A display device, a photomask for a display device and a method for fabricating a display device comprising the photomask is described. The display device comprises a plurality of pixels arranged to spatially modulate light having a first characteristic. The display device further comprises a pixel mask structure. The pixel mask structure comprises a diffractive pattern that is configured to diffract light having the first characteristic and to transmit light having a second characteristic (without diffraction). The diffractive pattern of the pixel mask structure substantially surrounds the plurality of pixels.

Provided is a technology for implementing an AR optical waveguide display capable of showing a hologram image by means of a small and simple system configuration by using an HOE. A holographic display according to an embodiment of the present invention comprises: a light source module for emitting a beam; an optical waveguide through which the emitted beam is incident and propagated; a plurality of holographic optical elements (HOES) for propagating the beam incident to the optical waveguide inside the optical waveguide while totally reflecting the beam; and a modulator for reproducing a holographic image through the progressing beam and propagating the beam to the inside of the optical waveguide while totally reflecting the beam. Accordingly, it is possible to implement, as a small and simple system, an optical waveguide display showing an AR hologram by using an optical waveguide and an HOE.

A method and display apparatus for reducing holographic speckle when displaying holographic images are described. A target image (10) is decomposed into input images (11). A first input image includes higher spatial frequency components of the target image and is imaged using a first display method (12) to generate a first holographic display image. The second input image includes lower spatial frequency components of the target image and is imaged using a second display method (12) to generate a second display image. The first and second display images are combined for display to a user. The second display method (12) is adapted to reduce holographic speckle or include no holographic speckle compared to the first holographic display method (12) thereby reducing holographic speckle in the combined display image (13).

A holographic display and a method, performed by the holographic display, of forming a holographic image are disclosed. The holographic display includes an electrically addressable spatial light modulator (EASLM); a diffractive optical element (DOE) mask array arranged on the EASLM; and a controller configured to operate the holographic display to form a hologram image, wherein the controller is further configured to address the EASLM to backlight the DOE mask array required to form a set of hologram image voxels by turning on a corresponding EASLM pixel.

Disclosed in the present invention is a floating hologram system. The floating hologram system includes a diffuser configured to form a projection image using light beams transmitted from an image transmitter and diffuse the formed image, and a holographic optical element on which the image diffused from the diffuser is incident and which generates a virtual image floating at a position a predetermined distance therefrom and has a convex lens characteristic. A distance between the diffuser and the holographic optical element is determined based on a focal length of the holographic optical element and a distance from the holographic optical element to the virtual image.

A backlight device includes: a light source to emit coherent light; an optical path difference generator on the light source, the optical path difference generator including an incident surface and a plurality of light emitting surfaces, the light emitting surfaces being parallel to the incident surface and having different separation distances from the incident surface; a light condenser on the optical path difference generator; a diffuser on the light condenser; and a collimator on the diffuser.

In described examples, a system (e.g., a projection system) can include a diffractive optical element adapted to be illuminated by at least one coherent light beam. A lens array is coupled to receive a diffracted beam of light from the diffractive optical element. The lens array includes a first and a second array lens. The first array lens is coupled to receive a first sector of a pattern of illumination of the diffracted beam of light, and the second array lens is coupled to receive a second sector of the pattern of illumination of the diffracted beam of light. A spatial light modulator is coupled to receive overlapping diffracted beams of light from the first and second array lenses to form an image beam.

There is described herein a diffuser assembly comprising a leaf spring, diffuser and at least one actuator. The leaf spring is arranged as a rectangular frame having a width, x, and height, y. The diffuser is suspended by the frame such as within the frame. The at least one actuator arranged to move, such as translate, the diffuser. The assembly is arranged such that the leaf spring provides in-plane (x-y plane) stiffness, k.sub.x and k.sub.y, less than the out-of-plane (z-direction) stiffness, k.sub.z.

An image projector arranged to project an image onto a display plane. The image projector comprises a processing engine, a display device, an optical element and a light source. The processing engine outputs a computer-generated diffractive pattern comprising a hologram of an image for projection and a lens function corresponding to a lens having a first optical power. The display device is arranged to display the computer-generated diffractive pattern. The optical element is disposed between the display device to the display plane. The optical element has second optical power. The light source is arranged to provide off-axis illumination of the display device in order to spatially-modulated light in accordance with the hologram and lens function. The lens function of the computer-generated diffractive pattern and the optical element collectively perform a hologram transform of the hologram such that a reconstruction of the image is formed on the display plane.

Holographic and diffractive optical encoding techniques for forming reflection or transmission holograms. The encoding device includes a substrate having an interference pattern that can propagate light along a light propagation path from one side of the substrate to another side of the substrate. Furthermore, an optical element may be used to propagate light according to a four-dimensional light field coordinate system.