New display technology for unconscious information

This paper reviews new techniques of displaying unconscious information and their applications. The key concept underlying the techniques is to display useful information for human activities that is imperceptible to the human visual system, even though it can be read out by other means. Various methods of making information imperceptible are described. Typical examples of these are those that use spatially or temporally imperceptible patterns. These techniques have great potential to enable attractive new applications to be created. Security is presently the most interesting application because it can conceal information and reveal it to select individuals; however, other promising applications are being studied extensively in various fields such as ubiquitous computing and augmented reality.