KR100948613B1 - Back light assembly and liquid crystal display device having the same - Google Patents

Abstract

Disclosed are a backlight assembly and a liquid crystal display device having the same for improving optical characteristics while reducing overall size. The lamp unit generates light, and the light guide plate provides an emitting surface for emitting the light, a reflecting surface for reflecting the light facing the emitting surface, and an accommodation space for accommodating the lamp unit below the incident surface to which the light is incident. do. The storage space is recessed inside the light guide plate. As a result, the overall size of the backlight assembly or the liquid crystal display device can be reduced, and the optical characteristics can be improved by providing a reflection sheet for preventing light from directly leaking to the emission surface side.

Description

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

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

2 is a cross-sectional view taken along the line A-A 'of FIG. 1.

3 is a perspective view illustrating a positional relationship between a light guide plate and a lamp unit employed in the liquid crystal display of FIG. 1.

<Explanation of symbols for main parts of the drawings>

700: backlight unit 751: lamp

755: lamp reflector 750: lamp unit

720: Light guide plate 727: Reflective sheet

730 optical sheet 740: reflector

400: mold frame 150: bottom chassis

759 electrode wire 1000 liquid crystal display device

The present invention relates to a backlight assembly and a liquid crystal display having the same, and more particularly, to a backlight assembly and a liquid crystal display having the same to improve the optical characteristics while reducing the overall size.

The liquid crystal display includes a display unit displaying an image and a backlight assembly disposed on a rear surface of the display unit to generate light.

The backlight assembly includes a lamp unit for generating light and a light guide plate for guiding the light to the display unit.

The lamp unit includes a lamp for generating the light and a lamp reflector for covering the lamp to reflect the light toward the light guide plate. The light guide plate includes a top surface for emitting the light and a bottom surface facing the top surface and reflecting the light to the top surface, and a side surface connecting the top surface and the bottom surface.

Recently, in order to secure the competitiveness of products, slim and light weight LCDs have been developed. In particular, in view of the fact that the liquid crystal display device is mainly used in portable computers and the like, the weight reduction is treated more heavily.

In particular, the size and the light efficiency of the liquid crystal display device are greatly changed according to the structure of the backlight assembly, and the mechanical and optical characteristics of the liquid crystal display device are affected.

SUMMARY OF THE INVENTION An object of the present invention for solving the above problems is to provide a backlight assembly for improving optical characteristics while reducing the overall size.

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

A backlight assembly for realizing the above object of the present invention includes a lamp unit for generating light; And a light guide plate having an emission surface for emitting the light, a reflection surface facing the emission surface and reflecting the light, and a storage space for accommodating the lamp unit below the incident surface to which the light is incident. And the accommodation space is recessed inside the light guide plate.

In addition, a liquid crystal display device for realizing another object of the present invention described above comprises: a liquid crystal panel provided with an effective display area and an ineffective display area; A lamp unit for generating light; A light guide plate having an emission surface for emitting the light, a reflection surface for facing the emission surface, for reflecting the light, and an accommodation space for accommodating the lamp unit below the entrance surface to which the light is incident; And a storage container accommodating the lamp unit and the light guide plate, wherein the storage space of the light guide plate is recessed inside the light guide plate.

According to such a backlight assembly and a liquid crystal display device having the same, the light guide plate can reduce the overall size of the backlight assembly or the liquid crystal display device by providing a storage space for accommodating the lamp unit, and light leaks directly to the exit surface side. By providing the reflective sheet for preventing the damage, the optical characteristics can be improved.

Therefore, it is possible to prevent the overall size of the backlight assembly from being increased by the lamp unit without affecting the optical characteristics.

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

1 is an exploded perspective view illustrating a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG. 1.

1 and 2, the liquid crystal display device 1000 includes a display unit 200 including a liquid crystal display panel 210 for displaying an image and a backlight for supplying uniform light to the display unit 200. Has assembly 750.

The liquid crystal display 1000 performs display using a liquid crystal in which light transmittance is changed according to an electric field.

In this case, the liquid crystal display 1000 is divided into an effective display area D for displaying an image and an ineffective display area NB for not displaying an image.

The backlight assembly 750 is provided to supply light to the liquid crystal display panel 210. The backlight assembly 750 is mounted on a lamp 751 that generates light, a lamp reflector 753, a light guide plate 720 that guides the light to the display unit 200, and a light guide plate 720. Optical sheets 730 for adjusting the viewing angle of light from the light source.

Meanwhile, the display unit 200 includes a liquid crystal display panel 210 for displaying an image and driving circuit boards 220 and 230 for driving the liquid crystal display panel 210.

Here, the liquid crystal display panel 210 includes a TFT substrate 211 having a TFT (not shown) and a pixel electrode (not shown), a color filter substrate 213 having a RGB pixel and a common electrode, and a TFT substrate 211 and a color. Liquid crystal (not shown) positioned between the filter substrate and 213.

The display unit 200 includes a liquid crystal display panel 210, a data printed circuit board 220, a gate printed circuit board 230, a data side tape carrier package (hereinafter referred to as TCP) 240, and a gate side. TCP 250 is included.

The liquid crystal display panel 210 includes a thin film transistor (hereinafter, referred to as TFT) substrate 211, a color filter substrate 213, and a liquid crystal (not shown).

The TFT substrate 211 is a transparent glass substrate on which a matrix TFT (not shown) is formed. A data line is connected to a source terminal of the TFTs, and a gate line is connected to a gate terminal.

In addition, a pixel electrode made of indium tin oxide (ITO), which is a transparent conductive material, is formed in the drain terminal. When an electrical signal is input to the data line and the gate line, an electrical signal is input to the source terminal and the gate terminal of each TFT, and the TFT is turned on or turned off according to the input of these electrical signals to the drain terminal. Electrical signals necessary for pixel formation are output.

The color filter substrate 213 is provided opposite to the TFT substrate 211. The color filter substrate 213 is a substrate in which RGB pixels, which are color pixels in which a predetermined color is expressed while light passes, are formed by a thin film process. The front surface of the color filter substrate 213 is coated with a common electrode made of ITO.

When power is applied to the gate terminal and the source terminal of the transistor of the TFT substrate 211 described above and the TFT is turned on, an electric field is formed between the pixel electrode and the common electrode of the color filter substrate. By this electric field, the arrangement angle of the liquid crystal injected between the TFT substrate 211 and the color filter substrate 213 is changed, and the light transmittance is changed according to the changed arrangement angle to obtain a desired pixel.

As shown, a data side TCP 240 for determining when to apply a data driving signal is attached to a source side of the liquid crystal display panel 210, and a gate side TCP for determining a timing for applying a driving signal of a gate to the gate side. 250 is attached.

The data printed circuit board 240 is connected to the data side TCP 240 to receive an image signal from the outside of the liquid crystal display panel 210 and apply a driving signal to the data line. The gate printed circuit board 230 is connected to the gate side TCP 250 to apply a driving signal to the gate line.

In FIG. 1, the liquid crystal display 1000 has a data printed circuit board 220 and a gate printed circuit board 230 separately, but the data printed circuit board 220 and the gate printed circuit board 230 are provided. Only one integrated integrated printed circuit board (not shown) may be provided.

In addition, a cold cathode tube is mainly used for the lamp 751, and the light generated from the lamp 751 is incident through the light guide plate 720. A reflecting member is formed on the inner surface of the lamp reflecting plate 753, and the lamp reflecting plate 753 reflects light toward the light guide plate 720 to improve the efficiency of the light.

Under the light guide plate 720, a reflector plate 740 is installed to reflect the light leaked to the light guide plate 720 without being reflected by the printing pattern of the light guide plate 720. Above the light guide plate 720, a plurality of optical sheets 730 are arranged to have a uniform brightness distribution of light emitted from the light guide plate 720 with a non-uniform brightness distribution.

The light guide plate 720, the lamp unit 750, the optical sheets 730, and the reflecting plate 740 are accommodated in the bottom chassis 150.

The bottom chassis 150 is accommodated in the mold frame 400 in a state where the light guide plate 720, the lamp unit 750, the optical sheets 730, and the reflecting plate 740 are accommodated. Thereafter, the display unit 200 is seated on the optical sheets 730, and the display unit 200 is guided by the top chassis 110 coupled to face the mold frame 400.

Specifically, the liquid crystal display panel 210 is accommodated in the mold frame 400, and a plurality of optical sheets 730 are seated thereon. A light guide plate 720 is accommodated above the plurality of optical sheets 730, a light reflection plate 740 is disposed on the light guide plate 720, and a lamp unit 750 positioned in parallel with the light reflection plate 740 is stored on the light guide plate 720. The bottom chassis 150 is sequentially stacked.

On the other hand, although not shown in the drawings, the rear case and the front case is coupled to accommodate the above backlight unit or the liquid crystal display module, both cases are hooked. That is, the rear case and the front case are coupled by forming a protrusion on one of the rear case and the front case and forming a groove on the other so that the protrusion is fitted into the groove.

As will be described in detail later, the light guide plate 720 employed in the embodiment of the present invention has a lamp receiving space recessed inwardly, and the light generated from the lamp 751 directly enters the display area of the liquid crystal display 1000. The reflective sheet 727 is provided to prevent leakage to (D).

The lamp unit 750 is provided below the incident surface. Since the lamp unit 750 is included in an area in which the light guide plate 720 is provided, it is possible to prevent a phenomenon in which the size of the backlight assembly 700 is increased by the lamp unit 750. The overall size of the liquid crystal display device 1000 may be reduced.

3 is a perspective view illustrating a positional relationship between a light guide plate and a lamp unit employed in the liquid crystal display of FIG. 1.

Referring to FIG. 3, the light guide plate 720 includes an emission surface 721 for emitting light, a reflection surface 722 for reflecting the light, an entrance surface 723 for entering the light, and the entrance surface ( And a connection surface 724 for connecting the light emitting surface 721 to the light emitting surface 721 and guiding the light toward the light emitting surface 721.

An accommodating space 725 for accommodating the lamp unit 750 is provided below the incident surface 723 of the light guide plate 720. Here, the storage space 725 includes a first surface 723a parallel to the emission surface 721 and a second surface 723b perpendicular to the first surface 723a.

As shown in FIG. 3, the storage space may be provided on only one side of the light guide plate 720, but the two sides, three side surfaces, and the entire light guide plate 720 may vary depending on the size or characteristics of the liquid crystal display. It may be provided on the side.

In general, when the shape of the light guide plate 720 is a polygon with corners, a light pooling phenomenon occurs where light accumulates at the corners, thereby reducing light reflection efficiency.

Therefore, in the design of the device, the rounding treatment is performed at the corners of the light guide plate to prevent the light accumulation phenomenon. In addition, the uniformity of the light may be secured by forming irregularities on the incident surface 723 to which light is incident.

On the other hand, before the lamp unit 750 is accommodated in the storage space 725 of the light guide plate 720, the reflection sheet 727 for preventing light from directly leaking toward the exit surface 721 on the first surface 723a side. ) Is provided. This is because when light leaks out toward the exit surface 721 and is directly visible in the area where the image is displayed, the uniformity of the light is not achieved, resulting in a decrease in display quality of the liquid crystal display.

After the reflective sheet 727 is provided, the lamp unit 750 is accommodated in the storage space 725 of the light guide plate 720. The lamp unit 750 includes a lamp 751 that generates light and a lamp reflector 753 that surrounds the lamp 751 and reflects light.

The lamp reflecting plate 753 includes a first reflecting plate 753a parallel to the reflecting surface 722 of the light guide plate 720 and a second reflecting plate 753b parallel to the connection surface 724 of the light guide plate 720.

As such, the sidewalls of the lamp reflector 753 may be arranged to be parallel to the reflecting surface 722 or the connection surface 724 of the light guide plate 720, so that the light generated from the lamp 751 may be disposed on the light guide plate 720 and the lamp reflector. This is to prevent leakage between 753 and consequently the display quality of the liquid crystal display device.

 According to the backlight assembly described above, the overall size of the liquid crystal display may be reduced by including a lamp accommodating space recessed inside the light guide plate.

In addition, the display sheet of the liquid crystal display may be improved by providing a reflective sheet which prevents light from directly leaking toward the emission surface side of the light guide plate.

Although described with reference to the above embodiments, 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 (7)

A lamp unit for generating light; And An emission surface for emitting the light, a reflection surface for facing the emission surface, and a reflection surface for reflecting the light, and a lower portion of the entrance surface to which the light is incident is recessed into the light guide plate to accommodate the lamp unit; And a light guide plate having a space formed therein. The backlight assembly of claim 1, further comprising a reflective sheet between a portion of the storage space and the lamp unit to block light emitted from the lamp unit from being directly guided to the emission surface side. The backlight assembly of claim 1, wherein the accommodation space has a first surface parallel to the emission surface and a second surface perpendicular to the first surface. The backlight assembly of claim 1, wherein the light guide plate further comprises a connection surface connecting the incident surface and the exit surface and guiding the light toward the exit surface. The method of claim 1, wherein the lamp unit, A lamp for generating the light; And And a lamp reflector for reflecting the light to the light guide plate. The method of claim 5, wherein the lamp reflector, And a first reflecting plate parallel to the reflecting surface and a second reflecting plate extending from the first reflecting plate and parallel to the incident surface. A liquid crystal panel having an effective display area and an ineffective display area; A lamp unit for generating light; A light guide plate having an emission surface for emitting the light, a reflection surface for facing the emission surface and reflecting the light, and a lower portion of the entrance surface to which the light is incident is embedded inward to accommodate the lamp unit; ; And a storage container accommodating the lamp unit and the light guide plate.

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