| 摘要 |
<p>The television set has a brightness control device for stabilizing the brightness of a cold cathode tube. The brightness control device includes a current value calculating device for generating a multiplication result from a ratio of an interval during which the output of a Pi-filter is higher than a threshold, and a period during which the output of the filter changes, and from the output of the filter during an interval during which the output is higher than the threshold, as an average current level. The duty ratio of an intermittent control signal from a duty control device is set to a value corresponding to the difference between the average current value and a target value. An independent claim is included for a cold cathode tube dimmer.</p> |
