| 摘要 |
PURPOSE:To correct the trapezoidal deflection and horizontal linear change of an image projected on a screen without using auxiliary means other than a deflecting yoke by a method wherein a magnetic field is generated in the direction of the tube axis of a projection CRT by providing a solenoid-like auxiliary coil in the vertical deflecting coil of the deflecting yoke. CONSTITUTION:A solenoid-like auxiliary coil 14 is wound on the fluorescent surface of a deflecting yoke 14 and connected to a vertical deflecting coil 15 in series or parallel. A horizontal deflecting coil 16 is composed of a pair of half bodies 16a, 16b of a coil in a manner that these bodies face each other. Use of a combination of the auxiliary coil 14 and vertical deflecting coil 15 makes it possible to offset arrow-shaped deflections regarding vertical lines of the raster on a projection CRT and, as to horizontal lines of the raster, to form an image in which trapezoidal deflections are allowed to strengthen each other. Moreover, by adding the horizontal deflecting coil to the above combination, it is possible to form trapezoidal deflection in the same direction as that of a desired raster shape and horizontal linear change. |
