To provide a display device capable of further improving reliability of the display device with respect to manufacturing variations, wavelength variations of light sources, and active variations (variations due to external factors). There is provided a display device including at least a light source, a first hologram, and a second hologram, in which the first hologram compensates for dispersion of light emitted from the light source and diffracts and emits the light, the second hologram diffracts the light diffracted with compensated dispersion, and emits the light in a direction of a pupil of a user, and the first hologram has an intensity distribution of different diffraction efficiency with respect to a wavelength of the light emitted from the light source depending on a position in a plane of the first hologram.

A holographic projection system including first, second and third light sources, SLMs, a lens, a combiner and a control module. The first, second and third light sources generate respective light beams. The light beams have respective wavelengths. The SLMs respectively diffract the light beams. The lens is disposed to adjust a divergence angle of one of the light beams, such that diffracted light out of each of the SLMs is at a same diffraction angle. The SLMs encode phase holograms including respective versions of a graphic image based on light generated by the light sources including light output from the lens to provide phase hologram beams. The combiner combines the phase hologram beams to provide a combined phase hologram beam projected for viewing a combined graphic image. The control module encodes a prism hologram on one of the SLMs to align outputs of the SLMs.

Systems, methods, and computer-readable media are disclosed for representing a transfer of a digital object using holographic images. User input is received that is indicative of a selection of the digital object for transfer from a sending device to a receiving device. Spatial attribute data is generated based at least in part on at least one of a distance or a relative orientation between the sending device and the receiving device, and a transition path is determined based at least in part on the spatial attribute data. Holographic image data is then generated based at least in part on the transition path, and the holographic image data is sent to one or more holographic projectors to cause a first holographic image representative of the digital object and a second holographic image representative of the transition path to be projected.

There is provided a method of projection using an optical element (502,602) having spatially variant optical power. The method comprises combining Fourier domain data representative of a 2D image with Fourier domain data having a first lensing effect (604a) to produce first holographic data. Light is spatially modulated (504,603a) with the first holographic data to form a first spatially modulated light beam. The first spatially modulated light beam is redirected using the optical element (502,602) by illuminating a first region (607) of the optical element (602) with the first spatially modulated beam. The first lensing effect (604a) compensates for the optical power of the optical element in the first region (607). Advantageous embodiments relate to a head-up display for a vehicle using the vehicle windscreen (502,602) as an optical element to redirect light to the viewer (505,609).

A method of displaying a Computer Generated Holographic (CGH) image by a display, including setting pixel values of a Spatial Light Modulator (SLM) included in a Head Mounted Display (HMD), producing a interference based holographic image at a first location by projecting coherent light onto the SLM, and re-imaging the holographic image from the first location to form a holographic image in front of an eye of a viewer wearing the HMD. Related apparatus and methods are also described.

Examples are disclosed that relate to a near-eye display device including a holographic display system. The holographic display system includes a light source configured to emit light that is converging or diverging, a waveguide configured to be positioned in a field of view of a user's eye, and a digital dynamic hologram configured to receive the light, and project the light into the waveguide such that the light propagates through the waveguide.

A holographic gun sight has a housing with a viewing end and an opposing target end, a viewing path being defined from the viewing end to the target end. A light source projects a light beam along a path to illuminate a reflection-type holographic optical element (HOE). The HOE reconstructs an object beam with an image of a reticle. The absolute difference between the incidence angle of the light beam on the HOE and the object beam angle is greater than zero and less than or equal to 30 degrees.

A holographic projector includes a waveguide that includes a pair of opposing reflective surfaces arranged to receive and waveguide a hologram/holographic wavefront therebetween. A first surface of the pair of complementary surfaces is partially reflective-partially transmissive such that a plurality of replicas of the hologram/holographic wavefront are emitted therefrom. The holographic projector further includes a diffractive optical element arranged to receive the plurality of replicas of the hologram/holographic wavefront from the first surface of the waveguide and principally redirect each replica into a respective non-zero diffractive order defined by a diffraction angle. The holographic projector also includes an array of louvres arranged to receive the hologram/holographic wavefront from the diffractive optical element, where the array of louvres is substantially transmissive at the non-zero diffraction angle and substantially non-transmissive at a zeroth diffraction angle of the diffractive optical element.

A system for training a machine learning algorithm to generate a plurality of ideal hologram phase correction maps includes a holographic head-up display (HUD) configured to display a plurality of duplicates of a graphic based on a hologram phase map. The system further includes a camera system configured to view each of the plurality of duplicates of the graphic. The system further includes a controller in electrical communication with the holographic HUD and the camera system. The controller is programmed to determine a plurality of ground-truth hologram phase correction maps using a genetic algorithm, the holographic HUD, and the camera system. The controller is further programmed to generate a training dataset including a plurality of images of the graphic and train the machine learning algorithm to generate the plurality of ideal hologram phase correction maps.

An optical system and a method of forming the same. The optical system may include a light source configured to generate a light beam, the light beam being coherent or partially coherent. The optical system may also include a spatial light modulator configured to modulate a phase of the light beam. The optical system may further include an eyepiece for directing the modulated light beam to an eye of a viewer, the eyepiece arranged such that an optical distance between the spatial light modulator and a main plane of the eyepiece is greater than a focal length of the eyepiece. The spatial light modulator may include an active display area having a dimension of less than 2 mm.