KR20070060210A - LCD Display - Google Patents

Abstract

The present invention relates to a liquid crystal display device. A liquid crystal display device according to the present invention includes a liquid crystal display panel; A light source unit positioned behind the liquid crystal display panel and supplying light to the liquid crystal display panel; And a diffusion plate positioned between the liquid crystal display panel and the light source unit and having a space formed therein. As a result, a liquid crystal display device capable of efficiently reducing heat transferred from a light source unit to a liquid crystal display panel is provided.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

1 is an exploded perspective view of a liquid crystal display according to a first embodiment of the present invention;

2 is an assembled cross-sectional view of a liquid crystal display device according to a first embodiment of the present invention;

3 is an essential part perspective view of a liquid crystal display device according to a first embodiment of the present invention; and

4 is a perspective view of an essential part of a liquid crystal display according to a second exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: upper chassis 20: liquid crystal display panel

25 drive unit 30 backlight unit

31: light control member 32, 33: diffusion plate

34, 35, 36: space part 37: prism film

38: protective film 39: reflector

40: light source portion 51: side mold

53: middle mold 60: lower chassis

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device including a diffusion plate performing a light diffusion function.

The liquid crystal display includes a thin film transistor substrate, a color filter, and a liquid crystal display panel in which liquid crystal is injected between both substrates. Since the liquid crystal display is a non-light emitting device, a backlight unit for supplying light is disposed on the rear surface of the thin film transistor substrate. Light transmitted from the backlight unit is adjusted according to the arrangement of liquid crystals. The liquid crystal display panel and the backlight unit are housed in the upper chassis.

The backlight unit is classified into a direct type and an edge type according to the position of the light source. The edge type is a structure in which a light source is installed on the side of the light guide plate, and is mainly applied to a relatively small liquid crystal display device such as a laptop type and a desktop computer. Such an edge type backlight unit has a long service life, is advantageous for thinning a liquid crystal display device, and has better light uniformity than a direct type backlight unit.

The direct type is a structure mainly developed as the size of the liquid crystal display device is enlarged. The direct type is a structure in which at least one light source is disposed on the rear surface of the liquid crystal display panel to supply light to the liquid crystal display panel. Such a direct type backlight unit has advantages in that a plurality of light sources can be used as compared to an edge type backlight unit, thereby ensuring a high luminance, but has a disadvantage in that luminance is uneven when thinned.

In order to compensate for luminance unevenness of the direct type backlight unit, a diffusion plate is disposed between the liquid crystal display panel and the light source. In order to prevent the position of the light source from being recognized by the user through the liquid crystal display panel and to make the overall luminance uniform, the diffuser scatters the light generated from the light source to make the luminance uniform and supply the same to the liquid crystal display panel.

As a light source for supplying light to the liquid crystal display panel, an external electrode fluorescent lamp (EEFL) or a cold cathode fluorescent lamp (CCFL), which is a linear light source, is mainly used. In addition, an LED, which is a point light source, is also used. These light sources receive electric energy and emit heat in addition to emitting light. The emitted heat reaches the diffuser plate at the upper part, and passes through the inside through most of the diffuser plate, and then is transferred to the liquid crystal display panel through the upper optical film. The liquid crystal of the liquid crystal display panel is sensitive to heat, and if the heat is continuously received from the light source, a problem occurs that causes the liquid crystal to malfunction.

Accordingly, an object of the present invention is to provide a liquid crystal display device capable of efficiently reducing heat transferred from a light source unit to a liquid crystal display panel.

The above object is, according to the present invention, a liquid crystal display panel; A light source unit positioned behind the liquid crystal display panel and supplying light to the liquid crystal display panel; A liquid crystal display panel is disposed between the liquid crystal display panel and the light source unit and includes a diffusion plate having a space portion formed therein.

It is preferable that the said space part is plural and extended in parallel with each other.

It is preferable that the said space part is a lattice shape.

It is preferable that the said space part is formed in several layer.

The diffusion plate is composed of an upper plate and a lower plate bonded to each other, it is preferable that at least one of the inner surface of the upper plate and the lower plate is formed with a groove for forming the space portion.

The inner surface of any one of the upper plate and the lower plate is formed with a groove for forming the space portion, the other inner surface is characterized in that the flat plate shape.

Hereinafter, the present invention will be described with reference to the accompanying drawings.

In various embodiments, like reference numerals refer to like elements, and like reference numerals refer to like elements in the first embodiment and may be omitted in other embodiments. Prior to the description, the lamp 41, which is a light source shown in the drawing, is a case where a cold cathode fluorescent lamp (CCFL) is used and is provided in a direct type.

A liquid crystal display device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. 1 to 3 are exploded perspective views, assembled cross-sectional views, and main parts perspective views of a liquid crystal display according to a first embodiment of the present invention, respectively.

The liquid crystal display device includes a liquid crystal display panel 20 for forming an image, a driver 25 provided on one side of the liquid crystal display panel 20, and a backlight unit 30 positioned behind the liquid crystal display panel 20.

The liquid crystal display panel 20 bonds the thin film transistor substrate 21 on which the thin film transistor is formed, the color filter substrate 22 facing the thin film transistor substrate 21, and the two substrates 21 and 22 to each other, thereby bonding a cell gap. a sealant 23 forming a gap), and a liquid crystal layer 24 positioned between both substrates 21 and 22 and the sealant 23. The liquid crystal display panel 20 adjusts the arrangement of the liquid crystal layer 24 to form a screen, but since it is a non-light emitting device, light must be supplied from the backlight unit 30 located behind.

The liquid crystal display panel 20 further includes a polarizing plate (not shown) attached to the front surface of the color filter substrate 22 and the rear surface of the thin film transistor substrate 21 so that light passing through the liquid crystal display panel 20 is cross-polarized. do. The liquid crystal display panel 20 is arranged in a matrix form of the liquid crystal cells forming a pixel unit, and forms an image by adjusting the light transmittance of the liquid crystal cells according to the image signal information transmitted from the driver 25.

One side of the thin film transistor substrate 21 is provided with a driver 25 for applying a drive signal. The driver 25 includes a flexible printed circuit board (FPC) 26, a driving chip 27 mounted on the flexible printed circuit board 26, and a circuit board connected to the other side of the flexible printed circuit board 26. 28). The driver 25 illustrated represents a chip on film (COF) method, and other known methods such as a tape carrier package (TCP) and a chip on glass (COG) may be used. In addition, the driver 25 may be formed on the thin film transistor substrate 21 during the wiring formation process.

The backlight unit 30 is a member for supplying light to the liquid crystal display panel 20, and includes a plurality of light adjusting members 31 and a light source unit 40 and a light source unit 40 covering the entire rear surface of the liquid crystal display panel 20. A reflector plate 39, a side mold 51, a middle mold 53, and a lower chassis 60 accommodating them are disposed below the reflector.

The light adjusting member 31 disposed on the rear surface of the liquid crystal display panel 20 includes a diffusion plate 32, a prism film 37, and a protective film 38.

The diffusion plate 32 has a plurality of lattice-shaped spaces 34 formed therein to reduce the heat conduction area and reduce heat transferred to the liquid crystal display panel 200. The diffusion plate 32 diffuses the light from the light source unit 40 and supplies the light to the liquid crystal display panel 20. The diffusion plate 32 includes polymethyl methacrylate (PMMA), methyl styrene (MS), polycarbonate (PC), It may be made of any one of polystyrene (PS) resin. Since the diffusion plate 31 is not supported by the light guide plate, unlike the edge type, the diffusion plate 31 may be slightly thicker for strength, and is generally provided with a thickness of about 1 mm to 2 mm.

On the other hand, the diffusion plate 32 according to the first embodiment of the present invention, in addition to the role of diffusing the light from the light source unit 40 to supply to the liquid crystal display panel 20, a space portion 34 for suppressing heat conduction therein It also forms a role to reduce the heat transferred from the light source unit 40 to the liquid crystal display panel 200. The lamp 41 of the light source unit 40 emits not only light energy but also thermal energy to the outside. The thermal conductivity is proportional to the conduction area and inversely proportional to the length. Therefore, when the space 34 inside the diffuser plate 32 is formed, the area capable of conducting heat within the diffuser plate 32 may be reduced, and the conduction path of heat transferred from the lamp 41 may be lengthened. As a result, heat transfer from the lamp 40 to the liquid crystal display panel 20 may be reduced by reducing the thermal conductivity of the diffusion plate 32. In addition, the lattice-shaped space portion 34 provided in the diffusion plate 32 forms a flow path of external air to discharge a part of the heat conducted to the diffusion plate 32 to the outside through convection to the liquid crystal display panel 20. Can further reduce the heat transferred.

In the present embodiment, the space 34 is provided in a lattice shape, but is not limited thereto. The space 34 may be reduced in shape and lengthened in the heat conduction path, and may be transformed into a shape capable of efficient convection by forming a flow path of external air. Of course. In addition, the space 34 may be provided in a plurality of layers.

The method of forming the diffuser plate 32 having the space portion 34 is a pressing machine having a shape of the recessed portion 34, and a pressing process using a UV curing agent, which is a known method, or hot pressing using heat. ) Can be formed by processing.

The prism film 37 is formed with a triangular prism-shaped prism on the upper surface with a constant arrangement. The prism film 37 collects light diffused from the diffusion plate 32 in a direction perpendicular to the plane of the upper liquid crystal display panel 20. Two prism films 37 are usually used, and the micro prisms formed on each prism film 37 form a predetermined angle. The light passing through the prism film 37 proceeds almost vertically to provide a uniform luminance distribution.

The protection film 38 located at the top protects the prism film 37 that is weak to scratches.

The light source unit 40 includes a lamp 41 which is a plurality of linear light sources arranged in parallel with each other. In the first embodiment of the present invention, the lamp 41 uses a cold cathode fluorescent lamp (CCFL), but is not limited thereto. It is also possible to use another linear light source such as an external electrode fluorescent lamp (EEFL). It is also possible to use LEDs. The lamp 41 receives power from an inverter (not shown) and is disposed over the entire rear surface of the liquid crystal display panel 20. Both ends of the lamp 41 are electrode portions (not shown) and are accommodated in the lamp holder 42. The lamp holder 42 is located in the side mold 51 through the receiving groove 52 formed in the side mold 51 and is not exposed.

The side molds 51 are provided in pairs on opposite sides of the liquid crystal display panel 20. The side molds 51 surround the lamp holder 42 and support the light adjusting member 31 as described above. The middle mold 53 supports the liquid crystal display panel 20.

The reflecting plate 39 is positioned between the light source unit 40 and the lower chassis 60 to reflect the light of the light source unit 40 and to supply the light toward the diffuser plate 32. The reflective plate 39 may be made of polyethylene terephthalate (PET) or polycarbonate (PC).

The light adjusting member 31, the light source unit 40, the reflecting plate 39, and the like are accommodated by the lower chassis 60.

The liquid crystal display panel 20, the driver 25, and the backlight unit 30 are accommodated in the upper chassis 10 and protected. The upper chassis 10 has a display window to expose the effective surface of the liquid crystal display panel 20 to the outside, and is coupled to the lower chassis 60 of the backlight unit 30.

According to the first embodiment of the present invention, it is possible to efficiently reduce heat transmitted from the lamp 41 of the light source unit 40 to the liquid crystal display panel 20 by the diffusion plate 32 having the space 34 formed therein. A liquid crystal display device is provided.

Hereinafter, a liquid crystal display according to a second exemplary embodiment of the present invention will be described with reference to FIG. 4. 4 is an enlarged cross-sectional view of a diffuser plate as a main part of a liquid crystal display according to a second exemplary embodiment of the present invention.

In the liquid crystal display according to the second exemplary embodiment of the present invention, the diffusion plate 33 is formed by bonding the upper plate 33a and the lower plate 33b, each of which has grooves for forming a plurality of spaces 35 and 36, to each other. It is prepared. That is, the spaces 35 and 36 are provided in double layers, and a plurality of passages connected to both spaces 35 and 36 by crossing are provided.

The diffusion plate 33 easily manufactures the upper plate 33a and the lower plate 33b having grooves forming the spaces 35 and 36, respectively, by known injection or extrusion molding, and then the spaces 35 and 36. ) Can be easily provided by pressing them so as to cross each other or by attaching them using an adhesive.

According to the second embodiment of the present invention, the liquid crystal display panel 20 is discharged from the lamp 41 of the light source unit 40 by the diffusion plate 33 having the spaces 35 and 36 formed therein, as in the first embodiment of the present invention. There is provided a liquid crystal display device that can efficiently reduce the heat transferred to the.

The above embodiments can be variously modified. In the liquid crystal display device according to the first and second embodiments of the present invention, the light source unit 40 is provided in a direct type, but is not limited thereto, and may be provided in an edge type.

Although some embodiments of the invention have been shown and described, it will be apparent to those skilled in the art that modifications may be made to the embodiment without departing from the spirit or spirit of the invention. . It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

As described above, according to the present invention, a liquid crystal display device capable of efficiently reducing heat transferred from a light source unit to a liquid crystal display panel is provided.

Claims (6)

A liquid crystal display panel; A light source unit positioned behind the liquid crystal display panel and supplying light to the liquid crystal display panel; And a diffuser plate disposed between the liquid crystal display panel and the light source unit and having a space formed therein. The method of claim 1, And a plurality of spaces, which extend in parallel to each other. The method of claim 1, And the space part has a lattice shape. The method of claim 1, And the space part is formed of a plurality of layers. The method according to any one of claims 1 to 4, The diffusion plate is composed of an upper plate and a lower plate which are bonded to each other, And a groove for forming the space part on an inner surface of at least one of the upper plate and the lower plate. The method of claim 5, The inner surface of any one of the upper plate and the lower plate is formed with a groove for forming the space portion, the other inner surface of the liquid crystal display device characterized in that the flat shape.

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