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:
Oct. 05, 1999
Filed:
Oct. 23, 1997
Mau-Song Chou, Rancho Palos Verdes, CA (US);
Christopher C Shih, Torrance, CA (US);
Bryan W Shirk, Mesa, AZ (US);
TRW Inc., Redondo Beach, CA (US);
Abstract
A method and apparatus for monitoring the quality of a laser process such as a welding process comprises monitoring the light emitted from the weld plasma above the surface of the workpiece being irradiated by the laser beam. The size of the plasma is determined from the light emission and compared to a predetermined value of the size as determined under process and workpiece conditions that produce welds of acceptable quality. Variations of the monitored plasma size greater than a preselected value can represent unacceptable welds. Such variations can be caused by changes in the laser beam power, the workpiece speed, laser focusing problems, insufficient shield gas flow, workpiece deformation and weld contamination. The process monitors the light emission from a selected range of wavelengths that correspond to the major emission peaks of the light spectrum. The process enables in-process control.