Method and device for detecting faults in flat glass, especially drips, threads and lines

US6570651B1 · kind B1 · utility

Assignee

• Lasor AG · DE

Inventors

• Wolfgang Haubold · Bielefeld, DE
• Josef Droste · Glandorf, DE
• Edmund Paneff · Bielefeld, DE

Key dates

• Filing date: Sep 25, 2000
• Grant date: May 27, 2003
• Expiry date: Sep 25, 2020

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N21/896
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention relates to a method of determining the optical quality of and detecting faults in flat glass (2) and other transparent materials, especially in float glass, wherein a video camera (1) is arranged to monitor an illuminating device (3) either through the glass (2) or by observing the reflection thereof, the focus being on the glass (2) and the sheet, respectively, and the video camera (1) generates signals in dependence on the quality of the glass (2) and these signals are evaluated, wherein use is made of at least one illuminating device (3), comprising a pattern (4) of adjacent partial portions (5a,5b) alternately different at least in color and/or in intensity, an observation spot of the video camera (1) picks up the pattern (4), two video signals U1,U2 are assigned to the signal of the pattern (4), and a change of the intensity of the video signals U1,U2 is used for evaluating the quality of the glass (2) and the sheet, respectively.