| 摘要 |
In a 1-2nd lens group, a reduction-side fixed lens group (first fixed lens group) as a fixed group is disposed on the outermost reduction side, an enlargement-side fixed lens group (second fixed lens group) as a fixed group is disposed on the outermost enlargement side, moving lens groups (lens groups), which move when focusing is performed in response to a magnification change, are disposed between the fixed groups, and thereby it is possible to perform effective correction in order to suppress aberration fluctuation to be reduced. Even in a case where the second optical group is configured of one mirror, it is possible for a primary image to have appropriate aberration and to hereby reduce aberration for a good image which is finally projected onto a screen through the second optical group. |
