Abstract: With push button operated switches having at least one movable and one stationary contact carrier, problems may occur when the push button is not actuated properly and centrally. This problem is overcome by a switch having corresponding annular contacts and concentric guide means.

Abstract: The apparatus for brightening cockpit instruments contains a passive optical brightening device for directing daylight which shines through front windows of the cockpit, to impinge upon the viewer-oriented cockpit instrument surface.

Abstract: A method of fabricating an optical fiber connector is disclosed using a transfer molding process employing a precision die whose interior surface defines a frustum for forming the mating surface of the connector. The fiber is inserted through the mold cavity and extends through an aperture in the end surface of the frustum and through an annulus disposed outside of the mold cavity immediately adjacent to the aperture. At the transfer molding temperature, the annulus expands inward radially, simultaneously sealing the aperture and centering the fiber. After curing, the excess fiber is removed, and a flexible, dome-shaped contacting member is formed over the fiber end.

Abstract: One or more glass or other brittle fiber ends are prepared by first embedding the fiber in epoxy or other plastic and then slicing the plastic and the fiber a first time to produce an oblique end face and a second time to produce an end face exhibiting intersecting planes. The slicing is continued with successive advancements of the slicing of approximately one thousandth of an inch to produce a squared end. The technique is applicable to fiber end preparation of single fibers and plural fibers as in optical fiber tapes and cables.

Abstract: An optical ternary pulse transmission system is disclosed in which a light emitting diode is caused to generate either one of two light intensity outputs in response to the voltage pulses presented at either one of two input terminals. The voltage pulse at each input terminal is coupled to the light emitting diode through a gain control network. Most of the light from the light emitting diode is coupled to an optical fiber, and a first photodetector is positioned close to the light emitting diode in order to capture stray light not coupled into the optical fiber. A second photodetector with an opaque coating is positioned such that its position and the position of the first photodetector are electrically symmetrical with respect to the light emitting diode. The electrical signal from the second photodetector representing parasitic coupling is subtracted from the signal developed by the first photodetector in order to develop a signal dependent only on light intensity variations.