JPS6217428B

• Main Author: MORITA KATSUMI
• Format: Patent
• Language: English
• Published: 17.04.1987
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

PURPOSE:To obtain the picture of high quality by uniformly suppressing fog over the entire screen, through the change of profile compensation amount at the center and the circumference of the screen. CONSTITUTION:The vertical profile compensation signal is formed with the 1H delay lines 31 and 32, addition circuit 33, and subtraction circuit 34 from the video signal fed to the input terminal 30. Further, the horizontal profile compensation signal is made by the delay lines 38, 39, addition circuit 40, and subtraction circuit 41. The both signals are added at the addition circuit 35 to obtain the profile compensation signal g. Further, the parabola waveforms h, i of horizontal and vertical period are obtained at the parabola production circuits 44 and 45, the signal g is modulated at the modulation circuit 36 for the waveform h to obtan the output of the waveform j. This output j is modulated by the modulation circuit 37 at the signal i to obtain the profile compensation signal k greater in the amplitude of the circumference than the center of screen. By adjusting the amplitude of the signals h and i, the amount of compensation at the center and circumference toward horizontal and vertical direction can be changed. Thus, the video signal with high quality in profile compensation can be obtained from the output terminal 47.