Abstract: Compact devices for distributing light from a small area source to evenly light a larger area each comprise a member having a first plurality of surfaces which intercept respective slices of a light beam extending in a first direction and internally reflect the slices to a second substantially perpendicular second direction. A second plurality of surfaces intercept respective portions of the slices of light travelling in the second direction and internally reflect those portions generally perpendicularly toward an output surface to evenly light the output surface.

Abstract: An optical thin line-tracking sensor comprises a small member mounting ends of a light source fiber and a pair of receiving fibers which receive reflected light. Reflected light transmitted through the receiving fibers operate photosensors whose outputs are differentially combined to provide a tracking error signal. Augmenting circuits enable operation over a wide range. Means to sense other indicia carried on a web or sheet are disclosed. A line-tracking head which includes a laser-light cutter is also disclosed.

Abstract: An extremely thin shutter is moved into and out of the space between closely-spaced ends of a pair of axially and angularly aligned optic fibers to prevent or establish transmission of light between the fibers. In one embodiment a cantilever shutter is rotated between two positions. In another embodiment a taut band-like shutter having an aperture is translated between two positions.

Abstract: The ends of plastic optical fibers forming a light-transmitting cable are fused in a manner so as to minimize light loss by applying heat to plasticize short end-length portions while containing portions rearwardly thereof within a cavity defined by means having sufficient thermal conductivity and mass that the rearward portions are not heated above the plastic fiber deformation temperature. Both methods and various forms of apparatus for practicing the methods are disclosed.

Abstract: Electro-optical apparatus for transmitting Boolean switching signals over substantial distances includes a transmitter having a light-emitting diode operable to apply light pulses at a line frequency rate (or double a line frequency rate) to an optic fiber. A remote receiver includes a photosensor for receiving light pulses from the optic fiber, means for amplifying signals from the photosensor, an opto-isolator comprising a light-emitter and a photo-thyristor operated by said light-emitter, an electronic switch connected to energize a load device, and means responsive to said photo-thyristor for controlling the electronic switch.