A method of manufacturing a full-color holographic optical element in a full-color holographic optical element manufacturing apparatus including a lens and a holographic recording medium located farther away than a focal length of the lens, the method including: allowing a signal beam including a mixture of laser beams having wavelengths of R (Red), G (Green), and B (Blue) to be incident on the lens; and recording a hologram in such a manner that a reference beam including a mixture of laser beams having wavelengths of R, G, and B is allowed to be incident on the holographic recording medium, wherein the holographic recording medium is configured with a single medium.

A floating image display device includes a floating-image-formation optical system that forms an image at an opening part as a floating image from an image displayed on an image display unit, an authentication unit that judges whether or not a subject passing through the opening part is an authorized subject, and an image control unit that makes the image display unit switch contents of the image when the subject is judged as the authorized subject. The floating-image-formation optical system can include a beam splitter and a retroreflective sheet. Another floating image display device includes an image display unit that displays a first image, a floating-image-formation optical system that forms an image at an opening part as a floating image from the first image, and an image projection unit that projects a second image onto a subject moving through the floating image when the subject passes through the opening part.

A floating image display device includes an image display unit that displays a display image based on a first image signal, a floating-image-formation optical system that forms an image in air as a floating image from the display image, a guide image display unit that displays a guide image based on a second image signal nearby the floating image to be visually recognized on the same plane as the floating image as viewed from a viewer, and an image control unit that supplies the first image signal and the second image signal respectively to the image display unit and the guide image display unit. The image control unit supplies an image signal as the second image signal to the guide image display unit after the image signal undergoes at least one of a process of adding blurring, a process of lowering luminance and a process of lowering contrast.

The invention relates to a preprocessing circuit for at least one hologram computation circuit that comprises an input interface device for receiving data of a scene to be displayed, a processing device for defined processing of the received data and for converting the data into a system-independent format with incorporation of specific parameters required for displaying the scene, and an output interface device for outputting and transmitting the converted data to at least one hologram computation circuit. An apparatus for computing a hologram for displaying a scene by means of a holographic display apparatus is also disclosed. The apparatus comprises at least one spatial light modulation device and a preprocessing circuit as described, and at least one hologram computation circuit for computing a hologram and for encoding the hologram for the at least one spatial light modulation device.

An illumination system is arranged to output a light beam for illuminating a scene. The system comprises a spatial light modulator arranged to receive incident light, and to output light comprising a first component and a second component. The first component comprises incident light that is output without modulation by the spatial light modulator. The second component comprises incident light that is spatially-modulated according to a hologram and output by the spatial light modulator. A control device is operable to control the proportion of light output by the spatial light modulator that corresponds to the second component.

Provided is a method of manufacturing a full-color holographic optical element in a full-color holographic optical element manufacturing apparatus including a lens and a holographic recording medium located farther away than a focal length of the lens, the method including: allowing a signal beam including a mixture of laser beams having wavelengths of R (Red), G (Green), and B (Blue) to be incident on the lens; and recording a hologram in such a manner that a reference beam including a mixture of laser beams having wavelengths of R, G, and B is allowed to be incident on the holographic recording medium, wherein the holographic recording medium is configured with a single medium.

A floating image display device includes a floating-image-formation optical system that forms an image at an opening part as a floating image from an image displayed on an image display unit, an authentication unit that judges whether or not a subject passing through the opening part is an authorized subject, and an image control unit that makes the image display unit switch contents of the image when the subject is judged as the authorized subject. The floating-image-formation optical system can include a beam splitter and a retroreflective sheet. Another floating image display device includes an image display unit that displays a first image, a floating-image-formation optical system that forms an image at an opening part as a floating image from the first image, and an image projection unit that projects a second image onto a subject moving through the floating image when the subject passes through the opening part.

A floating image display device includes an image display unit that displays a display image based on a first image signal, a floating-image-formation optical system that forms an image in air as a floating image from the display image, a guide image display unit that displays a guide image based on a second image signal nearby the floating image to be visually recognized on the same plane as the floating image as viewed from a viewer, and an image control unit that supplies the first image signal and the second image signal respectively to the image display unit and the guide image display unit. The image control unit supplies an image signal as the second image signal to the guide image display unit after the image signal undergoes at least one of a process of adding blurring, a process of lowering luminance and a process of lowering contrast.