Thursday, 9 June 2011

FEATURES OF 3D LED TV

A 3D television is a television that employs techniques of 3D presentation, such as stereoscopic capture, multi-view capture, or 2D plus depth, and 3D display—a special viewing device to project a television program into a realistic three-dimensional field. 3D episodes became moderately popular in the late 1990s when several shows in the USA used the technique to attract viewers and increase ratings.

3DTV sets are those that can operate in 3D mode, in conjunction with LCD shutter glasses, where the TV tells the glasses which eye should see the image being exhibited at the moment, creating a stereoscopic image. These TV sets usually support HDMI 1.4 and a minimum (input and output) refresh rate of 120Hz; glasses may be sold separately.



Mitsubishi and Samsung utilize DLP technology from Texas Instruments. As of January 2010, Toshiba, Samsung, Sony, Panasonic, and LG all had plans to introduce 3D capabilities (mostly in higher-end models) in TVs available sometime in 2010. 3D Blue-Ray players and DirecTV broadcasts are also expected in 2010.

The Chinese manufacturer TCL has developed a 42-inch LCD 3D TV called the TD-42F, which is currently available in China. This model uses a lenticular system and does not require any special glasses. It currently sells for approximately $20,000.

LG, Samsung, Sony & Phillips intend to increase their 3D TV offering with plans to make 3D TV sales account for over 50% of their respective TV distribution offering by 2012. It is expected that the screens will use a mixture of technologies until there is standardization across the industry.

3D imaging dates to the beginning of photography. In 1844, David Brewster introduced the Stereoscope, a device that could take photographic pictures in 3D. It was then improved by Louis Jules Duboscq and a famous picture of Queen Victoria was displayed at The Great Exhibition in 1851. By the Second World War, stereoscopic (3D) cameras for personal use were already fairly common.

3D movie development was parallel to that of 3D pictures and images. Already in 1855 the Kinematoscope was invented, i.e. the Stereo Animation Camera. The first anaglyph movie was produced in 1915 and in 1922 the first public 3D movie was displayed - The Power of Love. In 1935 the first 3D color movie was produced.

In the fifties, when TV became popular in the United States, many 3D movies were produced. 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 2D sound. Alfred Hitchcock originally made 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. The Soviet Union also developed 3D films.

There are several techniques to produce and display 3D moving pictures.

Common 3D display technology for projecting stereoscopic image pairs to the viewer include:

•Anaglyphic 3D (with passive red-cyan glasses)
•Polarization 3D (with passive polarized glasses)
•Alternate-frame sequencing (with active shutter glasses/headgear)
•Auto stereoscopic displays (without glasses/headgear)

Single-view displays project only one stereo pair at a time. Multi-view displays either use head-tracking to change the view depending of the viewing angle, or simultaneously project multiple independent views of a scene for multiple viewers (automultiscopic); such multiple views can be created on-the-fly using the 2D plus depth format.

Various other display techniques have been described, such as holography, volumetric display and the Pulfrich effect that was used by Doctor Who for Dimensions in Time in 1993 by 3rd Rock from the Sun in 1997 and by the Discovery Channel's Shark Week in 2000, among others. Real-Time 3D TV is essentially a form of auto stereoscopic display.

Stereoscopy is most widely accepted method for capturing and delivering 3D video. It involves capturing stereo pairs in a two-view setup, with cameras mounted side by side, separated by the same distance as between a person's pupils. If we imagine projecting an object point in a scene along the line-of-sight (for each eye, in turn) to a flat background screen, we may describe the location of this point mathematically using simple algebra. In rectangular coordinates with the screen lying in the Y-Z plane (the Z axis upward and the Y axis to the right) and the viewer centered along the X axis, we find that the screen coordinates are simply the sum of two terms, one accounting for perspective and the other for binocular shift.


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