The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 27, 2004
Filed:
Oct. 11, 2001
Makoto Yonezawa, Yokohama, JP;
Lasertec Corporation, Yokohama, JP;
Abstract
An image pickup apparatus having a higher resolution and S/N ratio by use of a line confocal optical system and a photomask defect inspection system using the same. A first spatial filter having a plurality of slits extending in a direction perpendicular to a direction of movement of a sample is arranged in front of a light source and illuminates the sample with lines of light. The transmitted light or reflected light from the sample is received by an image sensor through a second spatial filter having slits substantially the same as the first spatial filter. Each image sensor has light receiving elements arranged in a two-dimensional array and transfers charges stored in the light receiving elements for each line. A charge transfer speed of the image sensors and speed of movement of the sample are linked with each other. The sample is illuminated a plurality of times, the charge produced by each illumination is accumulated, and the cumulative charge is output. By configuring the apparatus in this way, a line confocal optical system is formed, a greater amount of charge is built up by the illumination by the plurality of lines of light, and the S/N ratio is remarkably improved.