Device and method for transilluminating a film

An apparatus for transilluminating a film, comprising:

• a light source emitting a light beam for transilluminating the film,
• a film guide for guiding the film so that the light beam transilluminates a section of the film, with the film guide comprising a support constructed for rotation about a rotation axis extending through a center of the support and having a circumferential surface formed rotationally symmetric with respect to the rotation axis,
• a film feed for feeding the film to the film guide, and
• a film removal for removing the film from the film guide,
• wherein the light source is arranged so that the light beam passes through the film when at least a portion of a width of the film is in contact with the circumferential surface along a section of the circumferential surface.

A method for transilluminating a film, comprising the steps of:

• transilluminating the film with a light beam exiting a light exit,
• guiding the film through a film guide to transilluminate with the light beam a section of the film, said film guide comprising a support constructed for rotation about a rotation axis extending through a center of the support and having a circumferential surface formed rotationally symmetric with respect to the rotation axis,
• feeding the film to the film guide with a film feed, and
• removing the film from the film guide with a film removal, wherein the light source is arranged so that the light beam passes through the film when at least a portion of a width of the film is in contact with the circumferential surface along a section of the circumferential surface.