| 摘要 |
PROBLEM TO BE SOLVED: To easily recognize the presence of a magnetic card even when the dark color side of the card is turned upward in a dark place, by forming a luminous display part on the dark color side of the card by means of the luminous ink. SOLUTION: The necessary items consisting of words including 'parking ticket', etc., are shown on the surface side of a magnetic card 1. Meanwhile, a magnetic surface 3 is formed in a whole area of the rear side of the card 1 in a dark color. A recording area 4 is secured at a prescribed position on the surface 3 together with a luminous display part 5 formed by means of the luminous ink. The part 5 consists of symbols such as sentences, words, patterns, etc., which are printed in the luminous ink. The luminous ink absorbs and stores the energy of the light such as the sunlight, fluorescent light, etc., that has the wavelength of about 350 nm when the ink is irradiated by such light longer than a fixed time. Thus, the luminous ink can continuously emit the visible light having wavelength of 500 to 600 nm in a dark place for a prescribed period of time. |
