Process and apparatus for inspecting vessel orifice by making use of infrared light energy emitted through the vessel bottom

摘要

Apparatus and method for inspecting a container (16) having an open mouth (14) and a closed bottom (24) spaced from the container mouth, while the container is hot from its manufacture, includes a light sensor (26) disposed with respect to the container to view the container bottom through the container mouth. Infrared light energy emitted from the container bottom that travels through the container mouth is directed onto the light sensor, and the inside diameter of the container mouth is measured as a function of the light energy directed onto the sensor. The light sensor preferably comprises an area array sensor (28) for developing a two-dimensional image of the container mouth, and the infrared light energy is directed onto the sensor by a telecentric lens arrangement (36). The area array sensor is disposed within a camera that has an entrance pupil (30) and the telecentric lens arrangement has one focus at infinity directed toward the container bottom and a second focus at the entrance pupil of the camera. The area array sensor is coupled to image processing electronics (38) for determining or calculating a circle of greatest diameter (14c) that will fit into the two-dimensional image (FIG. 2) of the container mouth, and treating such circle as indicative of the effective inside diameter of the container mouth.