Issue 36 – March 2012
Displays are central to all multimedia, information and communication technology (ICT), and to many other devices and systems, such as digital still cameras, mobile phones, digital signage, and cash or vending machines. Flat panel display (FPD) technology is now being used in all of these. The International Electrotechnical Commission's (IEC's) technical committee (TC) 110, 'Electronic display device', plays an essential role in this development by preparing international Standards for all types of electronic display devices, excluding cathode ray tubes.
From cathode ray to flat panel
Opinions differ about precisely when and where television was invented. However, what is certain is that its development (from the mid-1930s) was made possible thanks to the arrival of cathode ray tube (CRT) displays. CRT consists of an electron gun that fires electrons onto a phosphor-coated screen to produce moving images. CRT displays, first monochrome, then colour, were the unique choice for television sets, computers, and other systems for nearly 60 years before being phased out relatively rapidly by FPDs.
Swift shift in IT
Compared to CRT-based TV sets, which delivered a wide range of colours, the first CRT monitors for IT equipment, which were limited by inadequate graphic cards, were monochrome and didn't provide good or sharp pictures. Colour CRT monitors for IT equipment first appeared in the early 1980s.
FPDs were initially used in laptop computers, in the form of monochrome liquid crystal display (LCD) screens. Their limited size, weight, and power consumption made them a much better choice than the CRT displays used in the first 'portable' computers, which weighed well over 10 kilos. The first standalone flat panel displays for computers were introduced in the mid-1990s, but were quite expensive at the time. However, their widespread adoption followed quickly as their price dropped and as they offered many advantages over CRT monitors, including lower power consumption and a smaller footprint, major benefits in business environments where space is at a premium. From the mid-2000s, LCD screens, initially offered in the 4:3 aspect ratio, like CRT displays, became available in the wider 16:9 format.
Slower transition in television
Whilst CRT displays were replaced fairly rapidly by FPDs in IT equipment, consumers were more reluctant to adopt so-called flat-screen TVs. A 2002 document from the EBU (European Broadcasting Union) Technical Department noted that flat panel displays were just starting to make inroads into domestic TV households. 'CRTs still take 99% of the market,' the report said. Yet, less than 10 years later, the share of CRT TVs had dropped to 10% of worldwide shipments of sets.
The slow initial take-up rate of FPDs for TV sets was mainly due to the high prices of the first large flat TV screens, originally Plasma Display Panel (PDP), and to the protracted preparation and slow publication of international digital and High-Definition Television (HDTV) Standards and the resulting lack of sufficient and suitable content in the appropriate 16:9 format.
However, the sale of FPD TV sets then picked up rapidly, driven by lower prices of LCDs and the wide range of screen sizes, extending from under 20 inches (making them ideal replacements for CRTs in low-income countries) to over 40 inches (suitable for high-income markets). New international TV Standards, leading to the widespread introduction of content required by multichannel (digital) households and HDTV, also helped boost the sales of the new sets.
Beyond the traditional domains of TV sets and computers, flat panel displays are used in many other areas. They have enabled the spectacular expansion of mobile telephony and the emergence of entirely new devices, such as e-readers, which use electronic paper display (EPD), a technology designed to mimic the appearance of ordinary ink on paper. New FPD technologies are constantly being developed, opening up more possibilities for existing devices and paving the way for new ones.
Light-emitting diode (LED) backlighting, resulting in a better image contrast and lower consumption, has been gradually introduced into LCD displays. Different technologies using LEDs, such as organic light emitting diode display (OLED), have been developed to produce new types of FPDs for mobile phones and now TV sets. Beside multimedia and ICT, many industries such as medical, retail, automotive, aeronautics and avionics and transportation rely on displays, and FPDs in particular, to operate smoothly and effectively.
TC work central to FPD expansion
The FPD market, driven by high demand in emerging economies and an expanding range of possible applications, is expected to exceed USD 102 billion by 2015. LCD continues to be the largest product segment in the FPD market while the more recent OLED technology, driven by applications in mobile phones and television, represents the fastest growing sector.
TC 110 prepares international Standards for electronic display devices (excluding CRTs) and specific relevant components. It works on terms and definitions, letter symbols, essential ratings and characteristics, measuring methods, specifications for quality assurance and related test methods, and reliability.
With the growing global appetite for higher quality and new functions in multimedia devices, the range of applications and demand for FPDs keep expanding. To support this expansion, TC 110, which has so far published over 30 international Standards, can expect a significant workload over coming years.
Summarised from the International Electrotechnical Commission's e-tech, January/February 2012.