Backlight module, liquid crystal display device, display apparatus and manufacturing method

Abstract

Provided in the present disclosure is a backlight module, comprising: a first transparent substrate; a convergence enhancement layer, which is located on a first surface of the first transparent substrate and comprises a plurality of pyramid-structured prisms that are periodically arranged; a light-homogenizing structure layer, which is located on the convergence enhancement layer and comprises a plurality of dimming patterns; a driving trace layer, which is located on the light-homogenizing structure layer; an LED chip array, which is located on the driving trace layer; an encapsulation layer, which covers the LED chip array; and a reflective layer, which is located on the encapsulation layer. At least one of the plurality of dimming patterns comprises a plurality of dimming sub-patterns, wherein orthographic projections of the plurality of dimming sub-patterns on the first transparent substrate surround orthographic projections of corresponding LED chips on the first transparent substrate, and the transmittance of the plurality of dimming sub-patterns is positively correlated with the distance between the plurality of dimming sub-patterns and the corresponding LED chips. The present disclosure further relates to a liquid crystal display device comprising the backlight module, a display apparatus comprising the liquid crystal display device, and a manufacturing method for manufacturing the backlight module and the liquid crystal display device.

Description

Backlight module, liquid crystal display device, display device and manufacturing method TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of display, in particular to a backlight module, a liquid crystal display device comprising the backlight module, a display device comprising the liquid crystal display device, and a manufacturing method for manufacturing the backlight module and the liquid crystal display device. BACKGROUND

[0002] At present, display devices comprising liquid crystal display devices have been widely applied in various aspects of daily life, and thus the requirements for the light weight and thin type of liquid crystal display devices are also increasing. The existing liquid crystal display devices generally use three glass substrates and two separate polarizing plates, and thus have a large thickness and weight. In addition, in order to improve the light uniformity effect, the existing backlight module generally adopts a diffusion plate with a large thickness or adopts a plurality of optical film layers, so that the backlight module has a large thickness, thereby also leading to the difficulty in realizing the light weight and thin type of the liquid crystal display device. SUMMARY

[0003] According to a first aspect of the present disclosure, a backlight module is provided, comprising: a first transparent substrate comprising a first surface and a second surface parallel to each other; a convergence enhancement layer located on the first surface of the first transparent substrate and comprising a plurality of pyramid structure prisms arranged periodically; a light uniformity structure layer located on the convergence enhancement layer and comprising a plurality of light modulation patterns; a driving trace layer located on the light uniformity structure layer and comprising a plurality of driving traces; an LED chip array comprising a plurality of LED chips and arranged on the driving trace layer so as to be powered by the plurality of driving traces; an encapsulation layer located on the LED chip array and covering the LED chip array; a reflection layer located on the encapsulation layer; wherein at least one of the plurality of light modulation patterns comprises a plurality of light modulation sub-patterns, the orthographic projection of the plurality of light modulation sub-patterns on the first transparent substrate surrounds the orthographic projection of a corresponding LED chip on the first transparent substrate, and the transmittance of the plurality of light modulation sub-patterns and the distance thereof from the corresponding LED chip are in a positive correlation.

[0004] According to some exemplary embodiments, at least one light modulation sub-pattern of the plurality of light modulation sub-patterns comprises a dielectric film combination composed of a first refractive index layer and a second refractive index layer, wherein the first refractive index layer and the second refractive index layer have different refractive indexes, and each light modulation sub-pattern comprises a different number of stacked dielectric film combinations.

[0005] According to some example embodiments, at least one of the plurality of light modulation sub-patterns comprises a metal wire grid or a metal mesh structure, and a line width of the metal wires in the metal wire grid or the metal mesh structure in each light modulation sub-pattern is different.

[0006] According to some example embodiments, at least one of the plurality of light modulation sub-patterns comprises a metal wire grid or a metal mesh structure, and a line width of the metal wires in the metal wire grid or the metal mesh structure in each light modulation sub-pattern is different.

[0007] According to some example embodiments, the plurality of driving wires of the driving wire layer has a grid shape in orthographic projection on the first transparent substrate, and a vertex of each grid corresponds to one LED chip.

[0008] According to some example embodiments, the plurality of LED chips comprises blue LED chips, and the encapsulation layer comprises a color conversion material for converting blue light into white light.

[0009] According to some example embodiments, the plurality of LED chips comprises blue LED chips, and a color conversion layer for converting blue light into white light is arranged between the encapsulation layer and the reflective layer.

[0010] According to some example embodiments, the plurality of LED chips comprises white LED chips, and the encapsulation layer comprises a transparent material.

[0011] According to some example embodiments, a surface of the reflective layer facing the first transparent substrate comprises a texture for scattering light.

[0012] According to some example embodiments, the reflective layer comprises a plurality of air bubbles.

[0013] According to some example embodiments, a scattering layer for scattering light is arranged between the reflective layer and the encapsulation layer.

[0014] According to a second aspect of the present disclosure, there is provided a liquid crystal display device comprising: the backlight module according to the first aspect of the present disclosure and the example embodiments thereof; and a liquid crystal display panel located on a second surface of the first transparent substrate of the backlight module.

[0015] According to some exemplary embodiments, the liquid crystal display panel comprises: a first metal wire grid layer on the second surface of the first transparent substrate; a display array trace layer on the first metal wire grid layer; a second transparent substrate comprising a first surface and a second surface parallel to each other, and the first surface of the second transparent substrate is parallel and opposite to the second surface of the first transparent substrate; a color filter layer on the first surface of the second transparent substrate; a second metal wire grid layer on the first surface of the second transparent substrate, and the arrangement direction of the metal wire grid in the second metal wire grid layer is perpendicular to the arrangement direction of the metal wire grid in the first metal wire grid layer; and a liquid crystal material sealingly sandwiched between the color filter layer and the liquid crystal display array trace layer.

[0016] According to a third aspect of the present disclosure, there is provided a display device comprising the liquid crystal display apparatus according to the second aspect of the present disclosure and exemplary embodiments thereof.

[0017] According to a fourth aspect of the present disclosure, there is provided a backlight module manufacturing method for manufacturing the backlight module according to the first aspect of the present disclosure, the backlight module manufacturing method comprising: forming the convergence enhancement layer on the first surface of the first transparent substrate; forming the light homogenization structure layer on the convergence enhancement layer; forming the insulating layer on the light homogenization structure layer; forming the driving trace layer on the insulating layer; binding the LED chips on the driving trace layer to form the LED chip array; forming the encapsulation layer on the LED chip array; and forming the reflective layer on the encapsulation layer.

[0018] According to a fifth aspect of the present disclosure, there is provided a liquid crystal display device manufacturing method for manufacturing the liquid crystal display device according to the exemplary embodiments of the second aspect of the present disclosure, the liquid crystal display device manufacturing method comprising: forming the converging enhancement layer on a first surface of the first transparent substrate; forming the light homogenizing structure layer on the converging enhancement layer; forming the insulating layer on the light homogenizing structure layer; forming the driving trace layer on the insulating layer; binding the LED chips on the driving trace layer to form the array of LED chips; forming the encapsulation layer on the array of LED chips; forming the reflective layer on the encapsulation layer; forming the first metal wire grid layer on a second surface of the first transparent substrate; forming the display array trace layer on the first metal wire grid layer; forming the color filter layer on a first surface of the second transparent substrate; forming the second metal wire grid layer on a second surface of the second transparent substrate; opposing the first surface of the second transparent substrate to the second surface of the first transparent substrate, and aligning and adhering the second transparent substrate to the first transparent substrate; and injecting the liquid crystal material between the color filter layer and the display array trace layer, so that the liquid crystal material is sealedly sandwiched between the color filter layer and the display array trace layer to form a liquid crystal layer. BRIEF DESCRIPTION OF DRAWINGS

[0019] Various exemplary embodiments of the present disclosure will be described in detail herein below, with reference to the drawings; in the drawings:

[0020] FIG. 1 schematically illustrates a liquid crystal display device in the related art;

[0021] FIG. 2 schematically illustrates a backlight module according to an embodiment of the present disclosure;

[0022] FIGS. 3A to 3C schematically illustrate structures of a scattering layer and / or a reflective layer that can be used in the backlight module shown in FIG. 2, according to some embodiments of the present disclosure;

[0023] FIGS. 4A and 4B are schematic diagrams of angular spectrum of light emitted by each LED chip;

[0024] FIG. 5 schematically illustrates a driving trace design in a driving trace layer according to an embodiment of the present disclosure;

[0025] FIG. 6 schematically illustrates light intensity distribution of light emitted by a single LED and a corresponding dimming pattern;

[0026] FIG. 7 schematically illustrates light homogenization control according to an embodiment of the present disclosure;

[0027] FIG. 8 schematically illustrates influence of a multi-layer dielectric film on light transmittance;

[0028] FIG. 9 schematically illustrates a structure of a one-dimensional metal wire grid and a two-dimensional metal mesh for homogenization control according to an embodiment of the present disclosure;

[0029] FIGS. 10A, 10B and 10C respectively schematically illustrate the effects of respective parameters of a metal wire grid and a metal mesh on light transmittance and degree of polarization;

[0030] FIG. 11 schematically illustrates a structure of a collection enhancement layer that can be used in the backlight module shown in FIG. 2 according to some embodiments of the present disclosure;

[0031] FIG. 12 respectively schematically illustrates angular spectrum distributions of light after passing through the collection enhancement layer shown in FIG. 11;

[0032] FIG. 13 schematically illustrates a liquid crystal display device according to an embodiment of the present disclosure;

[0033] FIG. 14 schematically illustrates a display device according to an embodiment of the present disclosure;

[0034] FIGS. 15A to 15C schematically illustrate a process flow for manufacturing a backlight module and a liquid crystal display device according to an embodiment of the present disclosure.

[0035] It should be understood that the accompanying drawings are only schematic and are intended to provide a general illustration of the exemplary embodiments of the present disclosure, and are not a limitation on the present disclosure. In addition, in the drawings, the same or similar components are denoted by the same or similar reference numerals. DETAILED DESCRIPTION

[0036] The exemplary embodiments of the present disclosure are described below in conjunction with the accompanying drawings, so as to enable those skilled in the art to fully understand and implement the technical solutions according to the present disclosure.

[0037] Referring to FIG. 1, a liquid crystal display device in the related art is schematically shown. As shown in FIG. 1, the liquid crystal display device 100 includes a first glass substrate 101, a reflective layer 102 is disposed on the upper surface of the first glass substrate 101, an array of light emitting diode (i.e. light emitting diode, referred to as LED) chips 103 is disposed on the reflective layer 120, which includes a plurality of LED chips 104 arranged in an array, and the light emitted by each LED chip 104 propagates upward along the direction shown by the arrow A in FIG. 1. In the liquid crystal display device 100 shown in FIG. 1, the LED chips 104 are blue light LED chips. Continuing in the direction shown by the arrow A, the liquid crystal display device 100 further includes a diffusion plate 105 located above the array of LED chips 103, and in order to facilitate the diffusion of the light emitted by the LED chips 104, a certain optical distance OD is maintained between the diffusion plate 105 and the array of LED chips 103. A color conversion layer 106 is disposed above the diffusion plate 105, which is used to convert the blue light emitted by the LED chips 104 into white light, for example, the color conversion layer 106 can be implemented as a quantum dot film. A first prism layer 107 and a second prism layer 108 are sequentially disposed on the color conversion layer 106, which are used to bundle and enhance the white light from the color conversion layer 106. A diffusion film 109 is disposed on the second prism layer 108, which is used to diffuse and homogenize the white light after being bundled and enhanced. Continuing in the direction shown by the arrow A, a first polarizer 110 is disposed above the diffusion film 109, and a second glass substrate 111 is disposed above the first polarizer 110, and a display array trace layer 112 is disposed on the upper surface of the second glass substrate 111. Continuing in the direction shown by the arrow A, a third glass substrate 115 is disposed above the display array trace layer 112, and a color filter layer 114 is disposed on the lower surface of the second glass substrate 115, and a second polarizer 116 is disposed above the color filter layer 114. A liquid crystal material is sealingly sandwiched between the color filter layer 114 and the display array trace layer 112 to form a liquid crystal layer 113.

[0038] As can be seen, in the liquid crystal display device 100 in the related art, on the one hand, in order to ensure the diffusion of the light emitted from the LED chips 104 to achieve a better light homogenization effect, a certain optical distance OD needs to be provided between the array of LED chips 103 and the diffusion plate 105, or a diffusion plate 105 with a larger thickness is used, which leads to the difficulty of reducing the thickness of the backlight module in the liquid crystal display device 100; on the other hand, the liquid crystal display device 100 uses three glass substrates and two separate polarizers, which leads to a larger weight and thickness of the liquid crystal display device 100, and it is difficult to realize the lightweight and thin type of the liquid crystal display device.

[0039] Referring to FIG. 2, a backlight module is schematically shown, which can be used in a liquid crystal display device according to an embodiment of the present disclosure. As shown in FIG. 2, the backlight module 200 includes a transparent substrate 201, a convergence enhancement layer 202, a light homogenizing structure layer 203, a driving trace layer 204, an LED chip array 205, an encapsulation layer 206, a scattering layer 207, and a reflective layer 208. The transparent substrate 201 can be a glass substrate or a transparent resin substrate, or can be formed of any suitable transparent material, and the present disclosure does not limit the material forming the transparent substrate. The light emitted by each LED chip 205a in the LED chip array 205 propagates downward along a direction opposite to the direction indicated by arrow A in FIG. 2, passes through the encapsulation layer 206 and the scattering layer 207, is reflected by the reflective layer 208, and then propagates upward along the direction indicated by arrow A. Thus, the backlight module 200 is a direct-lit backlight module.

[0040] The LED chip array 205 can include a plurality of LED chips 205a. The size of each LED chip 205a can be set in a range of 10-150 μιη. The arrangement of the LED chips 205a can be square, rectangular, or equilateral triangular, and the light emission uniformity can meet the product requirements with the least number of chips, the least optical path, and the largest LED chip spacing. Hereinafter, the arrangement of the LED chips will be described by way of example with the equilateral triangular arrangement, but it should be understood that this is merely exemplary and not limiting. The present disclosure does not limit the specific arrangement of the LED chips.

[0041] The encapsulation layer 206 is arranged to cover the LED chip array 205. In some embodiments, each LED chip 205a in the LED chip array 205 can be a blue LED chip, for example, emitting blue light with a wavelength of 450 nm. Accordingly, the encapsulation layer 206 can include a color conversion material to convert the blue light emitted by the blue LED chip into white light. In other embodiments, a separate color conversion layer can be arranged between the encapsulation layer 206 and the scattering layer 207 to convert the blue light emitted by the blue LED chip into white light. The color conversion material can be a quantum dot material, a fluorescent material, or a nitride color conversion material. The present disclosure does not limit the color conversion material, as long as it has high conversion efficiency and is easy to mix uniformly in the encapsulation layer. As a non-limiting example, the color conversion material can be K2SiF6:Mn 4+(KSF) color conversion material, which can have a particle diameter in the range of 1-50 μm, in some embodiments, the particle diameter can be in the range of 5-30 μm. The KSF color conversion material can be mixed in the encapsulation layer 206, or can form a separate color conversion layer, whereby the blue light emitted by the blue LED chip is converted into white light. The thickness of the encapsulation layer 206 can be in the range of 0.2-2 mm, in some embodiments, in order to achieve light and thin, the thickness of the encapsulation layer 206 can be in the range of 0.3-0.5 mm. Further, in the case of forming a separate color conversion layer, the thickness of the color conversion layer can be 0.3 mm. It should be understood that in other embodiments of the present disclosure, each LED chip 205a in the LED chip array 205 can also be a white LED chip. In this case, the encapsulation layer 206 can be formed of any suitable transparent material, without incorporating color conversion material.

[0042] The scattering layer 207 is used to scatter the light emitted by the LED chip 205a, so as to facilitate the homogenization of the light. The reflective layer 208 is used to reflect the light, so that it propagates upward in the direction indicated by the arrow A. It should be understood that the scattering layer 207 can be a separate film layer, but can also be part of the reflective layer 208. For example, the scattering layer 207 can be a scattering structure formed on the surface of the reflective layer 208. The reflective layer 208 can be formed of any suitable material having high reflectivity, such as a film layer of silver or aluminum, but it can also be a glue material such as white oil, or can be a film material such as a white reflective film. The present disclosure does not limit the specific material used to form the reflective layer. In order to maximize the reflectivity, when a film layer of silver or aluminum is used, the film layer thickness needs to be greater than 60 nm, in some embodiments, the film layer thickness can be in the range of 60-150 nm. If a glue material such as white oil is used, the film layer thickness needs to be greater than 0.01 mm, in some embodiments, the film layer thickness can be in the range of 0.03-0.3 mm. If a film material such as a white reflective film is used, the film layer thickness needs to be greater than 0.01 mm, in some embodiments, the film layer thickness can be in the range of 0.03-0.3 mm.

[0043] The scattering layer 207 and the reflecting layer 208 can have various possible implementations. Referring to FIGS. 3A-3C, which schematically illustrate structures that can be used to implement the scattering layer and / or the reflecting layer in the backlight module shown in FIG. 2 according to some example embodiments of the present disclosure. As shown in FIG. 3A, the reflecting layer 208a in this embodiment has a texture 208a-1 formed on its upper surface adjacent to the encapsulation layer 206 by patterning, which forms scattering structures for scattering light, so that the reflecting layer 208a can both reflect and scatter the incident light. That is, the reflecting layer 208a has both reflecting and scattering functions. As shown in FIG. 3B, the reflecting layer 208b in this embodiment is provided with a glue layer 208b-1 such as a resin layer between the reflecting layer 208b and the encapsulation layer 206, and the side of the glue layer 208b-1 adjacent to the reflecting layer 208b is patterned so that when the reflecting layer 208b is provided, the reflecting material fills the patterned structures in this side of the glue layer 208b-1, thereby forming a texture structure for scattering light. As shown in FIG. 3C, the reflecting layer 208c can include a plurality of air bubbles 208c-1, so that the reflecting layer 208c can both reflect and scatter the incident light. For example, the reflecting layer 208c can be formed by a white reflecting film layer with air bubbles. In addition, it should also be understood that in other embodiments, when the light uniformization effect of the light uniformization structure layer 203 and the driving wire layer 204 is strong enough, the backlight module can also not be provided with a scattering layer, or the reflecting layer can not include scattering structures.

[0044] Referring to FIGS. 4A and 4B, which schematically illustrate the angular spectral distribution of the light emitted by each LED chip, respectively. Specifically, FIG. 4A shows the light intensity distribution in the range of about -60 degrees to 60 degrees of the light emitted by the LED chip 205a after passing through the encapsulation layer 206 and being converted by the color conversion material therein, and FIG. 4B shows the light intensity distribution in the range of about -60 degrees to 60 degrees of the light emitted by the LED chip 205a after passing through the encapsulation layer 206, being converted by the color conversion material therein, and further passing through the scattering structure. As can be seen, the point light emitted by the LED chip 205a is scattered into a large light spot after passing through the scattering structure, but still has a Lambertian light distribution, so further uniformization of the light is needed in subsequent steps to meet the uniformization requirement of the backlight light emission.

[0045] Continuing to refer to FIG. 2, the backlight module 200 is provided with a driving trace layer 204 above the LED chip array 205, for supplying power to each chip 205a in the LED chip array 205. Referring to FIG. 5, which schematically illustrates the orthographic projection of a plurality of driving traces in the driving trace layer on the transparent substrate 201 according to an embodiment of the present disclosure. As shown in FIG. 5, the orthographic projection of each driving trace in the driving trace layer 204 on the transparent substrate 201 has a grid shape comprising a plurality of triangular meshes, and each vertex of each triangular mesh corresponds to one LED chip 205a. In this way, the light incident to the driving trace layer 204 can be initially homogenized to meet the preliminary requirement of the product on the uniformity of light. In addition, the width of the driving trace is designed based on the criterion that it is invisible on the upper surface of the transparent substrate 201, and thus the width thereof can be less than or equal to 50 μιη, and in some embodiments, the width of the driving trace can be less than 30 μιη.

[0046] Continuing to refer to FIG. 2, the backlight module 200 is provided with a light homogenizing structure layer 203 above the driving trace layer 204, which controls the light output by different transmittances in different regions, so as to achieve the maximum degree of homogenization of light. Referring to FIG. 6, which schematically illustrates the light intensity distribution of the light emitted by a single LED and the corresponding light modulation pattern. As shown in view (a) of FIG. 6, a plurality of annular regions R1, R2,..., RN can be divided around the LED chip 205a, wherein the light intensity of the light emitted by the LED chip 205a is the largest in the annular region R1, the light intensity is the second largest in the annular region R2, and the light intensity is the smallest in the annular region RN. Therefore, as shown in view (b) of FIG. 6, the light homogenizing structure layer 203 is provided with a corresponding light modulation pattern for each LED chip 205a, which comprises a plurality of light modulation sub-patterns, the orthographic projection of the light modulation sub-patterns on the transparent substrate 201 surrounds the orthographic projection of the corresponding LED chip 205a on the transparent substrate 201, and the transmittance of the light modulation sub-patterns is positively correlated with the distance thereof from the LED chip 205a. As an example, the transmittance of the light modulation sub-patterns farther away from the LED chip 205a in the light modulation pattern is higher. Specifically, the light modulation sub-pattern S1 is provided for the annular region R1, the light modulation sub-pattern S2 is provided for the annular region R2, and the light modulation sub-pattern SN is provided for the annular region RN, and the transmittance of the light modulation sub-pattern S1 is the smallest, and the transmittance of the light modulation sub-pattern SN is the largest. In this way, by controlling the light output by different transmittances in different regions, the light homogenizing structure layer 203 can achieve the maximum degree of homogenization of light.

[0047] Referring to FIG. 7, which schematically illustrates the light uniformity control provided according to embodiments of the present disclosure. As shown in FIG. 7, the light emitted by each LED chip 205a is first subjected to a preliminary light uniformity control by the grid shape formed by the driving traces in the driving trace layer 204 after being reflected back by the reflective layer 208, and then subjected to light uniformity control by the light modulation patterns in the light uniformity structure layer 203 corresponding to each LED chip 205a in a manner that different regions control the light emission with different transmittances, so that the maximum degree of uniformity of the light can be achieved. It should be understood that in some embodiments, the light uniformity can also be achieved without the driving traces in the driving trace layer 204, but only by the light uniformity structure layer 203.

[0048] In some embodiments of the present disclosure, in order to achieve that each light modulation sub-pattern in the light modulation patterns of the light uniformity structure layer 203 has different transmittances, different film layer structures can be designed for at least one light modulation sub-pattern. For example, different transmittances can be achieved by using a medium film combination of high and low refractive index materials, i.e., at least one light modulation sub-pattern can include a medium film combination composed of a first refractive index layer and a second refractive index layer, wherein the first refractive index layer and the second refractive index layer have different refractive indices, and each light modulation sub-pattern includes a medium combination layer with different number of layers. In some embodiments, a medium film combination (MgF2 / ZnS) n (wherein the refractive index of ZnS (zinc sulfide) is 2.35, and the refractive index of MgF2 (magnesium fluoride) is 1.38, and the light is incident from the MgF2 layer and emitted from the ZnS layer). By designing the parameter n, different transmittances can be achieved. Generally, the larger the value of the parameter n, the smaller the transmittance of the medium film combination. Referring to FIG. 8, which schematically illustrates the transmittance of the medium film combination (MgF2 / ZnS) n The effect on the transmittance. Wherein the average transmittance of both P-polarized light and S-polarized light together is about 30%.

[0049] In some embodiments of the present disclosure, in order to realize that each light modulation sub-pattern in the light modulation pattern of the uniform light structure layer 203 has different transmittance, different metal micro-nano period structures can be arranged in at least one light modulation sub-pattern. Referring to FIG. 9, wherein view (a) of FIG. 9 schematically shows a structure of a metal wire grid for uniform light control provided according to an embodiment of the present disclosure, and view (b) of FIG. 9 schematically shows a structure of a metal mesh for uniform light control provided according to an embodiment of the present disclosure. As can be seen from the figures, the metal wire grid is a one-dimensional micro-nano period structure, and the metal mesh is a two-dimensional micro-nano period structure. By changing the thickness of the metal trace or the width of the metal trace in the micro-nano period structure, the transmittance and polarization degree of light can be controlled. Referring to FIGS. 10A, 10B and 10C, which respectively schematically show the influence of the corresponding parameters of the metal wire grid and the metal mesh on the transmittance and polarization degree of light. As shown in FIG. 10A, a micro-nano period structure of metal aluminum is arranged on a gallium nitride (i.e., GaN) substrate, and the top surface of the metal trace is covered with a covering layer of silicon dioxide (i.e., SiO2). The height (i.e., the thickness) of the metal trace is h1, the thickness of the SiO2 covering layer is h2, the width of the metal trace is W, and the pitch of the metal wire grid is P. FIG. 10B schematically shows the influence on the transmittance and polarization degree of incident light when the height of the metal trace of metal aluminum is changed. FIG. 10C schematically shows the influence on the transmittance and polarization degree of incident light when the width of the metal trace of metal aluminum is changed. Based on the contents shown in FIGS. 10B and 10C, by changing the thickness and / or width of the metal trace, the transmittance and polarization degree of incident light can be controlled. Referring to FIG. 6 in combination, in some embodiments, for a plurality of light modulation sub-patterns, the thickness of the metal trace of each light modulation sub-pattern can be different, so that the farther the light modulation sub-pattern is from the corresponding LED chip, the higher the transmittance of the light modulation sub-pattern is; in other embodiments, for a plurality of light modulation sub-patterns, the width of the metal trace of at least one light modulation sub-pattern can be different, and can be arranged to be smaller in the light modulation sub-pattern farther from the corresponding LED chip (i.e., so that the farther the light modulation sub-pattern is from the corresponding LED chip, the higher the transmittance of the light modulation sub-pattern is). It should be understood that in the case of using a metal wire grid or a metal mesh to realize uniform light in the uniform light structure layer 203, an insulating layer should be arranged between the uniform light structure layer 203 and the driving trace layer 204 to avoid short circuit therebetween.

[0050] Referring back to FIG. 2, the collection enhancement layer 202 in the backlight module 200 is used to collect the uniform white light from the light homogenizing structure layer 203 to the viewable angle to maximize the on-axis brightness. The collection enhancement layer 202 can include a plurality of prisms 202a in a periodic arrangement of positive pyramid structures. It should be understood that the prisms in the pyramid structures can be periodic arrangement of positive pyramid structures, inverted pyramid structures, or can also be random pyramid structures. Referring to FIG. 11, views (a), (b), and (c) thereof respectively show positive pyramid structures, inverted pyramid structures, and random pyramid structures. The base size of the pyramid structures can be in the range of (10-500 μm) x (10-500 μm), the height can be between 5-250 μm, and the duty cycle can be greater than 50%. In the embodiment shown in FIG. 2, the pyramid-shaped prisms 202a can have positive pyramid structures with a base size of (50 μm ± 10 μm) x (50 μm ± 10 μm), a height of 20 μm ± 5 μm, and a duty cycle of 100% (i.e., the base of the pyramid structure is closely connected). In other embodiments, the pyramid-shaped prisms 202a can have random pyramid structures. Referring to FIG. 12, views (a), (b), and (c) thereof respectively show the angular spectrum distribution of the uniform white light after passing through positive pyramid structures, inverted pyramid structures, and random pyramid structures, respectively.

[0051] Referring to FIG. 13, a liquid crystal display device is schematically shown according to one embodiment of the present disclosure. As shown in FIG. 13, the liquid crystal display device 500 includes the backlight module 200 described above based on the content shown in FIG. 2, and further includes a liquid crystal display panel 300, wherein the liquid crystal display panel 300 is disposed on the upper surface of the transparent substrate 201 in the backlight module 200 (the direction indicated by arrow A in FIG. 13 is the upward direction). It should be understood that the liquid crystal display panel 300 shown in FIG. 13 is merely exemplary and is not restrictive, and any suitable liquid crystal display panel can be disposed on the backlight module 200 to form the required liquid crystal display device according to actual needs. Referring to FIG. 13, the liquid crystal display panel 300 includes a first metal wire grid layer 301, a filling layer 302, a display array trace layer 303, a color filter layer 305, a transparent substrate 306, a second metal wire grid layer 307, and a liquid crystal material 304. The first metal wire grid layer 301 can be located on the upper surface of the transparent substrate 201 to achieve single-polarization filtering transmission while the other polarization is reflected. The metal material forming the first metal wire grid layer 301 can be silver, aluminum, copper, gold, etc. The period of the metal wire grid structure can be between 20-250 nm, the thickness of the metal layer can be between 50-500 nm, and the duty cycle can be between 20%-80%. In one embodiment, an aluminum film is used to make the first metal wire grid layer 301, the film thickness is 100 nm±40 nm, the duty cycle is 50%±10%, and the wire grid period is 120 nm±20 nm. The filling layer 302 is disposed on the upper surface of the first metal wire grid layer 301. The display array trace layer 303 is disposed on the upper surface of the filling layer 302. The transparent substrate 306 can also be a glass substrate or a transparent resin substrate, or can be formed of any suitable transparent material. The color filter layer 305 is disposed on the lower surface of the transparent substrate 306, and the second metal wire grid layer 307 is disposed on the upper surface of the transparent substrate 306 to achieve single-polarization filtering transmission while the other polarization is reflected. The arrangement direction of the wire grid in the second metal wire grid layer 307 is perpendicular to the arrangement direction of the wire grid in the first metal wire grid layer 301. The metal material forming the second metal wire grid layer 307 can also be silver, aluminum, copper, gold, etc. The period of the metal wire grid structure can be between 20-250 nm, the thickness of the metal layer can be between 50-500 nm, and the duty cycle can be between 20%-80%. In one embodiment, an aluminum film is used to make the second metal wire grid layer 307, the film thickness is 100 nm±40 nm, the duty cycle is 50%±10%, and the wire grid period is 120 nm±20 nm. The liquid crystal material 304 is filled between the color filter layer 305 and the display array trace layer 302, and is sealed between the color filter layer 305 and the display array trace layer 302 to form a liquid crystal layer.

[0052] By forming the first metal wire grid layer 301 on the upper surface of the transparent substrate 201, the liquid crystal display panel 300 and the backlight module 200 can share the transparent substrate 201, so that only two transparent substrates can be used in the liquid crystal display device 500. In addition, the first and second metal wire grid layers replace the separate polarizer. Therefore, the thickness and weight of the liquid crystal display device 500 can be greatly reduced, which is conducive to achieving its thinness and lightness.

[0053] Referring to Figure 14, a display device provided according to an embodiment of the present disclosure is schematically illustrated in block diagram form. As shown in Figure 14, the display device 600 includes a liquid crystal display device 610, which can be implemented as the liquid crystal display device 500 described above in conjunction with Figure 13. The display device 600 can be any suitable device including a liquid crystal display device, including but not limited to: televisions, MNT displays, NB displays, TPC displays, mobile electronic devices, interactive displays, conference all-in-one machines, monitors, and other various display products.

[0054] Referring to Figures 15A, 15B, and 15C, they schematically illustrate the process flow for manufacturing backlight modules and liquid crystal display devices according to embodiments of the present disclosure.

[0055] Figure 15A shows the process flow based on the first transparent substrate shared by the backlight module and the liquid crystal display panel. Specifically, after cleaning the first transparent substrate Glass-1, the following steps are performed as shown in Figure 15A:

[0056] Step 1): Coat its upper surface with a low refractive index adhesive layer;

[0057] Step 2): Imprint or etch the pyramid structure into the low-refractive-index adhesive layer;

[0058] Step 3): Fill the pyramid structure in the low-refractive-index adhesive layer with a high-refractive-index material;

[0059] Step 4): After planarizing the layer, the driving traces used for the LED chip are formed by exposure etching. Then, after filling the driving traces with an insulating layer, a metal (e.g., aluminum) layer is deposited and a resist layer is coated. The structure with different linewidths that control the transmittance is imprinted. The metal layer is etched through the resist layer to form a structural layer with different metal linewidths (i.e., a uniform light structure layer).

[0060] Step 5): Expose and etch the LED bonding pad area, then transfer and bond the LED chip;

[0061] Step 6): Encapsulate the surface of the LED chip using an adhesive layer doped with color conversion material;

[0062] Step 7) : High reflectivity film or material is deposited on the surface of the encapsulation layer by lamination or deposition;

[0063] After flipping the first transparent substrate Glass-1, the following steps are performed:

[0064] Step 8) : After flipping the first transparent substrate Glass-1, a metal layer (e.g. aluminum) is deposited thereon, a layer of stamping glue is coated, and a grating structure is formed by stamping the glue layer with a template;

[0065] Step 9) : The metal layer is etched by the grating of the glue layer to form a metal wire grid structure;

[0066] Step 10) : The resin layer is removed, the metal wire grid structure is coated with a glue layer, and is planarized;

[0067] Step 11) : A liquid crystal display array trace is formed on the surface thereof by multiple times of glue coating, exposure and etching, wherein the glue layer etching the metal layer can be removed or not removed according to the characteristics of the subsequent planarization layer, i.e. if the surface energy of the planarization layer is very low and the glue is easy to flow into the metal wire grid structure, the glue layer is not removed. Otherwise, the glue layer is removed.

[0068] It should be understood that, by using the process flow shown in FIG. 15A, a backlight module (e.g. the backlight module 200 shown in FIG. 2) provided according to the exemplary embodiments of the present disclosure can be prepared.

[0069] Referring to FIG. 15B and in combination with FIG. 15A, FIG. 15B shows a process flow implemented based on a second transparent substrate of a liquid crystal display panel. Specifically, after cleaning the second transparent substrate Glass-2, the following steps are performed as shown in FIG. 15B:

[0070] Step 12) : A metal layer (e.g. aluminum) is deposited on the upper surface of the second transparent substrate Glass-2, and a resin glue layer is sprayed;

[0071] Step 13) : A grating structure is formed on the glue layer by stamping with a template;

[0072] Step 14) : After etching the metal layer by the grating of the glue layer to form a metal wire grid structure, the resin glue layer is removed;

[0073] Step 15) : The metal layer is coated with a glue layer and is planarized, wherein if the surface energy of the planarization layer is very low and the glue is easy to flow into the metal wire grid structure, the glue layer is not removed. Otherwise, the glue layer is removed;

[0074] After flipping the second transparent substrate Glass-2, the following steps are performed:

[0075] Step 16) : A color filter layer is added.

[0076] Referring to FIG. 15C, and in conjunction with FIGS. 15A and 15B, in FIG. 15C, the first transparent substrate Glass-1 and the second transparent substrate Glass-2 are orthogonally aligned and attached, liquid crystal is filled in, and sealing is performed, thereby obtaining a liquid crystal display device.

[0077] The terminology used in the present disclosure is only for describing the embodiments of the present disclosure, and is not intended to limit the present disclosure. As used in the present disclosure, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and "comprising," when used in this specification, specify the presence of stated features, but do not preclude the presence or addition of one or more other features. As used in the present disclosure, the term "and / or" includes any and all combinations of one or more of the associated listed items. It will be understood that, although the terms "first," "second," "third," etc. can be used herein to describe various features, these features should not be limited by these terms. These terms are only used to distinguish one feature from another.

[0078] Unless otherwise defined, all terms (including technical and scientific terms) used in the present disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and / or the present specification, and will not be interpreted in an idealized or overly formal sense unless expressly so defined in the present disclosure.

[0079] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" or the like means that the specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present disclosure. Illustrative expressions of the above terms in the present specification do not necessarily refer to the same embodiment or example. Also, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. Furthermore, the person skilled in the art can combine and combine the different embodiments or examples described in the present specification and the features of the different embodiments or examples, or can omit some technical features from the different embodiments or examples described in the present specification, and the embodiments or examples obtained based on such combination, combination, or omission are also considered to fall within the scope of the present disclosure.

[0080] The methods described in the present disclosure include one or more steps or actions. The method steps and / or actions do not have to be performed in the order described in the present disclosure, but can be performed in different orders, for example, they can be performed simultaneously or in reverse order, as long as the principles of the technical solutions described in the present disclosure are not contradicted. In addition, according to actual needs, the steps or actions in the methods described in the present disclosure can be replaced by different steps or actions, or additional steps or actions can also be included.

[0081] Although the present disclosure has been described in detail in conjunction with some exemplary embodiments, it is not limited to the specific forms described in the present disclosure. Instead, the scope of the present disclosure is only defined by the appended claims.

Claims

1. A backlight module, comprising: a first transparent substrate comprising a first surface and a second surface parallel to each other; a collection enhancement layer on the first surface of the first transparent substrate and comprising a plurality of pyramid structures arranged periodically; a light uniformization structure layer on the collection enhancement layer and comprising a plurality of light modulation patterns; a driving trace layer on the light uniformization structure layer and comprising a plurality of driving traces; an LED chip array comprising a plurality of LED chips disposed on the driving trace layer so as to be powered by the plurality of driving traces; an encapsulation layer on the LED chip array and covering the LED chip array; a reflective layer on the encapsulation layer; wherein at least one of the plurality of light modulation patterns comprises a plurality of light modulation sub-patterns, a footprint of the plurality of light modulation sub-patterns on the first transparent substrate surrounds a footprint of a corresponding LED chip on the first transparent substrate, and a transmittance of the plurality of light modulation sub-patterns is positively correlated with a distance of the plurality of light modulation sub-patterns from the corresponding LED chip.

2. The backlight module of claim 1, wherein, at least one light modulation sub-pattern of the plurality of light modulation sub-patterns comprises a dielectric film combination composed of a first refractive index layer and a second refractive index layer, wherein the first refractive index layer and the second refractive index layer have different refractive indexes, and each light modulation sub-pattern comprises a different number of stacked dielectric film combinations.

3. The backlight module of claim 1, wherein, at least one light modulation sub-pattern of the plurality of light modulation sub-patterns comprises a metal wire grid or a metal mesh structure, and a thickness of a metal trace in the metal wire grid or the metal mesh structure in each light modulation sub-pattern is different.

4. The backlight module of claim 1, wherein, at least one light modulation sub-pattern of the plurality of light modulation sub-patterns comprises a metal wire grid or a metal mesh structure, and a line width of a metal trace in the metal wire grid or the metal mesh structure in each light modulation sub-pattern is different.

5. The backlight module of claim 1, wherein, a footprint of the plurality of driving traces of the driving trace layer on the first transparent substrate has a grid shape comprising a plurality of grids, and a vertex of each grid corresponds to an LED chip.

6. The backlight module of claim 1, wherein, the plurality of LED chips comprise blue LED chips, and the encapsulation layer comprises a color conversion material for converting blue light into white light.

7. The backlight module of claim 1, wherein, the plurality of LED chips comprise blue LED chips, and a color conversion layer for converting blue light into white light is disposed between the encapsulation layer and the reflective layer.

8. The backlight module of claim 1, wherein, the plurality of LED chips comprise white LED chips, and the encapsulation layer comprises a transparent material.

9. The backlight module of claim 1, wherein, a surface of the reflective layer facing the first transparent substrate comprises a texture for scattering light.

10. The backlight module of claim 1, wherein, the reflective layer comprises a plurality of bubbles.

11. The backlight module of claim 1, wherein, a scattering layer for scattering light is disposed between the reflective layer and the encapsulation layer. 12.A liquid crystal display device, comprising: the backlight module according to any one of claims 1 to 11; and a liquid crystal display panel on the second surface of the first transparent substrate of the backlight module. the liquid crystal display panel comprises:

13. The liquid crystal display device according to claim 12, wherein, a first metal wire grid layer on the second surface of the first transparent substrate; a display array trace layer on the first metal wire grid layer; and a second metal wire grid layer on the display array trace layer. a second transparent substrate comprising a first surface and a second surface parallel to each other, and the first surface of the second transparent substrate is parallel to and opposite to the second surface of the first transparent substrate; a color filter layer on the first surface of the second transparent substrate; a second metal wire grid layer on the first surface of the second transparent substrate, and the arrangement direction of the metal wire grids in the second metal wire grid layer is perpendicular to the arrangement direction of the metal wire grids in the first metal wire grid layer; a liquid crystal material sealingly sandwiched between the color filter layer and the liquid crystal display array trace layer.

14. A display device comprising the liquid crystal display device according to claim 12 or 13.

15. A backlight module manufacturing method for manufacturing the backlight module according to claim 1, the backlight module manufacturing method comprising: forming the light collection enhancement layer on the first surface of the first transparent substrate; forming the light homogenizing structure layer on the light collection enhancement layer; forming an insulating layer on the light homogenizing structure layer; forming the driving trace layer on the insulating layer; binding the LED chips on the driving trace layer to form the LED chip array; forming the encapsulation layer on the LED chip array; and forming the reflective layer on the encapsulation layer.

16. A liquid crystal display device manufacturing method for manufacturing the liquid crystal display device according to claim 13, the liquid crystal display device manufacturing method comprising: forming the light collection enhancement layer on the first surface of the first transparent substrate; forming the light homogenizing structure layer on the light collection enhancement layer; forming an insulating layer on the light homogenizing structure layer; forming the driving trace layer on the insulating layer; binding the LED chips on the driving trace layer to form the LED chip array; forming the encapsulation layer on the LED chip array; forming the reflective layer on the encapsulation layer; forming the first metal wire grid layer on the second surface of the first transparent substrate; forming the display array trace layer on the first metal wire grid layer; forming the color filter layer on the first surface of the second transparent substrate; forming the second metal wire grid layer on the second surface of the second transparent substrate; opposing the first surface of the second transparent substrate to the second surface of the first transparent substrate, and aligning and adhering the second transparent substrate to the first transparent substrate; and injecting the liquid crystal material between the color filter layer and the liquid crystal display array trace layer, so that the liquid crystal material is sealingly sandwiched between the color filter layer and the display array trace layer to form a liquid crystal layer.

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