| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a lighting device and lighting fixture whose size avoids enlarging, although they can operate in accordance with the length of an off period. <P>SOLUTION: The lighting device and fixture comprise a timer capacitor C3 to be charged only during an on period for which electric power is applied to a lighting circuit for lighting a light source and the light source is lit and a time constant circuit 6 having a discharge resistor R2 connected between both ends of the timer capacitor C3. A control circuit 3 for controlling the lighting circuit differentiates the control content during the on period in response to whether or not the voltage Vc across the timer capacitor C3 at the start point of the on period is higher than a prescribed changing voltage. The timer capacitor C3, assuming the case where an oscillator and counter are used in timing the length of an off period, can have less capacity and a smaller size than the capacitor required for the power supply of the oscillator and counter during the off period. In short, enlarging in size is avoided as compared to the case of using the oscillator and counter in timing the length of the off period. <P>COPYRIGHT: (C)2012,JPO&INPIT |
