Profile measurement apparatus using radiation

Claim 1

A profile measurement apparatus for measuring a thickness of a strip which is conveyed in a predetermined direction, comprising: (a) a plurality of stationary radiation sources disposed in an approximately linear manner and spaced apart from one surface of said strip, for simultaneously and continuously producing a plurality of radiation beams of sector shapes in a direetion substantially perpendicular to a travelling direction of the strip along the width of the strip, at least two of the radiation bemas being offset with respect to each other in the travelling direction, and the radiation beams in combination being simultaneously and continuously incident along a substantially linear surface area along the entire width of said one surface of said strip and at least partially transmitted through said strip; (b) a plurality of multi-channel detectors disposed to be spaced apart from the other surface of said strip and respectively corresponding to said plurality of radiation sources, for respectively and independently receiving the radiation beams of sector shapes which are continuously radiated from said radiation sources and which are transmitted through said strip to become incident on the corresponding one of the multi-channel detectors, and for producing first profile signals corresponding to intensities of said incident radiation beams and to thickness at the substantially linear surface area radiated by the radiation beams; and (c) operating means, connected to said multi-channel detectors, for producing an image signal indicating a sectional shape at the substantially linear surface area of said strip in accordance with the first profile signals, whereby the entire surface of said strip is scanned with the sector-shaped radiation beams and hence a section of said strip along the entire width thereof is continuously measured.