Abstract: A system enabling conversion of a conventional ringlight for differential illumination such as dark field or Rheinberg illumination is disclosed. The system comprises a ringlight having an annular light emitting portion and a hood that fits over the ringlight. The hood has an aperture and an annular reflective surface, disposed opposite the light emitting portion, that reflects the light from the ringlight through the aperture. An angle of the annular reflective surface is selected relative to a direction of light from the ringlight to form a cone of light exiting the aperture. To ensure good contrast, a light baffle in the form of a sleeve, inserted into the ringlight, may be incorporated to prevent stray light from the ringlight from directly exiting through the aperture. The differential illumination produced by the invention is applicable to machine vision applications, but also microscopy, gemology, and serology, for example.

Abstract: A system enabling conversion of a conventional ringlight for differential illumination such as dark field or Rheinberg illumination is disclosed. The system comprises a ringlight having an annular light emitting portion and a hood that fits over the ringlight. The hood has an aperture and an annular reflective surface, disposed opposite the light emitting portion, that reflects the light from the ringlight through the aperture. An angle of the annular reflective surface is selected relative to a direction of light from the ringlight to form a cone of light exiting the aperture. To ensure good contrast, a light baffle in the form of a sleeve, inserted into the ringlight, may be incorporated to prevent stray light from the ringlight from directly exiting through the aperture. The differential illumination produced by the invention is applicable to machine vision applications, but also microscopy, gemology, and serology, for example.

Abstract: A receiver device is provided with a low latency recovery apparatus for recovering serially transmitted digital data. The receiver device operates asynchronously in respect to a transmitting device. The low latency recovery apparatus synchronizes the receiver device in one clock time to support throughput of high speed transmission messages received from interconnection networks or interface cables. A metastability proof latch is provided. A synchronization method provides individual alignment for each incoming message. There is instantaneous response to back-to-back messages from different sources. Synchronization is accomplished in the receiving device by implementing a clocking system capable of generating N phase-shifted clocks all operating at the same frequency as the incoming data. The N clocks are shifted an approximately equal amount in relation to each other.

Abstract: An AC-coupled receiver is provided which allows data with long periods of no signal sent on a fiber optic bus to be received without the normally required preamble. The receiver provides a voltage signal which is AC-coupled to one side of a differential amplifier with a delayed voltage signal AC-coupled to the other input of the differential amplifier. If the time constant of the AC coupling network is much longer than the signal baud time, low-frequency variations at the two inputs of the differential amplifier will be nearly identical and the low frequency signals will effectively cancel each other.

Abstract: The electrical/optical modular coupler enables terminal units coupled to it to be interconnected over the optical and/or electrical bus by which they are physically intercoupled.

Abstract: A modular active fiber optic coupler unit system comprising: a plurality of modular active fiber optic coupler units; each modular active fiber optic coupler unit having an optical input port; an optical output port; an optical transmitter coupled to said optical output port; an optical receiver coupled to said optical input port, an electrical input port; an electrical output port; and logic control elements coupling the said optical transmitter, said optical receiver, said electrical output port and said electrical input port coupled for preventing any electrical input signal on said electrical input port from appearing at the electrical output port; but allowing an electrical input signal to be transmitted as an optical output signal and allowing an optical input signal to become an electrical output; and the system has the electrical output ports of a modular coupler unit of the system coupled to the electrical input ports of a pluarlity of other couplers, and it the system may be coupled to an unlimited

Abstract: A modular active fiber optic coupler unit system comprising: a plurality of modular active fiber optic coupler units; each modular active fiber optic coupler unit having an optical input port; an optical output port; an optical transmitter coupled to said optical output port; an optical receiver coupled to said optical input port, an electrical input port; an electrical output port; and logic control elements coupling the said optical transmitter, said optical receiver, said electrical output port and said electrical input port coupled for preventing any electrical input signal on said electrical input port from appearing at the electrical output port; but allowing an electrical input signal to be transmitted as an optical output signal and allowing an optical input signal to become an electrical output; and the system has the electrical output ports of a modular coupler unit of the system coupled to the electrical input ports of a plurality of other couplers, and it the system may be coupled to an unlimited