| 摘要 |
PURPOSE:To keep secrecy of the set digital data by actuating a display reset means with operations of plural specific control means having each proper function. CONSTITUTION:When a switch-off mode is reset to a normal mode, two mode switch keys are operated at the same time. This operating state must be continued for a prescribed time, e.g., four seconds. Such operating rule is scarcely detected by an outside even though the outsider operates various keys at random. That is, the leak of secrecy and an unexpected change can be completely prevented for the set digital data. |
