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US 4,054,388 AGranted
Optical control means
AssigneeTI (Group Services) Limited
InventorsDavid Malcolm Marsh, Richard Daniel Slater
Life of this patent
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AssigneeTI (Group Services) Limited
InventorsDavid Malcolm Marsh, Richard Daniel Slater
Estimating the term…
Improved optical means for automatically controlling or monitoring the position of a relatively moving member such as a tool tip in a numerically controlled machine tool has an image of a region of a datum line projected on to a slit in an optical system. Light passing through the slit falls on to a photoelectric detector device which comprises an array of discrete elements. The elements are electronically scanned sequentially and an electric circuit is provided to produce an output signal when a preset change in incident light intensity is detected by any of the photoelectric elements thus indicating the presence of the movable member at the datum line. There may be two slits projecting images of the region around two transverse datum lines on to two separate arrays so that the movable member can be controlled in two dimensions. Alternatively, in place of two separate arrays and two slits a single two dimensional array may be provided suitably masked.
Means for controlling the relative movement of a member towards a preset datum line, said means comprising an element in which an optical slit is formed, means causing an optical image of the region of said datum line to fall on said slit with said datum line extending longitudinally of said slit, a photoelectric detector device placed to receive light radiation passing through said slit and an electric circuit connected to said photoelectric detector device, improved in that the said photoelectric detector device comprises an array of discrete photoelectric elements each associated with a different portion of the slit, and said electric circuit is operative to scan said photoelectric elements sequentially and produce an output signal when a preset change in incident light intensity is detected by any of said photoelectric elements indicating the presence of the movable member at the datum line.
Means for controlling the relative movement of a member towards a preset datum line, said means comprising an element in which an aperture is formed, means causing an optical image of the region of said datum line to fall on said aperture, a photoelectric detector device placed to receive light radiation passing through said aperture and an electric circuit connected to said photoelectric detector device, improved in that the said photoelectric detector device comprises an array of discrete photoelectric elements each associated with a different portion of the aperture and said electric circuit is operative to scan said photoelectric elements sequentially and produce an output signal when a preset change in incident light intensity is detected by any of said photoelectric elements indicating the presence of the movable members at the datum line.
Dependencies are inferred from the claim text.