Reflective Liquid Crystal Displays

by Wu, Shin-Tson; Yang, Deng-Ke

• ISBN13: 9780471496113
• ISBN10: 0471496111
• Edition: 1st
• Format: Hardcover
• Copyright: 2001-06-08
• Publisher: WILEY

Summary

The evolution of portable communications applications has been facilitated largely by the development of reflective LCD technology. Offering a unique insight into state-of-the art display technologies, Reflective Liquid Crystal Displays covers the basic operations principles, exemplary device structures and fundamental material properties of device components. Display engineers, scientists and technicians active in the field will welcome this unique resource, as will developers of a wide range of systems and applicaations. Graduate students and researchers will appreciated the introduction and technical insight into this exciting technology. Featuring: * Direct-view, projection and micro (virtual projection) reflective displays in the context of multi-media projectors, mobile internet and personal entertainment displays. * Optimisation of critical display attributes: fast response time, low voltage operation and wide angle viewing. * Description of the basic properties of liquid crystal materials and their incorporation into configurations for transmissive and reflective applications. * Examination of the various operations modes enabling the reader to slect the appropriate display type to meet a variety of needs. * Overview and comparison of the complete range of reflective display technologies, and reflective LCD effects. The Society for Information Display (SID) is an international society which has the aim of encouraging the development of all aspects of the field of information display. Complementary to the aims of the society the Wiley-SID series is intended to explain the latest developments in information display technology at a professional level. The broad scope of the series addresses all facets of information displays from technical aspects through systems and prototypes to standards and ergonomics.

Author Biography

Dr Shin-Tson Wu, Provost Professor of Optics, University of Central Florida, School of Optics - CREOL, 4000 Central Florida Boulevard PO Box 162700, Orlando, Florida 32816-2700, USA.

Table of Contents

Series Editor's Foreword	xi
Preface	xiii
Foreword	xv
Overview of Reflective Displays	1	(34)
Introduction	1	(1)
Reflective Direct-view LCDs	2	(14)
Two-polariser R-LCD	3	(1)
Single-polariser R-LCD	4	(1)
Zero-polariser R-LCD	5	(3)
Reflectors	8	(5)
Color filters	13	(1)
Trans-reflective displays	14	(1)
Front lighting	15	(1)
Reflective Projection Displays	16	(7)
Liquid crystal on silicon (LCOS)	17	(1)
Key performance parameters	17	(5)
Virtual projection displays	22	(1)
Digital Micromirror Devices (DMD)	23	(3)
Operating principles	23	(2)
Key DMD features	25	(1)
Reliability	26	(1)
Grating Light Valves	26	(1)
Interferometric Modulation	27	(2)
Electrophoretic Displays	29	(6)
In-plane electrophoretic displays (IP-EPD)	29	(1)
Lines/plate EPD	30	(1)
Wall/post EPD	31	(1)
References	31	(4)
Liquid Crystal Materials	35	(30)
Introduction	35	(1)
Birefringence	36	(2)
Wavelength-dependent birefringence	36	(1)
Temperature-dependent birefringence	37	(1)
Dielectric Constants	38	(5)
LC resistivity	39	(1)
Mean field theory	40	(2)
Molecular simulations	42	(1)
Viscosity	43	(2)
Elastic Constants	45	(2)
LC Absorption	47	(3)
UV/ visible absorption	47	(1)
IR absorption	48	(2)
Some Commonly Used LC Compounds	50	(9)
LCs for TN	50	(1)
LCs for STN	50	(1)
LCs for AMLCD	51	(1)
Negative Δ&epsis; LCs	52	(2)
High birefringence LCs	54	(5)
Cholesteric Displays	59	(6)
References	61	(4)
Phase Retardation Effect	65	(24)
Introduction	65	(1)
Homogeneous Cell	66	(2)
LC alignment	66	(1)
Phase retardation effect	66	(2)
Film-compensated Homogeneous Cells	68	(7)
Computer simulations	68	(1)
Compensation principles	69	(1)
Electro-optic effect	69	(1)
Viewing angle	70	(1)
Cell gap tolerance	71	(1)
Temperature effect	72	(1)
Response time	73	(1)
Operating voltage	73	(1)
Gray scale	74	(1)
Phase-only modulation	75	(1)
Homeotropic Cell	75	(7)
Cell preparation	76	(2)
Transmissive displays	78	(2)
Reflective displays	80	(2)
Chiral-homeotropic Cell	82	(7)
Transmissive displays	83	(1)
Reflective displays	84	(2)
References	86	(3)
Twisted Nematic Cells	89	(24)
Introduction	89	(1)
Transmissive TN Cells	90	(8)
Bisector effect	91	(1)
90° TN cell	92	(2)
75° TN cell	94	(1)
60° TN cell	95	(1)
100° TN cell	96	(2)
Reflective MTN Cells	98	(10)
90° TN cell	100	(1)
90° MTN cell	100	(3)
80° and 70° MTN cells	103	(1)
63.6° MTN cell	104	(1)
60° MTN cell	105	(2)
Low twist MTN cells	107	(1)
Reflective TN Cells	108	(5)
45° TN cell	108	(1)
53° TN cell	109	(1)
Other TN cells	110	(1)
References	111	(2)
Super-twisted Nematic Displays	113	(12)
Introduction	113	(1)
Reflective STN	114	(1)
Jones matrix	114	(1)
Special cases	115	(1)
Computer simulations	115	(1)
Reflective 180° STN	115	(4)
Normalised reflectance	115	(1)
Electro-optic effects	116	(1)
Cell gap tolerance	117	(1)
Duty ratio	118	(1)
Reflective 210° STN	119	(1)
Reflective 240° STN	119	(6)
Single film approach	119	(1)
Double film approach	120	(1)
Twisted film-compensated STN	121	(1)
References	122	(3)
Guest-Host Displays	125	(24)
Introduction	125	(1)
Guest-Host Medium	125	(5)
LC alignment	126	(1)
Dichroic ratio	126	(1)
Absorption wavelengths	127	(3)
Solubility	130	(1)
Viscosity	130	(1)
Material stability	130	(1)
Liquid Crystal Dyes	130	(5)
Nitro-amino biphenyl azo dyes	130	(2)
Nitro-amino tolane dyes	132	(3)
Nitro-amino diphenyldiacetylene dyes	135	(1)
Cell Configurations	135	(10)
Heilmeier-Zanoni cell	135	(1)
Cole-Kashnow cell	136	(2)
White-Taylor cell	138	(4)
Double cell	142	(1)
Tri-layer GH cells	143	(2)
Amorphous cell	145	(1)
Chroma	145	(4)
References	146	(3)
Liquid Crystal/ Polymer Composites	149	(48)
Introduction	149	(1)
Polymer Dispersed Liquid Crystals	150	(12)
Liquid crystal droplet configurations in PDLC	151	(3)
Preparation of PDLC	154	(3)
Operation of PDLC	157	(1)
Drive voltage of a PDLC	158	(3)
Dichroic dye doped PDLC	161	(1)
Polymer Stabilised Liquid Crystals	162	(12)
Preparation of PSLCs	162	(1)
Working modes of PSLCs	163	(11)
Scattering Properties of Liquid Crystal/Polymer Composites	174	(12)
Basic Properties	174	(2)
Rayleigh--Gans scattering theory	176	(6)
Anomalous diffraction scattering theory	182	(1)
Multiple scattering and scattering profile	182	(4)
PDLC Reflective Displays	186	(11)
PDLC reflective display with a black background	186	(3)
PDLC reflective display with a mirror	189	(2)
Dichroic dye doped PDLC reflective display	191	(1)
References	192	(5)
Cholesteric Reflective Displays	197	(46)
Introduction	197	(2)
Optical Properties of Cholesteric Liquid Crystals	199	(12)
Basic optical properties of cholesteric liquid crystals	199	(1)
Reflection spectrum of cholesteric liquid crystals	200	(6)
Viewing angle of cholesteric displays	206	(2)
Gray scale of cholesteric displays	208	(1)
Cell design of cholesteric displays	208	(1)
Color of cholesteric displays	209	(2)
Polymer-dispersed cholesteric liquid crystal	211	(1)
Transition Among Cholesteric Textures	211	(16)
Transition between planar texture and focal conic texture	212	(2)
Transition between the focal conic texture and homeotropic texture	214	(8)
Transition between the homeotropic texture and the planar texture	222	(5)
Drive Schemes	227	(16)
Electro-optical response of bistable cholesteric liquid crystals	227	(2)
Conventional drive scheme	229	(5)
Dynamic drive schemes	234	(4)
References	238	(5)
Bistable Nematic Displays	243	(26)
Introduction	243	(1)
Bistable Twisted-untwisted Nematic Liquid Crystal Display	243	(18)
Bistability and switching mechanism	244	(5)
Optical properties	249	(9)
Drive schemes	258	(3)
Surface Stabilized Nematic Liquid Crystals	261	(8)
Zenithal bistable nematic display	261	(2)
Azimuthal bistable nematic display	263	(3)
References	266	(3)
Fast Response Liquid Crystals	269	(20)
Introduction	269	(1)
Figure of Merit	270	(2)
Temperature Effect	272	(1)
Material Effects	273	(2)
Viscosity effect	273	(2)
Elastic constant effect	275	(1)
Birefringence effect	275	(1)
Voltage Effect	275	(1)
Surface Stabilisation	276	(1)
Cell Gap Effect	277	(8)
Thin cell approach	277	(3)
Cell gap measurements	280	(5)
π-cell	285	(4)
References	286	(3)
Low Operating Voltage	289	(16)
Introduction	289	(1)
Self-phase Compensation Effect	289	(1)
Material Effects	290	(6)
Δ&epsis; effect	291	(1)
Push-pull effect	292	(2)
Colorless high Δ&epsis; compounds	294	(1)
Elastic constant effect	295	(1)
Pre-tilt Angle Effect	296	(1)
Twist Angle Effect	296	(1)
Polarisation Angle Effect	297	(4)
Transmissive displays	298	(1)
Reflective displays	299	(1)
Virtual displays	300	(1)
Compensation Films	301	(1)
Homeotropic Cells	301	(4)
References	303	(2)
Wide Viewing Angle	305	(28)
Introduction	305	(1)
Film-compensated TN Cells	306	(7)
Principles of phase compensation	307	(2)
Discotic compensation films	309	(3)
Twisted compensation films	312	(1)
Spectra Vue™	313	(1)
Transverse Field Effect	314	(5)
In-plane switching	314	(4)
Figure-on-plane mode	318	(1)
Fringing field switching (FFS)	318	(1)
Multi-domain TN	319	(3)
Two-domain TN	320	(1)
Four-domain TN	320	(2)
Amorphous-TN	322	(1)
Multi-domain Vertical Alignment	322	(5)
Protrusions method	323	(2)
Patterned vertical alignment (PVA)	325	(1)
Polymer-stabilised vertical alignment (PSVA)	325	(1)
Reverse exposure MVA	326	(1)
Axially Symmetric-aligned Microcell (ASM) Mode	327	(1)
Film-compensated π-cell	328	(5)
References	329	(4)
Index	333