JP2005182018A - Reflection plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflection plate in which reflection efficiency is improved and light diffusion is made to be uniform. <P>SOLUTION: A reflection plate at least includes a base material 21 whose main materials consist of PET (polyethylene terephthalate resin); a metal reflection layer 22 whose main materials consist of aluminum or silver, and which is provided at the upper part of the base material by making use of spattering or vacuum evaporation method; and a diffusion layer 23 which is coated at the upper part of the metal reflection layer 22, and whose main materials consist of titanium oxide or silicon dioxide. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a reflector used in a backlight module of a flat panel display, and more particularly to a reflector that improves reflection efficiency and makes light diffusion more uniform.

  A flat panel display is one of the technical terms that have attracted the most attention in recent years. Traditional CRT displays have dominated the market for decades, but have finally been challenged by a new generation of display technology. Any liquid crystal display (LCD), plasma display (PDP), or organic electroluminescent display (OLED) has the advantages of being light, thin, small, low in heat and power consumption, and free from radiation interference. , Has come to occupy a large part of the consumer information market. Among them, the progress of the technology of the thin film transistor liquid crystal display (TFT-LCD) is particularly remarkable, and it can be seen that the era of high quality display has already come even if the actual investment scale and mass production results are taken. It can be applied to a wide range of applications from small color mobile phones to large televisions, and liquid crystal displays have already become a major revolution in applied science and technology at the beginning of this century.

  The main structure of a liquid crystal display can be roughly divided into two main parts: a panel and a backlight module. The configuration of the panel includes ITO conductive glass, liquid crystal, alignment film, color filter, polarizing plate, driving IC, and the like, and the backlight module includes a fluorescent tube, a light guide plate, and various optical films. The optical performance of the entire liquid crystal display is affected by the mutual effects of every member in the module. Among them, the optical film plays an especially important role in monitor brightness, uniformity, contrast and viewing angle. As the size of the liquid crystal panel increases, the resolution also increases. On the one hand, the designer increases the number of fluorescent tubes or increases the tube current to increase the amount of incident light. On the other side, the panel aperture ratio (Aperture ratio) To reduce the consumption of the backlight source, and more actively introduce wide viewing angle liquid crystal alignment technology such as MVA (Multi-domain vertical alignment), ASV (Advanced Super V) or IPS (In-plane switching). Efforts are being made to improve the viewing angle and color of LCDs. However, if the brightness is increased by simply increasing the number of fluorescent tubes, an excessive amount of heat will be accumulated in the mechanism, affecting the life and quality of other components, and at the same time the power consumption will be too great, and the cable will It becomes impossible to satisfy the needs of many information products that are used in batteries without being used. In addition, high-level liquid crystal panels involve cost factors such as product positioning and non-defective product ratios, and technical factors such as patent rights and electrode design. The most economical and simple way to achieve the design goal is to use a new optical film to increase the overall brightness and use the light source at the highest efficiency without requiring cell design changes or extra energy consumption. Has been adopted as a solution for. For this reason, reflectors have been developed that improve the overall brightness and use the light source with maximum efficiency, but do not require cell design changes or extra energy consumption.

  The reflector has two roles in the backlight module. First, the light emitted from the light source is effectively reflected to the light guide plate, and its efficiency is determined by the reflectance of the specular reflection. Secondly, the diffusion of the light beam leaking from the light guide plate is returned to the light guide plate, thereby converting the plane light in the light guide plate traveling in parallel to a direction perpendicular to the light guide plate and deviating from the light guide plate. They both aim to improve the reflection efficiency and improve the overall luminance when reflecting incident light. However, the conventional reflector has drawbacks that the reflection effect is not ideal and the uniformity of diffusion of reflected light rays is insufficient.

The structure of a conventional reflector and backlight module is shown in FIG. The backlight module 1 is composed of a reflector 11, a cold cathode tube 12, a diffuser 13 and a second diffuser 14. Of these, as shown in the side sectional view of the conventional reflector of FIG. 11 the main material is PET (polyethylene terephthalate resin), and the diffusion layer 111 containing TiO ₂ (the titanium oxide) is applied to the surface, when the TiO ₂ (titanium oxide) is dried and solidified, white-like This is widely used because an atomized surface is formed, light rays are more uniformly diffused, and a constant reflection effect is obtained. However, since the diffusion layer 111 diffuses light rays, the reflectance is not ideal, a stronger light source is required, not only the current increases and the power consumption increases, but also a stronger light source In a situation where a large amount of light source is required, the space of a device (such as a mobile phone or a PDA) equipped with a general small flat display panel is limited, so it is not possible to install many light sources. Most of them are used in devices (such as LCDs for computers) equipped with a relatively large flat display panel.

FIG. 3 shows a side sectional view of another conventional reflector. As shown in the figure, the main material of the reflecting plate 11 ′ is a mixture of PET (polyethylene terephthalate resin) and TiO ₂ (titanium oxide), and the reflecting plate 11 ′ uses TiO ₂ bubbles 111 ′. Then, the incident light beam is diffused again, the light beam is more uniformly diffused, and a certain reflection effect can be obtained. This is also widely used. However, since the bubble 111 ′ diffuses the light beam, the reflectance becomes not ideal, and a stronger light source is required, not only the current increases and the power consumption increases, but also the stronger light source In situations where more are needed, the space of a device (such as a mobile phone or PDA) equipped with a general small flat display panel is limited, so that many light sources cannot be installed. Most of them are only used in devices (such as computer LCDs) with relatively large flat display panels.

  FIG. 4 is a side sectional view of still another conventional reflector. As shown in the figure, the main material of the reflector 11 is PET (polyethylene terephthalate resin), and a metal reflective layer 112 containing silver or aluminum is applied to the surface thereof, and the metal reflective layer 112 reflects light. As a result, the reflectance is greatly improved. However, when the light is reflected, the light distribution is non-uniform, and the reflector is reflected during assembly or manufacturing, and may be scratched or deformed at high temperatures. The screen light may become irregular or cannot be reflected, resulting in poor screen display. For this reason, when used in a device (such as a computer LCD) equipped with a large flat display panel, screen defects due to distortion, scratches, deformation due to high temperatures, etc. that occur during assembly or manufacture of the reflector are more prominent. It is not suitable for use. In order to minimize this drawback, most of them are currently used in devices (such as mobile phones and PDAs) having a relatively small flat display panel.

  In view of the drawbacks of conventional reflectors, the present invention has been developed by the inventor based on many years of experience in the industry and has overcome these drawbacks. It improves reflection efficiency and diffuses light. The reflector is made more uniform.

  A main object of the present invention is to provide a reflecting plate with improved reflection efficiency.

  Another object of the present invention is to provide a reflector having more uniform light diffusion.

  In order to achieve the above-described object, the reflector of the present invention includes a base material, a metal reflection layer provided above the base material, and a diffusion layer provided above the metal reflection layer. Thereby, reflection efficiency can be improved and light diffusion can be made more uniform.

With the above-described configuration, the reflector of the present invention has the following effects.
1. Good reflection efficiency By providing a metal reflection layer on the reflection plate by sputtering or vacuum vapor deposition, the reflection plate can obtain good reflection efficiency due to the high reflectivity of the metal reflection layer.
2. Making the diffusion of light more uniform The single diffusion layer applied on the metal reflection layer can make the diffusion of light more uniform and make the diffusion of reflected light by the reflector more uniform.
3. Applicable to flat display devices of various sizes Devices with a small flat display (cell phones, PDAs, etc.) without the need for a separate light source because the reflective efficiency of the reflector is increased by the design of the metal reflective layer Can be used inside. In addition, the diffused layer design can make the reflected light diffuse more evenly, so that the screen defects are not conspicuous, so in a device with a large flat display (computer LCD etc.) It can also be used. Therefore, it can be applied to flat display devices of various sizes.

  In order to facilitate understanding of the objects, features, and effects of the present invention, the reflector of the present invention will be described in detail below based on specific embodiments and drawings.

FIG. 5 shows a layout of the reflector and the backlight module of the present invention. In FIG. 6, side surface sectional drawing of the reflecting plate of this invention is shown. As shown in these drawings, the backlight module 1 includes a cold cathode tube 12, a diffusion plate 13, and a second diffusion plate 14, and a reflection plate 2 is installed below the cold cathode tube 12. Among them, the reflecting plate 2 has a base material 21 whose main material is made of PET (polyethylene terephthalate resin), can improve the light reflection efficiency, and the main material is made of aluminum or silver, A metal reflective layer 22 provided above the base material 21 using a vacuum deposition method, and the metal reflective layer 22 is applied above the metal reflective layer 22, and the main material is TiO ₂ (titanium oxide) or SiO ₂ (silicon dioxide). And a diffusion layer 23 made of

  The foregoing description has described the best embodiments of the present invention and is not intended to limit the scope of the claims of the invention, and any equivalent variations and modifications that do not depart from the gist of the invention It is considered to be included in the claims of the invention.

It is a side view which shows the structure of the conventional reflecting plate and a backlight module. It is side surface sectional drawing of the conventional reflecting plate. It is side surface sectional drawing of the other conventional reflecting plate. It is side surface sectional drawing of the other conventional reflector. It is a side surface layout diagram showing a reflector and a backlight module of the present invention. It is side surface sectional drawing of the reflecting plate of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Backlight module 2 Reflecting plate 11 Reflecting plate 11 'Reflecting plate 12 Cold cathode tube 13 Diffusion plate 14 Second diffusion plate 21 Base material 22 Metal reflecting layer 23 Diffusion layer 111 Diffusion layer 111' Bubble 112 Metal layer

Claims (5)

  A reflector comprising at least a base material, a metal reflective layer provided above the base material, and a diffusion layer provided above the metal reflective layer.   The reflector according to claim 1, wherein the main material of the base material is PET (polyethylene terephthalate resin).   The reflector according to claim 1, wherein the main material of the metal reflective layer is aluminum or silver.   The reflector according to claim 1, wherein the metal reflective layer is provided on the base material by sputtering or vacuum deposition. The reflector according to claim 1, wherein the main material of the diffusion layer is TiO ₂ (titanium oxide) or SiO ₂ (silicon dioxide).

Images