Layered waveguides, multi-layer waveguide displays with layered waveguides, and methods of fabricating layered waveguides with selective bonding material deposition and/or patterning.

There is disclosed herein a display device comprising a picture generating unit, a waveguide pupil expander and a viewer-tracking system. The picture generating unit comprises a first display channel, a second display channel and a controller. The first display channel is arranged to output first spatially-modulated light of a first colour. The first spatially-modulated light corresponds to a first picture. The second display channel is arranged to output second spatially-modulated light of a second colour. The second spatially-modulated light corresponding to a second picture. The controller is arranged to drive the first display channel and second display channel. The waveguide pupil expander comprises a pair of parallel reflective surfaces. The waveguide pupil expander defines an input port and a viewing window. The input port is arranged to receive the first spatially-modulated light and the second spatially-modulated light. The viewing window is an area or volume within which a viewer may view the first picture and the second picture. The pair of parallel reflective surfaces is arranged to guide the first spatially-modulated light and the second spatially-modulated light from the input port to the viewing window by a series of internal reflections. The reflectivity of a first reflective surface of the pair of parallel reflective surfaces is provided by a graded coating. The graded coating is partially transmissive to light of the first colour and light of the second colour. The transmissivity of the graded coating is non-achromatic. The viewer-tracking system is arranged to determine a viewing position within the viewing window. The controller is arranged to maintain as substantially constant the colour balance of the first and second picture as seen from the viewing position based on the viewing position determined by the viewer-tracking system.

An optical device includes: a light guide plate receiving, for each of N types of wavelength bands, a plurality of parallel light beams with different incident angles each corresponding to view angles, and guiding the received parallel light beams; a first and a second volume hologram gratings of reflection type having a diffraction configuration which includes N types of interference fringes each corresponding to the N types of wavelength bands, and diffracting/reflecting the parallel light beams. The optical device satisfies for each wavelength band, a relationship of ‘P>L’, where ‘L’ represents a central diffraction wavelength in the first and second volume hologram gratings, defined for a parallel light beam corresponding to a central view angle, and ‘P’ represents a peak wavelength of the parallel light beams.

The invention relates to a novel binder system and its use for bonding textile fabrics as well as products containing such bonded textile fabrics. The materials according to the invention are suitable for manufacturing base interlinings which may be used for manufacturing base interlinings for sarking, roofing and sealing membranes, particularly for manufacturing coated sarking, roofing and sealing membranes.

A display device includes a directional illuminator providing a light beam, a display panel downstream of a directional illuminator, for receiving and spatially modulating the light beam, and a beam redirecting module downstream of the display panel, for variably redirecting the spatially modulated light beam. Steering the illuminating light by the beam redirecting module enables one to steer the exit pupil of the display device to match the user's eye location(s).

A virtual image generation system comprises a planar optical waveguide having opposing first and second faces, an in-coupling (IC) element configured for optically coupling a collimated light beam from an image projection assembly into the planar optical waveguide as an in-coupled light beam, a first orthogonal pupil expansion (OPE) element associated with the first face of the planar optical waveguide for splitting the in-coupled light beam into a first set of orthogonal light beamlets, a second orthogonal pupil expansion (OPE) element associated with the second face of the planar optical waveguide for splitting the in-coupled light beam into a second set of orthogonal light beamlets, and an exit pupil expansion (EPE) element associated with the planar optical waveguide for splitting the first and second sets of orthogonal light beamlets into an array of out-coupled light beamlets that exit the planar optical waveguide.

Examples are disclosed that relate to calibration of a stereoscopic display system of an HMD via an optical calibration system comprising a waveguide combiner. One example provides an HMD device comprising a first image projector and a second image projector configured to project a stereoscopic image pair, and an optical calibration system. The optical calibration system comprises a first optical path indicative of an alignment of the first image projector, a second optical path indicative of an alignment of the second image projector, a waveguide combiner in which the first and second optical paths combine into a shared optical path, and one or more boresight sensors configured to detect calibration image light traveling along one or more of the first optical or the second optical path.

An optical arrangement for expanding and uniformizing a beam of light, including a first optical member arranged to receive a collimated incoming light beam, from an incoming beam direction, with a first polarization, the first optical member configured to expand and uniformize the collimated incoming light beam along a first axis to form a first collimated light beam exiting therefrom in a first beam direction; a second optical member adapted to receive the first collimated light beam, from the first beam direction, with the first polarization in relation thereto, the second optical member configured to expand and uniformize the first collimated light beam along a second axis to form a second collimated light beam exiting therefrom in a second beam direction.

According to examples, a system for image generation and delivery in a display device using two-dimensional (2D) field of view (FOV) expander is described. In addition, the system may include a first lens a first lens assembly having a first projector to propagate first display light associated with a first image and a first two-dimensional (2D) expander including a first waveguide for propagating the first display light to a first eye of a user and a second lens assembly having a second projector to propagate second display light associated with a second image and a second two-dimensional (2D) expander having a second waveguide for propagating the second display light to a first eye of a user.

A device includes a waveguide. The device also includes a plurality of grating sets coupled with the waveguide and configured to, during a plurality of time periods, couple a plurality of input image lights into and out of the waveguide as a plurality of output image lights. In a first grating set of the plurality of grating sets, a first vector sum of in-plane projections of grating vectors associated with all gratings included in the first grating set is a first non-null vector. In a second grating set of the plurality of grating sets, a second vector sum of in-plane projections of grating vectors associated with all gratings included in the second grating set is a second non-null vector. The first vector sum and the second vector sum have different directions.