Major players in the electronics market have
long been exploring
ways to turn organic
LED (OLED) displays
into a potential successor to LCD screens for TVs. Last month,
Sony became the first company to
announce plans to start selling the ultrathin TVs in Japan within the year.
The company's 11- and 27-in. OLED TV
displays were a hit at the January Consumer Electronics Show in Las Vegas and
at a recent display forum in Tokyo, where
participants were drawn to the 3-mm
thick screens, high-resolution images, and
wide-angle views ().
Smaller electronic devices, like cell
phones and digital cameras, already use
OLEDs in their displays since the technology consumes less power and allows
for thinner panels. Unlike LCD screens,
which require a fluorescent backlighting
source, OLEDs use electrophosphorescent materials that glow when an electric
current passes through them.
Here's how it works. When voltage is
applied to a thin, organic polymer film placed between two electrodes, the semiconductor emits patterns of light and color.
Each individual pixel can be controlled for
these patterns, which, when combined,
form a sharp, crisp picture.
One challenge for Sony, which began its
OLED display research in 1998, was in
creating displays large enough for watching TV, said company spokesperson Mina
Naito. Other companies such as Samsung, which has developed a 40-in. OLED
TV not currently on the market, have been
working with amorphous silicon (a-Si)
technology to increase display size.
A-Si supports larger substrate sizes
than polysilicon, the standard substrate
used in OLED displays. And since a-Si is
a mature technology used in most LCDs
on the market today, it could pave the
way to mass-production for OLED TVs.
For the 11-in. displays going to market,
however, Naito said Sony will use polysilicon technology because it generally "has
a higher electric carrier mobility than
amorphous silicon."
Another challenge, Naito said, is the
lifespan of the display. The blue LEDs,
which typically fail after 3000 to 5000 hours, are largely to blame. While red
and green LEDs last about 10,000 to
40,000 hours, the entire screen's lifetime is limited by that of the blue LEDs.
Due to these cost and production hurdles, Sony has not yet released information on unit targets or pricing for the
OLED TVs. The company also said it is
only considering the possibility of introducing the TVs in markets outside of
Japan at this point.
Sony isn't the only company with a
vested interest in OLED TVs. Seiko
Epson, Canon, and Toshiba have
announced plans to develop the technology. Before Samsung announced its 40in. a-Si OLED TV in May 2005, it had
developed a 21-in. display in January of
that year. But the company has not yet
taken these products to market.
As with any technology, given demand
and time, quirks and hurdles will be easier to overcome. Yet it remains to be seen
whether the OLED TV sales will transform into the multibillion-dollar market
some analysts expect it to become.