GB1486714A - Electronic timepieces - Google Patents

Abstract

1486714 Electronic timepieces DAINI SEIKOSHA KK 21 April 1975 [22 April 1974(2) 24 April 1974] 16382/75 Heading G3T An electronic timepiece has an electro-optical time display part of which is digital and at least one of the hours, minutes and seconds display sections comprises electronic display elements arranged to provide a dynamic analogue display. In an embodiment Figs. 1 and 2, the seconds display comprises a ring of LED's. In an embodiment Figs. 6a, 6b (not shown) every fifth display diode comprises GaP and emits green light while the other diodes comprise GaAsP and emit red light. The green diodes have a higher threshold voltage and their refusal to light up gives a warning of end of useful life of the timepiece battery. Flashing of the illuminated diodes is effected by a transistor T, Fig. 2, controlled by an output "C" of a frequency divider DIV. In the embodiment Fig 2 and Fig. 2A (not shown), if it is desired to know the time to seconds a manually operable switch S1 in an electronic switching circuit is closed whereupon the hours and minutes appear digitally and L.E.D's - Do to D 60 are sequentially illuminated until the actual time counted by seconds counter 1 is reached and the appropriate diode flashes until turned OFF. Thus assuming S1 is closed when the time is 12 hours 30 minutes and 20 seconds as in Fig. 1, a switching circuit S2 is caused to pass pulses from an output a of a frequency divider DIV to clock a shift register 14 and a counter 4. In addition a data generating circuit DG applies shift pulses to input D of the shift register 14 so that it starts shifting simultaneously with the commencement of counting by COUNT 4. The register has sixty output terminals the outputs from which sequentially drive light-emitting diodes in a display 16 via a driver 15. When the content of counter 4 becomes equal to that in counter 1 the Q output of a comparator COMP opens S2. Consequently clockpulses to counter 4 and register 14 are stopped and the register stays which its content at 25. In this state diode D 24 is lit and is caused to flash by driving a transistor T from the output c of the divider DIV. The Q output of the comparator also triggers a monostable multi-vibrator M which produces a pulse resetting the counter 4, register 14 switching circuit Sl and a flip-flop (f 2 ) at the output of the comparator so that the flashing diode is extinguished. Instead of L.E.Ds, the display may comprise liquid crystal, electro-chromic, EGCL (electrogenerated chemical luminescent) or PLZT (ceramic material including P b -T i O 2 , P b Z r O 2 , La) elements. An arrangement Fig. 5 (not shown) is used to indicate elapsed time.