| 摘要 |
1,274,238. Identity cards. SAAB-SCANIA A.B. 23 June, 1969 [24 June, 1968], No. 31499/69. Heading B6A. An identity card or like document 1 such as a passport includes an area of randomly distributed particulate material 4 to form a random pattern 7, Fig. 2, which is not discernable to the unaided eye, the material being such as to be detectable by means yielding an electric signal. Finely-powdered magnetic material may be employed, so that if, after the material has been magnetized, the card is passed under a magnetic reading head scanning, for example, two straight lines a, b, electrical signals are produced depending on the random pattern. These signals are amplified and stored in a memory device. Two kinds of material having different characteristics may be employed. To prove the identity of the person concerned, the card must be scanned in a similar manner by a reader at the place where the card is presented and this reader must be connected to the memory device. The card 1 may be made of paper reinforced by plastic or of metal with or without a plastic covering. The material 4 may be deposited directly on the card or indirectly on a transparent film 5 which is attached to the card, and may cover a photograph 2 mounted on the card. An area of the card separate from the patterned area may contain the owner's sig. nature aud magnetically-readable numerals. To obtain more sharply defined signals, the patterned surface may be divided into squares by means of a screen pattern or by scratching away material along the sides of the squares. As an alternative to the squares, a strip of aluminium or aluminium alloy has a coating of a crackable lacquer applied thereto, the aluminium is stretched to form cracks in the lacquer, and the powdered material is then applied to the cracks. Two such strips, one superposed on the other, may be employed. Instead of ferro-magnetic material, fluorescent or resistively or capacitively detectable material may be used. |
