KR20070001175U - Edge type backlight module - Google Patents

Abstract

The edge type backlight module includes a surface light source device and an optical film unit overlying the light emitting surface of the surface light source device.

Description

Edge Type Backlight Module {EDGE TYPE BACKLIGHT MODULE}

1 shows a cross-sectional view of a general edge type backlight module.

2 is a cross-sectional view illustrating an edge type backlight module according to an embodiment of the present invention.

3 is a cross-sectional view for describing an edge type backlight module according to another exemplary embodiment of the present invention.

4 is a cross-sectional view for explaining an edge type backlight module according to another embodiment of the present invention.

5 is a cross-sectional view illustrating an edge type backlight module according to another embodiment of the present invention.

6 is a cross-sectional view for describing an edge type backlight module according to another embodiment of the present invention.

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

10, 20, 30, 40, 50, 60: backlight module

1: surface light source device

2: optical film part

The present invention relates to a backlight module, and more particularly, to an edge type backlight module used in a liquid crystal display.

In general, a liquid crystal display (LCD) is largely composed of a display panel and a backlight module. The display panel is composed of, for example, indium tin oxide (ITO) glass, a liquid crystal, a polyimide, a color filter, a polarizer, a driving integrated cicuit, or the like. The backlight module consists of a lamp tube, light guides and various optical films. Liquid crystal displays having different sizes and structures require different types of backlight modules.

Typically, the backlight module is largely a direct type in which the light source shoots light from the rear of the liquid crystal display device to the front, and an edge type in which the light source is located at one edge of the liquid crystal display device. Divided into Direct backlights are suitable for small / medium liquid crystal displays, while edge backlights are suitable for medium / large liquid crystal displays. When considering battery powered portable devices, edge type backlights are commonly used in the industry for the purpose of minimizing power consumption. As illustrated in FIG. 1, the conventional edge type backlight module 10 includes a light source device 11, a light guide plate 12, a diffuser plate 13, and a prism sheet 14. The reflecting plate 15 is provided on one side of the light source device 11 to receive incident light of higher intensity from the light source device 11. In addition, a protective plate 16 may be provided on the top layer of the backlight module 10 to protect various optical devices inside the backlight module 10. As shown in FIG. 1, only one cold cathode fluorescent lamp is provided as the light source device 11 on one side of the conventional edge type backlight module 10. The light guide plate 12 and the reflecting plate 15 formed in the shape of a wedge uniformly reflect the light incident from the light source device 11 to the entire module. By using the structure of the backlight module, the thickness of the liquid crystal display may be reduced. However, it is difficult to control the uniformity of the brightness of the backlight module.

Various optical films have been used in the backlight module to improve the brightness and uniformity of the liquid crystal display so as to provide a wider viewing angle and better color in the liquid crystal display. Widely known as one of the optical films that can be used to increase the efficiency of the backlight is a "Brightness Enhancement Film (BEF)", or "Prism Film". An important function of the brightness enhancement film (BEF) is to collect scattered light emitted in all directions from the light guide plate using refraction and total internal reflection, and to concentrate light in a direction within ± 35 degrees in the axial direction. In this way, maximum brightness can be obtained within a normal working angle. Another optical film, such as “Dual Brightness Enhancement Film (DBEF)”, can be used to effectively increase the output of the backlight through reflection and polarized light recovery to increase the brightness of the backlight. By using the dual brightness enhancement film, not only the brightness of the liquid crystal display panel increases by 60%, but also the brightness increases over a wide viewing angle range. When used in combination with the brightness enhancement film, the dual brightness enhancement film can further increase the brightness of the panel by 160%.

The reflector of the backlight module not only reflects the light emitted from the light source device to the light guide plate but also reflects the leakage light emitted from the light guide plate to the light guide plate. Therefore, parallel surface light passing through the light guide plate is diverted in a direction perpendicular to the light guide plate and exits from the light guide plate. The reflectance can reach 98% and the overall brightness increases accordingly.

Diffusion film is a kind of optical film that makes the spread of light uniform.

The light source device can be utilized by utilizing various optical phenomena such as refraction, reflection, condensation, uniform distribution, etc. without taking component changes or through separate energy consumption. Effectively increasing the brightness of the backlight module to the fullest is believed to be the most economical and easy approach.

Accordingly, the present invention not only addresses the above problems, but also provides an advanced backlight module for a liquid crystal display device that can provide various advantages.

An object of the present invention is to provide an edge type backlight module for a liquid crystal display device that provides light having high brightness and high uniformity.

Another object of the present invention is to provide an edge type backlight module for a liquid crystal display device that is thin, light, compact, and low in manufacturing cost.

In order to achieve the above and other objects and advantages, the edge type backlight module according to an embodiment of the present invention is a surface light source device (optical film), and an optical film portion on the light emitting surface of the surface light source device (optical film) unit). The surface light source device includes a frame body having an opening and a hollow area formed in the opening, a high photodiffusive diffusion film immersed in the opening, within the frame body. A reflection film disposed, and a plurality of light sources disposed in the cavity area of the frame body and below the high light diffusing diffusion film. The high light diffusing film has a substrate and at least one high light diffusing particle coating coated on the substrate and having a thickness of 20 μm to 400 μm and having a haze of 98% or more as a value measured according to JIS K7136. High photodiffusive particle coating layer.

Therefore, according to the present invention, an edge type backlight module capable of being light, thin and compact and providing high brightness and uniformity without using a light guide plate is possible.

Hereinafter, with reference to the accompanying drawings, it will be described in detail a preferred embodiment of the present invention. The same reference numerals are used for the same elements in the drawings, and duplicate descriptions of the same elements are omitted.

2 is a cross-sectional view illustrating an edge type backlight module 20 according to an embodiment of the present invention. As shown in FIG. 2, the edge type backlight module 20 includes a surface light source device 1 and an optical film part 2 disposed on the surface light source device 1. The surface light source device 1 includes a frame body 1-1 having an opening and a cavity region 1-1a formed in the opening, and a high photodiffusive diffusion film covering the opening. ), A reflective film 1-3 disposed inside the frame body 1-1, and a plurality of light sources disposed on at least one side of the cavity region 1-1a inside the frame body 1-1. Devices 1-4. At this time, the high light diffusing film 1-2 is coated on the substrate (1-2a), the substrate (1-2a) and has a thickness of 20 to 400 micrometers and the numerical value measured in accordance with JIS K7136 standard At least one high photodiffusive particle coating layer (1-2b) having a haze of 98% or more. In addition, the reflective film 1-3 is an anti-UV high photodiffusive reflection film, the value measured when light is incident on the film with an incident angle of 60 degrees according to the ASTM D523 standard measurement method. It has a glossiness of less than 10%, and has greater than 95% reflectance for light with wavelengths between 380 nm and 780 nm.

Light generated by the light source device 1-4 may belong to a wavelength region of visible light of 380 nm to 780 nm. The light source device (1-4) used in the backlight module includes a cold cathode fluorescent lamp (CCFL), a light emitting diode (LED), an organic light emitting diode (OLED), a polymer Light Emitting Diode (PLED), External Electrode Fluorescent Lamp (EEFL), Flat Fluorescent Lamp (FFL), Carbon Nanotube Field Emission Element, Halogen Light source devices that generate light having a single to multiple wavelengths, such as halogen light source devices, xenon lamps, high pressure mercury lamps, and the like. The light source device 1-4 may be assembled anywhere in the frame body 1-1, such as the cavity region 1-1a or the lower part of the high light diffusing film 1-2.

Referring to FIG. 3, FIG. 3 is a cross-sectional view illustrating an edge type backlight module 30 according to another embodiment of the present invention. As shown in FIG. 3, the edge type backlight module 30 includes a surface light source device 1 and an optical film part 2 disposed on an emission surface of the surface light source device 1. The optical film portion 2 includes at least one diffusion film 2-1 disposed on the light emitting surface of the surface light source device 1. The diffusion film 2-1 has a high luminance. One to three diffusion films 2-1 may be stacked. The brightness gain of one diffusion film 2-1 is 26%, but the brightness gain of the three diffusion films 2-1 is 38%. It can reach%. Thus, the brightness gain is sufficiently increased and light diffusion and condensation are achieved.

Referring to FIG. 4, FIG. 4 is a cross-sectional view illustrating an edge type backlight module 40 according to another embodiment of the present invention. As shown in FIG. 4, the edge type backlight module 40 includes a surface light source device 1 and an optical film part 2 disposed above the light emitting surface of the surface light source device 1. The optical film portion 2 includes at least one diffusion film 2-1 disposed on the light emitting surface of the surface light source device 1 and a dual luminance enhancement film disposed on the diffusion film 2-1. (2-2) is included. An arrangement of the one diffusion film 2-1 may bring a 26% brightness gain, and an arrangement of the two diffusion films 2-1 may provide a 36% brightness gain. Since the dual brightness enhancement film increases the brightness by 60%, using two diffusion films 2-1 and one dual brightness enhancement film increases the brightness by 96% overall.

Referring to FIG. 5, FIG. 5 is a cross-sectional view illustrating an edge type backlight module 50 according to another embodiment of the present invention. As shown in FIG. 5, the edge type backlight module 50 includes a surface light source device 1 and an optical film part 2 disposed above the light emitting surface of the surface light source device 1. The optical film portion 2 includes at least one diffusion film 2-1 disposed on the light emitting surface of the surface light source device 1 and a prism film disposed on the diffusion film 2-1. (2-3), and the upper diffusion film 2-4 disposed on the prism film 2-3. This type of backlight module can increase the brightness by 60%.

Referring to FIG. 6, FIG. 6 is a cross-sectional view illustrating an edge type backlight module 60 according to another embodiment of the present invention. As shown in FIG. 6, the edge type backlight module 60 includes a surface light source device 1 and an optical film part 2 disposed on the light emitting surface of the surface light source device 1. The optical film portion 2 includes at least one diffusion film 2-1 disposed on the light emitting surface of the surface light source device 1 and a prism film disposed on the diffusion film 2-1. (2-3), and the double brightness enhancement film 2-2 disposed on the prism film 2-3. This type of backlight module can increase the brightness by 120%.

The surface light source device of the edge type backlight module according to the embodiment of the present invention is light and thin because no diffusion plate is required. Moreover, according to the present invention, uniformity of light is achieved through means of full reflection in the frame body 1-1 using a high light diffusing reflective film and a diffusing film. Therefore, since light is uniformly diffused, the nonuniformity of brightness is eliminated.

Seeing optical films combining optical phenomena of light generated by the properties of various optical films, for example, refraction, reflection, condensation, uniform distribution, etc. According to the invention, it is possible to produce a desirable backlight module by using it in an edge type backlight module. Thus, sufficiently increasing the brightness of the backlight module is made possible by extracting the maximum performance of the light source device without changing other factors or consuming additional energy.

Although described with reference to the embodiments above, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the present invention described in the utility model registration claims below. You will understand.

Claims (10)

A surface light source device; And An optical film portion on the light emitting surface of the surface light source device, The surface light source device includes a frame body having an opening and a cavity area formed in the opening, a high light diffusing diffusing film immersed in the opening, a reflective film disposed inside the frame body, and at least one side of the inside of the frame body. Including a plurality of arranged light sources, The high light diffusing diffusing film comprises a substrate and at least one high light diffusing particle coating layer coated on the substrate and having a thickness of 20 μm to 400 μm and having a haze of 98% or more as a numerical value measured according to JIS K7136. Edge type backlight module. The method according to claim 1, And the optical film part comprises at least one diffusion film placed on a light emitting surface of the surface light source device. The method according to claim 2, The at least one diffuser film is an edge type backlight module, characterized in that one to three diffuser film. The method according to claim 1, And the optical film part comprises at least one diffusion film placed on a light emitting surface of the surface light source device, and a dual luminance enhancement film disposed on the diffusion film. The method according to claim 4, The at least one diffuser film is at least one or two diffusion film, characterized in that the backlight module. The method according to claim 1, And the optical film part comprises a diffusion film placed on the light emitting surface of the surface light source device, a prism film disposed on the diffusion film, and an upper diffusion film placed on the prism film. The method according to claim 1, And the optical film part comprises a diffusion film placed on the light emitting surface of the surface light source device, a prism film disposed on the diffusion film, and a dual luminance enhancement film placed on the prism film. The method according to claim 1, The reflective film is a UV blocking high light diffusive reflective film, and when light is incident on the reflective film at an incident angle of 60 degrees, the glossiness of less than 10% is obtained by ASTM D523 measuring method and is 95 at a wavelength of 380 nm to 780 nm. Edge type backlight module, characterized in that having a reflectivity exceeding%. The method according to claim 1, Edge-type backlight module, characterized in that the light source generates light having a wavelength of 380 nm to 780 nm. The method according to claim 1, The light source may be one of cold cathode fluorescent lamps, light emitting diodes, organic light emitting diodes, polymer light emitting diodes, external electrode fluorescent lamps, and surface fluorescent lamps.

Images