| 摘要 |
PURPOSE:To improve peripheral resolution, by depositing conductive film on the inside of a bulb wall and using it as a grid formed in an electrostatic focusing lens. CONSTITUTION:Conductive film electrodes 21, 22, 23 are formed by spreading metalic thin film over the inside wall of a bulb 5 through vacuum evaporation and separating it by chemical etching. On the other hand, contact terminals 24 in which small pieces of conductive glass or metallic foil are enclosed are respectively arranged on the conductive film electrodes 21, 22, 23 through the tube wall of the bulb 5. Adequate voltage is impressed on each electrode of terminals 24 by means of springs 26 attached on a voltage impressing support 25 arranged on the inside of a deflecting coil 20 and electrodes 21, 22, 23 are used as an electrostatic forcusing lens. Thereby astigmatism along the periphery of a picture can be eliminated because it is possible to make this tube of a small size act as an electrostatic focusing lens of a diameter larger than that expected from its external shape. |
