How Does 3DTV Work?


Have you ever wondered how 3DTV works? How does the 3D image get produced? The basic principle behind 3DTV is quite simple, but the technology has definitely changed over the years.

What is 3DTV?

Before we delve into what 3DTV is, let’s first understand how our normal vision works. Our vision is binocular – we have two eyes that are about three inches apart and face forwards. This causes each eye to see a slightly different image to the other one. The brain puts these two images together and creates our perception of perspective and depth. So essentially, it is our brain that creates the 3-dimensional world that we see, when given slightly different visual information from each eye.

Old Style 3D

To create a 3D image, each of our eyes needs to receive a slightly different version of the image from the screen. Many years ago this was achieved by wearing specs with one green eyepiece and one red eyepiece to view an image made up of two slightly different versions of the image in red and green. Obviously there was always one major problem with this method, that you were unable to view colour images.

Modern 3DTV Technology

These days, the most common method of creating 3D images in most cinemas is to use polarised glasses. The screen transmits light in two slightly different directions, and each lens of the glasses only lets light in at one angle. This means that each eye gets a slightly different image, tricking the brain into seeing it as a 3-dimensional image.

Another method is called Active 3D and involves the use of “shutter glasses”. These glasses shut on and off at a rate faster than your eyes are able to see. The two eyepieces move alternately to each other, letting different images through to each eye, thereby giving the appearance of a 3D image. The problem with this method is that the glasses are expensive because they contain the technology that makes the 3D image work.

Wouldn’t it be great to not have to wear special glasses at all? Well, such technology is being developed which allows the viewing of 3D images without the need for glasses. This involves sending two different images out at slightly different angles so that each one is directed specifically at each eye. The major problem with this approach though is that you need to be in exactly the right position, otherwise the screen will just look blurry, so it’s no good for use in cinemas.

So, as you can see, there are various different methods for producing 3DTV images. The basic principle is always going to be the same: to provide each eye with a slightly different version of what is happening on the screen. The rest is done by the brain, which builds the 3D image from the different information coming into each eye.

Alastair who is passionate about new technology, provided this article for LG.