KR20150086888A - Light emitting module, and backlight unit - Google Patents

Abstract

An embodiment includes a light emitting device and a light guide member which receives light emitted from the light emitting device, reflects the received light, and emits the reflected light. The light guide member includes a guide body, a light incident part which is located on a side of the guide body and receives light from the light emitting device, a reflection part which is located in the guide body and has a reflection surface of reflecting light received from the light incident part, and a light emitting part which emits light reflected by the reflection surface. A separation distance from the light emitting part to the reflection surface gradually decreases from the light incident part.

Description

A light emitting module, and a backlight unit (LIGHT EMITTING MODULE, AND BACKLIGHT UNIT)

Embodiments relate to a light emitting module and a backlight unit.

In a liquid crystal display device that is a light-receiving type device without a self-emitting source, a separate light source device capable of illuminating the entire screen from the back side is required. Such a lighting device for a liquid crystal display device is generally referred to as a backlight unit.

Generally, a backlight unit can be distinguished by an edge-light method and a direct lighting method according to the manner in which a light source (e.g., an LED) is disposed.

In an edge-light system, a light source (e.g., an LED) may be disposed on a side surface of a light guide plate for guiding light. The edge-light method can be applied to a comparatively small liquid crystal display device such as a desktop computer or a monitor for a notebook computer, and has good uniformity of light and excellent durability.

In the direct-type method, the light source can be arranged at the lower part of the liquid crystal panel to directly illuminate the front surface of the liquid crystal panel. This direct-type method can be used for a medium-

BACKGROUND ART Generally, a backlight unit includes a light emitting module including a light emitting diode (LED) mounted on a bar-shaped circuit board, a light guide plate (LGP), a reflector sheet, And may include an optical sheet.

Embodiments provide a light emitting module and a backlight unit that can reduce power consumption and heat generation, and can provide uniform brightness and uniform color.

A light emitting module according to an embodiment includes a light emitting element; And a light guide member that receives light emitted from the light emitting device, reflects the received light, and emits the reflected light, the light guide unit comprising: a guide body; An incident portion located at one side of the guide body and receiving light from the light emitting element; A reflective part positioned in the guide body and having a reflective surface reflecting light received by the incidence part; And an exit portion for emitting the light reflected by the reflection surface, wherein a distance from the exit portion to the reflection surface decreases as the distance from the incidence portion increases.

The guide body may include an upper surface, a lower surface facing the upper surface, and side surfaces located between the upper surface and the lower surface, the incidence portion being located on one side of the guide body, And may be positioned on another side surface of the guide body.

The incident portion may be an opening formed on one side surface of the guide body.

The emitting portion may include a plurality of openings formed on the other side surface of the guide body so as to be spaced apart from each other.

Wherein one end of the reflecting surface is in contact with the inside of the first corner of the guide body and the other end of the reflecting surface is in contact with the inside of the second corner of the guide body, The corners can face each other.

A distance from the reflective surface may be smaller as the position of the plurality of apertures is located farther from the incident portion.

The inside of the guide body is empty, and air can be filled.

The reflection surface is flat, and the angle formed between the reflection surface and the incident portion may be an acute angle.

A backlight unit according to an embodiment includes a light emitting module that emits light; A light guide plate for guiding light emitted from the light emitting module; And an optical sheet disposed on the light guide plate and diffusing light emitted from the light guide plate, wherein the light emitting module may be an embodiment.

The emitting portion may include a plurality of openings spaced apart from each other, and a distance between the emitting portion and the reflecting surface may be smaller as the emitting portion is located farther from the incident portion.

The light guide plate has a light incidence surface through which light emitted from the light emitting module is incident, and a light scattering pattern corresponding to each of the plurality of apertures may be formed on the light incidence surface.

The embodiment can reduce power consumption and heat generation, and can provide uniform brightness and uniform color.

1 shows a display device including a backlight unit according to an embodiment.
2 is an exploded perspective view of the light emitting module shown in FIG.
FIG. 3 is a perspective view of the light emitting module shown in FIG. 2; FIG.
4 is a plan view of the light emitting module shown in Fig.
Fig. 5 shows a front view of the light emitting module shown in Fig. 2. Fig.
FIG. 6 shows light incident on the light-entering surface of the light guide plate shown in FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. In the description of the embodiments, it is to be understood that each layer (film), region, pattern or structure may be referred to as being "on" or "under" a substrate, each layer It is to be understood that the terms " on "and " under" include both " directly "or" indirectly " do. In addition, the criteria for the top / bottom or bottom / bottom of each layer are described with reference to the drawings.

In the drawings, dimensions are exaggerated, omitted, or schematically illustrated for convenience and clarity of illustration. Also, the size of each component does not entirely reflect the actual size. The same reference numerals denote the same elements throughout the description of the drawings. Hereinafter, a light emitting module and a backlight unit according to embodiments will be described with reference to the accompanying drawings.

1 shows a display device 100 including a backlight unit 120 according to an embodiment.

Referring to FIG. 1, a display device 100 includes a cover 110, a backlight unit 120, a liquid crystal panel 130, and a light shielding tape 140.

The cover 110 accommodates and fixes the backlight unit 220 and the liquid crystal panel 230.

The backlight unit 120 may be disposed inside the cover 110, and may generate light to be emitted to the liquid crystal panel 130. For example, the backlight unit 120 may be of an edge-light type that irradiates light to at least one side of the light guide plate 123 (hereinafter referred to as "light incoming surface").

The backlight unit 120 includes a light emitting module 121, a light guide plate 123, a reflector sheet 124, and an optical sheet 125.

The light emitting module 121 may be positioned adjacent to the light incident surface 101 on one side of the light guide plate 123 and may emit light to the light incident surface 101 of the light guide plate 123.

The light emitting module 121 may include a substrate 161, a light emitting element 165, and a light guide portion 167.

The substrate 161 may be a printed circuit board, for example, a flexible PCB (Printed Circuit Board).

A circuit pattern including the first conductive layer 212 and the second conductive layer 214 may be formed on the substrate 161. A first power source (e.g., a positive power source) may be supplied to the first conductive layer 212 and a second power source (e.g., negative power) may be supplied to the second conductive layer 212 .

The light emitting device 165 is mounted on the substrate 161 and can emit light. For example, on the substrate 161 so as to be electrically connected to the first conductive layer 212 and the second conductive layer 214.

The light emitting device 165 may be a light emitting diode (LED), or may be a chip or a light emitting device package. For example, the light emitting device 165 may be a side view type light emitting device package.

The number of the light emitting elements 165 to be mounted on the substrate 161 may be one or more. For example, one light emitting device 165 may be mounted on the substrate 161 to minimize the number of the light emitting devices 165.

The light guide portion 167 guides or reflects the light emitted from the light emitting device 165 to the light incidence surface 101 of the light guide plate 123. [

FIG. 2 is an exploded perspective view of the light emitting module 121 shown in FIG. 1. FIG. 3 is a perspective view illustrating the light emitting module 121 shown in FIG. And FIG. 5 shows a front view of the light emitting module 121 shown in FIG.

2 to 5, the light emitting module 121 includes a light emitting element 165 mounted on the substrate 161, and a light guiding plate 151 guiding the light emitted from the light emitting element to the light incident surface 101 of the light guiding plate 123 And may include a light guide portion 167.

The light guide portion 167 includes a guide body 310, an incidence portion 312 located on one side of the guide body 310, an exit portion 314 located on the other side of the guide body 310, And a reflection unit 316 disposed in the reflection unit 310 and reflecting or guiding light incident through the incident unit 312 to the emission unit 314.

The remaining portion of the guide body 310 excluding the incident portion 312 and the emitting portion 314 may be a non-transmissive material.

The guide body 310 may have a rectangular parallelepiped shape as shown in FIG. 2. However, the guide body 310 may have various shapes depending on the shape of the light guide plate 123 or the shape of the light entrance surface 101 of the light guide plate 123 Can be implemented.

For example, the guide body 310 may include a top surface 401, a bottom surface 402 facing the top surface 401, and side surfaces 403a, 403b positioned between the top surface 401 and the bottom surface 402 , 403c, and 403d.

The interior of the guide body 310 may be empty, filled with air, or in a vacuum state.

The incident portion 312 may be positioned on one side surface 403b of the guide body 310 and may allow light emitted from the light emitting device 165 to enter the inside of the guide body 310. [

The incidence part 312 may be in the form of an opening formed on one side surface 403b of the guide body 310 or in the form of a window of a translucent material.

The shape of the incident portion 312 may be the same as the shape of the light emitting surface of the light emitting device 165 and the area of the incident portion 312 may be equal to or larger than the area of the light emitting surface of the light emitting device 165.

For example, the incident portion 312 may correspond to one light emitting element 165. [

The light emitting surface of the light emitting device 165 may face the incident portion 312 and the light emitted from the light emitting surface of the light emitting device 165 may be irradiated into the guide body 310 through the incident portion 312 .

The emitting portion 314 may be positioned on the other side 403c of the guide body 310 and may emit light out of the guide body 310. [

The angle formed by the incident portion 312 and the emitting portion 314 may be vertical, but is not limited thereto. The emitting portion 314 may face the light incidence surface 101 of the light guide plate 123. [

The emitting portion 314 may be in the form of an opening formed in the other side surface 403c of the guide body 310 or may be in the form of a window of a light transmitting material.

For example, the emitting portion 314 includes a plurality of openings (openings 314-1 to 314-n, n> 1) formed on the other side surface 403c of the guide body 310 so as to be spaced apart from each other .

Scattering patterns 111-1 to 111-n and natural numbers of n> 1, which scatter light to be emitted, may be formed on the light incidence surface 101 of the light guide plate 123.

The light scattering patterns 111-1 to 111-n, n > 1 (n-1) formed on the light-incoming surface 101 of the light guide plate 123, Which is a natural number).

The area of each of the plurality of openings 314-1 to 314-n, n> 1 is equal to or larger than the area where the corresponding scattering pattern 111-1 to 111-n, n> 1 is formed have.

Further, the shape of each of the plurality of openings 314-1 to 314-n, natural number of n> 1 may be implemented in various shapes such as a polygon, a circle, and an ellipse.

The shape of the emitting portion 314 formed on the other side surface 403c of the guide body 310 is not limited to the above. For example, the emitting portion 314 may be one opening formed in the other side surface 403c of the guide body 310. [

The reflector 316 may be disposed inside the guide body 310 and may have a flat reflective surface 316-1 that reflects the light emitted from the light emitting device 165 to the output portion 314. [

The angle? Between the reflective surface 316 and the incident portion 312 may be an acute angle greater than 0 ° and less than 90 ° (0 ° <θ <90 °).

One end of the reflecting surface 316 may be in contact with the inside of the first corner 411 of the guide body 310 and the other end of the reflecting surface 316 may contact the inside of the second edge 412 of the guide body 310 And the first corner 411 and the second corner 412 can be opposed to each other. The upper end of the reflecting surface 316 may be in contact with the inner upper surface of the guide body 310 and the lower end of the reflecting surface 316 may be in contact with the inner lower surface of the guide body 310.

The distance d from the emitting portion 314 to the reflecting surface 316-1 can be reduced as the distance from the incident portion 312 or the light emitting element 165 increases.

The distance d between the opening and the reflecting surface 316 may be smaller as the opening located farther from the light incidence part 312 or the light emitting element 165 is.

The distance between any one of the openings (e.g., 314-5) and the reflective surface 316-1 of the plurality of openings 314-1 to 314-n, n > 1 is a plurality of openings 314-1 314-4) and the reflective surface 316-1, and any one of the apertures (e.g., 314-n, 314-n, n> 5 and the incident portion 132 may be larger than the spacing distance between any one of the openings 314-4 and the incident portion 132. [

The amount of light emitted from each of the openings can be uniform by making the distance d between the opening and the reflecting surface 316 smaller as the opening located farther from the incident portion 132 is.

Fig. 6 shows light incident on the light incidence surface 101 of the light guide plate 123 in Fig.

6, since the distance d between the opening and the reflecting surface 316 is smaller as the opening located far from the incident portion 132 or the light emitting element 165, the light amount of light emitted to each of the openings Can be uniform throughout.

Since light having a uniform light quantity can be irradiated onto the entire surface of the light incidence surface 101 of the light guide plate 123, the embodiment can provide uniform brightness and uniform color feeling.

4, the reflective portion 316 may be formed to fill an inner portion of the guide body 310, but is not limited thereto.

For example, in other embodiments, the reflective portion 316 may have only a reflective surface in the form of a plate or sheet.

The reflective portion 316 may be made of the same material as the guide body 310, but is not limited thereto. For example, the reflective portion 316 may be made of a reflective material, e.g., white silicon. Or the reflecting portion 316 may be made of a light transmitting material and may include a reflecting member coated on the reflecting surface 316-1.

The light guide plate 123 is disposed such that the light incidence surface 101 faces the light exit portion 314 of the guide body 310 and receives light emitted from the light exit portion 314 to guide the light toward the liquid crystal panel 130.

For example, the light guide plate 123 may be formed of poly methyl methacrylate (PMMA), polycarbonate (PC), or polyethylene (PE).

The reflective sheet 124 is disposed on the rear surface (or the bottom surface) of the light guide plate 123 and reflects light emitted to the rear surface of the light guide plate 123 and re-enters the light guide plate 123.

The reflective sheet 124 may be made of a material having a high reflectivity and being ultra-thin, and may be made of polyethylene terephthalate (PET).

The optical sheet 125 is disposed on the front surface (or the top surface) of the light guide plate 123 and diffuses the light emitted from the light guide plate 123 at a predetermined angle. For example, the optical sheet 125 can uniformly illuminate the light guided by the light guide plate 123 with the liquid crystal panel 130.

The optical sheet 125 may be a structure in which a plurality of optical sheets (e.g., a protective sheet, a prism sheet, a diffusion sheet) are laminated or a structure including a plurality of optical sheets and a microlens array.

The liquid crystal panel 130 is provided on the front surface of the optical sheet 125.

In the liquid crystal panel 130, the liquid crystal is positioned between the glass substrates and the polarizing plate is placed on both glass substrates to utilize the polarization of light. Here, the liquid crystal has an intermediate property between a liquid and a solid, and liquid crystals, which are organic molecules having fluidity like a liquid, are regularly arranged like crystals. The liquid crystal has a structure in which the molecular arrangement is changed by an external electric field And displays an image. A color filter (not shown) may be provided on the front surface of the liquid crystal panel 230.

The light shielding tape 140 may be composed of a double-sided black tape and is attached between the liquid crystal panel 130 and the cover 110 to block light leaking into a gap between the liquid crystal panel 130 and the cover 110 .

Compared to a backlight using a plurality of light emitting devices, the embodiment can reduce heat generation and power consumption since light is supplied to the light guide plate 123 by using one light emitting device.

Also, in the embodiment, light having a uniform light quantity can be irradiated to the entire surface of the light incidence surface 101 of the light guide plate 123, and uniform brightness and uniform color feeling can be provided.

The features, structures, effects and the like described in the embodiments are included in at least one embodiment of the present invention and are not necessarily limited to one embodiment. Further, the features, structures, effects, and the like illustrated in the embodiments can be combined and modified by other persons having ordinary skill in the art to which the embodiments belong. Therefore, it should be understood that the present invention is not limited to these combinations and modifications.

110: Cover 121: Light emitting module
123: light guide plate 124: reflective sheet
125: optical sheet 120: backlight unit
130: liquid crystal panel 140: shielding tape
161: substrate 165: light emitting element
167: light guide part 310: guide body
312: incident part 314:
316: Reflective portion.

Claims (11)

A light emitting element; And
And a light guide member for receiving the light emitted from the light emitting element, reflecting the received light, and emitting the reflected light,
The light guide portion
Guide body;
An incident portion located at one side of the guide body and receiving light from the light emitting element;
A reflector positioned in the guide body and having a reflective surface reflecting the light received by the incidence portion; And
And an exit portion for emitting the light reflected by the reflection surface,
And the distance from the emitting portion to the reflecting surface decreases as the distance from the incident portion increases. [2] The apparatus of claim 1,
An upper surface, a lower surface facing the upper surface, and side surfaces located between the upper surface and the lower surface,
Wherein the incidence portion is located at one side of the guide body and the exit portion is located at another side of the guide body. 3. The method of claim 2,
And the incident portion is an opening formed on one side surface of the guide body. 3. The method of claim 2,
And the emitting portion includes a plurality of openings formed on the other side of the guide body so as to be spaced apart from each other. 3. The method of claim 2,
One end of the reflecting surface is in contact with the inside of the first corner of the guide body,
Wherein the other end of the reflective surface abuts the inside of the second edge of the guide body, and the first edge and the second edge face each other. 5. The method of claim 4,
And a distance from the reflecting surface is smaller as the position of the plurality of openings is farther from the incident portion. The method according to claim 1,
Wherein the interior of the guide body is empty and filled with air. The method according to claim 1,
Wherein the reflective surface is flat, and the angle formed between the reflective surface and the incident portion is an acute angle. A light emitting module for emitting light;
A light guide plate for guiding light emitted from the light emitting module; And
And an optical sheet disposed on the light guide plate for diffusing light emitted from the light guide plate,
The light emitting module includes:
And a light guide part for receiving the light emitted from the light emitting element, reflecting the received light, and emitting the reflected light,
The light guide portion
A guide body;
An incident portion located at one side of the guide body and receiving light from the light emitting element;
A reflector positioned in the guide body and having a reflective surface reflecting the light received by the incidence portion; And
And an exit portion for emitting the light reflected by the reflection surface,
Wherein the distance from the emitting portion to the reflecting surface decreases as the distance from the incident portion increases. 10. The method of claim 9,
The exit portion includes a plurality of openings spaced from each other,
Wherein a distance from the reflective surface is smaller as the position of the plurality of apertures is farther away from the incidence portion. 11. The method of claim 10,
Wherein the light guide plate has a light incidence surface on which light emitted from the light emitting module is incident, and a light scattering pattern is formed on the light incidence surface corresponding to each of the plurality of apertures.

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