Reduction of converging distance change in an aquatic display formed with aerial imaging by retro-reflection in conjugated optical structure.

This paper proposes an optical system for aquatic display that shows an image in water. The aquatic image is formed by utilizing aerial imaging by retro-reflection, which converges light by a retro-reflector and a beam splitter. Refraction on intersection between air and another material causes spherical aberration, which changes light-converging distance. In order to reduce the converging distance change, the light-source component is filled with water so that the optical system becomes conjugate including the medium. We analyzed converging of light in water by simulations. Furthermore, we have confirmed effectiveness of conjugated optical structure experimentally by use of a prototype.

Floating aerial LED signage based on aerial imaging by retro-reflection (AIRR).

We propose a floating aerial LED signage technique by utilizing retro-reflection. The proposed display is composed of LEDs, a half mirror, and retro-reflective sheeting. Directivity of the aerial image formation and size of the aerial image have been investigated. Furthermore, a floating aerial LED sign has been successfully formed in free space.

Luminance addition of a stack of multidomain liquid-crystal displays and capability for depth-fused three-dimensional display application.

A stack of liquid-crystal displays is expected to reduce visual fatigue caused by a flat-panel three-dimensional (3D) display. We previously developed a compact depth-fused 3D (DFD) display by using a stack of two twisted-nematic (liquid-crystal) LC panels, but its viewing-angle characteristics and color reproducibility were not so good. Therefore recent wide-view LC panels should be used. We report calculated and measured luminance addition characteristics, which are essential for evaluating 3D display characteristics, of a stack of two multidomain LC panels. We found that LC panels with super in-plane switching, patterned vertical alignment, multiple vertical alignment, and continuous pinwheel alignment modes are suitable for DFD display application.

Apparent 3-D image perceived from luminance-modulated two 2-D images displayed at different depths.

An apparent 3-D image can be perceived from only two 2-D images displayed at different depths, when an observer views them from the direction in which they are overlapped. The two 2-D images are created from an original 2-D image by dividing its luminance according to independently obtained depth information. Subjective test results show that (1) an apparent 3-D image is perceived and (2) the perceived depth continuously varies according to the change in luminance ratio between the two 2-D images.