CN110646980B

CN110646980B - Liquid crystal display

Info

Publication number: CN110646980B
Application number: CN201910936195.3A
Authority: CN
Inventors: 黄海涛; 徐传祥; 舒适; 于勇; 岳阳; 李翔
Original assignee: BOE Technology Group Co Ltd
Current assignee: BOE Technology Group Co Ltd
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2022-07-29
Anticipated expiration: 2039-09-29
Also published as: CN110646980A

Abstract

The embodiment of the invention provides a liquid crystal display, relates to the technical field of display, and can solve the problem of poor color gamut or poor brightness of the liquid crystal display. The liquid crystal display includes a first liquid crystal cell; the first liquid crystal box comprises a first light-emitting pattern positioned at the first sub-pixel and a second light-emitting pattern positioned at the second sub-pixel; the backlight system is used for emitting monochromatic light; the first light-emitting pattern and the second light-emitting pattern emit first color light and second color light under the excitation of monochromatic light; the monochromatic light is third-color light; or the monochromatic light is different from the first color light, the second color light and the third color light, the first liquid crystal box further comprises a third light-emitting pattern located in a third subpixel, and the third light-emitting pattern emits the third color light under the excitation of the monochromatic light; the material of the first light-emitting pattern, the material of the second light-emitting pattern and the material of the third light-emitting pattern are quantum dot light-emitting materials or color conversion materials; the color conversion material is an up-conversion luminescent material or a down-conversion luminescent material.

Description

Liquid crystal display

Technical Field

The invention relates to the technical field of display, in particular to a liquid crystal display.

Background

In recent years, Liquid Crystal Displays (LCDs) have been widely used because of their advantages of low power consumption, light weight, soft picture, and no damage to eyes.

However, compared to an Organic Light-Emitting Diode (oled) display, the lcd has poor brightness and color gamut, which affects the display effect of the lcd and further affects the experience of the user.

Disclosure of Invention

The embodiment of the invention provides a liquid crystal display, which can solve the problem of poor color gamut or poor brightness of the liquid crystal display.

In order to achieve the above purpose, the embodiment of the invention adopts the following technical scheme:

providing a liquid crystal display comprising a first sub-pixel, a second sub-pixel and a third sub-pixel, the liquid crystal display comprising a first liquid crystal cell; the first liquid crystal cell includes a first light emitting pattern at the first sub-pixel and a second light emitting pattern at the second sub-pixel; the liquid crystal display further includes: a backlight system; the backlight system is used for emitting monochromatic light; the first light-emitting pattern emits first color light under the excitation of the monochromatic light; the second light-emitting pattern emits second color light under the excitation of the monochromatic light; the monochromatic light is third-color light; or the monochromatic light is different from the first color light, the second color light and the third color light, the first liquid crystal box further comprises a third light-emitting pattern located in the third sub-pixel, and the third light-emitting pattern emits the third color light under the excitation of the monochromatic light; the first, second, and third color lights are three primary colors of light; wherein the material of the first light emitting pattern, the material of the second light emitting pattern, and the material of the third light emitting pattern are quantum dot light emitting materials or color conversion materials; the color conversion material is an up-conversion luminescent material or a down-conversion luminescent material.

In some embodiments, the liquid crystal display further comprises a second liquid crystal cell; the sub-pixels in the first liquid crystal box correspond to the sub-pixels in the second liquid crystal box one by one.

In some embodiments, the monochromatic light is the third color light, the wavelength of the third color light being smaller than the wavelength of the first color light and the wavelength of the second color light; the material of the first light-emitting pattern and the material of the second light-emitting pattern are quantum dot light-emitting materials.

In some embodiments, the third color light is blue light, and the first and second color lights are red and green light, respectively.

In some embodiments, the monochromatic light is the third color light, and the wavelength of the third color light is greater than that of the second color light and less than that of the first color light; the material of the first light emitting pattern is a down-conversion light emitting material, and the material of the second light emitting pattern is an up-conversion light emitting material.

In some embodiments, the third color light is green light, the second color light is blue light, and the first color light is red light.

In some embodiments, the backlight system includes a backlight assembly and a monochromatic light exit layer disposed at a light exit side of the backlight assembly; the backlight assembly is used for emitting white light; the white light emitted by the backlight assembly passes through the monochromatic light emitting layer and then is emitted as monochromatic light.

In some embodiments, the monochromatic light exit layer comprises at least one layer of nano-metal grating; each layer of the nano metal grating comprises a grating layer, a metal layer and a protective layer which are sequentially stacked.

In some embodiments, the liquid crystal display further includes a color filter layer disposed on a side of the first, second, and third light emission patterns away from the backlight system; the color filter layer comprises a first photoresist pattern positioned at the first sub-pixel, a second photoresist pattern positioned at the second sub-pixel and a third photoresist pattern positioned at the third sub-pixel; the first photoresist pattern is used for transmitting the first color light; the second photoresist pattern is used for transmitting the second color light; the third photoresist pattern is used for transmitting the third color light.

In some embodiments, the liquid crystal display further includes a light blocking layer disposed at a side of the first and second light emitting patterns away from the backlight system; the monochromatic light is a third color light, the light blocking layer is positioned in the third sub-pixel, part of the light blocking layer is hollow, and the light blocking layer is used for blocking the third color light in the external environment light from being emitted to the first light emitting pattern and the second light emitting pattern.

The embodiment of the invention provides a liquid crystal display, which comprises a first liquid crystal box, wherein the first liquid crystal box comprises a first light-emitting pattern positioned at a first sub-pixel and a second light-emitting pattern positioned at a second sub-pixel. The liquid crystal display further includes: a backlight system; the backlight system is used for emitting monochromatic light; the first light-emitting pattern emits first color light under the excitation of the monochromatic light; the second light-emitting pattern emits second color light under the excitation of the monochromatic light; the monochromatic light is third color light; the first color light, the second color light and the third color light are three primary color lights; or the monochromatic light is different from the first color light, the second color light and the third color light, the first liquid crystal box further comprises a third light-emitting pattern located in a third sub-pixel, and the third light-emitting pattern emits the third color light under the excitation of the monochromatic light. Because the material of the first light-emitting pattern, the material of the second light-emitting pattern and the material of the third light-emitting pattern are quantum dot light-emitting materials or color conversion materials, and under the condition that the material of the first light-emitting pattern, the material of the second light-emitting pattern and the material of the third light-emitting pattern are quantum dot light-emitting materials, the color gamut of light emitted by exciting the quantum dot light-emitting materials by using monochromatic light is better, compared with the white light emitted by a backlight system, the color filters emit the first color light, the second color light and the third color light, the color gamut of the liquid crystal display can be improved, and the defect of the liquid crystal display in the color gamut aspect is compensated. Under the condition that the materials of the first light-emitting pattern, the second light-emitting pattern and the third light-emitting pattern are color conversion materials, the luminance of light emitted by the color conversion materials is higher by utilizing monochromatic light, so that compared with a backlight system, white light is emitted, and the first color light, the second color light and the third color light are emitted through the color filter, the luminance of the liquid crystal display can be improved, and the defect of the liquid crystal display in the luminance aspect is overcome. Based on this, the user experience of the product can be improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or technical solutions in related arts, the drawings used in the description of the embodiments or related arts will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a schematic diagram of area division of a liquid crystal display according to an embodiment of the present invention.

Fig. 2a is a first schematic structural diagram of a liquid crystal display according to an embodiment of the present invention;

fig. 2b is a schematic structural diagram of a liquid crystal display according to an embodiment of the invention;

fig. 3a is a schematic structural diagram of a liquid crystal display according to an embodiment of the invention;

fig. 3b is a schematic structural diagram of a liquid crystal display according to a fourth embodiment of the present invention;

fig. 4 is a schematic structural diagram of a first array substrate according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a color gamut provided by an embodiment of the present invention;

fig. 6a is an intensity curve of red light emitted by the first light-emitting pattern excited by green light and an intensity curve of red light emitted by white light after passing through the color filter according to the embodiment of the present invention;

FIG. 6b is a graph showing the intensity of green light emitted from a third subpixel and the intensity of green light emitted from a color filter after white light passes through the color filter according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a liquid crystal display according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a backlight assembly according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of another backlight assembly according to an embodiment of the present invention;

fig. 10 is a sixth schematic structural diagram of a liquid crystal display according to an embodiment of the present invention;

fig. 11a is a schematic structural diagram of a nanometal grating according to an embodiment of the present invention;

fig. 11b is a schematic structural diagram of another nanometal grating provided in the embodiment of the present invention;

FIG. 12a is a schematic view of a grating layer in a nanometal grating under a scanning electron microscope according to an embodiment of the present invention;

FIG. 12b is a schematic view of a grating layer under an atomic force microscope in a nano metal grating according to an embodiment of the present invention;

FIG. 13 is a simulated spectrum of transmission of a nano-metal grating according to an embodiment of the present invention;

FIG. 14 is a schematic diagram illustrating a structure of a photoresist layer formed on a third substrate according to an embodiment of the present invention;

Fig. 15 is a schematic structural diagram of forming a grating layer on a third substrate according to an embodiment of the present invention;

fig. 16 is a schematic structural diagram of forming a metal layer on a grating layer according to an embodiment of the present invention;

fig. 17 is a schematic structural diagram of forming a photoresist layer and a metal film on a third substrate according to an embodiment of the present invention;

FIG. 18 is a schematic structural diagram of a nanoimprinting template provided by an embodiment of the invention;

fig. 19 is a seventh schematic structural diagram of a liquid crystal display according to an embodiment of the invention;

fig. 20 is an eighth schematic structural diagram of a liquid crystal display according to an embodiment of the present invention.

Reference numerals:

01-a first subpixel; 02-second subpixel; 03-a third subpixel; 1-a display area; 2-a peripheral zone; 10-a first liquid crystal cell; 11-a first light emitting pattern; 12-a second light emitting pattern; 13-a third light emitting pattern; 14-a first array substrate; 15-a first pair of cassette substrates; 16-a first liquid crystal layer; 17-a spacer; 20-a second liquid crystal cell; 21-a second array substrate; 22-a second pair of cassette substrates; 23-a second liquid crystal layer; 30-a backlight system; 140-a first substrate base plate; 141-thin film transistors; 142-pixel electrodes; 143-a passivation layer; 150-a second substrate base; 151-black matrix pattern; 152-a first photoresist pattern; 153-second photoresist pattern; 154-third photoresist pattern; 155-a light blocking layer; 301-a backlight assembly; 302-monochromatic light emergent layer; 303-nano metal grating; 3011-a light source; 3012-a light guide plate; 3013-an optical film; 3014-a reflective sheet; 3031-a grating layer; 3032-a metal layer; 3033-protective layer; 3034-third substrate; 3035-nanoimprint template.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

An embodiment of the invention provides a liquid crystal display, as shown in fig. 1, including a display area 1 and a peripheral area 2 surrounding the display area 1, where the display area 1 includes a first sub-pixel 01, a second sub-pixel 02, and a third sub-pixel 03.

The first subpixel 01, the second subpixel 02, and the third subpixel 03 may be a red subpixel, a green subpixel, and a blue subpixel. Fig. 1 illustrates an example in which the first subpixel 01 is a red subpixel, the second subpixel 02 is a green subpixel, and the third subpixel 03 is a blue subpixel.

As shown in fig. 2a, 2b, 3a and 3b, the liquid crystal display comprises a first liquid crystal cell 10; the first liquid crystal cell 10 includes a first light emitting pattern 11 at the first subpixel 01 and a second light emitting pattern 12 at the second subpixel 02. The liquid crystal display further includes: a backlight system 30; the backlight system 30 is used for emitting monochromatic light; the first light-emitting pattern 11 emits a first color light under excitation of the monochromatic light; the second light emitting pattern 12 emits a second color light under excitation of the monochromatic light; as shown in fig. 2a and 3a, the monochromatic light is a third color light; the first color light, the second color light and the third color light are three primary color lights; alternatively, the monochromatic light is different from the first color light, the second color light and the third color light, as shown in fig. 2b and fig. 3b, the first liquid crystal cell 10 further includes a third light emitting pattern 13 located in the third subpixel 03, and the third light emitting pattern 13 emits the third color light under the excitation of the monochromatic light.

Wherein, the material of the first light emitting pattern 11, the material of the second light emitting pattern 12, and the material of the third light emitting pattern 13 are quantum dot light emitting materials or color conversion materials; the color conversion material is an up-conversion luminescent material or a down-conversion luminescent material.

It should be understood that, in the case where the monochromatic light is the third color light, the first liquid crystal cell 10 does not include the third light emitting pattern 13, and the monochromatic light passes through the third sub-pixel, which emits the third color light.

Here, the first, second, and third color lights are three primary colors, and the three primary colors may be red (R), green (G), and blue (B) lights, respectively.

It is considered that, in the case where the monochromatic light is the third color light, since the first liquid crystal cell 10 does not include the third light emitting pattern 13 at the third subpixel 03 but includes the first light emitting pattern 11 at the first subpixel 01 and the second light emitting pattern 12 at the second subpixel 02, the first subpixel 01, the second subpixel 02 and the third subpixel 03 are not flat. Based on this, in some embodiments, in the case that the monochromatic light is the third color light, the first liquid crystal cell 10 includes a filling pattern located at the third subpixel 03, and the filling pattern is in a transparent state.

As shown in fig. 2a, 2b, 3a and 3b, the first liquid crystal cell 10 includes a first array substrate 14 and a first pair of cell substrates 15 disposed opposite to each other, and a first liquid crystal layer 16 disposed between the first array substrate 14 and the first pair of cell substrates 15. In order to maintain the first liquid crystal cell 10 at a certain cell thickness, the first liquid crystal cell 10 further includes spacers (PS) 17 disposed between the first array substrate 14 and the first pair of cell substrates 15. In some embodiments, the Spacer 17 is a Black Photo Spacer (BPS).

The monochromatic light emitted by the backlight system 30 passes through the first liquid crystal cell 10 and then respectively emits the first color light, the second color light and the third color light, so as to avoid color mixing of the different colors of light and influence the display effect, therefore, in some embodiments, as shown in fig. 2a, fig. 2b, fig. 3a and fig. 3b, the first liquid crystal cell 10 further includes a black matrix pattern 151, and the black matrix pattern 151 is used for spacing the first subpixel 01, the second subpixel 02 and the third subpixel 03 so as to space the first color light, the second color light and the third color light.

Since the first liquid crystal cell 10 includes the first and second

light emitting patterns

11 and 12, and in some embodiments, the first liquid crystal cell 10 further includes the third light emitting pattern 13, the first liquid crystal cell 10 may be referred to as a display Panel (Panel).

As shown in fig. 4, the first array substrate 14 includes a first substrate 140, and a thin film transistor 141 and a pixel electrode 142 disposed on the first substrate 140 and at each sub-pixel. The thin film transistor 141 includes a Source electrode (Source), a Drain electrode (Drain), an Active layer (ACT for short), a Gate electrode (Gate), and a Gate insulating layer (GI for short), the Source electrode and the Drain electrode are respectively in contact with the Active layer, and the pixel electrode 142 passes through a via hole on a Passivation layer (PVX) 143 and is electrically connected to the Drain electrode of the thin film transistor 141.

Here, the thin film transistor 141 may be a top gate thin film transistor or a bottom gate thin film transistor.

The material of the pixel electrode 142 may be Indium Tin Oxide (ITO), for example.

The first array substrate 14 may be fabricated, for example, by: forming a gate electrode on the first substrate 140; forming a gate insulating layer on the gate electrode; forming an active layer on the gate insulating layer; forming a source electrode and a drain electrode on the active layer, the source electrode and the drain electrode being in contact with the active layer, respectively; forming a passivation layer 143 on the source and drain electrodes; a pixel electrode 142 is formed on the passivation layer 143, and the pixel electrode 142 is electrically connected to the drain electrode through a via hole on the passivation layer 143.

In some embodiments, the first array substrate 14 further includes a common electrode disposed on the first substrate 140. The pixel electrode 142 and the common electrode may be disposed at the same layer, in which case the pixel electrode 142 and the common electrode are each a comb-tooth structure including a plurality of strip-shaped sub-electrodes. The pixel electrode 142 and the common electrode may also be disposed at different layers, in which case the first insulating layer is disposed between the pixel electrode 142 and the common electrode. In the case where the common electrode is provided between the thin film transistor 141 and the pixel electrode 142, a second insulating layer is further provided between the common electrode and the thin film transistor 141. In other embodiments, the first pair of cartridge substrates 15 includes a common electrode.

The first liquid crystal cell 10 is manufactured by the following steps: after the first array substrate 14 and the first pair of cell substrates 15 are aligned, liquid crystal is poured to form the first liquid crystal cell 10.

On this basis, the first liquid crystal cell 10 includes the first light emitting pattern 11 and the second light emitting pattern 12, or further includes the third light emitting pattern 13, and it may be that the first array substrate 14 includes the first light emitting pattern 11, the second light emitting pattern 12, and the third light emitting pattern 13; the first pair of cassette substrates 15 may include the first light-emitting pattern 11, the second light-emitting pattern 12, and the third light-emitting pattern 13. Fig. 2b and 3b illustrate an example in which the first pair of cassette substrates 15 includes the first light-emitting pattern 11, the second light-emitting pattern 12, and the third light-emitting pattern 13. The first, second, and third

light emitting patterns

11, 12, and 13 may be disposed on the second substrate base 150 in the first pair of cassette bases 15.

It should be understood that the liquid crystal display further includes a first polarizer and a second polarizer disposed at both sides of the first liquid crystal cell 10.

It will be appreciated by those skilled in the art that quantum dot luminescent materials can absorb a broad spectrum of light and emit light of a narrow spectrum that has a color gamut superior to that of the broad spectrum. Referring to fig. 5, the region B is the NTSC color gamut and the region a is the color gamut of the light emitted by the quantum dot material, and as can be seen from fig. 5, the color gamut of the light emitted by the quantum dot material is larger. Based on this, compared to the case where the light emitted from the backlight system 30 passes through the color filter to emit the first color light, the second color light, and the third color light, in the embodiment of the present invention, when the material of the first light emitting pattern 11, the material of the second light emitting pattern 12, and the material of the third light emitting pattern 13 are quantum dot light emitting materials, the monochromatic light is used to excite the first light emitting pattern 11 to emit the first color light, excite the second light emitting pattern 12 to emit the second color light, and excite the third light emitting pattern 13 to emit the third color light, so that the color gamut of the first color light, the second color light, and the third color light is improved.

It should be understood that the upconversion luminescent material means a material that can continuously emit light with a shorter wavelength than the excitation wavelength under excitation of long wavelength light. Down-converting luminescent materials refer to materials that can continue to emit light at wavelengths longer than the excitation wavelength, under excitation of short wavelength light.

The up-converting luminescent material and the down-converting luminescent material both comprise a fluorescent material.

In the case where the material of the first light emitting pattern 11, the material of the second light emitting pattern 12, and the material of the third light emitting pattern 13 are color conversion materials (the color conversion materials are up-conversion light emitting materials or down-conversion light emitting materials), since the color conversion materials emit light under excitation of the monochromatic light and the luminance of the emitted light is greater than that of the monochromatic light, the luminance of the first color light and the second color light is greater than that of the monochromatic light. In the case where the monochromatic light and the third color light are not the same, the monochromatic light excites the third light emitting pattern 13 to emit the third color light having a luminance greater than that of the monochromatic light.

For example, the first color light is red, the second color light is blue, and the third color light is green, a curve a in fig. 6a is an intensity curve of red light emitted by the first light-emitting pattern 11 excited by the green light, a curve b is an intensity curve of red light emitted by the white light after passing through the color filter, a curve c in fig. 6b is an intensity curve of green light emitted from the third subpixel, and a curve d is an intensity curve of green light emitted by the white light after passing through the color filter. The luminance of the red sub-pixel is improved by 19.74% as seen in fig. 6a, and the luminance of the green sub-pixel is improved by 4.77% as seen in fig. 6b, which improves the overall luminance of the lcd by 9%.

The embodiment of the invention provides a liquid crystal display, which comprises a first liquid crystal box 10, wherein the first liquid crystal box 10 comprises a first light-emitting pattern 11 positioned at a first sub-pixel 01 and a second light-emitting pattern 12 positioned at a second sub-pixel 02. The liquid crystal display further includes: a backlight system 30; the backlight system 30 is used for emitting monochromatic light; the first light-emitting pattern 11 emits a first color light under excitation of the monochromatic light; the second light emitting pattern 12 emits a second color light under excitation of the monochromatic light; the monochromatic light is third color light; the first color light, the second color light and the third color light are three primary color lights; or, the monochromatic light is different from the first color light, the second color light, and the third color light, the first liquid crystal cell 10 further includes a third light emitting pattern 13 located in the third subpixel 03, and the third light emitting pattern 13 emits the third color light under excitation of the monochromatic light. Since the material of the first light emitting pattern 11, the material of the second light emitting pattern 12, and the material of the third light emitting pattern 13 are quantum dot light emitting materials or color conversion materials, in the case that the material of the first light emitting pattern 11, the material of the second light emitting pattern 12, and the material of the third light emitting pattern 13 are quantum dot light emitting materials, since the color gamut of light emitted by exciting the quantum dot light emitting materials with monochromatic light is more excellent, the color gamut of the liquid crystal display can be improved compared to the color gamut of the backlight system 30, and the first color light, the second color light, and the third color light are emitted through the color filter, so that the defect of the liquid crystal display in the color gamut can be compensated. In the case where the material of the first light emitting pattern 11, the material of the second light emitting pattern 12, and the material of the third light emitting pattern 13 are color conversion materials, since the luminance of light emitted by the color conversion materials is higher by excitation of monochromatic light, the luminance of the liquid crystal display can be improved and the defect of the liquid crystal display in luminance can be compensated by emitting the first color light, the second color light, and the third color light through the color filter, compared with the case where the backlight system 30 emits white light. Based on this, the user experience of the product can be improved.

Optionally, as shown in fig. 3a and 3b, the liquid crystal display further includes a second liquid crystal cell 20; the sub-pixels in the first liquid crystal cell 10 and the sub-pixels in the second liquid crystal cell 20 correspond one to one.

In the case where the liquid crystal display provided by the embodiment of the present invention further includes the second liquid crystal Cell 20, the liquid crystal display is a Dual Cell (Dual Cell) liquid crystal display. The double-box liquid crystal display can realize hundred thousand-level ultrahigh dynamic contrast by adopting a million-level pixel partition technology; meanwhile, the color depth can reach 12bit, the low-gray scale transition is more natural, the better color expression can be realized, each display detail is vivid, the ultra-high definition display effect of 'not only black' is realized, and a viewer can feel brand-new shocking experience.

The second liquid crystal cell 20 in a dual cell liquid crystal display may be referred to as a light control panel.

In some embodiments, the first liquid crystal cell 10 is proximate to the backlight system 30 relative to the second liquid crystal cell 20. In other embodiments, the second liquid crystal cell 20 is proximate to the backlight system 30 relative to the first liquid crystal cell 10.

As shown in fig. 3a and 3b, the second liquid crystal cell 20 includes a second array substrate 21 and a second pair of cell substrates 22 that are oppositely disposed, and a second liquid crystal layer 23 disposed between the second array substrate 21 and the second pair of cell substrates 22. In order to maintain the second liquid crystal cell 20 at a certain cell thickness, the second liquid crystal cell 20 further includes spacers 17 disposed between the second array substrate 21 and the second pair of cell substrates 22. In some embodiments, the spacer 17 is a black spacer.

The structure and the manufacturing method of the second array substrate 21 can refer to the structure and the manufacturing method of the first array substrate 14, and the structure and the manufacturing method of the second array substrate 21 can be the same as those of the first array substrate 14, and since the structure and the manufacturing method of the first array substrate 14 have been described in detail in the above embodiments, they are not described again here.

The first liquid crystal cell 10 and the second liquid crystal cell 20 are stacked, and the first array substrate 14 and the second pair of cell substrates 22 may be adjacent to each other; the first array substrate 14 and the second array substrate 21 may be close to each other; the first pair of cassette substrates 15 and the second pair of cassette substrates 22 may be close to each other; of course, the first pair of cassette substrates 15 and the second array substrate 21 may be close to each other. On this basis, the substrate boards of the two boards close to each other can be shared. For example, if the first array substrate 14 and the second pair of cassette substrates 22 are close to each other, the first substrate 140 of the first array substrate 14 and the substrate of the second pair of cassette substrates 22 may be shared.

The second liquid crystal cell 20 is fabricated in a similar manner to the first liquid crystal cell 10, and will not be described in detail herein. In the embodiment of the present invention, the first liquid crystal cell 10 and the second liquid crystal cell 20 may be manufactured first, and then the first liquid crystal cell 10 and the second liquid crystal cell 20 are bonded to each other, so that a sub-pixel of the first liquid crystal cell 10 is aligned with a sub-pixel of the second liquid crystal cell 20.

In case that the liquid crystal display includes the second liquid crystal cell 20, the liquid crystal display further includes a third polarizer disposed at a side of the second liquid crystal cell 20 adjacent to the backlight system 30.

In the case where the monochromatic light is a third color light, and the material of the first light emitting pattern 11 and the material of the second light emitting pattern 12 are quantum dot light emitting materials, the third color light is used to excite the first light emitting pattern 11 to emit the first color light and excite the second light emitting pattern 12 to emit the second color light, respectively. Considering that the quantum dot luminescent material is characterized by absorbing a short wavelength spectrum and emitting a long wavelength spectrum, in some embodiments, the wavelength of the third color light is smaller than the wavelength of the first color light and the wavelength of the second color light.

Here, since the light emission spectrum of the quantum dot light-emitting material is determined by the size of the quantum dot material, the quantum dot material having a corresponding size can be selected according to the light spectrum that the quantum dot light-emitting material needs to emit light.

Illustratively, the third color light is blue light, and the first and second color lights are red and green light, respectively. In this way, the first and second

light emitting patterns

11 and 12 may be excited with blue light to emit red and green light, respectively.

In the case where the monochromatic light is the third color light, the material of the first light emitting pattern 11 is the down-conversion light emitting material, and the material of the second light emitting pattern 12 is the up-conversion light emitting material, the wavelength of the third color light is greater than that of the second color light and less than that of the first color light.

Illustratively, the third color light is green light, the second color light is blue light, and the first color light is red light. By doing so, the green light may excite the first light emitting pattern (down-conversion light emitting material) 11 to emit red light, and excite the second light emitting pattern (up-conversion light emitting material) 12 to emit blue light.

The absorption spectrum of the down-converting luminescent material may be, for example, 430nm to 580nm, and the emission spectrum may be 580nm to 660 nm. The down-conversion luminescent material may be, for example, oxadiazole and its derivatives, triazole and its derivatives, rhodamine and its derivatives, coumarin derivatives, 1, 8-naphthalimide derivatives, pyrazoline derivatives, triphenylamine derivatives, porphyrin compounds, carbazole, pyrazine, thiazole derivatives, perylene derivatives, or the like.

The up-conversion luminescent materials all occur in compounds doped with rare earth ions, and the compounds mainly include fluoride, oxide, sulfur-containing compound, oxyfluoride, halide and the like. In some embodiments, the upconversion luminescent material is a rare earth doped NaYF4 nanocrystal-based material.

In some embodiments, as shown in fig. 7, the backlight system 30 includes a backlight assembly 301 and a monochromatic light exit layer 302 disposed at a light exit side of the backlight assembly 301; the backlight assembly 301 is for emitting white light; the white light emitted from the backlight assembly 301 passes through the monochromatic light emitting layer 302 and then is emitted as monochromatic light.

Here, as shown in fig. 8 and 9, the backlight assembly 301 includes a light source 3011, a light guide plate 3012, and an optical film 3013 disposed on the light exit side of the light guide plate 3012. In the embodiment of the present invention, the optical film 3013 may include a diffusion sheet, a brightness enhancement film, or the like. The Brightness Enhancement Film may include a prism Film (BEF), a reflection type polarization Brightness Enhancement Film (DBEF), and the like, and both of them may be used in combination. The light guide plate 3012 may be wedge-shaped or flat, and fig. 8 illustrates the light guide plate 3012 as a wedge. As shown in fig. 8, the light source 3011 may be disposed at a side surface of the light guide plate 3012, in which case the backlight assembly 301 is a side-in type backlight assembly. As shown in fig. 9, the light source 3011 may be disposed on a side of the light guide plate 3012 away from the light emitting side, in which case the backlight assembly 301 is a direct-type backlight assembly. The Light source 3011 may be, for example, a Light-Emitting Diode (LED).

In the case that the backlight assembly 301 is a direct-type backlight assembly, the lamp panel may be made of tiny blue LEDs arranged in an array manner, and the light emitting direction of the lamp panel faces the first liquid crystal cell 10 and the second liquid crystal cell 20.

On this basis, as shown in fig. 8 and 9, the backlight assembly 301 may further include a reflective sheet 3014, and the reflective sheet 3014 is disposed on a side of the light guide plate 3012 away from the light exit side.

For example, as shown in fig. 9, a direct type backlight assembly is provided, in which an LED is used as a light source 3011 to form a lamp panel, an optical film 3013 is disposed above the lamp panel, and a reflective sheet 3014 is disposed below the light source 3011.

On this basis, the monochromatic light exit layer 302 is not limited, and the light emitted after the white light passes through the monochromatic light exit layer 302 is referred to as monochromatic light. In some embodiments, the monochromatic light exit layer 302 is an optical filter. For example, if the monochromatic light emitted from the backlight system 30 is green light, the filter is a green filter. For another example, if the monochromatic light emitted from the backlight system 30 is blue light, the filter is a blue filter. In other embodiments, as shown in fig. 10, 11a and 11b, the monochromatic light exit layer 302 includes at least one layer of nano metal grating 303, and each layer of nano metal grating 303 includes a grating layer 3031, a metal layer 3032 and a protection layer 3033, which are sequentially stacked.

In the case where the monochromatic light exit layer 302 includes at least one layer of nano-metal grating 303, in some embodiments, the nano-metal grating 303 includes a plurality of sub-nano-metal gratings, one sub-nano-metal grating corresponding to one sub-pixel, and the monochromatic light exit layer 302 further includes a separation pattern for separating the plurality of sub-nano-metal gratings.

It will be understood by those skilled in the art that the nanometal grating 303 can also function as a polarizer, i.e., the light emitted from the nanometal grating 303 is polarized, in addition to the function of filtering, i.e., passing a specific wavelength band of light.

Here, the monochromatic light exit layer 302 may include a layer of nano-metal grating 303; two or more layers of the nanometal grating 303 may also be included. Fig. 10, 11a and 11b illustrate the monochromatic light emitting layer 302 including a layer of nano-metal grating 303 as an example.

Fig. 12a and 12b are a schematic diagram of the grating layer 3031 under a Scanning Electron Microscope (SEM) and an Atomic Force Microscope (AFM) in the nanometal grating 303 respectively.

In some embodiments, as shown in fig. 10, 11a, and 11b, the nanometal grating 303 may be disposed on a third substrate 3034, and the third substrate 3034 may be, for example, a glass substrate.

In some embodiments, as shown in fig. 11a, the orthographic projections of the grating layer 3031 and the protective layer 3033 on the third substrate 3034 have no overlapping region. In other embodiments, as shown in fig. 11b, the orthographic projections of the grating layer 3031 and the protective layer 3033 on the third substrate 3034 have an overlapping region.

Here, the material of the metal layer 3032 is not limited, and the material of the metal layer 3032 includes, but is not limited to, aluminum, copper, and silver. In addition, the thickness of the metal layer 3032 is not limited, and may be set as needed. In some embodiments, the metal layer 3032 has a thickness of 40nm to 70 nm. For example, when the monochromatic light emitted from the nanometal grating 303 is blue light, the thickness of the metal layer 3032 may be 50 nm. For example, when the monochromatic light emitted from the nanometal grating 303 is green light, the thickness of the metal layer 3032 may be 70 nm.

The material of the grating layer 3031 may be, for example, Photoresist (PR), which is typically an acrylic resin material. The period of the grating layer 3031 is not limited, and the period of the grating layer 3031 may be determined according to the wavelength of light emitted from the nanometal grating 303 as needed. The thickness of the grating layer 3031 is not limited, and may be set as needed. For example, when the monochromatic light emitted from the nanometal grating 303 is blue light, as shown in fig. 11a and 11b, the period L of the grating layer 3031 may be 420nm, and the duty ratio of the grating bars in the grating layer 3031 occupying the period of the grating layer 3031 may be 0.8. The sum of the heights of the grating layer 3031 and the metal layer 3032 may be 100 nm. For another example, when the monochromatic light emitted from the nanometal grating 303 is green light, the period L of the grating layer 3031 may be 520nm, and the duty ratio of the grating bars in the grating layer 3031 to the period of the grating layer 3031 may be 0.8. The sum of the heights of the grating layer 3031 and the metal layer 3032 may be 120 nm.

With respect to nanometal grating 303, it will be understood by those skilled in the art that the color of light exiting nanometal grating 303 can be controlled by controlling the period of grating layer 3031 and the refractive index of the material of protective layer 3033. Optionally, the refractive index of the material of the protective layer 3033 is 1-2.5. Based on this, for example, the period of the grating layer 3031 and the refractive index of the material of the protective layer 3033 may be adjusted to make the white light emit blue light after passing through the nano metal grating 303. For another example, the period of the grating layer 3031 and the refractive index of the material of the protective layer 3033 may be adjusted so that the white light emits green light after passing through the nanometal grating 303.

The principle of emitting light of different colors can be realized by using the nano metal grating 303 is described in detail below. The switching of emergent light colors can be realized by utilizing the surface plasma resonance effect of the nano metal grating 303 structure. The nano-metal grating 303 can be simulated by using a strict coupled-wave analysis (RCWA), and based on the double-layer nano-metal grating 303 with a specific period, the resonant wavelength of the double-layer nano-metal grating is changed by changing the refractive index of the material of the protective layer 3033, so that the switching of the emergent light color is realized. The incident light on the surface of the nano-metal grating 303 may generate diffraction phenomenon, at this time, diffraction waves with different energy levels may appear, and different diffraction waves may be separated according to different diffraction angles. If the wave vector of the light wave of a certain diffraction order can match with the wave vector of the plasma wave (SPW), Surface Plasmon Resonance (SPR) occurs. When the surface plasmon resonance of the nanometal grating 303 is excited, the following formula will be satisfied.

Wherein k is ₀ Represents the wave number in vacuum, theta represents the incident angle of TM (Transverse Magnetic) polarized light, and n represents _a Is the refractive index of the material of the protective layer 3033 in contact with the grating layer 3031, T is the grating period of the grating layer 3031, k _sp Is the wave number, ε, of a surface plasmon wave _m Is the dielectric constant of the metal layer 3032 under the Lorantz-Drudem model, and n is an integer and represents the diffraction order. According to k ₀ The wavelength of the light exiting the nanometal grating 303 can be calculated.

According to the above formula, it can be realized that different colors of light can be emitted by changing the period of the grating layer 3031 in the nano metal grating 303 and the refractive index of the protective layer 3033. Fig. 13 is a simulated spectrum of the transmission of the nanometal grating 303, in fig. 13, curve 1 is a spectrum of blue light, curve 2 is a spectrum of green light, and curve 3 is a spectrum of red light. As can be seen from fig. 13, the control of the emitted blue light, green light, or red light can be achieved by changing the period of the grating layer 3031 in the nanometal grating 303 and the refractive index of the protective layer 3033.

Based on the above, the process for manufacturing the nano metal grating 303 is not limited, and the process for manufacturing the nano metal grating 303 includes, but is not limited to, electron beam exposure, nano imprinting, or photolithography.

Two ways are provided below to describe in detail the preparation process of the grating layer 3031 and the metal layer 3032 in the nanometal grating 303.

The first method comprises the following steps: as shown in fig. 14, a photoresist layer 3031a is formed on the third substrate 3034. As shown in fig. 15, the photoresist layer 3031a is exposed (exposed by laser interference or light irradiation) to form a grating layer 3031. As shown in fig. 16, a metal thin film is evaporated using an electron beam to form a metal layer 3032 on the grating layer 3031.

And the second method comprises the following steps: as shown in fig. 17, a photoresist layer 3031a and a metal thin film 3032a are sequentially formed on the third base substrate 3034. The photoresist layer 3031a and the metal film 3032a are imprinted using the nanoimprint template 3035 shown in fig. 18, thereby forming the grating layer 3031 and the metal layer 3032 shown in fig. 11a and 11 b.

In the embodiment of the present invention, when the monochromatic light emitting layer 302 includes at least one layer of nano metal grating 303, the efficiency of the emitted monochromatic light is higher after the light emitted by the backlight system 30 passes through the nano metal grating 303. In addition, since the nanometal grating 303 can also function as a polarizer, in case the liquid crystal display does not include the second liquid crystal cell 20, the nanometal grating 303 can replace a conventional second polarizer disposed at a side of the first liquid crystal cell 10 close to the backlight system 30; in the case that the liquid crystal display includes the second liquid crystal cell 20, the nano-metal grating 303 may replace a conventional third polarizer disposed at a side of the second liquid crystal cell 20 close to the backlight system 30, and thus, both filtering and polarization functions may be performed by using the nano-metal grating 303. Because the thickness of the nano metal grating 303 is much smaller than that of a conventional polarizer, the effect of thinning the whole liquid crystal display can be achieved, and the experience of a user is further improved.

In some embodiments, as shown in fig. 19, the liquid crystal display further includes a color filter layer disposed on a side of the first light emitting patterns 11, the second light emitting patterns 12, and the third light emitting patterns 13 away from the backlight system 30; the color filter layer includes a first photoresist pattern 152 located in the first sub-pixel, a second photoresist pattern 153 located in the second sub-pixel, and a third photoresist pattern 154 located in the third sub-pixel; the first photoresist pattern 152 is used for transmitting the first color light; the second photoresist pattern 153 is used for transmitting the second color light; the third photoresist pattern 154 is used to transmit the third color light.

It should be understood that in case the liquid crystal display includes only the first and second

light emitting patterns

11 and 12, and does not include the third light emitting pattern 13, the color filter layer is disposed at a side of the first and second

light emitting patterns

11 and 12 away from the backlight system 30.

Here, in the case where the liquid crystal display includes the first liquid crystal cell 10 and the second liquid crystal cell 20, it may be that the first liquid crystal cell 10 includes a color filter layer; it is also possible that the second liquid crystal cell 20 comprises a color filter layer. In addition, the color filter layer and the first, second, and third light-emitting

patterns

11, 12, and 13 may be provided on the same base substrate or different base substrates. Illustratively, as shown in fig. 19, the first pair of cell substrates 15 in the first liquid crystal cell 10 includes a color filter layer and first, second and third

light emitting patterns

11, 12 and 13, that is, the color filter layer and the first, second and third

light emitting patterns

11, 12 and 13 are all disposed on the second substrate 150.

In addition, the first, second, and

third photoresist patterns

152, 153, and 154 may be spaced apart by the black matrix pattern 151.

On this basis, the first photoresist pattern 152, the second photoresist pattern 153 and the third photoresist pattern 154 can be respectively manufactured by utilizing the processes of coating photoresist, mask exposure, development and post-baking.

In some embodiments, the first liquid crystal cell 10 further includes a planarization layer (OC) disposed on a side of the first, second, and third

light emitting patterns

11, 12, and 13 adjacent to the first liquid crystal layer 16.

In the embodiment of the present invention, the color filter layer is disposed on the sides of the first light-emitting pattern 11, the second light-emitting pattern 12, and the third light-emitting pattern 13 away from the backlight system 30, on one hand, the color filter layer can make the wavelengths of the light emitted from the first sub-pixel, the second sub-pixel, and the third sub-pixel within a predetermined range; on the other hand, the color filter layer may block a portion of the external environment light from impinging on the first, second, and third

light emitting patterns

11, 12, and 13, thereby preventing the external environment light from exciting the first, second, and third

light emitting patterns

11, 12, and 13 to emit light in a dark state.

In some embodiments, as shown in fig. 20, the liquid crystal display further includes a light blocking layer 155 disposed at a side of the first and second

light emitting patterns

11 and 12 away from the backlight system 30; the monochromatic light is a third color light, the light blocking layer 155 is partially hollow out of the third subpixel 03, and the light blocking layer 155 is used for blocking the third color light in the external environment light from emitting to the first light emitting pattern 11 and the second light emitting pattern 12.

Here, since the light blocking layer 155 is partially hollowed out at the third subpixel 03, in order to avoid unevenness caused by the third blocking layer 155, in some embodiments, the liquid crystal display further includes a filling pattern at the third subpixel 03, and the filling pattern is in a transparent state.

In the embodiment of the invention, since the liquid crystal display further includes the light blocking layer 155, the light blocking layer 155 can block the third color light in the external environment light from being emitted to the first light emitting pattern 11 and the second light emitting pattern 12, thereby preventing the third color light in the external environment from exciting the first light emitting pattern 11 and the second light emitting pattern 12 to emit light in a dark state.

The above description is only for the specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A liquid crystal display comprises a first sub-pixel, a second sub-pixel and a third sub-pixel, and is characterized by comprising a first liquid crystal box; the first liquid crystal cell includes a first light emitting pattern at the first sub-pixel and a second light emitting pattern at the second sub-pixel;

the liquid crystal display further includes: a backlight system; the backlight system comprises a backlight component and a monochromatic light emergent layer arranged on the light emergent side of the backlight component; the monochromatic light emergent layer comprises at least one layer of nano metal grating; each layer of the nano metal grating comprises a grating layer, a metal layer and a protective layer which are sequentially stacked; the backlight system is used for emitting monochromatic light; the first light-emitting pattern emits first color light under the excitation of the monochromatic light; the second light-emitting pattern emits second color light under the excitation of the monochromatic light;

the monochromatic light is third-color light; or the monochromatic light is different from the first color light, the second color light and the third color light, the first liquid crystal box further comprises a third light-emitting pattern located in the third sub-pixel, and the third light-emitting pattern emits the third color light under the excitation of the monochromatic light; the first, second, and third color lights are three primary colors of light;

Wherein the material of the first light emitting pattern, the material of the second light emitting pattern, and the material of the third light emitting pattern are quantum dot light emitting materials or color conversion materials; the color conversion material is an up-conversion luminescent material or a down-conversion luminescent material;

the backlight assembly is used for emitting white light; the white light emitted by the backlight assembly passes through the monochromatic light emitting layer and then emits light as the monochromatic light;

the refractive index of the material of the protective layer is 1-2.5, the protective layer is matched with the period of the grating layer, and the protective layer is used for enabling white light emitted by the backlight assembly to pass through the corresponding nano metal grating and then to be emitted out of the monochromatic light.

2. The liquid crystal display of claim 1, further comprising a second liquid crystal cell; the sub-pixels in the first liquid crystal box correspond to the sub-pixels in the second liquid crystal box one by one.

3. The liquid crystal display according to claim 1 or 2, wherein the monochromatic light is the third color light, and the wavelength of the third color light is smaller than the wavelength of the first color light and the wavelength of the second color light;

the material of the first light-emitting pattern and the material of the second light-emitting pattern are quantum dot light-emitting materials.

4. The liquid crystal display of claim 3, wherein the third color light is blue light, and the first color light and the second color light are red light and green light, respectively.

5. The liquid crystal display according to claim 1 or 2, wherein the monochromatic light is the third color light, and the wavelength of the third color light is greater than the wavelength of the second color light and less than the wavelength of the first color light;

the first light emitting pattern is made of a down-conversion light emitting material, and the second light emitting pattern is made of an up-conversion light emitting material.

6. The liquid crystal display of claim 5, wherein the third color light is green light, the second color light is blue light, and the first color light is red light.

7. The liquid crystal display according to claim 1 or 2, further comprising a color filter layer disposed on a side of the first light emitting pattern, the second light emitting pattern, and the third light emitting pattern away from the backlight system; the color filter layer comprises a first photoresist pattern positioned at the first sub-pixel, a second photoresist pattern positioned at the second sub-pixel and a third photoresist pattern positioned at the third sub-pixel;

The first photoresist pattern is used for enabling the first color light to transmit; the second photoresist pattern is used for transmitting the second color light; the third photoresist pattern is used for transmitting the third color light.

8. The liquid crystal display according to claim 1 or 2, further comprising a light blocking layer disposed on a side of the first and second light emission patterns away from the backlight system;

the monochromatic light is a third color light, the light blocking layer is positioned in the third sub-pixel, part of the light blocking layer is hollow, and the light blocking layer is used for blocking the third color light in the external environment light from being emitted to the first light emitting pattern and the second light emitting pattern.