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:
Apr. 07, 1987
Filed:
Feb. 05, 1985
Massimo Cestaro, Vasto, IT;
Ciro Paudice, Vasto, IT;
Societa Italiana Vetro-Siv-S.p.A., Chieti, IT;
Abstract
An apparatus used directly on a flat sheet of transparent material, especially tempered glass, for simultaneous measurement of sign and amplitude of stress across the section of said glass sheet using scattered light. The apparatus allows reliable and repetitive measurements independently of the operator's subjective observations, since the data is read through an automatic system. The apparatus has a Helium-Neon (He-Ne) laser source of 1 to 5 mW, whose light beam is linearly polarized, then modulated with a series of wave plates (2,2', 2'), then passed through a collimator (3) and subsequently made to strike a prism (4) optically coupled with the glass sheet (V) being tested. Variation in intensity of the interference fringes is revealed by a TV camera (5) having a macrophotographic lens system (5') which focusses the scattered light on a solid-state array photodetector (5'). The photosensitive zone of the detector is positioned to detect intensity of the scattered light along path (BC) of the laser beam through the section of the glass sheet (V). An electronic circuit can thus convert the video signals transmitted by TV camera ( 5).