Abstract: A catadioptric reduction projection optical system having a first lens unit having negative refractive power and widening a light beam from a reticle, a prism type beam splitter for transmitting therethrough a light beam from the first lens unit, a concave reflecting mirror for returning the light beam emerging from the beam splitter to the beam splitter while converging it, and a second lens unit having positive refractive power and converging the light beam returned to the beam splitter and reflected by the beam splitter, and forming the reduced image of a pattern on the reticle on a wafer.

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: This invention relates to a catadioptric optical system in which, a large numerical aperture is attained on the image side and, while securing a sufficient working distance, the size of the beam splitter is reduced, thereby attaining a resolution of a quarter micron unit, and an exposure apparatus using the same. In order to form a reduced image of a pattern of a first surface on a second surface, this catadioptric optical system comprises, at least, a first lens group, a beam splitter, a concave mirror having an enlarging magnification, and a second lens group. These constitutional elements of the catadioptric optical system are disposed such that light from the first surface passes through the first lens group, the beam splitter, the concave mirror, the beam splitter, and the second lens group in this order.

Abstract: Disclosed is a projection optical system for projecting an original image onto a screen, including a projection lens comprising, in succession from the screen side, a first lens unit having positive refractive power, and a second lens unit having positive refractive power, and a reflecting member disposed between the first lens unit and the second lens unit of the projection lens for directing light from an illuminating light source to the original image through the second lens unit, one of a plurality of sub-lens units constituting the first lens unit being moved to thereby effect focusing.

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 apparatus is provided for magnifying the image of distant objects which has the unique feature that, unlike the Galilean telescope, the magnification is largely determined by how far the eye is located from the apparatus. Furthermore, unlike the Loupe, objects to be viewed can be at any arbitrarily large distance from the apparatus. In addition, the apparatus does not require positioning of the eye at the exit pupil of the instrument; it does not require centering of the eye on the optic axis of the instrument; and it does not require refocusing for different object distances. Still, it provides erect, non-inverted images to the viewer. The includes a positive optical element defining an optic axis for the apparatus and having a positive focal length for converging an incoming bundle of rays of electromagnetic radiation.

Abstract: The present invention relates to an optical element and catadioptric optical systems using the optical element. The optical element has a spherical surface with a reflective layer formed on at least a portion of the surface, and is formed of a radiant energy transmitting material having a radial gradient index of refraction. The catadioptric optical systems include at least two optical elements at least one of which is refractive, and at least one of which has a gradient index therein. One optical system includes first and second optical elements disposed sequentially along a longitudinal axis of the system. The second optical element is the optical element with the gradient index. The first optical element is formed of a homogeneous light transmitting material and includes a spherical surface, and a reflective layer formed on a central portion of one of the spherical surface.