| 摘要 |
PURPOSE:To attain ease of design of stabilization of a bias point of a vertical output amplifier and design of the correction of vertical linearity by disconnecting completely a DC feedback circuit and an AC feedback circuit. CONSTITUTION:An adder circuit 21 is provided between a drive amplifier 2 and a vertical output amplifier 3. Then a parabola form voltage VP obtained at a connecting point P1 is fed to a sample and hold circuit 22, the voltage VP is sampled by a sampling pulse SP obtained at a point of time delayed by a fixed time from a vertical synchronous pulse position and its sampling value is held. The hold voltage is fed to the adder circuit 21 via an LPF23 to form a DC feedback loop thereby stabilizing the bias point of the amplifier 3. Moreover, an AC component obtained at a connecting point P2 is fed to other input of the drive amplifier 2 to form the AC feedback loop thereby correcting the vertical linearity. |
