The next U.S. presidential candidate may well run on the theme of "a flat-panel TV in every home." It sure beats "a chicken in every pot," the slogan that launched Herbert Hoover in the 1920s.
Global sales of flat panel sets doubled last year to 50 million units, and are expected to grow again this year to more than 70 million units. Prices have dropped to as low as $750 for a 26-inch model, which is 40 percent below what they cost a year ago. The new price is still triple what a conventional tube set costs, but forget about it. One leading manufacturer isn't even shipping cathode ray tube sets to the U.S. any more. Experts predict that models under 30 inches will sell for less than $500 this year, while the more popular 42-inch models will drop below $1,000.
LCDs are made up of pixels that include a layer of liquid crystal molecules aligned between two transparent electrodes and two polarizing filters that feature newly developed films that are oriented on perpendicular axes. Thin polymer layers are used to treat the surfaces of the electrodes in contact with the liquid crystal material. The treatment aligns the molecules in a particular direction. Applying voltage selectively across the liquid crystal layer in each pixel allows light to pass through in varying amounts, lighting up the pixel.
Much of the early breakthrough work was done with treated polycarbonate film by 3M in Minneapolis. 3M was the first company to introduce prismatic brightness enhancement films called Vikuiti BEF followed by multilayer based reflective polarizer films called Vikuiti DBEF. These films enable efficient use of the backlight, making displays brighter. They can also be used to maintain display brightness while reducing power consumption, extending battery life in portable devices, such as cell phones. 3M says some Vikuiti films have hundreds of reflective layers in a sheet less than 1 mil thick.
Significant developments in polarizing films are coming from Japan. For example, Zeon Corp. developed ZeonorFilm with significant support from Japan's New Energy and Industrial Technology Development Organization and the New Industry Creation Hatchery Center of Tokyo University. ZeonorFilm offers low wavelength dispersion as well as high heat resistance. Optical compensation occurs after stretching, providing an important protective function for polarizing plates used in LCDs. Without that treatment, light can leak from the edge of the display area.
Zeon planned to open a manufacturing plant for ZeonerFilm this year, but accelerated the launch to last October because of exploding demand for LCD materials. Annual capacity for stretched film at the Japanese plant will be 322 million sq ft. ZeonerFilm is made from cyclic olefin copolymers, which was just a development polymer grade as recently as three years ago.
Thermoplastic polyesters are also used in the optical films market as diffusion film, film near the prism sheet, and film near the reflector. Eastman Chemical, once a part of Eastman Kodak, is researching new grades of polyester film for the LCD market, in part to replace rapidly declining demand for the plastic in photographic film.