| 摘要 |
<p>According to one embodiment, an assembly method of a projection optical system, including a lower tube and an upper tube, comprises: storing a relative positional relation between the lower tube and the upper tube in a state in which an optical characteristic of the projection optical system is adjusted; disassembling the lower tube and the upper tube; and adjusting relative positions of the lower tube and the upper tube, based on the stored relative positional relation, in next fixing the lower tube and the upper tube to each other.</p> |
