KR20060085066A - Back light unit - Google Patents

Abstract

The backlight unit according to the present invention includes a light source in which a plurality of channels including light emitting regions and non-light emitting regions capable of generating light are integrated, and a plurality of lenses corresponding to the channels are integrated and generated in each of the light emitting regions. A lens plate for enlarging the lights.

Backlight Unit, Surface Light Source, Luminance

Description

Backlight Unit {BACK LIGHT UNIT}             

1 is a view showing the configuration of a backlight unit including a diffusion plate according to the prior art,

2 is a view showing the configuration of a backlight unit according to a first embodiment of the present invention;

3 is a cross-sectional view of the backlight unit illustrated in FIG. 2;

4 is a view showing the configuration of a backlight unit according to a second embodiment of the present invention;

5A and 5B are views for explaining an operating principle of the backlight unit shown in FIG. 2;

6 is a view showing the configuration of a backlight unit including a tubular light source according to a third embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit, and more particularly to a backlight unit including a surface light source capable of emitting light with uniform brightness.

Unlike a cathode ray tube (CRT), a general liquid crystal display (TFT-LCD) is not a device capable of emitting light by itself, and in order to implement an image, an additional light source capable of emitting light is further included on a rear surface of the liquid crystal display panel. The above-described liquid crystal display may use a backlight unit including a surface light source in which a plurality of channels are integrated as a light source. The backlight unit diffuses the light generated in the respective channels through the light guide plate and the diffusion plate, and passes the light to the liquid crystal display panel.

In order to improve the image quality of the liquid crystal display, the backlight unit should be able to generate light of uniform luminance. The backlight unit may be classified into a form directly under the CCFL or a surface emitting form.

1 is a view showing the configuration of a backlight unit including a diffusion plate according to the prior art. Referring to FIG. 1, the conventional backlight unit 100 includes a surface light source 110 including a plurality of channels 111 capable of generating light, and uniform luminance of light generated by the surface light source 110. And a diffusion plate 120, a diffusion sheet 130, a brightness enhancement film 140, and the like, to diffuse to have a. The backlight unit 100 may further include a prism sheet (not shown) or a light guide plate (not shown).

Each channel 111 may be configured as a fluorescent lamp, and the channels 111 may be integrated to be spaced apart from each other at predetermined intervals, and may include a light emitting region 111b for emitting light and a non-light emitting region 111a for not emitting light. Is done.

Light generated in each of the channels 111 forms bright lines having brighter brightness by overlapping each other at a specific position. That is, the light generated in the conventional backlight unit 100 is formed by the non-light emitting region 111a and the bright line of each channel 111, which is a factor that inhibits the generated light has a uniform brightness do. The decrease in brightness of light degrades the image quality of an image screen generated by an imaging device on which the LCD is mounted, and hinders the realization of natural color and contrast that can be perceived by humans.

The diffusion plate 120 may use an optical film having a low transmittance as a means for ensuring that the light generated from the surface light source 110 has a uniform brightness, and suppresses the generation of bright lines by using a light scattering effect. The light generated in each channel 111 is diffused in the diffusion plate 120 and then passes through the diffusion sheet 130 and the brightness enhancement film 140 to have more uniform brightness.

However, the diffusion plate has a problem in that light transmittance is lowered by diffusing the light by scattering. That is, a backlight unit having a diffuser plate has a problem in that a screen is dark and a sharp image is not easily realized due to a large loss of light. Moreover, the backlight unit has a problem in that required voltage and heat generation amount are increased to realize a bright screen.

SUMMARY OF THE INVENTION An object of the present invention is to provide a backlight unit capable of suppressing occurrence of light loss and generating light of uniform brightness.                         

The backlight unit according to the present invention,

A light source integrated with a plurality of channels including a light emitting area and a non-light emitting area capable of generating light;

A plurality of lenses having a one-to-one correspondence are integrated in the channels, and includes a lens plate for enlarging the light generated in each of the emission areas.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; In describing the present invention, detailed descriptions of related well-known functions or configurations are omitted in order not to obscure the subject matter of the present invention.

2 is a view showing the configuration of a backlight unit according to a first embodiment of the present invention, Figure 3 is a view showing a cross-sectional view of the backlight unit shown in FIG. 2 and 3, the backlight unit 200 according to the first embodiment of the present invention includes a plurality of channels 211 including a light emitting area 211b and a non-light emitting area 211a capable of generating light. The integrated light source 210 includes a lens plate 220 corresponding to the channels 211 one-to-one and for enlarging the light generated in each of the channels 211. The backlight unit 200 according to the present invention may include a lamp of a vertical direct type or surface emitting type.

The light source 210 includes a plurality of channels 211 capable of generating light, and the light source 210 includes a surface emitting lamp and a cold cathode fluorescent lamp (CCFL) having a rod shape. An external electrode type fluorescent lamp (EEFL) or a light emitting diode (LED) having a dot shape may be used.

Each of the channels 211 may be selectively used according to needs of the above-described lamps, and the distance between the lamps and the distance between the lens and the lamp may be adjusted according to the needs of the user.

For example, specific structures of the light emitting and non-light emitting regions 211b and 211a may include an internal space into which discharge gas is injected, and the non-light emitting region 211a may include the light emitting regions ( Partitions (not shown) for dividing between 211b) into respective discharge spaces. The barrier ribs described above have a sufficient width so as not to become parasitic capacitors that serve as passages of current. In addition, the light source 210 includes an electrode (not shown) for applying a voltage to each of the channels 211.

The lens plate 220 is integrated such that a plurality of the lenses 221 corresponding to each of the channels 211 are continuously connected to other adjacent lenses 221, and is formed by extrusion of a transparent acrylic resin, or the like. Molding is possible. Each of the lenses 221 extends along the long axis of the corresponding channel 211, thereby enlarging the light generated in the corresponding channel 211. More preferably, each lens 221 collimates and generates light generated in the emission region of the corresponding channel.

Each lens 221 may be an aspherical lens or lenticular lenses. The light passing through each lens 221 overlaps the light passing through another adjacent lens 221 and prevents dark spots caused by the non-light emitting area 211a between the channels 211.

That is, in the lens plate 220 according to the present invention, the plurality of lenses 221 corresponding to each channel 211 enlarge the light generated in the corresponding channel 211 in order to obtain uniform luminance. You can get light. Conventional diffusion plates scatter light generated from a surface light source to obtain uniform brightness, whereas the present invention obtains light of uniform brightness by enlarging the light in the lens 211.

The lens plate 220 is spaced apart from the light source 210 to have a distance t such that the light generated in each channel 211 can be projected onto the entire area of the lens 221.

5A and 5B are diagrams for describing an operating principle of the backlight unit illustrated in FIG. 2. FIG. 5A illustrates an imaging relationship according to a positional relationship between a specific lens 221 constituting the lens plate 220 and a corresponding channel 211. FIG. 5A illustrates that when a corresponding channel 211 that is an object is located within an effective focal length (EFL: EFL) of the lens 221, the corresponding channel (a back focal length) of the lens 221 is located on the back focal length. The enlarged standing virtual image 201 of 211 is shown.

As shown in FIG. 5B, the light source 210 is positioned such that the channels 211 are included within the effective focal length of the lens plate 220 such that the non-light emitting area 211b is connected to the corresponding lens 221. As a result, the enlarged upright virtual image 201 is formed. The imaginary virtual images 201 of the non-emission area 211b formed by the lenses 221 form light having uniform luminance by overlapping with each other.

4 is a diagram illustrating a configuration of a backlight unit according to a second embodiment of the present invention. Referring to FIG. 4, the backlight unit 300 according to the second embodiment of the present invention includes a light source 310 in which a plurality of channels capable of generating light are integrated, and a plurality of lenses corresponding to the channels one-to-one. 321 is integrated and is positioned on the lens plate 320 for enlarging the light generated in each channel, the diffusion sheet 330 located on the lens plate 320, and the diffusion sheet 330 The brightness enhancement film 340.

The light source 310 includes a plurality of channels capable of generating light. The lens plate 320 is a form in which a plurality of lenses 321 connected in series are integrated. The lens plate 320 is manufactured in a form in which a plurality of lenses 321 are integrated by extrusion molding a transparent acrylic resin. Each lens 321 may be a cylindrical or aspherical lens or lenticular lens (cylindrical). The lens plate 320 is positioned such that the integrated lenses 321 correspond one-to-one to each of the channels, thereby enlarging the light generated in each of the channels, and passing through the respective lenses 321. The sizing virtual images overlap with the sizing virtual images enlarged in another adjacent lens 321 to suppress dark spots caused by the non-emitting region between the channels.

The diffusion sheet 330 and the brightness enhancing film 340 may increase the brightness uniformity of the light passing through the lens plate 320. In addition, it may further include a light guide panel.

The diffusion sheet 330 and the brightness enhancing film 340 may be selectively used as necessary.

6 is a view showing the configuration of a backlight unit including a capillary light source according to a third embodiment of the present invention. Referring to FIG. 6, the backlight unit 400 according to the third embodiment of the present invention includes a light source 410 including a plurality of channels 411 having a customs form, and a plurality of one-to-one correspondences to the respective channels. The lens plate 420 includes the lens plate 421 formed thereon.

The lenses 421 correspond one-to-one to the channels 411 and extend along the long axis of the channels 411.

The light source 410 includes power lead wires 411a and 411b for connecting the respective channels 411 to a power source, a reflector plate 412, and an outer housing 43.

4 illustrates a structure of a direct type backlight unit in the case where each channel 411 includes a cold cathode lamp (CCFL) or an EEFL.

The backlight unit according to the present invention can generate light having a uniform brightness without diffusing light generated by the light source by scattering or the like. That is, the backlight unit according to the present invention can minimize the amount of power consumed to generate light of the same intensity while suppressing light loss.

Claims (8)

A light source integrated with a plurality of channels including a light emitting area and a non-light emitting area capable of generating light; And a lens plate for integrating a plurality of lenses in one-to-one correspondence with the channels and for enlarging the light generated in each of the emission areas. The method of claim 1, wherein the backlight unit, A diffusion sheet positioned on the lens plate; And a brightness enhancing film positioned on the diffusion sheet. According to claim 1, And each lens is continuously connected to another adjacent lens. According to claim 1, The lens plate is a backlight unit, characterized in that made of a transparent acrylic resin According to claim 1, Each lens is an aspherical lens or a lenticular lens. According to claim 1, The lens plate is characterized in that the aspherical lens or lenticular lenses are formed. According to claim 1, The light source includes a surface light emitting lamp, a cold cathode ray tube lamp, an external electrode lamp, a dot-shaped light emitting diode or a tubular lamp. According to claim 1, Each lens extends in parallel with the major axis of the corresponding channel.

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