| 摘要 |
PURPOSE:To adjust easily and exactly the focus of an optical system which is constituted of a projection lens and a cathode ray tube, by adjusting the fitting angle of an optical block by using a spacer in which thickness of the corner parts is different from each other. CONSTITUTION:A cathode ray tube, a base 3, and a lens 4 are assembled by inserting a spacer 1 which is provided with parts 5-8 whose thickness is different from each other, on four corners, between the lens 4 and the base 3, and an angle of the lens 4 is adjusted. By constitution in which inclination of this cathode ray tube side is unnecessary, and many spacers are not required, the focus of an optical system can be adjusted easily and exactly. |
