Backlight module and display device

Abstract

The invention 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 field of display technology, and in particular to a backlight module and a display device. Background Art

[0002] The side-entry backlight in backlight technology has a simple structure and a small thickness. It uses a light guide plate to transmit the incident light from the side to achieve uniform backlighting. However, this type of backlight can only be full screen bright or full screen dark, and cannot be divided into zones for light control, so the display contrast is not high.

[0003] Therefore, the current technology still needs to be improved and enhanced. Summary of the invention

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

[0005] The present application provides a backlight module, including an optical film and a backlight source, the backlight source including a substrate and a plurality of light-emitting devices arranged on the substrate, each light-emitting device is provided with a light control component; the light control component is used to project the output light of the corresponding light-emitting device onto the optical film, and adjust the transmittance of the corresponding output light.

[0006] In the backlight module of some embodiments, the light control component includes a grating structure, the grating structure includes a plurality of grating units, and the plurality of grating units are arranged at intervals along the same direction.

[0007] In the backlight module of some embodiments, the light control component includes a grating structure, the grating structure includes a plurality of grating units, and the plurality of grating units are arranged at intervals along at least two directions.

[0008] In the backlight module of some embodiments, each grating unit includes a plurality of grating substructures arranged at intervals;

[0009] The grating substructure is in the shape of a strip, and the width of the grating substructure increases gradually along the arrangement direction of the grating units.

[0010] In the backlight module of some embodiments, each grating unit includes a plurality of grating sub-structures arranged at intervals, and the grating sub-structures are cylindrical structures, conical structures, prismatic structures or spherical structures.

[0011] In the backlight module of some embodiments, the structural dimensions of the multiple grating sub-structures in each grating unit vary according to a preset rule in the arrangement direction of the grating sub-structures.

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

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

[0014] In some embodiments of the backlight module, the light control component includes a photonic crystal.

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

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

[0017] In the backlight module of some embodiments, the crystal unit includes a plurality of dielectric structures, and the dielectric structures are nano-dielectric structures.

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

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

[0020] An embodiment of the present application further provides a display device, which includes the above-mentioned backlight module.

[0021] The present application provides a backlight module and a display device, the backlight module includes an optical film and a backlight; the backlight source includes a substrate and a plurality of light emitting devices arranged on the substrate, each light emitting device is provided with a light control component; the light control component controls the light emission angle and light emission direction of the corresponding light emitting device so that the emitted light of the light emitting device is projected onto the optical film to ensure the display of the display module. Each light emitting device is provided with a light control component, and the transmittance of the emitted light of the corresponding light emitting device can be controlled separately through the light control component to realize the backlight partition control, which is conducive to improving the display contrast. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The technical solution and other beneficial effects of the present application will be made apparent by describing in detail the specific implementation methods of the present application in conjunction with the accompanying drawings.

[0023] Figure 1 This is a schematic diagram of the structure of the backlight module provided in an embodiment of the present application.

[0024] Figure 2 This is a schematic structural diagram of a first embodiment of a light control assembly in a backlight module provided in an embodiment of the present application.

[0025] Figure 3 In the backlight module provided in the embodiment of the present application Figure 2 Schematic diagram of the center distance dimensions.

[0026] Figure 4 This is a schematic structural diagram of a second embodiment of a light control assembly in a backlight module provided in an embodiment of the present application.

[0027] Figure 5 In the backlight module provided in the embodiment of the present application Figure 4 Schematic diagram of the center distance dimensions.

[0028] Figure 6 This is a schematic structural diagram of a third embodiment of a light control assembly in a backlight module provided in an embodiment of the present application.

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

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

[0031] Reference numerals:

[0032] 10. Packaging shell; 20. Optical film; 30. Backlight source; 31. Substrate; 32. Light-emitting device; 33. Light control component; 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 described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0034] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of technical features indicated. The features specified as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0035] Backlight technology plays a very important role in LCD (Liquid Crystal Display) display. Currently, there are two technical routes: side-entry backlight and direct-down backlight. The side-entry backlight has a simple structure and a small thickness. It uses a light guide plate to achieve uniform backlighting of the light incident from the side. However, this type of backlight can only be full-screen bright or full-screen dark, and cannot be divided into zones to control the light, so the display contrast is not high. The direct-down backlight can control the lighting of each area individually through local dimming technology, thereby realizing the partition lighting function, so it has a very high image contrast. However, the direct-down backlight requires a certain distance to expand the light spot to meet the requirements. On the one hand, this puts higher requirements on the light expansion ability of the lens, and also makes it impossible to reduce the thickness of the backlight module.

[0036] See also Figure 1 The present embodiment provides a display module, which includes a packaging shell 10, an optical film 20 and a backlight source 30. The optical film 20 and the backlight source 30 are both arranged in the packaging shell 10. An accommodating space is formed between the optical module and the packaging shell 10. The backlight source 30 is located in the accommodating 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 includes a substrate 31 and a plurality of light emitting devices 32 arranged on the substrate 31, and a light control component 33 is correspondingly arranged on each light emitting device 32, and the light control component 33 is used to project the outgoing light of the light emitting device 32 onto the optical module and control the transmittance of the corresponding outgoing light. Specifically, the light emitting surface of the backlight source 30 intersects with the surface where the optical film 20 is located, and there is a certain angle between the corresponding substrate 31 and the optical film 20. At this time, the light control component 33 adjusts the light emission angle and light emission direction of the corresponding light emitting device 32, so that the outgoing light of the light emitting device 32 is projected onto the optical film 20 to ensure the display of the display module. A light control component 33 is separately arranged for each light emitting device 32, and the transmittance of the outgoing light of the corresponding light emitting device 32 can be individually controlled by the light control component 33 to realize backlight partition control, which is conducive to improving the display contrast.

[0038] The backlight source 30 is arranged at a certain angle with the optical film 20 on the side of the packaging shell 10. Compared with the direct-type backlight, it can be beneficial to reduce the thickness of the overall display module; compared with the edge-type backlight, it can achieve backlight partition control. To a certain extent, the display module in this embodiment does not need the setting of a light guide plate, which can simplify the overall structure of the display module.

[0039] See also Figure 2In some embodiments, the light control component 33 includes a grating structure 40, and the grating structure 40 includes a plurality of grating units 41, and 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 grating substructures 411 arranged at intervals. The grating substructure 411 in this embodiment can be formed in a variety of ways, such as the grating substructure 411 is a cylindrical structure, a conical structure, a prismatic structure or a spherical structure, etc. By setting different grating substructures 411, it is beneficial to achieve different light transmittances, thereby improving the contrast of the display module.

[0040] The multiple grating substructures 411 in each grating unit 41 change according to a preset rule in the arrangement direction of the grating substructures 411 , such as the structural size of the grating substructures 411 gradually increases, or gradually decreases, or first decreases and then increases along the arrangement direction.

[0041] like Figure 2 As shown, taking the grating substructure 411 as a strip-shaped one-dimensional grating structure 40 as an example, the arrangement direction of the grating unit 41 is recorded as the first direction, and the extension direction of the strip-shaped grating substructure 411 is recorded as the second direction. The width of the grating substructure 411 along the arrangement direction of the grating unit 41 increases gradually, and 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] See also Figure 3 , wherein, 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 a sub-wavelength or wavelength of the emitted light, that is, the period of the grating structure 40 is a sub-wavelength or wavelength. By adjusting the period of the grating structure 40, setting different grating substructures 411 and structure sizes, the size, direction and transmittance of the light emission angle can be adjusted, thereby meeting the display requirements and improving the display contrast.

[0043] As an embodiment, in this embodiment, the thickness of the grating structure 40 is nanometer size. If the grating substructure 411 is a strip grating substructure 411, the thickness of the strip grating substructure 411 is nanometer size. Correspondingly, the width of the strip grating substructure 411 is also set to nanometer size. Thus, by setting the grating substructure 411 to a nanometer size structure, the size is the same as the wavelength of the outgoing light, which is conducive to improving the regulation effect of the outgoing light.

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

[0045] See also Figure 4 and Figure 5 , taking the formation of a two-dimensional grating structure 40 as an example, a cylindrical grating substructure 411 is provided in each grating unit 41. A plurality of grating substructures 411 are arranged at intervals along the first direction, and the diameter of each cylindrical grating substructure 411 in the grating unit 41 gradually increases. In the 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 equivalent to the period of the grating structure 40, which is a sub-wavelength 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 setting different grating substructures 411, structural sizes and periods of the grating structure 40, the size, direction and transmittance of the light exit 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 greater the deflection angle of the outgoing light, which will make the light exit angle larger, so that the outgoing light is more inclined to be projected onto the optical film 20. Then, for the grating structure 40 of each light-emitting device 32 , the larger the deflection angle of the outgoing light that needs to be controlled by the grating structure 40 is, the smaller the arrangement period of the grating structure 40 corresponding to the light-emitting device 32 is.

[0046] As an embodiment, the size of the grating substructure 411 in this embodiment is nanometer size, for example, each size of the cylindrical grating substructure 411 is nanometer size, which is at the same level as the wavelength of the outgoing light, which is beneficial to improve the regulation effect of the outgoing light.

[0047] See also Figure 6 In some embodiments, the light control component 33 includes a photonic crystal 50. The photonic crystal 50 is a periodic optical structure. The photonic crystal 50 includes a plurality of crystal units 51. By setting the structure of the crystal unit 51, the energy band characteristics of the photonic crystal 50 can be adjusted. The energy band characteristics can make the outgoing light passing through the photonic crystal 50 have specific angle characteristics. In this embodiment, the photonic crystal 50 is used as the light control component 33, so that the outgoing light of the light emitting device 32 is projected onto the optical film 20 to ensure the display of the display module. At the same time, a light control component 33 is separately set for each light emitting device 32. The light control component 33 can be used to separately control the transmittance of the outgoing light of the corresponding light emitting device 32 to achieve backlight partition control, which is beneficial to improve 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 photonic crystal 50 as a two-dimensional photonic crystal 50 structure as an example, a plurality of crystal units 51 are arranged at intervals along the first direction and the second direction. In the same direction, the center distance between two adjacent crystal units 51 is equivalent to the same arrangement period in the direction. By adjusting the arrangement period of the crystal units 51, the energy band frequency range of the photonic crystal 50 can be adjusted, and then the characteristics of the outgoing light passing through the photonic crystal 50 can be regulated. For example, the smaller the arrangement period of the photonic crystal 50, the larger the light emission angle, that is, the larger the deflection angle of the outgoing light, then for the photonic crystal 50 of each light-emitting device 32, the larger the deflection angle of the outgoing light that needs to be 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 reading Figure 6 As an embodiment, the center distance between 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 a dielectric structure 511 is a structure formed by 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. 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 in the crystal unit 51, the size or number, etc., the energy band structure of the photonic crystal 50 can be finely controlled, thereby achieving a specific light emission direction and light emission angle and transmittance of the outgoing light.

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

[0052] As an embodiment, 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 a nano-size, which is the same size as the wavelength of the outgoing light, it is beneficial to improve the regulation effect of the outgoing light.

[0053] See also Figure 7In some embodiments, the optical film 20 includes a diffusion film 21, and the diffusion film 21 includes a plurality of diffusion units 211. The plurality of diffusion units 211 are arranged in one-to-one correspondence with the light emitting devices 32, and the shape of the diffusion unit 211 can be set according to the shape of the light spot projected by the light emitting device 32 to the optical film 20. In this embodiment, a diffusion unit 211 is arranged for each light emitting chip corresponding to a partition, and the light emitted by each light emitting chip is diffused independently by the diffusion unit 211, so as to ensure that the light emitted by each light emitting chip after being projected to the diffusion unit 211 has a uniform distribution of the emission angles through the diffusion unit 211, thereby achieving uniform light emission of the backlight module, thereby ensuring the consistency of the visual effect.

[0054] See also Figure 8 Specifically, a microlens 60 is provided on one side of each diffusion unit 211 close to the package shell 10, and the size of the microlens 60 gradually increases along the direction in which the brightness of the light projected to the diffusion unit 211 gradually decreases. The substrate 31 of the backlight source 30 is tilted relative to the diffusion film 21, and the light emitting device 32 is tilted 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 package shell 10. The brightness of the light projected on the diffusion unit 211 by the corresponding light emitting device 32 will gradually decrease as it moves away from the diffusion unit 211. Therefore, the structural size of the microlens 60 in the diffusion unit 211 along the direction in which the brightness of the light projected to the diffusion unit 211 gradually decreases. If the microlens 60 is a cylindrical lens structure, the height of the cylindrical lens structure can be gradually increased, so that the diffusion unit 211 will emit the corresponding light emitting device 32 after homogenization, so as to achieve light consistency and ensure the visual consistency of the display module.

[0055] The embodiment of the present application further discloses a display device, which includes the above-mentioned backlight module. Since the backlight module has been described in detail above, it will not be described again here.

[0056] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0057] The backlight module provided in the embodiments of the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solution and core idea of ​​the present application. Ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with 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 present application.

Claims

1. A backlight module, characterized in that: It 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 to project the output light corresponding to the light-emitting device onto the optical film and control the transmittance of the corresponding output light.

2. The backlight module according to claim 1, characterized in that: The light control component comprises a grating structure, the grating structure comprises a plurality of grating units, and the plurality of grating units are arranged at intervals along the same direction.

3. The backlight module according to claim 1, characterized in that: The light control component includes a grating structure, and the grating structure includes a plurality of grating units. The plurality of grating units are arranged at intervals along at least two directions.

4. The backlight module according to claim 2, characterized in that: Each of the grating units includes a plurality of grating substructures arranged at intervals; The grating substructure is in a strip shape, and the width of the grating substructure increases gradually along the arrangement direction of the grating units.

5. The backlight module according to claim 2 or 3, characterized in that: Each of the grating units includes a plurality of grating substructures arranged at intervals, and the grating substructures are cylindrical structures, conical structures, prismatic structures or spherical structures.

6. The backlight module according to claim 5, characterized in that: The structural dimensions of the plurality of grating substructures in each of the grating units vary according to a preset rule in the arrangement direction of the grating substructures.

7. The backlight module according to claim 5, characterized in that: The center distance between adjacent grating units is a sub-wavelength or wavelength of the emitted light.

8. The backlight module according to claim 6, characterized in that: The grating substructure is a nano substructure.

9. The backlight module according to claim 1, characterized in that: The light control component includes a photonic crystal.

10. The backlight module according to claim 9, characterized in that: The photonic crystal includes a plurality of crystal units, and the plurality of crystal units are arranged at intervals along at least two directions.

11. The backlight module according to claim 10, characterized in that: The center distance between adjacent crystal units is greater than the wavelength of the emitted light.

12. The backlight module according to claim 10, characterized in that: The crystal unit includes a plurality of dielectric structures, and the dielectric structures are nano-dielectric structures.

13. The backlight module according to claim 1, characterized in that: 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 in a one-to-one correspondence with the light-emitting devices.

14. The backlight module according to claim 13, characterized in that: A microlens is disposed in each diffusion unit, and the size of the microlens gradually increases along a direction in which the brightness of the light projected onto the diffusion unit gradually decreases.

15. A display device, characterized in that: Comprising the backlight module as described in any one of claims 1-14.

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