ABSTRACT
Today's state-of-the-art automotive head-up displays (HUD) possess single- or double layer focal planes that limit the observers' eye focus to these planes when crucial information is shown. Other visual 3D cues such as motion parallax also suffer from this limitation. The resulting viewing experience contradicts the natural way of viewing during driving or interaction, when alerts and hints should appear at the correct projection depth where real objects of interest are located. Here we present a real-time holographic HUD with continuous depth that supports the intuitive and natural way of viewing and interacting with virtual environments outside and inside the car. We demonstrate full-color, 3D real-time encoding within a field-of-view of 5∘×3∘.
Subject(s)
Depth Perception , Holography , Cues , MotionABSTRACT
A holographic 3D display with 300 mm×200 mm active area was built. The display includes a spatial light modulator that modulates amplitude and phase of light and thus enables holographic reconstruction with high efficiency. Furthermore, holographic optical elements in photopolymer films and laser light sources are used. The requirements on these optical components are discussed. Photographs taken at the display demonstrate that a 3D scene is reconstructed in depth, thus enabling selective accommodation of the observer's eye lenses and natural depth perception. The results demonstrate the advantages of SeeReal's holographic 3D display solution.
ABSTRACT
The investigation deals with earliest chemical changes in outermost enamel surfaces during initial caries development. After in vitro demineralization of enamel samples in acidulated hydroxyethylcellulose solution (pH = 5.1) for periods between 1 and 288 h the Ca/P molar ratios were determined in depths of 0.04 micron using the Rutherford Backscattering spectroscopy. The measured Ca/P ratios oscillate around the initial value. This behaviour is interpreted as a combined de/remineralization process.