Dismiss
The InnovationQ application will be updated on Sunday, May 31st from 10am-noon ET. You may experience brief service interruptions during that time.
Browse Prior Art Database

Optical Inspection System

IP.com Disclosure Number: IPCOM000042530D
Original Publication Date: 1984-May-01
Included in the Prior Art Database: 2005-Feb-04

Publishing Venue

IBM

Related People

Authors:
Tsukamoto, K [+details]

Abstract

The system serves to automatically detect defects on a photomask, a printed-circuit board or the like which has printed patterns thereon. In this system, the defects on the printed patterns are detected by the fact that the printed patterns have regular outlines and the defects have irregular outlines. This system has two or three linear image sensor arrays which scan the patterns. A logical exclusive OR of the outputs of two of the arrays is taken. The signal widths of the exclusive OR represent the edges of the patterns and of the defects. The signal widths of the exclusive OR caused by the patterns have predetermined values. On the contrary, the signal widths of the exclusive OR caused by the defects are not equal to the predetermined values.