Dolby 3D

Dolby 3D ( formerly known as Dolby 3D Digital Cinema ) is a digital 3D projection technology from Dolby Laboratories, Inc. An advantage over polarization method is that no special silver screen is required, which significantly reduces the cost of the cinema operators. In head inclinations of the audience also disadvantages for the 3D effect occur that exist at linear polarization.

With the same name, a 3D TV display technology without 3D glasses ( autostereoscopic ) is since 2012 in collaboration with Philips researchers developed: Dolby 3D

Technology

In the projector, between the lamp housing, and the projection unit, a dedicated filter is installed, which can also be removed for normal 2D playback. Viewers wear special passive glasses for 3- D effect. These glasses are more expensive than polarizing filter glasses and therefore are usually awarded to the cinemas, cleaned after use and used many times. The technique for the 3-D effect is called interference filter technology and was developed by Dolby by the German company Infitec GmbH (acronym for interference filter technology) licensed. As with the polarization method, there is the option to use two projectors with fixed filter or operate a projector with 144 Hz even with Dolby 3D. In the latter case, a filter (similar to the color wheel in a single-chip DLP - projectors ) are used instead of a fixed filter, which is rotating at 72 revolutions per second. This images are projected for the right and the left eye alternately.

Interference filter technology

The light filter separates the light of the primary colors red, green and blue, each in two different wavelength ranges. Through clear-cut interference filters in the glasses will ensure that each eye only sees the corresponding regions of the spectrum. The costs arising from the divergence of the primary colors differences in perception of color for the left and right eye are projector internally corrected before the ( digital ) projection, so that an identical color impression created by metamerism in both eyes. Due to the angle dependence of the interference filters of the Dolby 3D filter must be placed in the interior of the projector, at a location between the lamp and the projection unit. This complicates the retrofitting of home theater projectors and is in addition to the required color correction is the main reason that this technique is not widely used in the home.