Abstract: An apparatus provided for forming articles from thermoplastics sheet by free-blowing, without use of moulds, in which the sheet is pre-heated to elastic state, free-blown by establishing a differential fluid pressure between opposite faces of the sheet and maintained at optimum temperature during the period of free-blowing by heating or cooling by heat-exchange between the sheet and fluid flowing over at least one face. The apparatus comprises a tank divisible into two halves adapted to hold the sheet edgewise in between, the differential fluid pressures being established between the volumes in the two halves and fluid flow over the face of the sheet being established in one half.

Abstract: A laser system designed to minimize mode beating by splitting an incident laser beam into two approximately equal components, transmitting the components along separate paths of unequal lengths and recombining the components at a beam combiner to form the emergent laser beam. Laser mode beating is effected at frequencies dependent upon the interferometric path difference. Mode beating elimination at further frequencies is possible using further splitter/combiner combinations in series. A three-color laser modulator uses two different laser sources, each with splitter/combiner mode beating suppression optics. One beam is further split to provide, in all, three paths through three color modulators, the three paths being combined at a dichroic combiner. A color laser projection display system includes conventional line and frame scanning means following the dichroic combiner of the three-color modulator.

Abstract: A raster-scan display system for computer-generated images in which each raster line is quantized into a number (N) of sets of image elements each successive set being displaced in time, with respect to the line start, by 1/N of the duration of one element. The corresponding video signals are summed for each line and the resultant signal is displayed. The technique provides a visual image with graded intensity changes more nearly simulating a television type image, instead of a stepwise changing image. In one form of the invention, a triangular hold technique is used, that is, the display is delayed to permit of a linearly changing intensity charge between consecutive elements of different intensity.