Abstract: A method of locating a substrate within a field of view of an imaging system includes acquiring an image of a first marker on a substrate in the field of view. The first marker has a first spatial pattern representing a position of the first marker relative to the substrate. The method also includes determining possible positions of the substrate based on the first spatial pattern and moving the substrate relative to the field of view based on the possible positions of the substrate. The method also includes acquiring an image of a second marker on the substrate in the field of view. The second marker has a second pattern representing a position of the second marker relative to the substrate. The method further includes determining the position of the substrate relative to the field of view based on the position of the second marker on the substrate.

Abstract: A method of locating a substrate within a field of view of an imaging system includes acquiring an image of a first marker on a substrate in the field of view. The first marker has a first spatial pattern representing a position of the first marker relative to the substrate. The method also includes determining possible positions of the substrate based on the first spatial pattern and moving the substrate relative to the field of view based on the possible positions of the substrate. The method also includes acquiring an image of a second marker on the substrate in the field of view. The second marker has a second pattern representing a position of the second marker relative to the substrate. The method further includes determining the position of the substrate relative to the field of view based on the position of the second marker on the substrate.

Abstract: A whirlpool bath assembly with a recirculation pump fed from the bath by a suction pipe and then to venturi jet units through by system feed pipes. Further air pipes feed the venturi jet units. A drain-off valve connects the pump through a drain pipe to a waste-water drain. All the units forming the assembly are constructed so as to provide a gravity drain-off into the bath and drain pipe. This is done by ensuring that height of the surfaces over which drain-off water flows when the assembly is inoperative reduce continuously without forming any water retaining recesses.