| 摘要 |
PURPOSE:To reduce current consumption by setting the luminosity and lighting time of the lighting lamp of an electronic timepiece. CONSTITUTION:When an external switch 1 for lamp lighting and an external switch 14 for setting luminousity are turned on at the same time, the output terminal 12a of an NOR latch circuit 12 is held at a level L and the base current of a bipolar transistor 4 for current amplification is greater than that when the output terminal 12a of the NOR latch circuit 12 is held at a level H by turning on the external switch 1 and an external switch 13 for setting luminousity at the same time, giving luminousity more than that during lamp lighting. Further, a lighting lamp 2 is driven with pulses, whose duty ratio is varied to control the luminousity of the lighting lamp favorably. |
