| 摘要 |
PURPOSE:To reversibly display and erase visible information such as characters, numerals, figure, etc. having high reliability in a simple and inexpensive structure by disposing an invisible information record and a rewritable visible information display on a card board mainly made of specific polymer nematic liquid crystal. CONSTITUTION:An invisible information record 2 is disposed on the front face of a card 1, and a visible information display 3 mainly made of a polymer nematic liquid crystal is disposed on the rear face. The display 3 employs a polymer nematic liquid crystal in which isotropic transferring temperature Tcl for selectively taking a transparent state and an opaque state at an ambient temperature by reversibly dislocating its state by light or heat is presented at higher temperature side from a glass transition temperature Tg. If heat exceeding the temperature Tcl is applied to the display 3 by a thermal head or a light irradiation, information recorded on the record 2 is displayed. Similarly, after it is heated to the temperature Tcl by the heat or light radiation, it is erased by annealing. The display and the erasure can be reversibly conducted repeatedly any times. |
