Abstract

Apparatus for inspecting the sealing surface of a container finish that includes a light source positioned to direct light energy onto the container sealing surface as the container is held in stationary position and rotated about its central axis. A camera that includes an array of light sensitive elements is positioned and oriented with respect to the container axis of rotation to receive light energy reflected by the sealing surface, with the camera having an effective field of view limited to an angular portion less than the entire circumference of the container sealing surface. The camera array is scanned at increments of container rotation to develop information indicative of intensity of light at each array element as a function of such increments, and commercial variations in the container sealing surface are detected as a function of such information. The camera array is oriented with respect to the container axis of rotation and coupled to the scanning mechanism to scan the array in linear fields orthogonal to the axis of rotation, and scan information is stored for subsequent analysis in two-dimensional electronic memory as a function of array element and scan increment. The light source is strobed at increments of container rotation and the camera array, which may be either a linear array or an area array, is scanned at each strobe increment of container rotation.