Head-mounted projector with a wide visual-field and three degrees of freedom in electro-holography

Due to the problem of a narrow visual-field in electro-holography, visual-field enlargement methods that are not reliant on the pixel pitch of the spatial light modulator have been studied. This paper proposes a head-mounted projector (HMP), with which a reconstructed image is projected from the projector attached to the head, and the reconstructed image is observed by reflecting light on a concave-mirror screen. This HMP enables open view, suppresses image distortion due to concave mirrors, achieves three degrees of freedom, and responds to changes in the user-head rotation. HMP is expected to be applied to holographic-projection techniques.