Provided is a method of generating a computer-generated hologram (CGH), the method including obtaining complex data including amplitude data of object data and phase data of the object data corresponding to a spatial light modulator (SLM) plane by propagating the object data from an image plane to the SLM plane, encoding the complex data into encoded amplitude data, and generating a CGH based on the object data including the encoded amplitude data.

Provided is a method of generating a computer-generated hologram (CGH), the method including obtaining complex data including amplitude data of object data and phase data of the object data corresponding to a spatial light modulator (SLM) plane by propagating the object data from an image plane to the SLM plane, encoding the complex data into encoded amplitude data, and generating a CGH based on the object data including the encoded amplitude data.

An illumination device has a coherent light source that emits coherent light beam, and an optical device that diffuses the coherent light beam, wherein the optical device comprises a first diffusion region that diffuses the coherent light beam to illuminate a first area, and a second diffusion region that diffuses the coherent light beam to display predetermined information in a second area.

The present invention provides a holographic imaging device and a holographic imaging method that have improved performance in which the influence of a refractive index of a cube-type beam coupler constituting an optical system is considered. The holographic imaging device 1 comprises the beam coupler 3 consisting of the cube-type beam splitter arranged between the object 4 and the image sensor 5 and the calculation reference light hologram generation unit 14 for generating an inline reference light hologram j.sub.L representing a light wave on the hologram plane 50 by performing a light wave propagation calculation including propagation inside the beam coupler 3, on a spherical wave emitted from the condensing point P2 of the inline spherical wave reference light L. The inline reference light hologram j.sub.L is a computer-generated hologram and used for generating an object light hologram g by removing component of the reference light L from a complex-amplitude inline hologram J.sub.OL representing the object light O and the inline spherical wave reference light L on the hologram plane 50.

There is provided a holographic projector comprising a reflective liquid crystal display device. The reflective liquid crystal display device comprises a light-modulating layer between a first substrate and a second substrate substantially parallel to the first substrate. The light-modulating layer comprises planar-aligned nematic liquid crystals having positive dielectric anisotropy. The first substrate is substantially transparent and comprises a first alignment layer arranged to impart a first pre-tilt angle θ.sub.l on liquid crystals proximate the first substrate, wherein θ.sub.1>5°. The second substrate is substantially reflective and comprises a second alignment layer arranged to impart a second pre-tilt angle Θ.sub.2 on liquid crystals proximate the second substrate, wherein θ.sub.2>5°. The reflective liquid crystal display device further comprises a plurality of pixels defined on the light-modulating layer having a pixel repeat distance x, wherein x≤10 μm. The distance d between inside faces of the first substrate and second substrate satisfies 0.5 μm≤d≤3 μm, and the birefringence of the liquid crystal Δη≥0.20. The holographic projector further comprises a display driver arranged to drive the reflective liquid crystal display device to display a hologram by independently-driving each pixel at a respective modulation level selected from a plurality of modulation levels having a phase modulation value.

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 method of calculating a hologram having an amplitude and a phase component. The method comprises (i) receiving an input image comprising a plurality of data values representing amplitude. The method then comprises (ii) assigning a random phase value to each data value of the plurality of data values to form a complex data set. The method then comprises (iii) performing an inverse Fourier transform of the complex data set. The method then comprises (iv) constraining each complex data value (X1, X2) of the transformed complex data set to one of a plurality of allowable complex data values (GL1-GL8), each comprising an amplitude modulation value and a phase modulation value, to form a hologram, wherein, the phase modulation values (GL1-GL7) of the plurality of allowable complex data values substantially span at least 3π/2 and at least one of the allowable complex data values has an amplitude modulation value of substantially zero (GL8) and a phase modulation value of substantially zero.

Provided is an apparatus and method for encoding a hologram and evaluating a holographic image quality for an amplitude-modulated hologram. A hologram encoding method may include acquiring three-dimensional (3D) information of a scene or an object; generating hologram information based on the 3D information; deriving a real number hologram function by extracting a real number part and an imaginary number part from the hologram information; determining an intermediate hologram function based on a sign characteristic of the real number hologram function; and determining encoded hologram information based on the intermediate hologram function.

Provided are methods and devices for data superimposition, in which an imaging device comprises a diffuser and a holographic layer to provide a real or virtual image for an observer. In one variant, diffuser and holographic layer are provided on different sides of a transparent carrier. In other embodiments, the imaging device and holographic layer are arranged in smart glasses.

A holographic imaging device includes a laser device, a laser beam expanding and collimating system and a liquid crystal cell. The laser beam expanding and collimating system is configured to expand a light beam from the laser device and enable the expanded light beam to be transmitted substantially vertically to the liquid crystal cell. An amplitude-transmission coefficient distribution of the liquid crystal cell is determined in accordance with a brightness distribution of holographic interference fringes of an object to be displayed.