Abstract: A scanning projection optical device is disclosed which can be constructed using relatively small optical members, which employs a catadioptric system that is advantageous to attain a high NA, and which has arc-shaped object and image regions located out of an optical axis and a projecting magnification of 1. In the scanning projection optical device, the catadioptric system is an optical system telecentric in both object- and image- field sections, and has a first, positive power lens-system, a second, substantially non-power lens-system, and a concave mirror; the first, positive power lens-system and the concave mirror cooperatively satisfy Petzval condition to correct field curvature; and without impairing the Petzval condition satisfied by the first lens-system and the concave mirror, the second lens-system corrects aberration of the arc-shaped region centering around the optical axis.

Abstract: A wide-field exposure optical system in which the projection is performed by scanning an object to be projected with a predetermined scan width. The optical system comprises an illuminating section for illuminating the object to be projected in a circular arc region, a reflecting and refracting optical system for correcting the aberration of a circular arc region having its center on the optical axis and for forming, within an image surface, an image of the object to be projected illuminated by the illuminating section as a circular arc, a driving means for moving light-receiving members arranged on the object to be projected and on the image surface relative to the illuminating section and the reflecting and refracting optical system, and the reflecting and refracting optical system being formed by a first lens group, a second lens group and one concave mirror. The second lens group comprises a second lens which is a convex lens and a third lens which is a concave lens.

Abstract: An interferometer for measuring an aspherical shape uses a computer generated hologram. The interferometer comprises a hologram disposed at each of positions conjugate with plural types of aspherical surfaces to be examined and filed lens means disposed between a position conjugate with a convex aspherical surfaces and another position with a concave aspherical surface. The interferometer can measure plural types of aspherical surfaces to be examined without need of changing the position of the interferometer for each of the aspherical surfaces to be examined, even if the number of different surfaces to be examined increases.

Abstract: A holographic interferometer comprising a source of laser beams, a condenser lens for converging a laser beam supplied from said laser-beam source, a pinhole which allows the passage of said converged laser beam, a collimator lens having a focal point which lies on said pinhole, a beam splitter disposed in an inclined manner between said pinhole and said collimator lens, a spacial filter disposed on the optical axis of a light reflected from said beam splitter and at an optically conjugate position relative to said pinhole, and a hologram standard disposed between said spacial filter and said beam splitter.

Abstract: A holographic interferometer comprising a source of laser beams, a condenser lens for converging a laser beam supplied from said laser-beam source, a pinhole which allows the passage of said converged laser beam, a collimator lens having a focal point which lies on said pinhole, a beam splitter disposed in an inclined manner between said pinhole and said collimator lens, a spacial filter disposed on the optical axis of a light reflected from said beam splitter and at an optically conjugate position relative to said pinhole, and a hologram standard disposed between said spacial filter and said beam splitter.