KR20030017907A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: A liquid crystal display is provided to change the structure of a light guide to improve an assembled structure of a lamp cover and the light guide. CONSTITUTION: A liquid crystal display includes a back light assembly that is arranged under a display unit for displaying images to provide light to the display unit. The back light assembly includes a lamp(161) for emitting light, a lamp cover(162), a light guide(152) and a mold frame(131). The lamp cover is installed at one side of the lamp and extended in the direction of length of the lamp and has an opening at one side thereof. The light guide is set at one side of the lamp cover and has a stopper(152a) for stopping the top edge of the lamp cover, formed at one end of the light guide. The end of the light guide, which has the stopper, is engaged with the opening of the lamp cover to guide the light emitted from the lamp. The mold frame accommodates the back light assembly.

Description

Liquid crystal display {LIQUID CRYSTAL DISPLAY DEVICE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device having a backlight assembly having improved coupling structure of a lamp cover and a light guide plate.

Recently, with the rapid development of the information processing apparatus, the development of the display apparatus for displaying the information processed by the information processing apparatus so that a human can recognize is growing rapidly.

Until now, 'CRT-type display device' among display devices has been widely used because of its excellent image quality and low price. However, as the necessity of a light and small display device that emphasizes portability is gradually increasing, 'liquid crystal display device' ) 'S share is also growing day by day.

In general, a liquid crystal display device applies a voltage to a specific molecular array of a liquid crystal to convert it into another molecular array, and optical properties such as birefringence, photoreactivity, dichroism, and light scattering characteristics of the liquid crystal cell that emit light by the conversion of the molecular array. The display device converts a change into a visual change to display an image.

However, liquid crystal displays inevitably require light by using liquid crystal, which is a light receiving element that does not generate light by itself. The light may be light generated from sunlight or room lighting, or artificial light generated by consuming electrical energy from the liquid crystal display itself.

In the case of using the light generated from sunlight or room lighting for the display of the liquid crystal display device, since the display is often not performed in a dark place where there is no light at all, recently, the artificial light that can be displayed anywhere Mainly used. Artificial light mainly uses a cold cathode ray tube lamp with high heat generation and high luminance. However, the cold cathode ray tube lamp alone is also difficult to perform a precise display.

This is because a liquid crystal display device requires a surface light source distribution having a uniform optical distribution over the entire display area, but a cold cathode ray tube lamp has a linear light source distribution with high luminance unevenness. As a result, when the display is performed using only a cold cathode ray lamp, the display performance is not obtained due to the extremely uneven optical distribution.

For this reason, the liquid crystal display includes a light guide panel for changing the line light source distribution to a surface light source distribution, an optical sheet for further uniformizing the distribution of light changed from the light guide plate to the surface light source distribution, and recycling of leakage light. A reflector or the like is further provided.

1 is a cross-sectional view illustrating a structure of a conventional backlight assembly.

Referring to FIG. 1, the backlight assembly 10 guides a lamp unit 20 including a lamp 21 and a lamp cover 22 that generate light, and light from the lamp unit 20 to a liquid crystal display panel. The light guide plate 30 is provided. The lamp cover 22 is installed at one side of the lamp 21 to protect the lamp 21 and serves to reflect light generated from the lamp 21.

In addition, various types of sheets are provided on the upper part of the light guide plate 30 to uniformize the luminance of the light directed toward the liquid crystal display panel, and light leaked from the light guide plate 30 is further provided on the lower part of the light guide plate 30. A reflective plate 40 is provided to reflect the liquid crystal display panel to improve light efficiency.

The lamp unit 20, the reflecting plate 40, the light guide plate 30, and the optical sheets described above are sequentially received and fixedly supported in the mold frame 50, which is a storage container. As shown in FIG. 1, the lamp 21 is accommodated in the lamp cover 22 and stored in an accommodation space formed at one end of the mold frame 50. The lamp cover 22 has a '-' shape in which one side is opened and extends in the longitudinal direction of the lamp 21. At this time, both ends of the lamp cover 22 is fixed to the mold frame 50 and the screw.

In addition, the reflecting plate 40 is accommodated in the inner bottom surface of the mold frame 50, and the light guide plate 30 and the optical sheets are sequentially stored thereon. At this time, one end of the light guide plate 30 is engaged by engaging with the lamp cover 22. Specifically, the one open upper end and the lower end of the lamp cover 22 is engaged by engaging with the upper end and the lower end of the one end of the light guide plate 30, respectively.

However, in fixing the lamp cover 22 to the mold frame 50, both ends of the lamp cover 22 are coupled to the mold frame 50 so that the opening of the center portion of the lamp cover 22 is opened. Frequently, one side of the upper part is bent. As such, due to the warpage of the lamp cover 22, a light leakage phenomenon occurs in which light generated from the lamp 21 leaks at a portion where the lamp cover 22 and the light guide plate 30 are coupled to each other.

Accordingly, an object of the present invention is to provide a liquid crystal display device having a backlight assembly capable of improving the coupling structure of the lamp cover and the light guide plate by changing the structure of the light guide plate.

1 is a cross-sectional view illustrating a structure of a conventional backlight assembly.

2 is a schematic exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

3 is a partial perspective view illustrating in detail the structure of the backlight assembly shown in FIG. 2.

4 is a cross-sectional view taken along line IV-IV of the backlight assembly illustrated in FIG. 3.

5 is a cross-sectional view for describing a backlight assembly according to another exemplary embodiment of the present invention.

The liquid crystal display device according to the present invention for achieving the above object is provided in the lower portion of the display unit for displaying an image has a backlight assembly for providing light to the display unit.

The backlight assembly may include a lamp for generating light, a lamp cover provided at one side of the lamp, extending in the longitudinal direction of the lamp, a lamp cover having an opening at one side, and provided at one side of the lamp cover. A first latching jaw is formed to catch the upper edge of the lamp cover, and the one end portion is engaged with the opening of the lamp cover to accommodate the light guide plate for guiding the light generated from the lamp to the upper portion and to store and fix them. It includes a container.

In the present invention, the first locking step is formed by cutting one end of the light guide plate to a predetermined thickness.

The lamp cover further includes a second locking jaw that protrudes from an inner wall to cover an edge of one end of the light guide plate. In this case, the second locking step may be formed at the upper end or the lower end of the inner wall of the lamp cover.

According to the liquid crystal display device described above, the backlight assembly includes a lamp for generating light and a lamp cover for accommodating the lamp. One side of the lamp cover is coupled to the upper end and the lower end of the lamp cover is coupled to the light guide plate for guiding the light generated from the lamp to the top. In this case, the light guide plate is formed on the upper end of the engaging jaw that the upper edge of the lamp cover is caught.

Therefore, even if a warpage phenomenon occurs in the lamp cover, by preventing the phenomenon in which the coupling between the lamp cover and the light guide plate is distorted, it is possible to prevent the light leakage phenomenon in which the light generated from the lamp leaks.

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

2 is a schematic exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the liquid crystal display device 100 includes a liquid crystal display module 130 and front and rear cases 110 and 120 for covering the liquid crystal display module 130. The liquid crystal display module 130 includes a liquid crystal display panel assembly 170 for displaying an image, a backlight assembly 150 for supplying light to the liquid crystal display panel assembly 170, and a mold frame 131 for accommodating them. And a chassis 140.

The liquid crystal display panel assembly 170 includes a TFT substrate 172, a color filter substrate 173 positioned on the TFT substrate 172, and a liquid crystal (not shown) injected between two substrates. 171). A thin film transistor (not shown) that performs a switching role is formed in the TFT substrate 172, a gate line is connected to a gate electrode of each thin film transistor, a data line is connected to a source electrode, and a drain electrode. The pixel electrode is formed.

The data line and the gate line are electrically connected to the data printed circuit board 176 and the gate printed circuit board 175 through the data tape carrier package 178 and the gate tape carrier package 174. Therefore, when the data and gate printed circuit boards 176 and 175 receive an electrical signal from the outside, the data and gate printed circuit boards 176 and 175 determine the driving time and driving timing of the liquid crystal display panel assembly 170. Driving signals and timing signals for controlling are transmitted to the gate lines and the data lines through the data tape carrier package 178 and the gate tape carrier package 174.

The color filter substrate 173 is formed with an RGB pixel which is a color pixel for displaying an image. Therefore, the light transmitted through the liquid crystal is expressed in a predetermined color through the RGB pixel. In addition, a common electrode is formed on an entire surface of the color filter substrate 173. Therefore, when a voltage is applied to the liquid crystal display panel 171, an electric field is formed between the common electrode and the pixel electrode of the thin film transistor to change the arrangement of liquid crystals therebetween.

However, since the liquid crystal is a light-receiving element that does not generate light by itself, the liquid crystal display module 130 receives light from the lower portion of the liquid crystal display panel assembly 170 to the liquid crystal display panel 171 in addition to the liquid crystal display panel assembly 170. It further includes a backlight assembly 150 to provide.

The backlight assembly 150 includes a lamp unit 160 for generating light and a light guide plate 152 for guiding light generated from the lamp unit 160 to the liquid crystal display panel 171. The lamp unit 160 is provided at one side of the lamp 161 for generating light and the lamp 161 to protect the lamp 161 and to direct light from the lamp 161 to the light guide plate 152. Lamp cover 162 for reflection.

The light guide plate 152 is disposed under the liquid crystal display panel 171 and is formed to have a size corresponding to that of the liquid crystal display panel 171, and changes the path of the light generated from the lamp unit 160 to change the liquid crystal. It guides to the display panel 171. At one end of the light guide plate 152 in which the lamp 161 is located, a locking step 152a, which is partially cut, is formed.

In addition, various optical sheets 153 are provided on the upper part of the light guide plate 152 to uniformize the luminance of the light directed toward the liquid crystal display panel 171, and the lower part of the light guide plate 152 is provided on the light guide plate 152. A reflective plate 154 is provided to reflect the light leaking from the light toward the liquid crystal display panel 171 to improve the light efficiency.

The liquid crystal display module 130 further includes a mold frame 131 that accommodates the backlight assembly 150 and fixes the backlight assembly 150. Specifically, the reflector plate 154 is first accommodated in the mold frame 131, and then the light guide plate 152 and the lamp unit 160 are accommodated, and then the optical sheets 153 are disposed on the light guide plate ( 152 is stored above. In addition, the liquid crystal display panel 171 is seated thereon, and the data and gate printed circuit boards 176 and 175 for controlling the driving of the liquid crystal display panel 171 move toward the outer side of the mold frame 131. It is bent and fixed to the back side.

In addition, the upper and lower surfaces of the liquid crystal display panel 171 are coupled to face the mold frame 131 so as to fix the liquid crystal display panel 171 to the mold frame 131. Chassis 140 is provided. The chassis 140 covers the effective display area of the liquid crystal display panel 171 so that the inner wall contacts the outer wall of the mold frame 131.

3 is a partial cutaway perspective view illustrating the structure of the backlight assembly illustrated in FIG. 2. 4 is a cross-sectional view taken along line IV-IV of the backlight assembly illustrated in FIG. 3.

3 and 4, an accommodation space for accommodating the lamp unit 160 is formed at one end of the mold frame 131. The lamp cover 162 in which the lamp 161 is accommodated is first accommodated in the accommodation space. A first electrode line (not shown) for applying a high voltage and a second electrode line (not shown) for applying a low voltage are connected to opposite ends of the lamp 161. Lamp holders 161a and 161b for holding the position of the lamp 161 are respectively installed in the connection portion. Both ends of the lamp cover 162 are coupled to the mold frame 131 with screws, respectively.

In addition, a reflecting plate 154 is accommodated in the bottom surface of the mold frame 131, and the light guide plate 152 is stored thereon. The light guide plate 152 is engaged with the lamp cover 162 accommodated in one end of the mold frame 131. That is, the lamp cover 162 has a cross-section 'c' shape, is formed extending in the longitudinal direction of the lamp 161. At this time, one end of the light guide plate 152 is inserted into and coupled to the opened portion of the lamp cover 162. That is, the opened upper and lower ends of the lamp cover 162 are engaged with the upper and lower surfaces of one end of the light guide plate 152, respectively.

At this time, one end of the light guide plate 152 coupled to the lamp cover 162 is cut to form a first locking step 152a. The first locking step 152a is formed by providing a step with an adjacent portion of the light guide plate 152 that is not coupled to the lamp cover 162. Therefore, even if a bending phenomenon occurs at one open upper end portion of the lamp cover 162, the lamp cover and the light guide plate 152 are prevented from being caught by the first light guide 152a and the light guide plate 152. can do.

As such, by improving the structure of the light guide plate 152 to improve the coupling structure of the light guide plate 152 and the lamp cover 162, light leakage phenomenon in which light generated from the lamp 161 is leaked may be prevented.

5 is a cross-sectional view for describing a backlight assembly according to another exemplary embodiment of the present invention. However, in describing FIG. 5, the same components as in FIG. 4 are denoted by the same reference numerals, and a functional description of repeated components will be omitted.

Referring to FIG. 5, an accommodating space for accommodating the lamp unit 160 is formed at one end of the mold frame 131. The lamp cover 162 in which the lamp 161 is accommodated is first accommodated in the accommodation space. In this case, the reflective plate 154 is accommodated on the bottom surface of the mold frame 131, and the light guide plate 152 is stored thereon. The light guide plate 152 is engaged with the lamp cover 162 accommodated in one end of the mold frame 131.

In this case, the lamp cover 162 may further include a second locking step 162a protruding from the upper end. When the open side end of the lamp cover 162 and one end of the light guide plate 152 are coupled to each other, the second latching jaw 162a is engaged with the upper edge of the one end of the light guide plate 152. In this case, the second locking jaw 162a may be formed extending from the upper end of the inner wall of the lamp cover 162 in the longitudinal direction of the lamp 161. In addition, the second catching jaw 162a may be discontinuously protruded and formed in plural.

Although not shown in the drawing, the second locking jaw 162a may be formed at the lower end of the inner wall of the lamp cover 162. That is, the second locking jaw 162a protrudes from the lower end of the inner wall of the lamp cover 162 and is engaged with the lower edge of one end of the light guide plate 152. In this case, the second latching jaw 162a formed at the lower end of the inner wall of the lamp cover 162 may be formed to extend in the longitudinal direction of the lamp 161, and may also be discontinuously protruding. .

In addition, although not shown in the drawing, the second locking step 162a protruding from the upper end of the inner wall of the lamp cover 162 without forming the first locking step 152a formed at one end of the light guide plate 152. The coupling structure of the lamp cover 162 and the light guide plate 152 may be improved by forming a.

In this way, by improving the structure of the lamp cover 162, it is possible to prevent the light leakage phenomenon in which the light from the lamp 161 leaks due to the abnormal coupling of the lamp cover 162 and the light guide plate 152. In addition, the coupling structure of the light guide plate 152 and the lamp cover 162 may be improved by limiting the insertion of the light guide plate 152 coupled to the lamp cover 162.

According to the liquid crystal display device as described above, there is provided a lamp for generating light and a lamp cover for accommodating the lamp. One side of the lamp cover is coupled to the upper end and the lower end of the lamp cover is coupled to the light guide plate for guiding the light generated from the lamp to the top. In this case, the light guide plate is formed on the upper end of the engaging jaw that the upper edge of the lamp cover is caught.

Therefore, even if a warpage phenomenon occurs in the lamp cover, by preventing the phenomenon in which the coupling between the lamp cover and the light guide plate is distorted, it is possible to prevent the light leakage phenomenon in which the light generated from the lamp leaks.

Although described with reference to the examples, those skilled in the art can understand that the present invention can be variously modified and changed without departing from the spirit and scope of the invention described in the claims below. There will be.

Claims (4)

In the liquid crystal display device provided in the lower portion of the display unit for displaying an image having a backlight assembly for providing light to the display unit, The backlight assembly A lamp for generating light; A lamp cover provided at one side of the lamp and extending in a length direction of the lamp and having an opening at one side; It is provided on one side of the lamp cover, the upper end portion is formed with a first latching jaw that the upper edge of the lamp cover is caught, the one end is engaged by engaging the opening of the lamp cover, the upper portion of the light generated from the lamp Light guide plate for guiding to and And a storage container for storing and fixing them. The liquid crystal display of claim 1, wherein the first locking jaw is formed by cutting one end of the light guide plate to a predetermined thickness. The liquid crystal display device of claim 1, wherein the lamp cover further comprises a second locking step protruding from an inner wall to cover an edge of one end of the light guide plate. The liquid crystal display of claim 3, wherein the second locking step is formed at an upper end of an inner wall of the lamp cover.