Patent ID: 7355700

Claim:
A method of inspecting an inner surface area of a tubular sample, comprising the steps of: positioning said tubular sample with respect to a pair of cylindrical illuminating members, each said cylindrical illuminating member having a respective longitudinal axis, wherein said longitudinal axes of said cylindrical illuminating members are parallel, said tubular sample being positioned outside said cylindrical illuminating members and in a longitudinal axis parallel to the longitudinal axes of said cylindrical illuminating members; wherein said tubular sample is positioned with respect to an inspection location with a longitudinal edge of an outer surface area of said tubular sample nearest said inspection location being closer to said inspection location than any longitudinal edge of said cylindrical illuminating members, and with at least one longitudinal edge of said inner surface area of said tubular sample being farther from said inspection location than the respective longitudinal edges of said cylindrical illuminating members which are closest to said inspection location; and inspecting said tubular sample from said inspection location while said tubular sample is illuminated by light emitted from the surfaces of said cylindrical illuminating members.