| 摘要 |
PURPOSE:To detect tracking positions of two electron beams by correcting one vertical deflection position of the 1st and 2nd electron beams from a high voltage current difference of high voltage electrodes, detecting the occurrence of an index stripe and then correcting the other vertical position. CONSTITUTION:After three primary color signals from a decoder 11 are switched 12 at every horizontal scan, they are supplied to mixers 131 and 132, and mixed with signals from pilot generators 141 and 142. Then, after they are transmitted to an image receiving tube 1, they divide given high voltage electrodes Iya and Iyb into two parts, respectively. The high voltage current difference is fetched, thereby executing correction of one vertical deflection position of electron beams b1 and b2. For instance, the beams b1 and b2 are tracked at solid line positions in the 1st field. The vertical position of the beam b1 at the upper side is corrected upward and downward by the signal from the electrodes Iya and Iyb when there are a lot of signals from the electrode Iya and when there are a lot of signals from the electrode Iyb, respectively. On the other hand, the vertical position of the beam b2 at the lower side is corrected upward and downward by the signal from optical indexes Ixa and Ixb when there are a lot of signals from the index Ixb and when there are a lot of signals from the index Ixa, respectively. |
