Method and system for automatically visually inspecting an article

US4928313A · kind A · utility

Assignee

• Synthetic Vision Systems, Inc. · US

Inventors

• Patrick Leonard · Ann Arbor, US
• Donald J. Svetkoff · Ann Arbor, US
• Robert W. Kelley · Ann Arbor, US
• Donald K. Rohrer · Iron River, US
• E. North Coleman, Jr. · Ortonville, US

Key dates

• Filing date: May 19, 1989
• Grant date: May 22, 1990
• Expiry date: May 19, 2009

Classification

• Technology area (CPC G): Physics
• CPC primary: G06T2207/30148
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method and system are disclosed for automatically visually inspecting an article such as an electronic circuit wherein both reference and non-reference algorithms are utilized to detect circuit defects. The system includes a pipelined cellular image processor which is utilized to implement the non-reference algorithm and an arithmetic logic unit (ALU) is coupled to the output of the cellular image processor to perform the reference method. The non-reference method includes a spaces and traces algorithm and the reference method includes a topology matching algorithm. The system also includes an algorithm for locating and gauging critical areas of the circuit with sub-pixel accuracy. The cellular image processor is supported by a matched host image processor system