Provided is a holographic display apparatus. A holographic image display apparatus includes: a light source configured to emit light, the light source including a plurality of vertical-cavity surface-emitting lasers (VCSELs) that are spaced apart from one another; a spatial light modulator configured to, based on a hologram data signal, modulate the light emitted by the light source; and a focusing optical system configured to focus an image formed by the spatial light modulator using a Maxwellian view method.

An image processing engine and method of forming a hologram of a target image for projection using data streaming. An input or primary image is sub-sampled using a kernel and the secondary image output used to generate a hologram of the target image. A technique of kernel sub-sampling using a plurality of two or more data streams provides improvements in efficiency, including reduced data storage requirements and increased processing speed.

There is provided a holographic projector comprising a spatial light modulator, a light source and an assembly. The spatial light modulator is arranged to display a hologram. The light source is arranged to illuminate at least one region of the spatial light modulator with an input beam such that the input beam is spatially modulated by the spatial light modulator in accordance with the hologram to form a holographic reconstruction. The assembly is arranged to move at least one of the input beam and the spatial light modulator relative to the other.

The projection device includes a light source, a liquid crystal on silicon (LCoS) panel, and a circuit. The circuit is configured to obtain a target image including a target pattern, and generate two content images. Each content image includes a duplicated pattern of the target pattern, and the duplicated patterns are off-axis shifted to the same coordinate when performing a computer-generated hologram (CGH) algorithm, so as to generate a phase image. The LCoS panel is driven according to the phase image to display a reconstructive image at a reconstructive distance.

An image processing engine and method of forming a hologram of a target image for projection using data streaming. An input or primary image is sub-sampled using a kernel and the secondary image output used to generate a hologram of the target image. A technique of kernel sub-sampling using a plurality of two or more data streams provides improvements in efficiency, including reduced data storage requirements and increased processing speed.

There is provided a driver for a spatial light modulator. The spatial light modulator comprises [m×n] pixels. The driver is arranged to receive input holograms each comprising [x×y] pixels, wherein m≥x and n≥y. The driver is further arranged to drive the spatial light modulator to display thereon output holograms each comprising [m×n] pixels by tiling each input hologram onto the pixels of the spatial light modulator to form an output hologram corresponding to each input hologram using a tiling scheme. The driver is arranged to use a first tiling scheme to display a first output hologram and a second tiling scheme to display a second output hologram. Each output hologram comprises a plurality of tiles of the input hologram. Each tiling scheme defines the size of each tile and the position of each tile on the pixels of the spatial light modulator.

A method for encoding complex-valued signals of a computer-generated hologram into a phase-modulating optical element for the reconstruction of a three-dimensional object, and to a computer program product for encoding complex-valued signals of a computer-generated hologram, and to a holographic display for the reconstruction of a three-dimensional object. The object is to reduce the effort on encoding a complex-valued spatial distribution by an iteration method on the basis of phase encoding, so that the computer-generated hologram resulting therefrom can be represented more rapidly and with the same or an improved reconstruction quality. In particular, the convergence during the iterative optimization is intended to be accelerated. This is achieved by a method in which degrees of freedom of the hologram plane as well as the reconstruction plane are used for optimizing the iteration method for rapid convergence and maximization of the diffraction efficiency in the signal range.

A method for encoding complex-valued signals of a computer-generated hologram into a phase-modulating optical element for the reconstruction of a three-dimensional object, and to a computer program product for encoding complex-valued signals of a computer-generated hologram, and to a holographic display for the reconstruction of a three-dimensional object. The object is to reduce the effort on encoding a complex-valued spatial distribution by an iteration method on the basis of phase encoding, so that the computer-generated hologram resulting therefrom can be represented more rapidly and with the same or an improved reconstruction quality. In particular, the convergence during the iterative optimization is intended to be accelerated. This is achieved by a method in which degrees of freedom of the hologram plane as well as the reconstruction plane are used for optimizing the iteration method for rapid convergence and maximization of the diffraction efficiency in the signal range.

A display apparatus includes a coherent light source, a display unit, a light-diffusing element, and at least one optical element. The coherent light source is configured to provide coherent light beams. The display unit is configured to form a three-dimensional image beam based on interference of the coherent light beams, wherein the three-dimensional image beam is imaged on an intermediate imaging surface after passing through the display unit. The light-diffusing element is located on the intermediate imaging surface, wherein a diffusion angle of the three-dimensional image beam is sequentially changed by passing through the light-diffusing element. The at least one optical element is located on a transmission path of the three-dimensional image beam from the light-diffusing element, and is configured to project the three-dimensional image light beam passing through the display unit out of the display apparatus to display a three-dimensional image.

A direct-retina holographic projection system includes first and second spatial light modulators (SLMs) and a control module. The first SLM receives a beam of light and dithers the beam of light at a predetermined frequency to provide multiple instances of the beam of light. The second SLM receives the instances of the beam of light, displays an encoded phase hologram of a graphic image to be projected, and diffracts the instances of the beam of light to provide instances of the encoded phase hologram with the same graphic image but multiplied with dithered wavefronts. The control module: iteratively adjusts a parameter of the first SLM to generate the instances of the beam of light; and controls operation of the second SLM to, based on the instances of the beam of light, display multiple instances of the graphic image on a retina of an eye of a viewer.