Visibility control using revolving polarizer

We propose a novel display technique that presents information with different visibility to multiple users. The system projects information on a screen through a revolving linear polarizer in front of the projector, and it shows information through another polarizer in front of the user’s viewpoint. The brightness of the observed information is reduced according to the relative angle of the polarization axes between the two polarizers, thereby allowing applications to provide information at different arbitrary levels of brightness for each user by controlling the angle of the revolving polarizer. By measuring the brightness values of an implemented prototype, we demonstrate that the proposed method is effective. We then describe several example applications showing the benefit of the technique: concealment and classification of information for specific users. In addition, we describe an example of an entertainment application and a tangible polarizer on display.