A holographic projection system includes a SLM that receives a light beam and generates a modulated beam projected at an eyebox, where: the modulated beam includes multiple versions of a test image; and the test image includes bright objects and transparent regions, which are selected dark areas of interest for measuring luminance. A control module runs a test to characterize contrast in each of multiple virtual image planes including: controlling the SLM to generate the modulated beam; measuring luminance levels of each of the versions of the test image displayed in the virtual image planes; calculating contrast ratios based on the luminance levels of each of the versions of the test image; determining whether the contrast ratios are within predetermined ranges of predetermined contrast ratios; and adjusting operation of the SLM in response to one of the contrast ratios not being within a corresponding one of the predetermined ranges.

A holographic display apparatus including a freeform curved surface and an operating method of the holographic display apparatus are provided. The holographic display apparatus includes: an image generator configured to generate a hologram image by modulating light; an optical system including a freeform curved surface for forming the hologram image generated by the image generator in a predetermined depth; and a processor configured to generate a computer-generated hologram (CGH) based on three-dimensional image information by using a phase map including information about an optical aberration with respect to the freeform curved surface and to control the image generator to modulate the light based on the CGH.

Projection displays include a highlight projector and a main projector. Highlights projected by the highlight projector boost luminance in highlight areas of a base image projected by the main projector. Various highlight projectors are based on steerable beams, holographic projectors, and spatial light modulators. A Fourier transform component and a mask positioned on the Fourier plane thereof are used to attenuate or eliminate selected spatial frequencies, e.g., to increase peak luminance without raising the black level of the projected image.

Systems and methods of determining a hologram of an image for a system comprising a display device and viewing system are disclosed. Some embodiments implement a multi-stage procedure comprising (i) determining a first complex light field at an entrance pupil of the viewing system, (ii) determining a second complex light field at a sensor plane of a sensor of the viewing system, (iii) determining a third complex light field at the entrance pupil, and (iv) determining a fourth complex light field at the display plane. Some embodiments include extracting a hologram from a data set corresponding to the fourth complex light field.

Systems and method disclosed herein include, among other features, receiving an image for display within a display area of a display system, determining a first image component of the image, calculating a hologram of the image, displaying the hologram on a display device and spatially modulating light in accordance with the displayed hologram, and propagating the spatially modulated light through a pupil expander arranged to provide a plurality of different light propagation paths for the spatially modulated light from the display device to the viewing area, wherein each light propagation path corresponds to a respective continuous region of the image owing to the angular distribution of light from the hologram.

An augmented reality display system includes a first beam path for a foveal inset image on a holographic optical element, a second beam path for a peripheral display image on the holographic optical element, and pupil position tracking logic that generates control signals to set a position of the foveal inset as perceived through the holographic optical element, to determine the peripheral display image, and to control a moveable stage.

A cab having a human-machine interface to generate a holographic image in order to control comfort equipment installed in the cab. The human-machine interface includes: a camera capable of capturing images representing a gaze of an occupant, one image generation unit having (a) a computer capable of calculating the position of the location of the occupant's gaze from the captured images, the computer being adapted to generate the digital holographic image according to the position of the occupant's gaze, (b) a spatial light modulator receiving the generated digital holographic image, and (c) a light source illuminating the spatial light modulator. The human-machine interface also includes a reflector reflecting the light beams emitted by the spatial light modulator into a visualizing window to form a holographic image positioned between the windscreen and the seat.

Examples are disclosed that relate to computing devices, head-mounted display devices, and methods for displaying holographic objects using slicing planes or volumes. In one example a computing device causes a display system to display a holographic object associated with a holographic volume, the holographic object occluding an occluded holographic object that is not displayed. Location data of at least a portion of a hand is received from a sensor. The location data of the hand is used to locate a slicing plane or a slicing volume within the holographic volume. Based on the location of the slicing plane or the slicing volume, at least a portion of the occluded holographic object is displayed via the display system.

Provided is a multi-image display apparatus including a light source configured to emit light, a spatial light modulator configured to provide a first image by modulating the light emitted from the light source, and an optical system configured to transmit the first image provided by the spatial light modulator to a viewer, wherein the optical system is configured such that a travelling path of the first image provided by the spatial light modulator includes a first optical path in a first direction, a second optical path in a second direction orthogonal to the first direction, and a third optical path in a third direction orthogonal to the first direction and the second direction, respectively, and wherein the optical system is configured such that the first image and a second image provided from an optical path different from the travelling path of the first image are provided to the viewer.

An optical device includes a display configured to generate an image light; and a waveguide optically coupled with the display and configured to guide the image light to an exit pupil of the optical device. The waveguide includes an in-coupling element configured to couple the image light into the waveguide, and an out-coupling element configured to decouple the image light out of the waveguide. The out-coupling element includes a grating having a diffraction efficiency gradient along a predetermined direction at a plane of the grating.