​The brief development history of LCD screen

The brief development history of LCD screen

Half a century ago the first liquid crystal display was invented - a considerable turning point in the application of a material which until then was only of scientific interest.

Liquid crystals play in many ways a considerable and ever increasing role in our lives. Their first application celebrates a big birthday: In 1968, the invention of the first liquid crystal display (LCD) marks the origin of a whole new generation of technical devices. Learn more about half a century full of creativity – a fascinating history which surely will have more in store for us in the future.

The Milestones of LCD Technology

Before 1960s–Origin preparation

1911: Charles Mauguin, University of Paris, discovered the unique alignment liquid crystal material adopts on various surfaces.

1922: Georges Friedel in France named the three main liquid crystal phases smectic, nematic, and cholesteric.

1927: Vsevolod Frederiks in Russian devised the electrically switched light valve, called the Fréedericksz transition, the essential effect of all LCD technology.

1929: Zocher and Birstein in Germany first studied effects of magnetic and electric fields on liquid crystals.

1936: Barnett Levin and Nyman Levin, Marconi Wireless Telegraph Company in England, obtained the first patent on a liquid crystal light valve.

1959: Mohamed M. Atalla and Dawon Kahng at Bell Labs invented MOSFET (metal-oxide-semiconductor field-effect transistor).

The 1960s – The first liquid crystal display is built.

1962: Paul Weimer developed the first thin film transistor (TFT) at RCA’s David Sarnoff Research Center. George Gray, University of Hull in England, published the first book on liquid 41963: Richard Williams reported the formation of domains in a nematic liquid crystal under electrical excitation.

1966： Joseph Castellano and Joel Goldmacher developed the first l cyanobiphenyls liquid crystal material that operated at or below room temperature.Cholesteric liquid crystals are employed as temperature indicators in thermography and medicine, later also in fashion items and cosmetics.

1968: George Heilmeier, Radio Corporation of America (RCA), presents a liquid crystal display to the professional world. It requires an operating temperature of about 80°C. The dream of the flat television, hanging like a picture on the wall, was born.At our headquarters in Darmstadt research on nematic liquid crystals begins. “Nematic” stands for the “rodlike” shape the molecules align themselves into.

The 1960s bring promising news from the USA regarding new applications for liquid crystals – and the construction of the first liquid crystal display. The slumber of the Sleeping Beauty has ended – and our work on liquid crystals experiences its renaissance.

The 1970s – LCDs operate at room temperature

The most important question for liquid crystal chemists in the 1970s is: How can the operating temperature be lowered? Researchers at Darmstadt succeed in mixing liquid crystals to achieve a nematic phase at room temperature. A huge progress compared to the first LCD.

1970: The first LCD pocket calculator with our azoxy compounds and integrated yellow light filter is presented at the ACHEMA, World Forum and Leading Show for the Process Industries.

1971: James Fergason, then at Kent State University, Ohio, USA, as well as Martin Schadt and Wolfgang Helfrich in Switzerland almost simultaneously develop the “Twisted nematic cell” (TN cell) – a huge breakthrough which led to greater efforts in the area of nematic liquid crystals.

1972: A digital clock with “liquid figures” was constructed.

1973: George W. Gray, professor at the University of Hull, Great Britain, publishes his works on cyanobiphenyls and -terphenyls: For the first-time substances were available, which had a nematic phase stable at room temperature.

1976: The synthesis of phenylcyclohexanes (PCHs), liquid crystals that display better optical properties – and reduce switching times from several hundred milliseconds of the first LCD to 20 milliseconds in displays containing PCHs.

1978: Synthesized cyclohexylcyclohexanes (CCHs) which improve optical properties and switching times even more.

The 1980s – A buzzing decade of innovations

In the 1980s the application of liquid crystals booms. Enables the manufacturers to usher in new ideas for LCD applications: A fruitful alliance – a mutual stimulation by demand and promotion.

1980: Developed the “Viewing-Independent Panel" (VIP display), basis of all active matrix flat-panel LCDs.  Constructed an application laboratory for liquid crystals in Atsugi, Japan.

1984: The first color flat LCD TV is presented in Japan.

1888, the Austrian botanic physiologist Friedrich Reinitzer examines special properties of various derivatives of cholesterol and discovers  their two melting points.

1889:The German physicist Otto Lehman continues his research on these “flowing” crystals and eventually coins the term “cholesteric liquid crystals”. Thereafter, scientists are not really interested in these materials, which for long remain a curiosity.

The 1990s – LCDs gain in size

In the 1990s computer monitors, laptops, notebooks are produced with liquid crystals – and ever-larger flat television screens: At an electronics trade fair in Japan in 1994, the then largest liquid crystal screen is introduced as a prototype, with a 21-inch diagonal. By the end of the 1990s, these super-flat, high-resolution screens are already available as prototypes with diagonals of up to 40 inches.

1995: Development of In-Plane Switching (IPS) for a much lower viewing angle dependence. Constructed many application laboratory for liquid crystals.

1997: Developed an LCD video monitor based on Vertical Alignment (VA) technology with excellent contrast values and a black screen when no voltage is applied.

The 2000s – Speed for screens

A new generation of liquid crystals with negative dielectric anisotropy for the VA technology – these likewise superfluorinated liquid crystals, which our researchers succeed to develop, speed up screens due to their very short switching times. They enable response times of eight milliseconds – completely new dimensions, compared to the several hundred milliseconds displays at the end of the 1960s needed. Besides, the rapid picture formation, VA-based flat televisions display more pleasant advantages: Even at viewing angles of up to 170 degree they deliver satisfyingly high-quality colors, brightness and contrast.

2001: Samsung produced 42″ TFT LCD.

2002: LCD overtook CRT as desktop monitors.

2006: Polymer-stabilized vertical alignment (PS-VA) is co-developed. This technology increases the light transmission, lowers the energy needed for backlighting of displays and consequently reduces their energy consumption.

2007: The image quality of LCD televisions surpassed the image quality of cathode-ray-tube-based (CRT) TVs. In the fourth quarter of 2007, LCD televisions surpassed CRT TVs in worldwide sales for the first time.

The 2010s – The times of fast communication

As mobility gains in significance in our society, mobile communication likewise becomes more important. To communicate anytime anywhere requires fast-switching and energy-saving displays. Research and development keep pace and make smartphones and tablet computers more and more attractive in regards of handling and performance.

2012: The 3D experience in your own home has come true with reactive mesogens.

2014: UB-FFS technology is developed: Ultra-Brightness Fringe-Field Switching crystals allow brighter transmittance of the backlight and thus cut the energy demand of every LCD panel - for longer and brighter runtime.

2017: Introduction of Self-Aligned Vertical Alignment (SA-VA). It targets the trend towards further simplified production processes that can also reduce overall display production costs while delivering new display design and performance advantages.

In the end, throughout the history of development, rapid development of LCD makes people’s life more and more convenient. It is believed that it will continue to develop and benefit mankind profoundly.