A three-dimensional (3D) adapter is a device that translates one 3D signal to another. Using a 3D adapter comes into play primarily when someone is using an obsolete TV or projector that does not understand newer 3D signals. While some signals can produce 3D images without the use of glasses, a 3D adapter generally will require glasses for proper use. This device can be useful when using some older TVs or projectors, though the 3D image cannot be fixed if there are any problems.
Some people may think that most TVs and projectors use the same signal to produce 3D images, but there are many different signals in use. This can be to serve different forms of 3D images — such as passive and direct — or because one signal creates better images. What the 3D adapter does is take one signal and translate it into another signal that a second device can understand.
While a 3D adapter can be integrated with any 3D device, this generally is not required. This is most often needed when a TV or projector either does not understand a signal or is obsolete and does not have the new signal in its programming. For this to work, there normally has to be a player system that understands the signal, which is routed through the adapter and translated for the TV or projector. If the TV or projector — like most older models — does not emit 3D images, then the adapter cannot force it to send this information to 3D glasses.
TVs and projectors do not always require special glasses to enable viewers to see a 3D image. At the same time, the 3D adapter generally translates the signal into one that does require glasses. The most common glasses needed are direct, battery-powered devices. Passive, or non-battery powered, glasses also are sometimes supported by this system.
If the 3D image needs to be fixed, because it is skewed or the player device is having trouble projecting the right image, then a 3D adapter will refuse all changes. The adapter will accept two-dimensional (2D) image changes, but the 3D signal must remain as is. This means that, if the 3D signal is not fully integrated with the 2D images, the movie media has scratches or if there are any other problems, they cannot be fixed.