Abstract: An optical transmission system or its constituent repeater disposed optically between two terminals. The system includes at least two parallel optical paths between a first node and the repeater (one optical path being used as a backup for another), and another at least two parallel optical paths between a second node and the repeater (again, one optical path being used as a backup for another). The first nodes may, but need not, be terminals, but could also be repeaters, or other optical elements. For a signal traveling from the first terminal to the second terminal, the optical switching mechanism detects which of the at least two parallel optical paths an optical signal is being received from the first node, and channels the optical signal to at least one of the parallel optical paths leading from the repeater to the second node.

Abstract: A defect detection system includes a video camera with defect detection circuits for detecting defects in video signals being outputted by corresponding sections of an array sensor such as a TDI CCD two-dimensional array sensor. Each defect detection circuit includes a subtraction circuit for subtracting a prior stored pixel from an incoming pixel to generate a difference. Comparators compare the difference with positive and negative limits defining an acceptable range of difference values. The prior stored pixel is updated to the succeeding pixel only when the difference value is acceptable. Memories store the defect pixels from the respective detection circuits along with X-coordinates and end of line bits. The memories are sequentially read up to their end of line bits, and the defect pixel values along with coordinates expanded to include section indicating bits are transferred from the camera to further processing facilities.

Abstract: A dive profile recorder for monitoring conditions encountered by a diver under water includes a plurality of transducers to be carried by a diver for generating electrical signals representative of the conditions encountered by the diver. Encoding circuitry electrically connected to the transducers encodes the electrical signals to form a serial data stream and a transmitter electrically connected to the encoding circuitry transmits the serial data stream through the water. A receiver remote from the diver receives the transmitted serial data stream and decoding circuitry electrically connected to the receiver decodes the serial data stream to electrical signals representative of the conditions encountered by the diver. A display electrically connected to the decoding circuitry receives the electrical signals and displays human-perceptible indicia of the conditions encountered by the diver in response to the received electrical signals.

Abstract: This invention is a novel valve of the slidable-gate type. The valve is designed especially for long-term use with highly abrasive slurries. The sealing surfaces of the gate are shielded by the valve seats when the valve is fully open or closed, and the gate-to-seat clearance is swept with an inflowing purge gas while the gate is in transit.A preferred form of the valve includes an annular valve body containing an annular seat assembly defining a flow channel. The seat assembly comprises a first seat ring which is slidably and sealably mounted in the body, and a second seat ring which is tightly fitted in the body. These rings cooperatively define an annular gap which, together with passages in the valve body, forms a guideway extending normal to the channel. A plate-type gate is mounted for reciprocation in the guideway between positions where a portion of the plate closes the channel and where a circular aperture in the gate is in register with the channel.