| 摘要 |
PURPOSE:To prevent the focus deterioration of a CRT, by connecting a transistor (TR) in parallel between the base and the collector of a TR provided in a picture signal processing circuit to obtain an overload detection signal. CONSTITUTION:A luminance signal - Y supplied to a TR1 is supplied to an output TR15 to be turned into an R signal. This R signal is supplied to a CRT18 to reproduce a color picture. In this case, the high range of the R signal is compensated by an inductance 5 plus TRs 1 and 4, and accordingly the supplied - Y signal is supplied to a TR15 with its high range part emphasized according to the rise of frequency to compensate the attenuation at a high range that is caused by a stray capacitance 17. When the collector voltage of the TR4 drops to a level near zero, a detecting TR7 conducts. Thus a detection signal production control TR10 conducts to give the short circuit to the inductance 5. This prevents the supply of an excessive amount of current to the CRT18. |
