A new color filter developed by researchers at the University of
Michigan could enhance LCD efficiency
by 400 percent.
Professor
L. Jay Guo and his team have created an optical film that both
polarizes and colors the light that passes through
an LCD, which replaces the multiple layers of optical devices
that traditionally played the same role. With the use of these
conventional layers, an LCD would only emit eight percent of the
light produced by its backlight. With the newly developed film, 36
percent of light is emitted, which is an increase that enhances
overall LCD efficiency.
The
new color filter consists of two thin aluminum layers enclosing a
type of insulating material, and is less than 200 nanometers thick.
It also contains slits that create different colors when the
backlight illuminates them, and they are "matched in scale to
the wavelength of visible light" and their "length and
distance apart determine the color produced."
What
really increases LCD efficiency is the
grating pattern, which enhances efficiency by 400 percent.
Instead of absorbing half the light with the wrong polarization
like current
LCD polarizing filters, the new filter reflects the light
toward a mirror that "flips" some of its polarization and
allows more light to pass through the filter.
But
Guo's new filter doesn't only apply to color displays. It can also be
applied to solar cells to control polarizations and reflections of
light. In addition, Nicholas Fang from the University of Illinois at
Urbana-Champaign noted that these filter's could be combined with
Qualcomm's new low-power reflective displays to eliminate backlights
altogether.
The
next step, according to Guo and his team, is to find a way to mass
produce these new filters and integrate them into several types of
technological devices like televisions and cell phones.