castAR a Kickstarter campaign by technicalillusions that recently reached its 400K funding goals is developing a new pair of AR glasses. Two micro projectors one for each eye mounted onto a glasses frame either project onto a retro reflective surface or on a clip-on in front of the glasses. The projectors are running at 120 Hz. Apart from that a camera that is integrated into the glasses tracks a set of IR LED for position tracking. Overall they are exploring many different approaches to AR and 3D user-input. Have a look at the video for an in detail explanation.
an article at display-magazin.net
a paper on VRDs: Funktionsweise und Einsatzmöglichkeiten von Virtual Retinal Displays