A colour micro-LED display apparatus comprises an array of reflective optical elements and an array of micro-LED pixels with a uniform emission colour across the array arranged between the array of reflective optical elements and an output substrate. Light from the micro-LEDs is directed into the reflective optical elements and is incident on scattering regions in the apparatus. Colour converted scattered light is transmitted by the output substrate. A thin and efficient display apparatus may be provided with high spatial and angular colour uniformity and long lifetime.

A projection lens includes a first lens group, a second lens group and an aperture stop. The first lens group is disposed between a reduced side and a magnified side. The second lens is disposed between the first lens group and the magnified side. The second lens group has a light incident surface, a reflective surface and a light emitting surface, the light incident surface faces the first lens group, the light emitting surface faces a projection surface, the light incident surface, the light emitting surface and the first lens group are disposed at a single side of the reflective surface, and at least one of the light incident surface, the reflective surface and the light emitting surface is a freeform surface. The aperture stop is disposed between the first lens group and the second lens group. Moreover, a projection apparatus including the projection lens is also provided.

An optical path folding element includes an incident surface, a path folding surface and an exiting surface. The incident surface allows a light ray to pass into the optical path folding element. The path folding surface folds the light ray from the incident surface. The exiting surface allows the light ray to pass through and depart from the optical path folding element. At least one of the incident surface and the exiting surface includes an optical effective portion and at least one engaging structure symmetrically disposed around the optical effective portion. The engaging structure includes an annular surface portion and an inclined surface portion. The annular surface portion surrounds the optical effective portion, and the inclined surface portion is located between the annular surface portion and the optical effective portion. An angle between the annular surface portion and the inclined surface portion satisfies a specific condition.

An optical subsystem of a near-eye display system provides for projecting light of a virtual image of image content to an eye location, and provides for collecting light of the virtual image onto an exit pupil on a surface proximate to an outer surface of an eye when at the eye location. A subpupil modulator within an aperture in cooperation with the optical subsystem provides for forming a plurality of subpupils within the exit pupil, at least two of which overlap by at least 20 percent, and provides for less than all of the light of the virtual image associated with one or more less than all of the plurality of subpupils to be projected to the eye location.

A freeform prism-lens group includes: a primary prism; a first auxiliary lens; and a beamsplitter film between the primary prism and the first auxiliary lens and having a predetermined beamsplitting ratio; wherein: the first auxiliary lens has a first optical surface substantially conforming to a neighboring freeform surface of the primary prism; and the first auxiliary lens has a second opposing optical surface distal from the primary prism that is planar, aspheric, or spherical with a curvature radius greater than 100 mm.

An aerial display apparatus includes: a display device displaying an image; and a prism device reflecting light from the display device and causing an image to be displayed in an aerial space on a side opposite to the display device. The prism device includes a plurality of prism elements arranged in a horizontal plane. Each of the prism elements is formed of a hexahedron and includes a first and a second refraction surfaces refracting light and a first and a second reflection surfaces reflecting light. The first refraction surface corresponds to a bottom surface of the hexahedron and is inclined with respect to a first direction parallel with the horizontal plane. The second refraction surface corresponds to a top surface of the hexahedron and is inclined with respect to the first direction.

A virtual image display apparatus includes a display device (image forming unit), a lens configured to refract imaging light from the display device, a first mirror member configured to reflect imaging light that passed through the lens, a second mirror member being a refractive reflective optical member configured to reflect the imaging light reflected by the first mirror member, and a third mirror member of a transmissive type configured to reflect the imaging light reflected by the second mirror member toward a position of an exit pupil. The refractive reflective optical member includes, across a refractive member, a refractive surface and a mirror surface. The lens and the refractive reflective optical member are integrated as a composite member.

A virtual image display device includes an image element configured to display an image, a first lens disposed in an extraction position of image light and including at the image element side thereof a convex surface, a second lens disposed further toward the image element side than the first lens and including a concave surface bonded to the convex surface of the first lens, a half mirror provided in a bonding portion for bonding together the convex surface and the concave surface, a transmission/reflection selection member provided at a light emitting side of the first lens and configured to selectively perform transmission or reflection of the light depending on a polarization state of the light, and a light-guiding portion keeping close contact between the image element and the second lens and configured to guide the image light.

A spectral beam combining system includes a plurality of input fibers and a prism having a curved input surface. The plurality of input fibers are attached to the curved input surface. The spectral beam combining system also includes an immersion grating defined on a second surface of the prism, a protective cap disposed over the immersion grating, and an output surface.

A reflector sight (2) for a portable firearm has an optical system for generating a natural image of a target region, a display (4) for reproducing an electronic image of the target region created by an electronic image creation unit and a beam splitter cube (6) for overlaying the natural image with the electronic image of the target region reproduced by the display (4). According to the invention, the display (4) is arranged on a first flat face (10) of beam splitter cube (6), to which fiat face a correction lens (12) is connected (12), the face (14) of which facing the display is convex, wherein a mirror lens element (18) is connected to a second flat face (16) of the beam splitter cube, the mirrored face (20) of which mirror lens element facing away from the beam splitter cube (6) is convex and aspherical and wherein the beam splitter cube (6), the correction lens (12) and the mirror lens element (18) form a correction block that consists of silica glass and/or.