A hearing aid and related systems and methods. In one implementation, a hearing aid system may comprise a wearable camera configured to capture images from an environment of a user, a microphone configured to capture sounds from the environment of the user, and a processor. The processor may be programmed to receive images captured by the camera; receive audio signals representative of sounds captured by the microphone; operate in a first mode to cause a first selective conditioning of a first audio signal; determine, based on analysis of at least one of the images or the audio signals, to switch to a second mode to cause a second selective conditioning of the first audio signal; and cause transmission of the first audio signal selectively conditioned in the second mode to a hearing interface device configured to provide sound to an ear of the user.

A near-eye display device, including: a display screen (1) used for image display; an imaging lens (2) located at a light emission side of the display screen (1) and used for imaging a displayed image of the display screen (1); a flat plate (3) located on the side of the imaging lens (2) facing away from the display screen (1) and obliquely arranged relative to the optical axis of the imaging lens (2); a phase retardation layer (4) located on the side of the flat plate (3) facing the imaging lens (2); a polarization beam-splitting layer (5) located between the phase retardation layer (4) and the flat plate (3); a polarizing layer (6) located between the polarization splitting layer (5) and the flat plate (3); and a curved mirror (7).

The present invention relates to a reflective eyepiece optical system and a head-mounted near-to-eye display device. The system includes: a first lens group, a first optical element and a second lens group for transmitting and reflecting light from a miniature image displayer; the second lens group includes an optical reflection surface, and the optical reflection surface is the optical surface farthest from a human eye viewing side in the second lens group; the optical reflection surface is concave to human eyes; the first optical element reflects the light refracted by the first lens group to the second lens group, and then transmits the light refracted, reflected and again refracted by the second lens group to the human eyes.

An optical element includes a light guide plate, an incidence portion, and an emission portion, in which each of the incidence portion and the emission portion includes diffraction portions, the diffraction portion includes diffraction elements, the diffraction element includes a liquid crystal diffraction layer in which a direction of an optical axis of a liquid crystal compound changes while continuously rotating in one in-plane direction, and in a case where the direction in which the direction of the optical axis changes is set as an in-plane rotation direction and a length over which the optical axis rotates by 180° is set as an in-plane period, in-plane rotation directions of liquid crystal diffraction layers of incidence diffraction elements in at least two of a plurality of the incidence diffraction portions are different from each other.

The present invention relates to a reflective eyepiece optical system and a head-mounted near-to-eye display device. The system includes: a first optical element and a second optical element arranged successively in an incident direction of an optical axis of human eyes, and a first lens group located on an optical axis of a miniature image displayer. The first optical element is used for transmitting and reflecting an image light from the miniature image displayer. The second optical element includes an optical reflection surface. The first optical element reflects the image light refracted by the first lens group to the second optical element, and then transmits the image light reflected by the second optical element to the human eyes.

The present invention relates to a reflective eyepiece optical system and a head-mounted near-to-eye display apparatus. The system includes: a first lens group, and a first optical element and a second lens group for transmitting and reflecting a light from a miniature image displayer. The second lens group includes an optical reflection surface, and the optical reflection surface is an optical surface farthest from a human eye viewing side in the second lens group. The optical reflection surface is concave to a human eye viewing direction. The first optical element reflects the light refracted by the first lens group to the second lens group, and then transmits the light refracted, reflected, and refracted by the second lens group to the human eye.

The disclosed ultrasound devices may include at least one ultrasound transmitter positioned and configured to transmit ultrasound signals toward a user's face to reflect off a facial feature of the user's face and at least one ultrasound receiver positioned and configured to receive and detect the ultrasound signals reflected off the facial feature. At least one processor may be configured to receive data from the at least one ultrasound receiver and to determine, based on the received data from the at least one ultrasound receiver, at least one of the following eye measurements: an interpupillary distance of the user; an eye relief; or a position of a head-mounted display relative to the facial feature of the user. Various other devices, systems, and methods are also disclosed.

A light guide includes: a light guide board configured to allow light incident on an optical entrance to propagate through the light guide board, the light guide board including: the optical entrance; a first face; and at least one partial reflection layer within the light guide board and tilted to the first face. The at least one partial reflection layer is configured to reflect a part of light incident on the at least one partial reflection layer at an incident angle of greater than or equal to a critical angle θ.sub.r to allow the reflected light to exit the light guide board through the first surface while transmitting therethrough a remainder of the light incident on the at least one partial reflection layer. Formula below is satisfied: θ.sub.r=sin.sup.−1(n.sub.2/n.sub.1) where θ.sub.r is the critical angle; n.sub.1 is a refractive index of the light guide board; and n.sub.2 is a refractive index of the at least one partial reflection layer.

Augmented reality headsets. A plurality of tilted pin-mirrors imbedded between an inner surface and an outer surface of a combiner, where the plurality of tilted pin-mirrors are configured to reflect the guided image light towards the eye box, and wherein the plurality of pin-mirrors include one or more gaps between them wherein the one or more gaps allow the passage of an ambient light through the combiner towards the eye box.

A wearable display device includes a light source, a beam scanner, a pupil-replicating lightguide, and a detector. The light source is configured to emit an image beam and a ranging beam. The beam scanner co-scans both beams. The image beam is used to form an image in angular domain for displaying to a user of the wearable display device, and a ranging beam is used to scan outside environment at the same time. Light reflected from objects in the outside environment is detected by the detector, and a 3D map of the outside environment is built using time-of-flight measurements of the reflected signal and/or triangulation. For triangulation measurements, the detector may include a digital camera.