Post on 14-Feb-2016
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What is HDTV?
HDTV- is high-resolution digital television with Dolby Digital surround sound.
HDTV-is the highest digital television there is.
This allows HDTV to have extraordinary images with stunning sound
This requires new production and transmission equipment at the HDTV
stations.
Why High Definition TV?
HDTV-is one of the most talked about topics today
HDTV is one of the advance technology in TV systems.
It is with higher advancement and greater ability.
To Overcome Limitations
of Analog Television
Noise free pictures
Higher resolution images
Widescreen / HDTV
No Ghosting
Enhanced Sound Services
Other Data services.
Analog vs. Digital
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Analog
An analog signal is one that continuously varies and the strength of the signal carries the information.
Digital
A digital signal is one that contains coded information that carries the information.
What the Signals Look Like
Analog
Records Film (movies, and photos)
Most VCRs
Most TVs (except the new ones)
Waves (sound, radio, light, water… nobody’s sure about light)
All hearing aids, until about 10 years ago
Digital
DVDs
CDs
Digital Photos
Computers
The Internet
New TVs
Satellite Radios
All CIs and Almost all Hearing Aids
Some Examples
Digital TV
Displays as Pixels
Signal is just a bunch of bits
Define color and intensity of each point on the screen
Bit stream is heavily compressed
Captions are also digital
Type Of HDTV
Impact of HDTV
• Broadcasters & consumers spend more $
• Increased visual clarity has forced designers to spend
considerably more money on sets, set dressings
• Blu-Ray vs HD-DVD
3D TV
History
The stereoscope was first invented by Sir Charles Wheatstone in 1838. It showed that when two pictures are viewed stereoscopically, they are combined by the brain to produce 3D depth perception. The stereoscope was improved by Louis Jules Duboscq, and a famous picture of Queen Victoria was displayed at The Great Exhibition in 1851. In 1855 the Kinematoscope was invented. In the late 1890s, the British film pioneer William Friese-Greene filed a patent for a 3D movie process. On 10 June 1915, former Edison Studios chief director Edwin S. Porter and William E. Waddell presented tests in red-green anaglyph to an audience at the Astor Theater in New York City and in 1922 the first public 3D movie The Power of Love was displayed.
Stereoscopic 3D television was demonstrated for the first time on 10 August 1928, by John Logie Baird in his company's premises at 133 Long Acre, London. Baird pioneered a variety of 3D television systems using electro-mechanical and cathode-ray tube techniques. The first 3D TV was produced it 1935. By the Second World War, stereoscopic 3D still cameras for personal use were already fairly common. In the 1950s, when TV became popular in the United States, many 3D movies were produced for cinema. The first such movie was Bwana Devil from United Artists that could be seen all across the US in 1952. One year later, in 1953, came the 3D movie House of Wax which also featured stereophonic sound. Alfred Hitchcock produced his film Dial M for Murder in 3D, but for the purpose of maximizing profits the movie was released in 2D because not all cinemas were able to display 3D films. In 1946 the Soviet Union also developed 3D films, withRobinzon Kruzo being its first full-length 3D movie.
3D Television
Three-dimensional TV 3D Television is expected to be the next revolution
in the TV history. They implemented a 3D TV prototype system with real-
time acquisition transmission, & 3D display of dynamic scenes. They
developed a distributed scalable architecture to manage the high
computation & bandwidth demands. 3D displayshows high-resolution
stereoscopic color images for multiple viewpoints without special glasses.
This is first real time end-to-end 3D TV system with enough views &
resolution to provide a truly immersive 3D experience.Japan plans to make
this futuristic television a commercial reality by 2020as part of abroad
national project that will bring together researchers from the government,
technology companies and academia. The targeted "virtual reality"
television would allow people to view high definitionimages in 3D from any
angle, in addition to being able to touch and smell the objects being
projected upwards from a screen to the floor .
Why 3D Television
The evolution of visual media such as cinema and television is one of the
major hallmarks of our modern civilization. In many ways, these visual
media now define our modern life style. Many of us are curious: what is our
life style going to be in a few years? What kind of films and television are
we going to see? Although cinema and television both evolved over
decades, there were stages, which, in fact, were once seen as revolutions:
1) at first, films were silent, then sound was added;
2) cinema and television were initially black-and-white, then color was
introduced;
3) computer imaging and digital special effects have been the latest major
novelty.
3D DISPLAY
This is a brief explanation that we hope sorts out some of the confusion
about the many 3D display options that are available today. We'll tell you
how they work, and what the relative tradeoffs of each technique are.
Those of you that are just interested in comparing different Liquid Crystal
Shutter glasses techniques can skip to the section at the end. Of course,
we are always happy to answer your questions personally, and point you to
other leading experts in the field. They use 16 NEC LT-170 projectors with
1024'768 native output resolution. This is less that the resolution of
acquired & transmitted video, which has 1300'1030 pixels. However, HDTV
projectors are much more expensive than commodity projectors.
Commodity projector is a compact form factor. Out of eight consumer PCs
one is dedicated as the controller. The consumers are identical to the
producers except for a dual-output graphics card that is connected to two
projectors. The graphic card is used only as an output device. For real-
projection system as shown in the figure, two lenticular sheets are mounted
back-to-back with optical diffuser material in the center. The front projection
system uses only one lenticular sheet with a retro reflective front projection
screen material from flexible fabric mounted on the back. Photographs
show the rear and front projection.
The projection-side lenticular sheet of the rear-projection display acts as a
light multiplexer, focusing the projected light as thin vertical stripes onto the
diffuser. Close up of the lenticular sheet is shown in the figure 6.
Considering each lenticel to be an ideal Pinhole camera, the stripes
capture the view-dependent radiance of a threedimensional light field. The
viewer side lenticular sheet acts as a light de-multiplexer & projects the
view-dependent radiance back to the viewer. The single lenticular sheet of
the front-projection screen both multiplexes & demultiplexes the light. The
two key parameters of lenticular sheets are the field-of-view (FOV) & the
number of lenticules per inch (LPI). Here it is used 72" ' 48" lenticular
sheets with 30 degrees FOV & 15 LPI. The optical design of the lenticules
is optimized for multiview 3D display. The number of viewing zones of a
lenticular display is related to its FOV. For example, if the FOV is 30
degrees, leading to 180/30 = 6 viewing zones
This system is the first to provide enough view points and enough pixels
per view points to produce an immersive and convincing 3D experience.
Another area of future research is to improve the optical characteristic of
the 3D display computationally. This concept is computational display.
Another area of future research is precise color reproduction of natural
scenes on multiview display.
Advantages of 3D TV Even when not being used for their 3D capabilities, 3D TVs provide remarkable picture
quality. However, it should be noted that the picture is most impressive when displaying
high-definition, 1080p images in 3D. You’ll notice even better quality in the most high-
end varieties, with their less expensive counterparts sometimes displaying double
imaging and ghosting rather than a crisp, sharp image. But, if you’re wowed by the
three-dimensional experience and have sufficient access to 3D programming, it may be
worth your while to invest in this technology.
Disadvantages of 3D TV Though there has been talk of technology on the horizon that allows 3D images to be viewed without special glasses,
for now, they are a necessity. Many find this accessory cumbersome, and if you have a large number of people in
your household and have to purchase multiple pairs of glasses, the cost can add up. If you’re adverse to donning
glasses to view your television’s best feature, 3D TV might not be for you.
Another disadvantage is the amount of 3D programming available. If your desire to purchase one is based on wanting
to view things in 3D quality, you may be hard pressed to find a wide variety of options. There are an emerging
number of 3D Blu-ray disc options available however, and the more 3D TVs grow in popularity over the years, the
more content will become available.
OLED
An exciting technology has been available in many small devices
such as cell phones and digital camera displays for the last 13
years. Soon it may available for use in larger standard office and
home entertainment displays. The technology is organic light
emitting diode (OLED). It is possible that in the next 2-3 years you
may see an 80” OLED in your living room or board room that only
requires 10 or less volts of power to operate. OLED display
devices use organic carbon-based films, sandwiched together
between two charged electrodes. One is a metallic cathode and
the other a transparent anode, which is usually glass. Online
encyclopedia, Wikipedia, defines an organic compound as “any
member of a large class of chemical compounds whose
molecules contain carbon, with the exception of carbides,
carbonates, carbon oxides and gases containing carbon.” The
basic components of an OLED are:
• Substrate. This is support for the OLED.
• Anode. The anode removes electrons when a current flows
through the device.
• Organic layers. These layers are made of organic molecules or
polymers. - Conducting layer. This layer is made of organic plastic
molecules that send electrons out from the anode. - Emissive
layer. This layer is made of organic plastic mol- ecules (different
ones from the conducting layer) that trans- port electrons from the
cathode; this is where light is made.
• Cathode (may or may not be transparent depending on the type
of OLED). The cathode injects electrons when a current flows
through the device. Applying the organic layers to the substrate
can be accomplished in three ways:
1. Vacuum Deposition or Vacuum Thermal Evaporation (VTE). In
a vacuum chamber, the organic molecules are evaporated
through a slow heat process and then allowed to condense as
thin films onto a cooled substrate. This is a very inefficient and
expensive process.
2. Organic Vapor Phase Deposition (OVPD). This process
employs an inert carrier gas (such as nitrogen) to precisely
transfer films of organic material onto a cooled substrate in a hot-
walled, low-pressure chamber. The precise transfer and ability to
better control film thickness translates to lower material cost and
higher production throughput.
3. Inkjet Printing. OLEDs are sprayed onto the substrate the same
way our desktop inkjet printer sprays ink onto paper. This greatly
reduces the cost of manufacturing OLEDs and allows for printing
on very large films. This allows for a much lower cost and larger
home displays and PIPD products. One of the major benefits of
OLEDs is their low power consumption when compared to
traditional LEDs or LCDs. OLEDs also do not require backlighting
to function, which in addition to using less power, also lowers
manufacturing costs. Even with all the layers that make up an
OLED, this is an emissive technology – meaning it generates its
own light. An OLED display is very thin and compact, typically has
a viewing angle of 160 degrees and will operate on as little as 2
volts. Imagine today’s typical 60” flat-screen display, but instead
of an 8-in. thick, 250-lb. plasma display or a 65-lb. LCD, your 60”
OLED display is only 1/2” thick and weighs roughly 30 lbs.!
How do OLEDs work?
As previously mentioned, OLEDs are an emissive technology, which means they emits light
instead of diffusing or reflecting a secondary source, as LCDs and LEDs currently do. Below is a
graphic explanation of how the technology works.
Types of OLEDs There currently are six types of OLED screens, each designed for a different
type of use. The types are:
1. Passive Matrix OLEDs (PMOLEDs) have strips of cathode, organic layers and strips of
anode. The anode strips are arranged perpendicular to the cathode strips. The intersections of
the cathode and anode make up the pixels where light is emitted. External circuitry applies
current to selected strips of anode and cathode, determining which pixels get turned on and
which pixels remain off. Again, the brightness of each pixel is proportional to the amount of
applied current. PMOLEDs are easy to make, but they consume more power than other types of
OLED, mainly due to the power needed for the external circuitry. PMOLEDs are most efficient
for text and icons and are best suited for small screens (2- to 3-inch diagonal) such as those
you find in cell phones, PDAs and MP3 players. Even with the external circuitry, PMOLEDs
consume less battery power than the LCDs that are currently used in these devices.
2. Active-matrix OLEDs (AMOLEDs) have full layers of cathode, organic molecules and anode,
but the anode layer overlays a thin film transistor (TFT) array that forms a matrix. The TFT array
itself is the circuitry that determines which pixels get turned on to form an image. AMOLEDs
consume less power than PMOLEDs because the TFT array requires less power than external
circuitry, so they are efficient for large displays. AMOLEDs also have faster refresh rates
suitable for video. The best uses for AMOLEDs are computer monitors, large-screen TVs and
electronic signs or billboards.
3. Transparent OLEDs have only transparent components (substrate, cathode and anode) and,
when turned off, are up to 85% as transparent as their substrate. When a transparent OLED
display is turned on, it allows light to pass in both directions. A transparent OLED display can be
either active- or passive-matrix. This technology can be used for heads-up displays.
4. Top-emitting OLEDs have a substrate that is either opaque or reflective. They are best suited
to active-matrix design. Manufacturers may use top-emitting OLED displays in smart cards.
5. Foldable OLEDs have substrates made of very flexible metallic foils or plastics. Foldable
OLEDs are very lightweight and durable. Their use in devices such as cell phones and PDAs
can reduce breakage, a major cause for return or repair. Potentially, foldable OLED displays
can be sewn into fabrics for “smart” clothing, such as outdoor survival clothing with an
integrated computer chip, cell phone, GPS receiver and OLED display sewn into it. 6. White
OLEDs emit white light that is brighter, more uniform and more energy efficient than that emitted
by fluorescent lights. White OLEDs also have the true-color qualities of incandescent lighting.
Because OLEDs can be made in large sheets, they can replace fluorescent lights that are
currently used in homes and buildings. Their use could potentially reduce energy costs for
lighting.
OLED Advantages:
The LCD is currently the display of choice in small devices and is also popular in large-screen
TVs. Regular LEDs often form the digits on digital clocks and other electronic devices. OLEDs
offer many advantages over both LCDs and LEDs, including:
• The plastic, organic layers of an OLED are thinner, lighter and more flexible than the
crystalline layers in an LED or LCD.
• Because the light-emitting layers of an OLED are lighter, the substrate of an OLED can be
flexible instead of rigid. OLED substrates can be plastic rather than the glass used for LEDs and
LCDs.
• OLEDs are brighter than LEDs. Because the organic layers of an OLED are much thinner than
the corresponding inorgan- ic crystal layers of an LED, the conductive and emissive layers of an
OLED can be multi-layered. Also, LEDs and LCDs require glass for support, and glass absorbs
some light. OLEDs do not require glass.
• OLEDs do not require backlighting like LCDs. LCDs work by selectively blocking areas of the
backlight to make the im- ages that you see, while OLEDs generate light themselves. Because
OLEDs do not require backlighting, they consume much less power than LCDs (most of the
LCD power goes to the backlighting). This is especially important for battery-op- erated devices
such as cell phones.
• OLEDs are easier to produce and can be made to larger sizes. Because OLEDs are
essentially plastics, they can be made into large, thin sheets. It is much more difficult to grow
and lay down so many liquid crystals.
• OLEDs have large fields of view, about 170 degrees. Because LCDs work by blocking light,
they have an inherent viewing obstacle from certain angles. OLEDs produce their own light, so
they have a much wider viewing range.
OLED Disadvantages:
OLED seem to be the perfect technology for all types of displays, however, they do have some
problems, including:
• Lifetime. While red and green OLED films have long lifetimes (10,000 to 40,000 hours), blue
organics currently have much shorter lifetimes (only about 1000 hours).
• Manufacturing. Processes are expensive right now.
• Water. Water can easily damage OLEDs.
OLED Applications:
OLED technology was invented by Eastman Kodak in the early 1980s and, currently, OLEDs
are used in small-screen devices such as cell phones, PDAs and digital cameras. In March
2003, the company introduced the world’s first digital camera with an OLED display. In
September 2004, Sony Corporation announced that it was beginning mass production of OLED
screens for its CLIE PEG-VZ90 model of personal-entertainment handhelds. Several companies
have already built prototype computer monitors and large-screen TVs. In May 2005, Samsung
Electronics announced that it had developed the first 40” OLED-based, ultraslim TV. OLED
Research and development is moving forward at a rapid pace and may soon lead to
applications in heads-up displays (HUD), automotive dashboards, billboard-type displays, home
and office lighting, and flexible displays. OLEDs refresh approximately 1000 times faster than
LCDs. Although a device with an OLED display could change information in real time, the eye
cannot perceive changes to video faster than about 13ms. Refresh rate is also not the end-all in
display products. Many of the highend monitors take advantage of advanced engineering in
scalers and other components to make the view more pleasing to the eye.