The present invention provides a deformation apparatus that deforms a surface of a member, the apparatus comprising: a plurality of actuators each of which is configured to apply a force to the member to deform the surface; a measurement device configured to measure an induced electromotive force generated in a first actuator of the plurality of actuators; and a controller configured to control the plurality of actuators, wherein the controller causes the measurement device to measure a temporal variation of an induced electromotive force in the first actuator while vibrating the member by using a second actuator, of the plurality of actuators, which is different from the first actuator, converts the measured temporal variation of the induced electromotive force into a frequency spectrum, and detects an abnormality in the first actuator based on the frequency spectrum.

A light detection and ranging (LIDAR) device scans through a scanning zone while emitting light pulses and receives reflected signals corresponding to the light pulses. The LIDAR device scans the emitted light pulses through the scanning zone by reflecting the light pulses from an array of oscillating mirrors. The mirrors are operated by a set of electromagnets arranged to apply torque on the mirrors, and an orientation feedback system senses the orientations of the mirrors. Driving parameters for each mirror are determined based on information from the orientation feedback system. The driving parameters can be used to drive the mirrors in phase at an operating frequency despite variations in moments of inertia and resonant frequencies among the mirrors.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining the identity of a user. In one aspect, a method comprises: obtaining at least one image depicting a reflection of light from a lens that is included in a set of eyeglasses; determining, based on the reflection of light from the lens, a set of features characterizing the lens; and determining an identity of a corresponding user based at least in part on the set of features characterizing the lens.

A system for preventing motion sickness resulting from virtual reality or augmented reality is disclosed herein. In one embodiment, the system includes a virtual reality or augmented reality headset configured to be worn by a user, the virtual reality or augmented reality headset configured to create an artificial environment and/or immersive environment for the user; at least one fluidic lens disposed between an eye of the user and a screen of the virtual reality or augmented reality headset; and a fluid control system operatively coupled to the at least one fluidic lens. In another embodiment, the system includes at least one tunable prism disposed between an eye of the user and a screen of the virtual reality or augmented reality headset, the at least one tunable prism configured to correct a convergence problem associated with the eye of the user.

A mirror that has a mirror substrate (12), a reflection layer stack (21) reflecting electromagnetic radiation incident on the optical effective surface (11), and at least one piezoelectric layer (16) arranged between the mirror substrate and the reflection layer stack and to which an electric field for producing a locally variable deformation is applied by way of a first electrode arrangement and a second electrode arrangement situated on alternate sides of the piezoelectric layer. In one aspect, both the first and the second electrode arrangements have a plurality of electrodes (20a, 20b), to each of which an electrical voltage relative to the respective other electrode arrangement can be applied via leads (19a, 19b). Separate mediator layers (17a, 17b) set continuous electrical potential profiles along the respective electrode arrangement, and where said mediator layers differ from one another in their average electrical resistance by a factor of at least 1.5.

A mirror arrangement (30) includes: a substrate (31) with a front side (31a) having a mirror face (32a) reflecting radiation (5), and a rear side (31b) facing away from the front side and on which at least one actuator (27) generating deformations of the mirror face is arranged. A water vapor (36)-sorbing material (33, 42) is formed on the rear side (31b) and forms an adhesive layer (33) for securing the actuator. The layer extends into interspaces (35) between the actuators (27). A surface (33a, 42a) of the water vapor-sorbing material is covered at least partly by a coating (37) which forms a water vapor diffusion barrier.

Systems and methods for auto-calibrating a virtual reality (VR) or augmented reality (AR) head-mounted display to a given user with a refractive condition without adding corrective lenses to optical elements of the head-mounted display and without requiring subjective refraction procedures. An autorefractor assembly of the head-mounted display, or a separate autorefractor headset, measures refractive error and communicates the measurements to a control system of the head-mounted display. Based on the refractive error measurements, the head-mounted display can adjust adaptive lenses and other adaptive optics to modify transmitted images; can make compensating adjustments to images displayed by a stereoscopic display device of the head-mounted display; or can make both types of adjustment. These automatic calibrations correct displayed images to compensate for refractive aberration in one or both eyes of the user. In an embodiment, the head-mounted display can correct other vision defects of the given user measured by objective ophthalmic examination.

A mirror assembly includes a mirror housing and a mirror. The mirror is supported by the mirror housing. The mirror has an outer reflective surface. The mirror is bendable between a flat shape and a fisheye shape. The mirror assembly further includes an actuator assembly coupled to the mirror. Upon actuation, the actuator assembly is configured to bend the mirror between the flat shape and the fisheye shape to adjust a field of view of the mirror.

A device for thermally actuating a deformable mirror includes a monolithic block that includes a mirror plate having a front face forming or configured to support a mirror, a base, and a one-dimensional array of thermally expandable actuators. The thermally expandable actuators mechanically connect a rear face of the mirror plate to the base such that shape, tilt, and/or location of the front face depend on temperature of the thermally expandable actuators. The mirror plate, base, and thermally expandable actuators are defined by slits that span between opposite-facing top and bottom surfaces of the monolithic block. The monolithic block may be made of a metal and may be manufactured at relatively low cost by wire eroding the slits in a metal block, using a wire that passes through the metal block between its top and bottom surfaces.

A system for correcting the wavefront of a laser beam includes a beamsplitter for splitting off a fraction of the laser beam to be used as a diagnostic beam, a focusing element for bringing the diagnostic beam to a focus, a measurement subsystem for measuring sizes of the diagnostic beam at upstream and/or downstream locations with respect to a nominal location of the focus, and at least one adaptive optic, located upstream from the beamsplitter, for correcting the wavefront of the laser beam at least partly based on the measured sizes of the diagnostic beam at the upstream and/or downstream locations. The upstream and downstream locations correspond to mid-field locations in the laser beam as imaged by the focusing element. The system takes advantage of the sensitivity of the laser beam size to a waist location shift being greatest at one Rayleigh length from the nominal waist location.