KR20070044921A - Liquid crystal display - Google Patents

Abstract

A liquid crystal display device is provided. According to an exemplary embodiment of the present invention, a liquid crystal display device includes a liquid crystal display panel including a plurality of unit pixels two-dimensionally arranged in an area where a plurality of gate lines and a plurality of data lines intersect, A back light unit that supplies light and includes a lamp, a light guide plate, and an optical sheet, a cover bottom for accommodating / supporting the liquid crystal display panel and the back light unit, and protrudes from an upper surface of the cover bottom to position the light guide plate. At least one fixing piece for fixing / supporting the light guide plate.

Light guide plate, LCD, Cover bottom, Fixed piece

Description

Liquid crystal display

1 is an explanatory diagram schematically illustrating a coupling structure between a light guide plate and a cover bottom included in a conventional liquid crystal display.

FIG. 2 is an exploded cross-sectional view illustrating a coupling structure between a light guide plate, a cover bottom, and a fixing piece included in a liquid crystal display according to an exemplary embodiment of the present invention.

3A and 3B are schematic views illustrating a coupling structure between the light guide plate and the cover bottom using the coupling structure of FIG. 2.

<Explanation of symbols on main parts of the drawings>

210: cover bottom 215: hole

220: light guide plate 225: protrusion

230: fixed piece 235: double-sided tape

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having improved productivity and better quality.

In recent years, liquid crystal displays are spotlighted as display means.

The liquid crystal display performs display functions using the electrical and optical properties of the liquid crystal injected into the panel, and is widely applied to various fields such as computer monitors and mobile communication terminals due to the advantages of small size, light weight, and low power consumption. There is a trend.

The liquid crystal display device has an active matrix display method using a switching element and a twisted nematic liquid crystal and a passive matrix display method using a super-twisted nematic liquid crystal according to a difference in driving method. It can be divided into

The biggest difference between the two display methods is that the active matrix display method uses a thin film transistor (TFT) as a switch to drive the LCD, whereas the passive matrix display method does not use a transistor, and thus requires a complicated circuit. It is not to be. However, the liquid crystal display of the active matrix display method, which is technically superior in terms of image quality, is widely used.

Since the liquid crystal display device is not a self-luminous display device but a light-receiving display device, a separate light source such as a back light unit having a lamp is required. That is, by selectively transmitting the light applied from the backlight unit through the liquid crystal display panel, desired image information can be displayed.

The backlight unit may be classified into a light guide plate type and a light guide plate type according to the presence or absence of the light guide plate, and include a plurality of components such as a lamp, an optical sheet, and a reflective sheet, independently of the presence or absence of the light guide plate. do.

1 is an explanatory diagram schematically illustrating a coupling structure between a light guide plate and a cover bottom included in a conventional liquid crystal display.

As illustrated in FIG. 1, the light guide plate 120 provided in the conventional liquid crystal display device includes a protrusion 125 of the light guide plate 120 so as to correspond to a mark 115 marked on an upper surface of the cover bottom 110. ) And the support main (not shown) is joined from the top to complete the configuration.

However, in the conventional method of constructing the light guide plate 120, the position of the light guide plate 120 is designated by the mark 115 drawn on a plane, so that the flow of the light guide plate 120 may be reduced during the module process of the liquid crystal display. There are problems such as frequent occurrences that cause process delays.

In addition, the gap between the light guide plate 120 and the support main is kept very tight in order to prevent a crack of the lamp, and thus, the light guide plate 120 is not fixed to the correct position. In the assembly process between the main body 120 and the support main, scratches are generated, and as a result, foreign matter may be generated, which may affect the quality of the LCD.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a liquid crystal display device having improved productivity and better quality.

The objects of the present invention are not limited to the above-mentioned objects, and other objects which are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a liquid crystal display device according to an embodiment of the present invention, a liquid crystal display panel having a plurality of unit pixels arranged two-dimensionally in a region where a plurality of gate lines and a plurality of data lines intersect, liquid crystal A backlight unit which supplies light to the display panel and includes a lamp, a light guide plate, and an optical sheet, a cover bottom for accommodating / supporting the liquid crystal display panel and the backlight unit, and protruding from an upper surface of the cover bottom; At least one fixing piece for positioning the light guide plate and fixing / supporting the light guide plate.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various forms, and the present embodiments are merely provided to make the disclosure of the present invention complete and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, the invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

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

FIG. 2 is an exploded cross-sectional view illustrating a coupling structure between a light guide plate, a cover bottom, and a fixing piece included in a liquid crystal display according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the liquid crystal display according to the exemplary embodiment includes a cover bottom 210, a light guide plate 220, a fixing piece 230, and the like.

The cover bottom 210 is a lower casing means of the liquid crystal display, and a liquid crystal display panel (not shown), a backlight unit, or the like is mounted on the cover bottom 210.

The light guide plate 220 is positioned on the cover bottom 210. A side surface of the light guide plate 220 may include a lamp that is a light source, and an upper surface of the light guide plate 220 may be provided with an optical sheet for improving brightness of light. These constitute a backlight unit.

The configuration of the backlight unit will be briefly described as follows.

The light guide plate 220 may be classified into a flat plate type or a wedge type type according to its shape. In the case of the flat type light guide plate, a lamp is provided at one side or both sides thereof, and in the case of the wedge type light guide plate. The light guide plate 220 performs a function of guiding the light of the side incident from the lamp upwards, and may be formed of a material such as acrylic.

As the lamp, a cold cathode fluorescent lamp (CCFL), an external electrode fluorescent lamp (EEFL) or an LED lamp, and a surface light source using the same may be used, but is not limited thereto.

Various optical sheets, such as a prism sheet and / or a diffusion sheet, may be provided on the light guide plate 220 to improve upward luminance of light incident from the lamp and guided by the light guide plate 220.

A separate reflective sheet may be provided between the lower portion of the light guide plate 220, the cover bottom 210, and the light guide plate 220 to improve light efficiency of the backlight unit, but is not illustrated.

The fixing piece 230 protrudes from an upper surface of the cover bottom 210 and performs a function of positioning and fixing / supporting the light guide plate 220.

In this case, in the liquid crystal display according to the exemplary embodiment illustrated in FIG. 2, a predetermined hole 215 is formed in the cover bottom 210, and the fixing piece 230 is connected to the hole 215. Although shown to be fixed by the bond is not necessarily limited to the present invention. That is, the fixing piece 230 is formed integrally with the cover bottom 210 in the manufacturing process of the cover bottom 210 so as to protrude from the upper surface of the cover bottom 210 or formed at the cover bottom 210. It may be formed by any known method, such as formed to engage a predetermined groove.

Accordingly, the position of the light guide plate 220 is specified by the fixing piece 230 protruding to have a predetermined height, thereby preventing the flow of the light guide plate 220 in the process of performing a module process of the liquid crystal display. Efficiency can be improved. In addition, the light guide plate 220 can be fixed to the correct position by the fixing piece 230, thereby preventing defects such as scratches and foreign matters generated in the bonding process of the support main (not shown). .

In this case, an adhesive means 235 such as a double-sided tape may be additionally provided on the contact surface of the fixing piece 230 with the light guide plate 220 to enable more stable fixing of the light guide plate 220.

Here, the fixing piece 230 may be formed to have the same height as the light guide plate 220 within a predetermined error range, or may be formed to have a minimum or more height within a range in which the light guide plate 220 may be fixedly supported. The fixing piece 230 may be formed to have a predetermined height or more relative to the light guide plate 220 so that the optical sheets provided on the upper surface of the 220 may be fixedly supported.

The fixing piece 230 may or may not be formed of the same material as the cover bottom 210. If the fixing piece 230 is integrally formed with the cover bottom 210, the fixing pieces 230 may be formed of the same material. If the fixing piece 230 is formed to be separately coupled to correspond to the hole 215 or the groove as shown in the drawing, it may be preferable to form the fixing piece 230 by a material such as synthetic resin, which is easy to handle and inexpensive, but is not limited thereto. It is not.

3A and 3B are schematic views illustrating a coupling structure between a light guide plate and a cover bottom using the coupling structure of FIG. 2, and FIG. 3A illustrates a liquid crystal display device having a '-' shaped fixing piece 230. 3b shows a liquid crystal display device having a 'c' shaped fixing piece 230.

3A and 3B, a backlight unit including a light guide plate 220 is positioned on an upper portion of the cover bottom 210, and a liquid crystal display panel is positioned above the backlight unit.

The configuration and function of the liquid crystal display panel will be briefly described as follows.

The liquid crystal display panel includes a lower substrate and an upper substrate, and a liquid crystal, a gate driving circuit, a data driving circuit, and the like filled therebetween.

In general, a common electrode and a color filter are formed on an upper substrate facing the lower substrate on which the thin film transistor is formed, and a liquid crystal display panel is formed by encapsulating liquid crystal between two substrates.

The color filter substrate is constituted by sequentially stacking a black matrix, a color filter, an electrode, and the like on an insulating substrate. That is, a color filter consisting of R (Red), G (Green), and B (Blue) is provided on the insulating substrate, and a black matrix is formed at a position facing the thin film transistor array of the thin film transistor substrate, and a common electrode thereon. This is laminated to a uniform thickness.

An alignment film is formed on the common electrode.

The thin film transistor substrate is a substrate including a plurality of gate lines, data lines, a plurality of thin film transistors connected thereto, and a plurality of pixel electrodes connected to each other on an insulating substrate.

The thin film transistor is formed of a gate electrode, a source / drain electrode, or the like formed on an insulating substrate. The gate electrode and the source / drain electrode may be formed of a conductive film such as aluminum (Al), chromium (Cr), or molybdenum tungsten (MoW). Can be used.

An insulating layer having a contact hole for exposing the drain electrode is formed on the thin film transistor.

On the insulating layer, pixel electrodes electrically contacting the drain electrodes through the contact holes are stacked to have a uniform thickness. The pixel electrode may be made of indium tin oxide (ITO) or indium zinc oxide (IZO), which is a transparent conductive material.

The liquid crystal is formed in the space between the color filter substrate and the thin film transistor substrate.

Liquid crystal molecules formed in the space between the color filter substrate and the thin film transistor substrate are oriented at an angle designated by the alignment film formed on the electrodes (common electrode and pixel electrode) of the color filter substrate and the thin film transistor substrate. This is explained in more detail as follows.

That is, the thin film transistor formed on the lower substrate includes a gate electrode, a source electrode, a drain electrode, an active layer, an ohmic contact layer, and the like, and the drain electrode is connected to the pixel electrode to form a unit pixel. When the gate signal is applied to the gate electrode through the gate line, the thin film transistor having such a structure operates by transferring the data signal applied to the data line from the source electrode to the drain electrode through the ohmic contact layer and the active layer.

In other words, when a data signal is applied to the source electrode, a voltage corresponding thereto is applied to the pixel electrode connected to the drain electrode, which causes a voltage difference between the pixel electrode and the common electrode. In addition, due to the voltage difference between the pixel electrode and the common electrode, the molecular arrangement of the liquid crystal interposed therebetween changes, and the change in the molecular arrangement of the liquid crystal changes the amount of transmission for the light applied from the backlight unit of each pixel. As a result, the color difference of the pixel is generated according to the difference of the data signal applied to each pixel. By using the color difference, the screen of the liquid crystal display device can be controlled.

One side or both sides of the light guide plate 220 is provided with a lamp, the side is not provided with a lamp is formed with a protrusion 225 to facilitate the assembly of the light guide plate 220.

The light guide plate 220 is stably supported by being fixed by the fixing piece 230 protruding from the cover bottom 210, wherein the fixing piece 230 is a protrusion 225 as shown in FIGS. 3A and 3B. It can be configured in the form of a 'c' or 'c' to correspond to the form of.

In addition, although not shown, it will be obvious that the fixing piece 230 may be configured in various shapes such as 'a' to correspond to the shape of the edge of the light guide plate 220 instead of the protrusion 225. Therefore, it is preferable that four fixing pieces 230 are provided so as to correspond to the protrusions 225 of the light guide plate 220 or the edges of the light guide plate 220, respectively, but are not necessarily limited thereto.

An adhesive means 230 such as a double-sided tape for more stable support of the light guide plate 220 may be further provided on the contact surface of the fixing piece 230 with the light guide plate 220.

The fixing piece 230 may be integrally formed with the cover bottom 210 or fixedly formed by coupling with a groove or a hole formed in the cover bottom 210, and the fixing piece 230 and the light guide plate 220 may be fixed. As described above, it may be configured to have various heights such as the same height within the error range.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive.

According to the liquid crystal display device of the present invention as described above, it is possible to reduce the process delay caused by the flow of the light guide plate during the module process of the liquid crystal display device and the generation of foreign substances generated during the assembly of the light guide plate.

Accordingly, there is an advantage that it is possible to provide a liquid crystal display device having improved productivity and more excellent quality.

Claims (7)

A liquid crystal display panel including a plurality of unit pixels two-dimensionally arranged in an area where a plurality of gate lines and a plurality of data lines cross each other; A backlight unit for supplying light to the liquid crystal display panel and including a lamp, a light guide plate, and an optical sheet; A cover bottom to receive / support the liquid crystal display panel and the backlight unit; And at least one fixing piece protruding from an upper surface of the cover bottom to position the light guide plate and to fix / support the light guide plate. The method of claim 1, At least one hole or groove is formed in the cover bottom, and the fixing piece is fixed by coupling with the hole or groove. The method according to claim 1 or 2, And the fixing piece further comprises an adhesive means for stably fixing the light guide plate on a contact surface with the light guide plate. The method of claim 3, wherein And said adhering means is a double-sided tape. The method of claim 3, wherein And four holes or grooves formed in the cover bottom and four fixing pieces. The method of claim 3, wherein The fixing piece has a 'b' shape or a 'c' shape so as to correspond to the shape of the protrusion formed on the light guide plate. The method of claim 1, And the cover bottom and the fixing piece are integrally formed.

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