WO2023284641A1 - Backlight module and liquid crystal display - Google Patents

Abstract

The present application relates to a backlight module and a liquid crystal display. The backlight module comprises: a substrate, backlight lamps, an optical film and white dams, wherein one side surface of the substrate comprises a plurality of backlight areas, and a plurality of backlight lamps are arranged on the backlight areas; the optical film is laminated on the surface of the substrate provided with the backlight lamps and covers the backlight lamps; and the periphery of each backlight area is provided with a white dam, and the white dam protrudes relative to the surface of the optical film that is away from the substrate.

Description

Backlight Module and LCD Display technical field

This application relates to the field of display, in particular to a backlight module and a liquid crystal display (liquid crystal display, LCD).

Background technique

In the field of display technology, there are two display methods, cathode ray tube (CRT) and LCD. Compared with CRT, LCD takes up less space, has lower power consumption, lower radiation, no flicker, and is less prone to visual fatigue. Therefore, LCD has become a mainstream development trend in the display field.

The LCD itself cannot emit light, and it needs an additional light source to emit light. Usually, the additional component is called a backlight module. Because the LED has the characteristics of low power consumption, low heat generation, high brightness, and long life, it is generally used Choose to provide light source for LCD through LED chips to make LCD work smoothly. Generally, the backlight module is mostly a side-illuminated backlight module.

The above-mentioned backlight module generally consists of a substrate, an LED chip and an optical film, wherein the LED chip is fixed on one surface of the substrate, and the optical film is laminated on the surface of the substrate on which the LED chip is disposed. The light emitted by the LED enters the optical film layer from the light-incident surface, and then is reflected from the light-emitting surface of the optical film layer, and then enters the liquid crystal display module.

However, the current backlight module is prone to hotspot problems. The hot spot problem, that is, due to the limited divergence angle of the LED light source, a bright area of the light column appears in the area of the optical film close to the LED light source, which causes the backlight module. There is a bad phenomenon of uneven brightness and darkness on the light-emitting side of the light-incident side.

In order to solve the above problems, it is generally solved by adding a diffuser. However, after adding a diffuser, although the hot spot problem is solved, halo phenomenon is easy to appear.

technical problem

In view of the deficiencies of the above-mentioned prior art, the purpose of the present application is to provide a backlight module and a liquid crystal display, aiming at solving the problem of easy halation after adding a diffuser.

technical solution

In order to solve the above-mentioned technical problems, the purpose of the present application is to provide a backlight module and a liquid crystal display, aiming at solving the problem of easy halo after adding a diffuser.

The first aspect of the present application provides a backlight module, including: a substrate, a backlight, an optical film, and a white dam; one side surface of the substrate includes a plurality of backlight areas, and a plurality of backlight areas are provided on the backlight area. the backlight; the optical film is laminated on the surface of the substrate provided with the backlight, and covers the backlight; each of the backlight areas is provided with the white dam around, and the The white dam is raised relative to the surface of the optical film away from the substrate.

The above-mentioned white dam surrounds the backlight area, and the backlight area has multiple backlight lamps. Therefore, the white dam can uniformly light the entire backlight area, and the backlight area is color-converted by its corresponding optical film layer and so on. That is to say, the entire backlight module performs color uniformity and color conversion in units of the backlight area. At this time, the side light emitted by the backlight in the backlight area can be reflected by the white dam to the substrate after being emitted by the white dam, thereby Can prevent halo phenomenon.

Optionally, any two adjacent backlight regions share part of the white dam. This saves resources and reduces costs.

Optionally, the section of the white dam is slope-shaped. Specifically, the upper edge and the lower edge of the section of the white dam are parallel, and the length of the upper edge is smaller than the length of the lower edge, the left edge can be raised to the left in a slope shape, and the right edge can be raised to the right in a slope shape; Or the left edge is recessed to the right to form a slope, and the right edge is recessed to the left to form a slope. As a result, the white dam has a shape that is narrow at the top and wide at the bottom, so the structural stability of the white dam is stronger.

Optionally, the white dam includes a top surface and a bottom surface oppositely arranged along the thickness direction of the backlight module; the top surface faces away from the optical film, and the bottom surface is opposite to the optical film. Contact; in the width direction of the backlight module, the size of the top surface is smaller than the size of the bottom surface. Therefore, the structural stability of the white dam is strong, and it is not easy to tilt or collapse.

Optionally, the cross-sectional shape of the white dam is an isosceles trapezoid or an isosceles triangle; the width direction is perpendicular to the thickness direction of the backlight module and perpendicular to the extending direction of the white dam. Setting the section of the white dam to be an isosceles trapezoid or an isosceles triangle can facilitate processing, thereby reducing processing costs; and can increase the structural stability of the white dam.

Optionally, the white dam extends along the thickness direction of the backlight module to pass through the optical film, and is fixed to the surface of the substrate on which the backlight is provided. That is, the thickness of the white dam is relatively small. Thick, can run through the entire optical diaphragm, and is higher than the optical diaphragm. Thus, after the side light from the backlight is emitted to the white dam, it can be reflected by the white dam to the upper light-emitting surface, and then emitted from the upper light-emitting surface. This setting method can increase the intensity of light output, improve the utilization rate of light energy, and achieve the purpose of saving energy.

Optionally, the white dam extends into the optical film along the thickness direction of the backlight module, and the bottom surface of the white dam and the side light emitting surface of the backlight face toward the side of the substrate. Edges are flush. As a result, the white dam can not only reflect the side light of the backlight to the upper light emitting surface as much as possible, but also reduce the thickness of the white dam, thereby saving resources.

Optionally, the material of the white dam includes any one of white dam glue, white photosensitive glue and white paint.

Optionally, the size of the protrusion of the white dam relative to the surface of the optical film facing away from the substrate is greater than or equal to 10 microns. As a result, the white dam can not only play a supporting role, but also prevent halo phenomenon.

Optionally, the backlight area is square, and the white dam surrounding the backlight area is in a positive direction. The shape of the backlight area and the white dam are consistent, so that the white dam can not only enclose the backlight area, but also reduce the space occupied by the white dam.

Optionally, the optical film includes a color conversion layer, a diffusion layer and a reflection layer laminated sequentially from top to bottom; the diffusion layer faces the white dam, and the reflection layer faces the substrate. Among them, the reflective layer can homogenize the intensity of the light emitted by the backlight, the diffusion layer can make the color of the light emitted by the backlight more uniform, and the color conversion layer can convert the blue light emitted by the blue backlight into red light or green light. Thereby satisfying the multi-color display requirement of LCD.

Optionally, the color conversion layer is a mixture of glue, color conversion material and diffusion particles.

Optionally, in the thickness direction of the backlight module, the size of the optical film is greater than or equal to 63 microns and less than or equal to 330 microns. In general, the thickness of the backlight is between 10 microns and 100 microns, so the thickness of the optical film is set between 63 microns and 330 microns, so that the optical film can cover the backlight and make the optical film The thickness is within a reasonable range to reduce the thickness of the backlight module and save resources.

Optionally, the substrate is any one of a glass substrate, a silicon substrate, a printed circuit board or a flexible circuit board. Thus, the user can make a selection according to actual needs, which increases the applicability of the present application.

Optionally, the thickness of the backlight is between 10 microns and 100 microns.

Based on the same application idea, the present application also provides an LCD, including the backlight module described in any one of the above-mentioned first aspects and a plurality of liquid crystal layers, and the plurality of liquid crystal layers are laminated on the backlight module. On the light-emitting surface: the orthographic projection area of the frame of the liquid crystal layer on the substrate coincides with the orthographic projection area of the white dam on the substrate.

After applying the backlight module described in the first aspect of the present application to the above-mentioned LCD, under the action of the white dam, the halo phenomenon is obviously improved.

Beneficial effect

The white dam surrounds the backlight area, which has multiple backlights. Therefore, the white dam can evenly light the entire backlight area, and the backlight area is converted by its corresponding optical film layer and so on. That is to say, the entire backlight module performs color uniformity and color conversion in units of the backlight area. At this time, the side light emitted by the backlight in the backlight area can be reflected by the white dam to the substrate after being emitted by the white dam, thereby Can prevent halo phenomenon.

Description of drawings

FIG. 1 is a schematic structural diagram of an LCD in the prior art.

Figure 2 is a schematic diagram of the structure of the hot spot phenomenon.

Fig. 3 is a schematic diagram of the halo phenomenon structure.

FIG. 4 is a schematic structural diagram of a backlight module provided by an embodiment of the present application.

FIG. 5 is a schematic structural diagram of a corresponding display panel of the backlight module shown in FIG. 1 .

FIG. 6 is an enlarged view of A in FIG. 1 .

FIG. 7 is a schematic diagram of the layered structure of the backlight module shown in FIG. 6 and FIG. 1 along the thickness direction.

FIG. 8 is a cross-sectional view along the thickness direction of a backlight module provided by another embodiment of the present application.

FIG. 9 is a cross-sectional view along the thickness direction of a backlight module provided by another embodiment of the present application.

Explanation of reference signs: prior art: 10-backlight module, 11-optical film, 12-diffusion layer, 13-color conversion layer, 14-brightness enhancement film layer, 15-reflective polarized light enhancement film layer, 16 - substrate, 17 - backlight, 20 - display panel.

This application: 1000-backlight module, 100-substrate, 110-backlight area, 200-backlight, 300-optical film, 310-color conversion layer, 320-diffusion layer, 330-reflective layer, 400-white dam , 410-top surface, 420-bottom surface, 500-liquid crystal layer, 510-pixel; X-extension direction, Y-width direction, Z-thickness direction.

Embodiments of the present invention

In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Preferred embodiments of the application are shown in the accompanying drawings. However, the present application can be embodied in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the application more thorough and comprehensive.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terminology used herein in the description of the application is only for the purpose of describing specific embodiments, and is not intended to limit the application.

Referring to FIG. 1 , FIG. 1 is a schematic structural diagram of an LCD in an exemplary technology. The LCD includes a display panel 20 and a backlight module 10 . The backlight module 10 includes an optical film 11 , a substrate 16 and a backlight 17 . Wherein, the optical film 11 includes a diffusion layer 12, a color conversion layer 13, a brightness enhancement film layer 14 (brightness enhancement film, BEF) and a reflective polarized brightness enhancement film (dual-brightness enhancement film, DBEF) layer 15 stacked in sequence; The backlight 17 is disposed on the substrate 16 . The backlight 17 can be a mini-LED or micro-LED chip. This type of backlight module 10 is prone to the hot spot problem as shown in FIG. 2 , that is, some parts are very bright and some parts are very dark, forming an image with uneven brightness and darkness.

After adding the diffusion plate, although the hot spot problem is solved, the halo phenomenon as shown in Figure 3 is easy to appear. In order to solve the above problems, the embodiment of the present application provides a backlight module 1000 .

Please refer to Figure 4 to Figure 7 for details, Figure 4 is a schematic structural diagram of a backlight module provided by an embodiment of the present application, Figure 5 is a schematic structural diagram of a corresponding display panel of the backlight module described in Figure 1, Figure 6 is a schematic diagram of 1, FIG. 7 is a schematic diagram of the layered structure of the backlight module shown in FIG. 6 and FIG. 1 along the thickness direction. In this embodiment, the backlight module 1000 specifically includes: a substrate 100 , a backlight 200 , an optical film 300 and a white dam 400 .

Wherein, one side surface of the substrate 100 includes a plurality of backlight areas 110, on which a plurality of the backlight lamps 200 are arranged; the optical film 300 is stacked on the substrate 100 to provide the backlight on the surface of the lamp 200 and cover the backlight 200 . In the embodiments of the present application, multiple means more than two. The white dam 400 is disposed around each backlight area 110 , and the white dam 400 protrudes relative to the surface of the optical film 300 away from the substrate 100 .

The above-mentioned backlight 200 can be a cold cathode fluorescent lamp (cold Cathode fluorescent lamp (CCFL) for short, CCFL has the advantages of high power and high brightness. The above-mentioned backlight 200 can also be an LED, which has the advantages of high brightness, low power consumption, and long life. Therefore, those skilled in the art can select CCFL or LED as the backlight 200 according to actual needs.

In general, in LCD products, the display panel usually has a plurality of liquid crystal layers 500, and the liquid crystal layer 500 usually has a frame, which is generally black, and is not used to display images, but is used to lay the gate metal of the driving device. For routing, the black border area needs to be covered by setting a black matrix (black matrix, BM). Correspondingly, the liquid crystal layer 500 will be displayed in partitions separated by BM, and each partition has a plurality of pixels 510, and each pixel 510 includes a red pixel, a green pixel and a blue pixel. Each partition includes tens to thousands of pixels 510 , such as 2K display, if there are 516 partitions, each partition corresponds to more than 4000 pixels 510 . As shown in FIG. 5 , the BM divides the display panel into individual sub-pixels, and each individual sub-pixel repeats with a group of red, green, blue (RGB) as a unit.

It can be understood that when the backlight module 1000 is applied to an LCD, the edge of the backlight region 110 is aligned with the above-mentioned BM, because the BM is used as a barrier layer between the LCD pixels 510, and it is opaque, so it will not affect the Visual effects. Moreover, the plurality of backlight regions 110 on the backlight module 1000 correspond to each subregion in the liquid crystal layer 500 one by one, so that the halo phenomenon can be eliminated by partition, with low cost and good elimination effect.

It can be understood that one pixel 510 corresponds to three backlights 200, wherein the red pixel, the green pixel and the blue pixel correspond to one backlight 200 respectively, so if the LCD is 2K display, the corresponding backlight module needs 516 backlight areas 110 , each backlight area 110 corresponds to 4000*3 backlights 200 .

In this embodiment, the white dam 400 surrounds the backlight area 110 , therefore, the white dam 400 can evenly light the entire backlight area 110 , and the backlight area 110 can perform color conversion and the like by its corresponding optical film layer. That is, the entire backlight module 1000 performs color uniformity and color conversion with the backlight area 110 as a unit. Reflected toward the substrate 100, thereby preventing halation.

The backlight module 1000 has a plurality of backlight regions 110, and the plurality of backlight regions 110 correspond to the black matrix on the LCD. Each backlight area 110 is surrounded by a circle of white dams 400 , so that each backlight area 110 is uniformly colored, and finally the whole backlight module 1000 is uniformly colored.

In some embodiments, the material of the white dam 400 includes any one of white dam glue, white photosensitive glue and white paint. Among them, the white dam adhesive can be prepared by heat curing; the white photosensitive adhesive can be prepared by exposure, and the white paint can be prepared by transfer printing.

In some embodiments, among the plurality of backlight regions 110, any two adjacent backlight regions 110 may share part of the white dam 400, thereby saving resources and reducing costs. Specifically, taking the backlight area 110 as a square as an example, the white dam 400 surrounding the backlight area 110 is also a square. At this time, the white dam 400 can be shared with the backlight area 110 and another backlight area 110 on the right. the right side of the .

In some embodiments, the white dam 400 includes a top surface 410 and a bottom surface 420 oppositely disposed along the thickness direction Z of the backlight module 1000; the top surface 410 faces away from the optical film 300, and the The bottom surface 420 is in contact with the optical film; in the width direction Y of the backlight module 1000, the size of the top surface 410 is smaller than the size of the bottom surface 420; the width direction Y is perpendicular to the thickness The direction Z is perpendicular to the extension direction X of the white dam 400 .

That is to say, referring to the direction in the drawing, the cross section of the white dam 400 presents a shape with a narrow top and a wide bottom. Therefore, the white dam 400 has a relatively strong structural stability and is not prone to inclination or collapse. In addition, the structure with a wide top and a narrow bottom is easier to process in terms of technology, and the light reflected by the surrounding wall is directed towards the light-emitting surface, which can improve the light-emitting efficiency and increase the brightness of the light.

Specifically, the cross section of the white dam 400 can be in the shape of a gentle slope. Specifically, referring to the direction in FIG. The left side is convex to form a slope, and the right edge can be convex to the right to form a slope; or the left edge is concave to the right to form a slope, and the right edge is concave to the left to form a slope. This application is not limited.

In some embodiments, in the width direction Y of the backlight module 1000, the cross-sectional shape of the white dam 400 is an isosceles trapezoid or an isosceles triangle; the width direction Y is perpendicular to the backlight module 1000 The thickness direction Z of the white dam 400 is perpendicular to the extension direction X of the white dam 400 . Taking the direction in the figure as a reference, the extending direction X of the white dam 400 is a direction around the backlight area 110 . Setting the cross section of the white dam 400 as an isosceles trapezoid or an isosceles triangle can facilitate processing, thereby reducing processing costs; and can increase the structural stability of the white dam 400 .

Of course, in combination with the above-mentioned embodiment that the white dam 400 needs to be wide at the top and narrow at the bottom, when the cross-sectional shape of the white dam 400 is an isosceles trapezoid, the upper base of the isosceles trapezoid is away from the optical film layer, and the lower base faces the optical film. layer. When the cross-sectional shape of the white dam 400 is an isosceles triangle, the apex of the isosceles triangle is away from the optical film layer, and the bottom is facing the optical film layer. Of course, it can be understood that the corners of the isosceles triangle are rounded, so that processing can be facilitated.

In some embodiments, the size of the protrusion of the white dam 400 relative to the surface of the optical film 300 facing away from the substrate 100 is greater than or equal to 10 microns. Therefore, the white dam 400 can not only play a supporting role, but also prevent halo phenomenon. Specifically, if the thickness of the white dam 400 is less than 10 microns, the side light from the backlight 200 may bypass the white dam 400 to form a halo phenomenon. Therefore, it is necessary to set the thickness of the white dam 400 to be greater than or equal to 10 microns. Microns. In some embodiments, there will be a situation where a plurality of optical films 300 are superimposed on each other, and at this time the white dam 400 can play a role of supporting the optical film 300 .

In some embodiments, the substrate 100 can be any one of a glass substrate, a silicon substrate, a printed circuit board or a flexible circuit board, which can be selected according to actual needs, which is not limited in this embodiment of the present application.

In some embodiments, the optical film 300 includes a color conversion layer 310, a diffusion layer 320 and a reflective layer 330 stacked sequentially from top to bottom; the diffusion layer 320 faces the white dam 400, and the reflective layer 330 faces the substrate 100 . Wherein, the reflective layer 330 can homogenize the intensity of the light emitted by the backlight, the diffusion layer 320 can make the color of the light emitted by the backlight relatively uniform, and the color conversion layer 310 can convert the blue light emitted by the blue backlight 200 into red light Or green light, so as to meet the multi-color display requirements of LCD. In addition, the color conversion layer 310 and the diffusion layer 320 can be prepared separately, that is, the diffusion layer 320 is prepared on the reflective layer 330 first, and then the color conversion layer 310 is prepared on the diffusion layer 320 . It is also possible to prepare a film layer above the reflective layer 330, which has the functions of diffusion and color conversion at the same time, that is, the color conversion layer 310 and the diffusion layer 320 are mixed and prepared; specifically, the material of the color conversion layer 310 can be prepared Formed by adding reflective particles, etc.

In some embodiments, the color conversion layer 310 can be a mixture of glue, color conversion material and diffusion particles, wherein the glue can be silicone glue or epoxy glue, and the color conversion material can be color conversion material quantum dots or fluorescent powder, The diffusion particles may be silicon dioxide (SiO2). The reflective layer 330 can be made of white paint or white ink.

Wherein, in the thickness direction Z of the backlight module 1000 , the size of the optical film 300 is greater than or equal to 63 microns and less than or equal to 330 microns. Specifically, the sum of the thicknesses of the diffusion layer 320 and the color conversion layer 310 is greater than or equal to 60 microns and less than or equal to 300 microns; the thickness of the reflective layer 330 is greater than or equal to 3 microns and less than or equal to 30 microns.

Because in general, the thickness of the backlight 200 is between 10 microns and 100 microns, the thickness of the optical film 300 is set between 63 microns and 330 microns, so that the optical film 300 can cover the backlight 200 and can The thickness of the optical film 300 is kept within a reasonable range to reduce the thickness of the backlight module 1000 and save resources.

Referring to FIG. 8 , FIG. 8 is a cross-sectional view along the thickness direction of a backlight module provided by another embodiment of the present application. The backlight module 1000 provided in another embodiment of the present application is different from the backlight module 1000 in the above embodiment in that the white dam 400 extends along the thickness direction Z of the backlight module 1000 to penetrate the The optical film 300 is fixed to the surface of the substrate 100 provided with the backlight 200 .

That is, the thickness of the white dam 400 is relatively thick, can run through the entire optical film 300 , and is higher than the optical film 300 . Thus, after the side light from the backlight 200 is emitted to the white dam 400 , it can be reflected by the white dam 400 to the upper light-emitting surface, and then emitted from the upper light-emitting surface. This setting method can increase the intensity of light output, improve the utilization rate of light energy, and achieve the purpose of saving energy.

Referring to FIG. 9 , FIG. 9 is a cross-sectional view along the thickness direction of a backlight module provided by another embodiment of the present application. In the backlight module 1000 provided in another embodiment of the present application, the white dam 400 can extend downwards to the inside of the optical film layer, but does not penetrate the optical film 300 . More specifically, it is sufficient for the white dam 400 to extend until it is flush with the lower edge of the side light-emitting surface of the backlight 200 , thus enabling the white dam 400 to reflect the side-emitting light of the backlight 200 as far as possible upwards. The light-emitting surface can also reduce the thickness of the white dam 400, thereby saving resources.

Based on the backlight module 1000 provided in any of the above embodiments, an embodiment of the present application further provides an LCD, including the backlight module 1000 in any of the above embodiments. Of course, what needs to be understood is that the LCD also includes some LCD optical components, etc., and details will not be repeated here.

It should be understood that the application of the present application is not limited to the above examples, and those skilled in the art can make improvements or changes based on the above descriptions, and all these improvements and changes should belong to the protection scope of the appended claims of the present application.

Claims (16)

A backlight module, including: a substrate, a backlight, an optical film and a white dam; One side surface of the substrate includes a plurality of backlight areas, and a plurality of backlights are provided on the backlight area; the optical film is stacked on the surface of the substrate where the backlights are provided, and covers all backlight; The white dams are arranged around each backlight area, and the white dams protrude relative to the surface of the optical film facing away from the substrate. The backlight module according to claim 1, wherein any two adjacent backlight regions share part of the white dam. The backlight module according to claim 1, wherein a section of the white dam is slope-shaped. The backlight module according to claim 1, wherein the white dam includes a top surface and a bottom surface oppositely arranged along the thickness direction of the backlight module; the top surface faces away from the optical film, the The bottom surface is in contact with the optical film; in the width direction of the backlight module, the size of the top surface is smaller than the size of the bottom surface. The backlight module according to claim 4, wherein the cross-sectional shape of the white dam is an isosceles trapezoid or an isosceles triangle. The backlight module according to claim 1, wherein the white dam extends along the thickness direction of the backlight module to penetrate the optical film, and is fixed to the surface of the substrate on which the backlight is provided. . The backlight module according to claim 1, wherein the white dam extends into the optical film along the thickness direction of the backlight module, and the bottom surface of the white dam is in contact with the backlight The side light-emitting surface is flush with the edge of the substrate. The backlight module according to claim 1, wherein the material of the white dam comprises any one of white dam glue, white photosensitive glue and white paint. The backlight module according to claim 1, wherein the size of the protrusion of the white dam relative to the surface of the optical film facing away from the substrate is greater than or equal to 10 microns. The backlight module according to claim 1, wherein the backlight area is in a square shape, and the white dam surrounding the backlight area is in a positive direction. The backlight module according to claim 1, wherein the optical film comprises a color conversion layer, a diffusion layer, and a reflection layer stacked sequentially from top to bottom; the diffusion layer faces the white dam, and the reflection layer to the substrate. The backlight module according to claim 11, wherein the color conversion layer is a mixture of glue, color conversion material and diffusion particles. The backlight module according to claim 1, wherein, in the thickness direction of the backlight module, the size of the optical film is greater than or equal to 63 microns and less than or equal to 330 microns. The backlight module according to claim 1, wherein the substrate is any one of a glass substrate, a silicon substrate, a printed circuit board or a flexible circuit board. The backlight module according to claim 1, wherein the thickness of the backlight is between 10 microns and 100 microns. A liquid crystal display, comprising the backlight module and a plurality of liquid crystal layers according to any one of claims 1 to 15; A plurality of the liquid crystal layers are stacked on the light emitting surface of the backlight module; An orthographic projection area of the frame of the liquid crystal layer on the substrate coincides with an orthographic projection area of the white dam on the substrate.