| 摘要 |
PURPOSE: To correct a convergence error by transformation into an ITC and lateral trapezoidal strain by oscillating work by respectively changing electric currents flowing to vertical deflection coils and coma correcting coils by a variable resistor. CONSTITUTION: (1 and 1A) are a pair of left and right E-shaped cores, and wound coma correcting coils which generate a pin cushion type magnetic field in the same direction with a vertical deflecting magnetic field between respective upper leg parts 2L and 2R and lower leg parts 4L and 4R and generate a barrel type magnetic field in the inverse direction of the vertical deflecting magnetic field between intermediate leg parts 3L and 3R, are connected in series to each other, and are connected in series to a pair of left and right vertical deflection coils connected in series to each other, and are arranged in the bilateral symmetry in the rear of a deflection device, and a variable resistor is connected in parallel to the left and right vertical deflection coils, and the variable resistor is connected in parallel to the left and right coma correcting coils, and an electric current flowing to the left and right deflection coils is changed, and lateral trapezoidal strain is corrected. Therefore, deteriorating convergence on the vertical axis is corrected by changing an electric current flowing to the coma correcting coils. |
