KR20130044463A - Liguid crystal display device - Google Patents

Abstract

PURPOSE: A liquid crystal display is provided to improve the structure of a light source part and to reduce an optical gap. CONSTITUTION: A light guide plate(300) is located in the lower surface of a liquid crystal panel. The light source part of a backlight unit is positioned at the side of the light guide plate. A cover bottom receives the backlight unit. A light source(226) is combined with a light source support part(220). A light guide plate connection part(260) is combined with the light source part of the light guide plate. A bottom support part(240) is extended in the lower surface of the light source support part.

Description

Liquid Crystal Display Device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display device that displays an image using a change in transmittance of liquid crystal.

Liquid crystal display devices have a wide variety of applications ranging from notebook computers, monitors, spacecrafts and aircraft to the advantages of low power consumption and low power consumption and being portable. The liquid crystal display includes a liquid crystal panel and a backlight unit for supplying light to the liquid crystal panel.

1 is an exploded perspective view of a conventional liquid crystal display device.

As can be seen in FIG. 1, the liquid crystal display device includes a liquid crystal panel 60, an optical sheet 50, a diffusion plate 40, a light guide plate 30, a light source unit 20, and a cover bottom 10.

The liquid crystal panel 60 includes a first substrate on which a color filter array is formed, a second substrate on which a thin film transistor (TFT) array is formed, and a liquid crystal formed between the first substrate and the second substrate. (Liquid Crystal) layer.

The backlight unit may include a light source unit 20 for supplying light to the liquid crystal panel 60, a light guide plate 30 for uniformly supplying light emitted from the light source unit 20 toward the liquid crystal panel, and the light guide plate 30. Diffusion plate 40 for diffusing the emitted light, and an optical sheet 50 for uniformly supplying light.

The cover bottom 10 accommodates the backlight unit.

2 is an enlarged perspective view illustrating a combination of a light source unit and a cover bottom in a conventional liquid crystal display.

As can be seen in FIG. 2, the light source 20 includes a light source support 22, a bottom support 24, and a bottom fixing screw 26.

The light source supporter 22 is installed at the side of the light guide plate 30 to support the light source 21 so that light emitted from the light source 21 is incident on the light guide plate 30.

The bottom support part 24 extends from the bottom surface of the light source support part 22 and forms a right angle with the light source support part 22.

The bottom fixing screw 26 connects the light source 20 and the cover bottom 10 through holes formed in the bottom support part 24.

The power connector 28 is formed at one end of the light source support 22, and a power cable 29 for supplying power to the light source 21 is coupled.

However, such a conventional liquid crystal display has the following problems.

First, in the conventional liquid crystal display device, the optical beam (D1 of FIG. 2) formed between the light source 21 and the light guide plate 30 is maintained at about 1.0 mm, which causes a problem in luminance loss.

When the light guide plate 30 is expanded by expanding the bar light guide plate 30 fixed to the cover bottom 10 with the bottom fixing screw 26 through the bottom support part 24, the optical beam D1 is reduced. Therefore, in order to prevent the light guide plate 30 from colliding with the light guide plate 30 and the light source 21, the optical shock D1 should be designed to a predetermined level or more.

Second, a hole must be formed in order to insert the bottom fixing screw 26 into the bottom support part 24. In this process, a press process and a tap process are added to increase the cost.

Third, the power cable 29 is fitted to the bottom support part 24 and the cover bottom 10 in the process of coupling the bottom support part 24 to the cover bottom 10 using the bottom fixing screw 26. Defects occur and become a problem.

In this case, when the shrinkage tube is added to the power cable 29 or the tape is used to fix the power cable 29 to prevent the power cable 29 from being caught, the cost is increased.

The present invention is designed to solve the problems of the above-described liquid crystal display device,

SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal display device which prevents pinching of a power cable and reduces optical shock to increase luminance.

The present invention provides a liquid crystal panel comprising a liquid crystal layer between the first substrate and the second substrate to achieve the above object; A backlight unit including a light guide plate positioned on a bottom surface of the liquid crystal panel and a light source unit positioned on a side surface of the light guide plate; And a cover bottom accommodating the backlight unit, wherein the light source unit emits light; A light source support portion to which the light source is coupled; And a light guide plate fastening part extending from a side of the light source support part to couple the light source part to the light guide plate.

In addition, the present invention may include a protrusion projecting toward the light guide plate to the light guide plate fastening portion to achieve the above object.

In addition, the present invention, in order to achieve the above object, the cross section of the protrusion may be any one of semi-circular, triangular, or square.

In addition, the present invention, in order to achieve the above object, the light guide plate may be formed with a fastening groove formed concave corresponding to the protrusion.

In addition, the present invention may be combined with the light source plate spaced apart at a predetermined interval in order to achieve the above object.

In addition, the present invention, in order to achieve the above object, the light source support portion and the light guide plate fastening portion may be formed of a high thermal conductivity metal.

In addition, the present invention, in order to achieve the above object, the light source may be formed to extend from the lower surface of the light source support portion may include a bottom support for supporting the cover bottom.

In addition, the present invention may include a first light guide plate support portion formed to extend from the lower surface of the light source support portion to support the light guide plate in order to achieve the above object.

In addition, the present invention, in order to achieve the above object, the light source unit may include a second light guide plate support that is formed to extend from the lower surface of the light guide plate fastening portion to support the light guide plate.

In addition, the present invention to achieve the above object, the light source is a light emitting diode (LED), the light source unit is a substrate for mounting the light emitting diode, a power connector formed on one end of the substrate and the back of the substrate It may include a heat radiation pad attached to.

According to the present invention as described above, the following effects can be obtained.

First, there is an effect of improving the brightness by reducing the optical distance, which is the distance between the light source and the light guide plate.

In addition, according to the present invention as described above it is possible to omit the pressing step and the step required to form a hole for fixing the bottom fixing screw can reduce the cost.

In addition, there is an effect that can reduce the defect by preventing the pinch of the power cable.

1 is an exploded perspective view of a conventional liquid crystal display device.
2 is an enlarged perspective view illustrating a combination of a light source unit and a cover bottom in a conventional liquid crystal display.
3A is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention.
FIG. 3B is an assembled plan view of the liquid crystal display of FIG. 3A.
3C is a cross-sectional view of the liquid crystal display device taken along the line AA ′ of FIG. 3B.
4 is an assembled perspective view of a liquid crystal display according to another exemplary embodiment of the present invention.
FIG. 5A is an enlarged view of the first LGP support of FIG. 4, showing another embodiment of the LCD according to the present invention. FIG.
FIG. 5B is a cross-sectional view of the liquid crystal display device taken along the line BB ′ of FIG. 5A.
6A is an enlarged view of a second LGP supporter of FIG. 4, showing another embodiment of the LCD according to the present invention.
FIG. 6B is a cross-sectional view of the liquid crystal display device taken along the line BB ′ of FIG. 6A.

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

3A is an exploded perspective view of a liquid crystal display according to an exemplary embodiment of the present invention, and FIG. 3B is an assembled plan view of the liquid crystal display of FIG. 3A.

3A and 3B, a liquid crystal display according to the present invention includes a liquid crystal panel (not shown), a light guide plate 300 and a backlight unit including a light source unit 200, and a cover bottom 100.

The liquid crystal panel may include a first substrate on which a color filter array is formed, a second substrate on which a thin film transistor array is formed, and a liquid crystal layer formed between the first substrate and the second substrate. In this case, the liquid crystal panel may display an image by using a change in transmittance of the liquid crystal.

The liquid crystal display according to the present invention has various forms, such as a twisted nematic (TN) mode, a vertical alignment (VA) mode, an in plane switching (IPS) mode, and a fringe field switching (FFS) mode. The mode of may be applied.

The backlight unit includes a light source unit 200 and a light guide plate 300, and supplies light to the liquid crystal panel.

The light source part 200 includes a light source support part 220, a bottom support part 240, and a light guide plate fastening part 260. The light source unit 200 is coupled to the light guide plate 300 to supply light to the light guide plate.

The light source support part 220 may be formed to face the side surface of the light guide plate 300 on the side surface of the light guide plate 300, and may be formed to elongate according to the side shape of the light guide plate 300.

The light source support unit 220 is coupled to a light source 226 for emitting light, a substrate 224 on which the light source 226 is mounted, and a heat dissipation pad 222 coupled to the rear surface of the substrate 224.

The light source supporter 220 is combined with the heat dissipation pad 222 to absorb and radiate heat emitted from the light source 226 through the heat dissipation pad 222. Therefore, the light source support part 220 may be formed of a metal having high thermal conductivity.

The light guide plate fastening part 260 extends from both ends of the side surface of the light source support part 220 to couple the light source part 200 to the light guide plate 300.

The light guide plate fastening part 260 has a protrusion formed to protrude toward the light guide plate 300, and the side of the light guide plate 300 is provided with a fastening groove 310 recessed to correspond to the protrusion, and thus the protrusion and the fastening groove are formed. The light source unit 200 and the light guide plate 300 may be fixed by the combination of the 310.

The shape of the cross section of the protrusion may be any one of a semi-circular, triangular, or quadrangular cross section, but this is merely an example and is not limited thereto.

On the other hand, the light source unit 200 and the light guide plate 300 are coupled to be spaced apart at a predetermined predetermined interval (optical 겝: D2).

In this case, since the light source unit 200 is directly coupled to the light guide plate 300, the liquid crystal display device according to the present invention has a structure in which the light source unit 200 moves together even when the light guide plate 300 is thermally expanded, thereby significantly reducing optical shock D2. .

This is to solve the luminance deterioration problem caused by forming a large optical beam (D1 in FIG. 2) to prevent damage to the light source because the light source unit is fixed to the cover bottom in the above-described conventional technology. The effect is that the brightness is improved.

In one embodiment of the present invention, the optical shock (D2) is set to 0.2 mm as an example. This is a value considering that the light source is in contact with the light guide plate due to the assembly tolerance, and may be further reduced as necessary.

That is, in the above-described prior art, the optical zoom D1 is formed to 1.0 mm, thereby reducing the brightness. However, in the liquid crystal display according to the present invention, the optical zoom D2 is reduced to improve the brightness. Hereinafter, the change in luminance according to the optical beam will be described with Table 1.

Table 1 shows a change in luminance of the liquid crystal display according to the optical beam.

As can be seen from Table 1, it can be seen that the brightness of the liquid crystal display decreases as the optical zoom increases, and numerically, the optical zoom increases by 0.3mm and 0.8mm when the optical zoom is 0.5mm. It can be seen that the luminance is reduced by 5%.

This is because the amount of light decreases in inverse proportion to the square of the distance as the distance increases.

In an embodiment according to the present invention, the optical zoom (D2) was measured by implementing 0.2 mm, and as a result, the luminance was improved by 12% compared to the optical zoom of 1.0 mm.

Meanwhile, a light source 226, a substrate 224 on which the light source 226 is mounted, and a heat dissipation pad 222 may be formed between the light source support part 220 and side surfaces of the light guide plate 300.

The light source 226 is a device for supplying light to the light guide plate 300, and a light emitting diode (LED) may be used for the light source 226. The light source 226 may include a plurality of light emitting diodes spaced at regular intervals according to the size of the liquid crystal display.

The substrate 224 is a light source 226 is mounted may be a printed circuit board (PCB), a flexible printed circuit board (FPCB) and the like. The substrate 224 has printed wirings of a cathode and an anode to apply a driving voltage to the light emitting diodes.

A power connector 228 may be formed at one end of the substrate 224.

The power connector 228 has a function of a connector that can be connected to the power cable by collecting the wiring of the negative electrode and the positive electrode formed on the substrate 224.

The heat dissipation pad 222 is formed by being bonded between the substrate 224 and the light source support 220, and serves to quickly dissipate heat generated from the light emitting diode to the light source support 220.

The bottom supporter 240 extends from the bottom surface of the light source supporter 220, and contacts the cover bottom 100 to maintain the constant distance between the light source unit 200 and the cover bottom 100.

The bottom support part 240 may be formed in plural in a shape in which the bottom support part 240 is spaced apart from the lower surface of the light source support part 220 at a predetermined interval, and the number of the bottom support parts 240 may vary according to the size of the liquid crystal display device. .

This has the effect of reducing the material cost and weight compared to conventionally forming the bottom support in the form of a plate (plate).

In addition, in the present invention, the press process and the step process in the prior art can be performed only by the press process, so that the processing cost is reduced by about 70% as the process is omitted.

In this case, since the bottom support part 240 is not coupled to the cover bottom 100 unlike the prior art described above, when the light guide plate 300 flows finely according to thermal expansion, the light source unit 200 according to the light guide plate 300 is adapted. It can move integrally with

Due to this structure, the optical source 226 is not pressed against the light guide plate 300 even if the optical shock D2 is narrower than before, as described above.

In addition, since the bottom support portion 240 according to the present invention does not use the bottom fixing screw, there is an effect of reducing the defect that the power cable is caught between the bottom support portion and the cover bottom by the bottom fixing screw during the assembly process in the prior art. .

The light source support part 220, the bottom support part 240, and the light guide plate fastening part 260 may be formed of a metal having high thermal conductivity, and may be integrally formed in a pressing process. At this time, aluminum (Al), EGI (Electrolytic Galvanized Iron) steel sheet, etc. may be used as the metal having high thermal conductivity.

The light guide plate 300 is formed under the liquid crystal panel, and transmits the light emitted from the light source unit 200 to the liquid crystal panel.

The light guide plate 300 may change a path of light so that the light emitted from the light source unit 200 may be supplied to the liquid crystal panel. To this end, the light guide plate 300 may be formed with a variety of patterns for changing the path of light.

In addition, although not shown, the lower surface of the light guide plate 300 may include a reflector and an optical sheet on the upper surface of the light guide plate 300.

The reflective plate reflects the light exiting to the lower surface of the light guide plate 300 and condenses the light to the light guide plate 300 again.

The optical sheet is positioned between the liquid crystal panel and the light guide plate 300, and may be formed of a combination of a diffusion sheet and a prism sheet.

The optical sheet allows light incident from the light guide plate 300 to be uniformly supplied to the liquid crystal panel.

The cover bottom 100 accommodates and fixes the backlight unit including the light source unit 200 and the light guide plate 300.

3C is a cross-sectional view of the liquid crystal display device taken along the line AA ′ of FIG. 3B.

As shown in FIG. 3C, the light source 226, the substrate 224, and the heat dissipation pad 222 are sequentially bonded to the light source support 220, and face the light guide plate 300 while maintaining a constant optical beam D2. Seen and formed.

The bottom support part 240 extends from the light source support part 220 and is formed at an angle of 90 degrees with the light source support part 220.

In this case, since the bottom support part 240 is in contact with the cover bottom 100 but is not coupled, the bottom support part 240 may move on the cover bottom 100 when the light guide plate 300 is thermally expanded.

The light source supporter 220 and the bottom supporter 240 may be formed of a metal having high thermal conductivity, and may be integrally formed through a pressing process.

4 is an assembled perspective view of a liquid crystal display according to another exemplary embodiment of the present invention.

As can be seen in FIG. 4, another embodiment of the liquid crystal display according to the present invention includes a cover bottom 100 accommodating a backlight unit, a light source 226 for emitting light, and a substrate 224 for mounting the light source 226. ), A heat dissipation pad 222 for transferring heat generated from the light source 226 to the light source support 220, a light source support 220 that supports the light source 226 and is formed on the side of the light guide plate 300. A bottom support part 240 extending from a bottom surface of the light source support part 220, a light guide plate fastening part 260 extending from the light source support part 220 to be fastened to the light guide plate 300, and the light source support part 220 of the light source support part 220. The first light guide plate support part 282 extending from the bottom surface thereof, the second light guide plate support part 284 formed to extend from the light guide plate fastening part 260, and the light guide plate 300 are included.

Hereinafter, the first light guide plate support part 282 and the second light guide plate support part 284 will be described, without overlapping with the above-described liquid crystal display device according to the present invention.

The first LGP support part 282 extends from the bottom surface of the light source support part 220, and is spaced apart from the bottom support part 240 at a predetermined distance. The first LGP support 282 may be formed in plural, and the number thereof may be changed in proportion to the size of the LCD.

The first LGP support 282 is formed to contact the bottom surface of the LGP 300 to support the LGP 300.

Accordingly, the first LGP support 282 prevents the light guide plate 300 and the light source 226 from flowing in the vertical direction, so that the light emitted from the light source 226 can enter the light guide plate 300 to the side. There is an effect of keeping the height of the light guide plate 300 constant.

However, in this case, the separation between the first LGP support part 282 and the bottom support part 240 is exemplary, and in some cases, the cover bottom 100 and the LGP 300 are integrally formed with the bottom support part 240. It can be formed in a shape that can support at the same time.

The second LGP support 284 extends from a lower surface of the LGP fastening part 260 to support the LGP 300.

Accordingly, the second light guide plate support 284 prevents the light guide plate 300 and the light source 226 from flowing in the vertical direction, so that the light emitted from the light source 226 can enter the light guide plate 300 to the side. There is an effect of keeping the height of the light guide plate 300 constant.

FIG. 5A is an enlarged view of the first LGP support of FIG. 4 showing another embodiment of the LCD according to the present invention, and FIG. 5B is a cross-sectional view of the LCD along line BB ′ of FIG. 5A.

As shown in FIGS. 5A and 5B, the first LGP support 282 extends from the lower surface of the light source support 220 and contacts the lower surface of the LGP 300 to support the LGP 300.

In this case, the first LGP support part 282 may be simultaneously formed by the same pressing process as the light source support part 220.

In FIG. 5B, the first LGP support 282 extending from the light source support 220 has a curved shape due to the influence of the substrate 224. However, when the length of the substrate 224 is the same as the thickness of the LGP 300. The shape of the first LGP support 282 may be a straight line.

That is, the first LGP support 282 may be modified into various structures for supporting the LGP 300.

FIG. 6A is an enlarged view of the second LGP support of FIG. 4 showing another embodiment of the LCD according to the present invention, and FIG. 6B is a cross-sectional view of the LCD along line BB ′ of FIG. 6A.

As shown in FIGS. 6A and 6B, the second LGP support 284 extends from the lower surface of the LGP fastening part 260 and contacts the lower surface of the LGP 300 to support the LGP 300.

The second LGP support 284 may extend from a lower surface of the protrusion formed on the LGP fastening part 260, or may extend from one end of the LGP fastening part 260.

In this case, the second LGP support 284 may be simultaneously formed by the same pressing process as the LGP fastening part 260.

In FIG. 6B, the second LGP support 284 formed to extend from the LGP fastening part 260 has a curved shape, but may be a straight line in some cases.

That is, the second LGP supporter 284 may be modified in various structures to support the LGP 300.

The light source support part 220, the bottom support part 240, the light guide plate fastening part 260, the first light guide plate support part 282, and the second light guide plate support part 284 constituting the light source part 200 have high thermal conductivity. All of the metals can be formed integrally in the same press process.

In this case, the light source unit 200 may be formed by a single pressing process, thereby simplifying the manufacturing process, thereby reducing the processing cost.

It will be understood by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and not restrictive. The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and from the equivalent concept are to be construed as being included in the scope of the present invention .

100-Cover Bottom
200-light source
220-light source support
222-Thermal Pad
224-Board
226-Light Emitting Diode
228-power connector
240-bottom support
260-Light Guide Plate Fastening
282-First Light Guide Plate Support
284-second light guide plate support
300-light guide plate
310-Fastening Groove

Claims (10)

A liquid crystal panel in which a liquid crystal layer is formed between the first substrate and the second substrate;
A backlight unit including a light guide plate positioned on a bottom surface of the liquid crystal panel and a light source unit positioned on a side surface of the light guide plate; And
It includes a cover bottom for receiving the backlight unit,
The light source unit
A light source support unit to which a light source is coupled; And
And a light guide plate fastening part extending from a side of the light source support part to couple the light source part to the light guide plate. The method of claim 1,
The light guide plate fastening part includes a protrusion protruding toward the light guide plate. The method of claim 2,
And the protrusion is any one of a semicircular, triangular, or rectangular cross section. The method of claim 2,
And the light guide plate includes a fastening groove formed concave to correspond to the protrusion. The method of claim 1,
And the light source unit is coupled to the light guide plate at predetermined intervals. The method of claim 1,
And the light source support part and the light guide plate fastening part are made of a metal having high thermal conductivity. The method of claim 1,
And the bottom light source part extending from a bottom surface of the light source support part to contact the cover bottom. The method of claim 1,
And the light source unit includes a first light guide plate support part formed to extend from a lower surface of the light source support part to support the light guide plate. The method of claim 1,
And the light source unit includes a second light guide plate support part which extends from a bottom surface of the light guide plate fastening part and supports the light guide plate. The method of claim 1,
The light source is a light emitting diode (LED), and the light source unit includes a substrate on which the light emitting diode is mounted, a power connector formed at one end of the substrate, and a heat radiation pad attached to a rear surface of the substrate. Liquid crystal display device.

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