Study On Process Parameters And Accuracy Control Of Hot Embossing Micro Forming Of Micro-Lens Array LGP

Thin-walled LED panel light needs 3-mm-thickness LGP(light guide plate).Currently the surface micro-structure arrays of LGP are mainly fabricated by screen printing and laser processing,leading to inefficiency and high energy consumption.Hence,a die core is employed to emboss transparent LGP on the micro-groove array of its heated surface.This process only performs a thermal deformation for micron-scale surface layer inside core microgroove spaces to form the micro-lens array rapidly,and the macro workpiece size will not change during the process.It can contribute to the high-efficiency and low-energy-consumption hot embossing process of optic micro-lens array.However,the loading pressure and loading temperature of the machine tend to excurse during the actual hot embossing process,leading to error in the micro-structure height of hot embossing LGP.In this paper,light-sensing illumination was used to set up an on-line control model of micro-array height on the macro surface of hot embossing LGP.In addition,the experience database of technique expert was set up to compare with the actual micro forming height and then calibrate the form error of the LGP micro-lens array structure,making the error of the micro-forming height stably.First,process using micro-groove array die core to rapidly hot emboss micro-lens array LGP was presented and experiments were conducted,in which the results showed that the V-shape micro-lens array LGP fabricated by micro hot embossing could enhance lighting irradiance and irradiance uniformity by 14.4% and 4.8%,respectively,compared to the commercially available screen printing LGP,which indicated that micro hot embossing process had a relatively good application prospect in LED lighting industry.Then,on-line control system of micro hot embossing array was designed and set up.The light-sensing on-line detection device was built up,and the mutual real-time data communication hardwares were set up to connect hot embossing machine,on-line detection system and the control centre.Next,the experience relationship database between process parameters and LGP micro forming height,and the correlation database between on-line detected illumination and LGP micro forming height,were built through micro hot embossing experiment,respectively.Last,the on-line control manufacture model of micro hot embossing height was built up,in which the on-line micro forming height was gradually stabilized within a set range along with cyclic process of the control,assisted by the adjustment of process parameters through experience database.The results showed that an experience database with the most suitable loading temperature of 110? and a duration of 1 s could be erected through the researching experiments of micro hot embossing process parameters.Light-sensing on-line detection system could averagely reach a sensibility of 1.683 ?m/lux when it identified the micro forming heights of LGPs.Moreover,the actual error between LGP product micro forming height and the set value could be averagely controlled in 4 ?m through on-line control,which had an effect on guiding the micro hot embossing manufacturing of high-precision micro-lens array LGP practically.