Abstract: A fluid column projection apparatus and method provide a unique optical effect by providing a plurality of scoops that direct fluid into a hollow chamber. The fluid preferably contains one or more types of light-scattering material. The fluid exits the hollow chamber in a manner that projects the fluid to a considerable distance past the hollow chamber. The hollow chamber may be lit, or an external light source may illuminate the fluid, thereby providing a unique and pleasing optical effect in the form of a column of light.

Abstract: The invention divides the lens focusing process into two or more surfaces that incorporate multiple curved axial optic elements on each surface. The axial optics may be manufactured by molding, machining, or by suspended film. If suspended film is used, then both sides of an optic may have a suspended film that is transparent. Alternatively, one side of the suspend film optic may use a reflective film.

Abstract: A surface containing a plurality of individually-addressable encoded images comprises an array of curved specular reflectors. Reflectance modifying treatment is applied to a first region of at least one of the curved specular reflectors, such that beamable energy that is directed towards the array is viewable from a first subset of the curved specular reflectors only under a first set of viewing conditions. Reflectance modifying treatment is applied to a second region of at least one of the curved specular reflectors, such that beamable energy that is directed towards the array is viewable from a second subset of the curved specular reflectors only under a second set of viewing conditions.

Abstract: A controlled-depth matrix layer structure is formed by floating a plurality of geometric shapes in a solidifiable liquid, then solidifying the liquid to entrap the plurality of geometric shapes in a layer. Multiple layers of liquid may be used, one or more of which may be solidifiable, so long as the sum of displaced masses of all the layers is greater than the mass of the geometric shapes, thereby causing the geometric shapes to float. The resulting structure after solidification of the solidifiable layer is a solidified layer interconnecting the plurality of geometric shapes, wherein each of the plurality of geometric shapes is within the solidified layer a specified percentage. The geometric shapes are preferably of different sizes, and may be spheres, hemispheres, or other suitable shapes, and may be hollow, solid, transparent or reflective.

Abstract: A tracking system for measuring and recording the movements of a longwall shearer vehicle (10) includes an optical tracking assembly (B) carried at one end of a desired vehicle path and a retroreflector assembly (A) carried by the vehicle. Continuous horizontal and vertical light beams are alternately transmitted at (38) by means of a rotating Dove prism (58) to the reflector assembly (A). A vertically reciprocating reflector (34) interrupts the continuous light beams and converts these to discrete horizontal and vertical light beam images transmitted at (68) at spaced intervals along the path. A second rotating Dove prism (64) rotates the vertical images to convert them to a second series of horizontal images while the first mentioned horizontal images are left unrotated and horizontal. The images are recorded on a film (74, 104). An overlay (106) with X and Y co-ordinates may be utilized to view the images and provide a graphical representation of the vehicle's path along the longwall coal face.

Abstract: A protective window for use with high-energy infrared radiation sources, such as lasers, is described, together with a method for manufacturing the window. For visual applications, the window basically includes a sheet of light transmitting material such as glass or quartz, which has a partially-reflecting surface coating, such as gold, which primarily reflects infrared radiation while transmitting visible light. The reflectivity of the coating may be improved by an infrared laser scanning technique. Finally, one or both surfaces of the window are coated with a visible-light transmitting synthetic resin which, if rapidly heated to a suitable temperature, vaporizes without leaving any residue. This vaporization carries away any contamination, such as dirt or dust, on the resin coating, leaving a very clean reflection surface.