Abstract

The invention belongs to the technical field of displaying, and relates to a liquid crystal display device. The liquid crystal display device comprises a colorful film substrate, an array substrate and a backlight module, wherein the backlight module comprises a light source. An auxiliary light filter layer is arranged in the colorful film substrate. An optical excitation layer is arranged in the backlight module and is excited by main lasers sent out by the light source to generate excited light with specific wave length. The auxiliary light filter layer enables the excited light to selectively penetrate through the colorful film substrate and reflects the main lasers to the backlight module. The liquid crystal display device not only ensures excellent displaying chromaticity but also improves the using rate of light of the backlight module.

Description

A liquid crystal display device

technical field

The invention belongs to the field of display technology and relates to a liquid crystal display device.

Background technique

Liquid Crystal Display (LCD: Liquid Crystal Display) has become the mainstream product in flat panel displays due to its small size, low power consumption, and no radiation. With the development of display technology, display devices with high transmittance, large size, low power consumption and low cost will become the future development direction.

The existing liquid crystal panel includes a color filter (Color Filer) substrate, an array (Array) substrate and a backlight module (Back Light Module), and the liquid crystal is arranged between the color filter substrate and the array substrate. Liquid crystal itself does not emit light. Therefore, a backlight module is used in a liquid crystal display device to provide a uniform and high-brightness light source for the liquid crystal panel. Generally speaking, the backlight module can be divided into a side-type backlight module and a direct-type backlight module according to the position of the light sources in the backlight module. Wherein, the light source in the side-type backlight module is located at the side of the backlight module, and the light source in the direct-type backlight module is located at the bottom of the backlight module.

A color filter layer (also known as a color filter) is arranged on the color filter substrate, and the color filter layer is a key component for the colorization of the display device. Usually, the color filter layer includes multiple sub-color filter layers such as red, green, and blue. The white light emitted by the backlight module passes through the color filter layer, and uses the color photoresist of the color filter layer to generate three primary colors of red, green, and blue respectively. While realizing colorization, the light emitted by the light source is hindered by the color film layer, so that the light emitted by the backlight module cannot completely pass through the color film layer, that is, part of the light is absorbed after the light passes through the color film layer, resulting in a decrease in light utilization. ; At the same time, it also affects the display chromaticity, thereby affecting the display effect of the liquid crystal display device.

Contents of the invention

The technical problem to be solved by the present invention is to provide a liquid crystal display device which not only ensures good display chromaticity, but also improves the light utilization rate of the backlight module for the above-mentioned shortcomings in the prior art.

The technical solution adopted to solve the technical problem of the present invention is that the liquid crystal display device includes a color filter substrate, an array substrate, and a backlight module. The backlight module includes a light source, and an auxiliary filter layer is arranged in the color filter substrate. The backlight module is provided with a photo-excitation layer, the photo-excitation layer is excited by the main laser light emitted by the light source to generate a specific wavelength of the subject light, and the auxiliary filter layer can selectively transmit the subject light The color filter substrate reflects the main laser light back to the backlight module.

Preferably, the color filter substrate further includes a color filter layer, the color filter layer includes a plurality of sub-color filter layers capable of transmitting light of different wavelengths, and the auxiliary filter layer is arranged on the color filter layer corresponding to the The region of the sub-color filter layer that passes through a wavelength greater than the wavelength of the main laser light is closer to the backlight module than the color filter layer.

Preferably, the color filter layer includes a red sub-color filter layer, a green sub-color filter layer, and a blue sub-color filter layer. At least one region corresponding to the layer;

Alternatively, the color filter layer includes a red sub-color filter layer, a yellow sub-color filter layer, a green sub-color filter layer, and a blue sub-color filter layer, and the auxiliary filter layer is arranged on the same side as the red sub-color filter layer, the green sub-color filter layer, and the green sub-color filter layer. At least one region corresponding to the color filter layer and the yellow sub-color filter layer.

Preferably, the auxiliary optical filter layer includes multiple sub-layers successively stacked with high refractive index materials and low refractive index materials at intervals, the high refractive index material forms a high refractive sub-layer, and the low refractive index The material forms a low-refractive sublayer.

Preferably, the high refraction sub-layer is formed of titanium dioxide material, and its thickness is one-eighth of the central wavelength of the cut-off band; the low-refractive layer is formed of silicon dioxide material, and its thickness is one-quarter of the central wavelength of the cut-off band.

Preferably, the photoexcitation layer contains quantum dots, and the quantum dots are at least one of red quantum dots, green quantum dots or yellow quantum dots.

Preferably, the light source is a blue light source, and the light emitted by the quantum dots excited by the blue light source includes red light, green light or yellow light.

Further preferably, the color filter substrate further includes a protective layer, a transparent electrode layer, and an alignment layer laminated with the color filter layer, and the auxiliary filter layer is arranged between the color filter layer and the protective layer. between the protective layer and the transparent electrode layer, or between the transparent electrode layer and the alignment layer.

A preferred solution is that the backlight module is a side-entry backlight module, and the side-entry backlight module also includes a stacked reflection sheet, a light guide plate and a prism film, and the light source is arranged on the reflection sheet , the side surfaces of the light guide plate and the prism film, the photoexcitation layer is arranged between the light guide plate and the prism film.

Another preferred solution is that the backlight module is a direct-type backlight module, and the direct-type backlight module further includes a reflection sheet and a diffusion plate stacked, and the light source is arranged between the reflection sheet and the diffusion plate. Between the plates, the photoactive layer is disposed above the diffuser plate.

The beneficial effect of the present invention is: through the cooperation of the auxiliary filter layer in the color filter substrate and the light excitation layer in the backlight module, before the light reaches the color filter layer, the light with a relatively long wavelength is selectively allowed to pass through the color filter substrate , and reflect a part of the relatively short-wavelength light that may have been absorbed by the color filter layer back to the backlight module for reuse, so that the liquid crystal display device not only ensures good display chromaticity, but also improves the light utilization of the backlight module. Rate.

Description of drawings

1 is a schematic structural view of a liquid crystal display device in Embodiment 1 of the present invention;

Fig. 2 is a schematic diagram of the working principle of the auxiliary filter layer in Fig. 1;

Fig. 3 is a schematic structural view of the auxiliary filter layer in Fig. 2;

4 is a schematic diagram of an optical path of a liquid crystal display device in Embodiment 1 of the present invention;

5 is a schematic diagram of an optical path of a liquid crystal display device in Embodiment 2 of the present invention;

6 is a schematic diagram of an optical path of a liquid crystal display device in Embodiment 3 of the present invention;

In the figure: 1-color filter substrate; 10-substrate; 12-color filter layer; 13-auxiliary filter layer; 14-protective layer; 15-transparent electrode layer; 16-upper alignment layer; 17-upper polarizer; 121 -blue sub-color filter layer; 122-green sub-color filter layer; 123-yellow sub-color filter layer; 124-red sub-color filter layer;

2-array substrate; 20-substrate; 21-TFT; 22-lower alignment layer; 23-lower polarizer;

3-backlight module; 31-light source; 32-reflector; 33-light guide plate; 34-photoactive layer; 35-prism film; 36-diffusion plate;

4- LCD.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, the liquid crystal display device of the present invention will be further described in detail below with reference to the drawings and specific embodiments.

A liquid crystal display device, comprising a color filter substrate, an array substrate and a backlight module, the backlight module includes a light source, an auxiliary filter layer is arranged in the color filter substrate, and a light excitation layer is arranged in the backlight module , the photoexciting layer is excited by the main laser light emitted by the light source to generate a specific wavelength of the subject light, and the auxiliary filter layer can allow the subject light to selectively pass through the color filter substrate, and the main laser beam reflected back to the backlight module.

Example 1:

A liquid crystal display device, as shown in FIG. 1 , includes a color filter substrate 1 , an array substrate 2 and a backlight module 3 , and a liquid crystal 4 is arranged between the color filter substrate 1 and the array substrate 2 . Wherein, the backlight module includes a light source 31, the color filter substrate 1 is provided with an auxiliary filter layer 13, and the backlight module 3 is provided with a light excitation layer 34, and the light excitation layer 34 is influenced by the light source. 31 is excited by the main laser light to generate the subject light of a specific wavelength, the auxiliary filter layer 13 allows the subject light to selectively pass through the color filter substrate 1, and reflects the main laser light back to the backlight module 3 .

In the present invention, the main laser refers to the light actively emitted by the light source, and the subject laser refers to the passively emitted light excited by energy.

FIG. 1 shows the complete structure of a liquid crystal display device taking a TN-type TFT-LCD as an example. As shown in Figure 1, the color filter substrate 1 includes a substrate 10, a black matrix (not specifically shown in Figure 1), a color filter layer 12, an auxiliary filter layer 13, a protective layer 14, a transparent electrode layer 15, an upper orientation Layer 16 and upper polarizer 17. The array substrate 2 includes a substrate 20 , a TFT (Thin Film Transistor) 21 , a lower alignment layer 22 and a lower polarizer 23 .

Wherein, the auxiliary filter layer 13 is arranged between the color filter layer 12 and the protective layer 14 (that is, the structure shown in FIG. 1 ), or arranged between the protective layer 14 and the transparent electrode layer 15 or between the transparent electrode layer 15 and the upper alignment layer 16 .

According to the process conditions, the protective layer 14 may not be provided in the color filter substrate 1; at the same time, according to the different types of TFT-LCD, the transparent electrode layer 15 may also be provided in the array substrate 2, for example: in the ADS type (ADvanced Super Dimension Switch, advanced ultra-dimensional field switching technology) TFT-LCD, the transparent electrode layer 15 and the pixel electrode (electrically connected to the drain of the TFT, not shown in FIG. 1 ) are both arranged in the array substrate 2 . In the above structure, the position of the auxiliary filter layer 13 can be flexibly set, as long as the auxiliary filter layer 13 is closer to the backlight module 3 than the color filter layer 12 , there is no limitation here.

Wherein, the color filter layer 12 includes a plurality of sub-color filter layers capable of transmitting light of different wavelengths, and the auxiliary filter layer 13 is arranged on the color filter layer 12 corresponding to a wavelength that can pass through a wavelength greater than that of the main laser beam. The area of the sub-color filter layer of light rays, and is closer to the backlight module 3 than the color filter layer 12 . In this embodiment, the color filter layer 12 includes a red sub-color filter layer 124, a green sub-color filter layer 122, and a blue sub-color filter layer 121. At least one region corresponding to the film layer 124 and the green sub-color filter layer 122 . That is: the auxiliary filter layer 13 is arranged in the region corresponding to the red sub-color filter layer 124, or in the region corresponding to the green sub-color filter layer 122, or in a region corresponding to the red sub-color filter layer 124, the green The area corresponding to the sub-color filter layer 122 at the same time.

It should be understood here that, in consideration of reducing the step difference of each layer in the color filter substrate 1, a layer with A completely permeable transparent layer, such as a transparent layer formed of glass; furthermore, if the process conditions permit, no filling material can be provided in the area corresponding to the blue sub-color filter layer 121 to save costs.

Preferably, the auxiliary filter layer 13 includes multiple sub-layers successively stacked at intervals of a material with a high refractive index and a material with a low refractive index, the high-refractive-index material forms a high-refractive sub-layer, and the low-refractive The low-refractive sub-layer is formed by the low-refractive material. Wherein, preferably, the high-refractive sub-layer is formed of titanium dioxide material, and its thickness is one-eighth of the central wavelength of the cut-off band; the low-refractive layer is formed of silicon dioxide material, and its thickness is one-quarter of the central wavelength of the cut-off band.

The wavelength range of visible light commonly used in the field of display technology is: the wavelength range of red light is 620-770nm (red light is marked with R in the figure of the embodiment of the present invention), the wavelength range of yellow light is 560-590nm (in the figure of the embodiment of the present invention Yellow light is marked by Y in the middle), the wavelength range of green light is 500-530nm (green light is marked by G in the figure of the embodiment of the present invention), the wavelength range of blue light is 430-470nm (indicated by B in the figure of the embodiment of the present invention mark blue light), it can be seen that when the auxiliary filter layer 13 is arranged in the area corresponding to the red sub-color filter layer 124 and the green sub-color filter layer 122, the reflection of blue light corresponding to the two areas is realized to improve the blue light When the utilization rate is high, the wavelength value range of the light that can pass through the auxiliary filter layer 13 can be set to 500-770nm, for example: when the value is preferably set to 580nm, light with a wavelength greater than 580nm can pass through Auxiliary filter layer 13 , and light with a wavelength of less than 580nm will be reflected back to the backlight module 3 .

In the backlight module 3, the light excitation layer 34 contains at least one kind of quantum dots, wherein the quantum dots are excited by the incident blue light to emit visible light of other colors. Quantum Dot (Quantum Dot, QD) is a quasi-zero-dimensional nano-semiconductor light-emitting material, which is composed of a small number of atoms, which can emit visible light after absorbing a certain amount of energy. Energy includes photoexcitation energy and electrical excitation energy. Photoexcitation energy uses photoexcitation to make quantum dots emit light. Compared with phosphors, quantum dots have high quantum efficiency and narrow half-width of the emission spectrum. Only by replacing quantum dots The chemical composition of quantum dots or by adjusting the size of quantum dots can precisely control the excitation of different wavelengths of light, so as to obtain different colors of visible light.

In order to ensure that the quantum dots can be excited effectively, the wavelength of the main laser light emitted by the light source 31 is smaller than the wavelength of the stimulated laser light emitted by the quantum dots. In this embodiment, the light source 31 is a blue light source, the quantum dots at least include red quantum dots and green quantum dots, and the quantum dots are excited by the blue light source to emit light including red light and green light.

One of the outstanding advantages of quantum dots is that even if it is the same material, only by adjusting the size of the quantum dots, the emission wavelength of the quantum dots can be precisely controlled, so that visible light of different colors can be obtained. According to different needs of users, quantum dots of the same material can be adjusted to obtain visible light of different colors by adjusting its size; or quantum dots of the same size can be adjusted to obtain visible light of different colors by adjusting its chemical composition. Therefore, in practical applications, according to the luminescence characteristics of quantum dots, such as: half-peak width of luminescence spectrum, luminescence peak and luminescence wavelength, etc., by adjusting the ratio of quantum dots of different materials, or adjusting the ratio of quantum dots of different sizes Match to get different colors of light. Generally, the narrower the half-peak width of the quantum dot luminescence spectrum, the higher the color purity, and the better the color display effect of the liquid crystal display device; The wavelength range of the transmitted light of the film layer 124 is adjusted. At this time, the size of the quantum dot can be adjusted to control the peak position so that it is as close as possible to the wavelength range of the transmitted light of the corresponding sub-color film layer; Adjusting the distribution rate of quantum dots can change the amplitude of light emitted by quantum dots.

The blue light source can be LED, CCFL or EEFL (External Electrode Fluorescent Lamp, external electrode fluorescent lamp), etc. At present, the mass-produced blue LED wavelengths are concentrated in the range of 440-455nm. The shorter the wavelength of the light emitted by the blue light source, the higher the efficiency of exciting quantum dots.

In this embodiment, the backlight module 3 is a side-type backlight module. As shown in FIG. 4 , the side-type backlight module further includes a reflective sheet 32, a light guide plate 33 and a prism film 35 stacked, and the light source 31 is arranged on the reflective sheet 32, the light guide plate 33 and the prism film. The side surface of the prism film 35 , the photoactive layer 34 is disposed between the light guide plate 33 and the prism film 35 . Wherein, the reflection sheet 32 is used to reflect the light entering the light guide plate 33 to the light exit surface of the light guide plate 33 and emit it, and the prism film 35 is used to diffuse the light emitted from the light exit surface of the light guide plate 33, or to increase the brightness of the light, or Improve the uniformity of light.

In this embodiment, the expression of the main film system of the auxiliary filter layer 13 is:

${<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}\mathrm{<span\; class="notranslate">\; L</span>}\frac{\mathrm{<span\; class="notranslate">\; h</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

In the formula (1), L represents the thickness of the low refraction sub-layer with a low refractive index and a thickness of 1/4 the central wavelength of the cut-off band, and H represents the high refraction sub-layer with a high refractive index and a thickness of 1/4 the central wavelength of the cut-off band The thickness of the layer, H/2 represents the thickness of the high refraction sub-layer with a high refractive index and a thickness of 1/8 of the central wavelength of the cut-off band, and M is the period number. The auxiliary filter layer 13 is a symmetrical film system, centered on the middle sub-layer, symmetrical on both sides, and the total number of sub-layers is 2M+1, as shown in FIG. 3 .

The thicknesses of the high refraction sub-layer and the low refraction sub-layer in the auxiliary filter layer 13 and the period of the film system can be calculated according to formula (2) and formula (3):

$\mathrm{<span\; class="notranslate">\; \&Delta;\&lambda;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&Delta;g</span>}{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In formula (2), Δλ is the width of the cut-off band, λ ₀ is the center wavelength of the cut-off band, n _H and n _L are the refractive indices of the high-refractive-index material and the low-refractive-index material, respectively.

${\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 16</span>}{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}}{{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; \{</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; g</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; \}</span>}<span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In formula (3): T _R is the transmittance at the central wavelength of the cut-off band, n ₀ is the refractive index of the upper substrate (that is, the side of the auxiliary filter layer 13 that is relatively far away from the liquid crystal 4), and n _g is the lower substrate ( That is, the refractive index of the auxiliary filter layer 13 on the side relatively close to the liquid crystal 4), n _H and n _L are the refractive indices of high and low refractive index materials respectively, and M is the period number.

In the case of known high refractive index materials and low refractive index materials, for example: the refractive index of titanium dioxide (TiO ₂ ): n _H = 2.1; the refractive index of silicon dioxide (SiO ₂ ): n _L =1.46, then according to formula (2):

$\mathrm{<span\; class="notranslate">\; \&Delta;g</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&pi;</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; h</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; 3.14</span>}}{\mathrm{<span\; class="notranslate">\; sin</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; 2.1</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1.46</span>}}{\mathrm{<span\; class="notranslate">\; 2.1</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1.46</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 0.1151</span>}$

At the same time, by the formula (2):

Δλ=2Δgλ ₀ =0.2302λ ₀ …………………………(4)

For example: the auxiliary filter layer 13 corresponding to the area of the green sub-color filter layer 122 should be set so that the light with a wavelength greater than 500nm can pass through and propagate to the green sub-color filter layer 122, and the light with a wavelength of less than 500nm is reflected Return to the backlight module 3.

Then there are:

$\frac{\mathrm{<span\; class="notranslate">\; \&Delta;\&lambda;</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 500</span>}<span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; \&hellip;</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

Combine formula (4) and formula (5) to get:

λ ₀ =448.6nm,Δλ=103.2nm

Then the thickness of the single-layer refraction sublayer is:

$\mathrm{<span\; class="notranslate">\; L</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; h</span>}<span\; class="notranslate">\; =</span>\frac{{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}{\mathrm{<span\; class="notranslate">\; 4</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 11.2</span>}\mathrm{<span\; class="notranslate">\; nm</span>}$

Since the refractive index of the high-refractive sub-layer and the low-refractive sub-layer are known, only the transmittance at the center wavelength needs to be set, and the basic period number of the main film system can be calculated by formula (3) M, considering the error in the actual plating process and the influence of the stability of each layer of film parameters, the number of selected basic cycles can be appropriately increased.

Under the above-mentioned setting parameters, as shown in FIG. 2, the auxiliary filter layer 13 can reflect the blue visible light (wavelength 430-470nm) with a wavelength less than 500nm back to the backlight module 3, and then through the reflection inside the backlight module 3 The sheet 32 is re-reflected onto the liquid crystal panel to be reused again. Green visible light and red visible light with a wavelength greater than 500nm (green visible light wavelength 500-530nm, red visible light wavelength 620-770nm) pass through the auxiliary filter layer 13 to reach the corresponding color filter layer 12.

As shown in FIG. 4 , the propagation process of light in the liquid crystal display device is as follows: the light source 31 emits blue light, and the blue light enters the light guide plate 33 from the light incident surface (i.e. the side surface) of the light guide plate 33, and is reflected by the reflective sheet 32 and passes through the light guide plate 33. The light-emitting surface (i.e., the front side) of the light plate 33 propagates to the light-exciting layer 34, wherein, of the blue light rays incident on the quantum dots in the light-exciting layer 34, part of the blue light rays are absorbed by the quantum dots, thereby exciting red visible light (i.e., red light ) or green visible light (that is, green light); another part of the blue light passes through the photoexciting layer 34 and propagates to the prism film 35 together with the excited red visible light or green visible light to be mixed into white light (the white light spectrum is decomposed into R, G, B three peaks), propagates to the color filter substrate 1 through the array substrate 2 and the liquid crystal 4. In the color filter substrate 1, the blue light component in the white light corresponding to the area of the blue sub-color filter layer 121 is directly transmitted to the blue sub-color filter layer 121 in the color filter layer 12, and finally passes through the color filter substrate 1, and The green light component and the red light component corresponding to the blue sub-color filter layer 121 are absorbed by the blue sub-color filter layer 121; The light component is transmitted through the auxiliary filter layer 13 to the corresponding red sub-color filter layer 124 and green sub-color filter layer 122 in the color filter layer 12, and finally passes through the color filter substrate 1, so that the liquid crystal panel can display images normally, while The green light component corresponding to the red sub-color filter layer 124 is transmitted through the auxiliary filter layer 13, and then absorbed by the red sub-color filter layer 124; the red light component corresponding to the area of the green sub-color filter layer 122 passes through the corresponding auxiliary filter layer After 13 is transmitted, it is absorbed by the green sub-color filter layer 122; the blue light component corresponding to the red sub-color filter layer 124 and the green sub-color filter layer 122 is reflected back into the backlight module 3 by the auxiliary filter layer 13, and then passes through the reflection sheet 32 again It is reflected back to the color filter substrate 1, and finally transmitted from the area corresponding to the blue sub-color filter layer 121 to the blue sub-color filter layer 121 in the color filter substrate 1, which greatly improves the light utilization efficiency of the backlight module 3, and makes The liquid crystal panel achieves a better color display effect.

It should be understood here that, in this embodiment, the auxiliary filter layer can also be arranged in partitions. At this time, the auxiliary filter layer corresponding to the partition is set to: only correspond to the light components of the corresponding colors that can pass through the sub-color filter layer light components of other colors are all reflected back to the backlight module, so as to further improve the light utilization efficiency of the backlight module. That is: the auxiliary filter layer can be set in the area corresponding to the green sub-color filter layer so that only the green light component can pass through, while the blue light component is reflected back to the backlight module; similarly, in the area corresponding to the red sub-color filter layer The area can be set so that only the red light component can pass through, while both the blue light component and the green light component are reflected back to the backlight module. Correspondingly, at this time, the auxiliary filter layer corresponds to each sub-layer of the partition, and the thickness of the high-refraction sub-layer and the low-refraction sub-layer and the number of film system periods should be recalculated according to formula (2) and formula (3), and can be prepared by partition On different layers of the color filter substrate (for example, the green light division of the auxiliary filter layer is set on the protective layer, and the red light division is set on the transparent electrode layer).

Example 2:

The difference between this embodiment and Embodiment 1 is that in this liquid crystal display device, the color filter layer 12 and the auxiliary filter layer 13 provided in the color filter substrate 1 are different from the color filter layer 12 and the auxiliary filter layer 13 in Embodiment 1. Correspondingly, the structure of the photoactive layer 34 in the backlight module 3 is different from that of the photoactive layer 34 in Embodiment 1, as shown in FIG. 5 .

In this embodiment, the color filter layer 12 includes a red sub-color filter layer 124, a yellow sub-color filter layer 123, a green sub-color filter layer 122, and a blue sub-color filter layer 121, and the auxiliary filter layer 13 is set In at least one region corresponding to the red sub-color filter layer 124 , the yellow sub-color filter layer 123 and the green sub-color filter layer 122 . According to requirements, the light of a specific wavelength emitted by the quantum dots excited by the blue light source includes at least one of red light, yellow light or green light. Correspondingly, in an embodiment, the quantum dots are red quantum dots, yellow quantum dots, green quantum dots or blue quantum dots. The transmittance characteristics of the regions of the auxiliary filter layer 13 corresponding to the sub-color filter layers in the color filter layer 12 are set so that light of the corresponding color can pass through. The thicknesses of the high-refraction sub-layers and low-refraction sub-layers in the auxiliary filter layer 13 and the period number of the film system can be calculated according to the formula (2) and formula (3) in Embodiment 1, and will not be repeated here.

By extension, when the color filter layers 12 in the color filter substrate are different, the quantum dots arranged in the light excitation layer 34 in the backlight module 3 are also different. It is shown that the color of the light filtered by the color filter layer 12 should match the color of the visible light emitted by the quantum dots. When the color filter layer 12 of the color filter substrate in the liquid crystal display device changes, for example: when the color filter of the liquid crystal display device has four colors of red, green, blue, and white, the light excitation layer 34 should contain the excited energy Quantum dots that emit visible red and green light. According to this principle, if the color filter layer 12 of the liquid crystal display device is of other multiple colors, the light excitation layer 34 is doped with quantum dots that can emit different colors upon excitation according to the actual situation.

Other structures of the liquid crystal display device in this embodiment are the same as those in Embodiment 1, and the propagation process of light is similar to that in Embodiment 1, which will not be repeated here.

Example 3:

The difference between this embodiment and embodiments 1 and 2 lies in that in this liquid crystal display device, the backlight module 3 has a different structure from the backlight module 3 in embodiment 1.

In this embodiment, as shown in FIG. 6 , the backlight module 3 is a direct-type backlight module, and the direct-type backlight module 3 further includes a reflective sheet 32 and a diffuser plate 36 arranged in layers. The light source 31 It is disposed between the reflection sheet 32 and the diffusion plate 36 , and the light excitation layer 34 is disposed above the diffusion plate 36 . In order to obtain a better light source effect, the backlight module in this embodiment may further include a prism film (not shown in FIG. 6 ), and the prism film may be disposed above the light excitation layer 34 . The prism film is used to diffuse the light emitted from the diffuser plate 36, or to increase the brightness of the light, or to improve the uniformity of the light.

In this embodiment, the light propagation process differs from that in Embodiment 1 in that: in this embodiment, the light emitted by the light source 31 passes through the array substrate 2 , the liquid crystal 4 and the color filter substrate 1 from bottom to top. The reflection and transmission of the different color components in the light by the auxiliary filter layer 13 are the same as those in Embodiments 1 and 2, and will not be repeated here.

Other structures of the liquid crystal display device in this embodiment are the same as those in Embodiments 1 and 2, and will not be repeated here.

In the liquid crystal display device of the present invention, through the cooperation of the auxiliary filter layer that can reflect light of a specific wavelength in the color filter substrate and the photoexcitation layer that can emit light of a specific wavelength when excited by energy in the backlight module, first use a single The light of different colors is excited by the photoexciting layer to obtain light of various colors, and then before the light reaches the color filter layer, the auxiliary filter layer is used to selectively allow the light with a relatively long wavelength to pass through the color filter substrate, and a part of the original Light with a relatively short wavelength that may be absorbed by the color filter layer is reflected back to the backlight module. The liquid crystal display device not only ensures good display chromaticity, but also improves the light utilization rate of the backlight module.

It can be understood that, the above embodiments are only exemplary embodiments adopted for illustrating the principle of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims (10)

1. A liquid crystal display device, comprising a color filter substrate, an array substrate and a backlight module, the backlight module comprising a light source, characterized in that an auxiliary filter layer is arranged in the color filter substrate, and the backlight module A photoexciting layer is arranged in the center, and the photoexciting layer is excited by the main laser light emitted by the light source to generate a specific wavelength of the subject light, and the auxiliary filter layer can allow the subject light to selectively pass through the color filter substrate, and reflect the main laser light back to the backlight module. 2. The liquid crystal display device according to claim 1, wherein the color filter substrate further includes a color filter layer, the color filter layer includes a plurality of sub-color filter layers capable of transmitting light of different wavelengths, and the auxiliary The filter layer is arranged in a region of the color filter layer corresponding to the sub-color filter layer that can transmit wavelengths greater than the wavelength of the main laser, and is closer to the backlight module than the color filter layer. 3. The liquid crystal display device according to claim 2, wherein the color filter layer comprises a red sub-color filter layer, a green sub-color filter layer, and a blue sub-color filter layer, and the auxiliary filter layer is arranged on At least one area corresponding to the red sub-color filter layer and the green sub-color filter layer; Alternatively, the color filter layer includes a red sub-color filter layer, a yellow sub-color filter layer, a green sub-color filter layer, and a blue sub-color filter layer, and the auxiliary filter layer is arranged on the same side as the red sub-color filter layer, the green sub-color filter layer, and the green sub-color filter layer. At least one region corresponding to the color filter layer and the yellow sub-color filter layer. 4. The liquid crystal display device according to claim 3, wherein the auxiliary filter layer comprises a multi-layer sub-layer successively stacked at intervals by a material with a high refractive index and a material with a low refractive index, and the high refractive index The high refractive index material forms a high refractive sublayer, and the low refractive index material forms a low refractive sublayer. 5. The liquid crystal display device according to claim 4, wherein the high-refractive sub-layer is formed by titanium dioxide material, and the thickness is one-eighth of the central wavelength of the cut-off band; the low-refractive layer is formed by silicon dioxide material , the thickness is a quarter of the central wavelength of the cut-off band. 6 . The liquid crystal display device according to claim 5 , wherein the photoexcitation layer contains quantum dots, and the quantum dots are at least one of red quantum dots, green quantum dots or yellow quantum dots. 7. The liquid crystal display device according to claim 6, wherein the light source is a blue light source, and the light emitted by the quantum dots after being excited by the light emitted by the blue light source includes red light, green light or yellow light . 8. The liquid crystal display device according to any one of claims 1-7, wherein the color filter substrate further comprises a protective layer, a transparent electrode layer and an alignment layer stacked with the color filter layer, the The auxiliary filter layer is arranged between the color filter layer and the protective layer, or between the protective layer and the transparent electrode layer, or between the transparent electrode layer and the alignment layer . 9. The liquid crystal display device according to claim 8, wherein the backlight module is an edge-type backlight module, and the edge-type backlight module further comprises a reflective sheet, a light guide plate and a prism arranged in layers film, the light source is arranged on the sides of the reflective sheet, the light guide plate and the prism film, and the light excitation layer is arranged between the light guide plate and the prism film. 10. The liquid crystal display device according to claim 8, wherein the backlight module is a direct-type backlight module, and the direct-type backlight module further includes a reflection sheet and a diffusion plate stacked, and the light source It is arranged between the reflective sheet and the diffusion plate, and the light excitation layer is arranged above the diffusion plate.

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