Abstract: The apparatus and method measure the three-dimensional surface shape of a surface without contact with the surface, and without any physical constraint on the device during measurement. The device is a range-sensor or scanner, and in one embodiment is a laser-camera sensor, which has a portable camera and multi-line light projector encased in a compact sensor head, and a computer. The apparatus provides three-dimensional coordinates in a single reference frame of points on the surface. The sensor head does not have to be physically attached to any mechanical positioning device such as a mechanical arm, rail, or translation or rotation stage, and its position in three-dimensional space does not have to be measured by any position-tracking sensor. This allows unrestricted motion of the sensor head during scanning, and therefore provides much greater access to surfaces which are immovable, or which have large dimensions or complex shape, and which are in confined spaces such as interior surfaces.

Abstract: An electro-optical device for influencing the presentation of visual information when placed before the eyes of an observer, comprising one or more cholesteric liquid crystal cells which, under the control of an electric driving signal, can be rapidly switched, by means of the cholesteric-nematic phase change effect, between a clear, transparent texture and a cloudy, scattering texture. The invention is particularly suited for applications as a spectacle-mounted stroboscope, tachistoscope or stereoscopic viewer, wherein special features are the absence of color distortion, the continued illumination of the eye during visual occlusion and the very high switching speeds.