Abstract: The invention relates to a waveguide display element comprising a waveguide body and an in-coupling grating (21) arranged to the waveguide body. The in-coupling grating (21) is configured to couple incoming light into the waveguide body into two separate directions (26A, 26B) using opposite diffraction orders (IC:+1, IC:?1) for splitting the field of view of the incoming light. Further the in-coupling grating (21) is configured, typically by setting its period suitably short, such that said coupling takes place only at wavelengths below a threshold wavelength residing in the visible wavelength range. The invention also relates to a waveguide stack (51 A, 51 B, 51 C).

Abstract: There is provided an exit pupil expander (EPE) for use in a diffractive display, the EPE comprising a plurality of diffractive zones on a waveguide and a plurality of non-diffractive zones between at least some of the diffractive zones.

Abstract: The invention relates to a diffractive waveguide display device comprising an image projector capable of emitting laser rays at one or more wavelengths, a waveguide body having a first surface and an opposite second surface and adapted to guide said laser rays from the image projector between the first surface and the second surface, an out-coupling diffractive optical element on said first surface for coupling said laser rays out of the waveguide body, and an anti-interference coating (35) arranged on the second surface of the waveguide body aligned with the out-coupling diffractive optical element.

Abstract: A diffractive waveguide element for a personal display device includes a display waveguide extending in a waveguide plane, an in-coupling diffractive optical element arranged onto or into the display waveguide for diffractively coupling light rays into the display waveguide, and an out-coupling diffractive optical element arranged onto or into the display waveguide for coupling the diffractively coupled light rays out of the display waveguide. In addition, there is provided a ray multiplier element optically upstream of the out-coupling diffractive optical element, the ray multiplier element being capable of splitting a light ray incoming to the in-coupling grating into a plurality of parallel rays spatially displaced in the waveguide plane before they enter the out-coupling diffractive optical element. A waveguide display device is also provided.

Abstract: A lightguide of an augmented or virtual reality eyewear apparatus (10) comprises an additional grating (110) arranged between an in-coupling grating (102) and an out-coupling grating (104). The additional grating (110) comprises grating areas (112, 112?, 114, 114?), at least two of which have a common physical interface (116) and grating vectors of different directions. The grating vectors of the additional grating (110), the in-coupling grating (102) and the out-coupling grating (104) are linear combinations of two non-parallel and common base vectors, and a sum of the grating vectors of the in-coupling grating (102), the additional grating (110) and the out-coupling grating (104) is zero separately for each optical path, which guides light from the in-coupling grating (102) via the additional grating (110) to the out-coupling grating (104) and allows the light to be coupled out from the out-coupling grating (104).

Abstract: There is provided a diffractive display element comprising a waveguide body, an in-coupling region for diffractively coupling light into the waveguide body, and an out-coupling region for diffractively coupling light out of the waveguide body, said light being adapted to propagate from said in-coupling region to the out-coupling region along a primary route. According to the invention, the element further comprises at least one grating mirror outside said primary route for diffractively mirroring light strayed from said primary route back to said primary route. The invention allows for increasing the efficiency of waveguide-based personal displays.

Abstract: The invention relates to a diffractive waveguide display element comprising a waveguide body (13) having a first surface and a second surface opposite to the first surface, an outcoupling-diffractive optical element on said first surface for coupling light propagating inside the waveguide body out of the waveguide body, and a narrow-band reflector element (21) on said second surface. The invention also relates to a display device comprising such element.

Abstract: The invention relates to a laser projector for presenting an image on a waveguide plane. The projector comprises a laser source (10, 10A, 10B, 10C) capable of emitting a polychromatic light beam (11) or a plurality of narrow-wavelength light beams (11A, 11B, 11C), and a guidance element (12A, 12B) for directing light emitted by the light source to different pupils (16A, 16B, 16C) of the waveguide plane, the different pupils being displaced with respect to each other in the waveguide plane. The invention also concerns a personal display device comprising such projector.

Abstract: The invention concerns a multi-pupil lightguide element, a diffractive personal display, multi-pupil projector, a method for displaying an image and a use. The element comprises lightguide means, diffractive in-coupling means for coupling an image directed to the in-coupling means into the lightguide means, and diffractive out-coupling means for coupling said image out of the lightguide means. According to the invention, the diffractive in-coupling means comprise at least two in-coupling gratings laterally displaced from each other on said lightguide means for receiving segments of said image, and the diffractive out-coupling means is optically associated with said at least two in-coupling gratings for reproducing said image from said image segments. The invention allows for expanding the field-of-view of near-to-eye displays, for example.

Abstract: The invention relates to a waveguide display element comprising a waveguide comprising at least three waveguide layers stacked on top of each other. There is also provided diffractive in-coupling gratings associated with each waveguide layer and being displaced with respect to each other in the plane of the layers, the in-coupling gratings forming input pupils for different light wavelength ranges coupled to the waveguide, and a diffractive out-coupling means for coupling light in-coupled through the pupils and propagating in the layers out of the waveguide such that a polychromatic image is formed. The invention also concerns a personal display device comprising such element.

Abstract: The invention concerns a diffractive waveguide element for a personal display device, the element comprising a waveguide body (21), and at least two grating regions (23, 24) arranged on the waveguide body (21), at least some of the grating regions adapted to expand the exit pupil of the element. According to the invention, the grating regions (23, 24) are positioned with respect to each other so that and are provided with gratings having different grating vectors so that the grating regions (23, 24) interact to combine the functions of exit pupil expansion and outcoupling on at least some parts of the element. The invention allows for efficient use of waveguide area.

Abstract: The invention provides the present invention provides a faecal detection sensor for an absorbent article. The sensor includes a faeces-sensitive material that reacts to the presence of a constituent of faecal matter, wherein the sensor exhibits an electrical property that changes following the reaction of the faeces-sensitive material. In embodiments of the invention the faeces sensitive material is a material that reacts due to the presence of a sulfur-containing compound in faecal matter, such as metallic faeces-sensitive materials, or is a material that reacts with a faecal enzyme and/or other constituents of faecal matter, such as organic faeces-sensitive materials.

Abstract: The invention relates to a method of manufacturing a diffractive grating. The method comprises providing a first substrate and manufacturing onto the first substrate a first surface profile using temporary grating material. Next, the first surface profile is covered entirely by a layer of final grating material and a second substrate is bonded onto the final grating material. Finally, the first substrate and the temporary grating material are removed for producing on the final grating material a second surface profile, which is a negative of the first surface profile. The invention allows for conveniently producing high quality gratings using e.g. inorganic materials and height and/or fill factor modulation for diffraction efficiency control.

Abstract: The invention relates to a diffractive exit pupil expander arrangement for display applications. The arrangement comprises a first lightguide element (51) comprising an exit pupil expander (53) and arranged in a first plane and a second lightguide element (41) comprising an in-coupler (42) and arranged in a second plane. The in-coupler is optically coupled with the exit pupil expander (53). Further, the first lightguide element (51) is arranged to confine propagation of light laterally in said first plane by reflections, and the first plane and the second plane are arranged at an angle (a) with respect to each other.

Abstract: The invention relates to a diffractive optical grating and applications thereof. The grating comprises a first zone and a second zone each having a two-dimensionally periodic grating structure having a first period (dx) in a first direction, the first period being chosen to allow for diffraction of selected wavelengths of visible light along the first direction, and a second period (dy) in a second direction different from the first direction, the second period (dy) being short enough to prevent diffraction of said selected wavelengths along the second direction. According to the invention, the grating structures in the first zone and in the second zone have different modulation characteristics in said second direction for producing different diffraction efficiencies for the first and second zones. The invention provides a new design parameter, sub-wavelength modulation, for assisting in local adjustment of diffraction efficiency of gratings in particular in display applications.

Abstract: A waveguide display element includes waveguide layers stacked on top of each other and an in-coupler associated with each waveguide layer for coupling light within a predefined wavelength band into the waveguide layer. Each of the in-couplers includes an intermediate layer arranged on the waveguide layer, the intermediate layer having intermediate layer properties. Each of the in-couplers further includes an in-coupling grating arranged on the intermediate layer, the grating having grating properties. The combination of the intermediate layer properties and grating properties of each in-coupler is different with respect to other in-couplers.

Abstract: There is provided a diffractive display element comprising a waveguide body, an in-coupling region for diffractively coupling light into the waveguide body, and an out-coupling region for diffractively coupling light out of the waveguide body, said light being adapted to propagate from said in-coupling region to the out-coupling region along a primary route. According to the invention, the element further comprises at least one grating mirror outside said primary route for diffractively mirroring light strayed from said primary route back to said primary route. The invention allows for increasing the efficiency of waveguide-based personal displays.

Abstract: The invention relates to a method of manufacturing a diffractive grating. The method comprises providing a first substrate and manufacturing onto the first substrate a first surface profile using temporary grating material. Next, the first surface profile is covered entirely by a layer of final grating material and a second substrate is bonded onto the final grating material. Finally, the first substrate and the temporary grating material are removed for producing on the final grating material a second surface profile, which is a negative of the first surface profile. The invention allows for conveniently producing high quality gratings using e.g. inorganic materials and height and/or fill factor modulation for diffraction efficiency control.

Abstract: A waveguide display element includes waveguide layers stacked on top of each other and an in-coupler associated with each waveguide layer for coupling light within a predefined wavelength band into the waveguide layer. Each of the in-couplers includes an intermediate layer arranged on the waveguide layer, the intermediate layer having intermediate layer properties. Each of the in-couplers further includes an in-coupling grating arranged on the intermediate layer, the grating having grating properties. The combination of the intermediate layer properties and grating properties of each in-coupler is different with respect to other in-couplers.

Abstract: The invention relates to a waveguide display element comprising a waveguide body and an in-coupling grating (21) arranged to the waveguide body. The in-coupling grating (21) is configured to couple incoming light into the waveguide body into two separate directions (26A, 26B) using opposite diffraction orders (IC:+1, IC:?1) for splitting the field of view of the incoming light. Further the in-coupling grating (21) is configured, typically by setting its period suitably short, such that said coupling takes place only at wavelengths below a threshold wavelength residing in the visible wavelength range. The invention also relates to a waveguide stack (51 A, 51 B, 51 C).