Profiling of a component having reduced sensitivity to anomalous off-axis reflections

• US 6,870,631 B2
• Filed: 06/27/2002
• Issued: 03/22/2005
• Est. Priority Date: 08/06/1999
• Status: Expired due to Fees

• Current Assignee: Metronic Systems, LLC
• Original Assignee: Metron Systems, Inc., The Boeing Co.
• Inventors: Johnston, Kyle S., Nelson, Spencer G., Lock, Tomas E., Greenberg, Heath M., Clary, Thomas R.
• Primary Examiner(s): Pham, Hoa Q.
• Application Number:
  US10/183,696
• Publication Number:
  US 20020180988A1
• Time in Patent Office: 999 Days
• Field of Search: 356/601, 356/602, 356606-608, 356/614, 356/622, 356/623, 356/4.07, 356/624, 250234-236, 250/559.22, 250/559.24, 250/559.29, 359212-218, 359/204, 359/206
• US Class Current: 356/602
• CPC Class Codes: G01B 11/24 for measuring contours or curvatures

Abstract

A system and method for measuring the profile of an external surface of a part is provided. The system includes a source of light that directs light onto a region of the external surface of the part. The system also includes a linear, light-sensitive sensor, and a lens used to image locations within the region onto the sensor. The source of light and the sensor are located substantially within the same plane such that the sensor detects substantially only light scattered, diffracted, or reflected from the region and travelling substantially within the plane. The system additionally includes a re-positionable mirror that re-directs the light emitted from the source of light to the plurality of locations within the region and re-directs light scattered, diffracted, or reflected from the plurality of locations within the region to the lens and the sensor. An automatic gain control system which controls the output power of the source of light to thereby avoid saturating the exposure of the sensor may also be included in the above system. Further, a spring which functions as a low-pass filter may be used to couple the motor to the shaft of the rotating mirror. In another embodiment, a re-positionable polygon mirror system comprising standoffs with tangs which restrict the outside reflecting mirror surfaces to pre-aligned planes during rotation of the polygon mirror system is disclosed. A fail-safe eye safety technique is also disclosed which controls the power to the source of light. Even further, an optical scanning system is disclosed which utilizes bi-cell photo-detectors to determine the angular position of the source of light with high precision.

Claims

1. A system for measuring the profile of an external surface of a component comprising:

a plurality of profilometry systems surrounding the component, each profilometry system comprising;

a source of light that emits light destined to be incident onto a plurality of locations within a region of an external surface of a component;

a linear, light-sensitive sensor;

a lens used to image the plurality of locations within the region onto said linear, light-sensitive sensor; and

a re-positionable mirror positioned in the light path between the region and said source of light, said lens, and said linear, light-sensitive sensor, wherein said re-positionable mirror re-directs the light emitted from said source of light to said plurality of locations within the region and re-directs light scattered, diffracted, or reflected from said plurality of locations within the region to said lens and said linear, light-sensitive sensor;

wherein said source of light and said linear, light-sensitive sensor are positioned substantially within the same plane such that said linear, light-sensitive sensor detects substantially only light scattered, diffracted, or reflected from the region and traveling substantially within said plane; and

wherein each profilometry system is calibrated in a common coordinate system to produce an integrated profile of the component.