Abstract: An augmented reality display is disclosed. A colour projector (2) emits an image in a narrow beam comprising three primary colours: red, green and blue. A pair of waveguides (4, 6) is provided in the path of the projected beam. A first input grating (8) receives light from the projector (2) and diffracts the received light so that diffracted wavelengths of the light in first and second primary colours are coupled into the first waveguide (6), and so that diffracted wavelengths of the light in second and third primary colours are coupled out of the first waveguide in a direction towards the second waveguide (4). A second input diffraction grating (10) receives light coupled out of the first waveguide (6) and diffracts the second and third primary colours so that they are coupled into the second waveguide (4).

Abstract: An optical device or display is disclosed for use in an augmented reality or virtual reality device. The display includes a waveguide (2), an output element (4) and a plurality of input diffraction gratings (6, 8, 10, 12). Light from a plurality of projectors (16, 18, 20, 22) is diffracted by the input gratings (6, 8, 10, 12) so that it is coupled into the waveguide (2) by total internal reflection. The input gratings (6, 8, 10, 12) are provided in a staggered configuration in relation to the output element (4), with respect to a y-axis. Each input grating is adjacent another input grating that has a different separation distance from the output element (4). This can improve the evenness of illumination from the output element (4).

Abstract: An optical display device (600, 700) is disclosed. A diffractive optical element (618, 718) is mounted on a substrate (611, 711). The diffractive optical element comprises a blazed grating (619, 719) and a remnant layer (617, 717) which is formed of the same polymer-based material as the blazed grating. The remnant layer (617, 717) is positioned adjacent the substrate (611, 711) and a refractive index mismatch is provided between the two. The depth of the remnant layer is selected so that light diffracted by the grating and light reflected by the interface re-combine and interfere constructively for selected angles of incidence in order to undergo thin-film interference.

Abstract: A display system is disclosed for use in an augmented reality display (30), the system comprises a waveguide (32) having a front surface and a rear surface. A front input projector (34) projects polychromatic light through a front surface, and a back input projector (36) projects polychromatic light through the rear surface. Input light impinges on an input grating (38) on a rear surface of the waveguide (32), and light travels through the waveguide by total internal reflection. An output grating (40) is provided for coupling light out of the waveguide. A plurality of front and back input projectors (34, 36) are provided in a staggered configuration along the width of the waveguide (32) and respective edges of adjacent front and back input projectors are aligned along the width of the waveguide to permit a continuous projection of light.

Abstract: An optical device is disclosed for expanding input light in two dimensions in an augmented reality display. The device comprises a waveguide (12) and three linear diffraction grat-ings H0, H1, H2. An incident beam from a projector illuminates an input grating H0 with polychromatic light, and the light is coupled into the waveguide (12). The other two gratings H1, H2 are overlaid on top of one another. Light can be diffracted by one grating H1 into a first diffracted order and towards the other grating H2 which can couple the light out of the waveguide (12) towards a viewer. In another arrangement the crossed gratings H1, H2 may be replaced by a photonic crystal (19) having a regular array of pillars (20) which create a number effective diffraction gratings.

Abstract: An optical device is disclosed for expanding input light in two dimensions in an augmented reality display. The device comprises a waveguide (12) and three linear diffraction gratings H0, H1, H2. An incident beam from a projector illuminates an input grating H0 with polychromatic light, and the light is coupled into the waveguide (12). The other two gratings H1, H2 are overlaid on top of one another. Light can be diffracted by one grating H1 into a first diffracted order and towards the other grating H2 which can couple the light out of the waveguide (12) towards a viewer. In another arrangement the crossed gratings H1, H2 may be replaced by a photonic crystal (19) having a regular array of pillars (20) which create a number effective diffraction gratings.

Abstract: An optical display device (600, 700) is disclosed. A diffractive optical element (618, 718) is mounted on a substrate (611, 711). The diffractive optical element comprises a blazed grating (619, 719) and a remnant layer (617, 717) which is formed of the same polymer-based material as the blazed grating. The remnant layer (617, 717) is positioned adjacent the substrate (611, 711) and a refractive index mismatch is provided between the two. The depth of the remnant layer is selected so that light diffracted by the grating and light reflected by the interface re-combine and interfere constructively for selected angles of incidence in order to undergo thin-film interference.

Abstract: A display system is disclosed for use in an augmented reality display (30), the system comprises a waveguide (32) having a front surface and a rear surface. A front input projector (34) projects polychromatic light through a front surface, and a back input projector (36) projects polychro matic light through the rear surface. Input light impinges on an input grating (38) on a rear surface of the waveguide (32), and light travels through the waveguide by total internal reflection. An output grating (40) is provided for coupling light out of the waveguide. A plurality of front and back input projectors (34, 36) are provided in a staggered configuration along the width of the waveguide (32) and respective edges of adjacent front and back input projectors are aligned along the width of the waveguide to permit a continuous projection of light.