| 摘要 |
1,165,556. Identity cards, fraud preventing. INTERNATIONAL BUSINESS MACHINES CORP. 11 April, 1967 [2 May, 1966], No. 16423/67. Heading B6A. An identity card or like record structure 10 carrying visible data comprises a diffracting grating 13 superimposed on the data. The grating may be reflecting and the card may be encapsulated with an intimate bond by a transparent material 14 of a similar material to that of the card. The diffracting grating may comprise concentric circles or a complex pattern of curved lines and the data itself may also have an auxiliary diffracting grating. The grating may be on both sides of the card. |
