Backlight module and liquid crystal display deviceTechnical Field
The invention relates to the technical field of liquid crystal display, in particular to a backlight module and a liquid crystal display device.
Background
Liquid Crystal Display (LCD) devices have many advantages such as thin body, power saving, and no radiation, and are widely used. Such as: liquid crystal televisions, mobile phones, Personal Digital Assistants (PDAs), digital cameras, computer screens, notebook computer screens, or the like, are dominant in the field of flat panel displays. Most of the existing liquid crystal display devices in the market are Backlight liquid crystal display devices, which include a liquid crystal panel and a Backlight Module (Backlight Module). Generally, a Liquid Crystal panel is composed of a Color Filter Substrate (Color Filter), a Thin film transistor Array Substrate (TFT Array Substrate), and a Liquid Crystal Layer (Liquid Crystal Layer) disposed between the two substrates, and the Liquid Crystal panel operates by applying a driving voltage to the two glass substrates to control the rotation of Liquid Crystal molecules of the Liquid Crystal Layer, so as to refract light from a backlight module to generate a picture. Since the lcd panel does not emit light, the backlight module is one of the key components of the lcd device because the backlight module needs to provide a light source to normally display images.
The backlight modules used in the LCD at present are roughly classified into direct type backlight modules and side type backlight modules according to the light incident mode.
As shown in fig. 1, a schematic structural diagram of a conventional direct-type backlight module includes: anLED array 1 including a plurality of Light Emitting Diodes (LEDs) arranged in an array, a Diffuser Plate (DP) 2 disposed above theLED array 1, and an Optical film (Optical films)3 disposed above thediffuser plate 2. When the backlight module works, theLED array 1 is used as a light source to enter light from the lower part of thediffusion plate 2, the emitted light is mixed by thediffusion plate 2 and then is emitted out through the optical film 3, and therefore the surface of the whole backlight module uniformly emits light.
As shown in fig. 2, a schematic structural diagram of a conventional side-in type backlight module includes: the LED light source comprises a light guide plate 2 ', an LED light bar 1 ' arranged on one side of the light guide plate 2 ', a diffusion sheet 3 ' arranged above the light guide plate 2 ', and an optical film 4 ' arranged above the diffusion sheet 3 '. When the backlight module works, the LED lamp strips 1 ' serve as light sources to enter light from the side of the light guide plate 2 ', emitted light is scattered by the light guide plate 2 ' and then mixed by the diffusion plate 3 ', and then emitted by the optical film 4 ', so that the surface of the whole backlight module uniformly emits light.
With the development of LCD technology, consumers increasingly demand various aspects of LCD display device appearance, image quality, and the like, and accordingly, more demands are also put on LCD backlight module design, such as ultra-thin design, multi-partition Local backlight adjustment (Local Dimming) design, and High Dynamic contrast (HDR) technology. The traditional direct type backlight module and the traditional lateral type backlight module have different advantages and disadvantages due to different structures, and cannot simultaneously consider both the ultrathin design and the local backlight adjustment design.
For the direct type backlight module, because the LED light sources adopt an array type arrangement mode, the independent brightness control of multiple partitions can be easily realized, namely the local backlight adjustment and the display of HDR effect can be realized; however, in order to make the light mixing uniform, a certain light mixing space needs to be reserved between the light emitting surface of the LED and the diffusion plate, which inevitably results in a thicker backlight module and a failure to realize an ultra-thin design.
For the side-in backlight module, the light source is used for entering light from the side, and the light guide plate is used as a carrier for transmitting light, so that the ultrathin design can be realized.
Disclosure of Invention
The invention aims to provide a backlight module which can realize ultrathin design and local backlight adjustment design at the same time.
Another object of the present invention is to provide a liquid crystal display device which can achieve both an ultra-thin design and a local backlight adjustment design.
To achieve the above object, the present invention provides a backlight module, including: a plurality of backlight modules arranged in matrix and a diffusion sheet arranged above the backlight modules
Each backlight module comprises four backlight units arranged in a 2X2 matrix manner;
each backlight unit comprises a light guide plate and a light bar arranged on one side of the light guide plate;
the light bars of the four backlight units of each backlight module are independently controlled, so that the multi-partition local backlight adjusting effect of the backlight module is realized.
The light guide plate has relative upper surface and lower surface, and four sides of being connected with upper and lower surface, the light guide plate with the side definition that the lamp strip is relative is the income plain noodles, be equipped with the reflective membrane on the light guide plate and the relative side of income plain noodles.
The backlight unit further includes a light shielding strip covering a gap between the light bar and the light guide plate to prevent light leakage between the light bar and the light guide plate.
The light shading strip is made of light absorbing materials or light reflecting materials.
The light guide plate is provided with an upper surface, a lower surface and four side surfaces connected with the upper surface and the lower surface, the side surface of the light guide plate opposite to the light bar is defined as a light incident surface, and the light incident surfaces of the adjacent light guide plates in the four light guide plates of each backlight module are mutually vertical.
Among the four light guide plates and the four light bars of each backlight module, the four light bars are respectively arranged between the adjacent light guide plates and are in a cross shape.
The four lamp strips of each backlight module are respectively arranged at the outer side of the backlight module.
The backlight module also comprises an optical film group arranged above the diffusion sheet and a reflection sheet arranged below the plurality of backlight modules.
The diffusion sheet is directly contacted with the light guide plate of the backlight module or has a gap.
The invention also provides a liquid crystal display device which comprises the backlight module and a liquid crystal panel positioned above the backlight module.
The invention has the beneficial effects that: the backlight module comprises a plurality of backlight modules arranged in a matrix manner and a diffusion sheet arranged above the plurality of backlight modules, wherein the backlight modules comprise four backlight units arranged in a 2X2 matrix manner, each backlight unit comprises a light guide plate and a light bar arranged on one side of the light guide plate, and by adopting a backlight module combination manner, on one hand, the independent control of multi-partition brightness can be realized. The liquid crystal display device of the invention adopts the backlight module, and can realize ultrathin design and local backlight adjustment design at the same time.
Drawings
For a better understanding of the nature and technical aspects of the present invention, reference should be made to the following detailed description of the invention, taken in conjunction with the accompanying drawings, which are provided for purposes of illustration and description and are not intended to limit the invention.
In the drawings, there is shown in the drawings,
FIG. 1 is a schematic view of a conventional direct-type backlight module;
FIG. 2 is a schematic structural diagram of a conventional side-entry backlight module;
FIG. 3 is a schematic structural diagram of a backlight module according to the present invention;
fig. 4-5 are schematic structural views of a light bar and a light guide plate in a backlight unit of the backlight module according to the present invention;
FIGS. 6-7 are schematic structural views of a backlight unit in the backlight module of the present invention;
fig. 8 is a schematic structural view of a light bar and a light guide plate in a backlight module of the present invention;
FIGS. 9-11 show three combinations of light incident directions of four backlight units in a backlight module according to the present invention;
fig. 12 is a schematic diagram of a plurality of backlight modules arranged in an array in the backlight module of the present invention.
Detailed Description
To further illustrate the technical means and effects of the present invention, the following detailed description is given with reference to the preferred embodiments of the present invention and the accompanying drawings.
Referring to fig. 3, the present invention first provides a backlight module, including: the backlight module comprises a plurality ofbacklight modules 11 arranged in a matrix manner, adiffusion sheet 20 arranged above the plurality ofbacklight modules 11, anoptical film group 30 arranged above thediffusion sheet 20, and areflection sheet 40 arranged below the plurality ofbacklight modules 11.
Specifically, as shown in fig. 8, eachbacklight module 11 includes fourbacklight units 12 arranged in a 2X2 matrix manner.
Specifically, as shown in fig. 4-5, eachbacklight unit 12 includes alight guide plate 121, and alight bar 122 disposed on one side of thelight guide plate 121, wherein thelight bar 122 includes a plurality ofLEDs 125.
Specifically, as shown in fig. 12, thebacklight module 11 is combined to provide backlight, and in thebacklight module 11, thelight bars 122 of the fourbacklight units 12 are independently controlled, so that a multi-partition local backlight adjustment effect of the backlight module can be realized.
Specifically, as shown in fig. 6 to 7, thebacklight unit 12 further includes alight shielding bar 123, and thelight shielding bar 123 covers a gap between thelight bar 122 and thelight guide plate 121 to prevent light leakage between thelight bar 122 and thelight guide plate 121; thelight guide plate 121 has an upper surface and a lower surface opposite to each other, and four side surfaces connected to the upper and lower surfaces; among the four side surfaces of thelight guide plate 121, one side surface facing thelight bar 122 is defined as a light incident surface, and alight reflecting film 124 is disposed on the side surface of thelight guide plate 121 opposite to the light incident surface.
Specifically, the light-shielding strip 123 is a light-absorbing material or a light-reflecting material, such as a white reflecting sheet having a light-reflecting property, a black adhesive tape having a light-absorbing property, and the like, which are commonly used in the art.
Specifically, in the fourlight guide plates 121 of eachbacklight module 11, the light incident surfaces of the adjacentlight guide plates 121 are perpendicular to each other.
In the present invention, for eachbacklight unit 12, because the upper end of the light incident surface of thelight guide plate 121 is provided with thelight shielding strip 123, and the side surface opposite to the light incident surface is provided with thelight reflecting film 124, the central area of the light incident side and the area opposite to the light incident side on thelight guide plate 121 is represented as a dark area, and the areas on the other two sides are not shielded, so that part of the light leaks out, and the central area is represented as a bright area, that is, for eachbacklight unit 12, the light incident side and the opposite side are darker, and the other two non-light incident sides; therefore, in the present invention, the light incident surfaces of the adjacentlight guide plates 121 in eachbacklight module 11 are set to be perpendicular to each other, that is, the light incident directions of theadjacent backlight units 12 are perpendicular to each other, so that the bright and dark regions can be overlapped, thereby ensuring that thewhole backlight module 11 has a uniform light emitting effect. Specifically, as shown in fig. 9-11, the directions of the arrows in fig. 9-11 represent the light incident directions of thebacklight units 12 for three different combinations of the light incident directions of the fourbacklight units 12 in thebacklight module 11 of the present invention. Taking the combination manner of the light incident directions shown in fig. 9 as an example, the structure of thecorresponding backlight unit 12 is shown in fig. 6, at this time, of the fourlight guide plates 121 and the fourlight bars 122 of thebacklight module 11, the fourlight bars 122 are respectively disposed between the adjacentlight guide plates 121 and are cross-shaped, wherein the horizontal left and right sides of thelight guide plate 121 located at the upper left corner are darker, and the vertical upper and lower sides are brighter; the upper side of thelight guide plate 121 adjacent to and positioned at the lower left corner below the light guide plate is dark, and thelight guide plate 121 at the upper left corner is bright, so that the effect of uniform light emission can be achieved; the left side of thelight guide plate 121 at the upper right corner adjacent to thelight guide plate 121 at the upper left corner is brighter, and the right side of thelight guide plate 121 at the upper left corner is darker in combination to present an even light emitting effect, so as to realize that thewhole backlight module 11 presents an even light emitting effect. As shown in fig. 11, the combination of the light incident directions is taken as an example, at this time, the fourlight bars 122 of thebacklight module 11 are respectively disposed at the outer side of thebacklight module 11, the light incident directions of theadjacent backlight units 12 are perpendicular to each other, and theentire backlight module 11 can also exhibit a uniform light emitting effect. The combination of the light incident directions of thebacklight units 12 that can also achieve the uniform light emitting effect of thebacklight module 11 is not illustrated here.
In the present invention, thediffusion sheets 20 disposed above thebacklight modules 11 are used to uniformly mix the light emitted from thelight guide plates 121 and the light at the splicing positions of the adjacentlight guide plates 121, and specifically, thediffusion sheets 20 may be in direct contact with thelight guide plates 121 or may have a certain gap therebetween. Thereflective sheet 40 disposed under thebacklight modules 11 is used to improve the utilization rate of light.
It should be noted that, in practical applications, the backlight module of the present invention may be partitioned according to the area of a specific liquid crystal display device, determine the number and size of thebacklight modules 11, and finally determine the relevant size of thebacklight unit 12.
Based on the same inventive concept, the invention also provides a liquid crystal display device, which comprises the backlight module and a liquid crystal panel positioned above the backlight module. The liquid crystal display device can realize an ultra-thin design and a local backlight adjustment design at the same time. The description of the backlight module is not repeated herein.
In summary, the backlight module of the present invention includes a plurality of backlight modules arranged in a matrix manner, and a diffusion sheet disposed above the plurality of backlight modules, where the backlight module includes four backlight units arranged in a 2X2 matrix manner, and the backlight unit includes a light guide plate and a light bar disposed at one side of the light guide plate, and by adopting a backlight module combination manner, on one hand, independent control of multi-partition brightness can be achieved, and compared with a conventional side-entry backlight module, the backlight module can be used for local backlight adjustment and HDR effect display, and on the other hand, by utilizing a light-emitting homogenization effect of the light guide plate, compared with a conventional direct-illumination backlight module, a light mixing space is saved, thereby achieving an ultra-thin design. The liquid crystal display device of the invention adopts the backlight module, and can realize ultrathin design and local backlight adjustment design at the same time.
As described above, it will be apparent to those skilled in the art that various other changes and modifications can be made based on the technical solution and the technical idea of the present invention, and all such changes and modifications should fall within the protective scope of the appended claims.