Corning Hopes TV Makers Go Ape For Cover Glass
By Greg Tarr On May 23 2011 - 4:01am
NEW YORK –
Corning is helping Sony celebrate the
launch of its new 2011 Bravia LCD TV models, which
are among the first flat-panel sets to use Corning’s highly
durable Gorilla Glass formulation as screen covers.
Corning defines Gorilla Glass, which has seen applications
in cell phones, tablets and PC monitors, as an
environmentally friendly alkali-aluminosilicate thin-sheet
glass that is lightweight and durable under a range of
challenging conditions that could cause other glass approaches
Although the glass has been around for several years
in handheld devices including some smartphones,
Sony several weeks ago became the first manufacturer
to ship TVs using Gorilla Glass cover applications, said
John Bayne, Corning TV cover glass program director.
The company had an exclusive on the glass technology
until it announced its first sets using the material
several weeks ago. Corning is now pitching its use to
other set makers.
Bayne said Sony selected the glass for three stepup
Bravia LCD TV series that have an edge-to-edge
glass look that compliments the monolithic styling design.
Gorilla Glass is offered in three 2011 Sony Bravia
LCD series including: the XBR-HX929-series (46, 55
and 65 inches), the HX820 series (46 and 55 inches),
and the NX720 series (46, 55 and 60 inches).
To achieve panel strength in the past, glass panel
makers have traditionally relied on thermal tempering
techniques which give greater strength but require
3mm-5mm added thicknesses, which can add eight to
10 pounds to the weight of a 46-inch set, for example.
To make Gorilla Glass, Corning chemically treats the
glass in a bath of potassium nitrate. The potassium nitrate
molecules in the bath try to get into the glass as
the smaller sodium molecules in the glass try to get out
of the glass in a diffusion process. This puts the entire
surface under compression.
For glass to fail it requires a small flaw and tension
on the glass.
Bayne explained that the beauty of putting the surface
of Gorilla Glass under high compressive stress
is that it makes it hard to introduce a flaw, and even if
a flaw develops over time, breaking the glass requires
overcoming that compressive stress before putting the
surface it into tension.
Corning developed Gorilla Glass four years ago at a
request from the cellphone industry. It is currently used
on 350 products for 30 brands, representing over 200
million units in the market worldwide to date.
Most of those were handheld items, until Sony approached
Corning in late 2009 about working together
for larger TV displays. The formulation developed for
Sony enabled a .7mm thickness, which significantly
reduced unit weight from 3mm cover glass with even
greater damage resistance.
Gorilla Glass is used only used for cover glass over an
LCD panel and not in the panel itself, so it is put on in the
final assembly process at Sony factories, Bayne said.
Best of all, Bayne said, Gorilla Glass is optimal for use
on 3D sets, which he said can’t be built using thermally
“Our glass has very, very low stress by refringence
because of the diffusion platform we use,” Bayne, said.
He added that thermally tempered glass is full of nonuniform
stresses, which are bad for 3D.
“Based on polarization of light any stress by refringence
is bad for 3D because it means the polarization
for one axis is affected differently than the other, and that
can produce ghosting, cross-talk and other artifacts,” he
Corning is manufacturing Gorilla Glass in several facilities
in the U.S. and Asia, including a facility in Shizouka,
Japan, which was the first glass facility Corning built
in Asia, back in the mid 90s.
It is currently supplying Sony with sheets used to
cover up to 65-inch TVs right now, and he said, Corning
could probably produce panels of Gorilla Glass for
up to 70-inch sets, with the only limitation coming from
the size of ion-exchange tanks used to manufacture the
“We are actually making Gen 10 (LCD not Gorilla)
size sheets, which would be 3 meters on a side. The
manufacturing platform is capable of going larger, but
right now we don’t have any reason to,” said Bayne.
Corning can ship glass to Asian manufacturers out of
the Shizouka plant as well as several other facilities on
Bayne said Corning is now looking at plasma applications
for Gorilla Glass.
“My understanding of plasma is that they have been
using [cover glass] from the earliest days, but for a different
reason – to put on coatings to protect from electromagnetic
interference coming from the plasma set.
We haven’t seen as much of a pull from plasma makers
yet, but we are having discussions to see if they would
be interested in applying Gorilla Glass,” Bayne said.
Corning is beefing up its promotion and advertising
for Gorilla Glass, though Bayne stops short of comparing
the effort to Intel’s famous Intel Inside campaigns.
The company is running a Urban Gorilla campaign now
in print and Web advertising showing a gorilla playing
with cellphones, laptops and other devices that use Gorilla
“The goal of our [Urban Gorilla] campaign is to make
people aware that the cover material matters and that
Gorilla Glass is a great choice,” Bayne said, adding that
so far it has been very successful.
Corning is using co-branding with Sony on the new
Bravia TVs, advertising on the box the use of Gorilla
Glass in the set, while Sony added a microsite to its
Web site to explain the benefits of using Gorilla Glass.
As for reducing the tendency for some LCD TVs to
be susceptible to surface scratching, Bayne said it all
depends on whether the set maker using an AR film.
“Right now, almost every LCD set maker uses some
form of AG or AR coating process, just because viewing
with ambient light in the home is going to produce
some reflections off the screen,” Bayne said.