tft lcd flat panel display free sample

Established in 2010, Topfoison has devoted itself to the manufacturing and development of high-quality products for the Wearable device, Smart Watch, VR, Medical device, Industrial LCD display including Color LCD modules/OLED/LCD display/Round lcd screen/Round AMOLED/ Square transflective lcd screen/ IPS full wide display/ 1080p fhd AMOLED and 2K 1440p lcd. Topfoison focus on1.22-7.0 inch small size displays, all the products produced in our company enjoys the most advanced production craft and technology as well as the strictly ISO quality management system.

4 inch square TFT LCD display 720x720 IPS/ Free/Full/ All/ wide viewing angle, 300nits brightness, 4x2 LEDs, MIPI interface, YY1821 driver IC, 30pin, -20℃~70℃ Working Temperature , with capacitive touch, tape bonding

We have been also specializing in improving the things administration and QC system to ensure that we could preserve terrific gain within the fiercely-competitive company for Tft Color Lcd Module, Lcd Numeric Display Modules, Tft Touchscreens, We feel that our warm and professional support will bring you pleasant surprises as perfectly as fortune.

We know that we only thrive if we can guarantee our combined price competiveness and quality advantageous at the same time for Factory Free sample Monitor Lcd Panel - 3.2/3.5/3.97 inch Standard Color TFT LCD Display for interpreter device – DISEN , The product will supply to all over the world, such as: Malta, Riyadh, Lahore, With many years good service and development, we have a qualified international trade sales team. Our goods have exported to North America, Europe, Japan, Korea, Australia, New Zealand, Russia and other countries. Looking forward to build up a good and long term cooperation with you in coming future!

As a TFT LCD manufacturer, we import mother glass from brands including BOE, INNOLUX, and HANSTAR, Century etc., then cut into small size in house, to assemble with in house produced LCD backlight by semi-automatic and fully-automatic equipment. Those processes contain COF(chip-on-glass), FOG(Flex on Glass) assembling, Backlight design and production, FPC design and production. So our experienced engineers have ability to custom the characters of the TFT LCD screen according to customer demands, LCD panel shape also can custom if you can pay glass mask fee, we can custom high brightness TFT LCD, Flex cable, Interface, with touch and control board are all available.

TFT (Thin Film Transistor) LCD (Liquid Crystal Display) dominates the world flat panel display market now. Thanks for its low cost, sharp colors, acceptable view angles, low power consumption, manufacturing friendly design, slim physical structure etc., it has driven CRT(Cathode-Ray Tube) VFD ( Vacuum Fluorescent Display) out of market, squeezed LED (Light Emitting Diode) displays only to large size display area. TFT LCD displays find wide applications in TV, computer monitors, medical, appliance, automotive, kiosk, POS terminals, low end mobile phones, marine, aerospace, industrial meters, smart homes, handheld devices, video game systems, projectors, consumer electronic products, advertisement etc. For more information about TFT displays, please visit our knowledge base.

There a lot of considerations for how to choose a most suitable TFT LCD display module for your application. Please find the check list below to see if you can find a right fit.

It is the start point for every project. There aretwo dimensions to consider: outside dimension (width, height, thickness) and AA (active area or pixel area). Orient Display’s standard product line ranges from 1.0” to 32”. Our OLED size can go down to 0.66” which fit for wearable devices.

Resolution will decide the clearance. Nobody likes to see a display showing pixel clearly. That is the reason for better resolution, going from QVGA, VGA to HD, FHD, 4K, 8K. But higher resolution means higher cost, power consumption, memory size, data transfer speed etc. Orient Display offers low resolution of 128×128 to HD, FHD, we are working on providing 4K for our customers. For full list of resolution available, please see Introduction: LCD Resolution

TFT screen brightness selection is very important. You don’t want to be frustrated by LCD image washout under bright light or you drain the battery too fast by selecting a super brightness LCD but will be used indoor only. There are general guidance listed in the table below.

Orient Display offers standard brightness, medium brightness , high brightness, and high end sunlight readable IPS TFT LCD display products for our customers to choose from.

If the budget is tight, TN type TFT LCD can be chosen but there is viewing angle selection of either 6 o’clock or 12 o’clock. Gray scale inversion needs to be taken of carefully. If a high-end product is designed, you can pay premium to select IPS TFT LCD which doesn’t have the viewing angle issue.

It is similar to viewing angle selection, TN type TFT LCD has lower contrast but lower cost, while IPS TFT LCD has much high contrast but normally with higher cost. Orient Display provides both selections.

Normal TFT LCD displays provide wide enoughtemperature range for most of the applications. -20 to 70oC. But there are some (always) outdoor applications like -30 to 80oC or even wider, special liquid crystal fluid has to be used. Heater is needed for operating temperature requirement of -40oC. Normally, storage temperature is not an issue, many of Orient Display standard TFT display can handle -40 to 85oC, if you have any questions, feel free to contact our engineers for details.

Power consideration can be critical in some hand-held devices. For a TFT LCD display module, backlight normally consumes more power than other part of the display. Dimming or totally shutdown backlight technology has to be used when not in use. For some extreme power sensitive application, sleep mode or even using memory on controller consideration has to be in design. Feel free to contact our engineers for details.

Genetic Interfaces: Those are the interfaces which display or touch controller manufacturers provide, including parallel, MCU, SPI(,Serial Peripheral Interface), I2C, RGB (Red Green Blue), MIPI (Mobile Industry Processor Interface), LVDS (Low-Voltage Differential Signaling), eDP ( Embedded DisplayPort) etc. Orient Display has technologies to make the above interface exchangeable.

High Level Interfaces: Orient Display has technologies to make more advanced interfaces which are more convenient to non-display engineers, such as RS232, RS485, USB, VGA, HDMI etc. more information can be found in our serious products. TFT modules, Arduino TFT display, Raspberry Pi TFT display, Control Board.

Touch panels have been a much better human machine interface which become widely popular. Orient Display has been investing heavy for capacitive touch screen sensor manufacturing capacity. Now, Orient Display factory is No.1 in the world for automotive capacitive touch screen which took around 18% market share in the world automotive market.

Based on the above three types of touch panel technology, Orient Display can also add different kinds of features like different material glove touch, water environment touch, salt water environment touch, hover touch, 3D (force) touch, haptic touch etc. Orient Display can also provide from very low cost fixed area button touch, single (one) finger touch, double finger (one finger+ one gesture) touch, 5 finger touch, 10 points touch or even 16 points touch

Considering the different shapes of the touch surface requirements, Orient Display can produce different shapes of 2D touch panel (rectangle, round, octagon etc.), or 2.5D touch screen (round edge and flat surface) or 3D (totally curved surface) touch panel.

Considering different strength requirements, Orient Display can provide low cost chemical tampered soda-lime glass, Asahi (AGC) Dragontrail glass and Corning high end Gorilla glass. With different thickness requirement, Orient Display can provide the thinnest 0.5mm OGS touch panel, to thickness more than 10mm tempered glass to prevent vandalizing, or different kinds of plastic touch panel to provide glass piece free (fear) or flexible substrates need.

Of course, Orient Display can also offer traditional RTP (Resistive Touch Panel) of 4-wire, 5-wire, 8-wire through our partners, which Orient Display can do integration to resistive touch screen displays.

If you can’t find a very suitable TFT LCD Display in our product line, don’t be discouraged. The products listed on our website is only small part of standard products. We have thousands of standard products in our database, feel free to contact our engineers for details.

If you like to have a special display, Orient Display is always flexible to do partial custom solution. For example, to modify the FPC to different length or shape, or use as fewer pinouts as possible, or design an ultra-bright LCD display, or a cover lens with your company logo on it, or design an extreme low power or low cost TFT display etc. our engineers will help you to achieve the goals. The NER cost can start from hundreds of dollars to Thousands. In rare case, it can be tens of thousands of dollars.

A fully custom TFT LCD panel can have very high NRE cost. Depending on the size of the display, quantity and which generation production line to be used. The tooling cost can start from $100,000 to over $1M.

Boron Flat Panel Display Glass is an important mineral used in LCD and plasma television panels. It is commonly used in high-tech glass for LCD and plasma TV screens. Its use in these products significantly increased around 2000 as consumer preference shifted away from CRT TVs to flat-panel screens. Substitutes for boron are, however, beginning to appear given its presence in glass, which some consider an environmental hazard.

The term flat panel display (FPD) may be used to refer to any number of “flat” display technologies, such as liquid crystal displays (LCD), plasma displays, and field emission displays (FED).

FPDs use borosilicate glass primarily for TFT displays. Since flat panel displays (FPDs) have replaced cathode ray tubes (CRTs) in markets such as televisions (TVs) and computer monitors, thin-film transistor (TFT) glass has historically been an important market for borates. The most common type of FPD is the LCD, which utilizes TFTs glass in manufacturing the devices.

Using boron in flat panel display glass continues to be widespread. Boron exhibits advantages in heat resistance, processing range, and devitrification stability in Flat Panel Display Glass. Other benefits of boron in flat panel displays include improved brightness and colour rendering, and boron-infused glass can even improve the display’s contrast

Displays with TFTs are constructed using two sheets of alkaline-free borosilicate or boroaluminosilicate glass between which is a filling including TFTs (which control the electronic current to the pixels), transparent conductors, and colour filters.

The glass used in these substrates mustn’t contain alkaline elements, such as sodium, since these may interact with the TFT and degrade it. As a result of its purity, boric acid is commonly used to produce borosilicate TFT glass, which contains between 10-15% B₂O₃.

Boron’s low refractive index allows it to withstand high temperatures as well as thermal shock. Having the ability to be sealed to metal can make it an excellent choice for displays. Despite its lower density than soda-lime glass, it is still capable of breaking into large chunks. Creating flat panels requires a combination of low refractive index and low thermal shock resistance. Televisions rely on it for the technology behind flat panel displays.

Apart from TFT glass, borosilicate glass can also be used as a cover glass for touch screens on mobile devices such as smartphones and tablets. Asahi, for example, produces alkaline-free aluminosilicate glass for use in this market, so not all cover glass contains boron.

A form of borosilicate glass is also used to backlight LCD televisions and PC monitors with cold cathode fluorescent lamps (CCFLs). CCFLs began to be replaced by light-emitting diodes (LEDs) in the late 2000s, which do not use borosilicate glass.

However, there is a trend to lower usage of boron to reduce the volatile amount of boron during TFT-LCD base plate glass manufacturing. The presence of boron in flat panel display glass can cause an increase in the risk of radiation damage. It is a contaminant in flat panel display glass and will corrode it.

The use of boron in flat panel display glass is the subject of discussion in the industry, and the absence of this metalloid in the mirror makes the technology unreliable. Recently, substitute materials for TFT-LCD glassinclude rare earth elements such as lanthanum, yttrium, cerium, or Erbium. The rare earth elements are added to reduce the boron content in flat panel display glass.

The presence of boron in flat panel display glass is also a concern among consumers. While boron is harmless in small quantities, it is present in glass at levels that may be hazardous to the environment. The presence of boron in glass in flat-panel displays can also cause colour casts. Although the levels of uranium are low, this element is a significant pollutant that affects the performance of LCD and plasma panels.

TFT glass is primarily produced in Japan, South Korea, Taiwan, Singapore, and China. In addition, the logistical requirements of TFT glass panels require their production to take place mainly in these countries. Currently, only a few suppliers provide glass substrates for TFTs, mainly due to the high-quality requirements and the difficulty of manufacturing.

The global TFT-LCD display panel market attained a value of USD 148.3 billion in 2022. It is expected to grow further in the forecast period of 2023-2028 with a CAGR of 4.9% and is projected to reach a value of USD 197.6 billion by 2028.

The current global TFT-LCD display panel market is driven by the increasing demand for flat panel TVs, good quality smartphones, tablets, and vehicle monitoring systems along with the growing gaming industry. The global display market is dominated by the flat panel display with TFT-LCD display panel being the most popular flat panel type and is being driven by strong demand from emerging economies, especially those in Asia Pacific like India, China, Korea, and Taiwan, among others. The rising demand for consumer electronics like LCD TVs, PCs, laptops, SLR cameras, navigation equipment and others have been aiding the growth of the industry.

TFT-LCD display panel is a type of liquid crystal display where each pixel is attached to a thin film transistor. Since the early 2000s, all LCD computer screens are TFT as they have a better response time and improved colour quality. With favourable properties like being light weight, slim, high in resolution and low in power consumption, they are in high demand in almost all sectors where displays are needed. Even with their larger dimensions, TFT-LCD display panel are more feasible as they can be viewed from a wider angle, are not susceptible to reflection and are lighter weight than traditional CRT TVs.

The global TFT-LCD display panel market is being driven by the growing household demand for average and large-sized flat panel TVs as well as a growing demand for slim, high-resolution smart phones with large screens. The rising demand for portable and small-sized tablets in the educational and commercial sectors has also been aiding the TFT-LCD display panel market growth. Increasing demand for automotive displays, a growing gaming industry and the emerging popularity of 3D cinema, are all major drivers for the market. Despite the concerns about an over-supply in the market, the shipments of large TFT-LCD display panel again rose in 2020.

North America is the largest market for TFT-LCD display panel, with over one-third of the global share. It is followed closely by the Asia-Pacific region, where countries like India, China, Korea, and Taiwan are significant emerging market for TFT-LCD display panels. China and India are among the fastest growing markets in the region. The growth of the demand in these regions have been assisted by the growth in their economy, a rise in disposable incomes and an increasing demand for consumer electronics.

The report gives a detailed analysis of the following key players in the global TFT-LCD display panel Market, covering their competitive landscape, capacity, and latest developments like mergers, acquisitions, and investments, expansions of capacity, and plant turnarounds:

According to IMARC Group’s latest report, titled “TFT LCD Panel Market: Global Industry Trends, Share, Size, Growth, Opportunity and Forecast 2022-2027”, the global TFT LCD panel market size reached US$ 157 Billion in 2021. Looking forward, IMARC Group expects the market to reach US$ 207.6 Billion by 2027, exhibiting a growth rate (CAGR) of 4.7% during 2022-2027.

A thin-film-transistor liquid-crystal display (TFT LCD) panel is a liquid crystal display that is generally attached to a thin film transistor. It is an energy-efficient product variant that offers a superior quality viewing experience without straining the eye. Additionally, it is lightweight, less prone to reflection and provides a wider viewing angle and sharp images. Consequently, it is generally utilized in the manufacturing of numerous electronic and handheld devices. Some of the commonly available TFT LCD panels in the market include twisted nematic, in-plane switching, advanced fringe field switching, patterned vertical alignment and an advanced super view.

The global market is primarily driven by continual technological advancements in the display technology. This is supported by the introduction of plasma enhanced chemical vapor deposition (PECVD) technology to manufacture TFT panels that offers uniform thickness and cracking resistance to the product. Along with this, the widespread adoption of the TFT LCD panels in the production of automobiles dashboards that provide high resolution and reliability to the driver is gaining prominence across the globe. Furthermore, the increasing demand for compact-sized display panels and 4K television variants are contributing to the market growth. Moreover, the rising penetration of electronic devices, such as smartphones, tablets and laptops among the masses, is creating a positive outlook for the market. Other factors, including inflating disposable incomes of the masses, changing lifestyle patterns, and increasing investments in research and development (R&D) activities, are further projected to drive the market growth.

The competitive landscape of the TFT LCD panel market has been studied in the report with the detailed profiles of the key players operating in the market.

The TFT-LCD (Flat Panel) Antitrust Litigationclass-action lawsuit regarding the worldwide conspiracy to coordinate the prices of Thin-Film Transistor-Liquid Crystal Display (TFT-LCD) panels, which are used to make laptop computers, computer monitors and televisions, between 1999 and 2006. In March 2010, Judge Susan Illston certified two nationwide classes of persons and entities that directly and indirectly purchased TFT-LCDs – for panel purchasers and purchasers of TFT-LCD integrated products; the litigation was followed by multiple suits.

TFT-LCDs are used in flat-panel televisions, laptop and computer monitors, mobile phones, personal digital assistants, semiconductors and other devices;

In mid-2006, the U.S. Department of Justice (DOJ) Antitrust Division requested FBI assistance in investigating LCD price-fixing. In December 2006, authorities in Japan, Korea, the European Union and the United States revealed a probe into alleged anti-competitive activity among LCD panel manufacturers.

The companies involved, which later became the Defendants, were Taiwanese companies AU Optronics (AUO), Chi Mei, Chunghwa Picture Tubes (Chunghwa), and HannStar; Korean companies LG Display and Samsung; and Japanese companies Hitachi, Sharp and Toshiba.cartel which took place between January 1, 1999, through December 31, 2006, and which was designed to illegally reduce competition and thus inflate prices for LCD panels. The companies exchanged information on future production planning, capacity use, pricing and other commercial conditions.European Commission concluded that the companies were aware they were violating competition rules, and took steps to conceal the venue and results of the meetings; a document by the conspirators requested everybody involved "to take care of security/confidentiality matters and to limit written communication".

Companies directly affected by the LCD price-fixing conspiracy, as direct victims of the cartel, were some of the largest computer, television and cellular telephone manufacturers in the world. These direct action plaintiffs included AT&T Mobility, Best Buy,Costco Wholesale Corporation, Good Guys, Kmart Corp, Motorola Mobility, Newegg, Sears, and Target Corp.Clayton Act (15 U.S.C. § 26) to prevent Defendants from violating Section 1 of the Sherman Act (15 U.S.C. § 1), as well as (b) 23 separate state-wide classes based on each state"s antitrust/consumer protection class action law.

In November 2008, LG, Chunghwa, Hitachi, Epson, and Chi Mei pleaded guilty to criminal charges of fixing prices of TFT-LCD panels sold in the U.S. and agreed to pay criminal fines (see chart).

The South Korea Fair Trade Commission launched legal proceedings as well. It concluded that the companies involved met more than once a month and more than 200 times from September 2001 to December 2006, and imposed fines on the LCD manufacturers.

Sharp Corp. pleaded guilty to three separate conspiracies to fix the prices of TFT-LCD panels sold to Dell Inc., Apple Computer Inc. and Motorola Inc., and was sentenced to pay a $120 million criminal fine,

In South Korea, regulators imposed the largest fine the country had ever imposed in an international cartel case, and fined Samsung Electronics and LG Display ₩92.29 billion and ₩65.52 billion, respectively. AU Optronics was fined ₩28.53 billion, Chimmei Innolux ₩1.55 billion, Chungwa ₩290 million and HannStar ₩870 million.

Seven executives from Japanese and South Korean LCD companies were indicted in the U.S. Four were charged with participating as co-conspirators in the conspiracy and sentenced to prison terms – including LG"s Vice President of Monitor Sales, Chunghwa"s chairman, its chief executive officer, and its Vice President of LCD Sales – for "participating in meetings, conversations and communications in Taiwan, South Korea and the United States to discuss the prices of TFT-LCD panels; agreeing during these meetings, conversations and communications to charge prices of TFT-LCD panels at certain predetermined levels; issuing price quotations in accordance with the agreements reached; exchanging information on sales of TFT-LCD panels for the purpose of monitoring and enforcing adherence to the agreed-upon prices; and authorizing, ordering and consenting to the participation of subordinate employees in the conspiracy."

On December 8, 2010, the European Commission announced it had fined six of the LCD companies involved in a total of €648 million (Samsung Electronics received full immunity under the commission"s 2002 Leniency Notice) – LG Display, AU Optronics, Chimei, Chunghwa Picture and HannStar Display Corporation.

On July 3, 2012, a U.S. federal jury ruled that the remaining defendant, Toshiba Corporation, which denied any wrongdoing, participated in the conspiracy to fix prices of TFT-LCDs and returned a verdict in favor of the plaintiff class. Following the trial, Toshiba agreed to resolve the case by paying the class $30 million.

Liquid crystals (LCs) remained an academic curiosity until 1962, when Williams (1963), at the Radio Corporation of America’s (RCA) Sarnoff Research Center, discovered changes in the optical transmission of thin films of para-azoxyanisole held between two glass slides on the application of 12 V. Williams subsequently left the laboratory, but his lead was followed by George Heilmeier, who persuaded the RCA management to start an LC project. There was, at that time, no room-temperature LC, but the RCA chemists devised a mixture of three Schiff’s bases that had a nematic range from 22 to 105°C (Goldmacher & Castellano 1967). The effect that RCA wished to exploit in displays was called the dynamic scattering mode (DSM), in which the mixture turns from transparency to white opalescence over a range of a few volts (Heilmeier et al. 1968). LCs are anisotropic in almost all their physical characteristics. The values of refractive index, dielectric constant, conductivity, elasticity and viscosity are very different when measured along the long molecular axis or the short axes. Because of the dielectric anisotropy, the molecule will turn in an electric field, and nematics divide into two classes, positive crystals, which align along the field, and negative crystals, which try to lie across it. DSM can be generated in negative nematics, because charges build up along the molecules, giving rise to a field at right angles to the applied field. At higher fields, turbulence occurs. RCA publicized their discoveries in 1968, and, amid some excitement, many companies set about exploiting liquid crystal displays (LCD) in digital watches and calculators. Curiously, RCA was an exception.

RCA had little interest in small instruments. Their display involvement was in CRTs, and here their position was almost unique. Harold Law and Al Schroeder had invented the shadow-mask tube some 10 years earlier, and this was now being made in quantity at plants in Lancaster, Pennsylvania, and Harrison, New Jersey (Law 1950, 1976). The company had early adopted the principle of licensing their inventions, and shadow-mask tubes were now produced worldwide.1962a,b) would be the solution. In any case, they did not see the virtue in trying to replace their own world-leading display, and did not accept the moral, ‘If you don’t do it, someone else will’.

Looking back, it is obvious that RCA held most of the assets needed to forge and preserve world leadership in flat-panel displays, but they opted out. The management set a target of a 1200 pixel integrated display panel to be made early in 1968, but when no panel was made by the end of the year, the project was cancelled. In the next year they abandoned all work on LC TV, though some work on small displays continued until 1972.

It would not be an overstatement to say that US industry lost its way on displays in the 1970s. We have seen that the early running on LCs was made by RCA. That laboratory had not been in the forefront of discovery on transistors and chips, relying mainly on licensing from Bell Telephone Laboratories (BTL), but it had a proud record of innovation in vacuum tubes, culminating in the invention of the shadow-mask CRT. RCA led in the early research on TFTs and LCDs, but the belief that flat-panel displays were against their long-term interests led them to withdraw from the field in 1972. The other potential industrial leader, BTL, had stayed curiously aloof from the frenzied search for novel display technology, partly because of their increased involvement in semiconductor lasers for communications, but also because senior figures in their laboratory were unconvinced that new displays were required. They said (Gordon & Anderson 1973):Prospects for new display technologies are clouded by the fact that there exists a device, the familiar CRT, that has long provided a versatile, elegant, functional, economical, and largely satisfactory solution.

In circumstances where industry was unwilling to lead in long-term research programmes, defence funding had previously filled the gap, and we have seen that this indeed happened in the UK. In the USA, however, the Department of Defense (DoD) was also unconvinced about flat panels. The opposition was led, strangely, by the scientist who had contributed much to the earlier enthusiasm at RCA for LCs, George Heilmeier. He had left RCA in 1970, and within two years was holding a senior post in the US DoD with responsibility for electronic device research contracts. He told the main US Displays Conference (Heilmeier 1973):How many realistic scenarios are there in which we win because we have a flat-panel, matrix-addressed display in the cockpit? We must feed on existing technologies.

The lack of management interest in LCDs certainly led to a number of the RCA scientists leaving, and one of their best theorists, Wolfgang Helfrich, joined Hoffmann-La Roche (H-LR), the Swiss chemical and pharmaceutical company, in 1970. There he suggested to Martin Schadt, the LC group leader, that he should work on a new display effect that exploited positive nematics. Helfrich’s idea was to make a thin LC cell that rotated the plane of incident polarized light by 90°. It was known that nematic molecules would lie down on a glass substrate that had been rubbed with a polishing cloth in one direction. If that direction was orthogonal on the two surfaces, a 90° twist would be induced, and when the cell was put between parallel polarizers, no light could pass. However, if a field was applied across that cell, the molecules would align themselves along the field, the twist would disappear, and light could pass. Schadt made the cell, it worked, and the twisted nematic (TN) display was born (figure 6).

James Fergason was a scientist who had worked on cholesteric LCs at Westinghouse in the early 1960s, but left in 1966 to join Kent State University. Two years later he formed his own company, ILIXCO, to manufacture LC displays. In 1968 and 1970 he published two papers that effectively contained descriptions of the TN display (Arora et al. 1968; Fergason et al. 1970). He made no attempt then to patent the concept, and was surprised, and probably irritated, when a colleague reported back after a visit to H-LR that Schadt and Helfrich had invented a new form of LCD. In fact, it was as a result of this inadvertent disclosure that H-LR had rapidly taken the patenting and publishing actions. Fergason himself set about composing patents and, after an abortive attempt in February, submitted in April a patent, which was granted in 1973 (Fergason 1971). No mention was made in this patent of his earlier publications. Though the validity of Fergason’s patent could have been queried because of those disclosures, there could be no doubt that he had made and shown a device in April 1970, because he had recorded the invention in witnessed notebooks. He therefore had good grounds for contesting the H-LR patent, and after protracted legal proceedings this was withdrawn. However, H-LR regained legal ownership of TN rights by buying the Fergason patent from ILIXCO, which were in financial difficulties. A compromise agreement shared royalties amicably between all the interested parties except RCA.

Though the way was now legally clear for companies to exploit TN displays, the commercial position was unclear. A number of companies had taken licences from RCA to exploit dynamic scattering, and they were reluctant to adopt an untested technology. However, problems soon arose because of the LC material. DSM effects need negative nematics, and though RCA had now demonstrated a suitable Schiff’s base that was nematic at room temperature, it did not have an adequate working range. Sharp developed a eutectic mixture of three Schiff’s bases that worked over the range 0–40°C, but were then frustrated when their devices failed after only a few weeks of operation. It became apparent that there was no stable LC available, and LCDs were acquiring a poor reputation for reliability.

Up to then, the UK had played little part in LC development, though one or two university chemistry departments were involved in research, and one company, Marconi, had patented an LCD before the war (Levin & Levin 1934). Now events took a curious turn, because a politician became involved. Much UK semiconductor research had been carried out in government defence laboratories, and early development of LEDs and diode lasers had taken place at the Services Electronics Research Laboratory (SERL), Baldock, and at the Royal Radar Establishment (RRE), Malvern. One of the aims of the Labour Government elected in March 1966 had been to forge a ‘white-hot technological revolution’, and the next year they established a Ministry of Technology. This assimilated some of the defence laboratories, including RRE, and in March 1967 the Minister of State for Technology, John Stonehouse (figure 7), came to Malvern.

He was surprised to hear that royalties to RCA on the shadow-mask tube cost the UK more than Concorde, and after overnight deliberation authorized the Director of RRE, Dr (later Sir) George Macfarlane, to start a programme on flat-panel electronic displays. Surprised at this rapid decision, and informed by senior staff that there was no expertise within RRE to mount a meaningful development programme, he set up a committee to study the field. This recommended in December 1969 that the UK Government should fund research on flat-panel electronic displays, with LCs as the first priority (Hilsum 1969).

Though formal approval of this recommendation would normally have taken some months, and, indeed, was never granted, RRE had anticipated approval, and justified their action on the urgent need for displays for the portable radar sets they had invented. They established two consortia, one for materials, involving RRE, Hull University and BDH, and one for devices, involving RRE, SERL, Marconi, Rank and STL. The Plessey Research Laboratory at Caswell were also involved, specializing in electrophoretics. Though most of these organizations were ‘the usual suspects’ from the semiconductor R&D programmes, Hull University were unknown. They had come to the attention of RRE during a meeting held to probe UK expertise on LCs, when it became clear that Hull, led by Professor George Gray, were clear leaders in the understanding of LC chemistry. This trust was rewarded manifold. Gray was given the task of finding a stable LC, because RRE, schooled in defence requirements for reliable components, appreciated that consumers also would not tolerate short-lived equipment. All available LCs had serious shortcomings. Schiff’s bases gave erratic results, and stilbenes, more recently proposed, were degraded when exposed to ultraviolet radiation.

A crucial contribution was then made by Peter Raynes, who had joined the RRE Displays Group a year earlier, fresh from a PhD on superconductivity. He realized that the Schroeder–Van Laar equation for binary eutectics might be extended to predict mixture properties from thermodynamic data for the individual materials. However, the accuracy was not high enough, and Raynes then developed a more accurate semi-empirical method, which proved ideal. This was so useful commercially that it was not put into print for some years (Raynes 1980). Melting points of eutectic mixtures were then predictable to within 5°C, and clearing points, the change from nematic to isotropic behaviour, to within 2°C (Hulme et al. 1974). Raynes predicted that no mixture of biphenyls would operate well below zero. Gray then reasoned that adding a terphenyl component would give a wider range mixture, and though terphenyls were difficult to make, they proved to be the solution.

Meanwhile, production processes of pure biphenyls had been perfected at Poole, where Ben Sturgeon, the Technical Director of BDH, had made inspired contributions, and before long BDH was selling biphenyl eutectics widely, for though their temperature range was not ideal, their stability was very attractive. Late in August 1973, Raynes made a four-component eutectic that had a range of −9 to 59°C. It was called E7, and the composition is shown in figure 8. In almost all respects it met the specifications put to RRE by manufacturers of watch displays (table 2).

E7 could be said to be the saviour of the LC industry, for it was invented at a time when LCDs were suspected of being inherently unreliable, and it remained the preferred material for many years. The UK Ministry of Defence (MoD) chose a restricted licensing strategy, and originally only BDH and H-LR could sell biphenyls. Rapidly they dominated the market. By 1977 BDH were the largest manufacturers of LCs in the world (figure 9), and biphenyls had become their largest-selling product. Less than five years earlier, the company had never made an LC.

There are many physical parameters of LCs that control the electro-optical behaviour, but the most important for displays are the elastic constants and the rotational viscosity. Table 3 gives the room-temperature values for E7 for the splay (k11), twist (k22) and bend (k33) elastic constants and the viscosity (η).

The visual appearance of a TN cell depends strongly on the angle of view, and both the viewing angle and the contrast ratio came under criticism as the possibility of major markets became apparent. Major advances were made, both in the cell configuration and in the LC materials. A big step forward was the idea of increasing the twist from 90° to 270°. This supertwist nematic display (STN) was proposed and patented in 1982 by Waters & Raynes (1982) at RRE, and independently patented a year later by the Brown Boveri group, led by Terry Scheffer (Amstutz et al. 1983), afterwards ably assisted by Jurgen Nehring. STN gave the steep threshold necessary for passive matrix displays, and the response time and angle of view were similar to the simple TN device (Scheffer 1983; Waters et al. 1983). It became the preferred display for instruments and lap-top computers, and lost ground only when the production of TFTs over large areas was perfected. The STN display was patented and widely licensed by the MoD, and yielded royalties of over £100 million, the largest return for any MoD patent.

More radical changes to the TN mode were also introduced. Soref (1972, 1973), at Beckman Instruments and Sperry Rand, had proposed in 1972 displays using circular polarizers with interdigitated electrodes on just one of the glass surfaces. The concept of interdigitated electrodes was improved by the Freiburg Fraunhofer Institute, which invented the in-plane switching (IPS) display in 1990 (Baur et al. 1990; Kiefer et al. 1992).

The electrodes are on the same cell surface, and, in the absence of a voltage, the LC molecules lie parallel to the surfaces, which have the same rubbing direction, so there is no effect on polarized light. Application of a field between the electrodes induces a rotation on that cell surface, and a twist between the two surfaces. However, fringe fields and the effect of tilt make the operation more complicated, and can lead to increased response time. Moreover, each pixel needs two switching TFTs, and in early versions this reduced the transmittance. IPS was studied by a number of laboratories in the 1990s, notably Hosiden, NEC and, particularly, Hitachi (Ohe & Kondo 1995; Ohta et al. 1996). There are now a number of variants in commercial production.

Though TN mode devices showed clear advantages over dynamic scattering, several laboratories pursued other LC effects in the 1970s. Fred Kahn at BTL proposed in 1971 a switching effect based on negative nematics aligned homeotropically, i.e. at 90° to the cell walls, so that the electric field was parallel to the long axis of the molecules, the cell being placed between crossed or parallel polarizers. Application of the field will then cause the molecules to rotate through 90°, and the transmission through the cell will change (Kahn 1971, 1972). Kahn showed that VT was given by equation (4.1), with k=k33. For the LCs he used, VT was 3 V, and the birefringence increased steadily as the voltage was increased to 20 V. Though this seems a simple mode, the alignment requirements are severe. The homogeneous alignment used in TN cells is readily obtained by rubbing the glass surface in one direction. This creates microgrooves, and the long molecules lie in them. For Kahn’s vertical alignment (VA) mode, it is necessary not only to persuade the molecules to lie at 90° to the surface, but also to impose a slight tilt, to give a source of defined anisotropy. This proved difficult to achieve over areas practical for displays, and exploitation of VA awaited the sophisticated control over LC that developed during the next 20 years. A number of improvements were then proposed, one of the most effective being the Fujitsu multi-domain vertical alignment (MVA) mode (figure 10).

Naturally, this growth has had to be served by much R&D on materials to give better display performance. As I noted earlier, the most important parameters to consider in designing an LC for displays are the temperature range of the nematic phase, the magnitude of the elastic constants, the ratio of the bend constant k33 to the splay constant k11, and the viscosity η. Also relevant are the magnitude and sign of the dielectric anisotropy Δε, and the magnitude of the birefringence Δn.

Though biphenyls and phenyl-cyclohexanes served the LCD industry well during the first 15 years of development, there were obvious deficiencies in the display appearance and multiplexing capability. One serious problem was the resistivity, insufficiently high for large displays. LCs are insulating, but that is a relative term, and to ensure that the pixel voltage does not drain away in active matrix applications, the resistivity must be very high, above 1012 Ω cm, and that rules out some otherwise promising families. Another problem was the slow switching speed, with a failure to follow fast-changing images. The simple remedy of reducing viscosity led to both a smaller operating temperature range and a reduction in the dielectric anisotropy, giving a higher switching voltage. After much research at Hull University and Merck, the inclusion of fluorine groups was shown to give much improved performance (Gray et al. 1989; Reiffenrath et al.1989a,b; Coates et al. 1993). It should be noted that commercial LCs now are mixtures of from 10 to 30 individual molecules, but a typical core material is shown in figure 12. This material has a high Δε of over 17, satisfactory for both IPS and TN modes (Kirsch 2004).