| 摘要 |
The present invention relates to a method of setting the second-grid voltage of a television cathode ray tube so as to fix the maximum black level, this television set comprising an integrated circuit for processing the video signal (10) supplying control signals for the cathodes of the tube to a drive amplifier (13). This method consists in picking up, from the integrated circuit, the control signals (11-1, 11-2, 11-3) in conditions corresponding to the black level; determining the control signal for which the black level corresponds to an extreme voltage; comparing this extreme voltage with a reference voltage (ve) corresponding, in the ratio of the gain of the drive amplifier, to the extinction voltage sought for the television tube; and controlling the circuit for applying the voltage to the second grid as a function of the result of the comparison. <IMAGE>
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