CN116819824A

CN116819824A - Backlight module

Info

Publication number: CN116819824A
Application number: CN202210281789.7A
Authority: CN
Inventors: 李剑平; 杨秀清
Original assignee: Shenzhen Techaser Technologies Co Ltd
Current assignee: Shenzhen Techaser Technologies Co Ltd
Priority date: 2022-03-21
Filing date: 2022-03-21
Publication date: 2023-09-29

Abstract

The application relates to a backlight module, which is characterized in that a structural layer is arranged above a direct type backlight source in the backlight module, the structural layer comprises optical treatment layers corresponding to LED light sources one by one, and a conical structural member with gradually reduced conical angles is arranged in the optical treatment layers along the central position far away from the optical treatment layers, so that the reflectivity of the central position of the optical treatment layers to light is increased, light can be more uniformly refracted from the structural layer, the local bright spot effect is reduced, and the display uniformity is improved; on the basis, the gap between the LED light sources can be increased to a certain extent, and the number of the LED light sources is reduced under the condition that the total area of the backlight module is unchanged, so that the cost is reduced.

Description

Backlight module

Technical Field

The application relates to the field of display packaging, in particular to a backlight module.

Background

The backlight module is one of key components of the display, and is used for providing a light source with sufficient brightness and uniform distribution for the display, so that the display can normally display images. The backlight is a light source positioned behind the liquid crystal display, and the light-emitting effect of the backlight directly affects the visual effect of the liquid crystal display module. According to different structures, the backlight module can be divided into an edge light type backlight module and a direct type backlight module, wherein a light source of the edge light type backlight module is arranged on the side edge of the light guide plate, and the edge light type backlight module is generally applied to a medium and small-sized backlight module, and the side edge light entering mode has the characteristics of light weight, thinness, narrow frame and low power consumption, and is mostly applied to backlight sources of mobile phones, tablet computers and the like. For large-area displays, direct-type backlight modules are mostly adopted, wherein a plurality of LED chips are formed into an array on a plane, and then an integral surface light source is formed through the treatment of an upper optical film material. The brightness uniformity of the direct type backlight source is greatly influenced by the gaps among the LED chips, and when the gaps among the LED chips are large, local bright spots corresponding to the LED chips can appear, so that the display effect is greatly influenced, and the cost of the large-size backlight module is high.

Therefore, how to improve the display uniformity of the backlight module and reduce the local bright spot effect is a problem to be solved.

Disclosure of Invention

In view of the above-mentioned shortcomings of the related art, the present application is directed to a backlight module, which is aimed at solving the problems of poor display uniformity and high cost of the backlight module in the prior art.

The embodiment of the application provides a backlight module, which comprises:

the direct type backlight comprises a substrate and a plurality of LED light sources arranged on the substrate, and the LED light sources are distributed in an array manner;

the structure layer is arranged above the direct type backlight source; the upper surface of the structural layer is integrally formed with a plurality of optical treatment layers distributed along the planar array of the structural layer, and each optical treatment layer corresponds to the LED light source at the corresponding position below the optical treatment layer one by one; the optical treatment layer comprises cone-shaped structural members which are horizontally paved, and in the same optical treatment layer, the cone angle of the cone-shaped structural members, which is close to the central position of the optical treatment layer, is larger than the cone angle of the cone-shaped structural members, which is far away from the central position of the optical treatment layer;

the optical film group is arranged above the structural layer.

The structure layer is arranged above the direct type backlight source in the backlight module, the structure layer comprises optical treatment layers which are in one-to-one correspondence with the LED light sources, and the taper structural members with gradually reduced taper angles are arranged in the optical treatment layers along the positions far away from the center of the optical treatment layers, so that the reflectivity of the center of the optical treatment layers to light is increased, light can be more uniformly refracted from the structure layer, the local bright spot effect is reduced, and the display uniformity is improved; on the basis, the gap between the LED light sources can be increased to a certain extent, and the number of the LED light sources is reduced under the condition that the total area of the backlight module is unchanged, so that the cost is reduced.

Optionally, the intervals between the LED light sources are the same; and the boundary of each optical processing layer is positioned at a position corresponding to the middle part of the adjacent LED light source.

Optionally, the shape of the tapered structure comprises a conical or square taper.

Optionally, in the same optical processing layer, a gap between bottoms of the tapered structural members is less than or equal to a preset value.

Optionally, in the same optical treatment layer, the bottom shape and area of each tapered structure member are the same, and the height of each tapered structure member gradually decreases along a direction away from the central position of the optical treatment layer.

Optionally, in the same optical processing layer, the height of each tapered structure member is in a normal distribution.

Optionally, the lower surface of the structural layer is integrally formed with a light-scattering layer.

Optionally, in the optical film group, a quantum dot film, a diffusion film and a brightness enhancement film are sequentially stacked from a direction close to the structural layer to a direction far from the structural layer.

Optionally, the quantum dot film further comprises a blue light film, wherein the blue light film is arranged between the structural layer and the quantum dot film.

Optionally, the LED light source includes a mini LED or a micro LED.

Drawings

Fig. 1 is a schematic diagram of a backlight module according to an embodiment of the present application;

fig. 2 is an enlarged schematic view of a structural layer in a backlight module according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a backlight module according to another embodiment of the present application;

reference numerals illustrate:

1-direct type backlight source; 11-a substrate; 12-LED light source; 2-a structural layer; 21-an optical treatment layer; 211-conical structural member; 3-an optical film set; 31-quantum dot film; a 32-diffusion film; 33-a lower brightness enhancement film; 34-upper brightness enhancement film; 35-blue film.

Detailed Description

In order that the application may be readily understood, a more complete description of the application will be rendered by reference to the appended drawings. The drawings illustrate preferred embodiments of the application. This application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

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

When the side light type backlight source is applied to a middle-large size backlight module, the weight and the cost of the light guide plate can be increased along with the increase of the size, the luminous brightness and the uniformity are not ideal, and meanwhile, the display panel adopting the side light type backlight source can not realize the regional dynamic control because of adopting the light guide plate, and only simple one-dimensional dimming can be realized. In contrast, the direct type backlight source has better performance, and can realize regional dynamic control. The direct type backlight source does not need a light guide plate, an array type light source is arranged at the bottom, and light rays are emitted from an LED light source, uniformly mixed by an optical film set above and then emitted. However, in the direct type backlight, the requirement for the gaps between the LED light sources distributed in the array is larger, and if the gaps between the LED light sources are larger, the spots are formed one by one at the positions corresponding to the LED light sources, so that the overall display uniformity is affected. If the gap between the LED light sources is set smaller, the number of the LED light sources is larger, which makes the cost of the display panel high.

Based on this, the present application is intended to provide a solution to the above technical problem, the details of which will be described in the following examples.

Referring to fig. 1 and 2, the specific structure of the backlight module includes:

the direct type backlight 1, the direct type backlight 1 comprises a substrate 11 and a plurality of LED light sources 12 arranged on the substrate 11, and the LED light sources 12 are distributed in an array;

the structure layer 2 is arranged above the direct type backlight source 1; the upper surface of the structural layer 2 is integrally formed with a plurality of optical treatment layers 21 distributed along the planar array of the structural layer 2, and each optical treatment layer 21 corresponds to the LED light sources 12 at the corresponding positions below the optical treatment layer 21 one by one; the optical treatment layer 21 comprises cone-shaped structural members 211 which are horizontally arranged, and in the same optical treatment layer 21, the cone angle of the cone-shaped structural member 211 which is close to the center of the optical treatment layer 21 is larger than the cone angle of the cone-shaped structural member 211 which is far away from the center of the optical treatment layer 21;

the optical film group 3, the optical film group 3 is disposed above the structural layer 2.

The backlight module in the embodiment of the application belongs to a direct type backlight module, and the backlight source 1 is a corresponding direct type backlight source 1. The entire backlight 1 is formed by a plurality of point light sources which are arranged on the substrate 11 in an array, and the point light sources are LED light sources 12 in the embodiment of the present application. In general, the LED light sources 12 need only be arranged in an array on one surface of the substrate 11, and the LED light sources 12 need not be arranged on both surfaces.

In the embodiment of the present application, the specific type of the LED light source 12 may be a mini LED or a micro LED. Where mini LEDs refer to sub-millimeter light emitting diodes, means LEDs with die sizes of about 100-200 microns. Because the mini LED is arranged between the traditional LED and the micro LED, the micro LED is simply an improved version based on the traditional large-size LED, under the condition that the manufacturing technology is relatively mature, the micro LED can be directly regarded as an LED-to-micro LED transition scheme, because the key technical yield of the micro LED can not be reached all the time, the mini LED is a new generation novel display technology for replacing the traditional LED, the process yield is relatively higher than that of the micro LED, the relative mass production is easier, and the micro LED is also more easily applied to the liquid crystal display backlight market. micro LEDs are micro LEDs, which are smaller than mini LEDs in size, below 30 microns in size, and the key technology is huge transfer, and have the characteristics of high brightness, high contrast, high resolution, high reliability, quick response time, energy saving, low cost and the like. In the embodiment of the application, a mini LED may be generally used as the LED light source 12 in the direct type backlight 1, and in some cases, a micro LED may be also used as the LED light source 12, and a common large-sized LED may also be used as the LED light source 12.

The substrate 11 is used for carrying the LED light source 12, that is, the LED light source 12 is disposed on the substrate 11 by a patch or a package. The substrate 11 may also serve as a reflector for the LED light source 12, i.e. the light emitted by the LED light source 12 towards the substrate 11 may be reflected by the substrate 11 into the structural layer 2 above the LED light source 12.

In the embodiment of the application, the structural layer 2 is arranged above the direct type backlight source 1, and the purpose of arranging the structural layer 2 is to adjust the light output of the LED light source 12, thereby playing the roles of reducing the light spot display effect and increasing the display uniformity. In order to achieve the above-mentioned effects, in the embodiment of the present application, the upper surface of the structural layer 2 is provided with a plurality of optical treatment layers 21. The optical treatment layer 21 and the structural layer 2 are directly formed integrally, that is, the upper surface of the structural layer 2 is composed of a plurality of optical treatment layers 21. The optical treatment layers 21 are also distributed in an array, and the positions and the number of the distribution are in one-to-one correspondence with the LED light sources 12 below the optical treatment layers, and each LED light source 12 serving as a point light source is corresponding to one optical treatment layer 21 above the optical treatment layer, that is, the optical treatment layer 21 can directionally treat the light emitted by the LED light source 12.

In the embodiment of the present application, each optical processing layer 21 includes a plurality of tapered structures 211. The tapered structure 211 is a structure with a large bottom and a small top, the lower end of the tapered structure is directly located on the upper surface of the structural layer 2, the size is larger, and the upper end gradually decreases along with the upward extension. When the light emitted from the LED light source 12 is processed, each tapered structure 211 reflects and refracts the light emitted according to the angle of inclination of the tapered surface of the tapered structure 211. The angle formed by the inclination of the conical surface and the bottom surface is the conical surface angle.

The angle between the conical surface of the conical structure body and the bottom surface is different. Specifically, if the cone angle is greater, the angle between the cone surface and the bottom surface of the cone structure is closer to 90 degrees, which results in greater reflectivity of the LED light source 12, and correspondingly less refracted light, i.e., lower intensity of light directly refracted from that location; conversely, if the cone angle is smaller, the closer to 0 degrees the angle between the cone surface and the bottom surface of the cone-shaped structure is, which results in a smaller reflectance of the LED light source 12, and a correspondingly larger refracted light, i.e., a higher intensity of light directly refracted from that location. Corresponding to the distribution of the tapered structures 211 in the optical processing layer 21 in the embodiment of the present application, the tapered angles of the tapered structures 211 near the center of the optical processing layer 21 are larger, that is, the light extraction reflectivity near the center of the optical processing layer 21 is larger, the intensity of directly refracted light is smaller, and most of light is reflected to other places, thereby reducing local bright spots. The taper angle of the taper structure 211 far from the center of the optical processing layer 21 is smaller, the corresponding light-emitting reflectivity is smaller, and more light rays can be directly refracted and emitted, so that the light-emitting brightness of the light rays near the position is increased. The center of the optical processing layer 21 corresponds to the center of the LED light source 12 below the optical processing layer, so that the refractive intensity of the light is reduced, the local bright spots can be effectively reduced, and the overall uniformity is improved. And the light is reflected to other places, so that the overall brightness of the light can be effectively increased.

Accordingly, because the overall light emitting uniformity is increased, the interval between the LED light sources 12 can be increased within a certain range in the embodiment of the application, so that the number of the LED light sources 12 in the same display area is reduced, and the production cost is reduced.

In some alternative embodiments, the shape of the tapered structure 211 may specifically include a conical shape or a square taper. The conical surface of the conical structural member 211 serves as an interface of light emergent reflection and refraction of the LED light source 12, and the conical shape has the characteristic of consistent surrounding, so that the display uniformity can be further improved; the square cone is similar to a pyramid in shape, and four corresponding inclined planes can be arranged in the length-width direction of the backlight module.

In some alternative embodiments, the gap between the bottoms of the tapered structures 211 in the same optical processing layer 21 is less than or equal to a predetermined value. If there is a gap between adjacent tapered structures 211, the gap is most likely a plane, which would cause direct refraction of the light emitted by the LED light source 12; therefore, for better display, the bottom gap of each tapered structure 211 should be as small as possible, and preferably may be directly connected.

In some alternative embodiments, the bottom shape and area of each tapered structure 211 are the same in the same optical treatment layer 21, and the height of each tapered structure 211 decreases gradually in a direction away from the center of optical treatment layer 21. The bottom of the tapered structure 211 may have a different shape according to the overall shape thereof; for example, when the tapered structure 211 is conical in shape, its bottom shape is circular; when the tapered structure 211 is square in shape, its bottom is square in shape. Whereas if the bottom shape and size of each tapered structure 211 are uniform, the greater the taper angle of the tapered structure 211 near the center of the optical treatment layer 21, the higher its height will be, and the smaller the taper angle of the tapered structure 211 away from the center of the optical treatment layer 21, the lower its height will be.

In some alternative embodiments, the height of each tapered structure 211 is shown as a normal distribution in the same optical processing layer 21. Specifically, according to the position x of the tapered structure member 211 relative to the center of the optical processing layer 21 and the distance μ of the normal distribution curve center point relative to the center of the optical processing layer 21, the height f (x) of the corresponding tapered structure member 211 can be calculated as follows:

wherein the sigma value range is 3-15.

Accordingly, the cross-sectional area distribution F (x) of the tapered structure 211 is calculated as:

the embodiment provides a backlight module, which is characterized in that a structural layer 2 is arranged above a direct type backlight source 1 in the backlight module, and the structural layer 2 comprises optical treatment layers 21 which are in one-to-one correspondence with LED light sources 12, so that a conical structural member 211 with gradually reduced conical angles is arranged in the optical treatment layers 21 along the central position far away from the optical treatment layers 21, thereby increasing the reflectivity of the central position of the optical treatment layers 21 to light, enabling light rays to be more uniformly refracted from the structural layer 2, reducing the local bright spot effect and improving the display uniformity; on the basis, the gap between the LED light sources 12 can be increased to a certain extent, and the number of the LED light sources 12 is reduced under the condition that the total area of the backlight module is unchanged, so that the cost is reduced.

Another alternative embodiment of the application:

referring to the foregoing embodiments and fig. 3, the embodiment of the present application further provides a backlight module, where the specific structure of the backlight module includes:

Wherein, in some alternative embodiments, the spacing between the LED light sources 12 is the same; the boundary of each optical processing layer 21 is located at a position corresponding to the middle portion of the adjacent LED light sources 12. In the embodiment of the present application, the distribution of the LED light sources 12 is uniform in the lateral and longitudinal directions, and in this distribution manner, the boundary position of the optical treatment layer 21 is the intermediate position of the adjacent LED light sources 12.

In some alternative embodiments, the lower surface of the structural layer 2 is integrally formed with a light diffusing layer. In order to further improve the uniformity of light emission, a light scattering layer may be disposed on the lower surface of the structural layer 2, and the light emission of the LED light source 12 may be dispersed in advance, similar to a matte layer, so as to reduce the local speckle effect.

In some alternative embodiments, in the optical film group 3, the quantum dot film 31, the diffusion film 32, and the light enhancement film are sequentially laminated from the direction closer to the structural layer 2 to the direction farther from the structural layer 2. The quantum dot film 31 is used for adjusting the white light color of the backlight after mixing with the blue light of the light source; and the diffusion film 32 functions to optically adjust and mask flaws; the brightness enhancement film generally comprises an upper layer and a lower layer, and a lower brightness enhancement film 33 and an upper brightness enhancement film 34, which are used for optical adjustment, changing the optical polarization direction and improving the brightness of the outgoing light.

In some alternative embodiments, a blue light film 35 may also be included, the blue light film 35 being disposed between the structural layer 2 and the quantum dot film 31. The blue light film 35 can reflect the red light and the green light emitted by the LED light source 12, and allow the blue light to pass through, so that the light mixing effect with the quantum dot film 31 is improved. The LED light source 12 may be directly set as a blue LED, so as to improve uniformity of light emission.

The LED provided in the foregoing embodiment may be applied to various light emitting fields, for example, it may be manufactured into a backlight module applied to a display backlight field (may be a backlight module of a terminal such as a television, a display, a mobile phone, etc.). It can be applied to the backlight module at this time. The display device can be applied to the field of display backlight, key backlight, shooting, household illumination, medical illumination, decoration, automobile, traffic and the like. When the light source is applied to the field of key backlight, the light source can be used as a key backlight light source with key equipment such as a mobile phone, a calculator, a keyboard and the like; when the device is applied to the shooting field, the device can be manufactured into a flash lamp of a camera; when the LED lamp is applied to the field of household illumination, the LED lamp can be manufactured into a floor lamp, a desk lamp, an illuminating lamp, a ceiling lamp, a down lamp, a projection lamp and the like; when the light source is applied to the field of medical illumination, the light source can be manufactured into operating lamps, low-electromagnetic illumination lamps and the like; when the light is applied to the decoration field, various decorative lamps such as various colored lamps, landscape lighting lamps and advertisement lamps can be manufactured; when the material is applied to the field of automobiles, the material can be manufactured into automobile lamps, automobile indication lamps and the like; when the LED street lamp is applied to the traffic field, various traffic lamps can be manufactured, and various street lamps can also be manufactured. The above-described applications are only a few applications of the example shown in the present embodiment, and it should be understood that the application of the LED in the present embodiment is not limited to the fields of the above-described examples.

It is to be understood that the application is not limited in its application to the examples described above, but is capable of modification and variation in light of the above teachings by those skilled in the art, and that all such modifications and variations are intended to be included within the scope of the appended claims.

Claims

1. A backlight module, comprising:

the optical film group is arranged above the structural layer.

2. The backlight module according to claim 1, wherein the intervals between the LED light sources are the same; and the boundary of each optical processing layer is positioned at a position corresponding to the middle part of the adjacent LED light source.

3. The backlight module of claim 1, wherein the shape of the tapered structure comprises a conical shape or a square cone shape.

4. The backlight module according to claim 1, wherein a gap between bottoms of the tapered structural members in the same optical processing layer is equal to or smaller than a predetermined value.

5. The backlight module according to claim 1, wherein in the same optical processing layer, the bottom shape and area of each of the tapered structures are the same, and the height of each of the tapered structures is gradually reduced in a direction away from the center of the optical processing layer.

6. A backlight module according to claim 5, wherein the heights of the tapered structures in the same optical processing layer are normally distributed.

7. A backlight module according to any one of claims 1 to 6, wherein the lower surface of the structural layer is integrally formed with a light diffusing layer.

8. The backlight module according to any one of claims 1 to 6, wherein the quantum dot film, the diffusion film and the brightness enhancement film are laminated in this order from a direction close to the structural layer to a direction far from the structural layer in the optical film group.

9. The backlight module of claim 8, further comprising a blue film disposed between the structural layer and the quantum dot film.

10. The backlight module according to any one of claims 1-6, wherein the LED light source comprises a mini LED or a micro LED.