Catadioptric reduction projection optical system

A catadioptric reduction projection optical system for forming a reduced image of an object, including:

• a first partial optical system having first reflecting means and first refracting means to condense a light beam from the object and form a reduced primary image;
• and
• a second partial optical system having second reflecting means and second refracting means to form a further reduced secondary image from said primary image;
• said first reflecting means having only one concave reflecting mirror, said first refracting means having a lens group of positive refractive power disposed between said object and said concave reflecting mirror;
• said second reflecting means having only one concave reflecting mirror, said second refracting means having a lens group of positive refractive power disposed between said concave reflecting mirror of said second partial optical system and said second secondary image.

A catadioptric reduction projection optical system for forming a reduced image of an object, comprising:

• a first partial optical system for forming a primary image of the object;
• and
• a second partial optical system for forming a secondary image of the object based on light from the primary image,
• said first partial optical system having a first lens group of positive refractive power, a second lens group of negative refractive power, and a first concave reflection mirror in succession from a light incident side, and
• said second partial optical system having a second concave reflection mirror, and a fourth lens group of positive refractive power,
• wherein a third lens group is disposed in a light path between said first concave reflection mirror and said second concave reflection mirror,
• said first to fourth lens groups consist of at least one material selected from a group consisting of quartz glass and fluorite, and
• a magnification .beta..sub.M1 of said first concave reflection mirror and a magnification .beta..sub.M2 of said second concave reflection mirror meet conditions of:
• -1.0<.beta..sub.M1 <-0.7
• -2.5<.beta..sub.M2 <-1.2.