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:
Jun. 04, 2002
Filed:
Mar. 16, 2000
Kiyokazu Mori, Kanagawa, JP;
Yasuo Kojima, Kanagawa, JP;
Nissan Motor Co., Ltd., Kanagawa, JP;
Abstract
In a method for determining a quality of welding at a weld between working material pieces, an emission intensity of a visible light emitted from the weld during a laser welding using a laser device emitting a laser having a wavelength falling in a range of the wavelengths of near infra-red rays is detected, a first detection signal indicating the light emission intensity of the visible light is outputted, an intensity of a reflected light of the laser from the weld during the laser welding is detected, a second detection signal indicating the light intensity of the reflected light is outputted, frequencies of the first and second detection signals are analyzed and a determination is made whether a result of the laser welding falls in a favorable range of welding and an identification of a cause of welding failure of the weld if the determination that the result of the laser welding falls out of the favorable range is made on the basis of signal intensities of a first frequency component of each of the first and second detection signals lower than an arbitrary frequency in a range from 50 Hz to 200 Hz and of a second frequency component of each of the first and second detection signals higher than the arbitrary frequency.