Multiple channel interferometric surface contour measurement system

US7751063B2 · kind B2 · utility

Assignee

• Dimensional Photonics International, Inc.

Inventors

• Robert F. Dillon · Stoneham, US
• Neil Judell · Fresno Street, US
• Yi Qian · Nanhu, CN
• Yunqing Zhu · Andover, US
• D. Scott Ackerson · Easton, US
• Gurpreet Singh · Alwar, IN

Key dates

• Filing date: Apr 4, 2006
• Grant date: Jul 6, 2010
• Expiry date: Dec 10, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G01B11/2527
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

Described is a multiple channel interferometric surface contour measurement system. The measurement system includes a multiple channel interferometer projector, a digital camera and a processor. The projector includes two or more interferometer channels. Each channel has an optical axis spatially separate from the optical axes of the other channels. Each channel projects a fringe pattern onto the surface of an object to be measured. Image data for the fringe patterns projected on the object surface are acquired by the digital camera. The processor controls the projection of the fringe patterns of different spatial frequencies, adjusts the phase of each fringe pattern and generates surface contour data in response to the camera image data. The multiple channel interferometric surface contour measurement system provides numerous advantages over conventional single channel interferometric systems, including reduced sensitivity to optical noise, improved stability and increased measurement accuracy.