Study On Performance And Fabrication Of Micro-Optical Integrated Light Guide Plate

The backlight module(BLM),the second key component of the liquid crystal display(LCD),is widely used nowadays.Thinness and high performance are its development trend and research focus.Based on massive researches about the integrated light guide plate(ILGP)obtained by our lab,three aspects including of the high luminance uniformity of the integrated BLM,the spectral dispersion characteristics of micro-optical LGP and the fabrication technology of ILGP are further studied in this paper,and the following research results are obtained.(1)The coefficient-relation expressions of the micro-prism distribution of the ILGP are revised.Compared with the original coefficient-relation expressions,the revised ones are not only reduced by 1/4,1/3 and 1/2 in numerical terms respectively,making the physical characterization of each numerical term clearer,but also the luminance uniformities for all designed integrated BLMs of 7-inch or less in size are all achieved higher than 85%,through calculating the micro-prism distribution directly from the revised expressions with the coefficients adjusted slightly.The simulation analysis indicates that the revised coefficient-relation expressions are correct,effective,and universal in the integrated BLM of 7-inch or less in size with high luminance uniformity,which saves a lot of design time.(2)The expression for calculating the relationship between micro-optical structure parameters and dispersion under broadband diffraction is created.A theoretical model of micro-structure arrays with a broadband light source is established in this paper.The dispersion characteristic regularity of the diffraction spectrum is studied.The definition and its formula of dispersion parameter C are proposed in this paper,which can mainly measure the chromatic dispersion degree of the diffraction spectrum.Furthermore,the boundary criterion point of zero-dispersion is given explicitly.A rectangular phase grating sample with the period of 4?m,the groove depth of 1?m and the duty ratio of 0.5 is fabricated by applying micro-nano processing technology.The structural parameters of the fabricated sample are consistent with the designed ones.The dispersion parameter C under different light source parameters is measured.The consistency between theoretical analysis and experimental results verifies the correctness of the dispersion parameter C,the computational formula and the boundary criterion point of zero-dispersion.The research results have well guided the fabrication of a white zero-dispersion Fresnel lens sample and a rainbow dispersive Fresnel lens one.It indicates that the research conclusions in this paper,not only can provide guidance for the parameter design on the micro-optical LGP,but also can be applied to the design of other broadband diffraction elements when studying the dispersion characteristics.(3)A new method,which is an improved ultraviolet imprint technology to fabricate double-sided integrated microstructure sheet components,is proposed.It effectively overcomes the fabrication difficulties of double-sided integrated microstructure elements with high aspect ratios and without base film support,breaks through the limitations of current industry processing technology in cross-scale structure,integrated molding,thinning,high aspect ratio structure,and open space operation.It has low cost and fast response to the need to develop micro-optical integrated device samples.It has been successfully applied to make several samples of ILGP with different structural parameters.(4)A 5-inch ILGP sample with good performance is developed.A gray direct writing lithography system is jointly constructed.The template of two-dimensional micro-prism array on the bottom surface of LGP is etched.By using the improved ultraviolet imprint technology proposed in this paper,a 5-inch ILGP sample is made.By testing the BLM assembled from the 5-inch ILGP sample,the illumination uniformity is close to the industrial standard of the typical BLM,which basically realizes the purpose of thinness in the BLM.This paper focuses on the integrated light guide plate technology to further study.The coefficient-relation expressions of the micro-prism distribution of the ILGP are revised in the aspect of high luminance uniformity design,which are universal and efficient.The dispersion calculation expression and the boundary criterion point of zero-dispersion are proposed in the aspect of broadband diffraction dispersion analysis.The fabrication difficulties of double-sided integrated microstructure elements with the characteristics of high aspect ratios,thinning and without a base film support,are overcomed.A 5-inch ILGP sample with good performance is developed.