| 摘要 |
PURPOSE:To eliminate distortion of static convergence due to the effect of an external amgentic field with an inexpensive means, by covering the surrounding of electronic guns of a picture tube with a magnetic material of high permeability. CONSTITUTION:A picture displayed on plural picture tubes 1R, 1G, 1B is synthesized into a color picture by dichroic mirrors 3R, 3B and is enlarged and projected on a screen 5 via a lens 4. The surrounding of electron guns 8R, 8G, 8B of the picture tubes 1R, 1G, 1B is covered with magnetic shield members 14R, 14G, 14B made of a plate shaped magnetic material of high permeability from the outside of each glass tube. ''Permalloy'' is suitable for the magnetic material in terms of the permeability and the workability. |
