Abstract: A circuit arrangement is disclosed for sensing a presence or absence of a low-level output signal which may be used for detecting a change of resistance in a magnetic bubble detector. The circuit operates in a D.C. coupling mode whereby the low-level signals are directly coupled into a sense amplifier, which is preceded by the circuit above-mentioned. The circuit, which comprises a modified current mirror, is used as a resistance transducer which converts a change of resistance (.DELTA.R) into a direct change of voltage (.DELTA.E). The change of voltage provides an indication of the presence of, for example, a magnetic bubble.

Abstract: A magnetic bubble replication and transfer arrangement is disclosed which provides for replicating magnetic bubbles in thin planar layers of magnetic material without the need for electrical current carrying conductor elements. The arrangement includes a replicating half-disc permalloy element disposed in a particular way between first and second tracks formed from half-disc elements which are deposited on a surface of the magnetic layer. When a rotating magnetic field in the plane of the material is rotated in a predetermined direction with respect to the above arrangement, replication of a bubble in the first track occurs at a replication region where a portion of the replicating element is adjacent the first track. The original bubble continues movement within the first track while the newly formed bubble moves along the replicating element into the second track in response to rotation of the in-plane magnetic field.

Abstract: The present invention relates to apparatus for printing graphic forms simultaneously with information data. A graphic forms master is mounted on a relatively small forms drum which is coupled to rotate simultaneously with a photo-sensitive print drum. Light is reflected from the graphic forms master to a light sensitive transducer from where electrical signals, representing the graphics form, are transmitted to a signals merging circuit. Information data signals are also transmitted to the signals merging circuit. The signals merging circuit is connected to a single light source-optical system to selectively pass light to the photo-sensitive print drum in response to the electrical signals to provide an image thereon representing both the graphic form and the information data. Automatic lateral alignment of the graphic forms data and information data is accomplished through cooperation of an alignment mark on the graphic forms master with a portion of the signals merging circuit.

Abstract: A beam feedback synchronization system for optical sweeping apparatuses is disclosed. The system includes a multi-faceted rotating reflection mirror which acts on a collimated light beam such as a laser beam to cause it to sweep periodically in parallel straight lines across a rotating photoconducting drum. A portion of the light beam is split off and caused to sweep across an equispaced linear array of fiber optic apertures held in place by a fiber optic assembly. The light entering the fiber optic apertures is carried along fiber optic elements to one or more photodetectors which generate periodic electrical signals in response thereto. The frequency of occurrence of the electrical signals from the photodetector is a measure of the velocity of the sweeping light beam across the fiber optic array.

Abstract: A graphic forms overlay apparatus to be used with non-impact printers requiring the use of a movable light sensitive medium such as laser printers is disclosed. Laser printers use a sweeping laser beam and a movable light sensitive medium to image data from a data processing source for printing. A graphic forms pattern is overlayed on the data imaged on the light sensitive medium for simultaneous printing of the data and pattern. To accomplish this a negative of the pattern is mounted on a hollow rotatable forms drum, and inside the drum a fluorescent tube is fixedly mounted for illuminating the negative. A linear portion of the light image of the negative formed thereby is reflected by an optical system of lenses and mirrors onto adjacent linear portions of the light sensitive medium being swept by the laser beam for imaging of data.

Abstract: The present invention comprises selectively locating electrical shorting rings on the male section of an optical cable connector. The particular locations of the rings chosen is commensurate with the length of the cable and provides a basis for amplifying the signals being transmitted along the optical cable. On the female section of the cable connector there are electrical contact devices which can be shorted by the rings on the male section if such rings are present. There is a selectable amplifier circuit connected to the optical cable and the contact devices, and depending upon which contact devices are shorted the amplifier circuit provides the proper amplification to the optical signals which are being converted into electrical signals.

Abstract: The present invention is a method and apparatus for passive generation of magnetic bubbles in thin layers of magnetic materials, such as garnets, and uses specially designed permalloy elements which with the rotation of an in-plane magnetic field act to generate magnetic bubbles over a wide range of bias magnetic field values. The design of a special permalloy element includes an angular portion and a contiguous remaining portion having a large surface area relative to the angular portion. Pulsing of the in-plane rotating field to higher field values as it passes through a predetermined orientation with respect to the angular portion generates magnetic bubbles in a controllable manner for fixed values of the bias field.