KR20080038923A - A light guiding plate and a backlight assembly and a liquid crystal display device having the same - Google Patents

Abstract

A waveguide plate, a backlight assembly, and an LCD device are provided to improve brightness of the LCD device by forming an optical pattern to correspond to an active region of an LCD panel. An LCD(Liquid Crystal Display) device includes a display assembly and a backlight assembly. The display assembly includes an LCD panel(100) and a driver. The LCD panel includes a color filter substrate(110) and a TFT substrate(120). The driver is arranged on one side of data and gate lines on the TFT(Thin Film Transistor) substrate. The driver includes a data PCB(210a), a gate PCB(Printed Circuit Board)(210b), a tape carrier package(220a), and a gate TCP(220b). The tape carrier package connects the data and gate PCBs to the data and gate lines, respectively. The backlight assembly includes a light source(400), a waveguide plate(300), a refractive plate(500), plural optical sheets, and a mold frame(700). The refractive plate, the waveguide plate, and the optical sheet are sequentially received in the mold frame.

Description

LIGHT GUIDEING PLATE AND A BACKLIGHT ASSEMBLY AND A LIQUID CRYSTAL DISPLAY DEVICE HAVING THE SAME}

1 is an exploded perspective view showing a liquid crystal display device having a light guide plate according to the present invention.

2 is a plan view showing a light guide plate according to the present invention.

3 to 5 are a perspective view and a plan view showing a modification of the light guide plate according to the present invention.

6 is a graph illustrating luminance distribution test data of a light guide plate according to the related art and a light guide plate according to the present invention.

             <Description of the code | symbol about the principal part of drawings>

100: liquid crystal display panel 200: driver

300: Light guide plate 310: First region

320: second region 400: light source

500: reflector 610: diffusion sheet

620: prism sheet 700: mold frame

The present invention relates to a liquid crystal display, and more particularly, to a light guide plate for improving the light efficiency of a liquid crystal display, a backlight assembly having the same, and a liquid crystal display.

In general, a flat panel display (FPD) is a display device essential for realizing a compact and lightweight system such as a monitor of a desktop computer, a portable computer such as a notebook computer, a PDA, or a mobile phone terminal. The device includes a liquid crystal display (LCD), a plasma display panel (PDP), a field emission display (FED), and the like. In particular, LCD has been attracting attention as an alternative means of overcoming the shortcomings of conventional cathode ray tube (CRT) due to the advantages of miniaturization, light weight and low power consumption, and now requires a flat panel display device. It is applied to various small and medium sized products.

Since the LCD does not emit light by itself, the LCD displays the image by reflecting the external light transmitted through the liquid crystal display panel, or a backlight assembly including a separate light source is provided on the rear surface of the liquid crystal display panel to display the image.

The backlight assembly may include a light source unit emitting light, a light guide plate for guiding light emitted from the light source unit toward the liquid crystal display panel, a reflection sheet provided below the light guide plate to reflect leakage of the light to the light guide plate, and And an optical sheet for raising the luminance of the light transmitted from the light guide plate.

At this time, the prism shape is processed on one surface of the light guide plate in order to increase the brightness of the light. However, this causes a problem in that the brightness is increased while the appearance characteristics such as the uniformity and the bright line of the light incident part deteriorate.

In order to solve the above problems, an object of the present invention is to provide a light guide plate, a backlight assembly, and a liquid crystal display device having the same, which are spaced apart from the edge of the light guide plate to improve optical efficiency of the liquid crystal display device.

In addition, an object of the present invention is to provide a light guide plate that is spaced apart from the edge of the light guide plate to form an optical pattern to improve appearance characteristics, a backlight assembly and a liquid crystal display device having the same.

In order to achieve the above object, the light guide plate of the present invention is characterized in that an optical pattern is formed spaced apart from the edge of the base plate and the base plate by a predetermined interval.

The optical pattern may be formed on at least one of an upper surface and a lower surface of the base plate.

The optical pattern is a prism acid optical pattern formed by sequentially arranging prism acids.

The optical pattern is characterized in that the hemisphere is a lenticular optical pattern formed by successive arrangement.

The optical pattern may be a micro lens optical pattern formed by continuously arranging ellipses or circles.

The length of the pitch of the optical pattern is characterized in that 20 to 100 micrometers.

The optical pattern is formed to protrude or concave to the upper portion of the base plate.

In addition, the backlight assembly of the present invention includes a light source and an optical sheet for controlling light from the light source, wherein at least one surface of the optical sheet is characterized in that an optical pattern is formed spaced apart from an edge.

The optical sheet is characterized in that the light guide plate.

In addition, the liquid crystal display device of the present invention includes a liquid crystal display panel including an active area for displaying an image, a light source unit for generating light, and an optical sheet for providing light from the light source unit to the liquid crystal display panel, wherein the optical At least one surface of the sheet is characterized in that the optical pattern is formed spaced apart from the edge at a predetermined interval.

The optical pattern is formed to correspond to the active region.

The optical sheet is characterized in that the light guide plate.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention, and to those skilled in the art to the fullest extent. It is provided to inform you. Like reference numerals in the drawings refer to like elements.

1 is an exploded perspective view illustrating a liquid crystal display device having a light guide plate according to the present invention, FIG. 2 is a plan view showing a light guide plate according to the present invention, and FIGS. 3 to 5 are perspective views showing a modification of the light guide plate according to the present invention. And plan view.

1 and 2, the liquid crystal display includes a display assembly 1000 displaying an image and a backlight assembly 2000 providing light to the display assembly 1000.

The display assembly 1000 includes a liquid crystal display panel 100 and a driver 200 for driving the liquid crystal display panel 100.

The liquid crystal display panel 100 includes a color filter (CF) substrate 110 and a thin firt transistor (TFT) substrate 120 disposed under the CF substrate 110.

The CF substrate 110 is coated with a common electrode made of a color filter on one surface and a transparent conductor such as indium tin oxide (ITO) or indium zinc oxide (IZO) on the color filter. In the TFT substrate 120, a TFT having a matrix form is formed, and a data line and a gate line are respectively connected to a source terminal and a gate terminal of the TFTs, and a pixel electrode is connected to a drain terminal.

Therefore, the CF substrate 110 and the TFT substrate 120 having the above constitution are bonded together, and a liquid crystal is injected between the CF substrate 110 and the TFT substrate 120 or the liquid crystal is injected into the CF substrate 110 or the TFT. After dropping onto the substrate 120, the CF substrate 110 and the TFT substrate 120 are bonded to each other to complete the liquid crystal display panel 100. In this case, an area in which liquid crystal is injected between the CF substrate 110 and the TFT substrate 120 is an active area 130, and displays an actual image in this area.

The driver 200 is installed on one side of the liquid crystal display panel 100, that is, one side of a data line and a gator line of the TFT substrate 120, and a data printed circuit board (PCB) 210a and a gate PCB. 210b, a data tape carrier package (TCP 220a) and a gate TCP 220b for connecting the data PCB 210a and the gate PCB 210b to data lines and gate lines.

That is, the driver 200 generates a data signal for driving the liquid crystal display, a gate driving signal, and a plurality of driving signals for applying these signals at an appropriate time, thereby generating the gate driving signal and the data driving signal through the liquid crystal display panel ( Serves to apply to the gate line and the data line of (100).

The backlight assembly 2000 may include a light source unit 400, a light guide plate 300 coupled to the light source unit 400, a reflective plate 500 provided under the light guide plate 300, and an upper portion of the light guide plate 300. A plurality of optical sheets 600, and a reflecting plate 500, a light guide plate 300 and a mold frame 700 for receiving the optical sheet 600 in sequence.

The light source unit 400 includes a lamp 410 and a lamp cover 420, and is located on at least one side of the light guide plate 300. The lamp 410 may include an electroluminescent lamp (EL), a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), or the like. In addition, the lamp cover 420 is formed in an elliptic shape having an opening on one side, and surrounds a part of the lamp 410 so that the light generated by the lamp 410 is in one direction, that is, the mouth of the light guide plate 300. It serves to reflect to the miner. In the drawing, the light source unit 400 is installed on one side of the light guide plate 300, but may be installed on both sides of the light guide plate 300.

The light guide plate 300 is formed in a square or rectangular plate shape, and an optical pattern 330 formed of a plurality of prism mountains is formed in a central region of the upper surface of the light guide plate 300, that is, a region other than a circumferential region. . The light guide plate 300 serves to change light having an optical distribution in the form of a point light source or a linear light source into light having an optical distribution in the form of a surface light source. The light guide plate 300 will be described in detail later with reference to the drawings.

The reflective plate 500 is provided under the light guide plate 300 to reflect light emitted from the light guide plate 300. In this case, it is preferable that the reflective plate 500 uses a plate having a high light reflectance.

The optical sheet 600 includes one diffusion sheet 610 and a plurality of prism sheets 620 and plays a role of supplying light to the liquid crystal display panel 100 by securing luminance characteristics of the light. In this case, the prism sheet 620 may be omitted.

The mold frame 700 is formed in a rectangular frame shape of a rectangular parallelepiped in which upper and lower portions are opened, and accommodates the light source unit 400 and the plurality of optical sheets 300, 500, and 600 described above, and an upper portion of the mold frame 700. The liquid crystal display panel 100 is mounted thereon.

In addition, although not shown in the drawings, upper and lower cases may be further provided to protect the liquid crystal display panel 100 and the backlight assembly 2000 stacked as described above.

On the other hand, as shown in Figure 2, the light guide plate 300 according to the present invention is a plate having a square or rectangular shape, the first region 310, which is the central region of the upper surface of the light guide plate 300, and The second region 320 is formed to surround the first region 310.

The first region 310 has a size corresponding to the active region 130 of the liquid crystal display panel 100 displaying an image, and a plurality of prism mountains 330 protruding upward from the first region 310. The continuous prism acid 330 forms a single optical pattern.

The second region 320 is a range of a predetermined interval from an edge of the light guide plate 300, and corresponds to a region other than the active region 130 of the liquid crystal display panel 100, and the second region 320 is a mold frame ( 700 is stored. In this case, the width A of one side of the second region 320 is 1 to 3 mm, preferably 2 mm, and the width B of the other side of the second region 320 perpendicular to one side is 2 to 5 mm. Preferably it is formed to 3mm.

That is, the width A of one side of the second region is an area where the lamp cover 420 is coupled to the light guide plate 300, and the width B of the other side of the second area 320 is specifically, a mold frame. It is an area seated at 700.

Therefore, the optical pattern formed in the first region 310 of the light guide plate 300 may collect light to increase the light collecting efficiency, thereby efficiently supplying light to the active region 130 of the liquid crystal display panel 100. It is possible to increase the brightness of the light to increase the light efficiency.

In this case, the optical pattern formed in the first region 310 may be formed as shown in FIGS. 3 to 5.

That is, as shown in FIG. 3, the optical pattern may form a concave groove inward of an upper surface of the light guide plate 300, and specifically, may be inward in the first region 310 of the light guide plate 300. The prism acid optical pattern 340 may be formed by continuously arranging a plurality of prism-shaped prism mountains.

In addition, as shown in FIG. 4, the optical pattern is formed to protrude upward from the light guide plate 300, and specifically, a plurality of hemispheres protruding upward from the first region 310 of the light guide plate 300. An optical pattern may be formed by continuously arranging a lenticular optical pattern 350 having a shape. In this case, although the lenticular optical pattern 350 is formed to protrude upwards, the lenticular optical pattern 350 may be formed inside the first region 310 of the light guide plate 300. In addition, the pitch (C) of the lenticular optical pattern may be formed from 20 micrometers to 100 micrometers, preferably 60 micrometers.

In addition, as shown in FIG. 5, the optical pattern forms a plurality of ellipses on the light guide plate 300, specifically, a plurality of ellipses in a row direction in the first region 310 of the light guide plate 300. The microlens optical pattern 360 can be formed by arranging the 360s and arranging the plurality of ellipses 360 in the column direction. In this case, the microlens optical pattern may be formed to protrude upward or to concave inward in the first region 310 of the light guide plate 300. In addition, in the above, although the formation of the microlens is shown as an ellipse, it can be formed in various shapes such as a circle having a constant diameter.

Although the range of pitch in the lenticular optical pattern 350 has been mentioned above, the range of pitch may be applied to the prism scattering optical patterns 330 and 340 and the microlens optical pattern 360 as well.

Therefore, the structure of the light guide plate 300 as described above is formed to correspond to the active region 130 of the liquid crystal display panel 100, thereby efficiently emitting light by the optical pattern formed in the first region 310 of the light guide plate 300. The light efficiency of the active area 130 of the liquid crystal display panel 100 may be increased.

6 is a graph illustrating luminance distribution test data of a light guide plate according to the related art and a light guide plate according to the present invention. At this time, the vertical axis represents the luminance, and the horizontal axis represents the experimental measurement point. In addition, the third region of the experimental measurement point represents a center which is the center of the light guide plate, and the first, second, fourth, and fifth regions represent regions separated by a predetermined distance from the third region.

That is, as shown in FIG. 6, when the optical pattern is formed on the entire upper portion of the conventional light guide plate, and when the optical pattern is formed in the first region 310 of the light guide plate 300 according to the present invention;

In the third region, which is the central region of the light guide plate 300, the luminance D of the conventional light guide plate was 175.8 nit, whereas the luminance E of the light guide plate 300 according to the present invention was measured to be 182.4 nit. Accordingly, it can be seen that the luminance E of the light guide plate 300 according to the present invention is improved by 5.2% compared to the luminance C of the conventional light guide plate.

In addition, the average value of the luminance in the first to fifth regions was 164.8 nit, and the average value of the luminance E of the light guide plate 300 according to the present invention was measured to be 173.3 nit. . Therefore, it can be seen that the average value of the luminance E of the light guide plate 300 according to the present invention is improved by 3.7% compared to the average value of the luminance D of the conventional light guide plate.

In addition, when looking at the uniformity of the luminance in the first to fifth regions, the luminance D uniformity of the conventional LGP was 3.07, while the luminance E uniformity of the LGP 300 was 2.54. Therefore, it can be seen that the luminance E uniformity of the light guide plate 300 according to the present invention is improved compared to the luminance D uniformity of the conventional light guide plate.

Therefore, it can be seen that the structure having the optical pattern formed in the first region 310 of the light guide plate 300 according to the present invention has improved light efficiency than the structure of the conventional light guide plate.

In the above, various optical patterns are formed in the first region 310 on the light guide plate 300, but the optical patterns may be formed on the lower part of the light guide plate 300 corresponding to the active region 130 of the liquid crystal display panel 100. In addition, the optical pattern may be formed on the upper and lower portions.

In addition, in the above, although the optical pattern is formed on one surface of the light guide plate 300, the optical pattern is not limited thereto and may be formed on at least one surface of the reflective plate and the optical sheet.

In addition, although the flat light guide plate has been described above, it can be applied to the wedge type light guide plate.

In addition, although applied to the backlight assembly using the edge-type light source in the above, it can be applied to the backlight assembly in which the direct type light source is used.

Although described above with reference to the drawings and embodiments, those skilled in the art that the present invention can be variously modified and changed within the scope without departing from the spirit of the invention described in the claims below. I can understand.

As described above, the light guide plate according to the present invention, a backlight assembly and a liquid crystal display device having the same, are formed so as to correspond to an active region of the liquid crystal display panel displaying an image with an optical pattern formed on one surface of the light guide plate. Therefore, there is an effect of increasing the brightness of the light.

Moreover, this invention has the effect which can raise the uniformity of the light provided to the active area of a liquid crystal display panel.

In addition, the present invention does not form an optical pattern on the part in contact with the lamp cover and the component, there is an effect that can improve the appearance characteristics.

Claims (12)

With base plate, Light guide plate, characterized in that the optical pattern is formed spaced apart from the edge of the base plate. The light guide plate of claim 1, wherein the optical pattern is formed on at least one of an upper surface and a lower surface of the base plate. The light guide plate according to claim 2, wherein the optical pattern is a prism acid optical pattern formed by continuously arranging prism acids. The light guide plate according to claim 2, wherein the optical pattern is a lenticular optical pattern formed by successively arranging hemispheres. The light guide plate according to claim 2, wherein the optical pattern is a micro lens optical pattern formed by continuously arranging ellipses or circles. The light guide plate according to any one of claims 1 to 5, wherein the pitch of the optical pattern has a length of 20 micrometers to 100 micrometers. The light guide plate according to any one of claims 1 to 5, wherein the optical pattern is formed to protrude or concave above the base plate. A light source unit and an optical sheet for controlling light from the light source unit, And an optical pattern formed on at least one surface of the optical sheet at a predetermined distance from an edge thereof. The backlight assembly of claim 8, wherein the optical sheet is a light guide plate. A liquid crystal display panel including an active area for displaying an image, a light source unit for generating light, and an optical sheet for providing light from the light source unit to the liquid crystal display panel, And an optical pattern formed on at least one surface of the optical sheet at a predetermined interval from an edge thereof. The liquid crystal display of claim 10, wherein the optical pattern is formed to correspond to the active region. The liquid crystal display device according to claim 11, wherein the optical sheet is a light guide plate.

Images