| 摘要 |
PURPOSE:To prevent occurrence of jitter without using a special deflection correction circuit by vertical-deflection-scanning a picture tube by a vertical synchronizing signal, by delaying an image signal to be supplied to the picture tube of each field for a fixed time and maintaining an inter race ratio at a constant ratio. CONSTITUTION:A television receiver controls read out timing from memories 6a and 6b and obtains field two-fold image signal SVN' as shown in Fig.B from a switch circuit 6d. That is, an alternate long and short dash line in Fig.B denotes a signal missing part. From the memory 6a, the second F1 field is delayed for 0.25H and read and the first F2 field is delayed for 0.25H and read from the memory 6b. The signal SVN' is supplied to a horizontal synchronizing divider 14 and then supplied to a deflection coil 13 as a horizontal synchronizing signal PHN'. Fig.A shows writing-in condition and the arrow shows the position of a vertical synchronizing signal PV. The said arrow shows an output signal position of a multiplying device 11 and its period is equal. Therefore, each vertical period is equal and a horizontal deflection current waveform prepared by parabolic wave current of vertical synchronizing frequency being overlapped is equal, thereby occurring no jitter on the screen. |
