Backlight module and display device

Abstract

The utility model discloses a backlight module and a display device. The backlight module comprises an optical film and a backlight source. The backlight source comprises a substrate and a plurality of light-emitting devices arranged on the substrate, and each light-emitting device is provided with a light control assembly. The light control assembly is used for projecting the emergent light of the corresponding light emitting device to the optical film and controlling the transmittance of the corresponding emergent light; the problem that the display contrast ratio in an existing display module is not high can be solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of display, in particular to a backlight module and a display device. BACKGROUND

[0002] The side-in backlight structure in the backlight technology is simple and small in thickness. The side-in backlight realizes uniform backlight illumination by a light guide plate for the light incident from the side. However, the backlight can only be full-screen bright or full-screen dark, and cannot control the light in partition, so the display contrast is not high.

[0003] Therefore, the current technology still needs to be improved and enhanced. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a backlight module and a display device, which can alleviate the problem of low display contrast in the current display module.

[0005] The present application provides a backlight module, comprising an optical film and a backlight source, the backlight source comprising a substrate and a plurality of light emitting devices arranged on the substrate, and a light control assembly arranged on each light emitting device; the light control assembly is used for projecting the light emitted by the corresponding light emitting device onto the optical film and adjusting the transmittance of the corresponding emitted light.

[0006] In some embodiments, the light control assembly comprises a grating structure, and the grating structure comprises a plurality of grating units, and the plurality of grating units are arranged in the same direction.

[0007] In some embodiments, the light control assembly comprises a grating structure, and the grating structure comprises a plurality of grating units, and the plurality of grating units are arranged in at least two directions.

[0008] In some embodiments, each grating unit comprises a plurality of grating substructures arranged at intervals.

[0009] The shape of the grating substructure is strip-shaped, and the width of the grating substructure along the arrangement direction of the grating unit increases.

[0010] In some embodiments, each grating unit comprises a plurality of grating substructures arranged at intervals, and the grating substructure is a cylindrical structure, a conical structure, a prismatic structure or a spherical structure.

[0011] In some embodiments, the structure size of the plurality of grating substructures in each grating unit changes in a preset rule in the arrangement direction of the grating substructure.

[0012] In some embodiments, the center distance between adjacent grating units is a subwavelength or a wavelength of the emitted light.

[0013] In some embodiments, the backlight module, the grating substructure is a nano substructure.

[0014] In some embodiments, the backlight module, the light control assembly comprises a photonic crystal.

[0015] In some embodiments, the backlight module, the photonic crystal comprises a plurality of crystal units, and the plurality of crystal units are arranged at intervals along at least two directions.

[0016] In some embodiments, the backlight module, the center distance between adjacent crystal units is greater than the wavelength of the outgoing light.

[0017] In some embodiments, the backlight module, the crystal unit comprises a plurality of medium structures, and the medium structure is a nano medium structure.

[0018] In some embodiments, the backlight module, the optical film comprises a diffusion film, and the diffusion film comprises a plurality of diffusion units, and the plurality of diffusion units are arranged one-to-one corresponding to the light emitting devices.

[0019] In some embodiments, the backlight module, each diffusion unit is provided with a microlens, and along the direction in which the light intensity of the light projected onto the diffusion unit gradually decreases, the size of the microlens gradually increases.

[0020] The embodiments of the present application also provide a display device, which comprises the backlight module described above.

[0021] The backlight module and the display device provided by the present application, the backlight module comprises an optical film and a backlight; the backlight source comprises a substrate and a plurality of light emitting devices arranged on the substrate, and each light emitting device is provided with a light control assembly; the light control assembly controls the light emitting angle and the light emitting direction of the corresponding light emitting device, so that the outgoing light of the light emitting device is projected onto the optical film, and the display of the display module is ensured. Each light emitting device is provided with a light control assembly corresponding to each light emitting device, and the light control assembly can individually control the transmittance of the outgoing light of the corresponding light emitting device, realize the backlight partition control, and further improve the display contrast. BRIEF DESCRIPTION OF DRAWINGS

[0022] The technical solutions and other beneficial effects of the present application will become apparent through the following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings.

[0023] Figure 1 The structure schematic diagram of the backlight module provided by the embodiments of the present application.

[0024] Figure 2 The structure schematic diagram of the first embodiment of the light control assembly in the backlight module provided by the embodiments of the present application.

[0025] Figure 3 The structure schematic diagram of the light control assembly in the backlight module provided by the embodiments of the present application.Figure 2 schematic diagram of the center distance dimension.

[0026] Figure 4 schematic diagram of the second embodiment of the light control assembly in the backlight module provided by the embodiment of the present application.

[0027] Figure 5 schematic diagram of the third embodiment of the light control assembly in the backlight module provided by the embodiment of the present application. Figure 4 schematic diagram of the center distance dimension.

[0028] Figure 6 schematic diagram of the third embodiment of the light control assembly in the backlight module provided by the embodiment of the present application.

[0029] Figure 7 schematic diagram of the diffusion unit in the backlight module provided by the embodiment of the present application.

[0030] Figure 8 schematic diagram of the microlens structure of the diffusion unit in the backlight module provided by the embodiment of the present application.

[0031] Reference signs:

[0032] 10, package housing; 20, optical film; 30, backlight source; 31, substrate; 32, light emitting device; 33, light control assembly; 40, grating structure; 41, grating unit; 411, grating substructure; 50, photonic crystal; 51, crystal unit; 511, dielectric structure; 21, diffusion film; 211, diffusion unit; 60, microlens. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0034] In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features, so that the features with "first", "second" can explicitly or implicitly include one or more features, and in the description of the present application, the meaning of "multiple" is two or more than two, unless otherwise explicitly and specifically limited.

[0035] Backlight technology plays a very important role in LCD (Liquid Crystal Display) display, and there are two technical routes of side-in backlight and direct backlight. The side-in backlight structure is simple and small in thickness, and the light incident from the side is uniformly illuminated through the light guide plate, but this backlight can only be full screen bright and full screen dark, and cannot control the light in different areas, so the display contrast is not high. The direct backlight can control the illumination of each area through local dimming technology, so as to realize the function of partition lighting, and has high image contrast. However, the direct backlight needs a certain distance to expand the light spot to meet the requirements, which puts higher requirements on the light expansion capacity of the lens, and also makes the thickness of the backlight module unable to be reduced.

[0036] Please refer to Figure 1 The display module provided by the embodiment comprises an encapsulation shell 10, an optical film 20 and a backlight source 30. The optical film 20 and the backlight source 30 are arranged in the encapsulation shell 10, and a containing space is formed between the optical module and the encapsulation shell 10. The backlight source 30 is located in the containing space, and the light emitting surface of the backlight source 30 intersects with the surface where the optical film 20 is located.

[0037] The backlight source 30 comprises a substrate 31 and a plurality of light emitting devices 32 arranged on the substrate 31. A light control assembly 33 is arranged on each light emitting device 32. The light control assembly 33 is used for projecting the light emitted by the light emitting device 32 onto the optical module and controlling the transmittance of the corresponding emitted light. Specifically, the light emitting surface of the backlight source 30 intersects with the surface where the optical film 20 is located, and the substrate 31 and the optical film 20 form a certain angle. At this time, the light control assembly 33 adjusts the light emitting angle and light emitting direction of the corresponding light emitting device 32, so that the light emitted by the light emitting device 32 is projected onto the optical film 20, and the display of the display module is ensured. Each light emitting device 32 is separately provided with a light control assembly 33. The transmittance of the light emitted by the corresponding light emitting device 32 can be controlled by the light control assembly 33, the backlight partition control is realized, and the display contrast is improved.

[0038] The backlight source 30 is arranged at the side of the encapsulation shell 10 and forms a certain angle with the optical film 20. Compared with the direct backlight, the thickness of the overall display module can be reduced. Compared with the side-in backlight, the backlight partition control can be realized. To some extent, the display module in the embodiment can not need to be provided with a light guide plate, and the overall structure of the display module can be simplified.

[0039] Please refer to Figure 2In some embodiments, the light control component 33 includes a grating structure 40, which comprises a plurality of grating units 41. The plurality of grating units 41 are arranged at intervals along the same direction to form a one-dimensional grating structure 40. Each grating unit 41 includes a plurality of spaced-apart grating substructures 411. The formation of the grating substructures 411 in this embodiment can be varied, such as cylindrical, conical, prismatic, or spherical structures. By setting different grating substructures 411, it is beneficial to achieve different light transmittance, thereby improving the contrast of the display module.

[0040] Each grating unit 41 contains multiple grating substructures 411, which vary according to a preset rule in the arrangement direction of the grating substructures 411. For example, the structural size of the grating substructures 411 gradually increases or decreases along its arrangement direction, or decreases first and then increases.

[0041] like Figure 2 As shown, taking a strip-shaped one-dimensional grating structure 40 as an example, the arrangement direction of the grating units 41 is denoted as the first direction, and the extension direction of the strip-shaped grating substructure 411 is denoted as the second direction. The width of the grating substructure 411 increases along the arrangement direction of the grating units 41. The grating structure 40 deflects and adjusts the light emission angle of the corresponding light-emitting device 32, so that the light emitted by the light-emitting device 32 is projected onto the optical film 20 to form a corresponding light spot.

[0042] Please see Figure 3 Along the first direction, the center distance L1 between adjacent grating units 41 is equal to the arrangement period of the grating structure 40 being the subwavelength or wavelength of the emitted light, i.e., the period of the grating structure 40 is the subwavelength or wavelength. By adjusting the period of the grating structure 40, setting different grating substructures 411, and the structural dimensions, the size, direction, and transmittance of the light emission angle can be adjusted, thereby meeting display requirements and improving display contrast.

[0043] In one embodiment, the thickness of the grating structure 40 is in the nanometer dimension. If the grating substructure 411 is a strip grating substructure 411, the thickness of the strip grating structure 411 is also in the nanometer dimension. Correspondingly, the width of the strip grating structure 411 is also set to the nanometer dimension. Thus, by setting the grating substructure 411 to a nanometer-sized structure, which is at the same size as the wavelength of the emitted light, it is beneficial to improve the adjustment effect of the emitted light.

[0044] In some embodiments, a plurality of grating units 41 are arranged at intervals along at least two directions to form a two-dimensional grating structure 40 or a three-dimensional grating structure 40, etc.

[0045] Please see Figure 4 andFigure 5 For example, in the case of forming a two-dimensional grating structure 40, a cylindrical grating substructure 411 is arranged in each grating unit 41. The plurality of grating substructures 411 are arranged at intervals along a first direction, and the diameter of each cylindrical grating substructure 411 in the grating unit 41 gradually increases. In a second direction, a plurality of grating units 41 are arranged side by side. In the first direction, the center distance L1 between adjacent grating units 41 is equal to the period of the grating structure 40, which is subwavelength or wavelength of the outgoing light. In the second direction, the center distance L2 between adjacent grating units 41 can be the same as the center distance between adjacent gratings in the first direction. In this embodiment, by arranging different grating substructures 411, structure sizes, and periods of the grating structure 40, the size, direction, and transmittance of the outgoing light angle can be adjusted, thereby meeting the display requirements and improving the display contrast. For example, the smaller the period of the grating structure 40, the larger the deflection angle of the outgoing light, which will make the outgoing light more inclined to project onto the optical film 20. Therefore, for each light emitting device 32, the larger the deflection angle of the outgoing light controlled by the grating structure 40, the smaller the arrangement period of the grating structure 40 corresponding to the light emitting device 32.

[0046] As an example, the size of the grating substructure 411 in this embodiment is nanoscale, for example, each size of the cylindrical grating substructure 411 is nanoscale, which is the same order of magnitude as the wavelength of the outgoing light, which is beneficial to improve the adjustment effect of the outgoing light.

[0047] Please refer to Figure 6 In some embodiments, the light control assembly 33 includes a photonic crystal 50, which is a periodic optical structure. The photonic crystal 50 includes a plurality of crystal units 51. By arranging the structure of the crystal unit 51, the band characteristics of the photonic crystal 50 can be adjusted, and the band characteristics can make the outgoing light passing through the photonic crystal 50 have specific angular characteristics. In this embodiment, the photonic crystal 50 is used as the light control assembly 33, so that the outgoing light of the light emitting device 32 projects onto the optical film 20 to ensure the display of the display module. At the same time, each light emitting device 32 is provided with a separate light control assembly 33, and the transmittance of the outgoing light of the corresponding light emitting device 32 can be controlled by the light control assembly 33, thereby realizing backlight partition control and improving the display contrast.

[0048] In some embodiments, specifically, the photonic crystal 50 includes a plurality of crystal units 51, and the plurality of crystal units 51 are arranged at intervals along at least two directions to form a two-dimensional photonic crystal 50 or a three-dimensional photonic crystal 50, etc.

[0049] Taking the two-dimensional photonic crystal 50 as an example, a plurality of crystal units 51 are arranged at intervals along a first direction and a second direction. In the same direction, the center distance between two adjacent crystal units 51 is equal to the arrangement period in the direction. By adjusting the arrangement period of the crystal unit 51, the energy band frequency range of the photonic crystal 50 can be adjusted, and the characteristics of the outgoing light passing through the photonic crystal 50 can be controlled. For example, the smaller the arrangement period of the photonic crystal 50, the larger the outgoing light angle, that is, the larger the deflection angle of the outgoing light. Therefore, for each light emitting device 32, the larger the deflection angle of the outgoing light controlled by the photonic crystal 50, the smaller the arrangement period of the photonic crystal 50 corresponding to the light emitting device 32.

[0050] Please continue to refer to Figure 6 As an example, the center distance between two adjacent crystal units 51 is greater than the wavelength of the outgoing light. Each crystal unit 51 includes a plurality of dielectric structures 511, and one dielectric structure 511 is a structure formed of the same refractive index material. The dielectric structure 511 can be a hollow hole structure, a cylindrical structure, a prism structure, a pyramid structure, or a spherical structure, etc. The arrangement period of the photonic crystal 50 determines the frequency range of the energy band, and the structure of each crystal unit 51 determines the properties of the energy band, thereby determining the propagation characteristics of the outgoing light passing through the photonic crystal 50. In this embodiment, by setting the arrangement period of the photonic crystal 50, the dielectric structure 511, the size or the number of the crystal unit 51, etc., the energy band structure of the photonic crystal 50 can be finely controlled, and the specific light outgoing direction, the light outgoing angle, and the transmittance of the outgoing light can be realized.

[0051] The structure of each crystal unit 51 in the photonic crystal 50 is the same, and two cylindrical dielectric structures 511 are arranged in each crystal unit 51. One of the two cylindrical dielectric structures 511 has a large diameter, and the other has a small diameter. The two cylindrical dielectric structures 511 can be arranged along a third direction, and the third direction intersects the second direction and the first direction.

[0052] As an example, the dielectric structure 511 in the crystal unit 51 is a nano dielectric structure 511. By setting the size of the dielectric structure 511 in the photonic crystal 50 to be nanoscale, the wavelength of the outgoing light is of the same order of magnitude, which is beneficial to improve the adjustment effect of the outgoing light.

[0053] Please refer to Figure 7In some embodiments, the optical film 20 comprises a diffusion film 21, the diffusion film 21 comprises a plurality of diffusion units 211, the plurality of diffusion units 211 are arranged one-to-one corresponding to the light emitting devices 32, and the shape of the diffusion unit 211 can be arranged according to the spot shape of the light projected by the light emitting device 32 to the optical film 20. In this embodiment, one diffusion unit 211 is arranged corresponding to each light emitting chip, and the light emitted by each light emitting chip is independently diffused by the diffusion unit 211, so as to ensure that the emission angle distribution of each light emitting chip after being projected to the diffusion unit 211 is consistent through the diffusion unit 211, thereby realizing uniform light emission of the backlight module and ensuring the consistency of the visual effect.

[0054] Please refer to Figure 8 Specifically, a microlens 60 is arranged on the side of each diffusion unit 211 close to the packaging shell 10, and the size of the microlens 60 gradually increases along the direction in which the light intensity of the light projected to the diffusion unit 211 gradually decreases. The substrate 31 of the backlight source 30 is arranged obliquely relative to the diffusion film 21, and the light emitting device 32 is arranged obliquely relative to the diffusion unit 211. One side of the light emitting device 32 is close to the diffusion film 21, and the other side of the light emitting device 32 is close to the side of the packaging shell 10. Corresponding to the light intensity of the light projected to the diffusion unit 211 by the light emitting device 32, the light intensity gradually decreases in the direction away from the diffusion unit 211. Therefore, the size of the microlens 60 in the diffusion unit 211 gradually increases along the direction in which the light intensity of the light projected to the diffusion unit 211 gradually decreases. For example, the microlens 60 is a columnar lens structure, and the height of the columnar lens structure gradually increases. In this way, the diffusion unit 211 emits the light emitted by the corresponding light emitting device 32 after uniform processing, realizes the consistency of light emission, and ensures the consistency of the visual effect of the display module.

[0055] The application further discloses a display device comprising the backlight module.

[0056] In the above embodiments, the description of each embodiment has its own emphasis, and the parts not described in detail in a certain embodiment can be referred to the related description of other embodiments.

[0057] The backlight module provided by the embodiments of the application is described in detail above, and the principles and implementation manners of the application are described by applying specific examples. The above description of the embodiments is only used to help understand the technical solutions and core ideas of the application; those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the application.

Claims

1. A backlight module, characterized in that, The backlight module comprises an optical film and a backlight source; the backlight source comprises a substrate and a plurality of light emitting devices arranged on the substrate, and each of the light emitting devices is provided with a light control component; the light control component is used for projecting outgoing light corresponding to the light emitting device onto the optical film and controlling the transmittance of the outgoing light.

2. The backlight module of claim 1, wherein, The light control component comprises a grating structure, and the grating structure comprises a plurality of grating units arranged in the same direction.

3. The backlight module of claim 1, wherein, The light control component comprises a grating structure, and the grating structure comprises a plurality of grating units arranged in at least two directions.

4. The backlight module of claim 2, wherein, Each of the grating units comprises a plurality of grating substructures arranged in a spaced manner. The grating substructure is in a strip shape, and the width of the grating substructure along the arrangement direction of the grating unit increases.

5. The backlight module of claim 2 or 3, wherein, Each of the grating units comprises a plurality of grating substructures arranged in a spaced manner, and the grating substructure is in a cylindrical structure, a conical structure, a prismatic structure or a spherical structure.

6. The backlight module of claim 5, wherein, The structural size of the plurality of grating substructures in each of the grating units changes in a preset manner along the arrangement direction of the grating substructure.

7. The backlight module of claim 5, wherein, The center distance between adjacent grating units is a subwavelength or a wavelength of the outgoing light.

8. The backlight module of claim 6, wherein, The grating substructure is a nano substructure.

9. The backlight module of claim 1, wherein, The light control component comprises a photonic crystal.

10. The backlight module of claim 9, wherein, The photonic crystal comprises a plurality of crystal units arranged in at least two directions.

11. The backlight module of claim 10, wherein, The center distance between adjacent crystal units is greater than the wavelength of the outgoing light.

12. The backlight module of claim 10, wherein, The crystal unit comprises a plurality of medium structures, and the medium structure is a nano medium structure.

13. The backlight module of claim 1, wherein, The optical film comprises a diffusion film, and the diffusion film comprises a plurality of diffusion units arranged one-to-one with the light emitting devices.

14. The backlight module of claim 13, wherein, Each of the diffusion units is provided with a microlens, and the size of the microlens gradually increases along the direction in which the light intensity of the light projected onto the diffusion unit gradually decreases.

15. A display device comprising: The backlight module comprises the backlight module according to any one of claims 1-14.

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