Abstract: An air guard directs air toward a viewing window of an optoelectronic presence sensing device to reduce surface contamination thereon. The air guard may include a control valve, and possibly control circuits, to enable selective activation of the air guard. In one embodiment, the air guard includes one or more slits configured to vent pressurized air in a generally laminar (curtain like) flow in front of the window to prevent the deposition of airborne contaminants thereon. Alternatively, or additionally, the air guard may include one or more nozzles configured to vent pressurized air in directed air streams toward the window to remove surface contaminants thereon, and may include a control valve enabling selective operation in preventive, cleaning, or standby modes. Mode control may be effected by an external control system, by the presence sensing device, or by the air guard itself, which may include a timer or other control circuit.

Abstract: A coupling system allows interconnection of multiple light curtains segments but prevents interconnecting dissimilar segment types. A first connector half mounts to a segment while a second connector half mounts to another segment, such that mating the two halves interconnects the two segments. The two mating sections of the connector or coupling system may be formed as matched mating blocks that are mounted in different orientations, depending upon whether they are attached to transmitter or receiver type light curtain segments. One or both mating sections may rotatably mount to its respective segment, thereby providing an articulated connection between the joined segments. In other implementation, one mating section may be formed as a reversible coupler, with the other mating section formed as a mating receptacle that may be conveniently keyed to accept only a particular orientation of coupler.

Abstract: A mixed architecture light curtain system comprises a mix of flexibly and rigidly interconnected light curtain segments. For example, a number of light curtain segments may be rigidly interconnected in series at desired connection angles using one or more types of rigid connectors to form a set of rigidly connected segments. Another set of rigidly connected segments may be flexibly connected to this first set, or one or more individual segments may be flexibly connected in series with this first set. In general, a series of interconnected segments may be formed in any desired combination of rigidly and flexibly connected segments. In any such combination, differing types of rigid and flexible connectors may be used, such that rigidly and flexibly interconnected segments may be fixed at essentially any desired angle, offset, or relative spacing, allowing the mixed architecture light curtain to conform to complex and even disjointed protection zone shapes.

Abstract: A mixed architecture light curtain system comprises a mix of flexibly and rigidly interconnected light curtain segments. For example, a number of light curtain segments may be rigidly interconnected in series at desired connection angles using one or more types of rigid connectors to form a set of rigidly connected segments. Another set of rigidly connected segments may be flexibly connected to this first set, or one or more individual segments may be flexibly connected in series with this first set. In general, a series of interconnected segments may be formed in any desired combination of rigidly and flexibly connected segments. In any such combination, differing types of rigid and flexible connectors may be used, such that rigidly and flexibly interconnected segments may be fixed at essentially any desired angle, offset, or relative spacing, allowing the mixed architecture light curtain to conform to complex and even disjointed protection zone shapes.

Abstract: A coupling system allows interconnection of multiple light curtains segments but prevents interconnecting dissimilar segment types. A first connector half mounts to a segment while a second connector half mounts to another segment, such that mating the two halves interconnects the two segments. The two mating sections of the connector or coupling system may be formed as matched mating blocks that are mounted in different orientations, depending upon whether they are attached to transmitter or receiver type light curtain segments. One or both mating sections may rotatably mount to its respective segment, thereby providing an articulated connection between the joined segments. In other implementation, one mating section may be formed as a reversible coupler, with the other mating section formed as a mating receptacle that may be conveniently keyed to accept only a particular orientation of coupler.

Abstract: A modular articulated light curtain is formed by combining straight, curved, or angled modules with straight or angled couplers. Modules include an array of pitched light emitters or light detectors, and have rounded distal ends that mate, mechanically and electrically, with each other or with a coupler. Interconnection of adjacent modules is such that a constant pitch of light emitters or light detectors is maintained. The light curtain comprises an assembly of interconnected light emitting modules spaced-apart from interconnected light detecting modules. One end of each assembly is terminated, while the other assembly end has a cable end module that may include at least one light emitter or detector, and may include a visual indicator, and provides input/output electrical interface to the light curtain.

Abstract: A modular articulated light curtain is formed by combining straight, curved, or angled modules with straight or angled couplers. Modules include an array of pitched light emitters or light detectors, and have rounded distal ends that mate, mechanically and electrically, with each other or with a coupler. Interconnection of adjacent modules is such that a constant pitch of light emitters or light detectors is maintained. The light curtain comprises an assembly of interconnected light emitting modules spaced-apart from interconnected light detecting modules. One end of each assembly is terminated, while the other assembly end has a cable end module that may include at least one light emitter or detector, and may include a visual indicator, and provides input/output electrical interface to the light curtain.

Abstract: A method of operation of a light curtain system for sensing the intrusion of objects into detection planes which define a protected zone. A group of light beams are strobed from one transmitter in a first direction across a zone to a receiver, and another group of light beams are strobed from another transmitter across the zone to another receiver. Light beams within each group which intersect a desired entry area are deactivated for penetration of a permitted object, and other beams in the groups are enabled to detect intrusion into the objects in portions of the zone which lie around the entry area.

Abstract: A light curtain system for sensing the intrusion of objects into detection planes which define a protected zone. A plurality of light curtain segments are provided with each segment including spaced-apart transmitter and receiver heads. The transmitter and receiver heads are each connected in series by flexible cables which form a part of a control circuit. The series-connected segments permit the detection planes to be aligned in predetermined angular orientations as required by the particular application.