Abstract: This document relates to head mounted display devices. One example can include a housing configured to be positioned relative to a head and eye of a user and a transparent visual assembly positioned by the housing in front of the user's eye and comprising multiple eye tracking illuminators distributed across the transparent visual assembly and configured to emit non-visible light and multiple eye tracking detectors distributed across the transparent visual assembly and configured to detect the non-visible light reflected back from the eye of the user.

Abstract: An input-coupler of an optical waveguide includes one or more Bragg polarization gratings for coupling light corresponding to the image in two different directions into the optical waveguide. The input-coupler splits the FOV of the image coupled into the optical waveguide into first and second portions by diffracting a portion of the light corresponding to the image in a first direction toward a first intermediate component, and diffracting a portion of the light corresponding to the image in a second direction toward a second intermediate component. An output-coupler of the waveguide combines the light corresponding to the first and second portions of the FOV, and couples the light corresponding to the combined first and second portions of the FOV out of the optical waveguide so that the light corresponding to the image and the combined first and second portions of the FOV is output from the optical waveguide.

Abstract: An input-coupler of an optical waveguide includes one or more Bragg polarization gratings for coupling light corresponding to the image in two different directions into the optical waveguide. The input-coupler splits the FOV of the image coupled into the optical waveguide into first and second portions by diffracting a portion of the light corresponding to the image in a first direction toward a first intermediate component, and diffracting a portion of the light corresponding to the image in a second direction toward a second intermediate component. An output-coupler of the waveguide combines the light corresponding to the first and second portions of the FOV, and couples the light corresponding to the combined first and second portions of the FOV out of the optical waveguide so that the light corresponding to the image and the combined first and second portions of the FOV is output from the optical waveguide.

Abstract: The disclosure describes an apparatus including a micro-display including an array of individual display pixels positioned along a substantially planar emission surface. An optical fixture is coupled to the substantially planar emission surface and optically coupled to the individual display pixels, wherein the optical fixture forms a virtual or real non-planar object surface of the micro-display.

Abstract: Transmission apparatus for beam expansion are disclosed. A transmission apparatus includes a light source configured to emit an optical signal, a first feature comprising a diffractive element and a reflective element, and a second feature that is substantially aligned with the first feature. The diffractive element is substantially aligned with the light source to receive the optical signal. The second feature includes an inner surface that is partially reflective and partially transmissive. The first feature is located between the light source and the second feature. The diffractive element is configured to diffract the optical signal, the second feature is configured to: (a) reflect a first portion of the diffracted optical signal and (b) transmit a second portion of the diffracted optical signal to a destination balloon; and the second feature is further configured to transmit at least part of the first portion of the diffracted optical signal to the destination balloon.

Abstract: An apparatus for a head mounted display includes a display module for launching display light along a forward propagating path. The apparatus also includes a light relay to receive the display light. The light relay includes a first optic disposed along the forward propagating path. The light relay also includes a second optic disposed along the forward propagating path between the first optic and the display module. The first optic is configured to direct the display light in an eye-ward direction and the second optic is configured to direct the display light in an eye-ward direction.

Abstract: A head mounted display (“HMD”) includes a display module, an eyepiece, a switchable hologram, and a controller. The display module is configured for launching CGI light along a forward propagating path. The eyepiece is optically coupled to receive the CGI light and direct the CGI light to an eye-ward region of the eyepiece. The switchable hologram is disposed along a surface of the eyepiece and the switchable hologram is configured to redirect ambient light propagating toward the eyepiece, when activated. The controller is coupled to the switchable hologram to activate and deactivate the switchable hologram.

Abstract: An apparatus for a head mounted display includes a display module for launching display light along a forward propagating path. The apparatus also includes a light relay to receive the display light. The light relay includes a first optic disposed along the forward propagating path. The light relay also includes a second optic disposed along the forward propagating path between the first optic and the display module. The first optic is configured to direct the display light in an eye-ward direction and the second optic is configured to direct the display light in an eye-ward direction.

Abstract: An angle sensor for detecting an out-of-round condition includes a disc supporting angle coder rigidly attached to a rotating shaft and at least one fixed optical system including a coherent light source emitting a beam interfering with the angle coder of the support disc in order to code its angular position, a collimator of the said beam before interference and a photo detector of the modulated beam after interference. In one embodiment, two optical systems arranged 90° from each other are employed. An alternative embodiment includes one optical system and the disc includes a circular track radially centred in at least one of its angular positions relative to the incident collimated light beam, and a radially orientated photo detector.

Abstract: Optical rotation counter associated with a rotary disc of an angle sensor provided with means for coding the angular position of the disc, including at least one fixed source of coherent light emitting a light beam, a diaphragm and a support moved by the rotation of the coding disc. On its face facing the incident beam, the support includes at least one cell for coding its displacement orientated in the direction of the said displacement and generates an optical code by interference with the incident light beam, the said optical code being readable after interference on at least one photodetector.

Abstract: Device for detection of out-of-round on an angle sensor including a disc supporting angle coding means rigidly attached to a rotating shaft and at least one fixed optical system including a coherent light source emitting a beam interfering with the angle coding means of the support disc in order to code its angular position, means for collimation of the said beam before interference and a photodetector of the modulated beam after interference. In accordance with one possibility, it includes two optical systems arranged 90° from each other. Alternatively, there is only one optical system and the disc includes a circular track radially centred in at least one of its angular positions relative to the incident collimated light beam, and a radially orientated photodetector.

Abstract: Device for detection of out-of-round on an angle sensor including a disc supporting angle coding means rigidly attached to a rotating shaft and at least one fixed optical system including a coherent light source emitting a beam interfering with the angle coding means of the support disc in order to code its angular position, means for collimation of the said beam before interference and a photodetector of the modulated beam after interference. In accordance with one possibility, it includes two optical systems arranged 90° from each other. Alternatively, there is only one optical system and the disc includes a circular track radially centered in at least one of its angular positions relative to the incident collimated light beam, and a radially orientated photodetector.

Abstract: A method for determining the position of one of two components in relative motion with respect to each other, using optical means, comprises: directing at least one light beam emitted by a light source attached to one component towards a diffractive support attached to the second component, calculated and manufactured for generating an optical signal indicative of the positioning of said support, the optical signal being produced by the diffractive support in transmission and/or in reflection; detecting and reading at least one optical code formed by said signal, which corresponds to a unique position of the diffractive support relatively to the beam; and assigning a position to each detected optical code.

Abstract: Device for detection of out-of-round on an angle sensor including a disc supporting angle coding means rigidly attached to a rotating shaft and at least one fixed optical system including a coherent light source emitting a beam interfering with the angle coding means of the support disc in order to code its angular position, means for collimation of the said beam before interference and a photodetector of the modulated beam after interference. In accordance with one possibility, it includes two optical systems arranged 90° from each other. Alternatively, there is only one optical system and the disc includes a circular track radially centred in at least one of its angular positions relative to the incident collimated light beam, and a radially orientated photodetector.

Abstract: Optical rotation counter associated with a rotary disc of an angle sensor provided with means for coding the angular position of the disc, including at least one fixed source of coherent light emitting a light beam, a diaphragm and a support moved by the rotation of the coding disc. On its face facing the incident beam, the support includes at least one cell for coding its displacement orientated in the direction of the said displacement and generates an optical code by interference with the incident light beam, the said optical code being readable after interference on at least one photodetector.

Abstract: An optical encoder uses an encoder member with a digital diffractive track to optically manipulate an incident beam of light into manipulated beams of light, which are detected as spots of light that represent a digital absolute position value of the encoder member.

Abstract: Coder of position of a first element in displacement relatively to a second element, the latter including an optical system provided with at least one coherent light source emitting a beam intended to interfere, after collimation in a diaphragm, with the second element and at least one photodetector with contiguous cells in a line for detection of the light signal after interference. The second element includes a succession of primary coding cells provided with diffraction holograms each defining therein a single location, the cells interfering in succession with the light beam in the course of their relative displacement. The diffracted signal is sent to the photodetector or photodetectors for measurement of absolute position. The coder includes a series of secondary coding cells provided with diffraction holograms interfering successively with the light beam.

Abstract: A method for determining the position of one of two components in relative motion with respect to each other, using optical means, comprises: directing at least one light beam emitted by a light source attached to one component towards a diffractive support attached to the second component, calculated and manufactured for generating an optical signal indicative of the positioning of said support, the optical signal being produced by the diffractive support in transmission and/or in reflection; detecting and reading at least one optical code formed by said signal, which corresponds to a unique position of the diffractive support relatively to the beam; and assigning a position to each detected optical code.

Abstract: A diffractive lens constructed in accordance with the invention comprises a set of bands such that the diffractive gratings in each band are modified. This is done to ensure that even if the lens is tilted (e.g. to prevent light from reflecting off the lens and, introducing distortion into an optical system), the lens continues to focus light onto a small point on a target surface. (The target surface is typically an optical or magneto-optic data recording medium.

Abstract: A magneto optic or optical disk drive comprises a laser source for providing laser beam, and a lens or compound lens for focussing the laser onto a currently inserted recording disk with specific overcoat thickness. In one embodiment, the lens is a compound lens that can focus aberration-free spots on different types of disk media having recording layers located under overcoats of different thicknesses. When a specific disk is inserted, only one spot in focussed onto the current recording layer. Furthermore, if the disk spins rapidly, it can wobble. The lens or compound lens comprises different regions where the focal length may vary slightly and continuously or discretely. Because of this, as the disk wobbles, the lens can nonetheless continue to focus laser light onto a small spot on the recording media, providing increased depth of focus in the vicinity of the currently inserted recording media.