Patent attributes
An illuminator emits light obliquely to an end of an adhesive film. A CCD camera is provided in a direction perpendicular to the adhesive film to capture an image of the light reflected irregularly from the end of the adhesive film. A black plate is provided on a back side of the adhesive film. In the image obtained by the CCD camera, therefore, only the end of the adhesive film is displayed whitely in a line shape. A position of the adhesive film is determined based on a line corresponding to the end of the adhesive film. Since the light reflected from the end of the adhesive film is utilized, the position of the adhesive film can be determined accurately irrespective of a color of the adhesive film, a color of a base film to which the adhesive film is joined, and a depth of each color.