Abstract: A method is provided for detecting a junction between adjacent can ends which are arranged in a stack. The method enables a selected number of can ends in the stack to be counted. The method comprises the steps of illuminating the peripheral edge regions of can ends in the stack with a signal emitted by a emitter inclined at an oblique angle to a line normal to the central axis of the stack and detecting reflected signals from the ends of the peripheral edge regions of the can ends. Oblique illumination provides alternating regions of the stack reflecting a relatively high and relatively low light intensity. Detection of the light intensity across the length of the stack enables a junction between adjacent can ends to be determined.

Abstract: A method is provided for detecting a junction between adjacent can ends which are arranged in a stack. The method enables a selected number of can ends in the stack to be counted. The method comprises the steps of illuminating the peripheral edge regions of can ends in the stack with a signal emitted by a emitter inclined at an oblique angle to a line normal to the central axis of the stack and detecting reflected signals from the ends of the peripheral edge regions of the can ends. Oblique illumination provides alternating regions of the stack reflecting a relatively high and relatively low light intensity. Detection of the light intensity across the length of the stack enables a junction between adjacent can ends to be determined.