PURPOSE: To facilitate ready operation of a digital display electronic wrist watch and prevent the watch from erroneously desplaying by detecting that predetermined time is elapsed after a display selection switch is operated to thereby automatically reset it to the state before the switch is operated.
CONSTITUTION: A T flip-flop 16 opens an AND gate 18 by operating a display switch 11 to thereby generate hour and minute display signals 24. An AND gate 19 is opened by operating the switch 11 second times to thereby generate day and day- of-the week display signal 25. After predetermined time is elapsed, a watch is reset to hour and minute display signals 24 by a timer 15 and S-R flip-flop 17. When correction switches 12, 13 are operated while hour and minute display or day and day-of-the week display lamps are energized, hour correction signal 26, day correction signal 27, minute correction signal 28 and day-of-the week signal 29 are applied to a watch controller to thus correct the present display on the watch.
JPS4719868A |
US3672155A | 1972-06-27 |