Study On The Arrangement Of Microprisms On The Lower Surface Of A Small-sized Integrated Light Guide Plate

Backlight module(BLM)is an essential component in the liquid crystal display(LCD)application,and it mainly functions as a plane light source with high brightness and luminance uniformity.Typical BLM is usually comprised of light sources,double-cross brightness enhancement films(BEFs),a diffusion film(DF),a reflective film(RF),and a light guide plate(LGP),which has some problems like complex procedure and low energy efficiency.Our lab has studied the integrated LGP(ILGP),into which the BEFs,the DF,the RF and the LGP are integrated.Thereby it has the simplest structure.Whereas,the bottom surface of the ILGP is coated with a RF,which outruns the current mature replication process in the industry and it's not conducive to extend the design to the backlight industry.Therefore,in this paper,the prime research object is the partial ILGP,into which the BEFs,the DF and the LGP is integrated and the RF is separated,whereby it's accordant with the current replication process in the industry.Because of the air space between the partial ILGP and the RF,there are intrinsic differences between the partial ILGP and the ILGP according to the theory of optical wave guide,and it's necessary to redesign the structural parameters and study the related rules of the partial ILGP.Based on the micro-structure units on the top and bottom surface of the partial ILGP developed by our lab previously,in this paper,the principle of micro-prism distribution on the bottom surface of the partial ILGP is studied,a set of metal templates of 5 inch partial ILGP is designed and fabricated,and the feasibility of using laser processing technology to etch microstructures in the partial ILGP is explored.The research results are achieved as follows.(1)The micro-prism distribution expressions for partial ILGP is explored and established.Firstly,adjust the micro-prism distributions of partial ILGPs with various sizes(3 to 7 inch)to make luminance uniformities exceed 85%.Secondly,analyze micro-prism distributions numerically and fit the micro-prism distribution expression.And the coefficients in above expression are fitted as functions of structural parameters of the partial ILGP.Using the micro-prism distribution expressions proposed in this work,the micro-prism distribution can be calculated directly,which makes the luminance uniformity of BLM achieve 80%,thereby the efficiency of designing is improved.(2)A 5 inch partial ILGP is designed and its metal templates are fabricated.The tolerance analysis of a 5 inch partial ILGP designed in(1)is carried out,and the parameters of the partial ILGP model are modified according to fabrication technology.Eventually,a set of metal templates of 5 inch partial ILGP is fabricated successfully,which is used to make a prototype.(3)The feasibility of using laser processing technology to etched microstructures in the partial ILGP is studied.The bottom surface of ILGP is etched with microstructures by laser,and the microstructures that converged rays on the top surface of ILGP are redesigned and optimized.The luminance uniformity of the partial ILGP designed here is 73.24% in simulation,and the simulation result shows that this application is feasible.