Patent ID: 7060999

Claim:
Apparatus for inspecting a container having an axis and a sidewall with at least one circumferentially extending rib, which includes: a light source for directing a line-shaped light beam onto an external surface of the container sidewall, with said line-shaped light beam having a long dimension parallel to said axis and of sufficient length to illuminate a peak of said at least one rib and at least one valley adjacent to said at least one rib, said line-shaped light beam being at an angle to said sidewall such that, at said at least one peak, a first portion of said light beam is reflected from an external surface of said sidewall and a second portion of said light beam is reflected from an internal surface of said sidewall, and at said valley a third portion of said light beam is reflected from an external surface of said sidewall and a fourth portion of said light beam is reflected from an internal surface of said sidewall, a light sensor disposed to receive said first, second, third and fourth portions reflected from said external and internal surfaces at said peak and said valley, and an information processor coupled to said light sensor to determine: (1) thickness of said sidewall at said peak as a function of separation between said first and second portions at said sensor, (2) thickness of said sidewall at said valley as a function of separation between said third and fourth portions at said sensor, and (3) height of said rib with respect to said valley as a function of separation between said first and third portions at said sensor.