| 摘要 |
A transparent film for overwrapping. Adhered to the inside of the film is a tear tape. The tear tape bears an indicium which is either hidden and becomes visible by viewing the tear tape through the overwrap film or the appearance of which changes according to the viewing angle. The image on the tear tape may be coded. The overwrap film includes a decoding region which, when superimposed on the tear tape and in registration therewith, reveals the hidden image, or renders the image visible when viewed through the overwrap portion or creates the visual effect of changing the image according to the viewing angle. The decoding region typically comprises a diffraction structure, such as a grating, the characteristics of which, such as its pitch, are complementary with the scrambled or coded image and/or with the pitch of any grid or matrix from which the image is composed. |
