KR20140076723A - Light reflector, back light unit having the same, and display device having thereof - Google Patents

Abstract

A light reflection plate includes: a bottom plate in the shape of a plate; a main brightness increasing part formed by folding a portion of the bottom plate once; and sub-brightness increasing parts which is formed by folding each of both ending portions of the bottom plate facing the main brightness increasing part in the direction facing a first brightness increasing part.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a reflector, a backlight unit having the reflector,

The present invention relates to a reflector, a backlight unit having the same, and a display device having the same.

2. Description of the Related Art In recent years, liquid crystal displays (LCDs) for displaying information on a wide variety of fields such as various electronic devices such as a mobile phone, a game machine, a computer monitor, a notebook, and a tablet PC have been widely applied.

Recently developed liquid crystal display devices are required to have a very thin thickness and high luminance uniformity. In order to realize a thin thickness and a high luminance uniformity, a liquid crystal display device is applied with a direct type backlight unit.

In the direct-type backlight unit, a CCFL lamp or an LED array substrate is disposed under the liquid crystal display device.

Conventionally, the direct-type backlight unit has a problem of thickening the thickness or increasing the number of light sources in order to realize high luminance uniformity similar to a surface light source by using a point light source such as a CCFL lamp or a point light source such as an LED array substrate.

The present invention provides a reflective plate, a backlight unit having the same, and a display device having the same, which improve brightness uniformity of light while reducing the number of light sources and the total thickness.

The technical object of the present invention is not limited to the above-mentioned technical objects and other technical objects which are not mentioned can be clearly understood by those skilled in the art from the following description will be.

In one embodiment, the reflector includes a bottom plate having a plate shape, a main luminance enhancer formed by bending a part of the bottom plate, and a second luminance enhancer having both ends of the bottom plate facing the main luminance enhancer, And sub-luminance enhancing portions formed by bending each of the sub-luminance enhancing portions.

In one embodiment, the backlight unit includes a main luminance enhancing portion formed by bending a part of a bottom plate having a plate shape, and a second luminance enhancing portion facing both ends of the bottom plate facing the main luminance enhancing portion, A case including a reflector including sub-luminance enhancing portions formed by bending each of the sub-luminance enhancing portions, a support plate supporting the bottom plate, and side plates connected to the support plate for fixing the sub-luminance enhancing portions, And a light emitting diode (LED) which is mounted on the substrate and exposed through the reflection plate, the LED being interposed between the main luminance enhancing unit and the substrate.

In one embodiment, the display device includes a main luminance enhancing portion formed by bending a part of a bottom plate having a plate shape, and a second luminance enhancing portion facing both ends of the bottom plate facing the main luminance enhancing portion, A case including a reflecting plate including sub-luminance enhancing portions formed by bending each of the sub-luminance enhancing portions, a supporting plate for supporting the bottom plate, and side plates for fixing the sub-luminance enhancing portions respectively, And an LED unit mounted on the substrate and exposed through the reflection plate, and a liquid crystal display panel coupled to the case.

According to the reflector, the backlight unit having the same, and the display device having the reflector according to the present invention, the brightness distribution of the light generated from the LED, which is a point light source having a nonuniform brightness distribution, is improved by using the main brightness enhancer and the sub brightness enhancer By implementing a high luminance with a smaller number of LEDs, it has a low power characteristic and has the effect of further reducing the volume or thickness.

1 is a perspective view of a reflector according to an embodiment of the present invention.
2 is a cross-sectional view taken along line II 'of FIG.
3 is a partial cross-sectional perspective view of a backlight unit according to an embodiment of the present invention.
4 is an exploded sectional view of Fig.
5 is a cross-sectional view taken along line II-II 'of FIG. 3;
6 is a cross-sectional view illustrating a display device according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The sizes and shapes of the components shown in the drawings may be exaggerated for clarity and convenience. In addition, terms defined in consideration of the configuration and operation of the present invention may be changed according to the intention or custom of the user, the operator. The definitions of these terms should be interpreted based on the contents of the present specification and meanings and concepts in accordance with the technical idea of the present invention.

1 is a perspective view of a reflector according to an embodiment of the present invention. 2 is a cross-sectional view taken along line I-I 'of FIG.

In one embodiment of the present invention, the reflector 100 is a direct-type backlight in which an LED array bar or cold cathode fluorescent lamp (CCFL) with a light emitting diode (LED) Unit. ≪ / RTI >

Referring to FIGS. 1 and 2, the reflection plate 100 includes a LED light source, a LED light source, and a cold cathode ray tube (CCFL) The luminance uniformity is improved so as to have a luminance distribution similar to the light generated from the surface light source.

The reflection plate 100 can be formed by folding a reflection sheet having a plate shape in which a light reflecting material is mixed with a synthetic resin such as polyethylene terephthalate (PET), etc., into a specific shape.

The reflector 100 includes a bottom plate 10, a main luminance enhancer 20, and a sub-luminance enhancer 30. [

The bottom plate 10 is formed, for example, in a plate shape.

The main brightness enhancing unit 20 is formed at the center of the bottom plate 10 and the bottom plate 10 is divided into a plurality of areas by the main brightness enhancing unit 20. [

The main luminance enhancing section 20 is formed by bending a part of the bottom plate 10 and the main luminance enhancing section 20 is formed by a triangular prism column Shape.

The main luminance enhancing section 20 includes a first luminance enhancing section 22 and a second luminance enhancing section 24. [

The first brightness enhancing section 22 is bent, for example, obliquely to the bottom plate 10 in the clockwise direction. The first luminance enhancing portion 22 and the bottom plate 10 form, for example, an angle of an obtuse angle.

The second brightness enhancing section 24 is bent in a counterclockwise direction from the first brightness enhancing section 22 and the second brightness enhancing section 24 and the bottom plate 10 are bent at an obtuse angle .

The first and second brightness enhancing portions 22 and 24 are formed by bending the first and second brightness enhancing portions 22 and 24 from the bottom plate 10 and maintaining the bent shape after the first and second brightness enhancing portions 22 and 24 are bent, The groove 25 or the cutout portion 26 may be formed so that it can be easily bent from the base 10.

The groove 25 is formed in a portion bent from the bottom plate 10 and the groove 25 is formed in a straight groove shape with a depth shallower than the thickness of the bottom plate 10. [ The cutout portion 26 may be formed at a portion bent from the bottom plate 10 and the cutout portion 26 is formed intermittently along the portion bent from the bottom plate 10. [ In one embodiment of the present invention, the groove 25 and the cutout 26 may be formed singly or in combination.

The angle? 1 formed by the first luminance enhancing portion 22 and the bottom plate 10 and the angle 2 formed between the second luminance enhancing portion 22 and the bottom plate 10 are Substantially the same.

The light directed from the LED array bar or the cold cathode tube lamp disposed on both sides of the main luminance enhancing section 20 to the main luminance enhancing section 20 is transmitted to the first and second luminance enhancing sections 22 and 24 The brightness uniformity of the light generated from the LED array bar or the cold cathode tube lamp is improved by the main brightness enhancing unit 20. [

The vertical height h1 of the bent portion where the first and second brightness enhancing portions 22 and 24 of the main brightness enhancing portion 20 meet and the top surface of the bottom plate 10, The ratio of the vertical height h2 formed by the end of the sub luminance enhancer 30 and the top surface of the bottom plate 10 to be described later serves as an important factor for determining the luminance uniformity of light.

When the vertical height h1 of the main luminance enhancing section 20 is less than about 20% of the vertical height h2 of the sub luminance enhancing section 30, The generated light may be overlapped with each other, and the luminance uniformity may be rather reduced.

Conversely, when the vertical height h1 of the main luminance enhancing section 20 is greater than about 60% of the vertical height h2 of the sub-luminance enhancing section 30, The light generated from the light sources is blocked, and the main luminance enhancing unit 20 functions as a wall for blocking light, so that the luminance uniformity can be reduced.

Therefore, when the vertical height h2 of the sub-luminance enhancement unit 30 is set to 100% in the embodiment of the present invention, the vertical height h1 of the main luminance enhancement unit 20 is set to be the sub- About 20% to about 60% of the vertical height (h2).

The sub luminance enhancing section 30 is bent from the bottom plate 10 in the direction opposite to the first luminance enhancing section 22 and the second luminance enhancing section 24 of the main luminance enhancing section 20,

The sub-luminance enhancing unit 30 reflects or refracts light emitted from the LED array bar or the cold cathode ray tube lamp in a direction opposite to the main luminance enhancing unit 20 to generate light from the LED array bar or the cold cathode ray tube lamp Thereby further improving the luminance uniformity of the emitted light.

In one embodiment of the present invention, the sub-luminance enhancing portion 30 that is bent from the bottom plate 10 may be formed with a groove or a cut portion as shown in FIG.

The LED array bar may be disposed on both sides of the main brightness enhancing unit 20. The LED array bar may be mounted on the bottom plate 10 of the reflector 100, The LED array bar may be disposed on the rear surface of the reflection plate 100 so that a shadow area due to the substrate is not generated.

When the LED array bar is disposed on the rear surface of the reflector 100, since the light generated from the LEDs mounted on the LED array bar can not pass through the reflector 100, the LED array bar of the bottom plate 10 of the reflector 100 is arranged The first openings 12 and the second openings 14 are formed.

A plurality of first openings 12 are formed in a row on the bottom plate 10 adjacent to the first brightness enhancing section 22 of the main brightness enhancing section 20 along the first brightness enhancing section 22, A plurality of apertures 14 are formed in a row on the bottom plate 10 adjacent to the second brightness enhancing section 24 of the main brightness enhancing section 20 along the second brightness enhancing section 24. [

In one embodiment of the present invention, the first and second openings 12 and 14 are through holes that penetrate the upper surface of the bottom plate 10 of the reflector 100 and a lower surface opposed to the upper surface.

3 is a partial cross-sectional perspective view of a backlight unit according to an embodiment of the present invention. 4 is an exploded sectional view of Fig. 5 is a cross-sectional view taken along line II-II 'of FIG. 3; The reflector included in the backlight unit according to an embodiment of the present invention has substantially the same configuration as the reflector shown in Figs. Therefore, redundant description of the same configuration will be omitted, and the same names and the same reference numerals will be given to the same configurations.

1, 3 to 5, the backlight unit 200 includes a reflection plate 100, a case 110, and an LED unit 130. In addition, the backlight unit 200 may further include an optical member 150.

The reflector 100 includes a bottom plate 10, a main luminance enhancer 20, and a sub-luminance enhancer 30. [

The case 110 includes a support plate 112 and a side plate 114.

The support plate 112 of the case 110 is formed in a plate shape facing the bottom plate 10 of the reflector 100 and corresponds to the main brightness enhancer 20 of the reflector 100 of the support plate 112 A coupling portion 111 coupled to the main brightness enhancing portion 20 in a concavo-convex manner is formed. The engaging portion 111 has a shape and size corresponding to that of the main luminance enhancing portion 20.

The side plate 114 extends from the edge of the support plate 112 toward the upper side of the support plate 112 to form a storage space for accommodating the reflection plate 100 and the LED unit 130. The side plate 114 may be formed integrally with the support plate 112.

In one embodiment of the present invention, the case 110 may be formed by pressing a metal plate or by bending a metal plate.

The reflector 100 is disposed inside the case 110. The bottom plate 10 of the reflector 100 is disposed to face the support plate 112 of the case 110, The end portion of the side plate 30 is fixed to the upper end of the side plate 114 of the case 110.

The case 110 and the reflector 100 disposed inside the case 110 can be coupled to each other by fastening members or adhesives such as screws.

A reflector fixing part 113 is formed in the case 110 to prevent the reflection plate 100 from moving inside the case 110 or from separating the reflection plate 100 from the case 110.

The reflector fixing portion 113 is formed by cutting a part of the support plate 112 of the case 110 into a U shape and then bending the incised portion toward the upper surface of the support plate 112, The reflector fixing portion 113 may be formed at a position adjacent to the main luminance enhancing portion 20 of the reflection plate 100. [

The reflector fixing portion 113 can also serve as a guide for arranging the LED unit to be described later at a designated position.

A fixing hole 18 is formed at a position corresponding to the reflection plate fixing portion 113 of the bottom plate 10 of the reflection plate 100. The reflection plate fixing portion 113 is inserted into the fixing hole 18, 100 can be prevented from moving inside the case 110 or from separating the reflecting plate 100 from the case 110.

The reflector fixing part 113 may be formed to be perpendicular to the bottom plate 10 of the reflector 100 or may be bent in parallel with the bottom plate 10 after the reflector 100 is coupled to the case 110, (10) can be fixed.

The LED unit 130 includes a substrate 132, LEDs 134, and a lens 136. The LED unit 130 is interposed between the bottom plate 10 of the reflection plate 100 and the support plate 112 of the case 110, for example.

The substrate 132 is formed, for example, in the shape of a rectangular parallelepiped plate in which circuit wirings are formed, and the substrate 132 may include a circuit board having a thin thickness. The substrate 132 having a rectangular parallelepiped shape is arranged in parallel with the first luminance enhancement portion 22 and the second luminance enhancement portion 24 of the main luminance enhancement portion 20 of the reflection plate 100, for example.

The LEDs 134 may be formed in a chip shape and the LEDs 134 may be disposed in a line manner on the upper surface of the substrate 132. The LEDs 134 may be disposed on the bottom plate 10 (12) and the second opening (14) formed in the first opening (12).

The lens 136 is coupled to each LED 134, and the lens 136 improves the emission angle or luminance distribution of the light generated from the LED 134.

The backlight unit 200 according to an exemplary embodiment of the present invention may include a main brightness enhancer 20 and a sub brightness enhancer 30 of the lens 136 of the LED unit 130 and the reflector 100, 134, but may further include the optical member 150 to further improve the luminance distribution.

The optical member 150 may include a diffusing plate for diffusing light generated from the LEDs 134 again to improve uniformity of brightness, or a light guide plate for adjusting an emission angle of light.

The optical member 150 may be fixed to the side plate 114 of the case 110. [

6 is a cross-sectional view illustrating a display device according to an embodiment of the present invention. The backlight unit of the display device shown in FIG. 6 has substantially the same configuration as the backlight unit shown in FIGS. 3 to 5, and a duplicated description of the same configuration will be omitted. The same reference numerals will be given.

4 and 6, the display device 400 includes a reflective plate 100, a case 110, a backlight unit 200 including an LED unit 130, and a liquid crystal display panel 300.

The liquid crystal display panel 300 includes a lower substrate including ITO pixels and thin film transistors electrically connected to the respective ITOs, an upper substrate including a color filter formed at a position facing each ITO pixel, And a liquid crystal injected into a space formed by the sealant and the lower substrate, the upper substrate, and the sealant.

The liquid crystal display panel 300 improves the luminance distribution of light generated from the LEDs 134 of the LED unit 130 disposed under the liquid crystal display panel 300 using the reflector 100 and the optical member 140 Light having improved luminance distribution is provided to the liquid crystal display panel 300 to display a high-quality image.

As described above in detail, the luminance distribution of the light emitted from the LED, which is a point light source having a nonuniform luminance distribution, is improved by using the main luminance enhancing section and the sub luminance enhancing section formed on the reflector to realize a high luminance with a smaller number of LEDs And has the effect of reducing the volume or thickness further.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims. Accordingly, the true scope of the present invention should be determined by the following claims.

10 ... bottom plate 20 ... main luminance enhancing portion
30 ... Sub-luminance enhancement unit 100 ... Reflector
110 ... Case 130 ... LED unit
200 ... backlight unit 300 ... liquid crystal display panel
400 ... display

Claims (16)

A bottom plate having a plate shape;
A main luminance enhancer formed by bending a part of the bottom plate; And
And the sub luminance enhancers formed by bending both ends of the bottom plate facing the main luminance enhancer in the direction opposite to the first luminance enhancer.
The method according to claim 1,
Wherein the main luminance enhancer includes a first luminance enhancer inclined with respect to the bottom plate and a second luminance enhancer bent from the first luminance enhancer backward to the bottom plate.
3. The method of claim 2,
The bottom plate adjacent to the first brightness enhancing unit is formed with a plurality of first openings along the first brightness enhancing unit and the bottom plate adjacent to the second brightness enhancing unit is provided with a plurality of first openings along the second brightness enhancing unit, 2 Reflector with openings.
The method according to claim 1,
Wherein the height of the main luminance enhancing portion is 20% to 60% of the height of the sub luminance enhancing portion when measured from the bottom plate.
The method according to claim 1,
A groove having a depth shallower than a thickness of the reflector along the bent portion of the main luminance enhancer and the sub-luminance enhancer, or a cut-out portion in which the reflector is cut intermittently.
A main luminance enhancing portion formed by bending a part of the bottom plate having a plate shape and a sub luminance portion formed by bending both end portions of the bottom plate facing the main luminance enhancing portion in a direction facing the first luminance enhancing portion, A reflector including enhancers;
A support plate for supporting the bottom plate, and side plates connected to the support plate for fixing the sub-luminance enhancing portions, respectively; And
And a LED (Light Emitting Diode) interposed between the reflection plate and the support plate, the LED being mounted on the substrate and exposed through the reflection plate, .
The method according to claim 6,
Wherein the substrate is formed on both sides of the main brightness enhancing portion in parallel with the main brightness enhancing portion.
The method according to claim 6,
The backlight unit includes a reflector fixing part for cutting and bending a part of the support plate to fix the reflector.
9. The method of claim 8,
And a fixing hole into which the reflector fixing part is inserted is formed on the reflection plate corresponding to the reflection plate fixing part.
The method according to claim 6,
Wherein the main luminance enhancer includes a first luminance enhancer inclined with respect to the bottom plate and a second luminance enhancer bent from the first luminance enhancer backward to the bottom plate.
11. The method of claim 10,
Wherein the bottom plate adjacent to the first brightness enhancing unit is formed with a plurality of first openings exposing the LED along the first brightness enhancing unit and the bottom plate adjacent to the second brightness enhancing unit is provided with the second brightness enhancing unit And a plurality of second openings exposing the LEDs along the first and second openings.
The method according to claim 6,
Wherein the height of the main luminance enhancing portion is 20% to 60% of the height of the sub-luminance enhancing portion when measured from the bottom plate.
The method according to claim 6,
And an optical member fixed to the side plate so as to face the support plate.
The method according to claim 6,
Wherein the LED includes a lens for improving luminance uniformity of light emitted from the LED.
The method according to claim 6,
Wherein the bottom plate and the support plate are coupled to each other by one of a fastening member and an adhesive.
A main luminance enhancing portion formed by bending a part of the bottom plate having a plate shape and a sub luminance portion formed by bending both end portions of the bottom plate facing the main luminance enhancing portion in a direction facing the first luminance enhancing portion, A reflector including enhancers;
A support plate for supporting the bottom plate, and side plates connected to the support plate for fixing the sub-luminance enhancing portions, respectively;
An LED disposed between the reflection plate and the support plate and disposed parallel to the main brightness enhancement unit, and an LED mounted on the substrate and exposed through the reflection plate; And
And a liquid crystal display panel coupled to the case.

Images