| 主权项 |
1. A projection optical system comprising:
a unity magnification, first reflecting optical system that forms an intermediate image of an object positioned on an object plane; and a unity magnification, second reflecting optical system that projects the intermediate image onto an image plane, wherein the unity magnification, first reflecting optical system comprises:
a first mirror that reflects light emitted from the object plane and is incident thereon upon traveling in a first direction perpendicular to the object plane;a first optical system that reflects the light from the first mirror; anda second mirror that reflects the light from the first optical system, in the first direction toward a forming position of the intermediate image, and wherein the unity magnification, second reflecting optical system comprises:
a third mirror that reflects light emitted from the forming position of the intermediate image and is incident thereon upon traveling in the first direction;a second optical system that reflects the light from the third mirror; anda fourth mirror that reflects the light from the second optical system, in the first direction toward the image plane, wherein the first optical system comprises a first concave mirror, a first convex mirror, and a second concave mirror in order from a side of the first mirror in an optical path between the first mirror and the second mirror, wherein the second optical system comprises a third concave mirror, a second convex mirror, and a fourth concave mirror in order from a side of the third mirror in an optical path between the third mirror and the fourth mirror, and wherein the first mirror, the second mirror, the third mirror, the fourth mirror, the first optical system, and the second optical system are positioned to satisfy at least one of a condition in which a distance in the first direction between a position of reflection of the light on the second mirror and the forming position of the intermediate image is smaller than a distance in the first direction between a position of reflection of the light on the first mirror and the object plane and a distance in a second direction perpendicular to the first direction between the position of reflection of the light on the second mirror and the second concave mirror is larger than a distance in the second direction between the position of reflection of the light on the first mirror and the first concave mirror, or a condition in which a distance in the first direction between a position of reflection of the light on the third mirror and the forming position of the intermediate image is smaller than a distance in the first direction between a position of reflection of the light on the fourth mirror and the image plane and a distance in the second direction between the position of reflection of the light on the third mirror and the third concave mirror is larger than a distance in the second direction between the position of reflection of the light on the fourth mirror and the fourth concave mirror. |
