| 摘要 |
PURPOSE:To project a color picture of high quality with a reduced error of the dynamic convergence, by projecting a picture after a correction of the static convergence on a screen with reduced distortion and by using the center part of a lens system. CONSTITUTION:Three video tubes 1R, 1G and 1B and lens systems 2R, 2G and 2B are distributed in line, and the tube 1G and system 2G are located so that the axial line (g) is coincident with the center line S of a screen 3. The side tubes 1R and 1B and the systems 2R and 2B are set so that the axial lines (r) and (b) are out of the center line S, and accordingly the lines (r) and (b) are turned approximately at the center position of the screen 3. Thus a projection raster 4R formed by the tubes 1R and 1B and the systems 2R and 2B has a correct rectangular form. However, the projection rasters 4R and 4B formed by the tubes 1R and 1B and the systems 2R and 2B produce trapezoidal convergence errors. In this connection, the rasters on the fluorescent screens 5R and 5B are formed into adverse trapexoids respectively. |
