A device is provided. The device includes a first lens assembly controllable to switch between a first plurality of optical powers. The first lens assembly includes a plurality of directly optically coupled lenses, and is configured to converge or diverge a light transmitted therethrough. The device also includes a second lens assembly coupled with the first lens assembly, and controllable to switch between a second plurality of optical powers that are opposite to the first plurality of optical powers.

A metalens includes one or more regions of nanostructures. A first region of nanostructures directs a first field of view (FOV) of light incident on the first region of nanostructures to a first region of an image plane. A second region of nanostructures directs a second FOV of light incident on the second region of nanostructures to a second region of the image plane in which the second FOV is different from the first FOV, and the second region of the image plane is different from the first region of the image plane. A third region of nanostructures directs a third FOV of light to a third region of the image plane, in which the third FOV is different from the first FOV and the second FOV, and the third region of the image plane is different from the first region and the second region of the image plane.

A metalens includes one or more regions of nanostructures. A first region of nanostructures directs a first field of view (FOV) of light incident on the first region of nanostructures to a first region of an image plane. A second region of nanostructures directs a second FOV of light incident on the second region of nanostructures to a second region of the image plane in which the second FOV is different from the first FOV, and the second region of the image plane is different from the first region of the image plane. A third region of nanostructures directs a third FOV of light to a third region of the image plane, in which the third FOV is different from the first FOV and the second FOV, and the third region of the image plane is different from the first region and the second region of the image plane.

A spectacle lens includes a first volume element group containing a plurality of first volume elements. The plurality of first volume elements is made from a material with a first Abbe number in the form of grid points of a geometric grid. Further, the spectacle lens includes a second volume group containing a plurality of second volume elements, which form a second partial grid in the form of grid points of a geometric grid, the second volume elements being made of a second material having a second Abbe number, wherein the first Abbe number and the second Abbe number differ from each other. The first partial grid and the second partial grid are arranged offset from each other. The disclosure also relates to a corresponding computer-implemented method for designing a spectacle lens of the type and to a method for producing the type of spectacle lens.

An imaging apparatus including: an image sensor having a photo-sensitive surface; an optical device arranged on an optical path of light incidenting on the photo-sensitive surface, the optical device being electrically controllable to have a spatially variable focal length; and a processor configured to: generate and send a drive signal to the optical device to compensate for field curvature of optical device by adjusting focal lengths of different portions of the optical device to different extents, wherein a focal length of a first portion of the optical device is higher than a focal length of a second portion of the optical device surrounding the first portion; and control the image sensor to capture a distorted image of a real-world environment.

SMA actuators and related methods are described. One embodiment of an actuator includes a base; a plurality of buckle arms; and at least a first shape memory alloy wire coupled with a pair of buckle arms of the plurality of buckle arms. Another embodiment of an actuator includes a base and at least one bimorph actuator including a shape memory alloy material. The bimorph actuator attached to the base.

This lens unit comprises: a lens having a liquid crystal lens; a rim part that covers the peripheral edge section of the lens; a control unit that controls the liquid crystal lens; a conductive part that electrically connects the control unit and an electrode end section of the liquid crystal lens which is exposed at the peripheral edge section of the lens, and that is disposed between the rim part and the peripheral edge section of the lens; and a knob part that protrudes from the lens or rim part.

An illumination system includes an excitation light source, a first variable focus lens, a second variable focus lens, and a control unit. The excitation light source is adapted to provide an excitation light beam. The first variable focus lens is disposed on a transmission path of the excitation light beam. The first variable focus lens is located between the excitation light source and the second variable focus lens. The second variable focus lens is adapted to receive the excitation light beam exited from the first variable focus lens. The control unit is electrically connected to the first variable focus lens and the second variable focus lens, and is adapted to synchronously adjust focal lengths of the first variable focus lens and the second variable focus lens. A projection device including the above-mentioned illumination system of the invention is further provided.

An illumination system includes an excitation light source, a first variable focus lens, a second variable focus lens, and a control unit. The excitation light source is adapted to provide an excitation light beam. The first variable focus lens is disposed on a transmission path of the excitation light beam. The first variable focus lens is located between the excitation light source and the second variable focus lens. The second variable focus lens is adapted to receive the excitation light beam exited from the first variable focus lens. The control unit is electrically connected to the first variable focus lens and the second variable focus lens, and is adapted to synchronously adjust focal lengths of the first variable focus lens and the second variable focus lens. A projection device including the above-mentioned illumination system of the invention is further provided.

There are provided an imaging device, a distance measurement method, a distance measurement program, and a recording medium capable of accurately measuring a distance to a subject without depending on a color of the subject. A bifocal imaging lens, a first pixel and a second pixel that respectively pupil-divide and selectively receive luminous flux incident through a first region of the first region and a second region having different focusing distances of the imaging lens, an image sensor having a third pixel and a fourth pixel corresponding to the second region, a first image acquisition unit (41-1) and a second image acquisition unit (41-2) that acquire a first image and a second image having asymmetric blurs from a first pixel group (22A) and a third pixel group (22C) of the image sensor, a third image acquisition unit (43-1) and a fourth image acquisition unit (43-2) that add pixel values of adjacent pixels of the first and second pixels of the image sensor and add pixel values of adjacent pixels of the third and fourth pixels to acquire a third image and a fourth image having symmetric blurs, and a distance calculation unit (45) that calculates a distance to a subject in the image based on the acquired first and third images or the acquired second and fourth images are included.