Abstract: An optical data recording system and method for receiving an input data stream to be recorded on a recording medium; dividing the input data stream into a series of data sections; compressing each data section in the series into a period shorter than the period of the original section and providing data gaps between each compressed data section; recombining the compressed data sections including the data gaps into a gapped output data stream; and recording the gapped output data stream on a recording medium.

Abstract: An imaging system with an enlarged depth of field for use with a means for focusing an image, including: means for sensing an image sample from each of a plurality of portions of the image at each of a plurality of optical distances from the means for focusing; means for determining the relative focus of the image samples derived from a portion of the image at each of the plurality of distances; and means responsive to the means for determining for choosing, for each of the plurality of portions of the image, the image sample having a desired focus.

Abstract: A patching tape, comprising a diffraction grating structure embossed in one face of a transparent plastic tape and a conformal adhesive covering the other face thereof, is used both for correcting informational errors and for producing contrasting color stripes in formal diffractive subtractive filter viewgraphs.

Abstract: A layer of thermally deformable plastic used, for example, in a holographic recording medium has an undulated surface whereby the layer has an uneven thickness. Because of the uneven thickness, the layer has a composite spatial frequency pass band greater than the spatial frequency pass band of a layer of uniform thickness.

Abstract: A plastic sheet is embossed with three angularly-multiplexed holograms to represent three colors of an image. Light is directed to the holograms from three directions, in sequence, to recreate the three colors of the image in sequence on the face of a black-and-white vidicon. The three field sequential signals from the vidicon are sequentially stored in three solid state frame memories, from which the three color-representing signals are read out simultaneously to the three guns of a color kinescope. Alternatively, the three holograms represent red, blue and luminance, and only red and blue frame memories are required, and during display the luminance-representing signal is repeatedly read out from the vidicon to the color kinescope simultaneously with repeated readout from the red and blue frame memories.

Abstract: A layer of thermally deformable plastic used, for example, in a holographic recording medium has an undulated surface whereby the layer has an uneven thickness. Because of the uneven thickness, the layer has a composite spatial frequency pass band greater than the spatial frequency pass band of a layer of uniform thickness.