A freeform folded optical system that include two freeform prisms with optical power. At least one of the freeform prisms is configured to fold the optical axis twice. Thus, embodiments of the freeform folded optical system fold the optical axis three or four times. Folding the optical axis three or four times in the freeform prisms allows for long focal lengths required for telephoto lens applications without requiring additional lens elements between the prisms. In addition, the configuration of the freeform folded optical system provides reduced Z-axis height when compared to conventional folded lens systems with similar optical characteristics.

A device and system for augmenting the focal length of an electronic display. The device may comprise a display, a first mirror, a second mirror, and a lens. The display is operable to emit light corresponding to a first image in a first direction. The first mirror has a first focal length and is operable to reflect light from the first direction to a second direction. The second mirror has a second focal length and is operable to reflect light from the second direction to a third direction. The lens has a third focal length and is operable to transmit light from the third direction. Further, the light transmitted by the lens is viewable by a user as a second image. Additionally, the perceived distance from the user to the second image is greater than a distance from the user to the lens.

A display device includes: a first display panel having a first resolution; a second display panel having a second resolution; and a first multi-channel lens and a second multi-channel lens disposed on one surface of the first display panel and including a plurality of channels through which light emitted from the one surface of the first display panel passes, where the second resolution is higher than the first resolution.

A virtual image display apparatus includes a display element, a projection lens configured to converge image light emitted from the display element, a prism configured to cause the image light by an internal reflecting surface thereof and moreover emit the image light from an emission surface thereof while refracting the image light, and a see-through mirror configured to reflect the image light emitted from the prism toward a pupil position. The projection lens, the prism, and the see-through mirror are arranged to form an off-axis system. AT an off-axis surface of the off-axis system, an intermediate pupil is arranged between the projection lens and the internal reflecting surface, with the intermediate pupil being arranged to be farther to the incident surface sidfe of the prism than to the projection lens and the internal reflecting surface, and an intermediate image is formed between the prism and the see-through mirror.

A virtual image display apparatus includes a display element, an optical element configured to pass therethrough image light emitted from the display element, a reflecting mirror configured to reflect the image light emitted from the optical element, a see-through hologram mirror of a see-through type configured to reflect the image light, emitted from the reflecting mirror, to a pupil position, and a linear diffraction element of a transmissive type arranged on an optical path from the optical element to the hologram mirror. The optical element, the reflecting mirror, and the see-through hologram mirror are arranged to form an off-axis system, and the linear diffraction element compensates wavelength dispersion caused by the see-through hologram mirror at an off-axis surface of the off-axis system.

An optical system in which an aggressively compact reflective front end is combined with beam splitting elements and refractive relay optics to allow several imaging systems working in widely different wavelength bands to share a common aperture. The aggressively compact design results in significant field curvature at the uncorrected intermediate or virtual focus, which is corrected in the refractive relay optics for each band's imaging path.

An image display apparatus according to an aspect of the present technology includes a light source, an image generator, and a projection optical system. The image generator modulates light emitted from the light source and generates image light. The projection optical system includes a lens system and a concave reflective surface. The lens system is configured on a basis of a reference axis at a position on which the generated image light is incident, and has a positive refracting power as a whole. The concave reflective surface is configured on a basis of the reference axis, and reflects the image light emitted from the lens system toward a projection target. In addition, the concave reflective surface reflects at least one or more light beams included in the image light incident on the concave reflective surface, toward a direction that intersects with a direction along the reference axis at an angle of 80 degrees or more.

An optical system configured to guide a light beam from a display element includes a positive lens, a negative lens, and an optical element having at least three optical surfaces. The light beam from the display element is reflected a plurality of times inside the optical element via the positive lens and the negative lens, and then travels to an exit pupil. A predetermined condition is satisfied.

The invention discloses an optical system of near-eye see-through head-mounted display, comprising a first lens, a second lens and a micro image display, the first lens and the second lens are attached to the micro image display, and the first lens and the second lens are free-form lenses with a uniform thickness. The architecture of the optical system of near-eye see-through head-mounted display provided by the present invention can not only reduce the number of times the light is refracted in the architecture of the optical system, but also eliminate the aberration of the light emitted by the micro image display in all directions, making the images be viewed from all directions and angles with no aberration.

An optical system in which an aggressively compact reflective front end is combined with beam splitting elements and refractive relay optics to allow several imaging systems working in widely different wavelength bands to share a common aperture. The aggressively compact design results in significant field curvature at the uncorrected intermediate or virtual focus, which is corrected in the refractive relay optics for each band's imaging path.