The backlight module is usually used to increase visual angle and brightness of liquid crystal display (LCD). Thus, the design and fabrication of optical films, including light guide plate, diffuser film, and brightness enhancement film (BEF), are critical factors to decide the optical efficiency in a backlight module. In order to improve the optical efficiency for power-saved display with competitiveness, this study presents a new fabrication process combining precision machining, lithography, and hot-embossing techniques to form a two-side-patterned optical film. One side of the optical film is micro triangular-pyramidal array (MTPA) and the other is micro spherical lens array(MSLA). First, the Taguchi method is applied to design the optimal microstructure configuration by the assistance of the optical software, FRED. Second, a tungsten (W) steel mold (as the mold to hot emboss MTPA) is manufactured by precision machining including optical projection grinding, lapping, and polishing processes. Meanwhile, a nickel-cobalt (Ni-Co) mold (as the mold to hot emboss MSLA) is fabricated by electroplating process. Then, polydimethylsiloxane (PDMS) is used to replicate the MTPA and MSLA patterns, on W and Ni-Co metal molds, respectively, and the replicated PDMS films are used as the molds to form a two-side-patterned optical film. In addition, the optical property such as luminance is measured by photo research 650 (PR 650) to evidence the optical function of the two-side-patterned optical film. From the experimental results, both brightness and uniformity can be improved by this film;thus, optical efficiency is successfully increased in this study.

The liquid crystal display is high light, the advantage thin in thickness. In order to reach the thickness thinly, the request good in degree of consistency, it is important to design a qualified mould group in a poor light. This text introduces how to utilize Trace Pro optics to imitate the software , imitating to the diffusion board of the mould group in a poor light of the liquid crystal display , analysis and designing mainly. To the sidelight type mould group in a poor light, go to type in a poor light mould group construct comparatively simple , main optics for reflect board , spread scene , cold cathode tube and arris lens component its directly. The main use of reflection board lying below the mould group among them , in order to collect and reflect the light that come from the light source, make it penetrate above to in a poor light mould group, in order to increase the luminance of screen. Spread slice and function , arris of lens and the arris lens like mere sidelight type in a poor light mould diffusion slice of group, make their even to take in order to raise the luminance of screen light scattering separately. When the mould group in a poor light is thinner and thinner in thickness, brightness its disparity can more and more heavy too, so optics design more and more challenging. This text designs mainly to spread the distribution that the board adds the particle son to with the high degree of consistency, is it probe into in a poor light mould light neat degree that group can appear to come. Design a series of and reply the mould group which reflect the array, software Trace Pro is enabled being used for designing and replying the geometry structure which reflects the array and shut in the simulation optics route , analog quantity examines the result designed, and discuss its characteristic.

In this paper, we searched the parameter of BEF (Brightness enhancement film) using commercial FRED server for backlight module. The pattern analysis was carried out to understand its characteristic. The current structures used in LCD backlight are double-layer BEF. In addition, BEF of 3M takes the lion¡¦s share. But this may increase the thickness and cost of backlight module. In order to avoid those disadvantages, we tried to design single-layer BEF and characterize the effect through parameters study by using FRED software simulation. pyramid-shaped microlens array of BEF was constructed. Therefore, the effect of the variation of the structure parameters can be analyzed, such as prismatic degree (£c), prismatic structure on the brightness enhancement. It can be found from the result of simulation that the changes of the prismatic degree (£c) of 85 degree influence the brightness enhancement the most.

The development and application of portable LCD (Liquid crystal display) technology is the main trend on the market. The goal of this study is to fabricate a compound optical film, and we focus on the design and fabrication of a new type backlight module for side-LED (Light emitting diode) display. The optical efficiency can be improved via the compound optical film. The profile of optical film was determined using commercial optical software, FRED. The mold with multi aspect ratio and multi fill-factor microlens array by LIGA-like process (Lithographie galvanoformung abformung) was produced using THB-126N negative photoresist and AZ-4620 positive photoresist. The study presents many innovative processes, such as the homemade gray scale mask, and multi-step electroforming method, which both produces the microlens array with variable size and aspect ratio. In addition, the embedded micro-void caused light guide and diffusion under the quantitative control during the PDMS (Polydimethylsiloxane) optical film fabrication. The compound optical film with embedded micro-voids, multi aspect ratio and variable size microlens array can be fabricated quickly without substrate. Then the optical properties were analyzed by BM-7A to characterize the luminance, uniformity and optical efficiency.