In a projection optical system for use in an image projection apparatus illuminating an image display panel forming an image in accordance with a modulating signal with illumination light from a light source, the projection optical system includes first and second optical systems arranged along an optical path defining an upstream-downstream direction in the order described from upstream to downstream on the downstream side of the image display panel. The first optical system includes at least one dioptric system and has positive power. The second optical system includes at least one reflecting surface having power and has positive power. The image formed by the image display panel is formed as an intermediate image in the optical path, and the intermediate image is magnified and projected.

A projection exposure method and apparatus are disclosed for exposing a radiation-sensitive substrate with at least one image of a pattern of a mask under the control of an operating control system of a projection exposure apparatus, part of the pattern lying in an illumination region is imaged onto the image field on the substrate with the aid of a projection lens, wherein all rays of the projection radiation contributing to the image generation in the image field form a projection beam path.

A telecentric lens comprises a front optical group adapted to receive rays coming from an observed object, a rear optical group, adapted to convey said rays towards an image plane of a sensor, and a lens aperture positioned between the front optical group and the rear lens group, wherein the lens aperture lies on the focal plane at least of the front optical group. The front optical group is devoid of lenses and is consists of a concave curved primary mirror adapted to receive and reflect the rays coming from the observed object, and at least one secondary mirror adapted to receive and reflect towards the rear optical group the rays coming from the primary mirror.

A head up display can use a catadioptric collimating system. The head up display includes an image source. The head up display also includes a collimating mirror, and a polarizing beam splitter. The light from the image source enters the beam splitter and is reflected toward the collimating mirror. The light striking the collimating mirror is reflected through the beam splitter toward a combiner. A field lens can include a diffractive surface. A corrector lens can be disposed after the beam splitter.

An optical system includes a reflective optical system on a magnification side along an optical path of the projection optical system and a refractive optical system on a reduction side along the optical path. The reflective optical system includes one reflective optical element having a power. The refractive optical system includes a front group on the magnification side and a rear group on the reduction side. The front group having, in order from the magnification side toward the reduction side, a first lens group with a positive or negative refractive power, a second lens group, and a third lens group with a positive refractive power. The rear group has a positive refractive power. The first lens group moves to the magnification side, and the second lens group and the third lens group move to the reduction side in a change in focus from a long distance to a short distance.

The imaging optical system consists of, in order from a magnification side: a catoptric system; and a dioptric system that includes a plurality of lenses. The dioptric system forms a first intermediate image between the dioptric system and the catoptric system on an optical path and at a position conjugate to a reduction side imaging surface, and the catoptric system re-forms the first intermediate image on a magnification side imaging surface. The catoptric system consists of a first reflective surface, a second reflective surface, and a third reflective surface in order along the optical path from the magnification side. The first reflective surface and the third reflective surface are formed on one member and have the same surface shapes.

A optical projection device disposed close to a projection surface and capable of further widening an angle is provided. A optical projection device includes first optical system including lens groups movable and second optical system reflecting light emitted from the first optical system. The first optical system includes first lens frame which holds first lens group positioned at side closest to the second optical system among the movable lens groups and includes cam pin, guide barrel which includes straight groove, cam barrel which includes cam groove with which the cam pin is engaged, the first lens frame includes frame protruding portion protruding from the cam barrel to second optical system side and holding the first lens group, and notch is provided in such way that portion is formed to be cut out at side through which light reflected by the second optical system passes, in the frame protruding portion.

A projection optical system (10) projects from a first image plane (5) on a reducing side to a second image plane (6) on an enlargement side. The projection optical system (10) includes a first optical system (11) that includes a plurality of lenses and forms a first intermediate image (51) formed inside the first optical system (11) by light incident from the reducing side into a second intermediate image (52) on the enlargement side of the first optical system; a second optical system (12) that includes a first reflective surface (M1) with positive refractive power which is positioned further to the enlargement side than the second intermediate image (52); and a glass block (30) that is disposed between the first optical system (11) and the first reflective surface (M1), the glass block (30) passing light rays from the first optical system to the second intermediate image.

An optical apparatus for a near-eye display includes a microdisplay to emit image light and one or more field lenses positioned to receive the image light from the microdisplay. The one or more field lenses have a combined optical power to form a curved intermediate image. A freeform combiner, having an eyeward side and an external side, is positioned to receive the image light from the one or more field lenses and reflect the image light. A curved intermediate image is formed between the freeform combiner and the one or more field lenses.

A projection exposure method and apparatus are disclosed for exposing a radiation-sensitive substrate with at least one image of a pattern of a mask under the control of an operating control system of a projection exposure apparatus, part of the pattern lying in an illumination region is imaged onto the image field on the substrate with the aid of a projection lens, wherein all rays of the projection radiation contributing to the image generation in the image field form a projection beam path.