3D 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 a 3D display—a special viewing device to project a television program into a realistic

three-dimensional field.

How we see 3D?

Basic principle—tricking our dumb, binocular brain into interpreting a 2D image into one with depth.

A key part of this process is binocular disparity. It means each eye has a slightly different viewpoint. When an object is far away, the light traveling to one

eye is parallel with the light traveling to the other eye. But as an object gets closer, the lines are no longer parallel -- they converge and our eyes shift to compensate.

When you focus on an object, your brain takes into account the effort it required to adjust your eyes to focus on it as well as how much your eyes had to converge. Together, this information allows you to estimate how far away the object is.

How to create 3D?

It involves the usage of two cameras (or a camera having two lenses), placed side by side with the center of their lenses spaced approximately and ideally, the same distance as the space between our eyes.

Both cameras record in sync and the resulting left and right eye videos or images are then edited and presented to the viewer (in cinemas) via different techniques.

Common 3D display technology

Projecting stereoscopic image pairs to the viewer include:

Passive glass: Anaglyphic 3D (with red-blue glasses) Polarization 3D (with polarized glasses)

Active glass: Alternate-frame sequencing Auto stereoscopic displays (without

glasses/headgear)

Viewing through glasses

Two sets of images are meant to be seen by only a particular eye.

Hence each eye can only see one set of images, your brain interprets this to mean that both eyes are looking at the same object.

But eyes are converging on a point that's different from the focal point -- the focus will always be your television screen.

That's what creates the illusion of depth.

Anaglyphic 3DRed-Blue glasses

There are two sets of images slightly offset from one another. One will have a blue tint to it and the other will have a reddish hue.

Anaglyph glasses use two different color lenses to filter the images you look at on the television screen.

The two most common colors used are red and blue.

Red lens cancels red hued image & blue lens cancels blue hued images.

e.g.

Polarization 3DPolarized glasses

Light waves of two images are projected at certain angles.

Each lens only allows light to pass through that is polarized in a compatible way.

It is more popular than anaglyph glasses because the polarization don't distort the color of the image.

But it's very difficult to use the polarization technique for television-- most methods would require to coat television screen with a special polarizing film first.

Hence it is popular in projector based display.

Active glassesAlternate-frame sequencing

An active glasses system alternates between the two sets of images at very high speeds.

Active glasses have infrared (IR) sensors that allow them to connect wirelessly to television or display. As the 3-D content appears on the screen, the picture alternates between two sets of the same image.

The LCD lenses in the glasses alternate between being transparent and opaque in sync as the images alternate on the screen.

Thus two sets aren't shown at the same time -- they turn on and off at an incredible rate of speed.

Advantage of active glasses over passive glasses

It's easier to present 3-D in HD content using active glasses than with passive glasses.

That's because with a passive glass system, the television has to display two sets of images at the same time.

An active glasses system alternates between the two sets of images at very high speeds--it's less information for the television to handle at any particular moment.

But still have a problem with those glasses?

Stereoscopic method leads to two distinctive problems:

1) The glasses are really cumbersome and expensive, and you don’t want to accidentally sit on one or lose it. And what to do when we don’t have enough lenses.

2) Plus, it takes away the simplicity of television as it stands today, where you simply hit the remote and start watching.

3) Also, without the glasses, any 3D content is completely unusable. The screen has been calibrated to work with 3D content and so dropping the glasses would end up displaying garbled images. 

Auto stereoscopic display

Two main technologies that rely on it:

Lenticular lenses

Parallax barrier

Lenticular lenses

Basically A lenticular lens is an array of magnifying or directing lenses, designed so that when viewed from slightly different angles, different images are magnified.

Lenticules are tiny lenses on the base side of a special film.

The screen displays two sets of the same image. The lenses direct the light from the images to your eyes--each eye sees only one image.

It creates a particular space from which images can seen clearly called ‘sweet spot’.

Depending on the number of lenticules and the refresh rate of the screen, there can be multiple ‘sweet spots’.

Magnified view of lenticular lenses

Parallax barrier

On a 3D screen, a very fine grating, called a "parallax barrier", is placed in front of the LCD screen.

The parallax barrier is a fine grating of liquid crystals placed in front of the screen, with slits in it that correspond to certain columns of pixels of the screen.

It does the job of the polarizing glasses, directing light from each image slightly in different direction so that at a so-called "sweet spot" about 30 inches in front of the screen the two images are separated just enough that the brain will create a composite 3D image.

Advantage of parallax barrier over lenticular lenses

is that the parallax barrier can be switched on and off with ease (one button on the remote is all it would take), allowing the TV to be used for 2D or 3D viewing. So on a computer monitor, you could play video games in full 3D glory and then easily switch to 2D mode for your work requirements.

The other ways of creating 3D images

Light Field Display: creating images in 3D space (as opposed

to planar space). The system works by projecting high-

speed video onto a rapidly spinning mirror. As the mirror turns, it reflects a different and accurate image to each potential viewer.

The display consists of a high-speed video projector, a spinning mirror covered by a holographic diffuser, and FPGA circuitry to decode specially rendered DVI video signals. The display uses a standard programmable graphics card to render over 5,000 images per second of interactive 3D graphics, projecting 360-degree views with 1.25 degree separation up to 20 updates per second.

Overview of the 3D-image spatial drawing device

The other ways of creating 3D images

Using Laser Plasma: Device uses the plasma emission

phenomenon near the focal point of focused laser light.

By controlling the position of the focal point in the direction of the x-, y-, and z-axes, real 3D-images in air (3D-space) can be displayed.

The images are constructed from dot arrays produced by a technique combining a laser light source and galvanometric mirrors.

Standardization efforts

To adopt a common and compatible standard for 3D in home electronics.

Content providers, such as Disney, DreamWorks, and other Hollywood studios, and technology developers, such as Philips, asked SMPTE for the development of a 3DTV standard in order to avoid a battle of formats.

MPEG has been researching on it; the first result of this research is the Multiview Video Coding extension for MPEG-4 AVC that is currently undergoing standardization. MVC has been chosen by the Blu-ray disc association for 3D distribution. The format offers backwards compatibility with 2D Blu-ray players.

3D broadcasting

Starting on June 11, 2010 ESPN will launch a new channel dedicated to 3D sports with up to 85 live events a year in 3D.

Recently the British Sky Broadcasting company, better known as Sky UK, has announced that they will be launching a Sky 3D channel in April 2010. This will bring content such as sport, entertainment events, and other three-dimensional programming to its subscribers. The system will require a special "3D ready" television and Sky+HD DVR box. 

On 1 January 2010, the world's first 3D channel, SKY 3D, started broadcasting nationwide in South Korea by Korea Digital Satellite Broadcasting. The channel's slogan is "World No.1 3D Channel". This 24/7 channel uses the Side by Side technology at a resolution of 1920x1080i. 3D contents include education, animation, sport, documentary and performances.

A full 24 hour broadcast channel was announced at the 2010 Consumer Electronics show as a joint venture from IMAX, Sony, and the Discovery channel. The intent is to launch the channel in the United States by year end 2010.

3D-ready TV sets

Those that can operate in 3D mode (in addition to regular 2D 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 refresh rate of 120Hz.

Panasonic debuted the world’s first 3D Full HD Plasma Home Theater System in 2008 The system consist of a 50-inch Panasonic VT25 plasma 3D TV, 3D capable DMP-BDT350 Blu-ray player and one pair of active shutter glasses.

LG has announced the Infinia LX9900 LED 3DTV that will use active shutter glasses.

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. It currently sells for approximately $20,000.

3D mobile handset..!!

The Sharp mova SH251iS Japan's NTT DoCoMo unveiled

Sharp mova SH251iS It allows its user to take

images and then, using an editing system, convert them into 3D.

No special glasses are required, although in order to see a quality 3D image the user has to be positioned directly in front of the phone, and around 1ft away from its screen.

THANK YOU