Steven Wayne Reed

US Patent:

20130113919, May 9, 2013

Filed:

Jul 13, 2011

Appl. No.:

13/809440

Inventors:

Yi Qiao - Woodbury MN, US
Jack W. Lai - Lake Elmo MN, US
Jeffrey J. Fontaine - Woodbury MN, US
Steven C. Reed - Stillwater MN, US
Catherine P. Tarnowski - Mahtomedi MN, US
David L. Hofeldt - Oakdale MN, US

Assignee:

3M INNOVATIVE PROPERTIES COMPANY - ST. PAUL MN

International Classification:

G01N 21/95
H04N 7/18

US Classification:

348 92

Abstract:

An inspection device comprises a camera assembly including an objective lens that captures and collimates light associated with an object being inspected, an image forming lens that forms an image of the object based on the collimated light, and a camera that renders the image. The camera assembly defines a focal point distance from the objective lens that defines a focal point of the camera assembly. The inspection device comprises an optical sensor positioned to detect an actual distance between the objective lens and the object, an actuator that controls positioning of the objective lens to control the actual distance between the objective lens and the object, and a control unit that receives signals from the optical sensor indicative of the actual distance. Control signals from the control unit can control the actuator to adjust the actual distance such that the actual distance substantially equals the focal point distance.