| 摘要 |
<p>A projection television receiver has a cathode ray tube (24) with an electron gun for emitting an electron beam incident on a screen (22), an electromagnetic deflection yoke (L1, L2, L3) and an electromagnetic focusing coil (L4, L5, L6, L7, L8, L9). A horizontal deflection driving circuit (Q1) is coupled to a horizontal deflection coil (L4, L5, L6) and provides deflection current (iH) to the horizontal deflection coil for scanning the beam repetitively on the screen. The focusing coil is driven from a current step-down transformer (X2) having a primary winding (W1) coupled in series with the horizontal deflection coil. A secondary winding (W2) of the transformer is coupled to the focusing coil for driving the focusing coil with a horizontal rate parabolic current (If). A capacitor-resistor circuit (C1, R1) is coupled in parallel with the focusing coil and with the secondary winding of the transformer for adjusting a phase relationship of the parabolic current relative to the horizontal deflection current and for adjusting the amplitude of the parabolic current. <IMAGE></p> |
