Abstract: An optical waveguide comprising a body of material configured for the contained propagation of light therethrough, a surface relief grating configured to receive the propagating light and at least partially to diffract or reflect it out of the waveguide, and at least one layer of dielectric material of varying thickness having a first surface and a second surface which conforms to a profiled surface of the grating so that the grating exhibits a spatial variation in efficiency dependent on the varying thickness of the dielectric material.

Abstract: In a slab waveguide which expands an image-bearing pupil into a visible image, reflective edge surfaces are used to redirect once-diffracted light back through the same grating structure. The number of separate grating structures thereby can be reduced to two or even one, compared to three in the prior art.

Abstract: The present invention is directed to a display which presents an image along a line of sight of an observer, such that the image is overlaid on a real world scene has a first waveguide and an image source device to inject the image into the first waveguide. The first waveguide has a first grating to direct the image internally and to output the image from the first waveguide. A second waveguide has a coupling grating to receive the image from the first waveguide and to direct the image along the second waveguide. The second waveguide has an exit grating to diffract the received image out of the second waveguide towards the observer. The exit grating diffracts the image out of the second waveguide off axis to a normal axis of the second waveguide.

Abstract: A projection display 210 arranged to display an image to an observer 212 use waveguide techniques to generate a display defining a large exit pupil at the point of the observer 212 and a large field of view, whilst using a small image-providing light source device. The projection display 210 uses two parallel waveguides 214, 216 made from a light transmissive material. One waveguide 214 stretches the horizontal pupil of the final display and the other waveguide 216 stretches the vertical pupil of the final display and acts as a combiner through which the observer 212 views an outside world scene 220 and the image overlaid on the scene 220. In a colour display, each primary colour is transmitted within a separate channel R, G, B.

Abstract: A waveguide 112 includes a substrate of material 134 having optical layers 148, 152 applied to two external surfaces 146, 150. This reduces the critical angle c5 of the substrate of material 134 to provide greater interaction between image bearing light following a light path 140 and a grating element 142 and/or a greater total field of view 160, when compared to the total field of view 132 of a prior art waveguide 110, that is capable of being transmitted by the waveguide 112. Such a waveguide 112 can be used in a projection display.

Abstract: An image-providing light source device 58 is arranged to inject a non-coherent and collimated image into waveguide element 60. Light forming the image is dispersed by an optical element 76 so as to occupy a continuum of angles within the waveguide 60. The optical element 76 and a grating 70 are arranged such that the light exiting the waveguide occupies a single angle. Thereby, pupil banding of light exiting the waveguide 60 is mitigated.

Abstract: A projection display is provided including a rod-like waveguide (7), an image providing light source device (10) located at a first side (9) of the waveguide (7) to inject image bearing light into the waveguide (7), through the first side (9). An input means (12) is provided on the waveguide (7) adjacent one end (13) at a second side (14) opposite to the first side (9) to reflect the image bearing light internally along the waveguide (7). An output transmission grating (18) is provided along a third side (19) of the waveguide (7) through which image bearing light is outputted from the waveguide (7). A plate-like waveguide (8) is located with an edge surface (23) thereof adjacent to and in line with the third side (19) of the waveguide (7) to receive the image bearing light from the waveguide (7). The waveguide (8) includes an exit grating (25) on or at a first surface (26) thereof for diffracting the received image bearing light out of the waveguide (8) towards a viewer (6).

Abstract: A primary waveguide and a coupling waveguide are arranged so a user can view light from a forward scene through the primary waveguide. An image source generates an image which is diffractively coupled into the primary waveguide and internally reflected to an exit area for diffraction towards the user. Light from the forward looking scene is diffracted into the primary waveguide to be internally reflected and coupled to a image intensifier tube assembly. The image intensifier tube assembly enhances light from the forward looking scene and drives the image source such that an image of the enhanced light is overlaid on light from a forward scene at exit area.

Abstract: The present invention is directed to a display which presents an image along a line of sight of an observer, such that the image is overlaid on a real world scene has a first waveguide and an image source device to inject the image into the first waveguide. The first waveguide has a first grating to direct the image internally and to output the image from the first waveguide. A second waveguide has a coupling grating to receive the image from the first waveguide and to direct the image along the second waveguide. The second waveguide has an exit grating to diffract the received image out of the second waveguide towards the observer. The exit grating diffracts the image out of the second waveguide off axis to a normal axis of the second waveguide.

Abstract: A projection display which includes first and second waveguide elements, wherein the first waveguide element has a two input regions for injecting image bearing light into the first waveguide element. In this manner, the total field of view of the image to be displayed at the second waveguide element is divided into two sub-images prior to injection of one sub-image into one input region and the other sub-image into the other input region of the first waveguide element. This results in a smaller first waveguide element, thereby reducing obscuration of an observers view of a forward scene over which to the image to be displayed is overlaid.

Abstract: A helmet mounted display 30 includes a display source 31 arranged to be directly imaged by a primary relay optical arrangement 32 having relay optical elements 33A, 33B and 33C. Light exiting the primary relay optical arrangement 32 indicated by ray traces 34A, 34B and 34C continue towards a visor 35 which is arranged to reflect incident light to a exit pupil located in a convenient position for a viewer 36. The display source 31 includes a light source, beam splitter, reflective liquid crystal display and a display source relay optical arrangement to provide an output image at an output diffuser screen. The image at the output screen is then directly imaged by the primary relay optical arrangement 32. Should the reflective liquid crystal display require modification or replacement with a newer model, then the display source 31 can be redesigned to accommodate the new reflective liquid crystal display rather than re-engineering the primary relay optical arrangement 32 at greater expense.

Abstract: A projection display is provided including a first plate-like waveguide (7), an image providing light source device (10 and 11) located to inject image bearing light into the first plate-like waveguide 7. An input means (12) is provided on the waveguide (7) to reflect the image bearing light internally along the waveguide (7). A transmission grating (13) within the first plate-like waveguide (7) is provided to output image bearing light from the waveguide (7). A second plate-like waveguide (8) is located co-planar with the first plate-like waveguide (7) and has a coupling grating (17) therein to receive the image bearing light from the first plate-like waveguide (7). The second plate-like waveguide (8) also includes an exit grating (18) therein for diffracting the received image bearing light, diffracted by the coupling grating (17) out of the second plate-like waveguide (8) towards a viewer (6).

Abstract: A helmet mounted display 30 includes a display source 31 arranged to be directly imaged by a primary relay optical arrangement 32 having relay optical elements 33A, 33B and 33C. Light exiting the primary relay optical arrangement 32 indicated by ray traces 34A, 34B and 34C continue towards a visor 35 which is arranged to reflect incident light to a exit pupil located in a convenient position for a viewer 36. The display source 31 includes a light source, beam splitter, reflective liquid crystal display and a display source relay optical arrangement to provide an output image at an output diffuser screen. The image at the output screen is then directly imaged by the primary relay optical arrangement 32. Should the reflective liquid crystal display require modification or replacement with a newer model, then the display source 31 can be redesigned to accommodate the new reflective liquid crystal display rather than re-engineering the primary relay optical arrangement 32 at greater expense.

Abstract: A projection display is provided including a rod-like waveguide (7), an image providing light source device (10) located at a first side (9) of the waveguide (7) to inject image bearing light into the waveguide (7), through the first side (9). An input means (12) is provided on the waveguide (7) adjacent one end (13) at a second side (14) opposite to the first side (9) to reflect the image bearing light internally along the waveguide (7). An output transmission grating (18) is provided along a third side (19) of the waveguide (7) through which image bearing light is outputted from the waveguide (7). A plate-like waveguide (8) is located with an edge surface (23) thereof adjacent to and in line with the third side (19) of the waveguide (7) to receive the image bearing light from the waveguide (7). The waveguide (8) includes an exit grating (25) on or at a first surface (26) thereof for diffracting the received image bearing light out of the waveguide (8) towards a viewer (6).