A phase modulation data generating unit according to the present disclosure includes: a first calculating section; and a storage section. The first calculating section calculates basic phase modulation pattern data on the basis of a partial illumination image pattern that makes it possible to generate an intended illumination image pattern having a desired luminance distribution. The basic phase modulation pattern data makes it possible for a light phase modulation device to reconstruct the partial illumination image pattern. The storage section stores the basic phase modulation pattern data calculated by the first calculating section.

A device and method for recording and reproducing holographic information, and a display apparatus are disclosed. The device for recording holographic information comprises an electro-optical regulating element, which is arranged in a light path between an object to be reproduced and a recording medium, receives an object beam scattered by the object to be reproduced, and regulates an outgoing direction and a focal distance of the object beam to irradiate the recording medium. The recording medium is configured to receive the reference beam from the light source and the object beam regulated by the electro-optical regulating element. The reference beam and the object beam form information relevant with the object to be reproduced in the recording medium. By regulating the outgoing direction and focal distance of beam with the electro-optical regulating element, it is unnecessary to rotate the recording medium for recording and reproducing the holographic information.

A holographic head-up display device includes: a light source portion that emits coherent light; an optical modulation portion that modulates the coherent light; a relay optical system that focuses the modulated light; a filter mirror that includes a reflection area disposed at a focal position of the relay optical system and reflecting light incident through the relay optical system and an absorption area disposed at the periphery of the reflection area and absorbing light incident through the relay optical system; and a transflective mirror that partially transmits and partially reflects light reflected by the filter mirror.

A method for directing non-modulated light from a Spatial Light Modulator (SLM) and allowing through modulated light for producing an interference based holographic image, the method including illuminating the SLM with coherent light, thereby producing a mix of light modulated by the SLM and light not modulated by the SLM, and projecting the mix of the modulated light and the not modulated light along an optical axis onto a volume grating, wherein the volume grating directs the not modulated light away from the holographic image and allows through modulated light for producing the holographic image. Related apparatus and methods are also described.

A device and method for recording and reproducing holographic information, and a display apparatus are disclosed. The device for recording holographic information comprises an electro-optical regulating element, which is arranged in a light path between an object to be reproduced and a recording medium, receives an object beam scattered by the object to be reproduced, and regulates an outgoing direction and a focal distance of the object beam to irradiate the recording medium. The recording medium is configured to receive the reference beam from the light source and the object beam regulated by the electro-optical regulating element. The reference beam and the object beam form information relevant with the object to be reproduced in the recording medium. By regulating the outgoing direction and focal distance of beam with the electro-optical regulating element, it is unnecessary to rotate the recording medium for recording and reproducing the holographic information.

A holographic display apparatus for providing an expanded viewing window is provided. The holographic display apparatus includes a spatial filter configured to allow a plurality of holographic images generated by 0th order or higher diffraction in a spatial light modulator to pass therethrough, and an image path conversion element configured to adjust a light path of the plurality of holographic images so that the plurality of holographic images are spaced apart from each other on a focal plane of an optical system.

A holographic display (display) for a head-mounted display (HMD). The display includes a source configured to emit at least partially coherent light and a beam conditioner that conditions the light from the source into one or more beams of light. The display also includes one or more spatial light modulators configured to encode the one or more beams of light using a hologram of a virtual reality image. The display further includes an objective lens and a conversion lens. The objective lens is positioned to create an intermediate image at a Fourier plane, and the intermediate image is a Fourier transform of the hologram. The conversion lens performs a Fourier transform of the intermediate image to generate an output hologram. The conversion lens also magnifies a portion of the output hologram and directs the magnified portion of the output hologram to an exit pupil of the HMD.

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.

A holographic display (display) for a head-mounted display (HMD). The display includes a source configured to emit at least partially coherent light and a beam conditioner that conditions the light from the source into one or more beams of light. The display also includes one or more spatial light modulators configured to encode the one or more beams of light using a hologram of a virtual reality image. The display further includes an objective lens and a conversion lens. The objective lens is positioned to create an intermediate image at a Fourier plane, and the intermediate image is a Fourier transform of the hologram. The conversion lens performs a Fourier transform of the intermediate image to generate an output hologram. The conversion lens also magnifies a portion of the output hologram and directs the magnified portion of the output hologram to an exit pupil of the HMD.

A method for generating three dimensional (3D) displays. The method includes displaying a hologram that combines three (or more) images encoded into three (or more) different OAM channels, and the method also includes reflecting light from the displayed hologram to create a multichannel light beam. Then, the method involves decoding the multichannel light beam to decode and display the three encoded images. The decoding step includes displaying the three encoded images in decoded form in three view zones, three focal planes, or on three spaced-apart planes. The decoding is performed by a single decoding screen using holograms used for generating the three encoded images or is performed by three decoding screens configured based on a differing one of the holograms used for generating the three encoded images. The displaying of the hologram step includes operating a spatial light modulator (SLM) to display the hologram on a screen of the SLM.