| 摘要 |
For use in access-control apparatus, the character-to-key assignment in a keypad for inputting an authorization or identification code is changed at specified events so as to scroll the array of assigned characters. The security offered by the device against the inputted characters being surreptitiously "read" by observation of the keys actuated is thereby enhanced but without the operating difficulties encountered with keypads in which the character-to-key assignment is changed on a purely random basis. |
