May 12 , 2005 - Podcast #7

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This weeks show

On tap today we will cover the news. We'll explain how LCDs work. We'll look into the future of TV technology. And finally, we'll talk about what ever else comes up during our discussions.

Rear Projection LCD

Big screen televisions and projectors use three LCD image panels, one for red, one for green and one for blue light. Each panel uses small openings or pixels that either block or pass the light generated by the lamp. The light is split by special mirrors into red, green and blue and then focused onto these image panels. The TV uses a lens to project the image onto the screen. The actual image you watch on your screen is a magnification of a smaller image produced deep inside the TV.

Flat Screen LCD
Two sheets of polarized transparent material are stuck together. One of the sheets contains a special polymer coating that holds liquid crystals in place. Voltage is applied to the crystals which act like shutters to allow light of a specific color to either pass through or block it. Since the crystals do not produce light, the technology is non-emissive and does not radiate like an older TV. The light source is a Florescent tube so TVs based on this technology require less power to operate than tube based televisions and plasma displays.

Some advantages to owning an LCD
1) Either type of TV can double as computer display.
2) Bright picture and excellent color.
2) They are much lighter and thinner than traditional CRT based rear projection TV's.

They do have some issues though:
1) A pixel may become stuck in the on or off position. This results in a light, dark or even a particular colored dot remaining on the screen at all times.
2) Slow video response times can cause something known as motion blur.
3) Screen door effect - this the term used to refer to the dark space between pixels on LCD displays. Up close it can give the impression of looking through a screen door. The affect is reduced by sitting farther away. Newer LCDs have done a great job in reducing the screen door artifact
4) Blacks are not as good as DLPs – detail is lost in dark scenes.

The future for TV technology

Near Term
Summer, 2005 - Texas Instruments new xHD3 DLP chip will be available in televisions by Mitsubishi and Samsung. The new chip is a native 1080 display, offering a true 1080p viewing experience. This is a first for widely available digital displays.

Longer Term
SED - Surface-conduction Emission Display - SED works very much like traditional CRT technology, shooting a beam of electrons to excite phosphors on a screen. Unlike, CRTs, though SED uses a thin strip of Palladium Oxide as an electron emitter, instead of a huge cathode ray tube. This allows the whole display system to be manufactured as thin as 10 millimeters thick.

SED offers the bright, vivid colors and high contrast rations of traditional CRTs with the thin profile of LCD and Plasma. They're said to have very low power requirements and are supposedly very inexpensive to manufacture. The two companies behind SED technology are Canon and Toshiba, and there are rumors that SED TVs will be available by Christmas 2005.

If they live up to the hype, SED TVs could replace Plasma and LCD as the dominant large panel thin screen TV.

OLED - Organic Light Emitting Display - Also an emissive technology, OLED is said to have incredibly fast response time, i.e. no artifacting in fast motion like LCDs. OLED is also an emissive technology that works by placing a stack of organic thin films between two charged electrodes. As an emissive display, OLED doesn't require a backlight. The can be manufactured paper thin, as thin as 500 nanometers.

Backed by the likes of Kodak, Dupont, Xerox and Lucent, OLED is currently being used in very small format displays such as Digital Cameras, Cell Phones and PDAs. The technology is brighter, thinner, faster and lighter than LCDs, uses less power, offers higher contrast and is cheaper to manufacture. OLED displays are currently using glass as the transparent anode, but later they will be made from special, ultra-thin plastic that will produce same picture as glass but at lower costs and with greater flexibility.

There has been some difficulty getting the technology onto larger format screens, but there may be OLED TVs on the market within 3 to 4 years.

Also be on the lookout for PHOLED or phosphorescent OLED, these are supposed to be bendable, foldable OLED screens. You might some day be able to roll your TV up like a newspaper. Or, have a large screen TV that rolls up into the ceiling.

NED - Nano Emissive Display - A new technology that Motorola promises will produce a 42" flat panel HDTV that costs less than $400. They're hoping to have TVs on the market in less than two years. The technology is very similar to OLED, but instead of sandwiching an organic film between a piece of glass and a metallic cathode, Motorola is actually growing the organic Carbon Nanotubes directly on the glass itself. And, according to Motorola, the electron emission performance of their nanotubes "exceeds that achieved to date with the application of the CNT to the cathode via an organic paste, the process used by other companies."

Motorola has demonstrated a 5" working prototype, and is looking for licensees to mass manufacture large screen versions. Dr. James Jaskie, chief scientist at Motorola’s Microelectronic and Physical Sciences Labs, Nano-emissive Display (NED) technology claims that the new technology is both viable, and affordable. He believes that companies with current Plasma TV production could be producing NED TVs with very minor modifications to their production lines. If he's right, we might all have 60" NED HDTVs in our living rooms, for under $1000.

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