An on-axis four mirror anastigmat telescope includes an entrance pupil configured to receive light from an image, and a mirror assembly. The mirror assembly has a first reflective surface having a central aperture formed therein, a second reflective surface, a third reflective surface having a central aperture formed therein, a fourth reflective surface, and an aperture stop. The mirror assembly is configured to receive light from the image on a common axis and to reflect the light successively by the four coaxial reflective surfaces through the aperture stop. The telescope further comprises a detector configured to receive light from the mirror assembly. The central aperture formed in the first reflective surface defines a field stop to limit the field of view.

A method for displaying virtual content to a user, the method includes determining an accommodation of the user's eyes. The method also includes delivering, through a first waveguide of a stack of waveguides, light rays having a first wavefront curvature based at least in part on the determined accommodation, wherein the first wavefront curvature corresponds to a focal distance of the determined accommodation. The method further includes delivering, through a second waveguide of the stack of waveguides, light rays having a second wavefront curvature, the second wavefront curvature associated with a predetermined margin of the focal distance of the determined accommodation.

A method for displaying virtual content to a user, the method includes determining an accommodation of the user's eyes. The method also includes delivering, through a first waveguide of a stack of waveguides, light rays having a first wavefront curvature based at least in part on the determined accommodation, wherein the first wavefront curvature corresponds to a focal distance of the determined accommodation. The method further includes delivering, through a second waveguide of the stack of waveguides, light rays having a second wavefront curvature, the second wavefront curvature associated with a predetermined margin of the focal distance of the determined accommodation.

In one example, an on-mirror adaptive optics system may include a substrate including a deformable surface, a controller and a plurality of pockets defined in a substrate. Each of the pockets may include a an electrooptical sensor and an actuator. The controller may be communicatively coupled to the electrooptical sensor and the actuator. The controller may be configured to generate control voltages based on signals received from the electrooptical sensor to deform a portion of the deformable surface proximate a corresponding pocket of the plurality of pockets.

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 catadioptric lens includes at least two optical elements arranged along an optical axis. Both optical elements are configured as a mirror having a substrate and a highly reflective coating applied to an interface of the substrate. The highly reflective coating extends from the interface of the substrate along a surface normal. At least one of the highly reflective coatings has one or a plurality of layers. The optical total layer thickness of the one layer of the plurality of layers increases radially from the inner area outward.

A head-up display includes a display device and a projection optical system; the projection optical system includes first and second optical elements arranged in order of an optical path from the image; and when optical paths corresponding to an upper end and a lower end of the virtual image are defined as an upper ray and a lower ray, respectively, and a diverging effect and a converging effect are defined as being negative and positive, respectively, the first and the second optical elements satisfy conditional expressions P_u1−P_l1<0 and P_u2−P_l2>0 (where P_u1 denotes a local power of the first optical element acting on the upper ray, P_l1 denotes a local power of the first optical element acting on the lower ray, P_u2 denotes a local power of the second optical element acting on the upper ray, P_l2 denotes a local power of the second optical element acting on the lower ray).

A head-up display includes a display device and a projection optical system; the projection optical system includes first and second optical elements arranged in order of an optical path from the image; and when optical paths corresponding to an upper end and a lower end of the virtual image are defined as an upper ray and a lower ray, respectively, and a diverging effect and a converging effect are defined as being negative and positive, respectively, the first and the second optical elements satisfy conditional expressions P_u1−P_l1<0 and P_u2−P_l2>0 (where P_u1 denotes a local power of the first optical element acting on the upper ray, P_l1 denotes a local power of the first optical element acting on the lower ray, P_u2 denotes a local power of the second optical element acting on the upper ray, P_l2 denotes a local power of the second optical element acting on the lower ray).

A lens apparatus includes two optical systems each of which includes, in order from an object side to an image side, a negative first lens unit, a first reflective member, an aperture diaphragm, a second reflective member, and a positive second lens unit. Each optical system satisfies following inequalities:

5.9<DR/f<13.6

0.7<D2/f2<5.2

10.4<DP/f<19.8

DR represents a distance on an optical axis from a reflective surface of the first reflective member to a reflective surface of the second reflective member. f represents a focal length of the optical system. f2 represents a focal length of the second lens unit. D2 represents a distance on the optical axis from the reflective surface of the second reflective member to an image plane. DP represents a distance on the optical axis from the aperture diaphragm to the image plane.

A lens apparatus includes two optical systems each of which includes, in order from an object side to an image side, a negative first lens unit, a first reflective member, an aperture diaphragm, a second reflective member, and a positive second lens unit. Each optical system satisfies following inequalities:

5.9<DR/f<13.6

0.7<D2/f2<5.2

10.4<DP/f<19.8

DR represents a distance on an optical axis from a reflective surface of the first reflective member to a reflective surface of the second reflective member. f represents a focal length of the optical system. f2 represents a focal length of the second lens unit. D2 represents a distance on the optical axis from the reflective surface of the second reflective member to an image plane. DP represents a distance on the optical axis from the aperture diaphragm to the image plane.