KR102472917B1 - Direct Type Back Light Unit - Google Patents

Abstract

The present invention relates to a direct type backlight unit, and according to the present invention, a light-transmitting film; LEDs emitting light at positions spaced apart from the film by an arbitrary interval; a substrate on which a plurality of the LEDs are mounted; And a plurality of light control units disposed on one side of the film to correspond to each of the plurality of LEDs and provided with a light diffuser that transmits or diffuses light and a light reflector that reflects light; thus increasing the uniformity of brightness of the backlight unit. The technology that can do it is disclosed.

Description

Direct type back light unit {Direct Type Back Light Unit}

The present invention relates to a direct type backlight unit for improving uniformity of brightness.

With the recent development of the information society, the demand for display devices is increasing in various forms. In particular, Liquid Crystal Display (LCD) has excellent image quality, light weight, thin shape, and low power consumption. As a result, it is widely used not only in portable flat panel displays, but also in notebooks, computer monitors, and monitors of various video devices that are large-area and require high-quality images.

However, since such an LCD does not emit light itself, a separate external light source is essentially required to realize a high-quality image. Therefore, the structure of such an LCD further includes a backlight unit as a light source of the liquid crystal display panel in addition to the liquid crystal display panel, and the backlight unit uniformly supplies a high-brightness light source to the LCD panel to realize a high-quality image.

As a backlight or light source for flat panel displays such as LCDs, flat lamp elements with high luminance and capable of displaying various colors are AC-driven PDP (Plasma Display Panel) elements, EL (Electro Luminescence) elements, and LED (Light Emitting Elements). Diode) devices, Cold Cathode Fluorescent Lamps (CCFLs), Hot Cathode Fluorescent Lamps (HCFLs), and External Electrode Fuorescent Lamps (EEFLs) are widely used.

Depending on the position where the LED light source is disposed, a bright part and a relatively dark part are generated in the overall diffuser plate, resulting in poor luminance and uniformity of luminance. In order to solve this problem, a plurality of diffusion sheets may be further provided at the location where the diffusion plate is located, or the diffusion plate may be disposed by widening the distance from the light source. However, in this case, the thickness of the backlight becomes thicker.

Therefore, in a direct type backlight unit using LED as a light source, the light emitted from the light source is efficiently reflected, and the light that is not completely incident on the diffusion plate and partially reflected is reflected back to the diffusion plate to improve luminance and luminance uniformity. An efficient direct type backlight unit is required.

Republic of Korea Patent No. 10-0727856

An object of the present invention is to solve the conventional problems as described above, and to provide a direct type backlight unit capable of improving uniformity of brightness by eliminating shade differences.

A direct type backlight unit according to an embodiment of the present invention for achieving the above object includes a light-transmitting film; LEDs spaced apart from the film by a predetermined interval and emitting light toward the film; a substrate on which a plurality of the LEDs are mounted and an electric circuit pattern electrically connected to the LEDs is provided; And it is located between the LED and the film, and is disposed on one side of the film to correspond to each of the plurality of LEDs, and reflects the light emitted from the LED toward the light diffuser and the substrate for transmitting or diffusing It may be characterized as one including; a light control unit provided with a light reflector.

Here, each of the plurality of LEDs may have a smaller diameter or width than the corresponding light control unit as another feature.

Here, in the light control unit. Another feature may be that a spaced area is provided between a portion that transmits or diffuses the light emitted from the LED and a portion that reflects the light toward the substrate.

Here, in the light control unit, another feature may be that a plurality of light reflectors that reflect the light emitted from the LED are provided in a form that is separated from each other.

Here, a light reflector for reflecting the light emitted from the LED is positioned on the central portion of the light control unit, and a light diffuser for transmitting or diffusing the light emitted from the LED reflects the light emitted from the LED. Another feature may be that it is arranged in a form surrounding the light reflector.

Here, the light control unit may be formed by a screen printing method on one side of the film using an ink containing a light diffusion material or a light reflection material.

Here, another feature may be that the plurality of LEDs are disposed on the substrate while being spaced apart from each other at a predetermined interval.

Here, another feature may be that the plurality of light control units disposed on the film are spaced apart from each other at a predetermined interval.

A direct type backlight unit according to another embodiment of the present invention for achieving the above object includes a light-transmitting film; LEDs spaced apart from the film by a predetermined interval and emitting light toward the film; a substrate on which a plurality of the LEDs are mounted and an electric circuit pattern electrically connected to the LEDs is provided; And a plurality of light reflectors disposed between the LED and the film but disposed on one side of the film so as to correspond to each of the plurality of LEDs and reflecting the light emitted from the LED toward the substrate A size corresponding to the LED It may be characterized as one comprising a; light control unit provided with.

Here, in one light control unit, a plurality of light reflectors for reflecting the light emitted from the LED toward the substrate are provided so as to be distinguished from each other, and the plurality of light reflectors have a center point in the center of the light control unit. Another characteristic may be that it has a symmetrical center arrangement.

The direct type backlight unit according to an embodiment of the present invention suppresses the occurrence of a shade difference within the backlight unit, so that the brightness uniformity of the backlight unit is increased.

1 is a perspective view schematically illustrating a direct type backlight unit (BLU) according to an exemplary embodiment of the present invention.
2 is a side view schematically illustrating a side surface of a direct type backlight unit according to an embodiment of the present invention.
3 is a plan view schematically illustrating a light control unit of a direct type backlight unit according to an embodiment of the present invention.
4 and 5 are plan views schematically illustrating an applied form of a light control unit in a direct type backlight unit according to an embodiment of the present invention.
6 is a plan view schematically illustrating a light control unit of a direct type backlight unit according to another embodiment of the present invention.
7 is a plan view schematically illustrating another form of a light control unit in a direct type backlight unit according to another embodiment of the present invention.

Hereinafter, a preferred embodiment will be described with reference to the accompanying drawings so that the present invention can be more specifically understood.

Since the present invention can make various changes and have various embodiments, specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in the present application, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate overall understanding in the description of the present invention, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

1 is a perspective view schematically illustrating a direct type backlight unit according to an embodiment of the present invention, and FIG. 2 is a side view schematically showing a side surface of the direct type backlight unit according to an embodiment of the present invention.

1 and 2, the direct type backlight unit according to an embodiment of the present invention includes a light-transmitting film 300, an LED 200, a substrate 100, and a light control unit 400. include

The light-transmitting film 300 is a film 300 made of a transparent plastic material, and may be made of materials such as polymethyl methacrylate (PMMA), polycarbonate (PC), polyethylene terephthalate (PET), and polystyrene (PS). .

This film 300 is spaced apart from the substrate 100 on which the LEDs 200 are mounted by a predetermined distance, and supports a plurality of light control units 400 disposed on one side.

The LEDs 200 are spaced apart from the film 300 by an arbitrary interval, and are mounted on the substrate 100 to receive support from the substrate 100 . The LED 200 receives power through an electric circuit pattern provided on the substrate 100 and emits light toward the film 300 .

In addition, the plurality of LEDs 200 are spaced apart from each other at regular intervals and disposed on the substrate 100.

A plurality of LEDs 200 are mounted on the substrate 100 . In addition, an electric circuit pattern electrically connected to the plurality of LEDs 200 is provided on the substrate 100 .

In addition, the substrate 100 on which the LED 200 is mounted is spaced apart from the film 300 at a predetermined distance, and a spacer (not shown) may be disposed between the substrate 100 and the film 300 to set such a distance. .

On one side of the substrate 100 on which the LEDs 200 are mounted, a plurality of LEDs 200 are spaced apart from each other at regular intervals, between one LED 200 and another LED 200 adjacent thereto. It is preferable that the part is provided with a reflector.

The light control unit 400 is positioned between the plurality of LEDs 200 and the film 300, and is disposed on one side of the film 300 to correspond to each of the plurality of LEDs 200.

The plurality of light control units 400 disposed on the film 300 may be spaced apart from each other at a predetermined interval.

In addition, the light control unit 400 is provided with a light diffuser that transmits or diffuses the light emitted from the LED 200 and a light reflector that reflects the light toward the substrate 100.

The light control unit 400 includes a modified acrylic resin, a light diffusing material, and a light reflecting material. That is, the light diffuser of the light control unit 400 may include a modified acrylic resin and a light diffusion material, and the light reflector of the light control unit 400 may include a modified acrylic resin and a light reflection material. .

A plastic bead or silica may be used as a light diffusing material, and titanium dioxide (TiO 2 ) may be used as a light reflecting material.

As the modified acrylic resin, a heat drying type, a heat curing type, and an ultraviolet curing type acrylic resin may be used.

The light control unit 400 may be formed on one side of the film 300 by a screen printing method. The light control unit 400 can be formed through a method of screen printing on one side of the film 300 using an ink containing a light diffusion material or a light reflection material. When screen printing is used, it is possible to obtain an advantage of securing uniformity of printing of the light control unit 400 printed on the surface of the film 300 .

In addition, since the material of the light reflector part and the light diffuser part of the light control unit 400 are different, 2-color printing or 3-color printing can be applied as a form of screen printing.

Regarding the size of the light control unit 400 and the LED 200, each of the plurality of LEDs 200 preferably has a smaller diameter or width than the corresponding light control unit 400. In other words, it is preferable that the width or diameter of the light control unit 400 is equal to or larger than the corresponding width or diameter of the LED 200 . Accordingly, the light control unit 400 may have a width or diameter 2 to 3 times greater than the width or diameter of the LED 200 .

And in the light control unit 400. It is preferable that a spaced area is provided between the light diffuser, which transmits or diffuses the light emitted from the LED 200, and the light reflector 410, which reflects the light toward the substrate 100.

Further reference will be made to FIG. 3 here. 3 is a plan view schematically illustrating a light control unit of a direct type backlight unit according to an embodiment of the present invention.

3, the light reflector 410 is located at the center of one light control unit 400, and the light diffuser 430 has a ring-like shape surrounding the light reflector 410. are placed In addition, a spaced portion 420 is provided between the light reflector 410 and the light diffuser 430 .

Some of the light emitted from the LED 200 through the spaced area 420 may pass through the film 300 and travel straight. The light reflector 410 reflects the light emitted from the LED 200, and the light diffuser 430 diffuses the light emitted from the LED 200.

Accordingly, it is possible to suppress an area of relatively low brightness from being generated between one LED 200 and another LED 200 adjacent thereto.

And, within the light control unit 400, it is also preferable that a plurality of light reflectors 410 that reflect the light emitted from the LED 200 are spaced apart from each other and provided in a differentiated form. Here, further reference will be made to FIGS. 4 and 5 .

4 and 5 are plan views schematically showing an applied form of a light control unit in a direct type backlight unit according to an embodiment of the present invention.

First, as referenced in FIG. 4 , within one light control unit 401, a light reflector 410 is positioned at a center point CP. Further, a light reflector 412 is further disposed next to the region 420 spaced apart from the center point CP by a predetermined distance in an outward direction. Further, the light diffusing body 430 is disposed next to the area 422 spaced apart by a predetermined distance in the outward direction.

As such, in the light control unit 401, a part that reflects the light emitted from the LED 200 is located at the center point (CP) of the light control unit 401, and the light emitted from the LED 200 A portion that transmits or diffuses may be disposed in a form surrounding a portion that reflects light emitted from the LED 200 .

In this way, the area 410 where light is reflected, the area 420, 422 where light is transmitted, and the area 430 where light is diffused are It is also preferable that the light control units 401 are formed to appear in sequence.

On the other hand, the shape of the light control unit 402 as referenced in FIG. 5 is also possible.

Referring to FIG. 5, a light reflector 410 is disposed at the center point CP of the light control unit 402, and a plurality of light reflectors 414 with the light reflector 410 disposed in the center as a center of symmetry and the light diffuser 434 are arranged in a radial form.

The light diffuser 434 is disposed on both sides with one light reflector 414 interposed therebetween, and spaced apart 427 at a predetermined angle between the light diffuser 434 and the light reflector 414 adjacent to each other. have.

Alternatively, the light reflector 414 and the light diffuser 434 are alternately arranged with each other, and are sequentially arranged in a clockwise or counterclockwise direction centering on the light reflector 410 located at the center point CP. may be

In this way, the form in which the plurality of light reflectors 414 and the light diffuser 434 are arranged can also increase the brightness uniformity of the direct type backlight unit. Here, the area of one light reflector 414 and the area of one light diffuser 434 may be formed to be the same, and if necessary, the area of the light reflector 414 is the area of the light diffuser 434. The area of the light reflector 414 may be formed larger than that of the light diffuser 434 .

For reference, although some exemplary forms of the light control unit 400 according to the embodiment of the present invention are shown through FIGS. It is possible enough, and it is stated that this form is not excluded.

Meanwhile, a direct type backlight unit according to another embodiment is also possible as follows. A direct type backlight unit according to another embodiment of the present invention includes a film 300, an LED 200, a substrate 100, and a light control unit 400, wherein the film 300, the LED 200, and the substrate (100) is the same as described above.

The light control unit 400 is located between the LED 200 and the film 300, but is arranged in plurality on one side of the film 300 to correspond to each of the plurality of LEDs 200, and the light emitted from the LED 200 A portion that reflects the substrate 100 side is provided in a size corresponding to the LED 200.

Here, a description will be made with further reference to FIGS. 6 and 7 .

6 is a plan view schematically illustrating a light control unit of a direct type backlight unit according to another embodiment of the present invention, and FIG. 7 is a light control unit 400 in a direct type backlight unit according to another embodiment of the present invention. It is a plan view schematically showing the shape.

As referenced in FIG. 6 , a form in which one light reflector 410 is provided as the light control unit 403 is also possible. In this case, the light control unit 400 may have a larger width or diameter than that of the LED 200 . For example, it can be equipped with about twice the size.

Since the light control unit 403 reflects the light emitted from the LED 200, it is possible to suppress the occurrence of shadows between the LEDs 200 and to make the overall brightness of the backlight unit uniform. have.

In addition, as a more applied form, a plurality of light reflectors, which are parts that reflect the light emitted from the LED 200 toward the substrate 100, are provided in a single light control unit so that they can be distinguished. The reflector may have a disposition form in which the center point CP of the light control unit 400 is symmetrical.

As referenced in FIG. 7, one light reflector 410 is disposed in the center of one light control unit 404, and other light reflectors 416 divided around the light reflector 410 as a center can be placed. Here, preferably, a plurality of light reflectors 416 are arranged to have a radial shape with the central center CP of the light control unit 404 as a center of symmetry.

Such a light control unit 404 is also preferable because it can suppress the occurrence of shadows between the LEDs 200 and the LEDs 200 .

As such, the direct type backlight unit according to the present invention, unlike the conventional method, that is, the method of shielding the light emitted from the LED 200 without considering the reflection and diffusion of light, loses the amount of light and has low light uniformity, unlike the light source The part induces reflection to exhibit a shielding effect, and at the same time, it can disperse light between light sources.

Therefore, light scattered between the light sources is diffused or scattered to suppress the light intensity difference between the light sources and to suppress dark areas, thereby improving overall light uniformity of the backlight unit.

As described above, according to the direct type backlight unit according to the present invention, there is an advantage in that the uniformity of the brightness of the backlight unit can be increased by suppressing the generation of shade difference.

As described above, the specific description of the present invention has been made by the embodiments with reference to the accompanying drawings, but since the above-described embodiments have only been described with reference to preferred embodiments of the present invention, the present invention is the above It should not be understood as being limited only to the embodiments, and the scope of the present invention should be understood as the following claims and equivalent concepts thereof.

100: substrate 200: LED
300: film 400: light control unit
410: light reflector 430: light diffuser
CP: central point of light control unit

Claims (10)

A film that is transparent to light;
LEDs spaced apart from the film by a predetermined interval and emitting light toward the film;
a substrate on which a plurality of the LEDs are mounted and an electric circuit pattern electrically connected to the LEDs is provided; and
It is located between the LED and the film, but a plurality of light control units disposed on one side of the film to correspond to each of the plurality of LEDs; includes,
The light control unit is provided with a light diffuser that transmits or diffuses the light emitted from the LED and a light reflector that reflects the light toward the substrate,
A direct backlight unit, characterized in that a spaced area is provided between the light diffuser and the light reflector.
According to claim 1,
Each of the plurality of LEDs has a smaller diameter or width than the corresponding light control unit.
delete According to claim 1,
Within the light control unit,
Direct type backlight unit, characterized in that a plurality of light reflectors for reflecting the light emitted from the LED are provided in a form separated from each other.
According to claim 1,
A light reflector for reflecting the light emitted from the LED is located on the central portion of the light control unit,
Direct type backlight unit, characterized in that the light diffuser for transmitting or diffusing the light emitted from the LED is disposed in a form surrounding the light reflector for reflecting the light emitted from the LED.
According to claim 1,
The light diffuser and the light reflector provided in the light control unit
A direct type backlight unit characterized in that it is formed by a screen printing method on one side of the film using ink containing a light diffusion material or ink containing a light reflection material.
According to claim 1,
A direct type backlight unit, characterized in that the plurality of LEDs are disposed on the substrate while being spaced apart from each other at a predetermined interval.
According to claim 1,
The direct type backlight unit, characterized in that the plurality of light control units disposed on the film are spaced apart from each other at a predetermined interval.
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