Patent ID: 7580137

Claim:
An apparatus for determining one or more physical properties of a rolled smoking article or filter rod, said rolled smoking article or filter rod having a longitudinal axis, said apparatus comprising: an imaging device defining a field of view disposed along an optical axis, said imaging device imaging a rolled smoking article or filter rod in said field of view; a positioning unit which positions a smoking article or filter rod in said field of view such that the longitudinal axis of the smoking article or filter rod is substantially orthogonal to the optical axis of the imaging device; an illuminating unit which illuminates said field of view; a rotating mechanism which rotates said smoking article or filter rod about its longitudinal axis in said field of view; a processor which processes said image to determine one or more physical properties of a smoking article or filter rod in said field of view; and a control unit which controls said processor, said control unit comprising a database, which database is constructed and arranged to store a predetermined nominal diameter of said rolled smoking article or filter rod, said control unit defining two laterally spaced regions of interest of said field of view corresponding to the nominal width, each of which regions of interest encompasses all likely positions of a respective one of the opposite edges, and said control unit being configured to control the processor to process each image sample only within said two regions of interest to locate said opposite edges, wherein said processor repeatedly samples said image as said smoking article or filter rod is rotated by said rotating mechanism to obtain a plurality of image samples, wherein the processor processes each image sample to obtain a measurement of a diameter of said rolled smoking article or filter rod in each image sample, wherein the processor uses said measurements to obtain one or more physical properties of said rolled smoking article or filter rod selected from the mean diameter, ovality, circumference, roundness and shape of said rolled smoking article or filter rod, wherein said processor locates in each image sample two opposite edges of the rolled smoking article or filter rod in profile and calculates the distance between said opposite edges.