Eaton Corporation

Christopher Gavin Brickell

Kenneth A Langland

A mechanism for indicating the degree of alignment of a photoelectric sensing system produces a pulse width modulated signal in response to the intensity of light received by the sensing system. That signal has pulses which occur at a fixed frequency, but which vary in duration in response to the received light intensity. The pulse width modulated signal drives an indicator, such as a sound or light emitter. With this technique, the output of the indicator is pulse width modulated to indicate the intensity of the received light and thus the degree of alignment of the sensing system.

Alignment indicator for photoelectric sensors

A method and apparatus is described for addressing a plurality of interconnected electronic modules. One of the modules is initialized as a master module which sets its own internal address and broadcasts address information to each of the other modules during an addressing process. The other modules receive address information from the master module and set their internal addresses accordingly, such that each module has a unique internal address. The other modules also may broadcast information which may be received by the master module.

Apparatus and method for addressing electronic modules

An apparatus for detecting the presence or absence of an object within a monitor zone includes a sensor (12) operative to sense a condition of the monitored zone (Z) and provide a sensor signal indicative thereof. The sensor signal is processed, preferably according to two different transfer functions, to provide first and second signals that vary based on the sensor signal. A comparator (46) provides a comparator signal that varies as a function of the first and second signals. Additional circuitry (58) is operative to provide an indication of the presence or absence of an object within the monitored zone (Z) as based on the comparator signal.

Apparatus and method for sensing an object within a monitored zone

The positions of objects in a holder, such as a cassette containing semiconductor wafers, are determined by a system that projects a pair of coplanar light beams through the cassette from one side. A reflector on the opposite side reflects both light beams back though the cassette and onto separate photodetectors on the one side. A computer analyzes signals from the photodetectors as the cassette is moved through the light beams. As the cassette moves the light beams are interrupted by the wafers. The relative widths and timing of pulses in the signals indicate the location of wafers in the cassette and whether a wafer is misaligned.

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Mukilteo, WA, United States of America

Christopher Gavin Brickell