| 摘要 |
<p>A method of encoding data is for cards, such as identity cards, entry cards and the like, using conducting metallic film areas of slightly different shapes and a method prints such information and reads it from the cards. The method is similar and less expensive than that which entails etching the metal film from a card surface. The metallic film areas are essentially ring shaped (3) with one section of the ring narrower than the others (4). This narrow section may be interrupted by a narrow gap (5) or not according to the binary information stored. This is done by a head consisting of a electrode pair which discharge a capacitance through the metal film if a gap is to be created, and produce that gap simply by melting the film. The reading head consists of a double coil coupled across the card, and film, so that a much reduced coupling exists if there is no gap in the film.</p> |
