KR101289963B1 - Backlight unit and liquid crystal display device having the same - Google Patents

Abstract

A liquid crystal display device capable of improving luminance is disclosed.

According to an exemplary embodiment of the present invention, a liquid crystal display device includes a liquid crystal panel on which an image is displayed, a plurality of lamps for generating light irradiated to the liquid crystal panel, a bottom case accommodating the liquid crystal panel and a plurality of lamps, and both ends of the lamps. An electrode protection part having a plurality of pairs of opening grooves for protecting the electrode part positioned therein and a corner part of the bottom case, and formed at both ends of the electrode protection part, and the light generated by the lamp to the four corners of the liquid crystal panel. It characterized in that it comprises a light guide portion for reflecting

Support side, bottom case, light guide part

Description

Backlight unit and liquid crystal display device having same {Backlight unit and liquid crystal display device having the same}

1 is an exploded perspective view of a liquid crystal display device having a direct type backlight unit according to the present invention;

2 is a view showing in detail the support side of FIG.

FIG. 3 is a view of the support side of FIG. 2 viewed from the y-axis direction. FIG.

FIG. 4 is a view showing the support side of FIG. 2 as viewed in the z-axis direction. FIG.

5 is a view showing a state in which the bottom case and the lamp and the support side of FIG.

BRIEF DESCRIPTION OF THE DRAWINGS FIG.

102: liquid crystal panel 110: bottom case

112: backlight unit 115: top case

120: bottom case 130: lamp

140: Support side 140a: First light guide part

140b: second light guide portion 140c: electrode protection portion

150: optical sheet 160: support main

178: lamp holder

The present invention relates to a backlight unit, and more particularly, to a backlight unit capable of improving luminance and a liquid crystal display device having the same.

In recent years, research on flat panel displays has been actively conducted. Among them, liquid crystal display devices (LCDs), field emission display devices (FEDs), electro-luminescence display devices (ELDs), and PDPs (PDPs) Plasma Display Panels).

Among them, the liquid crystal display device is the most widely used as a substitute for the CRT (Cathode Ray Tube) for the mobile image display device because of the excellent image quality, light weight, thinness, and low power consumption. In addition to the use of the present invention has been developed a variety of monitors, such as television and computer for receiving and displaying broadcast signals.

On the other hand, since the liquid crystal display itself is non-luminescent, a separate external light source for irradiating light is required. In particular, in the case of a transmissive liquid crystal display device, a separate dimming device for emitting and guiding light to the rear surface of the liquid crystal panel is required.

The backlight unit includes an edge type method and a direct type method.

In the direct type, a light emitting lamp is disposed on a flat surface. Since the shape of the light emitting lamp appears on the liquid crystal panel, the gap between the light emitting lamp and the liquid crystal panel must be maintained, and light scattering means is disposed for uniform distribution of light quantity. There is a limit to thinning because it must be.

On the other hand, the edge type is to install a light emitting lamp on the outside and to distribute the light to the entire surface using a light guide plate, the light emitting lamp is installed on the side, there is a problem that the brightness is low because the light must pass through the light guide plate. In addition, high optical design and processing techniques for the light guide plate are required for uniform distribution of luminance.

Since the direct type and edge type have their disadvantages, the direct type type backlight unit is mainly used in liquid crystal display devices where brightness is more important than the screen thickness. In an important liquid crystal display device, an edge type backlight unit is mainly used.

The direct type backlight unit may include a plurality of lamps generating light, a bottom case accommodating the plurality of lamps, a reflector formed on a front surface of the bottom case, and reflecting light generated from the plurality of lamps to a liquid crystal panel; And a support side for fixing and supporting the plurality of lamps, an optical sheet housed on the support side and the lamp to uniform the light generated by the lamp, a mechanism for supporting the optical sheet, and the like.

In the liquid crystal display device using the direct type backlight unit, a plurality of lamps are evenly distributed on the bottom case, thereby increasing the front luminance of the liquid crystal panel, while decreasing the luminance of the four corners of the liquid crystal panel. Specifically, the front portion of the liquid crystal panel in which the plurality of lamps are evenly distributed has a high brightness because the light generated by the plurality of lamps is directly irradiated onto the liquid crystal panel, but the corner portion of the liquid crystal panel is the light generated by the plurality of lamps. Since it does not reach, the brightness is lowered.

In other words, the reflection plate formed on the front of the bottom case of the backlight unit reflects the light generated by the plurality of lamps to the front part of the liquid crystal panel to increase the brightness of the front part of the liquid crystal panel. Both side portions of the liquid crystal panel are also high in brightness because light generated by the plurality of lamps is reflected to both side portions of the liquid crystal panel by the support side of the backlight unit.

On the other hand, the blind spot where the light generated by the lamp is not reflected by the support side and the reflecting plate, that is, the corner portion of the liquid crystal panel has a lower brightness than the front portion and both side portions of the liquid crystal panel. Exactly, since the light generated by the lamp is not irradiated to the corner portion of the bottom case, the corner portion of the optical sheet corresponding to the corner portion of the bottom case is different from the light portion irradiated to the corner portion of the liquid crystal panel (liquid crystal Less than the front and both sides of the panel. As a result, the front and both side portions of the liquid crystal panel have high luminance while the corner portions of the liquid crystal panel have low luminance, resulting in uneven luminance as a whole. Uneven luminance generated in the liquid crystal panel may cause deterioration of image quality of the liquid crystal panel.

It is an object of the present invention to provide a backlight unit capable of improving luminance.

In addition, an object of the present invention is to provide a liquid crystal display device that can improve the brightness and image quality.

The backlight unit according to the present invention for achieving the above object is a bottom case, a plurality of lamps received on the bottom case to generate light, and a plurality of pairs of opening grooves for protecting the electrode portion located at both ends of the lamp And a light guide part accommodated in the electrode protection part and the corner case of the bottom case and formed at both ends of the electrode protection part to reflect the light generated by the lamp.

The liquid crystal display device according to the present invention for achieving the above object is a liquid crystal panel that displays an image, a plurality of lamps for generating light irradiated to the liquid crystal panel, a bottom case for receiving the liquid crystal panel and a plurality of lamps and An electrode protection part having a plurality of pairs of opening grooves protecting the electrode parts positioned at both ends of the lamp, and received at corner portions of the bottom case and formed at both ends of the electrode protection part to receive light generated from the lamp. It characterized in that it comprises a light guide portion for reflecting to the four corners of the liquid crystal panel.

Other objects, other features, and other advantages of the present invention in addition to the above objects will become apparent from the detailed description of the embodiments associated with the accompanying drawings. Best Mode for Carrying Out the Invention Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is an exploded perspective view of a liquid crystal display device having a direct type backlight unit according to the present invention.

As shown in FIG. 1, the liquid crystal display according to the present invention is configured to display an image on the liquid crystal panel 102 by irradiating light onto the liquid crystal panel 102 and the liquid crystal panel 102. It includes a backlight unit 112 to.

The liquid crystal panel 102 includes a first substrate on which a plurality of gate lines and data lines defining a pixel region are arranged, and a thin film transistor and a pixel electrode electrically connected to the thin film transistor at an intersection thereof, and the first substrate. And a liquid crystal layer formed between the first substrate and the second substrate, the second substrate having opposite color and having a red, green, and blue color filter formed thereon. The liquid crystal panel 102 displays an image whose luminance is determined according to the amount of light transmitted from the backlight unit 112.

The backlight unit 112 includes a plurality of lamps 130 for generating light, a reflector 120 for reflecting light generated by the plurality of lamps 130 toward the liquid crystal panel 102, and the plurality of lamps. A bottom case 110 accommodating the 130 and the reflecting plate 120, a pair of support side 140 covering both ends of the plurality of lamps 130, the lamp 130 and the support side 140. ) Includes an optical sheet 150 positioned above and a support main 160 surrounding an edge of the optical sheet 150.

The backlight unit 112 has a direct type. In addition, the liquid crystal panel 102 manufactured in a separate process is seated on the upper portion of the direct type backlight unit 112 having the above configuration, and a top case 115 is formed around the edge of the liquid crystal panel 102. do. The bottom case 110 accommodates and supports the top case 115, the liquid crystal panel 102, and the backlight unit 112.

The plurality of lamps 130 may use a CCFL (Cold Cathod Flourscent Lamp) or EEFL (External Electrode Flourescent Lamp). Lamp holders 178 are installed at both ends of the plurality of lamps 130 to fix and support the plurality of lamps 130. In the exemplary embodiment of the present invention, the plurality of lamps 130 are cold cathode fluorescent lamps (CCFLs), and internal electrodes (not shown) are formed in the plurality of lamps 130, and When the voltage is applied to the electrode, the lamp 130 is driven.

The plurality of lamps 130 is formed of a glass tube, the inner electrode is formed on both ends of the glass tube, the phosphor is coated on the inner wall of the glass tube. In addition, an inert gas such as argon (Ar) and neon (Ne) and mercury are enclosed in the glass tube. When a voltage is supplied to the internal electrode, electron emission by an electric field occurs from the surface of the internal electrode. The emitted electrons excite (ionize) mercury, and ultraviolet rays emitted as the mercury excites (ionize) collide with the phosphor coated inside the glass tube, thereby finally generating visible light.

The reflective plate 120 is disposed between the inside of the bottom case 110 and the plurality of lamps 130 to reflect the light generated from the lamps 130 to improve the efficiency of the light. The optical sheet 150 includes a diffusion plate for diffusing the light generated by the plurality of lamps 130, a prism sheet for improving the brightness of the light diffused from the diffusion plate, and a protective sheet for protecting the prism sheet. .

The diffusion plate serves to uniformly diffuse the light generated by the plurality of lamps 130. The prism sheet is used to increase brightness by refracting and condensing light that diffuses in both horizontal and vertical directions as the light passes through the diffusion plate, thereby causing the brightness to drop sharply. The protective sheet is positioned on an upper surface of the prism sheet to prevent scratches of the prism sheet. The optical sheet 150 including the diffusion plate, the prism, and the protective sheet is accommodated in the support main 160 and wrapped by the bottom case 110. The optical sheets 150 are supported on the support side 140 and spaced apart from the lamp 130 by a predetermined distance.

The support main 160 is a mold, and a side surface thereof is formed into a stepped stepped surface, and the optical sheet 150 described above is stacked and received on the stepped surface, and the liquid crystal panel 102 also It is stacked and stored. The bottom case 110 is a metal material to surround the side and the back of the support main 160.

Support ends 140 covering both ends of the lamp 130 are positioned at both ends of the plurality of lamps 130. The support side 140 is positioned at both ends of the lamp 130 to accommodate and support the optical sheet 150 to be spaced apart from the lamp 130 by a predetermined distance. The support side 140 covers both ends of the lamp 130 to protect electrode parts (internal electrodes) positioned at both ends of the lamp 130.

In addition, the support side 140 is made of the same material as the reflective plate 120 formed on the front of the bottom case 110, so that the light generated from the lamp 130, both side portions of the optical sheet 150 and It serves to reflect to the corner of the slope. The light reflected by both side portions and the corners of the slopes of the optical sheets 150 may be the corners of both side portions and the slopes of the liquid crystal panel 102 corresponding to both side portions and the corner portions of the slopes of the optical sheets 150. Investigate negatively.

In this case, the support side 140 includes first and second light guide parts 140a and 140b. Due to the first and second light guide parts 140a and 140b of the support side 140, the light generated by the lamp 130 is reflected to the corners of the optical sheet 150 to the liquid crystal panel 102. The brightness of the corner portion of the slope can be improved.

Description of the first and second light guide parts 140a and 140b of the support side 140 is as follows.

2 is a view illustrating the support side of FIG. 1 in detail, FIG. 3 is a view showing the support side of FIG. 2 in the y-axis direction, and FIG. 4 is a view of the support side of FIG. 2 in the z-axis direction. The figure shown.

As shown in FIGS. 1 and 2, the support side 140 of the present invention protects the electrode portions of the plurality of lamps (130 of FIG. 1) as a mold and accommodates and supports the optical sheets 150. And an electrode protection part 140c and first and second light guide parts 140a and 140b provided at both ends of the electrode protection part 140c.

The electrode protection part 140c of the support side 140 includes an opening groove having a predetermined portion of empty space at a position corresponding to the lamp 130 to cover both ends of the lamp 130 as described above. Protecting electrode parts located at both ends of the plurality of lamps 130. In addition, the electrode protection part 140c of the support side 140 supports the optical sheet 150 to allow the optical sheet 150 to be spaced apart from the plurality of lamps 130 by a predetermined distance.

The electrode protection part 140c protects the electrode parts of the plurality of lamps 130 and reflects the light generated by the plurality of lamps 130 to both side portions of the optical sheet 150 so that the liquid crystal panel ( It serves to improve the brightness of both side portions of the 102. The electrode protection part 140c of the support side 140 is made of a material capable of reflecting light generated by the plurality of lamps 130 toward the liquid crystal panel 102.

The first and second light guide portions 140a and 140b of the support side 140 include inclined surface portions, and the inclined surface portions are accommodated in the four corner corners of the bottom case 110 to be generated from the plurality of lamps 130. The reflected light is reflected to the corners of the slopes of the optical sheets 150. When the light generated from the plurality of lamps 13 is reflected to the four corners of the optical sheets 150, the four corners of the four sides of the liquid crystal panel 102 correspond to the four corners of the optical sheets 150. Light is irradiated. As a result, the luminance of the four corners of the liquid crystal panel 102 is improved.

In this case, the inclined surface portions of the first and second light guide portions 140a and 140b may include, for example, a “c” shape. Shapes of the inclined surface portions of the first and second light guide portions 140a and 140b are accommodated in corner portions of the bottom case 110 so that the light generated by the lamp 130 is sloped by the optical sheets 150. It may include a shape that can be reflected to the corner of the.

The first and second light guide parts 140a and 140b of the support side 140 may be integrally formed with the electrode protection part 140c. In addition, it may be formed of a separate mold and inserted or inserted at both ends of the electrode protection part 140c of the support side 140. In this case, the first and second light guide parts 140a and 140b are made of a material capable of reflecting light generated by the plurality of lamps 130 toward the optical sheets 150.

Looking at the support side 140 in the y-axis direction, as shown in FIG. 3, the inclined surface portion of the first light guide portion 140a rises in the vertical direction, and the opening groove of the electrode protection portion 140c is exposed. have. As described above, the inclined surface portion of the first light guide portion 140a is stored in the corner portion of the bottom case 110 to direct the light generated by the plurality of lamps 130 toward the optical sheet 150. Reflect. Referring to the support side 140 in the z-axis direction, as shown in FIG. 4, the inclined surface portion of the first light guide portion 140a is not exposed, and the electrode protection portion 140c accommodates and supports the optical sheet 150. Part of)

Since the support side 140 includes the first and second light guide parts 140a and 140b, the light generated by the plurality of lamps 130 is reflected to the sloped corners of the optical sheets 150. The luminance of the sloped corners of the liquid crystal panel 102 corresponding to the sloped corners of the optical sheet 150 may be improved.

5 is a view illustrating a state in which the bottom case and the lamp and the support side of FIG. 1 are fastened.

As shown in FIGS. 1 and 5, the reflector plate 120 and the plurality of lamps 130 are accommodated on the bottom case 110, and the electrode parts positioned at both ends of the plurality of lamps 130 may include a support side ( 140).

The reflecting plate 120 reflects the light of the lamp 130 irradiated toward the reflecting plate 120 to the front portion of the optical sheet 150 (FIG. 1). The electrode protection part 140c of the support side 140 reflects the light of the lamp 130 irradiated toward the electrode protection part 140c to both side portions of the optical sheet 150. In addition, the first light guide portion 140a of the support side 140 is a slope of the optical sheet 150 using the inclined surface portion of the light irradiated from the lamp 130 to the corner portion of the bottom case 110 Reflect to the corner.

In this case, the inclined surface portion of the first light guide portion 140a is accommodated in the corner portion of the bottom case 110. The light irradiated to the corner portion of the bottom case 110 is reflected by the inclined surface portion of the first light guide portion 140a to the sloped corner portions of the optical sheets 150 to be inclined corners of the optical sheets 150. Light may be irradiated to the sloped corners of the liquid crystal panel 102 corresponding to the portions.

As a result, the luminance of the four corner corners of the liquid crystal panel 102 is improved due to the first and second light guide portions 140a and 140b of the support side 140, thereby making it uniform throughout the liquid crystal panel 102. It is possible to have one luminance.

As described above, the liquid crystal display device according to the present invention includes a support side including a light guide portion respectively accommodated in the corner portion of the bottom case, so that the light irradiated to the corner portion of the bottom case by using the light guide portion. The brightness of the corners of the slopes of the liquid crystal panel can be improved by reflecting light to the slopes of the slopes of the optical sheets and irradiating light to the corners of the slopes of the liquid crystal panel corresponding to the slopes of the slopes of the optical sheets.

In addition, the liquid crystal display according to the present invention may have a uniform brightness throughout the liquid crystal panel due to the improved brightness of the four corners of the liquid crystal panel. The luminance of the image displayed on the liquid crystal panel may be improved by the uniform luminance throughout the liquid crystal panel.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. And other equivalent embodiments are possible. Accordingly, the technical scope and features of the present invention should not be limited to the description of the embodiments, but should be set by the matters set forth in the appended claims.

Claims (14)

Bottom case; A plurality of lamps accommodated on the bottom case to generate light; An electrode protection part having a plurality of pairs of opening grooves for protecting the electrode parts located at both ends of the lamp; And And a light guide part that is received at a corner of the bottom case and is formed at both ends of an electrode protection part to reflect the light generated by the lamp. The method of claim 1, And the light guide part comprises an inclined surface part. 3. The method of claim 2, The inclined surface portion of the light guide portion is a backlight unit, characterized in that stored in the corner portion of the bottom case. The method of claim 1, And the light guide part is integrally formed with the electrode protection part. The method of claim 1, And a reflector formed between the bottom case and the plurality of lamps and reflecting light generated by the plurality of lamps. 6. The method of claim 5, The light guide unit is a backlight unit, characterized in that formed of the same material as the reflector. The method of claim 1, The backlight unit further comprises an optical sheet received and supported on the electrode protection. A liquid crystal panel on which an image is displayed; A plurality of lamps generating light irradiated onto the liquid crystal panel; A bottom case accommodating the liquid crystal panel and a plurality of lamps; An electrode protection part having a plurality of pairs of opening grooves for protecting the electrode parts located at both ends of the lamp; And And a light guide part accommodated in the corner portion of the bottom case and formed at both ends of the electrode protection part to reflect the light generated by the lamp to the four corner corners of the liquid crystal panel. 9. The method of claim 8, And the light guide portion includes an inclined surface portion. 9. The method of claim 8, And the inclined surface portion of the light guide portion is accommodated in a corner portion of the bottom case. 9. The method of claim 8, And the light guide part is integrally formed with the electrode protection part. 9. The method of claim 8, And a reflector formed between the bottom case and the plurality of lamps and reflecting light generated by the plurality of lamps. 13. The method of claim 12, And the light guide part is formed of the same material as the reflective plate. 9. The method of claim 8, And an optical sheet housed on the electrode protective part.

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