GB1486696A - Watch having orientation controlled display actuator with delay - Google Patents

Abstract

1486696 Electronic watches TEXAS INSTRUMENTS Inc 18 March 1975 [19 March 1974] 11205/75 Heading G3T An electronic watch with electro-optical display, e.g. L.E.D.s, liquid crystal, electro-chromic, is provided with a display actuation switch responsive to the orientation of the watch and time delay circuitry which prevents actuation of the display unless the switch has been in its closed position for at least a predetermined period, e.g. ¥ second. Figs. 3a and 3b show one embodiment of the switch, which comprises a metal ball 5, e.g. of gold plated nickel, moveable by gravity in a triangular cavity and which bridges contacts 6a, 6b (not shown) when the watch is held in a predetermined orientation. Other embodiments are illustrated in Figs. 3c to 3g and 4a and 4b (not shown). The delay circuitry 20, Fig. 5a, receives a logic "1" signal from the attitude responsive switch 4 when closed. If the switch is maintained closed for more than ¥ second then the delay circuitry emits a single 2¢ second pulse from flip-flop 33, and this causes activation of the minutes and hours display for 1“ seconds and then the seconds for 1“ seconds. The display is automatically terminated 3“ seconds after closure of the gravity switch 4. The pulse in line 34 from flip-flop 33 is initiated by the output of an AND gate 30 having a 4Hz input and a 2Hz input from stages 26, 27 respectively of the delay circuit frequency divider and a "1" input from the gravity switch. The pulse is terminated by a signal on a line 36 from an AND gate 35 which resets the flip-flop 33, a flip-flop 24 and the divider chain 26-29. In an alternative delay circuit Fig 5b (not shown), the display is not terminated after 3“ seconds but is maintained for as long as the switch 4 is actuated thus permitting the seconds display to continue as desired. The timing and display drive circuitry of the timepiece is illustrated in Fig. 1 (not shown). De-coder (724) operates digits drivers with a 23-24% duty cycle so that only one digit is activated at a time. Arrangements for setting the display to the correct time are also described. A manual push-button display switch is also provided.