| 摘要 |
<p>In computer monitors having a picture tube, it may be seen that a small white picture area is displayed with the same white value as a large white picture area. If it were intended to achieve the same result for a television receiver with a picture tube, a voltage supply is necessary in which the power is permitted to fluctuate between 60 and 300 watts given a stable output voltage. On account of the lower luminous efficiency, this effect would have considerably intensified repercussions on the power consumption of plasma screens. The invention is based on the object of providing a simplified method for regulating the picture power in a television receiver. The method according to the invention is distinguished by the following steps. The power consumption of the picture power is obtained by the video voltage R, G, B. The video voltage is converted into an information item which is then a measure of the picture power. This information item is subsequently fed to two regulating loops. In the fast loop, the value of the picture power in a short period of time is averaged. The fast loop, that is to say the fast regulation, ensures fast falling of the amplitude of the picture power for the case where a large number of lines are displayed completely white. This serves to ensure that the power consumption, which is defined beforehand, is not exceeded.</p> |
