KR20070069332A - Back light assembly and liquid crystal display device having the same - Google Patents

Abstract

A backlight assembly and an LCD(Liquid Crystal Display) including the backlight assembly are provide to securely combine optical sheets with a receiving container by using fixing parts formed at the optical sheets. A backlight assembly(700) includes a first receiving container(200), a lamp(410), a light guide plate(300), an optical member(100), and a second receiving container(500). The first receiving container includes a bottom face(210) and sidewalls(220) extended from the edge of the bottom face to form a receiving space(230). The lamp is accommodated in the first receiving container and generates a first light. The light guide plate projects a second light having luminance more uniform than the luminance of the first light. The optical member includes a body(110) and at least one fixing part(120) protruded from the edge of the body and improves the optical characteristic of the second light to project a third light. The second receiving container covers the top of the fixing part.

Description

BACK LIGHT ASSEMBLY AND LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME}

1 is an exploded perspective view of a backlight assembly according to a first embodiment of the present invention;

FIG. 2 is a plan view of the optical sheet shown in FIG. 1,

3 is an enlarged perspective view of the boss shown in FIG. 1,

4 is a cross-sectional view taken along the line IX-IX after assembling the backlight assembly of FIG.

5A is an enlarged perspective view showing another embodiment of the boss,

5B is a perspective view of a fixing hole corresponding to the boss of FIG. 5A,

6 is a cross-sectional view showing another embodiment of the boss,

7 is a cross-sectional view showing another embodiment of the boss;

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

9 is a cross-sectional view taken along line XI-XI after assembling 8,

10 is a cross-sectional view of the liquid crystal display panel assembly of the liquid crystal display device shown in FIG.

11 is a conceptual diagram conceptually showing a pixel of a TFT substrate.

The present invention relates to a backlight assembly and a liquid crystal display device, and more particularly, to a backlight assembly and a liquid crystal display device including the same that can maintain a tight bond of the optical sheet.

In general, a liquid crystal display device (LCD) is a device that displays information according to a change in liquid crystal according to an applied voltage.

In order to display information, a conventional liquid crystal display device includes a light supply part for generating light necessary for a display, an optical part for making the luminance of the supplied light uniform, and a liquid crystal control part for controlling the liquid crystal.

The light supply part used in the liquid crystal display device includes a Cold Cathode Fluorescent Lamp (CCFL), which has a long life, generates white light, and has a relatively low heat generation amount.

The optical part plays a role of making the luminance of light generated in the cold cathode ray tube lamp uniform. The optical part is slightly different depending on the type of liquid crystal display device, but has an optical sheet in common.

The optical sheet is composed of a diffusion sheet for diffusing the light generated by the cold cathode ray tube type lamp to make the luminance distribution uniform, a prism sheet for condensing the processed light with the luminance distribution more uniform.

In addition, a light guide panel (LGP) may be used for the optical part. The light guide plate serves to make the light generated from the cold cathode ray tube lamp have a surface light source optical distribution.

The liquid crystal control part controls the liquid crystal in units of pixels so that the transmittance of light processed in the optical part is controlled in units of pixels. The image is displayed by the operation of the liquid crystal control part.

Although the light supply part, the optical part and the liquid crystal control part which make it possible to perform a display in the liquid crystal display are all important, among these, the optical part has a great influence on the display quality.

The optical sheet included in the aforementioned optical part, for example, a diffusion sheet or a prism sheet, is mainly fixed with a double-sided adhesive tape, or a boss is formed on a bottom chassis after extending a part to form a hole. ) Is fixed in such a manner as to be fixed.

However, a boss and a hole are mainly formed in a straight shape of a straight line or a circular shape, so that a defect that an optical sheet such as a diffusion sheet or a prism sheet falls out of the boss occurs.

In particular, in the process of assembling the light supply part, the optical part, and the like, a failure of the optical sheet is frequently caused by vibration or shock.

 Accordingly, it is a first object of the present invention to provide a backlight assembly capable of maintaining tight bonding of an optical sheet.

Another object of the present invention is to provide a liquid crystal display device having the backlight assembly of the present invention.

      According to an aspect of the present invention, there is provided a backlight assembly including a first storage container including a bottom surface and sidewalls extending from the edge of the bottom surface to form a storage space, the first storage container being generated in the storage space to generate first light. A light guide plate for emitting a second light having a luminance more uniform than the luminance of the first light, an optical member body and an edge of the optical member body to improve the optical characteristics of the second light to emit a third light. An optical member having at least one fixing part protruding from the optical member, and a second storage container installed through the side wall of the first storage container and covering an upper portion of the fixing part.

The backlight assembly may further include a boss having a cross-section having a groove corresponding to the fixing part and a groove corresponding to the fixing part and having a cross section with respect to an imaginary surface parallel to the optical member, wherein the fixing part is the boss. It further comprises a fixing hole corresponding to.

The fixing hole may be formed in a cross shape, and the boss may be fastened to the fixing hole, and formed in the same planar shape as the fixing hole.

In addition, the backlight assembly according to another embodiment of the present invention includes a lamp assembly, an optical sheet and a housing. The lamp assembly generates light. In addition, the optical sheet includes an optical sheet body for improving the characteristics of the light and a sheet body fixing portion protruding from the optical sheet body and having a fixing hole. In addition, the storage container includes an optical sheet receiving groove into which the seat body fixing part is inserted, and a boss protruding from the optical sheet receiving groove and inserted into the fixing hole. The boss also includes a boss body and a departure prevention part protruding from the boss body.

The liquid crystal display according to the present invention includes a first storage container including a bottom surface and sidewalls extending from the edge of the bottom surface to form a storage space, a lamp stored in the storage space to generate first light, and A light guide plate for emitting a second light having a luminance more uniform than the luminance of the first light, at least one protruding from the edge of the optical member body and the edge of the optical member body to improve the optical properties of the second light to emit the third light An optical member having a fixing portion of the first storage container, a second storage container covering an upper portion of the fixing portion, and a second storage container covering the upper portion of the first storage container, and passing through the optical member. A liquid crystal display panel assembly for converting a second light into image light including information, and a chassis for fixing the liquid crystal display panel assembly.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

These embodiments of the present invention are merely for illustrating the present invention, but the present invention is not limited thereto.

<First Embodiment>

1 is an exploded perspective view of a backlight assembly according to a first embodiment of the present invention, FIG. 2 is a plan view of the optical sheet shown in FIG. 1, FIG. 3 is an enlarged perspective view of the boss shown in FIG. 1, and FIG. 4 is 1 is a cross-sectional view taken along line IX-IX after assembling the backlight assembly of FIG. 1.

1 to 4, the backlight assembly 700 includes a first accommodating container 200, a light guide plate 300, a lamp assembly 400, an optical sheet 100, and a second accommodating container 500. .

The first accommodating container 200 includes a bottom plate 210 having a rectangular frame shape and sidewalls 220 protruding from an edge of the bottom plate 210 to form an accommodating space 230. As shown in FIG. 1, reference numerals 221, 223, 225, and 227 will be given to the sidewalls 220.

Two optical sheet receiving grooves 223a and 227a are formed in two sidewalls 223 and 227 facing each other among the sidewalls 220. The optical sheet accommodating grooves 223a and 227a are formed in the sidewalls 223 and 227 to be connected to the accommodating space 230.

Bosses 223b and 227b are provided in the optical sheet receiving grooves 223a and 227a, respectively.

The light guide plate 300 and the lamp assembly 400 are installed in the first storage container 200 having such a configuration.

The lamp assembly 400 is composed of a lamp 410 and a lamp reflection plate 420 for generating the first light again.

The lamp 410 is, for example, a cold cathode fluorescent lamp (CCFL) lamp for generating first light having a linear optical distribution. Hereinafter, reference numeral 410 will be given to the cold cathode ray tube lamp.

The cold cathode ray tube lamp 410 generates white light similar to sunlight, has a long lifespan, and has a very low heat generation value compared to an incandescent lamp in the process of generating the first light.

The lamp reflector 420 serves to allow the first light generated radially from the cold cathode ray tube type lamp 410 to be emitted only in one direction.

In order to implement this, the lamp reflector 420 surrounds most of the circumferential surface of the cold cathode ray tube lamp 410 at a distance from the cold cathode ray tube lamp 410 and opens only a portion thereof. .

The light guide plate 300 receives the first light having a linear optical distribution from the lamp assembly 400 to emit the second light modified to have a surface optical distribution.

In order to implement this, the light guide plate 300 has a rectangular parallelepiped plate shape having four sidewalls 330, a light emission surface 310 and a light reflection surface 320 connected to the sidewall 330.

The light guide plate 300 emits the light by using the property that the first light emitted from the cold cathode ray tube type lamp 410 is incident and then is reflected or transmitted according to the law of refraction when the first light emitted from the cold cathode ray tube type lamp 410 is incident. Most of the second light is emitted to the surface 310.

The lamp assembly 400 described above in detail in the side wall 330 of the light guide plate 300 in order to change the optical distribution of the first light in the light guide plate 300 and the second light is mostly emitted to the light exit surface 310. ) Is installed.

In this case, the second light emitted to the light exit surface 310 of the light guide plate 300 is mostly emitted from the light exit surface 310 with a smaller slope than the vertical angle based on the light exit surface 310. As described above, the second light emitted at a smaller slope than the vertical direction based on the light exit surface 310 is very difficult to use for the display.

The optical sheet 100 is installed in a position facing the light exit surface 310 of the light guide plate 300 and uniformity in the direction and brightness of the second light emitted from the light exit surface 310 of the light guide plate 300. Serves to improve

The optical sheet 100 is composed of at least one or more, preferably composed of three, for example, may be composed of one diffusion sheet 160 and two prism sheets 170.

The diffusion sheet 160 diffuses the second light emitted from the light exit surface 310 of the light guide plate 300 to form a luminance distribution more uniformly, and simultaneously corrects the directionality of the second light. 3 Let the light exit.

The prism sheet 170 secondaryly changes the directionality of the third light whose direction is corrected in the diffusion sheet 160 so that most of the third light is perpendicular to the light exit surface 310 of the light guide plate 300. Get directions.

As such, the liquid crystal display may display a higher quality image according to the operation of the optical sheet 100. As such, the optical sheet 100 essential for the display device using the liquid crystal has unique optical characteristics.

Referring to FIG. 2, the optical sheet 100 includes an optical sheet body 110 and an optical sheet body fixing part 120. The optical sheet 100 has a rectangular shape, for example, and the optical sheet body 110 occupies most of the area of the optical sheet 100 and changes the optical characteristics of light generated from the light source.

The optical sheet body fixing part 120 is formed by extending a portion of the edge of the optical sheet body 110 in parallel with the optical sheet body 110.

Preferably, the optical sheet body fixing part 120 is formed in the optical sheet body 110, four places, each optical sheet body fixing part 120 is formed with a fixing hole 125. The optical sheet body fixing part 120 is accommodated in the first storage container 200.

The fixing holes 125 are fitted into bosses 223b and 227b (see FIG. 1) to prevent the optical sheet body 110 from being disengaged from the designated position. In detail, the optical sheet body fixing part 120 is fitted into and fixed to bosses 223b and 227b formed in the optical sheet receiving grooves 223a and 227a of the first storage container 200.

At this time, the fixing hole 125, as shown in Figure 4, is formed in a cross shape so that the optical sheet body 110 is firmly fixed to the boss (223b, 227b). Here, the fixing hole 125 may be formed in a polygonal shape such as a mushroom shape, a triangle, a star shape, as well as a cross shape. Various embodiments of the fixing holes 125 or bosses 223b and 227b will be described in more detail with reference to FIGS. 5A-7.

At this time, in the case of a mushroom shape or triangle shape, if the upper part is widened and the lower part is formed narrow, the fixing holes 125 of the optical sheet 100 are coupled to the bosses 223b and 227b so that they do not easily fall out. Will be.

Here, since the optical sheet 100 is generally made of a synthetic resin material, it is easy to expand by heat. Therefore, when the optical sheet body 110 is fixed to the bosses 223b and 227b, the amount of expansion and contraction of the optical sheet 100 due to heat should be considered.

Specifically, in consideration of the amount of expansion and contraction of the optical sheet 100, the area of the fixing hole 125 of the optical sheet body fixing part 120 may move slightly in a state of being fitted into the bosses 223b and 227b. It is desirable to be made slightly larger than the areas of the bosses 223b and 227b.

Referring to FIG. 1 again, the second container 500 may not be separated from the lamp assembly 400, the light guide plate 300, and the optical sheet 100 accommodated in the first container 200. It serves to fix the liquid crystal display panel assembly to be described later in detail and to prevent the fixed role.

In order to implement this, the second storage container 500 has a rectangular frame shape with a central opening.

In this case, the second storage container 500 is coupled to the first storage container 200 so that a part of the second storage container 500 is adhered to the upper surface of the optical sheet 100 shown in FIG. 2. .

Referring to FIG. 4, the second storage container 500 covers an upper portion of the optical sheet body fixing part 120 of the optical sheet 100.

Figure 5a is an enlarged perspective view showing another embodiment of the boss, 5b is a perspective view of a fixing hole corresponding to the boss of Figure 5a. 5A and 5B, the bosses 223c and 227c according to another embodiment are formed by protruding the departure preventing unit 2231 on the straight boss body 2232. The departure preventing part 2231 protrudes in a direction perpendicular to the longitudinal direction of the straight boss body 2232. In FIG. 5A, the separation prevention unit 2231 protrudes in a direction toward the optical sheet 100 and a direction away from the optical sheet 100 of FIG. 1, and is shown to have a cross shape when viewed in plan view, but toward the optical sheet 100. Direction or a direction away from the optical sheet 100 may have a T-shape.

Referring to FIG. 5B, the fixing holes 125a corresponding to the bosses 223c and 227c illustrated in FIG. 5A have a straight shape. However, the second length T2 of the fixing hole 125a is larger than the first length T1 of the bosses 223c and 227c shown in FIG. 5A. Therefore, the bosses 223c and 227c may be easily inserted into the fixing holes 125a. In addition, after the boss bosses 223c and 227c are inserted into the fixing holes 125a, the optical sheet 100 is not easily separated from the bosses 223c and 227c.

Figure 6 is a cross-sectional view showing another embodiment of the boss.

Referring to FIG. 6, the bosses 223d and 227d according to another embodiment of the present invention include a straight boss body 2232a and a departure prevention part 2231b. The detachment preventing part 2231 may be easily inserted into a fixing hole (not shown) because the upper part is convex. In the plan view, the departure preventing unit 2231b may have various shapes such as a circle and a polygon. Fixing holes (not shown) corresponding to the bosses 223d and 227d may be formed to have the same planar view as the cross-shape shown in FIG. 2, the straight line shown in FIG. 5B, or the departure preventing part 2231b.

Figure 7 is a cross-sectional view showing another embodiment of the boss. The bosses 223e and 227e illustrated in FIG. 7 include a boss body 2232b and a departure prevention part 2231b. The departure prevention part 2231b is substantially the same as the departure prevention part 2231b shown in FIG. 6. Therefore, description of the departure prevention part 2231b is omitted.

The thickness of the boss body 2232b gradually decreases from the upper side to the lower side. Therefore, when the bosses 223e and 227e are inserted into the optical sheet insertion holes (not shown), the bosses 223e and 227e may be more firmly fixed.

Second Embodiment

FIG. 8 is an exploded perspective view of the liquid crystal display 1000 according to the second embodiment of the present invention. FIG. 9 is a cross-sectional view taken along line XI-XI after assembling 8, and FIG. 10 is shown in FIG. 8 of the present invention. 8 is a cross-sectional view of a liquid crystal display panel assembly, and FIG. 8 is a conceptual diagram conceptually showing pixels of a TFT substrate.

5 and 6, the liquid crystal display 1000 may further include a liquid crystal display panel assembly 800 and a chassis 900 in addition to the backlight assembly 700 illustrated in FIG. 1.

Therefore, the duplicated description of the above-described backlight assembly 700 will be omitted, and only components of the liquid crystal display device will be described.

The chassis 900 presses an edge of the liquid crystal display panel assembly 800 while the liquid crystal display panel assembly 800 is seated on the second storage container 500. 7 and 8, the liquid crystal display panel assembly 800 includes a TFT substrate 810, a color filter substrate 820, and a liquid crystal (LCD). 830).

The TFT substrate 810 includes a first transparent substrate 811, a thin film transistor 812, and a pixel electrode 813.

A plurality of thin film transistors 812 are formed in a matrix form on the first transparent substrate 811 by a thin film manufacturing process.

Each of the thin film transistors 812 includes a gate electrode 812a, a channel layer 812b, a source electrode 812c, and a drain electrode 812d. The gate electrode 812a and the channel layer 812b are insulated by the insulating layer 812e. The channel layer 812b is formed on the gate electrode 812a of the upper surface of the insulating layer 812e to be insulated from the gate electrode 812a.

The gate line 814 shown in FIG. 8 is connected to the gate electrode 812a of the thin film transistor 812 having the above configuration, and the data line 816 shown in FIG. 8 is connected to the source electrode 812c. ) Is connected.

The pixel electrode 813 is connected to the drain electrode 812d of the thin film transistor 812. The pixel electrode 813 is made of a transparent and conductive material such as, for example, an indium tin oxide film (ITO) or an indium zinc oxide film (IZO).

Referring to FIG. 7, the color filter substrate 820 includes a second transparent substrate 821, a color filter 823, and a common electrode 825.

The color filter 823 is disposed on the second transparent substrate 821 in a matrix form by a thin film process. In this case, the color filter 823 is formed at a position facing the pixel electrode 813 formed on the TFT substrate 810. The common electrode 825 is formed on the second transparent substrate 821 so as to cover all of the color filters 823.

The liquid crystal display panel assembly 800 includes the liquid crystal 830 between the TFT substrate 810 and the color filter substrate 820 in a state where the TFT substrate 810 and the color filter substrate 820 described above are assembled with each other. ) Is completed to complete the production.

As described in detail above, a defect of the optical sheet such as the diffusion sheet or the prism sheet from falling out of the boss formed in the bottom chassis or the like can be prevented, thereby maintaining a firm bond.

In the detailed description of the present invention described above with reference to a preferred embodiment of the present invention, those skilled in the art or those skilled in the art having ordinary knowledge in the scope of the invention described in the claims to be described later It will be understood that various modifications and variations can be made in the present invention without departing from the scope of the present invention.

Claims (14)

A first storage container including a bottom surface and sidewalls extending from an edge of the bottom surface to form a storage space; A lamp housed in the storage space to generate first light; A light guide plate for emitting a second light having a luminance more uniform than that of the first light; An optical member having an optical member body and at least one fixing portion protruding from an edge of the optical member body to enhance the optical properties of the second light to emit third light; And A second storage container installed through the sidewall of the first storage container and covering an upper portion of the fixing part; Including, The first storage container further includes a groove corresponding to the fixing part and a cross-shaped boss formed in the groove and having a cross section of an imaginary surface parallel to the optical member. The fixing unit further comprises a fixing hole corresponding to the boss. The method of claim 1, And the fixing hole is formed in a cross shape. The method of claim 1, The boss is coupled to the fixing hole, the backlight assembly, characterized in that formed in the same plane shape as the fixing hole. A first storage container including a bottom surface and sidewalls extending from the edge of the bottom surface to form a storage space; A lamp housed in the storage space to generate first light; A light guide plate for emitting a second light having a luminance more uniform than that of the first light; An optical member having an optical member body and at least one fixing portion protruding from an edge of the optical member body to enhance the optical properties of the second light to emit a third light; A second storage container installed through the side wall of the first storage container and covering an upper portion of the fixing part; A liquid crystal display panel assembly installed through the second storage container and configured to change the third light passing through the optical member into image light including information; And A chassis for fixing the liquid crystal display panel assembly, The first storage container further includes a groove corresponding to the fixing part and a cross-shaped boss formed in the groove and having a cross section on an imaginary surface parallel to the optical member. And the fixing part further comprises a fixing hole corresponding to the boss. The method of claim 4, wherein And the fixing hole is cross-shaped. The method of claim 4, wherein The boss is coupled to the fixing hole, the backlight assembly, characterized in that formed in the same plane shape as the fixing hole. A lamp assembly for generating light; An optical sheet including an optical sheet body for improving the characteristics of the light and a sheet body fixing portion protruding from the optical sheet body and having a fixing hole; And And a storage container including an optical sheet receiving groove into which the sheet body fixing part is inserted and a boss protruding from the optical sheet receiving groove and inserted into the fixing hole. Boss body; And And a departure prevention part protruding from the boss body. 8. The backlight assembly of claim 7, wherein the boss body has a straight shape when viewed in plan view, and the release preventing portion protrudes toward the optical sheet body such that the boss has a T shape when viewed in plan view. The backlight of claim 7, wherein the boss body has a straight shape when viewed in a plan view, and the release preventing portion protrudes toward the opposite direction of the optical sheet body, so that the boss has a T shape when viewed in a plan view. assembly. The backlight assembly of claim 9, wherein the fixing hole has a straight shape when viewed in plan view, and the length of the fixing hole is greater than the length of the boss body. The boss body of claim 7, wherein the boss body has a straight shape when viewed in plan view, and the release preventing portion protrudes in an opposite direction of the optical sheet body and the optical sheet body so that the boss has a cross shape when viewed in plan view. Backlight assembly. The backlight assembly of claim 11, wherein the fixing hole has a straight shape when viewed in plan view, and the length of the fixing hole is larger than the length of the boss body. The backlight assembly of claim 11, wherein the separation preventing part is formed to have a convex upper portion based on a cross section cut in a plane direction perpendicular to the optical sheet. 14. The backlight assembly of claim 13, wherein the cross section of the boss body gradually decreases in thickness from top to bottom.

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