Research On The Electro-Optical Propertices Of The SiO₂ Doped Optically Driving Liquid Crystal Display

Liquid Crystal Display(LCD)is an important device for the display function of various electronic products today.The traditional LCD display mechanism is to use a unified white backlight.The controller controls the LCD driver to generate an analog electrical signal through a digital signal,so that it corresponds to the three small liquid crystals with red,yellow and blue as the primary colors on the LCD dot matrix.The liquid crystal(LC)molecules in the cell rotate along the long axis of the molecule to realize its display function of different colors.Compared with traditional LCD,ODLCD is a new liquid crystal photo-alignment technology,which uses polarized light to change the orientation of the liquid crystal optical alignment layer,making liquid crystal(LC)molecules.The display function is realized by rotating along the long axis of the molecule,which has the advantage of ultra-low power consumption and can be used in e-books and other electronic reading devices.ODLCD is also known as Optical Driving Electronic Paper(ODEP).Cover the ODLCD with a mask engraved with characters or patterns and place it under polarized light,and the orientation of the liquid crystal in the area irradiated by the polarized light changes,thereby forming corresponding characters or patterns on the ODLCD.ODLCD can be repeatedly erased and written by different wavelength polarizations.At present,the application of ODLCD is limited by the long rewriting time of light-controlled orientation technology,and the research on ODLCD is still in the laboratory stage.In this paper,starting from the optimization of ODLCD rewriting time,threshold voltage and response time,the photoelectric properties of ODLCD are improved by doping SiO₂ nanoparticles.The research contents of this paper are as follows:1.To study the effect of SiO₂ nanoparticles doped with alignment agent SD1 and liquid crystal5CB on the optical rewriting time.In the experimental study of nanoparticle doping,11 experimental groups with different doped nanoparticle concentrations were designed for the two groups of doping,and the appearance and distribution of nanoparticles in the experimental samples were observed by scanning electron microscopy,transmission electron microscopy and atomic force electron microscopy.In the final test,the rewriting time data of the sample was obtained.In terms of doping of the alignment agent,the concentration of SD1-SiO₂-0.7 has the best effect.The rewriting time of SD1-SiO₂-0.7 is 0.428%of undoped.In terms of liquid crystal doping,the concentration of 5CB-SiO₂-1.0 has the best effect.The rewriting time of 5CB-SiO₂-1.0 is 0.513%undoped.2.To study the effect of SiO₂ nanoparticles doping in alignment agent and liquid crystal on the threshold voltage and response time of ODLCD under the same conditions,two groups of 11samples were also set up.Through threshold voltage data analysis,the threshold voltages of 5CB-SiO₂ samples are all higher than that of SD1-SiO₂ samples.This is because when nanoparticles are doped in the alignment layer,they have little effect on the dielectric anisotropy of liquid crystal molecules,while nanoparticles doped in liquid crystals can move in the liquid crystal molecules,which has little effect on the dielectric anisotropy of liquid crystal molecules.The effect is larger and therefore affects the threshold voltage.In terms of response time,the response time of SD1-SiO₂-1.2 concentration is the best,which is 17.543ms;the response time of 5CB-SiO₂-1.2concentration is the best,which is 3.731ms.Incorporating nanoparticles into liquid crystal can better reduce the response time,but will increase the threshold voltage;doping the alignment agent has little effect on the threshold voltage,and the response time is improved.Therefore,it is necessary to find a balance between threshold voltage and response time.3.A test system for ODLCD optical rewriting time designed to test the erasing and writing time.According to the test principle of erasing and writing time,the circuit system and software tools are designed,and the rewriting time is calculated by using discrete data fitting algorithm.