Provided is an optical system, which retains enhanced optical performance at any object distance, and has compact and light-weight focus lens units. Provided is an optical system including a plurality of lens units, in which an interval between adjacent lens units changes during focusing, the optical system including: a positive lens unit arranged closest to an object side; first and second focus lens units having negative refractive powers configured to move during focusing; and an intermediate lens unit having a positive refractive power and arranged between the first and second focus lens units. The first and second focus lens units are configured to move toward an image side during focusing.

Provided is an optical system, which retains enhanced optical performance at any object distance, and has compact and light-weight focus lens units. Provided is an optical system including a plurality of lens units, in which an interval between adjacent lens units changes during focusing, the optical system including: a positive lens unit arranged closest to an object side; first and second focus lens units having negative refractive powers configured to move during focusing; and an intermediate lens unit having a positive refractive power and arranged between the first and second focus lens units. The first and second focus lens units are configured to move toward an image side during focusing.

An optical relay system that is capable of re-imaging an image or a pupil from a shared location to two or more optical systems, or from two or more optical systems to a shared location is disclosed.

A display includes a source that establishes an exit pupil of far field content, a reconvergent sheet disposed along an optical axis to receive light of the far field content, the reconvergent sheet being configured to reconverge the far field content in position space, a reflective surface disposed along the optical axis for reflection of light of the position space back through the reconvergent sheet after reflection off of the reflective surface to re-form the exit pupil of the far field content, and a splitter disposed along the optical axis between the source and the reconvergent sheet and configured to redirect light exhibiting the re-formed exit pupil in a direction offset from the optical axis.

A lens system includes a first lens array assembly including a first plurality of cells, each cell of the first plurality of cells configured to exhibit a pair of first Fourier transform lenses, and a second lens array assembly including a second plurality of cells, each cell of the second plurality of cells configured to exhibit a pair of second Fourier transform lenses. The first Fourier transform lenses have a first pitch. The second Fourier transform lenses have a second pitch differing from the first pitch. The first and second lens array assemblies are positioned relative to one another along an optical axis of the lens system such that a Fourier transform of light from an object is developed at a plane between the first and second lens array assemblies and an image of the object is provided at an image conjugate distance from the second lens array assembly.

The depth of field of an erecting equal-magnification lens array unit as a whole is expanded. An erecting equal-magnification lens array unit (13) includes a first lens array (17) and a second lens array (18). The first lens array (17) includes a plurality of first lenses (20). The first lenses are arranged in the first lens array (17) along a first direction. The first direction is perpendicular to the optical axes of the first lenses (20). The second lens array (18) includes a plurality of second lenses. The optical axes of the second lenses overlap with the optical axes of the first lenses. The second lenses are arranged in the second lens array (18) along the first direction. Each first lens (20) and second lens with overlapping optical axes form an optical system.

The depth of field of an erecting equal-magnification lens array unit as a whole is expanded. An erecting equal-magnification lens array unit (13) includes a first lens array (17) and a second lens array (18). The first lens array (17) includes a plurality of first lenses (20). The first lenses are arranged in the first lens array (17) along a first direction. The first direction is perpendicular to the optical axes of the first lenses (20). The second lens array (18) includes a plurality of second lenses. The optical axes of the second lenses overlap with the optical axes of the first lenses. The second lenses are arranged in the second lens array (18) along the first direction. Each first lens (20) and second lens with overlapping optical axes form an optical system.

Techniques are disclosed for magnification compensation and/or beam steering in optical systems. An optical system may include a lens system to receive first radiation associated with an object and direct second radiation associated with an image of the object toward an image plane. The lens system may include a set of lenses, and an actuator system to selectively adjust the set of lenses to adjust a magnification associated with the image symmetrically along a first and a second direction. The lens system may also include a beam steering lens to direct the first radiation to provide the second radiation. In some examples, the lens system may also include a second set of lenses, where the actuator system may also selectively adjust the second set of lenses to adjust the magnification along the first or the second direction. Related methods are also disclosed.

A lens unit includes a first lens array including first lenses arranged in at least two lines; a second lens array including second lenses arranged in an arrangement relationship corresponding to the first lens array, the second lenses respectively facing the first lenses, the second lens array being arranged to face the first lens array so that each pair of the first and second lenses has a common optical axis; and a first light blocking member arranged between the first lens array and the second lens array and having first openings each being arranged to face the pair of the first and second lenses in a direction of the optical axis. An interval PXL from an array center position between two adjacent lines to the optical axis and an interval PXS from the array center position to an opening center of the first opening satisfy PXL<PXS.

A rod lens array 10a includes a plurality of gradient-index rod lenses 1b arrayed to have optical axes parallel to each other, and forms an erecting equal-magnification image. The gradient-index rod lenses 1b each have a refractive-index distribution in a radial direction thereof. The refractive-index distribution n(r) is approximated by n(r)=n.sub.0⋅{1-(A/2)⋅r.sup.2}, where a refractive index at a center of the gradient-index rod lens 1b is represented by n.sub.0, a refractive-index distribution constant of the gradient-index rod lens 1b is represented by \A, and a distance from the center of the gradient-index rod lens 1b is represented by r. The gradient-index rod lens 1b has an aperture angle θ of 3 to 6°, the aperture angle θ represented by θ=sin.sup.−1(n.sub.0\A⋅r.sub.0), where a radius of the gradient-index rod lens is represented by r.sub.0. The rod lens array 10a has an imaging distance of 45 to 75 mm and a depth of field of 1.5 to 3.0 mm with value of modulation transfer function (MTF) of 30% or more at a spatial frequency of 6 Ip/mm.