KR102128797B1 - Light reflector, back light unit having the same, and display device having thereof - Google Patents

Abstract

The reflector is a bottom plate having a plate shape, a main luminance enhancement portion formed by bending a portion of the bottom plate once, and both ends of the bottom plate facing the main luminance enhancement portion in a direction facing the first luminance enhancement portion. It includes sub-luminance enhancement parts formed by bending each.

Description

Reflector, backlight unit having the same, and display device having the same{LIGHT REFLECTOR, BACK LIGHT UNIT HAVING THE SAME, AND DISPLAY DEVICE HAVING THEREOF}

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 Recently, a liquid crystal display device displaying an image of information has been widely applied to various electronic devices, such as mobile phones, game machines, computer monitor devices, notebook computers, and tablet PCs.

The recently developed liquid crystal display device has a very thin thickness and requires high luminance uniformity. In order to realize a thin thickness and high luminance uniformity, a direct type backlight unit is applied to the liquid crystal display device.

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

In order to realize high luminance uniformity similar to a surface light source by using a linear light source such as a CCFL lamp or a point light source such as an LED array substrate, the conventional direct type backlight unit has a problem in that the thickness must be thickened or the number of light sources must be increased.

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

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by a person having ordinary knowledge in the technical field to which the present invention belongs from the following description. will be.

In one embodiment, the reflective plate is a bottom plate having a plate shape, a main luminance improving portion formed by bending a part of the bottom plate once, and both ends of the bottom plate facing the main luminance improving portion, the first luminance improving portion And sub-luminance enhancement units formed by bending each in a direction facing each other.

In one embodiment, the backlight unit is formed by bending a portion of the bottom plate having a plate shape once, and both ends of the bottom plate facing the main luminance improving portion and the main luminance improving portion facing the first luminance improving portion. Between the reflector and the reflector and the support plate connected to the support plate and the support plate for supporting the bottom plate formed by bending each of the sub-brightness, respectively, the side plate is fixed to each of the sub-brightness enhancers formed by bending in the direction It includes an LED unit interposed therebetween and mounted on the substrate and parallel to the main luminance improving unit, and an LED unit mounted on the substrate and including an LED exposed through the reflector.

In one embodiment, the display device is formed by bending a portion of the bottom plate having a plate shape once, and both ends of the bottom plate facing the main luminance improving portion and the main luminance improving portion facing the first luminance improving portion. Between the reflector including the sub-luminance enhancement parts formed by bending in each direction, a support plate supporting the bottom plate, and a case including side plates connected to the support plate and fixing the sub-luminance enhancement portions, respectively, between the reflector and the support plate It includes an LCD unit interposed therebetween and an LCD unit mounted on the substrate and an LED unit mounted on the substrate and exposed through the reflector, and a liquid crystal display panel coupled to the case.

According to the reflector according to the present invention, a backlight unit having the same, and a display device having the same, the luminance distribution of light generated from the LED, which is a point light source having a non-uniform luminance distribution, is improved by using a main luminance enhancement unit and a sub luminance enhancement unit formed on the reflection plate. By implementing high luminance with a smaller number of LEDs, it has low power characteristics and has the effect of reducing 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. 1.
3 is a partial cross-sectional perspective view of a backlight unit according to an embodiment of the present invention.
4 is an exploded cross-sectional view of FIG. 3.
5 is a cross-sectional view taken along line II-II' of FIG. 3.
6 is a cross-sectional view showing a display device according to an exemplary embodiment of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. In this process, the size or shape of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. Definitions of these terms should be interpreted as meanings and concepts consistent with the technical spirit of the present invention based on the contents throughout the present specification.

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. 1.

In an embodiment of the present invention, the reflector 100 is a direct-type backlight in which a LED array bar or a cold cathode ray tube lamp (CCFL) equipped with an LED (Light Emitting Diode) is mounted under the liquid crystal display. Can be applied to units.

1 and 2, the reflector 100 is a point light source (dot light source) included in the LED array bar or a linear light source (cold cathode ray tube lamp (CCFL)) generated from the surface The luminance uniformity is improved to have a luminance distribution similar to the light generated from the surface light source.

The reflective plate 100 may be formed by folding a reflective sheet having a plate shape in which a light-reflecting material is mixed with a synthetic resin such as polyethylene terephthalate (PET) in a specific shape.

The reflector 100 includes a bottom plate 10, a main luminance enhancement unit 20, and a sub luminance enhancement unit 30.

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

The main luminance improving unit 20 is formed in the center portion of the bottom plate 10, and the main plate 10 is divided into a plurality of regions by the main luminance improving unit 20.

The main luminance enhancing section 20 is formed by bending a part of the bottom plate 10 once, and the main luminance improving section 20 is a triangular prism pillar divided sideways on the bottom plate 10 when viewed in three dimensions. It has a shape.

The main luminance enhancement unit 20 includes a first luminance enhancement unit 22 and a second luminance enhancement unit 24.

The first luminance enhancement unit 22 is bent, for example, in a clockwise direction with respect to the bottom plate 10. The first luminance improving unit 22 and the bottom plate 10 form an angle of, for example, an obtuse angle.

The second luminance enhancement unit 24 is bent in a counterclockwise direction from the first luminance enhancement unit 22, and the second luminance enhancement unit 24 and the bottom plate 10 are, for example, an obtuse angle To form.

Of the first and second luminance enhancing parts 22 and 24, the portion bent from the bottom plate 10 maintains the bent shape even after the first and second luminance enhancing portions 22 and 24 are bent and the bottom plate A groove 25 or an incision 26 may be formed to bend easily from (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 to a depth shallower than the thickness of the bottom plate 10. The incision 26 may be formed in a portion bent from the bottom plate 10, and the incision 26 is intermittently formed along a portion bent from the bottom plate 10. In one embodiment of the present invention, the groove 25 and the incision 26 may be formed alone or in combination.

In one embodiment of the present invention, the angle θ1 formed by the first luminance enhancing unit 22 and the bottom plate 10 and the angle θ2 formed by the second luminance enhancing unit 22 and the bottom plate 10 are It is practically the same.

Among the light generated from the LED array bar or the cold cathode ray tube lamps arranged on both sides of the main luminance enhancement unit 20, the light directed to the main luminance enhancement unit 20 is the first and second luminance enhancement units 22 and 24. Because it is reflected and refracted by, the luminance uniformity of the light generated from the LED array bar or the cold cathode ray tube lamp is improved by the main luminance enhancement unit 20.

In an embodiment of the present invention, the vertical height h1 formed by the bent portion where the first and second luminance enhancing units 22 and 24 of the main luminance improving unit 20 meet and the upper surface of the bottom plate 10 and The ratio of the vertical height h2 formed by the end portion of the sub luminance enhancement unit 30 to be described later and the upper surface of the bottom plate 10 serves as an important factor for determining the luminance uniformity of light.

When the vertical height h1 of the main luminance enhancement section 20 is less than about 20% of the vertical height h2 of the sub luminance enhancement section 30, from the light sources respectively disposed on both sides of the main luminance enhancement section 20 Since the generated light overlaps each other, luminance uniformity may be reduced.

Conversely, when the vertical height h1 of the main luminance enhancement section 20 is greater than about 60% of the vertical height h2 of the sub luminance enhancement section 30, they are disposed on both sides of the main luminance enhancement section 20, respectively. Since the light generated from the light sources is blocked, the main brightness enhancing unit 20 acts as a wall to block light, so that the luminance uniformity can be reduced.

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

The sub luminance enhancement unit 30 is bent from the bottom plate 10 in the direction facing the first luminance enhancement unit 22 and the second luminance enhancement unit 24 of the main luminance enhancement unit 20, respectively.

The sub-luminance enhancement unit 30 reflects or refracts light traveling in the opposite direction of the main luminance-enhancing unit 20 among the light generated from the LED array bar or the cold cathode ray tube lamp, and thus is generated from the LED array bar or the cold cathode ray tube lamp. It further improves the luminance uniformity of the light.

In one embodiment of the present invention, a groove or cutout as shown in FIG. 1 may be formed in the sub-luminance enhancement unit 30 that is bent from the bottom plate 10.

Meanwhile, an LED array bar on which LEDs are mounted may be disposed on the bottom plate 10 of the reflector 100, and the LED array bars are disposed on both sides of the main luminance enhancement unit 20, and LEDs are mounted among the LED array bars. The LED array bar may be disposed on the rear surface of the reflector 100 so that a shaded area caused by the substrate is not generated.

When the LED array bar is disposed on the rear surface of the reflector 100, the LED array bar is disposed among the bottom plates 10 of the reflector 100 because light generated from LEDs mounted on the LED array bar cannot pass through the reflector 100. The first openings 12 and the second openings 14 are respectively formed in the portion to be made.

A plurality of first openings 12 are formed in a line along the first luminance enhancement unit 22 on the bottom plate 10 adjacent to the first luminance enhancement unit 22 of the main luminance enhancement unit 20, and the second A plurality of openings 14 are formed in a line along the second luminance enhancement unit 24 on the bottom plate 10 adjacent to the second luminance enhancement unit 24 of the main luminance enhancement unit 20.

In one embodiment of the present invention, the first and second openings 12 and 14 are through holes penetrating through the upper surface of the bottom plate 10 of the reflector 100 and the lower surface facing 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 cross-sectional view of FIG. 3. 5 is a cross-sectional view taken along line II-II' of FIG. 3. The reflector included in the backlight unit according to the exemplary embodiment of the present invention has substantially the same configuration as the reflector illustrated in FIGS. 1 and 2. Therefore, duplicate description of the same configuration will be omitted, and the same name and the same reference numeral will be assigned to the same configuration.

1, 3 to 5, the backlight unit 200 includes a reflector 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 enhancement unit 20 and a sub luminance enhancement unit 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 that faces the bottom plate 10 of the reflector 100, and corresponds to the main luminance enhancement unit 20 of the reflector 100 among the support plates 112. In the portion to be formed, the main luminance improving unit 20 and the engaging portion 111 coupled in an uneven manner are formed. The coupling portion 111 has a shape and size corresponding to the main luminance improving portion 20.

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

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

The reflector 100 is disposed inside the case 110, the bottom plate 10 of the reflector 100 is disposed facing the support plate 112 of the case 110, and the sub luminance enhancement unit of the reflector 100 The end of the 30 is fixed to the top of the side plate 114 of the case 110.

The case 110 and the reflector 100 disposed inside the case 110 may be mutually coupled by a fastening member such as a screw or an adhesive.

Meanwhile, in order to prevent the reflector 100 from moving inside the case 110 or the reflector 100 from being detached from the case 110, the reflector fixing part 113 is formed on the case 110.

The reflecting plate fixing part 113 is formed by cutting a part of the support plate 112 of the case 110 into, for example, an'U' shape, and then bending the cut portion toward the upper surface of the support plate 112, The reflector fixing part 113 may be formed at a position adjacent to the main luminance improving part 20 of the reflector 100.

The reflector fixing part 113 may also serve as a guide for the LED unit to be described later to be disposed at a designated position.

A fixing hole 18 is formed in a position corresponding to the fixing plate 113 of the bottom plate 10 of the reflecting plate 100, and the fixing plate 113 is inserted into the fixing hole 18, thereby causing the reflecting plate ( 100) can be prevented from moving inside the case 110 or the reflector 100 is separated from the case 110.

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

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

The substrate 132 is formed, for example, in the shape of a cuboid plate on 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 disposed, for example, 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 reflector 100.

The LED 134 may be formed in a chip shape, the LED 134 may be arranged in a serial manner on the top surface of the substrate 132, and the LED 134 may be a bottom plate 10 of the reflector 100 ) Is formed at positions corresponding to the first opening 12 and the second opening 14 formed in ).

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

The backlight unit 200 according to an exemplary embodiment of the present invention uses the main luminance enhancement unit 20 and the sub-luminance enhancement unit 30 of the lens 136 and the reflector 100 of the LED unit 130 to determine the LED ( 134) to sufficiently improve the luminance distribution of light generated, but additionally, to further improve the luminance distribution, an optical member 150 may be further included.

The optical member 150 may include a diffusion plate for diffusing light generated from the LED 134 again to improve luminance uniformity, or a light guide plate for adjusting the 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 showing a display device according to an exemplary embodiment of the present invention. The backlight unit of the display device illustrated in FIG. 6 has substantially the same configuration as the backlight unit illustrated in FIGS. 3 to 5, and a duplicate description of the same configuration will be omitted. The same reference numerals will be assigned.

4 and 6, the display device 400 includes a reflector 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 an ITO pixel and a lower substrate including a thin film transistor electrically connected to each ITO, an upper substrate including a color filter formed at a position facing each ITO pixel, along a border between the lower substrate and the upper substrate. And a liquid crystal injected into the space formed by the formed 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 LED 134 of the LED unit 130 disposed under the liquid crystal display panel 300 using the reflector 100 and the optical member 140, Light with improved luminance distribution is provided to the liquid crystal display panel 300 to display a high-quality image.

As described in detail above, the luminance distribution of light generated from the LED, which is a point light source having a non-uniform luminance distribution, is improved by using the main luminance enhancement unit and the sub luminance enhancement unit formed on the reflector, thereby realizing high luminance with fewer LEDs. By doing so, it has a low power characteristic and has the effect of further reducing volume or thickness.

Although the embodiments according to the present invention have been described above, they are merely exemplary, and those skilled in the art will understand that various modifications and equivalent ranges of the embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention should be defined by the following claims.

10...Bottom plate 20...Main luminance enhancement part
30...Sub luminance enhancement 100...Reflector
110...case 130...LED unit
200...backlight unit 300...liquid crystal display panel
400...display device

Claims (16)

delete delete delete delete delete A main luminance enhancement unit formed by bending a portion of the bottom plate having a plate shape, and a sub luminance enhancement formed by bending both ends of the bottom plate facing the main luminance enhancement unit in a direction facing the main luminance enhancement unit, respectively. Reflector including the parts;
A case including a support plate supporting the bottom plate and side plates connected to the support plate and fixing the sub luminance enhancing parts, respectively; And
Includes an LED unit interposed between the reflector and the support plate and mounted on the substrate parallel to the main luminance improving unit and the LED mounted on the substrate and exposed through the reflector (Light Emitting Diode, LED),
The bottom plate includes a first bottom plate and a second bottom plate,
The main luminance improving unit is disposed between the first bottom plate and the second bottom plate,
In the support plate, a part of the support plate is cut and bent to form a reflector fixing portion for fixing the reflector,
The main luminance enhancement portion includes a first luminance enhancement portion inclined with respect to the bottom plate and a second luminance enhancement portion bent from the first luminance enhancement portion with respect to the bottom plate.
The first bottom plate and the second bottom plate are disposed with fixing holes recessed from the side to the inside, respectively, so that the reflecting plate fixing portion penetrates,
The reflecting plate fixing part is bent so that a part passes through the fixing hole and is parallel to the bottom plate,
A backlight unit in which a groove is formed between the bottom plate and the main luminance enhancement unit, and between the first luminance enhancement unit and the second luminance enhancement unit.
The method of claim 6,
The substrate is a backlight unit formed on both sides of the main luminance improving portion parallel to the main luminance improving portion.
The method of claim 6,
The case includes a first coupling portion bent from the top of the side plate and disposed parallel to the support plate,
The reflective plate includes a second coupling portion that is bent outward from an end of the sub-luminance enhancement portion and is disposed parallel to the reflective plate,
The lower surface of the second coupling portion is a backlight unit coupled to the upper surface of the first coupling portion.
The method of claim 6,
The fixed hole is a backlight unit that is disposed closer to the main luminance enhancement portion than the sub luminance enhancement portion.
delete The method of claim 6,
A plurality of first openings exposing the LED are formed on the bottom plate adjacent to the first luminance enhancement portion, and the second luminance enhancement is provided on the bottom plate adjacent to the second luminance enhancement portion. A backlight unit having a plurality of second openings exposing the LED along a portion.
The method of claim 6,
The height of the main luminance improving unit is 20% to 60% of the height of the sub luminance improving unit when measured from the bottom plate.
The method of claim 6,
A backlight unit further comprising an optical member fixed to the side plate facing the support plate.
The method of claim 6,
The LED is a backlight unit including a lens for improving the luminance uniformity of light generated from the LED.
The method of claim 6,
The case and the reflector are backlight units that are mutually coupled by one of a fastening member and an adhesive.
A main luminance enhancement unit formed by bending a portion of the bottom plate having a plate shape, and a sub luminance enhancement formed by bending both ends of the bottom plate facing the main luminance enhancement unit in a direction facing the main luminance enhancement unit, respectively. Reflector including the parts;
A case including a support plate supporting the bottom plate and side plates connected to the support plate and fixing the sub luminance enhancing parts, respectively;
An LED unit interposed between the reflective plate and the support plate and including a substrate disposed parallel to the main luminance improving unit and an LED mounted on the substrate and exposed through the reflective plate; And
It includes a liquid crystal display panel coupled to the case,
The bottom plate includes a first bottom plate and a second bottom plate,
The main luminance improving unit is disposed between the first bottom plate and the second bottom plate,
In the support plate, a part of the support plate is cut and bent to form a reflector fixing portion for fixing the reflector,
The main luminance enhancement portion includes a first luminance enhancement portion inclined with respect to the bottom plate and a second luminance enhancement portion bent from the first luminance enhancement portion with respect to the bottom plate.
The first bottom plate and the second bottom plate are disposed with fixing holes recessed from the side to the inside, respectively, so that the reflecting plate fixing portion penetrates,
The reflecting plate fixing part is bent so that a part passes through the fixing hole and is parallel to the bottom plate,
A display device in which a groove is formed between the bottom plate and the main luminance enhancement unit, and between the first luminance enhancement unit and the second luminance enhancement unit.

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