| 摘要 |
PROBLEM TO BE SOLVED: To provide a protective sheet hardly broken even if used for a long period of time. SOLUTION: By making the protective sheet 210 in a double-layer structure equipped with a first layer 211 including a skin layer and a second layer 212 including, for instance, nonwoven fabric, durability at long-time use and durability against keyboard strokes is improved as compared with a one-layer-structure one. Therefore, fatigue of the protective sheet 210 is little even if keyboards 5 loading the protective sheet 210 are repeatedly pressed, and damage due to breaking is alleviated. Through improvement of strength of the protective sheet 210, liquid or dust is prevented from entering into a rear side of keytops. COPYRIGHT: (C)2011,JPO&INPIT |
