| 摘要 |
<p>In order to extend the life of a light source (100) such as a CCFL or the like being used in backlighting system for an LCD, the present invention includes an optical sensing circuit, an amplification circuit, an averaging circuit, a comparator, a controller (108), and inverter dimmer circuit (109). The initial power applied to the light source (100) is limited to a value which is less than its maximum rate power thus reducing the rate of light source degradation geometrically. The brightness of the light source (100) is monitored using a photosensitive element/sensor (104) and as the brightness reduces with the passing of time, the power that is supplied to the light source (100) is gradually increased. This both prolongs the life of the light source (100) and obviates any perceivable reduction in display brightness.</p> |
