Balancing high display performance with energy efficiency is crucial for global sustainability.Lowering operating frequencies—such as enabling 1 Hz operation in fringe-field switching(FFS)liquid crystal displays—red...Balancing high display performance with energy efficiency is crucial for global sustainability.Lowering operating frequencies—such as enabling 1 Hz operation in fringe-field switching(FFS)liquid crystal displays—reduces power consumption but is hindered by image flicker.While negative dielectric anisotropy liquid crystals(nLCs)mitigate flicker,their high driving voltages and production costs limit adoption.Positive dielectric anisotropy liquid crystals(pLCs)offer lower operating voltages,faster response times,and broader applicability,making them a more viable alternative.This study introduces a novel approach to minimizing flexoelectric effects in pLCs by investigating how single components influence flexoelectric behavior in mixtures through an effective experimental methodology.Two innovative measurement techniques—(1)flexoelectric coefficient difference analysis and(2)displacement-current measurement(DCM)—are presented,marking the first application of DCM for verifying flexoelectric effects.The proposed system eliminates uncertainties associated with previous methods,providing a reliable framework for selecting liquid crystal components with minimal flexoelectric effects while preserving key electro-optic properties.Given pLCs'higher reliability,lower production costs,and broader material selection,these advancements hold significant potential for low-power displays.We believe this work enhances flexoelectric analysis in nematic liquid crystals and contributes to sustainable innovation in the display industry,aligning with global energy-saving goals.展开更多
We report on generating uniaxial negative birefringent compensation films, made of specifically designedpolyimides. These polymers were synthesized via a polycondensation of dianhydride [such as 2, 2' -bis(3, 4-di...We report on generating uniaxial negative birefringent compensation films, made of specifically designedpolyimides. These polymers were synthesized via a polycondensation of dianhydride [such as 2, 2' -bis(3, 4-dicarboxyphenyl)hexafluoropropane dianhydride] and 2, 2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl. The uniaxial negative birefringent (n_x =n_y > n_z) polyimide substrates are achieved using a solution-casting method in conventional solvents, which exhibit thedesirable optical phase retardation [(n_x - n_z)×d] values from 50 to 400 nm varying with the film thickness. In thesepolyimide films, the long chain rigid molecules adopt intrinsic planar orientaion. In detail, the majority of phenylene-imiderings and phenylenes preferentially adopt nearly planar conformations parallel to the film substrae. In addition, these filmsalso possess high transparency (or transmittance) and little color shift. The unique color dispersion curve indicates that thistype of materials is very suitable for the applications in LCDs due to an excellent mimic for the retardation color dispersioncurve with respect to LC molecules. Significantly low in-plane retardation (< 1 nm) allows this new technology based film toachieve sufficiently high contrast ratio while highly negative retardation dramatically suppresses the gray scale inversion toimprove the viewing angle performance in a variety of new mode LCDs.展开更多
The main goal of this study was to recover indium from the waste liquid crystal display(LCD)panel.In this context,an ionic liquid Cyphos IL 101 was explored.The extraction parameters such as equilibration period,acid ...The main goal of this study was to recover indium from the waste liquid crystal display(LCD)panel.In this context,an ionic liquid Cyphos IL 101 was explored.The extraction parameters such as equilibration period,acid concentration,chloride ion concentration,hydrogen ion concentration were examined on the extraction efficiency of Cyphos IL 101 towards In(III).Quantitative extraction of indium was found at 2.0 mol/L HCl using 0.005 mol/L Cyphos IL 101 and quantitative stripping with 1.0 mol/L H2SO4.Job’s method was used to determine the extracted species and R3R'PInCl4(R=C6H13;R′=C14H29)was proposed.Based on the observations on multi-metal studies,Cyphos IL 101 was further employed for the removal of indium,tin and copper from the leach liquors of waste LCDs.Optimized conditions were generated for the recovery of indium from waste LCDs.McCabe−Thiele diagram analysis,counter-current extraction and selective stripping were carried out to separate the metal ions,i.e.,indium,tin and copper.Two stages at O/A ratio of 1:3 were required for complete removal of tin from the feed and selective stripping of In and Sn was achieved using 0.1 mol/L H2SO4.A scheme for separating indium from the waste LCDs was proposed.展开更多
Liquid crystal Pacharatnam-Berry phase optical elements(PBOEs)have found promising applications in augmented reality and virtual reality because of their slim formfactor,lightweight,and high optical efficiency.However...Liquid crystal Pacharatnam-Berry phase optical elements(PBOEs)have found promising applications in augmented reality and virtual reality because of their slim formfactor,lightweight,and high optical efficiency.However,chromatic aberration remains a serious longstanding problem for diffractive optics,hindering their broader adoption.To overcome the chromatic aberrations for red,green and blue(RGB)light sources,in this paper,we propose a counterintuitive multi-twist structure to achieve narrowband PBOEs without crosstalk,which plays a vital role to eliminate the chromatic aberration.The performance of our designed and fabricated narrowband Pacharatnam-Berry lenses(PBLs)aligns well with our simulation results.Furthermore,in a feasibility demonstration experiment using a laser projector,our proposed PBL system indeed exhibits a diminished chromatic aberration as compared to a broadband PBL.Additionally,polarization raytracing is implemented to demonstrate the versatility of the multi-twist structure for designing any RGB wavelengths with high contrast ratios.This analysis explores the feasibility of using RGB laser lines and quantum dot light-emitting diodes.Overall,our approach enables high optical efficiency,low fabrication complexity,and high degree of design freedom to accommodate any liquid crystal material and RGB light sources,holding immense potential for widespread applications of achromatic PBOEs.展开更多
The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the ...The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the finite-difference timedomain method,which is used to directly solve Maxwell＇s equations,can consider the lateral variation of the refractive index and obtain an accurate convergence effect.The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage.The finitedifference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change.展开更多
In this paper a novel method is proposed to determine the cell parameters including the twist angle, optic retardation and rubbing direction of twisted-nematic liquid crystal displays （TNLCD） by rotating the TNLCD. ...In this paper a novel method is proposed to determine the cell parameters including the twist angle, optic retardation and rubbing direction of twisted-nematic liquid crystal displays （TNLCD） by rotating the TNLCD. It is a single-wavelength method. Because using subtraction equation of transmittance as curve fitting equation, the influence of the light from environment and the absorption by polarizer, the sample of TNLCD and analyser on the transmittance is eliminated. Accurate results can also be obtained in imperfect darkness. By large numbers of experiments, we found that not only the experimental setup is quite simple and can be easily adopted to be carried out, but also the results are accurate.展开更多
The disadvantages of Normally White Twisted Nematic Liquid Crystal Display (NW-TN-LCD) were discussed. The reason that the negative birefringent polyimide thin films were used to compensate NW-TN-LCD to decrease off-a...The disadvantages of Normally White Twisted Nematic Liquid Crystal Display (NW-TN-LCD) were discussed. The reason that the negative birefringent polyimide thin films were used to compensate NW-TN-LCD to decrease off-axis leakage, improve contrast ratios and enlarge viewing angles was explained in this paper. A certain polyimide thin film was taken as an example to show compensation effect on NW-TN-LCD.展开更多
A transflective polymer-stabilized blue-phase liquid crystal display（BP-LCD） with a non-uniform etching substrate is proposed.In-plane switching（IPS） electrodes on the bottom substrate are put on the different gap...A transflective polymer-stabilized blue-phase liquid crystal display（BP-LCD） with a non-uniform etching substrate is proposed.In-plane switching（IPS） electrodes on the bottom substrate are put on the different gaps,and the bottom substrate between the electrodes is etched into different depths in transmissive（T） and reflective（R） regions.This structure can balance the optical phase retardation in the two regions and is helpful to achieve well-matched voltag-dependent transmittance and reflectance curves.This transflective display has high optical efficiency,a wide viewing angle,and low operating voltage（approximately 6 V）.展开更多
A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display（LCFLD） with a holographic screen was demonstrated.The proposed display system has high efficiency,simpl...A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display（LCFLD） with a holographic screen was demonstrated.The proposed display system has high efficiency,simple fabrication,and low manufacturing cost due to the absence of a polarizer and color filter.展开更多
This letter reports an autostereoscopic three-dimensional （3D） fiat panel display system employing a newly designed LCD-pixel-associated parallax barrier （LPB）. The battler＇s parameters can be conveniently determ...This letter reports an autostereoscopic three-dimensional （3D） fiat panel display system employing a newly designed LCD-pixel-associated parallax barrier （LPB）. The battler＇s parameters can be conveniently determined by the LCD pixels and can help to greatly simplify the conventional design. The optical system of the proposed 3D display is built and simulated to verify the design. For further experimental demonstration, a 508-mm autostereoscopic 3D displayprototype is developed and it presents good stereoscopic images. Experimental results agree well wlth the simulation, which reveals a strong potential for 3D display applications.展开更多
In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer （Boltom-TM H30） to prepare a hyperbranched photosensitive polymer （H30-Ci）. The polymer was characterized by UV absorp...In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer （Boltom-TM H30） to prepare a hyperbranched photosensitive polymer （H30-Ci）. The polymer was characterized by UV absorption spectrum and 1H- NMR spectrum. After processed by Linearly Polarized Polymerization （LPP） method, the spin-coated films of H30-Ci were used as photo-alignment layers to assemble liquid crystal （LC） cells containing nematic liquid crystal （5CB）. The observation by polarized microscope showed that the H30-Ci blended with a linear polymer （BP-AN-Ci） photo-alignment layers could align LC molecules in a very uniform way.展开更多
The liquid crystal composite materials consist of microdroplets of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization. The director configuration in liquid crysta...The liquid crystal composite materials consist of microdroplets of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization. The director configuration in liquid crystal droplets, the model of orientation of droplets, and the contrast ratios of a cell are investigated. Droplet size, spacing and distribution are readily controlled in these materials to allow optimization of displays based upon electrically controlled light scattering from the liquid crystal droplets. Preliminary experimental and theoretical studies of the light scattering and electro-optic response of new material show that these materials can offer new features suitable for large area displays and light valves.展开更多
The elimination of zig-zag defects in polyimide-coated surface-stabilized ferroelectric liquid crystal(SSFLC) cells is carried out by applying a low-frequency electric field. It has been achieved when the thickness of...The elimination of zig-zag defects in polyimide-coated surface-stabilized ferroelectric liquid crystal(SSFLC) cells is carried out by applying a low-frequency electric field. It has been achieved when the thickness of SSFLC cell is 3 μm. The optical spectral transmittance measurement confirmed that there is no change of layer structure, and the memory capability was not improved. The different effects of low-frequency electric field applied on the different thickness FLC cells have been observed, and experimental results were presented.展开更多
基金supported by Basic Science Research Program through the National Research Foundation(NRF)of Korea,funded by the Ministry of Science and ICT(MSIT),Korea[2022R1A2C2091671]by ITECH R&D Program of MOTIE/KEIT(Ministry of Trade,Industry&Energy/Korea Evaluation Institute of Industrial Technology)[20016808].
文摘Balancing high display performance with energy efficiency is crucial for global sustainability.Lowering operating frequencies—such as enabling 1 Hz operation in fringe-field switching(FFS)liquid crystal displays—reduces power consumption but is hindered by image flicker.While negative dielectric anisotropy liquid crystals(nLCs)mitigate flicker,their high driving voltages and production costs limit adoption.Positive dielectric anisotropy liquid crystals(pLCs)offer lower operating voltages,faster response times,and broader applicability,making them a more viable alternative.This study introduces a novel approach to minimizing flexoelectric effects in pLCs by investigating how single components influence flexoelectric behavior in mixtures through an effective experimental methodology.Two innovative measurement techniques—(1)flexoelectric coefficient difference analysis and(2)displacement-current measurement(DCM)—are presented,marking the first application of DCM for verifying flexoelectric effects.The proposed system eliminates uncertainties associated with previous methods,providing a reliable framework for selecting liquid crystal components with minimal flexoelectric effects while preserving key electro-optic properties.Given pLCs'higher reliability,lower production costs,and broader material selection,these advancements hold significant potential for low-power displays.We believe this work enhances flexoelectric analysis in nematic liquid crystals and contributes to sustainable innovation in the display industry,aligning with global energy-saving goals.
基金This work was supported by the NSF Science and Technology Center of Advanced Liquid Crystalline Optical Materials (ALCOM, DMR-91-57738) and Nitto Denko America as well as NSF DMR0203994.
文摘We report on generating uniaxial negative birefringent compensation films, made of specifically designedpolyimides. These polymers were synthesized via a polycondensation of dianhydride [such as 2, 2' -bis(3, 4-dicarboxyphenyl)hexafluoropropane dianhydride] and 2, 2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl. The uniaxial negative birefringent (n_x =n_y > n_z) polyimide substrates are achieved using a solution-casting method in conventional solvents, which exhibit thedesirable optical phase retardation [(n_x - n_z)×d] values from 50 to 400 nm varying with the film thickness. In thesepolyimide films, the long chain rigid molecules adopt intrinsic planar orientaion. In detail, the majority of phenylene-imiderings and phenylenes preferentially adopt nearly planar conformations parallel to the film substrae. In addition, these filmsalso possess high transparency (or transmittance) and little color shift. The unique color dispersion curve indicates that thistype of materials is very suitable for the applications in LCDs due to an excellent mimic for the retardation color dispersioncurve with respect to LC molecules. Significantly low in-plane retardation (< 1 nm) allows this new technology based film toachieve sufficiently high contrast ratio while highly negative retardation dramatically suppresses the gray scale inversion toimprove the viewing angle performance in a variety of new mode LCDs.
文摘The main goal of this study was to recover indium from the waste liquid crystal display(LCD)panel.In this context,an ionic liquid Cyphos IL 101 was explored.The extraction parameters such as equilibration period,acid concentration,chloride ion concentration,hydrogen ion concentration were examined on the extraction efficiency of Cyphos IL 101 towards In(III).Quantitative extraction of indium was found at 2.0 mol/L HCl using 0.005 mol/L Cyphos IL 101 and quantitative stripping with 1.0 mol/L H2SO4.Job’s method was used to determine the extracted species and R3R'PInCl4(R=C6H13;R′=C14H29)was proposed.Based on the observations on multi-metal studies,Cyphos IL 101 was further employed for the removal of indium,tin and copper from the leach liquors of waste LCDs.Optimized conditions were generated for the recovery of indium from waste LCDs.McCabe−Thiele diagram analysis,counter-current extraction and selective stripping were carried out to separate the metal ions,i.e.,indium,tin and copper.Two stages at O/A ratio of 1:3 were required for complete removal of tin from the feed and selective stripping of In and Sn was achieved using 0.1 mol/L H2SO4.A scheme for separating indium from the waste LCDs was proposed.
基金supports from the National Key Research and Development Program of China(2023YFB2806803)the National Natural Science Foundation of China(62075127).
文摘Liquid crystal Pacharatnam-Berry phase optical elements(PBOEs)have found promising applications in augmented reality and virtual reality because of their slim formfactor,lightweight,and high optical efficiency.However,chromatic aberration remains a serious longstanding problem for diffractive optics,hindering their broader adoption.To overcome the chromatic aberrations for red,green and blue(RGB)light sources,in this paper,we propose a counterintuitive multi-twist structure to achieve narrowband PBOEs without crosstalk,which plays a vital role to eliminate the chromatic aberration.The performance of our designed and fabricated narrowband Pacharatnam-Berry lenses(PBLs)aligns well with our simulation results.Furthermore,in a feasibility demonstration experiment using a laser projector,our proposed PBL system indeed exhibits a diminished chromatic aberration as compared to a broadband PBL.Additionally,polarization raytracing is implemented to demonstrate the versatility of the multi-twist structure for designing any RGB wavelengths with high contrast ratios.This analysis explores the feasibility of using RGB laser lines and quantum dot light-emitting diodes.Overall,our approach enables high optical efficiency,low fabrication complexity,and high degree of design freedom to accommodate any liquid crystal material and RGB light sources,holding immense potential for widespread applications of achromatic PBOEs.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11304074,61475042,and 11274088)the Natural Science Foundation of Hebei Province,China(Grant Nos.A2015202320 and GCC2014048)the Key Subject Construction Project of Hebei Province University,China
文摘The finite-difference time-domain method is used to simulate the optical characteristics of an in-plane switching blue phase liquid crystal display.Compared with the matrix optic methods and the refractive method,the finite-difference timedomain method,which is used to directly solve Maxwell＇s equations,can consider the lateral variation of the refractive index and obtain an accurate convergence effect.The simulation results show that e-rays and o-rays bend in different directions when the in-plane switching blue phase liquid crystal display is driven by the operating voltage.The finitedifference time-domain method should be used when the distribution of the liquid crystal in the liquid crystal display has a large lateral change.
基金Project supported by the National Natural Science Foundation of China(Grant No60576056)
文摘In this paper a novel method is proposed to determine the cell parameters including the twist angle, optic retardation and rubbing direction of twisted-nematic liquid crystal displays （TNLCD） by rotating the TNLCD. It is a single-wavelength method. Because using subtraction equation of transmittance as curve fitting equation, the influence of the light from environment and the absorption by polarizer, the sample of TNLCD and analyser on the transmittance is eliminated. Accurate results can also be obtained in imperfect darkness. By large numbers of experiments, we found that not only the experimental setup is quite simple and can be easily adopted to be carried out, but also the results are accurate.
基金Supported by’94 Outstanding Young Scientist Foundation of NSFC
文摘The disadvantages of Normally White Twisted Nematic Liquid Crystal Display (NW-TN-LCD) were discussed. The reason that the negative birefringent polyimide thin films were used to compensate NW-TN-LCD to decrease off-axis leakage, improve contrast ratios and enlarge viewing angles was explained in this paper. A certain polyimide thin film was taken as an example to show compensation effect on NW-TN-LCD.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61535007 and 61320106015)the National Basic Research Program of China(Grant No.2013CB328802)
文摘A transflective polymer-stabilized blue-phase liquid crystal display（BP-LCD） with a non-uniform etching substrate is proposed.In-plane switching（IPS） electrodes on the bottom substrate are put on the different gaps,and the bottom substrate between the electrodes is etched into different depths in transmissive（T） and reflective（R） regions.This structure can balance the optical phase retardation in the two regions and is helpful to achieve well-matched voltag-dependent transmittance and reflectance curves.This transflective display has high optical efficiency,a wide viewing angle,and low operating voltage（approximately 6 V）.
基金Project supported by Partner State Key Laboratory on Advanced Displays and Optoelectronics Technologies HKUST,Chinathe National Natural Science Foundation of China(Grant Nos.61435008 and 61575063)the Fundamental Research Funds for the Central Universities,China(Grant No.WM1514036)
文摘A novel see-through display with a liquid crystal lens array was proposed.A liquid crystal Fresnel lens display（LCFLD） with a holographic screen was demonstrated.The proposed display system has high efficiency,simple fabrication,and low manufacturing cost due to the absence of a polarizer and color filter.
基金supported by the Scientific Research Starting Foundation for Fuzhou University,China(No.022538)
文摘This letter reports an autostereoscopic three-dimensional （3D） fiat panel display system employing a newly designed LCD-pixel-associated parallax barrier （LPB）. The battler＇s parameters can be conveniently determined by the LCD pixels and can help to greatly simplify the conventional design. The optical system of the proposed 3D display is built and simulated to verify the design. For further experimental demonstration, a 508-mm autostereoscopic 3D displayprototype is developed and it presents good stereoscopic images. Experimental results agree well wlth the simulation, which reveals a strong potential for 3D display applications.
基金the National Natural Science Foundation of China (No. 50103005)Thanks for Professor Shi Wenfang of University of Science and Technology of China to supply the hyperbranched polymer(H30).
文摘In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer （Boltom-TM H30） to prepare a hyperbranched photosensitive polymer （H30-Ci）. The polymer was characterized by UV absorption spectrum and 1H- NMR spectrum. After processed by Linearly Polarized Polymerization （LPP） method, the spin-coated films of H30-Ci were used as photo-alignment layers to assemble liquid crystal （LC） cells containing nematic liquid crystal （5CB）. The observation by polarized microscope showed that the H30-Ci blended with a linear polymer （BP-AN-Ci） photo-alignment layers could align LC molecules in a very uniform way.
文摘The liquid crystal composite materials consist of microdroplets of liquid crystals which are spontaneously formed in a matrix of a polymer at the time of its polymerization. The director configuration in liquid crystal droplets, the model of orientation of droplets, and the contrast ratios of a cell are investigated. Droplet size, spacing and distribution are readily controlled in these materials to allow optimization of displays based upon electrically controlled light scattering from the liquid crystal droplets. Preliminary experimental and theoretical studies of the light scattering and electro-optic response of new material show that these materials can offer new features suitable for large area displays and light valves.
文摘The elimination of zig-zag defects in polyimide-coated surface-stabilized ferroelectric liquid crystal(SSFLC) cells is carried out by applying a low-frequency electric field. It has been achieved when the thickness of SSFLC cell is 3 μm. The optical spectral transmittance measurement confirmed that there is no change of layer structure, and the memory capability was not improved. The different effects of low-frequency electric field applied on the different thickness FLC cells have been observed, and experimental results were presented.
