| 摘要 |
<p>PURPOSE:To indicate a warning of an abnormal temperature increase by a method wherein a liquid crystal material changing its color in accordance with a temperature change is applied to the surface of an IC card incorporating a semiconductor element and other circuit elements. CONSTITUTION:An inner temperature of an IC card is increased by a heat generation of a semiconductor element incorporated in the IC card caused by a power loss. Furthermore, the surface temperature of a metallic panel 4 is also increased. A liquid crystal material 7 changing its color in accordance with the temperature of the metallic panel 4 when the inner temperature of the IC card reaches a rating temperature of the semiconductor inside the card is applied to the surface of the metallic panel 4. In this manner, a warning of an abnormal temperature change of the surface of the IC card can be indicated by a color change of the liquid crystal material 7. A warning against an abnormal ambient temperature increase outside the IC card caused by other factors can be similarly indicated, and a malfunction of the system can be prevented from occurring.</p> |
