1. Field of the Invention
The present invention relates to a light guidance module, and in particular to an ultra-thin film light guidance device having uniform illuminance, that is utilized in a backlight module of liquid crystal display (LCD) and a thin profile illumination device.
2. The Prior Arts
Nowadays, along with the rising demand for liquid crystal display screens in the market, and the demand of customer for LCD's of larger sizes and lower prices, backlight module has become one of the crucial components in reducing the size and lowering the price of LCD. The backlight module is built in and integrated wholly in a light crystal display (LCD), its major function is to provide a stable light source for a liquid crystal (LC) panel in front, so that LCD industry has now placed great emphasis on the light-weight, thin-profile, and uniform and high illuminance of backlight module.
Conventionally, a backlight module can be classified as: a direct type backlight module and an edge type backlight module according to its position of placement in an LCD, as shown in
In a structure mentioned above, a direct type backlight module is usually utilized in a large-sized LCD, that is because higher density backlight sources can be installed to provide higher illuminance. However, since in this structure, a diffusion plate is made of an opaque polymer, that will absorb parts of lights emitted by a light source, moreover, the application of a diffusion plate requires certain amount of diffusion space, thus being able to eliminate bright spots of a light source; therefore, the volume occupied by a direct type backlight module is larger than that of an edge type backlight module. As such, an edge type backlight module is mostly utilized in providing light to small size screen. Though, the design of edge type light source may have the benefits and advantages of light-weight, thin-profile, narrow-frame and low power consumption, however, since cold cathode fluorescent lamp (CCFL) is used as an edge type backlight light source, thus the density of a backlight source of a backlight module that can be raised is rather limited. Therefore, its light illuminance is rather low and is not suitable to be used as a light source for a larger size displayer.
However, in addition to fulfilling the requirements of high illuminance, uniform distribution, light-weight, and thin-profile of backlight module, the realization of modularized integration of a backlight module is the goal and direction of research and development of the LC screen for the next generation. Therefore, the research and development of a backlight module having various advantages integrated therein is a major goal for the LC industry at present. For this purpose, the present invention provides an ultra-thin light guidance device integrating a micro prism set and a micro grating set, that is capable of meeting the requirements of LCD backlight module at present. Furthermore, this kind of light guidance module can not only be utilized in a backlight module, but it can also be used in a thin profile illuminance device, hereby meeting the demands of market for products having uniform light distribution in a more sufficient manner.
In view of the problems and shortcomings of the prior art, a major objective of the present invention is to provide an ultra-thin light guidance device, wherein, the uniformity of emitted light is regulated by the density distribution of micro prism set and micro grating set, thus being able to eliminate bright spots in a light source.
Another objective of the present invention is to provide an ultra-thin light guidance device, and that is realized by directly integrating a micro prism set and a light guidance layer, hereby reducing the thickness of the entire backlight module.
Still another objective of the present invention is to provide an ultra-thin light guidance device, that is suitable to be used as light source of various designs, and for a variety of applications.
According to an aspect of the present invention, an ultra-thin light guidance device of the present invention includes a bottom light guidance layer, a set of micro prisms are disposed thereon, and a micro grating is embedded in the set of micro prisms. Moreover, an upper light guidance layer and a diffusion layer are disposed on the micro prism set. As such, when incident lights pass through the bottom light guidance layer and reach the micro prism set, part of the lights are refracted and transmitted through a micro grating by a refraction angle, and another portion of incident lights are reflected directly by the micro grating, and then is reflected back to the micro prism set through a bottom reflection plate. The above-mentioned processes are repeated until lights pass through the micro prism set, and then emerge by passing through an upper light guidance layer and a diffusion layer. Therefore, this kind of design of light guidance device can not only reduce the thickness of the module,-but it can also provide lights of uniform distribution and high illuminance as required by a liquid crystal display or an LED lighting device.
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the present invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art from this detailed description.
The related drawings in connection with the detailed description of the present invention to be made later are described briefly as follows, in which:
The purpose, construction, features, functions and advantages of the present invention can be appreciated and understood more thoroughly through the following detailed description with reference to the attached drawings.
The present invention discloses an ultra-thin light guidance device, its major purpose is to integrate the technical characteristics of light guidance, diffusion, and reflection of the prior art into a light guidance device, so that this light guidance device is thin enough without occupying too much space while having excellent light uniform distribution, hereby improving the light emission efficiency.
Firstly, referring to
Therefore, upon passing through bottom light guidance layer 52 and then reaching micro prism set 54, the incident lights from light source 58 will in part transmit through the micro prism set 54 via a refraction angle, thus exiting the micro prism set 54 and emitting lights into an uniform distribution; on the other hand, the other part of the incident lights will be reflected back to the bottom light guidance layer 52, and then will proceed to and reflected by the bottom reflection plate 60 back into micro prism set 54. Finally, the lights thus obtained will transmit through micro prism set 54 to form a uniformly distributed backlight source without having bright spots.
Furthermore, in addition to the first embodiment mentioned above, in a second embodiment of the present invention, an upper light guidance layer 62 is provided on the bottom light guidance layer and covers the micro prism set 54, while a diffusion layer 64 is covered on an upper surface of an upper light guidance layer, as shown in
Subsequently, referring to
Moreover, in the present invention, the bottom light guidance layer 52 is made of Polycarbonate (PC), Polyethylene Terephthalate (PET), or UV light curable glue (UV glue); the micro prism set 54 is made of UV light curable glue (UV glue) and a metal material; and the upper light guidance layer 60 is made of UV light curable glue (UV glue).
Summing up the above, through the application of the present invention, the ultra-thin light guidance device can be utilized in a backlight module of a liquid crystal display (LCD), or an illumination device of a light-emitting-diode (LED), wherein, micro prism set is embedded into light guidance layer to achieve modularized integration, as such, not only the cost, weight, and thickness of backlight module are reduced, but it also has the advantage in illuminance and uniformity of light as compared with ordinary light guidance module. Therefore, the ultra-thin light guidance device of the present invention is suitable for use in large amount in various optical devices.
The above detailed description of the preferred embodiment is intended to describe more clearly the characteristics and spirit of the present invention. However, the preferred embodiments disclosed above are not intended to be any restrictions to the scope of the present invention. Conversely, its purpose is to include the various changes and equivalent arrangements which are within the scope of the appended claims.