Patent ID: 7199386
Filing Date: 2007-04-03
Classification: G01N

Abstract:
1. A system for detecting defects in a light-management film, the film having a first side and a second side, comprising: a first light source configured to emit light onto the first side of the film in a first predetermined region of the film; a second light source configured to emit light onto the second side of the film in the first predetermined region of the film; a first camera configured to receive a first portion of light reflected from the first predetermined region of film from the first light source and a second portion of the light propagating through the film from the second light source, the first camera further configured to generate a first image from the first and second portions of light; a third light source configured to emit light onto the second side in a second predetermined region of the film; a fourth light source configured to emit light onto the first side of the light-management film in the second predetermined region of the film; a second camera configured to receive a third portion of light reflected from the second predetermined region of film from the third light source and a fourth portion of the light propagating through the film from the fourth light source, the second camera further configured to generate a second image from the third and fourth portions of light; and a signal-processing device operably coupled to the first and second cameras, the signal-processing device configured to provide a summed image by summing the first and second images, the signal-processing device further configured to detect at least one defect in the film based on the summed image.