KR20080016074A - Backlight unit - Google Patents

Abstract

A backlight unit is provided to use an optical fiber and a light guiding member in which the optical fiber is disposed, thereby reducing thickness and weight of the backlight unit. A backlight unit comprises a light source(102) for generating light, an optical fiber(121) of which both ends are connected to the light source, and a light guiding member(111) for diffusing the light. The optical fiber is disposed within the light guiding member. The optical fiber transfers the light, which is supplied from the light source, to the light guiding member. The optical fiber has a plurality of winding portions.

Description

Backlight Unit

1 is an exploded perspective view of a conventional direct type liquid crystal display device.

2 is an exploded perspective view of a conventional edge type liquid crystal display.

3 is a perspective view of a backlight unit according to a first embodiment of the present invention.

4A discloses a shape of an optical fiber according to the present invention.

4B is a light exit diagram of an optical fiber according to the present invention.

4C is a light emission diagram of the backlight unit according to the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a structure of a light source, an optical fiber, and a light guide member of a backlight unit to which two light sources are applied, which can be applied by the first embodiment of the present invention.

6 is a view showing the structure of a light source, an optical fiber and a light guide member of a backlight unit in which optical fibers are arranged in a zigzag form, which can be applied by the first embodiment of the present invention.

7A and 7B illustrate a structure of a light source, an optical fiber, and a light guide member of a backlight unit to which a light guide member having a prism pattern is printed, which can be applied by the first embodiment of the present invention, and light output of the optical fiber; It is a figure which shows a part.

FIG. 8 is a view showing the structure of a light source, an optical fiber, and a light guide member of a backlight unit in which a light source is disposed in a diagonal direction, which can be applied by the first embodiment of the present invention.

FIG. 9 is a diagram illustrating a structure of a light source, an optical fiber, and a light guiding member of a backlight unit including a plurality of light sources and arranged in a zigzag form, which may be applied by the first embodiment of the present invention.

10 is an exploded perspective view of a liquid crystal display according to a second exemplary embodiment of the present invention.

<Explanation of symbols for the main parts of the drawings>

100: light source 101: light source case

102: light source 103: lamp reflector

111 light guide member 112 light exit pattern on the light guide member

121: optical fiber 122: light output unit on the optical fiber

130: optical sheets 140: reflective sheet

150: backlight unit 210: lower storage container

220: storage frame 230: upper storage container

310: liquid crystal display panel 311: thin film transistor substrate

312: color filter substrate 320: driver

321: Gate Tape Carrier Package

322: data tape carrier package

323 printed circuit board

The present invention relates to a backlight unit using an optical fiber.

Commonly used display devices include a cathode ray tube (CRT), a plasma display panel (PDP), and a liquid crystal display (LCD). In particular, as a flat panel display device, a liquid crystal display device that is light in weight and easy to slim in recent years has been utilized in various fields including a mobile phone, a monitor, and a TV, and the demand thereof has increased greatly in recent years.

The liquid crystal display panel of the liquid crystal display device requires a backlight unit because it uses a method of adjusting the transmittance of light provided through a separate light source without emitting light by itself.

The backlight unit which is generally used is composed of a light source, a light guide member for diffusing the light of the light source and an optical sheet that functions as a diffusion or condensing, and a direct method (FIG. 1) for providing light under the light guide member. It is divided into an edge method (FIG. 2) that provides light at the side. However, such a structure is limited in light weight and ultra slim, and it is difficult to apply to a flexible image display device that is recently emerging.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a backlight unit that enables lightweight and ultra-slim.

According to the present invention, there is provided a backlight unit comprising: a light source; A light guiding member that diffuses light to one surface and uniformly distributes light in a light emission direction; And an optical fiber for transmitting the light provided from the light source to the light guide member.

Here, the light source includes an LED, a lamp, and other light sources, and the optical fiber is preferably connected to both ends of the light source and partially disposed in the light guide member.

In addition, the optical fiber is preferably formed with a plurality of scratches or grooves for emitting light.

In addition, the light guide member may include a plurality of hemispherical lens patterns having a predetermined pitch or a plurality of prism patterns having a predetermined pitch and parallel to each other.

Here, the optical fiber is preferably disposed along the edge of the inside of the light guide member or arranged in a zigzag shape, and the light source connected to the optical fiber at the end of the optical fiber is preferably located at the side of the light guide member.

In addition, the lower portion of the light guide member, that is, the surface opposite to the light exit surface of the light guide member is preferably coated with a film reflecting light or a reflective sheet is located.

On the other hand, the object is, according to the present invention, a liquid crystal display panel in which an image is displayed, a light source, an optical fiber which is connected to the light source and serves to transmit light, a light guide member having a portion of the optical fiber disposed therein, and It can be achieved by a liquid crystal display device comprising a reflective sheet disposed at a position opposite to the direction of the liquid crystal display panel from the light guide member.

Here, the light guide member of the liquid crystal display device preferably has a plurality of hemispherical lens patterns having a predetermined pitch or a plurality of prism patterns having a predetermined pitch and parallel to each other on a surface facing the liquid crystal display panel. Do.

In addition, the optical fiber connected to the light source and transmitting light to the light guide member may be disposed along an edge of the inside of the light guide member or disposed in a zigzag shape.

The light source connected to the optical fiber at the end of the optical fiber includes an LED, a lamp, and other light sources, and is preferably located at the side of the light guide member.

Here, the scratch or groove is formed to the outside of the optical fiber to function to emit light, the position and spacing of the scratch or groove is adjusted to increase the efficiency and uniformity of the luminance according to the pattern of the light guide member. desirable.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

3 is a perspective view of a backlight unit according to a first embodiment of the present invention. As shown in the drawing, the backlight unit according to the present invention includes a light source unit 100, an optical fiber 121, a light guide member 111, and optical sheets 130.

An LED, a lamp, and other light sources may be used as the light source 102, and are located at the side of the light guide member 111 and connected to the optical fiber. The method of connecting the light source 102 and the optical fiber 121 may be used in various ways according to those skilled in the art. In FIG. 3, a method of connecting the light source 102 and the optical fiber 121 through a case 101 having a hole for enclosing the light source 102 and inserting the optical fiber 121 is disclosed.

The light guide member 111 is formed of a transparent plastic material such as acrylic, and the optical fiber 121 is disposed at an inner edge portion of the light guide member 111, and thus, the liquid crystal display may display a direction of the light emitted from the optical fiber 121. Switch to the panel (not shown). A fine lens-shaped dot pattern 112 is formed in an upper direction of the light guide member 111 facing the liquid crystal display panel, and the pattern 112 is arranged according to a predetermined pitch. The lens dot pattern 112 is preferably in the range of 50 ~ 300㎛ diameter. The thickness of the light guide member 111 is preferably within 1 mm, and the pitch of the pattern 112 is a distance between the center point of the dot pattern 112 and the center point of the dot pattern closest to the dot pattern 112. The pitch is preferably between 1 and 6 times the diameter of the dot pattern 112, and the individual pitch may be changed according to the distance from the optical fiber 121.

In addition, the light guide member 111 may be a rigid plate form or a flexible sheet form that can be deformed according to the purpose of use.

The shape of the optical fiber 121 has been described with reference to Figure 4a. The surface of the optical fiber 121 is provided with a light emitting portion 122 made of a scratch or a groove to transmit the light provided from the light source 102 to the light guide member 111 through the light emitting portion.

The light exit through the optical fiber 121 has been described with reference to Figure 4b. As shown, light provided from the light source 102 exits the optical fiber through grooves or scratches formed in the optical fiber. In this case, the light output part 122 is preferably formed at the side of the optical fiber 121 to face the inside of the light guide member 111.

The lower surface of the light guide member 111 facing the upper light exit surface on which the pattern 112 is formed is preferably coated with an ink of a reflective material or a film (not shown) of a reflective material is attached.

Between the liquid crystal display panel and the light guide member 111, a diffusion sheet for diffusing the light emitted above the light guide member at a predetermined angle and a light collecting sheet for condensing the diffused light and transferring the light to the liquid crystal display panel are provided. do. The type of the optical sheets and the number of sheets provided may vary depending on the characteristics of the applied product.

4C discloses a light emission diagram according to the first embodiment of the present invention. Light emitted from the light output part 122 of the optical fiber 121 is diffused toward the upper direction of the light guide member 111 as shown through the inside of the light guide member 111.

5 to 9, the structure of the backlight unit applicable to the first embodiment of the present invention is disclosed.

5 is a plan view of a backlight unit in which both ends of the optical fiber 121 are connected to two light sources 102, and the optical fiber 121 is disposed at an edge portion of the light guide member 111.

6 is a plan view of a backlight unit in which both ends of the optical fiber 121 are connected to two light sources 102, and the optical fiber 121 is disposed in a zigzag form in the light guide member 111. As illustrated, when the optical fiber 121 is disposed in a zigzag form inside the light guide member 111, the light output part 122 of the optical fiber 121 faces the light exit surface of the light guide member 111. It is preferably formed on the optical fiber 121.

7A illustrates a light guide member 111 having a prism pattern formed in a light output part, two light sources 102, and both ends thereof connected to the light source, and a part of an edge portion inside the light guide member 111. It is a top view of the backlight unit provided with the optical fiber 121 arrange | positioned at. As shown in FIG. 7B, the light output part 122 of the optical fiber 121 is not formed in a portion parallel to the long axis direction of the prism pattern, and is uniformly pitched in a portion parallel to the short axis direction of the prism pattern. It is preferable to arrange | position accordingly in order to acquire uniform luminance characteristic. At this time, the angle between the two sides and the bottom surface constituting the protruding mountain region of the Prism pattern is preferably in the range of 80 to 120 degrees, the height from the bottom surface to the vertex of the mountain region is preferably in the range of 10 ~ 100um.

In general, in the case of plastic optical fibers, unlike the Si-based optical fibers, the optical loss is 0.2d / m, and 5% of the loss occurs when the light proceeds 1m. Therefore, a method of adjusting the amount of light emitted while the light proceeds should be considered.

8 and 9 are plan views of a backlight unit using a plurality of light sources 102 and a plurality of optical fibers 121 to increase light emission rate and uniformity. In particular, in the disposition of the optical fiber 121, the light guide member 111 is disposed at a portion where the optical fiber 121 and the light source 102 are close in consideration of the property that light loss occurs as the light proceeds in the optical fiber as described above. The gap between the dot pattern 112 and the optical fiber 121 is wider, and the distance between the dot pattern 112 and the optical fiber 121 is narrower at a portion away from the optical fiber 121 and the light source 102. The light emitted can be adjusted.

10 is an exploded perspective view of a liquid crystal display according to a second exemplary embodiment of the present invention.

As shown in the drawing, the liquid crystal display according to the present invention includes a backlight unit 150, a liquid crystal display panel 310, an upper accommodating container 230, an accommodating frame 220, and a lower accommodating container 210. .

The backlight unit 150 includes a light source 102, a light guide member 111, optical sheets 130, and a reflective sheet 140.

The light source 102 may use a lamp such as a light emitting diode (LED), a cold cathode fluorescent lamp (CCFL), an external electrofluorescent lamp (EEFL), or the like. The illustrated light source 102 generates light by a driving voltage applied from the outside, and is disposed on the side of the light guide member 111, and through the Si or plastic optical fiber 121 connected to the light source 102. The light is transmitted to the light guide member 111.

The optical fiber 121 is provided with a light output unit 122 made of a scratch or groove on the surface to transfer the light provided from the light source 102 to the light guide member 111 through the light output unit.

The light guide member 111 is formed of a transparent plastic-based material such as acrylic, and as shown in the figure, an optical fiber 121 is disposed therein, so that a light propagation direction of the light emitted from the optical fiber 121 is displayed in the liquid crystal display panel 310. ) To the side and spread. A fine lens-shaped dot pattern 112 is formed in an upper direction of the light guide member 111 facing the liquid crystal display panel, and the pattern 112 is arranged according to a predetermined pitch. The pitch of the pattern 112 may vary depending on the distance from the optical fiber 121.

The optical sheets 140 including the diffusion sheets and the light collecting sheets are positioned under the liquid crystal display panel 310, and have a light guide mainly for improving the brightness uniformity of the light under the optical sheets 140. The member 111 is located. The reflective sheet 140 is installed below the light guide member 111 and reflects light emitted downward.

The liquid crystal display panel 310 includes a thin film transistor substrate 311, a color filter substrate 312, and a driver 320, and the driver 320 is a gate connected to each gate line on the thin film transistor substrate 311. A printed circuit board on which a tape carrier package 321, a data tape carrier package 322 connected to each data line on the thin film transistor substrate 311, and various driving parts for processing both a gate driving signal and a data driving signal are mounted. 323). The illustrated driving unit 320 may be replaced by another known method, and may also be formed on the thin film transistor substrate during the wiring forming process.

The liquid crystal display panel 310 is installed on the optical sheets 130 and is supported by the storage frame 220 together with the backlight unit 150 and stored in the lower storage container 210. Herein, shapes of the storage frame 220 and the lower storage container 210 may be variously modified according to a method of accommodating the backlight unit 150 and the liquid crystal display panel 310.

The upper accommodating container 230 is disposed to cover an upper surface of the liquid crystal panel unit accommodated in the lower accommodating container 210 and is combined with the lower accommodating container. The upper housing 230 may be coupled to the lower housing in a variety of ways, such as screw coupling or hook coupling, the coupling may be modified in various ways.

As described above, according to the present invention, there is provided a backlight unit that enables light weight and ultra slim.

Claims (20)

A light source; An optical fiber connected to the light source and both ends thereof; It includes a light guide member that serves to diffuse light to one surface, The optical fiber is disposed in the light guide member, and transmits the light provided from the light source to the light guide member. The method of claim 1, And the optical fiber is disposed inside the light guide member with a plurality of bends. The method of claim 1, The optical fiber is a backlight unit is formed with a plurality of scratches or grooves for emitting light. The method of claim 1, The light guide member includes a plurality of hemispherical lens patterns having a predetermined pitch on one surface or a plurality of prism patterns having a predetermined pitch and parallel to each other. The method of claim 4, wherein The light guide member is a backlight unit made of a transparent acrylic material. The method of claim 1, The light source includes a LED (LED), a lamp and other light sources. The method of claim 6, And the light source is positioned at a side of the light guide member to provide light to the light guide member through the optical fiber. The method of claim 2, Both ends of the optical fiber are connected to the light source, and the backlight unit is disposed along the edge of the light guide member. The method of claim 2, Both ends of the optical fiber are connected to the light source, and the backlight unit is disposed in a zigzag form in the light guide member. The method of claim 1, The backlight unit is provided with one or a plurality of optical fibers. The method of claim 1, The backlight unit is provided with one or a plurality of light sources. The method of claim 1, The lower surface of the lower surface opposite to the light exit surface of the light guide member is coated with a reflecting member that functions to reflect the light traveling to the lower portion of the light guide member. The method of claim 1, And a reflective sheet having a function of reflecting light is disposed at a lower portion of the light guiding member facing the light output portion. A light source for generating light, An optical fiber connected to the light source and both ends thereof; It includes a light guide member that serves to diffuse light to one surface, The optical fiber is disposed in the light guide member, the backlight unit for transmitting the light provided from the light source to the light guide member; A liquid crystal display panel comprising at least two substrates and a liquid crystal formed between the substrates; And And a storage container accommodating the backlight unit and the liquid crystal display panel. The method of claim 14, The light guide member has a plurality of dot patterns having a predetermined pitch formed on one surface thereof. The method of claim 14, Both ends of the optical fiber are connected to the light source, and a plurality of scratches or grooves for emitting light are formed on a surface of the optical fiber. The method of claim 14, The light source includes an LED, a lamp, or other light source. The method of claim 14, The optical fiber is provided with one or a plurality, the liquid crystal display device connected to one or a plurality of light sources. The method of claim 14, And the backlight unit includes a reflective sheet disposed below the liquid crystal display panel of the light guide member and reflecting light. The method of claim 14, The lower surface of the light guide member facing the direction of the liquid crystal display panel is printed with a material that functions to reflect light.

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