Provided is a holographic display apparatus including a light source configured to emit light, a spatial light modulator configured to form a hologram pattern to modulate the light incident thereon and reproduce a hologram image, the spatial light modulator including a plurality of display pixels that are arranged two-dimensionally, and an optical element provided opposite a light incidence surface of the spatial light modulator or a light exit surface of the spatial light modulator, the optical element including an array of a plurality of light transmission patterns that are arranged irregularly.

A three-dimensional holographic display device includes a light emitting diode (LED) array including a plurality of light sources controlled to sequentially output light according to a preset pattern, a lens configured to refract light incident from the LED array, a spatial light modulator (SLM) configured to modulate light incident from the lens, and a processor configured to generate a plurality of holographic signals each comprising depth information adjusted according to an arrangement location of each of the plurality of light sources, and for each of the plurality of light sources, control the SLM to modulate the light based on a holographic signal corresponding to the light source.

The present invention relates to a controllable diffraction device for a light modulator device. The controllable diffraction device comprises at least two substrates, at least one electrode on each of said substrates facing each other, and liquid crystals forming at least one liquid crystal layer arranged between said electrodes on said substrates. The orientation of the liquid crystals is controllable by a voltage supplied to the electrodes. The liquid crystal layer is provided on at least one alignment layer arranged on at least one electrode on said substrates. The liquid crystals close to the alignment layer are pre-oriented by at least one pre-tilt angle relative to the alignment layer such that the resulting light diffraction in opposite spatial directions is approximately equal.

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).

The invention relates to a holographic display device for representing a two-dimensional and/or three-dimensional scene. The holographic display device comprises at least one spatial light modulator device and an optical component. The at least one spatial light modulator device is provided in order to reconstruct the scene and in order to generate at least one virtual visibility region in an observer plane. The optical component is configured with at least two regions that have a different transparency to one another, the value of the transparency respectively lying between 0 and 1. Furthermore, the optical component is arranged in the display device in such a way that it provides filtering, to be carried out at least partially, of a diffraction order spot in at least one diffraction order inside the virtual visibility region.

A liquid crystal grating and its fabrication method, and a display panel are provided in the present disclosure. The liquid crystal grating includes a first light adjustment component and a second light adjustment component, disposed oppositely. The first light adjustment component includes a first liquid crystal panel and a first polarization adjustment component; the second light adjustment component includes a second liquid crystal panel and a second polarization adjustment component; and using a second direction as an extending direction of a rotation axis, when the first light adjustment component is rotated 180° around the rotation axis, an alignment direction of the first liquid crystal panel is in parallel with an alignment direction of the second liquid crystal panel, and an optical axis direction of the first polarization adjustment component is in parallel with an optical axis direction of the second polarization adjustment component.

A backlight unit and a holographic display apparatus including the same are provided. The backlight unit includes a light guide plate and a uniformity changing element. The uniformity changing element has a light-incident surface and a light-exiting surface facing the light-incident surface, and the uniformity changing element receives the light output from the light guide plate through the light-incident surface, changes uniformity of the received light from the light guide plate and outputs the received light with the change in the uniformity of the received light through the light-exiting surface.

A spatial light modulator (SLM) includes a first liquid crystal panel and a second liquid crystal panel that are oppositely configured, and a polarization adjustment part configured between the first liquid crystal panel and the second liquid crystal panel. An alignment direction of the first liquid crystal panel is parallel to an alignment direction of the second liquid crystal panel. The first liquid crystal panel is configured to perform a phase modulation on incident linear-polarized light. The polarization adjustment part is configured to rotate, by a preset angle, a polarization direction of linear-polarized light exited from the first liquid crystal panel. The second liquid crystal panel is configured to adjust a polarization state of linear-polarized light exited from the polarization adjustment part to adjust an amplitude of exited light.

A beam deflection apparatus includes a first beam deflector that deflects light in a first direction and a second beam deflector that deflects light in a second direction perpendicular to the first direction, wherein the first beam deflector and the second beam deflector each include a first region for deflecting light of a first wavelength and a second region for deflecting light of a second wavelength, and a ratio of a spatial period of a signal applied to first drive electrodes arranged in the first region of the first beam deflector to the first wavelength is the same as a ratio of a spatial period of a signal applied to second drive electrodes arranged in the second region of the first beam deflector to the second wavelength.

A method of manufacturing a holographic optical element, including: irradiating a first surface of a photosensitive substrate with a first layer, and irradiating a second surface of the photosensitive substrate with a second laser. The light emitted by the first laser is spread in an irradiation direction and the light emitted by the second laser is collected in the irradiation direction to form a plurality of groups and a plurality of overlapping angles formed by a progress direction of the light emitted by the first laser and the progress direction of the light emitted by the second laser at a predetermined location of a photosensitive area, and each of the plurality of the overlapping angles are different from each other. A display device including the holographic optical element measured using this method.