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:
Aug. 03, 1976
Filed:
Sep. 16, 1974
Simon L Engel, Sunnyvale, CA (US);
Laurence R Peters, Peoria, IL (US);
Caterpillar Tractor Co., Peoria, IL (US);
Abstract
A method of focussing a laser beam having a ring-shaped cross-section to provide a depth of focus for use in cutting and the like, in which the laser beam is converged to and through a focus by reflection from a concave mirror, and in which the diverging laser beam emanating from the focus is passed into an axicon having a substantially cylindrical inner reflective surface for reflecting the diverging laser beams back to an elongated focus. In its apparatus form, focussing means is provided together with a substantially cylindrical axicon positioned to intercept said diverging laser beam and to bring it back to a focus along an extended axis. The cylindrical axicon is preferably formed from a pair of telescoped tubular members having a closed annular space therein for receiving a cooling fluid, with the inner cylinder having its inner surface highly polished and/or coated with some material to minimize the absorption of the incident laser beam.