Abstract: Packaging for an electronics assembly. A base card has a row of elongated slots. A number of individually insertable subassemblies have standoff feet and a pair of offset hooks at their sides. The hooks snap into the slots in such a way that each slot can hold the hooks for four different subassemblies, which are positioned adjacent each other and on both sides of the base card.

Abstract: A fully redundant safety interlock system is provided comprising, means for detecting the loss of light on a fiber optic link; controller means, coupled to said means for detecting, for determining the safety condition of the link based on the output of said means for detecting, and for controlling the radiant energy output of an optical transmitter, based on the determined safety condition, via redundant output control signals; and means, coupled to said controller means, responsive to said redundant control signals, for interconnecting the output of said controller means to transmitter drive circuitry to thereby adjust the radiant energy output by the transmitter. According to a preferred embodiment of the invention, the controller means includes an electronic implementation of two independent state machines, each of which redundantly determines the connection state of the optical link between two optical link cards.

Abstract: An optical fiber link card communication module, and process for fabricating the module, where the module provides a parallel electrical interface to the user, facilitates high speed serial transmission of data over an optical data link, and contains a plurality of converters for performing conversions between both electrical and optical signals. A preferred embodiment of the invention contemplates fabricating the optical communication module on a single multilayer card with all the transmitter electrical components being located on one side of the card, all receiver electrical components being located on the other side of the card, and the transmitter and receiver components being separated by shielding layers in the card. By using two transmitter/receiver pairs (with the transmitters and receivers being located on respective sides of the card) an embodiment of the invention provides for double full duplex communications.

Abstract: An optical fiber link card communication module, and process for fabricating the module, where the module provides a parallel electrical interface to the user, facilitates high speed serial transmission of data over an optical data link, and contains a plurality of converters for performing conversions between both electrical and optical signals. The module further includes edge mounted optical components having leads mounted on the surface of a card (as opposed to standard pin-in-hole type leads) to minimize lead capacitance and inductance from the optical components to the card electronics, on board card control means for the converters and safety shut down means on the same card as the electrical and optical components.

Abstract: An optical communication signal source package and assembly for coupling optical signals to the end of an optical fiber includes first and second semiconductor laser diodes capable of being operated in a redundant fashion for increased reliability or to provide wavelength division multiplexing for increases in bandwidth and information carrying capability. The laser diodes are supported with their mounting flanges in a common plane and are oriented to provide parallel beams of polarized light having perpendicular E-field vectors. A connector carried by the support positions the optical fiber at the target area where an optics system focuses the light beams. An optical coupling device such as a polarizing beam splitter or a holographic beam separator is responsive to the orthogonal light beams to direct both light beams toward the optical fiber with minimum decrease in amplitude. The package includes no moving parts or highly frequency selective components.

Abstract: The invention uses a small sized, low cost, high accuracy, semiconductor laser interferometer to position the transducer in a disc storage system. Light is reflected back over the path to be measured and directly back into the semiconductor laser. This causes the power present in the laser to be varied. Unexpectedly, the output of the photosensor associated with the laser has an asymmetric, sawtooth waveform.

Abstract: An optical serial data bus for connecting logic cards used in a data processing system. The bus uses semiconductor lasers and PIN diodes as transmitters and receivers, transmitting through free space without the use of lenses or other optical elements. Each logic card communicates only with the adjacent cards on either side to minimize the transmission distance.

Abstract: A phase retardation element, for use in an optical data storage system, which provides a 90.degree. phase difference between two perpendicular polarized components of an incident wave with a single internal reflection from a surface coated with a thin film of dielectric or metal material.

Abstract: A porcelain glazed metal bar has a rounded edge carrying a line of deposited print elements. Conductive lands deposited on both sides of the glazed bar connect the print elements to contacts for external circuitry.

Abstract: A driver circuit for a thermal printing element varies the power applied to the element, depending upon its recent history of energization, in order to maintain uniform print density desprite temperature variation in the element. A capacitor charges and discharges to measure time intervals since the last element energization to control the voltage applied by an output transistor.