Color multiplexing passive sensor array
First Claim
1. Apparatus for gathering data about a plurality of chemical or physical conditions comprises:
- (a) a plurality of passive optical sensors to modify light supplied to them as a function of changes in physical or chemical conditions applied to them;
(b) means for providing light for the sensors, comprising a broadband or multiband light source remote from the sensors and an optical fibre to distribute light from the source for access on behalf of each sensor;
(c) a plurality of dichroic beam splitters accessing the light distribution fibre to extract selected colours therefrom in turn while allowing the remainder of the light to continue along the distribution fibre for access by subsequent beam splitters, the colour extracted by each beam splitter being supplied to a single sensor and being different from that supplied to the other sensors, the breadth of the light source waveband or numbers of wavebands being at least sufficient to include all the colours selected for supply to the sensors;
(d) an optical fibre data bus connected to receive light from each of the sensors and to convey it to a place remote from the sensors;
(e) means for separating each of the selected colours from other light conveyed by the data bus; and
(f) detection means connected to receive the separated colours for measuring or detecting modifications made to each colour by the sensors.
1 Assignment
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Accused Products
Abstract
Apparatus for gathering data about a plurality of chemical or physical conditions, e.g. on industrial plants, utilizes a plurality of passive optical sensors. Light for the sensors is provided by a common broadband source, and distributed by an optical fiber from which light of a selected color is withdrawn for each sensor in turn, the color selected for each sensor being different from that selected for the other sensors. Each color is modified by its respective sensor as a function of changes in the conditions applied to the sensor, and all the modified colors are conveyed along a common data bus to be demultiplexed and the data displayed. The colors may be supplied by the data bus to detection means simultaneously or sequentially. Passive optical sensors avoid electrical interference and incendiary risks due to electrical sparking, and color multiplexing avoids difficulties associated with other forms of multiplexing in plant environments.
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Citations
20 Claims
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1. Apparatus for gathering data about a plurality of chemical or physical conditions comprises:
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(a) a plurality of passive optical sensors to modify light supplied to them as a function of changes in physical or chemical conditions applied to them; (b) means for providing light for the sensors, comprising a broadband or multiband light source remote from the sensors and an optical fibre to distribute light from the source for access on behalf of each sensor; (c) a plurality of dichroic beam splitters accessing the light distribution fibre to extract selected colours therefrom in turn while allowing the remainder of the light to continue along the distribution fibre for access by subsequent beam splitters, the colour extracted by each beam splitter being supplied to a single sensor and being different from that supplied to the other sensors, the breadth of the light source waveband or numbers of wavebands being at least sufficient to include all the colours selected for supply to the sensors; (d) an optical fibre data bus connected to receive light from each of the sensors and to convey it to a place remote from the sensors; (e) means for separating each of the selected colours from other light conveyed by the data bus; and (f) detection means connected to receive the separated colours for measuring or detecting modifications made to each colour by the sensors. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification