KR20030080764A - A Direct-lighting Backlight Unit - Google Patents

Abstract

PURPOSE: A direct backlight is provided to keep the thickness thin and obtain high and uniform luminance by using a diffusion element formed with a reverse pyramid type 2D prism part. CONSTITUTION: A direct backlight includes a light source(110) having a fluorescent lamp for emitting light, and reflecting elements(120) mounted at a lower part and both side parts of the light source for emitting light toward an image display device. A diffusion element(130) has a reverse pyramid type 2D prism part(132) and a predetermined light scattering pattern part(134) formed on an opposite surface from the prism part. The light scattering pattern part faces the light source for making the light incident from the light source and the reflecting elements uniform primarily. The light scattering pattern is formed by corrosion or sandblast. A diffusion sheet(140) contacts the diffusion element for improving the light uniformity additionally. The pyramid part is depressed toward the light scattering pattern part.

Description

Direct Backlighting Unit {A Direct-lighting Backlight Unit}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight device for an LCD-TV, and more particularly, to a direct backlight device using a fluorescent lamp and a light curtain without using a light guide plate.

In general, an image display device used in a notebook computer, a desktop computer, an LCD-TV, a mobile communication terminal, and the like is a kind of light receiving device, and thus requires a backlight device in addition to the liquid crystal display. The backlight device is generally divided into a side-down (edge light) type and a direct-type type according to the installation position of the fluorescent lamp (CCFL or HCFL). The edge-lighting backlight device has a structure in which the fluorescent lamp is disposed on the side of the light guide plate and the light of the fluorescent lamp is incident on the liquid crystal panel through the light guide plate so as to maintain uniform brightness of the screen of the image display system through the light guide plate. It is mainly used for laptops and monitors. A direct-lighting backlight device does not use a light guide plate, but maintains a uniform brightness of an image display system by arranging a kind of diffusing plate called a light curtain on a plurality of fluorescent lamps. However, since the luminance is relatively higher than the side-down type, it is mainly used in LCD-TVs that require high luminance.

1 is a configuration diagram schematically showing a structure of a general direct type backlight device.

As shown in FIG. 1, the direct backlight device 10 includes a diffusion plate 11 made of a milky white acrylic plate. The diffuser plate 11 is usually manufactured by extrusion or rolling, has a relatively thick thickness of about 1 mm to 5 mm, and is cut and used according to the size of an image display system (not shown).

However, as the thickness of the backlight device 10 is reduced, there is a problem that the light emitting part of the fluorescent lamp 13 is clearly visible from the outside through the diffusion plate 11. In order to solve such a problem, until now, the surface of the diffusion plate 11 is subjected to a predetermined process by screen printing or the like to reduce the luminance of the fluorescent lamp part and maintain the screen uniformity.

Even when the fluorescent lamp 13 is relatively bright due to the above-described method, it is impossible to obtain a uniform uniformity, a plurality of diffusing sheets 15 and / or prismatic sheets on the diffuser plate 11 may be obtained. 17) to maintain uniformity. Here, the sheets 15 and 17 are all manufactured by rolling, and their thickness is relatively thin, 0.5 mm or less. The prism sheet 17 maintains the uniformity of the image of the image display system by condensing as well as by diffusing the light emitting part of the fluorescent lamp. Reference numeral 19 denotes a reflecting plate. However, the milky white diffuser plate 11 has a problem in that light transmittance is relatively low, thereby decreasing luminance.

2 is a configuration diagram schematically showing the structure of another direct type backlight device.

As shown in FIG. 2, the backlight device 20 includes a lens or prism diffuser plate 21. Here, the lens-type or prism-type diffusion plate 21 is used to cut the product produced by rolling to fit the size or to be injected into a predetermined size. In addition, since the lens-type or prism-type diffuser plate 21 is disposed to face the fluorescent lamp 23, the uniformity is maintained by concealing the light emitting part of the fluorescent lamp 23 using the diffusion function rather than the light condensing function. Reference numeral 25 denotes a diffusion sheet, and reference numeral 27 denotes a reflecting plate. However, because the lenticular or prism diffusion plate 21 is one-way characteristic, when the fluorescent lamp 23 is arranged in the U-shaped or W-shaped, the fluorescent lamp 23 extends in two directions, so that in either direction The disadvantage is that it does not spread.

The present invention has been made to solve the above problems, by using a two-dimensional prism-type diffuser plate to simultaneously emit a plurality of fluorescent lamps to achieve a uniform and high brightness while having a small thickness, high brightness suitable for LCD-TV An object of the present invention is to provide a direct backlight device that can be implemented.

1 is a configuration diagram schematically showing the structure of a general direct type backlight device.

Figure 2 is a schematic diagram showing the structure of another direct type backlight device.

Figure 3 is a schematic diagram showing the structure of a direct type backlight device according to a preferred embodiment of the present invention.

4 is a plan view of a part of an inverse pyramid type two-dimensional prism portion of the diffusion member of FIG. 3;

5 is a perspective view of FIG. 4.

Figure 6 is a schematic view showing a direct type backlight device according to another embodiment of the present invention.

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

102 Fluorescent lamp 110 Light source 120 Reflector

130 ... Diffusion member 132 ... Inverse pyramid type two-dimensional prism part

134 Scattering pattern section 140 Diffusion sheet

The present invention for achieving the above object is a light source having a fluorescent lamp capable of emitting light; A reflection member for reflecting light emitted from the light source; And a diffusion member including an inverse pyramid type two-dimensional prism portion to diffuse light supplied from the light source and the reflection member.

The diffusion member includes a predetermined scattering pattern portion formed on a surface opposite to the inverse pyramid type two-dimensional prism portion.

The scattering pattern part is disposed to face the light source so as to make the light emitted from the light source and the reflective member primarily uniform, and a predetermined scattering pattern is formed by a corrosion method or a sand blast method (sandblast). It is preferable.

The direct type backlight device according to the present invention further includes a diffusion sheet disposed to contact the diffusion member in order to further diffuse light emitted from the diffusion member.

The diffusion member may be disposed such that the scattering pattern portion faces the light source.

Hereinafter, a direct backlight device according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a configuration diagram schematically illustrating a structure of a direct type backlight device according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the backlight device 100 includes a light source 110 having a fluorescent lamp 102 installed under the image display system (not shown) to emit light, and a light source 110. Diffuse the light from the light source 110 and the reflective member 120 and the reflective member 120 provided on the lower and both sides of the light source 110 to reflect the light from the light toward the image display system Diffusion member 130 comprising an inverted pyramid type two-dimensional prism portion 132 to maintain noodle hair and a predetermined scattering pattern portion 134 formed on a surface opposite thereto, and diffusion member 130 to further improve uniformity. The diffusion sheet 140 is installed to be in contact with the.

The diffusion member 130 includes a scattering pattern portion 134 formed on the light source 110 side and an inverse pyramid type two-dimensional prism portion 132 formed on the image display system side. The diffusion member 130 uses a conventional diffusion plate material, that is, a resin containing a pigment or scattering particles and a transparent resin such as an acrylic resin, a polyester resin, a polyvinyl chloride resin, a polyurethane resin, a silicone resin, and a polycarbonate. By injection molding or roller processing.

The scattering pattern part 132 is a part in which a mold is formed by corrosion or sandblasting and ejected through the mold, so that a scattering pattern is continuously formed on one surface of the diffusion member 130.

4 is a partial plan view of the reverse pyramid type two-dimensional prism portion 132 of the diffusion member 130, Figure 5 is a perspective view of FIG.

As shown in FIGS. 4 and 5, the inverted pyramid-type two-dimensional prism portion 132 formed on the exit surface side of the diffusion member 130 includes an internally cut vertex ("A" portion) and a ridge line ( "B" part) has a pattern arranged continuously in a two-dimensional direction. Accordingly, the structure of the two-dimensional prism portion 132 has a shape of inverted pyramid, that is, a recessed toward the scattering pattern portion 134 of the diffusion member 130.

The scattering pattern portion 134 formed on the incident surface side of the diffusion member 130 is preferably formed by dispersing the pigment scattering particles in a transparent resin or a semi-transparent resin in a range that does not impair light transmittance, such as a transparent substrate.

On the other hand, the diffusion member 130 may assume a two-dimensional prism of a convex shape, which is complicated and difficult, such as injection mold processing or roller processing by rolling, as well as damage and light of the diffusion sheet by the pyramid protrusion There is a high risk of leakage, and the manufacturing cost is high and inefficient compared with the diffusion member 130 having the reverse pyramid type two-dimensional prism portion as in the present embodiment. Therefore, the diffusion member 130 having the inverted pyramid type two-dimensional prism portion 132 is the most efficient and economical method.

As shown in FIG. 3, the diffusion sheet 140 has a function for protecting the surface of the anti-pyramid type two-dimensional prism portion 132 and a conventional diffusion sheet for increasing the uniformity of light by additional diffusion. Used.

Referring to the operation of the direct type backlight device according to an embodiment of the present invention configured as described above are as follows.

As shown in FIG. 3, the light emitted from the fluorescent lamp 102 is incident toward the diffusion member 130 together with the light reflected from the reflective member 120. The incident light is first diffused by the scattering pattern portion 134 formed on the fluorescent lamp 102, and is refracted in the X and Y axes while passing through the inverse pyramid type two-dimensional prism portion 132. It is increased to obtain a more uniform brightness. In this process, the light passing through the diffusion member 130 becomes more uniform while passing through the diffusion sheet 140 and then enters the image display system.

Here, since the inverse pyramid type two-dimensional prism portion 132 has a relatively high light transmittance and has a light diffusing function as well as a diffusing function, there is almost no problem of deterioration in luminance. In addition, the inverted pyramid-type two-dimensional prism unit 132 can secure high luminance and uniformity even at a small thickness regardless of the direction even if the fluorescent lamp 102 spans in various directions. In addition, the scattering pattern unit 134 may suppress an additional number of uses of the diffusion sheet 140.

6 is a configuration diagram schematically showing a direct type backlight device according to another embodiment of the present invention. The same components as those described in FIGS. 3 to 5 are the same members having the same functions.

Unlike the previous embodiment, the direct type backlight device 200 according to the present embodiment is a modification of the arrangement of the diffusion member 230, that is, the reverse pyramid type two-dimensional prism portion 232 to face the light source 110. It is arrange | positioned at the entrance surface, and the scattering pattern part 234 is arrange | positioned at the exit surface. In this case, although there is an advantage of not using the diffusion sheet 140 of the above embodiment, uniformity may be reduced.

As described above, the direct type backlight device according to the present invention has an advantage of obtaining uniform and high luminance characteristics while maintaining a thin thickness by using a diffusion member having a two-dimensional prism portion having an inverse pyramid shape.

Claims (2)

A light source having a fluorescent lamp capable of emitting light; A reflection member for reflecting light emitted from the light source; And And a diffusion member including an inverse pyramid type two-dimensional prism portion to diffuse light supplied from the light source and the reflection member. The method of claim 1, And the diffusion member includes a predetermined scattering pattern portion formed on a surface opposite to the inverse pyramid type two-dimensional prism portion.