| 摘要 |
1,268,023. Electron beam magnetic deflecting apparatus; electric coils; printed circuits. MARCONI CO. Ltd. 21 Sept., 1970 [20 Feb., 1970], No. 8166/70. Headings HID, HIP and HlR. A printed circuit deflection coil for a television camera tube, especially for colour television, is formed of two half-coils and is characterized in that the joint between the halves occurs along the transverse end portions, as illustrated in Fig. 3, so that variations in overlap, as between different coils, have little effect on the magnetic fields produced by the coils. In a preferred method of manufacture, a cylindrical core of glass, ceramic, synthetic resin bonded paper or fibreglass, is coated with a conductive layer of copper which is coated with a photo-resist; one half is exposed to light through a photo-master as shown in Fig. 3, whilst the other half is shielded from the light, and the cylinder is then rotated 180 degrees for exposure of the other half. The coils are then developed and etched in known manner. |
