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. 01, 1992
Filed:
Oct. 22, 1990
Lee K Galbraith, Mountain View, CA (US);
Tencor Instruments, Mountain View, CA (US);
Abstract
Flat-field telecentric scan systems, each having a planar scanning reflector situated in a light path and mounted for movement about a scan axis, a concave spherical mirror fixed in a position in the light path an effective focal length away from the scanning reflector to provide a telecentric scan of the light beam, and a lens or mirror with spherical surfaces placed in the light path for providing a flat-field scan. The concave mirror and the additional lens or mirror element may be placed off of the symmetry axis to avoid light obstruction problems provided the tilt of the scanning reflector and the positions and orientations of the concave mirror and additional optical element are selected for a straight-line scan. The additional lens can be either before or after the concave mirror in the light path. It can also be positioned in the path of both light incident on and reflected from the concave mirrors. The lens and concave mirror can be integrally formed by providing a reflective coating on one lens surface. In several embodiments, astigmatism and coma can also be eliminated or minimized.