The German display manufacturer A.C.T. Kern uses a technology devised by the German Fraunhofer Institute for its Free2C autostereoscopic displays. It employs a film covered with a very fine matrix of lenses, which is applied to the TFT display. The use of cylindrical lenticular lenses ensures a very good separation of the stereo images - the overlap is less than 2%!
To further improve the quality, the display is rotated by 90°, meaning it is used in portrait mode. By employing this trick, the company circumvents the problem of color artifacts. These usually occur because of the horizontal placement of the three primary colors of TFT screens, namely RGB.
Since the three basic colors in a TFT panel are arranged next to one another horizontally, this results in a color shift in combination with the lenticular screen plate. A.C.T. circumvents this problem by rotating the panel by 90°, to portrait mode. The drawback to this solution is that this mode is not supported by all full-screen applications.
The A.C.T. Kern line of stereoscopic 21" TFT displays currently consists of four different models. On the basic model, the lens matrix is applied to a Samsung TFT panel. The next higher model is based on an NEC panel. A.C.T. Kern also offers are two additional displays based on NEC panels. These allow the position of the lenticular screen plate to be adjusted to the position of the viewer as needed.
The smaller version uses an infrared system to determine the position of the viewers head. The flagship model, on the other hand, uses an eye-tracking system based on two cameras that precisely determine the position of the viewer's eyes and adjust the position of the lenticular screen plate as exactly as possible. This frees the user from the "cage" of the stereo zone, allowing greater freedom of movement. Both the principle and the eye-tracking software were also developed by the labs of the Fraunhofer Institute.
A typical workstation with A.C.T. Kern's Free2C stereo display (right). The current high-end model with eye-tracking is shown here. To the left is a normal TFT display for 2D input. In this picture, the Free2C display is showing an impressive stereoscopic image of the Martian surface.