Inspection of float glass using a novel retroreflective laser scanning system

Jonathan D. Holmes

doi:10.1117/12.277748

7 July 1997 Inspection of float glass using a novel retroreflective laser scanning system

Jonathan D. Holmes

Proceedings Volume 3131, Optical Scanning Systems: Design and Applications; (1997) https://doi.org/10.1117/12.277748
Event: Optical Science, Engineering and Instrumentation '97, 1997, San Diego, CA, United States

Abstract

Since 1988, Image Automation has marketed a float glass inspection system using a novel retro-reflective laser scanning system. The (patented) instrument scans a laser beam by use of a polygon through the glass onto a retro-reflective screen, and collects the retro-reflected light off the polygon, such that a stationary image of the moving spot on the screen is produced. The spot image is then analyzed for optical effects introduced by defects within the glass, which typically distort and attenuate the scanned laser beam, by use of suitable detectors. The inspection system processing provides output of defect size, shape and severity, to the factory network for use in rejection or sorting of glass plates to the end customer. This paper briefly describes the principles of operation, the system architecture, and limitations to sensitivity and measurement repeatability. New instruments based on the retro-reflective scanning method have recently been developed. The principles and implementation are described. They include: (1) Simultaneous detection of defects within the glass and defects in a mirror coating on the glass surface using polarized light. (2) A novel distortion detector for very dark glass. (3) Measurement of optical quality (flatness/refractive homogeneity) of the glass using a position sensitive detector.

Citation Download Citation

Jonathan D. Holmes "Inspection of float glass using a novel retroreflective laser scanning system", Proc. SPIE 3131, Optical Scanning Systems: Design and Applications, (7 July 1997); https://doi.org/10.1117/12.277748

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available