KR101939767B1 - Liquid crystal display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly to a liquid crystal display having improved efficiency of a light guide plate.
The feature of the present invention is that the light guide plate of the backlight unit is formed so that the lower surface thereof has a certain inclination toward the upper surface toward the central portion from the light incoming portion.
As a result, a larger amount of light can be spread to the center of the light guide plate, thereby improving the brightness of the central portion of the light guide plate, thereby realizing a more uniform planar light source and improving the efficiency of the light guide plate.
Further, the lenticular lens formed on the lower surface is formed at a high density per unit area as the lenticular lens toward the center of the light guide plate, so that the luminance of the central portion of the light guide plate can be further improved.
This makes it possible to provide a backlight unit of high brightness without adding a light source and an optical sheet, thereby improving the brightness of the liquid crystal display device.

Description

[0001] Liquid crystal display device [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display, and more particularly to a liquid crystal display having improved efficiency of a light guide plate.

A liquid crystal display device (LCD), which is advantageous for moving picture display and has a large contrast ratio and is actively used in TVs and monitors, has optical anisotropy and polarization properties, And the like.

Such a liquid crystal display device has a liquid crystal panel in which a liquid crystal panel is interposed between two adjacent substrates through a liquid crystal layer as an essential component and changes the alignment direction of the liquid crystal molecules in an electric field in the liquid crystal panel to realize a difference in transmittance do.

However, since the liquid crystal panel does not have its own light emitting element, a separate light source is required to display the difference in transmittance as an image. To this end, a backlight having a light source is disposed on the back surface of the liquid crystal panel.

The backlight of the liquid crystal display device is classified into a direct type and an edge type according to the arrangement of light sources. In the edge type, one or a pair of light sources is divided into one side of the light guide plate and two or two pairs The light source has a structure in which the light sources are disposed on both side portions of the light guide plate, and the direct light type structure has a structure in which several light sources are disposed under the liquid crystal panel.

In this case, the direct type type is mainly used in a liquid crystal display device in which lightness and thinness are limited and brightness is more important than the thickness and weight of the screen, and the edge type, which is lightweight and thinner than direct type, Is mainly used in a liquid crystal display device in which thickness and weight such as a PC are important.

In recent years, studies on lightweight and thin liquid crystal display devices have been actively carried out, and research on edge type backlights has been actively conducted.

In addition, a liquid crystal display device has proposed a backlight scanning driving method in which a plurality of light sources are sequentially turned on / off to provide a more vivid image, and light is supplied to specific areas of a liquid crystal panel.

Accordingly, the contrast ratio can be improved by making the bright image brighter or the dark image darker, thereby realizing a more vivid image.

Therefore, in recent years, a lenticular lens layer is formed on the upper surface of the light guide plate to improve the straightness of the light incident into the light guide plate, thereby allowing the light guide plate to be divided into a plurality of areas, thereby realizing a lightweight, thin and edge- Type backlight.

In recent years, there has been a growing demand for liquid crystal displays of high resolution and high brightness. However, when the number of light sources of the backlight unit is increased or the number of optical sheets is increased in order to realize high brightness, .

In recent years, studies have been actively made to provide a backlight unit of high luminance without increasing the number of light sources or optical sheets by improving the efficiency of the light guide plate.

SUMMARY OF THE INVENTION It is a first object of the present invention to provide a liquid crystal display device of high brightness and at the same time to provide a lightweight and thin liquid crystal display device.

A second object of the present invention is to realize a display screen of a liquid crystal display device with high uniformity of luminance.

In order to achieve the above-mentioned object, the present invention provides a liquid crystal display comprising: a reflection plate; A light guide plate which is seated on the reflection plate and is formed to have a predetermined inclination toward the upper surface as the lower surface faces the center portion from the light incident surface; An LED assembly arranged along the light incident surface of the light guide plate; An optical sheet that is seated on the light guide plate; And a liquid crystal panel mounted on the optical sheet.

At this time, the light guide plate includes first and second light incidence surfaces on which light is incident, an upper surface on which light is emitted, a lower surface facing the reflection plate, and opposite side surfaces facing each other, The thickness of the center portion of the light guide plate is greater than the thickness of the center portion, and the thickness of the center portion of the light guide plate is 1/2 of the thickness of the first and first light incident surfaces.

In addition, the lower surface may include a pattern in which the density becomes higher toward the central portion from the light incidence surface, and the pattern may be a lenticular lens layer in the form of an obtuse-angled lenticular lens with repeated cross- Prism lens layer.

The pattern is a selected one of an elliptical pattern, a polygon pattern, and a hologram pattern, and the pattern is formed at a predetermined interval from the light incidence surface.

The predetermined interval may be a flat portion parallel to the upper surface, and the lower surface may connect the first and second inclined portions to the first and second inclined portions formed to have a predetermined inclination toward the upper surface, And a flat portion corresponding to a central portion of the light guide plate, and the pattern is formed on the first and second inclined portions.

A lens pattern is formed on the flat portion, and the pattern is formed at a predetermined interval from the light incidence surface.

The back surface of the lower surface is provided with a light guide plate supporting portion corresponding to the shape of the lower surface.

The predetermined interval may be a flat portion parallel to the upper surface, and the lenticular lens layer may be formed on the upper surface of the lenticular lens layer so as to be perpendicular to the lenticular lens layer or the prism lens layer.

At this time, the optical sheet is a diffusion sheet and a light condensing sheet, and includes a support main which surrounds the edge of the liquid crystal panel, a cover bottom which is in close contact with the support main back surface, And a top cover to be joined.

As described above, according to the present invention, the light guide plate of the backlight unit is formed such that the lower surface thereof has a certain inclination toward the upper surface as it goes from the light incoming portion toward the central portion, whereby a larger amount of light spreads to the central portion of the light guide plate By improving the brightness of the central portion of the light guide plate, a more uniform surface light source can be realized and the efficiency of the light guide plate can be improved.

In addition, the lenticular lens formed on the lower surface is formed with a high density per unit area as the lenticular lens toward the center of the light guide plate, so that the luminance of the center portion of the light guide plate can be further improved.

Accordingly, it is possible to provide a backlight unit of high brightness without adding a light source and an optical sheet, thereby improving the brightness of the liquid crystal display device.

1 is an exploded perspective view of a liquid crystal display device according to an embodiment of the present invention;
FIG. 2A is a perspective view schematically showing a light guide plate according to an embodiment of the present invention. FIG.
Fig. 2b is a bottom perspective view of Fig. 3a. Fig.
Figures 3A-3B are cross-sectional views schematically showing the modularized Figure 1;
4A to 4B are views for explaining backlight scanning driving through a backlight unit including a light guide plate according to an embodiment of the present invention.
5A to 5B are simulation results of comparative measurement of luminance of a liquid crystal display device including a general light guide plate and a liquid crystal display device including a light guide plate according to an embodiment of the present invention.
6A to 6C are bottom perspective views of a light guide plate according to a second embodiment of the present invention.
7A to 7B are bottom perspective views of a light guide plate according to a third embodiment of the present invention.

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

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

The liquid crystal display device includes a liquid crystal panel 110 and a backlight unit 120 and includes a top cover 140 for modularizing the liquid crystal panel 110 and the backlight unit 120, ), And a cover bottom 150.

Let's take a closer look at each of these.

First, the liquid crystal panel 110 plays a key role in image display of a liquid crystal display device. The liquid crystal panel 110 includes a first substrate 112 and a second substrate 114 which are bonded to each other and a liquid crystal layer (Not shown).

Although not shown in the drawing, a plurality of gate lines and data lines intersect each other on the inner surface of a first substrate 112 called a lower substrate or an array substrate, pixels are defined, and thin- and a thin film transistor (TFT), which are connected in a one-to-one correspondence with the transparent pixel electrodes formed in the respective pixels.

On the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, color filters of red (R), green (G), and blue (B) And a black matrix for covering the gate lines, the data lines, and the thin film transistors.

In addition, color filters of red (R), green (G), and blue (B) colors and transparent common electrodes covering the black matrix are provided.

A polarizing plate (not shown) for selectively transmitting only specific light is attached to the outer surfaces of the first and second substrates 112 and 114, respectively.

A printed circuit board 117 is connected to at least one edge of the liquid crystal panel 110 via a connection member 116 such as a flexible circuit board or a tape carrier package (TCP) The support main body 130 or the cover bottom 150 is properly bent.

When the thin film transistor selected for each gate line is turned on by the on / off signal of the gate driving circuit, the liquid crystal panel 110 transmits the signal voltage of the data driving circuit to the corresponding pixel electrode through the data line. The alignment direction of the liquid crystal molecules in the liquid crystal layer is changed by the electric field between the pixel electrode and the common electrode to show a difference in transmittance.

In addition, a backlight unit 120 for supplying light to the back surface of the liquid crystal panel 110 is provided so that the difference in transmittance of the liquid crystal panel 110 is externally expressed.

The backlight unit 120 includes first and second LED assemblies 129a and 129b, a white or silver reflective plate 125, a light guide plate 200 mounted on the reflective plate 125, And a sheet 121.

The first and second LED assemblies 129a and 129b are positioned on opposite sides to face the first and second light incidence surfaces 201a and 201b of the light guide plate 200 and include a plurality of LEDs 127, And a PCB 128 on which a plurality of LEDs 127 are mounted with a predetermined spacing.

At this time, the plurality of LEDs 127 emit white light toward the light incoming surface of the light guide plate 200, including LED chips (not shown) that emit all the RGB colors or emit white light. The plurality of LEDs 127 emit light having colors of red (R), green (G) and blue (B), respectively. By lighting the plurality of RGB LEDs 127 at a time, white light It can also be implemented.

Here, the first and second LED assemblies 129a and 129b are independently driven by the respective LEDs 127, and can be divided into the LEDs 127 to perform block division driving.

That is, in order to display a more vivid image, the LCD 127 of the present invention is divided into a plurality of LEDs 127 along the longitudinal direction of the PCB 128, and each of the LEDs 127 is divided into a plurality of blocks It is possible to perform block division driving.

Accordingly, the first and second LED assemblies 129a and 129b of the present invention can implement a backlight scanning driving method that sequentially drives the LEDs 127 on and off.

Here, the backlight scanning driving is a driving method in which the block corresponding to the pixel is extinguished while the pixel is responding and the block is lighted after the response is completed. Each block is illuminated only for a predetermined time in each frame, Off.

By performing the backlight scanning drive through the blocks in which the respective LEDs 127 are divided and defined, only the light emitted for each block is supplied to the specific region of the liquid crystal panel 110 through the light guide plate 200, ) Can enhance the contrast ratio by brightening the bright image or making the dark image darker, thereby realizing a vivid image.

In addition, brightness suitable for an image can be adjusted, and an image with dark brightness has light of dark brightness, so that power consumption of the backlight unit 120 can be reduced.

The light guide plate 200 on which the light emitted from the first and second LED assemblies 129a and 129b is incident is formed such that the incident white light travels through the light guide plate 200 by total reflection several times and is incident on a specific area of the liquid crystal panel 110 And spreads evenly over a wide area of the corresponding light guide plate 200 to provide a surface light source to the liquid crystal panel 110.

In this case, when the first and second LED assemblies 129a and 129b are backlight-scanned and driven by the respective LEDs 127, the light incident to the inside of the light guide plate 200 is reflected by the light guide plate 200, The lenticular lens layer 210 is formed on the upper surface 201c of the light guide plate 200 so as not to overlap each other inside.

That is, the light incident from the first and second LED assemblies 129a and 129b into the light guide plate 200 through the lenticular lens layer 210 is improved in straightness, and the light guide plate 200 is divided into a plurality of areas .

Therefore, only the light emitted by each LED 127 can supply light to a specific region of the liquid crystal panel 110 through the divided region of the light guide plate 200.

Particularly, the light guide plate 200 of the present invention is formed such that the lower surface 201d is inclined toward the upper surface 201c formed with the lenticular lens layer 210 as the lower surface 201d is moved from the light entering portion toward the central portion. This improves the efficiency of the light guide plate 200.

Therefore, a more uniform surface light source can be supplied to the liquid crystal panel 110, and a larger amount of light can be supplied to the liquid crystal panel 110, thereby improving the brightness of the liquid crystal display device. Let me take a closer look at this later.

The reflection plate 125 is disposed on the back surface of the light guide plate 200 and reflects light passing through the back surface of the light guide plate 200 toward the liquid crystal panel 110 to improve the brightness.

The optical sheet 121 on the light guide plate 200 includes a diffusion sheet and at least one light collecting sheet and diffuses or condenses the light passing through the light guide plate 200 to form a more uniform surface light source to the liquid crystal panel 110 Let it enter.

The liquid crystal panel 110 and the backlight unit 120 are modularized through a top cover 140, a support main 130 and a cover bottom 150. The top cover 140 is disposed on the upper surface and the side surface of the liquid crystal panel 110, The top cover 140 is opened so that an image formed on the liquid crystal panel 110 is displayed.

The cover bottom 150 on which the liquid crystal panel 110 and the backlight unit 120 are mounted and the basis of assembling the entire structure of the liquid crystal display device includes a bottom surface which is in close contact with the back surface of the backlight unit 120.

The support main 130 mounted on the cover bottom 150 and having a rectangular frame shape covering the edges of the liquid crystal panel 110 and the backlight unit 120 is coupled with the top cover 140 and the cover bottom 150 .

Here, the top cover 140 may be referred to as a case top or a top case, and the support main 130 may be referred to as a guide panel or a main support or a mold frame, and the cover bottom 150 may be referred to as a bottom cover.

As described above, the liquid crystal display of the present invention is designed to drive the plurality of LEDs 127 of the first and second LED assemblies 129a and 129b, respectively, in spite of being a lightweight and thin edge type backlight unit 120. [ The liquid crystal display device capable of driving backlight scanning can realize a more vivid image display. Also, the power consumption of the backlight unit 120 can be reduced.

In particular, by forming the lower surface 201d of the light guide plate 200 to have a predetermined inclination, the efficiency of the light guide plate 200 can be improved. Accordingly, it is possible to provide the backlight unit 120 of high brightness without adding the light sources 129a and 129b and the optical sheet 121, thereby improving the brightness of the liquid crystal display device.

FIG. 2A is a perspective view schematically showing a light guide plate according to a first embodiment of the present invention, and FIG. 2B is a bottom perspective view of FIG. 2A.

As shown in the drawing, the light guide plate 200 may be made of a plastic material such as polymethylmethacrylate (PMMA) or polycarbonate (PC), which is one of acrylic transparent resins, which is one of transparent materials capable of transmitting light, PMMA is widely used because it has excellent transparency, weatherability and colorability, and induces light diffusion when light is transmitted.

The light guide plate 200 includes a first light incidence surface 201a corresponding to the first LED assembly (129a in FIG. 1) and a second light incidence surface (corresponding to 129b in FIG. 1) A lower surface 201d facing the reflector (125 in FIG. 1) and a lower surface 201d connecting the first and second light incidence surfaces 201a and 201b and emitting light, 201e, 201f.

The upper surface 201c of the light guide plate 200 is arranged adjacent to the first and second light incidence surfaces 201a and 201b of the light guide plate 200 so as to have a plurality of lenticules A lens 211 protrudes from the upper surface 201c to form a lenticular lens layer 210. [ At this time, each lenticular lens 211 has a hemispherical or semi-elliptical cross section.

Therefore, the light incident into the light guide plate 200 has high linearity due to the lenticular lens layer 210.

In this way, the light guide plate 200 can be divided for each lenticular lens 211 by improving the linearity of the light incident into the light guide plate 200 by the lenticular lens layer 210. [

1) of the LED assembly (129a and 129b in FIG. 1) is divided into blocks, and the liquid crystal panel (see FIG. 1) is driven through the lenticular lens layer 210 of the light guide plate 200, The light can be supplied only to a specific region of the light emitting diode 110. [

The lenticular lens layer 220 may be further formed on the lower surface 201d of the light guide plate 200 to provide a uniform surface light source corresponding to a specific area of the liquid crystal panel 110 .

The lenticular lens layer 220 formed on the lower surface 201d of the light guide plate 200 is formed on both sides 201e and 201f of the light guide plate 200 on the lower surface 201d of the light guide plate 200, And a plurality of lenticular lenses 221 having an oblique shape in which the mountains and the valleys are repeated in cross section.

That is, the lenticular lens layer 210 formed on the upper surface 201c of the light guide plate 200 and the lenticular lens layer 220 formed on the lower surface 201d are formed such that the arrangement of the patterns is perpendicular to each other .

Particularly, the lower surface 201d of the light guide plate 200 of the present invention is formed to have a certain inclination toward the upper surface 201c toward the center from the first and second light incidence surfaces 201a and 201b.

That is, the thickness of the light guide plate 200 becomes thinner from the light incident portion toward the center portion, and the first and second light incident surfaces 201a and 201b (see FIGS. 1 and 2) facing the first and second LED assemblies The thickness between the first and second light incidence surfaces 201a and 201b to the center portion has a second thickness t2 that is thinner than the first thickness t1, The thickness of the center portion of the light guide plate 200 is set to have a third thickness t3 that is thinner than the second thickness t2 so that the thickness of the light guide plate 200 is reduced from the first and second light incident surfaces 201a and 201b to the center (T1 > t2 > t3)

The first thickness t1 of the first and second light incidence planes 201a and 201b of the light guide plate 200 may be set to be a half of the first thickness t1. The third thickness t3 of the central portion of the light guide plate 200 is preferably 1.5 mm.

Accordingly, the efficiency of the light guide plate 200 is improved.

In detail, the light guide plate 200 exhibits a higher brightness of the light-incident portion where the first and second LED assemblies (129a and 129b in FIG. 1) are positioned than the brightness of the center portion, And the light incident through the second light incidence surfaces 201a and 201b are not uniformly spread in the light guide plate 200. [

Here, the efficiency of the light guide plate 200 can be confirmed by measuring the luminance of the planar light source realized through the light guide plate 200. The brightness of the light guide plate 200 is measured at each point of the liquid crystal display device in which the image is implemented. The point is a point corresponding to each corner portion and the center portion of the active region in which an image is displayed.

Therefore, in order to improve the efficiency of the light guide plate 200, the efficiency of the light guide plate 200 can be improved by improving the brightness of the central portion of the light guide plate 200. [

The light guide plate 200 according to the present invention is formed such that the lower surface 201d has a predetermined inclination toward the upper surface 201c as it goes from the light entering portion toward the center portion, The light incident into the light guide plate 200 through the light guide plate 200 is guided toward the center of the light guide plate 200 through the lower surface 201d of the light guide plate 200 having a predetermined inclination, So that a larger amount of light is spread out to the center.

That is, the light guide plate 200 of the present invention improves the brightness of the central portion of the light guide plate 200 by allowing the light incident into the light guide plate 200 to spread more evenly toward the central portion of the light guide plate 200. As a result, a more uniform planar light source can be realized and the efficiency of the light guide plate 200 can be improved.

The lenticular lens layer 220 formed on the lower surface 201d of the light guide plate 200 is formed so that the density of the lenticular lens 221 increases from the light incident portion of the light guide plate 200 toward the center portion of the light guide plate 200, It is preferable to form it at a high density.

That is, from the light entering portion of the light guide plate 200 where the first and second LED assemblies (129a and 129b of FIG. 1) are positioned, the lenticular lens 221 of the lenticular lens layer 220 ) Is dense.

More specifically, the lenticular lenses 221 formed on the lower surface 201d of the light incident portion of the light guide plate 200 having the first thickness t1 are spaced apart from each other with a first distance d1, The lenticular lens 221 formed on the lower surface 201d of the light guide plate 200 having the second thickness t2 between the light entrance portion of the light guide plate 200 and the center portion of the light guide plate 200 is narrower than the first distance d1 So as to have a second interval d2.

The lenticular lens 221 formed on the lower surface 201d of the central portion of the light guide plate 200 may have a third interval d3 narrower than the second interval d2, (D1 > d2 > d3)

Here, as the size of the lenticular lens 221 on the lower surface of the light guide plate 200 is small or dense, more light incident into the light guide plate 200 can be directed toward the liquid crystal panel (110 in Fig. 1).

That is, in the light guide plate 200 of the present invention, the lenticular lens 221 formed on the lower surface 201d is formed at a high density per unit area toward the central portion of the light guide plate 200, The luminance of the central portion of the light guide plate 200 can be further improved by increasing the amount of light emitted to the light guide plate (110 in Fig. 1).

The light guide plate 200 according to the present invention is formed such that the lower surface 201d has a certain inclination toward the upper surface 201c as it goes from the light entrance portion toward the center portion, The lenticular lens 221 formed on the lower surface 201d of the light guide plate 200 is guided toward the center of the light guide plate 200 so that a larger amount of light is emitted to the central portion of the light guide plate 200, It is possible to further improve the brightness of the center portion of the light guide plate 200 by increasing the amount of light emitted to the liquid crystal panel (110 in FIG. 1) through the central portion of the light guide plate 200.

Accordingly, a more uniform planar light source can be realized and the efficiency of the light guide plate 200 can be improved.

This makes it possible to provide a backlight unit (120 of FIG. 1) of high luminance without adding a light source (129a, 129b of FIG. 1) and an optical sheet (121 of FIG. 1) have.

Figures 3A-3B are cross-sectional views schematically illustrating the modularized Figure 1.

The first and second LED assemblies 129a and 129b formed on both sides of the light guide plate 200 and including the LED 127 and the PCB 128, The optical sheets 121 are stacked on the light guide plate 200 to form the backlight unit 120.

A liquid crystal panel 110 in which a liquid crystal layer (not shown) is interposed between the first and second substrates 112 and 114 and the first and second substrates 112 and 114 are disposed on the backlight unit 120, And 114 are attached with polarizing plates 119a and 119b selectively transmitting only specific light.

The backlight unit 120 and the liquid crystal panel 110 are surrounded by the support main body 130. The cover bottom 150 is coupled to the backside of the backlight unit 120 and the top cover covering the top edge and the side surface of the liquid crystal panel 110 140 are coupled to the support main body 130 and the cover bottom 150.

The lenticular lens layer 210 is formed on the upper surface 201c of the light guide plate 200 and the lenticular lens layer 210 formed on the upper surface 201c and the lenticular lens layer 210 formed on the lower surface 201d of the light guide plate 200, A lenticular lens layer 220 made of a lenticular lens 221 in which the arrays are staggered perpendicular to each other is formed.

The lower surface 201d of the light guide plate 200 is formed to have a predetermined inclination toward the upper surface 201c from the first and second light incidence surfaces 201a and 201b toward the center, The lenticular lens 221 formed with the light guide plate 201d is formed at a high density per unit area toward the center portion of the light guide plate 200. [

The light incident from the LEDs 127 of the first and second LED assemblies 129a and 129b into the light guide plate 200 is guided by the lenticular lens layer 210 formed on the upper surface 201c of the light guide plate 200 It is possible to improve the contrast ratio by enhancing the straightness and driving the backlight scanning even though the lightweight thin edge type backlight unit 120 is used so that the bright image is made brighter or the dark image is made darker . Therefore, a living image can be realized.

The lower surface 201d of the light guide plate 200 is formed so as to have a certain inclination toward the upper surface 201c as it goes from the light entering portion toward the center portion, so that the light incident through the first and second light entering surfaces 201a and 201b 200 is guided to the central portion of the light guide plate 200 to improve the brightness of the central portion of the light guide plate 200. [

As a result, a more uniform planar light source can be realized and the efficiency of the light guide plate 200 can be improved.

The lenticular lens 221 formed on the lower surface 201d of the light guide plate 200 is formed at a high density per unit area toward the central portion of the light guide plate 200 so that the light is transmitted through the central portion of the light guide plate 200 to the liquid crystal panel 110 The luminance of the central portion of the light guide plate 200 can be further improved by increasing the amount of light to be emitted.

At this time, since the lower surface 201d of the light guide plate 200 is formed so as to have a certain inclination toward the upper surface 201c as it goes from the light incoming portion toward the central portion, the thickness (t3 in Fig. 3B, the center portion of the light guide plate 200 may have a characteristic of being weak against impacts as compared with the light-incident portion. In order to prevent this, It is preferable to further include a light guide plate supporting part 300 corresponding to the shape of the lower surface 201d of the light guide plate 200 as a back surface.

The light guide plate 300 may be made of any material and may be made of the same material or a transparent material as the light guide plate 200 so as to transmit light in order to improve the reflection efficiency of the reflection plate 125 located on the back surface of the light guide plate 300 Or it may be formed of a reflective plate 125 to eliminate the reflective plate 125 located on the back surface of the light guide plate 200. FIGS. 4A and 4B are views for explaining backlight scanning driving through a backlight unit including a light guide plate according to a first embodiment of the present invention. FIGS. 5A and 5B illustrate a liquid crystal display device including a general light guide plate, 1 is a graph illustrating a comparison result of brightness of a liquid crystal display device including a light guide plate according to an embodiment of the present invention.

As shown in the drawing, the light guide plate 200 of the present invention has the lenticular lens layer 210 formed on the upper surface (201c in FIG. 3B), so that light incident into the light guide plate 200 is guided by the lenticular lens layer 210 High straightness is obtained.

3B through the lenticular lens layer 210 of the light guide plate 200 in the process of dividing the plurality of LEDs 127 of the first and second LED assemblies 129a and 129b into blocks, 110). ≪ / RTI >

That is, as shown in FIG. 4A, the plurality of LEDs 127 of the first LED assembly 129a are connected to the first to sixth LED packages 124a, 124b, 124c, 124d, 124e, and 124f And the plurality of LEDs 127 of the second LED assembly 129b are divided into second to first to sixth LED packages 126a, 126b, 126c, 126d, 126e, and 126f.

The plurality of LED packages 124a, 124b, 124c, 124d, 124e, 124f, 126a, 126b, 126c, 126d, 126e, 126f of the first and second LED assemblies 129a, The first and second LED assemblies 129a and 129b are divided into a plurality of lenticular lenses 211 of the lenticular lens layer 210 provided on the top surface 201c of the first and second LED assemblies 129a and 129b, The LED package 124a and the 2-1 LED package 126a correspond to the first to third lenticular lenses 211 defined as D1 on the drawing of the lenticular lens layer 210. [

Accordingly, the light guide plate 200 corresponds to the LED packages 124a, 124b, 124c, 124d, 124e, 124f, 126a, 126b, 126c, 126d, 126e, 126f of the first and second LED assemblies 129a, D2, D3, D4, D5, and D6, respectively.

3B) 110 corresponding to the first area D1, the third area D3 and the fifth area D5 of the light guide plate 200, The LED packages 124a, 124c and 124e of the LED assemblies 129a and the LED packages 12-1, 12-2 and 12-5 of the second LED assemblies 129b, 1-4, and 1-6 LED packages of the first and second LED assemblies 129a and 129b, respectively, by turning on the LEDs 126a, 126c, and 126e to cause the light to enter the light guide plate 200. At this time, And the LED packages 126b, 126d, and 126f are turned off to prevent light from being incident into the light guide plate 200.

At this time, the light incident on the first area D1, the third area D3 and the fifth area D5 of the light guide plate 200 is incident on the upper surface (201c in FIG. 3B) of the light guide plate 200, The directivity is improved by the light guide plate 210 and is not incident on other neighboring areas of the light guide plate 200. [

That is, the light guide plate 200 is defined by dividing the light incident from the inside of the light guide plate 200 through the lenticular lens layer 210 into the light guide plate 200 so as not to overlap each other.

3B) corresponding to the first area D1, the third area D3 and the fifth area D5 of the light guide plate 200 is brightly displayed and the light emitted from the light guide plate 200 (110 in FIG. 3B) corresponding to the second region, the fourth region and the six regions D2, D4 and D6 of the light guide plate 200 are formed in the first region D1 of the light guide plate 200, (110 in FIG. 3B) corresponding to the fifth area D3 and the fifth area D5, the contrast ratio of the image can be improved.

1-4, 1-6 LED packages 124b, 124d, 124f of the first LED assembly 129a and the second LED assembly 124b, 124d, 124f of the second LED assembly 129b, as shown in FIG. 4B, The second, fourth, and sixth areas D2, D4, and D6 of the light guide plate 200 can be formed by lighting the LED packages 126a, 126b, 126d, and 126f, The third region D3 and the fifth region D5 of the light guide plate 200. The first region D1, the third region D3, and the fifth region D5 of the light guide plate 200, 3B) 110 corresponding to the second, fourth, and sixth regions D2, D4, and D6 of the light guide plate 200. The liquid crystal panel (110 of FIG. 3B) The contrast ratio of the image can be improved.

Accordingly, the liquid crystal display of the present invention is able to drive the backlight scanning even though the light type thin edge type backlight unit (120 in FIG. 3B) is used, thereby brightening the bright image or making the dark image darker, The contrast ratio can be improved. Therefore, a living image can be realized.

The light guide plate 200 of the present invention is formed such that the lower surface 201d of FIG. 3b has a certain inclination toward the upper surface (201c of FIG. 3b) from the light entering portion toward the central portion, The light emitted from the light guide plate 200 is guided toward the center of the light guide plate 200 so that a larger amount of light is spread to the central portion of the light guide plate 200 and the lenticular lens 3b are formed at a high density per unit area toward the central portion of the light guide plate 200 to increase the amount of light emitted to the liquid crystal panel 110 of the light guide plate 200 through the central portion of the light guide plate 200, The luminance of the central portion can be further improved.

Accordingly, a more uniform planar light source can be realized and the efficiency of the light guide plate 200 can be improved.

The following Tables (1) and (5a) to (5b) show simulation results of luminance of a liquid crystal display device including a general light guide plate and a liquid crystal display device including the light guide plate according to the first embodiment of the present invention.

division Sample 1 Sample 2 Luminance average value 279.8 lm (100%) 321.9 lm (115%)

5A and 1 show a liquid crystal display device including a general light guide plate, and FIG. 5B shows a sample 2 in which the lower surface (201d in FIG. 3B) according to the first embodiment of the present invention is moved from the light- And a light guide plate 200 formed to have a predetermined inclination toward the upper surface (201c in Fig. 3B).

The luminance of the table (1) is obtained by digitizing the average of the luminance values corresponding to the respective points of the liquid crystal display device in which the image is implemented, and each point is a point corresponding to each corner of the active area Is a value obtained by measuring the luminance of light in the light source.

Referring to Table 1, when the luminance average value of 279.8 lm of sample 1 is defined as the luminance of 100%, the luminance average value of sample 2 is 321.9 lm and has a luminance of 115%.

That is, it can be seen that the luminance of the sample 2 is improved by 15% as compared with the luminance of the sample 1.

5A to 5B, it can be seen that, in the case of a liquid crystal display device including a general light guide plate, the brightness of the light-incident portion of the light guide plate where the first and second LED assemblies are located is higher than the brightness of the center portion of the light guide plate In the case of the liquid crystal display device including the light guide plate 200 according to the first embodiment of the present invention, the brightness of the central portion and the brightness of the light entrance portion of the light guide plate 200 are similar.

This is because the lower surface (201d in FIG. 3B) of the light guide plate 200 of the present invention is formed so as to have a certain inclination toward the upper surface (201c in FIG. 3B) from the light entering portion toward the central portion, The light emitted from the light guide plate 200 is guided toward the center of the light guide plate 200 so that a larger amount of light is spread to the central portion of the light guide plate 200 and the lenticular lens The amount of light emitted to the liquid crystal panel (110 of FIG. 3B) is increased through the central portion of the light guide plate 200 to increase the amount of light emitted from the light guide plate 200 toward the central portion of the light guide plate 200, The brightness of the central portion is improved.

Accordingly, the light guide plate 200 of the present invention can realize a more uniform planar light source and improve the efficiency of the light guide plate 200.

6A to 6C are bottom perspective views of a light guide plate according to a second embodiment of the present invention.

As shown in the drawing, the light guide plate 200 includes a first light incident surface 201a corresponding to the first LED assembly (129a in FIG. 3B) and a second LED assembly (129b in FIG. 3B) A lower surface 201d facing the reflective surface (125 in FIG. 3B) and the upper surface 201c connecting the first and second light incidence surfaces 201a and 201b and emitting light, And viewing sides 201e and 201f.

A lenticular lens layer 210 protruding from the upper surface 201c of the lenticular lens 211 is formed on the upper surface 201c of the light guide plate 200. The lower surface 201d of the light guide plate 200 is provided with an upper surface 201c, The lenticular lens layer 210 formed on the substrate 201c and the lenticular lens layer 220 made of a lenticular lens 221 having an oblique angle in which the arrangement of the patterns are perpendicular to each other are formed.

The lower surface 201d of the light guide plate 200 is formed to have a certain inclination toward the upper surface 201c toward the center from the first and second light incidence surfaces 201a and 201b.

At this time, the lenticular lens layer 220 of the negative shape formed on the lower surface 201d of the light guide plate 200 according to the second embodiment of the present invention is separated from the first and second light incidence surfaces 201a and 201b by a predetermined distance So as to be formed.

Therefore, the lower surface 201c of the light guide plate 200 on the side of the first and second light entrance surfaces 201a and 201b is partially exposed.

The light guide plate 200 according to the second embodiment of the present invention is configured such that light incident into the light guide plate 200 through the first and first light entrance surfaces 201a and 201b of the light guide plate 200 has a predetermined slope The brightness of the central portion of the light guide plate 200 is improved by guiding the light guide plate 200 toward the central portion of the light guide plate 200 through the lower surface 201d of the formed light guide plate 200. [

As a result, a more uniform planar light source can be realized and the efficiency of the light guide plate 200 can be improved.

The lenticular lens layer 220 is formed on the lower surface 201d of the light guide plate 200 so as to be spaced apart from the first and second light incidence planes 201a and 201b. It is possible to prevent the occurrence of light leakage in response to the light-incident portion of the light-

That is, in the light guide plate 200, a light leakage phenomenon occurs in which the light-incident portion where the first and second LED assemblies (129a and 129b in FIG. 3B) are visible is relatively bright compared with the other portions visually. Shaped lenticular lens layer 220 formed on the lower surface 201d of the light guide plate 200 is spaced apart from the first and second light incidence planes 201a and 201b by a predetermined distance, Can be prevented from being emitted to the upper portion of the light guide plate (200).

Therefore, it is possible to prevent light leakage from being generated in the light-incident portion of the light guide plate 200, and to prevent light leakage from occurring in response to the light-incident portion of the light guide plate 200, thereby realizing a more uniform surface light source So that a larger amount of light can be guided so as to be directed to the center of the light guide plate 200.

At this time, a portion of the lower surface 201d of the light guide plate 200 where the lenticular lens layer 220 is not formed is formed as a flat portion A parallel to the upper surface 201c as shown in FIG. 6C It is possible to further prevent the occurrence of light leakage at the light-incoming portion of the light guide plate 200. [

7A to 7B are bottom perspective views of a light guide plate according to a third embodiment of the present invention.

As shown in the drawing, the light guide plate 200 includes a first light incident surface 201a corresponding to the first LED assembly (129a in FIG. 3B) and a second LED assembly (129b in FIG. 3B) A lower surface 201d facing the reflective surface (125 in FIG. 3B) and the upper surface 201c connecting the first and second light incidence surfaces 201a and 201b and emitting light, And viewing sides 201e and 201f.

A lenticular lens layer 210 protruding from the upper surface 201c of the lenticular lens 211 is formed on the upper surface 201c of the light guide plate 200. The lower surface 201d of the light guide plate 200 is provided with an upper surface 201c, The lenticular lens layer 210 formed on the substrate 201c and the lenticular lens layer 220 made of a lenticular lens 221 having an oblique angle in which the arrangement of the patterns are perpendicular to each other are formed.

The lower surface 201d of the light guide plate 200 according to the third embodiment of the present invention is formed so as to have a predetermined inclination toward the upper surface 201c toward the center portion from the first and second light incidence surfaces 201a and 201b And a flat portion D parallel to the upper surface 201c of the light guide plate 200 corresponding to the central portion of the light guide plate 200. [

That is, the light guide plate 200 according to the third embodiment of the present invention has the lower surface 201d and the first and second inclined portions B and C inclined at a predetermined angle toward the upper surface 201c and the light guide plate 200, And a flat portion D connected to the first and second inclined portions B and C corresponding to the center portion of the flat portion D.

At this time, the lenticular lens layer 220 having a negative shape formed on the lower surface 201d of the light guide plate 200 is formed only on the first and second slopes B and C, and light is diffused in the flat portion D And a lens pattern 230 for total reflection is formed.

The light guide plate 200 according to the third embodiment of the present invention is formed such that light incident into the light guide plate 200 through the first and first light entrance surfaces 201a and 201b of the light guide plate 200 has a predetermined inclination The brightness of the central portion of the light guide plate 200 is improved by guiding the light guide plate 200 toward the center portion of the light guide plate 200 through the first and second inclined portions B and C of the light guide plate 200.

As a result, a more uniform planar light source can be realized and the efficiency of the light guide plate 200 can be improved.

The light guide plate 200 according to the third embodiment of the present invention is formed to have a flat portion D on the lower surface 201d corresponding to the center portion of the light guide plate 200 and to diffuse light to the flat portion D The light guided to the central portion of the light guide plate 200 is condensed through the first and second inclined portions B and C of the light guide plate 200 so that the light is guided to the upper portion of the light guide plate 200 It is possible to prevent the light from being emitted to the outside.

That is, when too much light is guided to the central portion of the light guide plate 200 through the first and second inclined portions B and C, the central portion of the light guide plate 200 is visually relatively bright compared to other portions The light guide plate 200 according to the third embodiment of the present invention has the flat portion D on the lower surface 201c corresponding to the center portion of the light guide plate 200 and the flat portion D So that the light guided to the center of the light guide plate 200 is diffused.

Accordingly, it is possible to prevent light leakage from occurring in the central portion of the light guide plate 200, thereby realizing a more uniform surface light source.

The third embodiment of the present invention is also characterized in that the lenticular lens layer 220 having a negative angular shape formed on the first and second inclined portions B and C of the light guide plate 200 has the first and second light incidence surfaces 201a, 201b of the light guide plate 200 to prevent light leakage of the light incident portion of the light guide plate 200 and to prevent the light leakage of the light guide plate 200 due to the lenticular shape of the first and second inclined portions B, It is also possible to form the portion where the lens layer 220 is not formed to form a flat portion (A in Fig. 6C) parallel to the upper surface 201c. As described above, in the liquid crystal display of the present invention, the light guide plate 200 of the backlight unit (120 of FIG. 3B) is adjusted so that the lower surface 201d has a certain inclination toward the upper surface 201c as it goes from the light- The light incident into the light guide plate 200 is guided toward the central portion of the light guide plate 200 so that a larger amount of light is spread to the center portion of the light guide plate 200. [

Accordingly, by improving the brightness of the central portion of the light guide plate 200, a more uniform planar light source can be realized and the efficiency of the light guide plate 200 can be improved.

The lenticular lens 221 formed on the lower surface 201d of the light guide plate 200 is formed at a high density per unit area toward the central portion of the light guide plate 200 so that the liquid crystal panel The luminance of the central portion of the light guide plate 200 can be further improved.

Thus, it is possible to provide a high-brightness backlight unit (120 in FIG. 3B) without adding the light sources 129a and 129b and the optical sheet 121 (FIG. 3B), thereby improving the brightness of the liquid crystal display device.

Although the light guide plate 200 having the lenticular lens layer 210 formed on the upper surface 201c has been described in the above description, the present invention is not limited to the flat light guide plate 200 having the lenticular lens layer 210 formed therein. The configuration of the light guide plate 200 is also applicable.

A prism lens layer (not shown) may be formed on the lower surface 201d of the light guide plate 200 in addition to the lenticular lens layer 220 having a negative lens shape. At this time, a prism lens layer (not shown) At this time, the acid of the prism lens layer (not shown) may have a sharp corner or a round shape so as to have a radius of curvature.

In addition to the lens layer, a pattern such as an elliptical pattern, a polygon pattern, and a hologram pattern may be formed.

Although the LED assemblies 129a and 129b, which are the light sources of the backlight unit 120 in FIG. 3B, are positioned on both sides of the light guide plate 200, the liquid crystal display device of the present invention includes LED assemblies 129a and 129b, Is disposed on only one side of the light guide plate 200 is also applicable.

2), a support main (130 in Fig. 2), and a cover bottom (150 in Fig. 2) modularizing the liquid crystal panel (110 in Fig. 2) and the backlight unit One can be deleted to implement the lightweight and thinness required recently.

The present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

200: light guide plate, 201a, 201b: first and second light incidence surfaces
201c: upper surface, 201d: lower surface, 201e, 201f: side surface
210: lenticular lens layer, 220: intaglio-shaped lenticular lens layer, 221: lenticular lens

Claims (16)

A reflector;
A light guide plate that is seated on the reflection plate and is formed to have a predetermined inclination toward the upper surface from the first and second light incidence surfaces toward the central portion;
An LED assembly arranged along the light incident surface of the light guide plate;
An optical sheet that is seated on the light guide plate;
And a liquid crystal panel
/ RTI >
Wherein the lower surface includes a pattern in which the density becomes higher toward the central portion from the light incidence surface,
Wherein the lower surface comprises first and second inclined portions formed to have a predetermined inclination toward the upper surface and a flat portion corresponding to the central portion of the light guide plate and connecting the first and second inclined portions, 1 and the second inclined portion.
The method according to claim 1,
Wherein the light guide plate is provided with the first and second light incidence surfaces on which light is incident, the upper surface on which light is emitted, the lower surface facing the reflection plate, and both opposite sides facing each other, and the thickness of the first and second light incidence surfaces Is thicker than the thickness of the central portion.
3. The method of claim 2,
Wherein a thickness of the center portion of the light guide plate is 1/2 of a thickness of the first and second light incidence planes.
delete The method according to claim 1,
Wherein the pattern is a lenticular lens layer in the form of an obtuse-angled lenticular lens in which mountains and valleys are repeated in cross-section, or a prismatic lens layer in an obtuse-angled shape with rounded corners.
The method according to claim 1,
Wherein the pattern is one selected from the group consisting of an elliptical pattern, a polygon pattern, and a hologram pattern.
The method according to claim 1,
Wherein the pattern is formed at a predetermined distance from the light incidence surface.
8. The method of claim 7,
Wherein the predetermined interval portion comprises a flat portion parallel to the upper surface.
delete The method according to claim 1,
And a lens pattern is formed on the flat portion.
delete delete The method according to claim 1,
And a light guide plate supporting portion corresponding to the shape of the lower surface is provided on a back surface of the lower surface.
6. The method of claim 5,
Wherein the lenticular lens layer is formed on the upper surface of the lenticular lens layer or the lenticular lens layer is perpendicular to the prismatic lens layer.
◈ Claim 15 is abandoned due to registration fee. The method according to claim 1,
Wherein the optical sheet is a diffusion sheet and a light condensing sheet.
◈ Claim 16 is abandoned due to registration fee. The method according to claim 1,
And a top cover covering the edge of the liquid crystal panel and being assembled to the support main and cover bottoms. The liquid crystal display device of claim 1, wherein the support main and the bottom cover are integrally formed.

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