| 摘要 |
PURPOSE:To lessen the deterioration of the picture quality as well as the occurrence of the moire by piling the rectangular wave type current which reverses every 1H- period onto the vertical deflecting current and then shifting the amplitude of the piled rectangular wave type current on the screen by + or -1/4 times as much as the scanning line space. CONSTITUTION:Synchronous isolator circuit 1 extracts the horizontal and vertical synchronous signals from the received composite video signals, supplies the horizontal synchronous signal to horizontal deflecting circuit 2, and sends the output of circuit 2 to horizontal deflecting yoke. On the other hand, vertical synchronus signal is supplied to vertical deflecting circuit 3, and the output is connected to vertical deflecting yoke to give the vertical scanning to the electron beam of picture tube 6. Here, the output of the circuit is amplified 5 via FF4 and then supplied to circuit 3, and the rectangular wave type current reversing every 1H-period is piled on the vertical deflecting current. This piled rectangular wave type current amplitude is set so that it may shift on the screen by + or -1/4 times as much as the scanning line space. As a result, the deterioration of the picture quality can be lessened with the reduced occurrence of the moire. |
