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Furthering the HDTV Revolution - The CNT-FED Display

Because the display is such a critical human interface of electronic entertainment systems, industry experts have been working for decades to create them larger, lighter, brighter, and thinner- particularly for television use. Cathode ray tube (CRT), liquid crystal display (LCD), plasma displays (PDP), organic light emitting diode (OLED) displays all promised to take the television industry where it has never gone before. And all were expected to gain wide acceptance for use in television receivers.

Unfortunately, each technology has advantages and disadvantages. CRT televisions are heavy, deep, and limited in size for direct view applications. PDP are very power-hungry, suffer from lower brightness and have the potential for screen burn-in. LCDs are limited in size due to manufacturing constraints, are costly, and suffer from narrow viewing angle and slow refresh rates. The OLEDs suffer from stability and lifecycle issues.

Most recently, plasma manufacturers had many believing that the search for the ultimate display was over. Plasma TVs are big, flat, and have a wide viewing angle. They also have significant flaws, including lower brightness, high power consumption, the potential for burn-in, a short life span, and an unaffordable price-point for the consumer masses.

To even further the quest for the exemplary display television is the introduction of High Definition Television (HDTV). HDTV provides means for transforming entertainment experiences. By delivering crystal clear video in high resolution, high-fidelity surround sound, full screen graphics and the ability to drive interactive applications, HDTV delivers an immersive user experience that is attracting consumers all over the world.

By the end of 2006, all American television broadcasters will have switched to a digital signal as mandated by the Federal Communications Commission. The availability of HDTV is worthless without the supportive display, a wide-screen high resolution low cost TV system. According to Japan's NHK Science and Technology Research Laboratories, the fundamental requirements for the future main home television display are a wide screen having a much larger capacity than high vision, excellent picture quality, and low power consumption. In fact, Japan's NHK predicted that the ultimate TV display will be as large as 100 inch diagonal.

Because of the inherent flaws in current display technology for HDTV, researchers have turned to carbon nanotubes to create a new class of large area, high resolution, low cost flat panel displays. Many believe that the field emission display (FED) utilizing carbon nanotubes (CNT) as electron emitter is the technology of choice for ultra-high definition, wide-screen televisions. It is this technology that will be able to support the HDTV revolution at adequate cost.

FED CNT addresses the power issue as they are intrinsically very efficient using the same phosphor as the old CRT technology and as result use substantially less power than plasma displays. Generating visible light from the surface of a plasma display is a three-step process that requires a gas to be ionized, which in turn emits ultraviolet light that stimulates a phosphor to produce visible light. FED CNT allows for the elimination of the energy-hungry ionization step by stimulating the phosphors directly with electrons emitted by carbon nanotubes.

The central element of the carbon nanotube field emission display (CNT-FED) television is the field-emission cathode, which works by combining the phenomenon of quantum tunneling with the operating principle of a traditional lightning rod. In essence, as in a regular CRT, a cathode is induced to emit electrons, but unlike a regular CRT, field emission does not rely on heating the cathode to boil off electrons. Cathodes can therefore be packed close together with their supporting electronics without causing the entire display to overheat. The assembly of cathodes can then be placed close enough to the glass face of the display. Instead of using one traveling electron beam to address a pixel (a dot on the display), the CNT FEDs can have an electron beam for each pixel and as a result the bulky electromagnetic beam-steering setup used in a CRT can be eliminated.

A large voltage sweeps the emitted electrons through a vacuum toward a positively charged anode just behind the glass face of the display, the rear of which is coated with phosphors that lights up when struck, forming a visible image. The result is a display that has the brightness and image quality of a CRT without any of the distortion or blurring issues, but in a configuration of an ultra thin display.

The FED CNT displays possess the flatness and the thinness of plasma display panels and LCDs, and they operate like CRTs. They have a short response time resulting in high quality motion picture without any smearing of the image. The FED CNT displays have the brightness and image quality of a CRT without any of the distortion or blurriness problems, at a fraction of the thickness.

Carbon nanotube field emission display (CNT-FED) televisions will also address the cost factor that keeps other technologies from mass consumption. For example, in order to install a manufacturing line for large area LCD TVs with the diagonal of 50 to 60 inches, the cost would be $3-4 billion. If this factory produces one million televisions per year, the unit price will reflect the cost of capital. In the case of CNT FED, due to new processes similar to printing techniques on large areas, the capital investment for the same volume of large area TVs would be approximately 1/10th of the capital investment for the alternative technologies. As a result, the CNT FED can achieve the cost adequate for providing both the ultimate large area thin TV at an affordable cost that will trigger the real HDTV revolution.

With the resolution of the high ownership cost, HDTV will outgrow its limitations and move into the mass market. In 2002, 2.5 million HD consoles were purchased - or one in ten television sets. Although only 5 million of the nation's households currently have digital TVs, the total number of HDTV enabled sets in use should double to about 11 million by 2005.

Analysts predict that the global field emission display (FED) market scale will reach over $20 billion by 2010, leaving the PDP market in its wake. Future market leadership is up for grabs in this emerging multi-billion dollar market by making the right technology choice.

About Zvi Yaniv, Ph.D.
Dr. Zvi Yaniv is the CEO of Applied Nanotech, Inc. (ANI) in Austin, TX, guiding the company to become a leader in nanotechnology applications, in particular in the display industry utilizing electron field emission from diamond/carbon films. Dr. Yaniv is an authority in electro-optics, liquid crystal technology, amorphous semiconductors, technology commercialization and business management. He has published over 100 articles, holds more than 50 patents, and has extensive contacts in the U.S., Europe, Israel and the Far East.

Reprinted with permission. Copyright © Dr. Zvi Yaniv

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