Projection optical system
First Claim
1. A projection optical system for performing enlargement projection from a primary image surface on a reduction side to a secondary image surface on a enlargement side, the projection optical system comprising, from a primary image surface side:
- a lens optical system including two or more lens elements sharing a common rotation-symmetry axis and each having an optical power;
a first reflective optical element having an optical power; and
a second reflective optical element having a negative optical power, wherein the projection optical system is non-telecentric toward the reduction side, and the following condition is fulfilled;
30°
≦
θ
≦
70°
where θ
represents an angle of incidence at which a central principal ray is incident on the secondary image surface.
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Accused Products
Abstract
A projection optical system for performing enlargement projection from a primary image surface on the reduction side to a secondary image surface on the enlargement side has, from the primary image surface side, a lens optical system including two or more lens elements sharing a common rotation-symmetry axis and each having an optical power, a first reflective optical element having an optical power, and a second reflective optical element having a negative optical power. The projection optical system is non-telecentric toward the reduction side, and a prescribed condition is.
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Citations
24 Claims
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1. A projection optical system for performing enlargement projection from a primary image surface on a reduction side to a secondary image surface on a enlargement side, the projection optical system comprising, from a primary image surface side:
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a lens optical system including two or more lens elements sharing a common rotation-symmetry axis and each having an optical power;
a first reflective optical element having an optical power; and
a second reflective optical element having a negative optical power, wherein the projection optical system is non-telecentric toward the reduction side, and the following condition is fulfilled;
30°
≦
θ
≦
70°where θ
represents an angle of incidence at which a central principal ray is incident on the secondary image surface. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A projection optical system for performing enlargement projection from a primary image surface on a reduction side to a secondary image surface on a enlargement side, the projection optical system comprising, from a primary image surface side:
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a rotation-symmetric lens optical system having a plurality of lens elements sharing a common lens optical axis;
a free-form curved surface lens element having a non-rotation-symmetric aspherical surface;
a first reflective optical element having an optical power; and
a second reflective optical element having a negative optical power, wherein the projection optical system is non-telecentric toward the reduction side.
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23. A projection optical system for performing enlargement projection from a primary image surface on a reduction side to a secondary image surface on a enlargement side, the projection optical system comprising, from a primary image surface side:
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a rotation-symmetric lens optical system having a plurality of lens elements sharing a common lens optical axis, the rotation-symmetric lens optical system being disposed, among all optically powered optical elements provided in the projection optical system, closest to the primary image surface;
a free-form curved surface lens element having a non-rotation-symmetric aspherical surface;
a first reflective optical element having an optical power; and
a second reflective optical element having a negative optical power.
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24. A projection optical system for performing enlargement projection from a primary image surface on a reduction side to a secondary image surface on a enlargement side, the projection optical system comprising, from a primary image surface side:
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a lens optical system including two or more lens elements sharing a common rotation-symmetry axis and each having an optical power;
a first reflective optical element having an optical power;
a second reflective optical element having a negative optical power, and a flat reflection mirror disposed parallel to the secondary image surface so as to bend an optical path, wherein the projection optical system is non-telecentric toward the reduction side, and the following condition is fulfilled;
30°
≦
θ
≦
70°where θ
represents an angle of incidence at which a central principal ray is incident on the secondary image surface.
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Specification