| 摘要 |
PURPOSE:To improve remarkably reliability by storing preliminarily the stop of a timepiece owing to the lack of the quantity of light and stopping the operation of a time display device even when the light is made incident again thereby giving warning to the wearer. CONSTITUTION:The output voltage VS of a power source circuit 54 decreases when the absent state of incident light to a solar battery 17 continues. The operation of a clocking circuit 10 is then stopped and a voltage detecting circuit 22 operates to output a warning signal EBD. A non-volatile memory 24 is put into the writing state by a driving circuit 25 and a state setting signal VF is supplied to a display prohibiting circuit 59, by which an RS.FF57 is reset. The voltage VS is increased by the reincidence of the light. Then the circuit 10 restarts the operation and generates a clock signal Pt but the RS.FF57 of a display inhibition circuit 59 is held reset by the signal VF from the memory 24 and therefore the signal Pt is blocked by an AND gate 58 and the time display operation by a hand operation display device 16 is prohibited. |
