| 摘要 |
Composite cards formed in accordance with the invention include a security layer comprising a hologram or diffraction grating formed at, or in, the center, or core layer, of the card. The hologram may be formed by embossing a designated area of the core layer with a diffraction pattern and depositing a thin layer of metal on the embossed layer. Additional layers may be selectively and symmetrically attached to the top and bottom surfaces of the core layer. A laser may be used to remove selected portions of the metal formed on the embossed layer, at selected stages of forming the card, to impart a selected pattern or information to the holographic region. The cards may be "lasered" when the cards being processed are attached to, and part of, a large sheet of material, whereby the "lasering" of all the cards on the sheet can be done at the same time and relatively inexpensively. Alternatively, each card may be individually "lasered" to produce desired alpha numeric information, bar codes information or a graphic image, after the sheets are die-cut into cards.
|
