Disclosed herein is a holographic display which enables stereoscopic display of colors by changing a structure and mitigates a flickering effect by lowering the response speed. The holographic display may deliver an image to different positions for the left eye and right eye at the same time, thereby lowering the frequency necessary for supply of holographic image information. Thereby, the holographic display may address the issues of the afterimage effect and flickering effect in a liquid crystal panel-based spatial light modulator.

Provided is a backlight unit having high optical efficiency and a holographic display device including the backlight unit. The backlight unit includes a light source unit configured to provide a light beam, a first beam expander configured to mix the light beam provided from the light source unit, expand the light beam in a first direction, and output the mixed and expanded light beam as white light, and a second beam expander configured to expand the white light output from the first beam expander in a second direction perpendicular to the first direction and output the expanded white light as surface light.

A holographic film is encoded on a pixel-by-pixel basis by sequentially irradiating each pixel using a movable laser that directs light against a suitable object that in turn deflects the light toward the film. The film can then be used as a display for playing back demanded images using a laser or in some cases LEDs to irradiate each pixel on a pixel-by-pixel basis according to the demanded image.

An illumination device has a coherent light source, an optical device that diffuses the plurality of coherent light beams and illuminates a predetermined illumination area, and a timing control unit that individually controls incident timing of the plurality of coherent light beams to the optical device or illumination timing of the illumination area, wherein the optical device has a plurality of diffusion regions, the diffusion regions being provided corresponding to the plurality of coherent light beams, the plurality of diffusion regions illuminate the illumination range by diffusion of incident coherent light beams, the plurality of diffusion regions have a plurality of element diffusion regions, the plurality of element diffusion regions illuminate partial regions in the illumination area by diffusion of incident coherent light beams, and at least parts of the partial regions illuminated by the plurality of element diffusion regions are different from one another.

The invention relates to a display device for holographic reconstruction. The display device comprises a spatial light modulator device having combined phase modulating pixels and amplitude modulating pixels, an illumination unit generating sufficiently coherent light and arranged to illuminate of the spatial light modulator device and a reflection plane. The device being arranged such that light enters the spatial light modulator device and passes both the phase modulating pixel and the amplitude modulating pixel of the spatial light modulator device. The light is reflected by the reflection plane in between.

An illumination device has an optical device and an irradiation unit. The irradiation unit has a light source emitting a coherent light beam, and a scanning device capable of adjusting a reflection angle of the coherent light beam emitted from the light source. The light source has light sources emitting a plurality of coherent light beams having an identical wavelength range, the hologram recording medium has a recording area to be scanned with each of a plurality of coherent light beams reflected by the scanning device, and the recording area has an interference fringe that diffracts an incident coherent light beam. The optical device uses the plurality of coherent light beams diffracted by the interference fringe of the recording area so that each of the coherent light beams diffracted by the hologram recording medium is superimposed on at least one portion to reproduce the image of the reference member.

According to the present invention, by providing a hologram displaying apparatus including a light source configured to output a plurality of lights of different wavelengths in a first direction, a generator configured to generate a plurality of color holograms of different wavelengths using the plurality of light, and output the plurality of color holograms in the first direction, a filter configured to filter an effective hologram which is an element of an effective band of the plurality of color holograms in the first direction, and a display configured to transmit the effective hologram in the first direction and display the effective hologram in space in the first direction, it is possible to effectively filter an effective band of a certain diffraction order of each color hologram forming a composing hologram.

An illumination device has a coherent light source, an optical device that diffuses the plurality of coherent light beams and illuminates a predetermined illumination area, and a timing control unit that individually controls incident timing of the plurality of coherent light beams to the optical device or illumination timing of the illumination area, wherein the optical device has a plurality of diffusion regions, the diffusion regions being provided corresponding to the plurality of coherent light beams, the plurality of diffusion regions illuminate the illumination range by diffusion of incident coherent light beams, the plurality of diffusion regions have a plurality of element diffusion regions, the plurality of element diffusion regions illuminate partial regions in the illumination area by diffusion of incident coherent light beams, and at least parts of the partial regions illuminated by the plurality of element diffusion regions are different from one another.

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.

The invention refers to an Illumination device for illuminating a spatial light modulator device. Sub-holograms are used for encoding a hologram into the spatial light modulator device. The Illumination device comprises at least one light source for emitting light for illuminating the spatial light modulator device and a beam shaping unit. The beam shaping unit provides a flat-top plateau-type distribution of an absolute value of a complex degree of mutual coherence of the light in a plane of the spatial light modulator device to be illuminated. The flat-top plateau-type distribution of the absolute value of the complex degree of mutual coherence has a shape that is at least similar to a shape of the largest sub-hologram used for encoding of object points into the spatial light modulator device.