| 摘要 |
PURPOSE:To display the video of different aspect ratio on a whole display screen while minimizing drop-out and distortion by displaying the video by distorting it so that magnification ratio or reduction ratio changes uniformly in respect of, at least, one of a vertical direction and a horizontal direction. CONSTITUTION:This display device is for a three-tube type projection television receiver, and it projects the video of the aspect ratio 4:3 on a screen of the aspect ratio 16:10.5. By synthesizing a pseudo sine wave signal to a saw tooth wave signal V1 issued from a vertical oscillation circuit 8 by a synthesis circuit 9, the waveform of the saw-tooth wave signal V1 is blunted at its upper and lower parts. A vertical deflecting current flows in vertical deflecting coils 3VDY to 5VDY in conformity with the saw-tooth wave signal blunted in this way. Thus, scanning speed at the upper and lower parts of the screen of CRTs 3 to 5 becomes slow, and as for the video, the horizontal lines of equal intervals in an original picture, for instance, come to shrink in the vertical direction at the upper and lower parts of the screen. |
