A projection lens system which is arranged between an object side at which a micro-display panel is located and an image side at which a screen is located, and includes an aperture stop; a front lens group arranged at an object-side of the aperture stop and having a positive refractive power; a rear lens group arranged at an image-side of the aperture stop, the rear lens group including a first aspherical lens at a position closest to the image side and a second aspherical lens adjacent to an object-side surface of the first aspherical lens; and an aspherical mirror having a negative refractive power and reflecting light coming from the rear lens group toward the image side.

Disclosed herein is a lens module for a projector of laser scanning type which is focus-free and has a short throw distance. In one example, a lens module includes a first optical member including a free-curved lens that passes a beam light reflected by a minute vibrating mirror; and a second optical member including a free-curved mirror to reflect the beam light which has passed through the first optical member, or a free-curved lens to pass the beam light which has passed through the first optical member. The beam light, which has been reflected by or has passed through the second optical member, has at the same position beam waists in horizontal and vertical directions perpendicular to a propagating direction of the beam light and also has beam radii coinciding in the horizontal and vertical directions.

A remote imaging apparatus, and corresponding method, includes a hyperbolic primary mirror that receives light from a remote object to be imaged. The primary mirror has a continuous surface that reflects, at least twice, the light from the remote object. The apparatus also includes a hyperbolic secondary mirror having a continuous surface that reflects, at least twice, the light from the remote object. The secondary mirror delivers the light to a field corrector via a port of the hyperbolic primary mirror, and the field corrector is configured to correct for an optical aberration of one or both of the hyperbolic primary and secondary mirrors. Embodiments can provide low distortion, small aspect ratios, and small form factors and moments of inertia for fleets satellite-based and other imaging systems.

The present invention provides a projection optical system including a first concave reflecting surface, a first convex reflecting surface, a second concave reflecting surface, and a third concave reflecting surface, wherein the first concave reflecting surface, the first convex reflecting surface, the second concave reflecting surface, and the third concave reflecting surface are arranged such that light from an object plane forms an image on an image plane by being reflected by the first concave reflecting surface, the first convex reflecting surface, the second concave reflecting surface, the first convex reflecting surface, and the third concave reflecting surface in an order named.

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 (11); 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 (11) to the second intermediate image (52).

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.

The present invention provides a projection optical system including a first concave reflecting surface, a first convex reflecting surface, a second concave reflecting surface, and a third concave reflecting surface, wherein the first concave reflecting surface, the first convex reflecting surface, the second concave reflecting surface, and the third concave reflecting surface are arranged such that light from an object plane forms an image on an image plane by being reflected by the first concave reflecting surface, the first convex reflecting surface, the second concave reflecting surface, the first convex reflecting surface, and the third concave reflecting surface in an order named.

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 (11); 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 (11) to the second intermediate image (52).

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.

An ultra-short throw projector device includes a lens system. The lens system includes a first lens group configured to form a first intermediate image from an incident display image; a second lens group configured to form a second intermediate image from the first intermediate image; an aperture configured to be disposed on a point where the first intermediate image is formed between the first lens group and the second lens group; a reflection mirror configured to reflect and magnify the second intermediate image and form an image on a screen; and a light path changing prism configured to change a light path in the vertical direction or other directions, the prism being disposed at a point on the light path of the lens system, at least one of an incident surface and a refracting surface being an aspherical surface or a freeform surface.