| 摘要 |
PURPOSE:To prevent a gas from being exposed in the effective picture screen when a projection-type cathode-ray tube is slanted by providing a gas reservoir in the position of an uneffective picture screen located above the face of a liquid-tight space and installing rolling members which move along the uneffective picture screen. CONSTITUTION:A gas reservoir 11 is provided in an uneffective picture screen 10a located above a liquid tight space 10. A rolling members 15 are placed in such a manner as to freely rotate along the uneffective picture screen 10a. The rolling members 15 roll on a linear projection 5c located apart from a front plate 7. When the cathode-ray tube is slanted while horizontally maintaining its axis, the rolling members 15 roll along the upper uneffective picture screen 10a into a cooling liquid 9. As the result, the volume of the gas reservoir 11 decreases by the volume of the rolling members 15 and the liquid level of the cooling liquid 9 is elevated. Consequently, the slanting angle can be increased while avoiding entering of the gas reservoir 11 into the effective picture screen and therefore only a small amount of the cooling liquid 9 is necessary. |
