Abstract: A kinematic optical mounting assembly secures an optical element to a base. A plurality of first bracket assemblies and second bracket assemblies are secured to the base and engage the optical element. Each first bracket assembly constrains the optical element from movement relative to the base in a direction substantially parallel to an axis of the base. Each second bracket assembly constrains the optical element from movement relative to the base in a direction substantially perpendicular to the axis of the base and substantially tangential to a periphery of the base. Six independent bracket assemblies constrain the optical element in six degrees of freedom to provide kinematic constraint without bending moments.

Abstract: A kinematic optical mounting assembly secures an optical element to a base. A plurality of first bracket assemblies and second bracket assemblies are secured to the base and engage the optical element. Each first bracket assembly constrains the optical element from movement relative to the base in a direction substantially parallel to an axis of the base. Each second bracket assembly constrains the optical element from movement relative to the base in a direction substantially perpendicular to the axis of the base and substantially tangential to a periphery of the base. Six independent bracket assemblies constrain the optical element in six degrees of freedom to provide kinematic constraint without bending moments.

Abstract: The exposure projection apparatus includes an illumination system which illuminates a mask with a light beam, and a optical projection system which projects the image of a pattern formed on the mask onto a substrate. The optical projection system includes a first barrel which holds a plurality of optical elements, at least three second barrels, each holding at least one optical element disposed between the mask and the first barrel, so that the coma, astigmatism, and distortion of the optical projection system can be adjusted, and a first optical element which is disposed between the substrate and the first barrel so that either the spherical aberration or curvature of field of the optical projection system, or both, can be adjusted.

Abstract: Four specified lenses 22.sub.1 to 22.sub.4 of a plurality of lenses in a projection optical unit are subjected to special processing (astigmatic surface processing) so that asymmetric component aberration relative to an optical axis is generated. Each of the lenses 22.sub.1 to 22.sub.4 is held by each of secondary lens frames 20 set in each of primary lens frames 14. Each of the secondary lens frames 20 is constructed so that it can be rotated from the outside of a lens barrel 12. The asymmetric component aberration relative to the optical axis of an optical system comprising all lenses for constituting the projection optical unit 10 can be easily corrected by rotating a pair of two of the lenses 22 subjected to the astigmatic surface processing. The projection optical unit is used for a projection exposure apparatus.

Abstract: In a projection-type optical apparatus in which a projection optical system projects an image of an object upon a substrate, a position detecting sensor mechanically connected to the projection optical system detects the position of the projection optical system relative to the substrate along the optical axis of the projection optical system. A displacement measuring device measures relative displacement between the position detecting sensor and the projection optical system along the optical axis. The substrate is brought into coincidence with an optimum image forming plane of the projection optical system on the basis of the position detected by the position detecting sensor and the displacement measured by the displacement measuring device.