CN112859430A

CN112859430A - Backlight module and liquid crystal display device

Info

Publication number: CN112859430A
Application number: CN202110310029.XA
Authority: CN
Inventors: 李芳林; 王贺陶; 罗雯倩; 张玉佳; 肖春蕾; 程乾
Original assignee: BOE Technology Group Co Ltd; Beijing BOE Display Technology Co Ltd
Current assignee: BOE Technology Group Co Ltd; Beijing BOE Display Technology Co Ltd
Priority date: 2021-03-23
Filing date: 2021-03-23
Publication date: 2021-05-28

Abstract

The embodiment of the application provides a backlight module and a liquid crystal display device. The backlight module is arranged on the back of the liquid crystal display screen and used for providing a backlight source for the liquid crystal display screen, and comprises a laser and an optical fiber; the laser is configured to generate laser light with a specific wavelength, and the optical fiber is provided with at least one light outlet and is used for conducting the laser light with the specific wavelength and enabling the laser light with the specific wavelength to be scattered to the back surface of the liquid crystal display screen through the light outlet. This embodiment utilizes the optic fibre that is provided with the light-emitting window with the laser conduction and the scattering of specific wavelength to liquid crystal display's the back, need not to utilize traditional LED as the backlight, is favorable to reducing display device's thickness to, the spectral monochromaticity of laser is better, and half peak width is narrower, is favorable to promoting display device's colour gamut, with promotion display device's display effect.

Description

Backlight module and liquid crystal display device

Technical Field

The application relates to the technical field of display, in particular to a backlight module and a liquid crystal display device.

Background

In the conventional lcd industry, the backlight module needs a large number of light-emitting diodes (LEDs), and particularly in the direct-type lcd product, the thickness of the backlight module is limited by the light mixing distance of the LEDs, which seriously affects the thickness of the backlight module. And the LED backlight source has poor spectral monochromaticity and wide half-peak width, and has great limitation on high-color-gamut products.

Disclosure of Invention

This application is directed against the shortcoming of current mode, provides a backlight unit and liquid crystal display device, not only is favorable to reducing backlight unit's thickness, is favorable to promoting display device's colour gamut moreover to promote display effect.

In a first aspect, an embodiment of the present application provides a backlight module, which is disposed on a back surface of a liquid crystal display screen to provide a backlight source for the liquid crystal display screen, and includes:

a laser configured to generate laser light of a specific wavelength;

and the optical fiber is provided with at least one light outlet and is used for conducting the laser with the specific wavelength and enabling the laser with the specific wavelength to be scattered to the back surface of the liquid crystal display screen through the light outlet.

Optionally, each optical fiber is provided with a plurality of light outlets, and the plurality of light outlets are located on the side surface of the optical fiber.

Optionally, the optical fiber includes a fiber core and a cladding layer covering the fiber core, the fiber core is provided with a plurality of breaking sites at the light outlet so that the laser light with the specific wavelength is scattered out from the light outlet, and the breaking sites are located on a side of the fiber core away from the light outlet.

Optionally, the optical fiber comprises a core and a cladding surrounding the core; the cladding is provided with a notch at the light outlet so that the laser with the specific wavelength is scattered out of the light outlet, or the refractive index of the cladding at the light outlet is lower than that of the cladding at the non-light outlet.

Optionally, the light outlet is a light outlet end face of the optical fiber, and the light outlet end face is roughened.

Optionally, the backlight module further includes: and the beam splitter is respectively connected with the laser and the optical fibers so as to distribute the laser light with the specific wavelength generated by the laser to each optical fiber.

Optionally, the backlight module comprises at least two lasers for emitting laser with different specific wavelengths; the optical fiber transmits laser light of one or more of the specific wavelengths.

Optionally, each light outlet for scattering laser light with a specific wavelength corresponds to a pixel point on the liquid crystal display screen; or, the light outlets for scattering laser light with a specific wavelength are in a group, and each group of light outlets corresponds to a plurality of pixel points on the liquid crystal display screen.

Optionally, the laser is external.

In a second aspect, an embodiment of the present application provides a liquid crystal display device, which includes a liquid crystal display panel and the backlight module described above.

The technical scheme provided by the embodiment of the application has the following beneficial technical effects:

the backlight module and the liquid crystal display device that this application embodiment provided utilize the optic fibre that is provided with the light-emitting window with the laser conduction and the scattering of specific wavelength to liquid crystal display's the back, need not to utilize traditional LED as the backlight, be favorable to reducing display device's thickness to, the spectral monochromaticity of laser is better, and half peak width is narrower, is favorable to promoting display device's colour gamut to promote display device's display effect.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic diagram of a relative position between a backlight module and a liquid crystal display provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a damage site of a fiber core in an optical fiber in a backlight module according to an embodiment of the present disclosure;

fig. 3 is a schematic structural diagram of a damage site of a fiber core in another optical fiber in a backlight module according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a damage site of a fiber core in another optical fiber in a backlight module according to an embodiment of the present disclosure;

fig. 5 is a schematic structural diagram of a cladding layer in an optical fiber in a backlight module according to an embodiment of the present disclosure;

fig. 6 is a schematic structural diagram of another cladding layer in an optical fiber in a backlight module according to an embodiment of the present disclosure;

fig. 7 is a schematic diagram illustrating a relative position between a backlight module and a liquid crystal display panel according to another embodiment of the present disclosure;

fig. 8 is a schematic structural diagram of a backlight module according to an embodiment of the present disclosure;

fig. 9 is a schematic structural diagram of another backlight module according to an embodiment of the present disclosure;

fig. 10 is a schematic structural diagram of a liquid crystal display device according to an embodiment of the present application.

Reference numerals:

1-a laser; 101-a first laser; 102-a second laser; 103-a third laser;

2-an optical fiber; 201-a fiber core; 2011 a-arc defects; 2011 b-triangle defects; 2011 c-irregularly shaped defects; 202-a cladding layer; 2021 a-gap; 2021 b-low refractive region; 10-a light outlet; 10/1-first light outlet; 10/2-second light outlet; 10/3-third light outlet;

3-a beam splitter;

4-liquid crystal display screen.

Detailed Description

Reference will now be made in detail to the present application, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar parts or parts having the same or similar functions throughout. In addition, if a detailed description of the known art is not necessary for illustrating the features of the present application, it is omitted. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present application and are not to be construed as limiting the present application.

It will be understood by those within the art that, unless otherwise defined, all terms (including 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. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

As used herein, the singular forms "a", "an", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

In the traditional liquid crystal display industry, a backlight module needs a large number of LEDs, and particularly in a direct type product, the thickness of the module is limited by the light mixing distance of the LEDs, so that the thickness of the module is seriously influenced. And the LED backlight source has poor spectral monochromaticity and wide half-peak width, and has great limitation on high-color-gamut products.

The application provides a backlight module and a liquid crystal display device, which aim to solve the technical problems in the prior art.

The embodiment of the application provides a backlight module, which is arranged on the back of a liquid crystal display screen 4 to provide a backlight source for the liquid crystal display screen 4, as shown in fig. 1, the backlight module provided by the embodiment includes a laser 1 and an optical fiber 2. The laser 1 is configured to generate laser light of a specific wavelength; the optical fiber 2 is provided with at least one light outlet 10, and the optical fiber 2 is used for conducting the laser light with the specific wavelength and enabling the laser light with the specific wavelength to be scattered to the back surface of the liquid crystal display 4 through the light outlet 10.

Specifically, the laser 1 in the present embodiment is a semiconductor laser 1.

It should be noted that the back surface of the liquid crystal display 4 is opposite to the light exit surface of the liquid crystal display 4, that is, the back surface of the liquid crystal display 4 is opposite to the light exit surface of the liquid crystal display 4.

The scattering means that the light emitting direction of the laser light is multi-directional, so that it is more favorable to form a surface light source as a backlight of the liquid crystal display 4.

The backlight unit that this embodiment provided, the back that utilizes optic fibre 2 that is provided with light-emitting window 10 to conduct the laser of specific wavelength and scatter to liquid crystal display 4 need not to utilize traditional LED as the backlight, is favorable to reducing display device's thickness to, the spectrum monochromaticity of laser is better, and half peak width is narrower, is favorable to promoting display device's colour gamut, with promotion display device's display effect.

Optionally, as shown in fig. 2 to fig. 6, in the backlight module provided in this embodiment, each optical fiber 2 is provided with a plurality of light outlets 10, and the plurality of light outlets 10 are all located on a side surface of the optical fiber 2.

The side surface of the optical fiber 2 is a curved surface of the optical fiber 2 around the axis, and in a specific embodiment, the light outlet 10 may be provided on the side surface of the optical fiber 2 in a different manner, which will be described in detail below.

Alternatively, as shown in fig. 2 to 4, in the backlight module provided in this embodiment, the optical fiber 2 includes a fiber core 201 and a cladding 202 that wraps the fiber core 201, the fiber core 201 is provided with a plurality of breaking points at the light exit 10 to scatter the laser light with a specific wavelength from the light exit 10, and the breaking point 2011 is located on a side of the fiber core 201 away from the light exit 10.

In particular, the failure site is a regularly shaped defect. For example, as shown in fig. 2, the defect of a regular shape is an arc defect 2011 a; alternatively, as shown in fig. 3, the defect having a regular shape is a triangular defect 2011 b. Alternatively, as shown in fig. 4, the failure site is a defect 2011c having an irregular shape.

Specifically, the failure site may be formed by impact, friction, or the like.

In the backlight module provided by this embodiment, the damage point is a defect made on the fiber core 201, and the defect causes that the laser cannot perform total reflection in the region, so that the laser can be scattered out from the region, that is, the defect is made on the fiber core 201 so that the light outlet 10 is formed on the opposite side of the damage point of the optical fiber 2.

Optionally, as shown in fig. 5, in the backlight module provided in this embodiment, the optical fiber 2 includes a fiber core 201 and a cladding 202 that wraps the fiber core 201; the cladding 202 is provided with a notch 2021a at the light exit 10 to scatter the laser light of a specific wavelength out of the light exit 10. Alternatively, as shown in fig. 6, the refractive index of the cladding layer at the light exit port 10 is lower than the refractive index of the cladding layer 202 at the non-light exit port 10, that is, the cladding layer 202 includes a low-refraction region 2021b, and the low-refraction region 2021b is the light exit port 10.

In the backlight module provided in this embodiment, the gap 2021a is formed on the cladding 202 or the low refractive region 2021b is disposed on the cladding 202, so that the laser light cannot be totally reflected at the gap 2021a or the low refractive region 2021b, and the laser light is scattered out at the low refractive region 2021b at the gap 2021a, and the gap 2021a of the cladding 202 or the low refractive region 2021b of the cladding 202 is also used as the light outlet 10.

Optionally, as shown in fig. 7, in the backlight module provided in this embodiment, the light outlet 10 is a light outlet end surface of the optical fiber 2, and the light outlet end surface is roughened. Specifically, one end of the optical fiber 2 is connected to the laser 1, i.e., the laser entrance end, and the other end is the light exit end of the laser, i.e., the light exit end face; after the light-emitting end face is subjected to roughening treatment, the laser can emit light in a larger angle range, so that a surface light source is more favorably obtained.

Optionally, as shown in fig. 7, the backlight module provided in this embodiment further includes a beam splitter 3, where the beam splitter 3 is respectively connected to the laser 1 and the optical fibers 2, so as to distribute the laser light with a specific wavelength generated by the laser 1 to each optical fiber 2.

Specifically, as shown in fig. 7, in the backlight module provided in this embodiment, each optical fiber 2 may be positioned at a corresponding position on the back surface of the liquid crystal display 4, or a plurality of optical fibers 2 may be used as one bundle, and then each optical fiber 2 is positioned at a corresponding position on the back surface of the liquid crystal display 4. It should be noted that "the corresponding point located on the back surface of the liquid crystal display 4" in this embodiment is not directly in contact with the back surface of the liquid crystal display 4, and a light homogenizing sheet (not shown in fig. 7) may be disposed between the optical fiber 2 and the liquid crystal display 4.

In the backlight module provided by this embodiment, the beam splitter 3 enables the laser 1 to provide laser with a specific wavelength for the plurality of optical fibers 2.

Optionally, as shown in fig. 7, in the backlight module provided in this embodiment, the laser 1 is externally disposed. Laser instrument 1 carries out externally also that laser instrument 1 is in with liquid crystal display 4 on the plane on orthographic projection and the liquid crystal display 4 non-overlapping, so can further reduce backlight unit's thickness to be favorable to reducing display device's thickness.

Optionally, as shown in fig. 8, the backlight module provided in this embodiment includes at least two lasers 1 for emitting laser beams with different specific wavelengths, and the optical fiber 2 transmits laser beams with one or more specific wavelengths.

Specifically, as shown in fig. 8, the backlight module provided in this embodiment includes a first laser 101 for emitting laser light with a first specific wavelength, a second laser 102 for emitting laser light with a second specific wavelength, and a third laser 103 for emitting laser light with a third specific wavelength. The laser light with the first specific wavelength, the laser light with the second specific wavelength and the laser light with the third specific wavelength are respectively red, green and blue laser light, so that white light is formed after light mixing. The color gamut can be customized according to the laser with different specific wavelengths by adjusting the wavelength of the laser emitted by each laser 1, so as to obtain the corresponding display effect.

Specifically, each optical fiber 2 may transmit only one specific wavelength of laser light, or a coupler (not shown in fig. 8) may be added between the laser 1 and the optical fiber 2, so that the optical fiber 2 transmits a plurality of specific wavelengths of laser light.

In the backlight module provided by the present application, the light exit 10 and the pixels in the liquid crystal display 4 may have different corresponding relationships, which will be described in detail below.

Optionally, as shown in fig. 8, in the backlight module provided in this embodiment, each light outlet 10 for scattering laser light with a specific wavelength corresponds to a pixel on the liquid crystal display 4. Specifically, the light exit port 10 is divided into a first light exit port 10/1 for scattering the laser light of the first specific wavelength, a second light exit port 10/2 for scattering the laser light of the second specific wavelength, and a third light exit port 10/3 for scattering the laser light of the third specific wavelength; one first light outlet 10/1, one second light outlet 10/2 and one third light outlet 10/3 correspond to one pixel 401.

Optionally, as shown in fig. 9, in the backlight module provided in this embodiment, a plurality of light outlets 10 for scattering laser light with a specific wavelength are in a group, and each group of light outlets 10 corresponds to a plurality of pixel points 401 on the liquid crystal display 4. Specifically, the light exit port 10 is divided into a first light exit port 10/1 for scattering the laser light of the first specific wavelength, a second light exit port 10/2 for scattering the laser light of the second specific wavelength, and a third light exit port 10/3 for scattering the laser light of the third specific wavelength; the laser light scattered from the group of first light outlets 10/1, the group of second light outlets 10/2, and the group of third light outlets 10/3 corresponds to an area of the liquid crystal display 4, and the area includes a plurality of pixels 401.

Further, the backlight module provided in this embodiment further includes a light uniformizing sheet antireflection film, a substrate for supporting and fixing the optical fiber, and the like, and these structures do not relate to the core invention point of the present application, and the description thereof is not provided in the present application.

Based on the same inventive concept, an embodiment of the present application further provides a liquid crystal display device, as shown in fig. 10, the liquid crystal display device provided in this embodiment includes a liquid crystal display and the backlight module in the above embodiment, and has the beneficial effects of the backlight module in the above embodiment, which are not described herein again.

By applying the embodiment of the application, at least the following beneficial effects can be realized:

In the description of the present application, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device or element must have a particular orientation, be constructed in a particular orientation, and be operated, and thus should not be construed as limiting the present application.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In the description herein, particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is only a partial embodiment of the present application, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present application, and these modifications and decorations should also be regarded as the protection scope of the present application.

Claims

1. The utility model provides a backlight unit, sets up in liquid crystal display's the back in order to be used for providing the backlight for liquid crystal display, its characterized in that includes:

a laser configured to generate laser light of a specific wavelength;

2. The backlight module according to claim 1, wherein each of the optical fibers has a plurality of light outlets disposed at a side surface thereof.

3. The backlight module according to claim 2, wherein the optical fiber comprises a core and a cladding covering the core, the core is provided with a plurality of breaking points at the light exit to scatter the laser light with the specific wavelength from the light exit, and the breaking points are located on a side of the core away from the light exit.

4. The backlight module of claim 2, wherein the optical fiber comprises a core and a cladding surrounding the core;

the cladding layer is provided with a notch at the light outlet to enable the laser with the specific wavelength to be scattered out from the light outlet, or

The refractive index of the cladding layer at the light exit is lower than that of the cladding layer at the non-light exit.

5. The backlight module according to claim 1,

the light outlet is the light outlet end face of the optical fiber, and the light outlet end face is subjected to roughening treatment.

6. The backlight module of claim 5, further comprising:

and the beam splitter is respectively connected with the laser and the optical fibers so as to distribute the laser light with the specific wavelength generated by the laser to each optical fiber.

7. A backlight module according to any of claims 1-6, characterized in that the backlight module comprises at least two lasers for emitting laser light of different specific wavelengths;

the optical fiber transmits laser light of one or more of the specific wavelengths.

8. The backlight module according to claim 7, wherein each of the light outlets for scattering the laser light with a specific wavelength corresponds to a pixel point on the lcd panel; alternatively, the first and second electrodes may be,

the light outlets for scattering laser with a specific wavelength are in a group, and each group of light outlets corresponds to a plurality of pixel points on the liquid crystal display screen.

9. A backlight module according to any one of claims 1-6, characterized in that the laser is external.

10. A liquid crystal display device, comprising:

a liquid crystal display screen;

a backlight module as claimed in any one of claims 1 to 9.