How 3D TV works

Web searches reveal tons of different technologies, so many that it’s hard to figure out which ones are actually used. It also appears that the format wars are well under way.

At CES last week I stopped in a booth lined with LCD TVs from several different manufacturers, displaying 3D images to people wearing polarizing glasses. According to a person manning the booth, the technique used in these TVs is to encode the images on alternate scan lines, and to have a polarizing filter attached to the screen, arranged in horizontal stripes, one stripe per row of pixels, with each row polarized orthogonally to the adjacent ones. The effect was very good, roughly equivalent to cinema 3D.

The booth also had a DLP projector projecting 3D onto a screen. This required bulkier glasses. According to the person in the booth, the technique used here was to encode the left and right images in alternating frames, with shuttering in the glasses synchronized with the display, occluding the right eye when a left frame is showing, and vice versa. This flavor of 3D didn’t work for me – maybe my glasses were broken…

Confirmation that these are currently the two primary methods of doing 3D on TVs comes from an excellent series of blog postings by Lenny Lipton.

Leave a Reply

Your email address will not be published. Required fields are marked *