| 摘要 |
PURPOSE: To reduce the variation in luminance owing to production variance or difference in quality, etc., of a CFL tube by making power consumption in the CFL tube constant. CONSTITUTION: The gain of an amplifier A2 in a current detecting circuit is changed when an output voltage value of a DC/DC converter is larger than a fixed value, and is smaller than this value, thus obtaining two voltage-current characteristics. Consequently, the voltage-current characteristics can be approximate to a characteristic of VE×I=W (W = a constant value), and hence the power consumption in the CFL tube is controllable to be constant. |
