KR20090073432A - Back lighting module - Google Patents

Abstract

A backlighting module is provided to take an LED package having a prism lens for concentrating light, thereby removing a prism sheet. One or more optical sheets(20) are arranged on an upper side of a plurality of LED(Light Emitting Diode) packages(10). Each of the LED packages has a prism lens(16) forming a pyramid pattern for concentrating light. The prism lens of a prism sheet function is installed at the LED package. Each of the LED packages emits white light. The prism lens collects light. The LED package emits light which is nearly similar to parallel light by the prism lens upward.

Description

Backlighting Module {BACK LIGHTING MODULE}

The present invention relates to a backlighting module, and more particularly, to a backlighting module whose thickness can be reduced by omitting the prism sheet.

Conventionally, Cold Cathode Fluorescent Lamps (CCFLs) have been mainly used as light sources of backlighting modules. However, since the cold cathode fluorescent lamp uses mercury gas, it is not environmentally friendly and has disadvantages such as slow response speed, low color reproducibility, and coarse structure.

On the other hand, an LED (Light Emitting Diode) has the advantage of being environmentally friendly, good response speed and color reproducibility, and the implementation of a relatively compact backlight unit. Therefore, the use of LED as a light source of the backlighting module of the LCD instead of the existing cold cathode fluorescent lamp is increasing trend.

In general, the backlighting module is largely divided into an edge type and a direct type, and a direct type backlighting module is used to illuminate an LCD of a large screen such as a TV. The direct backlight module is formed by arranging a plurality of LEDs of a package structure, that is, LED packages, directly under an illumination object such as an LCD. In this case, the plurality of LED packages includes red, blue, and green LED packages capable of realizing white light through color mixing of light, and they have a direct angle of approximately 120 degrees by reflectors.

In addition, the direct backlight module includes optical components including a diffuser plate, a diffusion sheet, and a prism sheet between the LED package and the illumination object. In order to secure the above-mentioned number of optical parts and a sufficient distance necessary for mixing light, the conventional direct backlight module has a big limitation in reducing its thickness. Of the above optical components, the prism sheet is an optical sheet for condensing purposes, which is one of the factors that greatly limit the slimming of the backlighting module.

Accordingly, the technical problem of the present invention is to provide a backlighting module in which the prism sheet can be omitted according to the employment of an LED package having a prism lens for condensing use, whereby the overall thickness can be reduced.

In order to solve the above technical problem, the present invention includes a plurality of LED packages, and at least one optical sheet disposed on the upper side of the plurality of LED packages, each of the plurality of LED packages is a pyramid for collecting light A backlighting module having a formed prism lens is provided. In this case, since the collection of light, that is, the light collection, is implemented in the LED package itself, the prism sheet can be omitted. In this case, the problem of color mixing of light for white light may be solved by using a plurality of LED packages as white LED packages. At this time, it is possible to obtain a surface light source under a simple condition of reducing the distance between neighboring LED packages.

Preferably, each of the plurality of LED packages includes a housing having an LED chip and a cavity in which the LED chip is accommodated, wherein the prism lens is a resin encapsulant filled in the cavity to protect the LED chip. Is made of. In addition, the prism lens may be interposed with a phosphor that produces white light through wavelength conversion of a part of the light.

In addition, the at least one optical sheet preferably includes a diffusion sheet. The pyramid pattern may be formed by a matrix array of square pyramids having four sides of an isosceles triangle or a matrix array of square pyramids having four sides of an equilateral triangle.

According to the present invention, according to the adoption of the LED package having a prism lens for condensing use, it is possible to omit the prism sheet, thereby obtaining a slim backlighting module having a reduced overall thickness.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples to ensure that the spirit of the present invention can be fully conveyed to those skilled in the art. Therefore, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 is a diagram illustrating a backlighting module according to an embodiment of the present invention.

Referring to FIG. 1, the backlighting module 1 according to the present embodiment is a direct backlighting module including a plurality of LED packages 10 and an optical sheet 20 disposed thereon. The plurality of LED packages 10 are mounted at regular intervals on an upper surface of a base (not shown) such as a PCB. The arrangement of the LED package 10 is preferably a matrix arrangement that can provide a wide surface light source to the illumination object. In addition, the optical sheet 20 is a diffusion sheet for diffusing light from the plurality of LED packages 10, the inside includes a reflective diffuser 21 having, for example, white, milky white or off-white. It is.

In addition to the optical sheet 20, an optical component such as another optical sheet or an optical panel may be installed on the upper side of the plurality of LED packages 10. However, as will be described in detail below, the backlight module 1 of the present embodiment includes a prism lens 16 functioning as a prism sheet in the LED package 10 itself, and thus, the prism sheet used in the existing backlight module. It can be omitted.

The backlighting module 1 may provide white light to an illumination object. To this end, each of the plurality of LED packages 10 is configured to emit white light. Each LED package 10 includes a phosphor that wavelength-converts a portion of light, and the LED package 10 includes, for example, a mixture of blue light that is not wavelength-converted and yellow light wavelength-converted by the phosphor, or White light can be realized by mixing blue light, green light, and red light.

The prism lens 16 functions to collect light, thereby allowing the LED package 10 to emit light, which is almost similar to parallel light, to the image side. As described above, since the plurality of LED packages 10 all emit white light, color mixing of the light above the LED package is not required. However, in order to obtain a desired surface light source, it is preferable to increase the number of LED packages 10 and to narrow the gap between the LED packages 10. When the LED package 10 has a cube or a cuboid structure as a whole, the LED package 10 may be arranged in a state of being in close contact.

2 is a cross-sectional view showing an LED package for a backlighting module according to an embodiment of the present invention, Figure 3 is a view showing a perspective view of the LED package of FIG.

Referring to FIG. 2, the LED package 10 of the present embodiment includes a LED chip 12 and a housing 14 having a cavity 141 in which the LED chip 12 is accommodated. The housing 14 has a power input means for the LED chip 12, the input means is a lead frame or plating pattern extending outward through the housing 14 inside the cavity 141. May be terminals. Then, wiring for electrical connection between the terminals and the LED chip 12 is provided.

Here, the terminals and the wires are well-known that can be variously installed in a deformable manner and are not directly related to the technical spirit of the present invention, and thus the drawings are omitted. In addition, in the drawings, only one LED chip 12 is installed in the cavity 141, but the present invention is not limited thereto. It is also within the scope of the present invention that a plurality of LED chips are installed.

As briefly mentioned above, the LED package 10 includes a prism lens 16 that collects light emitted from the LED chip 12 and emits the light toward the image side. In this embodiment, the prism lens 16 functions as an encapsulant that protects the LED chip 12 in a sealed state together with the function as a lens. To this end, the prism lens 16 may be made of a light transmitting resin. The resin constituting the prism lens 16 may be an epoxy resin or a silicone resin. In addition, the prism lens 16 may include a phosphor 162 for wavelength conversion of light. The upper surface of the prism lens 16, that is, the surface of the prism pattern, is preferably located lower than the upper surface of the housing 14.

Alternatively, the prism lens 16 may be installed as secondary optical means on top of a normal encapsulant which does not have a function as a lens, and this modification is well illustrated in FIG. 4. Referring to FIG. 4, the prism lens 16 is installed as the secondary optical means on the light-transmissive encapsulant 16 ′. In this case, the encapsulant 16 ′ may include a phosphor 162.

The prism lens 16 described with reference to FIGS. 2 to 4 is provided with a prism pattern 164 on an upper surface thereof, and the prism pattern 164 breaks the internal total reflection relationship when the encapsulant is flat. It is preferable that it is a pyramid pattern which raises the extraction amount of light in the angle range which collects light to a vertical direction.

In this case, the pyramid pattern is formed by a matrix arrangement of square pyramids 164a having four sides of the same isosceles triangle, as shown in FIG. 3. More preferably, the four sides of the square pyramid 164a are the same equilateral triangle. By the pyramid pattern by the matrix arrangement of the square pyramid 164 as described above, the light may be emitted in the form of a surface light source that is approximately square (or rectangular) while passing through the pyramid pattern.

1 is a view for explaining a backlight module according to an embodiment of the present invention.

2 is a cross-sectional view showing an LED package used in the backlighting module shown in FIG.

3 is a perspective view of the LED package shown in FIG.

4 is a cross-sectional view showing an LED package for a backlighting module according to another embodiment of the present invention.

Claims (7)

A plurality of LED packages; At least one optical sheet disposed on the upper side of the plurality of LED packages, And each of the plurality of LED packages includes a prism lens having a condensed pyramid pattern. The resin package of claim 1, wherein each of the plurality of LED packages includes a housing having an LED chip and a cavity in which the LED chip is accommodated, wherein the prism lens is encapsulated in a resin material filled in the cavity to protect the LED chip. Backlighting module, characterized in that made of ash. The backlight module of claim 1, wherein the at least one optical sheet comprises a diffusion sheet. The backlight module of claim 1, wherein the pyramid pattern is formed by a matrix arrangement of quadrangular pyramids having four sides of an isosceles triangle. The backlight module according to claim 1, wherein the pyramid pattern is formed by a matrix arrangement of square pyramids having four sides of an equilateral triangle. The backlight module of claim 1, wherein the prism lens comprises a phosphor for wavelength conversion of light. The backlighting module of claim 1, wherein each of the plurality of LED packages is a white LED package emitting white light.

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