KR20060065067A - Liquid crystal display device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlight unit of a liquid crystal display device, and forms an optical element on a thin reflector that can reflect light emitted from a light source device in a range of -30 degrees to +30 degrees, thereby controlling light as in a conventional backlight unit. The present invention relates to a liquid crystal display device including a backlight unit that does not require a plurality of optical films such as a diffusion plate or a plysm plate.

The liquid crystal display device of the present invention comprises a liquid crystal panel; And a backlight unit disposed below the liquid crystal panel, the backlight unit including a light source device generating light to one side, and a reflector plate attached to a lower end of one side of the light source device and having a plurality of optical elements formed on a surface thereof. Has technical features.

Accordingly, the liquid crystal display device of the present invention provides a liquid crystal display device including a backlight unit including a reflection plate on which an optical element is formed such that the reflection angle of light has a range of -30 degrees to +30 degrees, thereby providing light such as a diffusion film and a prism film. By not forming various films to control, not only the structure of the liquid crystal display device is simple but also there is an effect of increasing the light efficiency.

Optical element, reflector

Description

Liquid crystal display device             

1 is a perspective view of a liquid crystal display device having a conventional backlight unit.

2 is a cross-sectional view of a liquid crystal display device having a backlight unit of the present invention.

3 is a cross-sectional view of the backlight unit of the present invention.

4A to 4C are enlarged cross-sectional views of regions D and E of FIG. 3.

5 is a graph for explaining half angle.

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

301: light source device 302: reflector

303: screen 304: light

305: light reflected by the optical element 306: optical element

The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device including a backlight unit including a reflector on which an optical element capable of reflecting light emitted from a light source device in a range of -30 degrees to +30 degrees is formed. will be.

In general, the flat panel display (Plat Panel Display) in the information society is developing remarkably, its role is also important.

In this case, the liquid crystal display device of the flat panel display device is a light receiving device that does not emit light, and thus, a backlight unit for generating light is required.

That is, the liquid crystal display generally includes a light guide plate mounted at an edge of a lower liquid crystal panel, guiding light generated from the lamp, a reflector reflecting light leaked from the light guide plate below the light guide plate, and an upper portion of the light guide plate. Mount the diffuser plate and prism plate on the plate.

Referring to FIG. 1, the liquid crystal panel 103 and the liquid crystal panel 103 of the upper substrate 101, the lower substrate 102, and the liquid crystal filled between the upper substrate 101 and the lower substrate 102. A light source device 104, such as a lamp, is attached to one side of the lower portion, and a light guide plate 105 for guiding light 150 generated from the light source device 104 is attached, and a reflector plate is disposed below the light guide plate 105. 106) is installed. In addition, the reflection plate 106 is attached to the diffusion plate 107 and the prism plate 108. In this case, the light source device 104, the light guide plate 105, the reflecting plate 106, the diffusion plate 107, and the prism plate 108 are collectively referred to as a backlight unit.

At this time, the light 150 generated by the light source device 104 is totally reflected at a predetermined threshold angle or more, and light 105a incident to the light guide plate 105 below the predetermined threshold angle exits the light guide plate 105. . The light 150b having the total reflection at the surface of the light guide plate 105 is reflected by the reflector plate 106 and exits when the reflected light 150b enters a critical angle or less from the light guide plate 105.

Subsequently, the diffuser plate 107 serves to diffuse the light 150a and 150b incident from the light guide plate in each direction to form a uniform surface light source 151.

Subsequently, the light 150 incident on the prism plate 108 is concentrated 152 toward the front surface by the prism plate 108 to improve brightness in the effective viewing angle range. In this case, although only one sheet of the prism plate 108 is shown in the drawing, in general, two sheets are attached to refract light in up, down, left, and right directions to maximize the effect.

The light 150 changed as described above is incident on the liquid crystal panel 103, and an image signal is obtained by the liquid crystal panel 103.

However, the conventional backlight unit is not only complicated by requiring a plurality of optical plates, but also has a disadvantage in that light efficiency is deteriorated by the plurality of optical plates, which complicates the manufacturing process of the liquid crystal display device and results in poor light efficiency. have.

Accordingly, the present invention is to solve the above-mentioned disadvantages and problems of the prior art, and includes a reflector plate formed with an optical element designed to reflect light generated from the light source device to -30 degrees to +30 degrees with respect to the vertical line of the light emitting surface An object of the present invention is to provide a liquid crystal display device having a backlight unit.

The object of the present invention is a liquid crystal panel; And a light source device positioned below the liquid crystal panel and attached to a lower end of one side of the light source device, the backlight unit including a reflective plate having a plurality of optical elements formed on a surface thereof. Is achieved.

Details of the above object and technical configuration of the present invention and the effects thereof according to the present invention will be more clearly understood by the following detailed description with reference to the drawings showing preferred embodiments of the present invention. In the drawings, the length, thickness, etc. of layers and regions may be exaggerated for convenience. Like numbers refer to like elements throughout.

Referring to FIG. 2, a liquid crystal panel 200 including an upper substrate 201, a lower substrate 202, and a liquid crystal layer filled between the upper substrate 201 and the lower substrate 202 may include a backlight unit 300. It is located at the top. In this case, a first electrode is positioned on the lower substrate 202, and a second electrode is positioned at a predetermined position of the upper substrate 201 corresponding to the first electrode.

In addition, a first alignment layer and a second alignment layer may be formed on the first electrode and the second electrode, respectively, a first polarizing plate under the lower substrate 202, and a second polarizing plate on the upper substrate 202. Can be formed.

The backlight unit 300 attached to the lower portion of the liquid crystal panel 200 includes a light source device 301, a reflector 302, and a shielding film 303.

The light source device 301 may use a lamp, or may use LEDs of R (red), G (green), and B (blue) groups or LEDs of white (W). In this case, the light source device 301 is formed in a structure capable of emitting light 304 in an area of one side surface.

Some of the light 304 generated by the light source device is reflected by the shielding film 303 to be reflected by the reflector 302, and the remaining light 304 is directly reflected by the reflector 302. The light 304 reflected by the reflector 302 is reflected by an optical element formed on the reflector 302 and is -30 degrees to + + perpendicular to a vertical line perpendicular to the display surface 201a of the liquid crystal panel 200. The reflected light 304a has a range of 30 degrees and the light emitting surface is uniform.

Accordingly, the reflected light 304a formed by the reflecting plate having the optical element of the present invention has the same characteristics as the light passing through the reflecting plate, light guide plate, diffuser plate, and prism plate of the prior art, but the efficiency thereof is further improved. This is because in the prior art, light passes through the light guide plate, the diffusion plate, and the prism plate, and the light intensity decreases due to the respective light efficiency. In the present invention, there is an optical device having the same effect without the light guide plate, the diffusion plate, and the prism plate. to be.

Referring to FIG. 3, a cross-sectional view of line II ′ of the backlight unit is illustrated in FIG. 2D. When the reflecting plate 302 is attached to the light emitting surface of the light source device 301, it is formed to be slightly inclined. You can see that the far end is slightly higher. That is, the reflective plate 302 has a slight step h. The step h is formed to more effectively reflect the light 304 emitted from the light source device 301. The thickness is preferably 0.8 mm or less in consideration of the thickness of the whole unit and the like.

In this case, the reflective plate 302 is formed to a thickness of 0.1 to 0.2mm using a sus (SUS) -based metal, because even if the sus-based metal is formed thin, deformation does not occur well even with many physical and chemical changes. to be.

4A through 4C are enlarged cross-sectional views of regions D and E of FIG. 3, respectively.

Referring to FIG. 4A, an enlarged view of the region D of FIG. 3 may be a cross-sectional view of the region D in which the light source device 301, the shielding film 303, and the reflective film 302 contact each other.

Of the light 304 generated at one side of the light source device 301, light 304r generated at a predetermined angle or more is reflected by the shielding film 303 to be incident on the optical device of the reflector 302. The incident light is reflected by the optical element into light 305 having an angle of -30 degrees to +30 degrees.

In this case, the predetermined angle is determined according to the shape in which the shielding film 303 is formed, and the shielding film 303 is not reflected by the shielding film 303. It is preferable that the shape and size to be reflected by the optical element 306 at the end.

At this time, the light used in the present invention among the light generated from one side of the light source device 301 uses the light generated at an angle of 120 degrees (-60 degrees to +60 degrees of the vertical line of the one side). The reason for using only light within 120 degrees among the light generated by the light source device 301 as described above will be described with reference to FIG. 5. , The vertical line of one side of the light source device 301 is set to 0 degrees, the intensity is set to 100, and the area where the intensity of light is 50 or more from the result of graphing by measuring the intensity change of light according to the angle (light intensity) Is less than 50, it is because the light intensity is low so that an appropriate luminance cannot be obtained.) Is within +60 degrees and -60 degrees on the vertical line. That is, an angle at which light intensity is greater than 50 is generally referred to as a half-width angle 400. In FIG. 5, it can be seen that the angle is about 60 degrees.

At this time, the light 305 reflected by the optical device 306 formed on the reflective film 302 is generated only in a certain region by the light source device 301 and the shielding film 303, the optical device 306 A region in which the light 305 reflected by the light reaches the liquid crystal panel 200 to form the light emitting surface 201a is called a light emitting region B. The light 305 does not reach the non-light emitting surface 201b. The region which forms is a non-light emitting region (A).

In this case, the shielding film 303 may be formed using any one or more materials of aluminum, silver, magnesium, molybdenum, or calcium. That is, it is preferable to form the metal material capable of reflecting light with high efficiency.

Referring to FIG. 4B, the optical device 306 formed on the reflective plate 302 reflects the light 304 generated by the light source device 301 and has a uniform light source surface having an angle of −30 degrees to +30 degrees. Serve to form light 305 having 304a.

In this case, the optical device 306 is composed of a plurality of unit optical devices 306a, wherein the unit optical device 306a has a pitch P1 of 0.1 to 1 mm and a height P2 of 0.1 to 1 mm. The surface S may be formed to have the same curvature regardless of the position, but it is preferable to form the curvature differently depending on the position. This means that the incident position of the light 304 incident on the unit optical element 306a is different and the incident position is different, which means that the incident angle may be different, so that the light is uniformly reflected in a uniform direction and angle. The unit optical device 306a is designed so that the curvature changes to obtain 305. In this case, the curvature of the surface S of the unit optical device 306a is changed according to the pitch P1 and the height P2, so that the curvature may be changed by adjusting the pitch P1 and the height P2. . At this time, the curvature of the unit optical device 306a is formed in the range of 0.5 to 2mm.

In addition, the unit optical device 306a may be formed to have a different curvature according to the distance from the light source device 301. The closer to the light source device 301, the greater the curvature of the surface S, and the greater the distance. The curvature is formed to be smaller. For this reason, when the curvature of the unit optical device 306a is increased, the uniformity of the light reflected by the unit optical device 306a is increased, but the luminance tends to be lowered. Is higher. That is, as the distance from the light source device 306a becomes smaller, the amount of light that is reached becomes relatively smaller, so that the curvature of the unit optical element 306a decreases as the distance from the light source device 301 increases. .

Referring to FIG. 4C, the light 307a, 307b, and 307c generated by the light source device 301 is reflected by the light 307a, 307b, and 307c according to the angle and the position at which the unit optical device 306a is incident. As shown, the light 307a, 307b incident at the same angle among the light 307a, 307b, 307c has the direction of reflected light 308a, 308b according to the position incident on the optical element 306a. It can be seen that the light is different from the incident light 307a, 307b, and 307c even though the incident light is located at the same position as the light 307a, 307c. 308a and 308c are directed in different directions. At this time, the reflected light 308a, 308b, 308c is reflected in the range of -30 degrees to +30 degrees with respect to the vertical line.

Therefore, the optical elements 306a having different curvatures of the surface S enter light at the same position but have different angles of incidence so as to spread the light at different angles within a predetermined angle to spread the light as in the conventional diffusion plate. Even if incident at different positions and different angles, it reflects at a certain angle, that is, an angle within -30 degrees to +30 degrees with respect to the vertical line, thereby serving as a conventional prism plate. Therefore, in the present invention, the optical device 306a simultaneously performs the roles of the diffusion plate and the prism plate in the prior art, thereby omitting the diffusion plate and the prism plate.

In this case, the optical device 306 is formed of a metal such as aluminum, silver, magnesium, molybdenum or calcium to improve the light reflection efficiency. In addition, the optical device 306 is formed by forming the material of the optical device 306 on the reflector plate 302, and then patterning, or after processing the optical device 306 material by a machining method such as casting or forging And the method of attaching to the reflective plate 302.

Accordingly, the present invention includes a backlight unit including the park device 301, the reflective film 302 on which the optical element 306 is formed, and the shielding film 303, thereby providing excellent light efficiency, as well as a diffusion plate and a prism. There is provided a liquid crystal display device having the advantage of having a simple structure since no additional device such as a plate is required.

Accordingly, the liquid crystal display of the present invention does not form various films for controlling light such as a diffusion film and a prism film, thereby simplifying the structure of the liquid crystal display and increasing the light efficiency.

The present invention has been shown and described with reference to the preferred embodiments as described above, but is not limited to the above embodiments and those skilled in the art without departing from the spirit of the present invention. Various changes and modifications will be possible.

Claims (15)

Liquid crystal panels; And A backlight unit disposed below the liquid crystal panel and including a light source device generating light to one side, and a reflection plate attached to a lower end of one side of the light source device and having a plurality of optical elements formed on a surface thereof; Liquid crystal display comprising a. The method of claim 1, The pitch of the optical device is a liquid crystal display, characterized in that 0.1 to 1mm. The method of claim 1, And a radius of curvature of the optical device is 0.5 to 2 mm. The method of claim 1, And the curvature of the optical device decreases as it moves away from the light source device. The method of claim 1, And the reflected light reflected by the optical element is within -30 to +30 degrees of the vertical line of the light emitting surface. The method of claim 1, The optical device is formed of any one or more of aluminum, silver, magnesium, molybdenum or calcium. The method of claim 1, And a shielding film attached to an upper end portion of one side of the light source device. The method of claim 7, wherein The shielding film is formed of any one or more of aluminum, silver, magnesium, molybdenum or calcium. The method of claim 1, And an emission angle of less than 120 degrees of light generated by the light source device. The method of claim 1, The light source device is a liquid crystal display, characterized in that the LED. The method of claim 10, The LED is a liquid crystal display, characterized in that the LED of the R, G and B group or white LED. The method of claim 1, The reflective plate is formed of a sus liquid crystal display device. The method of claim 1, The thickness of the reflector is a liquid crystal display, characterized in that 0.1 to 0.2mm. The method of claim 1, The reflective plate is characterized in that the height of the other end portion is higher than the one end portion attached to the light source device. The method of claim 14, And a height difference between one end portion and the other end portion of the reflector is 0.8 mm or less.

Images