KR20130107608A - Liquid crystal display device - Google Patents

Abstract

PURPOSE: A liquid crystal display is provided to prevent a bowing phenomenon by using a support device for holding a diffusion plate. CONSTITUTION: A reflector is positioned in the upper part of an LED assembly. A first diffusion plate is separated from the upper part of the reflector at a first distance. A second diffusion plate is separated from the upper part of the first diffusion plate at a second distance. A backlight unit (120) is formed on the back surface of a liquid crystal panel (110). A support plate (200) maintains the second distance.

Description

[0001] LIQUID CRYSTAL DISPLAY DEVICE [0002]

The present invention relates to a direct type liquid crystal display device in which a light source is disposed below the liquid crystal panel.

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, exhibits optical anisotropy and polarization properties of a liquid crystal, And the like.

Such a liquid crystal display is an essential component of a liquid crystal panel bonded through a liquid crystal layer between two side-by-side substrates, and realizes a difference in transmittance by changing an arrangement direction of liquid crystal molecules with an electric field in the liquid crystal panel. do. A printed circuit board on which a driver integrated circuit for driving the liquid crystal panel is mounted is connected along at least one edge of the liquid crystal panel.

On the other hand, 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 unit having a light source is disposed on the back surface of the liquid crystal panel.

Such a backlight unit includes a light source and is divided into a direct type and an edge type according to the position of a light source.

A direct-type backlight unit is a method in which light emitted from a light source is directly supplied to a liquid crystal panel by disposing a light source under the liquid crystal panel. In a side-type backlight unit, a light guide plate is disposed under the liquid crystal panel, So that the light emitted from the light source is indirectly supplied to the liquid crystal panel by using refraction and reflection in the light guide plate.

Here, as a light source of the backlight unit, fluorescent lamps such as Cold Cathode Fluorescent Lamps (CCFLs) and External Electrode Fluorescent Lamps (EEFLs) have been widely used. BACKGROUND With light weight trends, light emitting diodes (LEDs), which have advantages in power consumption, weight, and brightness, are replacing fluorescent lamps.

When the LED is used as the light source, the direct type backlight unit is capable of local dimming driving to emit light of different luminance for each LED assembly by subdividing a plurality of LEDs, and the uniformity of the image quality is lateral type. Has an advantageous advantage over the backlight unit.

The direct type backlight unit includes a light source, a diffusion plate provided at a predetermined distance therefrom, and a plurality of optical sheets interposed thereon.

In this case, the diffuser plate is positioned to maintain a predetermined distance from the light source in order to diffuse the light from the light source widely, at which time the diffuser plate is struck as only the edge of the diffuser plate is supported and a uniform image cannot be realized in the liquid crystal display device. There is a problem.

SUMMARY OF THE INVENTION An object of the present invention for solving the above problems is to provide a liquid crystal display device having support means for preventing the diffusion plate from falling.

In addition, another object of the present invention is to provide a liquid crystal display device which can diffuse light emitted from each of a plurality of LEDs more widely without using a separate lens for each of the plurality of LEDs by using a double diffusion plate.

Liquid crystal display device according to the present invention for achieving the above object is a liquid crystal panel; An LED assembly, a reflector positioned on an upper portion of the LED assembly, a first diffuser positioned on a first interval and spaced apart from the upper portion of the reflector, and a second position positioned at a second interval on an upper portion of the first diffuser A backlight unit provided on a rear surface of the liquid crystal panel including a second diffusion plate and at least one optical sheet interposed between the second diffusion plate and the second diffusion plate; A cover bottom on which the backlight unit is seated; And a support plate positioned between the first diffusion plate and the second diffusion plate to maintain the second gap.

The support plate protrudes from a front surface thereof and is characterized in that it comprises a plurality of support parts for supporting the second diffusion plate.

In particular, the support plate has a rectangular frame shape, the cross-pattern crossing pattern is arranged in a repeating direction along the longitudinal direction therein, characterized in that the support is formed on the front of the cross point of the cross-pattern.

The support plate is made of one of polymethyl methacrylate (PMMA) and polymethacrylstyrene (MS) mixed with polymethyl methacrylate (PMMA) and polystyrene (PS). do.

The cover bottom may include a bottom portion having a rectangular plate shape, a first side portion vertically connected to the bottom portion, and a first support portion vertically connected to the first side portion to the outside to seat the first diffusion plate. And a second support part vertically connected to the first support part and a second support part vertically connected to the second side part to the outside so as to seat the second diffusion plate.

In addition, the support plate includes a coupling portion protruding from the back of each corner thereof, the first support portion of the cover bottom is characterized in that it comprises an insertion groove for inserting the coupling portion corresponding to the coupling portion.

In addition, a support pole for maintaining the first gap is further included between the reflecting plate and the first diffusion plate.

According to the liquid crystal display device according to the present invention, it is possible to prevent sagging by applying a support means capable of supporting the diffusion plate, thereby realizing a uniform image in the liquid crystal display device.

In addition, instead of the plurality of LED lenses that are provided corresponding to each of the plurality of LEDs, a rectangular plate-shaped diffuser plate is additionally provided to reduce component and assembly costs, thereby reducing the manufacturing cost of the entire liquid crystal display device, and assembling and disassembling process. It can be simplified.

1 is an exploded perspective view of a liquid crystal display according to a preferred embodiment of the present invention.
2 is a cross-sectional view of a liquid crystal display according to a preferred embodiment of the present invention.
3 is a perspective view of a support plate according to a preferred embodiment of the present invention.

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

1 is an exploded perspective view of a liquid crystal display according to a preferred embodiment of the present invention, Figure 2 is a cross-sectional view of the liquid crystal display according to a preferred embodiment of the present invention.

As shown in FIGS. 1 and 2, the liquid crystal display device 100 includes a liquid crystal panel 110, a backlight unit 120, and a support main for modularizing the liquid crystal panel 110 and the backlight unit 120. 130, the top cover 140, and the cover bottom 150.

The liquid crystal panel 110 is a part that plays a key role in image display and is composed of a first substrate 112 and a second substrate 114 which are bonded to each other with a liquid crystal layer interposed therebetween.

Although not shown in the drawing, a plurality of gate lines and data lines cross each other on the inner surface of a first substrate 112, which is usually referred to as a lower substrate or an array substrate, on the premise of an active matrix system, pixels are defined, And a thin film transistor (TFT) is provided and connected in a one-to-one correspondence with the transparent pixel electrode formed in each pixel.

On the inner surface of the second substrate 114 called an upper substrate or a color filter substrate, a color filter of red (R), green (G), and blue (B) A black matrix for covering non-display elements such as a gate line, a data line and a thin film transistor, and a transparent common electrode covering the gate lines and the data lines. Here, the transparent common electrode may be formed on the first substrate 112.

The first and second polarizers 119a and 119b selectively transmit only specific light to the outer surfaces of the first and second substrates 112 and 114, respectively.

Further, the printed circuit board 118 is connected and modularized along at least one edge of the liquid crystal panel 110 via a connecting member 116 such as a flexible circuit board or a tape carrier package (TCP). During the process, the side of the support main 130 or the cover bottom 150 is properly folded to be in close contact.

Accordingly, the liquid crystal panel 110 having the above-described structure is configured to have a data driving circuit when the thin film transistor selected for each gate line is turned on by an on or off signal of a gate driver circuit transmitted through the printed circuit board 118. The signal voltage is transmitted to the corresponding pixel electrode through the data line, and the arrangement direction of the liquid crystal molecules is changed by the electric field between the pixel electrode and the common electrode, thereby indicating a difference in transmittance.

On the rear surface of the liquid crystal panel 110, a backlight unit 120 is provided to supply light so that the difference in transmittance can be displayed as an image.

The backlight unit 120 may include a plurality of LED assemblies 129 disposed on the cover bottom 150, a reflector 121 disposed on the plurality of LED assemblies 129, and an upper portion of the reflector 121. First and second diffusion plates 123 and 124 and at least one optical sheet 126 interposed thereon.

Each of the plurality of LED assemblies 129 is formed by being mounted on a printed circuit board (PCB) 129b having a plurality of LEDs 129a spaced apart at regular intervals.

Here, the printed circuit board 129b on which the plurality of LEDs 129a are mounted may correspond to a metal core printed circuit board having a heat dissipation function.

There are a plurality of reflecting plates 121 formed with a plurality of first through holes 121a corresponding to each of the plurality of LEDs 129a included in the plurality of LED assemblies 129 and through which each of the plurality of LEDs 129a can pass. Is positioned above the LED 129a.

As a result, the reflecting plate 121 is seated on the printed circuit board 129b, and each of the plurality of LEDs 129a passes through each of the plurality of first through holes 121a and is exposed.

The reflecting plate 121 is a white or silver plate covering the entire surface of the printed circuit board 129b and the entire inner surface of the cover bottom 150 except for each of the plurality of LEDs 129a, and the light emitted from each of the plurality of LEDs 129a. Some of the light directed toward the cover bottom 150 is reflected toward the liquid crystal panel 110.

In the upper portion of the reflecting plate 121, a first diffusion plate 123 for diffusing light emitted from each of the plurality of LEDs 129a is positioned in a state spaced apart from the first interval A1, and the first diffusion plate ( In the upper portion of the 123, the second diffusion plate 124 is positioned to be spaced apart from the second interval A2 to maintain uniformity of luminance.

At this time, the second diffusion plate 124 is provided with a size larger than the first diffusion plate 123 is spaced apart from the first diffusion plate 123 and the second interval (A2), the cover bottom 150 to be described later It is seated on the second support 156.

The second diffusion plate 124 is typically emitted from each of the plurality of LEDs (129a) in place of the LED lens used on top of each LED to guide the path of light emitted from each of the plurality of LEDs (129a). It spreads light evenly and widely. Since the LED lenses are provided in a number corresponding to each LED, this increases the component cost, assembly and disassembly costs, and the assembly and disassembly procedures are complicated. However, the second diffusion plate 124 according to the present invention has a large number of LED lenses. Compared to the LED lens, it is inexpensive and has a single square plate, which can reduce component cost, assembly and disassembly cost, and simplify the assembly and disassembly procedure.

Each of the first and second diffusion plates 123 and 124 is usually made of relatively inexpensive polystyrene (PS). When the polystyrene forms perforations for penetrating insertion, cracking or cracking may occur.

Accordingly, in the present invention, the first interval A1 between the reflecting plate 121 and the first diffusion plate 123 and the second interval A2 between the first diffusion plate 123 and the second diffusion plate 124 are uniform. In order to maintain the support pole 180 and the support plate 200 is characterized by using each.

In more detail, at least one support pole 180 is provided between the reflecting plate 121 and the first diffusion plate 123, and the first diffusion plate 123 and the second diffusion plate 124 are provided. At least one support plate (support plate 200) is provided between.

The support pole 180 is inserted in the direction toward the liquid crystal panel 110 from the rear surface of the cover bottom 150 is hooked or screwed to be fixed to the cover bottom 150, the first diffusion plate 123, in particular It serves to support the center portion of the first diffusion plate 123 so as not to fall in the direction toward the cover bottom 150.

At this time, the support pole 180 is preferably disposed at a position that does not interfere with the light emitted from each of the plurality of LED (129a). In addition, the reflective plate 121 is preferably provided with a second through hole through which the support pole 180 can pass.

In addition, the support plate 200 is mounted on the upper portion of the first diffusion plate 123 and serves to support the second diffusion plate 124 so as not to be struck in the direction toward the cover bottom 150. Is provided with a coupling portion 250 and the front portion is provided with a support 270. The detailed structure thereof will be described later in detail.

In addition, at least one optical sheet 126 is disposed above the second diffusion plate 124 to collect light to allow a more uniform surface light source to enter the liquid crystal panel 110.

In this case, as the optical sheet 126, various functional sheets such as a reflective polarizing film called DBEF (dual brightness enhancement film) may be used.

Accordingly, the light emitted from each of the plurality of LEDs 129a is spread more widely through the first and second diffusion plates 123 and 124, and then sequentially passes through the at least one optical sheet 126, and then the liquid crystal panel. Incident on the 110, the liquid crystal panel 110 displays the high luminance image to the outside.

The liquid crystal panel 110 and the backlight unit 120 are modularized through the top cover 140, the support main 130, and the cover bottom 150.

Here, the support main 130 has a rectangular frame shape and surrounds edges of the liquid crystal panel 110 and the backlight unit 120 to distinguish the liquid crystal panel 110 and the backlight unit 120.

The top cover 140 is a rectangular frame having a cross section bent in a shape to cover the top and side edges of the liquid crystal panel 110. The top cover 140 opens an entire surface of the top cover 140 to be implemented in the liquid crystal panel 110. Configure to display.

In addition, the cover bottom 150, which is the basis for assembling the entire apparatus of the liquid crystal display device 100, may include a bottom portion 152 having a rectangular plate shape, and a first side portion 153 vertically connected to the bottom portion 152. The first support part 154 which is vertically connected to the first side part 153 to the outside, the second side part 155 which is vertically connected to the first support part 154, and the second side part 155 to the outside The second support portion 156 is vertically connected to the second support portion 156 and the third side portion 157 connected vertically downward. In this case, the triple coupling structure of the first to third side portions 153, 155, and 157 spaced apart from each other is formed as only two edges of the bottom portion 152 facing each other, but not limited thereto. Can be formed on.

Here, a third through hole (not shown) is provided at the bottom portion 152 to support the hook pole 180 to be hooked and fastened and fixed. A plurality of LED assemblies 129 are provided on the front surface of the bottom portion 152. Is placed.

The first side part 153, the first support part 154, and the second side part 155 and the second support part 156 form a predetermined space in which the backlight unit 120 may be seated.

In more detail, the first diffusion plate 123 is seated on the first support part 154, and the first side surface part 153 has a first gap A1 between the reflector plate 121 and the first diffusion plate 123. Serves to maintain.

In addition, a second diffusion plate 124 is seated on the second support part 156, and the second side surface part 155 fills a second gap A2 between the first diffusion plate 123 and the second diffusion plate 124. It plays a role.

At this time, the first support 154 is formed with an insertion groove 154a into which the coupling portion 250 of the support plate 200 according to the present invention can be inserted and fastened.

The third side portion 157 supports the second support portion 156 and can be omitted.

The backlight unit including the LED assembly 129, the reflector 121, the first diffuser 123, the second diffuser 124, and the at least one optical sheet 126 on the cover bottom 150 having the structure ( 120 is seated together with the support pole 180 and the support plate 200 and the support main 130 is coupled to the upper portion thereof. Then, the liquid crystal panel 110 is seated, and the top cover 140 bordering the front edge thereof is coupled.

Accordingly, the liquid crystal panel 110 and the backlight unit 120 have a top frame 140 and a backlight unit surrounding the top edge of the liquid crystal panel 110 in a state where the edges are surrounded by the support main 130 having a rectangular frame shape. Cover bottom 150 covering the back of the 120 is coupled in front and rear, respectively, is integrated and modularized via the support main 130.

As a result of this modularization, the light emitted from each of the plurality of LEDs 129a of the backlight unit 120 is combined with the light reflected by the reflector 121 and the first and second diffusers 123 and 124 and at least one light source. After overlapping and mixing with each other by the optical sheet 226, the light is incident on the liquid crystal panel 110 as a surface light source. Through this, the liquid crystal panel 110 displays a high brightness image to the outside.

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

3 is a perspective view of a support plate according to a preferred embodiment of the present invention, see FIGS. 1 and 2.

As shown in FIG. 3, the support plate 200 may be formed of a coupling part 250 and a first support part (154 of FIGS. 1 and 2) of the cover bottom (150 of FIGS. 1 and 2). The support part 270 for supporting the diffuser plate 124 of FIG. 1 and FIG. 2 is provided.

The support plate 200 has a rectangular frame shape, and the inside of the support plate 200 has a cross pattern 200a intersecting diagonally along the longitudinal direction. By forming the cross pattern 200a therein, there is an advantage in that the material cost and the mold cost can be reduced compared to the rectangular plate shape.

The intersecting pattern 200a is formed by a first diagonal line and a second diagonal line which are alternately repeated diagonally alternately along the first side and the second side of the support plate 200, and the front of the intersection point of the cross pattern 200a. There are a plurality of support portions 270 formed to protrude a certain height.

In this case, the support 270 may be formed while skipping a plurality of intersection points.

On the other hand, the coupling part 250 is formed to protrude from the back of each corner of the support plate 200, the insertion groove formed in the first support portion (154 of FIGS. 1 and 2) of the cover bottom (150 of FIGS. 1 and 2) ( Inserted and fastened to 154a of FIGS. 1 and 2, the support plate 200 is fixed to the cover bottom (150 of FIGS. 1 and 2). Here, the coupling part 250 of the support plate 200 and the first support part 154 of FIGS. 1 and 2 (154 of FIGS. 1 and 2) may be screwed or hooked to each other.

Support plate 200 having such a structure is preferably located so as to correspond between the plurality of LED assembly (129 of FIG. 1), but is not limited thereto.

The support plate 200 for this purpose is polymethyl methacrylate (PMMA) or polymethyl methacrylate (PMMA) and polystyrene (PS) mixed with the same material as that of the light guide plate. It may be made of polymethacrylstyrene (MS) resin, of which polymethyl methacrylate (PMMA), which is commonly used, is most preferred.

Through this, the light emitted from each of the plurality of LEDs (129a of FIG. 1) is not interfered by the support plate 200, and guided by the support plate 200 as the same material as the light guide plate for guiding light is applied. As a result, a more uniform image can be realized. That is, the light emitted from each of the plurality of LEDs (129a of FIG. 1) is guided through the support plate 200 to be realized as a higher quality surface light source.

Meanwhile, the present invention is not limited thereto, and the support plate 200 may be formed of a rectangular plate, or may be formed of a silicon pad made of silicon. At this time, the silicon pad is preferably formed as small as possible in a range that does not interfere with the light emitted from each of the plurality of LEDs (129a of FIG. 1).

As described above, according to the present invention, the first and second diffuser plates made of polystyrene may not only reduce the overall manufacturing cost of the liquid crystal display, but also may provide a first gap between the reflective plate and the first diffuser plate and the first and second diffuser plates. A uniform image may be realized on the screen of the liquid crystal display by keeping the second interval between them constant.

The embodiments of the present invention as described above are merely illustrative, and those skilled in the art can make modifications without departing from the gist of the present invention. Accordingly, the protection scope of the present invention includes modifications of the present invention within the scope of the appended claims and equivalents thereof.

100: liquid crystal display 110: liquid crystal panel
120: backlight unit 130: support main
140: top cover
150: cover bottom (152: bottom portion, 153: first side portion, 154: first support portion, 155: second side portion, 156: second support portion, 157: third side portion)
180: support pole
200: support plate (200a: cross pattern, 250: coupling part, 270: support part)

Claims (7)

A liquid crystal panel;
An LED assembly, a reflecting plate positioned to an upper portion of the LED assembly, a first diffusion plate positioned to be spaced first apart from the upper portion of the reflecting plate, and a second spaced apart spaced apart from the upper portion of the first diffusion plate; A backlight unit provided on a rear surface of the liquid crystal panel, including a diffusion plate and at least one optical sheet interposed between the diffusion plate and the second diffusion plate;
A cover bottom on which the backlight unit is seated;
A support plate positioned between the first diffusion plate and the second diffusion plate to maintain the second gap;
And the liquid crystal display device.
The method of claim 1,
The support plate
And a plurality of support parts protruding from the front surface thereof to support the second diffusion plate.
The method of claim 2,
The support plate
The rectangular liquid crystal display device, characterized in that the cross-section cross-hatched diagonally along the longitudinal direction therein, the support is formed on the front of the intersection point of the cross-pattern.
3. The method according to claim 2,
The support plate
A liquid crystal display device comprising one of polymethyl methacrylate (PMMA) and polymethacrylstyrene (MS) mixed with polymethyl methacrylate (PMMA) and polystyrene (PS).
The method of claim 1,
The cover bottom is
A bottom portion having a rectangular plate shape, a first side portion vertically connected to the bottom portion, a first support portion vertically connected to the first side portion to the outside to seat the first diffusion plate, and the first support portion And a second support portion vertically connected to the second side portion, and a second support portion vertically connected to the second side portion to the outside to seat the second diffusion plate.
6. The method of claim 5,
The support plate
A joining portion protruding from the back of each corner thereof,
The first support portion of the cover bottom
And an insertion groove corresponding to the coupling portion for inserting and coupling the coupling portion.
The method of claim 1,
And a support pole between the reflecting plate and the first diffusion plate to maintain the first gap.

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