Fast-response liquid crystals for high image quality wearable displays

We demonstrate two ultra-low viscosity liquid crystal mixtures to enable field-sequential-color wearable displays for low temperature operation, while keeping a wide color gamut. Our mixtures offer ~4X faster response time than a commercial material at 20°C and ~8X faster at −20°C. Other major attractive features include: (1) submillisecond response time at room temperature and vivid color even at −20°C without a heating device, (2) high brightness and excellent ambient contrast ratio, and (3) suppressed color breakup with 360Hz frame rate. ©2015 Optical Society of America OCIS codes: (120.2040) Displays; (160.3710) Liquid crystals; (230.3720) Liquid-crystal devices References and links 1. D. Armitage, I. Underwood, and S.-T. Wu, Introduction to Microdisplays (Wiley, 2006). 2. M. S. Brennesholtz and E. H. Stupp, Projection Displays, 2nd Ed. (Wiley 2008). 3. D. Cuypers, H. De Smet, and A. Van Calster, “VAN LCOS Microdisplays: A decade of technological evolution,” J. Display Technol. 7(3), 127–134 (2011). 4. Y.-W. Li, C.-W. Lin, K.-Y. Chen, K.-H. Fan-Chiang, H.-C. Kuo, and H.-C. Tsai, “18.5L: Late-News Paper: Front-lit LCOS for wearable applications,” SID Symp. Dig. Tech. Pap. 45(1), 234–236 (2014). 5. J. Bergquist and C. Wennstam, “49.2: Field-sequential-colour display with adaptive gamut,” SID Symp. Dig. Tech. Pap. 37(1), 1594–1597 (2006). 6. K.-H. Fan-Chiang, C.-C. Lai, J.-T. Cheng, C.-C. Yen, B.-J. Liao, Y.-Y. Ho, and Y.-C. Chen, ““P-173: A 0.38” Field-sequential-color liquid-crystal-on-silicon microdisplay for mobile projectors,” SID Symp. Dig. Tech. Pap. 40(1), 1770–1773 (2009). 7. Y.-P. Huang, F.-C. Lin, and H.-P. D. Shieh, “Eco-displays: The color LCD's without color filters and polarizers,” J. Display Technol. 7(12), 630–632 (2011). 8. Z. Luo and S.-T. Wu, “A spatiotemporal four-primary color LCD with quantum dots,” J. Display Technol. 10(5), 367–372 (2014). 9. S.-T. Wu and C.-S. Wu, “Mixed‐mode twisted nematic liquid crystal cells for reflective displays,” Appl. Phys. Lett. 68(11), 1455–1457 (1996). 10. K. H. Fan-Chiang, S.-T. Wu, and S. H. Chen, “Fringing-field effects on high-resolution liquid crystal microdisplays,” J. Display Technol. 1(2), 304–313 (2005). 11. S.-T. Wu and C.-S. Wu, “Rotational viscosity of nematic liquid crystals: A critical examination of existing models,” Liq. Cryst. 8(2), 171–182 (1990). 12. Y.-W. Li, K.-H. Fan-Chiang, C.-T. Wang, C.-L. Wu, C.-Y. Tsai, H.-C. Tsai, and H.-C. Huang, “P-121: Fastresponse reflective TN mode with enhanced contrast and reflectance,” SID Symp. Dig. Tech. Pap. 41(1), 1720– 1723 (2010). 13. Y. Chen, F. Peng, and S.-T. Wu, “Submillisecond-response vertical-aligned liquid crystal for color sequential projection displays,” J. Display Technol. 9(2), 78–81 (2013). 14. S. He, J.-H. Lee, H.-C. Cheng, J. Yan, and S.-T. Wu, “Fast-response blue-phase liquid crystal for colorsequential projection displays,” J. Display Technol. 8(6), 352–356 (2012). 15. L. Rao, S. He, and S.-T. Wu, “Blue-phase liquid crystals for reflective projection displays,” J. Display Technol. 8(10), 555–557 (2012). 16. F. Peng, Y. Chen, J. Yuan, H. Chen, S.-T. Wu, and Y. Haseba, “Low temperature and high frequency effects on polymer-stabilized blue phase liquid crystals with large dielectric anisotropy,” J. Mater. Chem. C 2(18), 3597– 3601 (2014). 17. H. Chen, F. Peng, Z. Luo, D. Xu, S.-T. Wu, M. Li, S. Lee, and W. Tsai, “High performance liquid crystal displays with a low dielectric constant material,” Opt. Mater. Express 4(11), 2262–2273 (2014). #232335 $15.00 USD Received 12 Jan 2015; revised 8 Feb 2015; accepted 10 Feb 2015; published 17 Feb 2015 (C) 2015 OSA 1 Mar 2015 | Vol. 5, No. 3 | DOI:10.1364/OME.5.000603 | OPTICAL MATERIALS EXPRESS 603 18. H. Takatsu, “Advanced liquid crystal materials for active matrix displays,” Conf. Proc. Advanced Display Materials and Devices, p.43 (Sendai, Japan, 2014). 19. J. Li, M. Hu, J. Li, Z. An, X. Yang, Z. Yang, and Z. Che, “Highly fluorinated liquid crystals with wide nematic phase interval and good solubility,” Liq. Cryst. 41(12), 1783–1790 (2014). 20. M. Schadt, R. Buchecker, and K. Muller, “Material properties, structural relations with molecular ensembles and electro-optical performance of new bicyclohexane liquid crystals in field-effect liquid crystal displays,” Liq. Cryst. 5(1), 293–312 (1989). 21. Z. Luo, Y. Chen, and S.-T. Wu, “Wide color gamut LCD with a quantum dot backlight,” Opt. Express 21(22), 26269–26284 (2013). 22. Y. W. Li, K. H. Fan-Chiang, C. Y. Tsai, C. L. Wu, C. T. Wang, W.-H. Chen, and H.-C. Tsai, “P-186: Compensated MTN mode field sequential microdisplays for pico projector applications,” SID Symp. Dig. Tech. Pap. 42(1), 1801–1803 (2011).