International Business Machines Corporation

Gerald M Heiling

Ronald L Soderstrom

Timothy Roy Block

David W Siljenberg

John T Trnka

Dennis L Karst

Ladd William Freitag

Marcia B Ebler

Spencer C Holter

Earl Albert Cunningham

Brian Andrew Schuelke

John L Regehr

James M Thompson

Tong Lu

LaVerne F Knappe

David C Kobliska

David E Cutshall

Charles J Rocca

Michael J Peterson

David A Knodel

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. The output from the state machines is used to adjust (for example, turn on and turn off) the drive circuitry for the transmitter via fully redundant paths which carry the redundant control signals.

Optical fiber link control safety system

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.

Optical fiber link card

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.

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. The package is employed in a compact communication signal coupling assembly permitting short electrical lead lengths and high circuit density.

Optical communication signal source

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.

Serial optical interconnect bus for logic cards and the like

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.

Compensating driver circuit for thermal print head

A non-impact thermal printer is formed using a pivoted stiffner-frame on which is mounted a printed circuit card-print head assembly. The card is slotted with the print heads mounted at the distal ends of the cantilevered portions to enable close compliance between print head read/write units and the print media through the torsional resilience of the circuit card cantilevered portions. Compact, simple structure is provided by having the printer control circuitry mounted on the same printed circuit card.

Thermal printer write head assembly

A flat disk contains a number of holograms made from the interference of a plane wavefront with spherical wavefront modified by a first cylindrical lens. The disk is rotated so that a plane reconstruction wavefront sweeps across the holograms. The resulting reconstructed wavefront is passed through a second cylindrical lens, resulting in a focussed point sweeping across an object surface in one or more substantially straight lines.

Growing community of inventors

Pine Island, MN, United States of America

Gerald M Heiling