Microdisplays with Near Photographic Image Quality
Imagine a technology that
provides crisp, clear images and bold,
intense colors – dramatically
enhancing the look of television. It would
be like looking out a window into a world
you could almost touch. Imagine crystal-clear,
detailed images that are free of haze,
dark shadows, lines, or other artifacts.
This technology brings television viewing
into perfect focus. This is the world of
Gen II liquid-crystal-on-silicon (LCoS™)
technology from Brillian.
As the industry’s first and only
provider of Gen II LCoS™ technology,
Brillian is leveraging its industry-leading
position to develop and manufacture rear-projection,
high-definition televisions for OEMs.
These HDTVs offer breakthrough image
quality at an incredible price/performance
level. In addition to television systems,
Brillian offers a complete line of LCoS™ microdisplay
products and subsystems. Leading companies integrate
these products and components into other
projection products, including multimedia
projectors and monocular and binocular
headsets.
LCoS
GEN II – THE PERFORMANCE LEADER
Brillian’s Gen II LCoS™ microdisplays offer powerful quality and performance
advantages that far outperform competing technologies.
•
Meets
or beats the contrast ratios of any other microdisplay
technology
•
High
image refresh rates are effectively free of flicker
and color breakup
•
Easily
scales to higher resolutions
•
Provides
high resolution, which offers a rich user experience
by supporting a full range of content including text,
graphics, multimedia, and full-motion video
•
High
fill factor delivers smooth images without pixelation
•
Rich
color depth for crisp, life-like images
•
Smooth
gray scale at all brightness levels, matching the
visual response of the eye
•
Fast
response times for artifact-free video reproduction
•
High
reliability and long lifetimes suitable for consumer
applications
•
High
lumen output for bright, intense images
Competing Technologies
DISPLAY TECHNOLOGIES 101
Display technologies continue
to evolve – driven
both by market dynamics and breakthrough technical developments.
As with other technologies, there is a relentless push
to provide greater performance at lower cost. Following
is a snapshot of the pros and cons of today’s
leading display technologies:
LIQUID CRYSTAL ON SILICON
Liquid-crystal-on-silicon technology has been in development for more than
10 years, and is still considered a relatively new liquid crystal display
(LCD) approach. In contrast to active matrix, flat-panel LCDs, where the
liquid crystal material is sandwiched between two glass plates (one with
thin film drive transistors at each picture element), liquid-crystal-on-silicon
microdisplays have the liquid crystal sandwiched between a single glass plate
and a silicon micro-chip.
The electronic circuits that control the formation of
the image are fabricated on the silicon chip, which is
coated with a highly reflective surface. Polarizers are
located in the light path both before and after the light
reflects from the chip. This cell structure offers the
following advantages. It makes the image less pixilated
because the circuitry is behind the pixel and does not
create an obstruction in the light path (the “screen
door” effect). This architecture enables liquid-crystal-on-silicon
microdisplays to more easily scale to higher resolution
because the pixels can remain smaller, and more pixels
can be etched into a smaller chip area. In addition,
enhanced video reproduction can be achieved because faster
switching liquid crystals can be utilized.
While the availability of liquid-crystal-on-silicon-based
HDTVs has been promised for some time, the performance,
quality, and delivery fell short of expectations. Brillian’s
Gen II LCoS™ technology is the first viable liquid-crystal-on-silicon
technology to break through the performance barrier to
become a serious contender in the fast-evolving HDTV
market.
HIGH
TEMPERATURE POLYSILICON
High-temperature polysilicon (HTPS) displays sandwich liquid crystal material
between two layers of quartz high-temperature glass. To produce images, light
passes from a projection lamp (e.g. UHP, xenon, etc.), into the color management
and display system. The image is optically magnified for projection onto the
screen. Because light passes through the display, each and every pixel has a
dark line around it where the light is blocked by the control circuitry around
each pixel. This results in visible pixelation or graininess to the image that
gives the viewer the feeling of looking through a screen door at the image. The
weaknesses of this technology include: relatively low contrast level; pixelation,
or the “screen door” effect; and slow video response times. Because
pixel size cannot be reduced very easily without further degrading the fill factor,
this technology is not easily scaled to higher resolutions at a reasonable cost – a
definite downside as product resolutions increase to meet the highest-definition
viewing standards.
DIGITAL
LIGHT PROCESSING™ (DLP™)
DLP technology, developed by Texas Instruments, was initially targeted to multimedia
front projectors and, over time, has also been adopted for rear-projection televisions.
This technology is manufactured with anywhere from 800,000 to more than one million
tiny, complex, electromechanical mirrors. These tiny mirrors vibrate, causing
them to reflect more or less light, creating grayscale and color images. Because
of the single-panel display optical engine architecture and the DLP digital drive
scheme for creating grayscale and color images, video artifacts and color break-up
are visible to the television viewer. Particularly in fast-action scenes, it
can appear as if some of the pixels have a rainbow effect or are shimmering,
similar to light reflecting off of water. There is only one supplier of this
technology –Texas Instruments– who is the sole source. Furthermore,
as demand moves from 720p to 1080p and higher resolutions, DLP technology encounters
issues with scaling its pixels to smaller sizes. This limits the speed with which
this technology can support higher resolutions at a cost-effective price.
PLASMA
Plasma technology is a direct-view display technology that has enabled the creation
of large, flat-panel televisions measuring less than six-inches deep. Because
they have the unique ability to be very thin, a plasma television frees up
a lot of the space that a conventional TV requires. While they have created
a lot of buzz, plasma televisions have some inherent disadvantages not commonly
understood by consumers. This technology suffers from the “screen door” effect,
a visible graininess to the image; very high power consumption; image burn-in;
and short lifetimes. Historically, plasma degrades about 50 percent of its
brightness in the first three years of standard consumer use (for high-use
environments they degrade faster) – and it degrades unevenly, resulting
in nonuniformity of the image, which appears as color variations in the viewing
area. In some lifetime tests, plasma televisions have been limited to a 5000-
to 7000-hour life span. In addition, greater than 50-inch, large-area, plasma-based
televisions are currently cost-prohibitive for the average consumer.
TFT-LCD
Originally developed for the display on laptop computers, TFT-LCD technology
has evolved to become a major display technology. In addition to enabling the
laptop market, it is in the process of replacing the CRT on the desktop. Recently,
TFT-LCD technology has also been gaining market share in the small-screen television
market. Its thin form factor and good image quality have combined to enable
it to overcome its higher cost. It is believed that TFT-LCD television will
become a major technology in the less than 40-inch television market, displacing
the direct-view CRT in all but the lowest price points. However, the cost structure
of TFT-LCD technology will make it less competitive in the greater than 40-inch,
larger-screen TV market.
