New Drive System and
Leading-Edge Fine Fabrication
Technology |
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Normally in LCD displays, the pixel potential
polarity of the LCD cell must be
inversely driven to prevent image retention.
Conventional LCD displays employ
the horizontal line inversion drive system
that inverts the pixel potential polarity
every pixel line, which is optimum for 60 Hz drive. However, in this case a horizontal
electric field is generated between
pixel electrodes as shown in Figure 6. This
disrupts the LCD alignment, so the optimum
LCD array for white display cannot
be obtained and the light transmittance
drops.
In contrast, the 1 field inversion drive
system employed by “BrightEra” devices
inverts the pixel potential polarity every
field. This decreases the electric field between
pixel electrodes, making it possible
to obtain the most efficient LCD array for
white display as well as high transmittance.
In addition, the use of leading edge
fine fabrication technology reduces the
TFT element area by approximately 70%
compared to the conventional method as
shown in Figure 7. This makes it possible
to reduce the electric wiring pitch, and increases
the aperture ratio by approximately
20% compared to the conventional
method.
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Normally Black Mode |
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Conventional high-brightness projectors
employ normally white mode, which is
advantageous for increasing brightness.
This mode uses the optimum LCD array
for white display, so when displaying
black the LCD must be controlled by applying
an electric field*3 to the inside of
the LCD cell.
In this case the LCD molecules on the
alignment film interface cannot be perfectly
aligned as shown in the figure below,
so the light scatters, resulting in light
leakage and lower contrast.
In contrast, the normally black mode employed
by “BrightEra” devices uses the
optimum LCD array for black display. As a result there is little light scattering, so
light leakage can be reduced and high
contrast can be obtained.
In addition, the inorganic alignment film
and new LCD device designs have been
optimized to efficiently control the LCD
array even during white display when an
electric field is applied. This makes it
possible to also simultaneously increase
brightness.
*3: The condition with voltage applied to the
upper electrode and the lower electrode to
create a potential difference |
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Future Developments |
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| The inorganic alignment film employed
in the new “BrightEra” panels is a core
technology that features high light resistance,
thus allowing use of even brighter
light sources.
Sony intends to deploy this “BrightEra”
light resistance technology to provide a
diverse lineup of ultrabright microdisplays
in the future, including devices that support
various resolutions at 3,000 lm and
higher, and also medium and large-sized
devices that support the ultrahigh brightness
of 5,000 to 10,000 lm or higher. |
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See
all articles with figures and tables.  |
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Vol.48 |
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