Projection optical system and projector
AssigneeSeiko Epson Corporation
InventorAkihisa Kageyama
Life of this patent
Estimating the term…
Abstract
A projection optical system includes first through ninth lens groups, and these lens groups are in an order from a magnification side to a reduction side. The projection optical system includes an aperture stop between the second lens group and the eighth lens group. The first lens group has negative power and includes one first aspherical lens. Any one of the second, the third, the fourth, the fifth, the sixth, the seventh, the eighth, and the ninth lens groups includes at least one second aspherical lens. During zooming, the first lens group and the ninth lens group are fixed, and the second lens group, the third lens group, the fourth lens group, the fifth lens group, the sixth lens group, the seventh lens group, and the eighth lens group move.
Claims16
A projection optical system comprising:
- a first lens group;
- a second lens group;
- a third lens group;
- a fourth lens group;
- a fifth lens group;
- a sixth lens group;
- a seventh lens group;
- an eighth lens group;
- and a ninth lens group, these lens groups being in an order from a magnification side to a reduction side;
- and
- an aperture stop disposed between the second lens group and the eighth lens group, wherein
- the first lens group has negative power and includes one first aspherical lens,
- any one of the second lens group, the third lens group, the fourth lens group, the fifth lens group, the sixth lens group, the seventh lens group, the eighth lens group, and the ninth lens group includes at least one second aspherical lens, and
- during zooming, the first lens group and the ninth lens group are fixed, and the second lens group, the third lens group, the fourth lens group, the fifth lens group, the sixth lens group, the seventh lens group, and the eighth lens group move.
Dependencies are inferred from the claim text.