A composite lens system may include one or more first optical elements configured to provide a first focal length selected from a first continuous range of focal lengths, as well as one or more second optical elements configured to provide a discrete focal length selected from a plurality of discrete focal lengths. The one or more first optical elements and the one or more second optical elements may be configured in series such that the composite lens system provides an output focal length based on a combination of the selected first focal length and the selected discrete focal length.

Certain exemplary embodiments can provide a system, machine, apparatus, device, manufacture, circuit, composition of matter, and/or user interface adapted for and/or resulting from, and/or a process, method, and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise and/or relate to, generating a gradient in an index of refraction of a material.

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.

According to one embodiment, a light control device includes a first liquid crystal cell, a second liquid crystal cell, and a polarization conversion element disposed between the first liquid crystal cell and the second liquid crystal cell. One substrate of each of the first liquid crystal cell and the second liquid crystal cell includes an insulating substrate, and first to fourth electrodes arranged on the insulating substrate and formed in a strip shape. The electric potential difference between the first electrode and the second electrode, the electric potential difference between the second electrode and the third electrode, and the electric potential difference between the third electrode and the fourth electrode are different from each other.

A speed sensor, a device for measuring a speed, and a method for measuring a speed are provided. The speed sensor includes: an imaging device; a liquid crystal lens on a side of the imaging device; and a controller configured to: apply different voltages to the liquid crystal lens, obtain, via the imaging device, images of a reference object formed through the liquid crystal lens under the different voltages, control, based on information of the images, the liquid crystal lens to realize focus for multiple times for the reference object, obtain a voltage that is correspondingly applied to the liquid crystal lens when each of the multiple times of focus is realized, and calculate a speed based on the voltages.

A liquid crystal element (100) includes a plurality of unit electrodes (10), a liquid crystal layer (LQ), and a plurality of wall members (WL). Each of the unit electrodes (10) includes a first electrode (1) and a second electrode (2). A voltage is applied to the liquid crystal layer (LQ) from each of the unit electrodes (10). The wall members (WL) are arranged in the liquid crystal layer (LQ). The liquid crystal layer (LQ) has a waveform retardation (RT). Two or more of a plurality of peaks (P1) in the retardation (RT) correspond to positions of respective wall members (WL).

Described are examples of adjustable focus glasses formed using liquid crystal. A pair of adjustable focus glasses can include a frame and two lenses arranged on the frame. In some examples, at least one of the two lenses is a lens assembly that includes a plano-concave lens, a Fresnel lens, and a liquid crystal layer between the plano-concave lens and the Fresnel lens. The plano-concave lens includes a planar surface and an opposing concave surface. The Fresnel lens includes a Fresnel surface and an opposing convex surface. The planar surface and the Fresnel surface face the liquid crystal layer. The focus position of the lens assembly can be adjusted through changing the refractive index of the liquid crystal layer, using appropriate control signals from an electronic controller. This conveniently allows the adjustable focus glasses to be multi-purpose and suitable for correcting both myopia and hyperopia.

The present disclosure provides a light field display device. The light field display device includes a plurality of imaging modules. Each of the imaging modules includes a liquid crystal lens array and a display screen, the liquid crystal lens array is disposed on a light exit side of the display screen, and images of the plurality of imaging modules are parallel to each other.

An optical combiner in a display system of a mixed-reality head-mounted display (HMD) device comprises a lens of birefringent material and a ferroelectric liquid crystal (FLC) modulator that are adapted for use with a reflective waveguide to provide multiple different focal planes on which holograms of virtual-world objects (i.e., virtual images) are displayed. The birefringent lens has two orthogonal refractive indices, ordinary and extraordinary, depending on the polarization state of the incident light. Depending on the rotation of the polarization axis by the FLC modulator, the incoming light to the birefringent lens is focused either at a distance corresponding to the ordinary refractive index or the extraordinary refractive index. Virtual image light leaving the birefringent lens is in-coupled to a see-through reflective waveguide which is configured to form an exit pupil for the optical combiner to enable an HMD device user to view the virtual images from the source.

Certain exemplary embodiments can provide a system, machine, apparatus, device, manufacture, circuit, composition of matter, and/or user interface adapted for and/or resulting from, and/or a process, method, and/or machine-readable medium comprising machine-implementable instructions for, activities that can comprise and/or relate to, generating a gradient in an index of refraction of a material.