Holographic image reproduction mechanism using ultraviolet light
AssigneeEmpire Technology Development LLC
InventorEiji Yamaichi
Life of this patent
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Abstract
A holographic image display system comprises a screen, a first and a second light source, a scanning mechanism, and a controller. The screen includes a photochromic material arranged thereon. The photochromic material has light absorption characteristics which change depending on illumination with a wavelength of an ultraviolet light beam. The first light source directs a visible light beam with a sufficiently large diameter onto the screen, whereas the second light source directs an ultraviolet light beam onto the screen through the scanning mechanism. The controller controls emissions and scanning of the ultraviolet light beam based on a holographic signal so that the ultraviolet light beam can be scanned across the screen.
Claims22
A holographic image display system comprising:
- a screen including a photochromic material having a band gap greater than about 3 eV, the photochromic material having an initial value of light absorption coefficient when not illuminated by ultraviolet light, wherein the photochromic material is transmissive to visible light when the light absorption coefficient has the initial value, and wherein the light absorption coefficient increases when the photochromic material is illuminated by ultraviolet light and reverts to the initial value when the illumination by the ultraviolet light is removed;
- a first light source configured to emit a visible coherent light beam that is applied to the screen;
- a second light source configured to emit an ultraviolet light beam that is applied to the screen;
- a scanning mechanism configured to allow the ultraviolet light beam to scan across the screen;
- and
- a controller configured to control emissions of the second light source and scanning of the scanning mechanism based on a holographic signal.
A method of reproducing a holographic image, the method comprising:
- directing a visible coherent light beam onto a screen, the screen including a photochromic material having a band gap greater than about 3 eV, the photochromic material having an initial value of light absorption coefficient when not illuminated by ultraviolet light, wherein the photochromic material is transmissive to visible light when the light absorption coefficient has the initial value, and wherein the light absorption coefficient increases when the photochromic material is illuminated by ultraviolet light and reverts to the initial value when the illumination by the ultraviolet light is removed;
- and
- directing an ultraviolet light beam onto the screen, while controlling emissions of the ultraviolet light beam and controlling scanning of the ultraviolet light beam across the screen, based on a holographic signal.
A method of manufacturing a holographic image display system, the method comprising:
- forming a photochromic layer on a surface of a transparent plate so as to obtain a screen, the photochromic layer having a band gap greater than about 3 eV and comprising a photochromic material having an initial value of light absorption coefficient when not illuminated by ultraviolet light, wherein the photochromic material is transmissive to visible light when the light absorption coefficient has the initial value, and wherein the light absorption coefficient increases when the photochromic material is illuminated by ultraviolet light and reverts to the initial value when the illumination by the ultraviolet light is removed;
- providing a first light source configured to emit a visible coherent light beam so as to direct the visible coherent light beam onto the screen;
- providing a scanning mechanism on a light path of an ultraviolet light beam so as to allow the ultraviolet light beam to scan across the screen;
- and
- providing a controller configured to control emissions of the second light source and scanning of the scanning mechanism, based on a holographic signal.
Dependencies are inferred from the claim text.