US 2003/0112525 A1Published application

Projection objective

AssigneeOptische Systeme Gottingen ISCO-Optic GmbH

InventorsWolfgang Reinecke, Horst Linge

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Abstract

The invention relates to a projection objective which consists of at least seven lenses that are adjacent to air on both sides. The inventive projection objective meets the criteria of the following equations in its totality: u≧12.8°; 100 mm≦LEP≦400 mm; σRBa≧1°; σRBi≦−14°, whereby u is the aperture angle (2u-entire angle) on the illumination side; LEP is the distance from the entrance pupil (on the illumination side) to the object level (the position in the direction of projection from the reference point: object level corresponds to a positive value); σRBa is the angle inclination of the beam in relation to the optical axis in the object space between the object and the 1. lens surface of the objective, said beam limiting the bundle for the field edge (outer field point in the object) towards the outside (away from the optical axis, far from the axis) and σRBi is the angle inclination of the beam in relation to the optical axis in the object space between the object and the 1. lens surface of the objective, said beam limiting the bundle for the field edge (outer field point in the object) towards the inside (towards the optical axis, close to the axis). The angles σRBa and σRBi are positive when the corresponding beams intersect the optical axis in a point which is situated in the opposite direction of projection when seen from the object. Said angles are negative when the beams intersect the optical axis in a point which is situated in the direction of projection when seen from the object.

Claims4

Dependent claims

A projection objective consisting of seven lenses bordering to space on both sides, characterized by the following conditional equations, which must be met in their entirety:

u≧12.8°, 100 mm≦LEP≦400 mm, σRBa≧1°, σRBi≧−14°,
whereby
u is the aperture angle (2u-entire angle) on the lighting side,
LEP is the distance of the entrance pupil (on the lighting side) to object level (the location in direction of projection from reference point object level is a positive number),
σRBa is the ray's angular slope opposite the optical axis in the object space between the object and the objective's 1st lens area, which limits the bundle for the field margin (object's outer field point) outwardly (away from the optical axis, distant from the axis) and
σRBi is the ray's angular slope opposite the optical axis in the object space between the object and the objective's 1st lens area, which limits the bundle for the field margin (object's outer field point) inwardly (toward the optical axis, near the axis),
as well as that angles σRBa and σRBi are positive, if the respective rays intersect the optical axis at a location, which, when seen from the object, is in the opposite direction to projection and negative, if intersecting the optical axis at a location, which, when seen from the object, is in direction of projection,
with the following lens locations in sequence from image (enlarged side) to object (shrunk and lighting side):
a first biconvex lens (1),
a second negative lens (2), with concave surface at image side,
a third positive lens (3), with convex surface at image side,
a fourth negative lens (4), with concave surface on object side,
a fifth negative lens (5), with concave surface at image side,
a sixth positive lens (6), with convex surface on object side, and
a seventh biconvex lens (7).

12 more elements

Dependencies are inferred from the claim text.