Apparatus, system and method for checking film for defects

A film defect check system for checking a film continuously conveyed for optical defects, said system comprising a plurality of film defect checking apparatuses placed in a path through which the film is conveyed, each of said film defect checking apparatuses having:

• a pair of polarizers placed on opposite sides of a film surface of the film to be checked with respect to said optical defects, said polarizers being parallel to the film;
• an illumination light source placed outside said pair of polarizers, said illumination light source projecting light onto the film through a first polarizer of said pair of polarizers;
• light receiving unit placed outside said pair of polarizers and opposite from a placed position of said illumination light source, said light receiving unit receiving light transmitted through a second polarizer of said polarizers;
• and
• a correction film having substantially birefringent characteristics identical to birefringent characteristics of a portion of the film having no optical defects, a direction in which said correction film is to be positioned being previously set according to the birefringent characteristics of the film, said correction film being placed in one of two spaces between said pair of polarizers and the film parallel to the film,
• wherein directions of polarizing transmission axes of said pairs of polarizers of said plurality of film defect checking apparatuses are respectively set at different angles from a direction of conveyance of the film continuously conveyed.