| 摘要 |
PURPOSE:To reproduce hue with fidelity by providing a changeover switch inputting selectively a composite luminance signal, a composite color signal and an output signal from a test pattern generating circuit to a primary color signal generating circuit and a white level adjusting variable resistor so as to allow the primary color signal generator side only to conduct the white level adjustment. CONSTITUTION:Three moving contacts of a changeover switch 19 are connected respectively to terminals 21b, 21d, 21f when a control signal fed to an input terminal 20 goes to an H level. Thus, a DC voltage is fed to a black/white test pattern generating circuit 22 via a terminal 21f. A signal,e.g., a primary color signal R corresponding to the output signal of the black/white test pattern generating circuit 22 is outputted from an output terminal 7 of a primary color signal generating circuit 4 and inputted to an amplifier transistor 25. The white level adjustment at a dark picture is applied to the primarycolor signal R by using a variable resistor 26 and the white level adjustment at a light picture is applied by using the variable resistor 27. Thus, the re-adjustment of the white level at the receiver 2 is not required and the picture is reproduced by a normal hue.
|
