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:
Dec. 02, 2008
Filed:
Nov. 09, 2005
Dong-woon Park, Anyang-si, KR;
Dong-Woon Park, Anyang-si, KR;
Samsung Electronics Co., Ltd., Suwon-si, Gyeonggi-do, KR;
Abstract
An auto focus system includes a stage on which a substrate is mounted, light sources that irradiate the substrate with a plurality of focus beams directed towards the substrate at different angles, sensors that detect the focus beams reflected from the substrate, and a controller that determines the relative location of a surface of the substrate according to the locations at which the focus beams are detected by the sensors and positions the substrate accordingly. To this end, the controller performs calculations that are free from the influence of variations in the refractive index of the medium through which the focus beams propagate to the surface of the substrate. Therefore, the autofocus process is carried out with a high degree of precision.